JP2011071132A - Battery pack and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery pack having film outer package batteries in which, even when gas generated inside the batteries is accumulated, the inner pressure hardly rises and safety is improved, and the battery characteristics are stabilized for a long period as adhesion of the electrode plates is maintained for a long period, and its manufacturing method. <P>SOLUTION: Since the length L1 in lead terminal extraction direction in the inner space of the batteries is longer than the length L2 in the same direction of the top face of a cup molded outer package 2, a gap 9 is formed at the outside portion of the cup molded outer package 2, With the existence of this gap 9, even if gas is generated inside the batteries, the lid side outer package below the gap 9, that is, the outer package in the vicinity of a sealing part of the lead terminal is deformed upward, thereby gas can be contained inside this. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an assembled battery in which a plurality of unit batteries are stacked and a method for manufacturing the battery. In addition, the vertical direction of the battery is always kept constant, such as when installed on a mobile vehicle such as an automobile, motorcycle or bicycle, or when used for a stationary power source used in an uninterruptible power supply or a distributed power storage system. The present invention relates to a battery having good sagging or sealing properties and a method for manufacturing the same.

  Conventionally, as a battery using a heat-fusible film as an exterior body, a film in which a metal layer and a heat-fusible resin layer are laminated, that is, a laminate film, encapsulates an electrode plate group, There is known a structure in which a heat sealing resin layer of a laminate film is face-to-face and heat-sealed so that the electrode lead-out lead terminal is sandwiched between the electrode terminals and heat-sealed so as to be hermetically sealed. This type of battery has an advantage that it can be easily thinned. In fact, most of the disclosed batteries have a flat shape as illustrated below.

For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 10-55792), when an internal pressure is abnormally increased due to generation of gas in a film exterior type battery by providing a portion having a low peel strength in a part of a film adhesion portion. A method for releasing gas from a portion having a weak peel strength has been proposed.
Patent Document 2 (Japanese Patent Application Laid-Open No. 2000-133216) discloses a battery in which an aluminum laminate film is subjected to rectangular drawing and a space for storing a power generation element is formed to minimize the extra space. Is disclosed.

Patent Document 3 (Japanese Patent Application Laid-Open No. 11-260408) describes a method of maintaining electrode plate adhesion using atmospheric pressure by sealing a unit cell with an exterior body and then sealing under reduced pressure. Has been.
Patent Document 4 (Japanese Patent Application Laid-Open No. 2000-100404) discloses a battery pack that presses a stored battery by storing the battery sealed with a film in a battery storage container.
Patent Document 5 (Japanese Patent Application Laid-Open No. 6-111799) discloses a battery in which a space portion is held around an electrode plate group and covered with a hermetic sheet made of a synthetic resin and sealed.

  This type of battery can be divided into the following two types when focusing on the front and back of the outer shape. That is, a film exterior body in which a molded part is provided in advance to accommodate the electrode plate group is used for both the front and back of the battery (FIG. 23 (a)), or a planar shape having no such molded part or A type of electrode plate covered with a bag-like film is a type (hereinafter referred to as R type), and the other is a group of electrode plates in which a flat film having no molding part is opposed to a film having a molding part. (FIG. 23B, hereinafter referred to as NR type). The R type is a type having no battery front and back, and the NR type is a type having a back side.

Focusing on how to pull out the lead terminals of this type of battery, most of the configurations disclosed so far have a positive lead terminal and a negative lead terminal in the same direction from one end as shown in FIG. It has a drawn shape (hereinafter referred to as a one-sided drawer type).
In many of this type of battery, a power generation element composed of a group of electrode plates is housed in a thin outer package such as a laminate film, which has a structure advantageous for thinning and downsizing of the battery. The laminate film has a structure in which a metal foil and a polymer resin layer as a sealing material are laminated. For example, the sealing material can be welded by heat sealing at 300 ° C. or lower, and the contents can be sealed. It attracts attention as a new type of battery case that does not require metal welding such as welding.

  A battery using a laminate film has an advantage that it can be produced at a very low cost and high efficiency as compared with a case where a molded metal can which has been a mainstream of a conventional exterior body is used. When forming metal cans, it is necessary to clean with a large amount of cleaning liquid because of the use of lubricating oil, which increases the process time. However, since the laminate film has a polymer resin layer, it can be used for dies and punches during deep drawing. Therefore, the lubricating oil is not necessarily required, so that the process time can be shortened and in-line molding becomes possible. In other words, it is possible to sequentially draw the laminate film from the state wound up in a roll shape and perform deep drawing molding into a cup shape, and immediately after that, it is possible to move to a power generation element storage step in the molding part without going through a cleaning step, Production efficiency is very good.

As in the case of using other exterior bodies, even in a battery with a laminate film as the exterior body, the sealing reliability of the sealing part is ensured so that the outside air does not enter the battery and the electrolyte in the battery does not leak. It is required to be done. In particular, in a battery containing a non-aqueous electrolyte (hereinafter also referred to as a non-aqueous electrolyte battery), seal reliability is an important problem. When there is a sealing failure, the electrolyte solution deteriorates due to the components of the outside air, and the battery performance is significantly deteriorated.
In particular, a battery having a laminate film as an exterior body is generally subjected to reduced-pressure sealing, and there is a problem in that the reduced-pressure state cannot be maintained when outside air enters due to defective sealing.

  Focusing on this type of battery sealing material, most of the conventionally proposed laminate films for batteries use a polyolefin-based material as the inner sealing material. For example, polyethylene, polypropylene, and these acid modified products. One reason for the frequent use of polyolefin-based materials is that they generally have better gas barrier properties than other types of resins and are resistant to non-aqueous electrolytes.

Japanese Patent Laid-Open No. 10-55792 JP 2000-133216 A Japanese Patent Laid-Open No. 11-260408 JP 2000-100404 A JP-A-6-111799

  In film-clad batteries such as those mentioned above, it is often said that the lead terminal lead-out sealing part is subject to sealing deterioration more easily than other parts, and that liquid leakage is likely to occur from this location if insufficient measures are taken. It has been broken. If the electrolyte leaks, the surroundings of the battery may be contaminated, or the liquid may splash on the battery peripheral circuit, causing problems such as malfunction of the circuit. According to the study by the present inventors, the sealing deterioration of the lead terminal lead-out sealing part is caused by the attack of the electrolyte component on the adhesive interface between the heat-fusible resin layer of the outer package film and the lead terminal surface. It was found to be promoted.

  When a battery is installed as a mobile vehicle such as an automobile, a motorcycle, or a bicycle, or when used as a stationary power source used for an uninterruptible power supply or a distributed power storage system, the battery always has a certain direction of gravity. It becomes. According to the study by the present inventors, when an NR type battery is used with the molded exterior body side (hereinafter referred to as the front side) facing upward and when it is used facing downward, When it was used in a rough environment, it was found that the liquid leaked more easily when turned up.

  It considers the mechanism described below. The electrolyte present in the battery is present not only between the electrode plates but also in the vicinity of the lead terminal sealing portion viewed from the inside of the battery, and the lead terminal / exterior body bonding interface (part A in FIG. 24 described later) Electrolyte attacks. If the battery is used at a high temperature outside the standard range, the attack may cause adhesion deterioration and may cause peeling. Furthermore, when a voltage outside the standard range is applied, gas species may be generated due to electrolysis of the electrolyte solvent and the internal pressure may increase. If the internal pressure rises in the state where the electrolyte exists in the vicinity of the lead terminal sealing portion, a liquid pressure is applied to the adhesion interface, which may promote adhesion deterioration and peeling progress. When an NR type battery is used with the front side facing up, when the gas is generated in the battery, the gas collects upward, so the vicinity of the lead terminal sealing part remains wet with the electrolyte. , Leading to the above-described increase in hydraulic pressure to the adhesion interface, adhesion deterioration, and progress of peeling.

  In addition to the electrolysis of the electrolyte solvent described above, the gas generation described above occurs when an abnormality occurs such as when a voltage outside the standard range is applied during charging or when it is used in a temperature environment outside the standard range. There is. Basically, it is ideal to use within the standard so as not to generate gas. However, sudden control errors in the battery control circuit, instantaneous large current generation, insufficient battery cooling, etc. Depending on the intended use of the battery, it may be difficult to completely eliminate the cause of the generation of a small amount of gas inside the battery depending on the intended use of the battery due to generation of a high temperature or temporary high temperature.

  As mentioned above, it is ideal to prevent gas from being generated inside the battery. However, if a small amount of gas is generated inside the battery, the gas will accumulate during long-term use. There are things to follow. If the gas accumulates in the battery in this way, there is a possibility that the sealing and sealing by the film enclosing the power generation body may be broken, or depending on the design of the exterior body, the gas may burst due to the pressure of the gas. When the power generator used has a possibility that the performance is lowered when it is in contact with the outside air, there is a problem that the performance is lowered. This performance degradation may cause the battery to become unusable or the charge / discharge characteristics may deteriorate rapidly depending on the situation.

From the above viewpoints, the following problems can be raised when looking at each of the conventional techniques described above.
What is proposed in Patent Document 1 is a method of “safely dying a battery” without causing an explosion or the like when gas is generated. That is, even when the power generation element is exposed to the outside air, the performance is degraded, and the film adhesive portion of the battery is opened to be exposed to the outside air. In this method, even if a small amount of gas is generated during battery use, gas accumulates as the internal pressure rises over a long period of time, and if the internal pressure exceeds the threshold, the safety valve is activated even during normal use. Outside air enters through the safety valve that opens after the gas is released. In the case of a non-aqueous electrolyte battery, when outside air containing moisture enters the inside of the battery, the performance is significantly deteriorated and the battery becomes unusable. If the threshold is a low value, the battery automatically becomes unusable in a short period of time.

  On the other hand, the battery described in Patent Document 2 is not provided with a safety valve. In this case, if the sealing is good, even if gas is generated inside, it is considered that the gas can be held up to a considerable internal pressure. However, the proposal in Patent Document 2 minimizes the gap between the power generation body and the exterior body by matching the shape of the exterior body to the shape (size) of the power generation body for the purpose of improving volumetric efficiency. The volume of the power generation body and the molded volume of the exterior body are substantially the same. Referring to FIG. 25, the battery has almost no extra space inside the battery as shown in FIG. 25 (a), and as soon as gas is generated, the exterior body has a bellows shape as shown in FIG. 25 (b). Will be deformed. Since the exterior body material is an aluminum laminate, it hardly exhibits elongation due to elastic deformation. Therefore, if gas is continuously generated, the internal pressure continues to rise. The high internal pressure generated in this way eventually causes a strong force F to try to peel off the exterior body sealing portion as shown in FIG. 25 (b), and eventually leads to the exterior body cleavage. That is, when the nonaqueous electrolyte battery of this example is used for a long time, when a small amount of gas is generated little by little, the internal pressure is likely to rise, so that the outer body is easily cleaved due to gas accumulation, and the above-described unusable state is caused. Sometimes.

Further, Patent Document 3 describes that the electrode plate adhesion is maintained by using atmospheric pressure by sealing under reduced pressure, but there is no room inside the battery, so as soon as gas is generated. As described above, the exterior body is deformed into a bellows shape, the pressing force due to the atmospheric pressure disappears, and the electrode plate adhesion is easily impaired. That is, when the battery of this example is used for a long period of time, when a small amount of gas is generated little by little, battery performance deterioration is likely to occur due to loss of electrode plate adhesion.
Further, as described above, even when mechanical pressing by a battery pack is performed as in the example of Patent Document 4, as described above, when the gas continues to be generated and the internal pressure rises, the exterior body also in the stacking direction of the electrode plates However, since the force that tries to expand in the form of a drum is applied and the pack case is expanded, there is a possibility that the electrode plate adhesion cannot be maintained.

  Further, the sealed storage battery described in Patent Document 5 uses an unmolded (no recessed portion) hermetic sheet. Unless the exterior body is deformed so as to expand the internal volume, such as a concave shape, the exterior body has a curved shape that provides sufficient gas receptivity while maintaining close contact in the stacking direction of the electrode plates Cannot be obtained. That is, if the internal volume is not deformable so as to expand in a direction other than the electrode stacking direction, there is a risk that adhesion in the electrode stacking direction cannot be maintained when gas is generated and accumulated. is there.

  Furthermore, the assembled battery has the following problems. In the case of a power supply source for a mobile vehicle, a battery for a stationary power supply device, and the like, an assembled battery in which unit cells are stacked and arranged in many cases is often used. At that time, there is a case where the unit cell needs to be flattened and stacked in the horizontal direction due to the shape of the battery mounting space and various reasons. Further, when forming an assembled battery with a flat shape, stacking with the flat surfaces facing each other is convenient because the terminals of adjacent batteries are close to each other, making electrical connection easy. Here, when the flat-shaped film-clad batteries as described above are stacked in the vertical direction in a horizontal orientation, the following problems arise from the viewpoint of lead terminal sealing performance. That is, it becomes difficult for the batteries sandwiched between the layers to swell in volume, and when the gas is generated, the internal pressure is likely to increase. Is likely to occur.

As described above, in a film-clad battery, it is desired to improve sealing reliability (hereinafter referred to as lead terminal sealing property or leakage resistance) that prevents leakage of electrolyte from the lead terminal lead-out sealing portion. It was. Moreover, in the film-clad battery that has been proposed so far, an adverse effect is exerted on the lead terminal sealing performance when stacked to form an assembled battery.
On the other hand, when the conventionally known flat film-clad batteries are stacked in the vertical direction in the horizontal direction and are connected in series to form an assembled battery, the following problems arise.

When the stacked batteries are to be connected in series, it is preferable to stack the positive electrode lead terminal of one battery and the negative electrode lead terminal of another battery to be connected. Because, it is possible to connect the lead terminals directly in contact with each other, and even if not, it is possible to connect with a sufficiently short conductor, so the connection resistance between the batteries can be reduced as much as possible, This is because loss of power output can be minimized.
Here, a case where the above-described NR type and one-side drawer type batteries are stacked in the vertical direction and connected in series will be considered, and a method of obtaining a preferable lead terminal positional relationship in the above-described series connection will be considered.

  FIG. 26 shows this as an example. FIG. 26A is a diagram in which the upper and lower sides of the molded exterior body side (hereinafter referred to as the front side) and the opposite side (hereinafter referred to as the back side) of the flat exterior body are alternately stacked. In this case, it is possible to use only a battery in which the positive electrode lead terminal (negative electrode lead terminal) is drawn to the left side (right side) when viewed from the front side of the battery. On the other hand, FIG. 26B shows a case where all the batteries are stacked with the front side facing down. In this case, the positive electrode lead terminal (negative electrode lead terminal) is drawn to the left side (right side) as viewed from the front side. Batteries and the reverse (positive electrode right, negative electrode left) batteries are stacked alternately.

Considering mass production of batteries here, if two types of batteries with different positive and negative lead terminals are made separately, two lines of manufacturing equipment are required, or one line of device settings is set manually or automatically. Therefore, it is preferable to avoid as much as possible because there are problems in device costs such as the necessity to change them as needed, and problems in product management such that the two types of batteries are easily mixed with each other. From that point of view, it can be said that the configuration as shown in FIG.
On the other hand, from the viewpoint of lead terminal sealing properties, in the form of FIG. 26A, even if gas is generated, the gas accumulates on top and the electrolyte remains in the vicinity of the lead terminal sealing portion. There will always be a battery that has an adverse effect on the sealing performance.
As described above, in the film-clad batteries that have been proposed so far, when stacking and connecting in series, all of connection resistance reduction, mass production convenience, and leakage resistance are selected to be better simultaneously. I couldn't.

  Furthermore, in the laminate film sealing material described above, all of the polyolefin resins used so far have a melting point of 200 ° C. or lower. For example, the battery is exposed to heat of 200 ° C. or higher, or 200 ° C. or higher from the inside of the battery. When this heat was generated, the sealing material melted and it was difficult to maintain the sealing.

  A configuration in which a resin having a high melting point is simply used as a sealing material has been disclosed so far, and there is a publication that mentions polyethylene terephthalate as an example of the sealing material (Japanese Patent Laid-Open No. 2000-353500). However, since polyethylene terephthalate does not necessarily have sufficient gas barrier properties, it is difficult to fully enjoy the advantage of using a laminate film. One of the advantages of using the laminate film is that the power generation element is pressurized by atmospheric pressure by the reduced pressure sealing, and as a result, the adhesion between the electrodes is improved. When a sealing material that does not have sufficient gas barrier properties, such as polyethylene terephthalate film, is used, outside air enters and the degree of decompression inside the seal is gradually lost over the long term, and the power generation element pressure decreases. In some cases, the adhesion between the electrodes deteriorates and the battery characteristics deteriorate.

In the case of a battery in which a metal can is used as the outer package and the metal is directly welded and sealed by laser welding or the like, there is less concern about the heat resistance of the seal compared to the conventional laminated film outer package, but it is completely by local metal welding. Performing hermetic sealing requires a high level of technology, so that it costs more to prevent the occurrence of defective sealing than in the case of a heat seal type exterior body. In particular, as described above, the washing process at the time of deep drawing is necessary for the can type and not necessary for the laminated film, and the laminated film exterior type is advantageous in terms of production efficiency.
As described above, the battery using the outer package formed by heat-sealing the laminate film is superior in terms of production efficiency than the can type, but is inferior in heat resistance compared to the can type. It was.

The purpose of the reference technology is to provide a stationary battery in which the electrolyte solution is less likely to leak from the lead terminal lead-out sealing part, and the object of the present invention is to stack the unit battery or the unit battery to form an assembled battery. An object of the present invention is to provide an assembled battery that does not adversely affect terminal sealing performance even when it is configured, and a method for manufacturing the battery pack.
Another object of the present invention is to provide a stationary battery and a method for manufacturing the same, which simultaneously improve the connection resistance reduction, mass production convenience, and leakage resistance when stacked and connected in series.

Still another object of the present invention is that even when gas generated inside the battery is accumulated, the internal pressure is hardly increased and the safety is excellent, and the electrode plate adhesion is maintained for a long period of time. It is in providing the film-clad battery which can be stabilized over a long period of time, the clamp device used for the battery, and the battery manufacturing method.
Still another purpose of the reference technology is to use a heat-seal-type exterior body with good production efficiency, and to maintain the sealing even when exposed to temperatures of 200 ° C or higher, and to maintain a reduced pressure for a long period of time. It is in providing the nonaqueous electrolyte battery.

  According to the present invention, a first exterior body element including a first exterior body element and a cup-shaped molded portion containing a power generation body in which electrode plates are laminated and having an electrolyte solution is provided from the cup-shaped molded portion. In a stationary battery that is bonded and sealed to each other on the outside and is installed so that the second exterior body element is located on the lower side, a positive electrode lead terminal located in the pasted and sealed portion of both exterior bodies and A unit battery (hereinafter referred to as Reference Technology 1), characterized in that the height of at least one of the negative electrode lead terminals is not lower than the height of the uppermost electrode plate of the electrode plate group. And a second exterior body element having a cup-shaped molded part containing a power generation body in which electrode plates are laminated and having an electrolyte solution is bonded to each other outside the cup-shaped molded part and sealed, 2 So that the exterior body element is located on the lower side In the installed type battery, the positive electrode lead terminal and the negative electrode lead terminal for taking out the current are drawn out from one end side of the bonded exterior bodies and the opposite end side, respectively. A battery pack (hereinafter referred to as a first invention) having a unit battery, and thirdly, a battery body in which an electrode lead is provided on a power generator in which electrode plates are laminated, and the electrode lead can be electrically connected to the outside. A film-covered battery that is exposed and sealed with a film, wherein the film is deformably formed so that the sealed internal volume is expanded in a direction other than the stacking direction of the electrode plates. A battery pack (hereinafter referred to as a second invention) having a film-clad battery, and fourthly, a power generation element and an exterior body that houses the power generation element, and at least a part of the exterior body is a shim. A non-aqueous electrolyte battery sealed with a sealing material, wherein the sealing material comprises an aromatic polyester resin and a gas barrier resin (hereinafter referred to as Reference Technique 2). It is said).

The present invention and the reference technique will be described in detail below.
In the battery of Reference Technology 1, the outer shape is usually flat, and is installed with the flat surface horizontal, the electrode plate surface of the electrode plate group is parallel to the flat surface, the positive electrode lead terminal and the negative electrode The surface of the sealing portion through which the lead terminal passes is substantially parallel to the flat surface and is located at substantially the same height as or above the uppermost electrode plate of the electrode plate group.
Therefore, when the gas is generated in the battery, the gas collects on the top, so that the gas accumulates in the vicinity of the lead terminal sealing portion. Peeling deterioration due to attacking the exterior body adhesion interface can be prevented.

  In the unit cell used in the assembled battery of the first invention, the positive electrode lead terminal and the negative electrode lead terminal for taking out the current are respectively drawn out from one end side of the both exterior bodies and the opposite end side. ing. Therefore, when these unit cells are stacked in the vertical direction so that the positive electrode lead terminal and the negative electrode lead terminal of the adjacent unit cells face in the opposite direction, the positive electrode lead terminal and the negative electrode lead terminal to be connected are close to each other and can be easily connected to each other. The stationary assembled battery as a battery group composed of the plurality of single cells can be obtained.

In the assembled battery of this configuration, when a plurality of batteries are stacked in the vertical direction and connected in series, two types of batteries having opposite polarity of lead terminals are not used unlike the conventionally known one-side drawer type battery. In both cases, connect only one type of battery to the positive lead terminal of one battery by stacking the lead terminals so that the polarities of the lead terminals are opposite each other one by one with the top and bottom sides aligned. The negative electrode lead terminal of another battery can be adjacent. In this way, the batteries can be connected in series with low resistance, and all the batteries in the interconnected battery group can be placed with the electrode plate housing part facing down, so it is better for all batteries. Liquidity can be imparted.
Thus, it is possible to simultaneously improve the connection resistance reduction, the mass production convenience, and the liquid leakage resistance when stacked and connected in series.

In the second aspect of the invention, the film, which is an exterior body element, can be deformed by the generated gas pressure, and even when gas is generated and accumulated inside, the film is deformed in the battery inner direction at the time of molding. By returning to the original, gas can be stored in a portion other than the electrode plate stacking direction with respect to the power generation body, and it is easy to maintain close contact between the stacked electrode plates and hardly increase the internal pressure. Can be made.
As a modification of the second invention, at least part of the upper part of the first exterior body element in the vicinity of the lead terminal sealing portion of the lower battery among the two adjacent battery cells of the assembled battery in which the battery cells are stacked, There is a form in which there is a gap for allowing the first exterior body element in the vicinity of the lead terminal sealing portion to be deformed upward.

In the assembled battery of this configuration, since there is a gap, even if gas is generated inside the battery, the first exterior body element in the vicinity of the lead terminal sealing portion can be deformed upward, and the gas is introduced into the inside thereof. Gas can easily accumulate around the lead terminal sealing part, the lead terminal sealing part does not get wet with the electrolytic solution, and the electrolytic solution attacks the lead terminal / exterior body bonding interface. Deterioration can be prevented.
Reference technology 2 specifies a film constituting all or part of the exterior body element, and the present inventors have newly used a new inner surface layer and heat seal portion of the exterior body element that can be used in the above-described battery and the like. As a result of intensive studies on the sealing material from the viewpoint of electrolyte resistance, heat resistance, and gas barrier properties, the use of a specific material has led to Reference Technology 2.

  According to Reference Technology 2, the non-aqueous electrolyte battery includes a power generation element and an exterior body element that houses the power generation element, and at least a part of the exterior body element is sealed with a sealing material, The material includes an aromatic polyester resin and a gas barrier resin, and a nonaqueous electrolyte battery is provided.

This battery has a configuration in which at least a part of the exterior body element is sealed with a sealing material, and a heat-seal type exterior body element with high production efficiency can be employed. In addition, since a sealing material containing an aromatic polyester resin having high heat resistance and good moldability and a gas barrier resin is used, the sealing is maintained even when exposed to high temperatures, and the decompressed state is long-lasting. Thus, a long-life nonaqueous electrolyte battery that is maintained at the same time can be realized.
In Reference Technology 2, at least a part of the exterior body element is sealed via a sealing material, but other parts may be sealed by other means, and the sealing material and May be sealed with different types of sealing materials. In addition, if it is set as the structure by which the sealing material is arrange | positioned at all the sealing parts of an exterior body element, a more reliable battery will be obtained.

  The said nonaqueous electrolyte battery can employ | adopt the structure which the edge part surface of an exterior body element consists of a metal. The edge part of the exterior body element becomes the contact surface of the heating member at the time of heat sealing, and by constituting the edge surface with metal, the resin sticking to the heater is prevented and productivity is improved. Excellent sealing performance can be realized stably.

Further, according to the reference technique 2, an exterior body element in which a resin-coated metal member in which at least one surface of a metal plate is coated with a resin layer and a metal member having a metal surface are sealed via a sealing material is provided. A non-aqueous electrolyte battery in which a power generation element is housed in a recess provided in the resin-coated metal member, wherein an edge of the resin-coated metal member is covered by a folded portion of the metal member. A non-aqueous electrolyte battery is provided.
According to this reference technique 2, since the resin-coated metal member is used as the member for storing the power generation element, the recess for storing the power generation element can be easily formed in a desired dimension. For this reason, the battery of the outstanding productivity and quality stability can be obtained. In addition, the problem of resin sticking to the heater, which is a concern when using a resin-coated metal member, has been solved by covering the edge surface with the folded portion of the metal member, thereby improving productivity. At the same time, excellent sealing performance is stably realized. Further, the structure in which the edge surface is covered with the folded portion of the metal member makes it difficult for the seal to be broken when the internal pressure of the battery increases.

  In this non-aqueous electrolyte battery, at least one surface of the resin-coated metal member may be covered with a metal adhesive resin layer. As the metal adhesive resin layer, a copolyester resin containing an ethylene terephthalate unit or the like can be used. Moreover, in this non-aqueous electrolyte battery, as described above, the sealing material can include an aromatic polyester resin and a gas barrier resin.

  In the nonaqueous electrolyte battery of Reference Technology 2, it is possible to employ a configuration in which the lead terminal connected to the exterior body element is further provided and the lead-out portion of the lead terminal is covered with a sealing material. A plurality of lead terminals are usually provided, but it is desirable to employ a configuration in which the lead portions are covered with a sealing material and sealed for all of them. Since the lead-out portion of the lead terminal is a portion where liquid leakage or gas outflow easily occurs, the life can be further extended by covering this portion with a sealing material. Further, as described above, when the sealing material is configured to include the aromatic polyester resin and the gas barrier resin, the reduced pressure state inside the battery is maintained for a longer period of time, thereby further extending the life. be able to. In addition, the sealing material that covers the lead terminal lead portion and the sealing material that is used to seal the exterior body element at other locations may be made of the same material or different materials.

  By adopting the configuration of Reference Technology 1, the electrolyte solution wetting of the lead terminal sealing portion can be further effectively suppressed, and the peeling deterioration due to the electrolyte attacking the lead terminal / exterior body adhesion interface can be further effectively prevented. .

Furthermore, according to the first invention, when stacking a plurality of batteries in the vertical direction and connecting them in series, two types of batteries having opposite polarity of lead terminals are used, such as a conventionally known one-side drawer type battery. At least one type of battery is connected to the positive lead terminal of one battery by stacking the lead terminals so that the polarities of the lead terminals are opposite each other one by one with the top and bottom sides aligned. The negative electrode lead terminal of another battery to be tried can be adjacent. In this way, the batteries can be connected in series with low resistance, and all the batteries of the interconnected battery group can be provided with leakage resistance with the electrode plate housing portion facing downward.
Thus, it is possible to simultaneously improve the connection resistance reduction, the mass production convenience, and the liquid leakage resistance when stacked and connected in series.

  Next, according to the film-clad battery of the second invention, the sandwicher used in the battery, and the battery manufacturing method, the film can be deformed so that the internal volume sealed by the film is expanded in a direction other than the laminating direction of the electrode plates. As a result, even if gas is generated inside, the gas can be accommodated in directions other than the laminating direction of the electrode plates, the internal pressure can be made difficult to increase by this accommodation, and the internal volume of the electrode plates can be reduced. It can suppress that the pressure which tries to expand | swell to a lamination direction acts. A battery that is excellent in safety by making it difficult to increase the internal pressure in this way, and that the internal volume is prevented from expanding in the stacking direction of the electrode plates, so that the electrode plate adhesion is maintained for a long time, and the battery characteristics are stable for a long time. Can be obtained.

Further, according to the second invention, after forming a convex shape in at least a part of the power generating body in the film in a direction other than the laminating direction of the electrode plates, the convex portion is inverted by decompression sealing. Thus, the above gas can be easily stored and the volume that can be stored can be increased.
Furthermore, after forming a recess having a larger bottom area than the power generator in the film, the film is deformed by vacuum sealing, whereby the gas can be easily accommodated and the volume that can be accommodated can be increased.

Further, in the film that is the exterior body, at least a part in the vicinity of the power generation body among the portions that face each other as a pair by sandwiching the battery main body is an interior to a portion that is in the stacking direction of the electrode plates with respect to the power generation body By joining so as to suppress the expansion of the volume, it is possible to easily maintain the adhesion between the stacked electrode plates even when gas is generated inside. By maintaining this adhesion, the battery characteristics can be stabilized over a long period of time.
Further, by maintaining the close contact between the electrode plates, it is possible to easily maintain the close contact between the stacked electrode plates even when gas is generated inside. By maintaining this adhesion, the battery characteristics can be stabilized over a long period of time.

Furthermore, by holding the film-clad battery with a clamp so that the power generator is pressed in the stacking direction, it is easy to maintain close contact between the stacked electrode plates even when gas is generated inside. Can do. By maintaining this adhesion, the battery characteristics can be stabilized over a long period of time.
In addition, even if gas generated due to temporary abnormality or long-term use of the battery accumulates inside, the curved part of the film deformed toward the inside of the battery at the time of sealing returns to the original, so that the concave part or curvature formed in the film Gas can be stored in a margin space due to the difference between the volume of the section and the volume of the power generation body, and the internal pressure can be made difficult to increase while maintaining the adhesion in the stacking direction of the electrode plates. By suppressing this increase in internal pressure, it is possible to obtain a battery that is excellent in safety and that maintains the electrode plate adhesion for a long period of time and has stable battery characteristics over a long period of time.

  Furthermore, according to Reference Technique 2, while using a heat-seal-type exterior body with good production efficiency, the sealing is maintained even when exposed to a temperature of 200 ° C. or higher, and the decompressed state is maintained for a long time. A nonaqueous electrolyte battery is obtained.

Sectional drawing which shows the installation type cell as an example of Embodiment of the reference technique 1 and 1st invention. The schematic diagram of the external appearance of the assembled battery which connected the installation type cell of FIG. 1 in series. FIG. 3 is a schematic cross-sectional view taken along line A-A ′ in FIG. 2. Sectional drawing which illustrates the assembled battery which is one embodiment of 1st invention. The typical cross section of the state which provided the pressing board in the film-clad battery as 1st Embodiment of 2nd invention. The typical top view which looked at the battery of FIG. 5 from the top. (A), (b) and (c) is a figure which shows a series of manufacturing-process examples of the film-clad battery of FIG. 5 and 6. FIG. (A), (b) and (c) are the schematic diagrams of the cross section which show the manufacturing process of the film-clad battery which is embodiment of 2nd invention. The exterior battery which is other embodiment of 2nd invention is shown, (a) is the top view seen from the top before pressure reduction sealing, (b), (c) is the perspective view which turned up the lower film, FIG. 4B is a perspective view showing before pressure reduction sealing and FIG. The top view of the film-clad battery which is further another embodiment of 2nd invention. The typical perspective view of the nonaqueous electrolyte battery which has a sheet-like exterior body which is one Embodiment of the reference technique 2. FIG. FIG. 12 is a longitudinal sectional view taken along line A-A ′ of FIG. 11. FIG. 12 is a longitudinal sectional view taken along line B-B ′ of FIG. 11. FIG. 12 is a longitudinal sectional view taken along line C-C ′ of FIG. 11. The longitudinal cross-sectional view which illustrates the sealing plan part by the exterior body of the lead terminal in embodiment of the reference technique 2. FIG. Sectional drawing which represents other embodiment of the reference technique 2 typically. Sectional drawing which represents further another embodiment of the reference technique 2. FIG. Sectional drawing which represents other embodiment of the reference technique 2 typically. The longitudinal cross-sectional view which shows the lead terminal sealing condition of the nonaqueous electrolyte battery which has the sheet-like exterior body in the reference example 6. FIG. The longitudinal cross-sectional view which shows the state which accommodated the battery of FIG. 19 in the pack case. The perspective view which shows the state which faced the side which provided the concave mold part of the film-clad battery in the reference example 1. FIG. The longitudinal cross-sectional view which shows the state which accommodated the film-clad battery of the reference example 1 in the pack case. (A), (b) is a perspective view which shows the conventional cell, respectively. (A), (b) is sectional drawing which shows the adhesion part of the lead terminal and exterior body in a conventional single cell, respectively. (A), (b) is sectional drawing which shows the inside of the conventional cell, respectively. (A), (b) is sectional drawing which shows the connection state at the time of comprising the assembled battery which each connected the conventional cell.

  Next, a stationary battery according to an embodiment of the present invention will be described with reference to the drawings.

[Reference Technology 1 and Embodiments of the First Invention]
First, each component of the battery usable in the reference technique 1 and the first invention will be described in detail.

[Lead terminal]
The lead terminal (electrode lead) may be made of Al, Cu, phosphor bronze, Ni, Ti, Fe, brass, stainless steel, etc., and may be annealed if necessary. The shape is preferably a flat plate shape, and the thickness is preferably in the range of 20 μm to 2 mm. It may be bent into a crank shape.

[Exterior body]
The exterior body is not particularly limited as long as the upper side of the battery has a cup-shaped molded part having a size that can accommodate the electrode plate group, but the opposing surface to which these are bonded is heat-sealed. Is preferable. For example, a base material plate having a thickness of 10 μm to 1 mm and a heat-fusible resin having a thickness of 3 μm to 200 μm attached thereto can be used. As the base material plate, Al, Ti, Ti alloy, Fe, stainless steel, Mg alloy, polypropylene, polyethylene, polyphenylene sulfide, polytetrafluoroethylene, polyethylene terephthalate, or other polyesters can be used. Examples of the heat-fusible resin that can be used include polypropylene, polyethylene, acid modified products thereof, polyesters such as polyphenylene sulfide and polyethylene terephthalate, polyamide, and ethylene-vinyl acetate copolymer. When the thickness of the exterior body is about the thickness of a flexible film, the cup-shaped molded part is pressed with a punch and a die while holding the exterior body around the part to be molded in a slidable state. Drawing forming (deep drawing forming) is preferable. The recesses may be formed by an overhang forming method in which the film around the part to be formed is fixed without sliding, and the film is stretched and formed with a die. Moreover, you may produce the exterior body which has a recessed part with the injection molding method. In the case where the thickness of the exterior body is such that it has rigidity, press molding, casting, or the like can be used as a method for forming the cup-shaped molded portion.

The lid-side exterior body and the cup-molded exterior body may be individually manufactured, but one film is folded back, with one part being the lid-side exterior body and another part being the cup-molded exterior body It may be used.
The lid-side exterior body is preferably a film-like material, that is, a thin member having flexibility exemplified by a metal foil, a resin thin film, and a laminate thereof.

[Plate group (power generator)]
As a configuration of the electrode plate group, a laminate in which a flat positive electrode, a negative electrode, and a separator are laminated is preferable. The positive electrode is not particularly limited as long as it absorbs positive ions or discharges negative ions at the time of discharge. (I) Metal oxide such as LiMnO ₂ , LiMn ₂ O ₄ , LiCoO ₂ , LiNiO ₂ , (ii) Conductive polymers such as polyacetylene and polyaniline, (iii) general formula (R-Sm) n (R is aliphatic or aromatic, S is sulfur, m, n is m ≧ 1, a secondary battery such as a disulfide compound (dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol, etc.) represented by n ≧ 1 Conventionally known materials can be used as the positive electrode material. Alternatively, a positive electrode active material (not shown) can be mixed with an appropriate binder or functional material on the positive electrode. These binders include halogen-containing polymers such as polyvinylidene fluoride, and functional materials include conductive polymers such as acetylene black, polypyrrole, and polyaniline to ensure electron conductivity, and ion conductivity. For example, a polymer electrolyte, a composite thereof, and the like. The negative electrode is not particularly limited as long as it is a material capable of occluding and releasing cations, natural graphite, crystalline carbon such as graphitized carbon obtained by heat treatment of coal / petroleum pitch at high temperature, coal, petroleum pitch coke, Conventionally known negative electrode active materials for secondary batteries, such as amorphous carbon obtained by heat treatment of acetylene pitch coke and the like, lithium alloys such as metallic lithium and AlLi, can be used.

Examples of the electrolyte solution included in the electrode plate group include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, N, N′-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, m - secondary cell having a high basic solvent to Li or K polar available as an electrolyte of cresol, the alkali metal cations and _ClO such as Na ^{_{4 -, BF 4 -, PF}} 6 -, CF 3 SO 3 - , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ^{— and} other halogen-containing compounds And a salt composed of the above anion. Moreover, the solvent and electrolyte salt which consist of these basic solvents can also be used individually or in combination. Moreover, it is good also as a gel electrolyte made into the polymer gel containing electrolyte solution. A small amount of sulfolane, dioxane, dioxolane, 1,3-propane sultone, tetrahydrofuran, vinylene carbonate, or the like may be added.
The above is a material system as a lithium ion secondary battery, but the present invention can also be applied to a lead battery, a nickel cadmium battery, and a nickel metal hydride battery. Moreover, you may combine components, such as a lead terminal, an exterior body, and a power generation body, with the component described in embodiment of 2nd invention and the reference technique 2. FIG.

Next, reference technology 1 and an embodiment of the first invention will be described based on the drawings.
FIG. 1 shows a cross section of a stationary unit cell as an example of the embodiment of the reference technique 1 and the first invention, and FIG. 2 schematically shows an external appearance of an assembled battery in which the stationary unit cells of FIG. 1 are connected in series. FIG. 3 is a schematic cross-sectional view taken along line AA ′ in FIG.

  Referring to FIGS. 1 to 3, as an embodiment of the installed battery according to the reference technique 1 and the first invention, an electrode plate group (power generation body) 3 includes a lid side exterior body (first exterior body element) 1 and a cup. It is encapsulated by a molded exterior body (second exterior body element) 2 and the exterior bodies around the electrode plate group (portion 6) are bonded together and hermetically sealed. This sealing part is bowl-shaped, and if the battery shape is rectangular, it is located at four end sides or three end sides. The positive electrode lead terminal 51 and the negative electrode lead terminal 52 are drawn out through a bowl-shaped sealing portion located at one end side and the opposite end side opposite to each other (portion 61). An electrolytic solution is contained in at least the electrode group inside the battery. Here, the battery is installed so that the cup-molded outer body 2 always faces downward.

As a method of forming the sealing portion passing portion 61 of the positive electrode lead terminal 51 and the negative electrode lead terminal 52, the end side of the cup-molded exterior body 2 and the end side of the lid-side exterior body 1 with these lead terminals pulled out Thus, the outer terminals can be formed by heat-sealing with the lead terminals interposed therebetween. Thus, the exterior body and the surface of the lead terminal are bonded to each other, and hermetic sealing is possible.
In the battery of this configuration, when gas is generated in the battery, the gas collects on the top, so that the gas accumulates in the vicinity of the lead terminal sealing portion, and the lead terminal sealing portion does not get wet with the electrolyte, Peeling deterioration due to the attack of the liquid on the lead terminal / exterior body bonding interface can be prevented.

  In the reference technology 1 and the first invention, “installation” is used for installation on a mobile vehicle such as an automobile, a motorcycle, or a bicycle, or for a stationary installation type power source used for an uninterruptible power supply or a distributed power storage system. When mounted on equipment where the top and bottom are almost always constant, as in the case of a mobile phone, or to be fixed to a part of a building such as the ground, floor, or wall directly or through a housing, such as a wristwatch or mobile phone It does not include mounting on equipment where the top and bottom are not constant.

  As shown in FIGS. 1 to 3, the stationary battery of Reference Technology 1 and the first invention has a flat shape, and is installed with the flat surface horizontal, and the electrode plate surface of the electrode plate group It is preferable to be parallel to the flat surface. In the present embodiment, the surface of the bowl-shaped sealing portion 61 through which the positive electrode lead terminal 51 and the negative electrode lead terminal 52 pass is substantially parallel to the flat surface and substantially the same as the uppermost electrode plate of the electrode plate group. Located at or above the same height. By doing so, wetting of the electrolyte solution of the lead terminal sealing portion 61 can be further effectively suppressed, and peeling degradation due to the electrolyte solution attacking the lead terminal / exterior body adhesion interface can be further effectively prevented. Moreover, if the lid side exterior body 1 consists of a film, gas can be accommodated there by swelling a film to the upper side, and the electrolyte solution wetting of the lead terminal sealing part 61 can be suppressed more effectively. Further, it is possible to more effectively prevent the peeling deterioration due to the electrolytic solution attacking the lead terminal / exterior body adhesion interface.

  The batteries of Reference Technology 1 and the first invention have the following advantages as shown in FIGS. 2 and 3 when assembled. In other words, when a plurality of batteries are stacked in the vertical direction and connected in series, only one type is used without using two types of batteries in which the polarity of the lead terminals is reversed as in the case of a conventionally known one-side drawer type battery. As shown in FIGS. 2 and 3, the positive and negative leads of one battery are stacked by stacking the lead terminals so that the polarities of the lead terminals are opposite to each other alternately with the top and bottom sides aligned as shown in FIGS. The negative electrode lead terminal of another battery to be connected can be adjacent to the terminal. In this way, the batteries can be connected in series with low resistance, and all the batteries in the interconnected battery group can be placed with the electrode plate housing part facing down, so it is better for all batteries. Liquidity can be imparted.

  In the example of FIG. 3, the length L1 in the lead terminal pull-out direction of the battery internal space is longer than the length L2 in the same direction of the top surface of the cup-molded outer package 2. Thereby, a gap 9 is formed in the outer portion of the cup-molded outer package 2. Even if gas is generated inside the battery due to the presence of the gap 9, the lid side exterior body under the gap 9, that is, the exterior body in the vicinity of the lead terminal sealing portion is deformed upward, so that the gas is introduced into the inside. Can be accommodated. This is shown in FIG. The lid-side exterior body swells at the portion where the gap 9 exists, and a gas storage portion such as 99 is formed. As a result, gas tends to accumulate around the lead terminal sealing portion, and the electrolyte solution wetting of the lead terminal sealing portion 61 can be further effectively suppressed, and peeling due to the electrolyte attacking the lead terminal / exterior body bonding interface. Deterioration can be prevented more effectively.

L2 is preferably substantially equal to the length of the electrode plate group. The difference between L1 and L2 is preferably 6 mm or more and 40 mm or less (one side: 3 mm or more and 20 mm or less). If it is less than 6 mm, it becomes difficult to produce the welded portion 4. If it exceeds 40 mm, it is not preferable in terms of space efficiency.
In addition to the above method, a similar gap 9 can be formed by a method in which a spacer is sandwiched between batteries. That is, even if L2 is equal to L1, a gap shorter than L1 is sandwiched between the batteries, so that a gap is formed beside the spacer, and similarly around the lead terminal sealing portion. It becomes easy to accumulate gas, and it can suppress that electrolyte solution attacks a lead terminal / exterior body adhesion interface. However, since the space efficiency is lost in the thickness direction by the amount of the spacer, the structure as shown in FIG. 3 is preferable.

  In order to form a bulge such as 99 in FIG. 4, the lid-side exterior body is preferably made of a film from the viewpoint of flexibility.

[Second Embodiment]
Each component of the battery that can be used in the second invention will be described in detail.

[Lead terminal]
The lead terminal (electrode lead) may be made of Al, Cu, phosphor bronze, Ni, Ti, Fe, brass, stainless steel, etc., and may be annealed if necessary. The thickness is preferably in the range of 20 μm to 2 mm, and may be bent in a crank shape. Two terminals may be drawn out from only one of the four sides of the battery, or the positive electrode lead and the negative electrode lead may face each other through the sealing portion 113a as shown in FIG. And you can pull it out. In this case, the portion from which the sealing portion 113a is drawn out may be at a height that is substantially the same as or higher than the upper end of the power generator. This vertical height is the top and bottom in the cross section of FIG. 5, and the electrode plate group is horizontal with the film (the lower film 232 in FIG. 5) provided with the concave molding portion directed in the direction of gravity (lower side). Install the battery. By installing in this way, the electrolytic solution accumulates below and the gas collects above, so that when the gas is generated, the gas is stored near the portion sealed with the lead terminal 112 (hereinafter referred to as the lead sealing portion). Further, the lead sealing portion is not wetted with the electrolytic solution, and the peeling deterioration due to the electrolytic solution attacking the adhesive interface between the lead terminal 112 and the film can be prevented. Also, even if the sealing at the lead sealing part is broken, the electrolyte solution is not immediately ejected, but only the gas can be released. Problems caused by scattering can be prevented.

  When such a method of pulling out the lead terminals 112 is taken, a film that is in a curved state due to a synergistic effect with the feature of the second invention in which at least a part of the film as the exterior body is deformed in the battery inner direction. The electrolyte solution can be received in the space formed by returning to the original, and the lead sealing portion can be more reliably prevented from getting wet with the electrolyte solution. As shown in FIG. 5, when the positive electrode lead and the negative electrode lead are pulled out through the lead sealing portion as shown in FIG. 5, the molded body and the non-molded body are used as the outer package (film). It is obtained by setting the battery so that the electrode plate group is horizontal with the molded body side (the film side provided with the concave molding part) facing the gravitational direction (lower side). This configuration is convenient when the battery is used without changing the vertical direction, such as a stationary type such as a building, a car, a bicycle, or the like. The above effect is most effective when the electrolyte is liquid rather than solid, semi-solid or gel.

[Exterior body]
As the outer package, a film-like material, that is, a thin member having flexibility exemplified by a metal foil, a resin thin film, a laminate of these, and the like can be used, and is referred to as a film in this specification. As thickness, 10-300 micrometers is preferable, More preferably, it is 50-200 micrometers. When the thickness is less than 10 μm, the mechanical strength as a battery outer body is poor, and inconvenience such as easy breakage occurs. It becomes inconvenient. The formation of the concave mold part is preferably drawing (deep drawing) in which the film around the part to be molded is pressed in a slidable state and the film is pressed with a punch and a die. Alternatively, the concave molding portion may be formed by an overhang molding method in which the film around the portion to be molded is fixed without sliding, and the film is stretched and formed with a die. Moreover, you may produce the exterior body which has a recessed mold part by injection molding.

[Power generator]
The configuration and form of the power generation body are not particularly limited as long as the electrode plates are laminated. For example, the power generation body is composed of a positive electrode, a negative electrode, and a separator. What wound the thing of this thing, Furthermore, what was wound flatly etc. may be sufficient. The material of the electrode plate comprising a positive electrode is not particularly limited as long as it emits what or negative ions to absorb positive ions during _{discharge, (i) LiMnO 2, LiMn} 2 O 4, LiCoO 2, LiNiO 2 , etc. Metal oxide, (ii) conductive polymer such as polyacetylene, polyaniline, (iii) general formula (R-Sm) n (R is aliphatic or aromatic, S is sulfur, m, n is a disulfide compound represented by m ≧ 1, n ≧ 1 (dithioglycol, 2,5-dimercapto-1,3,4-thiadiazole, S-triazine-2, 4,6-trithiol, etc.) ) And the like as a positive electrode material of a secondary battery. Alternatively, a positive electrode active material (not shown) can be mixed with an appropriate binder or functional material on the positive electrode. Examples of these binders include halogen-containing polymers such as polyvinylidene fluoride, and functional materials include conductive polymers such as acetylene black, polypyrrole, and polyaniline for ensuring electron conductivity, ion conductivity. For example, a polymer electrolyte, a complex thereof, and the like. The material of the electrode plate to be the negative electrode is not particularly limited as long as it is a material capable of occluding and releasing cations, natural graphite, crystalline carbon such as graphitized carbon obtained by heat treating coal / petroleum pitch at high temperature, A known negative electrode active material for a secondary battery may be amorphous carbon obtained by heat treatment of coal, petroleum pitch coke, acetylene pitch coke, or the like, or a lithium alloy such as metallic lithium or AlLi.

Examples of the non-aqueous electrolyte solution contained in the power generator include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, N, N′-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, Examples of highly polar basic solvents that can be used as an electrolyte for secondary batteries such as m-cresol include alkali metal cations such as Li, K, and Na, ClO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and CF ₃ SO _3. ^- , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ^{− and the} like It may be one in which a salt composed of an anion of the compound is dissolved. Moreover, it is good also as using the solvent and electrolyte salt which consist of these basic solvents individually or in combination. Moreover, it is good also as a gel electrolyte made into the polymer gel containing electrolyte solution. A small amount of sulfolane, dioxane, dioxolane, 1,3-propane sultone, tetrahydrofuran, vinylene carbonate, or the like may be added.

  The second invention can be used in thin devices other than batteries and other various articles, and the same applies to various devices to which film exterior bodies can be applied, such as electric double layer capacitors, electrolytic capacitors, and various sensors. An effect can be obtained. Moreover, you may combine components, such as a lead terminal, an exterior body, and a power generation body, with the component described in Embodiment of the reference technique 1, 1st invention, and the reference technique 2. FIG.

Next, an embodiment of the second invention will be described based on the drawings.
FIG. 5 is a diagram schematically showing a cross-section in a state in which a pressing plate is provided in the film-clad battery as the first embodiment of the second invention. FIG. 6 is a view schematically showing the external appearance of the battery as viewed from above. As shown in FIGS. 5 and 6, the film-covered battery 1 as the first embodiment of the second invention includes a lead terminal (electrode lead) 112 corresponding to each of the positive electrode and the negative electrode as a power generation body (power generation element) 111. The battery main body provided in is encapsulated by a film (exterior body) 113 and hermetically sealed so as to expose each lead terminal 112 to the outside. The power generator 111 is configured by laminating a sheet-like positive electrode plate, an electrode plate such as a negative electrode plate, and a separator. The above-described hermetic sealing is performed by heat-sealing the film 113 with a sealing portion 113a that is a range having a margin in a direction other than the stacking direction of the electrode plate or the like. The film 113 is composed of an upper film 231 and a lower film 232, and the heat seal described above uses the two films to connect the lead terminal 112 so that the battery main body can be energized with the outside of the battery. It is performed between.

Note that the order of stacking described above is not limited to the order of sandwiching the separator between the positive electrode plate and the negative electrode plate. For example, a plurality of positive electrode plates and negative electrode plates are stacked with the separator interposed therebetween, The uppermost part and the lowermost part may be either the positive electrode plate or the negative electrode plate.
In the present specification, the film refers to a thin member having flexibility with respect to bending deformation, and in the second invention, a metal foil alone or a laminate of a metal foil and a resin film generally called a laminate film is preferable.

The upper film (upper exterior body) 231 is a flat film that does not have a concave portion (the concave portion is not formed in advance) before sealing under reduced pressure. As the lower film (lower exterior body) 232, a film in which a concave portion for housing the power generation body 111 is formed in advance is used. The formed concave portion is hereinafter referred to as a concave mold portion. This concave mold part is formed so that the volume is larger than the volume of the power generator 111. That is, the concave mold portion is formed so that the bottom area is larger than that of the power generation body 111 in a direction orthogonal to the stacking direction of the electrode plate or the like in the power generation body 111.
The film-clad battery 101 is sealed under reduced pressure by performing sealing and sealing by heat-sealing the upper film 231 and the lower film 232 under reduced pressure (so that the inside of the battery is in a reduced pressure state). By this decompression sealing, the curved portion 231b which is a part of the upper film 231 is curved toward the inside of the battery, and the lower film 232 is also of the curved portion 232b located in the excessive concave molding portion outside the power generator. It is crushed by curving in the battery inner direction at the part.

The relationship between the concave molding part of the exterior body and the shape and size of the power generation body will be described in more detail with reference to FIG. 7 together with an example of the battery manufacturing method of the present invention. FIG. 7 is a diagram showing an example of the manufacturing process of the film-clad battery 101 as the first embodiment of the second invention.
First, as shown in FIGS. 7A and 7B, the power generation body 111 is placed on a concave molding portion formed in advance on the lower film 232. A lead terminal 112 corresponding to each of the positive electrode and the negative electrode is previously welded to the current collector foil extending from the power generator 111 at the welded portion 112a (the lead terminal is omitted in FIG. 7B). In the example of FIG. 7, the volume at the time of forming the concave mold portion (hereinafter referred to as a molding volume) is calculated by y · x · d, which is the product of the vertical and horizontal depths of the concave mold portion. The volume of the power generator 111 is made smaller than the molding volume by setting the following size. That is, the size of the power generator 111 in the horizontal direction (vertical direction in FIG. 7B) is substantially equal to x, but the size in the vertical direction and the thickness direction are smaller than y and d, respectively.

  Here, the molding volume is preferably in the range of 1.15 to 2 times the volume of the power generator 111. If it is less than 1.15 times, there is not enough room to store gas, and the effect of the second invention is difficult to obtain. If it exceeds twice, it will take too much space, which is not preferable from the viewpoint of volume energy density. However, if the lower film 232 is formed with a concave molded portion having a larger bottom area (y · x is larger) than the power generator 111 in a direction perpendicular to the electrode plate stacking direction of the power generator 111, the molding volume is not necessarily limited to the power generator. It may not be larger than the volume of 111 (for example, when d is smaller than the thickness of the power generator 111).

  Next, as shown in FIG. 7C, a flat film that does not form a recess is covered as the upper film 131 from above. At this time, since the relationship between the concave mold portion of the lower film 232 and the size of the power generation body 111 is as described above, there is an excess space above and beside the power generation body 111. Next, after heat-sealing the exterior body under reduced pressure and then releasing to the atmosphere, the concave mold part of the lower film 232 that forms the excess space is crushed in the battery inner direction by atmospheric pressure. In this manner, as shown in FIG. 5, a battery having curved portions 231b and 232b in the upper film 231 and the lower film 232 is obtained.

By manufacturing as described above, even when gas is accumulated inside due to temporary abnormality of the battery or long-term use, a film deformed in the battery inner direction at the time of decompression sealing, that is, 231b and / or in FIG. Alternatively, by returning the portion of 232b to the original state, the gas can be stored in a marginal space due to the difference between the volume of the concave molded portion of the exterior body film and the volume of the power generation body 111, and the gas can be stored without substantially increasing the internal pressure. Can be saved.
This effect is obtained because the shape at the time of forming the concave molding portion of the lower film 232, that is, the natural shape is deformed inward by the reduced pressure sealing at the time of producing the battery, so that it becomes an unnatural shape. That is, even if gas is generated inside the battery, the gas is stored while the upper film 231 and the lower film 232 return to their natural shapes, so that the gas can be stored with almost no increase in internal pressure.

  In conventional proposals, it has been considered preferable to make the molding volume of the film (exterior body) and the volume of the power generation body substantially the same with emphasis on space efficiency. In the case of almost the same, when gas is generated inside, the film has to swell more than the original molding volume, that is, in the form of a bellows, and the internal pressure tends to increase even if the amount of generated gas is small.

  In the example of FIGS. 5 to 7, the thickness and the length of the power generation body 111 are smaller than the molding depth and the molding length of the concave molding portion of the lower film 232, respectively. Only the length may be smaller than the molding length of the exterior body. Moreover, you may make the horizontal width of the electric power generation body 111 smaller than the shaping | molding horizontal width of an exterior body. When the length or width of the power generation body 111 is made smaller than the molding length or molding width of the exterior body, the power generation body 111 has a curved portion 232b. Even if the pressing plate 101C is pressed in the vertical direction (the stacking direction of the electrode plates), the effect of the second invention is not affected. In addition, when holding down dynamically, it is preferable that a curved part exists in the area | region which 101 C of pressing plates in a film do not contact | connect. This is to prevent the curved portion of the film from being deformed to the outside by the pressing plate 101C and restricting the gas accommodation amount. By performing such battery holding, it is possible to obtain the effect of maintaining the close contact of the electrode plate and the like in the power generator 111.

On the other hand, when this holding plate 101C is not used, when the gas is contained in the curved portion of 231b, the adhesion between the polar plates is maintained even if the atmospheric pressure is not suppressed by the curved portion of 231b. Is preferably adhered.
There are two methods for adhering the electrode plates: a method in which an adhesive layer is provided between the electrode plates and the separator, and a method in which the electrode plates and the separator are made porous and the electrolyte filled in the holes For example, there is a method in which the electrode plate and the separator are integrated and substantially bonded as a solid, semi-solid, or gel that is continuous in the holes of the separator and the separator.

  Specifically, the method of adhering between the electrode plates is an adhesive polymer so as to be a continuous body over three regions of the pores inside the positive electrode, the pores inside the negative electrode, and the porous separator located between them. And a method in which a polymer solution is applied to a separator, bonded to the electrode plate and dried to bond the electrode plate and the separator (Japanese Patent Application Laid-Open No. 10-172606). And a method of impregnating an electrode plate laminate with an electrolyte containing a precursor before gelation, and gelling (semi-solidifying) the electrolyte in a laminated state.

In the example shown in FIG. 5, the thickness direction of the battery (stacking direction of the electrode plates) is dynamically pressed by the pressing plate 101C. In FIG. 5, means for fixing the pressing plate 101C or applying force is omitted, but the pressing plate may be attached to the rigid pack case surrounding the battery, or the battery may be pressed by the rigid pack case itself. A force may be applied to the pressing plate 1C by an elastic body such as a spring, rubber, an air bag, or an air cylinder. It may be pressed with a rigid case made of a rigid body. Such a battery plate retainer is positioned as one of the means (a sandwiching device) for maintaining close contact between the electrode plates when the power generator 11 is composed of electrode plates.
Even if gas is accumulated inside the battery due to long-term use, a part of the concave mold part of the film is crushed in the battery inner direction and the power generator 111 is mechanically pressed from the outside of the film. The portion collapsed in the battery inner direction, that is, the portion 232b in FIG. 5, returns to its original state, so that the gas can be stored while maintaining the close contact between the electrode plates of the power generator 111 without increasing the internal pressure. . This effect is obtained when the curved portion of the film is provided on the side of the power generation body 111 (at least a part of the power generation body in a direction other than the stacking direction of the electrode plates), that is, the plate that dynamically presses the battery contacts This can be obtained when a curved portion is provided in the exterior body portion of the surface that is not provided.

FIG. 8 is a schematic cross-sectional view showing the manufacturing process of the film-clad battery as the second embodiment and the third embodiment of the second invention. FIGS. 8A and 8B show the film-clad battery 2 as the second embodiment, in which FIG. 8A is before decompression sealing and FIG. 8B is after decompression sealing. FIG.8 (c) is a figure which shows the lower film 332 of the film-clad battery as 3rd Embodiment. Hereinafter, parts common to the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
As shown in FIG. 8 (a), at least a part (332b in FIG. 8 (a)) of the lower film 332 that is not in contact with the power generation body 111 of the concave mold portion is initially removed from the battery before sealing. It is good also as shape | molding previously in the shape swelled in the direction. The magnitude | size which the inner side deformation | transformation part by the pressure reduction sealing of an exterior body swells by the raise of the internal pressure by gas generation will be limited to the range which a film does not extend. In particular, a laminate film hardly extends because it contains a metal foil. Therefore, as in the second embodiment shown in FIGS. 8A and 8B, by extending the lower film 332 in a direction that swells outside the battery in advance, the amount of gas received when the internal pressure increases can be increased. it can.

  If the film is pre-stretched in the direction that swells outside the battery, the number of surfaces facing the battery outside in the film will increase.Therefore, deformation gussets in the direction that swells can be kept in the film without increasing the internal pressure. This is convenient for the purpose of the second invention for accepting the generated gas. This is because even if gas is generated inside the battery, the gas is stored while returning to its natural shape, which is the original shape, so that the gas can be stored with almost no increase in internal pressure. On the other hand, if a part of the film has a dent-shaped part that faces the inside of the battery, the part has a large number of surfaces facing the inside of the battery in the film. It does not meet the purpose of the second invention.

  In the second invention, the film may be stretched in advance in the direction to swell toward the outside of the battery, and the exterior body may be contracted by atmospheric pressure at the time of sealing under reduced pressure as shown in FIG. As shown in FIG. 8 (c), the curved portion 432b of the lower film 432 that is preliminarily shaped in a direction that swells outside the battery (formed in a convex shape toward the outside of the battery) is inverted and deformed in advance before battery assembly. Then, after that, the procedure of storing the power generator 111 and sealing under reduced pressure may be taken. Since the film deformation portion facing inward when formed in this way has a deformation gusset in the direction of swelling even when facing inward, unlike the case of forming a recess facing inward from the beginning, the second Meets the purpose of the invention. In order to enable reverse deformation as the third embodiment, the boundary line between the convex portion (curved portion 432b) and the flat portion is a curved surface when the lower film 432 is formed in the direction of swelling outward of the battery. However, specific conditions are required for the molded shape, such as being included in a flat surface.

  FIG. 9 is a view showing a film-clad battery 104 as a fourth embodiment of the second invention. FIG. 9A is a plan view seen from above before decompression sealing, FIG. 9B and FIG. 9C are perspective views with the lower film 532 provided with a concave molding portion up, and FIG. Before pressure reduction sealing, (c) is after pressure reduction sealing. As shown in FIG. 9, at least a part of the shape of sealing and sealing by heat sealing of the film (the shape of the sealing portion 143a) may have a structure having a convex portion toward the inside of the battery. That is, a convex portion facing the inside of the battery is formed in the lower film 532 in advance so as to be positioned in the vicinity of the power generation body, and the tip of the convex portion is a sealing convex portion 143a ′ in the vicinity of the power generation body 111, that is, the upper film 531. It is good also as fusing (joining) to the part which faces and contacts as a pair. If the power generator 111 is not pressed from the outside of the film in the laminating direction of the electrode plates with a pressing plate or the like, the area in contact with the power generator 111 also swells when the periphery of the power generator 111 is inflated by the internal pressure due to gas generation Therefore, the adhesion between the electrode plates of the power generator 111 may be deteriorated. Therefore, in order to suppress the expansion of the internal volume to the portion in the stacking direction of the electrode plates with respect to the power generation body 111, a sealing portion 143a is provided slightly outside the power generation body 111, and a part of the sealing portion 143a is provided. Is provided with a projecting convex portion 143a ′ extending in a convex shape to the vicinity of the power generator 111. A convex portion for the sealing convex portion 143a ′ is formed in advance on the lower film 532 and sealed under reduced pressure, thereby providing a portion where the upper film 531 and the lower film 532 are joined in the vicinity of the power generator 111. It is possible to regulate the expansion of the internal volume in the stacking direction of the electrode plates when the internal pressure rises.

  FIG. 10 is a plan view of a film-clad battery 105 as a fifth embodiment of the second invention as viewed from above. As shown in FIG. 10, a heat seal portion (joint portion) in the vicinity of the power generator 111 may be provided independently of the sealing portion 153a. That is, the expansion of the internal volume to a portion in the electrode stacking direction in the vicinity of the power generator 111 independently of the sealing portion 153a that is a heat seal portion that seals the periphery of the film slightly outside the power generator 111 It is good also as providing partial melt | fusion part 153a 'so that it may suppress. Thus, by providing the partial fusion | melting part 153a 'in at least one part of electric power generation body 111 vicinity, expansion | swelling to the lamination direction of the electrode plate of the electric power generation body 111 can be controlled.

  In the configuration that has been proposed in the past, the volume in the concave molding part of the film and the volume of the power generation body are almost the same with emphasis on space efficiency, so the internal pressure tends to rise even if the amount of generated gas is small, and the electrode plate from outside the battery Even if it is pressed with a pressing plate in the laminating direction of the film, if gas is generated inside, the film will try to expand strongly in the form of a bellows due to the strong pressure raised by the accumulation of gas, and the pressing plate will be spread out. Adhesion could not be maintained.

In the second invention, as a method for maintaining the close contact between the electrode plates of the power generation body, a method of creating the power generation body 111 by winding the stacked electrode plates may be used. In this method, for example, an electrode plate or the like is wound around a winding core, and then the power generating body 111 is created by the wound electrode plate group by pulling out the winding core, and the electrode plate is formed on the power generating body 111. A part formed so as to be deformable so as to expand the internal volume is provided in at least a part of the direction other than the stacking direction as shown in any of the above-described embodiments.
Moreover, you may use the method of stopping an electrode group (electric power generation body by which an electrode plate etc. are laminated | stacked) in the lamination direction with an adhesive tape. In this method, an adhesive tape is affixed to at least a part including a part other than the laminating direction in the electrode plate group and stopped in the laminating direction, and then sealed with a film as shown in any of the above-described embodiments. It is what is sealed. Moreover, if it can hold | maintain an electrode plate in the lamination direction, it will not be limited to these methods, The electric power generation body of the film-clad battery shown in any one of each embodiment mentioned above is pressed in the lamination direction of an electrode plate using another method. It is good as well.

  Patent Document 5 (Japanese Patent Laid-Open No. 6-111799) described above discloses a battery in which a space portion is held around an electrode plate group and sealed with a synthetic resin hermetic sheet. As described above, an unmolded sheet (not provided with a concave molding portion) is used. If the concave molding part is not formed in advance on the film (exterior body), a sufficient gas-accepting external body curve shape as indicated by 232b in FIG. 5 cannot be obtained. If the concave mold part is formed in advance in the film, as described above, the curved part 232b is curved toward the inside of the battery when sealed under reduced pressure, is convex toward the outside in the gas receiving state, and is curved in the opposite direction. Gas can be stored. As in the example of Patent Document 5, when an unmolded sheet (not provided with a concave molding part) is used as an exterior body, the film is substantially planar when decompressed, and the exterior body is in a state where gas is accumulated. Even if the protrusion is deformed outwardly, the volume difference due to the protrusion deformation is much smaller than when the present invention is implemented, and the amount of gas that can be received is reduced.

[Embodiment of Reference Technology 2]
Each component of the battery that can be used in Reference Technology 2 will be described in detail.

[Lead terminal]
The lead terminal can be made of Al, Cu, Ni, Ti, Fe, brass, stainless steel or the like, and may be annealed if necessary. The thickness is preferably in the range of 20 μm to 2 mm. It is not preferable that the surface is contaminated with oil or the like, and it is preferable to perform a degreasing treatment. It is also preferable to apply some surface treatment in order to improve the adhesion to the sealing material. For example, roughening by chemical etching or the like, a film made of a partially aminated phenolic polymer, a phosphoric acid compound and a titanium compound, phosphoric acid It is also preferable to perform a surface treatment exemplified by a corrosion-resistant coating base treatment with a zinc-based coating or the like, or a surface treatment with a titanium-based coupling agent or an aluminate-based coupling agent.

[Exterior body]
Various metal flat plates can be used as the exterior body, and Al, Cu, Ni, Ti, Fe, brass, stainless steel, steel, or the like can be used as the material. The thickness of the metal flat plate is, for example, 20 to 1000 μm. In the reference technique 2, as shown in FIGS. 11 to 14, a deep-drawn outer package is preferably used in order to store the power generation element with high space efficiency. In this case, for example, if a laminate film or a laminate thin plate is used, in which one or both surfaces of an Al plate having a thickness of 30 to 500 μm or a steel plate are coated with a thermoplastic resin having a thickness of 5 to 100 μm (corresponding to a metal adhesive resin). It is preferable because oil-free deep drawing and the like can be performed, and in-line processing into the battery manufacturing process can be performed. In the reference technique 2, it is particularly preferable to use a metal flat plate coated on both sides with a polyethylene terephthalate resin composition for at least the outer casing of the power generation element housing portion. In particular, the thickness of the polyethylene terephthalate resin composition layer is 5 -50 μm is preferable, and the metal flat plate is preferably an Al plate of 50-500 μm. Moreover, it is not preferable that the metal surface is contaminated with oil or the like, and it is preferable to perform a degreasing treatment. It is also preferable to perform some surface treatment in order to improve the adhesion with the thermoplastic resin, for example, roughening by chemical etching treatment or the like, a film comprising a partially aminated phenolic polymer, a phosphoric acid compound and a titanium compound, It is also preferable to perform a surface treatment exemplified by a corrosion-resistant coating base treatment with a zinc phosphate-based coating or the like, or a surface treatment with a titanium-based coupling agent or an aluminate-based coupling agent.

  In Reference Technology 2, a metal flat plate not covered with resin may be used as part or all of the exterior body, such as the lower exterior body in FIGS. 11 to 14 and the upper and lower exterior bodies in FIG. it can. The metal flat plate and the power generation element may be electrically connected to combine the function as a terminal and the function as an exterior body.

In the example shown in FIG. 11 to FIG. 14, the lower exterior body and the upper exterior body are placed with the sealing material 203 interposed between the folded back lower exterior bodies in the sealed portion of the piece that is not the lead terminal takeout piece. Therefore, the sealing is less likely to be broken when the internal pressure of the battery is increased than in the case of FIGS. 16 and 17.
Further, this sealing structure is convenient when a laminated plate having a resin coated on both sides is used as an exterior body on one side as in this example. That is, in consideration of performing deep drawing, it is preferable to use a double-sided resin-coated laminate plate for one side of the exterior body from the viewpoint of process oil-free and no need for cleaning. In that case, as shown in FIG. If the two sheets are simply opposed to each other through the sealing material without folding back and the heaters are pressed on the top and bottom to perform heat sealing, the upper surface heater melts the resin covering the battery surface (battery outside). Therefore, inconveniences in production such as resin sticking to the heater occur. Therefore, as shown in FIG. 11 to FIG. 14, if the covering resin layer on the heater contact surface at the time of thermal adhesive sealing has a sealing structure protected by a metal surface exposed member, the resin surface directly contacts the heater. Therefore, the above production inconvenience does not occur.

Conventionally proposed laminated film-clad batteries use a laminate film in which the outermost layer side of the battery is coated with a resin having a melting point higher than that of the sealing material. If this is the case, the resin will not stick to the heater, but in the case of Reference Technique 2, the melting point of the sealing material is high and the heat sealing temperature must be increased. In order to avoid the problem of resin sticking to the heater, it is necessary to provide a sealing structure in which the coating resin layer on the heater contact surface at the time of thermal adhesive sealing is protected by a metal surface exposed member. It is preferable to do.
In addition, as the metal surface exposed member for protecting the coating resin of the laminate sheet, a metal member other than the lower exterior body is prepared and bent to cover the thermal bonding end portion between the upper exterior body and the lower exterior body. You may make it adhere | attach (FIG. 18).
In addition, an exterior body is not limited to the structure which sealed the several member as shown in FIGS. 11-16, The structure which wound the one sheet member, and the one sheet member turned up A configuration can also be adopted.

[Sealant]
The sealing material in Reference Technique 2 preferably includes an aromatic polyester resin and a gas barrier resin of the aromatic polyester resin. The sealing material may be a two-layer structure or a three-layer structure, such as the sealing material 203 in FIGS. 11 to 15 or the sealing material 203 in FIG. It does not have to be included. Of course, it may be a single layer made of a resin containing a gas barrier resin.

As the gas barrier resin referred to herein, polyalkylene naphthalate such as polyethylene naphthalate or aromatic polyamide is preferably used. Because these are relatively close in melting point to aromatic polyester resins such as polyethylene terephthalate, have excellent homogeneity when melt-kneaded, do not easily cause partial leak paths, and have excellent outside air blocking performance, and are aromatic. This is because the polymer is superior in solvent resistance, that is, electrolyte solution resistance. From the above viewpoint, polyamides containing a xylene group or a xylylene group are particularly preferably used among aromatic polyamides. The content of the gas barrier resin with respect to the entire sealing material is preferably 5 to 50% by weight, and more preferably 10 to 30% by weight.
As the aromatic polyester resin used together with the gas barrier resin, polyalkylene terephthalate is preferable. This is because the heat-sealing property is excellent, the sealing property is good at the time of heat sealing, and the excellent gas barrier property can be obtained.

  Examples of the dicarboxylic acid constituting the ester-forming unit of polyalkylene terephthalate include terephthalic acid, isophthalic acid, 4,4′-diphenyldicarboxylic acid, 3,4′-diphenyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5 Examples include aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid. In the case of having an aromatic ring on the diol side, aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid, etc., or 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, decalindicarboxylic acid Dicarboxylic acids such as acids and tetralin dicarboxylic acids can also be used.

  On the other hand, as the diol constituting the ester forming unit, an aliphatic glycol such as propylene glycol, trimethylene glycol, diethylene glycol, 1,4-butanediol, or 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol And alicyclic glycols such as 1,6-cyclohexanediol, and aromatic glycols such as bisphenol A.

The xylylene group-containing polyamide used in the present reference technique is a polyamide obtained by polycondensation reaction of a xylylenediamine component and a dicarboxylic acid component.
The xylylenediamine component is mainly composed of xylylenediamine such as metaxylylenediamine and paraxylylenediamine as the diamine component. In the present invention, the diamine component containing 70 mol% or more of metaxylylenediamine is used. Particularly preferred are those containing 80 mol% or more of metaxylylenediamine from the viewpoint of gas barrier properties.

  In the xylylenediamine component, as other diamine components, in addition to the above paraxylylenediamine, aliphatic methylene such as tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, octamethylenediamine, nonamethylenediamine, paraphenylenediamine, etc. Aromatic diamines such as alicyclic diamines such as 1,3-bisaminomethylcyclohexane and 1,4-bisaminomethylcyclohexane can also be used.

  The dicarboxylic acid component is a dicarboxylic acid component mainly composed of an α, ω-linear aliphatic dibasic acid, and an α, ω-linear aliphatic dibasic acid having 6 to 12 carbon atoms is preferred. used. Specific examples of dicarboxylic acid components that can be used include adipic acid, succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid and other aliphatic dicarboxylic acids, and other terephthalates. Aromatic dicarboxylic acids such as acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid can also be used by blending to the extent that the function of the present invention is not impaired.

In Reference Technology 2, the aromatic polyester resin and the gas barrier resin of the aromatic polyester resin can be obtained by mixing in a molten state, but the mixture in a solid state is melt-kneaded and formed into a film shape And it is good also as a sealing material. For example, it can be melt kneaded in a molding machine generally used for plastics such as an extruder and an injection molding machine.
The sealing material can have a laminated structure of a gas barrier resin layer composed of an aromatic polyester resin, a gas barrier resin of an aromatic polyester resin, and another resin layer. As the other resin layer, a metal adhesive resin layer can be appropriately disposed. The thickness of the layer made of the gas barrier resin composition is preferably 10 to 100 μm. When it has a metal adhesive resin layer, the thickness of the metal adhesive resin layer is preferably 5 to 50 μm. Examples of the metal adhesive resin include polyethylene terephthalate resin. Polyethylene terephthalate single resin may be used and other components may be blended. In this case, the blend amount is preferably 0 to 50% by weight. Further, a copolymerized polyester resin mainly composed of ethylene terephthalate may be used. In this case, the copolymer component other than the ethylene terephthalate unit is preferably 0 to 50% by weight. Examples of blend components and copolymer components include (poly) butylene terephthalate, (poly) ethylene isophthalate, (poly) ethylene sebacate, (poly) ethylene adipate, and poly (oligo (oxytetramethylene) -terephthalate) oxy Examples thereof include polyester having an alkylene repeating unit.

  In the reference technique 2, the sealing material may be previously coated on at least a part or the entire inner surface of the exterior body. If the coating resin layer itself of the laminate sheet contains a gas barrier resin and also functions as a sealing material, the laminate sheets can be directly heat-bonded and sealed without separately preparing a sealing material film. (FIG. 18).

[Power generation element]
The configuration and form of the power generation element 204 are not particularly limited. For example, the power generation element 204 includes a positive electrode, a negative electrode, and a separator. From a flat plate, two or more sets simply stacked, a long one wound, A flat wound or the like is used. The positive electrode is not particularly limited as long as it absorbs positive ions or discharges negative ions during discharge,
(i) metal oxides such as LiMnO ₂ , LiMn ₂ O ₄ , LiCoO ₂ , LiNiO ₂ ,
(ii) conductive polymers such as polyacetylene and polyaniline,
(iii) General formula (R- _Sm ) _n
(R is aliphatic or aromatic, S is sulfur, and m and n are integers of m ≧ 1 and n ≧ 1) (dithioglycol, 2,5- Conventionally known materials can be used as positive electrode materials for secondary batteries such as dimercapto-1,3,4-thiadiazole, S-triazine-2,4,6-trithiol and the like. Alternatively, a positive electrode active material (not shown) can be mixed with an appropriate binder or functional material on the positive electrode. These binders include halogen-containing polymers such as polyvinylidene fluoride, and functional materials include conductive polymers such as acetylene black, polypyrrole, and polyaniline to ensure electron conductivity, and ion conductivity. For example, a polymer electrolyte, a composite thereof, and the like. The negative electrode is not particularly limited as long as it is a material capable of occluding and releasing cations, natural graphite, crystalline carbon such as graphitized carbon obtained by heat treatment of coal / petroleum pitch at high temperature, coal, petroleum pitch coke, Conventionally known negative electrode active materials for secondary batteries, such as amorphous carbon obtained by heat treatment of acetylene pitch coke and the like, lithium alloys such as metallic lithium and AlLi, can be used.

Examples of the non-aqueous electrolyte solution contained in the power generation element include ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, methyl ethyl carbonate, γ-butyrolactone, N, N′-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, Examples of highly basic solvents that can be used as an electrolyte for secondary batteries such as m-cresol include alkali metal cations such as Li, K, and Na, ClO ₄ ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , and CF ₃ SO _3. ^- , (CF ₃ SO ₂ ) ₂ N ⁻ , (C ₂ F ₅ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , (C ₂ F ₅ SO ₂ ) ₃ C ^{— and} other halogens What melt | dissolved the salt which consists of an anion of a compound is mentioned. Moreover, the solvent and electrolyte salt which consist of these basic solvents can also be used individually or in combination. Moreover, it is good also as a gel electrolyte made into the polymer gel containing electrolyte solution. A small amount of sulfolane, dioxane, dioxolane, 1,3-propane sultone, tetrahydrofuran, vinylene carbonate, or the like may be added.

  Reference technology 2 can be used in thin devices other than batteries and other various articles, and in various devices to which sheet-like exterior bodies can be applied, such as electric double layer capacitors, electrolytic capacitors, and various sensors. Similar effects can be obtained. Moreover, you may combine components, such as a lead terminal, an exterior body, and a power generation body (electric power generation element), with the component described in Embodiment of the reference technique 1, 1st invention, and 2nd invention.

Next, an embodiment of the reference technique 2 will be described based on the drawings.
FIG. 11 is a diagram schematically showing the outer appearance of a nonaqueous electrolyte battery having a sheet-shaped outer package as one embodiment of Reference Technique 2, and FIGS. 12, 13, and 14 are respectively A- It is sectional drawing equivalent to an A 'line, a BB' line, and CC 'line.

  Referring to FIGS. 11 to 14, as one embodiment of the film-seal type non-aqueous electrolyte battery of the present invention, a power generation element 204 containing a non-aqueous electrolyte solution is enclosed in an exterior body (201, 202). The upper exterior body 201 is obtained by thermally bonding the metal adhesive resin layer 211 to both surfaces of the metal layer 212, and is deep-drawn into a cup shape to secure a storage space for the power generation element and to draw out the lead terminals. ing. The lower exterior body 202 is made of a metal flat plate not coated with a resin, and is folded back at a seal portion with the upper exterior body on the side that is not the lead terminal take-out side. In this seal portion, the lower exterior body and the upper exterior body are fusion-sealed via the seal material 203 so that the upper exterior body is sandwiched between the folded lower exterior bodies (FIG. 12). Here, the sealing material 203 has a configuration in which a metal adhesive resin layer 231 and a gas barrier resin layer 232 are laminated by thermal welding. Both layers are made of the same or different polyethylene terephthalate resin composition, and at least the gas barrier resin layer 232 contains a gas barrier resin. The metal adhesive resin layer side of the sealing material 203 is thermally bonded to the metal surface of the lower exterior body, and the gas barrier resin layer side is thermally welded to the coating resin layer (metal adhesive resin layer 211) of the upper exterior body. Yes. The lead terminal 205 is electrically connected to the power generation element 204 and is drawn out from the inside of the battery to the outside via the sealing portion of the exterior body (FIG. 14). In the sealed portion of the lead terminal (FIG. 13), the gap between the lead terminal and the exterior body and between the upper and lower exterior bodies is sealed with the sealing material 203 having the same two-layer structure as described above. It is preferable that a sealing material is thermally bonded in advance to the portion to be sealed by the exterior body of the lead terminal as shown in FIG. The sealing material 203 having the two-layer structure described above can also be used as the sealing material here. In this case, the metal adhesive resin layer is thermally bonded to the lead terminal side. Further, as shown in FIG. 13, the lead terminal lead-out portion of the outer package is preferably formed in a shape having a relief at a portion where the lead terminal passes in consideration of the thickness of the lead terminal. By doing so, it is possible to effectively prevent the metal layer in the exterior body and the lead terminal from coming into contact with each other and short-circuiting when the lead terminal portion is heat sealed.

  FIG. 16 is a cross-sectional view schematically showing another embodiment of the reference technique 2, and the cross-sectional position in the battery is the same as the position in FIG. In this case, both the upper exterior body 201 and the lower exterior body 202 are metal flat plates that are not resin-coated. The sealing material 203 sandwiched between the exterior bodies has a three-layer structure of a metal adhesive resin layer 231 / gas barrier resin layer 232 / metal adhesive resin layer 231, and a metal adhesive resin layer on one surface and the other surface. Are thermally bonded to the upper and lower exterior bodies, respectively. Further, the lower exterior body does not have a folded structure. The upper exterior body is deep-drawn into a cup shape to secure a storage space for the power generation element and to draw out the lead terminals.

  FIG. 17 is a cross-sectional view schematically showing still another embodiment of the reference technique 2. The cross-sectional position in the battery is the same as the position in FIG. In this case, both the upper exterior body 201 and the lower exterior body 202 are metal flat plates that are not resin-coated. The sealing material 203 sandwiched between the exterior bodies has a uniform composition made of a gas barrier resin. The sealing material 203 is thermally bonded to the upper exterior body and the lower exterior body.

18 is a cross-sectional view schematically showing still another embodiment of the reference technique 2. The cross-sectional position in the battery is the same as the position in FIG. In this case, both the upper exterior body 201 and the lower exterior body 202 are formed by coating a metal layer with a resin layer having a uniform composition on both surfaces of the metal layer. The sealing portion between the upper exterior body and the lower exterior body is directly heat-bonded without using other film materials. That is, the coating resin of both exterior bodies also serves as a sealing material for battery sealing. The metal member 209 is bent and thermally bonded so as to cover the thermal bonding end portion between the upper exterior body and the lower exterior body. Although not shown in this example, a seal resin that is preliminarily thermally bonded to the lead terminal is also made of a uniform composition made of a gas barrier resin.
Of the examples described above, in the examples of FIGS. 17 and 18, it is desirable that the gas barrier resin of the sealing material also has a metal adhesive function. In the other two examples, the gas barrier resin layer does not necessarily have a metal adhesive function.

[Example]
Hereinafter, the details of the first invention and the second invention, and the reference technique 1 and the reference technique 2 will be specifically described using examples and reference examples. However, the first invention and the second invention are limited to these examples. It is not done.

<Example 1>
A lithium manganate powder having a spinel structure, a carbonaceous conductivity imparting material, and polyvinylidene fluoride were mixed and dispersed in NMP at a weight ratio of 90: 5: 5 and stirred to form a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a 20 micron thick aluminum foil serving as a positive electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. Similarly, the slurry was applied to the other surface and vacuum-dried. At this time, the uncoated portions on the front and back sides were made to coincide. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Eight sheets were cut out into rectangles including uncoated portions.

The active material uncoated portion is a portion to be connected to the lead terminal. In this way, a positive electrode having a total theoretical capacity of 3 Ah was prepared.
On the other hand, amorphous carbon powder and polyvinylidene fluoride were mixed in NMP at a weight ratio of 91: 9, dispersed and stirred to obtain a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a 10 micron thick copper foil serving as a negative electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. At this time, the film thickness of the active material layer was adjusted so that the theoretical capacity per unit area of the negative electrode layer and the theoretical capacity per unit area of the positive electrode layer were 1: 1. Similarly, the slurry was applied to the other surface and vacuum-dried. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Nine sheets were prepared by cutting this into a size 2 mm longer and wider than the size of the positive electrode, including a non-coated portion, into a rectangle.
The active material uncoated portion is a portion to be connected to the lead terminal. In this way, a negative electrode was prepared.

  Between the positive electrode and negative electrode prepared as described above, a microporous separator having a three-layer structure of polypropylene / polyethylene / polypropylene having a size that is 2 mm longer and wider than the size of the negative electrode (Celgard, manufactured by Hoechst Celanese) 2300). The outermost side of the electrode was a negative electrode, and a separator was placed on the outer side of the negative electrode (in the order of separator / negative electrode / separator / positive electrode / separator /.. ./Negative electrode / separator). The positive electrode active material uncoated portion and the negative electrode active material uncoated portion were aligned in the opposite direction. Next, an aluminum plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a positive electrode lead terminal and eight positive electrode active material uncoated portions were collectively ultrasonically welded. Similarly, a nickel plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a negative electrode lead terminal and nine negative electrode active material uncoated portions were ultrasonically welded together. In addition, the positive electrode lead terminal and the negative electrode lead terminal are heat-sealed with a sealing material made of a film-like acid-modified polypropylene having a thickness of 30 μm in advance on a portion to be sealed by the outer package prior to the above welding connection, In addition, as in the case shown in FIG. 2, it was bent in a crank shape so that it was pulled out horizontally at a position slightly above the upper surface of the electrode laminate.

On the other hand, a film made of a laminate of 25 μm nylon, 40 μm soft aluminum, and 30 μm acid-modified polypropylene was prepared as a laminate film for an exterior body, cut into a predetermined size, and deep-drawn into a cup shape. The side where the punch hits was the side coated with acid-modified polypropylene (hereinafter referred to as the sealing surface). The depth of the deep drawing was slightly larger than the thickness of the electrode laminate. The size of the punch was substantially the same as the size of the surface of the electrode laminate, and the size of the die was larger than the punch by 10 mm on one side in the lead drawing direction and by 1 mm in the orthogonal direction. In this way, a cup-molded exterior body having a shape in which the side surface is slanted and dish-shaped was obtained.
After this molding, the film around the cup, which was like a cap collar, was trimmed leaving a side with a width of 10 mm. The electrode laminate was accommodated in the cup molding portion of the laminate film thus molded. When stored, the laminate with the lead terminal lead-out surface facing up and the electrode surface horizontal was stored in a cup of laminate film with the sealing surface facing up. The lead terminals were placed on two portions of the collar portion of the trimmed film.

Next, the laminate film was cut out to a predetermined size without being molded, and placed on the cup molding part containing the power generation element so that the sealing surface was directed inward. . The size of the lid was the same as the size after the above molding / trimming, and matched when overlapped.
Next, the lead terminals drawn out via the trimmed film collar are sandwiched between the film collar and the lid, heat sealed at two locations of the lead terminal lead, and then the side that is not the lead terminal lead One side (hereinafter referred to as long side A) of the following (hereinafter referred to as long side A and long side B) was heat-sealed. In addition, the heat seal conditions of the lead terminal lead-out part were set with care so as not to cause a short circuit between the lead terminal and the aluminum foil in the laminate film.

Next, the long side A was inclined downward, and an electrolyte solution was poured into the electrode laminate from the gap between the long side B, which was the last unsealed portion. The electrolytic solution uses 1 mol / liter LiPF6 as a supporting salt and a mixed solvent of propylene carbonate and methylethyl carbonate (weight ratio 50:50) as a solvent. The amount of liquid injection was an amount corresponding to 5% of the volume of the power generation element. After pouring, vacuum degassing was performed. Finally, the long side B was heat-sealed in a reduced pressure state using a vacuum sealing machine to complete the battery. In addition, the exterior body on the lid side was slightly recessed inward as shown in 1 of FIG.
The three batteries thus produced were stacked as shown in FIGS. 1 and 2, and the lead was welded to the metal member 7, thereby being interconnected as shown in FIG. The assembled battery was fixed in a vertical relationship according to the top and bottom of FIG. 2, and this assembled battery was subjected to a high temperature and high humidity test in which it was stored at 60 ° C. and 90% relative humidity for 30 days, and the liquid leakage from the lead terminal lead was observed. . The liquid leakage determination was made based on whether liquid or deposits were observed at the base of the lead terminal lead-out part. If leakage occurred even in one of the six lead terminals of the positive and negative electrodes of three batteries, it was determined as “leakage”.

<Comparative Example 1>
In Example 1, the assembled battery was fixed upside down with respect to FIG.

<Comparative Example 2>
A battery having the configuration shown in FIG. 3A was produced as follows.
After the electrode was cut out into a rectangle including the active material non-applied portion in the same manner as in Example 1, 75% of the active material non-applied portion became an ear shape with the remaining 25% portion approaching the long side on one side. Cut out like so. Separator / Negative electrode / Separator / Positive electrode / Separator /.../ Negative electrode / Separator so that the ears gather on the opposite side in the short side direction (the same side as the long side direction) between the positive electrode and the negative electrode It was laminated in the order. Next, an aluminum plate having a thickness of 0.1 mm, a width of 10 mm, and a length of 50 mm serving as a positive electrode lead terminal and eight positive electrode active material uncoated portions were collectively ultrasonically welded. Similarly, a nickel plate having a thickness of 0.1 mm, a width of 10 mm, and a length of 50 mm serving as a negative electrode lead terminal and nine negative electrode active material uncoated portions were ultrasonically welded together. In addition, the positive electrode lead terminal and the negative electrode lead terminal were heat-sealed with a sealing material made of a film-like acid-modified polypropylene having a thickness of 30 μm in advance on the portion to be sealed by the outer package prior to the above welding connection. .

On the other hand, a film made of a laminate of 25 μm nylon, 40 μm soft aluminum, and 30 μm acid-modified polypropylene was prepared as a laminate film for an exterior body, cut into a predetermined size, and deep-drawn into a cup shape. The side where the punch hits was the side coated with acid-modified polypropylene (hereinafter referred to as the sealing surface). The depth of deep drawing was half the thickness of the electrode stack. After molding, the film around the cup, which looks like a brim of a hat, was trimmed leaving a side with a width of 10 mm.
The electrode laminate was accommodated in the cup molding portion of the laminate film thus molded. At the time of storage, the laminate with the electrode surface horizontal was stored in a laminate film cup with the sealing surface facing upward. The lead terminal was placed on the collar part of the trimmed film. Since the lead terminals are drawn out on the same side in the long side direction, the positive and negative lead terminals are placed on one short side collar portion (hereinafter referred to as a lead drawing side).
Next, the laminated film that was molded and trimmed in the same manner as described above was placed on the cup molding portion in which the power generating element was accommodated so that the sealing surface was directed inward.

Next, the lead terminals pulled out via the trimmed film collars are sandwiched between the upper and lower film collars, the lead lead sides are heat sealed, and then the side that is not the lead terminal lead part (hereinafter referred to as the long side) The long side A and the opposite side were heat sealed.
Next, the long side A was inclined downward, and an electrolyte solution was poured into the electrode laminate from the gap between the long side B, which was the last unsealed portion. The electrolytic solution uses 1 mol / liter of LiPF ₆ as a supporting salt and a mixed solvent of propylene carbonate and methyl ethyl carbonate (weight ratio 50:50) as a solvent. The amount of liquid injection was an amount corresponding to 5% of the volume of the power generation element. After pouring, vacuum degassing was performed. Finally, the long side B was heat-sealed in a reduced pressure state using a vacuum sealing machine to complete the battery.
The three batteries thus produced were stacked with the lead-out sides aligned on the same side in the long side direction and the front and back alternately stacked so that the positive and negative electrodes were alternated, and the batteries were interconnected by metal members ( The connection form was the same as in FIG. 4), and three assembled batteries were obtained. This assembled battery was fixed flatly in the same manner as in Example 1 and subjected to the same high temperature and high humidity test as in Example 1.

<Results of high temperature and high humidity test>
Table 1 shows the results obtained by subjecting the assembled batteries of Example 1, Comparative Example 1, and Comparative Example 2 prepared as described above to the high temperature and high humidity test in this order. In each battery, it was confirmed that gas was generated inside the battery.

<Discussion>
The reason that no leakage occurred in the examples in the two comparative examples is that the surface of the sealing portion through which the positive electrode lead terminal and the negative electrode lead terminal pass is the uppermost electrode plate of the electrode plate group in the example Because it is located slightly above, the gas generated in the battery gathers upward, the gas accumulates in the vicinity of the lead terminal sealing part, the lead terminal sealing part does not get wet with the electrolyte, and the electrolyte is the lead terminal / It is presumed that peeling deterioration due to attacking the exterior body adhesion interface was suppressed.
On the other hand, in Comparative Example 1 and Comparative Example 2, the lead terminal sealing portion was still immersed in the electrolytic solution even when gas was generated in the battery, so that the peeling deterioration progressed and the liquid leakage occurred. It is done.

<Reference Example 1>
A lithium manganate powder having a spinel structure, a carbonaceous conductivity imparting material, and polyvinylidene fluoride were mixed and dispersed in NMP at a weight ratio of 90: 5: 5 and stirred to form a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a 20 micron thick aluminum foil serving as a positive electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. Similarly, the slurry was applied to the other surface and vacuum-dried. At this time, the uncoated portions on the front and back sides were made to coincide. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Eight sheets were cut out into rectangles including uncoated portions. The active material uncoated portion is a portion to be connected to the lead terminal 12. In this way, a positive electrode having a total theoretical capacity of 3 Ah was prepared.

  On the other hand, amorphous carbon powder and polyvinylidene fluoride were mixed in NMP at a weight ratio of 91: 9, dispersed and stirred to obtain a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a copper foil having a thickness of 10 microns serving as a negative electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. At this time, the film thickness of the active material layer was adjusted so that the theoretical capacity per unit area of the negative electrode layer and the theoretical capacity per unit area of the positive electrode layer were 1: 1. Similarly, the slurry was applied to the other surface and dried in vacuum. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Nine sheets were prepared by cutting this into a size 2 mm longer and wider than the size of the positive electrode, including a non-coated portion, in a rectangular shape. The active material uncoated portion is a portion to be connected to the lead terminal 12. In this way, a negative electrode was prepared.

  Between the positive electrode and the negative electrode prepared as described above, a microporous separator having a three-layer structure of polypropylene / polyethylene / polypropylene having a size larger by 2 mm in length and width than the size of the negative electrode (manufactured by Hoechst Celanese, It was laminated via Celgard 2300). The outermost side of the laminated electrode plate was a negative electrode, and a separator was placed on the outer side of the negative electrode (in the order of separator / negative electrode / separator / positive electrode / separator /.../ negative electrode / separator). . The positive electrode active material uncoated portion and the negative electrode active material uncoated portion were aligned in the opposite direction. Next, an aluminum plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a positive electrode lead terminal and eight positive electrode active material uncoated portions were collectively ultrasonically welded. Similarly, a nickel plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a negative electrode lead terminal and nine negative electrode active material uncoated portions were ultrasonically welded together. In addition, the positive electrode lead terminal and the negative electrode lead terminal are heat-sealed with a sealing material made of a film-like acid-modified polypropylene having a thickness of 30 μm in advance on a portion to be sealed by the outer package prior to the above welding connection, And like the thing shown by FIG. 5, it was made to draw out horizontally in the position slightly above the upper surface of an electrode plate laminated body by bending in the shape of a crank.

  On the other hand, a film made of a laminate of 25 μm nylon, 40 μm soft aluminum, and 30 μm acid-modified polypropylene was prepared as a laminate film for an exterior body, cut into a predetermined size, and deep-drawn into a cup shape. The side where the punch hits was the side coated with acid-modified polypropylene (hereinafter referred to as the sealing surface). The volume of the deep drawing (the product of the punch area and the drawing depth) was set to 124% of the volume of the power generator 111 (the portion of the electrode plate laminate not including the lead terminal). The vertical size and horizontal size (the vertical size and horizontal size of the punch) of deep drawing were 16 mm and 6 mm larger than those of the power generator 111, respectively. The drawing depth is slightly deeper than the thickness of the power generator 111 (thickness in the stacking direction of the electrode plate laminate) (a plane including two lead terminals bent in a crank shape and horizontal, and the electrode plate) The distance to the bottom of the laminate). After molding, the film around the cup, which looks like a brim of a hat, was trimmed leaving a side with a width of 10 mm. The electrode plate laminate was accommodated in the cup molding part (concave molding part) of the laminate film thus molded. When stored, the laminate with the lead terminal lead-out surface facing up and the electrode plate surface horizontal was stored in a laminate film cup with the sealing surface facing up. The lead terminals were placed on two portions of the collar portion of the trimmed film. The electrode plate laminate was placed in the center of the cup so that a gap of 8 mm, 3 mm, 8 mm, and 3 mm was formed around the electrode plate laminate.

Next, the laminate film that has been cut out to a predetermined size without being molded is placed on the cup molding part (concave molding part) in which the power generator 11 is stored with the sealing surface facing inward. Placed like a lid. The size of the lid was the same as the size after the above molding / trimming, and matched when overlapped.
Next, the lead terminal 12 drawn out via the top of the trimmed film collar is sandwiched between the film collar and the lid, and the lead terminal is pulled out so as to be energized to the outside (lead sealing part). The part was heat-sealed, and then one side (hereinafter referred to as long side A) of the sides (hereinafter referred to as long side A and long side B) without the lead sealing portion was heat sealed. When heat sealing the long side A, a 5 μm thick, 10 mm square square PET film was sandwiched to provide a portion that functions as a safety valve that peels off and releases gas when the internal pressure is abnormally increased. This is indicated by the portion 164 in FIG.

Next, the long side A was tilted downward, and the electrolyte solution was poured into the electrode plate laminate from the gap between the long side B, which was the last unsealed portion. The electrolytic solution uses 1 mol / liter of LiPF ₆ as a supporting salt and a mixed solvent of propylene carbonate and methyl ethyl carbonate (weight ratio 50:50) as a solvent. The amount of liquid injection was an amount corresponding to 5% of the volume of the power generation body. After pouring, vacuum degassing was performed.
Finally, the long side B was heat-sealed in a reduced pressure state using a vacuum sealing machine to complete the battery. After the final sealing, the inside of the vacuum sealing machine was opened to the atmosphere. As a result, surplus portions (8 mm, 3 mm, 8 mm, 3 mm portions) of the film were recessed inward due to atmospheric pressure. In particular, the dent of the cup-molded film (lower film) was large. This is shown in FIG. FIG. 21 is a perspective view of the film-clad battery 206 of Reference Example 1 when the molded body side (the side on which the concave molding portion is provided) is directed upward. The surface (part) shown as the curved portion 732b is recessed.

In addition, the film (upper film) that is not cup-molded also has the same 8 mm, 3 mm, 8 mm, and 3 mm portions as described above, and is drawn slightly deeper than the thickness of the power generator 111. Therefore, the top surface of the exterior film that was not cup-shaped was lower inward than the lead sealing portion.
The film-clad battery 206 of Reference Example 1 produced in this way was stored in a pack case (clamp) 106C2 as shown in FIG. The orientation was stored with the molded body side (side on which the concave molding portion was provided) facing downward. The pack case 106C2 is provided with a pressing plate 106C1 having substantially the same size as the vertical and horizontal sizes of the power generator 111. The pressing plate 106C1 is attached to the outer pack case 106C2 with a column that is thinner than the pressing plate 106C1. The number of the columns included in the pack case 106C2 is schematically two in FIG. 22, but may actually be 2 × 2 = 4. The pack case 106C2 is made of polyester resin, and the pressing plate 106C1 is made of bakelite. Due to the elasticity of the pack case 106C2, the film-clad battery 106 is clamped in the stacked direction of the electrode plates via the pressing plate 106C1, and the electrode plate adhesion of the power generator 111 is maintained.

  The film-clad battery 106 was subjected to a charge / discharge cycle test with a voltage of 3V-4.8V and a current of 3A. During charging, the battery was charged by a constant current up to 4.8 V and then kept at 4.8 V for 2 hours, and the discharge was a constant current discharge. Since 4.8V is a voltage outside the normal battery use range, this charge / discharge cycle test is referred to as an overcharge cycle test below. When the overcharge cycle test was continued, the curved portion 732b of the lower film 732 gradually returned to the initial state (the shape at the time of drawing), and thereafter, the curved portions 731b and 732b gradually expanded outward. The pressed outer body part (the part in contact with the film pressing plate 106C1) did not swell at all. When the film was further continued, the bulging film became tight and the internal pressure increased. After about 300 cycles, the safety valve 164 was activated and the gas was released. The discharge capacity in the charge / discharge cycle hardly changed until the safety valve 164 was activated.

<Reference Example 2>
The same film-clad battery 206 as in Reference Example 1 was not housed in a pack case and was not pressurized with a holding plate, and the same overcharge cycle test as in Example 1 was performed. As a result, the curved portions 731b and 732b of the film were The film gradually returned to its original state, and the entire film gradually expanded outward from the 200th cycle. When further continued, the internal pressure increased, the safety valve worked in about 400 cycles, and the gas was released. The charge / discharge cycle capacity hardly changed until the curved portions 731b and 732b returned to the original state, but the charge / discharge cycle capacity gradually decreased at the same time as the entire film started to swell. The capacity immediately before the safety valve 164 worked was reduced to 20% of the initial capacity.

<Reference Example 3>
By the production process of Reference Example 1, a film-clad battery having the electrode plate laminated body in which the separator and the electrode plate were bonded and integrated as a power generation body 111 as described below was produced. A toluene solution in which 1,2-polybutadiene (trade name RB810, manufactured by JSR, 90% of 1,2-bond ratio, melting point 71 ° C., average molecular weight 100,000) is 5% by weight and lauroyl peroxide is 0.1% by weight dissolved. Was sprayed onto the separator by spraying and dried to form a polymer adhesive layer in a dot-like manner on both sides of the separator. When observed with a microscope, the polymer adhesive adhered to the separator surface at a coverage of about 2% in terms of area ratio. In the same manner as in Reference Example 1, the adhesive-coated separator thus prepared was laminated together with the electrode plate. Next, this laminate was hot-pressed with a desktop hot press. The conditions were preheating at 80 ° C. for 5 minutes, and then the press was set at a pressure of 5 kg / cm ² , a temperature of 80 ° C., and a time of 5 minutes. Next, the pressure was reduced to 1 kg / cm ² , and the heating was continued for 12 hours while maintaining the temperature at 80 ° C. Through the above steps, an integrated electrode plate laminate in which the positive electrode, the negative electrode, and the separator were strongly bonded to each other was obtained. Thereafter, a film-clad battery was produced in the same manner as in Reference Example 1.

  When the overcharge cycle test similar to the reference example 1 was performed without storing the film-clad battery in the pack case and applying pressure by the pressing plate, the curved portions 731b and 732b of the film gradually returned to the initial state. Returning, from around the 200th cycle, the entire exterior body gradually expanded outward. When further continued, the internal pressure increased and the safety valve 164 was activated in about 400 cycles, and the gas was released. The charge / discharge cycle capacity hardly changed until the safety valve 164 was activated.

<Reference Example 4>
In Reference Example 3, a film formed by drawing the surplus portions of 8 mm, 3 mm, 8 mm, and 3 mm around the power generation body 111 to 2 mm, 0 mm, 2 mm, and 0 mm so that there is almost no gap is used. Otherwise, in the same manner as in Reference Example 3, a film-covered battery having an electrode plate laminate in which the positive electrode, the negative electrode, and the separator were strongly bonded to each other was produced. Although the curved part of the film was hardly formed beside the power generation body 111, the top surface of the film (upper film) that was not cup-molded was lower on the inner side than the lead sealing part.
When the overcharge cycle test similar to the reference example 1 was performed without storing the film-clad battery in the pack case and applying pressure by the pressing plate, the curved portion of the film gradually returned to the initial state, and 100 From around the cycle, the entire film gradually expanded outward. When further continued, the internal pressure increased, the safety valve worked in about 200 cycles, and the gas was released. The charge / discharge cycle capacity hardly changed until the safety valve worked.

<Reference Example 5>
Reference Example 4 was prepared in the same manner as in Reference Example 4 except that a film-clad battery having a power plate 111 having an electrode plate laminate simply laminated in the same manner as in Reference Example 1 without bonding the electrode plates.
When the overcharge cycle test similar to that in Reference Example 1 was performed without storing the film-clad battery in the pack case and applying pressure by the holding plate, the curved portion of the film gradually returned to the initial state, and 100 From around the cycle, the entire exterior body gradually expanded outward. When further continued, the internal pressure increased, the safety valve worked in about 200 cycles, and the gas was released. At the same time as the entire exterior body began to swell, the charge / discharge cycle capacity gradually decreased. The capacity just before the safety valve worked was reduced to 30% of the initial capacity.

<Comparative Example 3>
In Reference Example 1, the size of the outer body draw-molding was set to a vertical and horizontal size that eliminates the gap of the portion of 8 mm, 3 mm, 8 mm, and 3 mm around the power generation body 111 and the same drawing depth as the thickness of the power generation body 111. . In addition, the lead drawing height was set slightly inside the top surface of the film. Others were the same as in Reference Example 1 to produce a film-clad battery in which there was no portion where the film was curved inward (curved portion).
When the overcharge cycle test was conducted in the same manner as in Reference Example 1 with this film-clad battery being pressed with a holding plate in the same manner as in Reference Example 1, the entire exterior body gradually expanded outward from the beginning of the cycle. Then, the press plate was pushed outward by the battery internal pressure from around 45 cycles, and the whole pack case was slightly distorted outward. In 50 cycles, the safety valve worked and the gas was released. The charge / discharge cycle capacity suddenly decreased from around 45 cycles when the pressing plate began to be pushed outward.

<Comparative example 4>
In Reference Example 3, the size of the outer body draw-molding is set to a vertical and horizontal size that eliminates the gap of 8 mm, 3 mm, 8 mm, and 3 mm around the power generation body 111 and the same drawing depth as the thickness of the power generation body 111. Say it. Also, the lead lead height was set slightly inside the top surface of the exterior body. Others were made in the same manner as in Reference Example 3 to produce a film-clad battery having an electrode plate laminate in which the electrode plates were bonded and integrated, and the exterior body did not have a curved portion inside.
This film-clad battery was not housed in a pack case as in Reference Example 3 and was not pressurized with a pressure plate, and an overcharge cycle test was conducted in the same manner as in Reference Example 1. Gradually expanded outward, the safety valve worked in 70 cycles, and the gas was released. The charge / discharge cycle capacity hardly changed until the safety valve worked.

<Discussion>
When the reference example 1 and the comparative example 3 are compared, the number of cycles until the safety valve operates is significantly larger when the margin portion capable of accommodating the gas is formed in the film, compared with the case where the gas is not formed, that is, the gas It can be seen that the period from the generation to the increase in internal pressure is long. From this, it can be seen that even if a temporary abnormality occurs in the film-covered battery and gas is generated little by little, the accumulation margin of the gas is greatly improved. Further, in Comparative Example 3, when gas is generated, the pressure plate is pushed outward and the pack case swells so that the pack case is distorted, and the force for pressing the electrode plates in the stacking direction disappears, and the electrode plate contact state is impaired. Although the cycle capacity decreased due to this, in Example 1, the electrode plate contact state was maintained until the end, and the capacity decrease hardly occurred.

Comparing Reference Example 1 and Reference Example 2, when the electrode plates are not bonded, it is better to use the film-clad battery of the second invention in a pressurized state in the stacking direction of the electrode plates by a pack case (clamp). It can be seen that even if gas is generated inside, the battery can be continuously used without deteriorating the battery characteristics. On the other hand, when Reference Example 2 and Reference Example 3 are compared, it can be seen that, when the electrodes are bonded together, it is possible to suppress the deterioration of characteristics at the time of gas generation without applying pressure by the pack case from the outside of the battery. .
In Reference Example 4, the horizontal portion of the power generator 111 (at least a portion in a direction other than the stacking direction with respect to the power generator) has almost no margin for accommodating gas, but the top surface, that is, the upper film is decompressed. The inner deformed portion formed by the sealing becomes a margin portion, and the inner deformed portion returns to its original state so that the gas can be accommodated. In addition, when Reference Example 3 and Reference Example 4 are compared, whether or not there is a surplus part that can accommodate gas in the horizontal part of power generator 111 (at least a part in a direction other than the stacking direction with respect to the power generator). It can be seen that the number of cycles that can be held is different.

Further, in both Reference Example 4 and Reference Example 5, there is almost no marginal part that can accommodate gas in the side part of the power generation body 111, but the inner surface deformation formed by pressure reduction sealing on the top surface, that is, the upper exterior body. Since the gas was able to be accommodated by returning the part to its original state, it was thought that it held up to 200 cycles. In contrast, in Comparative Example 4, the size of the exterior body has no room in the vertical, horizontal, and top surfaces, so there is no room for gas storage, and it is thought that it had only 70 cycles.
Comparing between Reference Example 4 and Reference Example 5, when the electrode plate is not adhered and not, the characteristic deterioration at the time of gas generation when pressure is not applied from the outside of the battery in the stacking direction of the electrode plate by the pack case It can be seen that the degree is different.

When the reference example 3 and the comparative example 4 are compared, when the horizontal part of the power generator 111 (at least a part in a direction other than the stacking direction with respect to the power generator) does not have a surplus part that can accommodate gas. In comparison, it can be seen that the number of cycles that can be held is greatly improved.
The results of these examples are the results when a voltage outside the normal battery use range is intentionally applied. However, in actual use of the battery, a temporary control error of the battery control circuit or an instantaneous Even when a small amount of gas generation is accumulated due to sudden and temporary high temperature generation due to generation of a large current or insufficient cooling of the battery, it can be said that the same consideration as in the above embodiment can be said.

In the above-described series of embodiments, the concave molded portion having a volume larger than the volume of the power generator 111 is described as being formed on one of the two films, but in a direction other than the laminating direction of the electrode plates. The forming method is not limited as long as it is deformable so as to expand the internal volume of the battery. For example, a concave molding portion having a height lower than that of the power generator 111 may be used. Even in the case of providing this low concave molding part, the film is deformed by reducing the pressure inside the sealed seal (depressurization sealing), so that the same effect can be obtained depending on the molding shape of the curved part 232b. Is possible. For example, you may provide a concave molding part in both films.
In the series of embodiments described above, the film is described as being composed of an upper film and a lower film. However, the above-described battery body is not limited to these two sheets as long as the battery body can be hermetically sealed. It may be. For example, a single film may be folded 180 °.

  Further, in the above-described series of examples, the sandwicher that holds the film-clad battery in a pressurized state in the laminating direction of the electrode plate is described as a pack case having a column. It is not limited to this as long as it can be sandwiched in a pressurized state in the direction. For example, when a film-clad battery is a stationary type installed in a building or the like, it is a structure integrated with the building or the like. Also good. That is, the shape and the structure are not limited as long as it has an elastically deformable elastic portion and can be clamped in the above-described pressure state by its elasticity. As shown in the above embodiment, the elastic part may be formed of a material that can be elastically deformed as a whole, or may have an elastic part that can be elastically deformed in part.

<Reference Example 6>
A lithium manganate powder having a spinel structure, a carbonaceous conductivity imparting material, and polyvinylidene fluoride were mixed and dispersed in NMP (N-methyl-2-pyrrolidone) at a weight ratio of 90: 5: 5 and stirred to form a slurry. . The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a 20 micron thick aluminum foil serving as a positive electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. Similarly, the slurry was applied to the other surface and vacuum-dried. At this time, the uncoated portions on the front and back sides were made to coincide. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Eight sheets were cut out into rectangles including uncoated portions. The active material uncoated portion is a portion to be connected to the lead terminal. In this way, a positive electrode having a total theoretical capacity of 3 Ah was prepared.

  On the other hand, amorphous carbon powder and polyvinylidene fluoride were mixed in NMP at a weight ratio of 91: 9, dispersed and stirred to obtain a slurry. The amount of NMP was adjusted so that the slurry had an appropriate viscosity. This slurry was uniformly applied to one side of a copper foil having a thickness of 10 microns serving as a negative electrode current collector using a doctor blade. At the time of application, the unapplied part (the part where the current collector was exposed) was made to be slightly streaked. Next, this was vacuum-dried at 100 ° C. for 2 hours. At this time, the film thickness of the active material layer was adjusted so that the theoretical capacity per unit area of the negative electrode layer and the theoretical capacity per unit area of the positive electrode layer were 1: 1. Similarly, the slurry was applied to the other surface and dried in vacuum. Thus, the sheet | seat which apply | coated the active material on both surfaces was roll-pressed. Nine sheets were prepared by cutting this into a size 2 mm longer and wider than the size of the positive electrode, including a non-coated portion, in a rectangular shape. The active material uncoated portion is a portion to be connected to the lead terminal. In this way, a negative electrode was prepared.

  Between the positive electrode and the negative electrode prepared as described above, a microporous separator having a three-layer structure of polypropylene / polyethylene / polypropylene having a size 2 mm larger by 2 mm than the size of the negative electrode (manufactured by Hoechst Celanese, Cellguard) 2300). The outermost side of the electrode was a negative electrode, and a separator was placed on the outer side of the negative electrode (in the order of separator / negative electrode / separator / positive electrode / separator /.../ negative electrode / separator). The positive electrode active material uncoated portion and the negative electrode active material uncoated portion were aligned in the opposite direction. Next, an aluminum plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a positive electrode lead terminal and eight positive electrode active material uncoated portions were collectively ultrasonically welded. Similarly, a nickel plate having a thickness of 0.1 mm, a width of 50 mm, and a length of 50 mm serving as a negative electrode lead terminal and nine negative electrode active material uncoated portions were ultrasonically welded together. In addition, prior to the above-described welding connection, the positive electrode lead terminal and the negative electrode lead terminal were previously formed with a sealing material (described later) on the portion to be sealed by the exterior body by thermal bonding as shown in FIG.

  On the other hand, a laminate film obtained by laminating a resin film having a thickness of 8 μm made of a copolymer polyester resin composed of 88% by weight of polyethylene terephthalate (hereinafter referred to as PET) and 12% by weight of polyethylene isophthalate on both surfaces of an aluminum foil having a thickness of 50 mm, Cut into a predetermined size and deep drawn into a cup shape. The volume of the deep drawing (the product of the punch area and the drawing depth) was 110% of the volume of the power generation element (the portion of the electrode laminate not including the lead terminal). However, the drawing depth is equivalent to the thickness of the power generation element. The electrode laminate was accommodated in the cup molding portion of the laminate film thus molded.

Next, an electrolytic solution was poured into the electrode laminate. The electrolytic solution uses 1 mol / liter LiPF ₆ as a supporting salt and a mixed solvent of propylene carbonate and ethylene carbonate (weight ratio 50:50) as a solvent. The amount of liquid injection was an amount corresponding to 5% of the volume of the power generation element.
Next, a rectangular aluminum plate having a predetermined size and a thickness of 100 μm was placed so as to cover the cup molding portion in which the power generation element was accommodated. The size of the aluminum plate was such that the lateral width protruded by 10 mm on both the left and right sides of the cup-shaped laminate film. The lateral part of this aluminum plate was folded back 10 mm at the left and right, and the cup-shaped laminate film was sandwiched between them. At that time, a sealing material was inserted. The situation is as shown in FIG. In the figure, the actual arrangement and the vertical direction are reversed.

As a sealing material, a resin film 30 μm blended with 20% by weight of nylon (hereinafter referred to as MX nylon) obtained by polycondensation of metaxylylenediamine and adipic acid, and 80% by weight of PET, and 88% by weight of PET A resin film 8 μm made of a copolyester resin composed of 12% by weight of polyethylene isophthalate was heat-sealed. Here, the blended MX nylon corresponds to the gas barrier resin layer, and the copolymerized polyethylene isophthalate corresponds to the metal adhesive resin layer.
The resin film obtained by blending MX nylon and PET was prepared by melting and kneading both to produce a pellet, and using this pellet obtained by the T-die method using a single screw extruder.

  Next, the left and right folded portions of the aluminum plate were heated and pressurized with a 300 ° C. heater to melt and seal the sealing material. Next, a seal attachment made of two copper plates having a thickness of 0.5 mm and a width of 12 mm was fixed and installed with a spring clip so as to be sandwiched from outside into the lead terminal sealing planned portion. This is shown in FIG. One side of the copper plate is formed with a depth of 0.1 mm at a portion where the lead terminal passes. Although not shown in the drawing, the surface of the seal attachment at the portion that comes into contact with the lead terminal sealing planned portion is coated with a releasable coating with a fluororesin. By heating and pressurizing with a 320 ° C. heater from the outside of the seal attachment, the seal material in the seal attachment and the lead terminal sealing planned portion was melted, and the lead terminal was sealed. The width of the sealing part is 10 mm for both the electrode lead lead-out part and the non-leading part. The positive electrode lead terminal was sealed first, and then the negative electrode lead terminal was sealed using a vacuum sealing machine under reduced pressure. Whether the positive electrode lead was sealed or the negative electrode lead was sealed, the seal attachment was removed after the temperature fell below the melting point of the sealing material by cooling. After sealing the negative electrode lead terminal in a reduced pressure state, the atmosphere inside the vacuum sealing machine was opened, and a part of the battery outer body was dented by atmospheric pressure. This dent can be formed only when the size of the power generation element is smaller than the drawing size of the exterior body and sealed under reduced pressure, and there is room for gas storage when gas is generated inside the battery due to some abnormality. It becomes.

  It should be noted that a sealing method using a seal attachment as described above, or a power generation element size that is smaller than the draw forming size of the exterior body and is sealed under reduced pressure, so that a part of the battery exterior body can be removed by atmospheric pressure. This method can also be used in a conventionally sealed package, that is, a battery sealed with a package using a polyolefin-based material such as polyethylene, polypropylene, and these acid-modified products as a sealing material. Further, the seal attachment is not particularly limited as long as it is suitable for the following method. That is, the lead terminal in a state of being pulled out from the battery element side is sandwiched between the edge of the exterior body made of the film having the heat-sealable resin on the inner surface, and further, the lead terminal sealing portion is applied from the outer side. A method of sealing a lead terminal by fixing the metal member so as to be in contact with the detachable means and heating the metal member together to melt the sealing material in the lead terminal sealing planned portion, that is, the heat-sealing resin. And as a seal attachment, what is necessary is just to be suitable for the use as a metal member here, and aluminum or copper which is excellent in thermal conductivity is preferable. After heating, when the metal member is lowered to a temperature below the melting point of the heat-sealing resin and then the metal member is removed, the object can be fixed in a pressed state until the heat-sealing resin is sufficiently hardened. Can be heat-sealed. Moreover, it is preferable that the seal attachment is formed with a concave shape in a portion where the lead terminal passes. The surface of the seal attachment is preferably provided with releasability imparting means, and examples thereof include silicone resin, fluororesin, and those containing glass cloth in these resins.

The battery of Reference Example 6 produced in this way was stored in a pack case as shown in FIG. This pack case has a holding plate of almost the same size as the vertical and horizontal sizes of the power generation element, and the holding plate is attached to the outer pack case with a column that is thinner than the holding plate (in the figure, the column is typically 1). It is a book, but in reality it is 2 × 2 = 4). The pack case and the pressing plate are made of polyester resin. Due to the elasticity of the outer pack case, the battery is sandwiched in a pressurized state via the pressing plate.
In this state, after the battery was fully charged at room temperature, the ambient temperature was gradually raised to 210 ° C. As a result, the battery of Reference Example 6 was kept sealed, and liquid was discharged from any part. There was no leak. This result is considered to be because the reduced-pressure sealed state was maintained well because the sealing material had excellent gas barrier properties and heat resistance.
Moreover, even if the same experiment was conducted with FIG. 20 upside down (with the cup-shaped laminate film side down), the results were the same.

<Reference Example 7>
A battery was prepared in the same manner as in Reference Example 6 except that polyethylene naphthalate was used instead of MX nylon as the gas barrier resin, and the temperature rise leak test described in Reference Example 6 was performed in the same manner. Liquid leakage did not occur from any location regardless of the top and bottom. This result is considered to be because the reduced-pressure sealed state was maintained well because the sealing material had excellent gas barrier properties and heat resistance.

<Comparative Example 5>
As a laminate for drawing into a cup shape, a sealing material and a top and bottom exterior body for heat bonding to a planned sealing portion of a lead terminal using a laminate of 8 μm thick acid-modified polypropylene on both sides of a 50 mm thick aluminum foil A battery was fabricated in the same manner as in Reference Example 6 except that a sealing material sandwiched between heat-sealing polypropylene film 30 μm and acid-modified polypropylene film 8 μm was used.

  The battery of Comparative Example 5 produced in this way was stored in a pack case as shown in FIG. This pack case has a holding plate of almost the same size as the vertical and horizontal sizes of the power generation element, and the holding plate is attached to the outer pack case with a column thinner than the holding plate. The pack case and the pressing plate were made of polyester resin. Due to the elasticity of the outer pack case, the battery was held in a pressurized state via the presser plate.

In this state, after the battery was fully charged at room temperature, the ambient temperature was gradually raised to 210 ° C., and the battery of Comparative Example 5 had a lead terminal sealing portion at a temperature of about 170 ° C. A slight liquid leak occurred. This result is considered to be due to the fact that the sealing material does not have sufficient gas barrier properties and heat resistance, so that a good reduced pressure sealing state was not maintained.
In addition, when the same experiment was performed with the battery upside down in FIG. 20 (with the cup-shaped laminate film side down), a slight leak of gas occurred from the lead terminal sealing portion at a temperature of about 170 ° C. did.

<Gas barrier property evaluation>
When the oxygen permeation coefficient of the sealing materials used in Reference Example 6, Reference Example 7 and Comparative Example 5 (PET / MX nylon blend film, PET / polyethylene naphthalate blend film and polypropylene / acid-modified polypropylene laminated film, respectively) was measured, The ratio was 1: 3: 80. The measurement method conformed to ASTM D3985 and JIS K7126.

<Discussion>
From the above results, the sealing of the battery of Comparative Example 5 cannot be maintained when exposed to a temperature of 170 ° C. or higher, whereas the sealing of the batteries of Reference Examples 6 and 7 is maintained even when exposed to a temperature of 200 ° C. or higher. I understand that Further, the gas barrier property of the sealing material is remarkably improved in Reference Examples 6 and 7 as compared with Comparative Example 5, and the battery of Reference Examples 6 and 7 has a reduced pressure state of the battery compared to the battery of Comparative Example 5. It is thought that it will be maintained over the long term.

1: cover side exterior body 2: cup molding exterior body 3: electrode plate group 4: welded portion 51: positive electrode lead terminal 52: negative electrode lead terminal 6: sealing portion 61: lead sealing portion 7: connection means 8: electrolyte 9: Gap 99: Gas bulge portion L1: Internal space length L2: Cup-molded exterior body top surface length 101: Film exterior battery 111: Power generation body 112: Lead terminal (electrode lead)
112a: Welded part 113: Film (exterior body)
113a, 143a, 153a: Sealing portions 231, 331, 531: Upper film (upper exterior body)
231b: curved portions 232, 332, 532, 732: lower film (lower exterior body)
232b, 332b, 532b, 732b: curved portions 101C, 106C1: pressure plate 106C2: pack case (clamp)
143a ′: Sealing convex portion 153a ′: Partially fused portion 164: Safety valve 201: Upper exterior body 211: Metal adhesive resin layer 212: Metal layer 202: Lower exterior body 203: Sealing material 231: Metal adhesive resin layer 232 : Gas barrier resin layer 204: Power generation element 205: Lead terminal 206: Seal attachment 207: Spring clip 208: Pack case 281: Press plate 209: Metal member

Claims (12)

An assembled battery having a film-clad battery in which a battery body provided with electrode leads on a power generating body in which electrode plates are laminated is exposed so that the electrode leads can be energized externally and hermetically sealed with a film,
Between the power generation body and the film, a surplus space exists before the hermetic sealing in a direction orthogonal to the electrode plate stacking direction of the power generation body, and the surplus space is formed between the power generation body and the electrode lead. The space inside the battery where there is a weld, the portion of the film that formed the surplus space is crushed in the battery inner direction by the external atmospheric pressure after the sealing and sealing,
When gas is generated inside the battery, at least two of the film-clad batteries that return so that the crushed film part restores its original shape are stacked vertically and electrically connected to each other. An assembled battery comprising at least one battery group.   The gap which permits expansion | swelling of the said film is formed in the part adjacent to the said electric power generation body in the direction orthogonal to the lamination direction of the said electric power generation body between two adjacent film-clad batteries. The assembled battery as described.   3. The assembled battery according to claim 2, wherein the length of the battery internal space in the lead terminal drawing direction is longer than the length of the top surface of the film in the same direction, and the gap is formed in the vicinity of the outside of the side surface of the film.   4. The assembled battery according to claim 3, wherein a difference between the length in the lead terminal pull-out direction of the battery internal space and the length in the same direction of the top surface of the film is 3 mm or more per lead terminal lead-out portion.   The assembled battery according to claim 3 or 4, wherein a concave molding part for accommodating the power generator is formed on the film, and the top surface is a top surface of the concave molding part.   The assembled battery according to any one of claims 2 to 5, wherein a spacer is provided between the two adjacent stacked film-clad batteries, and the gap is formed in the vicinity of a side surface of the spacer.   A plurality of the film-clad batteries are stacked vertically so that the polarities of the electrode leads are opposite to each other, and a positive electrode lead terminal of one adjacent film-clad battery and a negative electrode lead terminal of the other adjacent film-clad battery are The assembled battery according to any one of claims 1 to 6, comprising a battery group formed by electrical connection.   The assembled battery according to claim 1, wherein the stacked electrode plates are bonded to each other.   The assembled battery according to any one of claims 1 to 8, wherein a maintenance unit that maintains the adhesion of the electrode plate is provided at least at a part including a portion orthogonal to the stacking direction of the power generation body.   The assembled battery according to claim 9, wherein the maintaining means is an adhesive tape, and the adhesive tape is attached.   The assembled battery according to any one of claims 1 to 10, wherein the film-clad battery is a nonaqueous electrolyte battery. A recess forming step of forming a film so that a recess having a larger bottom area than a power generation body in which a plurality of electrode plates are stacked is convex in a direction in which the electrode plates are stacked and away from the power generation body. When,
A battery body provided with an electrode lead on the power generator, and a vacuum sealing step of vacuum sealing with a film so that the power generator is housed in the recess and the electrode lead is exposed to the outside,
Between the power generation body and the film, a surplus space exists in the direction orthogonal to the electrode plate stacking direction of the power generation body before the decompression sealing step, and the surplus space is formed between the power generation body and the electrode lead. A space in the battery where there is a welded portion, and the decompression sealing step makes it possible to restore the original shape of the portion of the film that formed the excess space when gas is generated inside the battery. In addition, it is a process of crushing toward the inside of the battery by the external atmospheric pressure,
When gas is generated inside the battery, at least two of the film-clad batteries that return so that the crushed film part restores its original shape are stacked vertically and electrically connected to each other. A method for producing an assembled battery, comprising at least one battery group.

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