JP2016171091A - Outer packaging material and battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat dissipation properties of a battery that is enclosed with a laminate film.SOLUTION: An outer packaging material has a layer that contains a black body material capable of utilizing black body radiation and has an emissivity of 0.6 or more. The outer packaging material includes at least an outer layer film, a metal foil and an inner layer film, and a layer containing a black body material is preferably located on the more outer side than the metal foil. The black body material is at least one of a carbon material, a silicate material and a metal oxide material, and preferably has an average particle size of 1.0 μm or less.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an exterior material and a battery, and particularly to an exterior material and a battery having high heat dissipation.

  In recent years, mobile information terminals such as mobile phones, notebook personal computers, and PDAs (Personal Digital Assistants) have been rapidly reduced in size and weight, and batteries for driving power sources are required to have higher capacities. Yes. A non-aqueous electrolyte secondary battery represented by a lithium ion secondary battery has a high energy density and a high capacity, and is therefore widely used as a driving power source for the mobile information terminal as described above.

  Development of safety technology related to conventional lithium-ion batteries has been performed assuming various misuse situations. From the viewpoint of suppressing heat generation, it can be further divided into two categories: improvement of the physical properties of the battery material and utilization of the structure / mechanism of the battery. Development of flame retardant electrolytes, adoption of positive and negative electrode active materials with low calorific value, etc. entered the former domain, prevention of overcharge and overdischarge by external protection circuit, reduction of internal pressure at gas ejection by safety valve, etc. Goes into the latter.

  For example, as disclosed in Patent Document 1 below, regarding a structure for improving heat conduction, one of an anode and a cathode is in thermal contact with a metal package.

JP 2002-208439 A JP-A-62-119859

  However, in Patent Document 1, with respect to the promotion of heat dissipation, the focus was only on the heat conduction inside the battery and the heat transfer between the battery outer surface and the external atmosphere. The adoption of battery materials with high safety is currently difficult, considering the trade-off relationship with performance aspects such as battery capacity and the period for searching for new substances. On the other hand, prevention of heat generation by a new battery structure / mechanism has been waiting for the next step.

  From the viewpoint of heat dissipation, which is another approach to safety technology development, it is considered that the adoption of battery materials with good thermal conductivity leads to this purpose. However, because of this trade-off relationship with performance, it was not possible to change it easily.

  By the way, for heat dissipation, heat conduction and heat transfer, in addition to releasing heat by a heat flux proportional to the temperature difference, a phenomenon of heat radiation giving a heat flux proportional to the fourth power of the temperature is known. There have been few attempts to take advantage of this phenomenon. Behind that, radiation prevails when the temperature in question is several thousand degrees, which is extremely large compared to room temperature, so there is a prejudice that it may not be effective for internal heat generation of batteries of several hundred degrees at most. It is speculated that there was.

  The present invention has been made in view of such a problem, and an object of the invention is to improve the heat dissipation of the battery, and to provide a high safety even when heat is generated inside the battery, and the battery. Is to provide.

In order to solve the above-described problem, a first invention is an exterior material for a battery, and includes a first layer, a black material layer containing a black body material, and a metal layer, The exterior material has a color different from that of the metal layer and is provided between the first layer and the metal layer.
2nd invention is equipped with the battery element and the exterior | packing material which coat | covers the said battery element, The said exterior material is provided with the 1st layer, the black material layer containing a black body material, and a metal layer, and is black. The material layer is a battery having a color different from that of the metal layer and provided between the first layer and the metal layer.

  The exterior material includes at least an outer layer film, a metal foil, and an inner layer film, and includes a black body material in at least one of the outer layer film and the inner layer film, or between the outer layer film and the metal foil, or between the metal foil and the outer layer. A black body material layer containing a black body material is preferably provided between the film and the film.

  It is preferred that the layer containing the black body material is between the metal foil and the outer layer film, or the black body material is contained in the outer layer film.

  The black body material used in the present invention is composed of at least one of a carbon material, a silicate material, and a metal oxide material, and the average particle size of the black body material is preferably 1.0 μm or less.

  In this invention, the heat dissipation by radiation | emission can be improved by providing the layer containing a black body material in a laminate film, and making it an exterior material of a battery element.

  According to this invention, the temperature rise of the battery can be suppressed and safety can be enhanced.

It is a basic diagram which shows the example of 1 structure of the nonaqueous electrolyte battery of 1st Embodiment of this invention. It is sectional drawing which shows the example of 1 structure of the battery element of 1st Embodiment of this invention. It is sectional drawing which shows one structural example of the exterior material used for the nonaqueous electrolyte battery of 1st Embodiment of this invention. It is sectional drawing which shows the other structural example of the exterior material used for the nonaqueous electrolyte battery of 1st Embodiment of this invention. It is sectional drawing which shows the other structural example of the exterior material used for the nonaqueous electrolyte battery of 1st Embodiment of this invention. It is sectional drawing which shows the other structural example of the exterior material used for the nonaqueous electrolyte battery of 1st Embodiment of this invention. It is a basic diagram which shows the example of 1 structure of the nonaqueous electrolyte battery of 2nd Embodiment of this invention. It is a basic diagram which shows the example of 1 structure of the nonaqueous electrolyte battery of 2nd Embodiment of this invention. It is a basic diagram which shows the example of 1 structure of the nonaqueous electrolyte battery of 2nd Embodiment of this invention. It is a basic diagram which shows the example of 1 structure of the nonaqueous electrolyte battery of 2nd Embodiment of this invention.

Hereinafter, the best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described.
(1) First embodiment (example of nonaqueous electrolyte battery covered with a laminate film)
(2) Second embodiment (an example of a nonaqueous electrolyte battery covered with a hard laminate film and a soft laminate film)

(1) First Embodiment (1-1) Configuration of Nonaqueous Electrolyte Battery First, the configuration of a nonaqueous electrolyte battery according to an embodiment of the present invention will be described. FIG. 1 is an exploded perspective view showing the configuration of the nonaqueous electrolyte battery 20, and FIG. 2 is a cross sectional view showing the configuration of a cross section taken along the line II of the main part of the nonaqueous electrolyte battery 20 shown in FIG. The nonaqueous electrolyte battery 20 described here is, for example, a so-called lithium ion secondary battery in which the capacity of the negative electrode is represented by a capacity component associated with insertion and extraction of light metal (for example, lithium).

  As shown in FIG. 1, the nonaqueous electrolyte battery 20 has a thin battery structure in which a battery element 10 to which a positive electrode terminal 15A and a negative electrode terminal 15B are attached is housed in a film-like laminate film 17. ing. The nonaqueous electrolyte battery 20 is housed and packaged in a battery element housing portion 18 which is a recess for housing the battery element 10 formed on the laminate film 17, and the peripheral portion of the battery element 10 is sealed. It is produced by doing. The laminate film 17 has a heat fusion layer made of a resin material on the surface facing the battery element 10. Then, by sandwiching the two layers of the laminate film 17 in which the heat-seal layers are opposed to each other with a heater block made of metal or the like, the heat-seal layers are melted and the laminate film 17 is bonded. The detailed configuration of the laminate film 17 will be described later.

[Configuration of battery element]
Hereinafter, the configuration of the battery element 10 will be described.

  As shown in the cross section of FIG. 2, the battery element 10 of the present invention has a belt-like positive electrode 11, a separator 13, a belt-like negative electrode 12, and a separator 13 that are sequentially laminated and wound in the longitudinal direction. From the battery element 10, a positive electrode terminal 15 </ b> A connected to the positive electrode 11 and a negative electrode terminal 15 </ b> B connected to the negative electrode 12 (hereinafter referred to as an electrode terminal 15 when not referring to a specific terminal) are derived. An adhesion member 16 that is a sealing member for improving adhesiveness is disposed between the positive electrode terminal 15 </ b> A and the negative electrode terminal 15 </ b> B and the laminate film 17 that covers the battery element 10 as an exterior member. For the adhesion member 16, for example, a resin film made of polypropylene (PP) or the like can be used. Alternatively, a resin film made of a modified resin material having high adhesion to the electrode terminal 15 made of metal may be used.

  For example, both the positive electrode terminal 15 </ b> A and the negative electrode terminal 15 </ b> B are led out in the same direction from the inside of the laminate film 17 toward the outside. The positive electrode terminal 15A is made of, for example, a metal material such as aluminum (Al) and has a thin plate-like or mesh-like structure. Aluminum (Al) is preferable because it is passivated and does not dissolve, and has good electrical conductivity. The negative electrode terminal 15B is made of, for example, a metal material such as copper (Cu), nickel (Ni), or stainless steel, and has a thin plate or network structure. Copper (Cu), nickel (Ni), stainless steel, and the like are preferable because they are not alloyed with lithium. Among these, copper is particularly preferable because it has high electrical conductivity.

[Positive electrode]
In the positive electrode 11, for example, a positive electrode active material layer 11B is provided on both surfaces of a positive electrode current collector 11A. The positive electrode current collector 11A is made of, for example, a metal material such as aluminum (Al). The positive electrode active material layer 11B includes a positive electrode active material and a binder, and may further include a conductive agent as necessary.

The positive electrode active material can occlude and release lithium, which is an electrode reactant, and includes any one or more of positive electrode materials having a reaction potential of, for example, 3 to 4.5 V with respect to lithium. It is out. Examples of such a positive electrode material include a composite oxide containing lithium. Specifically, as a complex oxide of lithium and a transition metal, lithium cobaltate (LiCoO ₂ ) having a layered structure, lithium nickelate (LiNiO ₂ ), or a solid solution containing these (LiNi _x Co _y Mn _z O ₂ ; In the formula, 0 <x <1, 0 <y <1, 0 <z <1, x + y + z = 1 can be used for the values of x, y, and z, respectively.

As a positive electrode material, lithium manganate (LiMn ₂ O ₄ ) having a spinel structure or a solid solution thereof (Li (Mn _{2 -v} Ni _v ) O ₄ ; in the formula, the value of v is v <2). Can also be used. Further, as the positive electrode material, for example, a phosphate compound such as lithium iron phosphate (LiFePO ₄ ) having an olivine structure can be used. This is because a high energy density can be obtained. In addition to the above-described materials, the positive electrode material may be, for example, an oxide such as titanium oxide, vanadium oxide or manganese dioxide, a disulfide such as iron disulfide, titanium disulfide or molybdenum sulfide, sulfur, polyaniline or It may be a conductive polymer such as polythiophene.

  As the positive electrode binder, a polymer containing vinylidene fluoride (VdF) as a component is contained. This is because the adhesiveness of the electrolyte layer 14 to the positive electrode 11 is improved by containing vinylidene fluoride as one component as in the electrolyte layer 14. This polymer may be a homopolymer (polyvinylidene fluoride) or a copolymer containing vinylidene fluoride as one component. The content of the positive electrode binder in the positive electrode active material layer 11B is not particularly limited, but is, for example, in the range of 1 wt% to 10 wt%. This content is preferably small when the polymer constituting the positive electrode binder has a large weight average molecular weight, while it is preferably large when the weight average molecular weight is small. The binder may contain, for example, one or two or more other polymers and copolymers together with the above-described polymer containing vinylidene fluoride as a component. Examples of the conductive agent include carbon materials such as graphite and acetylene black.

[Negative electrode]
In the negative electrode 12, for example, a negative electrode active material layer 12B is provided on both surfaces of a negative electrode current collector 12A. The negative electrode current collector 12A is made of, for example, a metal material such as copper, nickel, or stainless steel. The negative electrode active material layer 12B includes a negative electrode active material and a negative electrode binder, and may further include a conductive agent (for example, a carbon material) as necessary.

  The negative electrode active material contains any one or more of negative electrode materials capable of inserting and extracting lithium. Examples of the negative electrode material include carbon materials, metals, metal oxides, silicon, and polymer materials. The carbon material is any one of carbon materials such as non-graphitizable carbon, graphitizable carbon, graphites, pyrolytic carbons, cokes, glassy carbons, organic polymer compound fired bodies, carbon fibers and activated carbon. Species or two or more can be used. In particular, natural graphite, artificial graphite, and other graphites are rich in chemical stability, can repeatedly and stably undergo lithium ion deinsertion reactions, and are easily available industrially. Widely used. In addition, as a kind of graphite, artificial graphite, natural graphite, etc., such as a mesophase carbon micro bead, carbon fiber, or coke, are mentioned, for example. A carbon material is preferable because the crystal structure changes very little with insertion and extraction of lithium, and also functions as a conductive agent.

  Moreover, as a negative electrode material, the material which contains at least 1 sort (s) of the metallic element and metalloid element which can form an alloy with lithium as a constituent element is mentioned, for example. This type of material is preferable because a high energy density can be obtained. This negative electrode material may be any of a simple substance, an alloy or a compound of a metal element or a metalloid element, and may have one or more of these phases at least in part. The alloys in the present invention include those containing one or more metal elements and one or more metalloid elements in addition to those composed of two or more metal elements. Of course, the alloy may contain non-metallic elements. This structure includes a solid solution, a eutectic (eutectic mixture), an intermetallic compound, or one in which two or more of them coexist.

  Examples of the material containing at least one of a metal element and a metalloid element as a constituent element include a material containing silicon or tin. This is because a high energy density can be obtained because the ability to occlude and release lithium is large. These may be used alone or in combination of two or more.

  As a specific example of this material, a material containing tin as the first constituent element and, in addition thereto, a second constituent element and a third constituent element are preferable. Among them, a substance containing tin, cobalt and carbon as constituent elements (CoSnC material) ) Is preferred. This is because a higher energy density can be obtained and excellent cycle characteristics can be obtained. This CoSnC-containing material may further contain other constituent elements as necessary. This is because the battery capacity and cycle characteristics are further improved.

  Specific examples of the above-described materials include a simple substance, an alloy or a compound of tin, or a simple substance, an alloy or a compound of silicon. In this case, for example, the negative electrode active material layer 12B is formed by using a vapor phase method, a liquid phase method, a thermal spraying method, a firing method, or two or more of these methods, and the negative electrode active material layer 12B The anode current collector 12A is preferably alloyed at least at a part of the interface. This is because the negative electrode active material layer 12B is less likely to be destroyed due to expansion and contraction associated with charge / discharge, and the electron conductivity is improved between the negative electrode current collector 12A and the negative electrode active material layer 12B. As the vapor phase method, for example, physical deposition method or chemical deposition method, more specifically, vacuum vapor deposition method, sputtering method, ion plating method, laser ablation method, thermal chemical vapor deposition (CVD; Chemical Vapor Deposition). ) Method or plasma enhanced chemical vapor deposition. As the liquid phase method, a known method such as electroplating or electroless plating can be used. The firing method is, for example, a method in which a particulate negative electrode active material and a binder are mixed and dispersed in a solvent, followed by heat treatment at a temperature higher than the melting point of the negative electrode binder or the like. . A known method can be used for the firing method, and examples thereof include an atmospheric firing method, a reactive firing method, a hot press firing method, and the like.

  As the negative electrode binder, for example, vinylidene fluoride (VdF) can be used.

  In this secondary battery, the charge capacity of the negative electrode active material is larger than the charge capacity of the positive electrode active material, so that lithium metal does not deposit on the negative electrode 12 even during full charge, between the positive electrode 11 and the negative electrode 12. The magnitude relationship of the charging capacity has been adjusted.

[Separator]
The separator 13 separates the positive electrode 11 and the negative electrode 12 and allows lithium ions to pass through while preventing a short circuit of current caused by contact between the two electrodes. The separator 13 is made of, for example, a porous film made of a synthetic resin such as polytetrafluoroethylene (PTFE), polypropylene (PP), or polyethylene (PE), or a porous film made of ceramic. The separator 13 may be a laminate of these two or more porous films.

[Electrolytes]
The electrolyte 14 contains an electrolytic solution and a holding body containing a polymer compound that holds the electrolytic solution, and has a so-called gel shape. The electrolytic solution includes an electrolyte salt and a solvent that dissolves the electrolyte salt. A lithium salt can be used as the electrolyte salt. Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), and antimony hexafluoride. Inorganic lithium salts such as lithium oxalate (LiSbF ₆ ), lithium perchlorate (LiClO ₄ ), lithium tetrachloroaluminate (LiAlCl ₄ ), lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), lithium bis (trifluoromethanesulfonyl) ) Imide (LiN (CF ₃ SO ₂ ) ₂ ), lithium bis (pentafluoroethanesulfonyl) imide (LiN (C ₂ F ₅ SO ₂ ) ₂ ), and lithium tris (trifluoromethanesulfonyl) methide (LiC (CF ₃ SO _{2) 3)} perfluoroalkane sulfonic acids derived such And the like, it is also possible to use them in combination of at least one kind alone or in combination. Among these, lithium hexafluorophosphate (LiPF ₆ ) is preferable because high ion conductivity can be obtained and cycle characteristics can be improved.

  Examples of the solvent include lactone solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, and ε-caprolactone, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, dimethyl carbonate, ethyl methyl carbonate, or diethyl carbonate. Carbonate ester solvents such as 1,2-dimethoxyethane, 1-ethoxy-2-methoxyethane, 1,2-diethoxyethane, ether solvents such as tetrahydrofuran or 2-methyltetrahydrofuran, nitrile solvents such as acetonitrile, Nonaqueous solvents such as sulfolane-based solvents, phosphoric acids, phosphate ester solvents, or pyrrolidones are mentioned. Any one type of solvent may be used alone, or two or more types may be mixed and used.

  The solvent preferably contains a compound in which part or all of hydrogen of the cyclic ester or chain ester is fluorinated. As the fluorinated compound, difluoroethylene carbonate (4,5-difluoro-1,3-dioxolan-2-one) is preferably used. Even when the negative electrode 14 containing a compound such as silicon (Si), tin (Sn), or germanium (Ge) is used as the negative electrode active material, the charge / discharge cycle characteristics can be improved. In particular, difluoroethylene carbonate is used. This is because the cycle characteristic improvement effect is excellent.

  The polymer compound may be any one that gels upon absorption of a solvent. For example, a fluorine-based polymer compound such as polyvinylidene fluoride or a copolymer of vinylidene fluoride and hexafluoropropylene, polyethylene oxide or polyethylene oxide. And ether-based polymer compounds such as crosslinked products containing polyacrylonitrile, polypropylene oxide, or polymethyl methacrylate as repeating units. Any one of these polymer compounds may be used alone, or two or more thereof may be mixed and used. In particular, from the viewpoint of redox stability, a fluorine-based polymer compound is desirable, and among them, a copolymer containing vinylidene fluoride and hexafluoropropylene as components is preferable.

[Laminate film]
The laminate film 17 has a resin film provided on both surfaces of a metal foil. Further, the laminate film 17 has a layer containing a black body material having a characteristic that black body radiation can be used. Hereinafter, the laminate film will be described in detail.

  As the laminate film 17, for example, an outer layer film as a protective layer, a metal foil, and an inner layer film as a heat fusion layer are basically used. An adhesive layer can be provided between the layers. In the present invention, a black body material layer including a black body material having characteristics capable of utilizing black body radiation is provided, or at least one of the outer layer film, the inner layer film, and the adhesive layer contains the black body material. It is. Moreover, in order to give additional characteristics, such as the intensity | strength of a packaging material, the structure which loaded the intermediate resin layer between the outer layer and metal foil or the inner layer and metal foil as needed can also be employ | adopted. In this case, the characteristics of the resin are not limited, and resin characteristics (for example, resin type, mechanical characteristics, thickness, crystallinity, multilayering, etc.) can be selected according to the characteristics to be given to the packaging material.

Examples of the laminate film 17 include the following configurations.
(1) outer layer film / black body material layer / adhesive layer / metal foil / adhesive layer / inner layer film (2) outer layer film / adhesive layer / black body material layer / metal foil / adhesive layer / inner layer film (3) black body material Outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film (4) outer layer film / adhesive layer with dispersed black body material / metal foil / adhesive layer / inner layer film (5) outer layer film / black body Material layer / Outer layer film / Adhesive layer / Metal foil / Adhesive layer / Inner layer film (6) Outer layer film / Adhesive layer / Metal foil / Adhesive layer / Black body material layer / Inner layer film (7) Outer layer film / Adhesive layer / Metal foil / Black body material layer / adhesive layer / inner layer film (8) outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film in which black body material is dispersed (9) outer layer film / adhesive layer / metal foil / black body material Adhesive layer / inner layer film

  The nonaqueous electrolyte battery 20 has a structure in which, for example, an inner layer film faces the battery element 10 and outer edges of two rectangular laminate films 17 are bonded to each other by fusion bonding or an adhesive. .

Here, as black body materials having black, graphite materials, carbon materials such as fullerenes, silicate materials, iron oxides (magnetite type triiron tetroxide), copper (Cu) and chromium (Cr) A composite oxide or a black metal oxide material such as a composite oxide of copper (Cu), chromium (Cr), zinc (Zn), and titanium (Ti) can be used. Specifically, carbon black, graphite, aniline black, iron black (FeOFe ₂ O ₃ ), chromite spinel solid solution, or the like can be used. Also, other materials can be used as long as they have sufficient characteristics to utilize black body radiation.

  Note that black is a color in which all of C (cyan), M (magenta), and Y (yellow) are 70 or more in the CMY color model.

  The average particle diameter of the black body material powder is preferably 1.0 μm or less, and more preferably 0.5 μm or less. In the case of providing a black body material layer, it is possible to suppress deterioration of characteristics as an outer layer material by making the layer as thin as possible. The amount of radiation is proportional to the surface area. For these reasons, finer particle diameters are preferred.

  Hereinafter, each configuration will be described in detail.

(A) In the case where a black body material layer is provided A configuration (for example, (1), (2), (5), (6) and (7)) where a black body material layer is provided will be described below. For example, the configuration of (1) is shown in FIG. As shown in FIG. 3, the laminate film 17 having the configuration (1) includes a metal foil 17a, an outer layer film 17b, an inner layer film 17c, a black body material layer 17d, and an adhesive layer 17e.

  The black body material layer 17d is made of a black body material and a base resin, and has an emissivity of 0.6 or more. An additive is added to the black body material layer 17d as necessary. As the base resin, for example, an acrylic ester resin, a urethane resin, or an epoxy resin can be used. As the additive, a curing agent, an antioxidant, or the like can be used.

The emissivity was obtained by forming a material containing a black body material with a thickness of 10 μm on the surface of an aluminum (Al) foil and measuring the emissivity of the surface of the formed black body material-containing layer by a reflection measurement method. The emissivity is obtained by measuring the reflectivity average in the wavelength region of 4 μm to 24 μm (2500 cm ^{−1 to} 400 cm ⁻¹ ) using an FT-IR (Fourier Transform Infrared Spectrometer) infrared spectrophotometer. The emissivity (0 or more and 1 or less) was determined from (1-reflectance).

  Here, the emissivity is determined by the type of black body material. On the other hand, if the black body material is the same material, the emissivity does not change when the thickness of the black body material-containing layer changes, but the amount of radiation changes. For this reason, the emissivity measured from the black body material-containing layer having a thickness of 10 μm should be equivalent to the emissivity of the black body material layer formed with a thickness of 2 μm, for example, if the included black body material is the same material. Can do.

  Further, the thickness of the black body material layer 17d is preferably set to 1 μm or more and 10 μm or less from the viewpoint of suppressing deterioration in characteristics as an exterior body. The black body material layer 17d is preferably made as thin as possible under the condition of an emissivity of 0.6 or more.

  In addition to improving the strength of the exterior material, the metal foil 17a has a function of protecting the battery element 10 by preventing moisture, oxygen, and light from entering. A soft metal material is used as the metal foil 17a, and aluminum (Al), stainless steel (SUSU), titanium (Ti), copper (Cu), and tin (Pb), zinc (Zn), and nickel (Ni). Iron (Fe) or the like plated with either of them can be used as appropriate. Among them, it is preferable to use, for example, annealed aluminum (JIS A8021P-O) or (JIS A8079P-O).

  The thickness of the metal foil 17a is preferably 50 μm or more and 150 μm or less. When the thickness is less than 50 μm, the material strength is inferior. Moreover, when it exceeds 150 μm, processing becomes extremely difficult and the thickness of the laminate film 17 increases, leading to a decrease in volumetric efficiency of the nonaqueous electrolyte battery 20.

  As the outer layer film 17b, beauty of appearance, toughness, flexibility, etc. are required, and nylon (Ny), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate. (PBN) or the like can be used.

  The thickness of the outer layer film 17b is preferably 5 μm or more and 30 μm or less. When the outer layer film is too thick, the heat dissipation is reduced. Moreover, when an outer layer film is too thin, there exists a possibility that the function as a protective layer may fall.

  A character, a pattern, etc. may be described as needed on the outer surface of the outer layer film 17b. Alternatively, the black body material layer 17d may be formed by removing characters and patterns. The color, shape or arrangement of the characters and patterns is not particularly limited, and it is not necessary for the characters and patterns to be concentrated on a part of the outer surface. Regardless of the form of these letters and patterns, the heat radiation effect appears as much as the area of the black body material that appears on the outer surface. It is necessary to design letters and patterns together with the heat dissipation effect.

  The inner layer film 17c is a portion that is melted and fused with heat or ultrasonic waves, and polypropylene (PP), non-axially stretched polypropylene (CPP), polyethylene terephthalate (PET), or the like can be used. It is also possible to select and use a plurality of types from these. And as polyethylene (PE), low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE) can be used.

  The thickness of the inner layer film 17c is preferably 10 μm or more and 50 μm or less. When the inner layer film 17c is too thick, heat conduction from the battery element 10 to the metal foil 17a is slow, and heat dissipation is reduced. Moreover, when the inner layer film 17c is too thin, the sealing performance at the time of packaging and sealing the battery element 10 is deteriorated.

  As an adhesive material used for the adhesive layer 17e, for example, an adhesive conventionally used for manufacturing a laminate film such as urethane resin, acrylic resin, styrene resin, or the like can be used. In addition, if a resin material having a thermal bonding effect on a metal is used, it can be directly bonded by a heat roller, and can be bonded by coating a molten or diluted resin material by extrusion or the like. .

  In the configuration in which the black material layer 17d is provided, only the black material layer 17d is newly provided in the conventional basic configuration. Therefore, the difference in characteristics is small compared to the basic configuration, and production and use are easy. Further, the adhesive layer 17e is not necessarily required, and may be used when necessary for lamination.

(B) When using an outer layer film in which a black body material is dispersed Hereinafter, a configuration using an outer layer film in which a black body material is dispersed (for example, (3)) will be described. The configuration of (3) is shown in FIG. As shown in FIG. 4, the laminate film 17 as shown in (3) includes a metal foil 17a, an outer layer film 17b ′ in which a black body material is dispersed, an inner layer film 17c, and an adhesive layer 17e.

  As the outer layer film 17b ′ in which the black body material is dispersed, materials such as nylon (Ny), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN) are used. A film formed by dispersing a black body material can be used.

  At this time, the outer layer film 17b 'alone has an emissivity of 0.6 or more. The content of the black body material in the outer layer film 17b 'is preferably 50% by weight or more and 80% by weight or less of the outer layer film 17b'. When there is too little content of a black body material, heat dissipation will fall. Moreover, when there is too much content of a black body material, there exists a possibility that the intensity | strength and function of an outer layer film may fall.

  Moreover, it can be set as the structure similar to (a) except using the outer layer film 17b 'which disperse | distributed blackbody material, and not providing a blackbody material layer. Further, the adhesive layer 17d is not always necessary, and may be used when necessary for lamination.

(C) When using an inner layer film in which a black body material is dispersed Hereinafter, a configuration using an inner layer film in which a black body material is dispersed (for example, (8)) will be described. The configuration of (8) is shown in FIG. As shown in FIG. 5, the laminate film 17 as shown in (8) includes a metal foil 17a, an outer layer film 17b, an inner layer film 17c ′ in which a black body material is dispersed, and an adhesive layer 17e.

  As the inner layer film 17c ′ in which the black body material is dispersed, polypropylene (PP), non-axially stretched polypropylene (CPP), polyethylene terephthalate (PET), low density polyethylene (LDPE), high density polyethylene (HDPE), linear A film formed by dispersing a black body material in a material such as low density polyethylene (LLDPE) can be used.

  At this time, the inner layer film 17c 'alone has an emissivity of 0.6 or more. The black body material content in the inner layer film 17c 'is preferably 60% by weight or more and 80% by weight or less of the inner layer film. When there is too little content of a black body material, heat dissipation will fall. Moreover, when there is too much content of a black body material, there exists a possibility that the intensity | strength and function of an inner layer film may fall.

  Moreover, it can be set as the structure similar to (a) except using the inner layer film 17c 'which disperse | distributed the black body material, and not providing the black body material layer 17d. Further, the adhesive layer 17e is not necessarily required, and may be used when necessary for lamination.

(D) In the case of providing an adhesive layer in which a black body material is dispersed Hereinafter, a configuration using an adhesive layer in which a black body material is dispersed (for example, (4) and (9)) will be described. As an example, the configuration of (4) is shown in FIG. As shown in FIG. 6, the laminate film 17 as shown in (4) includes a metal foil 17a, an outer layer film 17b, an inner layer film 17c, and an adhesive layer 17e 'in which a black body material is dispersed.

  The adhesive layer 17e 'in which the black body material is dispersed can be formed of an adhesive in which the black body material is dispersed in a material such as urethane resin, acrylic resin, or styrene resin. At this time, the adhesive layer 17e 'alone has an emissivity of 0.6 or more. The content of the black body material in the adhesive layer 17e 'is preferably 60% by weight or more and 80% by weight or less of the adhesive layer 17e'. When there is too little content of a black body material, heat dissipation will fall. Moreover, when there is too much content of a black body material, there exists a possibility that the function of an contact bonding layer may fall.

  The configuration can be the same as (a) except that the adhesive layer 17e 'is formed using an adhesive in which a black body material is dispersed and the black body material layer is not provided.

  As described above, by using the laminate film 17 having a layer containing a black body material, it is possible to enhance the heat dissipation effect to the outside using black body radiation. In the above-described configurations (1) to (9), the layer containing the black body material is provided on the outer side of the metal foil 17a (the direction corresponding to the outer side of the battery when the battery element 10 is packaged). The configuration 4) is more preferable. It is considered that providing the layer containing the black body material on the outside of the metal foil can shorten the time until the radiated heat propagates to the outer surface.

  Moreover, the external appearance from the outer-layer film side of the laminate film 17 can be made black by providing the layer containing a black body material on the outside of the metal foil. Thereby, it is more preferable because pinholes and cracks generated in the laminate film 17 can be easily detected.

(1-2) Nonaqueous Electrolyte Battery Manufacturing Method This nonaqueous electrolyte battery 20 can be manufactured, for example, by the following procedure.

[Production of positive electrode]
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. Here, the positive electrode active material, the conductive agent, and the binder need only be uniformly dispersed, and the mixing ratio is not limited. Next, the slurry is applied uniformly on the positive electrode current collector 11A by a doctor blade method or the like, and then compressed and dried by a high-temperature roll press machine or the like to drive off the solvent, thereby forming the positive electrode active material layer 11B. The positive electrode active material layer 11B is provided on both surfaces of the positive electrode current collector 11A, for example. Depending on the structure of the battery element 10, the positive electrode active material layer 11B may be provided on one surface of the positive electrode current collector 11A. In addition, as a solvent, N-methyl-2-pyrrolidone etc. are used, for example. Finally, the positive electrode terminal 15A is attached to the unformed portion of the positive electrode active material layer 11B on the positive electrode current collector 11A.

[Production of negative electrode]
The negative electrode active material and the binder composed of the above two-component copolymer are uniformly mixed to form a negative electrode mixture, and the negative electrode mixture is dispersed in a solvent to form a slurry. Here, the negative electrode active material and the binder need only be uniformly dispersed, and the mixing ratio thereof is not limited. Moreover, you may add a electrically conductive agent as needed. Next, the slurry is uniformly applied on the negative electrode current collector by a doctor blade method or the like, and compressed and dried by a high-temperature roll press machine or the like to drive off the solvent, thereby forming a negative electrode active material layer. Here, the negative electrode active material layer 12 </ b> B may be provided on at least one surface of the negative electrode current collector 12 </ b> A, similarly to the configuration of the positive electrode 11. Finally, the negative electrode terminal 15B is attached to an unformed portion of the negative electrode active material layer 12B on the negative electrode current collector 12A.

[Production of battery element]
A gel electrolyte layer 14 is formed on the surface of the positive electrode active material 11B of the positive electrode 11 and the surface of the negative electrode active material layer 12B of the negative electrode 12 produced as described above, respectively. First, a sol-shaped precursor solution containing an electrolytic solution, a polymer compound, and a diluting solvent is prepared. As the polymer compound, a material composed of a ternary copolymer is used. Subsequently, a sol-form precursor solution is applied to each surface of the positive electrode active material layer 11B and the negative electrode active material layer 12B, and then the diluted solvent in the precursor solution is volatilized. Thereby, the gel electrolyte layer 14 is formed.

  Subsequently, the positive electrode 11 and the negative electrode 12 provided with the electrolyte layer 14 are laminated via the separator 13 and then wound in the longitudinal direction. At this time, the wound electrode or the like is fixed by the protective tape 19. Thereby, the battery element 10 is formed.

[Production of laminate film]
(A) In the case of providing a black body material layer The black body material layer 17d is formed by, for example, applying or spraying a coating material obtained by adding a solvent to a black body material and a base resin to the outer layer film 17b, the inner layer film 17c, or the metal foil 17a. Formed to remove. As the solvent used at this time, for example, toluene, ethyl acetate, xylene and 2-butanone can be used.

  Subsequently, the outer layer film 17 b, the metal foil 17 a, and the inner layer film 17 c are attached via, for example, an adhesive layer 17 e to obtain a laminate film 17. At this time, the black body material layer 17d formed on one surface of the outer layer film 17b, the metal foil 17a, or the inner layer film 17c is adjusted to a desired position.

(B) When using an outer layer film in which a black body material is dispersed When forming the outer layer film 17b ', the black body material is mixed with the film material to form the outer layer film 17b'. Subsequently, the outer layer film 17 b ′, the metal foil 17 a, and the inner layer film 17 c are attached via, for example, the adhesive layer 17 e to obtain a laminate film 17.

(C) When using the outer layer film in which the black body material is dispersed When the inner layer film 17c ′ is formed, the black body material is mixed with the film material to form the inner layer film 17c ′. Subsequently, the outer layer film 17 b, the metal foil 17 a, and the inner layer film 17 c ′ are attached via, for example, an adhesive layer 17 e to obtain a laminate film 17.

(D) In the case of providing an adhesive layer in which a black body material is dispersed Using an adhesive mixed with a black body material, the outer layer film 17b, the metal foil 17a, and the inner layer film 17c are connected, for example, via an adhesive layer 17e '. The laminate film 17 is attached.

  Subsequently, the battery element accommodating portion 18 is formed on the laminate film 17 by deep drawing from the inner layer film 17c side to the outer layer film 17a side. Then, the battery element 10 is accommodated in the battery element accommodating portion 18, the battery element 10 is packaged with the laminate film 17, and the outer edge portions of the battery element 10 are adhered to each other by heat fusion or the like, thereby encapsulating the battery element 10. . At that time, the adhesion member 16 is inserted between the positive electrode terminal 15 </ b> A and the negative electrode terminal 15 </ b> B and the laminate film 17. Thereby, the nonaqueous electrolyte battery 20 shown in FIGS. 1 and 2 is completed.

(2) Second Embodiment (2-1) Configuration of Nonaqueous Electrolyte Battery In the second embodiment, a battery element 10 similar to that of the first embodiment is used, and a hard laminate film and a soft laminate film are used. The nonaqueous electrolyte battery 30 in which the battery element 10 is packaged will be described. In the second embodiment, the description of the same configuration as in the first embodiment is omitted.

  In the second embodiment, a battery element covered with a hard laminate film and a soft laminate film is called a nonaqueous electrolyte battery, a circuit board is connected to the nonaqueous electrolyte battery, and a top cover and a rear cover are fitted. Is called a battery pack. In battery packs and nonaqueous electrolyte batteries, the positive electrode terminal and negative electrode terminal lead-out side is referred to as the top portion, the side facing the top portion is referred to as the bottom portion, and the other is referred to as the side portion. Further, the length in the side portion direction is referred to as the width direction, and the length in the top portion-bottom portion direction is referred to as the height.

(2-1) Configuration of Battery Pack FIG. 7 shows a configuration example of the battery pack 40 according to the second embodiment of the present invention. The battery pack 40 is, for example, a battery pack of a lithium ion polymer secondary battery having a square shape or a flat shape, and as shown in FIG. 7, both ends are opened and openings are formed, and the battery pack 40 is formed in the exterior material. A non-aqueous electrolyte battery 30 in which the element 10 is accommodated, and a top cover 25 a and a bottom cover 25 b fitted into openings at both ends of the non-aqueous electrolyte battery 30 are provided.

  In FIG. 8, the state in the middle of manufacture of the nonaqueous electrolyte battery 30 in 2nd Embodiment is shown. The exterior material has a plate shape as a whole, and has a rectangular shape when viewed from the surface direction, and a soft laminate film 27 having a rectangular shape whose length in the side portion direction is shorter than that of the hard laminate film 26. Consists of. The openings at both ends of the nonaqueous electrolyte battery 30 have a rectangular shape as a whole, and both short sides swell outwardly to form an elliptical arc.

  The nonaqueous electrolyte battery 30 includes a soft laminate film 27 provided with a battery element housing portion 28, a battery element 10 housed in the battery element housing portion 28, and an opening of the battery element housing portion 28 housing the battery element 10. It consists of the hard laminate film 26 provided so that it might cover.

  Further, from the sealing portion where the hard laminate film 26 and the soft laminate film 27 are sealed, the positive electrode terminal 15A and the negative electrode terminal 15B that are electrically connected to the positive electrode and the negative electrode of the battery element 10 are led out. .

  The top cover 25a and the bottom cover 25b have shapes that can be fitted into openings at both ends of the nonaqueous electrolyte battery 30. Specifically, when viewed from the front, the top cover 25a and the bottom cover 25b have a rectangular shape as a whole. The side swells outward to form an elliptical arc. In addition, the front has shown the direction which sees the nonaqueous electrolyte battery 30 from the top side.

  Hereinafter, the exterior material, the circuit board, the top cover 25a, and the bottom cover 25b will be described with reference to FIGS.

[Exterior material]
As shown in FIGS. 7 and 8, the exterior material includes a soft laminate film 27 provided with a battery element housing portion 28 for housing the battery element 10, and a battery element housing portion 28 on the soft laminate film 27. And a hard laminate film 26 which is stacked so as to cover.

  Hereinafter, the hard laminate film 26 will be described.

  The hard laminate film 26 has a rectangular shape, and has a top-side long side 36a and a bottom-side long side 36b having the same length, and both side-side short sides 36c and 36d having the same length. As shown in FIG. 9, the lengths of the top long side 36a and the bottom long side 36b of the hard laminate film 26 are short on both sides in the state where the battery element accommodating portion 28 in which the battery element 10 is accommodated is wrapped. The sides 36c and 36d are set to contact each other or face each other with a slight gap.

  Moreover, as shown in FIG. 8, the notch part 38 may be provided in the top side long side 36a of the hard laminate film 26. As shown in FIG. As shown in FIG. 7, the notch portions 38 are provided so as to be located on both short sides when viewed from the front of the nonaqueous electrolyte battery 30. By providing the notch 38, the top cover 25a can be easily fitted.

  The hard laminate film 26 has the same configuration as the laminate film 17 except that the metal foil 26a is made of a hard metal foil. That is, at least a metal foil 26a, an outer layer film 26b, and an inner layer film 26c are provided, and for example, as described in (1) above, a black body material layer 26d is provided. Further, like the laminate film 17, it may have the same configuration as any one of the configurations (2) to (9).

  The metal foil 26a in the hard laminate film 26 has a function of maintaining the shape after bending and resisting deformation from the outside, and is a hard metal material such as aluminum (Al), stainless steel (SUS), iron (Fe). Copper (Cu) or nickel (Ni) can be appropriately used as a material. Among them, aluminum (Al) and stainless steel (SUS) are most preferable, and in particular, hard aluminum (JIS A3003P-H18) or (JIS A3004P-H18) without annealing treatment, or austenitic stainless steel (SUS304) is used. Is preferred.

  The thickness of the metal foil 26a is preferably 50 μm or more and 150 μm or less. When the thickness is less than 50 μm, the material strength is inferior. Moreover, when it exceeds 150 μm, processing becomes extremely difficult, and the thickness of the hard laminate film 26 increases, leading to a decrease in volumetric efficiency of the battery pack 40.

  Hereinafter, the soft laminate film 27 will be described.

  The laminated structure of the soft laminate film 27 is the same as that of the laminate film 17. That is, at least a metal foil 27a, an outer layer film 27b, and an inner layer film 27c are provided, and the black body material layer 27d is provided as in the above-described configuration (1), for example. Further, like the laminate film 17, it may have the same configuration as any one of the configurations (2) to (9).

  The flexible laminate film 27 has a rectangular shape, and has a top-side long side 37a and a bottom-side short side 37b having the same length, and both side-side long sides 37c and 37d having the same length. The battery element accommodating portion 28 for accommodating the battery element 10 is formed by drawing or the like. The lengths of the top-side long side 37a and the bottom-side short side 37b of the soft laminate film 27 are set to be larger than the width of the battery element housing portion 28 in which the battery element 10 is housed. In one embodiment, two opposite sides on the top side and bottom side of the soft laminate film 27 are long sides and two opposite sides on the side side are short sides, but depending on the shape of the battery element 10, the top side The bottom side may be a short side and the side side may be a long side.

  Further, the short sides 37 c and 37 d on both sides of the soft laminate film 27 are slightly shorter than the long sides 36 c and 36 d on both sides of the hard laminate film 26. Thereby, the soft laminate film 27 can be laminated on the hard laminate film 26 so that only the hard laminate film 26 exists on the top side and the bottom side of the nonaqueous electrolyte battery 30. Since the inner layer film 26c of the hard laminate film 26 is exposed at a portion where only the hard laminate film 26 exists, the inner layer film 26c, the top cover 25a, and the bottom when the top cover 25a and the bottom cover 25b are fitted later. The cover 25b can be bonded by thermal fusion.

[Circuit board]
The circuit board 34 is one to which the positive terminal 15A and the negative terminal 15B of the battery element 10 are electrically connected. The circuit board 34 is mounted with a protection circuit including a temperature protection element such as a fuse, a thermal resistance element (Positive Temperature Coefficient; PTC element), and a thermistor, and an ID resistor for identifying the battery pack. (For example, three) contact portions are formed. The protection circuit includes a charge / discharge control FET (Field Effect Transistor), an IC (Integrated Circuit) that monitors the battery element 10 and controls the charge / discharge control FET, and the like.

  The heat-sensitive resistance element is connected in series with the battery element 10, and when the temperature of the battery becomes higher than the set temperature, the electrical resistance increases rapidly and substantially interrupts the current flowing through the battery. The fuse is also connected in series with the battery element 10, and when an overcurrent flows through the battery, the fuse is blown by its own current to cut off the current. In addition, a heater resistor is provided in the vicinity of the fuse. When an overvoltage is applied, the temperature of the heater resistor rises, so that the current is cut off.

  Moreover, when the terminal voltage of the battery element 10 exceeds 4.3 V to 4.4 V, there is a possibility that a dangerous state such as heat generation or ignition may occur. For this reason, the protection circuit monitors the voltage of the battery element 10, and when the voltage exceeds 4.3V to 4.4V and is overcharged, the charge control FET is turned off to prohibit charging. Furthermore, when the terminal voltage of the battery element 10 is overdischarged to a discharge prohibition voltage or lower and the battery element 10 voltage becomes 0 V, the battery element 10 may be in an internal short-circuit state and cannot be recharged. For this reason, when the voltage of the battery element 10 is monitored and an overdischarge state occurs, the discharge control FET is turned off to prohibit discharge.

[Top cover]
The top cover 25a is fitted into the top side opening of the nonaqueous electrolyte battery 30 and has a rectangular shape as a whole when viewed from the front direction, and both sides on the short side are elliptical toward the outside. It swells to form an arc. A side wall for fitting into the bottom side opening is provided on the surface of the top cover 25a on the battery element 10 side. The side wall is provided along a part or the whole of the outer periphery of the top cover 25a, and the side wall and the end of the hard laminate film 26 are thermally fused and bonded.

  A circuit board 34 is accommodated in the top cover 25a. The top cover 25a is provided with a plurality of openings at positions corresponding to the contact portions so that the plurality of contact portions of the circuit board 34 are exposed to the outside. The contact portion of the circuit board 34 contacts the electronic device through the opening of the top cover 25a. Thereby, the battery pack 40 and the electronic device are electrically connected. Such a top cover 25a is produced in advance by injection molding.

[Bottom cover]
The bottom cover 25b is fitted into the bottom side opening of the nonaqueous electrolyte battery 30 and has a rectangular shape as a whole when viewed from the front direction, and both sides on the short side are elliptical toward the outside. It swells to form an arc. On the surface of the bottom cover 25b on the battery element 10 side, a side wall for fitting into the bottom side opening is provided along part or all of the outer periphery of the bottom cover 25b. The ends of 26 are heat-sealed and bonded.

  The bottom cover 25b may be provided with one or more, preferably two or more through holes penetrating from the surface facing the battery element 10 toward the opposite surface. In this case, the nonaqueous electrolyte battery 30 and the bottom cover 25b can be more firmly bonded by injecting hot melt resin from the through hole. When two or more through holes are provided, at least one through hole can be used for venting air between the battery element 10 and the bottom cover 25b at the time of resin injection. Can be improved.

  Such a bottom cover 25b is produced in advance by injection molding. It is also possible to use a method in which the nonaqueous electrolyte battery 30 is installed in a mold and a hot melt resin is poured into the bottom portion so as to be molded integrally with the nonaqueous electrolyte battery 30.

(2-2) Method for Producing Battery Pack Hereinafter, a method for producing the battery pack 40 will be described.

[Production of battery element]
The battery element 10 can be manufactured similarly to the first embodiment.

  Subsequently, as shown in FIGS. 10 and 11, the inner layer film 26 c of the hard laminate film 26 and the inner layer film 27 c of the soft laminate film 27 are disposed so as to face each other. Then, the battery element 10 is accommodated in the battery element accommodating portion 28, and the hard laminate film 26 and the soft laminate film 27 are overlapped so that the opening of the battery element accommodating portion 28 is covered with the hard laminate film 26. Thereafter, the overlapping portion of the hard laminate film 26 and the soft laminate film 27 is sealed along the periphery of the battery element housing portion 28. Sealing is performed by using a metal heater head (not shown) and thermally welding the inner layer film 26c of the hard laminate film 26 and the inner layer film 27c of the soft laminate film 27 while reducing the pressure.

  Next, as shown in FIG. 9, the hard laminate film 26 is deformed so that the short sides 36c and 36d on the side side come into contact with each other. At this time, the adhesive film 29 is disposed on one surface where the joint of the short sides 37c and 37d of the deformed soft laminate film 27 faces the outside of the bottom of the battery element housing portion 28 provided on the soft laminate film 27, and the heater head Is heated to adhere the outer layer films 27b of the soft laminate film 27 to form the non-aqueous electrolyte battery 30. In addition, when a temperature higher than necessary is applied to the battery element 10, the battery element 10 may be damaged. For this reason, the heater head is set to a temperature at which the resin material of the adhesive film 29 is melted. The adhesive film 29 is preferably made of a material that melts at a temperature that does not damage the battery element 10.

[Production of battery pack]
Subsequently, as shown in FIG. 7, after the positive electrode terminal 15 </ b> A and the negative electrode terminal 15 </ b> B are connected to the circuit board 34, the circuit board 34 is attached to the top cover 25 a using a holder 25 c that can be fitted. Store in 25a. Then, after changing the direction so that the holder 25 c is on the nonaqueous electrolyte battery 30 side, the top cover 25 a is fitted into the top opening of the nonaqueous electrolyte battery 30. Further, the bottom cover 25 b is fitted into the bottom side opening of the nonaqueous electrolyte battery 30.

  Finally, the fitting portions of the top cover 25a and the bottom cover 25b are respectively heated by the heater head, and the top cover 25a and the bottom cover 25b and the inner layer film 26c of the hard laminate film 26 are welded. Thereby, the battery pack 40 having the appearance shown in FIG. 10 is created.

  As described in the second embodiment, by providing the hard laminate film 26 and the soft laminate film 27 with a layer containing a black body material, the heat dissipation can be enhanced also in the battery pack of the second embodiment. .

  Specific examples of the present invention will be described in detail below, but the present invention is not limited thereto.

In addition, the laminate film of the structure in any one of following (1)-(9) was used as a laminate film used by each following Example.
(1) outer layer film / black body material layer / adhesive layer / metal foil / adhesive layer / inner layer film (2) outer layer film / adhesive layer / black body material layer / metal foil / adhesive layer / inner layer film (3) black body material Outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film (4) outer layer film / adhesive layer with dispersed black body material / metal foil / adhesive layer / inner layer film (5) outer layer film / black body Material layer / Outer layer film / Adhesive layer / Metal foil / Adhesive layer / Inner layer film (6) Outer layer film / Adhesive layer / Metal foil / Adhesive layer / Black body material layer / Inner layer film (7) Outer layer film / Adhesive layer / Metal foil / Black body material layer / adhesive layer / inner layer film (8) outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film in which black body material is dispersed (9) outer layer film / adhesive layer / metal foil / black body material Adhesive layer / inner layer film (basic structure) ) Outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film

[Example 1]
In Example 1, a battery pack was produced using a laminate film produced by changing the black body material, and the battery surface temperature during high temperature storage was measured.

<Example 1-1>
[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 on both surfaces of an aluminum 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.

  Then, this was pressure-formed with a roll press to obtain a positive electrode sheet, the positive electrode sheet was cut into a strip shape to be a positive electrode, and a positive electrode terminal made of aluminum foil was welded to an uncoated portion of the active material. Further, an adhesive member made of a polypropylene resin film was bonded to a portion of the positive electrode terminal that faces the heat-sealing layer when being covered with a laminate film.

[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.

  Subsequently, this was pressure-formed with 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 negative electrode terminal made of nickel foil was welded to an uncoated portion of the substance. Further, a sealant made of a polypropylene resin film was bonded to a portion of the negative electrode terminal facing the heat-sealing layer when the negative electrode terminal was covered with a laminate film.

[Preparation of electrolyte]
Ethylene carbonate (EC) and propylene carbonate (PC) were mixed at a weight ratio of 6: 4, and 0.8 mol / kg of LiPF64 was dissolved to prepare an electrolytic solution. As a matrix polymer dispersed in the electrolytic solution, a copolymer obtained by polymerizing hexafluoropropylene (HFP) at a concentration of 7% by weight with respect to vinylidene fluoride (VdF) was used.

  The matrix polymer, the electrolytic solution, and the dilution solvent were mixed at a weight ratio of 1:10:10 to prepare a sol-like precursor solution. Dimethyl carbonate (DMC) was used as a dilution solvent. After applying this sol-form precursor solution on the positive electrode active material layer and the negative electrode active material layer, the diluting solvent was volatilized in an environment of 100 ° C. to form a gel electrolyte layer having a thickness of 15 μm on the positive electrode and the negative electrode. .

[Production of laminate film]
As shown in the above (1), a laminate film having a configuration of outer layer film / black body material layer / adhesive layer / metal foil / adhesive layer / inner layer film was produced. At this time, an aluminum foil having a thickness of 50 μm was used as the metal foil, and polypropylene (PP) having a thickness of 30 μm was used as the inner layer film.

  Moreover, as an outer layer film, the film which provided the black body material layer on the metal foil side surface of a 30-micrometer-thick polyethylene terephthalate (PET) was used. The black body material layer uses a black body solution in which 70% by weight of carbon black having an average particle diameter D50 = 0.5 μm as a black body material and 30% by weight of an acrylic ester resin are mixed. The black body solution was applied to a thickness of 2.0 μm.

At this time, a black body material layer having a thickness of 10 μm was formed on the surface of the aluminum foil, and the emissivity of the surface of the black body material layer was determined by a reflection measurement method. The emissivity is obtained by measuring the reflectivity average in the wavelength region of 4 μm to 24 μm (2500 cm ^{−1 to} 400 cm ⁻¹ ) using an FT-IR (Fourier Transform Infrared Spectrometer) infrared spectrophotometer. The emissivity (0 or more and 1 or less) was determined from (1-reflectance). In Example 1-1, the emissivity was 0.82.

  The outer layer film on which the black body material layer was formed and the inner layer film were bonded to the metal foil through an adhesive layer having a thickness of 5 μm. At this time, the black body material layer provided on the exterior film was on the metal foil side.

[Assembly of non-aqueous electrolyte battery]
The positive electrode and the negative electrode on which the gel electrolyte layer was formed were laminated via a porous polyethylene separator and wound to prepare a flat battery element. At this time, the battery element was prepared so that the discharge capacity was 900 mAh when the height was 60 mm, the width was 40 mm, and the thickness was 5 mm, the full charge voltage was 4.2 V, and the discharge end voltage was 3.0 V. The battery element was packaged with an exterior material made of an aluminum laminate film using carbon black as the black body material. The battery element was housed in a recess formed in an aluminum laminate film and packaged, and each side around the battery element was bonded by heat sealing under vacuum, and vacuum sealed to prepare a test battery.

<Example 1-2>
A test battery was produced in the same manner as in Example 1-1 except that graphite was used as the black body material when producing the laminate film. In addition, when the emissivity of the blackbody material layer using graphite was measured in the same manner as in Example 1-1, the emissivity was 0.85.

<Example 1-3>
A test battery was produced in the same manner as in Example 1-1 except that iron black (FeOFe ₂ O ₃ ) was used as the black body material when producing the laminate film. In addition, when the emissivity of the blackbody material layer using iron black (FeOFe ₂ O ₃ ) was measured in the same manner as in Example 1-1, the emissivity was 0.79.

<Example 1-4>
A test battery was produced in the same manner as in Example 1-1 except that a chromite-based spinel solid solution was used as the black body material when producing the laminate film. In addition, when the emissivity of the black body material layer using the chromite-based spinel solid solution was measured in the same manner as in Example 1-1, the emissivity was 0.81.

<Example 1-5>
A test battery was produced in the same manner as in Example 1-1 except that aniline black was used as the black body material when producing the laminate film. When the emissivity of the blackbody material layer using aniline black was measured in the same manner as in Example 1-1, the emissivity was 0.83.

<Comparative Example 1-1>
A test battery was produced in the same manner as in Example 1-1 except that the laminate film was not provided with a black body material layer as described above (basic configuration). In Comparative Example 1-1, since the black body material layer was not provided, when the emissivity was measured for the aluminum metal layer in the same manner as in Example 1-1, the emissivity was 0.83.

<Comparative Example 1-2>
A test battery was produced in the same manner as in Example 1-1, except that carbon black was used as the black body material when the laminate film was produced, and the carbon black content in the black body material layer was 45% by weight. In addition, when the emissivity of the blackbody material layer using the carbon black of Comparative Example 1-2 was measured in the same manner as in Example 1-1, the emissivity was 0.53.

[Battery evaluation]
(A) High temperature storage test About the battery for a test of each such Example and a comparative example, it charged until the voltage reached 4.35V, Then, it mounted in the oven whose environmental temperature is 130 degreeC. And the surface temperature of the battery for a test was measured 30 minutes and 60 minutes after preserve | saved in 130 degreeC environment. The surface temperature of the test battery was measured by pressing a thermocouple against the battery surface.

  Table 1 below shows the results of the above evaluation.

  As can be seen from Table 1, it was found that by providing a layer containing a black body material on the laminate film, the heat dissipation was improved and the surface temperature of the battery after high-temperature storage was hardly increased. Moreover, when Example 1-1 thru | or Example 1-5 were compared with Comparative Example 1-2, when the emissivity became 0.6 or more, it turned out that a especially high effect is acquired.

[Example 2]
In Example 2, the configuration of the laminate film was changed to produce a battery pack, and the battery surface temperature during high temperature storage was measured.

<Example 2-1>
A test battery was produced in the same manner as in Example 1-1.

<Example 2-2>
As shown in (2) above, a laminate film having a configuration of outer layer film / adhesive layer / black body material layer / metal foil / adhesive layer / inner layer film was produced. At this time, a black body material layer was formed on the exterior film side of the metal foil. The black body material layer uses a black body solution in which 70% by weight of carbon black having an average particle diameter D50 = 0.5 μm as a black body material and 30% by weight of an acrylic ester resin are mixed, and one side of the metal foil The black body solution was applied to a thickness of 2.0 μm. Except for this, a test battery was produced in the same manner as in Example 1-1.

<Reference Example 2-3>
As shown in (3) above, a laminate film having a configuration of an outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film in which a black body material was dispersed was produced. At this time, the outer layer film in which the black body material was dispersed was a polyethylene terephthalate (PET) film having a thickness of 30 μm and containing 70% by weight of the black body material.

<Example 2-4>
As shown in (4) above, a laminate film having a configuration of outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film in which a black body material was dispersed was produced. At this time, the adhesive layer in which the black body material was dispersed was a 5 μm thick adhesive layer containing 70% by weight of the black body material.

<Example 2-5>
As shown in the above (5), a laminate film having a configuration of outer layer film / black body material layer / outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film was produced. At this time, a black body material layer was formed on one surface of the outer layer film, and a polyethylene terephthalate (PET) layer having a thickness of 30 μm was formed on the surface of the exterior film on which the black body material layer was formed. Except for this, a test battery was produced in the same manner as in Example 1-1.

<Reference Example 2-6>
As shown in the above (6), a laminate film having a configuration of outer layer film / adhesive layer / metal foil / adhesive layer / black body material layer / inner layer film was produced. At this time, a black body material layer was formed on the metal layer side of the inner layer film. Except for this, a test battery was produced in the same manner as in Example 1-1.

<Reference Example 2-7>
As shown in (7) above, a laminate film having a configuration of outer layer film / adhesive layer / metal foil / black body material layer / adhesive layer / inner layer film was produced. At this time, a black body material layer was formed on the inner film side of the metal foil. Except for this, a test battery was produced in the same manner as in Example 1-1.

<Reference Example 2-8>
As shown in (8) above, a laminate film having a configuration like an inner layer film in which an outer layer film / adhesive layer / metal foil / adhesive layer / black body material was dispersed was produced. At this time, the inner layer film in which the black body material was dispersed was a polypropylene (PP) film having a thickness of 30 μm and containing 70% by weight of the black body material.

<Reference Example 2-9>
As shown in the above (9), a laminate film having a configuration such as an outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film in which a black body material was dispersed was produced. At this time, the adhesive layer in which the black body material was dispersed was a 5 μm thick adhesive layer containing 70% by weight of the black body material.

<Comparative Example 2-1>
Example 1-1, except that the laminate film was not provided with a black body material layer such as an outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film, as shown in the above (basic configuration). A test battery was prepared in the same manner.

[Battery evaluation]
(A) High temperature storage test About the battery for a test of each such Example and a comparative example, it charged until the voltage reached 4.35V, Then, it mounted in the oven whose environmental temperature is 130 degreeC. Then, after storing in a 130 ° C. environment, the surface temperature of the test battery was measured after 5 minutes, 10 minutes, 30 minutes and 60 minutes. The surface temperature of the test battery was measured by pressing a thermocouple against the battery surface.

  Table 2 below shows the results of the above evaluation.

  As can be seen from Table 2, it was found that providing a layer containing a black body material on the laminate film improves the heat dissipation and makes it difficult to increase the surface temperature of the battery after high-temperature storage. In particular, it has been found that when the layer containing the black body material is provided outside the battery with respect to the metal foil of the laminate film, the heat dissipation effect is further enhanced. This is thought to be because the time until the heat dissipated is propagated to the outer surface can be shortened when the layer containing the black body material is present outside the metal foil.

  Further, it is preferable to provide a black body material layer rather than including the black body material in the outer layer film, the inner layer film or the adhesive layer. This is because when the black body material is included in the outer layer film, the inner layer film, or the adhesive layer, it is difficult for the black body material-containing layer to maintain the film characteristics, and the layer characteristics are likely to deteriorate. For example, when it is contained in the adhesive layer, the adhesive effect may be reduced.

  In contrast to the configurations of (3) and (4) in which the black body material is contained in the outer layer film and the adhesive layer, the configurations of (1) and (2) in which the black body material layer is provided are particularly 10 minutes after high temperature storage It was found that particularly high heat dissipation was obtained in the time until later. Moreover, in the structure of (5) which made the outer layer film 2 layers through the black body material layer, a decrease in the heat dissipation effect due to the increase in the thickness of the outer layer film was observed, but the layer containing the black body material was removed from the metal foil. In addition, a higher heat dissipation effect was obtained than the configurations (6) to (9) provided inside.

  In addition, even when the black body material-containing layer was provided on the inner side of the metal foil, a higher heat dissipation effect was obtained when the laminate film having the black body material layer was used.

[Example 3]
In Example 3, a battery pack was produced using a laminate film produced by changing the particle size of the black body material, and the battery surface temperature during high-temperature storage was measured.

<Example 3-1>
A test battery was fabricated in the same manner as in Example 1-1 except that the particle diameter D50 of carbon black, which is a black body material, was 0.1 μm.

<Example 3-2>
A test battery was produced in the same manner as in Example 1-1 except that the particle diameter D50 of carbon black, which is a black body material, was 0.3 μm.

<Example 3-3>
A test battery was prepared in the same manner as in Example 1-1, with the particle size D50 of carbon black, which is a black body material, set to 0.5 μm.

<Example 3-4>
A test battery was produced in the same manner as in Example 1-1 except that the particle size D50 of carbon black, which is a black body material, was changed to 0.75 μm.

<Example 3-5>
A test battery was produced in the same manner as in Example 1-1 except that the particle size D50 of carbon black, which is a black body material, was 1.0 μm.

<Example 3-6>
A test battery was produced in the same manner as in Example 1-1 except that the particle diameter D50 of carbon black, which is a black body material, was 2.0 μm.

<Example 3-7>
A test battery was produced in the same manner as in Example 1-1 except that the particle diameter D50 of carbon black, which is a black body material, was set to 3.0 μm.

<Comparative Example 3-1>
A test battery was produced in the same manner as in Example 1-1 except that the laminate film was not provided with a black body material layer as described above (basic configuration).

[Battery evaluation]
(A) High temperature storage test About the battery for a test of each such Example and a comparative example, it charged until the voltage reached 4.35V, Then, it mounted in the oven whose environmental temperature is 130 degreeC. And the surface temperature of the battery for a test was measured 30 minutes and 60 minutes after preserve | saved in 130 degreeC environment. The surface temperature of the test battery was measured by pressing a thermocouple against the battery surface.

  Table 3 below shows the results of the above evaluation.

  As can be seen from Table 3, in Examples 3-1 to 3-7 provided with the black body material layer, the heat dissipation effect is higher as the particle diameter of the black body material is smaller, and the heat dissipation effect is obtained as the particle diameter is larger. I found it difficult. Further, as the particle size of the black body material is larger, it is necessary to increase the thickness in order to obtain the stability of the black body material layer, and the volume efficiency of the battery pack may be reduced.

[Example 4]
In Example 4, the heat dissipation effect of the battery pack was confirmed by changing the thickness of the inner layer film of the laminate film.

<Example 4-1>
Similarly to Example 1-1, a test battery was fabricated with the inner layer film having a thickness of 30 μm.

<Example 4-2>
A test battery was produced in the same manner as in Example 1-1 except that the thickness of the inner layer film was 40 μm.

<Example 4-3>
Similarly to Example 1-1, a test battery was fabricated with the inner layer film having a thickness of 50 μm.

<Example 4-4>
Similarly to Example 1-1, a test battery was fabricated with the inner layer film having a thickness of 60 μm.

<Example 4-5>
Similarly to Example 1-1, a test battery was manufactured with the inner layer film having a thickness of 75 μm.

<Example 4-6>
Similarly to Example 1-1, a test battery was manufactured with the inner layer film having a thickness of 100 μm.

<Comparative Example 4-1>
A test battery was produced in the same manner as in Example 1-1 except that the laminate film was not provided with a black body material layer as described above (basic configuration).

[Battery evaluation]
(A) High temperature storage test About the battery for a test of each such Example and a comparative example, it charged until the voltage reached 4.35V, Then, it mounted in the oven whose environmental temperature is 130 degreeC. And the surface temperature of the battery for a test was measured 30 minutes and 60 minutes after preserve | saved in 130 degreeC environment. The surface temperature of the test battery was measured by pressing a thermocouple against the battery surface.

  Table 4 below shows the results of the above evaluation.

  As can be seen from Table 4, Example 4-1 using a laminate film provided with a black body material layer is Comparative Example 4 using a laminate film having no black body material layer having the same inner layer film thickness. Compared with 1, a high heat dissipation effect was obtained. Moreover, when a black body material layer was provided and the inner layer film was changed, it was found that the thinner the inner layer film, the higher the heat dissipation effect. It was found that when the inner layer film was thick, the heat conduction from the battery element was delayed, and the heat generated in the battery element was not sufficiently dissipated.

[Example 5]
In Example 5, the surface color of the laminate film was changed depending on the presence or absence of the black body material layer, and the pinhole detection system was confirmed.

<Example 5-1>
As shown in (1) above, the laminate film was composed of an outer layer film / black body material layer / adhesive layer / metal foil / adhesive layer / inner layer film.

<Comparative Example 5-1>
As shown in the above (basic configuration), the configuration of the laminate film was an outer layer film / adhesive layer / metal foil / adhesive layer / inner layer film.

(B) Confirmation of pinhole detection limit diameter Pinholes were formed in the laminate films of Examples and Comparative Examples, light was irradiated from the inner layer film side, and pinholes were confirmed visually from the outer layer film side. The diameter of the pinhole was reduced in order, and the detection limit diameter at which the pinhole could not be visually confirmed from the outer layer film side was confirmed by the above-described method.

  Table 5 below shows the results of the above evaluation.

  As can be seen from Example 5, in Example 5-1, in which the surface color was black due to the black body material layer, the detection limit diameter of the pinhole was 0.275 mm, and the surface color was silver in Comparative Example 5-1. It was confirmed that the pinhole was sufficiently small with respect to the pinhole detection limit diameter of 0.450 mm.

  As described above, by providing the black body material layer on the outer side of the metal layer, the surface of the battery pack was made black, and the detection accuracy of pinholes, cracks, etc. could be improved.

  The present invention has been described with reference to the embodiments and examples. However, the present invention is not limited to the above-described embodiments and examples, and various modifications can be made. For example, the materials and numerical values used for the battery element and the laminate film are examples, and different materials and numerical values may be used.

  In addition, a configuration other than that shown in the present invention can also be used for a laminate film having a layer containing a black body material.

DESCRIPTION OF SYMBOLS 10 ... Battery element 11 ... Positive electrode 11A ... Positive electrode collector 11B ... Positive electrode active material layer 12 ... Negative electrode 12A ... Negative electrode collector 12B ... Negative electrode active material layer 13. ..Separator 14 ... electrolyte 15A ... positive electrode terminal 15B ... negative electrode terminal 16 ... adhesion member 17 ... laminate film 18 ... battery element housing part 19 ... protective tape 20,30 ..Non-aqueous electrolyte battery 25a ... Top cover 25b ... Bottom cover 26 ... Hard laminate film 27 ... Soft laminate film 29 ... Adhesive film 34 ... Protection circuit 40 ... Battery pack

Claims (32)

A battery exterior material,
A first layer;
A black material layer containing a black body material;
With a metal layer,
The black material layer has a color different from that of the metal layer, and is provided between the first layer and the metal layer.   The exterior material according to claim 1, wherein the emissivity of the black body material is 0.6 or more.   The exterior material according to claim 1 or 2, wherein the black material layer further contains a resin.   The exterior material according to any one of claims 1 to 3, wherein the black body material includes at least one of a carbon material, a silicate material, and a metal oxide material. The average particle size of the black body material is 1.0 μm or less,
The exterior material according to claim 1, wherein the black material layer has a thickness of 1 μm or more and 5 μm or less.   The packaging material according to claim 5, wherein the black body material has an average particle size of 0.5 μm or less.   The exterior material according to any one of claims 1 to 6, wherein a content of the black body material in the black material layer is 60 wt% or more and 80 wt% or less.   The exterior material according to any one of claims 1 to 7, wherein the black material layer has a CMY value in which C (cyan), M (magenta), and Y (yellow) are each 70 or more.   The exterior material according to any one of claims 1 to 8, wherein the first layer includes an outer layer.   The non-aqueous electrolyte battery according to claim 9, wherein the outer layer includes at least one of nylon, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate.   The exterior material according to any one of claims 1 to 10, further comprising an adhesive layer between the black material layer and the metal layer.   The packaging material according to any one of claims 1 to 11, further comprising an inner layer having a thickness of 10 µm or more and 50 µm or less.   The packaging material according to any one of claims 1 to 12, wherein the metal layer includes at least one of aluminum, stainless steel, titanium, copper, and iron plated with any of tin, zinc, and nickel.   The packaging material according to claim 1, wherein the metal layer has a thickness of 50 μm or more and 150 μm or less.   The packaging material according to any one of claims 1 to 14, further comprising a second layer.   The exterior material according to claim 15, wherein the second layer is provided between the metal layer and the black material layer.   The exterior material according to claim 15, wherein the second layer is provided between the first layer and the black material layer.   The packaging material according to any one of claims 1 to 10, wherein the black material layer and the metal layer are in direct contact with each other. A battery element;
An exterior material for packaging the battery element,
The exterior material is
A first layer;
A black material layer containing a black body material;
With a metal layer,
The battery, wherein the black material layer has a color different from that of the metal layer and is provided between the first layer and the metal layer.   The battery according to claim 19, wherein the emissivity of the black body material is 0.6 or more.   The battery according to claim 19 or 20, wherein the black material layer further contains a resin.   The battery according to any one of claims 19 to 21, wherein the black body material includes at least one of a carbon material, a silicate material, and a metal oxide material. The average particle size of the black body material is 1.0 μm or less,
The battery according to any one of claims 19 to 22, wherein the black material layer has a thickness of 1 µm to 5 µm.   The battery according to any one of claims 19 to 23, wherein the black material layer has a CMY value in which C (cyan), M (magenta), and Y (yellow) are each 70 or more.   The battery according to any one of claims 19 to 24, wherein the first layer includes an outer layer.   The battery according to claim 25, wherein the outer layer includes at least one of nylon, polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate.   27. The battery according to claim 19, wherein the metal layer includes at least one of aluminum, stainless steel, titanium, copper, and iron plated with tin, zinc, or nickel.   The battery according to any one of claims 19 to 27, further comprising an inner layer having a thickness of 10 µm to 50 µm.   The battery according to any one of claims 19 to 28, further comprising a second layer.   30. The battery according to claim 29, wherein the second layer is provided between the metal layer and the black material layer.   30. The battery according to claim 29, wherein the second layer is provided between the first layer and the black material layer.   The battery according to any one of claims 19 to 31, wherein the black material layer and the metal layer are in direct contact with each other.

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