JP2011048990A - Nonaqueous electrolyte battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a nonaqueous electrolyte having an excellent battery performance by improving the impregnating, liquid-retaining, and adhesion properties of a gel electrolyte with respect to an active material layer. <P>SOLUTION: In a nonaqueous electrolyte battery, the negative electrode includes a negative electrode active material and a negative active binder agent containing a two-component copolymer composed of vinylidene fluoride and monomethyl-maleic-acid ester, the copolymerization quantity of the monomethyl-maleic-acid ester in the two-component copolymer being 0.3 wt.% or more and 2 wt.% or less; the electrolyte includes an electrolytic solution and a high molecular compound containing a three-component copolymer composed of vinylidene fluoride, hexafluoropropylene, and monomethyl-maleic-acid ester, the copolymerization quantities of the hexafluoropropylene and monomethyl-maleic-acid ester in the three-component copolymer being 8 wt.% or more and 15 wt.% or lower and 0.3 wt.% or more and 2 wt.% or less, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to, for example, a non-aqueous electrolyte battery, and more particularly to a non-aqueous electrolyte battery that is packaged with a laminate film and has good sealing properties.

  In recent years, portable electronic devices such as a camera-integrated VTR (video tape recorder), a mobile phone, or a laptop computer have been widely used, and there is a strong demand for miniaturization, weight reduction, and long life. Accordingly, as a power source for portable electronic devices, development of a battery, in particular, a secondary battery that is lightweight and can obtain a high energy density and a high output density is in progress.

  As such secondary batteries, for example, lithium ion secondary batteries as described in Patent Documents 1 to 6 below are widely used. A lithium ion secondary battery has a structure in which a positive electrode and a negative electrode are stacked or wound via a resin thin film separator as a diaphragm, and contains an electrolyte composed of an electrolyte salt and a nonaqueous solvent.

The positive electrode is formed by forming an active material layer containing a positive electrode active material on the surface of a positive electrode current collector made of, for example, aluminum (Al) foil. For the positive electrode active material layer, for example, in addition to lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, graphite as a conductive agent, polyvinylidene fluoride (PVdF) as a binder, polytetrafluoroethylene (PTFE) Contains binders.

  The negative electrode is formed by forming an active material layer containing a negative electrode active material on the surface of a negative electrode current collector made of, for example, copper (Cu) foil. In the negative electrode active material layer, for example, non-crystalline carbon, coke, graphite, etc. as a negative electrode active material, binders such as polyvinylidene fluoride (PVdF), polyacrylonitrile, styrene butadiene rubber (SBR) as a binder are used. Contains a dressing.

  As the electrolyte, a liquid electrolyte is widely used. This type of electrolyte is generally called an “electrolytic solution” and includes a solvent and an electrolyte salt. As this electrolytic solution, an organic electrolyte such as a propylene carbonate solution is known in addition to an inorganic electrolyte such as a sulfuric acid aqueous solution of a lead battery or a potassium hydroxide aqueous solution of a dry battery. The electrolytic solution is an ionic liquid having a high salt concentration, and may exhibit strong acidity or strong alkalinity depending on the specification or use of the battery, or may be a non-aqueous solution. For this reason, in a battery including an electrolytic solution, if the electrolytic solution leaks, there is a possibility that an electric circuit or the like is corroded or a resin component is dissolved. Therefore, in order to use the battery stably, it is important to prevent leakage of the electrolytic solution.

  Further, as described in Patent Document 7 below, a polymer lithium ion secondary battery using a gel electrolyte obtained by gelling an electrolytic solution with a polymer (matrix polymer) has been put into practical use. As the matrix polymer, polyvinylidene fluoride (PVdF), polyacrylonitrile (PAN), polyethylene oxide (PEO) or the like is used. By using the gel electrolyte, the gel electrolyte is fixed inside the electrode and between the electrode and the separator, and also has an effect of fixing the position of the battery member. The polymer lithium ion secondary battery is highly reliable with no electrolyte leakage. Moreover, since an aluminum laminate film can be used as an exterior material, it is lightweight, and a thin large-area battery that is difficult to process with a metal can exterior can also be made.

  In order to form a gel electrolyte inside the battery, a sol that is in a polymer solution state is applied or injected, and the gel is cooled or evaporated to form a gel, and a monomer and a polymerization initiator are mixed. There exists the method of making it melt | dissolve in electrolyte solution and superposing | polymerizing inside a battery and gelatinizing. In addition, there is a method in which a gel containing an appropriate solvent is once prepared, and then the solvent is extracted to form a xerogel and the electrolyte is injected to form a gel. Among them, the method of applying a sol on an electrode to form a coating film is an excellent method because an electrolyte layer having a certain thickness can be formed on the electrode.

JP-A-8-315817 Japanese Examined Patent Publication No. 7-70319 JP 2003-282061 A JP 2003-317722 A Japanese Patent No. 2548460 JP 2003-132893 A JP 2001-167797 A

The electrochemical energy of the battery is stored in a material called an active material. As described above, a carbon material such as graphite is used as the negative electrode active material, and lithium cobaltate (LiCoO ₂ ) or lithium nickelate is used as the positive electrode active material. A lithium transition metal oxide such as (LiNiO ₂ ) is used. When forming the electrode, if the active material layer is formed thick on the metal current collector, the volume of the metal current collector, separator, or the like that is not directly related to the battery capacity can be relatively reduced. That is, by using an electrode having a thick active material layer, a battery having a high energy density and a long duration can be provided.

  The gel electrolyte as described above is formed on the surface of the active material layer by coating, but the electrolyte needs to be present in the vicinity of the active material particles. Since the electrode of the non-aqueous electrolyte battery has active material particles of 5 to 30 μm applied to the current collector with a binder, the active material layer has a porous structure. In order to obtain a good battery reaction, the electrolyte needs to sufficiently permeate into the active material layer having a porous structure. However, since the sol before gelation of the electrolyte is a polymer solution, the viscosity is high, and there is a problem that even if it is applied to the active material layer having a porous structure, it is difficult to impregnate the inside. If the electrolytic solution does not impregnate the active material layer, the battery reaction does not proceed.

  In particular, in the negative electrode, if the electrolyte impregnation into the negative electrode active material layer is insufficient, metallic lithium is deposited during charging. Since the deposited metal lithium does not contribute to the charge / discharge reaction, the deposited metal lithium increases as the charge / discharge progresses, and the battery capacity is impaired by the amount of the deposited metal lithium.

  In Japanese Patent No. 4163295, a proposal has been made to increase the affinity between polyvinylidene fluoride (PVdF) as an electrolyte and polyvinylidene fluoride as a binder for an active material layer as a copolymer with another polymer. For example, a copolymer of polyvinylidene fluoride and hexafluoropropylene (HFP) is used as the matrix polymer. However, in this case, if the copolymerization ratio of hexafluoropropylene becomes too large, the matrix polymer is only dissolved in the electrolytic solution and does not become a semi-solid gel electrolyte. In addition, in the binder of the active material layer, if the copolymerization ratio of the copolymer such as hexafluoroprepylene becomes too large, the binder swells with the electrolytic solution, so that the negative electrode active material layer is separated from the current collector. It will come off.

  Accordingly, the present invention has been made in view of such problems, and the object thereof is to improve the battery performance by improving the impregnation property, liquid retention property and adhesion property of the gel electrolyte to the active material layer. Is to provide a simple battery.

In order to solve the problem, the present invention comprises a positive electrode,
A negative electrode active material, and a negative electrode binder containing a two-component copolymer composed of vinylidene fluoride and monomethylmaleate as components,
A negative electrode in which the copolymerization amount of monomethylmaleic acid ester in the two-component copolymer is in the range of 0.3 wt% to 2 wt%
An electrolytic solution and a polymer compound containing a ternary copolymer containing vinylidene fluoride, hexafluoropropylene and monomethylmaleic acid ester as components,
The copolymerization amount of hexafluoropropylene and monomethylmaleic acid ester in the ternary copolymer is in the range of 8% by weight to 15% by weight and in the range of 0.3% by weight to 2% by weight, respectively. A non-aqueous electrolyte battery comprising an electrolyte in which the weight average molecular weight of the ternary copolymer is in the range of 600,000 to 1,500,000.

  In the present invention, the solvent includes, for example, two or more members selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate and diethyl carbonate, and the electrolyte salt includes, for example, lithium hexafluorophosphate, tetrafluoride It preferably contains at least one member selected from the group consisting of lithium borate, bis (trifluoromethanesulfonyl) imide lithium and bis (pentafluoroethanesulfonyl) imide lithium.

  In the present invention, a stable electrolyte layer is formed, and the adhesion between the negative electrode active material layer and the electrolyte layer, and the negative electrode current collector and the negative electrode active material layer is improved.

  According to this invention, the gel electrolyte layer and the negative electrode active material layer can be formed satisfactorily and high cycle characteristics can be obtained.

It is a perspective view which shows one structural example of the nonaqueous electrolyte battery by embodiment of this invention. It is sectional drawing along the II-II line of the battery element 10 shown in FIG.

Hereinafter, the best mode for carrying out the invention (hereinafter referred to as an embodiment) will be described. The description will be made as follows.
1. 1st Embodiment (example which seals electrode terminal derivation | leading-out part in two steps)

<1. First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

(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 non-aqueous electrolyte battery 20 is produced by housing the battery element 10 in a battery element housing portion 17A, which is a recess formed in the laminate film 17, and sealing the periphery of the battery element 10. . 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. Between the positive electrode terminal 15A and the negative electrode terminal 15B and the laminate film 17 that covers the battery element 10 as an exterior member, a sealant 16 that is a sealing member for improving adhesiveness is disposed. As the sealant 16, for example, a resin film made of polypropylene (PP) or the like can be used. Moreover, you may use the resin film which consists of a modified resin material with high adhesiveness with the electrode terminal which consists of metals. Moreover, you may make it provide the insulating member 19 in the positive electrode 11 and the negative electrode 12 as needed.

  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.

  The negative electrode binder contains a two-component copolymer containing vinylidene fluoride (VdF) and monomethylmaleic acid ester (MMM) as components. In particular, the copolymerization amount of monomethyl maleate in the two-component copolymer is in the range of 0.3 wt% to 2.0 wt%, preferably in the range of 0.4 wt% to 2.0 wt%. The inside is preferable. When the copolymerization ratio of monomethyl maleate is low, the affinity between the electrolyte layer 14 and the negative electrode active material layer 12A is lacking, and the adhesion between the electrolyte layer 14 and the negative electrode active material layer 12A decreases. On the other hand, if the copolymerization ratio of monomethyl maleate is too large, the negative electrode active material layer 12A swells and peels off from the negative electrode current collector 12B.

  As will be described later, the electrolyte layer 14 of the nonaqueous electrolyte battery 20 of the present invention contains vinylidene fluoride as one component. By including vinylidene fluoride as a component in the negative electrode active material layer 14 </ b> A, the adhesion of the electrolyte layer 14 to the negative electrode 12 is improved. Similarly, the electrolyte layer 14 contains monomethyl maleate as a component. By including monomethyl maleate as a component in the negative electrode active material layer 14A, the adhesion of the negative electrode 12 to the electrolyte layer 14 is stabilized, and the adhesion of the negative electrode active material layer 12B to the negative electrode current collector 12A is improved. improves. The content of the negative electrode binder in the negative electrode active material layer 12B is not particularly limited, but is, for example, in the range of 2 wt% to 10 wt%. In addition, the negative electrode binder may contain other 1 type, or 2 or more types of polymers and copolymers with the two-component copolymer mentioned above, for example.

  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.

  The electrolyte layer 14 is a so-called gel electrolyte containing an electrolytic solution and a matrix polymer that is a polymer compound that holds the electrolytic solution. The gel electrolyte is preferable because high ion conductivity (for example, 1 mS / cm or more at room temperature) is obtained and leakage of the electrolytic solution is prevented. For example, the electrolyte layer 14 is provided between the positive electrode 11 and the separator 13 and between the negative electrode 12 and the separator 13.

  The polymer compound contains a ternary copolymer containing vinylidene fluoride (VdF), hexafluoropropylene (HFP) and monomethylmaleic acid ester (MMM) as components. In particular, the copolymerization amount of hexafluoropropylene in the ternary copolymer is in the range of 8% by weight to 15% by weight. In addition, the copolymerization amount of monomethylmaleic acid ester in the ternary copolymer is within the range of 0.3 wt% to 2.0 wt%, preferably 0.4 wt% to 1.8 wt%. Within range. This is because the liquid retention and adhesion of the electrolyte layer 14 are improved by the combination and composition of the three components, so that excellent battery capacity, cycle characteristics, and load characteristics can be obtained.

  Specifically, when the copolymerization amount is smaller than the lower limit described above, the state (gel state) of the electrolyte layer 14 becomes unstable due to a decrease in liquid retention. Moreover, even if the electrolyte layer 14 itself is stable, the affinity / adhesiveness between the electrolyte layer 14 and the negative electrode active material layer 12B is lacking. As a result, the battery capacity is reduced, and the cycle characteristics and load characteristics are reduced due to the deposition of lithium metal during charging and discharging. On the other hand, if the copolymerization amount is larger than the above-described upper limit, the electrolyte layer 14 is not gelled and becomes a high-viscosity polymer solution state. Thereby, since the adhesiveness of the electrolyte layer 14 falls, cycling characteristics and load characteristics fall. The copolymerization amount of vinylidene fluoride in the ternary copolymer can be appropriately set according to the copolymerization amount of hexafluoropropylene and monomethylmaleic acid ester.

  The weight average molecular weight of the ternary copolymer is in the range of 600,000 to 1,500,000, preferably 700,000 to 1,400,000. This is because the liquid retention of the electrolyte layer 14 is improved, and the adhesion of the electrolyte layer 14 to the positive electrode 11, the negative electrode 12, and the separator 13 is improved. More specifically, when the weight average molecular weight is less than 600,000, the electrolyte layer 14 does not gel and becomes a sherbet shape, so that the liquid retaining property decreases. On the other hand, when the weight average molecular weight is larger than 1,500,000, the viscosity of the electrolyte layer 14 becomes too high, so that the adhesion is lowered.

  The content of the polymer compound in the electrolyte layer 14 varies depending on, for example, the compatibility between the two and the molecular weight of the polymer compound, but is in the range of 6.0 wt% to 20 wt%, and preferably 8.0. It is in the range of not less than 12% by weight. When there is too little content, the retainability of the electrolyte solution as a gel may become inadequate. On the other hand, if the content is too large, the volume of the liquid portion in the electrolyte layer 14 is decreased, which may reduce the ionic conductivity.

  The polymer compound may contain, for example, one or two or more other polymers and copolymers together with the above-described ternary copolymer.

  The electrolytic solution contains a nonaqueous solvent and an electrolyte salt. Examples of the non-aqueous solvent include ethylene carbonate, propylene carbonate, butylene carbonate, 1,3-dioxol-2-one, dimethyl carbonate, ethyl methyl carbonate, diethyl carbonate, methyl propyl carbonate, 繃 -butyrolactone, 繃 -valerolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, 1,3-dioxane, 1,4-dioxane, methyl acetate, ethyl acetate , Methyl propionate, ethyl propionate, methyl butyrate, methyl isobutyrate, methyl trimethyl acetate, ethyl trimethyl acetate, acetonitrile, glutaronitrile, adiponitrile, methoxyacetonitrile, 3-methoxypropionitrile, N, N-dimethylformami , N- methylpyrrolidinone, N- methyl-oxazolidinone, N, N'-dimethylimidazolidinone, nitromethane, nitroethane, sulfolane or dimethyl sulfoxide phosphate is used. This is because excellent battery capacity, cycle characteristics and load characteristics can be obtained. These may be used alone or in combination of two or more.

  Especially, it is preferable that a solvent is 2 or more types in the group which consists of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate. This is because the dissociation property of the electrolyte salt and the ion mobility are improved, so that a higher effect can be obtained. Examples of the solvent combination in this case include a binary mixed solvent composed of ethylene carbonate and propylene carbonate, a ternary mixed solvent composed of ethylene carbonate, propylene carbonate and ethyl methyl carbonate, or ethylene carbonate, propylene carbonate and ethyl carbonate. Examples thereof include a ternary mixed solvent composed of methyl, dimethyl carbonate and diethyl carbonate. The solvent may contain a fluorinated carbonate represented by fluorinated ethylene carbonate or fluorinated propylene carbonate.

The electrolyte salt includes, for example, a light metal salt such as a lithium salt. Examples of the lithium salt include lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium perchlorate (LiClO ₄ ), lithium hexafluoroarsenate (LiAsF ₆ ), lithium tetraphenylborate _{(LiB (C 6 H 5)} 4), methanesulfonic acid lithium (LiCH ₃ SO _3), lithium trifluoromethanesulfonate (LiCF ₃ SO _3), tetrachloroaluminate lithium (LiAlCl _4), six Lithium fluorosilicate (Li ₂ SiF ₆ ), lithium chloride (LiCl), lithium bromide (LiBr), bis (trifluoromethanesulfonyl) imide lithium (LiN (CF ₃ SO ₂ ) ₂ ), bis (pentafluoroethanesulfonyl) ) imide _{(LiN (C 2 F 5 SO} 2) 2), 1,2- perfluoro Tanji sulfonyl imide, 1,3-perfluoropropanedisulfonylimide lithium or tris (trifluoromethanesulfonyl) Mechidorichiumu _{(LiC (CF 3 SO 2)} 3) , and the like. This is because excellent battery capacity, cycle characteristics and load characteristics can be obtained. These may be used alone or in combination of two or more. Among them, the electrolyte salt includes at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (trifluoromethanesulfonyl) imide and lithium bis (pentafluoroethanesulfonyl) imide. It is preferable. This is because a higher effect can be obtained because the internal resistance is lowered.

  The concentration of the electrolyte salt in the electrolytic solution is in the range of 0.8 mol / kg or more and 1.2 mol / kg or less. This is because the number of ions involved in charge transport is ensured, so that an excellent battery capacity can be obtained. Specifically, when the concentration is lower than 0.8 mol / kg, the absolute number of ions involved in charge transport decreases, and the ionic conductivity decreases. For this reason, when the overvoltage is applied to the interface between the positive electrode active material layer 11B and the negative electrode active material layer 12B and the electrolyte layer 14, the side reaction is increased. On the other hand, when the concentration is higher than 1.2 mol / kg, the dissociation property of the electrolyte salt is lowered, so that the number of ions involved in charge transport is substantially reduced. Moreover, since electrolyte salt increases and the viscosity of electrolyte solution becomes high, ionic conductivity falls by the mobility of ion falling. Moreover, since the interaction between the electrolyte salt and the solvent becomes larger than the interaction between the polymer compound and the solvent, the liquid retention of the gel electrolyte layer 14 is lowered.

  The reason why the concentration of the electrolyte salt is preferably 1.2 mol / kg or less is also due to the following reason. That is, the electrolyte salt reacts with moisture to generate hydrogen fluoride (HF). This phenomenon is affected by moisture content, salt concentration, temperature, and the like. Generation of hydrogen fluoride causes harmful effects such as gas generation and acid corrosion. Since the generation amount of hydrogen fluoride increases when the salt concentration is high, the upper limit of the salt concentration is 1.2 mol / kg in order to prevent adverse effects on the battery characteristics due to the generation of hydrogen fluoride. Is preferred.

[Laminate film]
The laminate film 17 has a resin layer provided on both surfaces of a metal foil. As the laminate film 17, for example, a nylon film as a protective layer, an aluminum foil as a metal layer, and a polyethylene film as a heat fusion layer are laminated in this order. The nonaqueous electrolyte battery 20 has a structure in which, for example, a polyethylene film faces the battery element 10 and outer edges of two rectangular aluminum laminate films are bonded to each other by fusion or an adhesive. .

  Note that the laminate film 17 may be formed of a laminate film having another laminated structure instead of the above-described aluminum laminate film. For example, the protective layer requires aesthetic appearance, toughness, flexibility, and the like, such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), polybutylene naphthalate (PBN), etc. Can also be used. The heat-fusible layer is a part that is melted by heat or ultrasonic waves and is fused to each other, and is a part that is melted by heat or ultrasonic waves and is fused to each other. Etc. can be used. It is also possible to select and use a plurality of types from these. As the polyethylene, low density polyethylene (LDPE), high density polyethylene (HDPE), and linear low density polyethylene (LLDPE) can be used.

  An adhesive film 17 is inserted between the laminate film 17 and the positive electrode terminal 15A and the negative electrode terminal 15B in order to prevent intrusion of outside air. The adhesion film 17 is made of a material having adhesion to the positive terminal 15A and the negative terminal 15B. Examples of this type of material include polyolefin resins such as polyethylene (PE), polypropylene (PP), modified polyethylene, and modified polypropylene.

[Method for producing non-aqueous electrolyte battery]
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-methylpyrrolidone 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]
The 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 18. Thereby, the battery element 10 is formed. Subsequently, for example, after the battery element 10 is sandwiched between two film-like laminate films 17, the battery elements 10 are encapsulated by bonding the outer edges of the laminate film 17 by heat fusion or the like. At that time, the adhesion film 17 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.

In the nonaqueous electrolyte battery 20, when charged, for example, lithium ions are extracted from the positive electrode 11 and inserted into the negative electrode 12 through the electrolyte layer 14. On the other hand, when discharging is performed, for example, lithium ions are released from the negative electrode 12 and inserted into the positive electrode 11 via the electrolyte layer 14.

  In the nonaqueous electrolyte battery 20, the following actions are obtained based on the type and composition of the polymer compound and the type and composition of the negative electrode binder.

  First, the polymer compound in the electrolyte layer 14 contains a ternary copolymer having vinylidene fluoride, hexafluoropropylene and monomethylmaleic acid ester as components, and the hexafluoropropylene in the ternary copolymer and Since the copolymerization amount of monomethylmaleic acid ester is in the range of 8% by weight or more and 15% by weight or less and in the range of 0.3% by weight or more and 2% by weight or less, the copolymerization amount satisfies the above range conditions. The state (gel state) of the electrolyte layer 14 is stabilized even when the concentration of the electrolyte salt is increased as compared with the case where it is not satisfied. Thereby, since the liquid retention property of the electrolyte layer 14 improves, the adhesiveness of the electrolyte layer 14 with respect to the positive electrode 11, the negative electrode 12, and the separator 13 also improves.

  Secondly, since the weight average molecular weight of the above-mentioned ternary copolymer is in the range of 600,000 to 1,500,000, compared with the case where the weight average molecular weight does not satisfy the above-mentioned range conditions, The state (gel state) of the electrolyte layer 14 is stabilized.

  Third, since the concentration of the electrolyte salt in the electrolytic solution is in the range of 0.8 mol / kg or more and 1.7 mol / kg or less, the charge transport is compared with the case where the concentration does not satisfy the above-described range condition. The number of ions involved in is secured.

  Fourthly, when the polymer compound in the electrolyte layer 14 contains a ternary copolymer containing vinylidene fluoride as a component, the positive electrode binder in the positive electrode 11 is a resin containing vinylidene fluoride as a component. Since the coalescence is contained, the adhesion of the electrolyte layer 14 to the cathode 11 is improved as compared with the case where the cathode binder does not contain a polymer containing vinylidene fluoride as a component.

  In this case, the negative electrode binder in the negative electrode 12 contains a two-component copolymer, and the copolymerization amount of monomethyl maleate in the two-component copolymer is 0.3 wt% or more and 2 wt% or less. Is within the range. For this reason, even if the negative electrode binder does not contain the above-mentioned two-component copolymer, or even if it contains a two-component copolymer, the copolymerization amount of monomethylmaleic acid ester satisfies the above-mentioned range condition. Compared with the case where it does not satisfy | fill, while the adhesiveness of the electrolyte layer 14 with respect to the negative electrode 12 improves, the adhesiveness is stabilized. Thereby, even if the laminate film 17 has a defect such as a tear, the electrolytic solution is less likely to leak. Therefore, battery capacity, cycle characteristics, load characteristics, and the like are improved, so that excellent battery performance can be obtained.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these examples.

<Sample 1>
[Production of positive electrode]
Lithium cobaltate (LiCoO ₂ ) as a positive electrode active material, graphite as a conductive agent, and polyvinylidene fluoride as a binder are mixed in a weight ratio of 91: 6: 3, and N-methyl-2 as a solvent. -Dispersed in pyrrolidone to obtain a positive electrode mixture slurry. Here, a homopolymer was used as vinylidene fluoride. Subsequently, this positive electrode mixture slurry was uniformly applied onto an aluminum foil current collector having a thickness of 20 μm, dried, and compression-molded with a roll press to form a positive electrode active material layer, and then cut into a required size. Thus, a positive electrode was produced. Finally, an aluminum positive electrode terminal was attached to one end of the positive electrode current collector.

[Production of negative electrode]
Artificial graphite as a negative electrode active material, vapor-grown carbon fiber as a conductive agent, and a binder are mixed at a weight ratio of 94: 1: 5 and dispersed in N-methyl-2-pyrrolidone as a solvent. A negative electrode mixture slurry was obtained. As the binder, polyvinylidene fluoride (PVdF) obtained by copolymerizing 1% by weight of monomethyl maleate (MMM) was used. As artificial graphite used for the negative electrode active material, mesophase carbon micro beads having an average particle diameter of 20 μm were used.

  Subsequently, the negative electrode mixture slurry was uniformly applied onto a 15 μm thick copper foil current collector, dried, and compression-molded with a roll press to form a negative electrode active material layer, which was then cut into a required size. Thus, a negative electrode was produced. Finally, a nickel negative electrode terminal was attached to one end of the negative electrode current collector.

[Gel electrolyte]
As a mixed solvent used for the electrolytic solution, a mixture of ethylene carbonate (EC) and propylene carbonate (PC) so as to have a weight ratio of EC: PC = 4: 6 was used. Further, as the electrolyte salt, lithium hexafluorophosphate (LiPF ₆ ) was used and mixed with the mixed solvent so that the molar concentration was 1.0 mol / kg to obtain an electrolytic solution.

  As the matrix polymer in which the electrolyte solution is dispersed, a ternary copolymer having vinylidene fluoride (VdF), hexafluoropropylene (HFP), and monomethylmaleic acid ester (MMM) as components is used. The ternary copolymer contains 1% by weight of monomethylmaleic acid ester (MMM) and 7% by weight of hexafluoropropylene (HFP) with respect to vinylidene fluoride (VdF), and has a number average molecular weight of 700,000. is there.

  A matrix polymer composed of the above-mentioned ternary copolymer, the electrolytic solution, and the diluent solvent were mixed at a weight ratio of 1:10:10 to prepare a sol electrolyte. Dimethyl carbonate (DMC) was used as a dilution solvent. After applying this sol electrolyte 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 electrode.

[Assembly of non-aqueous electrolyte battery]
The positive electrode and the negative electrode on which the gel electrolyte layer was formed as described above were laminated via a porous polyethylene separator having a thickness of 12 μm and wound to produce a flat battery element. This battery element was inserted into an exterior using an aluminum laminate film, and the periphery of the battery element was sealed. The aluminum laminate film is obtained by bonding a nylon film having a thickness of 30 μm as an exterior layer to both surfaces of an aluminum foil and a crystalline polypropylene film having a thickness of 30 μm as a heat sealing layer. The battery element is housed in a recess formed in an aluminum laminate film and packaged, and the sides around the battery element are bonded together by heat sealing under vacuum and vacuum sealed. The aluminum laminate film is pressed at atmospheric pressure and has a slack exterior. A resin piece that adheres well to a metal such as an ionomer was adhered to a portion where the electrode terminal of the battery was taken out, and a non-aqueous electrolyte battery was fabricated so as to increase the airtightness.

<Sample 2>
A non-aqueous electrolyte battery was produced in the same manner as Sample 1 except that the content of hexafluoropropylene (HFP), which is a ternary copolymer used in the gel electrolyte layer, was 8% by weight.

<Sample 3>
A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of hexafluoropropylene (HFP), which is a ternary copolymer used in the gel electrolyte layer, was 10% by weight.

<Sample 4>
A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of hexafluoropropylene (HFP), which is a ternary copolymer used for the gel electrolyte layer, was 15% by weight.

<Sample 5>
A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of hexafluoropropylene (HFP), which is a ternary copolymer used in the gel electrolyte layer, was 18% by weight.

<Sample 6>
Sample 1 except that the content of hexafluoropropylene (HFP) in the ternary copolymer used in the gel electrolyte layer is 10% by weight and the content of monomethylmaleic acid ester (MMM) is 0.1% by weight. A nonaqueous electrolyte battery was produced in the same manner as described above.

<Sample 7>
Sample 1 except that the content of hexafluoropropylene (HFP) in the ternary copolymer used in the gel electrolyte layer is 10% by weight and the content of monomethylmaleate (MMM) is 0.3% by weight. A nonaqueous electrolyte battery was produced in the same manner as described above.

<Sample 8>
Same as Sample 1 except that the content of hexafluoropropylene (HFP) of the ternary copolymer used in the gel electrolyte layer is 10 wt% and the content of monomethyl maleate (MMM) is 2 wt%. Thus, a non-aqueous electrolyte battery was produced.

<Sample 9>
Sample 1 except that the content of hexafluoropropylene (HFP) of the ternary copolymer used in the gel electrolyte layer is 10% by weight and the content of monomethyl maleate (MMM) is 2.5% by weight. A nonaqueous electrolyte battery was produced in the same manner as described above.

<Sample 10>
The content of hexafluoropropylene (HFP) in the ternary copolymer used for the gel electrolyte layer is 10% by weight. In addition, a nonaqueous electrolyte battery was produced in the same manner as Sample 1, except that the content of monomethyl maleate (MMM) of the binary copolymer used for the negative electrode active material layer was 0.1 wt%.

<Sample 11>
The content of hexafluoropropylene (HFP) in the ternary copolymer used for the gel electrolyte layer is 10% by weight. A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of monomethyl maleate (MMM) of the binary copolymer used for the negative electrode active material layer was 0.3 wt%.

<Sample 12>
The content of hexafluoropropylene (HFP) in the ternary copolymer used for the gel electrolyte layer is 10% by weight. A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of monomethyl maleate (MMM) of the binary copolymer used for the negative electrode active material layer was 2 wt%.

<Sample 13>
The content of hexafluoropropylene (HFP) in the ternary copolymer used for the gel electrolyte layer is 10% by weight. A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the content of monomethyl maleate (MMM) of the binary copolymer used for the negative electrode active material layer was 2.5 wt%.

<Sample 14>
The content of hexafluoropropylene (HFP) in the ternary copolymer used for the gel electrolyte layer is 10% by weight. A nonaqueous electrolyte battery was produced in the same manner as in Sample 1, except that the binary copolymer used for the negative electrode active material layer further contained 3% by weight of hexafluoropropylene (HFP).

[Evaluation of non-aqueous electrolyte battery]
(A) State of electrolyte layer First, it is confirmed whether a good gel electrolyte layer is formed on the electrode surface when forming the electrolyte layer.

(B) Cycle characteristics About the nonaqueous electrolyte battery of each sample described above, constant current discharge is performed at a current rate of 1 ItA relative to the battery capacity (1 ItA = 1 A in a battery having a battery capacity of 1 Ah). Then, when the battery voltage reached 4.2 V, switching to low voltage charging was performed, and charging was terminated when the total charging time reached 2.5 hours. Subsequently, discharging was performed at 1 ItA, and discharging was terminated when the battery voltage reached 3V. The discharge capacity at this time was defined as the initial capacity.

  Subsequently, charging / discharging was repeated until 400 cycles under the same conditions as the above-described charging / discharging, and the discharge capacity at the 400th cycle was measured. Subsequently, the capacity retention rate was calculated from {(discharge capacity at 400th cycle / initial capacity) × 100}.

(B) State of peeling / peeling of negative electrode active material layer Regarding the non-aqueous electrolyte battery of each of the above samples, is the battery immediately after assembly disassembled and whether the negative electrode active material layer is peeled off or peeled off from the negative electrode current collector? It was confirmed visually.

  Table 1 below shows the results of the above evaluation.

  As can be seen from each sample, by appropriately setting the amount of polymer in the gel electrolyte layer and the negative electrode active material layer, the gel electrolyte layer and the negative electrode active material layer can be formed well and high cycle characteristics can be obtained. it can.

  On the other hand, when the content of hexafluoropropylene (HFP), which is the main component of the ternary copolymer in the electrolyte layer, is small as in Sample 1, the state of the electrolyte layer and the negative electrode active material layer is good. Even in such a case, the cycle characteristics have deteriorated. This is because the adhesion between the gel electrolyte layer and the negative electrode active material layer has decreased.

  Further, as in Samples 5 and 6, when the content of hexafluoropropylene (HFP) in the electrolyte layer is too high, that is, when the copolymerization ratio of the polymer to be copolymerized is inappropriate, the electrolyte is gel. It did not turn. In addition, cycle characteristics have also deteriorated.

  As can be seen from Sample 3 and Samples 6 to 9, when the content of monomethyl maleate (MMM) copolymerized with the main component of the ternary copolymer in the electrolyte layer is small, the electrolyte layer and the negative electrode Even if the state of the active material layer was good, the cycle characteristics were deteriorated. This is because the copolymerization ratio of the polymer to be copolymerized was inappropriate.

  As in Sample 9, when the content of monomethyl maleate (MMM) in the electrolyte layer was too much, the electrolyte did not gel. In addition, cycle characteristics have also deteriorated.

  When the content of monomethylmaleic acid ester (MMM) of the two-component copolymer was too small in the negative electrode active material layer as in sample 10, the negative electrode active material layer was peeled off from the negative electrode current collector. . In addition, the cycle characteristics also deteriorated due to the decrease in the negative electrode active material layer contributing to the battery reaction. This is because the adhesion of the negative electrode active material layer to the negative electrode current collector is reduced.

  When the content of monomethylmaleic acid ester (MMM) in the negative electrode active material layer was too large as in Sample 13, the negative electrode active material layer was peeled off from the negative electrode current collector. In addition, the cycle characteristics also deteriorated due to the decrease in the negative electrode active material layer contributing to the battery reaction. This is because the negative electrode active material layer swells.

  Even when hexafluoropropylene (HFP) was further mixed with the polymer as the binder used for the negative electrode active material layer as in Sample 14, the negative electrode active material layer was peeled off from the negative electrode current collector. . In addition, the cycle characteristics also deteriorated due to the decrease in the negative electrode active material layer contributing to the battery reaction. This is because the negative electrode active material layer is more easily swollen by the addition of hexafluoropropylene (HFP).

  The embodiments of the present invention have been specifically described in the embodiments and examples. However, the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention. Is possible. The present invention is not limited to the modes described in the above-described embodiments and examples, and various modifications can be made. Specifically, in the above-described embodiments and examples, the lithium ion secondary battery in which the capacity of the negative electrode is represented by the capacity component accompanying the insertion and extraction of lithium has been described as the battery of the present invention. It is not limited to. For example, in the battery of the present invention, the negative electrode active material has a charge capacity smaller than that of the positive electrode active material, so that the capacity of the negative electrode is a capacity component associated with insertion and extraction of lithium and a capacity associated with precipitation and dissolution of lithium. The present invention is also applicable to a secondary battery that includes a component and is represented by the sum of the capacity components.

  In the above-described embodiments and examples, the case where lithium is used as the electrode reactant has been described. However, other Group 1A elements such as sodium (Na) or potassium (K), magnesium or calcium (Ca), etc. Other light metals such as 2A group elements and aluminum may be used. Also in this case, the negative electrode material described in the above-described embodiment can be used as the negative electrode active material.

  Further, in the above-described embodiment or example, the laminated film type has been described as an example of the battery structure of the battery of the present invention. However, the battery of the present invention may be a cylindrical type, a coin type, a button type, a square type, or the like. The present invention is also applicable to secondary batteries having other battery structures. In the above-described embodiment or example, the winding type electrode body in which the positive electrode and the negative electrode are stacked and then wound is described. However, the stacked electrode body in which the positive electrode and the negative electrode are stacked, and the stacked layers are stacked. Then, a zigzag type electrode body that is zigzag folded without being wound may be used. Of course, the present invention is not limited to the secondary battery but can be similarly applied to other batteries such as a primary battery.

  In the above-described embodiments and examples, the appropriate ranges derived from the results of the examples are described for the copolymerization amounts of hexafluoropropylene and monomethyl maleate in the ternary copolymer. The explanation does not completely deny the possibility that the respective copolymerization amounts are outside the above-mentioned range. That is, the appropriate range described above is a particularly preferable range for obtaining the effects of the present invention, and the amount of each copolymerization may deviate somewhat from the range described above as long as the effects of the present invention are obtained. The same applies to the appropriate ranges of the weight average molecular weight of the ternary copolymer, the concentration of the electrolyte salt, and the copolymerization amount of monomethyl maleate in the binder of the negative electrode.

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 layer 15A ... positive electrode terminal 15B ... negative electrode terminal 16 ... sealant 17 ... laminate film 18 ... protective tape 19 ... insulating member

Claims (6)

A positive electrode;
A negative electrode active material, and a negative electrode binder containing a two-component copolymer composed of vinylidene fluoride and monomethylmaleate as components,
A negative electrode in which the copolymerization amount of the monomethylmaleic acid ester in the two-component copolymer is in the range of 0.3 wt% to 2 wt%;
An electrolytic solution and a polymer compound containing a ternary copolymer containing vinylidene fluoride, hexafluoropropylene and monomethylmaleic acid ester as components,
The copolymerization amount of the hexafluoropropylene and the monomethylmaleic acid ester in the ternary copolymer is within the range of 8% by weight to 15% by weight and within the range of 0.3% by weight to 2% by weight, respectively. And a non-aqueous electrolyte battery comprising an electrolyte having a weight average molecular weight in the range of 600,000 to 1,500,000 or less. The nonaqueous electrolyte battery according to claim 1, wherein the solvent includes two or more members selected from the group consisting of ethylene carbonate, propylene carbonate, dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate. The electrolyte salt includes at least one selected from the group consisting of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium bis (trifluoromethanesulfonyl) imide and lithium bis (pentafluoroethanesulfonyl) imide. 2. The nonaqueous electrolyte battery according to 2. The non-aqueous electrolyte battery according to claim 1, wherein the positive electrode active material is capable of inserting and extracting lithium and contains a composite oxide containing lithium. The negative electrode active material is capable of inserting and extracting lithium, and has at least one of a carbon material or a metal element and a metalloid element capable of forming an alloy with lithium as a constituent element. The nonaqueous electrolyte battery according to claim 1, which contains a material to be contained. The non-aqueous electrolyte battery according to claim 1, wherein the positive electrode, the negative electrode, and the electrolyte are housed inside a film-shaped exterior member.

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