JP2009070605A - Lithium polymer battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lithium polymer battery having superior battery performance and higher safety. <P>SOLUTION: In the lithium polymer battery, an electrolyte for a solid electrolyte including a crosslinkable material, a solvent, and lithium electrolyte salt is poured into a container capable of sealing up together with a battery material including a separator and an electrode material, the electrolyte for a solid electrolyte made into a solid electrolyte by making the electrolyte for a solid electrolyte gel on the basis of crosslinking of the crosslinkable material. The separator is made of a non-conductive porous material and electrically-insulated particles. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lithium polymer battery.

  Lithium-ion secondary batteries are small, lightweight, rechargeable batteries with a large storage capacity per unit volume or unit weight, and are widely used in mobile phones, notebook computers, personal digital assistants (PDAs), video cameras, digital cameras, etc. It is indispensable for each portable device that is small, light and relatively large in power consumption. In recent years, the development of medium- or large-sized lithium ion secondary batteries to be mounted on electric bicycles and electric vehicles has been promoted, and the development is expected as a means for reducing environmental load.

  At present, most of the electrolyte solution of the lithium ion secondary battery uses a liquid electrolyte solution in which a lithium electrolyte salt is dissolved in an electrolyte solvent mainly composed of propylene carbonate, ethylene carbonate, or the like. However, in the case of a battery using a liquid electrolyte, in addition to the risk of leakage of the electrolyte, there are problems of safety such as temperature increase, internal pressure increase, rupture and ignition due to use environment, misuse and accident. In particular, when used in high capacity / high output applications such as bicycles and cars, a very large amount of energy is required, so battery safety is an important issue. In order to solve this problem, it has been proposed to form an electrolyte with a gel or solid electrolyte (Patent Documents 1 and 2, etc.).

On the other hand, by using a porous substrate having an electrically insulating inorganic film as a separator for an electrolyte electrolyte lithium ion secondary battery, a shutdown mechanism is provided in the battery, and the safety of the battery is dramatically improved. The manufacturing method of the separator which can be performed is reported (patent document 3, 4 etc.).
JP 2001-176555 A JP 2002-110245 A JP 2005-536857 A JP 2005-536860 Publication

  In order to avoid dangers such as cell expansion, heat generation, and ignition due to electrolyte leakage, short circuit, etc., which is a problem with electrolyte-based lithium ion secondary batteries, it is made into a gel or solid electrolyte. However, as long as a combustible material is used as a constituent material of the battery such as an active material or an electrolytic solution, further safety measures are required.

  From the viewpoint of battery production, improvement in productivity, product stability, and the like are also important. The point is how quickly and uniformly a high viscosity polymer solution is poured, and there are many problems to be solved including the examination of the monomer composition, the impregnation into the separator, and the electrode microstructure. In order to solve these problems, it is necessary to extend the impregnation time and introduce new equipment, which causes a decrease in battery production efficiency.

  In view of the above problems, the present invention performs selection and examination of battery constituent materials to improve safety which is strongly required for lithium ion secondary batteries, and has battery performance superior to conventional polymer batteries and higher. It is an object to provide a lithium polymer battery having safety.

  By combining a gel electrolyte using a crosslinkable material with a separator made of a non-conductive porous material and electrically insulating particles, the performance of the polymer battery and the safety of the battery are dramatically improved. I found out. In addition, by improving the impregnation of the electrolyte into the separator, it is possible to prevent accidents such as leakage, smoke, and ignition of the electrolyte while maintaining the conventional battery performance, and the present invention is completed. It was.

  That is, the present invention injects a solid electrolyte electrolyte containing a crosslinkable material, a solvent, and a lithium electrolyte salt into a sealable container together with a battery material including a separator and an electrode material, and the crosslinkable material crosslinks the above. The lithium polymer battery is characterized in that a solid electrolyte is formed by gelling an electrolyte solution for a solid electrolyte, and the separator is made of a non-conductive porous material and electrically insulating particles.

  In the present invention, the crosslinkable material is preferably a copolymer of a monomer having a ring-opening polymerizable functional group and a monomer having no ring-opening polymerizable functional group.

（式中、Ｒ^１はＨまたはＣＨ_３を表し、Ｒ^２は下記化学式（３）で表される置換基を表し、化学式（３）におけるＲ^３は炭素数１〜６のアルキル基を表す。）

The monomer having a ring-opening polymerizable functional group is preferably a monomer represented by the following general formula (1) or (2).

(In the formula, R ¹ represents H or CH ₃ , R ² represents a substituent represented by the following chemical formula (3), and R ³ in the chemical formula (3) represents an alkyl group having 1 to 6 carbon atoms. )

（式中、Ｒ^４はＨまたはＣＨ_３を表し、およびＲ^５は−ＣＯＯＣＨ_３、−ＣＯＯＣ_２Ｈ_５、−ＣＯＯＣ_３Ｈ_７、−ＣＯＯＣ_４Ｈ_９、−ＣＯＯＣＨ_２ＣＨ（ＣＨ_３）_２、−ＣＯＯ（ＣＨ_２ＣＨ_２Ｏ）_１〜_３ＣＨ_３、−ＣＯＯ（ＣＨ_２ＣＨ_２Ｏ）_１〜_３Ｃ_２Ｈ_５、−ＣＯＯ（ＣＨ_２ＣＨ_２Ｏ）_１〜_３Ｃ_４Ｈ_９、−ＣＯＯ（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_１〜_３ＣＨ_３、−ＣＯＯ（ＣＨ_２ＣＨ（ＣＨ_３）Ｏ）_１〜_３Ｃ_２Ｈ_５、−ＯＣＯＣＨ_３、−ＯＣＯＣ_２Ｈ_５、又は−ＣＨ_２ＯＣ_２Ｈ_５を表す。） The monomer having no ring-opening polymerizable functional group is preferably a monomer represented by the following general formula (4).

(Wherein R ⁴ represents H or CH ₃ , and R ⁵ represents —COOCH ₃ , —COOC ₂ H ₅ , —COOC ₃ H ₇ , —COOC ₄ H ₉ , —COOCH ₂ CH (CH ₃ ) ₂ , _{-COO (CH 2 CH 2 O)} 1 ~ 3 CH 3, -COO (CH 2 CH 2 O) 1 ~ 3 C 2 H 5, -COO (CH 2 CH 2 O) 1 ~ 3 C 4 H 9, - _{COO (CH 2 CH (CH 3} ) O) 1 ~ 3 CH 3, -COO (CH 2 CH (CH 3) O) 1 ~ 3 C 2 H 5, -OCOCH 3, -OCOC 2 H 5, or -CH ₂ represents OC ₂ H ₅ )

  Furthermore, in the present invention, the nonconductive porous material of the separator is a non-woven fabric made of nonconductive polymer fibers, and is preferably coated with electrically insulating inorganic particles.

    According to the present invention, it is possible to manufacture a lithium battery having performance superior to that of a conventional polymer battery and high safety. In other words, battery trouble may cause a major accident due to internal temperature increase, internal pressure increase, and further explosion and ignition, but in this application, in addition to polymer electrolyte, in addition to polymer electrolyte, In the unlikely event that the material melts or shrinks, it uses heat-resistant material particles that do not melt, so it does not cause a large area internal short circuit, and the conventional electrolyte solution due to the double effect of the polymer electrolyte and separator Safety higher than that of a lithium-based battery can be provided.

  Moreover, this lithium secondary battery can be manufactured with the same manufacturing equipment as before, and does not require new equipment.

  Furthermore, not only the safety of the battery is improved by the use of the separator mentioned in the present invention, but the wettability of the separator surface is improved, so that the time for impregnation with the electrolyte can be shortened, and the polymer electrolyte is used. In addition, the interface resistance of the battery is reduced, and excellent battery performance can be obtained.

  Embodiments of the present invention will be described below.

  The crosslinkable material is not particularly limited as long as it is a material that can be gelled to form a solid electrolyte, but is preferably gelled by ring-opening polymerization of a compound having a ring-opening polymerizable functional group.

  Examples of the ring-opening polymerizable functional group are groups having an atomic group such as ether, amine, ester, amide and the like containing a hetero atom (O, N, S, Si, P, etc.), an alicyclic epoxy group, An oxetane group, a tetrahydrofurfuryl group, a cyclic ether group and the like can be mentioned, and an alicyclic epoxy group, an oxetane group and a tetrahydrofurfuryl group are preferable, and an alicyclic epoxy group and an oxetane group are most preferable. A plurality of these groups and / or two or more kinds thereof may be contained in one molecule.

  Although it will not specifically limit if the compound which has a ring-opening polymerizable functional group is a monomer which has a radically polymerizable functional group, The radical of the monomer which has one or more types of functional groups among a (meth) acryl group, a vinyl group, and an allyl group A polymer is preferable, and a (meth) acryl group and an allyl group are most preferable.

  Examples of monomers having a ring-opening polymerizable functional group include glycidyl ether monomers such as glycidyl methacrylate and alicyclic rings such as 3,4-epoxycyclohexylmethyl (meth) acrylate as specific examples of monomers having a (meth) acryl group. Formula epoxy monomer, (3-oxetanyl) methyl (meth) acrylate, (3-methyl-3-oxetanyl) methyl (meth) acrylate, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, (3-butyl- Oxetane monomers such as 3-oxetanyl) methyl (meth) acrylate, (3-hexyl-3-oxetanyl) methyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl (meth) acrylate, tetrahydride Furfuryl monomer, and the like.

  Examples of the monomer having an allyl group include allyl glycidyl ether.

  Examples of the monomer having a vinyl group include 4-vinyl 1-cyclohexene 1,2-epoxide and 2-vinyloxytetrahydropyran.

  A plurality of these monomers may be used.

  The amount of the monomer having a ring-opening polymerizable functional group, (meth) acryl group, allyl group, vinyl group is not particularly limited, but is preferably 5 to 50% in the total amount of the monomer. Is preferably in the range of 10 to 30%. If it is less than 5%, the amount of polymer required for gelation increases, and if it exceeds 50%, the electrolyte tends to separate (bleed) from the gel.

  In the present invention, “(meth) acryl” means acryl and methacryl, and “(meth) acrylate” means acrylate and methacrylate.

  Examples of the monomer having no ring-opening polymerizable functional group include, as specific examples of the monomer having a (meth) acryl group, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, Aliphatics such as n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, n-lauryl (meth) acrylate, tridecyl (meth) acrylate and n-stearyl methacrylate Aliphatic (meth) acrylates such as ethylene oxide modified (meth) acrylates such as (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and cyclohexyl (meth) acrylate , Aromatic (meth) acrylates such as benzyl (meth) acrylate, methoxypropylene glycol (meth) acrylate, methoxydipropylene glycol (meth) acrylate, methoxytripropylene glycol (meth) acrylate, ethoxypropylene glycol (meth) acrylate And propylene oxide-modified (meth) acrylates such as ethoxydipropylene glycol (meth) acrylate and ethoxytripropylene glycol (meth) acrylate.

  Examples of the monomer having an allyl group include aliphatic allyl ethers such as allyl ethyl ether.

  Examples of the monomer having a vinyl group include vinyl acetate, vinyl propionate, vinyl pivalate, vinyl butyrate, vinyl cinnamate, vinyl crotonate, vinyl decanate, and vinyl ethyl ether.

  Examples of the monomer having two or more radical polymerization functional groups in one molecule include allyl methacrylate and 1,3-butylene glycol dimethacrylate.

  In the present invention, the crosslinkable material can be easily obtained by a copolymer of a monomer having a ring-opening polymerizable functional group and a monomer having no ring-opening polymerizable functional group. The molecular weight of the crosslinkable material is preferably 8,000 to 1,000,000, more preferably 100,000 to 700,000, and most preferably 200,000 to 500,000.

  In the radical copolymerization, a radical polymerization initiator is usually used. Examples of the radical polymerization initiator include azo initiators such as N, N′-azobisisobutyronitrile and dimethyl N, N′-azobis (2-methylpropionate), benzoyl peroxide, lauroyl peroxide. And organic peroxide initiators such as Moreover, you may use molecular weight modifiers, such as mercaptans, as needed. In that case, solution polymerization performed at a temperature of about 60 to 80 ° C. in a solvent is suitable. As the solvent, cyclic carbonates, chain carbonates, and low-molecular carboxylic acid esters are preferable.

  In the present invention, a good gel can be obtained even in a small amount of polymer by crosslinking in the presence of a cationic polymerization initiator in a solution of the crosslinkable material containing the polymer, a lithium electrolyte salt, and a solvent. And the above electrolyte for solid electrolyte can be made into a solid electrolyte.

As the cationic polymerization initiator, various onium salts (for example, -BF ₄ , -PF ₆ , -SbF ₆ , -CF ₃ SO ₃ , -ClO of cations such as ammonium, phosphonium, arsonium, stibonium, sulfonium, iodonium, etc.) ₄ ) and lithium salts such as LiBF ₄ and LiPF ₆ can be used.

  Examples of the solvent in which the electrolyte salt is soluble include ethylene carbonate (EC), dimethyl carbonate (DMC), propylene carbonate (PC), methylpropyl carbonate (PMC), butylene carbonate (BC), and diethyl carbonate (DEC). Carbonates, cyclic carboxylic acid esters such as γ-butyrolactone (GBL) and γ-valerolactone, cyclic ethers such as tetrahydrofuran and methyltetrahydrofuran, sulfolane and the like can be used. Such an electrolytic solution is usually preferably 0.1 to 5 mol / L, particularly preferably 0.5 to 2 mol / L as an electrolyte salt.

  The electrolytic solution may contain an additive. Additives include nitrogen- and sulfur-containing compounds such as azaindole, benzimidazole, benzodithiol, benzofuran, benzothiazole, 1-benzothiophene, 1H-benzotriazole, benzylcapton, 1-bromo-3-fluorobenzene In addition to vinyl compounds such as vinylene carbonate, vinyl acrylate and vinyl butyrate, sucrose fatty acid esters may be mentioned, and the amount added is 10% or less, preferably 3% or less. Further, the additive may be a combination of two or more of these.

Lithium electrolyte salts include LiPF ₆ , LiBF ₄ , LiClO ₄ , LiAsF ₆ , LiCF ₃ SO ₄ , LiClO ₄ , lithium bisoxalatoborate (LiBOB) and / or lithium-bis (trifluoromethylsulfonyl) imide (LiN ( SO ₂ CF ₃ ) ₂ ), bis (fluorosulfonyl) imidolithium (LiFSI), and the like, and LiPF ₆ is particularly preferable. The electrolyte salt may be used alone or in combination of two or more.

  Further, in order to increase the ionic conductivity of the electrolytic solution, it is possible to use an electrolyte salt other than Li as a cationic polymerization initiator.

For example, bis (fluorosulfonyl) imide (FSI) ⁻ , BF ₄ ⁻ , PF ₆ ⁻ , SbF ₆ ⁻ , NO ₃ ⁻ , CF ₃ SO ₃ ⁻ , (CF ₃ SO ₂ ) ₂ N ⁻ , TFSI ⁻ , (C Anions such as ₂ F ₅ SO ₂ ) ₂ N ⁻ , (CF ₃ SO ₂ ) ₃ C ⁻ , CF ₃ CO ₂ ⁻ , C ₃ F ₇ CO ₂ ⁻ , CH ₃ CO ₂ ⁻ , and (CN) ₂ N ⁻ A salt composed of a combination of cations may be used.

  As the cation, a compound containing any of N, P, S, O, C, Si or two or more elements in the structure and having a chain structure or a cyclic structure such as a 5-membered ring or a 6-membered ring in the skeleton Examples of chain compounds include alkyl ammonium. Examples of cyclic compounds include furan, thiophene, pyrrole, pyridine, oxazole, isoxazole, thiazol, isothiazol, furazane, imidazole, pyrazole, pyrazine, pyrimidine, pyridazine, pyrrolidine, piperidine and the like. Examples thereof include condensed heterocyclic compounds such as a ring compound, benzofuran, isobenzofuran, indole, isoindole, isodolidine, and carbazole.

When LiPF ₆ or LiBF ₄ is used as the lithium salt, it can act as a cationic polymerization initiator that crosslinks the ring-opening polymerizable functional group, and therefore other cationic polymerization initiators need not be used.

  The electrode material is not particularly limited as long as it can insert and desorb lithium ions.

For example, as the positive electrode active material, metal oxides such as CuO, Cu ₂ O, MnO ₂ , V ₂ O ₅ , CrO ₃ , MoO ₃ , Fe ₂ O ₃ , Ni ₂ O ₃ , CuO ₃ , Li _x CO ₂ , Li _x NiO ₂ , Li _x Mn ₂ O ₄ , LiFePO ₄ and other complex oxides of lithium and transition metals, TiS ₂ , MoS ₂ , NbSe _{3 and} other metal chalcogenides, polyacene, polyparaphenylene, polypyrrole, Examples thereof include conductive compounds such as polyaniline.

In particular, in the present invention, a composite oxide of lithium and at least one selected from transition metals such as cobalt, nickel, manganese, and iron is preferable. Specific examples of the composite oxide of lithium include LiCoO ₂ , LiMnO ₂ , Examples include LiMn ₂ O ₄ , LiNi _x Co (1-x) O ₂ , LiMn _a Ni _b Co _c (a + b + c = 1), LiFePO _{4, and the} like.

  These lithium composite oxides may be doped with a small amount of elements such as fluorine, boron, aluminum, chromium, zirconium, molybdenum, and iron.

  A mixture of these active materials may be used as the positive electrode active material.

  Examples of the negative electrode active material include an active material capable of inserting and extracting lithium and an active material capable of reversibly occluding and releasing lithium, and examples thereof include alkali metals, alkali metal alloys, transition metal chalcogenides, and carbon materials.

Specifically, lithium storage metals such as metallic lithium, Al, Mg, Pt, Sn, Si, Zn, and Bi, Al-based lithium alloys such as Al—Ni, Al—Ag, and Al—Mn, SbSn, InSb, and CoSb ₃ , antimony series lithium alloys such as Mi ₂ MnSb, Sn ₂ M (M = Fe, Co, Mn, V, Ti), Sn ₅ Cu ₆ , Sn ₃ V ₂ , Sn ₁₂ Ag ₁₃ , SnSb ₀ . Sn-based lithium alloys such as ₄ , Sn oxides such as SnO ₂ , Sn ₂ P ₂ O ₇ , SNPBO ₆ , SnPO ₄ Cl, Si-based such as Si—C composite, Si—Ti composite, and Si—M thin film Examples include lithium alloy, nanocomposite materials such as Sn and Si, amorphous alloy materials such as Sn, Co, and carbon, Sn-based plating alloys such as Sn-Ag and Sn-Cu, and Si-based amorphous thin films. There are carbon, mesocarbon microbeads, graphite, natural graphite, non-graphitizable carbon (hard carbon, hereinafter referred to as HC), and surface modified products of these carbon materials are preferable materials.

  A conductive agent is used for the positive electrode and the negative electrode. Any conductive material that does not adversely affect battery performance can be used as the conductive agent. Usually, carbon black such as acetylene black and kettin black is used, but carbon fiber such as natural graphite, artificial graphite, carbon whisker, vapor grown carbon, carbon nanotube, fullerene, conductive ceramic material, etc. may be used. Often, these can be included as a mixture of two or more.

  The current collector for the electrode active material may be any electronic conductor as long as it does not adversely affect the constructed battery. For example, as a current collector for a positive electrode, in addition to aluminum, titanium, stainless steel, nickel, baked carbon, conductive polymer, conductive glass, etc., aluminum is used for the purpose of improving adhesiveness, conductivity, and oxidation resistance. Or a surface treated with carbon, nickel, titanium, silver or the like can be used.

  As a negative electrode current collector, in addition to copper, stainless steel, nickel, aluminum, titanium, calcined carbon, conductive polymer, conductive glass, Al-Cd alloy, etc., the purpose of improving adhesion, conductivity, and oxidation resistance And what processed the surface, such as copper, with carbon, nickel, titanium, silver, etc. can be used.

  The surface of these current collector materials can be oxidized. As for these shapes, in addition to the foil shape, a film shape, a sheet shape, a net shape, a punched or expanded material, a vitreous body, a porous body, a foamed body and the like are also used.

  As a binder for binding the active material to the current collector, a copolymer of polyvinylidene fluoride (PVDF), hexafluoropropylene (HFP), perfluoromethyl vinyl ether (PFMV), and tetrafluoroethylene (TFE), etc. Fluorine resins such as PVDF copolymer resin, polytetrafluoroethylene (PTFE), fluorine rubber, and polymers such as styrene-butadiene rubber (SBR), ethylene-propylene rubber (EPDM), and styrene-acrylonitrile copolymer. In addition, a polysaccharide such as carboxymethyl cellulose (CMC) and a thermoplastic resin such as a polyimide resin can be used in combination, but the present invention is not limited thereto. Moreover, you may use these in mixture of 2 or more types. The amount added is preferably 0.2 to 30%, more preferably 0.5 to 10%, based on the amount of active material.

As for the positive electrode active material whose surface is coated with carbon such as LiFePO ₄ , a carboxylic acid-modified PVDF or SBR aqueous binder can also be mentioned as a preferable material.

  As the separator, a porous film is used, and usually a porous polymer film or a nonwoven fabric is preferably used.

  In the present invention, those composed of a non-conductive porous material and electrically insulating particles are particularly suitable. The non-conductive porous material is selected from polyacrylonitrile, polyester (PET), polyimide, polyamide, polytetrafluoroethylene, polyolefin, glass, ceramic and the like. In particular, a nonwoven fabric having an electrically insulating inorganic film on a flat flexible substrate is suitable, and polyester (PET) and polyamide are particularly preferred.

  The insulating particles used in the separator include inorganic materials such as at least one kind of alumina, titania, silicon and / or zirconia, and organic materials such as fluororesin, polystyrene resin and acrylic resin. Particles are used.

The separator may further have a shutdown mechanism by the presence of a very thin wax particle layer that melts at a desired blocking temperature or a blocking particle of a polymer particle layer in the separator. Advantageous materials for forming the blocking particles include natural or artificial waxes, low melting polymers such as polyolefins, which melt at the desired blocking temperature and close the pores of the separator. Further current during the abnormal operation of the battery can be suppressed.
The lithium polymer battery of the present invention can be formed into a cylindrical shape, a coin shape, a rectangular shape, or any other shape, and the basic configuration of the battery is the same regardless of the shape, and the design is changed and implemented according to the purpose. be able to.

  In the lithium polymer battery of the present invention, for example, in a cylindrical shape, a negative electrode formed by applying a negative electrode active material to a negative electrode current collector and a positive electrode formed by applying a positive electrode active material to a positive electrode current collector are interposed via a separator. It is obtained by storing the wound body in a battery can, injecting a polymer electrolyte before curing, sealing it with the insulating plates placed on the top and bottom, and curing the polymer by heating.

  When producing the lithium polymer battery of the present invention, the selected electrode active material generates a large amount of gas during the first charge, which may affect the cell performance. After injecting into the pre-battery, the polymer may be subjected to heat treatment after being charged or charged / discharged as a pretreatment.

  EXAMPLES Next, although an Example demonstrates this invention more concretely, this invention is not limited to these Examples.

<Example 1>
[Creation of positive electrode]
As a cathode active material _{LiNi 1/3 Co 1/3} Mn 1/3 O 2 100g, acetylene black as a conductive agent (Denki Kagaku Kogyo Co., Ltd. Denka Black) 6 g, PVDF as a binder (Co. Kureha KF Binder # 1120 NMP 12 wt% solution) 50 g (6 g as a solid content) and 16.3 g N-methyl-2-pyrrolidone as a dispersion medium were diluted to prepare a positive electrode coating solution to a solid content of 65 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm by a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
95 g of mesocarbon microbeads (MCMB) (MCMB25-28 manufactured by Osaka Gas Chemical Co., Ltd.), 5 g of hard carbon (Carbotron PS (F) manufactured by Kureha Chemical Co., Ltd.), which is a negative electrode active material, acetylene black (electric Chemical Industry Co., Ltd. Denka Black) 5g, PVDF (Kureha Co., Ltd. KF Binder # 1120 NMP 12wt% solution) 41.7g (5g as solids), NMP 36.7g as a dispersion medium with a planetary mixer A negative electrode coating solution having a solid content of 60 wt% was prepared by mixing. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C., and then subjected to a roll press treatment, with an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ² (per one side). A double-sided coated negative electrode was obtained.

[Method for producing polymer]
In a fully dried container, 74 wt% ethyl acrylate as a monomer having no ring-opening polymerizable functional group and (3-ethyl-3oxetanyl) methyl methacrylate 26 wt% as a monomer having a ring-opening polymerizable functional group are charged. Ethylene carbonate (EC): diethyl carbonate (DEC) = 3: 7 (volume ratio) as a reaction solvent, N, N′-azobisisobutyronitrile as a polymerization initiator is added at 2500 ppm based on the monomer weight, and dry nitrogen gas is added. The reaction is carried out at 65 to 70 ° C. while cooling, and then cooled to room temperature. Thereafter, EC: DEC = 3: 7 (volume ratio) is added as a diluent solvent, and the mixture is stirred and dissolved until the whole becomes uniform. was gotten.

[Preparation of polymer solution]
4 wt% of a molecular weight of 200,000, EC: DEC = 3: 7 (volume ratio) polymer solution and EC: DEC = 3: 7 (volume ratio) electrolyte solution containing 2 mol / L of LiPF ₆ as a lithium electrolyte salt Then, a 2% polymer electrolyte solution was prepared by mixing at a weight ratio of 1: 1.

[Production of lithium battery]
A laminate having a structure in which a 30 μm-thick Separion S240P30 (Degussa Japan Co., Ltd.) in which a non-woven fabric of PET material is coated with SiO ₂ and Al ₂ O ₃ as a separator is sandwiched between the obtained positive electrode and negative electrode is prepared. After welding the tab lead for taking out the child, it was put in an aluminum laminate packaging material, and heat-sealed in three directions to produce a bag-shaped pre-battery having an opening in one direction. After injecting 3 g of the polymer / electrolyte mixed solution prepared in advance into the pre-battery, the aluminum laminate in the open part was sealed with a vacuum heat sealer, and the polymer was cured at 60 ° C. for 20 hours to produce a test cell. did.

<Example 2>
[Creation of positive electrode]
LigMn ₂ O ₄ 100 g as a positive electrode active material, acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 g as a conductive agent, PVDF as a binder (KF Binder # 1120 NMP 12 wt% solution manufactured by Kureha Co., Ltd.) A positive electrode coating solution was prepared by diluting with 3 g (7 g as a solid content) and 1.4 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 68 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
95 g of MCMB (Osaka Gas Chemical Co., Ltd. MCMB10-28), 5 g of non-graphitizable carbon (Kureha Carbotron P (S)), 5 g of acetylene black as a conductive agent, and PVDF as a binder Kreha KF Binder # 1120 NMP 12 wt% solution) 41.7 g (5 g as solid content) and 36.7 g NMP as a dispersion medium were mixed with a planetary mixer to prepare a negative electrode coating solution having a solid content of 53.6%. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C., and then subjected to a roll press treatment, with an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ² (per one side). A double-sided coated negative electrode was obtained.

[Method for producing polymer]
In a sufficiently dry container, 74 wt% methyl methacrylate as a monomer having no ring-opening polymerizable functional group and (3-ethyl-3oxetanyl) methyl methacrylate 26 wt% as a monomer having a ring-opening polymerizable functional group are charged. Ethylene carbonate (EC): dimethyl carbonate (DMC) = 3: 7 (volume ratio) as a reaction solvent, N, N′-azobisisobutyronitrile as a polymerization initiator is added at 2500 ppm based on the monomer weight, and dry nitrogen gas is added. The mixture is cooled to room temperature after a heating reaction at 65 to 70 ° C. Thereafter, EC: DMC = 3: 7 (volume ratio) is added as a diluent solvent, and dissolved by stirring until the whole becomes uniform. 4 wt% of molecular weight 250,000, EC: DMC = 3: 7 (volume ratio) polymer solution was gotten.

[Preparation of polymer solution]
4 wt% of the molecular weight 250,000, EC: DMC = 3: 7 (volume ratio) polymer solution and EC: DMC = 3: 7 (volume ratio) electrolyte solution containing 2 mol / L of LiPF ₆ as a lithium electrolyte salt. The polymer / electrolyte mixed solution was prepared by mixing at a weight ratio of 1: 1.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 3>
[Creation of positive electrode]
The positive electrode active material LiNi ₀ . ₈ Co ₀ . ₁₅ Al ₀ . ₀₅ O ₂ 100 g, ₅ g of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, 50 g of PVDF (KF Binder # 1120 NMP 12 wt% solution manufactured by Kureha Co., Ltd.) as a binder (6 g as a solid content), A positive electrode coating solution was prepared by diluting with 3.6 g of N-methyl-2-pyrrolidone as a dispersion medium so as to have a solid content of 70 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
100 g of natural graphite having an average particle diameter of 12 μm and a specific surface area of 4.3 m ² / g as a negative electrode active material, 5 g of acetylene black (DENKA BLACK manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, and PVDF (manufactured by Kureha Corporation) as a binder KF binder # 1120 NMP 12 wt% solution) 41.7 g (5 g as a solid content) and 36.7 g NMP as a dispersion medium were mixed with a planetary mixer to prepare a negative electrode coating solution having a solid content of 60 wt%. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C., and then subjected to a roll press treatment, with an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ² (per one side). A double-sided coated negative electrode was obtained.

[Method for producing polymer]
Propyl methacrylate 20 wt% and methyl methacrylate 54 wt% as monomers having no ring-opening polymerizable functional group, 3-ethyl-3oxetanyl) methyl methacrylate 26 wt% as a monomer having ring-opening polymerizable functional group, EC: PC: Except that DEC = 6: 1: 13 (volume ratio) was used, 4 wt% of a molecular weight of 300,000, EC: PC: DEC = 6: 1: 13 (volume ratio) polymer solution was obtained in the same manner as in Example 1. Obtained.

[Preparation of polymer solution]
4 wt% ethylene carbonate (EC): propylene carbonate (PC): diethyl carbonate (DEC) = 6: 1: 13 (volume ratio) polymer solution having a molecular weight of 300,000 and 2 mol / liter of LiPF ₆ as a lithium electrolyte salt An electrolyte solution containing 2 wt% of the polymer was prepared by mixing the electrolyte solution containing L: EC: PC: DEC = 6: 1: 13 (volume ratio) at a weight ratio of 1: 1.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that a separator having a thickness of 25 μm in which polyamide ₂ was coated with SiO ₂ and Al ₂ O ₃ was used.

<Example 4>
[Creation of positive electrode]
LiCoO ₂ 100 g which is a positive electrode active material, acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 g as a conductive agent, PVDF (Kureha KF Binder # 1120 NMP 12 wt% solution) 50 g (solid content) as a binder As a dispersion medium, a positive electrode coating solution was prepared so as to be diluted with 21.8 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 63 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
100 g of natural graphite having an average particle diameter of 20 μm and a specific surface area of 1.7 m ² / g, which is a negative electrode active material, 5 g of acetylene black (DENKA BLACK, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, and PVDF (manufactured by Kureha Corporation) KF Binder # 1120 NMP 12 wt% solution) 41.7 g (5 g as solid content) and NMP 36.7 g as a dispersion medium were mixed with a planetary mixer to prepare a negative electrode coating solution having a solid content of 60 wt%. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C., and then subjected to a roll press treatment, with an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ² (per one side). A double-sided coated negative electrode was obtained.

[Method for producing polymer]
15% by weight of n-butyl acrylate and 55% by weight of methyl methacrylate as a monomer having no ring-opening polymerizable functional group, 30% by weight of allyl glycidyl ether as a monomer having a ring-opening polymerizable functional group, EC: GBL: DEC = 5: A polymer solution was obtained in the same manner as in Example 1 except that 1:12 (volume ratio) was used, and 4 wt% of a molecular weight of 440,000, EC: GBL: DEC = 5: 1: 12 (volume ratio).

[Preparation of polymer solution]
EC: GBL: DEC = 5: 1: 12 (4 wt% EC: GBL: DEC = 5: 1: 12 (volume ratio) polymer solution) having a molecular weight of 440,000 and 2 mol / L of LiPF ₆ as a lithium electrolyte salt. The electrolyte solution of volume ratio) was mixed at a weight ratio of 1: 1 to prepare a 2 wt% polymer electrolyte solution.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S450P35 (Degussa Japan Co., Ltd.) having a thickness of 35 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 5>
[Creation of positive electrode]
100 g LiFePO ₄ with a coated carbon amount of 2 wt%, which is a positive electrode active material, ₅ g acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, and a carboxylic acid-modified PVDF (Kureha Co., Ltd. KF binder) # 9130 NMP 13 wt% solution) 61.5 g (8 g as a solid content) and N-methyl-2-pyrrolidone 84.6 g as a dispersion medium were diluted to prepare a positive electrode coating solution so that the solid content was 45 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 1.8 g / cm ³ , a positive electrode active material of 13 mg / cm ² (single side Per) was obtained.

[Creation of negative electrode]
It was prepared in the same manner as in Example 4 except that 100 g of artificial graphite having an average particle size of 28 μm and a specific surface area of 2.1 m ² / g was used as the negative electrode active material.

[Method for producing polymer]
20 wt% of methoxydiethylene glycol acrylate and 50 wt% of methyl methacrylate as a monomer having no ring-opening polymerizable functional group, 20 wt% of glycidyl methacrylate as a monomer having a ring-opening polymerizable functional group, and 10 wt% of (3-ethyl-3oxetanyl) methyl methacrylate, Except that EC: PC: DEC = 5: 2: 13 (volume ratio) was used as a reaction solvent, 4 wt% EC: PC: DEC = 5: 2: 13 having a molecular weight of 400,000 was obtained in the same manner as in Example 1. Volume ratio) A polymer solution was obtained.

[Preparation of polymer solution]
4 wt% EC: PC: DEC = 5: 2: 13 (volume ratio) with a molecular weight of 400,000% EC: PC: DEC = 5: 2: 13 (volume) containing 2 mol / L of LiPF ₆ as a polymer solution and a lithium electrolyte salt Ratio) electrolyte solution was mixed at a weight ratio of 1: 1 to prepare a 2 wt% polymer electrolyte solution.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 6>
[Creation of positive electrode]
The positive electrode active material LiNi ₀ . ₈ Co ₀ . ₂ O ₂ 100 g, ₇ g of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.) as the conductive agent, 41.7 g of PVDF (KF Binder # 1120 NMP 12 wt% solution, manufactured by Kureha Co., Ltd.) 41.7 g (5 g as solid content) A positive electrode coating solution was prepared so as to be diluted with 23.6 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 65 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
It was produced in the same manner as in Example 4 except that artificial graphite having an average particle size of 28 μm and a specific surface area of 1.5 m ² / g was used as the negative electrode active material.

[Method for producing polymer]
20 wt% of methoxytriethylene glycol acrylate and 48 wt% of methyl methacrylate, 2 wt% of vinyl propionate as a monomer having no ring-opening polymerizable functional group, 30 wt% of tetrahydrofurfuryl methacrylate as a monomer having a ring-opening polymerizable functional group, reaction solvent As in Example 1, except that EC: PC: EMC = 6: 1: 13 (volume ratio) was used, 4 wt% of molecular weight 500,000, EC: PC: EMC = 5: 2: 13 (volume) Ratio) A polymer solution was obtained.

[Preparation of polymer solution]
EC: PC: EMC = 5: 2: 13 containing 4 mol% of the above-mentioned molecular weight of 500,000: EC: PC: EMC = 5: 2: 13 (volume ratio) polymer solution and 2 mol / L of LiPF ₆ as a lithium electrolyte salt The electrolyte solution of (volume ratio) was mixed at a weight ratio of 1: 1 to prepare a 2 wt% polymer electrolyte solution.

[Production of lithium battery]
It was prepared in the same manner as in Example 1 except that Separion S240P25 (Degussa Japan Co., Ltd.) having a thickness of 25 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ was used as a separator between the obtained positive electrode and negative electrode.

<Example 7>
[Creation of positive electrode]
As a cathode active material _{LiNi 1/3 Co 1/3} Mn 1/3 O 2 30g / LiMn 2 O 4 70g, acetylene black as a conductive agent (Denki Kagaku Kogyo Co., Ltd. Denka Black) 5 g, PVDF as a binder (( Kfha KF Binder # 1120 NMP 12 wt% solution) 50 g (6 g as a solid content), positive electrode coating solution so as to be diluted with 3.6 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 70 wt% Was prepared. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
MCMB (Osaka Gas Chemical Co., Ltd. MCMB25-28) 100g, vapor grown carbon (VGCF manufactured by Showa Denko KK) 2g as a negative electrode active material Acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent 3 g, 41.7 g PVDF (Kureha Co., Ltd. KF Binder # 1120 NMP 12 wt% solution) 41.7 g (5 g as solid content), NMP 36.7 g as a dispersion medium mixed with a planetary mixer, and negative electrode with solid content 60 wt% A coating solution was prepared. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C., and then subjected to a roll press treatment, with an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ² (per one side). A double-sided coated negative electrode was obtained.

[Method for producing polymer]
20% by weight of methoxydipropylene glycol acrylate and 45% by weight of methyl methacrylate, 5% by weight of allyl ethyl ether as a monomer having no ring-opening polymerizable functional group, and (3-ethyl-3oxetanyl) methyl methacrylate as a monomer having a ring-opening polymerizable functional group 4 wt%, EC: GBL = 3: 7 (volume ratio) polymer having a molecular weight of 550,000, except that 30 wt% and EC: GBL = 3: 7 (volume ratio) were used as the reaction solvent. A solution was obtained.

[Preparation of polymer solution]
Example except that 4 wt% of the above molecular weight 550,000, EC: GBL = 3: 7 (volume ratio) polymer solution, and the solvent of the electrolyte was ethylene carbonate (EC): γ-butyrolactone (GBL) = 3: 7 As in Example 1, a 2 wt% electrolyte solution mixture was obtained.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 8>
[Creation of positive electrode]
The positive electrode active material LiNi ₀ . ₈ Co ₀ . _{2 O 2 30g / LiMn 2 O} 4 70g, acetylene black as a conductive agent (Denki Kagaku Kogyo Co., Ltd. Denka Black) 5 g, a binder as PVDF (Co. Kureha KF Binder # 1120 NMP 12% solution) 50 g (solid The positive electrode coating solution was prepared such that the solid content was 70 wt% after dilution with 3.6 g of N-methyl-2-pyrrolidone as a dispersion medium. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
It was prepared in the same manner as in Example 4 except that 100 g of artificial graphite having an average particle size of 14 μm and a specific surface area of 1.3 g / cm ² was used as the negative electrode active material.

[Method for producing polymer]
7 wt% vinyl acetate as a monomer having no ring-opening polymerizable functional group, 65 wt% methyl methacrylate, 2 wt% allyl methacrylate, 26 wt% (3-ethyl-3oxetanyl) methyl methacrylate as a monomer having a ring-opening polymerizable functional group, reaction 4 wt% of molecular weight 550,000, EC: PC: DEC = 3: 3: 4 (volume ratio), except that EC: PC: DEC = 33: 4 (volume ratio) was used as the solvent. ) A polymer solution was obtained.

[Preparation of polymer solution]
4 wt% of the above molecular weight 550,000, EC: PC: DEC = 3: 3: 4 (volume ratio) The same as Example 1 except that the solvent of the polymer solution and the electrolytic solution was EC: PC: DEC = 3: 3: 4 A polymer solution was prepared to obtain a 2 wt% electrolyte solution mixture.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 9>
[Creation of positive electrode]
As a cathode active material _{LiNi 1/3 Co 1/3} Mn 1/3 O 2 100g, acetylene black (Denki Kagaku Kogyo Co., Ltd. Denka Black) as a conductive agent 6 g, the binder as PVDF (Co. Kureha KF Binder A positive electrode coating solution was prepared so as to be diluted with 50 g of # 1120 NMP 12 wt% solution (6 g as a solid content) and 4.0 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 70 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
Artificial graphite 100 g having an average particle diameter of 25 μm and a specific surface area of 3.1 g / cm ² was used as the negative electrode active material, 5 g of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.), and carboxymethyl cellulose WS-C (binder component) Daiichi Kogyo Seiyaku Co., Ltd.) 2 wt% solution 100 g (2 g as solid content), styrene butadiene rubber (SBR) BM-400B (Nippon Zeon Corporation) 40 wt% solution 5 g (2 g as solid content), distilled as dispersion medium 8 g of water was mixed with a planetary mixer to prepare a negative electrode coating solution having a solid content of 50 wt%. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C. and then subjected to a roll press treatment, and a double-side coated negative electrode having an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ^2. Got.

[Method for producing polymer]
Methyl methacrylate 74 wt% as a monomer having no ring-opening polymerizable functional group, (3-ethyl-3oxetanyl) methyl methacrylate 20 wt%, 3,4-epoxycyclohexylmethyl methacrylate 6 wt% as a monomer having a ring-opening polymerizable functional group A 4 wt% EC: DEC = 3: 7 (volume ratio) polymer solution having a molecular weight of 600,000 was obtained in the same manner as in Example 1 except that EC: DEC = 3: 7 (volume ratio) was used as the reaction solvent. It was.

[Preparation of polymer solution]
4 wt% EC: DEC = 3: 7 (volume ratio) with a molecular weight of 600,000 The 2 wt% electrolyte solution mixture as in Example 1 except that the solvent of the polymer solution and the electrolyte solution was EC: DEC: = 3: 7 Got.
[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 10>
[Creation of positive electrode]
The positive electrode active material LiNi ₀ . ₈ Co ₀ . _{2 O 2 30g / LiMn 2 O} 4 70g and, acetylene black (Denki Kagaku Kogyo Co., Ltd. Denka Black) as a conductive agent 6 g, the binder as PVDF (Co. Kureha KF Binder # 1120 NMP 12 wt% solution) 50 g ( A positive electrode coating solution was prepared so that the solid content was 6 g) and the dispersion medium was diluted with 4.0 g of N-methyl-2-pyrrolidone to a solid content of 70 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 2.6 g / cm ³ , a positive electrode active material of 13 mg / cm ² (one side Per) was obtained.

[Creation of negative electrode]
Artificial graphite 100 g having an average particle size of 25 μm and a specific surface area of 3.1 g / cm ² is used as the negative electrode active material, 5 g of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.), and carboxymethyl cellulose WS-C (the first component) Ichi Kogyo Seiyaku Co., Ltd.) 2% solution 10g, styrene butadiene rubber (SBR) emulsion (Nippon ZEON Co., Ltd. BM-400B) 40wt% solution 5g, distilled water 8g as a dispersion medium is mixed with a planetary mixer, solid content A 50 wt% negative electrode coating solution was prepared. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C. and then subjected to a roll press treatment, and a double-side coated negative electrode having an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ^2. Got.

[Method for producing polymer]
74 wt% of methyl methacrylate as a monomer having no ring-opening polymerizable functional group, 26 wt% of (3-ethyl-3oxetanyl) methyl methacrylate as a monomer having a ring-opening polymerizable functional group, EC: DEC = 3: 7 ( A 10 wt% EC: DEC = 3: 7 (volume ratio) polymer solution having a molecular weight of 10,000 was obtained in the same manner as in Example 1 except that the volume ratio) was used.

[Preparation of polymer solution]
EC: DEC = 3: 7 (volume ratio) containing 10 mol% of ethylene carbonate (EC): diethyl carbonate (DEC) = 3: 7 (volume ratio) polymer solution and 2 mol / L of LiPF ₆ as a lithium electrolyte salt. ) Was mixed at a weight ratio of 1: 1 to prepare a 5 wt% polymer electrolyte solution.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 11>
[Creation of positive electrode]
100 g of LiFePO ₄ having a coating carbon amount of 2 wt% as a positive electrode active material, 8 g of acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, carboxymethyl cellulose WS-C (Daiichi Kogyo Seiyaku Co., Ltd.) as a binder A planetary mixer containing 100 g of a 2 wt% solution (2 g as a solid content), 5 g of a styrene butadiene rubber (SBR) emulsion BM-400B (Nihon Zeon Co., Ltd.) 40 wt% aqueous solution (2 g as a solid content), and 60 g of distilled water as a dispersion medium. A positive electrode coating solution having a solid content of 41 wt% was prepared by mixing.

[Creation of negative electrode]
Artificial graphite 100 g having an average particle size of 25 μm and a specific surface area of 3.1 g / cm ² is used as the negative electrode active material, 5 g of acetylene black (Denka Black, manufactured by Denki Kagaku Kogyo Co., Ltd.), and carboxymethyl cellulose WS-C (binder component) Daiichi Kogyo Seiyaku Co., Ltd.) 2% solution 10g, styrene butadiene rubber (SBR) emulsion (Nippon ZEON Co., Ltd. BM-400B) 40 wt% solution 5g, distilled water 8g as a dispersion medium are mixed with a planetary mixer and solid A negative electrode coating solution of 50 wt% was prepared. This coating solution is coated on an electrolytic copper foil having a thickness of 10 μm, dried at 130 ° C. and then subjected to a roll press treatment, and a double-side coated negative electrode having an active material density of 1.45 g / cm ³ and a negative electrode active material of 8 mg / cm ^2. Got.

[Method for producing polymer]
Except for using 70% by weight of methyl methacrylate as a monomer having no ring-opening polymerizable functional group, 30% by weight of glycidyl methacrylate as a monomer having a ring-opening polymerizable functional group, and EC: DEC = 3: 7 (volume ratio) as a reaction solvent. In the same manner as in Example 1, a 4 wt% EC: DEC = 3: 7 (volume ratio) polymer solution having a molecular weight of 300,000 was obtained.

[Preparation of polymer solution]
A polymer solution containing 4 wt% ethylene carbonate (EC): diethyl carbonate (DEC) = 3: 7 (volume ratio) having a molecular weight of 300,000 is prepared, and 2 mol / L of LiPF ₆ is contained as a lithium electrolyte salt. The electrolyte solution of EC: DEC = 3: 7 (volume ratio) was mixed at a weight ratio of 1: 1 to prepare an electrolyte solution mixture of 2 wt% polymer.

[Production of lithium battery]
The separator was prepared in the same manner as in Example 1 except that Separion S240P30 (Degussa Japan Co., Ltd.) having a thickness of 30 μm obtained by coating PET with SiO ₂ and Al ₂ O ₃ as a separator was used.

<Example 12>
[Creation of positive electrode]
100 g LiFePO ₄ with a coated carbon amount of 6 wt%, which is a positive electrode active material, ₅ g acetylene black (DENKA BLACK, manufactured by Denki Kagaku Kogyo Co., Ltd.) as a conductive agent, and a carboxylic acid-modified PVDF (Kureha KF binder) as a binder # 9130 NMP 13 wt% solution) 61.5 g (8 g as a solid content) and N-methyl-2-pyrrolidone 84.6 g as a dispersion medium were diluted to prepare a positive electrode coating solution so that the solid content was 45 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed, an active material density of 1.8 g / cm ³ , a positive electrode active material of 13 mg / cm ² (single side Per) was obtained.

  The same procedure as in Example 11 was performed except for the positive electrode.

<Example 13>
[Creation of positive electrode]
LiFePO ₄ 100 g with a coated carbon amount of 6% as a positive electrode active material, acetylene black (Denka Black manufactured by Denki Kagaku Kogyo Co., Ltd.) 5 g as a conductive agent, PVDF (Kureha Co., Ltd. KF binder # 1120 NMP 12 wt% as a binder Solution) A positive electrode coating solution was prepared so that it was diluted with 66.7 g (8 g as a solid content) and 79.4 g of N-methyl-2-pyrrolidone as a dispersion medium to a solid content of 45 wt%. This coating solution is coated on an aluminum foil having a thickness of 15 μm with a coating machine, dried at 130 ° C. and roll-pressed to obtain an active material density of 1.8 g / cm ³ , a positive electrode active material of 13 mg / cm ² (single side Per) was obtained.

  The same procedure as in Example 11 was performed except for the positive electrode.

<Comparative example 1>
In the production of the lithium battery, a test cell was produced in the same manner as in Example 1 except that a polyolefin microporous membrane (porosity 36%, thickness 25 μm) was used instead of the separator of Example 1.

<Comparative example 2>
A polymer solution in which 10 wt% of 3,4-epoxycyclohexylmethyl having a molecular weight of 252, which is a low molecular weight alicyclic epoxy, is used as a solvent in ethylene carbonate (EC): diethyl carbonate (DEC) = 3: 7 (volume ratio). An electrolyte mixed solution of 5% polymer was prepared by adjusting and mixing EC: DEC = 3: 7 (volume ratio) electrolytic solution containing 2 ML of LiPF ₆ as a lithium electrolyte salt at a weight ratio of 1: 1. It did not solidify at 60 ° C. for 20 hours.

[Evaluation methods]
[Impregnation test]
After pouring the polymer solution into the pre-battery, vacuum sealing was performed, and after 1 minute, a cell that started curing at 60 ° C. and a cell that was allowed to stand at 20 ° C. for 20 minutes and then started curing at 60 ° C. were prepared. After confirming the 0.2C discharge capacity for each cell, the influence of the impregnation time was confirmed by confirming the cycle retention after 500 cycles during 1C charge / discharge. The cell capacity was about 1 Ah.

[Overcharge test]
An overcharge test was conducted at a test ambient temperature of 20 ° C. ± 5 ° C. The maximum temperature of the battery surface temperature under charging condition 3C CC-CV 12V was confirmed.

  The lithium polymer battery of the present invention can be used for various portable devices such as a mobile phone, a notebook computer, a personal digital assistant (PDA), a video camera, and a digital camera. Furthermore, it is also useful for medium-sized or large-sized lithium batteries mounted on electric bicycles and electric vehicles.

Claims (5)

  An electrolyte solution for a solid electrolyte containing a crosslinkable material, a solvent, and a lithium electrolyte salt is injected into a sealable container together with a battery material including a separator and an electrode material, and the electrolyte solution for a solid electrolyte is obtained by crosslinking the crosslinkable material. A lithium polymer battery characterized in that it is made into a solid electrolyte by gelation, wherein the separator comprises a non-conductive porous material and electrically insulating particles.   2. The lithium polymer battery according to claim 1, wherein the crosslinkable material is a copolymer of a monomer having a ring-opening polymerizable functional group and a monomer having no ring-opening polymerizable functional group. The lithium polymer battery according to claim 2, wherein the monomer having the ring-opening polymerizable functional group is a monomer represented by the following general formula (1) or (2).

(In the formula, R ¹ represents H or CH ₃ , R ² represents a substituent represented by the following chemical formula (3), and R ³ in the chemical formula (3) represents an alkyl group having 1 to 6 carbon atoms. )

The lithium polymer battery according to claim 2, wherein the monomer having no ring-opening polymerizable functional group is a monomer represented by the following general formula (4).

(Wherein R ⁴ represents H or CH ₃ , and R ⁵ represents —COOCH ₃ , —COOC ₂ H ₅ , —COOC ₃ H ₇ , —COOC ₄ H ₉ , —COOCH ₂ CH (CH ₃ ) ₂ , _{-COO (CH 2 CH 2 O)} 1 ~ 3 CH 3, -COO (CH 2 CH 2 O) 1 ~ 3 C 2 H 5, -COO (CH 2 CH 2 O) 1 ~ 3 C 4 H 9, - _{COO (CH 2 CH (CH 3} ) O) 1 ~ 3 CH 3, -COO (CH 2 CH (CH 3) O) 1 ~ 3 C 2 H 5, -OCOCH 3, -OCOC 2 H 5, or -CH ₂ represents OC ₂ H ₅ )   The lithium polymer according to any one of claims 1 to 4, wherein the non-conductive porous material of the separator is a non-woven fabric made of non-conductive polymer fibers and is coated with electrically insulating inorganic particles. battery.