JPH05283106A - Battery positive electrode sheet, its manufacture, fully-solid secondary battery - Google Patents

Abstract

PURPOSE:To provide a battery positive electrode sheet easy to manufacture and having a high positive electrode utilization factor by forming the positive electrode sheet with a mixture of positive electrode active material particulates using a polymer solid electrode as a binder and electron conducting material particulates. CONSTITUTION:A polymer particulate dispersion liquid containing a polymer soluble in a dispersion medium made of water and a polar solvent and a surface active agent and containing positive electrode active material particulates and electron conducting material particulates is heated and removed with the dispersion medium to form a sheet. It is then impregnated with a metal salt electrolyte to form a positive electrode sheet. A polymer solid electrolyte can be also formed with a dispersion liquid. When a high-ion conductivity polymer electrolyte using a metal salt electrolyte is used for an ion transmission path, the ion diffusion in the sheet is accelerated. The polymer matrix in the solid electrolyte is separated from the ion transmission path, thus the plasticization due to the infiltration of the electrolyte can be suppressed. The positive electrode utilization factor is improved, and the manufacture is facilitated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is particularly applicable to high energy density batteries such as lithium secondary batteries and the like, has high efficiency and is easy to manufacture, and a battery positive electrode sheet composed of the battery positive electrode sheet. The present invention relates to a solid secondary battery.

[0002]

2. Description of the Related Art In recent years, there has been an increasing need for batteries having a high energy density as a power source for small and portable electronic devices. As a typical battery that meets such needs, a battery using an alkali metal, particularly lithium, as a negative electrode can be given. At present, lithium batteries use an organic electrolytic solution in which a lithium salt is dissolved as an electrolyte, and therefore safety cannot be said to be sufficient in terms of liquid leakage, dendrite short circuit, etc. Therefore, realization of an all-solid-state battery using a solid electrolyte made of an inorganic material or a polymer is expected. In the polymer solid electrolyte type battery, the electrolyte is a sheet-shaped polymer material, and the positive electrode is composed of a sheet in which fine particles of positive electrode active material and fine particles of electron conductive material are dispersed in the polymer electrolyte.
Since polymer materials have good workability and both the electrolyte and the electrodes can be composed of large-area sheets, it is expected that a large-capacity battery based on a polymer solid electrolyte will be realized, and in recent years vigorous studies have been made. For such a polymer solid electrolyte, a system in which a metal salt is dissolved in a polyether compound such as polyethylene oxide (PEO) has been extensively studied in the past [Watanabe, Ogata, Metal Surface Technology, Vol. 37. , No. 5,
214-221 (1986)], it was impossible to develop an ionic conductivity of 10 ^-4 S / cm or more near room temperature. In recent years, electrolyte-impregnated polymer solid electrolytes in which polar polymers are impregnated with a metal salt electrolyte solution have attracted attention [eg Koksbang, Journal of Power Sources (Journal of Power
f Power Sources), Vol. 32, pp. 175-185 (1990)], and its ionic conductivity is 10 ^-3 S / c.
Although the number has reached m, there is a problem in the manufacturing process such as a risk of radiation irradiation and a costly process.
On the other hand, as a research example of a conventional positive electrode sheet, an example in which a solid polymer electrolyte in which a metal salt is dissolved in PEO is used as a binder for a positive electrode active material and an electron conductive material [eg, M. Z. A.
MZAMunshi and solid state
Solid State Ionics, Vol. 41, pp. 41-46 (1988)], but at 60 ° C or higher at which PEO softens, the ion diffusion in the sheet is fast and good characteristics are exhibited, but the battery operates. In the vicinity of room temperature, which is the temperature, the ion diffusion in the positive electrode sheet is slow, and the contact between the positive electrode active material and the solid polymer electrolyte is poor, so that the positive electrode has a low utilization rate.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to be applicable to a battery having a high energy density such as a lithium battery and having a high positive electrode utilization efficiency. An object of the present invention is to provide a battery positive electrode sheet that can be easily manufactured, and an all-solid secondary battery configured using the battery positive electrode sheet.

[0004]

The present invention will be summarized. The first invention of the present invention is an invention relating to a battery positive electrode sheet, in which a battery positive electrode active material fine particle and an electron conductive material fine particle are contained in a polymer solid electrolyte. In a dispersed battery positive electrode sheet, the polymer solid electrolyte comprises a polymer matrix containing a crosslinked structure as a first component, a metal salt electrolyte as a second component, and a polymer as a third component, a surfactant or a mixture of both. And the third component is soluble in water, a polar solvent or a mixture of both, and stabilizes the mutual dispersion of the first component and the second component.
A second invention of the present invention is an invention relating to the method for producing a battery positive electrode sheet, comprising water, a polar solvent or a mixture of both as a dispersion medium, a polymer soluble in the dispersion medium, a surfactant or both. The dispersion of self-crosslinking low-polarity polymer fine particles containing the battery positive electrode active material fine particles and the electron conductive material fine particles, while containing the mixture as a stabilizer, removes the water, the polar solvent, or a mixture of both by heating. In this way, the polymer fine particles are fused and crosslinked to form a battery positive electrode sheet precursor structure having the battery positive electrode active material fine particles and the electron conductive material fine particles dispersed therein, and then the battery positive electrode sheet. It is characterized in that a metal salt electrolyte is impregnated into the precursor structure. A third invention of the present invention is an invention relating to a method for producing the battery positive electrode sheet, wherein water, a polar solvent or a mixture of both is used as a dispersion medium, and a polymer soluble in the dispersion medium, a surfactant or both are used. From a dispersion of self-crosslinking low-polarity polymer fine particles containing a mixture of a metal salt as a stabilizer, fine particles of a battery positive electrode active material and fine particles of an electron conductive material, and water by heating, a polar solvent or a mixture of both. By removing the, the polymer particles are fused together,
A cross-linking reaction is performed to form a battery positive electrode sheet precursor structure having the metal salt, battery positive electrode active material particles and electron conductive material particles dispersed therein, and then water, solvent or both in the battery positive electrode sheet precursor structure. It is characterized in that it is impregnated with the mixture of. A fourth invention of the present invention relates to an all-solid-state secondary battery, wherein in the all-solid-state secondary battery including a negative electrode, a polymer solid electrolyte, and a positive electrode, the polymer solid electrolyte is the same as the first invention. It is characterized in that it is a polymer solid electrolyte and that the positive electrode is the battery positive electrode sheet of the first invention.

The battery positive electrode sheet of the present invention is composed of a sheet of positive electrode active material fine particles using a solid polymer electrolyte as a binder, and an electron conductive material fine particle mixture. The binder consisting of this polymer solid electrolyte uses a polymer electrolyte with high ion conductivity, which uses a metal salt electrolyte in the ion conduction path, so that the ion diffusion in the sheet is fast, and when a battery is constructed. An increase in the utilization rate of the positive electrode active material and the specific capacity can be expected. Further, since the polymer matrix in the polymer solid electrolyte that is the binder of the positive electrode sheet of the present invention and the ion conduction path are phase-separated, plasticization of the polymer matrix due to the invasion of the electrolytic solution is suppressed, and further polymer Since the matrix has a cross-linking structure, the mechanical strength can be prevented from lowering even if the amount of electrolyte impregnated into the sheet is large.

The process for producing the battery positive electrode sheet of the present invention will be described. A dispersion liquid containing positive electrode active material particles and electron conductive material particles in a polymer particle dispersion liquid, or a polymer dispersion in which a metal salt is previously dissolved. The dispersion medium is heated and removed from the dispersion liquid containing the positive electrode active material fine particles and the electron conductive material fine particles in the liquid to form a sheet, which is then impregnated with an electrolytic solution or an electrolytic solution solvent. Since the polymer solid electrolyte can also be produced from the polymer particle dispersion liquid by the same process as the above-mentioned method for producing the positive electrode sheet, the production efficiency of the solid battery is good, and a low production cost can be expected.

Examples of the positive electrode active material used for the battery positive electrode sheet of the present invention include V ₂ O ₅ , MnO ₂ , TiS ₂ and V ₆ O.
₁₃ , ₁₃ , Cr ₃ O ₈ , MoS ₂ , MoS ₃ , NbSe, or a mixture thereof, and the electron conductive material is preferably pyrolytic graphite, acetylene black, a mixture thereof, or the like.

As the component of the polymer fine particles used in the production of the polymer solid electrolyte in the battery positive electrode sheet of the present invention, what is necessary is that the ionic conduction paths undergo phase separation when the solid electrolyte is formed. However, a polymer having a low polarity, for example, one containing an inexpensive hydrocarbon polymer or a copolymer thereof as a component is preferable. Examples of the polymer component in the polymer fine particles include the following alone or as a mixture: polystyrene, polypropylene, polyisobutene, polyethylene, polybutadiene, polyisoprene, poly (α-methylstyrene),
Polybutyl methacrylate, polybutyl acrylate,
Poly (2-ethylhexyl acrylate), polydibutyl phthalate, polyvinyl butyl ether, polyvinyl butyral, polyvinyl formal and copolymers containing these components.

The crosslinked structure can be obtained by an esterification reaction, an amidation reaction, an epoxy group ring opening reaction and the like. In order to carry out this cross-linking between molecules or within the molecule (self-crosslinking), it is sufficient that the polymer chain has two or more kinds of amide groups, hydroxyl groups, carboxyl groups, and epoxy groups. For example, a self-crosslinking polymer can be obtained by copolymerizing the above-mentioned polymer fine particle component monomer with two or more of the following polymerizable monomers: acrylamide, diacetone acrylamide, hydroxyethyl acrylate, hydroxyethyl. Methacrylate, hydroxypropyl acrylate, acrylic acid, methacrylic acid, itaconic acid, glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, etc. The polymer fine particles may be a mixture of plural kinds of fine particles having different components. The particle size of the polymer particles is preferably 0.01 to 50 μm.

Surfactants are preferably used as stabilizers for the fine polymer particle dispersion, and examples thereof include the following: fatty acid metal salts, alkylbenzenesulfonic acid metal salts, alkylsulfate metal salts, dioctyl. Metal sulfosuccinate, polyoxyethylene nonyl phenyl ether, polyoxyethylene stearic acid ester, polyoxyethylene sorbitan monolauric acid ester, polyoxyethylene-polyoxypropylene block copolymer, polyether modified silicone oil, etc., alone or in a mixture. Further, the polymer fine particles may be dispersed by using a polymer which is soluble in a dispersion medium as a stabilizer. Examples of such a polymer include hydroxyethyl cellulose, polyvinyl alcohol, polyacrylic acid metal salt, and methyl cellulose when water is the dispersion medium, although it depends on the dispersion medium. Water is preferably used as the dispersion medium of the polymer particle dispersion, but polar organic solvents such as alcohols can be used.

The metal salt, which is a component of the electrolytic solution forming the ionic conduction path, differs depending on the intended use of the polymer electrolyte to be produced.
ClO ₄ , LiAlCl ₄ , LiBF ₄ , LiPF ₆ ,
LiAsF ₆ , LiNbF ₆ , LiSCN, LiCl,
Examples include lithium salts such as Li (CF ₃ SO ₃ ), Li (C ₆ H ₅ SO ₃ ), and mixtures thereof.

Similarly, assuming the application to a lithium battery as an example, the solvent of the electrolytic solution is propylene carbonate, ethylene carbonate, γ-butyrolactone,
Dimethyl carbonate, dimethyl sulfoxide, acetonitrile, sulfolane, dimethylformamide, dimethylacetamide, 1,2-diethoxyethane, 1,2-
Examples include aprotic polar solvents such as dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, methyl acetate, and mixtures thereof. The mixing ratio of the metal salt and the solvent is preferably adjusted so that the metal salt concentration is 0.01 to 5 mol / l in the ion conduction path formed in the solid polymer electrolyte.

The polymer fine particle dispersion can be produced by developing and dispersing a polymer solution in a dispersion medium to form fine particles, and stabilizing it with a surfactant or a soluble polymer in the dispersion medium. It is preferable to manufacture by an emulsion polymerization method in an aqueous dispersion medium. The polymer fine particle dispersion can also be produced by dispersion polymerization in a polar solvent such as alcohol [eg, Y. Y. Almog, as well as British Polymer Journal
er Journal), Vol. 14, p. 131 (1982)].

The method for dispersing the positive electrode active material fine particles and the electron conductive material fine particles in the polymer fine particle dispersion or the polymer fine particle dispersion in which a metal salt is previously dissolved may be an ordinary method. The fine particles of the electron conductive substance may be placed in a polymer particle dispersion liquid or a polymer particle dispersion liquid in which a metal salt is previously dissolved, and agitated.

In order to obtain a battery having a large capacity, it is necessary to increase the mixing ratio of the positive electrode active material, and to increase the mixing ratio of the polymer fine particles to obtain sufficient mechanical strength as a sheet. Therefore, in order to obtain a positive electrode sheet having sufficient mechanical strength and capable of increasing the capacity of a battery, in order to satisfy these contradictory relationships, a positive electrode active material and an electron conductive material in a mixed dispersion liquid are used. , X, y, and z are the weight mixing ratios of the polymer particles, respectively, x + y + z = 1 and 0.3 ≦ x ≦ 0.8, 0.05 ≦ y ≦ 0.2, 0.2
It is necessary to set the range of ≦ z ≦ 0.6.

The method of removing water, the polar solvent, or a mixture of both from the above-mentioned polymer particle dispersion containing the cathode active material particles and the electron conductive material particles may be an ordinary method, for example, heating, depressurizing or a combination thereof. It can be evaporated with. By this process, the dispersed polymer fine particles are fused with each other to form a polymer matrix, which serves as a binder for the positive electrode active material fine particles and the electron conductive material fine particles, and the precursor structure of the battery positive electrode sheet of the present invention is produced. To be done. The production needs to be performed in a temperature range not lower than the glass transition temperature of the polymer matrix and at which the positive electrode active material and the metal salt are not decomposed. If necessary, the sheet can be pressed into a desired shape by pressurizing. When the water or solvent of the dispersion medium adversely affects the battery or the like to which the solid electrolyte is applied, heat the dispersion medium to the boiling point or higher, or
A combination of heating and vacuum treatment must be used to remove the dispersion medium.

The impregnation with the electrolytic solution may be carried out by an ordinary method. For example, in the case of the second inventive method of the present invention, the positive electrode sheet precursor structure may be immersed in the electrolytic solution. The impregnation amount of the electrolytic solution can be controlled by the temperature at the time of immersion and the length of the immersion time, but it is preferable to impregnate the polymer solid electrolyte component with 10% by weight or more.

When the metal salt is previously dissolved in the fine polymer particle dispersion as in the third aspect of the present invention, the solvent or water or a mixture of both may be impregnated by a usual method. Well, for example, the prepared positive electrode sheet precursor structure may be immersed in a solvent, water, or a mixture of both. The impregnated amount of the solvent or water or the mixture of both can be controlled by the temperature at the time of immersion and the length of the immersion time, but it is preferable to impregnate the polymer matrix component with 10% by weight or more.

On the other hand, the characteristics of the structure of the all-solid-state secondary battery of the present invention will be described. The negative electrode used in the all-solid-state secondary battery of the present invention is a lithium metal foil in consideration of application to, for example, a lithium secondary battery. A low potential intercalation compound such as a lithium / aluminum alloy, or lithium / carbon is preferably used.

The polymer fine particles used in the polymer solid electrolyte constituting the all-solid secondary battery of the present invention, the stabilizer and the metal salt constituting the electrolytic solution, and the solvent were used as the binder of the battery positive electrode sheet of the present invention. It may be the same as the substance constituting the polymer solid electrolyte. In addition, the fabrication is Japanese Patent Application No. 3-35439.
The method described in the specification No. 3 is used. Basically, a polymer matrix is formed from a polymer particle dispersion liquid,
It is prepared by a method of impregnating a polymer matrix with a metal salt electrolyte.

As the positive electrode constituting the all solid state secondary battery of the present invention, the battery positive electrode sheet of the first invention of the present invention is used.

The all-solid secondary battery of the present invention is manufactured by stacking the negative electrode, the solid polymer electrolyte, and the positive electrode in this order. Other structural materials that constitute the battery may be conventionally known materials.

[0023]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A styrene-butadiene latex (trade name: Nipol 2570 × manufactured by Nippon Zeon Co.) containing a surfactant and self-crosslinking polymer particles as a polymer particle dispersion liquid.
5) 10 g was taken and diluted with 10 g of water. The alkali metal ions in the latex were replaced with lithium ions with an ion exchange resin (Amberlite IR-120B manufactured by Rohm and Haas Co.) replaced with lithium ions. 3 g of divanadium pentoxide (manufactured by Kanto Chemical Co., Inc.) and 0.6 g of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.) were dispersed in this latex. It was dried at a temperature of 60 ° C. until the solid content in the dispersion became about 70%, and then spread into a sheet with a film applicator having a coating thickness of 100 μm. It was vacuum dried at room temperature for 7 hours and at 90 ° C. for 24 hours to obtain a positive electrode sheet precursor structure. Next, an electrolyte solution was prepared by dissolving lithium perchlorate at a concentration of 1 mol / l in an equal volume mixed solvent of γ-butyrolactone / 1,2-dimethoxyethane, and the positive electrode sheet precursor structure prepared here was prepared for 24 hours. It was dipped to obtain the positive electrode sheet of the present invention. The obtained positive electrode sheet was a sheet having sufficient mechanical strength, and the impregnated electrolytic solution did not exude even when the sheet was pressed.

Next, a coin type battery was produced using the positive electrode sheet of the present invention. The constituent components are lithium metal foil (thickness 70 μm) for the negative electrode, γ-butyrolactone for the electrolyte, 1,
A composition comprising 2-dimethoxyethane, polyacrylonitrile, polyethylene glycol diacrylate and lithium perchlorate in a weight ratio of 35: 40: 16: 1: 8 is irradiated with ultraviolet rays (using a Hg-Xe lamp manufactured by USHIO INC. For 10 m).
Then, the solid electrolyte (thickness: 32 μm) obtained by curing was performed at W / cm ² for 30 minutes, and the positive electrode sheet of the present invention (thickness: 98 μm) was used as a positive electrode. Negative electrode, electrolyte,
The positive electrode was laminated in this order, and this was enclosed in a coin cell case. All the steps for producing the battery were performed in a glove box in an argon atmosphere. This battery has a voltage range of 3.5-
As a result of conducting a charge / discharge test under the conditions of 1.8 V, discharge current 1 mA and charge current 1 mA, a specific capacity of 148 mAh / g was obtained.

Example 2 A styrene-butadiene latex (trade name: Nipol 2570 × manufactured by Nippon Zeon Co., Ltd.) containing a surfactant and self-crosslinking polymer particles as a polymer particle dispersion liquid.
5) 10 g was taken and diluted with 10 g of water. The alkali metal ions in the latex were replaced with lithium ions with an ion exchange resin (Amberlite IR-120B manufactured by Rohm and Haas Co.) replaced with lithium ions. 3 g of divanadium pentoxide (manufactured by Kanto Chemical Co., Inc.) and 0.6 g of acetylene black (manufactured by Denki Kagaku Kogyo Co., Ltd.) were dispersed in this latex. Lithium perchlorate (0.07 g) was dissolved in this dispersion, and the mixture was dried at a temperature of 60 ° C. until the solid content in the dispersion was about 70%, and then the sheet was coated with a film applicator having a coating thickness of 100 μm. I stretched it out. It was vacuum dried at room temperature for 7 hours and at 90 ° C. for 24 hours to obtain a positive electrode sheet precursor structure. Then, the prepared positive electrode sheet precursor structure is immersed in an equal volume mixed solvent of γ-butyrolactone / 1,2-dimethyoxyethane for 20 minutes,
A positive electrode sheet of the present invention was obtained. The obtained positive electrode sheet was a sheet having sufficient mechanical strength, and the impregnated electrolytic solution did not exude even when the sheet was pressed.

Next, a coin type battery was produced using the positive electrode sheet of the present invention. The constituent components are lithium metal foil (thickness 70 μm) for the negative electrode, γ-butyrolactone for the electrolyte, 1,
A composition comprising 2-dimethoxyethane, polyacrylonitrile, polyethylene glycol diacrylate and lithium perchlorate in a weight ratio of 35: 40: 16: 1: 8 is irradiated with ultraviolet rays (using a Hg-Xe lamp manufactured by USHIO INC. For 10 m).
The solid electrolyte (thickness: 38 μm) obtained by curing the resulting solid electrolyte (W / cm ² , 30 minutes) and the positive electrode sheet of the present invention (thickness: 92 μm) were used as positive electrodes. Negative electrode, electrolyte,
The positive electrode was laminated in this order, and this was enclosed in a coin cell case. All the steps for producing the battery were performed in a glove box in an argon atmosphere. This battery has a voltage range of 3.5-
As a result of conducting a charge / discharge test under the conditions of 1.8 V, discharge current 1 mA and charge current 1 mA, a specific capacity of 152 mAh / g was obtained.

Example 3 A positive electrode sheet was produced by the method shown in Example 1. The solid polymer electrolyte was prepared by the following method. Styrene-butadiene latex (trade name: Nipol 2570 × 5) manufactured by Nippon Zeon Co., Ltd. containing a surfactant and self-crosslinking polymer particles as a polymer particle dispersion liquid 10
g was taken and diluted with 10 g of water. After replacing the alkali metal ions in the latex with lithium ions with an ion exchange resin (Amberlite IR-120B manufactured by Rohm and Haas Co.) substituted with lithium ions, the atmospheric pressure was set to 95.
After heating at 0 ° C. and drying until the solid content became 95% by weight, it was drawn into a sheet shape with a film applicator having a coating thickness of 30 μm. After further drying at 105 ° C for 1 hour,
It was dried under reduced pressure at 100 ° C. and 0.1 Torr for 20 hours to obtain a polymer matrix sheet. Next, an electrolyte was prepared by dissolving lithium perchlorate at a concentration of 1 mol / l in an equal volume mixed solvent of γ-butyrolactone / 1,2-dimethyoxyethane, and the polymer matrix prepared here was immersed for 2 hours. A polymer solid electrolyte was obtained.

Next, a lithium metal foil (thickness 70 μm),
The polymer solid electrolyte (thickness: 27 μm) and the positive electrode sheet (thickness: 99 μm) were laminated in this order, and this was enclosed in a coin cell case. All the steps for producing the battery were performed in a glove box in an argon atmosphere. This battery was subjected to a charge / discharge test under the conditions of a voltage range of 3.5 to 1.8 V, a discharge current of 1 mA and a charge current of 1 mA, and as a result, a specific capacity of 18
5 mAh / g was obtained.

Example 4 A positive electrode sheet was produced by the method shown in Example 2. The solid polymer electrolyte was prepared by the following method. Styrene-butadiene latex (trade name: Nipol 2570 × 5) manufactured by Nippon Zeon Co., Ltd. containing a surfactant and self-crosslinking polymer particles as a polymer particle dispersion liquid 10
g was taken and diluted with 10 g of water. After the alkali metal ions in the latex were replaced with lithium ions with an ion exchange resin (Amberlite IR-120B manufactured by Rohm and Haas Co.) replaced with lithium ions, 0.4 g of lithium perchlorate was dissolved under normal pressure. After heating at 95 ° C and drying until the solid content reaches 95% by weight, the coating thickness is 30μ
The film was stretched into a sheet with a m film applicator.
After further drying at 105 ° C for 1 hour, 100 ° C at 0.1T
It was dried under reduced pressure at orr for 20 hours to obtain a polymer matrix sheet. Next, the polymer matrix sheet prepared in an equal volume mixed solvent of [gamma] -butyrolactone / 1,2-dimethoxyethane was immersed for 20 minutes to obtain a polymer solid electrolyte.

Next, a lithium metal foil (thickness 70 μm),
The polymer solid electrolyte (thickness: 27 μm) and the positive electrode sheet (thickness: 99 μm) were laminated in this order, and this was enclosed in a coin cell case. All the steps for producing the battery were performed in a glove box in an argon atmosphere. This battery was subjected to a charge / discharge test under the conditions of a voltage range of 3.5 to 1.8 V, a discharge current of 1 mA and a charge current of 1 mA, and as a result, a specific capacity of 18
8 mAh / g was obtained.

[0032]

As is clear from the above description, the battery comprising the battery positive electrode sheet of the present invention has a large specific capacity, and when this battery positive electrode sheet is applied to a high energy battery such as a lithium secondary battery. In addition, there is an advantage that a safe solid battery with high energy density, high efficiency and no liquid leakage can be obtained.

Claims (4)

[Claims] 1. A battery positive electrode sheet in which fine particles of a battery positive electrode active material and fine particles of an electron conductive material are dispersed in a solid polymer electrolyte, wherein the solid polymer electrolyte comprises a polymer matrix containing a crosslinked structure as a first component, It is composed of a metal salt electrolyte as the second component, a polymer, a surfactant or a mixture of both as the third component, and the third component is soluble in water, a polar solvent or a mixture of both, and the first component A battery positive electrode sheet, characterized in that the mutual dispersion of the second component is stabilized. 2. Water, a polar solvent, or a mixture of both as a dispersion medium, and a polymer soluble in the dispersion medium, a surfactant or a mixture of both as a stabilizer, and at the same time, fine particles of battery positive electrode active material and From a dispersion liquid of self-crosslinking low-polarity polymer particles containing electron conductive material particles,
By removing the water, the polar solvent or a mixture of both by heating, the polymer fine particles are fused together, and a cross-linking reaction is performed to disperse the battery positive electrode active material fine particles and the electron conductive material fine particles in the battery positive electrode sheet. The method for producing a battery positive electrode sheet according to claim 1, wherein a precursor structure is formed and then the battery positive electrode sheet precursor structure is impregnated with a metal salt electrolyte. 3. Water, a polar solvent or a mixture of both are used as a dispersion medium, and a polymer soluble in the dispersion medium, a surfactant or a mixture of both are contained as a stabilizer, and a metal salt and a battery positive electrode active material. From the dispersion liquid of the self-crosslinking low-polarity polymer fine particles containing the fine particles and the electron conductive substance fine particles, the water, the polar solvent, or a mixture of both are removed by heating to fuse the polymer fine particles to each other and crosslink them. The metal salt, the battery positive electrode active material fine particles and the electron conductive material fine particles are dispersed to form a battery positive electrode sheet precursor structure, and thereafter, water, a solvent or both of them is added to the battery positive electrode sheet precursor structure. The method for producing a battery positive electrode sheet according to claim 1, wherein the mixture is impregnated. 4. An all-solid secondary battery comprising a negative electrode, a solid polymer electrolyte and a positive electrode, wherein the solid polymer electrolyte is the solid polymer electrolyte according to claim 1, and the positive electrode is according to claim 1. An all-solid secondary battery, which is the battery positive electrode sheet described above.