Inorganic solid electrolyte-containing composition, sheet for all-solid-state secondary battery, all-solid-state secondary battery, and method for manufacturing sheet for all-solid-state secondary battery and all-solid-state secondary battery

Abstract

Provided is an inorganic solid electrolyte-containing composition which contains an inorganic solid electrolyte, a polymer binder and a dispersion medium. The polymer binder comprises a polymer that has: a polymer chain with an ethylenic unsaturated bond on the main chain; and a partial structure including at least one of the below flexible functional groups. Also provided are: a sheet for an all-solid state secondary battery and an all-solid-state secondary battery, both using the inorganic solid electrolyte-containing composition; a method for producing a sheet for an all-solid state secondary battery; and a method for producing an all solid-state secondary battery.

Description

[Technical Field]

[0001] The present invention relates to an inorganic solid electrolyte-containing composition, a sheet for an all-solid-state secondary battery, an all-solid-state secondary battery, and a method for producing the sheet for an all-solid-state secondary battery and the all-solid-state secondary battery. [Background technology]

[0002] All-solid-state secondary batteries, in which the negative electrode, electrolyte, and positive electrode are all solid, can significantly improve the safety and reliability that are issues with secondary batteries that use organic electrolytes. It is also believed that they can achieve longer life. Furthermore, all-solid-state secondary batteries can be configured with electrodes and electrolytes directly arranged in series. This allows for higher energy density than secondary batteries that use organic electrolytes, and they are expected to be used in electric vehicles, large-scale storage batteries, and other applications.

[0003] In such all-solid-state secondary batteries, inorganic solid electrolytes, active materials, etc. are used as materials forming constituent layers (solid electrolyte layer, negative electrode active material layer, positive electrode active material layer, etc.) Inorganic solid electrolytes, particularly oxide-based inorganic solid electrolytes and sulfide-based inorganic solid electrolytes, have recently attracted attention as electrolyte materials with high ionic conductivity approaching that of organic electrolyte solutions. Materials containing the above-mentioned inorganic solid electrolytes have been proposed as materials for forming the constituent layers of all-solid-state secondary batteries (constituent layer-forming materials). For example, Patent Document 1 describes a solid electrolyte composition containing a block polymer and an inorganic solid electrolyte having ion conductivity for a metal belonging to Group 1 or Group 2 of the periodic table, in which the block polymer contains at least one block composed of repeating units having at least one functional group having affinity for an electrode active material or the inorganic solid electrolyte. The block polymer specifically described in Patent Document 1 is a polymer having a main chain skeleton formed by a copolymer skeleton composed of blocks polymerized from ethylenically unsaturated monomers. Furthermore, Patent Document 2 describes a solid electrolyte composition containing an inorganic solid electrolyte having ion conductivity for a metal belonging to Group 1 or Group 2 of the periodic table and a binder composed of a polymer, in which the binder contains non-spherical binder particles composed of secondary particles formed from primary particles having an average primary particle diameter of 1 to 1,000 nm. Patent Document 2 specifically describes (meth)acrylic polymers having polar groups, or polyurethane polymers having soft segments such as polyetherol, polybutadiene polyol, and polycarbonate polyol. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2017 / 030154 [Patent Document 2] International Publication No. 2020 / 075749 Summary of the Invention [Problem to be solved by the invention]

[0005] Constituent layer-forming materials used in the production of all-solid-state secondary batteries are required to have dispersion properties that stably maintain excellent dispersibility of solid particles immediately after preparation, from the viewpoints of manufacturing aspects such as ease of handling and reproducibility, or from the viewpoint of improving battery performance. Moreover, in recent years, from the viewpoints of reducing environmental impact and further reducing production costs, the use of highly concentrated (thickened) constituent layer-forming materials with increased solid content has been considered. However, as the solid content concentration increases, aggregation or precipitation of solid particles over time is inevitable (deterioration of dispersion properties). Furthermore, in order to suppress the deterioration of battery performance (e.g., cycle characteristics) due to charge and discharge, the constituent layer forming material is also required to be able to form constituent layers in which solid particles are adhered with strong adhesion. This is because the constituent layers of all-solid-state secondary batteries are formed from solid particles (inorganic solid electrolyte, active material, conductive additive, etc.), and the state of interfacial contact between the solid particles is restricted, making it difficult to ensure sufficient adhesion between the solid particles. With regard to the above-mentioned demand for improved dispersion properties or improved adhesion, the constituent layer forming materials described in Patent Documents 1 and 2 are expected to have a certain degree of improvement effect. However, in recent years, research and development into improving the performance and practical application of electric vehicles has progressed rapidly, and the demand for battery performance required of all-solid-state secondary batteries has become even higher, so there is a demand for the development of constituent layer forming materials that can achieve both higher levels of dispersion properties and adhesion.

[0006] An object of the present invention is to provide an inorganic solid electrolyte-containing composition that exhibits excellent dispersion properties even when the solid content concentration of solid particles is increased, and that can form a constituent layer in which solid particles are firmly adhered. Another object of the present invention is to provide a sheet for an all-solid-state secondary battery, an all-solid-state secondary battery, and a method for manufacturing the sheet for an all-solid-state secondary battery and the all-solid-state secondary battery, using the inorganic solid electrolyte-containing composition. [Means for solving the problem]

[0007] The present inventors conducted extensive research into binders used in combination with inorganic solid electrolytes and dispersion media, and came up with the idea that the main chain structure of the polymer constituting the binder can effectively contribute to improving the dispersion properties and adhesion of solid particles containing inorganic solid electrolytes. Based on this idea, the present inventors conducted further research and found that by forming a binder from a polymer having a main chain containing a segment composed of a polymer chain of ethylenically unsaturated bonds and a partial structure (preferably a segment) containing a specific flexible functional group, solid particles can be stably dispersed not only immediately after preparation but also over time (excellent dispersion properties), even when the solid content is increased, and further solid particles can be firmly adhered during film formation of an inorganic solid electrolyte-containing composition. The present invention was completed through further research based on these findings.

[0008] That is, the above problems were solved by the following means. <1> An inorganic solid electrolyte-containing composition comprising an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, a polymer binder, and a dispersion medium, An inorganic solid electrolyte-containing composition comprising a polymer binder, the polymer binder comprising a polymer having, in its main chain, a polymer chain of an ethylenically unsaturated bond and a partial structure containing at least one of the following flexible functional groups: <Flexible functional group group> Ether group, ester group, amide group, silyl ether group, carbonate group, hydrocarbon group

[0009] <2> The polymer has a polymer chain represented by the following formula (1): <1> The inorganic solid electrolyte-containing composition according to claim 1. [ka] In formula (1), A represents a hydrogen atom or a hydrocarbon group. Y represents an ester bond, an amide bond, an aromatic ring group, or a heterocyclic group. L represents a single bond or a linking group. Z represents a hydrogen atom or a substituent. n is a number greater than or equal to 2. <3> The polymer has a polymer chain represented by the following formula (2): <1> or <2> The inorganic solid electrolyte-containing composition according to claim 1. [ka] In formula (2), X represents an alkylene group or a silylene group, and m is a number of 2 or more.

[0010] <4> The polymer contains 10% by mass or more of polymer chains with ethylenically unsaturated bonds, <1> ~ <3> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <5> The polymer chain represented by formula (2) is selected from a polyethyleneoxy chain, a polypropyleneoxy chain, and a polysilyleneoxy chain. <3> or <4> The inorganic solid electrolyte-containing composition according to claim 1. <6> The glass transition temperature of the polymer is -30°C or lower. <1> ~ <5> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <7> The polymer contains a component having an alkyl group having 8 or more carbon atoms as a side chain. <1> ~ <6> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <8> The polymer has a component having at least one polar functional group selected from the following polar functional group group (a): <1> ~ <7> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <Polar functional group group (a)> Sulfonic acid group, phosphoric acid group, phosphonic acid group, hydroxy group, carboxy group, oxetane group, epoxy group, dicarboxylic acid anhydride group, thiol group, ether group, thioether group, thioester group, fluoroalkyl group, and salts thereof <9> containing an active material, <1> ~ <8> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <10> Contains a conductive additive, <1> ~ <9> 10. The inorganic solid electrolyte-containing composition according to claim 9, wherein the inorganic solid electrolyte-containing composition is a hydroxybenzoate. <11> the above <1> ~ <10> 1. A sheet for an all-solid-state secondary battery, comprising a layer made of the inorganic solid electrolyte-containing composition according to any one of 1 to 8. <12> An all-solid-state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, At least one of the positive electrode active material layer, the solid electrolyte layer and the negative electrode active material layer is <1> ~ <10> 10. An all-solid-state secondary battery, wherein the layer is made of the inorganic solid electrolyte-containing composition according to any one of 1 to 8. <13> the above <1> ~ <10> 10. A method for producing a sheet for an all-solid-state secondary battery, comprising forming a film from the inorganic solid electrolyte-containing composition according to any one of the above items. <14> the above <13> 2. A method for producing an all-solid-state secondary battery, comprising the steps of: producing an all-solid-state secondary battery through the method for producing an all-solid-state secondary battery according to claim 1 ; [Effects of the Invention]

[0011] The present invention can provide an inorganic solid electrolyte-containing composition that exhibits excellent dispersion properties even when the solid content concentration of solid particles is increased and can form a constituent layer in which the solid particles are firmly adhered. The present invention can also provide a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery having a layer constituted by this excellent inorganic solid electrolyte-containing composition. Furthermore, the present invention can provide a method for producing a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery using this inorganic solid electrolyte-containing composition. The above and other features and advantages of the present invention will become more apparent from the following description, taken in conjunction with the accompanying drawings where appropriate. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a longitudinal sectional view schematically showing an all-solid-state secondary battery according to a preferred embodiment of the present invention. [Figure 2] FIG. 2 is a longitudinal sectional view schematically showing a coin-type all-solid-state secondary battery produced in the example. DETAILED DESCRIPTION OF THE INVENTION

[0013] In the present invention, a numerical range expressed using "to" means a range that includes the numerical values ​​written before and after "to" as the lower and upper limits. In the present invention, when multiple numerical ranges are set for the content of a component, physical properties, etc., the upper and lower limits forming the numerical range are not limited to the specific combination written before and after "to" as a specific numerical range, but can be a numerical range obtained by appropriately combining the upper and lower limits of each numerical range. In the present invention, the expression of a compound (for example, when it is referred to by adding "compound" to the end) is used to mean not only the compound itself, but also its salts and ions. It also means to include derivatives that have been partially modified, such as by introducing a substituent, within the scope that does not impair the effects of the present invention. In the present invention, (meth)acrylic means one or both of acrylic and methacrylic. The same applies to (meth)acrylate. In the present invention, substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) that are not specified as substituted or unsubstituted mean that the group may have an appropriate substituent. Therefore, even when simply described as a YYY group in the present invention, this YYY group includes not only an embodiment in which it has no substituent, but also an embodiment in which it further has a substituent. This also applies to compounds in which it is not specified as substituted or unsubstituted. Preferred substituents include, for example, the substituent Z described below. In the present invention, when there are multiple substituents, etc., designated by a specific symbol, or when multiple substituents, etc., are simultaneously or alternatively specified, it means that the respective substituents, etc., may be the same or different from each other. Furthermore, even if not otherwise specified, when multiple substituents, etc., are adjacent, they may be linked to each other or condensed to form a ring. In the present invention, the term "polymer" refers to a polymer, and is synonymous with the term "polymer compound." The term "polymer binder" (also simply referred to as "binder") refers to a binder made of a polymer, and includes both the polymer itself and a binder formed containing a polymer.

[0014] [Inorganic solid electrolyte-containing composition] The inorganic solid electrolyte-containing composition of the present invention contains an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, a binder containing a polymer binder made of a polymer described below, and a dispersion medium. The inorganic solid electrolyte-containing composition of the present invention is preferably a slurry in which the inorganic solid electrolyte is dispersed in the dispersion medium.

[0015] The polymer binder functions to enhance the dispersion characteristics of solid particles such as inorganic solid electrolytes by dispersing in a dispersion medium and interacting with, and preferably adsorbing to, solid particles such as inorganic solid electrolytes in the inorganic solid electrolyte-containing composition. In the present invention, the adsorption of the polymer binder to solid particles includes not only physical adsorption but also chemical adsorption (adsorption through chemical bond formation, adsorption through electron transfer, etc.). The dispersion characteristics exhibited by the polymer binder can be maintained even when the solid content of the solid particles is increased. Therefore, the solid content of the inorganic solid electrolyte-containing composition of the present invention can be increased (the composition can be thickened). The solid content concentration is not uniquely determined by changes in the composition temperature, the type of solid particles, etc., but can be, for example, 40% by mass or more at 25°C, and even 50% by mass or more. Furthermore, the polymer binder functions as a binder that firmly binds (adheres) solid particles such as inorganic solid electrolytes (and further coexisting active materials and conductive additives) together (for example, between inorganic solid electrolytes, between inorganic solid electrolytes and active materials, between active materials) in a constituent layer formed from the inorganic solid electrolyte-containing composition. It also functions as a binder that firmly binds solid particles to a substrate such as a current collector. In the inorganic solid electrolyte-containing composition, the polymer binder may or may not have the function of binding solid particles together.

[0016] The inorganic solid electrolyte-containing composition of the present invention exhibits excellent dispersion properties even at an increased solid content concentration, and when used as a constituent layer, the solid particles can be firmly adhered to other solid particles and to a substrate. Therefore, by using this inorganic solid electrolyte-containing composition as a constituent layer-forming material, it is possible to realize a sheet for an all-solid-state secondary battery having a constituent layer in which the solid particles are firmly adhered, and further an all-solid-state secondary battery having excellent cycle characteristics.

[0017] The details of the reason for this are not yet clear, but it is thought to be as follows. Specifically, when a polymer binder is formed from a polymer having a main chain formed by incorporating a polymer chain of an ethylenically unsaturated bond and a partial structure containing at least one flexible functional group, as described below, it is believed that the effect of enhancing the excluded volume effect between polymer binders in the inorganic solid electrolyte-containing composition (dispersion medium) is more enhanced than when a partial structure containing a flexible functional group is introduced into the side chain, and the repulsion between binders can also be increased. The increased excluded volume effect and repulsion can improve the dispersibility of the binder itself (suppressing aggregation and adhesion between binders), and as a result, solid particles adsorbed to the binder can be highly dispersed by suppressing their aggregation and precipitation. This allows the excellent initial dispersibility of solid particles immediately after preparation to be stably maintained (excellent dispersion stability) even when the solid content is increased. Furthermore, the binder does not entirely cover the surfaces of the solid particles, maintaining interfacial contact between the solid particles, and thus allowing the solid particles to firmly adhere to each other during the film-forming process of the constituent layer (e.g., during application and drying of the inorganic solid electrolyte-containing composition). Furthermore, since the mechanical properties (elongation properties) of the polymer, particularly the main chain, are improved, the binder can follow and offset external stresses such as vibration and bending, as well as expansion and contraction of the constituent layers due to charging and discharging, thereby maintaining strong adhesion. As described above, the inorganic solid electrolyte-containing composition of the present invention can increase the excluded volume effect and repulsive force of the polymer binder and the mechanical properties of the main chain to a high level in a well-balanced manner, and as a result, it is thought that the solid particles can be dispersed highly stably while also being firmly adhered or bound to each other during the film-forming process. In this way, the inorganic solid electrolyte-containing composition of the present invention can form a constituent layer in which solid particles are firmly adhered to one another. An all-solid-state secondary battery having such a constituent layer can maintain the solid particles in a firmly adhered state even after repeated charge and discharge. Therefore, even after repeated charge and discharge, a significant deterioration in battery characteristics can be avoided, and an all-solid-state secondary battery exhibiting excellent cycle characteristics can be realized.

[0018] When an active material layer is formed on a current collector using the inorganic solid electrolyte-containing composition of the present invention, strong adhesion between the current collector and the active material can be achieved. Therefore, an all-solid-state secondary battery in which an active material layer is formed on a current collector using the inorganic solid electrolyte-containing composition of the present invention also strengthens the adhesion between the current collector and the active material, enabling further improvement in cycle characteristics.

[0019] The inorganic solid electrolyte-containing composition of the present invention can be preferably used as a forming material (constituent layer forming material) for a solid electrolyte layer or an active material layer of an all-solid-state secondary battery sheet (including an electrode sheet for an all-solid-state secondary battery) or an all-solid-state secondary battery. In particular, it can be preferably used as a forming material for an electrode sheet or an active material layer for an all-solid-state secondary battery, and in this embodiment, high cycle characteristics can also be achieved. As described above, in the present invention, unless otherwise specified, the term "adhesion of solid particles" refers to adhesion between solid particles and the current collector, in addition to adhesion between solid particles themselves.

[0020] The inorganic solid electrolyte-containing composition of the present invention is preferably a non-aqueous composition. In the present invention, the non-aqueous composition includes not only an embodiment that does not contain water, but also an embodiment in which the water content (also referred to as water content) is preferably 500 ppm or less. In a non-aqueous composition, the water content is more preferably 200 ppm or less, even more preferably 100 ppm or less, and particularly preferably 50 ppm or less. When the inorganic solid electrolyte-containing composition is a non-aqueous composition, deterioration of the inorganic solid electrolyte can be suppressed. The water content refers to the amount of water contained in the inorganic solid electrolyte-containing composition (mass ratio relative to the inorganic solid electrolyte-containing composition), and specifically refers to the value measured by Karl Fischer titration after filtering through a 0.02 μm membrane filter.

[0021] The inorganic solid electrolyte-containing composition of the present invention also includes an embodiment containing an active material and further a conductive additive in addition to the inorganic solid electrolyte (the composition in this embodiment is referred to as an electrode composition). Components contained in the inorganic solid electrolyte-containing composition of the present invention and components that can be contained therein will be described below.

[0022] <Inorganic solid electrolyte> The inorganic solid electrolyte-containing composition of the present invention contains an inorganic solid electrolyte. In the present invention, the term "inorganic solid electrolyte" refers to an inorganic solid electrolyte, and a solid electrolyte is a solid electrolyte capable of transferring ions therein. Because inorganic solid electrolytes do not contain organic substances as the main ion-conducting material, they are clearly distinguished from organic solid electrolytes (polymer electrolytes such as polyethylene oxide (PEO) and organic electrolyte salts such as lithium bis(trifluoromethanesulfonyl)imide (LiTFSI)). Furthermore, inorganic solid electrolytes are solid in a steady state and are not typically dissociated or liberated into cations and anions. In this respect, they are also clearly distinguished from electrolytic solutions or inorganic electrolyte salts (such as LiPF, LiBF, lithium bis(fluorosulfonyl)imide (LiFSI), and LiCl) that are dissociated or liberated into cations and anions in a polymer. The inorganic solid electrolyte is not particularly limited as long as it has ionic conductivity for metals belonging to Group 1 or Group 2 of the periodic table, but generally does not have electronic conductivity. When the all-solid-state secondary battery of the present invention is a lithium-ion battery, the inorganic solid electrolyte preferably has ionic conductivity for lithium ions. The inorganic solid electrolyte may be selected from solid electrolyte materials typically used in all-solid-state secondary batteries. Examples of inorganic solid electrolytes include (i) sulfide-based inorganic solid electrolytes, (ii) oxide-based inorganic solid electrolytes, (iii) halide-based inorganic solid electrolytes, and (iv) hydride-based inorganic solid electrolytes. Sulfide-based inorganic solid electrolytes are preferred because they can form a better interface between the active material and the inorganic solid electrolyte.

[0023] (i) Sulfide-based inorganic solid electrolyte The sulfide-based inorganic solid electrolyte preferably contains sulfur atoms, has the ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and has electronic insulation. The sulfide-based inorganic solid electrolyte preferably contains at least Li, S, and P as elements and has lithium ion conductivity, but may contain elements other than Li, S, and P as appropriate.

[0024] An example of the sulfide-based inorganic solid electrolyte is a lithium ion conductive inorganic solid electrolyte that satisfies the composition represented by the following formula (S1). L a1 M b1 P c1 S d1 A e1 (S1) In the formula, L represents an element selected from Li, Na, and K, and Li is preferred. M represents an element selected from B, Zn, Sn, Si, Cu, Ga, Sb, Al, and Ge. A represents an element selected from I, Br, Cl, and F. a1 to e1 represent the composition ratio of each element, and a1:b1:c1:d1:e1 satisfies the ratio 1-12:0-5:1:2-12:0-10. a1 is preferably 1-9, and more preferably 1.5-7.5. b1 is preferably 0-3, and more preferably 0-1. d1 is preferably 2.5-10, and more preferably 3.0-8.5. e1 is preferably 0-5, and more preferably 0-3.

[0025] The composition ratio of each element can be controlled by adjusting the blending amounts of raw material compounds when producing the sulfide-based inorganic solid electrolyte, as described below.

[0026] The sulfide-based inorganic solid electrolyte may be amorphous (glass) or crystallized (glass-ceramic), or may be only partially crystallized. For example, a Li-PS-based glass containing Li, P, and S, or a Li-PS-based glass-ceramic containing Li, P, and S may be used. The sulfide-based inorganic solid electrolyte can be produced by reacting at least two or more raw materials selected from the group consisting of lithium sulfide (LiS), phosphorus sulfide (e.g., diphosphorus pentasulfide (PS)), elemental phosphorus, elemental sulfur, sodium sulfide, hydrogen sulfide, lithium halides (e.g., LiI, LiBr, LiCl), and sulfides of the elements represented by M above (e.g., SiS, SnS, GeS).

[0027] In the Li-PS glass and Li-PS glass ceramics, the ratio of Li2S to P2S5 is preferably 60:40 to 90:10, more preferably 68:32 to 78:22, in terms of the molar ratio of Li2S:P2S5. By setting the ratio of Li2S to P2S5 within this range, the lithium ion conductivity can be increased. Specifically, the lithium ion conductivity is preferably 1×10 -4 S / cm or more, preferably 1×10 -3 S / cm or more. There is no upper limit, but it is 1×10 -1 It is practical to have a value of S / cm or less.

[0028] Specific examples of sulfide-based inorganic solid electrolytes, including combinations of raw materials, are shown below: Li2S-P2S5, Li2S-P2S5-LiCl, Li2S-P2S5-H2S, Li2S-P2S5-H2S-LiCl, Li2S-LiI-P2S5, Li2S-LiI-Li2O-P2S5, Li2S-LiBr-P2S5, Li2S-Li2O-P2S5, Li2S-Li3PO4-P2S5, Li2S-P2S5-P2O5, Li2S-P2S5-SiS2, Li2S-P2S5-SiS2-LiCl, Li2S-P2S5-SnS, and Li2S-P2S5-Al2S3 , Li2S-GeS2, Li2S-GeS2-ZnS, Li2S-Ga2S3, Li2S-GeS2-Ga2S3, Li2S-GeS2-P2S5, Li2S-GeS2-Sb2S5, Li2S-GeS2-Al2S3, Li2S-SiS2, L i2S-Al2S3, Li2S-SiS2-Al2S3, Li2S-SiS2-P2S5, Li2S-SiS2-P2S5-LiI, Li2S-SiS2-LiI, Li2S-SiS2-Li4SiO4, Li2S-SiS2-Li3PO4, Li 10 GeP2S 12 However, the mixing ratio of each raw material is not important. As a method for synthesizing a sulfide-based inorganic solid electrolyte material using such a raw material composition, for example, an amorphization method can be mentioned. Examples of the amorphization method include a mechanical milling method, a solution method, and a melt quenching method. This is because processing at room temperature becomes possible, and the manufacturing process can be simplified.

[0029] (ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte preferably contains oxygen atoms, has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and has electronic insulation properties. The oxide-based inorganic solid electrolyte preferably has an ionic conductivity of 1×10 -6 S / cm or more, more preferably 5×10 -6 [[ID=**11**]]S / cm or more, and particularly preferably **1×10 -5 S / cm or more. The upper limit is not particularly limited, but it is practical that it is 1×10 -1 S / cm or less. \n

[0030] Specific compound examples include, for example, Li xa La ya TiO3 [xa satisfies 0.3 ≤ xa ≤ 0.7, and ya satisfies 0.3 ≤ ya ≤ 0.7.](LLT); Li xb La yb Zr zb M bb mb O nb (M bb ) is one or more elements selected from Al, Mg, Ca, Sr, V, Nb, Ta, Ti, Ge, In, and Sn. xb satisfies 5 ≤ xb ≤ 10, yb satisfies 1 ≤ yb ≤ 4, zb satisfies 1 ≤ zb ≤ 4, mb satisfies 0 ≤ mb ≤ 2, and nb satisfies 5 ≤ nb ≤ 20.); Li xc B yc M cc zc O nc (M cc is one or more elements selected from C, S, Al, Si, Ga, Ge, In, and Sn. xc satisfies 0 < xc ≤ 5, yc satisfies 0 < yc ≤ 1, zc satisfies 0 < zc ≤ 1, and nc satisfies 0 < nc ≤ 6.); Li xd (Al,Ga) yd (Ti,Ge) zd Si ad P md [[ID=*57*]]O nd Note: There seems to be a formatting issue in the original text where the superscript numbers in the ionic conductivity expressions are not properly formatted. I've tried to keep the translation as close as possible while making the superscript numbers more distinguishable in the translation for better readability. Also, I'm not sure if the "mb" and "nb" in the chemical formulas have specific formatting or meaning that might be lost in translation. If there are any specific instructions regarding these, please let me know and I can adjust accordingly.(xd satisfies 1 ≤ xd ≤ 3, yd satisfies 0 ≤ yd ≤ 1, zd satisfies 0 ≤ zd ≤ 2, ad satisfies 0 ≤ ad ≤ 1, md satisfies 1 ≤ md ≤ 7, and nd satisfies 3 ≤ nd ≤ 13.); Li (3-2xe) M ee xe D ee O(xe represents a number greater than or equal to 0 and less than or equal to 0.1, M ee represents a divalent metal atom. D ee represents a halogen atom or a combination of two or more halogen atoms.); Li xf Si yf O zf (xf satisfies 1 ≤ xf ≤ 5, yf satisfies 0 < yf ≤ 3, and zf satisfies 1 ≤ zf ≤ 10.); Li xg S yg O zg (xg satisfies 1 ≤ xg ≤ 3, yg satisfies 0 < yg ≤ 2, and zg satisfies 1 ≤ zg ≤ 10.); Li3BO3; Li3BO3 - Li2SO_{4}; Li2O - B2O3 - P2O5; Li2O - SiO2; Li6BaLa2Ta2O 12 ; Li3PO (4-3 / 2w) N w [[ID=​​​​​​​​​​​​​​​​​​​​​​​​​Also desirable are phosphorus compounds containing Li, P, and O. For example, lithium phosphate (Li3PO4), LiPON, in which some of the oxygen atoms in lithium phosphate are replaced with nitrogen atoms, and LiPOD. 1 (D 1 is preferably one or more elements selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, and Au. Furthermore, LiA 1 ON(A 1 is one or more elements selected from Si, B, Ge, Al, C and Ga.) can also be preferably used.

[0031] (iii) Halide-based inorganic solid electrolytes The halide-based inorganic solid electrolyte is preferably a compound that contains a halogen atom, has ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and has electronic insulation properties. The halide-based inorganic solid electrolyte is not particularly limited, but examples thereof include LiCl, LiBr, LiI, and compounds such as Li3YBr6 and Li3YCl6 described in ADVANCED MATERIALS, 2018, 30, 1803075. Of these, Li3YBr6 and Li3YCl6 are preferred.

[0032] (iv) Hydride-based inorganic solid electrolytes The hydride-based inorganic solid electrolyte is preferably a compound that contains hydrogen atoms, has the ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and has electronic insulation properties. The hydride-based inorganic solid electrolyte is not particularly limited, but examples thereof include LiBH4, Li4(BH4)3I, 3LiBH4-LiCl, and the like.

[0033] The inorganic solid electrolyte is preferably in the form of particles. In this case, the particle size (volume average particle size) of the inorganic solid electrolyte is not particularly limited, but is preferably 0.01 μm or more, more preferably 0.1 μm or more. The upper limit is preferably 100 μm or less, more preferably 50 μm or less. The particle size of inorganic solid electrolytes is measured using the following procedure. A 1% by mass dispersion of inorganic solid electrolyte particles is prepared by diluting them in water (or heptane if the substance is unstable in water) in a 20 mL sample bottle. The diluted dispersion sample is irradiated with 1 kHz ultrasound for 10 minutes and then immediately used for testing. Using this dispersion sample, a laser diffraction / scattering particle size analyzer LA-920 (product name, manufactured by HORIBA) is used to acquire data 50 times at 25°C using a quartz measurement cell to obtain the volume-average particle size. For other detailed conditions, refer to the description in Japanese Industrial Standards (JIS) Z 8828:2013, "Particle Size Analysis - Dynamic Light Scattering Method," as necessary. Five samples are prepared for each level, and the average value is used.

[0034] The inorganic solid electrolyte may be contained in one kind or in two or more kinds. The content of the inorganic solid electrolyte in the inorganic solid electrolyte-containing composition is not particularly limited, but from the viewpoints of adhesion and dispersibility, it is preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more, based on 100% by mass of the solid content. From the same viewpoint, the upper limit is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and particularly preferably 99% by mass or less. However, when the inorganic solid electrolyte-containing composition contains an active material described below, the content of the inorganic solid electrolyte in the inorganic solid electrolyte-containing composition is preferably such that the total content of the active material and the inorganic solid electrolyte falls within the above range. In the present invention, the solid content (solid components) refers to components that do not volatilize or vaporize when the inorganic solid electrolyte-containing composition is dried at 150°C under a nitrogen atmosphere at an atmospheric pressure of 1 mmHg for 6 hours. Typically, this refers to components other than the dispersion medium described below.

[0035] <Polymer binder> The polymer binder contained in the inorganic solid electrolyte-containing composition of the present invention contains one or more polymer binders formed of a polymer having a main chain, which will be described later. By using this polymer binder in combination with the inorganic solid electrolyte and the dispersion medium, the inorganic solid electrolyte-containing composition can exhibit excellent dispersion properties even when the solid content is increased, and the adhesion of solid particles can be strengthened when the inorganic solid electrolyte-containing composition is used as a constituent layer.

[0036] (Binder-forming polymer) The polymer that forms the polymer binder contained in the inorganic solid electrolyte-containing composition of the present invention (also referred to as a binder-forming polymer) will be described. This binder-forming polymer (also simply referred to as a polymer) has a main chain having a polymer chain of an ethylenically unsaturated bond and a partial structure containing at least one of the flexible functional groups described below. This main chain is preferably a polymer having a polymer chain of an ethylenically unsaturated bond as a segment, and is preferably a block polymer having a partial structure containing at least one of the flexible functional groups as a segment. In the present invention, the main chain of a polymer refers to a linear molecular chain in which all other molecular chains constituting the polymer can be considered as branched chains or pendant groups relative to the main chain. Typically, the longest chain among the molecular chains constituting the polymer becomes the main chain, although this depends on the mass average molecular weight of the branched chains considered as branched chains or pendant groups. However, terminal groups at the polymer ends are not included in the main chain. Furthermore, the side chain of a polymer refers to branched chains other than the main chain, and includes short and long chains. Although a segment generally refers to an aggregate of multiple constituent components derived from a monomer, in the present invention, it also includes a partial structure composed of a single constituent component derived from a monomer or a single non-polymerized molecular chain. For example, the partial structure "NN" contained in polymer S-13 synthesized in the Examples described below is an example of a segment composed of a single non-polymerized molecular chain as a partial structure containing a flexible functional group.

[0037] The molecular structure of the binder-forming polymer (main chain) is not particularly limited, and examples thereof include a linear structure, a branched structure, a multi-branched structure (graft structure, star structure, dendritic structure, etc.), etc. Among these, a linear structure, a branched structure, or a graft structure is more preferred.

[0038] The polymer chains and partial structures of the ethylenically unsaturated bonds are not particularly limited in number of types and bonding pattern as long as they constitute the main chain (are incorporated into the main chain). For example, the polymer chains and partial structures constituting the main chain may each be one type or two or more types, but are preferably one type. Two or more of the same polymer chains and partial structures may be incorporated into the main chain. The bonding pattern of the polymer chains and partial structures, where "A" represents the polymer chain and "B" represents the partial structure, may be AB type (a polymer in which one polymer chain A and one partial structure B are linearly bonded to form one main chain), ABA type (a polymer in which two polymer chains A are bonded to both ends of one partial structure B to form one main chain), (AB)n type (n is an integer of 2 or more), etc. Among these, AB type or ABA type is preferred, and ABA type is more preferred. As the binder-forming polymer, various polymers can be appropriately selected, but vinyl polymers or (meth)acrylic polymers are preferred. In the present invention, the type of binder-forming polymer is determined based on the type and content of the constituent components that constitute the polymer chain of ethylenically unsaturated bonds.

[0039] - Polymer chain of ethylenically unsaturated bonds - The polymer chain of the ethylenically unsaturated bond may be any molecular chain made of a polymer of a polymerizable compound having an ethylenically unsaturated bond, and is incorporated as a block (segment) into the main chain of the binder-forming polymer. By forming the main chain of the binder-forming polymer from the polymer chain and the partial structure described below, the polymer chain and the partial structure work together to achieve the above-mentioned effects. The polymerizable compound that forms a polymer chain is not particularly limited as long as it has an ethylenically unsaturated bond, and examples thereof include a (meth)acrylic acid compound (M1) and a vinyl compound (M2) described below. This polymer chain may be a molecular chain consisting of constituent components derived from one type of polymerizable compound, or may be a molecular chain having constituent components derived from two or more types of polymerizable compounds. When two or more types of constituent components are contained, the bonding mode (arrangement) of each constituent component is not particularly limited and may be any of random bonding, alternating bonding, block bonding, etc. The content of each constituent component in a polymer chain having two or more types of constituent components is not particularly limited and may be set appropriately, as will be described in detail below. Examples of polymers constituting a polymer chain of ethylenically unsaturated bonds include chain-polymerized polymers such as fluorine-based polymers (fluorine-containing polymers), hydrocarbon-based polymers, vinyl polymers, and (meth)acrylic polymers, with vinyl polymers and (meth)acrylic polymers being preferred.

[0040] Examples of (meth)acrylic polymers suitable as binder-forming polymers include copolymers of appropriate (meth)acrylic compounds (M1), which contain 50% by mass or more of components derived from (meth)acrylic compounds based on the total mass of polymer chains with ethylenically unsaturated bonds. When components such as the long-chain alkyl group-containing component and the polar functional group-containing component described below are derived from the (meth)acrylic compound (M1), the content of each component is included in the total content of the components derived from the (meth)acrylic compound. The content of the components derived from the (meth)acrylic compound is preferably 60% by mass or more, and more preferably 70% by mass or more. The upper limit of the content can be 100% by mass, but can also be 97% by mass or less. A preferred embodiment of the (meth)acrylic polymer is a copolymer of a (meth)acrylic compound (M1) and a vinyl compound (M2) other than the (meth)acrylic compound (M1). In this case, the content of the constituent component derived from the vinyl compound (M2) is 50% by mass or less, preferably 3 to 40% by mass, and more preferably 3 to 30% by mass.

[0041] Vinyl polymers suitable as binder-forming polymers include copolymers of an appropriate vinyl compound (M2), which contain 50% by mass or more of vinyl compound-derived components based on the total mass of the ethylenically unsaturated bond polymer chain. When components such as the long-chain alkyl group-containing component and the polar functional group-containing component described below are derived from the vinyl compound (M2), the content of each component is included in the content of the vinyl compound-derived components. The content of the vinyl compound-derived components is preferably 60% by mass or more, and more preferably 65% ​​by mass or more. The upper limit of the content can be 100% by mass, but is preferably 95% by mass or less, and more preferably 90% by mass or less. A preferred embodiment of the vinyl polymer is a copolymer of a vinyl compound (M2) and a (meth)acrylic compound (M1). In this case, the content of the component derived from the (meth)acrylic compound (M1) may be less than 50% by mass, for example, preferably 0 to 40% by mass, and more preferably 0 to 30% by mass.

[0042] The polymer chain of the ethylenically unsaturated bond may contain a partial structure containing a flexible functional group described later or a polymer chain represented by formula (2) described later, but in one preferred embodiment, it does not contain such a partial structure. The mass average molecular weight (Mw) and glass transition temperature (Tg) of the polymer chain are appropriately determined taking into consideration the content of the polymer chain in the binder-forming polymer, the mass average molecular weight and glass transition temperature of the binder-forming polymer, etc. For example, the mass average molecular weight of the polymer chain can be 2,000 to 2,000,000, and the glass transition temperature can be -100 to 200°C.

[0043] - Substructure containing flexible functional groups - This partial structure (which can also be called a soft segment) contains at least one flexible functional group selected from the group of flexible functional groups described below. By combining this partial structure with a polymer chain and incorporating it into the main chain of the binder-forming polymer, the polymer chain and the partial structure work together to improve dispersion properties and adhesion. By incorporating this partial structure into the main chain of the binder-forming polymer, the polar functional group possessed by the partial structure is incorporated into the side chain of the binder-forming polymer. This partial structure may be a partial structure composed of a non-polymerized molecular chain (hydrocarbon groups such as alkylene groups and alkenylene groups are not usually included in polymerizable molecular chains), or may be a partial structure composed of a polymerized chain. [Flexible functional group group] Ether group, ester group, amide group, silyl ether group, carbonate group, hydrocarbon group

[0044] In the present invention, the flexible functional group generally refers to a group or structure that exhibits flexibility and extensibility compared to rigid groups (such as aromatic ring groups, heteroaromatic ring groups, and aliphatic alicyclic groups) that constitute the "hard segments" of a polymer, and that exhibits properties that impart elasticity (flexibility) to the polymer, and includes those that correspond to those that constitute the "soft segments" of a polymer. In the present invention, each of the functional groups shown in the above group is used as the flexible functional group.

[0045] The ether group is -R E It means a linking group (also called a bond or structure) represented by -O-. E represents a divalent group, and is appropriately selected from a group obtained by further removing one hydrogen atom from a group appropriately selected from the substituent Z described below, or from the linking group L described below. Eis preferably a hydrocarbon group, and is preferably an alkylene group or an arylene group, and is preferably an alkylene group in that it can improve dispersion properties and adhesion in a balanced manner. The alkylene group may contain a cyclic structure, but is preferably linear or branched. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably 1 to 10, more preferably 2 to 6, and even more preferably 2 to 4, in that it can improve dispersion properties and adhesion in a balanced manner. The number of carbon atoms in the arylene group is not particularly limited, and can be, for example, 6 to 12.

[0046] The ester group is -R ES It means a linking group represented by -C(=O)O-. ES represents a divalent group, and is appropriately selected from a group obtained by further removing one hydrogen atom from a group appropriately selected from the substituent Z described below, or from the linking group L described below. ES The alkylene group is preferably, for example, an alkylene group, an arylene group, or a heteroarylene group. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably, for example, 1 to 10, and more preferably 2 to 6. The number of carbon atoms in the arylene group is not particularly limited, and can be, for example, 6 to 12.

[0047] The amide group is -R A1 -C(=O)NR A2 -, where R A1 represents a divalent group, and is appropriately selected from a group obtained by further removing one hydrogen atom from a group appropriately selected from the substituent Z described below, or from the linking group L described below. A1 R is preferably, for example, an alkylene group, an arylene group, or a heteroarylene group. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably, for example, 1 to 10, and more preferably 2 to 6. The number of carbon atoms in the arylene group is not particularly limited, and can be, for example, 6 to 12. A2 represents a hydrogen atom or a substituent, and a hydrogen atom is preferred. A2The substituent that can be taken as is not particularly limited and can be appropriately selected from the substituents Z, and an alkyl group is preferred.

[0048] The silyl ether group is -Si(R S )2-O-, where R S represents a hydrogen atom or a substituent, and a substituent is preferred. The substituent is not particularly limited and may be selected from the substituent Z described below, and is preferably an alkyl group or an aryl group, more preferably an alkyl group having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms.

[0049] The carbonate group is -R C It means a linking group represented by -OC(=O)O-. C represents a divalent group, and is appropriately selected from a group obtained by further removing one hydrogen atom from a group appropriately selected from the substituent Z described below, or from the linking group L described below. C The alkylene group is preferably, for example, an alkylene group, an arylene group, or a heteroarylene group. The number of carbon atoms in the alkylene group is not particularly limited, but is preferably, for example, 1 to 12, and more preferably 2 to 6. The number of carbon atoms in the arylene group is not particularly limited, and can be, for example, 6 to 12.

[0050] The hydrocarbon group refers to a low-molecular-weight hydrocarbon group, and is preferably a normal (non-polymerizable) hydrocarbon group. Examples of such hydrocarbon groups include aliphatic or aromatic hydrocarbon groups, and specifically, alkylene groups (preferably having 1 to 100 carbon atoms, more preferably 4 to 30 carbon atoms, and even more preferably 10 to 20 carbon atoms), alkenyne groups (preferably having 1 to 100 carbon atoms, more preferably 4 to 30 carbon atoms, and even more preferably 10 to 20 carbon atoms), arylene groups (preferably having 6 to 22 carbon atoms, and more preferably 6 to 10 carbon atoms), or groups formed from a combination thereof are preferred. Among these, alkylene groups or alkenyne groups are more preferred in terms of dispersion properties and adhesion. In the present invention, as will be described later, one preferred form of the partial structure is a hydrocarbon polymer chain, and therefore, the alkylene group, alkenylene group, etc. that can be used as the hydrocarbon group include alkylene groups and alkenylene groups, which are one of the constituent components that make up a hydrocarbon polymer.

[0051] The partial structure may be a structure containing at least one of the flexible functional groups, but in terms of dispersion characteristics and adhesion, a partial structure containing two or more of the flexible functional groups is preferred. The number of (bonds between) flexible functional groups constituting a preferred partial structure is appropriately determined taking into consideration the content of the partial structure in the binder-forming polymer, the weight average molecular weight of the binder-forming polymer, etc. For example, it is preferably set within a range that satisfies the number average molecular weight described below.

[0052] When the partial structure contains two or more flexible functional groups, the combination is not particularly limited, and two or more flexible functional groups appropriately selected from the above group can be combined. Among them, a chain (block, segment) combining multiple flexible functional groups of the same type is preferred. Preferred examples of such chains include polyether chains, polyester chains, polyamide chains, polysilyleneoxy chains, polycarbonate chains, and hydrocarbon polymer chains.

[0053] The polyether chain (also referred to as a polyalkylene oxide chain or a polyalkyleneoxy chain) in which a plurality of the above ether groups are combined includes chains made of known polyalkyleneoxy groups, and polyethyleneoxy chains and polypropyleneoxy chains are preferred. The polyester chains, polyamide chains and polycarbonate chains each comprising a combination of a plurality of the ester groups, amide groups or carbonate groups include known chains made of polyester, polyamide or polycarbonate, respectively. Examples of the polysilyleneoxy chains in which a plurality of silyl ether groups are combined include chains made of known polysiloxanes, with chains made of dialkylpolysiloxanes being preferred, and chains made of dimethylpolysiloxanes being more preferred. Examples of hydrocarbon polymer chains that combine multiple hydrocarbon chains include polymer chains formed by polymerizing at least two of the above hydrocarbon groups as polymerizable hydrocarbons. The number of carbon atoms constituting the main chain of the hydrocarbon polymer chain is not particularly limited, but is preferably 30 or more, more preferably 50 or more. The upper limit is not particularly limited, and can be, for example, 3,000. Such hydrocarbon polymer chains are preferably hydrocarbon polymer chains whose main chain is composed of an aliphatic hydrocarbon, and more preferably chains composed of a polymer (preferably an elastomer) composed of an aliphatic saturated hydrocarbon (alkylene group) or an aliphatic unsaturated hydrocarbon (alkenylene group). Specific examples of hydrocarbon polymer chains include diene polymers having double bonds in the main chain and non-diene polymers having no double bonds in the main chain. Examples of diene polymers include styrene-butadiene copolymers, styrene-ethylene-butadiene copolymers, copolymers of isobutylene and isoprene (preferably butyl rubber (IIR)), butadiene polymers, isoprene polymers, and ethylene-propylene-diene copolymers. Examples of non-diene polymers include olefin polymers such as ethylene-propylene copolymers and styrene-ethylene-butylene copolymers, as well as hydrogen reduction products of the above diene polymers.

[0054] As a chain combining multiple flexible functional groups of the same type, among the above, a polyether chain or a polysilyleneoxy chain is preferred, and a polyethyleneoxy chain, a polypropyleneoxy chain, or a polysilyleneoxy chain is more preferred, in that it can achieve both high levels of dispersion properties and adhesion. The mass-average molecular weight or number-average molecular weight of a chain combining multiple flexible functional groups cannot be uniquely determined depending on the molecular weight of the flexible functional groups and the number of bonds of the flexible functional groups, but is appropriately determined taking into consideration the content of the partial structure in the binder-forming polymer, the mass-average molecular weight of the binder-forming polymer, etc. For example, the number-average molecular weight of a chain combining multiple flexible functional groups can be 100 to 2,000,000, and preferably 500 to 30,000. In particular, the number-average molecular weight of a polyether chain can be 100 to 100,000, and preferably 500 to 10,000, and the number-average molecular weight of a polysilyleneoxy chain can be 500 to 100,000.

[0055] The partial structure may be composed of the flexible functional group described above, but typically has a linking moiety that links to the polymer chain described above. This linking moiety is typically bonded to an end of the partial structure, with the bonding position and number of bonds being appropriately determined depending on the main chain structure of the binder-forming polymer. For example, if the main chain is the AB type described above, it is bonded to either end of the partial structure, and if the main chain is the ABA type or (AB)n type described above, it is bonded to both ends of the partial structure. If the partial structure has multiple linking moieties, the linking moieties may be the same or different, but from the viewpoint of synthesis of the binder-forming polymer, it is preferable that the linking moieties be the same. The linking moiety has a smaller effect on dispersion properties and adhesion than the polymer chains and flexible functional groups described above, and its chemical structure is not particularly limited as long as it is a group (atomic group) that can be linked to the polymer chains described above. Examples of linking groups include the linking group L described below. In terms of facilitating synthesis of the binder-forming polymer, it is preferably a residue of a polymerization initiator or chain transfer agent, and more preferably a residue of an azo polymerization initiator. In this case, the chemical structure of the linking moiety is not uniquely determined by the polymerization initiator selected, but an example is the linking group (—C(CN)(CH3)—CH2—CH2—CO—O— group) contained in polymer S-10 synthesized in the Examples. Even if the linking portion contains a partial structure corresponding to the flexible functional group, this partial structure is not considered to be the flexible functional group.

[0056] The partial structure may contain the above-mentioned polymer chain of an ethylenically unsaturated bond or the polymer chain represented by formula (1) described below, but in one preferred embodiment it does not contain any of them.

[0057] The method for incorporating the partial structure into the main chain will be explained in the synthesis method for the binder-forming polymer.

[0058] The binder-forming polymer may have one or more of the above-mentioned polymer chains of ethylenically unsaturated bonds and the above-mentioned partial structures.

[0059] - Polymer chain represented by formula (1) - The binder-forming polymer may have the aforementioned main chain, but from the viewpoint of dispersion properties and adhesion, it preferably has a polymer chain represented by the following formula (1) (hereinafter, sometimes referred to as polymer chain (1)). This polymer chain (1) may be contained in either a polymer chain of an ethylenically unsaturated bond or the partial structure described above, and is preferably contained in a polymer chain of an ethylenically unsaturated bond, and more preferably is a polymer chain of an ethylenically unsaturated bond.

[0060] [ka]

[0061] In formula (1), A represents a hydrogen atom or a hydrocarbon group. The hydrocarbon group that can be taken as A is not particularly limited and includes saturated or unsaturated aliphatic hydrocarbon groups or aromatic hydrocarbon groups. Among them, alkyl groups that are saturated aliphatic hydrocarbons are preferred, and alkyl groups having 1 to 6 carbon atoms are more preferred. A is preferably a hydrogen atom or a methyl group.

[0062] Y is an ester bond (-CO-O-), an amide bond (-CO-NR A2 -), an aromatic ring group or a heterocyclic group. A2 is R in the above amide group A2 is synonymous with. Examples of the aromatic ring group include groups in which one hydrogen atom has been further removed from the aryl group in the substituent Z described below, and a benzene ring group is preferred. Examples of the heterocyclic group include groups in which one hydrogen atom has been further removed from the heterocyclic group in the substituent Z described below. Y is preferably an ester bond, an amide bond or a benzene ring group, and more preferably an ester bond.

[0063] L represents a single bond or a linking group. The linking group that can be taken as L is not particularly limited and has the same meaning as the linking group L described below, but an alkylene group or an arylene group is more preferred, and an alkylene group is even more preferred. L is preferably a single bond or an alkylene group.

[0064] Z represents a hydrogen atom or a substituent. The substituent Z may be any of, but is not limited to, the substituent Z described below, and a polar functional group selected from the polar functional group group (a) described below. The substituent Z is preferably an alkyl group, an aryl group, or a heterocyclic group. From the viewpoint of dispersion properties and adhesion, an alkyl group (e.g., having 1 to 24 carbon atoms) is more preferable. A long-chain alkyl group having 8 or more carbon atoms is even more preferable, since it can achieve high levels of both dispersion properties and adhesion. The number of carbon atoms constituting this long-chain alkyl group is preferably 8 to 24, more preferably 8 to 16, and even more preferably 10 to 14. The alkyl group may have a cyclic structure (a cycloalkyl group or a cycloalkylene group) in part, but a linear or branched alkyl group is preferred, and a linear alkyl group is more preferred. The carbon number of the alkyl group refers to the number of carbon atoms constituting this alkyl group. If this alkyl group further has a substituent, the number of carbon atoms constituting the further substituent is included in the calculation. Z is preferably a hydrogen atom, an alkyl group or a polar functional group. In the present invention, when the -LZ group in formula (1) represents one type of substituent (for example, an alkyl group), L is interpreted as a single bond and Z as one type of substituent (for example, an alkyl group).

[0065] n represents the average degree of polymerization of the polymer chain (1) and is a number equal to or greater than 2. The average degree of polymerization n is appropriately determined in consideration of the mass average molecular weight of the binder-forming polymer, the mass average molecular weight of the polymer chain of the ethylenically unsaturated bond, the content of the polymer chain (1) in the binder-forming polymer, etc. For example, the average degree of polymerization is set to a range that satisfies the mass average molecular weight of the polymer chain of the ethylenically unsaturated bond.

[0066] In the above formula (1), the carbon atom adjacent to the carbon atom to which A is bonded has two hydrogen atoms, but in the present invention, it may have one or two substituents. The substituent is not particularly limited, but examples thereof include the substituent Z described below, and groups other than polar functional groups selected from the polar functional group group (a) described below are preferred.

[0067] The constituent components (repeating units represented by the above formula (1)) constituting the polymer chain (1) may be one type or two or more types, as long as they satisfy the above formula (1). When two or more constituent components are present, for example, a constituent component in which Z in formula (1) is a long-chain alkyl group, a constituent component in which Z is a polar functional group, and a constituent component in which Z is a short-chain alkyl group having 7 or less carbon atoms can be appropriately combined. The bonding mode (arrangement) of each constituent component is not particularly limited and may be any of random bonding, alternating bonding, block bonding, etc. The content of each constituent component in a polymer chain having two or more constituent components is not particularly limited and may be appropriately set, as will be described in detail below. This polymer chain may contain repeating units other than the repeating unit represented by the above formula (1) in the chain.

[0068] The polymer chain (1) may be any known polymer, such as the chain-polymerized polymer described above, without any particular limitation. In the present invention, a polymer chain made of a (meth)acrylic polymer is preferred because it can achieve both high levels of dispersion properties and adhesion. The compound that forms the polymer chain (1) is not particularly limited, and examples thereof include a (meth)acrylic acid compound (M1) and a vinyl compound (M2) described below. The polymer chain (1) made of a (meth)acrylic polymer contains a component derived from a (meth)acrylic compound (M1) described below, and may also contain a component derived from a vinyl compound (M2) described below. Among these, a polymer chain containing a component derived from one or more (meth)acrylic acid ester compounds is more preferred, and a polymer chain containing a component derived from a (meth)acrylic acid alkyl ester compound is even more preferred. The (meth)acrylic acid alkyl ester compound preferably contains an ester compound of the long-chain alkyl group described above, and may further contain an ester compound of a short-chain alkyl group having 7 or less carbon atoms. The content of each component in the polymer chain is not particularly limited and may be appropriately determined. For example, the content of the component derived from the (meth)acrylic compound (M1) in the polymer chain is preferably 30 to 100% by mass, more preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass. The content of the component derived from a (meth)acrylic acid alkyl ester compound is preferably 50 to 100% by mass, and even more preferably 80 to 100% by mass.

[0069] - Polymer chain represented by formula (2) - The binder-forming polymer may have the aforementioned main chain, but preferably has a polymer chain represented by the following formula (2) (hereinafter sometimes referred to as polymer chain (2)) in that it can achieve high levels of both dispersion properties and adhesion. This polymer chain (2) may be contained in either the polymer chain of the ethylenically unsaturated bond or the partial structure described above, and is preferably contained in the partial structure containing a flexible functional group, and more preferably contained in the partial structure as a polyether chain in which multiple ether groups are combined, or a polysilyleneoxy chain in which multiple silyl ether groups are combined.

[0070] [ka]

[0071] In formula (2), X represents an alkylene group or a silylene group. The alkylene group that can be taken as X is not particularly limited, but may be any of the above R E The alkylene group has the same meaning as the alkylene group which can be taken as the alkylene group. The silylene group that can be taken as X is not particularly limited, but may be the above-mentioned —Si(R S )2- is synonymous with

[0072] m represents the average degree of polymerization of the polymer chain (2) and is a number equal to or greater than 2. The average degree of polymerization m is determined appropriately in consideration of the weight average molecular weight of the binder-forming polymer, the content of the polymer chain (1) in the partial structure, the number of flexible functional groups constituting the partial structure, etc. For example, the average degree of polymerization is set to a range that satisfies the weight average molecular weight of the polyether chain or polysilyleneoxy chain.

[0073] Examples of the polymer chain (2) include polyether chains and polysilyleneoxy chains, and among these, polyethyleneoxy chains, polypropyleneoxy chains, and polysilyleneoxy chains are preferred because they can achieve both high levels of dispersibility and adhesion.

[0074] The constituent components (repeating units represented by the above formula (2)) constituting the polymer chain (2) may be one type or two or more types, as long as they satisfy the above formula (2). When two or more types of constituent components are contained, the bonding mode (arrangement) of each constituent component is not particularly limited and may be any of random bonding, alternating bonding, block bonding, etc. The content of each constituent component in a polymer chain having two or more types of constituent components is not particularly limited and may be set appropriately.

[0075] As the polymer chain (2), various known polyether chains and polysilyleneoxy chains can be used without any particular limitation.

[0076] The binder-forming polymer may have one or more types of the polymer chains (1) and (2).

[0077] - A component having an alkyl group with 8 or more carbon atoms as a side chain - The binder-forming polymer may have the above-described main chain, but preferably has a component having an alkyl group having 8 or more carbon atoms as a side chain, in order to achieve high levels of both dispersion properties and adhesion. This component may be contained in either the polymer chain of the ethylenically unsaturated bond or the partial structure described above, and is preferably contained in the polymer chain of the ethylenically unsaturated bond, and more preferably contained in the polymer chain (1). The constituent having an alkyl group having 8 or more carbon atoms as a side chain (hereinafter also referred to as a long-chain alkyl group-containing constituent) has an alkyl group having 8 or more carbon atoms directly or via a linking group in the main chain forming portion incorporated into the main chain of the binder-forming polymer.

[0078] The main chain forming portion is appropriately selected depending on the type of binder-forming polymer (portion to be incorporated), etc. When incorporated into a polymer chain of an ethylenically unsaturated bond, a carbon chain (carbon-carbon bond) is used, and when incorporated into the above partial structure, the above-mentioned flexible functional group is used. The alkyl group having 8 or more carbon atoms has the same meaning as the long-chain alkyl group that can be taken as Z in the constituent components that make up the polymer chain (1). The linking group is not particularly limited and has the same meaning as the linking group L described below, but may be a -CO-O- group, a -CO-N(R N )-group(R N is as described below.) is more preferred, and a group containing a -CO-O- group or a -CO-N(R N )-group(R N is as described below.) is particularly preferred, and a —CO—O— group is the most preferred.

[0079] The main chain-forming moiety, the linking group, and the alkyl group having 8 or more carbon atoms may each have a substituent. Such a substituent is not particularly limited, and examples include groups selected from the substituent Z described below. The long-chain alkyl group-containing component may have a polar functional group selected from the polar functional group group (a) below as a substituent, but preferably does not have such a substituent. In other words, it is preferable that the long-chain alkyl group-containing component does not correspond to a polar functional group-containing component. Note that even if the long-chain alkyl group-containing component contains the polar functional group described below as the linking group, this polar functional group functions as a linking group and is not a polar functional group selected from the polar functional group group (a) below.

[0080] The long-chain alkyl group-containing component can be formed by appropriately combining the above-mentioned main chain forming portion, alkyl group having 8 or more carbon atoms, and further linking group, and for example, a component represented by the following formula (1-1) is preferred. [ka]

[0081] In formula (1-1), R 1 represents a hydrogen atom or an alkyl group (preferably having 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms). 1 The alkyl group may have a substituent. The substituent is not particularly limited, but examples thereof include the above-mentioned substituent Z, and is preferably a group other than a polar functional group selected from the polar functional group group (a) described below, such as a halogen atom.

[0082] R 2 represents a group having an alkyl group having 8 or more carbon atoms. In the present invention, the group having an alkyl group is a group consisting of an alkyl group itself (the alkyl group is 1 is bonded directly to the carbon atom in the above formula to which R 2 a group consisting of an alkyl group and a linking group connecting the carbon atom in the above formula to which R is bonded and the alkyl group (wherein the alkyl group is R 1is bonded to the carbon atom in the above formula via a linking group. R 2 and R 2 The linking group that may be possessed by R is as described above. 2 As the alkyl group, —C(═O)—O-, a long chain alkyl group having 8 or more carbon atoms is particularly preferred. In the above formula (1-1), R 1 The carbon atom adjacent to the carbon atom to which is bonded has two hydrogen atoms, but in the present invention, it may have one or two substituents. The substituent is not particularly limited, but examples thereof include the substituent Z described below, and groups other than polar functional groups selected from the polar functional group group (a) described below are preferred.

[0083] The long-chain alkyl group-containing component is not particularly limited, but examples include a component derived from a compound having an alkyl group with 8 or more carbon atoms among the (meth)acrylic compounds (M1) described below, and a component derived from a compound having an alkyl group with 8 or more carbon atoms among the vinyl compounds (M2) described below, and a (meth)acrylic acid long-chain alkyl ester compound (having 8 or more carbon atoms) is preferred. Specific examples of components having an alkyl group with 8 or more carbon atoms include the components in the polymers synthesized in the examples, but the present invention is not limited to these.

[0084] - Components with polar functional groups - The binder-forming polymer may have the aforementioned main chain, but preferably has a constituent having at least one polar functional group selected from the polar functional group group (a) below (sometimes simply referred to as a polar functional group-containing constituent). The binder-forming polymer having a polar functional group-containing constituent can enhance the adsorption of the binder to solid particles, improving dispersion properties and adhesion in a well-balanced manner. The polar functional group-containing constituent may be contained in either the polymer chain of the ethylenically unsaturated bond or the partial structure described above. In order to achieve high levels of both dispersion properties and adhesion, it is preferable for the polar functional group-containing constituent to be contained in the polymer chain of the ethylenically unsaturated bond, and more preferably in the polymer chain (1). The polar functional group-containing constituent component may have at least one (one type) polar functional group, and typically preferably has one to three types of polar functional groups.

[0085] [Polar functional group group (a)] Sulfonic acid group (sulfo group), phosphoric acid group, phosphonic acid group, hydroxy group, carboxy group, oxetane group, epoxy group, dicarboxylic acid anhydride group, thiol group (sulfanyl group), ether group, thioether group, thioester group, fluoroalkyl group, and salts thereof

[0086] The sulfonic acid group, phosphoric acid group (phosphoryl group), phosphonic acid group, and the like included in the polar functional group group (a) are not particularly limited, but each has the same meaning as the corresponding group of the substituent Z described below. The dicarboxylic acid anhydride group is not particularly limited, but includes groups formed by removing one or more hydrogen atoms from a dicarboxylic acid anhydride, as well as the constituent components themselves formed by copolymerization of polymerizable dicarboxylic acid anhydrides. As the group formed by removing one or more hydrogen atoms from a dicarboxylic acid anhydride, a group formed by removing one or more hydrogen atoms from a cyclic dicarboxylic acid anhydride is preferred. Examples include acyclic dicarboxylic acid anhydrides such as acetic anhydride, propionic anhydride, and benzoic anhydride, and cyclic dicarboxylic acid anhydrides such as maleic anhydride, phthalic anhydride, fumaric anhydride, succinic anhydride, and itaconic anhydride. The polymerizable dicarboxylic acid anhydride is not particularly limited, but includes dicarboxylic acid anhydrides having an unsaturated bond in the molecule, preferably polymerizable cyclic dicarboxylic acid anhydrides. Specific examples include maleic anhydride and itaconic anhydride.

[0087] In the polar functional group group (a), the ether group (-O-), the thioether group (-S-), and the thioester group (-CO-S-, -CS-O-, -CS-S-) each represent the bond shown in parentheses. The terminal group bonded to these groups is not particularly limited, and examples thereof include groups selected from the substituent Z described below, such as alkyl groups. Note that ether groups include carboxy groups, hydroxy groups, oxetane groups, epoxy groups, and dicarboxylic anhydride groups, but the -O- contained in these groups is not considered an ether group. The same applies to thioether groups. The fluoroalkyl group is an alkyl group or a cycloalkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the number of carbon atoms therein is preferably 1 to 20, more preferably 2 to 15, and even more preferably 3 to 10. The number of fluorine atoms on the carbon atom may be such that some or all of the hydrogen atoms have been replaced (perfluoroalkyl group). Groups capable of forming salts, such as sulfonic acid groups (sulfo groups), phosphoric acid groups, phosphonic acid groups, and carboxy groups, may form salts, such as various metal salts, ammonium salts, and amine salts. The polar functional group contained in the polar functional group-containing component is preferably a carboxy group or a hydroxy group in terms of adsorptivity (adhesion) to solid particles and dispersion characteristics.

[0088] The polar functional group-containing constituent has the polar functional group directly or via a linking group (at a side chain portion) in a main chain forming portion incorporated in the main chain of the binder-forming polymer. The main chain forming portion is appropriately selected depending on the type of binder forming polymer (portion to be incorporated), and has the same meaning as the partial structure incorporated into the main chain of the long chain alkyl group-containing constituent component. The linking group is not particularly limited, and has the same meaning as the linking group L described below, but includes -CO-O- group, -CO-N(R N )-group(R N is as described below.) is more preferred, and a group containing a -CO-O- group-alkylene group or a -CO-N(R N )-group-alkylene group (R N is as described below.) is particularly preferred, and a -CO-O-alkylene group is most preferred.

[0089] The main chain forming portion and the linking group may each have a substituent. Such a substituent is not particularly limited and may, for example, be a group selected from the substituent Z described below. The polar functional group-containing component may have the above-mentioned alkyl group having 8 or more carbon atoms as a substituent, but preferably does not have such an alkyl group. In other words, it is preferable that the polar functional group-containing component does not correspond to a long-chain alkyl group-containing component.

[0090] The polar functional group-containing constituent is not particularly limited, but examples thereof include a constituent derived from a compound having a polar functional group among (meth)acrylic compounds (M1) described below, and a constituent derived from a compound having a polar functional group among vinyl compounds (M2) described below, and (meth)acrylic acid compounds and (meth)acrylic acid polar functional group-containing alkyl ester compounds are preferred.

[0091] The binder-forming polymer may contain one or more of each of the above constituent components.

[0092] - Linking group L - In the present invention, the linking group L is not particularly limited, and examples thereof include an alkylene group (preferably having 1 to 12 carbon atoms, more preferably having 1 to 6 carbon atoms, and even more preferably having 1 to 3 carbon atoms), an alkenylene group (preferably having 2 to 6 carbon atoms, and more preferably having 2 to 3 carbon atoms), an arylene group (preferably having 6 to 24 carbon atoms, and more preferably having 6 to 10 carbon atoms), an oxygen atom, a sulfur atom, an imino group (—NR N -:R N represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. ), a carbonyl group, a phosphate linking group (-OP(OH)(O)-O-), a phosphonate linking group (-P(OH)(O)-O-), or a group relating to a combination thereof. The linking group is preferably a group formed by combining an alkylene group, an arylene group, a carbonyl group, an oxygen atom, a sulfur atom, and an imino group, and more preferably a group formed by combining an alkylene group, an arylene group, a carbonyl group, an oxygen atom, a sulfur atom, and an imino group. Preferred examples of the linking group include linking groups containing a structural moiety derived from a chain transfer agent, a polymerization initiator, or the like used in the synthesis of the binder-forming polymer, and further linking groups in which this structural moiety is bonded to a structural moiety derived from the (meth)acrylic compound (M1) that reacts with the chain transfer agent. Specific examples of the linking group include the linking group contained in polymer S-10 synthesized in the Examples. The number of atoms constituting the linking group and the number of linking atoms are as follows: In the present invention, the number of atoms constituting the linking group is preferably 1 to 36, more preferably 1 to 24, and even more preferably 1 to 12. The number of linking atoms in the linking group is preferably 12 or less, more preferably 10 or less, and particularly preferably 8 or less. The lower limit is 1 or more. The number of linking atoms refers to the minimum number of atoms connecting predetermined structural moieties. For example, in the case of a -C(CN)(CH3)-CH2-CH2-CO-O- group, the number of atoms constituting the linking group is 16, but the number of linking atoms is 5.

[0093] The substituent that the binder-forming polymer may have is not particularly limited, but preferably includes a group selected from the following substituent Z. - Substituent Z - alkyl groups (preferably alkyl groups having 1 to 20 carbon atoms, for example, methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), alkenyl groups (preferably alkenyl groups having 2 to 20 carbon atoms, for example, vinyl, allyl, oleyl, etc.), alkynyl groups (preferably alkynyl groups having 2 to 20 carbon atoms, for example, ethynyl, butadiynyl, phenylethynyl, etc.), cycloalkyl groups (preferably cycloalkyl groups having 3 to 20 carbon atoms, for example, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), In the present invention, the term "alkyl group" generally includes a cycloalkyl group, but will be described separately here.), aryl groups (preferably aryl groups having 6 to 26 carbon atoms, for example, phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl, etc.), aralkyl groups (preferably aralkyl groups having 7 to 23 carbon atoms, for example, benzyl, phenethyl, etc.), heterocyclic groups (preferably heterocyclic groups having 2 to 20 carbon atoms, more preferably a 5- or 6-membered heterocyclic group having at least one oxygen atom, sulfur atom, or nitrogen atom. Heterocyclic groups include aromatic heterocyclic groups and aliphatic heterocyclic groups.For example, a tetrahydropyran ring group, a tetrahydrofuran ring group, 2-pyridyl, 4-pyridyl, 2-imidazolyl, 2-benzimidazolyl, 2-thiazolyl, 2-oxazolyl, a pyrrolidone group, etc.), an alkoxy group (preferably an alkoxy group having 1 to 20 carbon atoms, for example, methoxy, ethoxy, isopropyloxy, benzyloxy, etc.), an aryloxy group (preferably an aryloxy group having 6 to 26 carbon atoms, for example, phenoxy, 1-naphthyloxy, 3-methylphenoxy, 4-methoxyphenoxy, etc.), a heterocyclic oxy group (the above heterocyclic group having -O- group bonded thereto), alkoxycarbonyl groups (preferably alkoxycarbonyl groups having 2 to 20 carbon atoms, for example, ethoxycarbonyl, 2-ethylhexyloxycarbonyl, dodecyloxycarbonyl, etc.), aryloxycarbonyl groups (preferably aryloxycarbonyl groups having 6 to 26 carbon atoms, for example, phenoxycarbonyl, 1-naphthyloxycarbonyl, 3-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), heterocyclic oxycarbonyl groups (groups in which the above heterocyclic groups are bonded to an -O-CO- group), amino groups (preferably includes an amino group, an alkylamino group, or an arylamino group having 0 to 20 carbon atoms, such as amino (-NH), N,N-dimethylamino, N,N-diethylamino, N-ethylamino, or anilino; a sulfamoyl group (preferably a sulfamoyl group having 0 to 20 carbon atoms, such as N,N-dimethylsulfamoyl or N-phenylsulfamoyl); an acyl group (including an alkylcarbonyl group, an alkenylcarbonyl group, an alkynylcarbonyl group, an arylcarbonyl group, or a heterocyclic carbonyl group, preferably an acyl group having 1 to 20 carbon atoms, such as acetyl, propionyl, butyryl, octanoyl, hexadecanoyl, acryloyl, methacryloyl, or crotoyl); noyl, benzoyl, naphthoyl, nicotinoyl, etc.), acyloxy groups (including alkylcarbonyloxy groups, alkenylcarbonyloxy groups, alkynylcarbonyloxy groups, and heterocyclic carbonyloxy groups, preferably acyloxy groups having 1 to 20 carbon atoms, for example, acetyloxy, propionyloxy, butyryloxy, octanoyloxy, hexadecanoyloxy, acryloyloxy, methacryloyloxy, crotonoyloxy, etc.), aryloyloxy groups (preferably aryloyloxy groups having 7 to 23 carbon atoms, for example, benzoyloxy, naphthoyloxy, etc.), carbamoyl groups (preferably carbamoyl groups having 1 to 20 carbon atoms, for example, N,N-dimethylcarbamoyl, N-phenylcarbamoyl, etc.), acylamino groups (preferably acylamino groups having 1 to 20 carbon atoms, for example, acetylamino, benzoylamino, etc.), alkylthio groups (preferably alkylthio groups having 1 to 20 carbon atoms, for example, methylthio, ethylthio, isopropylthio, benzylthio, etc.), arylthio groups (preferably arylthio groups having 6 to 26 carbon atoms, for example, phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio, etc.), heterocyclic thio groups (groups in which an -S- group is bonded to the above heterocyclic group), alkylsulfonyl groups (preferably alkylsulfonyl groups having 1 to 20 carbon atoms, for example, methylsulfonyl, ethylsulfonyl, etc.), arylsulfonyl groups (preferably carbon an arylsulfonyl group having 6 to 22 carbon atoms, such as benzenesulfonyl; an alkylsilyl group (preferably an alkylsilyl group having 1 to 20 carbon atoms, such as monomethylsilyl, dimethylsilyl, trimethylsilyl, triethylsilyl); an arylsilyl group (preferably an arylsilyl group having 6 to 42 carbon atoms, such as triphenylsilyl); an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 20 carbon atoms, such as monomethoxysilyl, dimethoxysilyl, trimethoxysilyl, triethoxysilyl); an aryloxysilyl group (preferably an aryloxysilyl group having 6 to 42 carbon atoms, such as triphenyloxysilyl); a phosphoryl group (preferably a phosphate group having 0 to 20 carbon atoms, such as -OP(=O)(R, P )2), a phosphonyl group (preferably a phosphonyl group having 0 to 20 carbon atoms, for example, —P(═O)(R P )2), a phosphinyl group (preferably a phosphinyl group having 0 to 20 carbon atoms, for example, —P(R P )2), a phosphonic acid group (preferably a phosphonic acid group having 0 to 20 carbon atoms, for example, —PO(OR P ) 2), sulfo group (sulfonic acid group), carboxy group, hydroxy group, sulfanyl group, cyano group, halogen atom (e.g., fluorine atom, chlorine atom, bromine atom, iodine atom, etc.). P is a hydrogen atom or a substituent (preferably a group selected from the substituent Z). Furthermore, each of the groups listed as the substituent Z may be further substituted with the above-mentioned substituent Z. The alkyl group, alkylene group, alkenyl group, alkenylene group, alkynyl group, alkynylene group, etc. may be cyclic or chain-like, and may be straight-chain or branched.

[0094] - (Meth)acrylic compound (M1) - Examples of the (meth)acrylic compound (M1) include (meth)acrylic acid ester compounds, (meth)acrylamide compounds, and (meth)acrylonitrile compounds. Among these, (meth)acrylic acid ester compounds are preferred. Examples of the (meth)acrylic acid ester compounds include (meth)acrylic acid alkyl ester compounds and (meth)acrylic acid aryl ester compounds, with (meth)acrylic acid alkyl ester compounds being preferred. The number of carbon atoms in the alkyl group constituting the (meth)acrylic acid alkyl ester compound is not particularly limited, but can be, for example, 1 to 24. From the viewpoints of dispersion properties and adhesion, it is preferably 3 to 20, more preferably 4 to 16, and particularly from the viewpoint of excellent dispersibility improvement effect, it is even more preferably 8 to 16. The number of carbon atoms in the aryl group constituting the aryl ester is not particularly limited, but can be, for example, 6 to 24, preferably 6 to 10, and preferably 6. In the (meth)acrylamide compound, the nitrogen atom of the amide group may be substituted with an alkyl group or an aryl group.

[0095] - Vinyl compounds (M2) - The vinyl compound (M2) is not particularly limited, but is preferably a vinyl compound copolymerizable with the (meth)acrylic compound (M1), such as aromatic vinyl compounds such as styrene compounds, vinyl naphthalene compounds, vinyl carbazole compounds, vinyl imidazole compounds, and vinyl pyridine compounds, as well as allyl compounds, vinyl ether compounds, vinyl ester compounds (e.g., vinyl acetate compounds), and dialkyl itaconate compounds. Examples of the vinyl compound include the "vinyl monomers" described in JP-A-2015-88486. The (meth)acrylic compound (M1) and the vinyl compound (M2) may have a substituent, but in one preferred embodiment they are unsubstituted. The substituent is not particularly limited and may be a group selected from the above-mentioned substituent Z, and in one preferred embodiment it may be a polar functional group included in the above-mentioned polar functional group group (a).

[0096] - A compound represented by formula (b-1) - As the (meth)acrylic compound (M1) and the vinyl compound (M2), compounds represented by the following formula (b-1) are preferred.

[0097] [ka]

[0098] In the formula, R 1 represents a hydrogen atom, a hydroxy group, a cyano group, a halogen atom, an alkyl group (preferably having 1 to 24 carbon atoms, more preferably having 1 to 12 carbon atoms, and particularly preferably having 1 to 6 carbon atoms), an alkenyl group (preferably having 2 to 24 carbon atoms, more preferably having 2 to 12 carbon atoms, and particularly preferably having 2 to 6 carbon atoms), an alkynyl group (preferably having 2 to 24 carbon atoms, more preferably having 2 to 12 carbon atoms, and particularly preferably having 2 to 6 carbon atoms), or an aryl group (preferably having 6 to 22 carbon atoms, and more preferably having 6 to 14 carbon atoms). Among these, a hydrogen atom or an alkyl group is preferred, and a hydrogen atom or a methyl group is more preferred.

[0099] R 2 represents a hydrogen atom or a substituent. 2 The substituents that can be adopted as R are not particularly limited, but examples thereof include an alkyl group (which may be branched but is preferably straight), an alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 6, and particularly preferably 2 or 3), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14), an aralkyl group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15), and a cyano group. The number of carbon atoms in the alkyl group is the same as the number of carbon atoms in the alkyl group constituting the above-mentioned (meth)acrylic acid alkyl ester compound, and the preferred range is also the same. 2The substituents which may be taken as the substituent may further have the above-mentioned substituents.

[0100] L 1 is a linking group, and is not particularly limited, but the above-mentioned linking group L can be applied without any particular limitation. 1 is particularly preferably a —CO—O— group.

[0101] n is 0 or 1, preferably 1, provided that -(L 1 ) n -R 2 When R represents one type of substituent (for example, an alkyl group), n is set to 0, and R 2 is the substituent (alkyl group). In the above formula (b-1), the carbon atom forming the polymerizable group is R 1 The carbon atom to which R is not bonded is represented as an unsubstituted carbon atom (HC=), but it may have a substituent. The substituent is not particularly limited, but for example, R 1 Examples of the groups that can be taken as the substituent include the above groups. Furthermore, groups that may have a substituent, such as an alkyl group, an aryl group, an alkylene group, or an arylene group, may have a substituent within a range that does not impair the effects of the present invention. The substituent is not particularly limited, and examples thereof include groups selected from the substituent Z described below, and specific examples thereof include a halogen atom.

[0102] Specific examples of the (meth)acrylic compound (M1) and the vinyl compound (M2) include compounds that lead to the constituent components of the polymers synthesized in the examples in addition to those mentioned above, but the present invention is not limited to these. The binder-forming polymer may contain one or more of the above (meth)acrylic compounds (M1) or vinyl compounds (M2).

[0103] - Other partial structures, polymer chains and constituent components - The binder-forming polymer may have a polymer chain of an ethylenically unsaturated bond and a partial structure other than the above partial structure. It may also have a polymer chain other than the polymer chain represented by formula (1) and formula (2), and further a component other than the long-chain alkyl group-containing component and the polar functional group-containing component. The above partial structure, polymer chain, and component that the binder-forming polymer may have may be any component that can constitute the main chain of the binder-forming polymer (can be incorporated into the main chain). The content of these components is determined appropriately within a range that does not impair the effects of the present invention.

[0104] - Terminal structure - The group bonded to the end of the main chain is not particularly limited and can be an appropriate group depending on the polymerization method, post-polymerization treatment, etc. Examples include a hydrogen atom, an alkyl group, an aryl group, and a hydroxy group, and from the viewpoint of dispersion characteristics, an alkyl group (preferably having 1 to 20 carbon atoms, more preferably 4 to 20 carbon atoms) is preferred. This group may further have a substituent, but is preferably unsubstituted.

[0105] Specific examples of binder-forming polymers include the polymers synthesized in the examples, but the present invention is not limited to these.

[0106] - Partial structure, polymer chain and component content - The content of each component (partial structure, polymer chain, constituent component) in the binder-forming polymer is not particularly limited and is determined taking into consideration the physical properties of the entire polymer, etc., as appropriate, and is set, for example, within the following ranges. The content of each component in the binder-forming polymer is set, for example, within the following range so that the total content of all components is 100% by mass. The content specified in this specification can be a range that appropriately combines the upper and lower limits of each range.

[0107] The content of the ethylenically unsaturated bond polymer chain constituting the main chain of the binder-forming polymer and the above partial structure in the total mass of the binder-forming polymer is appropriately determined, taking into consideration dispersion characteristics and adhesion. For example, the content of the ethylenically unsaturated bond polymer chain is preferably 5 to 95% by mass, more preferably 10% by mass or more, even more preferably 10 to 90% by mass, particularly preferably 20 to 80% by mass, and most preferably 30 to 70% by mass. The content of the above partial structure is preferably 5 to 95% by mass, more preferably 10 to 90% by mass, even more preferably 20 to 80% by mass, and particularly preferably 30 to 70% by mass.

[0108] When the main chain of the binder-forming polymer has at least one of the polymer chains (1) and (2), the content of each polymer chain in the total mass of the binder-forming polymer is appropriately determined taking into consideration the dispersion characteristics and adhesion. For example, the content of the polymer chain (1) can be in the same range as the content of the polymer chain of the ethylenically unsaturated bond, and the content of the polymer chain (2) can be in the same range as the content of the partial structure.

[0109] The main chain of the binder-forming polymer does not necessarily have to contain a long-chain alkyl group-containing component. However, if a long-chain alkyl group-containing component is present, the content of the long-chain alkyl group-containing component relative to the total weight of the binder-forming polymer can be greater than 0% by weight and less than 100% by weight. From the viewpoint of enhancing adhesion and improving dispersion characteristics, the content of the long-chain alkyl group-containing component is preferably 10 to 90% by weight, and even more preferably 30 to 70% by weight. The content of the long-chain alkyl group-containing component in the ethylenically unsaturated bond polymer chain or the partial structure, and in polymer chain (1) or polymer chain (2), is determined appropriately taking into account the content in the binder-forming polymer. For example, each content is preferably 5 to 95% by weight, more preferably 10 to 90% by weight, and even more preferably 20 to 90% by weight. The main chain of the binder-forming polymer does not necessarily have to contain a polar functional group-containing component. However, if a polar functional group-containing component is present, the content of the polar functional group-containing component relative to the total weight of the binder-forming polymer can be greater than 0% by weight and less than 100% by weight. From the viewpoint of achieving excellent effects in improving adhesion in addition to improving dispersion characteristics, the content of the polar functional group-containing component is more preferably 1 to 50% by weight, even more preferably 2 to 20% by weight, and particularly preferably 3 to 10% by weight. The content of the polar functional group-containing component in the polymer chain or partial structure of the ethylenically unsaturated bond, and the content in polymer chain (1) or polymer chain (2) are determined appropriately taking into account the content in the binder-forming polymer. For example, the content of each is preferably 1 to 50% by weight, more preferably 1.5 to 30% by weight, even more preferably 2 to 20% by weight, and particularly preferably 5 to 15% by weight. The main chain of the binder-forming polymer may not contain any component other than the long-chain alkyl group-containing component and the polar functional group-containing component, such as a component containing a short-chain alkyl group having 7 or less carbon atoms. However, if such a component is present, the content of this component in the total mass of the binder-forming polymer is determined appropriately and can be greater than 0% by mass but less than 100% by mass, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass. The content of this component in the ethylenically unsaturated bond polymer chain or the partial structure, and in the polymer chain (1) or polymer chain (2), are each determined appropriately taking into account the content in the binder-forming polymer. For example, both contents can be 100% by mass or less, preferably 10 to 90% by mass, and more preferably 20 to 80% by mass.

[0110] The binder-forming polymer can be synthesized by selecting raw material compounds by a known method depending on the type of bond in the main chain, and polymerizing the raw material compounds by a known polymerization method such as chain polymerization. For example, a method of forming a polymer chain of an ethylenically unsaturated bond by polymerizing a polymerizable compound having an ethylenically unsaturated bond in the presence of a polymerization initiator or chain transfer agent containing a flexible functional group can be mentioned. As the polymerization initiator and chain transfer agent used in such a polymerization method, various known compounds can be mentioned, and an azo polymerization initiator is preferred. The polymerization initiator or chain transfer agent containing a flexible functional group may be synthesized as appropriate, or a commercially available product may be used. Examples of the synthesis method include reacting a compound containing a flexible functional group and a reactive group with a polymerization initiator or chain transfer agent having a reactive group capable of reacting with the reactive group. The reaction used here is not particularly limited, and examples include nucleophilic substitution reactions, addition reactions, and condensation reactions (e.g., esterification reactions). Specific examples include the methods and conditions described in the Examples below. Examples of commercially available products include polymeric azo polymerization initiators having a structure in which polymer segments and azo groups are repeatedly bonded, such as polymeric azo polymerization initiator VPS-1001N (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) having a polydimethylsiloxane segment as the polymer segment, and polymeric azo polymerization initiator VPE-0201 (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) having a polyethylene glycol segment as the polymer segment. When an azo polymerization initiator is used, block polymers such as the above-mentioned AB type (A represents a polymer chain of an ethylenically unsaturated bond, and B represents a partial structure in which residues of an azo polymerization initiator are bonded to both ends of a flexible functional group) and ABA type can be obtained.

[0111] (Physical properties or characteristics of binder-forming polymer or polymer binder) The polymer binder or binder-forming polymer used in the present invention preferably has the following physical properties or characteristics.

[0112] The glass transition temperature Tg of the binder-forming polymer is not particularly limited, but in terms of further enhancing adhesion, it is preferably −10° C. or lower, more preferably −30° C. or lower, even more preferably −40° C. or lower, and particularly preferably −50° C. or lower. When the binder-forming polymer has two or more Tgs, it is preferable that the Tg on the lower temperature side falls within the above range. The glass transition temperature Tg of the binder-forming polymer is the glass transition temperature measured by the following method. That is, the glass transition point is the value measured using a dry sample of the binder-forming polymer with a differential scanning calorimeter (DSC7000, manufactured by SII Technology Co., Ltd.) under the following conditions. The measurement is performed twice on the same sample, and the result of the second measurement is used. Measurement chamber atmosphere: Nitrogen (50 mL / min) Heating rate: 5℃ / min ·Measurement start temperature: -100℃ Measurement end temperature: 200℃ Sample pan: Aluminum pan Measurement sample mass: 5 mg Calculation of Tg: Calculate Tg by rounding off the midpoint between the start and end points of the decline on the DSC chart. The glass transition temperature Tg can be adjusted by the type or composition of the polymer chain or the partial structure incorporated into the binder-forming polymer, or the content (content ratio), etc.

[0113] The binder-forming polymer has, in terms of dispersibility, for example, an SP value of 13.0 to 25.0 MPa. 1 / 2 Preferably, the pressure is 15.0 to 23.0 MPa. 1 / 2 More preferably, the pressure is 17.0 to 21.0 MPa. 1 / 2 More preferably, the pressure is 18.0 to 20.5 MPa. 1 / 2 The SP value of the polymer can be adjusted by the type or composition (type and content of constituent components) of the partial structure and polymer chain that constitute the binder-forming polymer. The method for calculating the SP value will be explained. First, the SP value (MPa) of each component that makes up the binder-forming polymer 1 / 2 ) is determined by the Hoy method (HL Hoy JOURNAL OF PAINT TECHNOLOGY Vol. 42, No. 541, 1970, 76-118, and POLYMER HANDBOOK 4 th , Chapter 59, VII, p. 686, Table 5, Table 6 and the following formula in Table 6). If necessary, the SP value obtained in accordance with the above literature may be expressed as the SP value (MPa 1 / 2 ) (for example, 1 cal 1 / 2 cm -3 / 2 ≒2.05J 1 / 2 cm -3 / 2 ≒2.05 MPa 1 / 2 )do.

[0114]

number

[0115] The SP value (MPa) of each component obtained as above 1 / 2 ) to determine the SP values ​​(MPa) of the partial structure containing a flexible functional group and the polymer chain of an ethylenically unsaturated bond, the polymer chains (1) and (2), etc., which constitute the binder-forming polymer. 1 / 2 ) is calculated from the following formula: Next, in the same manner as in the following formula, the calculated SP value is multiplied by the mass fraction of the partial structure or polymer chain, and the sum of these multiplied values ​​is taken as the SP value of the binder-forming polymer. SP p 2 =(SP1 2 ×W1)+(SP2 2 ×W2)+··· In the above formula, SP1, SP2... represent the SP values ​​of the constituent components, and W1, W2... represent the mass fractions of the constituent components. In the present invention, the mass fractions of the constituent components are the mass fractions in the partial structure or polymer chain of the constituent component (the raw material compound from which the constituent component is derived).

[0116] It is preferable that the SP value of the binder-forming polymer satisfy the difference (absolute value) in SP value between the SP value of the dispersion medium and the SP value within the range described below, in order to realize even higher level of dispersion characteristics.

[0117] The weight average molecular weight of the binder-forming polymer is not particularly limited. For example, it is preferably 2,000 or more, more preferably 4,000 or more, and even more preferably 6,000 or more. The upper limit is essentially 5,000,000 or less, but is preferably 100,000 or less, more preferably 50,000 or less, and even more preferably 30,000 or less.

[0118] - Molecular weight measurement - In the present invention, unless otherwise specified, the molecular weight of a polymer or polymer chain refers to the mass average molecular weight or number average molecular weight measured by gel permeation chromatography (GPC) in terms of standard polystyrene. The measurement method can be basically the following condition 1 or condition 2 (preferred). However, depending on the type of polymer, an appropriate eluent may be selected and used. (Condition 1) Column: Two TOSOH TSKgel Super AWM-H (product name, manufactured by Tosoh Corporation) connected together Carrier: 10mM LiBr / N-methylpyrrolidone Measurement temperature: 40℃ Carrier flow rate: 1.0 ml / min Sample concentration: 0.1% by mass Detector: RI (refractive index) detector (Condition 2) Column: A column connected with TOSOH TSKgel Super HZM-H, TOSOH TSKgel Super HZ4000, or TOSOH TSKgel Super HZ2000 (all trade names, manufactured by Tosoh Corporation) is used. Carrier: Tetrahydrofuran Measurement temperature: 40℃ Carrier flow rate: 1.0 ml / min Sample concentration: 0.1% by mass Detector: RI (refractive index) detector

[0119] The polymer binder may be dispersed in particulate form without exhibiting the property of dissolving (solubility) in the dispersion medium contained in the inorganic solid electrolyte-containing composition, but it is preferable that it exhibits solubility. That is, the polymer binder in the inorganic solid electrolyte-containing composition is preferably present in a state dissolved in the dispersion medium in the inorganic solid electrolyte-containing composition, although this depends on its content. When the polymer binder is dissolved, it stably exhibits the function of dispersing the solid particles in the dispersion medium, further enhancing the excellent dispersion properties of the solid particles in the inorganic solid electrolyte-containing composition. In addition, the adhesion of the solid particles can be further strengthened. In the present invention, the polymer binder being dissolved in the dispersion medium in the inorganic solid electrolyte-containing composition is not limited to an embodiment in which all of the polymer binder is dissolved in the dispersion medium, and a part of the polymer binder may be insoluble in the inorganic solid electrolyte-containing composition as long as the solubility in the dispersion medium is, for example, 80% or more. The solubility is measured as follows. Specifically, a specified amount of the polymer binder to be measured is weighed into a glass bottle, and 100 g of the same type of dispersion medium as the dispersion medium contained in the inorganic solid electrolyte-containing composition is added thereto. The mixture is stirred for 24 hours at 80 rpm on a mix rotor at a temperature of 25°C. The transmittance of the mixture thus obtained after 24 hours of stirring is measured under the following conditions. This test (transmittance measurement) is performed by changing the amount of binder dissolved (the above-specified amount), and the upper limit concentration X (mass%) at which the transmittance becomes 99.8% is defined as the solubility of the polymer binder in the above-specified dispersion medium. - Transmittance measurement conditions - Dynamic light scattering (DLS) measurements Equipment: DLS measurement equipment DLS-8000 manufactured by Otsuka Electronics Laser wavelength, output: 488nm / 100mW Sample cell: NMR tube

[0120] When the polymer binder is dispersed in particulate form, the shape of the polymer binder is not particularly limited and may be flat, amorphous, etc., but is preferably spherical or granular. In this case, the particle size of the particulate polymer binder in the inorganic solid electrolyte-containing composition is not particularly limited, but is preferably 1 nm or more, more preferably 10 nm or more, and even more preferably 30 nm or more. The upper limit is preferably 5 μm or less, more preferably 1 μm or less. The particle size of the polymer binder can be measured in the same manner as the particle size of the inorganic solid electrolyte. The particle size of the polymer binder can be adjusted, for example, by the type of dispersion medium, the composition of the binder-forming polymer, etc.

[0121] The water concentration of the binder (binder-forming polymer) is preferably 100 ppm (by mass) or less. The binder may be prepared by crystallizing the polymer and drying it, or the binder dispersion may be used as is. The binder-forming polymer is preferably amorphous. In the present invention, a polymer being "amorphous" typically means that no endothermic peak due to crystalline melting is observed when measured at the glass transition temperature.

[0122] The binder-forming polymer may be a non-crosslinked polymer or a crosslinked polymer. Furthermore, when crosslinking of the polymer progresses due to heating or application of voltage, the molecular weight may be larger than the above-mentioned molecular weight. Preferably, the binder-forming polymer has a mass average molecular weight within the above-mentioned range at the start of use of the all-solid-state secondary battery.

[0123] (Other polymer binders) The inorganic solid electrolyte-containing composition of the present invention may contain, as the polymer binder, one or more binders (other polymer binders) other than the polymer binder formed of the polymer having the above-mentioned main chain. Examples of such polymer binders include polymer binders formed of polymers that do not have at least one of an ethylenically unsaturated bond polymer chain and a partial structure containing at least one of flexible functional groups in the main chain, and those used as polymer binders for all-solid-state secondary batteries can be used without any particular limitation.

[0124] (Polymer binder content) The inorganic solid electrolyte-containing composition may contain one or more types of polymer binders. The total content of the polymer binder in the inorganic solid electrolyte-containing composition is not particularly limited, but is preferably 0.1 to 5.0 mass%, more preferably 0.2 to 4.0 mass%, and even more preferably 0.3 to 2.0 mass%, in terms of dispersion characteristics, adhesion, and ionic conductivity. For the same reasons, the total content of the polymer binder in 100 mass% of the solid content of the inorganic solid electrolyte-containing composition is preferably 0.1 to 6.0 mass%, more preferably 0.3 to 5.0 mass%, and even more preferably 0.4 to 2.5 mass%. The content of the polymer binder composed of the binder-forming polymer having the above-mentioned main chain can be set to the same range as the total content above. On the other hand, the content of the other polymer binders can be set appropriately as long as it does not impair the function of the binder-forming polymer described above.

[0125] In the present invention, at 100% by mass of solid content, the mass ratio of the combined mass (total amount) of the inorganic solid electrolyte and the active material to the mass of the polymer binder [(mass of inorganic solid electrolyte + mass of active material) / (total mass of polymer binder)] is preferably in the range of 1,000 to 1. This ratio is more preferably 500 to 2, and even more preferably 100 to 10.

[0126] <Dispersion medium> The inorganic solid electrolyte-containing composition of the present invention contains a dispersion medium that disperses or dissolves the above-mentioned components. The dispersion medium contained in the inorganic solid electrolyte-containing composition may be any organic compound that is liquid in the usage environment, and examples thereof include various organic solvents, and specific examples thereof include alcohol compounds, ether compounds, amide compounds, amine compounds, ketone compounds, aromatic compounds, aliphatic compounds, nitrile compounds, and ester compounds. The dispersion medium may be a non-polar dispersion medium (hydrophobic dispersion medium) or a polar dispersion medium (hydrophilic dispersion medium), but a non-polar dispersion medium is preferred in that it can exhibit excellent dispersion properties. A non-polar dispersion medium generally refers to a medium with low affinity for water, and in the present invention, examples of such a medium include ester compounds, ketone compounds, ether compounds, aromatic compounds, and aliphatic compounds.

[0127] Examples of alcohol compounds include 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-2,4-pentanediol, 1,3-butanediol, and 1,4-butanediol.

[0128] Examples of the ether compound include alkylene glycols (diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, etc.), alkylene glycol monoalkyl ethers (ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol monobutyl ether, etc.), alkylene glycol dialkyl ethers (ethylene glycol dimethyl ether, etc.), dialkyl ethers (dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, etc.), and cyclic ethers (tetrahydrofuran, dioxane (including 1,2-, 1,3-, and 1,4-isomers), etc.).

[0129] Examples of the amide compound include N,N-dimethylformamide, N-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, formamide, N-methylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropanamide, and hexamethylphosphoric triamide.

[0130] Examples of the amine compound include triethylamine, diisopropylethylamine, and tributylamine. Examples of ketone compounds include acetone, methyl ethyl ketone, methyl isobutyl ketone (MIBK), cyclopentanone, cyclohexanone, cycloheptanone, dipropyl ketone, dibutyl ketone, diisopropyl ketone, diisobutyl ketone (DIBK), isobutyl propyl ketone, sec-butyl propyl ketone, pentyl propyl ketone, and butyl propyl ketone. Examples of aromatic compounds include benzene, toluene, xylene, and perfluorotoluene. Examples of aliphatic compounds include hexane, heptane, octane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane, decalin, paraffin, gasoline, naphtha, kerosene, and diesel. Examples of the nitrile compound include acetonitrile, propionitrile, and isobutyronitrile. Examples of the ester compound include ethyl acetate, propyl acetate, butyl acetate, ethyl butyrate, propyl butyrate, isopropyl butyrate, butyl butyrate, isobutyl butyrate, butyl pentanoate, pentyl pentanoate, ethyl isobutyrate, propyl isobutyrate, isopropyl isobutyrate, isobutyl isobutyrate, propyl pivalate, isopropyl pivalate, butyl pivalate, and isobutyl pivalate.

[0131] In the present invention, among these, ether compounds, ketone compounds, aromatic compounds, aliphatic compounds, and ester compounds are preferred, and ester compounds, ketone compounds, aromatic compounds, and ether compounds are more preferred.

[0132] The number of carbon atoms in the compound constituting the dispersion medium is not particularly limited, and is preferably 2 to 30, more preferably 4 to 20, even more preferably 6 to 15, and particularly preferably 7 to 12.

[0133] The dispersion medium has a dispersibility of solid particles, for example, an SP value of 14 to 24 MPa. 1 / 2 Preferably, the pressure is 15 to 22 MPa. 1 / 2 More preferably, the pressure is 16 to 20 MPa. 1 / 2 The difference (absolute value) in the SP value between the dispersion medium and the binder-forming polymer is not particularly limited, but it is more preferably 3 MPa in that the dispersion property of the binder-forming polymer in the dispersion medium is improved, thereby further improving the dispersion property of the solid particles. 1 / 2 Preferably, the pressure is 0 to 2 MPa or less. 1 / 2 More preferably, the pressure is 0 to 1 MPa. 1 / 2 It is more preferable that: The SP value of the dispersion medium is calculated by the Hoy method described above, and is expressed in units of MPa. 1 / 2 The SP value is a value converted into a mass fraction of the dispersion medium. When an inorganic solid electrolyte-containing composition contains two or more dispersion media, the SP value of the dispersion media means the SP value of the dispersion media as a whole, and is the sum of the products of the SP values ​​of the dispersion media and the mass fractions of the dispersion media. Specifically, the SP value is calculated in the same manner as the SP value of the polymer described above, except that the SP value of each dispersion media is used instead of the SP value of the constituent components. The SP values ​​(units omitted) of major dispersion media are shown below. MIBK (18.4), diisopropyl ether (16.8), dibutyl ether (17.9), diisopropyl ketone (17.9), DIBK (17.9), butyl butyrate (18.6), butyl acetate (18.9), toluene (18.5), ethylcyclohexane (17.1), cyclooctane (18.8), isobutyl ethyl ether (15.3), N-methylpyrrolidone (NMP, 25.4), perfluorotoluene (13.4)

[0134] The boiling point of the dispersion medium at normal pressure (1 atmosphere) is preferably 50° C. or higher, more preferably 70° C. or higher. The upper limit is preferably 250° C. or lower, more preferably 220° C. or lower.

[0135] The inorganic solid electrolyte-containing composition may contain one or more dispersion media. An example of a dispersion medium containing two or more dispersion media is a mixed xylene (a mixture of o-xylene, p-xylene, m-xylene, and ethylbenzene). In the present invention, the content of the dispersion medium in the inorganic solid electrolyte-containing composition is not particularly limited and can be set appropriately. For example, the content of the dispersion medium in the inorganic solid electrolyte-containing composition is preferably 20 to 80 mass %, more preferably 30 to 70 mass %, and particularly preferably 40 to 60 mass %. When setting a high solid content concentration, the content of the dispersion medium can be set to 60 mass % or less, 50 mass % or less, or even 40 mass % or less. The lower limit is not particularly limited, but can be, for example, 20 mass %.

[0136] <Active material> The inorganic solid electrolyte-containing composition of the present invention preferably contains an active material capable of inserting and releasing ions of a metal belonging to Group 1 or 2 of the periodic table. Examples of the active material include a positive electrode active material and a negative electrode active material, as described below. In the present invention, an inorganic solid electrolyte-containing composition containing an active material (positive electrode active material or negative electrode active material) may be referred to as an electrode composition (positive electrode composition or negative electrode composition).

[0137] (Cathode active material) The positive electrode active material is an active material capable of inserting and releasing ions of a metal belonging to Group 1 or 2 of the periodic table, and is preferably one that can insert and release lithium ions reversibly. The material is not particularly limited as long as it has the above properties, and may be a transition metal oxide, an organic substance, or an element that can be composited with Li, such as sulfur. Among these, it is preferable to use a transition metal oxide as the positive electrode active material, and a transition metal element M a A transition metal oxide containing at least one element selected from Co, Ni, Fe, Mn, Cu, and V is more preferred. b (Elements of Group 1 (Ia) of the periodic table other than lithium, elements of Group 2 (IIa), Al, Ga, In, Ge, Sn, Pb, Sb, Bi, Si, P, B, etc.) may be mixed. The amount of the mixed element is determined by the following formula: a The amount of Li / M is preferably 0 to 30 mol % relative to the amount of Li (100 mol %). a More preferably, the compounds are synthesized by mixing them so that the molar ratio is 0.3 to 2.2. Specific examples of transition metal oxides include (MA) transition metal oxides having a layered rock salt structure, (MB) transition metal oxides having a spinel structure, (MC) lithium-containing transition metal phosphate compounds, (MD) lithium-containing transition metal halide phosphate compounds, and (ME) lithium-containing transition metal silicate compounds.

[0138] (MA) Specific examples of transition metal oxides with a layered rock salt structure include LiCoO2 (lithium cobalt oxide [LCO]), LiNi2O2 (lithium nickel oxide), and LiNi0.85 Co 0.10 Al 0.05 O2 (nickel cobalt lithium aluminate [NCA]), LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (lithium nickel manganese cobalt oxide [NMC]) and LiNi 0.5 Mn 0.5 O2 (lithium manganese nickel oxide). (MB) Specific examples of transition metal oxides having a spinel structure include LiMn2O4 (LMO), LiCoMnO4, Li2FeMn3O8, Li2CuMn3O8, Li2CrMn3O8, and Li2NiMn3O8. (MC) Examples of lithium-containing transition metal phosphate compounds include olivine-type iron phosphates such as LiFePO4 and Li3Fe2(PO4)3, iron pyrophosphates such as LiFeP2O7, cobalt phosphates such as LiCoPO4, and monoclinic Nasicon-type vanadium phosphates such as Li3V2(PO4)3 (lithium vanadium phosphate). (MD) Examples of lithium-containing transition metal halide phosphate compounds include iron fluorophosphates such as Li2FePO4F, manganese fluorophosphates such as Li2MnPO4F, and cobalt fluorophosphates such as Li2CoPO4F. (ME) Examples of lithium-containing transition metal silicate compounds include Li2FeSiO4, Li2MnSiO4, and Li2CoSiO4. In the present invention, transition metal oxides having a layered rock salt structure (MA) are preferred, and LCO or NMC are more preferred.

[0139] The shape of the positive electrode active material is not particularly limited, but is preferably particulate. The particle size (volume average particle size) of the positive electrode active material is not particularly limited. For example, it can be 0.1 to 50 μm. The particle size of the positive electrode active material particles can be measured in the same manner as the particle size of the inorganic solid electrolyte. To adjust the positive electrode active material to a predetermined particle size, a conventional grinder or classifier is used. For example, a mortar, ball mill, sand mill, vibration ball mill, satellite ball mill, planetary ball mill, swirling airflow jet mill, or sieve is preferably used. Wet grinding in the presence of a dispersion medium such as water or methanol can also be performed during grinding. Classification is preferably performed to achieve the desired particle size. Classification is not particularly limited and can be performed using a sieve, air classifier, or the like. Classification can be performed using either a dry method or a wet method. The positive electrode active material obtained by the baking method may be used after being washed with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

[0140] The positive electrode active material may be used alone or in combination of two or more.

[0141] The content of the positive electrode active material in the inorganic solid electrolyte-containing composition is not particularly limited, and is preferably 10 to 97 mass %, more preferably 30 to 95 mass %, still more preferably 40 to 93 mass %, and particularly preferably 50 to 90 mass %, based on 100 mass % of the solid content.

[0142] (Negative electrode active material) The negative electrode active material is an active material capable of inserting and releasing ions of a metal belonging to Group 1 or 2 of the periodic table, and is preferably one that can insert and release lithium ions reversibly. The material is not particularly limited as long as it has the above-mentioned properties, and examples thereof include carbonaceous materials, metal oxides, metal composite oxides, lithium alone, lithium alloys, and negative electrode active materials that can form an alloy (can be alloyed) with lithium. Among these, carbonaceous materials, metal composite oxides, and lithium alone are preferably used from the viewpoint of reliability. Active materials that can be alloyed with lithium are preferred in that they enable the production of all-solid-state secondary batteries with a large capacity.

[0143] The carbonaceous material used as the negative electrode active material is a material essentially composed of carbon. Examples include carbon black such as petroleum pitch and acetylene black (AB), graphite (natural graphite, artificial graphite such as vapor-grown graphite, etc.), and carbonaceous materials obtained by calcining various synthetic resins such as PAN (polyacrylonitrile)-based resins and furfuryl alcohol resins. Further examples include various carbon fibers such as PAN-based carbon fiber, cellulose-based carbon fiber, pitch-based carbon fiber, vapor-grown carbon fiber, dehydrated PVA (polyvinyl alcohol)-based carbon fiber, lignin carbon fiber, glassy carbon fiber, and activated carbon fiber, as well as mesophase microspheres, graphite whiskers, and tabular graphite. These carbonaceous materials can be divided into non-graphitizable carbonaceous materials (also called hard carbon) and graphite-based carbonaceous materials depending on the degree of graphitization. Furthermore, the carbonaceous material preferably has the interplanar spacing, density, and crystallite size described in JP-A-62-22066, JP-A-2-6856, and JP-A-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 with a coating layer described in JP-A-6-4516, and the like can also be used. As the carbonaceous material, hard carbon or graphite is preferably used, and graphite is more preferably used.

[0144] The oxide of a metal or metalloid element used as the negative electrode active material is not particularly limited as long as it is an oxide capable of absorbing and releasing lithium, and examples thereof include oxides of metal elements (metal oxides), composite oxides of metal elements, or composite oxides of metal elements and metalloid elements (collectively referred to as metal composite oxides), and oxides of metalloid elements (metalloid oxides). Amorphous oxides are preferred as these oxides, and chalcogenides, which are reaction products of metal elements and elements of Group 16 of the periodic table, are also preferred. In the present invention, the term "metalloid element" refers to an element exhibiting properties intermediate between metal elements and non-metalloid elements, and typically includes six elements: boron, silicon, germanium, arsenic, antimony, and tellurium, as well as three elements: selenium, polonium, and astatine. Furthermore, "amorphous" refers to an element that exhibits a broad scattering band with a peak in the 2θ range of 20° to 40° in X-ray diffraction using CuKα radiation, and may also have crystalline diffraction lines. The strongest intensity of the crystalline diffraction lines seen at 2θ values ​​of 40° to 70° is preferably 100 times or less, more preferably 5 times or less, the diffraction line intensity at the apex of the broad scattering band seen at 2θ values ​​of 20° to 40°, and it is particularly preferable that there are no crystalline diffraction lines.

[0145] Among the compounds consisting of the amorphous oxides and chalcogenides, amorphous oxides or chalcogenides of metalloid elements are more preferred, and (composite) oxides or chalcogenides consisting of one or a combination of two or more elements selected from the elements of Groups 13 (IIIB) to 15 (VB) of the Periodic Table (e.g., Al, Ga, Si, Sn, Ge, Pb, Sb, and Bi) are particularly preferred. Specific examples of preferred amorphous oxides and chalcogenides include Ga2O3, GeO, PbO, PbO2, Pb2O3, Pb2O4, Pb3O4, Sb2O3, Sb2O4, Sb2O8Bi2O3, Sb2O8Si2O3, Sb2O5, Bi2O3, Bi2O4, GeS, PbS, PbS2, Sb2S3, and Sb2S5. Suitable examples of negative electrode active materials that can be used in combination with amorphous oxides mainly containing Sn, Si, or Ge include carbonaceous materials that can occlude and / or release lithium ions or lithium metal, lithium alone, lithium alloys, and negative electrode active materials that can be alloyed with lithium.

[0146] From the viewpoint of high current density charge / discharge characteristics, it is preferable that the oxides of metals or semimetal elements, particularly the metal (composite) oxides and the chalcogenides contain at least one of titanium and lithium as a constituent component. Examples of lithium-containing metal composite oxides (lithium composite metal oxides) include composite oxides of lithium oxide and the metal (composite) oxides or the chalcogenides, more specifically Li2SnO2. The negative electrode active material, for example, a metal oxide, preferably contains titanium (titanium oxide). Specifically, Li4Ti5O 12 Lithium titanate (LTO) is preferred because it has small volume fluctuations when absorbing and releasing lithium ions, has excellent rapid charge and discharge characteristics, suppresses electrode deterioration, and can improve the life of lithium ion secondary batteries.

[0147] The lithium alloy used as the negative electrode active material is not particularly limited as long as it is an alloy that is commonly used as a negative electrode active material for secondary batteries, and examples thereof include lithium-aluminum alloys, specifically lithium-aluminum alloys having lithium as the base metal and 10 mass % of aluminum added thereto.

[0148] The lithium-alloyable negative electrode active material is not particularly limited as long as it is commonly used as the negative electrode active material of a secondary battery. Such an active material has a large expansion and contraction due to charge and discharge in an all-solid-state secondary battery, which accelerates the deterioration of cycle characteristics. However, since the inorganic solid electrolyte-containing composition of the present invention contains the above-described polymer binder, the deterioration of cycle characteristics can be suppressed. Examples of such active materials include (negative electrode) active materials (such as alloys) having a silicon element or a tin element, such as various metals including Al and In. A negative electrode active material having a silicon element (a silicon element-containing active material), which enables a higher battery capacity, is preferable, and a silicon element-containing active material having a silicon element content of 50 mol% or more of all constituent elements is more preferable. Generally, a negative electrode containing these negative electrode active materials (for example, a Si negative electrode containing a silicon element-containing active material, a Sn negative electrode containing an active material having a tin element, etc.) can occlude more Li ions than a carbon negative electrode (such as graphite and acetylene black). That is, the amount of Li ions occluded per unit mass increases. Therefore, the battery capacity (energy density) can be increased. As a result, there is an advantage that the battery driving time can be extended. Examples of the silicon element-containing active material include silicon materials such as Si and SiOx (0 < x ≦ 1), and further, silicon-containing alloys containing titanium, vanadium, chromium, manganese, nickel, copper, lanthanum, etc. (for example, LaSi2, VSi2, La-Si, Gd-Si, Ni-Si), or organized active materials (for example, LaSi2 / Si). In addition, active materials containing a silicon element and a tin element such as SnSiO3 and SnSiS3 can also be mentioned. Note that SiOx can be used as a negative electrode active material (a semimetal oxide) itself, and since Si is generated by the operation of an all-solid-state secondary battery, it can be used as a negative electrode active material (its precursor material) alloyable with lithium. Examples of the negative electrode active material having a tin element include Sn, SnO, SnO2, SnS, SnS2, and further, active materials containing the above-described silicon element and tin element. In addition, a composite oxide with lithium oxide, for example, Li2SnO2, can also be mentioned.

[0149] In the present invention, the above-mentioned negative electrode active material can be used without any particular limitation. However, in terms of battery capacity, a negative electrode active material that can be alloyed with lithium is a preferred embodiment. Among these, the above-mentioned silicon material or silicon-containing alloy (alloy containing silicon element) is more preferred, and it is even more preferred that the negative electrode active material contains silicon (Si) or a silicon-containing alloy.

[0150] The chemical formula of the compound obtained by the above calcination method can be measured by inductively coupled plasma (ICP) emission spectroscopy, or simply calculated from the difference in mass of the powder before and after calcination.

[0151] The shape of the negative electrode active material is not particularly limited, but is preferably particulate. The particle size of the negative electrode active material is not particularly limited, but is preferably 0.1 to 60 μm. The particle size of the negative electrode active material particles can be measured in the same manner as the particle size of the inorganic solid electrolyte. To achieve the desired particle size, a conventional grinder or classifier is used, as with the positive electrode active material.

[0152] The negative electrode active materials may be used singly or in combination of two or more. The content of the negative electrode active material in the inorganic solid electrolyte-containing composition is not particularly limited, and is preferably 10 to 90 mass %, more preferably 20 to 85 mass %, even more preferably 30 to 80 mass %, and still more preferably 40 to 75 mass %, based on 100 mass % of the solid content.

[0153] In the present invention, when the negative electrode active material layer is formed by charging the secondary battery, ions of a metal belonging to Group 1 or 2 of the periodic table that are generated in the all-solid-state secondary battery can be used instead of the above-mentioned negative electrode active material. The negative electrode active material layer can be formed by bonding these ions with electrons and precipitating them as a metal.

[0154] (Coating of active material) The surfaces of the positive electrode active material and the negative electrode active material may be coated with another metal oxide. Examples of the surface coating agent include metal oxides containing Ti, Nb, Ta, W, Zr, Al, Si, or Li. Specific examples include titanate spinel, tantalum-based oxides, niobium-based oxides, and lithium niobate-based compounds, such as Li4Ti5O 12 , Li2Ti2O5, LiTaO3, LiNbO3, LiAlO2, Li2ZrO3, Li2WO4, Li2TiO3, Li2B4O7, Li3PO4, Li2MoO4, Li3BO3, LiBO2, Li2CO3, Li2SiO3, SiO2, TiO2, ZrO2, Al2O3, B2O3, etc. The surface of the electrode containing the positive electrode active material or the negative electrode active material may be surface-treated with sulfur or phosphorus. Furthermore, the particle surfaces of the positive electrode active material or negative electrode active material may be subjected to a surface treatment with active rays or active gas (plasma, etc.) before or after the above surface coating.

[0155] <Conductive additive> The inorganic solid electrolyte-containing composition of the present invention preferably contains a conductive aid, and for example, the silicon atom-containing active material as the negative electrode active material is preferably used in combination with a conductive aid. The conductive additive is not particularly limited, and may be any of those known as general conductive additives. For example, it may be an electron conductive material, such as graphites (e.g., natural graphite, artificial graphite), carbon blacks (e.g., acetylene black, ketjen black, furnace black), amorphous carbon (e.g., needle coke), carbon fibers (e.g., vapor-grown carbon fiber, carbon nanotube), carbonaceous materials (e.g., graphene, fullerene), metal powders (e.g., copper, nickel), metal fibers, or conductive polymers (e.g., polyaniline, polypyrrole, polythiophene, polyacetylene, polyphenylene derivatives). In the present invention, when an active material and a conductive additive are used in combination, the conductive additive is one among the above-mentioned conductive additives that does not insert or release ions of metals belonging to Group 1 or Group 2 of the periodic table (preferably Li ions) when the battery is charged and discharged, and does not function as an active material. Therefore, among conductive additives, one that can function as an active material in the active material layer when the battery is charged and discharged is classified as an active material rather than a conductive additive. Whether or not a conductive additive functions as an active material when the battery is charged and discharged is not uniquely determined, but is determined by the combination with the active material.

[0156] The conductive additive may contain one kind or two or more kinds. The shape of the conductive additive is not particularly limited, but a particulate shape is preferred. When the inorganic solid electrolyte-containing composition of the present invention contains a conductive aid, the content of the conductive aid in the inorganic solid electrolyte-containing composition is preferably 0 to 10 mass % relative to 100 mass % of the solid content.

[0157] <Lithium salt> The inorganic solid electrolyte-containing composition of the present invention also preferably contains a lithium salt (supporting electrolyte). The lithium salt is preferably a lithium salt that is usually used in this type of product, and is not particularly limited. For example, the lithium salts described in paragraphs 0082 to 0085 of JP-A No. 2015-088486 are preferred. When the inorganic solid electrolyte-containing composition of the present invention contains a lithium salt, the content of the lithium salt is preferably 0.1 parts by mass or more, more preferably 5 parts by mass or more, relative to 100 parts by mass of the solid electrolyte, and the upper limit is preferably 50 parts by mass or less, more preferably 20 parts by mass or less.

[0158] <Dispersant> The inorganic solid electrolyte-containing composition of the present invention may contain no dispersant other than the polymer binder because the polymer binder also functions as a dispersant. However, the dispersant may contain a dispersant. As the dispersant, a dispersant typically used in all-solid-state secondary batteries may be appropriately selected and used. In general, a compound intended for particle adsorption and steric and / or electrostatic repulsion is preferably used.

[0159] <Other additives> The inorganic solid electrolyte-containing composition of the present invention may contain, as appropriate, other components in addition to the above components, such as an ionic liquid, a thickener, a crosslinking agent (such as one that undergoes a crosslinking reaction by radical polymerization, condensation polymerization, or ring-opening polymerization), a polymerization initiator (such as one that generates an acid or radical by heat or light), an antifoaming agent, a leveling agent, a dehydrating agent, and an antioxidant. The ionic liquid is contained to further improve ionic conductivity, and any known ionic liquid can be used without particular limitation. Furthermore, the composition may contain a polymer other than the binder-forming polymer described above, a commonly used binder, and the like.

[0160] (Preparation of inorganic solid electrolyte-containing composition) The inorganic solid electrolyte-containing composition of the present invention can be prepared as a mixture, preferably as a slurry, by mixing an inorganic solid electrolyte, the above-mentioned polymer binder, a dispersion medium, preferably a conductive additive, and further optionally a lithium salt and other optional components, for example, in any of various commonly used mixers. In the case of an electrode composition, an active material is further mixed therein. The mixing method is not particularly limited, and can be performed using a known mixer such as a ball mill, bead mill, planetary mixer, blade mixer, roll mill, kneader, disk mill, planetary mixer, narrow gap disperser, etc. The components may be mixed all at once or sequentially. The mixing environment is not particularly limited, and examples include dry air or an inert gas. The mixing conditions are also not particularly limited, and can be set appropriately.

[0161] [Sheet for all-solid-state secondary batteries] The sheet for an all-solid-state secondary battery of the present invention is a sheet-like molded article capable of forming a constituent layer of an all-solid-state secondary battery, and includes various embodiments depending on its application. Examples include a sheet preferably used for a solid electrolyte layer (also referred to as a solid electrolyte sheet for an all-solid-state secondary battery), a sheet preferably used for an electrode, or a laminate of an electrode and a solid electrolyte layer (an electrode sheet for an all-solid-state secondary battery), etc. In the present invention, these various sheets are collectively referred to as a sheet for an all-solid-state secondary battery. In the present invention, each layer constituting the sheet for an all-solid-state secondary battery may have a single-layer structure or a multi-layer structure.

[0162] In the sheet for an all-solid-state secondary battery, the solid electrolyte layer or the active material layer on the substrate is formed from the inorganic solid electrolyte-containing composition of the present invention. Therefore, by appropriately peeling off the substrate from this sheet for an all-solid-state secondary battery and using it as the solid electrolyte layer of the all-solid-state secondary battery or as an electrode (a laminate of a current collector and an active material layer) as it is, the cycle characteristics of the all-solid-state secondary battery can be improved.

[0163] The solid electrolyte sheet for an all-solid-state secondary battery of the present invention may be a sheet having a solid electrolyte layer, and may be a sheet in which the solid electrolyte layer is formed on a substrate, or a sheet formed from the solid electrolyte layer without a substrate (a sheet from which the substrate has been peeled off). The solid electrolyte sheet for an all-solid-state secondary battery may have other layers in addition to the solid electrolyte layer. Examples of other layers include a protective layer (release sheet), a current collector, and a coating layer. The solid electrolyte layer of the solid electrolyte sheet for an all-solid-state secondary battery is formed from the inorganic solid electrolyte-containing composition of the present invention. The content of each component in this solid electrolyte layer is not particularly limited, but is preferably the same as the content of each component in the solid content of the inorganic solid electrolyte-containing composition of the present invention. The layer thickness of each layer constituting the solid electrolyte sheet for an all-solid-state secondary battery is the same as the layer thickness of each layer described in the all-solid-state secondary battery described below.

[0164] The substrate is not particularly limited as long as it can support the solid electrolyte layer, and examples thereof include sheets (plates) of materials described below for the current collector, organic materials, inorganic materials, etc. Examples of organic materials include various polymers, specifically polyethylene terephthalate, polypropylene, polyethylene, cellulose, etc. Examples of inorganic materials include glass, ceramics, etc.

[0165] The electrode sheet for an all-solid-state secondary battery of the present invention (also simply referred to as "electrode sheet") may be an electrode sheet having an active material layer. It may be a sheet in which the active material layer is formed on a substrate (current collector), or a sheet formed from the active material layer without a substrate (a sheet from which the substrate has been peeled off). This electrode sheet typically has a current collector and an active material layer, but it may also include an embodiment in which the current collector, active material layer, and solid electrolyte layer are formed in this order, as well as an embodiment in which the current collector, active material layer, solid electrolyte layer, and active material layer are formed in this order. The solid electrolyte layer and active material layer of the electrode sheet are preferably formed from the inorganic solid electrolyte-containing composition of the present invention. The content of each component in this solid electrolyte layer or active material layer is not particularly limited, but is preferably synonymous with the content of each component in the solid content of the inorganic solid electrolyte-containing composition (electrode composition) of the present invention. The layer thickness of each layer constituting the electrode sheet of the present invention is the same as the layer thickness of each layer described in the all-solid-state secondary battery described below. The electrode sheet may also have other layers as described above. When the solid electrolyte layer or the active material layer is not formed from the inorganic solid electrolyte-containing composition of the present invention, it is formed from a normal constituent layer forming material.

[0166] In the sheet for an all-solid-state secondary battery of the present invention, at least one of the solid electrolyte layer and the active material layer is formed from the inorganic solid electrolyte-containing composition of the present invention. Therefore, the sheet for an all-solid-state secondary battery of the present invention has a constituent layer in which solid particles containing an inorganic solid electrolyte are tightly adhered. By using this constituent layer as a constituent layer of an all-solid-state secondary battery, excellent cycle characteristics of the all-solid-state secondary battery can be achieved.

[0167] [Method of manufacturing a sheet for all-solid-state secondary batteries] The method for producing the sheet for an all-solid-state secondary battery of the present invention is not particularly limited, and the sheet can be produced by forming each of the above layers using the inorganic solid electrolyte-containing composition of the present invention. For example, a method is preferably used in which a layer (coated and dried) of the inorganic solid electrolyte-containing composition is formed on a substrate or a current collector (optionally via another layer) by film formation (coating and drying). This method allows for the production of a sheet for an all-solid-state secondary battery having a substrate or a current collector and a coated and dried layer. In particular, when the inorganic solid electrolyte-containing composition of the present invention is formed on a current collector to form a film, the adhesion between the current collector and the active material layer can be strengthened. Here, the coated and dried layer refers to a layer formed by coating the inorganic solid electrolyte-containing composition of the present invention and drying the dispersion medium (i.e., a layer formed using the inorganic solid electrolyte-containing composition of the present invention and having a composition obtained by removing the dispersion medium from the inorganic solid electrolyte-containing composition of the present invention). The active material layer and the coated and dried layer may contain residual dispersion medium as long as it does not impair the effects of the present invention. The residual amount can be, for example, 3 mass% or less in each layer. In the method for producing a sheet for an all-solid-state secondary battery of the present invention, each step such as coating and drying will be described in the method for producing an all-solid-state secondary battery below.

[0168] In the method for producing a sheet for an all-solid-state secondary battery of the present invention, the coated and dried layer obtained as described above can also be pressed. The pressing conditions and the like will be described later in the method for producing an all-solid-state secondary battery. In addition, in the method for producing a sheet for an all-solid-state secondary battery of the present invention, the substrate, protective layer (particularly the release sheet), etc. can also be peeled off.

[0169] [All-solid-state secondary battery] The all-solid-state secondary battery of the present invention has a positive electrode active material layer, a negative electrode active material layer facing the positive electrode active material layer, and a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode active material layer. The all-solid-state secondary battery of the present invention is not particularly limited in other configuration as long as it has a solid electrolyte layer between the positive electrode active material layer and the negative electrode active material layer, and for example, a known configuration related to all-solid-state secondary batteries can be adopted. The positive electrode active material layer is preferably formed on a positive electrode current collector and constitutes a positive electrode. The negative electrode active material layer is preferably formed on a negative electrode current collector and constitutes a negative electrode. In the present invention, each of the constituent layers (including the current collector, etc.) that constitute the all-solid-state secondary battery may have a single-layer structure or a multi-layer structure.

[0170] <Cathode active material layer, solid electrolyte layer, negative electrode active material layer> The solid electrolyte layer contains an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, a polymer binder, and the optional components described above within the scope of not impairing the effects of the present invention, and typically does not contain a positive electrode active material and / or a negative electrode active material. The positive electrode active material layer contains a positive electrode active material, an inorganic solid electrolyte preferably having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, a polymer binder, and the above-mentioned optional components and the like within the scope of not impairing the effects of the present invention. The negative electrode active material layer contains a negative electrode active material, an inorganic solid electrolyte preferably having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, a polymer binder, and the above-mentioned optional components and the like within the range not impairing the effects of the present invention.

[0171] In the all-solid-state secondary battery of the present invention, at least one of the negative electrode active material layer, positive electrode active material layer, and solid electrolyte layer is formed from the inorganic solid electrolyte-containing composition of the present invention, and it is preferred that at least one of the negative electrode active material layer and the positive electrode active material layer is formed from the inorganic solid electrolyte-containing composition of the present invention. In the present invention, forming all layers from the inorganic solid electrolyte-containing composition of the present invention is also a preferred embodiment. In the present invention, forming the constituent layers of the all-solid-state secondary battery from the inorganic solid electrolyte-containing composition of the present invention includes an embodiment in which the constituent layers are formed from the sheet for the all-solid-state secondary battery of the present invention (however, if a layer other than the layer formed from the inorganic solid electrolyte-containing composition of the present invention is present, this layer is removed from the sheet). When the active material layer or the solid electrolyte layer is not formed from the inorganic solid electrolyte-containing composition of the present invention, known materials can be used.

[0172] The active material layer or solid electrolyte layer formed from the inorganic solid electrolyte-containing composition of the present invention preferably has the same component types and contents as those in the solid content of the inorganic solid electrolyte-containing composition of the present invention. The thicknesses of the negative electrode active material layer, the solid electrolyte layer, and the positive electrode active material layer are not particularly limited. Taking into consideration the dimensions of a typical all-solid-state secondary battery, the thickness of each layer is preferably 10 to 1,000 μm, and more preferably 20 μm or more and less than 500 μm. In the all-solid-state secondary battery of the present invention, it is further preferable that the thickness of at least one of the positive electrode active material layer and the negative electrode active material layer is 50 μm or more and less than 500 μm. The positive electrode active material layer and the negative electrode active material layer may each have a current collector on the side opposite to the solid electrolyte layer.

[0173] <Current collector> The positive electrode current collector and the negative electrode current collector are preferably electronic conductors. In the present invention, either the positive electrode current collector or the negative electrode current collector, or both of them together, may be simply referred to as the current collector. As the material for forming the positive electrode current collector, aluminum, aluminum alloy, stainless steel, nickel, titanium, etc., as well as aluminum or stainless steel surface treated with carbon, nickel, titanium or silver (thin film formed), are preferred, and among these, aluminum and aluminum alloy are more preferred. As the material for forming the negative electrode current collector, aluminum, copper, a copper alloy, stainless steel, nickel, titanium, etc., as well as aluminum, copper, a copper alloy, or stainless steel whose surface is treated with carbon, nickel, titanium, or silver are preferred, and aluminum, copper, a copper alloy, and stainless steel are more preferred.

[0174] The collector is usually in the form of a film sheet, but it may also be in the form of a net, a punched material, a lath, a porous material, a foam, or a molded fiber material. The thickness of the current collector is not particularly limited, but is preferably 1 to 500 μm. It is also preferable to make the surface of the current collector uneven by surface treatment.

[0175] <Other configurations> In the present invention, a functional layer or member may be appropriately interposed or disposed between or on the outside of each of the negative electrode current collector, negative electrode active material layer, solid electrolyte layer, positive electrode active material layer, and positive electrode current collector.

[0176] <Case> Depending on the application, the all-solid-state secondary battery of the present invention may be used as an all-solid-state secondary battery with the above structure as it is, but it is preferable to further encapsulate it in an appropriate casing to make it into a dry battery. The casing may be made of metal or resin (plastic). When a metallic casing is used, for example, an aluminum alloy or stainless steel may be used. It is preferable that the metallic casing is divided into a positive electrode casing and a negative electrode casing, and that the positive electrode current collector and the negative electrode current collector are electrically connected, respectively. It is preferable that the positive electrode casing and the negative electrode casing are joined and integrated via a gasket to prevent short circuits.

[0177] An all-solid-state secondary battery according to a preferred embodiment of the present invention will be described below with reference to FIG. 1, but the present invention is not limited thereto.

[0178] FIG. 1 is a cross-sectional view showing a schematic diagram of 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 has, as viewed from the negative electrode side, 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 this order. Each layer is in contact with each other and has an adjacent structure. By adopting such a structure, electrons (e - ) is supplied to the battery, and lithium ions (Li + On the other hand, during discharge, the lithium ions (Li + ) is returned to the positive electrode side, and electrons are supplied to the operating part 6. In the illustrated example, a light bulb is used as a model for the operating part 6, and it is lit by the discharge.

[0179] When an all-solid-state secondary battery having the layer structure shown in FIG. 1 is placed in a 2032-type coin case (see, for example, FIG. 2), this all-solid-state secondary battery is referred to as a laminate 12 for an all-solid-state secondary battery, and a battery produced by placing this laminate 12 for an all-solid-state secondary battery in a 2032-type coin case 11 is sometimes referred to as a (coin-type) all-solid-state secondary battery 13.

[0180] (positive electrode active material layer, solid electrolyte layer, negative electrode active material layer) In the all-solid-state secondary battery 10, the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer are all formed from the inorganic solid electrolyte-containing composition of the present invention. This all-solid-state secondary battery 10 exhibits excellent battery performance. The inorganic solid electrolytes and polymer binders contained in the positive electrode active material layer 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 may be the same or different from one another. In the present invention, either the positive electrode active material layer or the negative electrode active material layer, or both together, may be simply referred to as an active material layer or an electrode active material layer. Also, either the positive electrode active material or the negative electrode active material, or both together, may be simply referred to as an active material or an electrode active material.

[0181] In the all-solid-state secondary battery 10, the negative electrode active material layer can be a lithium metal layer. Examples of the lithium metal layer include a layer formed by depositing or molding lithium metal powder, lithium foil, and a lithium vapor deposition film. The thickness of the lithium metal layer can be, for example, 1 to 500 μm, regardless of the thickness of the negative electrode active material layer.

[0182] In the all-solid-state secondary battery 10, when a constituent layer other than the constituent layer formed from the inorganic solid electrolyte-containing composition of the present invention is present, a layer formed from a known constituent layer-forming material can also be applied.

[0183] (current collector) The positive electrode current collector 5 and the negative electrode current collector 1 are as described above.

[0184] [Manufacturing all-solid-state secondary batteries] The all-solid-state secondary battery can be manufactured by a conventional method. Specifically, the all-solid-state secondary battery can be manufactured by forming each of the above-mentioned layers using the inorganic solid electrolyte-containing composition of the present invention, etc., as described in detail below.

[0185] The all-solid-state secondary battery of the present invention can be produced by a method (a method for producing a sheet for an all-solid-state secondary battery of the present invention) including (via) a step of applying the inorganic solid electrolyte-containing composition of the present invention to a suitable substrate (for example, a metal foil to be used as a current collector) and forming (forming) a coating film. For example, a cathode sheet for an all-solid-state secondary battery is produced by applying an inorganic solid electrolyte-containing composition containing a cathode active material as a cathode material (cathode composition) to a metal foil cathode current collector to form a cathode active material layer. Next, an inorganic solid electrolyte-containing composition for forming a solid electrolyte layer is applied to the cathode active material layer to form a solid electrolyte layer. Furthermore, an inorganic solid electrolyte-containing composition containing a negative electrode active material as a negative electrode material (negative electrode composition) is applied to the solid electrolyte layer to form a negative electrode active material layer. By overlaying a negative electrode current collector (metal foil) on the negative electrode active material layer, an all-solid-state secondary battery with a structure 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. This can also be enclosed in a housing to form a desired all-solid-state secondary battery. Alternatively, the method for forming each layer may be reversed, and an all-solid-state secondary battery may be produced by forming an anode active material layer, a solid electrolyte layer, and a cathode active material layer on an anode current collector as a substrate, and then stacking the layers on top of the anode current collector.

[0186] Another method is as follows. That is, a positive electrode sheet for an all-solid-state secondary battery is produced as described above. Furthermore, an inorganic solid electrolyte-containing composition containing a negative electrode active material is applied as a negative electrode material (negative electrode composition) onto a metal foil serving as a negative electrode current collector to form a negative electrode active material layer, thereby producing a negative electrode sheet for an all-solid-state secondary battery. Next, a solid electrolyte layer is formed on the active material layer of either of these sheets as described above. Furthermore, the other of the positive electrode sheet for an all-solid-state secondary battery and the negative electrode sheet for an all-solid-state secondary battery is laminated on the solid electrolyte layer so that the solid electrolyte layer and the active material layer are in contact with each other. In this manner, an all-solid-state secondary battery can be produced. Another method is as follows. That is, a positive electrode sheet for an all-solid-state secondary battery and a negative electrode sheet for an all-solid-state secondary battery are prepared as described above. Separately, an inorganic solid electrolyte-containing composition is applied to a substrate to prepare a solid electrolyte sheet for an all-solid-state secondary battery comprising a solid electrolyte layer. Furthermore, the positive electrode sheet for an all-solid-state secondary battery and the negative electrode sheet for an all-solid-state secondary battery are laminated so as to sandwich the solid electrolyte layer peeled from the substrate. In this manner, an all-solid-state secondary battery can be manufactured.

[0187] Furthermore, a positive electrode sheet or a negative electrode sheet for an all-solid-state secondary battery, and a solid electrolyte sheet for an all-solid-state secondary battery are produced as described above. Next, the positive electrode sheet or the negative electrode sheet for an all-solid-state secondary battery and the solid electrolyte sheet for an all-solid-state secondary battery are superimposed on each other with the positive electrode active material layer or the negative electrode active material layer in contact with the solid electrolyte layer, and pressurized. In this way, the solid electrolyte layer is transferred to the positive electrode sheet or the negative electrode sheet for an all-solid-state secondary battery. Thereafter, the solid electrolyte layer from which the substrate of the solid electrolyte sheet for an all-solid-state secondary battery has been peeled is superimposed on the negative electrode sheet or the positive electrode sheet for an all-solid-state secondary battery (with the negative electrode active material layer or the positive electrode active material layer in contact with the solid electrolyte layer), and pressurized. In this way, an all-solid-state secondary battery can be produced. The pressurization method and pressurization conditions in this method are not particularly limited, and the method and pressurization conditions described in the pressurization step described below can be applied.

[0188] The solid electrolyte layer or the like can be formed, for example, by pressure molding an inorganic solid electrolyte-containing composition or the like on a substrate or an active material layer under pressure conditions described below, or a sheet molded product of the solid electrolyte or active material can also be used. In the above-described production method, the inorganic solid electrolyte-containing composition of the present invention may be used for any one of the positive electrode composition, the inorganic solid electrolyte-containing composition, and the negative electrode composition. It is preferable to use the inorganic solid electrolyte-containing composition of the present invention for the inorganic solid electrolyte-containing composition or at least one of the positive electrode composition and the negative electrode composition, and the inorganic solid electrolyte-containing composition of the present invention may be used for any of the compositions.

[0189] <Formation of each layer (film formation)> The method for applying the inorganic solid electrolyte-containing composition is not particularly limited and can be appropriately selected, for example, by coating (preferably wet coating), spray coating, spin coating, dip coating, slit coating, stripe coating, or bar coating. In this case, the inorganic solid electrolyte-containing composition may be dried after each coating, or may be dried after multiple coatings. The drying temperature is not particularly limited. The lower limit is preferably 30°C or higher, more preferably 60°C or higher, and even more preferably 80°C or higher. The upper limit is preferably 300°C or lower, more preferably 250°C or lower, and even more preferably 200°C or lower. Heating within this temperature range allows the dispersion medium to be removed and the resulting layer to be in a solid state (coated, dried layer). In addition, it is preferable not to raise the temperature too high, as this prevents damage to the components of the all-solid-state secondary battery. This allows the all-solid-state secondary battery to exhibit excellent overall performance, as well as to obtain good adhesion and good ionic conductivity.

[0190] After applying the inorganic solid electrolyte-containing composition, after stacking the constituent layers, or after fabricating the all-solid-state secondary battery, it is preferable to pressurize each layer or the all-solid-state secondary battery. Examples of a pressurizing method include a hydraulic cylinder press. The pressure is not particularly limited, and is generally preferably in the range of 5 to 1500 MPa. The applied inorganic solid electrolyte-containing composition may be heated simultaneously with pressing. The heating temperature is not particularly limited and is generally in the range of 30 to 300°C. Pressing may also be performed at a temperature higher than the glass transition temperature of the inorganic solid electrolyte. Note that pressing may also be performed at a temperature higher than the glass transition temperature of the polymer contained in the polymer binder. However, the temperature is generally not higher than the melting point of the polymer. The pressure may be applied after the application solvent or dispersion medium has been dried in advance, or may be applied while the solvent or dispersion medium remains. The compositions may be applied simultaneously, or coating, drying and pressing may be carried out simultaneously and / or sequentially. After being applied to separate substrates, the compositions may be laminated by transfer.

[0191] The atmosphere in the film-forming method (coating, drying, and pressurization (under heating)) is not particularly limited, and may be any of the atmosphere, dry air (dew point -20°C or lower), and inert gas (e.g., argon gas, helium gas, and nitrogen gas). The pressing time may be short (for example, within a few hours) and high pressure may be applied, or long (for example, one day or more) and moderate pressure may be applied. In the case of an all-solid-state secondary battery other than a sheet for an all-solid-state secondary battery, for example, a restraining device for the all-solid-state secondary battery (such as a screw tightening pressure) may be used to continuously apply moderate pressure. The pressing pressure may be uniform or may vary with respect to the pressed portion such as the sheet surface. The pressure can be varied depending on the area or thickness of the pressed portion, or the same portion can be subjected to different pressures in stages. The press surface may be smooth or roughened.

[0192] The inorganic solid electrolyte-containing composition of the present invention can maintain excellent dispersion properties even when the solid content is increased. Therefore, the inorganic solid electrolyte-containing composition can be applied at a high solid content. In addition, in the present invention, the formation (film formation) of each of the above-mentioned layers, particularly the application and drying of the inorganic solid electrolyte-containing composition of the present invention, can be performed using a sheet-like substrate in a so-called batch system, but can also be performed by a roll-to-roll method, which is one of the most productive industrial production methods.

[0193] <Initialization> The all-solid-state secondary battery produced as described above is preferably initialized after production or before use. The initialization is not particularly limited, and can be performed, for example, by carrying out initial charge and discharge under an elevated pressure, and then releasing the pressure until the pressure reaches the general operating pressure of an all-solid-state secondary battery.

[0194] [Applications of all-solid-state secondary batteries] The all-solid-state secondary battery of the present invention can be used in a variety of applications. While there are no particular limitations on the application, examples of applications include electronic devices such as notebook computers, pen-input PCs, mobile PCs, electronic book players, mobile phones, cordless phone handsets, pagers, handheld terminals, portable fax machines, portable copiers, portable printers, headphone stereos, video camcorders, LCD televisions, handheld vacuum cleaners, portable CD players, mini-discs, electric shavers, transceivers, electronic organizers, calculators, memory cards, portable tape recorders, radios, and backup power supplies. Other consumer applications include automobiles (e.g., electric vehicles), electric vehicles, motors, lighting fixtures, toys, game consoles, road conditioners, clocks, flash devices, cameras, and medical devices (e.g., pacemakers, hearing aids, and shoulder massagers). Furthermore, the battery can be used for various military and space applications. It can also be combined with solar cells. [Example]

[0195] The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited thereto. In the following examples, "parts" and "%" representing compositions are based on mass unless otherwise specified. In the present invention, "room temperature" means 25°C.

[0196] 1. Polymer Synthesis and Binder Solution Preparation Each binder-forming polymer shown in Table 1 below was synthesized as follows to prepare each binder solution. [Synthesis Example S-1: Synthesis of Polymer S-1 and Preparation of Binder Solution S-1] A mixed solution prepared by mixing 25 g of methyl methacrylate, 25 g of VPE-0201 (trade name, polyethylene glycol unit-containing polymeric azo polymerization initiator, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 50 g of butyl butyrate was stirred at 80°C for 4 hours under a nitrogen atmosphere. In this way, block polymer S-1 was synthesized, and binder solution S-1 (concentration 50% by mass) consisting of this polymer was prepared. The ethylenically unsaturated bond polymer chain was a (meth)acrylic polymer.

[0197] [Synthesis Examples S-2 to S-7: Synthesis of Polymers S-2 to S-7 and Preparation of Binder Solutions S-2 to S-7] Block polymers S-2 to S-7 were synthesized in the same manner as in Synthesis Example S-1, except that compounds were used to derive the respective constituent components so that polymers S-2 to S-7 had the compositions (types and contents of constituent components) shown in Table 1. Binder solutions S-2 to S-7 comprising each polymer were prepared in the same manner as in Synthesis Example S-1. The polymerization chains of the ethylenically unsaturated bonds in polymers S-2 to S-7 were all (meth)acrylic polymers, and the bonding mode of the (meth)acrylic polymers in polymers S-5 to S-7 was random bonding.

[0198] [Synthesis Example S-8: Synthesis of Polymer S-8 and Preparation of Binder Solution S-8] Block polymer S-8 was synthesized in the same manner as in Synthesis Example S-1, except that VPS-1001N (trade name, polymeric azo polymerization initiator containing polydimethylsiloxane units) was used instead of the polymeric azo polymerization initiator VPE-0201 in Synthesis Example S-1, and a binder solution S-8 consisting of this polymer was prepared. The ethylenically unsaturated bond polymer chain of polymer S-8 is a (meth)acrylic polymer.

[0199] [Synthesis Example S-9: Synthesis of Polymer S-9 and Preparation of Binder Solution S-9] Block polymer S-9 was synthesized in the same manner as in Synthesis Example S-8, except that compounds were used to induce each component so that polymer S-9 would have the composition (type and content of component) shown in Table 1. A binder solution S-9 consisting of this polymer was prepared in the same manner as in Synthesis Example S-8. The polymer chain of the ethylenically unsaturated bond in polymer S-9 is a randomly bonded (meth)acrylic polymer.

[0200] [Synthesis Example S-10: Synthesis of Polymer S-10 and Preparation of Binder Solution S-10] First, a polymeric polymerization initiator used in the synthesis of polymer S-10 was synthesized. To a mixed solution prepared by mixing 20 g (0.02 mol) of polypropylene glycol (number average molecular weight Mn 1,000, manufactured by Aldrich Chemicals), 5.6 g (0.02 mol) of azo initiator V-501 (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and 100 g of tetrahydrofuran, 4 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the mixture was allowed to react at room temperature for 4 hours. Then, 200 g of ethyl acetate and 100 g of water were added to the reaction mixture. The ethyl acetate phase separated from the aqueous phase was concentrated to synthesize the desired polymeric azo initiator. Next, block polymer S-10 was synthesized in the same manner as in Synthesis Example S-6, except that the polymeric azo polymerization initiator VPE-0201 was replaced with the synthesized polymeric azo polymerization initiator, and a binder solution S-10 consisting of this polymer was prepared. The ethylenically unsaturated polymer chain of polymer S-10 was a randomly bonded (meth)acrylic polymer.

[0201] [Synthesis Examples S-11 and S-12: Synthesis of Polymers S-11 and S-12, and Preparation of Binder Solutions S-11 and S-12] Block polymers S-11 and S-12 were synthesized in the same manner as in Synthesis Example S-10 (synthesis of a polymer polymerization initiator), except that 0.02 moles (equimolar to the azo initiator V-501) of polypropylene glycol (Mn 2,000, manufactured by Aldrich) or polypropylene glycol (Mn 4,000, manufactured by Aldrich) were used instead of polypropylene glycol (number average molecular weight Mn 1,000) in Synthesis Example S-10 (synthesis of a polymer polymerization initiator). Binder solutions S-11 and S-12 composed of each polymer were prepared, respectively. The ethylenically unsaturated polymer chains of polymers S-11 and S-12 were randomly bonded (meth)acrylic polymers.

[0202] [Synthesis Examples S-13 to S-16: Synthesis of Polymers S-13 to S-16, and Preparation of Binder Solutions S-13 to S-16] Block polymers S-13 to S-16 were synthesized in the same manner as in Synthesis Example S-10 (synthesis of a polymeric polymerization initiator), except that in Synthesis Example S-10 (synthesis of a polymeric polymerization initiator), 1,9-nonanediol (manufactured by Tokyo Chemical Industry Co., Ltd.), NISSO-PB GI-1000 (trade name, manufactured by Nippon Soda Co., Ltd.), ETERNACOLL UH-100 (trade name, manufactured by Ube Industries, Ltd.), or 0.02 moles (equimolar to the azo initiator V-501) of Polylite OD-X-2251 (trade name, manufactured by DIC Corporation) were used instead of polypropylene glycol (number average molecular weight Mn 1,000). Binder solutions S-13 to S-16 composed of each polymer were prepared, respectively. The ethylenically unsaturated polymer chains of polymers S-13 to S-16 were randomly bonded (meth)acrylic polymers.

[0203] [Synthesis Example T-1: Synthesis of Polymer T-1 and Preparation of Binder Solution T-1] A monomer solution was prepared by adding 30 g of dodecyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.) and 0.5 g of azo polymerization initiator V-601 (trade name, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and dissolving them in 70 g of butyl butyrate. The monomer solution was added dropwise to 70 g of butyl butyrate over 2 hours while stirring at 80°C. After the dropwise addition was completed, the temperature was raised to 90°C and the mixture was stirred for 2 hours to synthesize polymer T-1. The resulting polymerization solution was poured into 480 g of methanol, stirred for 10 minutes, and then allowed to stand for 10 minutes. The supernatant was removed and the resulting precipitate was dissolved in 80 g of butyl butyrate. The methanol was distilled off by heating at 30 hPa and 60°C for 1 hour to prepare binder solution T-1 (concentration 27% by mass) consisting of polymer T-1.

[0204] [Synthesis Examples T-2 and T-3: Synthesis of Polymers T-2 and T-3, and Preparation of Binder Solutions T-2 and T-3] Random-bonded (meth)acrylic polymers T-2 and T-3 were synthesized in the same manner as in Synthesis Example T-1, except that in Synthesis Example T-1, compounds were used that lead to each component so that polymers T-2 and T-3 had the compositions (types and contents of components) shown in Table 1, and binder solutions T-2 and T-3 composed of each polymer were prepared, respectively. In addition, for the synthesis of polymer T-3, methoxy-polyethylene glycol acrylate (MOPEOA) was used as a monomer having a polyethylene oxide chain in the side chain.

[0205] [Synthesis Example T-4: Synthesis of Polymer T-4 and Preparation of Binder Solution T-4] Polymer T-4, which is the same as polymer P-1 described in paragraph

[0172] of the above-mentioned Patent Document 2, was synthesized in accordance with the synthesis method of polymer P-1 described in paragraph

[0165] of the same document, and a binder solution T-4 (concentration 30% by mass) consisting of this urethane polymer was prepared.

[0206] The average molecular weight and glass transition temperature of each synthesized polymer were measured according to the above method, and the results are shown in Table 1. When a polymer has two glass transition temperatures, they are classified as "low temperature (side Tg)" and "high temperature (side Tg)" according to the temperatures.

[0207] [Table 1]

[0208] In the table, "-" in each component column indicates that the corresponding component is not contained. Although the components constituting polymers T-3 and T-4 do not correspond to the partial structure, polymer chain (1), and polar functional group-containing component in Table 1, they are listed in the respective columns for convenience. In the "polar functional group-containing component" column for polymer T-4, DMBA and GI-1000 are listed in two separate lines. In Table 1, "content" indicates the content (mass%) of each component in the polymer, but the units are omitted in the table. Also, the unit "°C" for glass transition temperature is omitted in the table.

[0209] The partial structures and constituent components of each polymer are described in detail below, and their chemical formulas are given later. - Flexible functional groups in partial structures containing flexible functional groups - PEO: Polyethyleneoxy chain (average molecular weight 2,000) PSE: Polydimethylsilyleneoxy chain (average molecular weight 10,000) PPO1000: Polypropylene oxy chain (average molecular weight 1,000) PPO2000: Polypropylene oxy chain (average molecular weight 2,000) PPO4000: Polypropylene oxy chain (average molecular weight 4,000) NN: 1,9-nonanediol PBD: Polybutadiene chain (average molecular weight 1,500) PC: Polycarbonate chain (average molecular weight approximately 1,000) PEST: Polyester chain (average molecular weight 2,000) MOPEOA (side chain): methoxy-polyethylene glycol acrylate (trade name: Light Acrylate 130A, degree of polymerization of polyethylene oxide chain: approximately 9, manufactured by Kyoeisha Chemical Co., Ltd.) PEG200: polyethylene glycol (average molecular weight 200, Aldrich)

[0210] - Components of polymer chain (1) - MMA: Methyl methacrylate LA: Dodecyl acrylate MDI: Diphenylmethane diisocyanate

[0211] - Polar functional group-containing constituents of polymer chains with ethylenically unsaturated bonds - HEA: 2-hydroxyethyl acrylate MAA: methacrylic acid GMA: Glycidyl methacrylate DMBA: 2,2-bis(hydroxymethyl)butyric acid GI-1000: NISSO PB GI-1000 (trade name, hydrogenated polybutadiene with hydroxyl groups at both ends, manufactured by Nippon Soda Co., Ltd.)

[0212] The chemical structures of each component are shown below. In the chemical structures below, Me represents a methyl group. However, the components of MOPEOA and polymer T-4 are not shown. In the following PEO, A1 and B1 are residues derived from a polyethylene glycol unit-containing polymeric azo polymerization initiator. In the following PSE, A2 and B2 are residues derived from a polymeric azo polymerization initiator containing a polydimethylsiloxane unit. In the PC below, A3, E1, and B3 are residues derived from the reaction product of ETERNACOLL UH-100 and azo initiator V-501. In the PEST below, A4, E2, and B4 are residues derived from the reaction product of Polylite OD-X-2251 and azo initiator V-501.

[0213] [ka]

[0214] 2. Synthesis of sulfide-based inorganic solid electrolytes [Synthesis example A] The sulfide-based inorganic solid electrolyte was synthesized with reference to the non-patent literature of T. Ohtomo, A. Hayashi, M. Tatsumisago, Y. Tsuchida, S. Hama, K. Kawamoto, Journal of Power Sources, 233, (2013), pp. 231-235, and A. Hayashi, S. Hama, H. Morimoto, M. Tatsumisago, T. Minami, Chem. Lett., (2001), pp. 872-873. Specifically, in a glove box under an argon atmosphere (dew point -70°C), 2.42 g of lithium sulfide (Li2S, Aldrich, purity >99.98%) and 3.90 g of diphosphorus pentasulfide (P2S5, Aldrich, purity >99%) were weighed out, placed in an agate mortar, and mixed for 5 minutes using an agate pestle. The molar ratio of Li2S to P2S5 was Li2S:P2S5 = 75:25. Next, 66 g of 5 mm diameter zirconia beads were placed in a 45 mL zirconia container (manufactured by Fritsch), and the entire lithium sulfide and diphosphorus pentasulfide mixture was added. The container was then completely sealed under an argon atmosphere. The container was then placed in a planetary ball mill (trade name, manufactured by Fritsch) and mechanically milled at 25°C and 510 rpm for 20 hours to obtain 6.20 g of a yellow sulfide-based inorganic solid electrolyte powder (Li-PS-based glass, hereafter sometimes referred to as LPS). The particle diameter of the Li-PS-based glass was 15 μm.

[0215] [Example 1] Each of the compositions shown in Tables 2-1 to 2-4 (collectively referred to as Table 2) was prepared as follows. <Preparation of Inorganic Solid Electrolyte-Containing Composition> A 45 mL zirconia container (manufactured by Fritsch) was charged with 60 g of zirconia beads with a diameter of 5 mm, and then charged with 5.40 g of LPS synthesized in Synthesis Example A above, 0.10 g (solid content by mass) of the binder solution shown in Tables 2-1 and 2-4, and 4.50 g of butyl butyrate as a dispersion medium. The container was then placed in a planetary ball mill P-7 (trade name). Mixing was performed for 10 minutes at a temperature of 25°C and a rotation speed of 150 rpm to prepare inorganic solid electrolyte-containing compositions (slurries) K-1 to K-16 and Kc11 to Kc14, respectively.

[0216] <Preparation of Positive Electrode Composition> 60 g of zirconia beads with a diameter of 5 mm were placed in a 45 mL zirconia container (manufactured by Fritsch), and 2.30 g of the LPS synthesized in Synthesis Example A and 2.80 g (total amount) of butyl butyrate as a dispersion medium were added. The container was placed in a planetary ball mill P-7 (trade name) and stirred at 25 °C and 200 rpm for 30 minutes. Then, 4.68 g of NMC (manufactured by Aldrich) as a positive electrode active material, 0.13 g of acetylene black (AB) as a conductive additive, and 0.07 g (solid content by mass) of the binder solution shown in Tables 2-2 and 2-4 were placed in the container. The container was then placed in a planetary ball mill P-7 (trade name) and continued mixing at 25 °C and 200 rpm for 30 minutes to prepare positive electrode compositions (slurries) PK-1 to PK-16 and PKc21 to PKc24, respectively.

[0217] <Preparation of negative electrode composition> A 45 mL zirconia container (manufactured by Fritsch) was charged with 60 g of zirconia beads with a diameter of 5 mm, 2.20 g of the LPS synthesized in Synthesis Example A, 0.06 g (solid mass) of the binder solution shown in Tables 2-3 and 2-4, and 4.50 g (total amount) of butyl butyrate. The container was placed in a planetary ball mill P-7 (trade name) and mixed at 25°C and 300 rpm for 60 minutes. Subsequently, 3.03 g of silicon (Si) as the negative electrode active material and 0.22 g of VGCF (manufactured by Showa Denko K.K.) as the conductive additive were added. Similarly, the container was placed in a planetary ball mill P-7 (trade name) and mixed at 25°C and 100 rpm for 10 minutes to prepare negative electrode compositions (slurries) NK-1 to NK-16 and NKc21 to NKc24, respectively.

[0218] In Table 2, the composition content is the content (mass%) relative to the total mass of the composition, and the solid content is the content (mass%) relative to 100% by mass of the solid content of the composition, and units are omitted in the table.

[0219] [Table 2-1]

[0220] [Table 2-2]

[0221] [Table 2-3]

[0222] [Table 2-4]

[0223] LPS: LPS synthesized in Synthesis Example A NMC:LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2 Si: Silicon (APS 1-5 μm, manufactured by Alfa Aesar) AB: Acetylene black VGCF: Carbon nanotubes

[0224] <Preparation of solid electrolyte sheets for all-solid-state secondary batteries> Each of the inorganic solid electrolyte-containing compositions shown in the "Solid Electrolyte Composition" column of Table 3-1 or Table 3-4 obtained above was applied to a 20 μm-thick aluminum foil using a Baker-type applicator (product name: SA-201, manufactured by Tester Sangyo Co., Ltd.) and heated at 80°C for 2 hours to dry the inorganic solid electrolyte-containing composition (removing the dispersion medium). The dried inorganic solid electrolyte-containing composition was then heated and pressed at 120°C and 40 MPa for 10 seconds using a heat press to produce solid electrolyte sheets for all-solid-state secondary batteries (referred to as solid electrolyte sheets in Tables 3-1 and 3-4) 101 to 116 and c11 to c14, respectively. The film thickness of the solid electrolyte layer was 40 μm.

[0225] <Preparation of positive electrode sheet for all-solid-state secondary battery> Each of the positive electrode compositions shown in the "Electrode Composition" column of Table 3-2 or Table 3-4 obtained above was applied to a 20 μm-thick aluminum foil using a Baker-type applicator (product name: SA-201), heated at 80°C for 1 hour, and then heated at 110°C for 1 hour to dry the positive electrode composition (removing the dispersion medium). Thereafter, using a heat press, the dried positive electrode composition was pressed (10 MPa, 1 minute) at 25°C to produce positive electrode sheets for all-solid-state secondary batteries (referred to as positive electrode sheets in Tables 3-2 and 3-4) 201 to 216 and c21 to c24, respectively, each having a positive electrode active material layer with a thickness of 70 μm.

[0226] <Preparation of negative electrode sheet for all-solid-state secondary battery> Each of the negative electrode compositions shown in the "Electrode Composition" column of Table 3-3 or Table 3-4 obtained above was applied to a copper foil with a thickness of 20 μm using a Baker-type applicator (product name: SA-201), heated at 80°C for 1 hour, and then heated at 110°C for 1 hour to dry the negative electrode composition (remove the dispersion medium). Thereafter, using a heat press, the dried negative electrode composition was pressed (10 MPa, 1 minute) at 25°C to produce negative electrode sheets for all-solid-state secondary batteries (referred to as negative electrode sheets in Tables 3-3 and 3-4) 301 to 316 and c31 to c34, respectively, each having a negative electrode active material layer with a thickness of 60 μm.

[0227] <Evaluation 1: Storage stability test> For each composition prepared as described above, LPS, polymer binder, dispersion medium, active material, and conductive additive were mixed in the same proportions as the composition content and solid content shown in Table 2 under the same conditions as for the preparation of each composition to prepare a composition (slurry) for dispersibility evaluation. The occurrence (presence) of agglomerates of solid particles was confirmed for each of the obtained compositions using a grind meter (manufactured by Asahi Soken Co., Ltd.) If agglomerates were present, the size of the agglomerates was recorded as X (μm). Next, each composition was left to stand at 25°C for 24 hours, and then the occurrence (presence or absence) of agglomerates of solid particles was confirmed using a grind meter (manufactured by Asahi Research Institute Co., Ltd.) The size of the agglomerates that had occurred was designated Y (µm). The size of the aggregates was determined by the point at which significant spots appeared on the applied material to the grind meter (see JIS K-5600-2-5 6.6). The tendency for aggregates to form (aggregation tendency or sedimentation tendency) was evaluated as the storage stability of the solid electrolyte composition based on whether the aggregate sizes X and Y fell within the following evaluation criteria. In this test, a smaller aggregate size X indicates better initial dispersibility, and a smaller aggregate size Y indicates better storage stability. In this test, an aggregate size Y of "D" or higher was considered acceptable, and when the aggregate size Y was "D" or higher, the aggregate size X was also included in the evaluation. The results are shown in Tables 3-1 to 3-4 (collectively referred to as Table 3). - Evaluation Criteria - A: Y≦5μm and X≦5μm B: 5μm <Y≦8μm かつ 5μm<X≦8μm C: 8μm <Y≦12μm かつ 8μm<X≦12μm D: 8μm <Y≦10μm かつ 12μm<X E: 10 μm <Y≦100μm F: 100 μm <Y

[0228] <Evaluation 2: Slurry thickening test (solids concentration test)> For each composition prepared as described above, LPS, polymer binder, dispersion medium, active material, and conductive additive were mixed in the same proportions as the composition content and solid content shown in Table 2 under the same conditions as for the preparation of each composition to prepare a composition (slurry) for dispersibility evaluation. The resulting compositions were evaluated using a grind meter (manufactured by Asahi Research Institute Co., Ltd.) to determine whether agglomerates of solid particles had formed, and whether the compositions could be applied uniformly (at a consistent coating thickness without running out of liquid) using a Baker-type applicator (product name: SA-201) at 25°C. This evaluation (presence or absence of agglomerates and applicability) was repeated by gradually increasing the solids concentration in the composition until agglomerates formed or uniform application became impossible. The dispersibility at high solids concentrations was evaluated based on which of the following evaluation criteria the maximum solids concentration at which uniform application was possible without the formation of agglomerates fell under. The results are shown in Table 3. In this test, the presence or absence of agglomerates was evaluated by observing the particle size at which linear or granular marks appeared using a grindmeter, and a particle size of 5 μm or less was defined as no agglomerates having appeared. In this test, a higher maximum solids concentration indicates that excellent dispersibility of solid particles can be maintained even when the solids concentration of the composition is increased, and a rating of "D" or higher is considered a passing level. The results are shown in Table 3. - Evaluation Criteria - A: 70% by mass or more B: Less than 70% by mass, 60% by mass or more C: Less than 60% by mass, 50% by mass or more D: Less than 50% by mass, 40% by mass or more E: Less than 40% by mass, 30% by mass or less F: Less than 30% by mass

[0229] <Evaluation 3: Adhesion test (film strength test)> Each prepared sheet was cut into a rectangle measuring 3 cm wide x 14 cm long. The cut sheet specimens were bent using a cylindrical mandrel testing machine (product code 056, mandrel diameter 10 mm, manufactured by Allgood) in accordance with Japanese Industrial Standards (JIS) K5600-5-1 (flex resistance (test using a cylindrical mandrel: type 2 testing device), the same test as International Standard (ISO) 1519). The sheet specimens were set with the current collector facing the mandrel (the solid electrolyte layer facing away from the mandrel) and the width direction parallel to the axis of the mandrel. The test was performed by changing the mandrel diameter in the following order: 32 mm, 25 mm, 20 mm, 16 mm, 12 mm, 10 mm, 8 mm, 6 mm, 5 mm, 3 mm, and 2 mm. After bending, a 3 cm x 8 cm area including the bent portion (the state where the sheet shape had not been restored after unwrapping) was visually observed to check for defects (cracks, breaks, chips, etc.) due to breakdown of the adhesion of the solid particles. The mandrel diameter (minimum diameter) when no defects were observed was used to evaluate the adhesion between the solid particles in the solid electrolyte layer or active material layer (strength of the sheet-like test piece) according to the following evaluation criteria. In this test, the smaller the minimum diameter, the stronger the adhesion between the solid particles in the solid electrolyte layer or active material layer, and an evaluation standard of "D" or higher is a passing level. The results are shown in Table 3. In the electrode sheet, at the minimum diameter obtained according to the above criteria, no peeling between the active material layer and the current collector was observed, and the adhesion between the active material layer and the current collector was also strong. - Evaluation Criteria - A: 5mm or less B: 6mm or 8mm C: 10mm D: 12mm or 16mm E: 20mm or 25mm F:32mm

[0230] [Table 3-1]

[0231] [Table 3-2]

[0232] [Table 3-3]

[0233] [Table 3-4]

[0234] <Manufacturing of all-solid-state secondary batteries> First, a positive electrode sheet for an all-solid-state secondary battery having a solid electrolyte layer and a negative electrode sheet for an all-solid-state secondary battery having a solid electrolyte layer were produced, both of which were to be used in the production of an all-solid-state secondary battery.

[0235] - Fabrication of a cathode sheet with a solid electrolyte layer for all-solid-state secondary batteries - On the positive electrode active material layer of each positive electrode sheet for all solid state secondary batteries shown in the "Electrode active material layer (sheet No.)" column of Table 4, the solid electrolyte sheet prepared above shown in the "Solid electrolyte layer (sheet No.)" column of Table 4 was superimposed so that the solid electrolyte layer was in contact with the positive electrode active material layer, and after transferring (laminating) by applying a pressure of 50 MPa at 25°C using a press, pressure was applied at 25°C and 600 MPa to prepare positive electrode sheets for all solid state secondary batteries Nos. 201 to 216 and c21 to c24 (positive electrode active material layer thickness 50 μm) each having a solid electrolyte layer with a thickness of 25 μm.

[0236] - Fabrication of a negative electrode sheet with a solid electrolyte layer for all-solid-state secondary batteries - The solid electrolyte sheet shown in the "Solid electrolyte layer (sheet No.)" column of Table 4, prepared above, was placed on the negative electrode active material layer of each negative electrode sheet for all solid state secondary batteries shown in the "Electrode active material layer (sheet No.)" column of Table 4 so that the solid electrolyte layer was in contact with the negative electrode active material layer, and a press was used to transfer (laminate) the sheets at 25°C and 50 MPa, followed by pressure at 25°C and 600 MPa to prepare negative electrode sheets for all solid state secondary batteries 301 to 316 and c31 to c34 (negative electrode active material layer thickness: 40 μm) each having a solid electrolyte layer with a thickness of 25 μm.

[0237] An all-solid-state secondary battery No. 101 having the layer structure shown in FIG. 1 was fabricated as follows. The positive electrode sheet for all-solid-state secondary batteries No. 201 with a solid electrolyte layer obtained above (the aluminum foil of the solid electrolyte-containing sheet had been peeled off) was cut into a disk shape with a diameter of 14.5 mm and placed in a stainless steel 2032-type coin case 11 incorporating a spacer and a washer (not shown in FIG. 2), as shown in FIG. 2. Next, lithium foil cut into a disk shape with a diameter of 15 mm was placed on top of the solid electrolyte layer. Stainless steel foil was then placed on top of that, and the 2032-type coin case 11 was then crimped to produce the all-solid-state secondary battery No. 101 shown in FIG. 2. The all-solid-state secondary battery produced in this manner has the layer structure shown in FIG. 1 (where the lithium foil corresponds to the negative electrode active material layer 2 and the negative electrode current collector 1).

[0238] All solid state secondary batteries Nos. 102 to 116 and c101 to c104 were produced in the same manner as in the production of all solid state secondary battery No. 101, except that in the production of the all solid state secondary battery No. 101, positive electrode sheets for all solid state secondary batteries having a solid electrolyte layer, represented by the numbers shown in the "Electrode active material layer (sheet No.)" column in Table 4, were used instead of positive electrode sheet No. 201 for all solid state secondary batteries having a solid electrolyte layer.

[0239] An all-solid-state secondary battery No. 117 having the layer structure shown in FIG. 1 was fabricated as follows. The solid electrolyte-containing negative electrode sheet No. 301 for an all-solid-state secondary battery obtained above (the aluminum foil of the solid electrolyte-containing sheet had been peeled off) was cut into a disk shape with a diameter of 14.5 mm and placed in a stainless steel 2032-type coin case 11 incorporating a spacer and a washer (not shown in FIG. 2 ) as shown in FIG. 2 . Next, a positive electrode sheet (positive electrode active material layer) punched out to a diameter of 14.0 mm from the positive electrode sheet for an all-solid-state secondary battery prepared below was placed on top of the solid electrolyte layer. A stainless steel foil (positive electrode current collector) was further placed on top of the positive electrode sheet to form an all-solid-state secondary battery laminate 12 (a laminate consisting of stainless steel foil-aluminum foil-positive electrode active material layer-solid electrolyte layer-negative electrode active material layer-copper foil). The 2032-type coin case 11 was then crimped to produce the all-solid-state secondary battery No. 117 shown in FIG. 2 .

[0240] A positive electrode sheet for a solid secondary battery used in the production of all-solid-state secondary battery No. 117 was prepared as follows. - Preparation of positive electrode composition - A 45 mL zirconia container (manufactured by Fritsch) was charged with 180 zirconia beads with a diameter of 5 mm, and 2.7 g of the LPS synthesized in Synthesis Example A above, 0.3 g of KYNAR FLEX 2500-20 (trade name, PVdF-HFP: polyvinylidene fluoride hexafluoropropylene copolymer, manufactured by Arkema) as a solid content mass, and 22 g of butyl butyrate were added. The container was placed in a Fritsch planetary ball mill P-7 (trade name) and stirred at 25°C at 300 rpm for 60 minutes. LiNi was then added as a positive electrode active material. 1 / 3 Co 1 / 3 Mn 1 / 3 7.0 g of O2 (NMC) was added, and the container was similarly set in the planetary ball mill P-7, and mixing was continued for 5 minutes at 25°C and 100 rpm to prepare a positive electrode composition. - Fabrication of positive electrode sheets for solid secondary batteries - The positive electrode composition obtained above was applied to a 20 μm-thick aluminum foil (positive electrode current collector) using a Baker-type applicator (product name: SA-201, manufactured by Tester Sangyo Co., Ltd.), and heated at 100° C. for 2 hours to dry the positive electrode composition (remove the dispersion medium). Thereafter, using a heat press, the dried positive electrode composition was pressed (10 MPa, 1 minute) at 25° C. to produce a positive electrode sheet for an all-solid-state secondary battery having a positive electrode active material layer with a thickness of 80 μm.

[0241] All solid state secondary batteries Nos. 118 to 132 and c201 to c204 were produced in the same manner as in the production of all solid state secondary battery No. 117, except that in the production of the all solid state secondary battery No. 117, negative electrode sheets for all solid state secondary batteries having a solid electrolyte layer, represented by the numbers shown in the "Electrode active material layer (sheet No.)" column in Table 4, were used instead of negative electrode sheet No. 301 for all solid state secondary batteries having a solid electrolyte layer.

[0242] <Evaluation 4: Cycle characteristics> The discharge capacity retention rate of each of the produced all-solid-state secondary batteries was measured using a charge / discharge evaluation device TOSCAT-3000 (trade name, manufactured by Toyo Systems Co., Ltd.). Specifically, each all-solid-state secondary battery was charged at a current density of 0.1 mA / cm in an environment of 25°C. 2 The battery was charged at a current density of 0.1 mA / cm until the battery voltage reached 4.3 V. 2 The battery was discharged at 1000 kJ / s until the battery voltage reached 2.5 V. This one charge and one discharge constituted one charge / discharge cycle, and three charge / discharge cycles were repeated under the same conditions to initialize the battery. Thereafter, the above charge / discharge cycle was repeated, and the discharge capacity of each all-solid-state secondary battery was measured after each charge / discharge cycle using a charge / discharge evaluation device: TOSCAT-3000 (product name). The discharge capacity of the first charge / discharge cycle after initialization (initial discharge capacity) was taken as 100%, and the number of charge / discharge cycles at which the discharge capacity retention rate (discharge capacity relative to the initial discharge capacity) reached 80% was evaluated based on which of the following evaluation criteria the battery performance (cycle characteristics) fell into. In this test, the higher the evaluation criterion, the better the battery performance (cycle characteristics), and the more likely the battery is to maintain its initial battery performance even after multiple charge / discharge cycles (even during long-term use). In this test, cycle characteristics that achieved an evaluation criterion of "D" or higher were considered acceptable. The results are shown in Table 4. All of the all solid state secondary batteries Nos. 101 to 132 exhibited initial discharge capacities sufficient to function as all solid state secondary batteries. - Evaluation Criteria - A: More than 600 cycles B: 450 cycles or more, less than 600 cycles C: 300 cycles or more, less than 450 cycles D: 150 cycles or more, less than 300 cycles E: 80 or more cycles, less than 150 cycles F: 40 cycles or more, less than 80 cycles

[0243] [Table 4]

[0244] The results shown in Tables 3 and 4 reveal the following. The comparative inorganic solid electrolyte-containing compositions containing polymer binders composed of polymers T-1 to T-4, which do not have at least one of an ethylenically unsaturated bond polymer chain and a partial structure containing a flexible functional group in the main chain, all exhibit poor dispersion characteristics in terms of storage stability tests and slurry thickening, or poor adhesion of solid particles.As a result, the comparative all-solid-state secondary batteries having constituent layers composed of these compositions also have insufficient cycle characteristics. In contrast, the inorganic solid electrolyte-containing compositions of the examples, which contain polymer binders composed of polymers S-1 to S-16 having main chains with both a polymer chain of an ethylenically unsaturated bond and a partial structure containing a flexible functional group, all achieve excellent dispersion properties and strong adhesion of solid particles. Therefore, by using these inorganic solid electrolyte-containing compositions as materials for forming constituent layers of all-solid-state secondary batteries, the resulting all-solid-state secondary batteries can achieve excellent cycle characteristics.

[0245] While the present invention has been described in connection with embodiments thereof, we do not intend to limit our invention to any of the details of the description unless otherwise specified, and believe that the claims should be construed broadly without departing from the spirit and scope of the invention as set forth in the appended claims.

[0246] This application claims priority based on Japanese Patent Application No. 2021-051778, filed in Japan on March 25, 2021, the contents of which are incorporated herein by reference as part of the present specification. [Explanation of symbols]

[0247] 1 Negative electrode current collector 2 Negative electrode active material layer 3 Solid electrolyte layer 4 Cathode active material layer 5 Positive electrode current collector 6. Operating parts 10 All-solid-state secondary battery 11 2032 type coin case 12. Laminates for all-solid-state secondary batteries 13 Coin-type all-solid-state secondary battery

Claims

1. An inorganic solid electrolyte-containing composition comprising a sulfide-based inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, a polymer binder, and a dispersion medium, The inorganic solid electrolyte-containing composition includes a polymer binder comprising a polymer having, in its main chain, a polymer chain of an ethylenically unsaturated bond and a partial structure containing at least one of the following flexible functional groups: <Flexible functional group group> Ether group, ester group, amide group, silyl ether group, carbonate group, hydrocarbon group

2. The inorganic solid electrolyte-containing composition according to claim 1 , wherein the polymer has a polymer chain represented by the following formula (1): 【Chemistry 1】 In formula (1), A represents a hydrogen atom or a hydrocarbon group. Y represents an ester bond, an amide bond, an aromatic ring group, or a heterocyclic group. L represents a single bond or a linking group. Z represents a hydrogen atom or a substituent. n is a number of 2 or more.

3. The inorganic solid electrolyte-containing composition described in claim 1 or 2, wherein the polymer contains 10 mass% or more of the polymer chains of the ethylenically unsaturated bonds.

4. The inorganic solid electrolyte-containing composition according to claim 1, wherein the polymer has a polymer chain represented by the following formula (2): 【Chemistry 2】 In formula (2), X represents an alkylene group or a silylene group, and m is a number of 2 or more.

5. 5. The inorganic solid electrolyte-containing composition according to claim 4, wherein the polymer chain represented by the formula (2) is selected from a polyethyleneoxy chain, a polypropyleneoxy chain, and a polysilyleneoxy chain.

6. 6. The inorganic solid electrolyte-containing composition according to claim 1, wherein the polymer has a glass transition temperature of −30° C. or lower.

7. 7. The inorganic solid electrolyte-containing composition according to claim 1, wherein the polymer contains a constituent having an alkyl group having 8 or more carbon atoms as a side chain.

8. The inorganic solid electrolyte-containing composition according to any one of claims 1 to 7, wherein the polymer has a constituent component having at least one polar functional group selected from the following polar functional group group (a): <Polar functional group group (a)> Sulfonic acid group, phosphoric acid group, phosphonic acid group, hydroxy group, carboxy group, oxetane group, epoxy group, dicarboxylic acid anhydride group, thiol group, ether group, thioether group, thioester group, fluoroalkyl group, and salts thereof

9. The inorganic solid electrolyte-containing composition according to any one of claims 1 to 8, which contains an active material.

10. The inorganic solid electrolyte-containing composition according to any one of claims 1 to 9, further comprising a conductive assistant.

11. A sheet for an all-solid-state secondary battery having a layer constituted of the inorganic solid electrolyte-containing composition according to any one of claims 1 to 10.

12. An all-solid-state secondary battery comprising a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, An all-solid-state secondary battery, wherein at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is a layer constituted by the inorganic solid electrolyte-containing composition according to any one of claims 1 to 10.

13. A method for producing a sheet for an all-solid-state secondary battery, comprising forming a film from the inorganic solid electrolyte-containing composition according to any one of claims 1 to 10.

14. A method for producing an all-solid-state secondary battery, comprising producing an all-solid-state secondary battery through the method according to claim 13.

Images