JP2003007344A - Lithium ion battery and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noble lithium ion battery and a manufacturing method of the same, wherein the lithium ion battery can be made thinner and lighter while its superior rigidity is maintained so that break of the battery can be sufficiently prevented. SOLUTION: The lithium ion battery comprises a frame body 2 into which a positive lead plate 3 and a negative lead plate 4 are inserted, an electrode group 6 housed in the frame body and comprising a positive electrode terminal 7 and a negative electrode terminal 8, each of which is electrically connected to each corresponding lead plate, and an outer sheath film sealing an opening of the frame body to seal up the electrode group in the frame body. Each lead plate has a part projecting into the inside of the frame body, wherein each terminal of the electrode group is connected to each part.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lithium ion battery and a method for manufacturing the same. More specifically, the present invention relates to a lithium ion battery in which a power generating element is sealed by using a film as an exterior member and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, portable devices such as mobile phones, PHSs, and small personal computers have been remarkably miniaturized and lightened with the progress of technology, and batteries used as power sources for these devices are also compact. And weight reduction are required. Among them, the demand for lithium ion batteries is increasing because they have high energy density. For example, Japanese Utility Model Application Laid-Open No. 60-162362 and Japanese Patent Laid-Open No. 61-20.
6157 discloses a pole group in which a strip-shaped positive electrode, a separator, and a negative electrode are laminated in this order for the purpose of thinning, weight reduction, and freedom of shape, which are housed in a bag of an aluminum laminate film and heat-welded. Discloses a lithium ion battery having a sealed structure.

It has been pointed out that the conventional lithium-ion battery has a problem of electrolyte leakage, and now, as a next-generation battery, a polymer (solid polymer) thin film electrolyte (a gel in which an organic solvent electrolyte is swollen) is being used. Lithium ion polymer batteries using electrolytes) are in the spotlight. For example, JP 2
No. 001-84984 and JP 2001-68158.
The publication discloses a lithium ion polymer battery having a structure in which an electrode group is sealed using an aluminum laminate film, like the lithium ion battery.

[0004]

However, lithium ion batteries including the above lithium ion polymer battery and using a film as the exterior member have poor rigidity and are easily deformed. In such a case, for example, JP 2001-8
In the lithium ion battery disclosed in Japanese Patent Publication No. 4984 or JP-A No. 2001-68158, not only does the peripheral portion have an indefinite shape having a curved portion but the appearance is impaired, but also when the corner portion of the battery is deformed. Has a problem that it affects the internal pole group and causes an internal short circuit and accompanying heat generation, resulting in deterioration of battery performance.

In addition to the above problems, in the lithium ion batteries described in Japanese Utility Model Laid-Open No. 60-162362 and Japanese Patent Laid-Open No. 61-206157, in addition to the above problems, the film is torn or the heat-welded portion of the film is welded. There is a problem that the electrolytic solution leaks due to peeling and damage. In particular,
The above-mentioned problem is likely to occur in the terminal sealing portion where the positive electrode terminal and the negative electrode terminal cross the heat-sealing portion. That is,
The heat-sealing portion is sealed by fusion of the fusible resins on the inner surface of the metal resin composite film and fusion of the metal positive electrode terminal or negative electrode terminal and the fusible resin. here,
Before the fusion bonding, the electrolytic solution adhered to the surface of the fusible resin and was contaminated, which was apt to cause defective fusion.

Further, there is a problem that electrical insulation failure easily occurs in the terminal sealing portion. That is, since the thermal conductivity of the fusible resin material and that of the metal positive / negative electrode terminal material are significantly different, the thermal fusion condition of the terminal sealing portion is slightly changed, resulting in poor sealing due to insufficient heating. In some cases, the heat-sealing resin melts due to excessive heating and the metal foil as the core material and the terminals come into electrical contact with each other, resulting in poor electrical insulation.

Therefore, the present invention has been made in view of the above demands, and is excellent in rigidity while achieving thinning and weight reduction.
An object of the present invention is to provide a novel lithium-ion battery that can prevent damage suitably and a manufacturing method thereof.

[0008]

[Means for Solving the Problems] In order to solve the above problems,
A lithium ion battery according to the present invention is a frame body in which a positive electrode lead plate and a negative electrode lead plate are inserted, and is housed in the frame body, and a positive electrode terminal and a negative electrode terminal are electrically connected to the corresponding lead plates. It is characterized by comprising a pole group and an exterior film which is sealed to the opening surface of the frame to seal the pole group.

According to the lithium ion battery having the above structure, the pole group is encapsulated by the frame body and the exterior film,
Since the frame body ensures the regularity, it is possible to obtain a product having excellent rigidity without causing the mold shape to be lost.

Further, in the lithium ion battery according to the present invention, as described in claim 2, the lead plate has a portion projecting into the frame body, and the terminal of the pole group is connected to the portion. can do. In this case, if the projecting portion is formed wider than the terminals of the pole group as described in claim 3, variations in the width direction of the pole group in the mounting accuracy of the terminals of the pole group are adopted. Even if there is, the terminals of the pole group and the lead plate are surely brought into contact with each other, and the two can be electrically connected.

Further, the lithium ion battery according to the present invention can adopt a structure in which the lead plate is inserted in a state of being connected to the terminals of the pole group as described in claim 4. In this case, even when the connecting portion between the terminal of the pole group and the lead plate is covered with the constituent material of the frame and the electrolytic solution is filled, the electrolytic solution does not come into contact with the connecting portion. Therefore, local corrosion due to dissimilar metal bonding does not occur at the connection portion on the negative electrode side, and the lead plate is made of nickel-based metal for both the positive electrode and the negative electrode, and the positive electrode and the negative electrode are both formed. It is possible to obtain a lead plate that is excellent in terms of reliability of soldering with lead wires and strength.

Further, in the lithium ion battery according to the present invention, as described in claim 6, the frame has a liquid injection port for injecting an electrolytic solution, and a lid is provided on an opening surface of the liquid injection port. A configuration in which the film is sealed can be adopted. Such a configuration is a type that replenishes the electrolytic solution inside,
With this configuration, even when the electrolytic solution rapidly expands and rises to a pressure equal to or higher than the predetermined internal pressure, the electrolyte film bursts first to release the internal pressure and prevent the exterior film 9 from bursting.

Further, in the lithium ion battery according to the present invention, as described in claim 7, the opening surface of the frame is
A configuration may be adopted in which an annular ridge is formed along the circumferential direction of the frame between the outer surface and the inner surface of the frame, and the exterior film is welded by melting the ridge. According to this structure, the raised portion melted by heating is spread by the pressure bonding force of the heating and pressurizing means, but it does not protrude to the outer peripheral surface or the inner peripheral surface of the frame body, and has a beautiful appearance and requires no rework. Wearing is possible.

Here, the lithium ion battery according to the invention described in claims 1, 2, 3 and 7 is as described in claim 8.
A step of inserting a positive electrode lead plate and a negative electrode lead plate to form a frame body, accommodating a pole group in the frame body, and electrically connecting a positive electrode terminal and a negative electrode terminal of the pole group to the corresponding lead plates. The process can be manufactured by the process of sealing the exterior film to the opening surface of the frame.

In this case, as described in claim 9, the rewinding of one metal plate coil body is punched out to form a strip-shaped positive electrode leader in which a plurality of positive electrode lead plates are projected at regular intervals in the carrying direction. Punching out the rewinding of another metal plate coil body to form a strip-shaped negative electrode leader in which a plurality of negative electrode lead plates are projected at regular intervals in the transport direction,
The step of stacking the pair of leaders so that the positive electrode lead plate and the negative electrode lead plate are at proper intervals in the transport direction is provided ahead of the frame body molding step, and the leaders are transported at a constant pitch to form a frame body. It is possible to adopt a configuration in which the components are sequentially molded and conveyed at a constant pitch.

More preferably, as in claim 10,
In the leader forming step, pilot holes are formed at regular intervals in the conveying direction, and in the leader superposing step, the pilot holes of the pair of leaders are aligned with each other to convey the positive electrode lead plate and the negative electrode lead plate. It is possible to adopt a configuration in which the readers are fed at a constant pitch by using the pilot holes by setting the proper intervals in the direction.

On the other hand, in the lithium ion battery according to the invention described in claims 4 and 5, as in claim 11, the positive electrode terminal of the electrode group is electrically connected to the positive electrode lead plate, and the negative electrode terminal is the negative electrode lead plate. Can be manufactured by a step of electrically connecting to the above, a step of inserting at least the connecting portion and molding a frame body having a shape surrounding the outer periphery of the pole group, and a step of sealing the exterior film to the opening surface of the frame body.

In this case, as in claim 12, the rewinding of one metal plate coil body is punched out, and a plurality of pairs of positive electrode lead plates and negative electrode lead plates are projected at a constant interval in the transport direction so as to project in a strip shape. It is possible to adopt a configuration in which the step of forming the step is provided ahead of the frame forming step, and the leader is conveyed at a constant pitch so that the frame having the pole group is sequentially molded and conveyed at a constant pitch.

More preferably, as described in claim 13,
In the leader forming step, it is possible to adopt a configuration in which pilot holes are provided at regular intervals in the carrying direction, and thereby the leaders are carried at a constant pitch using the pilot holes.

In any one of the inventions, the lithium ion battery according to claim 14 is characterized in that, in the frame forming step, the connecting strips projecting in the carrying direction from both ends of the frame in the carrying direction are simultaneously formed. When the molding is performed and the next frame is molded, the connecting band of the frame and the connecting band of the previous frame are configured to be joined to each other. A step of aligning the rewinding with the opening surface of the frame body and press-bonding to the frame body with a pressure roller is provided at the end of the exterior film sealing step, and further, the connection band, the unnecessary exterior film between the frame bodies and the leader. Even when the step of cutting is provided after the exterior film sealing step, the frame does not have an unexpected posture during transportation or at the positioning position in each step, and the occurrence of defective products can be suppressed. it can.

According to a sixth aspect of the present invention, in the lithium ion battery according to the sixteenth aspect, in the frame body molding step, a liquid injection port communicating between the inside and outside of the frame body is molded at the same time, and It can be manufactured by providing a step of injecting the electrolytic solution into the frame through the injection port and a step of sealing the lid film to the opening surface of the injection port after the exterior film sealing step.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION <First Embodiment> A first embodiment of a lithium ion battery according to the present invention will be described below with reference to the drawings.

Lithium-ion battery 1 according to the present embodiment
Is a state in which a pole group 6 which is a power generating element is housed in a synthetic resin frame body 2, and the opening of the frame body 2 is sealed with a pair of exterior films 9 and 9 made of, for example, an aluminum laminate film. is there.

The frame 2 is a resin molded product made of polypropylene, for example, and has a flat (thickness of about 0.5 to 5 mm) rectangular shape. Further, on one side of the frame body 2, the positive electrode lead plate 3 and the negative electrode lead plate 4 are insert-molded with a space therebetween. The positive electrode lead plate 3 and the negative electrode lead plate 4 are formed by punching in a substantially T-shape from a plate material of aluminum or its alloy, and a negative electrode lead plate 4 from a plate material of nickel or its alloy.

Each of the lead plates 3 and 4 has a short wide portion arranged in the frame body 2 and a long narrow portion protruding from the frame body 2 to the outside of the frame body 2. It is installed. The positive electrode terminal 7 and the negative electrode terminal 8 of the pole group 6 accommodated in the frame body 2 are electrically connected to the wide portions of the lead plates 3 and 4, respectively.

The pole group 6 was obtained by applying a positive electrode mixture containing lithium cobalt oxide, which is a positive electrode active material, as a main component on a positive electrode current collector made of a long strip of aluminum foil, and at one end of the positive electrode current collector. A positive electrode terminal 7 made of aluminum or an alloy thereof so as to project to one side in the width direction, a separator made of a gel electrolyte having substantially the same shape as the positive electrode current collector, and a substantially same shape as the positive electrode current collector. A negative electrode mixture mainly composed of carbon, which is a negative electrode active material, is applied onto a negative electrode current collector made of copper foil, and at one end of the negative electrode current collector, a negative electrode terminal 8 made of copper or an alloy thereof is widened. A negative electrode that is attached so as to project to one side in the direction is laminated in this order, is wound in a flat vortex shape, and the end of the winding is stopped with an imide resin tape, which is a wound type electrode group.

The exterior film 9 has a rectangular shape which is substantially the same as the frame body 2, and in the state where the pole group 6 is housed in the frame body 2,
The outer surface of the frame body 2 is sealed by heat welding on four sides of the outer film 9, and the film-opposing surface of the frame body 2 has an annular protrusion along the circumferential direction as shown in FIG. A portion 2a is provided. The raised portion 2a is a frame 2
Is provided at a substantially central portion of the film facing surface with a predetermined distance A, B from the outer surface and the inner surface.

A liquid injection port 2c for communicating the inside and outside of the frame body 2 is provided at a predetermined position on the outer surface of the frame body 2 (in this embodiment, the outer surface on the side where the lead plates 3 and 4 are provided). The projection 2b having the above is provided, and the electrolytic solution is injected into the frame body 2 to which the exterior films 9 and 9 are adhered from the injection port 2c. Rapture (lid film) 5
Is, for example, an aluminum laminate film which is heat-welded to the end surface of the protrusion 2b to close the liquid injection port 2c in order to prevent the leakage of the internal solution.

Lithium-ion battery 1 according to the present embodiment
Has the above-mentioned structure, and a method for manufacturing the battery 1 will be described below. <First Manufacturing Method> In the first manufacturing method, the lead plates 3 and 4 are previously prepared.
2A in which a continuous body of the frame body 2 having a thickness of 3 mm or less and having a liquid injection port 2c formed therein is wound.
Is used. As shown in FIG. 3, first, the coil body 2A is pulled out and cut into a predetermined size (process P).
1). As the coil body 2A, one in which the frame body 2 is continuous in a band shape with a cutting margin, or one in which the frame body 2 is continuous with a connecting band 2d (see FIG. 9) at a constant interval is used in the cutting process. It is possible to use a connecting band 2d that is cut off.

Next, the pole group 6 prepared in advance with a thickness substantially equal to that of the frame body 2 is taken into the line, and the pole group 6 is inserted into the frame body 2.
While being housed inside, the contact portions between the terminals 7 and 8 and the lead plates 3 and 4 of the frame body 2 are welded (process P2). The lead plates 3 and 4 have a laterally wide projecting portion in the frame body 2. Therefore, the position error at the time of inserting the lead plates 3 and 4 or the position error at the manufacturing stage of the terminals 7 and 8. Regardless of this, the contact area between them can be obtained. Welding is performed by spot welding or the like.

Next, as shown in FIG. 4, a pair of aluminum laminate film coil bodies 9A, 9A arranged at the upper and lower positions of the line are pulled out and cut into a predetermined size (process P).
3) In the state where the pair of exterior films 9 and 9 are aligned with the openings of the frame body 2, heat sealing is performed on each of the four sides (process P4). The pair of upper and lower heat plates 10 used for heat sealing are brought into contact with and separated from the exterior film 9 by the expansion and contraction of the cylinder 11, respectively. Contact part 10 with the hot plate 10
a is provided, and the annular ridge 10 is provided in the peripheral area.
b is provided.

The raised portion 10b of the heating plate 10 is dimensioned so as to substantially coincide with the raised portion 2a of the frame body 2. The contact portion 10a of the heat plate 10 regulates the interval between the heat plates 10 and 10 so that only the raised portions 10b and 10b of the pair of heat plates 10 and 10 press the exterior films 9 and 9 onto the frame body 2. The dimensions are set. In this respect, the contact portion 10a functions as a stopper that determines the pressure bonding force, and prevents the frame body 2 from being excessively melted. In order to prevent the liquid injection port 2c of the frame body 2 from being crushed by the pressure applied during heat sealing, the liquid injection port 2c
It is more preferable to insert a pin having the same diameter into. Further, in heat sealing, it is necessary to pay attention to the shape of the hot plate and the processing temperature so that the separator is not melted by this heat.

Next, as shown in FIG. 5, the injection pipe 12 is connected to the protrusion 2b of the frame body 2, and the electrolytic solution in the electrolytic solution measuring tank 13 is vacuum-pressurized and injected into the frame body 2 (step P5). As the electrolytic solution, a non-aqueous electrolytic solution prepared by dissolving an electrolyte salt in a non-aqueous solvent, for example, a solution prepared by dissolving a lithium salt in a single solvent or a mixed solvent composed of carbonic acid ester or cyclic ester is used.

Finally, the rapture 5 created in advance is taken into the line, and the rupture 5 is attached to the frame body 2.
In a state of being aligned with the end surface of the protrusion 2b, the rupture 5 is heat-sealed by using the heat plate 15 which comes into contact with and separates from the protrusion 2b of the frame 2 by the expansion and contraction of the cylinder 14 (process P6), and the lithium ion battery 1 is completed. The rupture 5 is for preventing the exterior film 9 from bursting by bursting first to release the internal pressure when the internal solution rapidly expands and is pressurized to a predetermined internal pressure or more. <Second Manufacturing Method> The second manufacturing method is started by molding the frame body 2. As shown in FIG. 6, first, the aluminum plate coil body 3A and the nickel plate coil body 4A are respectively pulled out, and punching is intermittently performed using the die 16 (process P7). By this punching process, the leader plates 3B and 4B that are continuous in the carrying direction are connected to each other at their leading end portions with the lead plates 3 and 4 at regular intervals in the length direction.

Pilot holes 3C and 4C are formed in each of the leaders 3B and 4B at the time of punching, and the leaders 3B and 4B are superposed so that the pilot holes 3C and 4C of both leaders 3B and 4B coincide with each other ( Step P8), and then, using the pilot holes 3C and 4C, the leader 3
B and 4B are fed at a constant pitch (rod feed) at the same time.

Pilot hole 3 of both leaders 3B and 4B
When C and 4C are the same, the lead plates 3 and 4 realize a set interval when assembled in the frame body 2. In this state,
It is conveyed to the injection molding machine 17, and the frame body 2 is molded while both lead plates 3 and 4 are insert-held in the mold (process P9). At this time, the liquid injection port 2c of the frame body 2 is also formed.

Next, with respect to the frame body 2 delivered from the injection molding machine 17, a connecting portion between the lead plates 3 and 4 and the leaders 3B and 4B is cut by using a cutter (not shown), and the frame body 2 is a leader. Separate from 3B and 4B (process P10). The frame 2 completed in this way is then subjected to the same steps as the step P2 and subsequent steps of the first manufacturing method to complete the lithium ion battery 1. The cutting / separation of the leaders 3B and 4B is performed in the step P2 of the first manufacturing method.
It may be performed at any timing from P6 to P6. In addition, by leaving the leaders 3B and 4B, the positive electrode terminal 7 and the negative electrode terminal 8 of the pole group 6 become the positive electrode lead plate 3,
It becomes conductive through the readers 3B and 4B and the negative electrode lead plate 4, but there is no problem because it is before charging of the pole group 6. Second Embodiment Next, a second embodiment of the lithium-ion battery according to the present invention will be described with reference to the drawings.

The lithium ion battery 1 according to the present embodiment is different from the lithium ion battery 1 according to the first embodiment in that the positive electrode lead plate 3 is also made of nickel or a plate material of this alloy. And each terminal 7, 8
Welding is performed before insert molding, and the welded portion is also covered with molding resin. Originally, nickel is preferable to aluminum because it is superior in terms of reliability of soldering with a lead wire and strength, but as in the first embodiment,
When the welded part is immersed in the electrolytic solution, aluminum is used for the positive electrode lead plate 3 because the part causes local corrosion and the product life is shortened. However, in the case of the present embodiment, the welded part is a frame. Since the body 2 is covered and protected by the resin, the problem does not occur and nickel can be used.

Next, a method of manufacturing the battery 1 will be described. <First Manufacturing Method> The first manufacturing method is an application example of the second manufacturing method of the first embodiment. As shown in FIG. 8, first, a pair of positive electrode lead plate 3 and negative electrode lead plate 4 are simultaneously drawn out by drawing out from the nickel plate coil body 4A and intermittently punching using the mold 16 (process P11). A pilot hole 4C is formed in the leader 4B at the time of punching, and the leader 4C is used to make the leader 4B.
B is fed at a constant pitch (rod feed).

Next, the pole group 6 prepared in advance is taken into the line, and the contact portions between the terminals 7 and 8 and the lead plates 3 and 4 are welded (process P12). And both lead plates 3,
4 and the pole group 6 are conveyed to the injection molding machine 17,
The frame body 2 is molded with both the lead plates 3 and 4 held by the insert in the mold (process P13). At this time, the liquid injection port 2c of the frame body 2 is also formed. When molding, it is necessary to pay attention to the shape of the mold and the processing temperature so that the separator will not be melted by this heat.

Next, with respect to the frame body 2 delivered from the injection molding machine 17, a connecting portion between the lead plates 3 and 4 and the leader 4B is cut using a cutter (not shown),
The frame body 2 is separated from the leader 4B (process P14). After that, the frame body 2 thus completed is subjected to the same steps as and after the step P3 of the first manufacturing method of the first embodiment to complete the lithium ion battery 1. <Second Manufacturing Method> The second manufacturing method is another example after the step P13 of the first manufacturing method. As shown in FIG. 9, the mold of the injection molding machine 17 used in this manufacturing method is
The width is wider in the carrying direction than the mold used in the first manufacturing method, and the connecting bands 2d projecting in the carrying direction from both ends of the frame body 2 in the carrying direction are also molded at the same time. . The connecting band 2d is fed at a constant pitch and is joined to the connecting band 2d of the frame 2 to be molded next (process P13). 2 are connected so that the position of the frame 2 with respect to the leader 4B is guaranteed.

Next, it is pulled out from the pair of aluminum laminate film coil bodies 9A, 9A arranged at the upper and lower positions of the line, and is aligned with the openings of the frame body 2, respectively, between the pair of upper and lower pressure bonding rollers 18, 18. Send in (Process P
14). Then, in a state where the exterior films 9 and 9 are pressure-bonded to the frame body 2, the four sides of the frame body 2 are heat-sealed by using the pair of upper and lower heat blocks 10 and 10 (process P15).
Since the exterior films 9 and 9 are continuously supplied without being cut, the exterior films 9 and 9 in each frame body 2 are connected to the exterior films 9 and 9 in the adjacent frame body 2 and the heat blocks 10 and 10 are kept. Sent from.

Then, next, with respect to the frame 2 sent out,
Using a cutter (not shown), the connecting portions between the lead plates 3 and 4 and the leader 4B are cut, and the connecting bands 2d, ... Between the adjacent frame bodies 2 and 2 and the unnecessary exterior films 9 and 9 are removed. It cuts and separates the single frame 2 from the leader 4B (process P16). After that, the frame body 2 thus completed is subjected to the same steps as and after the step P5 of the first manufacturing method of the first embodiment to complete the lithium ion battery 1.

The adjacent frames 2 and 2 are connected to each other by connecting bands 2d, ...
The measure for guaranteeing the fixed position at the time of heat sealing and cutting is not applied only to the lithium ion battery 1 according to the second embodiment, but is applied to the lithium ion battery 1 according to the first embodiment. Is naturally applicable.
That is, in step P9 of the second manufacturing method of the first embodiment, the connecting band 2d may be molded at the same time.

As described above, the lithium ion batteries 1 according to the first and second embodiments use not only the exterior film but also the frame body as the exterior member, so that they are thin but have a regularity. There is no risk of the film being torn or the heat-welded portion of the film peeling off and being damaged. Also,
Using a rupture 5 that is weaker than the exterior film 9,
By setting the heat-welding strength of the rupture 5 to be lower than that of the exterior film 9, there is no risk of the film being torn or the heat-welded portion of the film being peeled off and damaged even if an unexpected increase in internal pressure occurs.

Further, when the four sides of the exterior film 9 are heat-welded, only the ridges 2a of the frame 2 are heated by the ridges 10b of the heat plate 10 and the heat block 10. The portion 2a does not protrude to the outside of the frame body 2 due to the pressure bonding force of the heat plate 10 or the heat block 10, and a heat seal having a beautiful appearance and requiring no modification can be performed. Further, by making the distance between the heat source and the pole group 6 further, it is possible to reduce the thermal influence on the pole group 6 and prevent the separator from melting.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the gist of the present invention.

For example, the shape, thickness, material type of the frame body 2, the position of the injection port 2c, the shape and position of the lead plates 3 and 4, the material type of the rupture 5, the material type of the exterior sheet 9, etc. It is a matter that can be freely decided within the scope of the invention.

Further, in the above-mentioned embodiment, although the battery of the type filled with the electrolytic solution is referred to, the present invention is not limited to this, and a lithium ion battery having only a separator as an electrolyte may be used. In this case, the projection 2b on the frame 2
Also, it is not necessary to form the liquid injection port 2c, and the heat sealing step of the rupture 5 is omitted.

Further, as the power generating element, not the winding type electrode group, but a positive electrode current collector coated with the positive electrode mixture inside, a separator, and a negative electrode current collector coated with the negative electrode mixture inside in this order. It may be a laminated pole group formed by laminating. A lithium ion battery using an organic solvent electrolytic solution without using a polymer electrolyte may be used.

In the above embodiment, both sides of the frame are open, but only one is open and the other is a frame closed by the constituent material of the frame. Good.

[0052]

As described above, since the lithium ion battery according to the present invention uses not only a film but also a frame having a regularity as an exterior member, it is thin and lightweight, but excellent in rigidity. It is possible to preferably prevent damage without deformation.

Particularly, in the terminal sealing portion, which has been a problem in the battery using the conventional aluminum laminate film, it is caused by the difference in thermal conductivity between the fusible resin material and the metal positive and negative electrode terminal materials. Since it is possible to completely avoid poor hermeticity and poor electrical insulation, its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is a lithium-ion battery according to a first embodiment of the present invention, in which (a) is an external perspective view and (b) is a partial cross-sectional plan view.

FIG. 2 is a frame body of the same embodiment, in which (A) is an external perspective view and (B) is a sectional view of (A).

FIG. 3 is an explanatory view of the first manufacturing method of the same embodiment,
The steps from cutting the frame body to a predetermined size and then welding the pole group are shown.

FIG. 4 is an explanatory view of the first manufacturing method of the same embodiment,
The steps from welding the pole groups to heat sealing the exterior film are shown.

FIG. 5 is an explanatory view of the first manufacturing method of the same embodiment,
The steps from filling the electrolytic solution to completion are shown.

FIG. 6 is an explanatory view of a second manufacturing method of the same embodiment,
A step of molding the frame by holding the lead plate in an insert is shown.

FIG. 7 is a lithium-ion battery according to a second embodiment of the present invention, in which (a) is an external perspective view and (b) is a partial cross-sectional plan view.

FIG. 8 is an explanatory view of the first manufacturing method of the same embodiment,
The step of molding the frame body by holding the lead plate welded to the pole group with the insert is shown.

FIG. 9 is an explanatory view of the second manufacturing method of the same embodiment,
A process is shown in which a lead plate welded to the pole group is insert-held to form a frame, and then the exterior film is heat-sealed and cut.

[Explanation of symbols]

1 lithium-ion battery 2 frame 2a Raised part 2c Injection port 2d connection belt 3B leader 3C pilot hole 3 Positive electrode lead plate 4B leader 4C pilot hole 4 Negative electrode lead plate 5 Rupture 6 pole group 7 Positive terminal 8 Negative electrode terminal 9 Exterior film

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 5H011 AA01 AA03 BB03 CC02 CC06                       CC10 DD01 DD13 DD26 EE04                       FF06 GG01 HH13 JJ25                 5H022 AA09 BB03 BB12 BB28 BB29                       CC03 CC12 CC16 CC21 EE01                 5H023 AA03 AS02 CC01                 5H029 AJ03 AJ11 BJ03 CJ05 DJ02                       DJ03 DJ05 EJ01 EJ12

Claims (16)

[Claims] 1. A frame body in which a positive electrode lead plate and a negative electrode lead plate are inserted, and a group of electrodes housed in the frame body and in which positive electrode terminals and negative electrode terminals are electrically connected to the corresponding lead plates, respectively. A lithium-ion battery comprising an exterior film which is sealed to the opening surface of the frame body to seal the electrode group. 2. The lead plate has a portion protruding into the frame body, and the terminal of the pole group is connected to the portion.
The lithium ion battery described. 3. The lithium ion battery according to claim 2, wherein the protruding portion is formed wider than the terminals of the pole group. 4. The lithium ion battery according to claim 1, wherein the lead plate is inserted while being connected to the terminals of the pole group. 5. The lithium ion battery according to claim 4, wherein both the positive electrode and the negative electrode of the lead plate are made of a nickel-based metal. 6. The frame according to claim 1, wherein the frame body is provided with a liquid injection port for injecting an electrolytic solution, and a lid film is sealed on an opening surface of the liquid injection port. The lithium ion battery described. 7. An annular ridge is formed on the opening surface of the frame between the outer surface and the inner surface of the frame along the circumferential direction of the frame, and the ridge is melted. The lithium ion battery according to any one of claims 1 to 6, wherein an outer film is welded. 8. A step of molding a frame body by inserting a positive electrode lead plate and a negative electrode lead plate, accommodating a pole group in the frame body, and connecting the positive electrode terminal and the negative electrode terminal of the pole group to the corresponding lead plates, respectively. A method of manufacturing a lithium-ion battery, comprising a step of electrically connecting and a step of sealing an exterior film to an opening surface of a frame body. 9. A metal plate coil body is punched out to form a strip-shaped positive electrode leader in which a plurality of positive electrode lead plates are projected at regular intervals in the transport direction, and another metal plate coil body is wound. A step of punching out the return to form a strip-shaped negative electrode leader in which a plurality of negative electrode lead plates are projected at regular intervals in the transport direction, the pair of positive electrode lead plates and the negative electrode lead plates being arranged at appropriate intervals in the transport direction. 9. The lithium ion battery according to claim 8, wherein the step of stacking the leaders is provided ahead of the frame forming step, and the leaders are conveyed at a constant pitch so that the frame bodies are sequentially molded and conveyed at a constant pitch. Manufacturing method. 10. In the leader forming step, pilot holes are formed at regular intervals in the carrying direction, and in the leader superposing step, the pilot holes of a pair of leaders are aligned with each other to form a positive electrode lead plate and 10. The method for manufacturing a lithium ion battery according to claim 9, wherein the negative electrode lead plates are arranged at proper intervals in the transport direction, and thereby the leader is transported at a constant pitch using the pilot holes. 11. A step of electrically connecting a positive electrode terminal of a pole group to a positive electrode lead plate and electrically connecting a negative electrode terminal to a negative electrode lead plate, at least inserting the connecting portion to surround the outer periphery of the pole group. A method of manufacturing a lithium-ion battery, comprising a step of molding a frame body having a shape and a step of sealing an exterior film to an opening surface of the frame body. 12. A step of forming a strip-shaped leader by punching out rewinding of one metal plate coil body and projecting a plurality of pairs of positive electrode lead plates and negative electrode lead plates at a constant interval in the carrying direction, The method for producing a lithium ion battery according to claim 11, wherein, in advance of the body molding step, the leader is conveyed at a constant pitch to sequentially mold the frame body in which the pole group is incorporated and to convey the frame at a constant pitch. 13. The leader forming step according to claim 12, wherein pilot holes are formed at regular intervals in the carrying direction, and thereby the leader is carried at a constant pitch using the pilot holes. Manufacturing method of lithium ion battery. 14. In the frame molding step, at the same time, the connecting strips protruding in the carrying direction from both side ends of the frame in the carrying direction are simultaneously molded, and when the next frame is molded, the connecting band and the tip of the frame are first formed. 14. The method for manufacturing a lithium ion battery according to claim 8, wherein the connection band of the frame body is joined. 15. A step of aligning the unwinding of each of the pair of exterior film coil bodies with the opening surface of the frame body and crimping to the frame body with a pressure bonding roller is provided prior to the exterior film sealing step, and the connection is also provided. The method for manufacturing a lithium ion battery according to claim 14, further comprising a step of cutting an unnecessary exterior film between the band and the frame and a leader after the exterior film sealing step. 16. In the frame molding step, a step of simultaneously molding a liquid injection port communicating the inside and outside of the frame body, and further injecting an electrolytic solution into the frame body through the liquid injection port, 16. The method for manufacturing a lithium ion battery according to claim 8, further comprising a step of sealing the opening surface of the liquid injection port after the step of sealing the exterior film.