JP2016139511A - Solid electrolyte composition, battery electrode sheet using the same, and method of manufacturing battery electrode sheet and all-solid secondary battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte composition material that can implement an excellent binding capacity, an excellent film state when a coating film is formed and a cycle characteristic, a battery electrode sheet using the same, and a method of manufacturing a battery electrode sheet and an all-solid secondary battery.SOLUTION: A solid electrolyte composition for forming an all-solid secondary battery containing a positive electrode active material layer, an inorganic solid electrolyte layer and a negative electrode active material layer forms at least one layer of the positive electrode active layer, the inorganic solid electrolyte layer and the negative electrode active layer. The composition contains inorganic solid electrolyte having electrical conductivity of metal ions belonging to the first group or second group of the periodic table, polymer particles and dispersion medium. The dispersion medium contains at least one kind of solvent dissolving the polymer particles, and at least one kind of solvent which does not dissolve the polymer particles. A battery electrode sheet and an all-solid secondary battery that use the solid electrolyte composition, and a method of manufacturing the battery electrode sheet and the all-solid secondary battery are provided.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a solid electrolyte composition, a battery electrode sheet using the same, a battery electrode sheet, and a method for producing an all-solid secondary battery.

An electrolyte solution is used for the lithium ion battery. Attempts have been made to replace the electrolytic solution with a solid electrolyte to obtain an all-solid-state secondary battery in which the constituent materials are all solid. One of the advantages of the technology using an inorganic solid electrolyte is reliability. A flammable material such as a carbonate-based solvent is used as a medium for the electrolytic solution used in the lithium ion secondary battery. Although various safety measures have been taken, it cannot be said that there is no risk of malfunctions during overcharge, and further measures are desired. An all-solid-state secondary battery that can make the electrolyte nonflammable is positioned as a fundamental solution.
A further advantage of the all-solid-state secondary battery is that it is suitable for increasing the energy density by stacking electrodes. Specifically, a battery having a structure in which an electrode and an electrolyte are directly arranged in series can be obtained. At this time, since the metal package for sealing the battery cell, the copper wire and the bus bar for connecting the battery cell can be omitted, the energy density of the battery is greatly increased. In addition, good compatibility with the positive electrode material capable of increasing the potential is also mentioned as an advantage.

  From the above advantages, the development of a next-generation lithium ion secondary battery has been vigorously advanced (Non-patent Document 1). On the other hand, in an inorganic all-solid secondary battery, since the electrolyte is a hard solid, there is a point that needs to be improved. For example, the interfacial resistance between the solid particles and between the solid particles and the current collector is increased. In order to improve this, a technique using a binder made of a polymer compound has been proposed.

  Patent Document 1 discloses an example in which polyoxyethylene lauryl ether is applied as an emulsifier to an acrylic resin. Patent Document 2 discloses the use of an acrylic binder, a fluorine-containing binder, and a rubber binder.

JP 2013-008611 A JP 2012-212552 A

NEDO Technology Development Organization, Fuel Cell / Hydrogen Technology Development Department, Energy Storage Technology Development Office “NEDO Next-Generation Automotive Storage Battery Technology Development Roadmap 2008” (June 2009)

The binders disclosed in Patent Documents 1 and 2 are not yet sufficient to meet the recent demand for higher performance of lithium ion secondary batteries, and further improvements have been desired.
Therefore, the present invention has a positive binding material, an inorganic solid electrolyte layer, or a negative electrode active material layer (hereinafter also referred to as a coating film) of an all-solid-state secondary battery due to the good binding property of the binder to the active material and the inorganic solid electrolyte. An object of the present invention is to provide a solid electrolyte composition that is free from defects such as chipping, cracking, cracking, and peeling when formed, and that can realize excellent battery voltage and cycle characteristics as an all-solid secondary battery. Furthermore, this invention aims at provision of the manufacturing method of the electrode sheet for batteries using this solid electrolyte composition, the electrode sheet for batteries, and an all-solid-state secondary battery.

(1) A composition for making an all-solid secondary battery comprising a positive electrode active material layer, an inorganic solid electrolyte layer, and a negative electrode active material layer, the positive electrode active material layer, the inorganic solid electrolyte layer, and the negative electrode active material layer A composition for forming at least one layer of
An inorganic solid electrolyte having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table;
Containing polymer particles and a dispersion medium,
A solid electrolyte composition, wherein the dispersion medium is a dispersion medium comprising at least one solvent that dissolves polymer particles and at least one solvent that does not dissolve polymer particles.
(2) The solid electrolyte composition according to (1), wherein the dispersion medium is a non-aqueous solvent.
(3) The solid electrolyte composition according to (1) or (2), wherein the boiling point of the solvent that dissolves the polymer particles is higher than the boiling point of the solvent that does not dissolve the polymer particles.
(4) The boiling point of the solvent that dissolves the polymer particles is 100 ° C. or more and less than 250 ° C., the boiling point of the solvent that does not dissolve the polymer particles is 80 ° C. or more and less than 220 ° C., and the boiling point of the solvent that dissolves the polymer particles is The solid electrolyte composition according to any one of (1) to (3), which is 20 ° C. or more higher than the boiling point of a solvent that does not dissolve particles.
(5) The ratio of the mass of the solvent that dissolves the polymer particles to the mass of the solvent that does not dissolve the polymer particles (the mass of the solvent that dissolves the polymer particles: the mass of the solvent that does not dissolve the polymer particles) is 0.1: 99.9 to The solid electrolyte composition according to any one of (1) to (4), which is 50:50.
(6) The LogP value of the solvent that dissolves the polymer particles is less than 3.0, and the LogP value of the solvent that does not dissolve the polymer particles is 3.0 or more, and any one of (1) to (5) The solid electrolyte composition described in 1.
(7) The solvent that dissolves the polymer particles is a ketone solvent, an ester solvent, a carbonate solvent, a nitrile solvent, an ether solvent, or an amide solvent, and the solvent that does not dissolve the polymer particles is a hydrocarbon solvent (1) to (6). Solid electrolyte composition as described in any one of these.
(8) The solid electrolyte composition according to any one of (1) to (7), wherein the average particle diameter of the polymer particles is 0.01 μm to 100 μm.
(9) The solid electrolyte composition according to any one of (1) to (8), wherein the polymer particles are an acrylic resin or a urethane resin.
(10) The content of the polymer particles is 0.1 to 20 parts by mass and the content of the dispersion medium is 50 to 2,000 parts by mass with respect to 100 parts by mass of the inorganic solid electrolyte. The solid electrolyte composition as described in any one of (1).
(11) The solid electrolyte composition according to any one of (1) to (10), further containing an electrode active material.
(12) The solid electrolyte composition according to any one of (1) to (11), wherein the inorganic solid electrolyte is a sulfide-based inorganic solid electrolyte.
(13) The solid electrolyte composition according to any one of (1) to (11), wherein the inorganic solid electrolyte is an oxide-based inorganic solid electrolyte.
(14) The solid electrolyte composition according to (13), wherein the inorganic solid electrolyte is selected from compounds of the following formula.
· _Li x _La y TiO ₃
x = 0.3-0.7, y = 0.3-0.7
・ Li ₇ La ₃ Zr ₂ O ₁₂
・ Li _3.5 Zn _0.25 GeO ₄
LiTi ₂ P ₃ O ₁₂ ,
_{· Li 1 + x + y (} Al, Ga) x (Ti, Ge) 2 -xSi y P 3 -yO 12
0 ≦ x ≦ 1, 0 ≦ y ≦ 1
・ Li ₃ PO ₄
・ LiPON
・ LiPOD
D is Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au
At least one selected from LiAON
A is at least one selected from Si, B, Ge, Al, C, Ga, etc. (15) The solid electrolyte composition according to any one of (1) to (14) is manufactured on a metal foil. Film electrode sheet for battery.
(16) A method for producing a battery electrode sheet, wherein the solid electrolyte composition according to any one of (1) to (14) is formed on a metal foil.
(17) The method for producing an electrode sheet for a battery according to (16), comprising a step of heating at 80 ° C. or higher after film formation.
(18) A method for producing an all-solid secondary battery, comprising producing an all-solid secondary battery using the battery electrode sheet according to (15).

In this specification, a numerical range expressed using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value.
Further, in this specification, when there are a plurality of substituents or linking groups indicated by a specific symbol, or when a plurality of substituents etc. (same definition of the number of substituents) are specified simultaneously or alternatively, The substituents and the like may be the same as or different from each other. Further, when a plurality of substituents and the like are close to each other, they may be bonded to each other or condensed to form a ring.

  The solid electrolyte composition of the present invention has no defects such as chipping, cracking, cracking, and peeling when a coating film of an all-solid-state secondary battery is formed due to the good binding property of the binder to the active material and the inorganic solid electrolyte. In addition, excellent battery voltage and cycle characteristics can be realized as an all-solid secondary battery. Moreover, the battery electrode sheet of the present invention enables the production of an all-solid secondary battery having the above-described excellent performance. Moreover, according to the manufacturing method of this invention, the battery electrode sheet of this invention and the all-solid-state secondary battery which has said outstanding performance can be manufactured efficiently.

It is sectional drawing which shows typically the all-solid-state lithium ion secondary battery which concerns on preferable embodiment of this invention. It is a longitudinal cross-sectional view which shows typically the testing apparatus utilized in the Example.

  In the present invention, the all-solid-state secondary battery includes at least one of a positive electrode active material layer, a negative electrode active material layer, and an inorganic solid electrolyte layer that conducts metal ions belonging to Group 1 or Group 2 of the periodic table. Formed from a solid electrolyte composition containing an inorganic solid electrolyte having a property, polymer particles, a solvent that dissolves at least one polymer particle, and a solvent that does not dissolve at least one polymer particle. Hereinafter, the preferable embodiment will be described.

FIG. 1 is a cross-sectional view schematically showing an all solid state secondary battery (lithium ion secondary battery) according to a preferred embodiment of the present invention. The all-solid-state secondary battery 10 of this embodiment includes a negative electrode current collector 1, a negative electrode active material layer 2, a solid electrolyte layer 3, a positive electrode active material layer 4, and a positive electrode current collector 5 in order from the negative electrode side. Each layer is in contact with each other and has a laminated structure. With such a structure, at the time of charging, electrons (e ⁻ ) are supplied to the negative electrode side, and lithium ions (Li ⁺ ) are accumulated therein. On the other hand, at the time of discharge, lithium ions (Li ⁺ ) accumulated in the negative electrode are returned to the positive electrode side, and electrons are supplied to the working part 6. In the illustrated example, a light bulb is illustrated as the operation site 6, but this is turned on by discharge. The solid electrolyte composition of the present invention is preferably used as a molding material for the negative electrode active material layer, the positive electrode active material layer, and the solid electrolyte layer, and particularly preferably used for molding the solid electrolyte layer.

  The thicknesses of the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 are not particularly limited, but are preferably 1,000 μm or less, more preferably 1 to 1,000 μm in consideration of general battery dimensions, 3-400 micrometers is still more preferable.

<Solid electrolyte composition>
(Inorganic solid electrolyte)
The inorganic solid electrolyte is a solid electrolyte made of an inorganic substance, and the solid electrolyte is a solid electrolyte that can move ions inside. From this point of view, it may be referred to as an ion conductive inorganic solid electrolyte in consideration of distinction from an electrolyte salt (supporting electrolyte) described later.

Since inorganic solid electrolytes do not contain organic substances (carbon atoms), organic solid electrolytes, polymer electrolytes typified by PEO (polyethylene oxide), etc., organic electrolytes typified by LiTFSI (lithium bistrifluoromethanesulfonimide), etc. It is clearly distinguished from salt. Further, since the inorganic solid electrolyte is solid in a steady state, it is not dissociated or released into cations and anions. In this respect, it is also clearly distinguished from inorganic electrolyte salts (LiPF ₆ , LiBF ₄ , LiFSI [lithium bis (fluorosulfonyl) imide], LiCl, etc.) in which cations and anions are dissociated or liberated in the electrolyte and polymer. . The inorganic solid electrolyte is not particularly limited as long as it contains a metal belonging to Group 1 or Group 2 of the periodic table and has conductivity of this metal ion (preferably lithium ion), and does not have electron conductivity. Things are common.

  The inorganic solid electrolyte used in the present invention has conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table. As the inorganic solid electrolyte, a solid electrolyte material applied to this type of product can be appropriately selected and used. Typical examples of inorganic solid electrolytes include (i) sulfide-based inorganic solid electrolytes and (ii) oxide-based inorganic solid electrolytes.

(I) Sulfide-based inorganic solid electrolyte A sulfide-based inorganic solid electrolyte (hereinafter, also simply referred to as a sulfide solid electrolyte) contains a sulfur atom (S) and belongs to Group 1 or Group 2 of the periodic table. Those having the ionic conductivity of the metal to which they belong and having electronic insulation are preferred. For example, a lithium ion conductive inorganic solid electrolyte that satisfies the composition formula represented by the following formula (1) can be given.

Li _{a Mb} P _c S _d (1)

  In formula (1), M represents an element selected from B, Zn, Si, Cu, Ga, and Ge. a to d represent the composition ratio of each element, and a: b: c: d satisfies 1 to 12: 0 to 1: 1: 2 to 9, respectively.

  In the formula (1), the composition ratio of Li, M, P and S is preferably such that b is 0, more preferably b = 0 and the composition of a, c and d is a: c: d = 1 -9: 1: 3-7, more preferably b = 0 and a: c: d = 1.5-4: 1: 3.25-4.5. As will be described later, the composition ratio of each element can be controlled by adjusting the blending amount of the raw material compound in producing the sulfide-based solid electrolyte.

  The sulfide-based solid electrolyte may be amorphous (glass) or crystallized (glass ceramic), or only a part may be crystallized.

The ratio of Li ₂ S to P ₂ S ₅ in the Li—PS glass and the Li—PS glass glass ceramic is a molar ratio of Li ₂ S: P ₂ S ₅ , preferably 65:35 to 35:35. 85:15, more preferably 68:32 to 75:25. By setting the ratio of Li ₂ S to P ₂ S ₅ within this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity can be preferably 1 × 10 ⁻² S / m or more, more preferably 0.1 S / m or more.

Specific examples of the compound include those using a raw material composition containing, for example, Li ₂ S and a sulfide of an element belonging to Group 13 to Group 15.
More specifically, for _{example, Li 2 S-P 2 S} 5, Li 2 S-GeS 2, Li 2 S-GeS 2 -ZnS, Li 2 S-Ga 2 S 3, Li 2 S-GeS 2 -Ga _{2 S 3, Li 2 S-} GeS 2 -P 2 S 5, Li 2 S-GeS 2 -Sb 2 S 5, Li 2 S-GeS 2 -Al 2 S 3, Li 2 S-SiS 2, Li 2 S _{-Al 2 S 3, Li 2 S} -SiS 2 -Al 2 S 3, Li 2 S-SiS 2 -P 2 S 5, Li 2 S-SiS 2 -LiI, Li 2 S-SiS 2 -Li 4 SiO 4 _{, Li 2 S-SiS 2 -Li} 3 PO 4, Li 10 GeP 2 S 12 and the like. Among them, Li ₂ S—P ₂ S ₅ , Li ₂ S—GeS ₂ —Ga ₂ S ₃ , Li ₂ S—GeS ₂ —P ₂ S ₅ , Li ₂ S—SiS ₂ —P ₂ S ₅ , Li _{2 S-SiS 2 -Li 4 SiO 4} , Li 2 S-SiS 2 -Li 3 crystalline and or amorphous material composition consisting of PO ₄ are preferred as they have a high lithium ion conductivity.
Examples of a method for synthesizing a sulfide solid electrolyte material using such a raw material composition include an amorphization method. Examples of the amorphization method include a mechanical milling method and a melt quenching method. Among these, the mechanical milling method is preferable because processing at normal temperature is possible and the manufacturing process can be simplified.

  Examples of the sulfide solid electrolyte include T.I. Ohtomo, A .; Hayashi, M .; Tatsumisago, Y. et al. Tsuchida, S .; Hama, K .; Kawamoto, Journal of Power Sources, 233, (2013), pp231-235 and A.K. Hayashi, S .; Hama, H .; Morimoto, M .; Tatsumisago, T .; Minami, Chem. Lett. , (2001), pp 872-873, and the like.

(Ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte (hereinafter, also simply referred to as “oxide-based solid electrolyte”) contains an oxygen atom (O), and is group 1 or group 2 of the periodic table. It is preferable to include a metal belonging to the above, to have ionic conductivity, and to have electronic insulation.

Specifically, for example, Li _xa La _ya TiO ₃ [xa = 0.3 to 0.7, ya = 0.3 to 0.7] (LLT), Li ₇ La ₃ Zr ₂ O ₁₂ (LLZ), Li _3.5 Zn _0.25 GeO ₄ having a LIICON (Lithium super ionic conductor) type crystal structure, LiTi ₂ P ₃ O ₁₂ having a NASICON (Natium super ionic conductor) type crystal structure, Li _{1 + xb + bb (Ti, Ge) 2-xb} Si yb P 3-yb O 12 ( provided that, 0 ≦ xb ≦ 1,0 ≦ yb ≦ 1), Li 7 La 3 Zr 2 O 12 having a garnet-type crystal structure.
A phosphorus compound containing Li, P and O is also preferable. For example, lithium phosphate (Li ₃ PO ₄ ), LiPON obtained by substituting a part of oxygen atoms of lithium phosphate with nitrogen atoms, LiPOD (D is Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, Au or the like is selected. Moreover, LiAON (A shows at least 1 sort (s) chosen from Si, B, Ge, Al, C, Ga, etc.) etc. can be used preferably.
Among them, Li _{1 + xb + yb} (Al, Ga) _xb (Ti, Ge) _2-xb Si _yb P _3-yb O ₁₂ (where 0 ≦ xb ≦ 1, 0 ≦ yb ≦ 1) is high in lithium ion conduction. It is preferable because it has good properties, is chemically stable, and is easy to handle. These may be used alone or in combination of two or more.

The lithium ion conductivity of the oxide-based solid electrolyte is preferably 1 × 10 ⁻⁴ S / m or more, more preferably 1 × 10 ⁻³ S / m or more, and further preferably 5 × 10 ⁻³ S / m or more.

  The average particle size of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, and more preferably 0.1 μm or more. As an upper limit, 100 micrometers or less are preferable and 50 micrometers or less are more preferable. The average particle size of the inorganic solid electrolyte is measured by the same method as the method for measuring the average particle size of the polymer particles shown in the section of Examples described later.

The concentration of the inorganic solid electrolyte in the solid electrolyte composition is preferably 50% by mass or more, and 80% by mass or more in 100% by mass of the solid component, considering both battery performance and reduction / maintenance effect of interface resistance. More preferably, 90 mass% or more is further more preferable. From the same viewpoint, the upper limit is preferably 99.9% by mass or less, more preferably 99% by mass or less, and further preferably 98% by mass or less.
In the present specification, the solid component refers to a component that does not disappear by volatilization or evaporation when dried at 170 ° C. for 6 hours. Typically, it refers to components other than the dispersion medium described below.

(Polymer particles)
The polymer particles used in the present invention serve as a binder that binds to the inorganic solid electrolyte, optionally in combination with additives and the like.
The polymer particles used in the present invention may be organic polymer particles or organic-inorganic hybrid polymer particles as long as they exhibit good binding properties between the active material and the inorganic solid electrolyte as a binder. Particles are preferred.
The structure is not particularly limited as long as it is organic polymer particles. For example, fluorine resin (polyvinylene difluoride (PVdF), etc.), hydrocarbon resin (hydrogenated styrene butadiene rubber (HSBR), styrene butadiene rubber (SBR), etc.), acrylic resin, styrene resin, amide resin, imide resin, Examples of the resin include urethane resin, urea resin, ester resin, ether resin, phenol resin, epoxy resin, carbonate resin, silicone resin, and combinations thereof. Among these, acrylic resin or urethane resin is particularly preferable, and urethane resin is most preferable.
In the present invention, the resin used for the polymer particles is not limited to one type, but may be two or more types, or a combination thereof.

  Here, the polymer particles used in the present invention may be any particles of a block copolymer, an alternating copolymer, or a random copolymer.

Further, when a sulfide-based solid electrolyte is used, the water content of the polymer is 100 ppm from the viewpoint of suppressing the generation of hydrogen sulfide due to the reaction between the sulfide-based solid electrolyte and water and suppressing the decrease in ionic conductivity. The following is preferred.
The water content was determined by measuring the moisture content (g) in the sample by the Karl Fischer method using Karl Fischer liquid Aquamicron AX (trade name, manufactured by Mitsubishi Chemical Corporation) using the polymer after vacuum drying at 80 ° C. Measure and calculate by dividing the amount of water (g) by the sample mass (g).

  The glass transition temperature of the polymer particles used in the present invention is preferably −100 ° C. or higher and lower than 100 ° C., more preferably −80 ° C. or higher and lower than 80 ° C., and further preferably −60 ° C. or higher and lower than 50 ° C. When the glass transition temperature is within the above range, good ionic conductivity can be obtained.

The glass transition temperature (Tg) is measured under the following conditions using a dry sample and a differential scanning calorimeter “X-DSC7000” (trade name, manufactured by SII Nanotechnology Co., Ltd.). The measurement is performed twice on the same sample, and the second measurement result is adopted.
Measurement chamber atmosphere: Nitrogen (50 mL / min)
Temperature increase rate: 5 ° C / min
Measurement start temperature: -100 ° C
Measurement end temperature: 200 ° C
Sample pan: Aluminum pan Mass of measurement sample: 5 mg
Calculation of Tg: Tg is calculated by rounding off the decimal point of the intermediate temperature between the lowering start point and the lowering end point of the DSC chart.

The mass average molecular weight of the polymer particles used in the present invention is preferably 10,000 or more and less than 500,000, more preferably 20,000 or more and less than 300,000, and even more preferably 30,000 or more and less than 200,000.
When the mass average molecular weight of the polymer particles is within the above range, better binding properties are exhibited and handling properties (manufacturability) are improved.

  As the mass average molecular weight of the polymer particles used in the present invention, a value measured in terms of the following standard sample by gel permeation chromatography (GPC) is adopted. The measuring device and measurement conditions are basically based on the following condition 1 and are allowed to be set to condition 2 depending on the solubility of the sample. However, depending on the polymer type, an appropriate carrier (eluent) and a column suitable for it may be selected and used.

(Condition 1)
Measuring instrument: EcoSEC HLC-8320 (trade name, manufactured by Tosoh Corporation)
Column: Two TOSOH TSKgel Super AWM-H (trade name, manufactured by Tosoh Corporation) are connected. Carrier: 10 mM LiBr / N-methylpyrrolidone Measurement temperature: 40 ° C.
Carrier flow rate: 1.0 ml / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector Standard sample: Polystyrene

(Condition 2)
Measuring instrument: Same as above Column: TOSOH TSKgel Super HZM-H,
TOSOH TSKgel Super HZ4000,
TOSOH TSKgel Super HZ2000 (both trade names, manufactured by Tosoh Corporation)
Carrier: tetrahydrofuran Measurement temperature: 40 ° C
Carrier flow rate: 1.0 ml / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector Standard sample: Polystyrene

The polymer particles used in the present invention are not limited in shape as long as they can bind an active material and an inorganic solid electrolyte as a binder.
The polymer particles may be spherical or flat and may be amorphous. Further, the surface of the polymer particles may be smooth or may have an uneven shape. Further, the inside of the polymer particles may be filled with the same material as the side wall or may be filled with a different material. Moreover, it may be hollow and the hollow ratio is not limited.
The polymer particles may be monodispersed or polydispersed.

The polymer particles used in the present invention can be synthesized by a method of polymerizing a polymerizable monomer in the presence of a surfactant, an emulsifier or a dispersant, a method of depositing in a crystalline form as the molecular weight increases.
Alternatively, the existing polymer may be mechanically crushed into polymer particles, or the polymer particles dissolved in the polymer solution may be reprecipitated into polymer particles.

The average particle diameter of the polymer particles used in the present invention is not particularly limited, but is preferably 0.01 μm to 100 μm, more preferably 0.05 μm to 50 μm, further preferably 0.1 μm to 20 μm, and particularly preferably 0.2 μm to 10 μm. preferable. Here, the average particle diameter of the polymer particles is that before adding the dispersion medium.
The average particle size of the polymer particles is measured by the same method as the method for measuring the volume average particle size of the polymer particles shown in the Examples section described later.

  As the polymer particles used in the present invention, those obtained by the above-described method may be used, and general commercial products may be used. Hereinafter, although the specific example of the polymer particle used for this invention is given, this invention is not limited to these.

Fluororesin As the fluororesin that can be used as the polymer particles in the present invention, microdispers-200 (polytetrafluoroethylene (PTFE) particles, average particle size: 200 nm, manufactured by Techno Chemical Co., Ltd.), microdispers- 3000 (PTFE particles, average particle size: 3 μm, manufactured by Technochemical Co., Ltd.), Microdispers-8000 (PTFE particles, average particle size: 8 μm, manufactured by Technochemical Co., Ltd.), Disperse Easy-300 (PTFE particles) Average particle size: 200 nm, manufactured by Techno Chemical Co., Ltd.), Fluon AD911E (produced by Asahi Glass Co., Ltd.), Fluon AD915E (produced by Asahi Glass Co., Ltd.), Fluon AD916E (produced by Asahi Glass Co., Ltd.), Fluon AD939E (produced by Asahi Glass Co., Ltd.) , Algoflon F ( TFE particles, average particle size: 15-35 μm, Solvay Co., Ltd.), Algoflon S (PTFE particles, average particle size: 15-35 μm, Solvay Co., Ltd.), Lubron L-2 (PTFE particles, average particle) Diameter: 3.5 μm, Daikin Co., Ltd.), Lubron L-5 (PTFE particles, average particle size: 5 μm, Daikin Co., Ltd.), Lubron L-5F (PTFE particles, average particle size: 4.5 μm) Daikin Co., Ltd.) (both are trade names) and the like are available as commercial products.

Hydrocarbon Resin Hydrocarbon resins that can be used as the polymer particles in the present invention include soft beads (manufactured by Sumitomo Seika Co., Ltd.), Syxen (polyolefin emulsion, manufactured by Sumitomo Seika Co., Ltd.), Sepoljon G (polyolefin emulsion). , Manufactured by Sumitomo Seika Co., Ltd.), Sepolex IR100 (polyisoprene latex, manufactured by Sumitomo Seika Co., Ltd.), Sepolex CSM (chlorosulfonated polyethylene latex, manufactured by Sumitomo Seika Co., Ltd.), Frocene (polyethylene powder, Sumitomo Seifeng Co., Ltd.), Flocene UF (polyethylene powder, manufactured by Sumitomo Seika Co., Ltd.), Flowbrene (polypropylene powder, manufactured by Sumitomo Seika Co., Ltd.), Flow beads (Polyethylene-acrylic copolymer powder, Sumitomo Seiki) (All are trade names), etc., available as a commercial product.

Acrylic resin As the acrylic resin that can be used as the polymer particles in the present invention, Art Pearl GR (manufactured by Negami Kogyo Co., Ltd.), Art Pearl SE (manufactured by Negami Kogyo Co., Ltd.), Art Pearl G (Negami Kogyo Co., Ltd.) Art Pearl GR (manufactured by Negami Kogyo Co., Ltd.), Art Pearl GR (manufactured by Negami Kogyo Co., Ltd.), Art Pearl GS (manufactured by Negami Kogyo Co., Ltd.), Art Pearl J (manufactured by Negami Kogyo Co., Ltd.) Art Pearl MF (Negami Kogyo Co., Ltd.), Art Pearl BE (Negami Kogyo Co., Ltd.), Tufic AR-650 (Toyobo Co., Ltd.), Tufic AR-750 (Toyobo Co., Ltd.), Tuftic FH-S (manufactured by Toyobo Co., Ltd.), Chemisnow MP-1451 (manufactured by Soken Chemical Co., Ltd.), Chemisnow MP-2200 (manufactured by Soken Chemical Co., Ltd.), Chemisnow MP-1000 (Sokenka) Chemisnow MP-2701 (produced by Soken Chemical Co., Ltd.), Chemisnow MP-5000 (produced by Soken Chemical Co., Ltd.), Chemisnow MP-5500 (produced by Soken Chemical Co., Ltd.), Chemisnow MP-300 (produced by Soken Chemical Co., Ltd.) Soken Chemical Co., Ltd.), Chemisnow KMR-3TA (Souken Chemical Co., Ltd.), Chemisnow MX-80H3wT (Soken Chemical Co., Ltd.), Chemisnow MX-150 (Soken Chemical Co., Ltd.), Chemisnow MX- 180TA (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-300 (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-500 (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-500H (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-1000 (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-1500H (manufactured by Soken Chemical Co., Ltd.), Chemisnow MX-2000 (manufactured by Soken Chemical Co., Ltd.), Chemisno MX-3000 (manufactured by Soken Chemical Co., Ltd.), FS-101 (manufactured by Nippon Paint Co., Ltd.), FS-102 (manufactured by Nippon Paint Co., Ltd.), FS-106 (manufactured by Nippon Paint Co., Ltd.), FS- 107 (manufactured by Nippon Paint), FS-201 (manufactured by Nippon Paint), FS-301 (manufactured by Nippon Paint), FS-501 (manufactured by Nippon Paint), FS-701 ( Nippon Paint Co., Ltd.), MG-155E (Nihon Paint Co., Ltd.), MG-451 (Nihon Paint Co., Ltd.), MG-351 (Nihon Paint Co., Ltd.), Techpolymer MBX (Sekisui Co., Ltd.) Seiko Sangyo Co., Ltd.), Techpolymer SBX (Sekisui Chemicals Co., Ltd.), Techpolymer MSX (Sekisui Plastics Co., Ltd.), Techpolymer SSX (Sekisui Plastics Co., Ltd.), Techpolymer BMX (Sekisui Seiko Kogyo Co., Ltd.), Techpolymer ABX (Sekisui Chemicals Co., Ltd.), Techpolymer ARX (Sekisui Plastics Co., Ltd.), Techpolymer AFX (Sekisui Kasei Kogyo Co., Ltd.), Techpolymer MB (manufactured by Sekisui Plastics Co., Ltd.), Techpolymer MBP (manufactured by Sekisui Plastics Kogyo Co., Ltd.), Advancel HB-2051 (manufactured by Sekisui Chemical Co., Ltd.), Hayabies L-11 (Hayakawa Rubber ( Co., Ltd.), Hayabies M-11 (manufactured by Hayakawa Rubber Co., Ltd.), Aron T series (manufactured by Toa Gosei Co., Ltd.), Aron A series (manufactured by Toa Gosei Co., Ltd.), Aron SD-10 (Toa Gosei Co., Ltd.) Co., Ltd.), Aron AC Series (manufactured by Toa Gosei Co., Ltd.), Jurimer AC Series (manufactured by Toa Gosei Co., Ltd.), Eposta MA (manufactured by Nippon Shokubai Co., Ltd.), Eposta MX (manufactured by Nippon Shokubai Co., Ltd.) (All are trade names) etc. Ri, available as a commercial product.

Preferably, the acrylic resin includes particles having the following structure.
The numbers in the structure of the following particles represent the molar ratio of structural units in parentheses, and the particles may be any of a block copolymer, an alternating copolymer, and a random copolymer.
xx represents an integer of 1 or more.

  Moreover, the acrylic latex obtained by superposing | polymerizing the acrylic monomer as described in Japanese Patent Application No. 2013-198397 can also be used suitably.

Styrene resin Examples of the styrene resin that can be used as the polymer particles in the present invention include Chemisnow KSR-3A (manufactured by Soken Chemical Co., Ltd.) and Eposter ST (manufactured by Nippon Shokubai Co., Ltd.), which are commercially available.

Amide resin Examples of amide resins that can be used as the polymer particles in the present invention include Sephojon PA (copolymerized nylon emulsion, manufactured by Sumitomo Seika Co., Ltd.), Trepal PAI (polyamideimide particles, manufactured by Toray Industries, Inc.) (Trade name) etc., and can be obtained as a commercial product.

Imide resin Examples of the imide resin that can be used as the polymer particles in the present invention include polyimide powder P84 (R) NT (manufactured by Daicel Evonik Co., Ltd.), polyimide powder PIP-3 (manufactured by Seishin Enterprise Co., Ltd.), and polyimide powder. PIP-25 (manufactured by Seishin Enterprise Co., Ltd.), polyimide powder PIP-60 (manufactured by Seishin Enterprise Co., Ltd.), polyimide powder UIP-R (manufactured by Ube Industries), polyimide powder UIP-S (Ube Industries, Ltd.) )) (All are trade names), etc., and are available as commercial products.

Urethane resin As urethane resin that can be used as the polymer particles in the present invention, dimic beads UCN-8070CM (average particle size: 7 μm, manufactured by Dainichi Seika Co., Ltd.), dimic beads UCN-8150CM (average particle size: 15 μm, Dainichi Seika Co., Ltd.), Art Pearl C (Negami Kogyo Co., Ltd.), Art Pearl P (Negami Kogyo Co., Ltd.), Art Pearl JB (Negami Kogyo Co., Ltd.), Art Pearl U (Negami Kogyo Co., Ltd.), Art Pearl CE (Negami Kogyo Co., Ltd.), Art Pearl AK (Negami Kogyo Co., Ltd.), Art Pearl HI (Negami Kogyo Co., Ltd.), Art Pearl MM (Negami) Kogyo Co., Ltd.), Art Pearl FF (Negami Kogyo Co., Ltd.), Art Pearl TK (Negami Kogyo Co., Ltd.), Art Pearl C-TH (Negami Kogyo Co., Ltd.), Art Par Le RW (Negami Kogyo Co., Ltd.), Art Pearl RX (Negami Kogyo Co., Ltd.), Art Pearl RY (Negami Kogyo Co., Ltd.), Art Pearl RZ (Negami Kogyo Co., Ltd.), Art Pearl RU (Negami Kogyo Co., Ltd.), Art Pearl RV (Negami Kogyo Co., Ltd.), Art Pearl BP (Negami Kogyo Co., Ltd.), Grosdale S Series (Mitsui Chemicals Co., Ltd.), Grosdale M Series (Mitsui Chemicals Co., Ltd.), Grosdale V Series (Mitsui Chemicals Co., Ltd.), Grosdale T Series (Mitsui Chemicals Co., Ltd.), Infinergy (BASF Co., Ltd.) (all trade names) , Available as a commercial product.

Preferably, the urethane resin includes particles having the following structure.
The numbers in the structure of the following particles represent the molar ratio of structural units in parentheses, and the particles may be any of a block copolymer, an alternating copolymer, and a random copolymer.
Urethane resin particles having these chemical structures are generally obtained by polymerizing a diisocyanate compound and a diol compound and then mechanically pulverizing or dispersing the obtained polyurethane resin in a poor solvent.

Urea resin The urea resin particles that can be used as the polymer particles in the present invention preferably include particles having the following structure.
The numbers in the structure of the following particles represent the molar ratio of structural units in parentheses, and the particles may be any of a block copolymer, an alternating copolymer, and a random copolymer.
Urea resin particles having these chemical structures are generally obtained by polymerizing a diisocyanate compound and a diamine compound and then mechanically pulverizing or dispersing the resulting polyurea resin in a poor solvent.

Polyester resin Examples of the polyester resin that can be used as the polymer particles in the present invention include Sepoljon ES (trade name, copolymerized polyester emulsion, manufactured by Sumitomo Seika Co., Ltd.), and are commercially available.

Polyether resin Polyether resins that can be used as the polymer particles in the present invention include Trepal PPS (polyphenylene sulfide particles, manufactured by Toray Industries, Inc.), Trepearl PES (Polyethersulfone particles, manufactured by Toray Industries, Inc.) (all (Trade name) etc., and can be obtained as a commercial product.

Phenol resin As the phenol resin that can be used as the polymer particles in the present invention, LPS series (manufactured by Lignite Co., Ltd.), Marilyn FM series (manufactured by Gunei Chemical Industry Co., Ltd.), Marilyn HF series (Gunei Chemical Industry Co., Ltd.) Co., Ltd.) (both are trade names), etc., and are available as commercial products.

Epoxy resin As an epoxy resin that can be used as the polymer particles in the present invention, there is Trepearl EP (trade name, epoxy resin particles, manufactured by Toray Industries, Inc.) and the like, which are available as commercial products.

Polycarbonate resin The polycarbonate resin that can be used as the polymer particles in the present invention can be synthesized, for example, by the method described in WO 2011/004730. Specifically, it is possible to polymerize by reacting an epoxy compound with carbon dioxide.

Silicone Resin Silicone resins that can be used as the polymer particles in the present invention include Seahoster KE-E series (manufactured by Nippon Shokubai Co., Ltd.), Seahoster KE-W series (manufactured by Nippon Shokubai Co., Ltd.), Seahoster KE-P series. (Manufactured by Nippon Shokubai Co., Ltd.), Sea Hoster KE-S series (manufactured by Nippon Shokubai Co., Ltd.), silicone composite powder KMP-600 (manufactured by Shin-Etsu Silicone Co., Ltd.), silicone composite powder KMP-601 (Shin-Etsu Silicone Co., Ltd.) Manufactured), silicone composite powder KMP-602 (manufactured by Shin-Etsu Silicone Co., Ltd.), silicone composite powder KMP-605 (manufactured by Shin-Etsu Silicone Co., Ltd.), silicone composite powder X-52-7030 (manufactured by Shin-Etsu Silicone Co., Ltd.), Silicone resin powder KMP-590 (Shin-Etsu Silicone Co., Ltd. Silicone resin powder KMP-701 (Shin-Etsu Silicone Co., Ltd.), silicone resin powder X-52-854 (Shin-Etsu Silicone Co., Ltd.), silicone resin powder X-52-1621 (Shin-Etsu Silicone Co., Ltd.) ), Silicone rubber powder KMP-597 (manufactured by Shin-Etsu Silicone), silicone rubber powder KMP-598 (manufactured by Shin-Etsu Silicone), silicone rubber powder KMP-594 (manufactured by Shin-Etsu Silicone), silicone rubber powder X-52-875 (manufactured by Shin-Etsu Silicone Co., Ltd.), Charine R-170S (silicone acrylic copolymer, manufactured by Nissin Chemical Industry Co., Ltd.) (both are trade names), etc. are available as commercial products.

The content of the polymer particles in the solid electrolyte composition is preferably 0.1 parts by mass or more with respect to 100 parts by mass of the inorganic solid electrolyte (including this when an active material is used), 0.3 The amount is more preferably at least 1 part by mass, and particularly preferably at least 1 part by mass. The upper limit is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less.
For the solid electrolyte composition, the polymer particles in the solid content is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and more preferably 1% by mass or more. Particularly preferred. The upper limit is preferably 20% by mass or less, more preferably 10% by mass or less, and particularly preferably 5% by mass or less.

By using the amount of polymer particles within the above range, it is possible to more effectively achieve both the binding property of the inorganic solid electrolyte and the suppression of the interface resistance.
In addition, as mentioned above, you may use the binder applied to this invention combining another binder and various additives other than what consists of the said specific polymer particle. The above blending amount is defined as the amount of polymer particles, but may be read as the total amount of binder.

(Lithium salt)
The lithium salt that can be used in the present invention is preferably a lithium salt that is usually used in this type of product, and is not particularly limited. For example, those described below are preferable.

(L-1) Inorganic lithium salts: inorganic fluoride salts such as LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ ; perhalogenates such as LiClO ₄ , LiBrO ₄ , LiIO ₄ ; inorganic chloride salts such as LiAlCl ₄ etc.

(L-2) Fluorine-containing organic lithium salt: Perfluoroalkane sulfonate such as LiCF ₃ SO ₃ ; LiN (CF ₃ SO ₂ ) ₂ , LiN (CF ₃ CF ₂ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , Perfluoroalkanesulfonylimide salts such as LiN (CF ₃ SO ₂ ) (C ₄ F ₉ SO ₂ ); perfluoroalkanesulfonylmethide salts such as LiC (CF ₃ SO ₂ ) ₃ ; Li [PF ₅ (CF ₂ CF ₂ CF ₃ )], Li [PF ₄ (CF ₂ CF ₂ CF ₃ ) ₂ ], Li [PF ₃ (CF ₂ CF ₂ CF ₃ ) ₃ ], Li [PF ₅ (CF ₂ CF ₂ CF ₂ CF _{3 )], Li [PF 4 (} CF 2 CF 2 CF 2 CF 3) 2], Li [PF 3 (CF 2 CF 2 CF 2 CF 3) 3] fluoroalkyl fluoride such as potash Acid salts, and the like.

(L-3) Oxalatoborate salt: lithium bis (oxalato) borate, lithium difluorooxalatoborate and the like.
Among these, LiPF ₆ , LiBF ₄ , LiAsF ₆ , LiSbF ₆ , LiClO ₄ , Li (Rf ¹ SO ₃ ), LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ), preferably LiPF ₆ , LiBF ₄ , LiN (Rf ¹ SO ₂ ) ₂ , LiN (FSO ₂ ) ₂ , and LiN (Rf ¹ SO ₂ ) (Rf ² SO ₂ ) More preferred are imide salts. Here, Rf ¹ and Rf ² each independently represents a perfluoroalkyl group.
In addition, lithium salt may be used individually by 1 type, or may combine 2 or more types arbitrarily.

  The content of the lithium salt is preferably more than 0 parts by mass with respect to 100 parts by mass of the solid electrolyte, and more preferably 5 parts by mass or more. As an upper limit, 50 mass parts or less are preferable, and 20 mass parts or less are more preferable.

(Dispersion medium)
In the solid electrolyte composition of the present invention, a dispersion medium in which the above components are dispersed is used. When producing an all-solid secondary battery, it is preferable to add a dispersion medium to the solid electrolyte composition to form a paste from the viewpoint of uniformly applying the solid electrolyte composition to a current collector and forming a film. When forming the solid electrolyte layer of the all-solid secondary battery, the dispersion medium is removed by drying.

The dispersion medium used in the present invention contains a solvent that dissolves at least one polymer particle (hereinafter also referred to as a good solvent) and a solvent that does not dissolve at least one polymer particle (hereinafter also referred to as a poor solvent). To do.
After applying the solid electrolyte composition to the current collector or the like, the solvent that does not dissolve the polymer particles is volatilized before the solvent that dissolves the polymer particles or the solvent that does not dissolve the polymer particles when drying. It is preferable to evaporate prior to the solvent that dissolves the polymer particles. Thereby, the ratio of the solvent which dissolves the polymer particles to the solvent which does not dissolve the polymer particles in the solid electrolyte composition can be increased. As a result, since the surface of the polymer particles is dissolved, the wettability is increased, and the binding property of the polymer particles to the inorganic solid electrolyte is improved.

Solvent that dissolves polymer particles (good solvent)
The solvent for dissolving the polymer particles used in the present invention is that the polymer particles are added so as to have a concentration of 0.1% by mass, and the mixture is stirred at 80 ° C. for 24 hours. A solvent that reduces the average particle size by 10% or more and 100% or less is shown.
In the present invention, the solvent for dissolving the polymer particles is preferably one that reduces the average particle diameter by 50% or more and 100% or less, and more preferably 80% or more and 100% or less.
Note that “100% reduction” indicates a state in which the polymer particles are completely dissolved.

Solvent that does not dissolve polymer particles (poor solvent)
The solvent that does not dissolve the polymer particles used in the present invention is that the polymer particles are added so that the concentration becomes 0.1% by mass, and after stirring for 24 hours at 80 ° C., the average particle size with respect to the average particle size before dissolution A solvent that lowers the diameter by 8% or less is shown.
In the present invention, the solvent that does not dissolve the polymer particles is preferably one that lowers the average particle size by 5% or less, and more preferably one that reduces by 0% or more and 0.1% or less.
Note that “0% reduction” indicates a state in which the polymer particles are not dissolved at all.

The dispersion medium used in the present invention is preferably a non-aqueous solvent.
Here, the non-aqueous solvent means all organic solvents other than water. A specific example of the dispersion medium will be described later.

  As described above, since the ratio of the solvent that dissolves the polymer particles to the solvent that does not dissolve the polymer particles in the solid electrolyte composition may be increased by evaporation, in the present invention, the boiling point of the solvent that dissolves the polymer particles is It is preferably higher than the boiling point of the solvent that does not dissolve the polymer particles. In the present specification, the “boiling point” of the solvent means the boiling point at normal pressure.

The boiling point of the solvent that dissolves the polymer particles is preferably 100 ° C. or higher and lower than 250 ° C., more preferably 120 ° C. or higher and lower than 220 ° C., and particularly preferably 140 ° C. or higher and lower than 200 ° C.
The boiling point of the solvent that does not dissolve the polymer particles is preferably 80 ° C. or higher and lower than 220 ° C., more preferably 90 ° C. or higher and lower than 180 ° C., and particularly preferably 100 ° C. or higher and lower than 160 ° C.

  From the viewpoint of evaporating the solvent that does not dissolve the polymer particles before the solvent that dissolves the polymer particles, the difference between the boiling point of the solvent that does not dissolve the polymer particles and the boiling point of the solvent that dissolves the polymer particles (the solvent that does not dissolve the polymer particles) Of the solvent for dissolving the polymer particles) is preferably 5 ° C. or higher, more preferably 10 ° C. or higher, and particularly preferably 20 ° C. or higher. The upper limit is not particularly limited, but 100 ° C. or lower is practical.

When using a solvent having a high boiling point, the drying temperature during coating and drying may be increased, or the drying time may be lengthened. Further, the solvent may be evaporated by air drying or drying under reduced pressure.
The drying temperature is preferably 25 ° C to 250 ° C, more preferably 60 ° C to 150 ° C, and particularly preferably 80 ° C to 120 ° C. The drying time is preferably 10 seconds to 3 hours, more preferably 1 minute to 1 hour, particularly preferably 3 minutes to 10 minutes.
Blow drying and vacuum drying are more preferable because the solvent can be evaporated at a lower temperature and in a shorter time than normal pressure because of high drying efficiency.

  The ratio of the mass of the solvent that dissolves the polymer particles to the mass of the solvent that does not dissolve the polymer particles in the solid electrolyte composition of the present invention (the mass of the solvent that dissolves the polymer particles: the mass of the solvent that does not dissolve the polymer particles) is 0. 1: 99.9-50: 50 is preferable, 1: 99-30: 70 is more preferable, and 3: 97-20: 80 is particularly preferable.

  When the ratio of the mass of the solvent that dissolves the polymer particles to the mass of the solvent that does not dissolve the polymer particles is within the above range, the polymer particles in the solid electrolyte composition are excessively dissolved, and the active material and the inorganic solid electrolyte The binding property of the polymer particles to the inorganic solid electrolyte can be made sufficient without covering the surface and increasing the resistance.

  From the viewpoint of the solubility of the polymer particles, the LogP value of the solvent that dissolves the polymer particles is preferably less than 2.5, and the LogP value of the solvent that does not dissolve the polymer particles is preferably 3 or more. The LogP value is a value calculated by ChemBioDrawUltra10.2.1076 (manufactured by CambridgeSoft).

The LogP value of the solvent that dissolves the polymer particles is preferably less than 3.0, more preferably less than 2.0, and particularly preferably less than 1.8. On the other hand, the LogP value of the solvent that does not dissolve the polymer particles is preferably 3.0 or more, more preferably 3.2 or more, and particularly preferably 3.5 or more.
The difference between the LogP value of the solvent that dissolves the polymer particles and the LogP value of the solvent that does not dissolve the polymer particles is preferably 0.6 or more, and more preferably 1.2 or more.

The method for preparing the solid electrolyte composition of the present invention is not particularly limited. For example, the composition containing an inorganic solid electrolyte having conductivity of metal ions belonging to Group 1 or Group 2 of the periodic table and polymer particles, It is preferable to add a solvent that does not dissolve the polymer particles, and then add a solvent that dissolves the polymer particles.
In addition, an inorganic solid electrolyte having conductivity of metal ions belonging to Group 1 or Group 2 of the Periodic Table, in which a solvent that dissolves polymer particles with an appropriate composition and a solvent that does not dissolve polymer particles are mixed in advance. It is also preferred to add to a composition comprising polymer particles. You may add the solvent which melt | dissolves a polymer particle to the slurry liquid just before application | coating.

In the present invention, the solvent that dissolves the polymer particles is preferably a ketone solvent, an ester solvent, a carbonate solvent, a nitrile solvent, an ether solvent, or an amide solvent, and the solvent that does not dissolve the polymer particles is preferably a hydrocarbon solvent.
The solvent that does not dissolve the polymer particles and the hydrocarbon solvent means an organic solvent such as an aromatic solvent and an aliphatic solvent, which will be described later, and has no atoms other than carbon atoms and hydrogen atoms.
More preferably, the solvent that dissolves the polymer particles is an ether solvent or a nitrile solvent, and the solvent that does not dissolve the polymer particles is a hydrocarbon solvent. Most preferably, the solvent that dissolves the polymer particles is an aromatic nitrile solvent, and the solvent that does not dissolve the polymer particles is a hydrocarbon solvent.

  Examples of the dispersion medium include organic solvents such as alcohol solvents, ether solvents (including hydroxyl group-containing ether solvents), amide solvents, ester solvents, carbonate solvents, ketone solvents, aromatic solvents, aliphatic solvents, halogen solvents, and nitrile solvents. The combination of is mentioned. Specific examples include the following.

  As alcohol solvents, methyl alcohol, ethyl alcohol, 1-propyl alcohol, 2-propyl alcohol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol, 2-methyl Examples include -2,4-pentanediol, 1,3-butanediol, and 1,4-butanediol.

  Examples of ether solvents (including hydroxyl group-containing ether solvents) include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, anisole, tetrahydrofuran, alkylene glycol alkyl ether, ethylene glycol monomethyl. Ether, ethylene glycol monobutyl ether, diethylene glycol, dipropylene glycol, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol, polyethylene glycol, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, di Tylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, dipropylene glycol dimethyl ether, Examples include dipropylene glycol diethyl ether, tripropylene glycol dimethyl ether, and tripropylene glycol diethyl ether.

  Examples of amide solvents include N, N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε-caprolactam, formamide, and N-methylformamide. , Acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide and the like.

  Ester solvents include methyl acetate, ethyl acetate, propyl acetate, butyl acetate, hexyl acetate, methyl propionate, ethyl propionate, propylene glycol monomethyl ether acetate, ethylene glycol diacetate, propylene glycol diacetate, methyl isobutyrate, isobutyric acid Examples include ethyl, isopropyl isobutyrate, and isobutyl isobutyrate.

  Examples of the carbonate solvent include dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, and the like.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, dipropyl ketone, diisopropyl ketone, diisobutyl ketone, and cyclohexanone.

  Examples of the aromatic solvent include benzene, toluene, xylene, mesitylene, chlorobenzene, dichlorobenzene and the like.

  Examples of the halogen solvent include dichloromethane and chloroform.

  Examples of the aliphatic solvent include hexane, heptane, cyclohexane, methylcyclohexane, octane, pentane, cyclopentane, nonane and decane.

  Nitrile solvents include acetonitrile, propionitrile, butyronitrile, isobutyronitrile, benzonitrile, m-tolunitrile, o-tolunitrile, p-tolunitrile, 2,3-dimethylbenzonitrile, 2,5-dimethylbenzonitrile, 2 , 4-dimethylbenzonitrile, 2,6-dimethylbenzonitrile, 3,5-dimethylbenzonitrile, 4-t-butylbenzonitrile, 4-chlorobenzonitrile, 3-chlorobenzonitrile, 2-chlorobenzonitrile, 4 -Bromobenzonitrile, 3-bromobenzonitrile, 2-bromobenzonitrile, 4-fluorobenzonitrile, 3-fluorobenzonitrile, 2-fluorobenzonitrile, 4-iodobenzonitrile, 3-iodobenzonitrile, 2-iodo Benzonitrile, 4 Trifluoromethyl benzonitrile, 3-trifluoromethyl-benzonitrile, 2-trifluoromethyl benzonitrile, 3-methoxy benzonitrile, 2-methoxybenzonitrile, Anisonitoriru the like.

The content of the dispersion medium in the solid electrolyte composition can be set to any amount depending on the balance between the viscosity of the solid electrolyte composition and the drying load.
In the present invention, the content of the dispersion medium with respect to the total solid content in the solid electrolyte composition is 50 parts by mass with respect to 100 parts by mass of the total solid content (optional components such as inorganic solid electrolyte, polymer particles, and active material described later). It is preferable that it is no less than 2,000 parts by mass, more preferably no less than 60 parts by mass and no greater than 500 parts by mass, and particularly preferably no less than 80 parts by mass and no greater than 200 parts by mass.

The solid electrolyte composition of the present invention may contain an electrode active material such as the following positive electrode active material or negative electrode active material.
(Positive electrode active material)
The solid electrolyte composition containing a positive electrode active material can be used as a composition for a positive electrode material. It is preferable to use a transition metal oxide for the positive electrode active material, and it is preferable to have a transition element M ^a (one or more elements selected from Co, Ni, Fe, Mn, Cu, and V). Further, mixed element M ^b (elements of the first (Ia) group of the metal periodic table other than lithium, elements of the second (IIa) group, Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si , P, B, etc.) may be mixed.
Transition metal oxides include, for example, specific transition metal oxides including those represented by any of the following formulas (MA) to (MC), or other transition metal oxides such as V ₂ O ₅ and MnO _2. Can be mentioned. As the positive electrode active material, a particulate positive electrode active material may be used.
Specifically, a transition metal oxide capable of reversibly inserting and releasing lithium ions can be used, and the specific transition metal oxide is preferably used.

Transition metal oxides, oxides containing the above transition element M ^a is preferably exemplified. At this time, a mixed element M ^b (preferably Al) or the like may be mixed. The mixing amount is preferably 0 to 30 mol% with respect to the amount of the transition metal. That the molar ratio of li / ^{M a} is synthesized by mixing so that 0.3 to 2.2 is more preferable.

[Transition metal oxide represented by formula (MA) (layered rock salt structure)]
As the lithium-containing transition metal oxide, those represented by the following formula are preferable.

Li _a M ¹ O _b Formula (MA)

Wherein (MA), ^{M 1} are as defined above ^{M a,} and the preferred range is also the same. a represents 0 to 1.2 (preferably 0.2 to 1.2), and preferably 0.6 to 1.1. b represents 1-3 and 2 is preferable. A part of M ¹ may be substituted with the mixed element M ^b .
The transition metal oxide represented by the formula (MA) typically has a layered rock salt structure.

  The transition metal oxide represented by the formula (MA) is more preferably represented by the following formulas.

_{(MA-1) Li g CoO} k
_{(MA-2) Li g NiO} k
_{(MA-3) Li g MnO} k
_{(MA-4) Li g Co} j Ni 1-j O k
_{(MA-5) Li g Ni} j Mn 1-j O k
_{(MA-6) Li g Co} j Ni i Al 1-j-i O k
_{(MA-7) Li g Co} j Ni i Mn 1-j-i O k

Here, g is synonymous with the above-mentioned a, and its preferable range is also the same. j represents 0.1 to 0.9. i represents 0 to 1; However, 1-j-i is 0 or more. k has the same meaning as b above, and the preferred range is also the same.
Specific examples of these transition metal compounds include LiCoO ₂ (lithium cobaltate [LCO]), LiNi ₂ O ₂ (lithium nickelate) LiNi _0.85 Co _0.01 Al _0.05 O ₂ (nickel cobalt aluminum acid Lithium [NCA]), LiNi _0.33 Co _0.33 Mn _0.33 O ₂ (nickel manganese lithium cobaltate [NMC]), LiNi _0.5 Mn _0.5 O ₂ (lithium manganese nickelate) .

  The transition metal oxide represented by the formula (MA) partially overlaps, but when represented by changing the notation, those represented by the following are also preferable examples.

(I) Li _g Ni _xc Mn _yc Co _zc O ₂ (xc> 0.2, yc> 0.2, zc ≧ 0, xc + yc + zc = 1)
Representative:
_{Li g Ni 1/3 Mn 1/3 Co 1/3} O 2
Li _g Ni _1/2 Mn _1/2 O ₂

_{(Ii) Li g Ni xd Co} yd Al zd O 2 (xd> 0.7, yd>0.1,0.1> zd ≧ 0.05, xd + yd + zd = 1)
Representative:
_{Li g Ni 0.8 Co 0.15 Al 0.05} O 2

[Transition metal oxide represented by formula (MB) (spinel structure)]
Among the lithium-containing transition metal oxides, those represented by the following formula (MB) are also preferable.

Li _c M ² ₂ O _d Formula (MB)

Wherein (MB), ^{M 2} are as defined above ^{M a,} and the preferred range is also the same. c represents 0-2, 0.2-2 are preferable and 0.6-1.5 are more preferable. d represents 3-5, and 4 is preferable.

  The transition metal oxide represented by the formula (MB) is more preferably represented by the following formulas.

_{(MB-1) Li m Mn} 2 O n
_{(MB-2) Li m Mn} p Al 2-p O n
_{(MB-3) Li m Mn} p Ni 2-p O n

m is synonymous with c, and its preferable range is also the same. n is synonymous with d, and its preferable range is also the same. p represents 0-2.
Examples of these transition metal compounds include LiMn ₂ O ₄ and LiMn _1.5 Ni _0.5 O ₄ .

  Preferred examples of the transition metal oxide represented by the formula (MB) include those represented by the following formulas.

(A) LiCoMnO ₄
(B) Li ₂ FeMn ₃ O ₈
(C) Li ₂ CuMn ₃ O ₈
(D) Li ₂ CrMn ₃ O ₈
(E) Li ₂ NiMn ₃ O ₈

  Of these, an electrode containing Ni is more preferable from the viewpoint of high capacity and high output.

[Transition metal oxide represented by formula (MC)]
The lithium-containing transition metal oxide is preferably a lithium-containing transition metal phosphate, and among them, one represented by the following formula (MC) is also preferable.

^{_{Li e M 3 (PO 4)}} f ··· formula (MC)

  In formula (MC), e represents 0 to 2 (preferably 0.2 to 2), and preferably 0.5 to 1.5. f represents 1-5, and 1-2 are preferable.

M ³ represents one or more elements selected from the group consisting of V, Ti, Cr, Mn, Fe, Co, Ni, and Cu. M ³ represents, other mixing element ^{M b} above, Ti, Cr, Zn, Zr, may be substituted by other metals such as Nb. Specific examples include, for example, olivine-type iron phosphates such as LiFePO ₄ and Li ₃ Fe ₂ (PO ₄ ) ₃ , iron pyrophosphates such as LiFeP ₂ O ₇ , cobalt phosphates such as LiCoPO ₄ , and Li _3. Monoclinic Nasicon type vanadium phosphate salts such as V ₂ (PO ₄ ) ₃ (lithium vanadium phosphate) can be mentioned.

  The a, c, g, m, and e values representing the composition of Li are values that change due to charge and discharge, and are typically evaluated as values in a stable state when Li is contained. In the formulas (a) to (e), the composition of Li is shown as a specific value, which also changes depending on the operation of the battery.

  The average particle diameter of the positive electrode active material used in the nonaqueous secondary battery of the present invention is not particularly limited. In addition, 0.1 micrometers-50 micrometers are preferable. In order to make the positive electrode active substance have a predetermined particle size, a normal pulverizer or classifier may be used. The positive electrode active material obtained by the firing method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent. The average particle size of the positive electrode active material particles is measured by the same method as the method for measuring the average particle size of the polymer particles shown in the section of Examples described later.

  The concentration of the positive electrode active material is not particularly limited. In addition, 20-90 mass% is preferable in 100 mass% of solid components in a solid electrolyte composition, and 40-80 mass% is more preferable. In addition, when a positive electrode active material layer contains another inorganic solid (for example, solid electrolyte), said density | concentration is interpreted as containing it.

(Negative electrode active material)
The solid electrolyte composition of the present invention may contain a negative electrode active material. The solid electrolyte composition containing the negative electrode active material can be used as a composition for a negative electrode material. As the negative electrode active material, those capable of reversibly inserting and releasing lithium ions are preferable. Such materials are not particularly limited, and are carbonaceous materials, metal oxides such as tin oxide and silicon oxide, metal composite oxides, lithium alloys such as lithium alone and lithium aluminum alloys, and lithiums such as Sn and Si. And metals capable of forming an alloy. These may be used individually by 1 type, or may use 2 or more types together by arbitrary combinations and a ratio. Of these, carbonaceous materials or lithium composite oxides are preferably used from the viewpoint of safety. In addition, the metal composite oxide is preferably capable of inserting and extracting lithium. The material is not particularly limited, but preferably contains titanium and / or lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics.

  The carbonaceous material used as the negative electrode active material is a material substantially made of carbon. Examples thereof include carbonaceous materials obtained by firing artificial graphite such as petroleum pitch, natural graphite, and vapor-grown graphite, and various synthetic resins such as PAN-based resins and furfuryl alcohol resins. Furthermore, various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA-based carbon fiber, lignin carbon fiber, glassy carbon fiber, activated carbon fiber, mesophase micro Examples thereof include spheres, graphite whiskers, and flat graphite.

  These carbonaceous materials can be divided into non-graphitizable carbon materials and graphite-based carbon materials depending on the degree of graphitization. Further, the carbonaceous material preferably has the surface spacing, density, and crystallite size described in JP-A-62-222066, JP-A-2-6856, and 3-45473. The carbonaceous material does not need to be a single material, and a mixture of natural graphite and artificial graphite described in JP-A-5-90844, graphite having a coating layer described in JP-A-6-4516, and the like. It can also be used.

  As the metal oxide and metal composite oxide applied as the negative electrode active material, an amorphous oxide is particularly preferable, and chalcogenite, which is a reaction product of a metal element and an element of Group 16 of the periodic table, is also preferably used. It is done. The term “amorphous” as used herein means an X-ray diffraction method using CuKα rays, which has a broad scattering band having an apex in the region of 20 ° to 40 ° in terms of 2θ values, and is a crystalline diffraction line. You may have. The strongest intensity of crystalline diffraction lines seen from 2 ° to 40 ° to 70 ° is 100 times the diffraction line intensity at the peak of the broad scattering band seen from 2 ° to 20 °. Is preferably 5 times or less, and more preferably not having a crystalline diffraction line.

Among the group of compounds consisting of the above amorphous oxide and chalcogenide, amorphous metal oxides and chalcogenides are more preferable, and elements in Groups 13 (IIIB) to 15 (VB) of the periodic table are more preferable. Further preferred are oxides and chalcogenides composed of one kind of Al, Ga, Si, Sn, Ge, Pb, Sb, Bi or a combination of two or more kinds thereof. Specific examples of preferable amorphous oxides and chalcogenides include, for example, Ga ₂ O ₃ , SiO, GeO, SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₂ O ₄ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , Bi ₂ O ₃ , Bi ₂ O ₄ , SnSiO ₃ , GeS, SnS, SnS ₂ , PbS, PbS ₂ , Sb ₂ S ₃ , Sb ₂ S ₅ , such as SnSiS ₃ may preferably be mentioned. Moreover, these may be a complex oxide with lithium oxide, for example, Li ₂ SnO ₂ .

  The average particle diameter of the negative electrode active material is preferably 0.1 μm to 60 μm. In order to obtain a predetermined particle size, a well-known pulverizer or classifier is used. For example, a mortar, a ball mill, a sand mill, a vibrating ball mill, a satellite ball mill, a planetary ball mill, a swirling air flow type jet mill or a sieve is preferably used. When pulverizing, wet pulverization in the presence of water or an organic solvent such as methanol can be performed as necessary. In order to obtain a desired particle diameter, classification is preferably performed. The classification method is not particularly limited, and a sieve, an air classifier, or the like can be used as necessary. Classification can be used both dry and wet. The average particle diameter of the negative electrode active material particles is measured by the same method as the method for measuring the average particle diameter of the polymer particles shown in the section of Examples described later.

  The composition formula of the compound obtained by the above firing method can be calculated from an inductively coupled plasma (ICP) emission spectroscopic analysis method as a measurement method and a mass difference between powders before and after firing as a simple method.

  Examples of the negative electrode active material that can be used in combination with the amorphous oxide negative electrode active material centering on Sn, Si, and Ge include carbon materials that can occlude and release lithium ions or lithium metal, lithium, lithium alloys, lithium A metal that can be alloyed with is preferable.

The negative electrode active material preferably contains a titanium atom. More specifically, Li ₄ Ti ₅ O ₁₂ has excellent rapid charge / discharge characteristics due to small volume fluctuations during the insertion and release of lithium ions, and it is possible to improve the life of lithium ion secondary batteries by suppressing electrode deterioration. This is preferable. By combining a specific negative electrode and a specific electrolyte, the stability of the secondary battery is improved even under various usage conditions.

In the all solid state secondary battery in the present invention, it is also preferable to apply a negative electrode active material containing Si element. In general, a Si negative electrode can occlude more Li ions than current carbon negative electrodes (graphite, acetylene black, etc.). That is, since the amount of Li ion storage per weight increases, the battery capacity can be increased. As a result, there is an advantage that the battery driving time can be extended, and use in a battery for vehicles is expected in the future. On the other hand, it is known that the volume change associated with insertion and extraction of Li ions is large. In one example, the volume expansion of the carbon negative electrode is about 1.2 to 1.5 times, and the volume of Si negative electrode is about three times. There is also an example. By repeating this expansion and contraction (repeating charge and discharge), the durability of the electrode layer is insufficient, and for example, contact shortage is likely to occur, and cycle life (battery life) is shortened.
According to the solid electrolyte composition according to the present invention, even in an electrode layer in which such expansion / contraction increases, the high durability (strength) can be exhibited, and the excellent advantages can be exhibited more effectively. is there.

  Although the density | concentration of a negative electrode active material is not specifically limited, 10-80 mass% is preferable in 100 mass% of solid components in a solid electrolyte composition, and 20-70 mass% is more preferable. In addition, when a negative electrode active material layer contains another inorganic solid (for example, solid electrolyte), said density | concentration is interpreted as containing it.

In the above embodiment, an example in which the solid electrolyte composition according to the present invention contains a positive electrode active material or a negative electrode active material has been shown, but the present invention is not construed as being limited thereto.
Moreover, you may make the active material layer of a positive electrode and a negative electrode contain a conductive support agent suitably as needed. As a general conductive assistant, graphite, carbon black, acetylene black, ketjen black, carbon fiber, metal powder, metal fiber, polyphenylene derivative, and the like can be included as an electron conductive material.

<Current collector (metal foil)>
The positive and negative current collectors are preferably electron conductors that do not cause chemical changes. As the current collector of the positive electrode, in addition to aluminum, stainless steel, nickel, titanium, etc., the surface of aluminum or stainless steel is preferably treated with carbon, nickel, titanium, or silver. Among them, aluminum and aluminum alloys are preferable. More preferred. As the negative electrode current collector, aluminum, copper, stainless steel, nickel, and titanium are preferable, and aluminum, copper, and a copper alloy are more preferable.

As the shape of the current collector, a film sheet shape is usually used, but a net, a punched material, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like can also be used.
Although it does not specifically limit as thickness of the said electrical power collector, 1 micrometer-500 micrometers are preferable. Moreover, it is also preferable that the current collector surface is roughened by surface treatment.

<Preparation of all-solid secondary battery>
The all-solid-state secondary battery may be manufactured by a conventional method. Specifically, there is a method in which the solid electrolyte composition of the present invention is applied onto a metal foil serving as a current collector to form a coating electrode film (film formation).
For example, a composition serving as a positive electrode material is applied onto a metal foil that is a positive electrode current collector and then dried to form a positive electrode active material layer. Next, the solid electrolyte composition is applied onto the positive electrode sheet for a battery and then dried to form a solid electrolyte layer. Furthermore, after applying the composition used as a negative electrode material on it, it dries and forms a negative electrode active material layer. A structure of an all-solid-state secondary battery in which a solid electrolyte layer is sandwiched between a positive electrode active material layer and a negative electrode active material layer can be obtained by stacking a negative electrode side current collector (metal foil) thereon. it can. In addition, the application | coating method of said each composition should just follow a conventional method. At this time, a drying treatment may be performed after each application of the composition forming the positive electrode active material layer, the composition forming the inorganic solid electrolyte layer (solid electrolyte composition), and the composition forming the negative electrode active material layer. Then, after the multilayer coating, a drying process may be performed. Although drying temperature is not specifically limited, 30 degreeC or more is preferable and 80 degreeC or more is more preferable. The upper limit is preferably 300 ° C. or lower, and more preferably 250 ° C. or lower. By heating in such a temperature range, a dispersion medium can be removed and it can be set as a solid state. Thereby, in an all-solid secondary battery, good binding properties and non-pressurized ion conductivity can be obtained.

<Uses of all-solid-state secondary batteries>
The all solid state secondary battery in the present invention can be applied to various uses. Although there is no particular limitation on the application mode, for example, when installed in an electronic device, a notebook computer, a pen input personal computer, a mobile personal computer, an electronic book player, a mobile phone, a cordless phone, a pager, a handy terminal, a mobile fax machine, a mobile phone Copy, portable printer, headphone stereo, video movie, LCD TV, handy cleaner, portable CD, minidisc, electric shaver, transceiver, electronic notebook, calculator, memory card, portable tape recorder, radio, backup power supply, memory card, etc. It is done. Other consumer products include automobiles, electric vehicles, motors, lighting equipment, toys, game equipment, road conditioners, watches, strobes, cameras, medical equipment (such as pacemakers, hearing aids, and shoulder grinders). Furthermore, it can be used for various military use and space use. Moreover, it can also combine with a solar cell.

  In particular, it is preferably applied to applications that require high capacity and high rate discharge characteristics. For example, in power storage facilities and the like that are expected to increase in capacity in the future, high reliability is indispensable and further compatibility of battery performance is required. In addition, electric vehicles and the like are equipped with high-capacity secondary batteries and are expected to be charged every day at home, and thus more reliability is required for overcharging. According to the present invention, it is possible to exhibit the excellent effect correspondingly to such a usage pattern.

According to a preferred embodiment of the present invention, the following applications are derived.
(1) A solid electrolyte composition (a composition for a positive electrode or a negative electrode) containing an active material capable of inserting and releasing metal ions belonging to Group 1 or Group 2 of the Periodic Table.
(2) A battery electrode sheet obtained by forming the solid electrolyte composition on a metal foil.
(3) An all-solid secondary battery comprising a positive electrode active material layer, a negative electrode active material layer, and a solid electrolyte layer, wherein at least one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer is All-solid-state secondary battery made into the layer comprised with the solid electrolyte composition.
(4) The manufacturing method of the battery electrode sheet which arrange | positions the said solid electrolyte composition on metal foil, and forms this into a film.
(5) The manufacturing method of the all-solid-state secondary battery which manufactures an all-solid-state secondary battery via the manufacturing method of the said battery electrode sheet.
Moreover, in preferable embodiment of this invention, it has the advantage that inhibitor particles, such as a side reaction accompanying it, can form binder particle | grains without adding surfactant and can reduce it. In addition, the inversion emulsification step can be omitted, which leads to relatively improved production efficiency.

An all-solid secondary battery refers to a secondary battery in which the positive electrode, the negative electrode, and the electrolyte are all solid. In other words, it is distinguished from an electrolyte type secondary battery using a carbonate-based solvent as an electrolyte. In this, this invention presupposes an inorganic all-solid-state secondary battery. The all-solid-state secondary battery includes an organic (polymer) all-solid-state secondary battery that uses a polymer compound such as polyethylene oxide as an electrolyte, and an inorganic all-solid-state secondary that uses the above Li-PS, LLT, LLZ, or the like. It is divided into batteries. The application of the polymer compound to the inorganic all-solid secondary battery is not hindered, and the polymer compound can be applied as a binder for the positive electrode active material, the negative electrode active material, and the inorganic solid electrolyte particles.
The inorganic solid electrolyte is distinguished from an electrolyte (polymer electrolyte) using the above-described polymer compound as an ion conductive medium, and the inorganic compound serves as an ion conductive medium. Specific examples include Li-PS, LLT, and LLZ. The inorganic solid electrolyte itself does not release cations (Li ions) but exhibits an ion transport function. On the other hand, a material that is added to the electrolytic solution or the solid electrolyte layer and serves as a source of ions that release cations (Li ions) is sometimes called an electrolyte, but it is distinguished from the electrolyte as the ion transport material. This is sometimes referred to as “electrolyte salt” or “supporting electrolyte”. Examples of the electrolyte salt include LiTFSI (lithium bistrifluoromethanesulfonimide).
In the present invention, the term “composition” means a mixture in which two or more components are uniformly mixed. However, as long as the uniformity is substantially maintained, aggregation or uneven distribution may partially occur within a range in which a desired effect is achieved.

  Below, based on an Example, it demonstrates still in detail about this invention. The present invention is not construed as being limited thereby. In the following examples, “parts” and “%” are based on mass unless otherwise specified.

Production of polymer particles of the present invention (polymer synthesis)
Synthesis of Exemplary Compound (B-5) 10 mL of propylene glycol monomethyl ether acetate was added to a 200 mL three-necked flask and heated to 80 ° C. under a nitrogen stream. While heating and stirring at 80 ° C., 12.3 g of benzyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 0.86 g of methacrylic acid (manufactured by Wako Pure Chemical Industries, Ltd.), 2-hydroxyethyl methacrylate (Wako Pure Chemical Industries, Ltd.) 2.6 g of a propylene glycol monomethyl ether acetate solution of 2.61 g (produced by Wako Pure Chemical Industries, Ltd.) 0.21 g as a radical polymerization initiator was added dropwise over 2 hours. After dropping, the mixture was further heated and stirred at 80 ° C. for 4 hours. Thereafter, the reaction solution was added to hexane / ethyl acetate = 90/10 to reprecipitate the polymer. The obtained powder was collected by filtration and dried in vacuo at 80 ° C. to obtain 12.9 g of a polymer powder shown in Example Compound (B-5).

Synthesis of Exemplary Compound (B-34) 2.8 g of 1,4-butanediol (manufactured by Wako Pure Chemical Industries, Ltd.) in a 200 mL three-neck flask, Etanacol UH-100 (trade name, manufactured by Ube Industries, Ltd.) 7.6 g and dimethylformamide 45 g were added and heated at 50 ° C. to dissolve. 10.5 g of dicyclohexylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added while heating and stirring at 50 ° C., followed by heating and stirring at 80 ° C. 10 minutes after heating to 80 ° C., 0.2 g of a bismuth polymerization catalyst Neostan U-600 (trade name, manufactured by Nitto Kasei Co., Ltd.) was added, and the stirring was continued for 8 hours. Thereafter, 2 mL of methanol was added to terminate the polymerization. Thereafter, the reaction solution was added to methanol to reprecipitate the polymer. The obtained powder was collected by filtration and dried in vacuo at 80 ° C. to obtain 17.9 g of a polymer powder shown in Example Compound (B-34).

Synthesis of Exemplary Compound (B-38) In a 200 mL three-necked flask, 7.6 g of etanacol UH-100 (manufactured by Ube Industries), 2,2-bis (hydroxymethyl) propionic acid (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.9 g, 1.1 g of Bremer GLM (trade name, manufactured by NOF Corporation), 0.1 g of 2,6-di-t-butylphenol polymerization inhibitor and 45 g of dimethylformamide were added and heated at 50 ° C. to dissolve. I let you. To this, 10 g of diphenylmethane diisocyanate (manufactured by Wako Pure Chemical Industries, Ltd.) was added and heated and stirred at 80 ° C. 10 minutes after heating to 80 ° C., 0.2 g of a bismuth polymerization catalyst Neostan U-600 (trade name, manufactured by Nitto Kasei Co., Ltd.) was added and the mixture was heated and stirred as it was for 4 hours, and the terminal was isocyanate-treated. A polymer was synthesized. After cooling the reaction solution to room temperature, 2.0 g of 1,4-butanediamine (manufactured by Wako Pure Chemical Industries, Ltd.) was added over 30 minutes, and the mixture was further stirred at room temperature for 1 hour. Thereafter, 2 mL of methanol was added to terminate the polymerization. Thereafter, the reaction solution was added to methanol to reprecipitate the polymer. The obtained powder was collected by filtration and dried in vacuo at 80 ° C. to obtain 18.3 g of a polymer powder shown in Example Compound (B-38).

Acrylic resin: Synthesis of exemplary compounds (B-1), (B-8) and (B-9) In the same manner as in the synthesis of exemplary compound (B-5), exemplary compounds (B-1), (B- The polymer powder shown in 8) and (B-9) was obtained.

Urethane resin: Exemplified compounds (B-18) (B-21), (B-26), (B-28), (B-29), (B-35), (B-36) and (B-37) ) In the same manner as in the synthesis of the above exemplified compound (B-34), exemplified compounds (B-18) (B-21), (B-26) (B-28), (B-29), (B Polymers shown in -35), (B-36), and (B-37) were obtained.

(Create polymer particles)
Into a 45 mL zirconia container (manufactured by Fritsch), 50 zirconia beads having a diameter of 5 mm are charged, 1.2 g of the polymer of the exemplified compound obtained above and 10 g of xylene are charged, and the container is completely sealed under an argon atmosphere. did. A container was set in a planetary ball mill P-7 manufactured by Fricht, and mechanical milling was performed at a temperature of 25 ° C. and a rotation speed of 500 rpm for 4 hours to obtain a polymer slurry. This was vacuum dried to obtain polymer particles of the exemplified compound.
In addition, the average particle diameter was put together in Tables 1-3 and described as “particle diameter”.

(Measurement of average particle size of binder)
The average particle diameter of the binder particles was measured according to the following procedure. The binder synthesized above is an optional solvent (dispersion medium used for preparing each solid electrolyte composition. For example, in the case of the binder (B-5) used for the solid electrolyte composition, diisobutyl ketone, the binder used for the negative electrode composition In the case of (B-5), a 1% by mass dispersion was prepared using o-fluorobenzonitrile. Using this dispersion liquid sample, the volume average particle diameter of the polymer particles was measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by HORIBA).

(Measurement of mass average molecular weight)
As the mass average molecular weight of the polymer particles used in the present invention, a value measured by gel permeation chromatography (GPC) in terms of the following standard sample was adopted. The measurement apparatus and measurement conditions were based on the following condition 1 and were set to condition 2 depending on the solubility of the sample. However, depending on the polymer type, an appropriate carrier (eluent) and a column suitable for the carrier were selected as appropriate. In Tables 1 to 3 below, the mass average molecular weight is indicated as Mw.
(Condition 1)
Measuring instrument: EcoSEC HLC-8320 (trade name, manufactured by Tosoh Corporation)
Column: Two TOSOH TSKgel Super AWM-H (trade name, manufactured by Tosoh Corporation) are connected Carrier: 10 mM LiBr / N-methylpyrrolidone Measurement temperature: 40 ° C.
Carrier flow rate: 1.0 ml / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector Standard sample: Polystyrene (Condition 2)
Measuring instrument: Same as above Column: TOSOH TSKgel Super HZM-H,
TOSOH TSKgel Super HZ4000,
TOSOH TSKgel Super HZ2000 (both trade names, manufactured by Tosoh Corporation)
Carrier: Tetrahydrofuran Measurement temperature: 40 ° C
Carrier flow rate: 1.0 ml / min
Sample concentration: 0.1% by mass
Detector: RI (refractive index) detector Standard sample: Polystyrene

(Measurement of glass transition temperature)
The glass transition temperature (Tg) of the synthesized exemplary compound was measured for the polymer under the following conditions using a differential scanning calorimeter “X-DSC7000” (trade name, manufactured by SII Nanotechnology Co., Ltd.). The measurement was performed twice on the same sample, and the second measurement result was adopted.
Measurement chamber atmosphere: Nitrogen (50 mL / min)
Temperature increase rate: 5 ° C / min
Measurement start temperature: -100 ° C
Measurement end temperature: 200 ° C
Sample pan: Aluminum pan Mass of measurement sample: 5 mg
Calculation of Tg: Tg was calculated by rounding off the decimal point of the intermediate temperature between the lowering start point and the lowering end point of the DSC chart.

Synthesis of sulfide-based inorganic solid electrolyte (Li-PS-based glass) Ohtomo, A .; Hayashi, M .; Tatsumisago, Y. et al. Tsuchida, S .; Hama, K .; Kawamoto, Journal of Power Sources, 233, (2013), pp231-235 and A.K. Hayashi, S .; Hama, H .; Morimoto, M .; Tatsumisago, T .; Minami, Chem. Lett. , (2001), pp872-873.

Specifically, in a glove box under an argon atmosphere (dew point −70 ° C.), 2.42 g of lithium sulfide (Li ₂ S, manufactured by Aldrich, purity> 99.98%), diphosphorus pentasulfide (P ₂ S) ₅ , 3.90 g manufactured by Aldrich, purity> 99%) was weighed, put into an agate mortar, and mixed for 5 minutes using an agate mortar. Incidentally, Li ₂ S and _P 2 _{S 5} at a molar ratio of _{Li 2 S: P 2 S 5} = 75: was 25.
66 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, the whole mixture of lithium sulfide and diphosphorus pentasulfide was put therein, and the container was completely sealed under an argon atmosphere. A container is set in a planetary ball mill P-7 manufactured by Fricht, and mechanical milling is performed at a temperature of 25 ° C. and a rotation speed of 510 rpm for 20 hours to obtain 6.20 g of a yellow powder sulfide solid electrolyte material (Li / P / S glass). Obtained.

<Example 1>
Preparation of Solid Electrolyte Composition (1) Preparation of Solid Electrolyte Composition (K-1) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and an inorganic solid electrolyte LLZ (Corporation) 9.0 g, Daimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd.) and 12.0 g of toluene as a dispersion medium were added and stirred with a spatula for 10 minutes. Thereafter, 3.0 g of diethylene glycol dimethyl ether was added. Thereafter, the container was set on a planetary ball mill P-7 manufactured by Fritsch, and stirring was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm to produce a solid electrolyte composition (K-1).

(2) Preparation of Solid Electrolyte Composition (K-2) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and 9.0 g of the Li—PS system glass synthesized above. Then, 0.3 g of dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd.) and 12.0 g of toluene as a dispersion medium were added. Thereafter, the container was set on a planetary ball mill P-7 manufactured by Fritsch, and stirring was continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. Thereafter, 3.0 g of diethylene glycol dimethyl ether was added and stirred with a spatula for 10 minutes to produce a solid electrolyte composition (K-2).

(3) Preparation of Solid Electrolyte Compositions (K-3) to (K-10) and (HK-1) to (HK-4) The above-mentioned solid electrolyte composition, except that it was changed to the configuration shown in Table 1 below A solid electrolyte composition (K-3) was produced in the same manner as (K-1). In addition, the solid electrolyte compositions (K-4) to (K-10) and (HK−) were produced in the same manner as the solid electrolyte composition (K-2) except that the structure shown in Table 1 was changed. 1) to (HK-4) were produced.

Table 1 summarizes the configuration of the solid electrolyte composition.
Here, the solid electrolyte compositions (K-1) to (K-10) are the solid electrolyte compositions of the present invention, and the solid electrolyte compositions (HK-1) to (HK-4) are comparative solid electrolyte compositions. It is a thing.

<Notes on Table 1>
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle diameter 5.06 μm, manufactured by Toshima Seisakusho Co., Ltd.)
Li-PS: Li-PS system glass synthesized above B-S1: Urethane particles, dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd., average particle size: 7 μm)
B-S2: acrylic particles, Chemisnow MX-150 (manufactured by Soken Chemical Co., Ltd., average particle size: 1.5 μm)
HSBR: Hydrogenated Styrene Butadiene Rubber The LogP value is a value calculated by ChemBioDrawUltra10.2.1076 (manufactured by CambridgeSoft). Indicates that no value is shown.

Preparation of composition for secondary battery positive electrode (1) Preparation of positive electrode composition (U-1) 180 zirconia beads having a diameter of 5 mm were placed in a 45 mL zirconia container (manufactured by Fritsch), and an inorganic solid electrolyte LLZ ( (Toshima Seisakusho Co., Ltd.) 2.7g, Dymic beads UCN-8070CM (Daiichi Seika Co., Ltd.) 0.3g, toluene 9.3g was added as a dispersion medium, and stirred with a spatula for 10 minutes. Thereafter, 3.0 g of diethylene glycol dimethyl ether was added. A container is set on a planetary ball mill P-7 manufactured by Fricht Co., and mechanical dispersion is continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. In the same manner, a container was set in the planetary ball mill P-7, and mechanical dispersion was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 100 rpm to produce a positive electrode composition (U-1).

(2) Preparation of composition for positive electrode (U-2) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and 2.7 g of the Li—PS system glass synthesized above. Then, 0.3 g of dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd.) and 9.3 g of heptane as a dispersion medium were added. A container is set on a planetary ball mill P-7 manufactured by Fricht Co., and mechanical dispersion is continued for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm. In the same manner, a container was set in the planetary ball mill P-7, and mechanical dispersion was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 200 rpm. Thereafter, 3.0 g of benzonitrile was added as a dispersion medium and stirred with a spatula for 10 minutes to produce a positive electrode composition (U-2).

(3) Preparation of compositions for positive electrode (U-3) to (U-10) and (HU-1) to (HU-4) The composition for positive electrode described above, except that the composition is changed to that shown in Table 2 below. A positive electrode composition (U-3) was produced in the same manner as (U-1). Moreover, except having changed into the structure of following Table 2, it is the method similar to the said composition for positive electrodes (U-2), and the composition for positive electrodes (U-4)-(U-10), (HU- 1) to (HU-4) were produced.

Table 2 below collectively describes the composition of the positive electrode composition.
Here, the positive electrode compositions (U-1) to (U-10) are the positive electrode compositions of the present invention, and the positive electrode compositions (HU-1) to (HU-4) are comparative positive electrode compositions. It is a thing.

<Notes on Table 2>
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle diameter 5.06 μm, manufactured by Toshima Seisakusho Co., Ltd.)
Li-PS: Li-PS-based glass synthesized above B-S1: Urethane particles: Dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd., average particle size: 7 μm)
B-S3: PTFE particles: Microdispers-200 (manufactured by Techno Chemical Co., Ltd., average particle size: 200 nm)
HSBR: hydrogenated styrene butadiene rubber LogP value calculated by ChemBioDrawUltra10.2.1076 (manufactured by CambridgeSoft) LCO: LiCoO ₂ lithium cobaltate NMC: Li (Ni _1/3 Mn _1/3 Co _1/3 ) O ₂ Nickel, Manganese, Lithium Cobaltate “-” indicates that the corresponding component is not included, and that no value is indicated because the corresponding component is not included.

(1) Preparation of negative electrode composition (S-1) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and an inorganic solid electrolyte LLZ (manufactured by Toshima Seisakusho Co., Ltd.). 0 g, dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd.) 0.3 g, and toluene 11.3 g as a dispersion medium were added. After setting the container on the planetary ball mill P-7 manufactured by Fricht and continuing the mechanical dispersion for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm, 7.0 g of acetylene black was put into the container. Similarly, the planetary ball mill P-7 The container was set in the container, and mechanical dispersion was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 100 rpm. Thereafter, 1.0 g of o-tolunitrile was added as a dispersion medium and stirred with a spatula for 10 minutes to obtain a negative electrode composition (S-1).

(2) Preparation of Composition for Negative Electrode (S-2) 180 zirconia beads having a diameter of 5 mm were put into a 45 mL container (manufactured by Fritsch) made of zirconia, and 9.0 g of the Li—PS system glass synthesized above. Then, 0.3 g of dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd.) and 11.3 g of heptane as a dispersion medium were added. After setting the container on a planetary ball mill P-7 manufactured by Fricht and continuing mechanical dispersion for 2 hours at a temperature of 25 ° C. and a rotation speed of 300 rpm, 7.0 g of acetylene black as an active material was charged into the container. The container was set in P-7, and machine dispersion was continued for 15 minutes at a temperature of 25 ° C. and a rotation speed of 200 rpm. Benzonitrile (1.0 g) was added as a dispersion medium and stirred with a spatula for 10 minutes to produce a negative electrode composition (S-2).

(3) Preparation of Composition for Negative Electrode (S-3) to (S-10) and (HS-1) to (HS-4) The composition for negative electrode described above, except that the composition shown in Table 3 below was changed. A negative electrode composition (S-3) was produced in the same manner as (S-1). Moreover, except having changed into the structure of following Table 3, it is the method similar to the said composition for negative electrodes (S-2), and the composition for negative electrodes (S-4)-(S-10), (HS- 1) to (HS-4) were produced.

Table 3 below collectively describes the composition of the negative electrode composition.
Here, the negative electrode compositions (S-1) to (S-10) are the negative electrode compositions of the present invention, and the negative electrode compositions (HS-1) to (HS-4) are comparative negative electrode compositions. It is a thing.

<Notes on Table 3>
LLZ: Li ₇ La ₃ Zr ₂ O ₁₂ (average particle diameter 5.06 μm, manufactured by Toshima Seisakusho Co., Ltd.)
Li-PS: Li-PS-based glass synthesized above B-S1: Urethane particles: Dimic beads UCN-8070CM (manufactured by Dainichi Seika Co., Ltd., average particle size: 7 μm)
B-S3: PTFE particles: Microdispers-200 (manufactured by Techno Chemical Co., Ltd., average particle size: 200 nm)
HSBR: hydrogenated styrene butadiene rubber LogP value calculated with ChemBioDrawUltra10.2.1076 (manufactured by CambridgeSoft) AB: acetylene black

Production of secondary battery positive electrode sheet The above-prepared secondary battery positive electrode composition was applied onto an aluminum foil having a thickness of 20 μm with an applicator with adjustable clearance, heated at 80 ° C. for 1 hour, and further at 110 ° C. The coating solvent was dried by heating for 1 hour. Then, it heated and pressurized so that it might become arbitrary density using the heat press machine, and the positive electrode sheet for secondary batteries was obtained.

Production of Secondary Battery Electrode Sheet On the secondary battery positive electrode sheet produced above, the solid electrolyte composition produced above was applied with an applicator capable of adjusting the chestnut, heated at 80 ° C. for 1 hour, and further 110 Heated at 0 ° C. for 1 hour. Then, the secondary battery negative electrode composition produced above was further applied onto the dried solid electrolyte composition, heated at 80 ° C. for 1 hour, and further heated at 110 ° C. for 1 hour. A copper foil having a thickness of 20 μm was combined on the negative electrode active material layer, and heated and pressurized to a desired density using a heat press machine, to obtain an electrode sheet for a secondary battery described in Table 4 below. The secondary battery electrode sheet has the configuration of FIG. Each of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer has a film thickness described in Table 4 below.

Production of an all-solid secondary battery The secondary battery electrode sheet 15 produced above was cut into a disk shape having a diameter of 14.5 mm and placed in a stainless steel 2032 type coin case 14 incorporating a spacer and a washer. Using the test specimen shown, a restraint pressure (screw tightening pressure: 8 N) was applied from the outside of the coin case 14, and test Nos. Described in Table 4 below were applied. 101 to 110 and c11 to c14 all solid state secondary battery 13 were manufactured. In FIG. 2, 11 is an upper support plate, 12 is a lower support plate, and S is a screw.
Test No. manufactured above. The following evaluation was performed about the all-solid-state secondary battery of 101-110 and c11-c14.

<Evaluation of state of coating film (positive electrode active material layer, negative electrode active material layer and solid electrolyte layer)>
A secondary battery electrode sheet is cut into a disk shape having a diameter of 14.5 mm, and the positive electrode active material layer, the negative electrode active material layer and the solid electrolyte layer are cut or cracked, cracks, a positive electrode active material layer, or a negative electrode in the cut section. The presence or absence of peeling of the active material layer from the solid electrolyte layer or the current collector was evaluated with an inspection optical microscope (Eclipse Ci (manufactured by Nikon Corporation)) and evaluated according to the following criteria. In addition, evaluation "C" or more is a pass level of this test.
A: No defects (chips, cracks, cracks, peeling) were observed at all.
B: The area of the defect portion is more than 0% to 10% or less of the total area to be observed. C: The area of the defect portion is more than 10% to 30% or less of the total area to be observed. D: The area of the defect portion. Is more than 30% of the total area to be observed

<Measurement of battery voltage>
The battery voltage of the all-solid-state secondary battery manufactured above was measured with a charge / discharge evaluation apparatus “TOSCAT-3000” manufactured by Toyo System Co., Ltd.
Charging was performed until the battery voltage reached 4.2 V at a current density of 2 A / m ^2. After reaching 4.2 V, constant voltage charging was performed until the current density was less than 0.2 A / m ² . Discharging was performed at a current density of 2 A / m ² until the battery voltage reached 3.0V. This was repeated, and the battery voltage after 5 mAh / g discharge in the third cycle was read and evaluated according to the following criteria. In addition, evaluation "C" or more is a pass level of this test.

A: 4.0 V or more B: 3.9 V or more and less than 4.0 V C: 3.8 V or more and less than 3.9 V D: Less than 3.8 V

<Evaluation of cycle characteristics>
The cycle characteristics of the all-solid secondary battery produced above were measured by a charge / discharge evaluation apparatus “TOSCAT-3000” manufactured by Toyo System Co., Ltd. Charging / discharging was performed under the same conditions as the battery voltage evaluation. The discharge capacity at the third cycle was set to 100, and the following criteria were evaluated from the number of cycles when the discharge capacity was less than 80. In addition, evaluation "C" or more is a pass level of this test.

A: 50 times or more B: 40 times or more and less than 50 times C: 30 times or more and less than 40 times D: Less than 30 times

  As is apparent from the results shown in Table 4, the all-solid-state secondary battery having any one of the positive electrode active material layer, the negative electrode active material layer, and the solid electrolyte layer prepared from the solid electrolyte composition of the present invention is a coated film. This state is good and shows high battery voltage and cycle characteristics.

  On the other hand, c11 of the test example in which none of the layers has a polymer had a poor coating film state and insufficient cycle characteristics. Moreover, c12 and c13 of the test example using the solid electrolyte composition which does not contain either a good solvent or a poor solvent had a poor coating film state and insufficient cycle characteristics.

Moreover, c14 of a test example used the composition for positive electrodes (HU-2) and the solid electrolyte composition (HK-2) which do not contain the solvent which melt | dissolves a polymer particle.
In addition, heptane and dibutyl ether used as dispersion media in the negative electrode composition (HS-4) are both “solvents that dissolve polymer particles” in relation to HSBR.
From the above, none of the positive electrode composition (HU-2), the solid electrolyte composition (HK-2), and the negative electrode composition (HS-4) used in Test Example c14 satisfies the provisions of the present invention.
Therefore, in Test Example c14, the voltage, the state of the coating film, and the cycle characteristics were insufficient.

DESCRIPTION OF SYMBOLS 1 Negative electrode collector 2 Negative electrode active material layer 3 Solid electrolyte layer 4 Positive electrode active material layer 5 Positive electrode collector 6 Working part 10 All-solid secondary battery 11 Upper support plate 12 Lower support plate 13 Coin battery 14 Coin case 15 Secondary Battery electrode sheet S Screw

Claims (18)

A composition for making an all-solid secondary battery comprising a positive electrode active material layer, an inorganic solid electrolyte layer, and a negative electrode active material layer, the positive electrode active material layer, the inorganic solid electrolyte layer, and the negative electrode active material layer A composition for forming at least one layer of
An inorganic solid electrolyte having conductivity of ions of metals belonging to Group 1 or Group 2 of the Periodic Table;
Containing polymer particles and a dispersion medium,
A solid electrolyte composition, wherein the dispersion medium is a dispersion medium containing at least one solvent that dissolves polymer particles and at least one solvent that does not dissolve polymer particles.   The solid electrolyte composition according to claim 1, wherein the dispersion medium is a non-aqueous solvent.   The solid electrolyte composition according to claim 1 or 2, wherein a boiling point of a solvent that dissolves the polymer particles is higher than a boiling point of a solvent that does not dissolve the polymer particles.   The boiling point of the solvent that dissolves the polymer particles is 100 ° C. or more and less than 250 ° C., the boiling point of the solvent that does not dissolve the polymer particles is 80 ° C. or more and less than 220 ° C., and the boiling point of the solvent that dissolves the polymer particles is The solid electrolyte composition according to any one of claims 1 to 3, which is higher by 20 ° C or more than a boiling point of a solvent that does not dissolve the polymer particles.   The solid electrolyte according to any one of claims 1 to 4, wherein a ratio of a mass of the solvent that dissolves the polymer particles to a mass of the solvent that does not dissolve the polymer particles is 0.1: 99.9 to 50:50. Composition.   The LogP value of the solvent that dissolves the polymer particles is less than 3.0, and the LogP value of the solvent that does not dissolve the polymer particles is 3.0 or more. Solid electrolyte composition.   The solvent that dissolves the polymer particles is a ketone solvent, an ester solvent, a carbonate solvent, a nitrile solvent, an ether solvent, or an amide solvent, and the solvent that does not dissolve the polymer particles is a hydrocarbon solvent. 2. The solid electrolyte composition according to item 1.   The solid electrolyte composition according to claim 1, wherein the polymer particles have an average particle diameter of 0.01 μm to 100 μm.   The solid electrolyte composition according to claim 1, wherein the polymer particles are an acrylic resin or a urethane resin.   The content of the polymer particles is 0.1 to 20 parts by mass with respect to 100 parts by mass of the inorganic solid electrolyte, and the content of the dispersion medium is 50 to 2,000 parts by mass. The solid electrolyte composition according to any one of the above.   Furthermore, the solid electrolyte composition of any one of Claims 1-10 containing an electrode active material.   The solid electrolyte composition according to claim 1, wherein the inorganic solid electrolyte is a sulfide-based inorganic solid electrolyte.   The solid electrolyte composition according to claim 1, wherein the inorganic solid electrolyte is an oxide-based inorganic solid electrolyte. The solid electrolyte composition according to claim 13, wherein the inorganic solid electrolyte is selected from the following formulae.
· _Li x _La y TiO ₃
x = 0.3-0.7, y = 0.3-0.7
・ Li ₇ La ₃ Zr ₂ O ₁₂
・ Li _3.5 Zn _0.25 GeO ₄
LiTi ₂ P ₃ O ₁₂ ,
_{· Li 1 + x + y (} Al, Ga) x (Ti, Ge) 2 -xSi y P 3 -yO 12
0 ≦ x ≦ 1, 0 ≦ y ≦ 1
・ Li ₃ PO ₄
・ LiPON
・ LiPOD
D is Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au
At least one selected from LiAON
A is at least one selected from Si, B, Ge, Al, C, Ga, etc.   The battery electrode sheet which formed the solid electrolyte composition of any one of Claims 1-14 into a film on metal foil.   The manufacturing method of the electrode sheet for batteries which forms the solid electrolyte composition of any one of Claims 1-14 on metal foil.   The manufacturing method of the battery electrode sheet of Claim 16 including the process heated at 80 degreeC or more after film forming.   The manufacturing method of the all-solid-state secondary battery which manufactures an all-solid-state secondary battery using the electrode sheet for batteries of Claim 15.

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