JP2007115678A - Nonaqueous electrolyte battery and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the adhesion and sealing property of a battery using a laminate film exterior package by solving the problem of insufficient welding at the electrode terminal lead portion. <P>SOLUTION: A sealant used has a shape having a first projection and a second projection protruded from the edge of a laminate film in only each portion facing a positive electrode terminal and a negative electrode terminal, wherein the other area has a protruded shape having a width that is the same as that of a so-called terrace. A nonaqueous electrolyte battery is formed using the protruded sealant by placing the protruded sealant between the positive and negative electrode terminals and the laminate film to seal the periphery of a battery element. The protruded sealant has a thickness not smaller than 5 μm and not larger than 200 μm. The protruded sealant includes a stacked layered resin film stacking at least two layers, or a heat resistant coating composition, wherein the stacked layered structure comprises a single layered resin film having a high adhesive property for the electrode terminal, a resin material having a high adhesive property for the electrode terminal, and a resin material having a high adhesive property for the laminate film. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a non-aqueous electrolyte battery and a method for manufacturing the same, and more particularly to a non-aqueous electrolyte battery that is excellent in sealing performance and moisture permeability resistance and realizes high capacity and high safety.

  In recent years, many portable electronic devices such as a camera-integrated VTR (Videotape recorder), a mobile phone, or a laptop computer have appeared, and their size and weight have been reduced. Along with this, the demand for batteries used as power sources for portable electronic devices is growing rapidly, and the battery design is lighter, thinner, and more efficient in the storage space in devices to realize smaller and lighter devices. It is required to use. As a battery satisfying such requirements, a lithium ion battery having a large energy density and output density is most suitable.

  Among them, a battery having a high degree of freedom of shape, a thin and large area sheet type battery, a thin and small area card type battery, and the like are desired. However, in the conventional method using a metal can as an exterior, it is thin. It is difficult to produce a battery. Therefore, it is possible to obtain a battery as described above by producing a thin battery using a film-like exterior material such as an aluminum laminate film.

  Such a battery is produced by laminating a positive electrode and a negative electrode through a separator, covering a wound or zigzag battery element with a laminate film, and sealing the periphery of the battery element. A positive electrode terminal and a negative electrode terminal connected to the negative electrode (hereinafter referred to as an electrode terminal as appropriate unless otherwise specified) are derived from the sealing portion of the laminate film to the outside of the battery.

  A laminate film used for a battery exterior is a multilayer film having moisture resistance and insulating properties, in which a metal layer is sandwiched between an outer resin layer and an inner resin layer made of a resin film. The metal layer plays the most important role in preventing moisture, oxygen and light from entering and protecting the contents. Aluminum (hereinafter referred to as “Al” as appropriate) is the most lightweight because of its lightness, extensibility, price, and ease of processing. Often used. Nylon or polyethylene terephthalate (hereinafter referred to as PET as appropriate) is used for the outer resin layer because of its beautiful appearance, toughness, and flexibility. In addition, since the inner resin layer is a portion that is melted and fused together by heat or ultrasonic waves, polyolefin is suitable, and unstretched polypropylene (hereinafter referred to as CPP as appropriate) is often used. An adhesive layer is provided between the metal layer and the outer resin layer and between the metal foil and the inner resin layer.

  The laminate film accommodates the battery element such that the inner resin layers face each other, and is sealed by welding the laminate film along the periphery of the battery element. However, in such a battery structure, there is a problem that moisture easily enters from the laminated film welded portion in the top portion where the electrode terminals are led out. When the battery element is covered with a laminate film and the periphery is sealed, the inner resin layer is melted and bonded, but the electrode terminal and the inner resin layer derived from the battery element have poor adhesion. For this reason, moisture easily enters through the interface between the electrode terminal and the laminate film. When moisture enters the battery, an undesirable electrochemical reaction is caused inside the battery to deteriorate battery characteristics, or gas is generated inside and the battery expands.

Therefore, in Patent Document 1 and Patent Document 2 shown below, there is a method for improving the sealing property by covering the electrode terminal with a welding member having good adhesion to the electrode terminal (hereinafter referred to as a sealant as appropriate). Are listed.
JP 11-31514 A JP 2004-111303 A

  As shown in FIG. 1, in Patent Document 1 and Patent Document 2, a part of the electrode terminal sandwiched between the welded portions of the laminate film is coated with a sealant having better adhesiveness than the inner resin layer on the electrode terminal. The adhesion between the electrode terminal and the sealant and between the sealant and the inner resin layer can be improved, and the sealing property of the laminate film can be improved.

  In particular, in Patent Document 1, the sealant is coated so as to protrude from the end of the laminate film, thereby preventing contact between the metal layer such as Al exposed at the end of the laminate film and the electrode terminal.

  In Patent Document 1 and Patent Document 2, a resin piece having a width slightly larger than that of the electrode terminal is used as the sealant. However, when such a resin piece is used, the adhesion between the surface of the resin piece and the inner resin layer is good, but welding does not occur at the interface portion where the end of the resin piece contacts the inner resin layer. There is a risk of moisture entering.

  As shown in FIG. 2A and FIG. 2B, in general, in a battery having such a configuration, a heat source member (hereinafter referred to as a notch 10a) provided with a notch 10a so that pressure is not applied to the electrode terminal portion when the electrode terminal lead-out portion is welded. The laminate film 4 composed of the metal layer 4a, the outer resin layer 4b, and the inner resin layer 4c is sealed by using 10). This is to prevent the electrode terminal 2 from being broken by the pressure of the heater head 10 or from being short-circuited when the electrode terminal 2 and the metal layer 4a of the laminate film 4 are pressurized by the heater head.

  FIG. 3 shows the configuration of the periphery of the electrode terminal 2. When the heater head 10 having the notch 10a is used, the heat of the sealants 3a and 3b (hereinafter referred to as the sealant 3 as appropriate) is less likely to be transmitted as compared to the portion without the electrode terminal 2. The sealant melts due to residual heat and fills the gap between the sealant end portion and the inner resin layer with the flowed resin. However, since the peripheral portion of the electrode terminal 2 is not directly subjected to the pressure of the heater head 10, reference numeral 11 As shown in FIG. 2, the gap could not be completely filled, and insufficient welding was sometimes performed.

  Therefore, in view of the above problems, an object of the present invention is to provide a nonaqueous electrolyte battery having excellent sealing performance and penetration resistance, high capacity and high safety, and a method for producing the same.

  In order to solve the above problems, in the present invention, only the portion facing the positive electrode terminal and the negative electrode terminal has the first convex portion and the second convex portion protruding from the end of the laminate film, and the other portions are A non-aqueous electrolyte battery is manufactured by using a sealant with a shape approximately equivalent to the width of the so-called terrace part, placing this sealant on the upper and lower surfaces of the positive and negative terminals, and then sealing the periphery of the battery element To do.

  Note that the terrace portion is a portion in the vicinity of the lead-out side from which the positive electrode terminal and the negative electrode terminal are derived in the nonaqueous electrolyte battery, and the terrace width is a width indicated by DT in FIG.

  The above-described sealant is not limited to a shape that is integral with the entire sealing edge of the top portion, but includes a sealant having a first convex portion and a sealant having a second convex portion, respectively for a positive electrode terminal and a negative electrode terminal. You may arrange | position and use above and below. Moreover, the sealant which integrated the all sides which has the 1st convex part and the 2nd convex part on one side of the upper and lower sides is used, and the sealant which has the 1st convex part and the sealant which has the 2nd convex part on the other side is positive electrode You may make it adhere | attach to each of a terminal and a negative electrode terminal.

  Such a sealant can be a single-layer resin film made of, for example, a polyolefin resin, an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, a carboxyl resin, or an ionomer resin.

  In addition, a two-layer structure in which an electrode layer and an inner surface layer using a highly adhesive resin material and a laminate film and a surface layer using an adhesive resin material are laminated, or between the surface layer and the inner surface layer, A three-layer structure in which an intermediate layer using a resin material having a melting point higher than that of the surface layer and the inner surface layer is provided. In this case, the electrode terminal and the surface using a resin material having high adhesiveness are arranged so as to face the electrode terminal. In the case of a two-layer structure, the resin layer is preferably selected so that the intermediate layer and the surface layer have a melting point difference of 5 ° C. or more when the surface layer and the inner surface layer have a three-layer structure.

  In the present invention, since a gap as in the prior art is not formed in the electrode terminal lead-out portion of the battery, insufficient welding can be prevented and sealing can be performed without creating a minute gap. Further, by using a sealant having a multilayer structure of two or more layers, the adhesion between the electrode terminal and the sealant, and the laminate film and the sealant can be further improved. Furthermore, with respect to the sealant having a multilayer structure, by providing the melting point difference as described above, the high melting point resin material becomes an insulating layer and can prevent conduction / short circuit between the electrode terminal and the metal layer of the laminate film. .

  According to this invention, it is possible to improve the sealing performance while maintaining high adhesion at the electrode terminal portion. Further, since the sealing property is high, the sealing width can be reduced, and the capacity of the battery element can be increased. Furthermore, high safety can be obtained by using a sealant having a multilayer structure.

(1) First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 4 shows a configuration of a nonaqueous electrolyte battery 30 manufactured by applying the present invention. The non-aqueous electrolyte battery 30 is produced by sealing a peripheral portion of the battery element 20 in which the battery element 20 is housed in a battery housing part 27 a that is a recess formed in the laminate film 27. . Hereinafter, the configuration of the battery element 20 will be described.

  FIG. 5 shows the structure of the battery element 20. The battery element 20 includes a belt-like positive electrode 21, a separator 23a, a belt-like negative electrode 22 disposed to face the positive electrode 21, and a separator 23b, which are sequentially stacked and wound in the longitudinal direction. A gel electrolyte 24 is applied to both surfaces of the negative electrode 22. A positive electrode terminal 25a connected to the positive electrode 21 and a negative electrode terminal 25b connected to the negative electrode 22 are led out from the battery element 20 (hereinafter referred to as an electrode terminal 25 when not referring to a specific terminal). 25a and the negative electrode terminal 25b are made of polyethylene (PE) or the like having a thickness of 5 μm or more and 200 μm or less in order to improve adhesiveness with a laminate film 27 to be packaged later. The positive electrode terminal 25a and the negative electrode terminal 25b The sealant 26a provided with convex portions at the opposing portions is disposed.

[Positive electrode]
In the positive electrode, a positive electrode active material layer containing a positive electrode active material is formed on both surfaces of a positive electrode current collector. As the positive electrode current collector, for example, a metal foil such as an aluminum (Al) foil, a nickel (Ni) foil, or a stainless steel (SUS) foil can be used.

  The positive electrode active material layer includes, for example, a positive electrode active material, a conductive agent, and a binder. Here, the positive electrode active material, the conductive agent, and the binder need only be uniformly dispersed, and the mixing ratio is not limited.

As the positive electrode active material, a metal oxide, a metal sulfide, or a specific polymer can be used depending on the type of the target battery. For example, in the case of constituting a lithium ion battery, Li _x MO ₂ (wherein M represents one or more transition metals, and x varies depending on the charge / discharge state of the battery, and is usually 0.05 or more and 1.10 or less. ) And a composite oxide of lithium and transition metal. As the transition metal constituting the lithium composite oxide, cobalt (Co), Ni, manganese (Mn) or the like is used.

Specific examples of such a lithium composite oxide include LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiNi _y Co _1-y O ₂ (0 <y <1). A solid solution in which a part of the transition metal element is substituted with another element can also be used. Examples thereof include LiNi _0.5 Co _0.5 O ₂ and LiNi _0.8 Co _0.2 O ₂ . These lithium composite oxides can generate a high voltage and have an excellent energy density. _{Furthermore, TiS 2, MoS 2, NbSe} 2, V 2 O no lithium metal sulfides such as ₅ or may be used an oxide as the positive electrode active material. These positive electrode active materials may be used alone or in combination of two or more.

  As the conductive agent, for example, a carbon material such as carbon black or graphite is used. As the binder, for example, polyvinylidene fluoride, polytetrafluoroethylene or the like is used.

  The above-described positive electrode active material, binder, and conductive agent are uniformly mixed to form a positive electrode mixture, and this positive electrode mixture is dispersed in a solvent to form a slurry. Next, the slurry is uniformly applied on the positive electrode current collector by a doctor blade method or the like, and then dried at a high temperature to drive off the solvent, thereby forming the positive electrode active material layer 11b. In addition, as a solvent, N-methylpyrrolidone etc. are used, for example.

  The positive electrode 21 has a positive electrode terminal 25a connected to one end of the positive electrode current collector by spot welding or ultrasonic welding. The positive electrode terminal 25a is preferably a metal foil or a mesh-like one, but there is no problem even if it is not metal as long as it is electrochemically and chemically stable and can conduct electricity. Examples of the material of the positive electrode terminal 25a include aluminum.

[Negative electrode]
In the negative electrode, a negative electrode active material layer containing a negative electrode active material is formed on both surfaces of a negative electrode current collector. The negative electrode current collector is made of a metal foil such as a copper (Cu) foil, a nickel foil, or a stainless steel foil.

  The negative electrode active material layer includes, for example, a negative electrode active material, a conductive agent if necessary, and a binder. These are uniformly mixed to form a negative electrode mixture, and this negative electrode mixture is dispersed in a solvent to form a slurry. Next, the slurry is uniformly applied on the negative electrode current collector by a doctor blade method or the like, dried at a high temperature, and the solvent is blown off to form a negative electrode active material layer. Here, the mixing ratio of the negative electrode active material, the conductive agent, the binder, and the solvent is not limited as in the positive electrode active material.

As the negative electrode active material, lithium metal, a lithium alloy, a carbon material that can be doped / undoped with lithium, or a composite material of a metal material and a carbon material is used. Specific examples of the carbon material that can be doped / undoped with lithium include graphite, non-graphitizable carbon, and graphitizable carbon. More specifically, pyrolytic carbons, cokes (pitch coke, needle coke, petroleum coke), graphites, glassy carbons, organic polymer compound fired bodies (phenolic resin, furan resin, etc.) at an appropriate temperature. Carbon materials such as those obtained by firing and carbonization), carbon fibers, activated carbon, and the like can be used. Furthermore, as a material that can be doped / undoped with lithium, polymers such as polyacetylene and polypyrrole, and oxides such as SnO ₂ can be used.

  In addition, various types of metals can be used as materials capable of alloying lithium, and these alloys are often used. When metallic lithium is used, it is not always necessary to use powder as a coating film with a binder, and a method of pressure bonding a rolled lithium metal foil to a current collector may be used.

  As the binder, for example, polyvinylidene fluoride, styrene butadiene rubber or the like is used. Moreover, as a solvent, N-methylpyrrolidone, methyl ethyl ketone, etc. are used, for example.

  The above-described negative electrode active material, binder, and conductive agent are uniformly mixed to form a negative electrode mixture, which is dispersed in a solvent to form a slurry. Subsequently, after apply | coating uniformly on a negative electrode electrical power collector by the method similar to a positive electrode, the negative electrode active material layer 12b is formed by making it dry at high temperature and flying a solvent.

  Similarly to the positive electrode 21, the negative electrode 22 has a negative electrode terminal 25b connected to one end of the negative electrode current collector by spot welding or ultrasonic welding, and the negative electrode terminal 25b is electrochemically and chemically stable. There is no problem even if it is not metal as long as it can conduct electricity. Examples of the material of the negative electrode terminal 25b include copper and nickel.

  The positive electrode terminal 25a and the negative electrode terminal 25b are preferably derived from the same direction, but there is no problem even if they are derived from any direction as long as no short circuit or the like occurs and there is no problem in battery performance. Moreover, the connection location of the positive electrode terminal 25a and the negative electrode terminal 25b is not limited to the above-described example as long as electrical contact is established.

[Electrolyte]
As the electrolytic solution, an electrolyte salt and an organic solvent that are generally used in lithium ion batteries can be used.

  Specific examples of the non-aqueous solvent include ethylene carbonate, propylene carbonate, γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, dipropyl carbonate, ethyl propyl carbonate, or hydrogen of these carbonic acid esters to halogen. Examples include substituted solvents. One of these solvents may be used alone, or a plurality of these solvents may be mixed with a predetermined composition.

Moreover, as lithium salt, it is possible to use the material used for normal battery electrolyte solution. Specifically, LiCl, LiBr, LiI, LiClO ₃ , LiClO ₄ , LiBF ₄ , LiPF ₆ , LiNO ₃ , LiN (CF ₃ SO ₂ ) ₂ , LiN (C ₂ F ₅ SO ₂ ) ₂ , LiAsF ₆ , LiCF ₃ SO ₃ , LiC (SO ₂ CF ₃ ) ₃ , LiAlCl ₄ , LiSiF _{6 and the} like can be mentioned, but LiPF ₆ and LiBF ₄ are preferable from the viewpoint of oxidation stability. These lithium salts may be used alone or in combination of two or more. There is no problem as long as the lithium salt can be dissolved in the above solvent, but the lithium ion concentration is 0.4 mol / kg or more and 2.0 mol / kg or less with respect to the non-aqueous solvent. Preferably there is.

  In the case of using a gel electrolyte, the above-described electrolytic solution is gelled with a matrix polymer. The matrix polymer only needs to be compatible with a nonaqueous electrolytic solution in which the electrolyte salt is dissolved in the nonaqueous solvent and can be gelled. Examples of such a matrix polymer include a polymer containing polyvinylidene fluoride, polyethylene oxide, polypropylene oxide, polyacrylonitrile, and polymethacrylonitrile in repeating units. Such a polymer may be used individually by 1 type, and may mix and use 2 or more types.

Among them, particularly preferred as the matrix polymer is polyvinylidene fluoride or a copolymer in which hexafluoropropylene is introduced at a ratio of 7.5% or less to polyvinylidene fluoride. Such polymers have a number average molecular weight in the range of 5.0 × 10 ⁵ to 7.0 × 10 ⁵ (500,000 to 700,000) or a weight average molecular weight of 2.1 × 10 ⁵ to 3. The range is 1 × 10 ⁵ (210,000-310,000), and the intrinsic viscosity is in the range of 1.7 to 2.1.

[Separator]
The separator 23 is composed of, for example, a porous film made of a polyolefin-based material such as polypropylene (PP) or polyethylene (PE), or a porous film made of an inorganic material such as a ceramic nonwoven fabric. The porous film may be laminated. Among these, polyethylene and polypropylene porous films are the most effective.

  In general, the thickness of the separator is preferably 5 to 50 μm, more preferably 7 to 30 μm. If the separator is too thick, the amount of the active material filled decreases, the battery capacity decreases, and the ionic conductivity decreases and the current characteristics deteriorate. On the other hand, if the film is too thin, the mechanical strength of the film decreases.

[Production of battery]
The gel electrolyte solution prepared as described above is uniformly applied to the positive electrode 21 and the negative electrode 22 and impregnated in the positive electrode active material layer and the negative electrode active material layer, and then stored at room temperature or subjected to a drying process. Layer 14 is formed. Next, using the positive electrode 21 and the negative electrode 22 on which the gel electrolyte layer 14 is formed, the positive electrode 21, the separator 23 a, the negative electrode 22, and the separator 23 b are stacked and wound in this order to form the battery element 20.

  Next, a convex sealant 26a and a convex sealant 26b made of a resin film having a shape as shown in FIG. 6 are bonded to the upper surface and the lower surface of the positive electrode terminal 25a and the negative electrode terminal 25b derived from the battery element 20, respectively. However, FIG. 6 shows only the convex sealant 26a, and the convex sealant 26b has the same shape as the convex sealant 26a.

  At the time of bonding the sealant, the convex sealant 26a and the convex sealant 26b are disposed on the upper surface and the lower surface of the positive electrode terminal 25a and the negative electrode terminal 25b derived from the battery element 20, respectively. A method in which the convex sealant 26b is bonded and then covered with a laminate film can be used. Further, after the battery element 20 is first packaged with a laminate film, a convex sealant 26a and a convex sealant 26b are respectively disposed between the electrode terminal and the laminate film when the electrode terminal lead-out side is thermally welded. The film may be heat-welded at the same time.

At this time, the width Ds ₁ of the convex sealant 26a is made substantially equal to the width of the terrace portion of the battery to be manufactured, and convex portions (hereinafter, appropriately referred to as convex portions) 28a, 28b provided in the electrode terminal portion. The width ds ₁ (hereinafter referred to as a convex portion 28 unless otherwise specified) is set to a length that protrudes from the end of the laminate film. Further, as shown in FIG. 7C, the lateral length L ₁ of the convex sealant 26a is equal to the outer portion of the cutout portion 29a corresponding to the positive electrode terminal 25a provided in the heater head 29 used for welding the laminate film. It is longer than the distance between the outer portion of the notch 29b corresponding to the negative electrode terminal 25b, and the lateral length l ₁ of the convex portion is equal to or slightly wider than the electrode terminal.

For processing into such a shape, for example, a metal cutter may be used, or the convex portion 28 may be provided by laser processing. The resin film may be formed into a shape having the convex portions 28 by a metal cutter or laser processing in advance, and after the battery 30 is manufactured by sandwiching a strip-shaped resin film having a horizontal length L ₁ and a width ds ₁ , Unnecessary portions may be cut by laser processing to form the convex sealant 26.

  Note that the terrace width varies depending on the sealing width, and the smaller the sealing width, the smaller the terrace width. Here, FIG. 7A is a top view of the heater head 29, FIG. 7B is a top view showing the terrace portion of the battery element 20, and the positive electrode terminal 25a and the negative electrode terminal 25b to be led out, and FIG. 7C is a convex sealant to be used. It is a top view of 26a (or convex sealant 26b).

  Materials used for the convex sealant 26a include thermoplastic resins such as polyolefin resins, ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, carboxyl resins and ionomer resins, thermosetting properties, and electrode terminals. A resin material having strong heat-fusibility can be used. Examples of the polyolefin resin include modified polypropylene and modified polyethylene, and more specifically, maleic acid-modified polypropylene and polypropylene introduced with a carbonyl group.

  In addition, a heat-resistant paint can be used. When using a heat-resistant paint, each of the positive electrode terminal 25a and the negative electrode terminal 25b led out from the battery element before being connected to the positive electrode 21 and the negative electrode 22 or after being connected to the positive electrode 21 and the negative electrode 22 is opposed to the laminate film welding portion. Apply heat-resistant paint to the area to be covered. At this time, the heat-resistant paint is applied to the portions of the positive terminal 25a and the negative terminal 25b that protrude from the end portions of the laminate film.

  Further, a heat-resistant paint is applied in a strip shape along each of the welded portions of the inner resin layer of the laminate film positioned above and below the electrode terminal. Thereafter, by laminating the laminate film, the heat resistant paint has the same shape as the case where the convex sealant is used, and an equivalent effect can be obtained.

  The configuration of the battery element 20 when the convex sealant 26a is used is as shown in FIG. FIG. 8 shows the external appearance of the nonaqueous electrolyte battery 30 when the laminate film 27 is packaged and thermally welded. A portion indicated by a dotted line in FIG. 8 indicates a position where the convex sealant 26 a sandwiched between the welded portions of the laminate film 27 is disposed.

Further, the sealant is not limited to the shape shown in FIGS. 6 and 7, and convex sealants 26c, 26d, 26e, and 26f having the shapes shown in FIGS. 9 to 12 can also be used. The width ds ₂ of width Ds ₂ and the convex portion of the convex sealant 26c may be similar to the case of the above-described convex sealant 26a. Further, as shown in FIG. 10C, the lateral length L ₂ of the convex sealant 26c is wider than the notch portion 29a or the notched portion 29b of the heater head 29 used at the time of welding, the lateral protrusion length l ₂ is equal to or slightly wider than the electrode terminal. Here, FIG. 10A is a top view of the heater head 29, FIG. 10B is a top view showing the terrace portion of the battery element 20, and the positive electrode terminal 25a and the negative electrode terminal 25b to be led out, and FIG. 10C is a convex sealant used. 26c and a convex sealant 26d (or a convex sealant 26e and a convex sealant 26f).

  In this case, as shown in FIG. 11, the convex sealants 26c, 26d, 26e, and 26f are used for the upper and lower sides of the positive electrode terminal 25a and the negative electrode terminal 25b, respectively. 26d may be used, and the other may be a sealant 26b. When the convex sealants 26c, 26d, 26e, and 26f are used above and below the electrode terminal 25, the convex sealants 26c, 26d, 26e, and 26f are first provided on the positive electrode terminal 25a and the negative electrode terminal 25b, and then the positive electrode terminal 25a and the negative electrode terminal 25b. These may be bonded to the positive electrode 21 and the negative electrode 22, respectively.

When the convex sealants 26c, 26d, 26e, and 26f are used above and below the electrode terminals, there is a portion where the sealant material is not disposed between the positive terminal 25a and the negative terminal 25b, but the horizontal length of the convex sealant 26c. the L ₂ by taking larger than the width of the notch of the heater head, is pressurized by the heater head at the time of welding. Thereby, heat is sufficiently applied, and the sealant melted by the pressure flows and is sealed without a gap.

  Such a battery element 20 is packaged with a laminate film 27, and after the positive electrode terminal 25a and the negative electrode terminal 25b are led out, the periphery of the battery element 20 is thermally welded and sealed.

  At this time, the thickness of the convex sealant used is preferably 5 μm or more and 200 μm or less. When the thickness of the convex sealant is less than 5 μm, the adhesive property of the convex sealant is lowered, and there is a possibility that it may be easily peeled off or not adhered. In such a case, moisture easily penetrates, resulting in deterioration of battery characteristics and battery expansion.

  Further, when the thickness of the convex sealant exceeds 200 μm, the adhesiveness is good, but the bulge to the outside of the battery increases by the thickness of the convex sealant, which is disadvantageous in terms of thinness and volume efficiency. If the convex sealant is too thick, the circuit board and the sealing portion may interfere with each other when the circuit board is inserted, and the electrode terminal may be pressed and broken, or moisture may flow through the resinous convex sealant. Infiltration may easily occur, and battery characteristics may be deteriorated or the battery may expand.

  Furthermore, the sealing width can be in the range of 0.5 mm to 2.0 mm. By using the convex sealant, the adhesiveness and the sealing property are improved, and it becomes possible to make the sealing width narrower than the sealing width of the conventional laminated film exterior battery.

  Here, the sealing width is a width of a portion where heat is actually applied and the inner resin layers are welded to each other via a convex sealant. In the case of a battery using a laminate film as an exterior, burrs may be generated at the ends of the laminate film when the laminate film is cut into a predetermined size, and the burrs may be short-circuited with the electrode terminals 25 in some cases. In addition, even if burrs are facing the outside of the battery or there are no burrs, it is possible that the metal layer of the laminate film and the heater block will short-circuit when the heater block applies pressure to the end of the laminate film. It is done. Therefore, a short circuit can be prevented by welding the laminate film while avoiding the end of the laminate film.

  In this case, the cross-sectional view of the battery has a shape as shown in FIG. 13, but the sealing width does not include the end of the laminated film that was not welded by avoiding the heater block, and the electrode terminal is heated by the heater block. It is the width d in which 25 upper and lower laminate films 27 are welded.

  The laminated film 27 to be packaged has a structure as shown in FIG. 14, and is made of a multilayer film having moisture resistance and insulation properties, in which a metal foil 31 is sandwiched between an outer resin layer 32 and an inner resin layer 33 made of a resin film. . The metal foil 31 plays the most important role of protecting the contents by preventing the ingress of moisture, oxygen and light, as well as improving the strength of the exterior material, and appropriately uses stainless steel or nickel-plated iron as a material. However, aluminum (Al) is most suitable because of its lightness, extensibility, price, and ease of processing. If necessary, adhesive layers 44 and 45 may be provided between the metal foil 31 and the outer resin layer 32 and the inner resin layer 33, respectively.

  Nylon (Ny), polyethylene terephthalate (PET), or polyethylene (PE) is used for the outer resin layer 32 because of its beautiful appearance, toughness, flexibility, and the like, and a plurality of types can be selected and used. is there.

  The inner resin layer 33 is a portion that melts and fuses with heat or ultrasonic waves, and has a low density in addition to polyethylene (PE), unstretched polypropylene (CPP), polyethylene terephthalate (PET), nylon (Ny). Polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE) can be used, and a plurality of types can be selected and used.

  By producing the battery in this way, it is possible to prevent a gap from being formed between the convex sealant and the laminate film, to suppress moisture intrusion, and to narrow the sealing width of the top portion. For this reason, it becomes possible to make the volume of a battery element accommodating part large, and it can attain the high capacity | capacitance of a battery.

  Moreover, since it can be set as the structure which does not come out of a laminate film except an electrode terminal part, it can prevent that a sealant interferes with the circuit board connected with an electrode terminal. For this reason, the space between the sealant and the circuit board can be reduced, and a battery with high volumetric efficiency can be manufactured.

(2) Second Embodiment Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. In the second embodiment, the convex sealant 46a, 26b used in the first embodiment or the convex sealant 46 having a multilayer structure of two or more layers is used for each of the convex sealants 26c, 26d, 26e, 26f. Thus, the nonaqueous electrolyte battery 30 that realizes higher sealing performance and penetration resistance will be described. In the following description, parts that are the same as or correspond to members constituting the nonaqueous electrolyte battery 30 according to the first embodiment are denoted by the same reference numerals.

  In 2nd Embodiment, since the structure and material similar to 1st Embodiment are used except convex sealant 46, description except convex sealant 46 is abbreviate | omitted. Moreover, since the shape of the convex sealant 46 is the same as that used in the first embodiment, the description thereof is omitted.

  For example, the convex sealant 46 is formed by laminating a surface layer 41 facing the laminate film 27 as an exterior material and an inner surface layer facing the positive electrode terminal 25a and the negative electrode terminal 25b as shown in a cross section in FIG. 15A. A surface layer 41 facing the laminated film 27 side, an inner surface layer 42 facing the positive electrode terminal 25a and the negative electrode terminal 25b side, a surface layer 41 and an inner surface layer as shown in FIG. A three-layer structure in which an intermediate layer 43 sandwiched between 42 and 42 is laminated.

  As in the first embodiment, the total thickness of the convex sealant 46 is preferably 5 μm or more and 200 μm or less. When the thickness of the convex sealant 46 is less than 5 μm, the adhesiveness is lowered. On the other hand, if the thickness exceeds 200 μm, the thickness of the battery exterior increases, making it difficult to realize a thin and high capacity.

  The surface layer 41 is a material such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and vinyl chloride that has high adhesion to the inner resin layer 33 of the laminate film 27 and can be bonded at a relatively low temperature. Can be used.

  The inner surface layer 42 is made of modified polyolefin resin such as modified polypropylene and modified polyethylene having strong adhesion to the positive electrode terminal 25a and the negative electrode terminal 25b, an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, and an ionomer resin. Can be used. Among these, maleic acid-modified polyolefin resin is preferable.

  In the case of a two-layer structure, the surface layer 41 is preferably made of a resin material having a lower melting point than that of the inner surface layer 42, and the difference in melting point is 5 ° C. or more. Thereby, the inner surface layer 42 having a high melting point serves as an insulating layer, and conduction / short circuit between the electrode terminal and the metal layer 31 of the laminate film can be prevented.

  As the intermediate layer 43 provided in the case of a three-layer structure, a resin material having a melting point higher than each of the surface layer 41 and the inner surface layer 42, for example, high-density polyethylene (HDPE), stretched polypropylene, unstretched polypropylene, or the like is used. Can do.

  In the case of a three-layer structure, the melting point difference between the surface layer 41 and the intermediate layer 43 is preferably 5 ° C. or more. By making the intermediate layer 43 the material having the highest melting point, the intermediate layer 43 plays the role of an insulating layer, so that the surface layer 41 and the inner resin layer 33 of the laminate film and the electrode terminal and the inner surface layer 42 have high adhesion. It is possible to prevent conduction / short circuit between the electrode terminal and the metal layer of the laminate film while maintaining.

  In addition, as a resin material used for the above-mentioned surface layer 41, the inner surface layer 42, and the intermediate | middle layer 43, all use the material of low moisture permeability.

  As the convex sealant 46 having such a multilayer structure, for example, a resin film produced by a co-extrusion method of two or more kinds of resin materials is used.

  When the convex sealant 46 as described above is used, when the top portion from which the electrode terminal is derived is heated by the heater head, the inner resin layer 33 and the surface layer 41 of the laminate film 27, the positive electrode terminal 25a, and the negative electrode terminal 25b. And the inner surface layer 42 are firmly bonded to each other, and the sealing performance is improved.

  Further, for example, by providing a melting point difference of 5 ° C. or more, the resin layer having a high melting point serves as an insulating layer. Therefore, conduction / short circuit between the positive electrode terminal 25a and the negative electrode terminal 25b and the metal layer 31 exposed on the end face of the laminate film 27 can be avoided, and the long-term reliability of the battery performance can be improved and the battery swells. Can be further suppressed.

  When the melting point difference is less than 5 ° C., the prevention of conduction / short circuit has substantially the same performance as the single-layer convex sealant 26 as in the first embodiment, but the resin has different properties. Since the convex sealant 46 in which materials are laminated is used, the sealing performance is still improved.

  Such a convex sealant 46 can use either the shape shown in FIG. 6 or the shape shown in FIG. 9 as in the first embodiment.

[Example 1]
The present invention will be specifically described below. In Example 1, a test battery is manufactured by changing the shape and thickness of the sealant disposed on both surfaces of the electrode terminal and the sealing width of the top portion, and the moisture intrusion amount, the capacity retention rate, and the battery swelling amount are measured. . First, a battery element is produced.

[Production of positive electrode]
92% by weight of lithium cobaltate (LiCoO ₂ ), 3% by weight of powdered polyvinylidene fluoride, and 5% by weight of powdered graphite were uniformly mixed and dispersed in N-methylpyrrolidone to form a slurry-like positive electrode composite. An agent was prepared. This positive electrode mixture was uniformly applied to both surfaces of an Al foil serving as a positive electrode current collector, and dried under reduced pressure at 100 ° C. for 24 hours to form a positive electrode active material layer.

  Next, this was pressure-formed by a roll press machine to obtain a positive electrode sheet. The positive electrode sheet was cut into a strip shape to form a positive electrode, and an Al ribbon lead having a width of 3 mm was welded to an uncoated portion of the active material.

[Production of negative electrode]
Artificial graphite (91% by weight) and powdery polyvinylidene fluoride (9% by weight) were uniformly mixed and dispersed in N-methylpyrrolidone to prepare a slurry-like negative electrode mixture. Next, this negative electrode mixture was uniformly applied to both surfaces of a copper foil serving as a negative electrode current collector, and dried under reduced pressure at 120 ° C. for 24 hours to form a negative electrode active material layer.

  Next, this was pressure-formed by a roll press machine to obtain a negative electrode sheet, the negative electrode sheet was cut into a strip shape to form a negative electrode, and a Ni ribbon lead having a width of 3 mm was welded to an uncoated portion of the substance.

[Production of gel electrolyte]
A polyvinylidene fluoride copolymerized with 6.9% of hexafluoropropylene, a non-aqueous electrolyte, and dimethyl carbonate (DMC) as a diluting solvent are mixed, stirred and dissolved to obtain a sol electrolyte solution. Obtained. The electrolyte was prepared by mixing ethylene carbonate and propylene carbonate in a weight ratio of 6: 4 and dissolving 0.8 mol / kg LiPF ₆ and 0.2 mol / kg LiBF ₄ . The mixing ratio was a weight ratio of polyvinylidene fluoride: electrolyte: DMC = 1: 6: 12. Next, the obtained sol-form electrolyte solution was uniformly applied to both surfaces of the positive electrode and the negative electrode. Then, it was made to dry at 50 degreeC for 3 minute (s), the solvent was removed, and the gel electrolyte layer was formed on both surfaces of the positive electrode and the negative electrode.

  Next, a battery element was obtained by winding a belt-like positive electrode having a gel electrolyte layer formed on both sides and a belt-like negative electrode having a gel electrolyte layer formed on both surfaces in the longitudinal direction via a separator. As the separator, a porous polyethylene film having a thickness of 10 μm and a porosity of 33% was used.

  Next, the battery element produced as described above is packaged with a laminate film, and a sealant made of maleic acid-modified polypropylene is sandwiched between the laminate film and the electrode terminal, and then the laminate film around the battery element is attached. A test battery was prepared by welding. The test batteries were prepared with a thickness of 3.8 mm, a width of 34 mm, and a height of 50 mm so that the outer dimensions were the same. At this time, the length of the sealing side in the electrode terminal lead-out portion of the battery element was 40 mm, and the side portion was folded to have a width of 34 mm. Here, as the laminate film, a metal layer made of aluminum, an outer resin layer made of nylon, and an inner resin layer made of polypropylene was used.

<Example 1-1>
In the test battery described above, a convex sealant having a thickness of 5 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.5 mm.

<Example 1-2>
In the test battery described above, a convex sealant having a thickness of 5 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 2.0 mm.

<Example 1-3>
In the test battery described above, a convex sealant having a thickness of 200 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.5 mm.

<Example 1-4>
In the test battery described above, a convex sealant having a thickness of 200 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 2.0 mm.

<Comparative Example 1-1>
In the test battery described above, a convex sealant having a thickness of 4 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.5 mm.

<Comparative Example 1-2>
In the test battery described above, a convex sealant having a thickness of 500 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 2.0 mm.

<Comparative Example 1-3>
In the test battery described above, a convex sealant having a thickness of 5 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.4 mm.

<Example 1-4>
In the test battery described above, a convex sealant with a thickness of 200 μm was used, and the sealing width of the electrode terminal lead-out portion was 2.5 mm.

<Comparative Example 1-5>
In the test battery described above, a conventional sealant having a thickness of 5 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.5 mm.

<Comparative Example 1-6>
In the test battery described above, a conventional sealant having a thickness of 5 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 2.0 mm.

<Comparative Example 1-7>
In the test battery described above, a conventional sealant having a thickness of 200 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 0.5 mm.

<Comparative Example 1-8>
In the test battery described above, a conventional sealant having a thickness of 200 μm was used, and the sealing width of the electrode terminal lead-out portion was set to 2.0 mm.

  For the test batteries of the examples and comparative examples thus manufactured, after performing constant voltage and constant current charging at 4.2 V for 3 hours, discharging at 0.2 C was performed, and the voltage became 3.2 V. At the point of time, the discharge was terminated. Next, after storing for 120 hours in an atmosphere at a temperature of 80 ° C. and a relative humidity of 90%, the moisture intrusion amount [ppm], the capacity retention rate [%], and the battery swelling amount [mm] were measured. The moisture intrusion amount was measured by Karl Fischer measurement. Moreover, the battery swelling amount was measured by measuring the battery thickness before and after storage, and the difference was taken as the battery swelling amount.

  The measurement results are shown in Table 1 below.

  In addition, a moisture intrusion amount of less than 100 [ppm], a capacity retention rate of 90 [%] or more, and a battery swelling amount of less than 1.0 [mm] were regarded as non-defective products.

  From Example 1-1 to Example 1-4, a high-quality battery can be obtained by using a convex sealant to have a thickness of 5 μm to 200 μm and a sealing width of 0.5 mm to 2.0 mm. I understand that I can do it. On the other hand, as in Comparative Example 1-1 and Comparative Example 1-3, even when a convex sealant is used, if the thickness is thin or the sealing width is too small, a large amount of moisture enters. It can be seen that the capacity retention rate is low and the battery swells greatly.

  In addition, as in Comparative Example 1-2, when the thickness of the convex sealant is excessively increased, the circuit board and the electrode terminal lead-out portion interfere with each other during battery assembly, and the battery is swelled in the battery thickness direction and specified. It will be oversized and not good. Furthermore, when the sealing width is made too large as in Comparative Example 1-4, the volume of the power generation element portion becomes small, and the nominal capacity of the battery having a thickness of 3.8 mm, a width of 34 mm, and a height of 50 mm is increased to 780 mAh. Did not reach.

  Further, when a conventional sealant is used as in Comparative Example 1-5 to Comparative Example 1-7, water intrusion is large even when the thickness is 5 μm to 200 μm and the sealing width is 0.5 mm to 2.0 mm, It becomes a defective product. As in Comparative Example 1-8, when the thickness is 200 μm and the sealing width is 2.0 mm, the battery is a good product, but the convex sealant is used and the conditions for the thickness and the sealing width are the same. Performance becomes low compared with the battery of Example 1-4.

  From the above results, when the convex sealant is used, it is possible to largely block the amount of moisture that penetrates into the battery as compared with the conventional sealant, and it is possible to maintain a high battery capacity. When the conventional sealant is used, the sealing width is about 2.5 mm. However, even in a narrower range of 0.5 mm or more and 2.0 mm or less, moisture penetration can be suppressed and a good battery state can be maintained. Therefore, it is possible to increase the capacity by narrowing the sealing width.

[Example 2]
In Example 2, with respect to a test battery manufactured using a convex sealant in which the layer structure (single layer, two layers, three layers) and the resin material of each layer was changed, the fusion temperature at the time of sealing the top portion was Change and confirm the conduction between the metal layer of the laminate film and the electrode terminal. The following test batteries used nylon as an outer resin layer, aluminum as a metal layer, and polypropylene as an inner resin layer as a laminate film for exterior use.

  In the following examples, a convex sealant having a thickness of 50 μm was used. Further, in the case of the two-layer structure, the inner layer and the surface layer were configured such that the temperature difference between the surface layer and the intermediate layer was about 15 ° C. in the case of the three-layer structure.

<Example 2-1>
Example 1 except that a two-layered convex sealant using modified polypropylene (modified PP) for the inner surface layer and low density polyethylene (LDPE) for the surface layer was used and the sealing width of the top portion was 2.0 mm. A test battery was produced in the same manner as in Example 1.

<Example 2-2>
A test battery was prepared in the same manner as in Example 2-1, except that a two-layer convex sealant using modified polyethylene (modified PE) for the inner layer and low density polyethylene (LDPE) for the surface layer was used.

<Example 2-3>
Test battery as in Example 2-1, except that a two-layered convex sealant using ethylene / acrylic acid copolymer (EAA) for the inner surface layer and low density polyethylene (LDPE) for the surface layer is used. Was made.

<Example 2-4>
Test battery as in Example 2-1, except that a two-layered convex sealant using ethylene / methacrylic acid copolymer (EMAA) for the inner surface layer and low density polyethylene (LDPE) for the surface layer is used. Was made.

<Example 2-5>
A test battery was prepared in the same manner as in Example 2-1, except that a two-layered convex sealant using an ionomer resin for the inner surface layer and low density polyethylene (LDPE) for the surface layer was used.

<Example 2-6>
A test battery was prepared in the same manner as in Example 2-1, except that a two-layered convex sealant using modified polypropylene (modified PP) for the inner layer and linear low density polyethylene (LLDPE) for the surface layer was used. Produced.

<Example 2-7>
A test battery was prepared in the same manner as in Example 2-1, except that a two-layered convex sealant using modified polyethylene (modified PE) for the inner surface layer and vinyl chloride for the surface layer was used.

<Example 2-8>
Example 2-1 except that a three-layer convex sealant using modified polypropylene (modified PP) for the inner layer, biaxially oriented polypropylene (OPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer was used. A test battery was prepared in the same manner as described above.

<Example 2-9>
Example 2-1 except that a three-layer convex sealant using modified polyethylene (modified PE) for the inner layer, biaxially oriented polypropylene (OPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer was used. A test battery was prepared in the same manner as described above.

<Example 2-10>
Implemented except using a three-layer convex sealant with ethylene / acrylic acid copolymer (EAA) for the inner layer, biaxially oriented polypropylene (OPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer A test battery was produced in the same manner as in Example 2-1.

<Example 2-11>
Implemented except using a three-layer convex sealant with ethylene / methacrylic acid copolymer (EMAA) for the inner layer, biaxially oriented polypropylene (OPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer A test battery was produced in the same manner as in Example 2-1.

<Example 2-12>
The same procedure as in Example 2-1 except that a three-layer convex sealant using an ionomer resin for the inner surface layer, biaxially oriented polypropylene (OPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer was used. A test battery was prepared.

<Example 2-13>
Example 2-1 except that a three-layer convex sealant using modified polypropylene (modified PP) for the inner layer, high density polyethylene (HDPE) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer is used. A test battery was prepared in the same manner.

<Example 2-14>
Example 2-1 except that a three-layer convex sealant using modified polypropylene (modified PP) for the inner layer, unstretched polypropylene (CPP) for the intermediate layer, and low density polyethylene (LDPE) for the surface layer is used. Similarly, a test battery was produced.

<Comparative Example 2-1>
A test battery was produced in the same manner as in Example 2-1, except that a convex sealant having a modified polypropylene (modified PP) single layer structure was used.

<Comparative Example 2-2>
A test battery was produced in the same manner as in Example 2-1, except that a convex sealant having a modified polyethylene (modified PE) single layer structure was used.

<Comparative Example 2-3>
A test battery was produced in the same manner as in Example 2-1, except that a convex sealant having an ethylene / acrylic acid copolymer (EAA) single layer structure was used.

<Comparative Example 2-4>
A test battery was produced in the same manner as in Example 2-1, except that a convex sealant having an ethylene / methacrylic acid copolymer (EMAA) single layer structure was used.

<Comparative Example 2-5>
A test battery was produced in the same manner as in Example 2-1, except that a convex sealant having a single layer structure of an ionomer resin was used.

  When producing the test batteries of the examples and comparative examples thus produced, the peripheral part of the electronic device including the top part was thermally fused at temperatures of 160 ° C. or lower, 160 to 210 ° C., or 210 ° C. or higher. Wear and seal. Furthermore, after performing constant voltage and constant current charging at 4.2 V for 3 hours, discharging at 0.2 C was performed, and discharging was terminated when the voltage reached 3.2 V. For each of these test batteries, the resistance between the electrode terminal and the metal layer of the laminate film is measured, and when about several ohms that are considered to be in contact with each other are detected, they are conductive. Judged to be. The resistance measurement was performed by connecting a positive / negative probe of a tester (manufactured by Hioki Electric Co., Ltd., Digital High Tester 3802) to the metal layer exposed on the end face of the laminate film and each of the positive electrode terminal and the negative electrode terminal. It was measured.

  The measurement results are shown in Table 2 below.

  As can be seen from Table 2, by using a resin material having high adhesion to the electrode terminal for the inner surface layer and a resin material having high adhesion to the inner resin layer of the laminate film for the inner surface layer, the electrode terminal and the metal layer of the laminate film are used. Can be prevented from conducting. In addition, it is possible to select the fusing temperature of the top portion in a wider temperature range than when using a single-layer convex sealant, and high sealing performance can be obtained even at a relatively low temperature. Therefore, it can be judged that the sealant is rich in usage and versatility.

  The embodiment of the present invention has been specifically described above, but the present invention is not limited to the above-described embodiment, and various modifications based on the technical idea of the present invention are possible.

  For example, the numerical values and materials given in the above-described embodiment are merely examples, and different numerical values and materials may be used as necessary.

  Moreover, it is applicable if it is a battery of the structure which uses a laminate film as an exterior. For example, as the electrolyte, either a gel or a liquid can be used. Further, the battery element is not limited to the winding type, and may be a zigzag shape, for example. Furthermore, the present invention can be applied to a battery using a hard laminate film and using this as the outermost layer of the battery.

It is an external view which shows the conventional battery structure. It is a schematic diagram which shows the mode of welding of an electrode terminal derivation | leading-out part. It is a schematic diagram which shows the mode of welding of an electrode terminal peripheral part. It is a schematic diagram which shows the structure of the nonaqueous electrolyte battery to which this invention is applied. It is a schematic diagram which shows the battery element of the nonaqueous electrolyte battery to which this invention is applied. It is a schematic diagram which shows the sealant used for the nonaqueous electrolyte battery to which this invention is applied. FIG. 7A is a top view of the heater head, FIG. 7B is a top view showing a terrace portion of the battery element, and a positive terminal and a negative terminal that are led out, and FIG. 7C is a top view of the convex sealant used. It is an external view which shows the structure of the nonaqueous electrolyte battery to which this invention is applied. It is a schematic diagram which shows the sealant used for the nonaqueous electrolyte battery to which this invention is applied. FIG. 10A is a top view of the heater head, FIG. 10B is a top view showing a terrace portion of the battery element, and a positive terminal and a negative terminal that are led out, and FIG. 10C is a top view of the convex sealant used. It is a schematic diagram which shows the mode of arrangement | positioning of a sealant. It is a schematic diagram which shows the mode of arrangement | positioning of a sealant. It is sectional drawing of the nonaqueous electrolyte battery to which this invention is applied. It is a schematic diagram which shows the structure of the laminate film used for the nonaqueous electrolyte battery to which this invention is applied. It is sectional drawing which shows the structure of the sealant made into the multilayer structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Battery 2a, 25a ... Positive electrode terminal 2b, 25b ... Negative electrode terminal 3a, 3b ... Sealant 4,27 ... Laminate film 4a, 31 ... Metal layer 4b, 32 ... Outer resin layer 4c, 33 ... Inner resin layer 10 ... Heater head 10a ... Notch 20 ... Battery element 21 ... Positive electrode 22 ... Negative electrode 23a, 23b ... Separator 24 ... Gel electrolyte 26, 26a, 26b, 26c, 26d, 26e, 26f, 46 ... convex sealant 27a ... battery housing part 28a, 28b, 28c, 28d, 28e, 28f ... convex part 30 ... Battery 34, 35 ... Adhesive layer 41 ... Surface layer 42 ... Inner surface layer 43 ... Intermediate layer

Claims (25)

In a non-aqueous electrolyte battery in which a battery element is accommodated in an exterior material made of a laminate film having an inner resin layer provided on the inner surface of the metal layer, and the exterior material is sealed along the periphery of the battery element,
A welding member having moisture barrier properties is provided between the positive electrode terminal and the negative electrode terminal derived from the battery element and the inner resin layer,
The width of the welding member is substantially equal to the terrace width of the nonaqueous electrolyte battery,
The non-aqueous electrolyte battery according to claim 1, wherein the welding member has first and second protrusions protruding only from the positive electrode terminal and the negative electrode terminal from the laminate film.   2. The non-aqueous solution according to claim 1, wherein the welding member is made of a single-layer resin film and has thermoplasticity or thermosetting property and strong heat-fusibility to the positive electrode terminal and the negative electrode terminal. Electrolyte battery.   The non-aqueous electrolyte according to claim 2, wherein the resin film is selected from the group consisting of a polyolefin resin, an ethylene / acrylic acid copolymer, an ethylene / methacrylic acid copolymer, a carboxyl resin, and an ionomer resin. battery.   The non-aqueous electrolyte battery according to claim 3, wherein the polyolefin resin is modified polypropylene or modified polyethylene.   The welding member is composed of a two-layer resin film in which a surface layer and an inner surface layer are laminated, has thermoplasticity or thermosetting, and the surface layer is strongly heat-sealed to the inner surface resin layer of the laminate film. The nonaqueous electrolyte battery according to claim 1, wherein the non-aqueous electrolyte battery is made of a resin material having a property, and the inner surface layer is made of a resin material having strong heat-fusibility to the positive electrode terminal and the negative electrode terminal. 6. The nonaqueous electrolyte battery according to claim 5, wherein the surface layer is a resin material having a lower melting point than the resin material of the inner surface layer. The nonaqueous electrolyte battery according to claim 6, wherein a difference in melting point between the resin material of the surface layer and the inner surface layer is 5 ° C. or more.   6. The nonaqueous electrolyte battery according to claim 5, wherein the surface layer is selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and vinyl chloride.   6. The inner surface layer is selected from the group consisting of modified polyolefin resins such as modified polypropylene and modified polyethylene, ethylene / acrylic acid copolymers, ethylene / methacrylic acid copolymers, and ionomer resins. The nonaqueous electrolyte battery described.   The non-aqueous electrolyte battery according to claim 5, wherein the two-layer resin film is a co-extruded film of two kinds of resin materials.   The welding member includes a three-layer resin film in which a surface layer, an intermediate layer, and an inner surface layer are laminated, has thermoplasticity or thermosetting property, and the surface layer is stronger than the inner surface resin layer of the laminate film. The inner layer is made of a resin material having strong heat-fusibility to the positive electrode terminal and the negative electrode terminal, and the intermediate layer is a resin of the surface layer and the inner surface layer. The non-aqueous electrolyte battery according to claim 1, comprising a resin material having a melting point higher than that of the material. The nonaqueous electrolyte battery according to claim 11, wherein a difference in melting point between the resin material of the surface layer and the intermediate layer is 5 ° C. or more.   The non-aqueous electrolyte battery according to claim 11, wherein the intermediate layer is selected from the group consisting of high-density polyethylene (HDPE), stretched polypropylene, and unstretched polypropylene.   The non-aqueous electrolyte battery according to claim 11, wherein the three-layer resin film is a coextruded film of three types of resin materials.   The nonaqueous electrolyte battery according to claim 1, wherein a thickness of the welding member is 5 μm or more and 200 μm or less.   The nonaqueous electrolyte battery according to claim 1, wherein a sealing width in which the outer packaging material is sealed is 0.5 mm or more and 2.0 mm or less.   The non-aqueous electrolyte battery according to claim 1, wherein the welding member is a heat resistant paint.   2. The nonaqueous electrolyte according to claim 1, wherein the welding member is provided with a welding member having the first convex portion and the second convex portion on an upper surface and a lower surface of the positive electrode terminal and the negative electrode terminal, respectively. battery. The heat source member for welding the laminate film is provided with a notch corresponding to the positive terminal and a notch corresponding to the negative terminal,
The lateral length of the welding member is longer than a distance between an outer portion of the notch corresponding to the positive electrode terminal and an outer portion of the notch corresponding to the negative electrode terminal. 18. The nonaqueous electrolyte battery according to 18.   The first welding member having the first protrusion and the second welding member having the second protrusion are provided on the upper surface and the lower surface of the positive terminal and the negative terminal, respectively. 1. The nonaqueous electrolyte battery according to 1. The heat source member for welding the laminate film is provided with a notch corresponding to the positive terminal and a notch corresponding to the negative terminal,
The lateral length of the first welding member and the second welding member is longer than each of the cutout portion corresponding to the positive electrode terminal and the cutout portion corresponding to the negative electrode terminal. Item 21. The nonaqueous electrolyte battery according to item 20. In a method for producing a non-aqueous electrolyte battery in which a battery element is housed in an exterior material made of a laminate film having an inner resin layer provided on the inner surface of a metal layer, and the exterior material is sealed along the periphery of the battery element,
Between the inner resin layer of the exterior material and the positive electrode terminal and the negative electrode terminal derived from the battery element, has a moisture barrier property, and has a width substantially equal to the terrace width of the nonaqueous electrolyte battery, A step of disposing a welding member having a first convex portion and a second convex portion, wherein only the positive electrode terminal and the portion facing the negative electrode terminal protrude from the laminate film;
And a step of thermally welding the terrace portion of the nonaqueous electrolyte battery with a heat source member provided with a cutout portion corresponding to the positive electrode terminal and a cutout portion corresponding to the negative electrode terminal. A method for producing a water electrolyte battery.   The lateral length of the welding member is longer than a distance between an outer portion of the notch corresponding to the positive electrode terminal and an outer portion of the notch corresponding to the negative electrode terminal. 23. A method for producing a non-aqueous electrolyte battery according to 22. In a method for producing a non-aqueous electrolyte battery in which a battery element is housed in an exterior material made of a laminate film having an inner resin layer provided on the inner surface of a metal layer, and the exterior material is sealed along the periphery of the battery element,
Between the inner resin layer of the exterior material and the positive electrode terminal and the negative electrode terminal derived from the battery element, has a moisture barrier property, and has a width substantially equal to the terrace width of the nonaqueous electrolyte battery, A step of disposing a first welding member having a first protrusion protruding from the laminate film and a second welding member having the second protrusion only in a portion facing the positive electrode terminal and the negative electrode terminal; ,
A step of sheathing the battery element with the sheathing material;
And a step of thermally welding the terrace portion of the nonaqueous electrolyte battery with a heat source member provided with a cutout portion corresponding to the positive electrode terminal and a cutout portion corresponding to the negative electrode terminal. A method for producing a water electrolyte battery.   The lateral length of the first welding member and the second welding member is longer than each of the cutout portion corresponding to the positive electrode terminal and the cutout portion corresponding to the negative electrode terminal. Item 25. A method for producing a nonaqueous electrolyte battery according to Item 24.

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