Binder for all-solid-state secondary battery, inorganic solid electrolyte-containing composition, sheet for all-solid-state secondary battery, and all-solid-state secondary battery

Abstract

Provided are: a binder for an all-solid secondary battery, the binder containing a polymer represented by formula (I) and having an acid value of 3 mgKOH / g or less; an inorganic solid electrolyte-containing composition that contains the binder, an inorganic solid electrolyte, and a dispersion medium; and a sheet for an all-solid secondary battery and an all-solid secondary battery that include the composition. In formula (I), R1 represents a (m + n)-valent linking group. A1 represents a hydrogen atom or a functional group or a polymer chain containing at least one amide substituent. A2 represents a functional group or a polymer chain containing at least one of a fluorine atom and a polysiloxane structure. n is an integer from 1 to 8, and m is an integer from 1 to 9. Here, m + n is an integer from 2 to 10.

Description

Binder for all-solid-state secondary battery, inorganic solid electrolyte-containing composition, sheet for all-solid-state secondary battery, and all-solid-state secondary battery

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

[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, the constituent layers (e.g., solid electrolyte layer, anode active material layer, cathode active material layer) are composed of solid particles such as inorganic solid electrolyte, active material, and conductive additive. A binder is typically used to bind these solid particles together within the constituent layers. These constituent layers are typically formed using a constituent layer-forming material containing solid particles and a binder, taking into consideration factors such as improved productivity. Therefore, binders and constituent layer-forming materials have been studied. For example, Patent Document 1 describes a binder comprising a hyperbranched polymer, which is an amorphous polymer and has a core and at least three polymeric arms bonded to the core, and a solid electrolyte composition comprising this hyperbranched polymer and an inorganic solid electrolyte. Specifically, the solid electrolyte composition described includes a particulate hyperbranched polymer in which all the arms bonded to the core are polymer chains having the same constituent components, and which are copolymer chains of an acidic group-containing (meth)acrylic acid monomer and an alkyl methacrylate monomer, or homopolymer chains or copolymer chains of an alkyl methacrylate monomer; an inorganic solid electrolyte; and a dispersion medium. Patent Document 2 describes a polymer represented by the following formula 1 as a binder, and a solid electrolyte composition containing this polymer and an inorganic solid electrolyte. Patent Document 2 describes a polymer represented by the following formula 1 as an example of the polymer represented by the following formula 1, which is a polymer represented by the following formula 1: １ ) p-R２ Polymer D-14 (acid value: about 4 mg KOH / g) having a polymer chain of methacrylamide having a sulfonic acid group is described as "-".

[0004] "During the ceremony, R １ represents a (m+n)-valent linking group. １ represents an acidic group, a group having a basic nitrogen atom, a urea group, a urethane group, an alkoxysilyl group, an epoxy group, an isocyanate group, or a hydroxyl group. p is an integer of 1 to 10. ２ and R ３ represents a single bond or a linking group. Ｃ represents a polymer chain having a constituent component containing at least one selected from a fluoroalkylene group and a siloxane structure. m is an integer of 1 to 8, and n is an integer of 2 to 9, with the proviso that m+n is an integer of 3 to 10.

[0005] JP 2015-164125 A International Publication No. 2020 / 067106

[0006] In all-solid-state secondary batteries having a constituent layer formed using a constituent layer-forming material, from the viewpoint of improving battery performance (e.g., reducing battery resistance), the constituent layer-forming material is required to have solid particles dispersed in a dispersion medium without degradation or decomposition (solid particle dispersion state). Moreover, in recent years, research and development into improving the performance and practical application of electric vehicles has progressed rapidly, and the performance required of all-solid-state secondary batteries has also increased, so there is a need to further improve the dispersion state of solid particles in the constituent layer-forming material. To meet this demand, the present inventors have conducted extensive research on constituent layer-forming materials and polymers that function as binders used therein. As a result, they have come up with the idea that when preparing a constituent layer-forming material by mixing solid particles such as an inorganic solid electrolyte with a binder, heat generation, particularly when mixing the inorganic solid electrolyte and the binder, can be a factor in reducing the dispersion state of solid particles in the constituent layer-forming material. However, various studies of conventional constituent layer-forming materials and binders have focused on the dispersibility of solid particles in the constituent layer-forming material after mixing, but no study has been conducted on heat generation during mixing.

[0007] An object of the present invention is to provide a binder for an all-solid-state secondary battery that can be used to prepare a constituent layer-forming material while suppressing heat generation when mixed with an inorganic solid electrolyte, and an inorganic solid electrolyte-containing composition that contains the binder for an all-solid-state secondary battery and an inorganic solid electrolyte. Another object of the present invention is to provide a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery that use the inorganic solid electrolyte-containing composition.

[0008] The present inventors continued their research based on the above-mentioned idea and found that a binder formed from a hyperbranched polymer having a specific chemical structure represented by the following formula (I) and having an acid value of 3 g KOH / g or less can be used in combination with an inorganic solid electrolyte to prepare an inorganic solid electrolyte-containing composition while suppressing the amount of heat generated when mixed with the inorganic solid electrolyte and, more preferably, suppressing excessive interactions between binders and excessive adsorption of the binder to solid particles. Furthermore, they found that by using an inorganic solid electrolyte-containing composition containing this specific binder, an inorganic solid electrolyte, and a dispersion medium as a constituent layer-forming material, it is possible to realize a sheet for an all-solid-state secondary battery having a low-resistance constituent layer, and even a low-resistance all-solid-state secondary battery. The present invention was completed through further research based on these findings.

[0009] That is, the above-mentioned problems have been solved by the following means: <1> A binder for an all-solid-state secondary battery, which comprises a polymer represented by the following formula (I) and having an acid value of 3 mgKOH / g or less. In formula (I), R １ represents a (m+n)-valent linking group. １ represents a hydrogen atom, or a functional group or polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group. ２ represents a functional group or polymer chain containing at least one of a fluorine atom and a polysiloxane structure, where n is an integer of 1 to 8 and m is an integer of 1 to 9, provided that m+n is an integer of 2 to 10.

[0010] <2> Note A １<3> The binder for an all-solid-state secondary battery according to <1>, wherein A represents a functional group or a polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group. ２ <4> The binder for an all-solid-state secondary battery according to any one of <1> to <3>, wherein the polymer has an acid value of 0.5 mgKOH / g or less and a base value of 0.5 mgKOH / g or less. １ <6> The binder for an all-solid-state secondary battery according to any one of <1> to <4>, wherein A contains a polymer chain of a (meth)acrylamide compound. １ <7> The binder for an all-solid-state secondary battery according to any one of <1> to <5>, wherein A in the polymer contains a hydrogen atom and a polymer chain of a (meth)acrylamide compound. １ <1> The binder for an all-solid-state secondary battery according to any one of <1> to <6>, wherein the content of the polymer is 1 to 30 mass %. <8> The binder for an all-solid-state secondary battery according to any one of <1> to <7>, wherein the weight-average molecular weight of the polymer is 30,000 or less. <9> An inorganic solid electrolyte-containing composition containing the binder for an all-solid-state secondary battery according to any one of <1> to <8> above, an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and a dispersion medium. <10> The inorganic solid electrolyte-containing composition according to <9>, which contains an active material. <11> The inorganic solid electrolyte-containing composition according to <9> or <10>, which contains a conductive additive. <12> A sheet for an all-solid-state secondary battery, having a layer formed using the inorganic solid electrolyte-containing composition according to any one of <9> to <11> above. <13> An all-solid-state secondary battery including a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, wherein at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is formed using the inorganic solid electrolyte-containing composition according to any one of <9> to <11>.

[0011] The present invention provides a binder for an all-solid-state secondary battery that can be used to prepare a constituent layer-forming material while suppressing heat generation when mixed with an inorganic solid electrolyte, and an inorganic solid electrolyte-containing composition containing this binder for an all-solid-state secondary battery and an inorganic solid electrolyte. The present invention also provides a sheet for an all-solid-state secondary battery and an all-solid-state secondary battery having a layer formed from 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.

[0012] Fig. 1 is a longitudinal sectional view schematically showing an all-solid-state secondary battery according to a preferred embodiment of the present invention, and Fig. 2 is a longitudinal sectional view schematically showing a coin-type all-solid-state secondary battery fabricated in Examples.

[0013] In the present invention, when describing the content, physical properties, etc. of a component by indicating a numerical range, if the upper and lower limits of the numerical range are described separately, any of the upper and lower limits can be appropriately combined to form a specific numerical range. On the other hand, when describing multiple numerical ranges expressed using "to", 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 any numerical range obtained by appropriately combining the upper and lower limits of each numerical range. Note that 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 upper and lower limits. In the present invention, when a compound is referred to (for example, when "compound" is added to the end), it is used to mean not only the compound itself, but also its salts and ions. It also means derivatives that have been partially modified, such as by introducing a substituent, to the extent that the effects of the present invention are not impaired. In the present invention, "(meth)acrylic" means one or both of acrylic and methacrylic. The same applies to (meth)acrylate. In the present invention, with respect to substituents, linking groups, etc. (hereinafter referred to as substituents, etc.) that are not specified as substituted or unsubstituted, this means 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 substituted or unsubstituted is not specified. A preferred substituent is, 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 specified simultaneously, this means that the respective substituents, etc. may be the same or different from each other. Furthermore, unless otherwise specified, when multiple substituents, etc., are adjacent, they may be linked to each other or fused to form a ring. In the present invention, polymer means a polymer, but is synonymous with so-called polymeric compound.

[0014] [Binder for All-Solid-State Secondary Battery] The binder for an all-solid-state secondary battery of the present invention (hereinafter sometimes simply referred to as the "binder of the present invention") contains a polymer represented by the following formula (I) and having an acid value of 3 mgKOH / g or less. In the present invention, the binder for an all-solid-state secondary battery (hereinafter sometimes simply referred to as the "binder") containing a polymer includes both binders consisting of the polymer itself and binders containing the polymer and other components. Other components that may be contained in the binder are not particularly limited, but include polymer synthesis by-products, decomposition products (residues) of polymerization catalysts, etc., and residual synthetic solvents. The content of other components in the binder of the present invention is appropriately set within a range that does not impair the effects of the present invention, and can be, for example, 10% by mass or less. The binder of the present invention may contain one or more types of polymer represented by formula (I). Furthermore, the binder of the present invention is typically formed from a polymer represented by formula (I) as the polymer component, but may also contain other polymers, etc., within a range that does not impair the function of the polymer represented by formula (I). Examples of other polymers include polymers that do not have the chemical structure represented by formula (I), and for example, polymers that are commonly used as binders for all-solid-state secondary batteries can be used without any particular limitation.

[0015] The binder of the present invention can suppress heat generation during mixing with solid particles, particularly inorganic solid electrolytes, during preparation of an inorganic solid electrolyte-containing composition. Therefore, it is believed that deterioration and decomposition of solid particles, particularly inorganic solid electrolytes, can be suppressed and solid particles can be dispersed in a dispersion medium without setting preparation conditions (mixing conditions), for example, without performing excessive cooling operations. Furthermore, since the binder of the present invention has an acid value of 3 mg KOH / g, excessive interactions between binders and excessive adsorption of the binder to solid particles can be suppressed in the dispersion medium, thereby suppressing excessive aggregation and precipitation of the binder and solid particles. As a result, the solid particles can be dispersed in a dispersion medium while suppressing deterioration and decomposition, thereby improving the dispersion state of the solid particles. By using the inorganic solid electrolyte-containing composition of the present invention, which has an excellent dispersion state of solid particles, as a material for forming a constituent layer of an all-solid-state secondary battery, a sheet for an all-solid-state secondary battery having a constituent layer with low resistance (high conductivity) and a low-resistance (high conductivity) all-solid-state secondary battery can be realized. As described above, the binder of the present invention functions as a dispersant that suppresses deterioration and decomposition of solid particles and disperses them in a dispersion medium during the preparation of an inorganic solid electrolyte-containing composition. Furthermore, the binder of the present invention also functions as a binder that adsorbs to solid particles in a constituent layer formed from the inorganic solid electrolyte-containing composition to bind the solid particles and further binds the solid particles to a current collector. Note that, in the inorganic solid electrolyte-containing composition, the binder of the present invention may or may not have the function of binding solid particles. The adsorption of the binder of the present invention to solid particles includes not only physical adsorption but also chemical adsorption (adsorption by chemical bond formation, adsorption by electron transfer, etc.). The binder of the present invention, which exhibits the above-described excellent effects, can be preferably used as a material for forming a sheet for an all-solid-state secondary battery (including an electrode sheet for an all-solid-state secondary battery) or a solid electrolyte layer or active material layer of an all-solid-state secondary battery.

[0016] <Polymer represented by formula (I)> The polymer represented by the following formula (I) (hereinafter, may be simply referred to as "polymer (I)") is a hyperbranched polymer (also called a star polymer) having a chemical structure represented by the following formula (I). In formula (I), R １represents a (m+n)-valent linking group. １ represents a hydrogen atom, or a functional group or polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group. ２ represents a functional group or polymer chain containing at least one of a fluorine atom and a polysiloxane structure, n is an integer of 1 to 8, and m is an integer of 1 to 9, provided that m+n is an integer of 2 to 10. In the above formula (I), A １ and A ２ If there are multiple A's, １ and A ２ may be the same or different.

[0017] (R of formula (I) １ In formula (I), R １ is a (m+n)-valent linking group, and is usually a linking group (organic linking group) made of an organic group containing a skeleton in which carbon atoms are linked by covalent bonds, and a linking group further containing an oxygen atom is preferred. Examples of this linking group include the linking group R １Ｃ The linking group R １ The molecular weight of is not particularly limited, and is, for example, preferably 100 or more, more preferably 200 or more, and even more preferably 300 or more. The upper limit of the molecular weight is preferably 5,000 or less, more preferably 4,000 or less, and particularly preferably 3,000 or less. It is preferable that this linking group does not have only one tetravalent carbon atom. The valence of this linking group is divalent to decavalent, and is synonymous with the sum of m and n (m+n) described below, and the preferred range is also the same.

[0018] The linking group preferably has a group represented by the following formula 1a: １ The number of groups represented by formula 1a that R １ When the linking group has a plurality of such groups, they may be the same or different. ｆ ２ ) ｎ -O(C=O)-(CR ｆ ２ )ｎ - (Formula 1a) In formula (1a), n is an integer of 0 to 10, preferably an integer of 1 to 6, and more preferably 1 or 2. Two n's may be the same or different. R ｆ represents a hydrogen atom or a substituent, and a hydrogen atom is preferred. ｆ The substituent that can be adopted as (I) is not particularly limited, but examples thereof include the substituent Z described below. Specific examples include halogen atoms (e.g., fluorine, chlorine, iodine, and bromine atoms), alkyl groups (preferably having 1 to 12 carbon atoms, more preferably having 1 to 6 carbon atoms, and particularly preferably having 1 to 3 carbon atoms), alkoxy groups (preferably having 1 to 12 carbon atoms, more preferably having 1 to 6 carbon atoms, and particularly preferably having 1 to 3 carbon atoms), acyl groups (preferably having 2 to 12 carbon atoms, more preferably having 2 to 6 carbon atoms, and particularly preferably having 2 to 3 carbon atoms), aryl groups (preferably having 6 to 22 carbon atoms, more preferably having 6 to 10 carbon atoms), alkenyl groups (preferably having 2 to 12 carbon atoms, more preferably having 2 to 5 carbon atoms), hydroxy groups, nitro groups, cyano groups, mercapto groups, amino groups, amide groups, and acidic groups (such as carboxyl groups, phosphate groups, and sulfonic acid groups). The acidic group may be a salt. Examples of counter ions that form salts include alkali metal ions, alkaline earth metal ions, ammonium ions, and alkylammonium ions.

[0019] Linking group R １ is more preferably a linking group represented by the following formula 1A or 1B.

[0020] In both formulas, R ｆ and n is R in formula 1a above. ｆ The meanings and preferred meanings of n are the same as those of n. * indicates the bond to the sulfur atom in Formula 1. In Formula 1A, R １Ａ represents a hydrogen atom or a substituent. １Ａ The substituents that can be adopted as R are not particularly limited, and examples thereof include ｆ Examples of the substituents that can be taken as R include the above-mentioned substituents, and further include the group represented by the above formula 1a. Among these, an alkyl group or a group represented by the above formula 1a is preferred. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and particularly preferably 1 to 3. １ＡThe substituent that can be adopted as R may further have one or more substituents, and the substituent that may further have is not particularly limited, and examples thereof include R ｆ Examples of the substituents that can be used as R include the above-mentioned substituents. Among them, a hydroxy group is preferred. Examples of the substituent that may further have one or more substituents include a hydroxyalkyl group (having the same number of carbon atoms as above), and specifically, hydroxymethyl is preferred. In Formula 1B, R １Ｃ represents a linking group. １Ｃ The linking group that can be used as the linking group is not particularly limited, and examples thereof include an alkylene group having 1 to 30 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, an arylene group having 6 to 24 carbon atoms, a heteroarylene group having 3 to 12 carbon atoms, an ether group (—O—), a sulfide group (—S—), a phosphinidene group (—PR—: R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), a silylene group (—SiR Ｓ１ R Ｓ２ -:R Ｓ１ , R Ｓ２ is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), a carbonyl group, an imino group (—NR Ｎ -:R Ｎ is preferably a bonding site, a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms, or a linking group formed by combining two or more of these (preferably 2 to 10 groups). Among these, an alkylene group, an ether group, a sulfide group, or a carbonyl group, or a linking group formed by combining two or more of these (preferably 2 to 5 groups), is preferred, and an ether group is more preferred. １Ｂ represents a hydrogen atom or a substituent, and a hydrogen atom is preferred. １Ｂ The substituents that can be adopted as R are not particularly limited, and examples thereof include R ｆ In Formula 1A and Formula 1B, groups represented by the same symbol may be the same or different.

[0021] Linking group R １ In addition to the above-mentioned linking groups, for example, in the above formula 1B, one or more groups represented by the above formula 1a are R ｆA linking group substituted with any of the above substituents that can be taken as the substituent, particularly hydroxymethyl, is also a preferred embodiment.

[0022] Linking group R １ is also preferably a linking group represented by any one of the following formulae 1C to 1H: In each formula, * indicates the bond to S in formula 1.

[0023]

[0024] In formulas 1C to 1H, T is a linking group, preferably a group represented by any of formulas T1 to T6 below, or a linking group formed by combining two or more (preferably two or three) of these groups. Examples of combined linking groups include a linking group (-OCO-alkylene group) formed by combining a linking group represented by formula T6 with a linking group represented by formula T1. In the groups represented by formulas T1 to T6, any of the bonding moieties bonded to the sulfur atom in formula 1 above may be present, but when T is an oxyalkylene group (a group represented by formulas T2 to T5) or an -OCO-alkylene group, it is preferable that the terminal carbon atom (bonding moiety) be bonded to the sulfur atom in formula 1 above. Multiple Ts present in each of the above formulas may be the same or different. In formulas 1C to 1H, n is an integer, preferably an integer of 0 to 14, more preferably an integer of 0 to 5, and particularly preferably an integer of 1 to 3.

[0025]

[0026] Z Ｄ is a linking group, and is preferably a group represented by Z1 or Z2 below. In formulas T1 and Z1, m is an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably an integer of 1 to 3. In formula Z2, Z ３ is a linking group, which is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 6 carbon atoms. Of these, a 2,2-propanediyl group is particularly preferred.

[0027] The linking group R １ Specific examples of the compounds are listed below, but the present invention is not limited to these. In each specific example, * indicates the bond to the sulfur atom in formula 1.

[0028]

[0029] (A of formula (I) １ In formula (I), A １ represents any one of the following (A-1) to (A-3): (A-1) a hydrogen atom; (A-2) a functional group containing at least one of an amide group, a sulfonamide group, and an imide group; (A-3) a polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group; １ When the binder of the present invention has the above structure, the amount of heat generated when the binder is mixed with the inorganic solid electrolyte can be suppressed, and further, the adsorption of the active material and the like onto the solid particles can be promoted, thereby suppressing the deterioration of the solid particles. １ may be any one of the above (A-1) to (A-3), but from the viewpoint of inhibiting deterioration of the solid particles, it preferably contains a polymer chain (A-3) containing at least one of an amide group, a sulfonamide group, and an imide group, and more preferably contains a polymer chain containing an amide group. １ When the composition contains two or three of (A-1) to (A-3), the combination thereof is not particularly limited, and (A-1) to (A-3) can be combined as appropriate. For example, a combination of (A-1) and (A-2) and a combination of (A-1) and (A-3) can be mentioned, and from the viewpoint of suppressing deterioration of solid particles, a combination of (A-1) and (A-3) is preferred. In these combinations, A １ In the present invention, the functional group or polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group (hereinafter, sometimes referred to as an "amide substituent") includes both an embodiment in which the functional group or polymer chain is composed of an amide substituent, and an embodiment in which the functional group or polymer chain is composed of an amide substituent and another partial structure.

[0030] In the present invention, the amide group is represented by *-CONR ＮＡ１A sulfonamide group is a group having an amide bond represented by -**. However, the amide group does not form other functional groups containing an amide bond, such as a urethane group, a urea group, an imide group, or a carbamate group. A sulfonamide group is a group represented by *-SO ２ NR ＮＡ１ An imide group is a group having a sulfonamide bond represented by *-CO-NR ＮＡ２ It refers to a group having an imide bond represented by -CO-**. * and ** indicate the bond site. R ＮＡ１ represents a hydrogen atom or a substituent, and R ＮＡ２ represents a bond, a hydrogen atom or a substituent. ＮＡ１ and R ＮＡ２ The substituents that can be adopted as are not particularly limited, and examples thereof include the substituent Z described below. Among these, alkyl groups (including cycloalkyl groups), aryl groups, heterocyclic groups, and alkoxy groups are preferred, and alkyl groups or aryl groups are more preferred. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 1 to 12, and even more preferably 1 to 6. The number of carbon atoms in the aryl group is preferably 6 to 26, more preferably 6 to 20, and even more preferably 6 to 12. R in the amide group and sulfonamide group ＮＡ１ are each preferably a hydrogen atom, and R ＮＡ２ is preferably a bond or a hydrogen atom, more preferably a bond.

[0031] In each of the above groups, which of the two bonding portions * and ** is R １ The amide group and sulfonamide group may be bonded to the R １ The imide group is preferably bonded to the R ＮＡ２ is R of polymer (I). １It is preferable that the amide group, sulfonamide group, and imide group are bonded to the aryl group side. The amide group, sulfonamide group, and imide group may each form a cyclic structure directly or via a linking group described later at the two bonded portions * and **. For example, it is preferable that the imide group forms a cyclic imide group, specifically a cyclic imide group derived from maleimide or phthalimide. On the other hand, it is preferable that the other bonded portion of the amide group and the sulfonamide group is bonded to a terminal group described later to form a non-cyclic molecular structure.

[0032] The amide group, sulfonamide group, and imide group each have a terminal group bonded to the end of the group (one bond). The terminal group is not particularly limited, and examples thereof include a hydrogen atom or a substituent. The substituent that can be adopted as the terminal group is not particularly limited, and examples thereof include the substituent Z described below. Among these, alkyl groups (including cycloalkyl groups), aryl groups, heterocyclic groups, and alkoxy groups are preferred, and alkyl groups or aryl groups are more preferred. The number of carbon atoms in the alkyl group is preferably 1 to 20, more preferably 2 to 8, and even more preferably 3 or 4. The number of carbon atoms in the aryl group can be selected from R ＮＡ１ In the present invention, the number of carbon atoms in the aryl group R ＮＡ１ When either the terminal group or the group has a hydrogen atom, this hydrogen atom is ＮＡ１ Interpret as follows.

[0033] In the polymer (I), A １ The amide substituent that the solid particles have is preferably an amide group in terms of the dispersion state of the solid particles and resistance.

[0034] A １ The type of amide substituent contained therein may be at least one type, and preferably one or two types. １ When A has a plurality of amide substituents, the combination thereof is not particularly limited and can be determined appropriately. １ The number of amide substituents in the polymer (I) is not particularly limited and may be determined appropriately depending on the functional group or polymer chain.

[0035] (Functional group A containing at least one of an amide group, a sulfonamide group, and an imide group) １Ｇ ) a functional group A containing at least one of an amide group, a sulfonamide group, and an imide group; １Ｇ (A-2) above may be a functional group consisting of at least one of an amide group, a sulfonamide group, and an imide group, but the linking group L Ａ１ That is, each of the amide group, sulfonamide group and imide group is preferably a functional group further containing the following: Ａ１ The linking group L Ａ１ It is preferable that the linking group L Ａ１ is not particularly limited, and examples thereof include an alkylene group (preferably having 1 to 12 carbon atoms, more preferably having 2 to 6 carbon atoms, and even more preferably having 2 or 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 (-O-P(OH)(O)-O-), a phosphonate linking group (-P(OH)(O)-O-), or a group relating to a combination thereof. Ａ１ The linking group L is preferably an alkylene group, an arylene group, a carbonyl group, an oxygen atom, a sulfur atom, an imino group, or a group relating to a combination thereof, and more preferably an alkylene group, an arylene group, or a group relating to a combination thereof. Ａ１ As the linking group L, a group containing an alkylene group is more preferred, and an alkylene group or an alkylene group-arylene group is particularly preferred. Ａ１ is a group different from an amide group, a sulfonamide group, and an imide group. Ａ１ The number of atoms constituting the linking group L is preferably 1 to 36, more preferably 1 to 24, and even more preferably 1 to 12. Ａ１The number of linking atoms 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 the predetermined structural parts. For example, -CH ２ -CH ２ -(p-C ６ H ４ In the case of the aryl group, the number of atoms constituting the linking group is 16, but the number of linking atoms is 6.

[0036] Functional group A containing one amide substituent １Ｇ is preferably a group derived from a low molecular weight compound, and A １ The polymer chain A described later can be １Ｐ It is more preferable that the functional group A １Ｇ It is preferable that the functional group A does not have a fluorine atom or a polysiloxane structure. １Ｇ is preferably a functional group containing an amide group in terms of the dispersion state of the solid particles and resistance.

[0037] A １ Possible functional groups A １Ｇ The compound from which the compound is derived is not particularly limited, and for example, a compound in which a group reactive with a sulfanyl group and at least one amide substituent are bonded directly or via a linking group L Ａ２ Examples of the reactive group include reactive compounds bonded via a reactive group (excluding the reactive groups described above), and preferred are reactive compounds in which a reactive group is directly bonded to at least one amide substituent. The reactive group is appropriately selected depending on the type of reaction with the sulfanyl group, and examples include an ethylenically unsaturated group capable of undergoing an ene-thiol reaction or radical polymerization, a carboxyl group capable of condensation reaction, or a halogenated alkyl group capable of thioetherification. An example of the ethylenically unsaturated group is a vinyl group. The reactive compound may have one or more reactive groups at the terminal or side chain of its molecular structure, and it is preferable that the reactive compound has one to four reactive groups, and it is more preferable that the reactive compound has one reactive group. Ａ２ is not particularly limited, and the linking group L Ａ１ The linking group L Ａ２As the linking group L, an arylene group is more preferable. Ａ１ is the reactive group and the linking group L after reacting with the sulfanyl group Ａ２ is the same as the group formed by

[0038] Functional group A １Ｇ The reactive compound from which the above is derived is not particularly limited, but preferably includes a reactive compound having an ethylenically unsaturated bond, such as (meth)acrylic compounds (M1) such as (meth)acrylic acid compounds, (meth)acrylic acid ester compounds, (meth)acrylamide compounds, and (meth)acrylonitrile compounds; vinyl compounds (M2) such as vinyl aromatic compounds such as styrene compounds, vinyl naphthalene compounds, and vinyl carbazole compounds, allyl compounds, vinyl ether compounds, vinyl ester compounds, cyclic olefin compounds, diene compounds, and vinyl carboxylic acid ester compounds; and reactive compounds in which at least one of the above-mentioned amide substituents has been introduced into compounds such as dialkyl itaconate compounds and unsaturated carboxylic acid anhydrides. In addition to these compounds, examples include (meth)acrylamide compounds, maleimide compounds, N-vinyl-substituted imide compounds, and vinyl succinimide compounds. Among these, styrene compounds, vinyl naphthalene compounds, reactive compounds in which at least one of the above-mentioned amide substituents has been introduced, (meth)acrylamide compounds, and N-vinyl-substituted imide compounds are preferred. Examples of (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, preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. 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 more preferably 6.

[0039] Examples of reactive compounds that introduce functional groups containing an amide group include (meth)acrylamide compounds such as N-unsubstituted (meth)acrylamide compounds and N-mono- or di-substituted (meth)acrylamide compounds, vinyl compounds containing an amide group, (meth)acrylic acid ester compounds containing an amide group, and (meth)acrylamide compounds containing an amide group. Specific examples of the reactive compounds that introduce functional groups containing an amide group include N-unsubstituted (meth)acrylamide compounds, N-alkyl(meth)acrylamide compounds, N,N-dialkyl(meth)acrylamide compounds, N-aryl(meth)acrylamide compounds, and N,N-diaryl(meth)acrylamide compounds. Examples of the substituent that substitutes the nitrogen atom in the acrylamide compound include R ＮＡ１ Alternatively, an end group bonded to the end of the amide bond may be mentioned, with an alkyl group being preferred. As a reactive compound that derives a functional group containing an amide group, a compound that derives a group having a chemical structure represented by formula (A1) described below is also preferred. The end group bonded to one end of the chemical structure represented by formula (A1) is the same as the end group possessed by the amide substituent described above.

[0040] Examples of reactive compounds that lead to functional groups containing sulfonamide groups include vinyl aromatic sulfonamide compounds, (meth)acrylic compounds (M1) containing sulfonamide groups, etc., and preferably include compounds in which a sulfonamide group is introduced into a vinyl aromatic compound such as a styrene compound or a vinyl naphthalene compound, and more preferably include vinylbenzenesulfonamide, etc. The reactive compound that leads to functional groups containing sulfonamide groups may be an N-mono- or di-substituted sulfonamide compound, and examples of the substituent that substitutes the nitrogen atom of the sulfonamide group include R ＮＡ１ Alternatively, the reactive compound may be an end group bonded to the end of the amide bond, and an alkyl group is preferred. Examples of the reactive compound that can introduce a functional group containing an imide group include maleimide compounds and N-vinyl-substituted imide compounds, and preferred examples include maleimide, vinylphthalimide compounds, and vinylsuccinimide compounds.

[0041] (Polymer chain A containing at least one of an amide group, a sulfonamide group, and an imide group) １Ｐ) This polymer chain A １Ｐ Although (A-3) above may be a polymer chain comprising at least one of an amide group, a sulfonamide group, and an imide group, it is preferably a polymer chain (polymer chain) introduced into polymer (I) by reacting with a group that introduces a sulfur atom in formula (I) (e.g., a sulfanyl group). Such a polymer chain is not particularly limited, and a chain comprising a normal polymer can be used. For example, it is preferably a chain comprising a polymer having a polymer chain of a carbon-carbon double bond as the main chain. In the present invention, a polymer chain of a carbon-carbon double bond refers to a polymer chain formed by polymerization of a carbon-carbon double bond (ethylenically unsaturated group), and specifically refers to a polymer chain formed by polymerization (homopolymerization or copolymerization) of a monomer having a carbon-carbon unsaturated bond. Examples of polymers having a polymer chain of a carbon-carbon double bond as the main chain include chain-polymerized polymers such as hydrocarbon polymers, vinyl polymers, and (meth)acrylic polymers, with vinyl polymers and (meth)acrylic polymers being preferred. Here, the (meth)acrylic polymer may be a polymer made of a (co)polymer containing 50% by mass or more of a component derived from the above-mentioned (meth)acrylic compound (M1). The vinyl polymer may be a polymer made of a copolymer containing 50% by mass or more of a component derived from the above-mentioned vinyl-based compound (M2) (provided that the content of the component derived from the (meth)acrylic compound (M1) is less than 50% by mass). In addition to the above, examples of polymer chains containing imide groups include polymer chains obtained by homopolymerizing or copolymerizing maleimides such as polybismaleimide. However, A １ Possible polymer chains A １Ｐ It is preferable that the compound does not have a fluorine atom or a polysiloxane structure.

[0042] A １ Possible polymer chains A １ＰIn the above, the amide substituent may be present in the main chain or at the end of the main chain of the polymer chain, but is preferably present in the molecular chain that serves as the side chain. For example, it is more preferable that the amide substituent be incorporated into the interior or end of the molecular chain that serves as the side chain of the polymer chain. In the present invention, the molecular chain that serves as the side chain of the polymer chain refers to the molecular chain that constitutes the side chain of the polymer chain, and is the molecular chain that is bonded to the molecular chain (atomic group) that constitutes the main chain of the polymer chain. In addition, in the present invention, the main chain of the polymer and the polymer chain refers to a linear molecular chain in which all other molecular chains that constitute the polymer or polymer chain can be considered as branched chains or pendant groups relative to the main chain. Depending on the weight-average molecular weight of the branched chains considered as branched chains or pendant groups, typically, the longest chain among the molecular chains that constitute the polymer is the main chain. However, the terminal groups of the polymer are not included in the main chain. In contrast, the side chain of the polymer and the polymer chain refers to branched chains other than the main chain, including short chains and long chains (graft chains). The terminal groups of the polymer and polymer chain are not particularly limited and may be any appropriate group depending on the polymerization method, etc. Examples include a hydrogen atom, an alkyl group, an aryl group, a hydroxy group, and a residue of a polymerization initiator.

[0043] Polymer Chain A １Ｐ Examples of the polymer chain include a polymer chain having a component containing at least one amide substituent (hereinafter, sometimes referred to as an amide substituent-containing component). １Ｐ Among the amide substituent-containing components, it is preferable that the composition contains a component containing one of an amide group, a sulfonamide group, and an imide group, and it is more preferable that the composition contains a component containing an amide group in terms of the dispersion state of the solid particles and resistance. １Ｇ Examples of components include those derived from reactive compounds that lead to the above.

[0044] Polymer Chain A １Ｐ Examples of the functional group A include １Ｇ The polymer chain A is a chain made of a homopolymer or copolymer of a reactive compound that leads to the above-mentioned １ＰAmong chains consisting of homopolymers or copolymers of reactive compounds, polymer chains containing a component derived from at least one reactive compound selected from (meth)acrylic acid, a (meth)acrylic acid ester compound, a (meth)acrylamide compound, and a (meth)acrylonitrile compound are preferred (referred to as chains consisting of a (meth)acrylic polymer), polymer chains containing a component derived from at least one reactive compound selected from (meth)acrylic acid, a (meth)acrylic acid ester compound, and a (meth)acrylamide compound are more preferred, polymer chains containing a component derived from at least one reactive compound selected from a (meth)acrylic acid ester compound and a (meth)acrylamide compound are even more preferred, polymer chains containing a component derived from a (meth)acrylamide compound (also referred to as polymer chains of a (meth)acrylamide compound) are even more preferred, polymer chains consisting of a homopolymer of a (meth)acrylamide compound are particularly preferred, and polymer chains consisting of a homopolymer of an N-unsubstituted (meth)acrylamide compound are most preferred. Preferred examples of components derived from a (meth)acrylamide compound include the component represented by formula (A1) described below.

[0045] This polymer chain A １Ｐ may contain components other than the amide substituent-containing component (referred to as "other components"). The other components are not particularly limited as long as they do not have an amide group, a sulfonamide group, or an imide group, and examples thereof include components derived from a polymerizable compound copolymerizable with a reactive compound that leads to the amide substituent-containing component. Examples of other components include components derived from a low-molecular-weight polymerizable compound having an ethylenically unsaturated group. More specifically, components derived from each of the compounds listed above as the reactive compounds (before the amide substituent is introduced), and compounds obtained by introducing the functional group (a) described below into these compounds, etc. are included. Preferably, components derived from a reactive compound selected from a (meth)acrylic acid compound, a (meth)acrylic acid ester compound, and a (meth)acrylonitrile compound, and components derived from a compound obtained by introducing the functional group (a) described below into a (meth)acrylic acid ester compound, etc. are included. In the present invention, the polymer chain A１Ｐ When polymer chain A has a component derived from a (meth)acrylic acid ester compound, particularly a (meth)acrylic acid unsubstituted alkyl ester, the content of the component derived from the (meth)acrylic acid ester compound in the polymer chain is preferably 50% by mass or less, more preferably 25% by mass or less, and even more preferably 10% by mass or less. １Ｐ In one preferred embodiment, the composition does not contain any constituents derived from (meth)acrylic acid ester compounds.

[0046] Examples of the (meth)acrylic acid ester compound from which other components are derived 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. The number of carbon atoms in the alkyl group is usually preferably 1 to 12, more preferably 1 to 6. From the standpoint of solubility in the dispersion medium, etc., it is preferably 3 to 16, more preferably 6 to 14. 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, more preferably 6. The (meth)acrylic acid ester compound may have a substituent. The substituent is not particularly limited, but examples include the substituent Z described below (excluding groups contained in the functional group (a) described below). Preferred substituents include fluorine atoms.

[0047] Polymer Chain A １Ｐ When the polymer chain A contains other components, １Ｐ The primary structure (bonding pattern of the constituent components) of the polymer chain A is not particularly limited, and may be any of a random structure, a block structure, an alternating structure, a graft structure, etc., but a random structure or a block structure is preferred. １Ｐ The group bonded to the terminal of is not particularly limited, and as described above, an appropriate group can be selected depending on the polymerization method, etc.

[0048] Polymer Chain A １ＰWeight average molecular weight Mw １Ｐ is not particularly limited and is appropriately set in consideration of the weight average molecular weight of the polymer (I) described below, and is, for example, preferably 200 to 10,000, more preferably 400 to 3,000. １Ｐ The degree of polymerization of all the constituent components is not particularly limited, but is preferably 2 to 100, and more preferably 4 to 30.

[0049] Polymer Chain A １Ｐ The content of the amide-substituted component in the polymer chain A is not particularly limited, but is preferably 10% by mass or more, and from the viewpoint of the dispersion state of the solid particles and the resistance, is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more, and 100% by mass is also one preferred embodiment. １Ｐ When the polymer chain A contains other components, １Ｐ The upper limit of the content of the amide-substituted component in the polymer chain A can be determined appropriately, but can be, for example, 99% by mass or less. １Ｐ The content of the other constituent components in the polymer chain A is set within a range that does not impair the effects of the present invention, but from the viewpoint of dispersibility and binding property of the solid particles, the content is preferably 0 to 85% by mass, more preferably 0 to 80% by mass, further preferably 0 to 50% by mass, and particularly preferably 0 to 40% by mass. １Ｐ The content of the component (I) is appropriately determined in consideration of the total content of the other constituent components, and is, for example, preferably 0 to 70 mass %, more preferably 0 to 50 mass %, and even more preferably 2 to 40 mass %.

[0050] - Functional group A １Ｇ or polymer chain A １Ｐ A preferred form of -A １ Possible functional groups A １Ｇ or polymer chain A １Ｐ is preferably a functional group having a chemical structure represented by the following formula (A1), or a polymer chain having a constituent component represented by the following formula (A1): １ Possible functional groups A １Ｇis a functional group having a chemical structure represented by formula (A1), the group bonded to one of the bonding sites is preferably the terminal group of the amide substituent. １ Possible polymer chains A １Ｐ is a polymer chain having a component represented by formula (A1), the terminal groups of this polymer chain are as described above.

[0051] In the above formula (A1), X １ represents a hydrogen atom or a substituent. １ The substituent that can be adopted as X is not particularly limited, and examples thereof include groups selected from the substituent Z described below, among which an alkyl group is preferred. １ is preferably a hydrogen atom or a methyl group.

[0052] L １ represents a single bond or a linking group, and a single bond is preferred. １ The linking group that can be taken as the linking group L Ａ２ can be applied without any particular limitation. １ The linking group which can be taken as the linking group does not form a urethane group, a urea group or an imide group together with the amide group in formula (A1).

[0053] Y １ and Y ２ Each of Y represents a hydrogen atom or a substituent. １ and Y ２ The substituents that can be taken as R are not particularly limited, and one of the substituents can be the same as R ＮＡ１ The other substituent is the same as the terminal group of the amide substituent, and Y １ is preferably a hydrogen atom, and Y ２ is more preferably an alkyl group. １ and Y ２ The substituents that can be taken as Y do not form an imide group together with the amide group in formula (A1). １ and Y ２ may be the same or different. １ and Y ２ When both are alkyl groups, Y １ and Y２ The alkyl group that can be taken as R ＮＡ１ Alternatively, the alkyl group preferably has the same meaning as the alkyl group that can be used as the terminal group bonded to the terminal of the amide bond, and examples thereof include methyl, ethyl, normal propyl, isopropyl, normal butyl, tertiary butyl, a linear or branched octyl group, and a linear or branched dodecyl group. １ and Y ２ The combination of alkyl groups that can be taken as the alkyl group is not particularly limited, and the alkyl groups listed above can be combined appropriately.

[0054] The functional group or constituent represented by formula (A1) may have a substituent. For example, in formula (A1), X １ The carbon atom bonded to the carbon atom having the formula ２ Although the substituent is represented as "-", it may have a substituent. Such a substituent is not particularly limited, but for example, X １ Examples of the substituents that can be taken include the above.

[0055] In the present invention, A １ Possible functional groups A １Ｇ or polymer chain A １Ｐ It is preferable that A does not have a fluorine atom or a polysiloxane structure. １ Possible functional groups A １Ｇ or polymer chain A １Ｐ , for example, the terminal group of an amide substituent, Y １ and Y ２ may have a substituent, but preferably does not have a functional group (a) described below, and more preferably is unsubstituted.

[0056] A １ Possible functional groups A １Ｇ or polymer chain A １Ｐ Specific examples of the polymer include the specific examples of polymers shown below, the constituent components of the polymers synthesized in the Examples, and further, constituent components derived from acrylamide compounds, but the present invention is not limited to these.

[0057] (A in formula (I)２ In formula (I), A ２ is a functional group A containing at least one of a fluorine atom and a polysiloxane structure; ２Ｇ or polymer chain A ２Ｐ and preferably contains a functional group or a polymer chain containing a polysiloxane structure, and more preferably contains a polymer chain containing a polysiloxane structure. ２ When the binder of the present invention has the above structure, the amount of heat generated when the binder of the present invention is mixed with the inorganic solid electrolyte can be reduced, and further, adsorption of the active material and the like to the solid particles can be promoted, thereby suppressing deterioration of the solid particles. Furthermore, the surface energy of the polymer (I) is reduced, which can suppress excessive aggregation of the solid particles and improve the dispersion state of the solid particles. In the present invention, the functional group or polymer chain containing a fluorine atom or a polysiloxane structure includes both an embodiment in which the functional group or polymer chain is composed of a fluorine substituent or a polysiloxane structure substituted with a fluorine atom, and an embodiment in which the functional group or polymer chain is composed of a fluorine substituent or a polysiloxane structure and another partial structure.

[0058] In the present invention, A ２ The polysiloxane structure contained in is -(Si(R Ｓ ２ )-O)ns-. Ｓrepresents a hydrogen atom or a substituent, and the substituent is not particularly limited and includes those selected from the substituent Z described below. Examples thereof include a hydroxy group, an alkyl group (preferably having 1 to 12 carbon atoms, more preferably 1 to 6, and particularly preferably 1 to 3), an alkenyl group (preferably having 2 to 12 carbon atoms, more preferably 2 to 6, and particularly preferably 2 or 3), an alkoxy group (preferably having 1 to 24 carbon atoms, more preferably 1 to 12, even more preferably 1 to 6, and particularly preferably 1 to 3), an aryl group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14, and particularly preferably 6 to 10), an aryloxy group (preferably having 6 to 22 carbon atoms, more preferably 6 to 14, and particularly preferably 6 to 10), an aralkyl group (preferably having 7 to 23 carbon atoms, more preferably 7 to 15, and particularly preferably 7 to 11), an alkylsilyl group, an arylsilyl group, an alkoxysilyl group, and a group represented by the formula Z described below. Among these, an alkyl group having 1 to 3 carbon atoms, a phenyl group, or a group represented by the formula Z described below is more preferred, and an alkyl group having 1 to 3 carbon atoms is even more preferred. ns indicates the degree of polymerization (average repeat number) of the siloxane structure, and is appropriately determined taking into consideration the number average molecular weight of the polymer chain described below, and is preferably as described below. The polysiloxane structure has a terminal group bonded to its end. This terminal group is not particularly limited, and examples thereof include a hydrogen atom or a substituent. Examples of substituents that can be used as the terminal group include, for example, R Ｓ Examples of the substituents that can be taken include:

[0059] The polysiloxane structure is preferably a polysiloxane structure represented by the following formula 4A.

[0060] In formula 4A, R １５ and R １６ represents an alkyl group or an aryl group, and Z represents a group represented by the following formula (Z): １５ , R １６ and Z are R in Formula 4 described below. １５ , R １６and Z. In Formula 4A, x1, x2, and x3 are integers of 0 or more, and y1 is an integer of 1 to 30. x1, x2, x3, and y1 in Formula 4A are the same as x1, x2, x3, and y1 in Formula 4 described below, respectively.

[0061] A ２ The type of fluorine atom and polysiloxane structure contained therein may be at least one type, and preferably one or two types. ２ The number of fluorine atoms and polysiloxane structures contained therein is not particularly limited and is determined appropriately depending on the functional group or polymer chain. ２Ｇ or polymer chain A ２Ｐ Preferably, does not have an amide substituent.

[0062] (Functional group A containing at least one of a fluorine atom and a siloxane structure) ２Ｇ ) - functional group A containing a fluorine atom ２ＧＦ - A ２ A functional group A containing a fluorine atom that can be ２ＧＦ is not particularly limited, and may be a group substituted with a fluorine atom (sometimes referred to as a "fluorine substituent") and a linking group L which links to "S" (sulfur atom) in formula (I). Ａ３ It is preferable that the group contains

[0063] The fluorine substituent is not particularly limited, and examples thereof include groups in which a fluorine atom has been introduced into the substituent Z described below. A group in which a fluorine atom has been introduced into an alkyl group, an aryl group, or a heterocyclic group is preferred, and a fluoroalkyl group in which a fluorine atom has been introduced into an alkyl group is preferred. The fluoroalkyl group is a fluoroalkyl group in which at least one hydrogen atom in the alkyl group has been substituted with a fluorine atom, and the molecular structure may be linear, branched, or cyclic, with linear or branched being preferred. The number of carbon atoms in the fluoroalkyl group is not particularly limited, but is preferably 1 to 20, more preferably 1 to 12, and even more preferably 2 to 8. A preferred embodiment is that the lower limit of the number of carbon atoms is 3 or more, and when the fluoroalkyl group is linear, it is also preferred that the lower limit is 4 or more. In the fluoroalkyl group, some or all of the hydrogen atoms may be substituted with fluorine atoms. In the present invention, a fluoroalkyl group in which some of the hydrogen atoms have been substituted with fluorine atoms is preferred, and the linking group L Ａ３ A methylene group (-CH ２ A fluoroalkyl group containing - is more preferred, and the linking group L Ａ３ an ethylene group (-CH) in which none of the two or three consecutive carbon atoms, including the carbon atom bonded to ２ -CH ２ -) or propylene group (-CH ２ -CH ２ -CH ２ In such a fluoroalkyl group in which some of the hydrogen atoms are substituted with fluorine atoms, the remaining alkyl groups bonded to carbon atoms that are not substituted with fluorine atoms are preferably perfluoroalkyl groups in which all of the hydrogen atoms are substituted with fluorine atoms. The fluoroalkyl group may have a substituent other than a fluorine atom, and for example, ｆ The group may have a substituent (excluding a fluorine atom) that can be taken as follows:

[0064] Linking group L Ａ３ is not particularly limited, and examples thereof include a linking group L Ａ１However, the linking group L Ａ３ is more preferably an alkylene group, an alkenylene group, an arylene group, a carbonyl group, an oxygen atom, a sulfur atom, or an imino group, or a group relating to a combination thereof, and further preferably a group containing an alkylene group, and is preferably an alkylene group -CO-O- group, or a group containing an alkylene group and B of formula 4 described below. ２ A group in which an alkylene group and B of Formula 4 described below are combined is particularly preferred. ２ Examples of the group combining these groups include an alkylene group -CO-O-alkylene group. Ａ３ Preferably, the compound does not contain a fluorine atom or a polysiloxane structure.

[0065] Functional group A containing a fluorine atom ２ＧＦ is preferably a group derived from a low molecular weight compound, and A ２ The polymer chain A described later can be ２Ｐ It is more preferable that the functional group A ２ＧＦ Preferably, does not have an amide substituent.

[0066] A ２ A functional group A containing a fluorine atom that can be ２ＧＦ The compound from which the compound is derived is not particularly limited, and examples thereof include a compound which comprises a group reactive to a sulfanyl group, the above-mentioned fluorine substituent, and a linking group L Ａ４ (However, the reactive groups mentioned above are excluded.) Examples of the reactive group include a reactive compound having A １ A functional group A containing one amide substituent that can be １Ｇ The linking group L is the same as the reactive group in the compound from which Ａ４ is not particularly limited, and the linking group L Ａ３ Although each group described above can be used, a group containing a —CO—O— group is more preferred, and a —CO—O— group or B ２ The linking groups described in are particularly preferred.

[0067] Functional group A ２ＧＦThe reactive compound from which the formula (I) is derived is not particularly limited, but preferably includes a reactive compound having an ethylenically unsaturated bond, such as (meth)acrylic compounds (M1) such as (meth)acrylic acid compounds, (meth)acrylic acid ester compounds, (meth)acrylamide compounds, and (meth)acrylonitrile compounds; vinyl compounds (M2) such as vinyl aromatic compounds (e.g., styrene compounds, vinyl naphthalene compounds, and vinyl carbazole compounds), allyl compounds, vinyl ether compounds, vinyl ester compounds, cyclic olefin compounds, diene compounds, and vinyl carboxylic acid ester compounds; and reactive compounds in which the above-mentioned fluorine substituents have been introduced into compounds such as dialkyl itaconate compounds and unsaturated carboxylic acid anhydrides. Among these, reactive compounds in which the above-mentioned fluorine substituents have been introduced into (meth)acrylic acid compounds, (meth)acrylic acid ester compounds, and (meth)acrylamide compounds are preferred, and reactive compounds that lead to a constituent represented by the formula (3) described below are more preferred, with fluorine-substituted (meth)acrylic acid ester compounds being even more preferred.

[0068] - Functional group A containing a siloxane structure ２ＧＳ - A ２ Functional group A containing a polysiloxane structure that can be ２ＧＳ is not particularly limited, but may be the above-mentioned linking group L Ａ３ However, it is preferable that the linking group L bonded to the polysiloxane structure is a group containing Ａ３ Preferably, the compound does not contain a fluorine atom or a polysiloxane structure.

[0069] Functional group A containing a polysiloxane structure ２ＧＳ are the same except that in the functional group containing a fluorine atom, the fluorine substituent is replaced with a polysiloxane structure. ２ＧＳ is preferably a group derived from a low molecular weight compound, and A ２ The polymer chain A described later can be ２Ｐ It is more preferable that the functional group A ２ＧＳ Preferably, A does not have an amide substituent. ２Functional group A containing a polysiloxane structure that can be ２ＧＳ As a compound leading to A, except that the fluorine substituent is replaced with a siloxane structure, ２ A functional group A containing a fluorine atom that can be ２ＧＦ Specifically, the compound is the same as the compound that leads to a group having a structure represented by formula 4 described below.

[0070] (Polymer chain A containing at least one of a fluorine atom and a siloxane structure) ２Ｐ ) This polymer chain may be a polymer chain consisting of a fluorine substituent or a polysiloxane structure, but is preferably a polymer chain (polymer chain) introduced into the polymer (I) by reaction with a group (e.g., a sulfanyl group) that introduces a sulfur atom in formula (I). Such a polymer chain is not particularly limited, and a chain consisting of a normal polymer can be used. For example, the above-mentioned chain consisting of a polymer having a polymer chain of carbon-carbon double bonds as the main chain is preferred, and a chain consisting of a vinyl polymer or a (meth)acrylic polymer is more preferred. However, A ２ Possible polymer chains A ２Ｐ Preferably, does not have an amide substituent.

[0071] A ２ Possible polymer chains A ２Ｐ In the formula, the fluorine atom and the polysiloxane structure are polymer chain A ２Ｐ The polymer chain A may have the hydroxyl group in the main chain or at the end of the main chain, but it is preferably in a molecular chain that will become a side chain thereof, and more preferably, it is incorporated, for example, into the interior or end of a molecular chain that will become a side chain of the polymer chain. ２Ｐ Examples of the polymer chain include a polymer chain having a component containing at least one of a fluorine atom and a polysiloxane structure. ２ＰPreferably, the composition contains a component containing either a fluorine atom or a polysiloxane structure, and more preferably a component containing a polysiloxane structure. The component containing a fluorine atom is preferably a component containing the above-mentioned fluorine substituent. The component containing a polysiloxane structure is preferably a component containing the above-mentioned siloxane structure.

[0072] Polymer Chain A ２Ｐ Examples of the functional group A include ２Ｇ The polymer chain A is a chain made of a homopolymer or copolymer of a reactive compound that leads to the above-mentioned ２Ｐ Among chains consisting of homopolymers or copolymers of reactive compounds, a polymer chain containing a component derived from at least one reactive compound selected from the above-mentioned (meth)acrylic compounds (M1) (referred to as a chain consisting of a (meth)acrylic polymer) is preferred, a polymer chain containing a component derived from at least one reactive compound selected from (meth)acrylic acid and a (meth)acrylic acid ester compound is more preferred, and a polymer chain of a (meth)acrylic acid ester compound having a fluorine substituent or a polysiloxane structure is even more preferred. Preferred examples of the component derived from a (meth)acrylic acid ester compound having a fluorine substituent or a polysiloxane structure include the components represented by Formula 3 or Formula 4 described below.

[0073] This polymer chain may have components (referred to as "other components") other than the component containing at least one of a fluorine atom and a polysiloxane structure. The other components are not particularly limited as long as they do not have a fluorine atom or a polysiloxane structure, and are not particularly limited, for example, as long as they are derived from a polymerizable compound copolymerizable with a reactive compound that leads to a component containing at least one of a fluorine atom and a polysiloxane structure. Examples of other components include components derived from low-molecular polymerizable compounds having an ethylenically unsaturated group. More specifically, components derived from the compounds listed above as reactive compounds (before the introduction of the fluorine-containing substituent and the polysiloxane structure), and compounds obtained by introducing the functional group (a) described below into these compounds, etc. are included. Preferably, components derived from reactive compounds selected from (meth)acrylic acid compounds, (meth)acrylic acid ester compounds, (meth)acrylamide compounds, and (meth)acrylonitrile compounds, and components derived from compounds obtained by introducing the functional group (a) described below into (meth)acrylic acid ester compounds, etc. are included. The (meth)acrylic acid ester compounds include polymer chain A. １Ｐ This is as explained in the previous section.

[0074] Polymer Chain A ２Ｐ When the polymer chain A contains other components, ２Ｐ The primary structure (bonding pattern of the constituent components) of the polymer chain A is not particularly limited, and may be any of a random structure, a block structure, an alternating structure, a graft structure, etc., but a random structure or a block structure is preferred. ２Ｐ The group bonded to the terminal of is not particularly limited, and as described above, an appropriate group can be selected depending on the polymerization method, etc.

[0075] Polymer Chain A ２Ｐ Weight average molecular weight Mw ２Ｐ is not particularly limited and is appropriately set in consideration of the weight average molecular weight of the polymer (I) described later, and is, for example, preferably 100 to 30,000, more preferably 400 to 10,000. ２ＰThe degree of polymerization of all the constituent components in the polymer chain A is not particularly limited, but is preferably 1 to 200, and more preferably 1 to 50. ２Ｐ When is a polymer chain containing a polymer chain of a polysiloxane structure, the degree of polymerization of all structural units forming this polymer chain is not particularly limited, but is preferably 2 to 1,000, more preferably 2 to 200, and even more preferably 6 to 80. The number average molecular weight of the polymer chain is not particularly limited, but is preferably 400 or more, more preferably 800 or more, and even more preferably 2,000 or more. The upper limit is not particularly limited, but is preferably 500,000 or less, more preferably 100,000 or less, and especially preferably 30,000 or less. The number average molecular weight of the polymer chain can be measured as a number average molecular weight converted into standard polystyrene in the same manner as the weight average molecular weight of polymer (I).

[0076] Polymer Chain A ２Ｐ The content of the component containing at least one of a fluorine atom and a polysiloxane structure in the polymer chain A is not particularly limited, but is preferably 10% by mass or more, and from the viewpoint of the dispersion state of the solid particles and the resistance, is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 50% by mass or more, and 100% by mass is also one preferred embodiment. ２Ｐ The total content of the other constituent components is set within a range that does not impair the effects of the present invention, but is preferably 0 to 90% by mass, more preferably 0 to 70% by mass, and even more preferably 0 to 50% by mass, from the viewpoint of dispersibility and binding property of solid particles. ２Ｐ The content of the component (I) is appropriately determined taking into consideration the total content of the other constituent components, and is, for example, preferably 0 to 70 mass %, more preferably 0 to 50 mass %, and even more preferably 0 to 30 mass %.

[0077] - Functional group A ２Ｇ or polymer chain A ２Ｐ A preferred form of -A ２ A functional group A containing a fluorine atom that can be ２ＧＦor polymer chain A ２ＰＦ is preferably a functional group having a chemical structure represented by the following formula 3, or a polymer chain having a constituent component represented by the following formula 3: ２ A functional group A containing a fluorine atom that can be ２ＧＦ is a functional group having a chemical structure represented by formula 3, the group bonded to one of the bonding sites is preferably a terminal group of the fluorine substituent. ２ Possible polymer chains A ２ＰＦ is a polymer chain having a moiety represented by formula 3, the end groups of this polymer chain are as described above.

[0078] In formula 3, R １１ represents a hydrogen atom or methyl. １ represents a single bond or a linking group, and a linking group is preferred. １ The linking group that can be used as the linking group is not particularly limited, but the linking group L Ａ４ Among them, an ether group, a sulfide group, an imino group, a carbonyl group, or a linking group formed by combining two or more (preferably 2 to 5) of these groups is preferred, and a —CO—O— group is more preferred. １２ and R １３ R each represents a hydrogen atom, a hydroxy group, or an alkyl group having 1 to 4 carbon atoms (which may have a fluorine atom as a substituent, but preferably does not have a fluorine atom), and a hydrogen atom or a hydroxy group is preferred. １２ and R １３ may be the same or different. １４ represents a hydrogen atom or a fluorine atom. Ｆ１ and R Ｆ２ R represents a fluorine atom or a fluoroalkyl group having 1 to 4 carbon atoms. Ｆ１ and R Ｆ２ The fluoroalkyl group may have some of its hydrogen atoms substituted with fluorine atoms, but is preferably a perfluoroalkyl group. The number of carbon atoms in the fluoroalkyl group is preferably 1 or 2, and more preferably 1. Ｆ１ and R Ｆ２R is preferably a fluorine atom or trifluoromethyl, more preferably a fluorine atom. Ｆ１ and R Ｆ２ may be the same or different, but preferably both are fluorine atoms. a1 is not particularly limited as long as it is an integer of 0 or more, and is preferably an integer of 0 to 10, more preferably an integer of 1 to 5, and even more preferably an integer of 1 to 3. b1 is not particularly limited as long as it is an integer of 1 or more, and is preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and even more preferably an integer of 2 to 6. In Formula 3, the sum of a1 and b1 is not particularly limited as long as a1 and b1 are each within the above ranges, and is, for example, the same as the number of carbon atoms in the fluoroalkyl group as the fluorine substituent, and the preferred range is also the same. When a1 and b1 each take an integer of 2 or more, in Formula 3, a plurality of -C(R １２ ) (R １３ )-group, and —C(R Ｆ１ ) (R Ｆ２ )- groups may be the same or different.

[0079] Specific examples of the functional group or constituent component represented by the above formula 3 include the specific examples of the polymers shown later and those shown in the polymers synthesized in the examples shown later, but the present invention is not limited to these.

[0080] A ２ A containing a polysiloxane structure that can be ２ＧＳ or polymer chain A ２ＰＳ is preferably a functional group having a chemical structure represented by the following formula 4, or a polymer chain having a constituent component represented by the following formula 4: ２ Functional group A containing a polysiloxane structure that can be ２ＧＳ is a group having a chemical structure represented by formula 4, the group bonded to one of the bonding sites is preferably a terminal group of the fluorine substituent. ２ Possible polymer chains A ２ＰＳ is a polymer chain having a moiety represented by formula 4, the end groups of this polymer chain are as described above.

[0081] In formula 4, R １１ represents a hydrogen atom or methyl. ２ represents a linking group. ２ The linking group that can be used as the linking group is not particularly limited, but the linking group L Ａ１ Among them, B ２ The linking group as R is preferably an alkylene group, an alkenylene group, an arylene group, an oxygen atom, a sulfur atom, a carbonyl group, or a group relating to a combination thereof, more preferably a group containing a —CO—O— group, and even more preferably a —CO—O— group or a —CO—O-alkylene group. １５ represents an alkyl group or an aryl group, and an alkyl group is preferable. １５ The alkyl group and aryl group that can be taken as R in the polysiloxane structure are respectively Ｓ The alkyl and aryl groups that can be taken as R are the same as those that can be taken as R, and the preferred groups are also the same. １５ Methyl is particularly preferred. Two R's bonded to the same silicon atom １５ may be the same or different, but preferably all are methyl. １６ represents an alkyl group or an aryl group, and an alkyl group is preferred. １６ may be the same or different. １６ The alkyl group and aryl group that can be taken as R in the polysiloxane structure are respectively Ｓ The alkyl and aryl groups that can be taken as R are the same as those that can be taken as R, and the preferred groups are also the same. １６ Particularly preferably, R is methyl. １６Ａ represents a hydrogen atom or a substituent. １６Ａ The substituents that can be taken as R are not particularly limited, and examples thereof include the substituent Z described below. Ｓ The substituents that can be represented by R are preferred. １６Ａ The substituents which can be taken as the aryl group are preferably an alkyl group, an alkenyl group, an aralkyl group, an aryl group, an alkoxy group, or an aryloxy group, and more preferably an alkyl group.

[0082] Z represents a group represented by the following formula (Z).

[0083]

[0084] In formula (Z), R １７ and R １８ R represents an alkyl group or an aryl group. １７ and R １８ The alkyl group and aryl group that can be taken as R in the polysiloxane structure are respectively Ｓ The alkyl and aryl groups that can be taken as R are the same as those that can be taken as R, and the preferred groups are also the same. １７ and R １８ may be the same or different. １９ represents an unsubstituted alkyl group having 1 to 4 carbon atoms. y2 represents an integer of 1 to 100, preferably an integer of 1 to 50, and more preferably an integer of 1 to 20.

[0085] In the constituents represented by Formula 4, x1, x2, x3, y1, and y2 are appropriately determined, and the sum (degree of polymerization) of x1, x2, x3, y1, and y2 is the same as the degree of polymerization in the polymer chain of the polysiloxane structure described above. In particular, it is preferable that the value of (x1 + x2 + x3) × y1 is the same as the degree of polymerization in the polymer chain of the polysiloxane structure described above. In Formula 4, x1, x2, and x3 are each an integer of 0 or greater. x1 is preferably an integer of 0 to 50, more preferably an integer of 0 to 20. x2 is preferably an integer of 0 to 50, more preferably an integer of 0 to 20. x3 is preferably an integer of 1 to 100, more preferably an integer of 1 to 30. The sum of x1, x2, and x3 is an integer of 1 to 100, preferably an integer of 2 to 70, and more preferably an integer of 2 to 50. When x1 and x3 each represent an integer of 2 or more, in Formula 4, two Z or R groups bonded to the same silicon atom １５ may be the same or different. y1 is an integer of 1 to 30, preferably an integer of 1 to 20, and more preferably an integer of 1 to 10. With regard to x1, x2, x3, y1, and y2, it is preferable that x1, x2, and y2 are 0, x3 is an integer of 1 to 100, and y1 is an integer of 1 to 30.

[0086] Specific examples of the functional group or constituent component represented by the above formula 4 include, for example, terminally (meth)acrylic-modified silicone compounds, specifically, those shown in the specific examples of polymers shown later or in the polymers synthesized in the examples shown later, but the present invention is not limited to these.

[0087] In the polymer represented by formula (I), A １ and A ２ The combination of A is not particularly limited. １ Possible functional groups A １Ｇ Or polymer chain A １Ｐ And, A ２ Possible functional groups A ２Ｇ Or polymer chain A ２Ｐ can be combined appropriately. １ and A ２ As a combination of １ Suitable functional groups A that can be １Ｐ Or polymer chain A １Ｐ And, A ２ Suitable functional groups A that can be ２Ｇ Or polymer chain A ２Ｐ A is preferably used in combination with １ Suitable polymer chains A may be １Ｐ And, A ２ Suitable polymer chains A may be ２Ｐ More preferred is a combination of, for example, the combination in the polymer shown in the Examples.

[0088] The polymer (I) may have a substituent. The substituent that may be had is not particularly limited, but includes the substituent Z described below. Of the substituents (a) below, groups other than acidic groups are preferred in terms of adsorption to solid particles, etc. In the present invention, the polymer (I) may have an acidic group among the substituents (a) below, as long as the acid value satisfies 3 mgKOH / g or less. However, in terms of being able to keep the acid value low and further in terms of the dispersion state and resistance of the solid particles, it is also a preferred embodiment that the polymer (I) does not have an acidic group among the substituents (a) below. In terms of being able to keep the acid value low and the base value low, it is also a more preferred embodiment that the polymer (I) does not have any of the substituents (a) below. - Substituent (a) - Acidic group, group having a basic nitrogen atom, urea group, urethane group, alkoxysilyl group, epoxy group, isocyanate group, and hydroxyl group

[0089] The acidic group is not particularly limited, and examples thereof include a carboxylic acid group (carboxy group), a sulfonic acid group (sulfo group), a phosphoric acid group (also called a phospho group or a phosphoryl group), a phosphonic acid group, and a phosphinic acid group (phosphinyl group). The sulfonic acid group, phosphoric acid group, phosphonic acid group, etc. are not particularly limited, and are synonymous with the corresponding groups of the substituent Z described below. Note that groups that can form salts, such as acidic groups, may form salts. Examples of salts include various metal salts, ammonium or amine salts, etc. Examples of groups having a basic nitrogen atom include an amino group, a pyridyl group, an imino group, and an amidine. The amino group is synonymous with the amino group of the substituent Z described below.

[0090] Examples of the urea group include —NR Ａ１ CONR Ａ２ R Ａ３ (where R Ａ１ , R Ａ２ and R Ａ３ represents a hydrogen atom or an alkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms. Ａ１ CONHR Ａ３ (where R Ａ１ and R Ａ３represents a hydrogen atom or an alkyl group, aryl group or aralkyl group having 1 to 10 carbon atoms. Ａ３ (where R Ａ３ represents a hydrogen atom or an alkyl group, an aryl group, or an aralkyl group having 1 to 10 carbon atoms.) is particularly preferred. Examples of the urethane group include -NHCOR Ａ４ , -NR Ａ５ COOR Ａ６ , -OCONHR Ａ７ , -OCONR Ａ８ R Ａ９ (where R Ａ４ , R Ａ５ , R Ａ６ , R Ａ７ , R Ａ８ and R Ａ８ represents an alkyl group, an aryl group, or an aralkyl group having 1 to 20 carbon atoms. Preferred examples include groups containing at least an imino group and a carbonyl group, such as —NHCOOR Ａ４ , -OCONHR Ａ７ (where R Ａ４ , R Ａ７ represents an alkyl group, an aryl group, or an aralkyl group having 1 to 20 carbon atoms. Ａ４ , -OCONHR Ａ７ (where R Ａ４ , R Ａ７ represents an alkyl group, an aryl group, or an aralkyl group having 1 to 10 carbon atoms. Ａ１ ~R Ａ８ The number of carbon atoms of the aryl group that can be taken as R is preferably 6 or more and 24 or less. Ａ１ ~R Ａ８ The aralkyl group which can be taken as the aryl group preferably has 7 or more carbon atoms, preferably 23 or less, and more preferably 10 or less carbon atoms.

[0091] The alkoxysilyl group is not particularly limited, and examples thereof include mono-, di-, or trialkoxysilyl groups, preferably alkoxysilyl groups having 1 to 20 carbon atoms, more preferably alkoxysilyl groups having 1 to 6 carbon atoms. Examples thereof include methoxysilyl, ethoxysilyl, t-butoxysilyl, cyclohexylsilyl, dimethoxysilyl, trimethoxysilyl, and triethoxysilyl.

[0092] - Substituent Z - An alkyl group (preferably an alkyl group having 1 to 20 carbon atoms, for example, methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl, etc.), an alkenyl group (preferably an alkenyl group having 2 to 20 carbon atoms, for example, vinyl, allyl, oleyl, etc.), an alkynyl group (preferably an alkynyl group having 2 to 20 carbon atoms, for example, ethynyl, butadiynyl, phenylethynyl, etc.), a cycloalkyl group (preferably a cycloalkyl group having 3 to 20 carbon atoms, for example, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, etc.), In the present invention, alkyl groups usually include cycloalkyl groups, 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 5- or 6-membered heterocyclic groups 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 (a group in which an -O- group is bonded to the above heterocyclic group), an alkoxycarbonyl group (preferably or an alkoxycarbonyl group having 2 to 20 carbon atoms, for example, ethoxycarbonyl, 2-ethylhexyloxycarbonyl, dodecyloxycarbonyl, etc.), an aryloxycarbonyl group (preferably an aryloxycarbonyl group having 7 to 26 carbon atoms, for example, phenoxycarbonyl, 1-naphthyloxycarbonyl, 3-methylphenoxycarbonyl, 4-methoxyphenoxycarbonyl, etc.), a heterocyclic oxycarbonyl group (a group in which an —O—CO— group is bonded to the above heterocyclic group), an amino group (preferably an amino group having 0 to 20 carbon atoms, an alkylamino group, or an arylamino group, for example, amino(—NH ２), N,N-dimethylamino, N,N-diethylamino, N-ethylamino, anilino, etc.), sulfamoyl group (preferably a sulfamoyl group having 0 to 20 carbon atoms, for example, N,N-dimethylsulfamoyl, N-phenylsulfamoyl, etc.), 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, for example, acetyl, propionyl, butyryl, octanoyl, hexadecanoyl, acryloyl, methacryloyl, crotonoyl, benzoyl, naphthoyl, nicotinoyl, etc.), acyl Oxy 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, and nicotinoyloxy), aryloyloxy groups (preferably aryloyloxy groups having 7 to 23 carbon atoms, for example, benzoyloxy and naphthoyloxy), 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 an arylsulfonyl group having 6 to 22 carbon atoms, for example, benzenesulfonyl; an alkylsilyl group (preferably an alkylsilyl group having 1 to 20 carbon atoms, for example, monomethylsilyl, dimethylsilyl, trimethylsilyl, triethylsilyl; an arylsilyl group (preferably an arylsilyl group having 6 to 42 carbon atoms, for example, triphenylsilyl; an alkoxysilyl group (preferably an alkoxysilyl group having 1 to 20 carbon atoms, for example, monomethoxysilyl, dimethoxysilyl, trimethoxysilyl, triethoxysilyl; an aryloxysilyl group having 6 to 42 carbon atoms, for example, triphenyloxysilyl; an aryloxysilyl group having 6 to 42 carbon atoms, for example, triphenyloxysilyl; a phosphoryl group (preferably a phosphoric acid group having 0 to 20 carbon atoms, for example, -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 (for example, fluorine atom, chlorine atom, bromine atom, iodine atom, etc.). Ｐis a hydrogen atom or a substituent (preferably a group selected from the substituent Z). Each of the groups listed as the substituent Z may be further substituted with the substituent Z. The alkyl group, alkylene group, alkenyl group, alkenylene group, alkynyl group and / or alkynylene group may be cyclic or chain-like, and may be linear or branched.

[0093] (m and n in formula (I)) In the above formula (I), m is A ２ n represents the number of -S- groups, and is an integer of 1 to 9, preferably an integer of 2 to 5, and more preferably an integer of 3 to 5. １ represents the number of -S- groups, and is an integer of 1 to 8, preferably an integer of 1 to 4, more preferably an integer of 1 to 3, and even more preferably 1 or 2. １ When the compound (A-1) has two or three of the above (A-1) to (A-3), the number of (A-1)-S- groups (HS- groups), (A-2)-S- groups, and (A-3)-S- groups is not particularly limited as long as it satisfies the possible values ​​for n, and can be determined appropriately. For example, the number of (A-1)-S- groups and each of the (A-3)-S- groups can be the same as n1 and n2 in formula (IA) described below. However, m+n is an integer of 2 to 10, preferably an integer of 3 to 8, more preferably an integer of 3 to 6, and even more preferably an integer of 4 to 6.

[0094] R in polymer (I) １ The content of A in polymer (I) is not particularly limited, but can be 1 to 90% by mass in total with "S" in polymer (I), and from the viewpoint of the dispersion state of the solid particles and the resistance, it is preferably 2 to 60% by mass, more preferably 3 to 40% by mass, and even more preferably 5 to 30% by mass. １The total content of is not particularly limited, but can be 1 to 90% by mass. The lower limit of the total content is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, from the viewpoint of the dispersion state of the solid particles and the resistance. The upper limit of the total content is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, from the viewpoint of the dispersion state of the solid particles and the resistance. Here, A １ is a hydrogen atom of (A-1) above, taking into consideration the weight average molecular weight of polymer (I), this A １ Since the content of "A" is small, １ In other words, it will not be included in the total content of "A １ The total content of "A １ When A is (A-2) or (A-3) １ In the present invention, A has the same meaning as the total content in the polymer (I). １ is a hydrogen atom in (A-1) above, １ The total content of these in the polymer (I) is not particularly limited, but is a small value, and is therefore specified by, for example, n in formula (I) or n2 in formula (IA).

[0095] A in polymer (I) ２ The total content of A is not particularly limited, but can be 1 to 98% by mass, and from the viewpoint of the dispersion state of the solid particles and the resistance, it is preferably 10 to 90% by mass, more preferably 20 to 80% by mass, and even more preferably 30 to 70% by mass. １ A relative to the total content of ２ The ratio of the total content [A ２ Total content of / A １ [total content of] is not particularly limited and can be, for example, 0.01 to 99, and from the viewpoint of the dispersion state and resistance of the solid particles, it is preferably 0.1 to 80, more preferably 1 to 50, even more preferably 2 to 30, and particularly preferably 5 to 20.

[0096] In one preferred embodiment, the polymer represented by formula (I) is a polymer represented by the following formula (IA):

[0097] In formula (IA), R １ is a (m+n1+n2)-valent linking group, and the R １ In formula (IA), A １１ represents a functional group or a polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group, and A in formula (I) １ It is the same as (A-2) or (A-3) above. １１ In terms of inhibiting deterioration of the solid particles, A preferably contains a polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group, and more preferably contains a polymer chain containing an amide group. １２ represents a hydrogen atom. ２ represents a functional group or a polymer chain containing at least one of a fluorine atom and a polysiloxane structure, and A in formula (I) ２ In formula (IA), m is the same as A ２ n1 represents the number of -S- groups and is the same as m in formula (I). １１ n2 represents the number of -S- groups, and is an integer of 0 to 8, with the upper limit being any integer from 2 to 4 and the lower limit being any integer from 0 to 2. １２ It represents the number of -S- groups and is an integer from 0 to 8, with the upper limit being any integer from 2 to 4 and the lower limit being 1 or 2. However, the total number of n1 and n2 (n1+n2) is an integer from 1 to 8 and is the same as n in formula (I). Furthermore, the total number of m, n1, and n2 (m+n1+n2) is an integer from 2 to 10 and is the same as m+n in formula (I).

[0098] Specific examples of the polymer represented by formula (I) or formula (IA) include the specific examples of polymers shown below and polymers synthesized in the examples described below, but the present invention is not limited thereto. In the following polymers, TMS represents a trimethylsilyl group, and X１ is a linking group, and X ２ is a substituent. In the following chemical formula, A １ (including SH) and A ２ The overall structure of each polymer is shown by specifying the bonding position of A １ and A ２ As long as the numbers (n and m) are the same, １ and A ２ The bonding position of A is not limited to the position specified by the following chemical formula. １ Both of the two molecules show a chemical structure in which the central oxygen atom is bonded to the left structural part. １ may be bonded to the right structural portion relative to the central oxygen atom.

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] Polymer (I) (including the polymer represented by formula (IA), which is one of the preferred embodiments of the present invention) may be a commercially available product or a synthetic product. Polymer (I) may be synthesized by selecting raw material compounds according to a known method. For example, surfactants, emulsifiers or dispersants, A １ (above (A-2) or (A-3)) and a reactive compound capable of forming A ２ and further, a copolymerizable compound, etc., are used to form R １Polymer (I) can be synthesized by addition reaction with a polyvalent thiol compound corresponding to the following formula (IA): Specifically, polymer (I) can be synthesized by the method described in Patent Document 2, or by the method described in the Examples below. Among the polymers represented by formula (IA), polymers in which n2 is an integer of 1 or more can be synthesized by addition reaction with a polyvalent thiol compound corresponding to the following formula (IA): １ and a polyvalent thiol compound corresponding to A ２ and a reactive compound capable of forming the compound A in a ratio satisfying m in formula (IA), and １ and a reactive compound capable of forming the above (A-2) or (A-3) in a ratio that satisfies n1 in formula (IA). Here, among the polymers represented by formula (IA), polymers in which n1 is 0 can be synthesized by the above synthesis method using R １ and a polyvalent thiol compound corresponding to A ２ and a reactive compound capable of forming the above in a ratio that satisfies m in formula (IA), and can be synthesized as a synthetic intermediate in the method for synthesizing polymer (I) described in the examples below.

[0107] The method for incorporating a functional group such as the substituent (a) is not particularly limited, and examples thereof include a method of copolymerizing a compound having a functional group, a method using a polymerization initiator or chain transfer agent having (generating) a functional group, a method utilizing a polymer reaction, an ene reaction to a double bond, an ene-thiol reaction, or an ATRP (Atom Transfer Radical Polymerization) polymerization method using a copper catalyst. Alternatively, a functional group can be introduced by using a functional group present in the main chain, side chain, or terminal of a polymer as a reaction point. For example, a functional group can be introduced by using a compound having a functional group to carry out various reactions with a dicarboxylic acid anhydride group in a polymer chain.

[0108] Physical Properties or Characteristics of Polymer (I) or the Binder of the Present Invention: Polymer (I) has an acid value of 3 mgKOH / g or less. It is believed that an acid value of 3 mgKOH / g or less can suppress excessive aggregation and precipitation of the binder and solid particles, as described above. From the viewpoint of the dispersion state of the solid particles, the acid value of polymer (I) is preferably 2 mgKOH / g or less, more preferably 1 mgKOH / g or less, and even more preferably 0.5 mgKOH / g or less. The lower limit of the acid value of polymer (I) is preferably 0 mgKOH / g. The acid value of polymer (I) indicates the number of milligrams of potassium hydroxide required to neutralize the acidic groups present in 1 g of polymer (I) and can be measured by the following method. The acidic group is not particularly limited as long as it can be neutralized with potassium hydroxide, and examples thereof include a carboxylic acid group (carboxy group), a sulfonic acid group (sulfo group), a phosphoric acid group (phospho group), a phosphonic acid group, a phosphinic acid group, or salts thereof. (Measuring Method) 1 g of polymer (I) is dissolved in 25 g of tetrahydrofuran, and the solution is titrated with a 0.01 N-KOH solution using a potentiometric titrator to determine the content.

[0109] The polymer (I) or the binder of the present invention preferably has the following physical properties or characteristics. The polymer (I) preferably has a base number of 2 mgKOH / g or less. A base number of 2 mgKOH / g or less is thought to be able to suppress excessive aggregation and precipitation of the binder and solid particles. In terms of the dispersion state of the solid particles, the base number of the polymer (I) is more preferably 1 mgKOH / g or less, and even more preferably 0.5 mgKOH / g or less. The lower limit of the base number of the polymer (I) is preferably 0 mgKOH / g. The base number of the polymer (I) is expressed as the number of milligrams of potassium hydroxide equivalent to the number of moles of acid required to neutralize the basic groups present in 1 g of the polymer (I), and can be measured by the following method. The basic group is not particularly limited as long as it can be neutralized with HCl, and examples thereof include groups having a basic nitrogen atom, preferably groups having a basic nitrogen atom bonded to a hydrogen atom, and specific examples include amino groups, pyridyl groups, imino groups, amidine groups, and the above-mentioned urea or urethane groups having a hydrogen atom bonded to a nitrogen atom. (Measurement Method) 1 g of polymer (I) is dissolved in 25 g of tetrahydrofuran, and the solution is titrated with a 1N-HCl solution using a potentiometric titrator, and the number of moles of HCl required for neutralization can be calculated by converting it into milligrams of potassium hydroxide.

[0110] The acid value and base value of the polymer (I) may be within the above ranges, but it is more preferable that the acid value is 0.5 mgKOH / g or less and the base value is 0.5 mgKOH / g or less.

[0111] The weight-average molecular weight of the polymer (I) is not particularly limited. For example, it is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 7,000 or more. The upper limit is essentially 100,000 or less, but is preferably 50,000 or less, and from the viewpoint of the dispersion state and resistance of the solid particles, is more preferably 30,000 or less. The weight-average molecular weight of the dispersant polymer can be appropriately adjusted by changing the type, content, polymerization time, polymerization temperature, etc. of the polymerization initiator.

[0112] - Molecular Weight Measurement - In the present invention, unless otherwise specified, the molecular weight of a polymer or polymer chain refers to a weight-average molecular weight or number-average molecular weight measured by gel permeation chromatography (GPC) in terms of standard polystyrene. Examples of the measurement method include a method set under the following condition 1 or condition 2 (priority). However, depending on the type of polymer or polymer chain, an appropriate eluent may be selected and used. (Condition 1) Column: Two TOSOH TSKgel Super AWM-H (trade name, manufactured by Tosoh Corporation) connected together Carrier: 10 mM LiBr / N-methylpyrrolidone Measurement temperature: 40°C Carrier flow rate: 1.0 ml / min Sample concentration: 0.1 mass% Detector: RI (refractive index) detector (Condition 2) Column: A column connected together with TOSOH TSKgel Super HZM-H, TOSOH TSKgel Super HZ4000, and TOSOH TSKgel Super HZ2000 (all trade names, manufactured by Tosoh Corporation) is used. Carrier: Tetrahydrofuran Measurement temperature: 40°C Carrier flow rate: 1.0 ml / min Sample concentration: 0.1 mass% Detector: RI (refractive index) detector

[0113] The polymer (I) may be a non-crosslinked polymer or a crosslinked polymer. When crosslinking of the polymer (I) progresses due to heating or application of voltage, the molecular weight may be larger than the above-mentioned molecular weight. Preferably, the polymer (I) has a weight-average molecular weight within the above-mentioned range at the start of use of the all-solid-state secondary battery.

[0114] The polymer (I) is preferably amorphous. In the present invention, the term "amorphous" typically means that an endothermic peak due to crystalline melting is not observed when measured at the glass transition temperature. The water concentration of the polymer (I) is preferably 100 ppm (by mass) or less. The polymer (I) may be crystallized and dried, or the polymer dispersion may be used as is.

[0115] [Inorganic Solid Electrolyte-Containing Composition] The inorganic solid electrolyte-containing composition of the present invention contains the above-mentioned polymer (I) of the present invention, an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and a dispersion medium. The inorganic solid electrolyte-containing composition of the present invention has an excellent dispersion state of the inorganic solid electrolyte, and by using it as a material for forming a constituent layer of an all-solid-state secondary battery, it is possible to realize a sheet for an all-solid-state secondary battery having a constituent layer with low resistance, and an all-solid-state secondary battery with low resistance (high conductivity). Therefore, the inorganic solid electrolyte-containing composition of the present invention can be preferably used as a material for forming a solid electrolyte layer or an active material layer of a sheet for an all-solid-state secondary battery (including an electrode sheet for an all-solid-state secondary battery) or an all-solid-state secondary battery.

[0116] The binder of the present invention may be dispersed in a particulate form without exhibiting the property of dissolving (solubility) in the dispersion medium contained in the inorganic solid electrolyte-containing composition, but preferably exhibits solubility. That is, the binder of the present invention in the inorganic solid electrolyte-containing composition is preferably present in a dissolved state in the dispersion medium in the inorganic solid electrolyte-containing composition, depending on its content. When the binder of the present invention is dissolved, it stably exhibits the function of dispersing solid particles in the dispersion medium, thereby further improving the dispersion state of the solid particles in the inorganic solid electrolyte-containing composition. In the present invention, "the binder of the present invention being dissolved in the dispersion medium" is not limited to an embodiment in which all of the binder of the present invention is dissolved in the dispersion medium. For example, as long as the solubility in the dispersion medium is 80% or more, a portion of the binder of the present invention may be present in an insoluble state in the inorganic solid electrolyte-containing composition. The solubility is measured as follows. That is, a specified amount of the binder of the present invention to be measured is weighed into a glass bottle, 100 g of the same type of dispersion medium as the dispersion medium contained in the inorganic solid electrolyte-containing composition is added thereto, and the mixture is stirred for 24 hours at a rotation speed of 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-mentioned 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-mentioned dispersion medium. <Transmittance Measurement Conditions> Dynamic Light Scattering (DLS) Measurement Apparatus: DLS Measurement Apparatus DLS-8000 manufactured by Otsuka Electronics Laser Wavelength, Output: 488 nm / 100 mW Sample Cell: NMR Tube

[0117] When the binder of the present invention is particulate (insoluble in the dispersion medium contained in the inorganic solid electrolyte-containing composition), its shape is not particularly limited and may be flat, amorphous, etc., but is preferably spherical or granular. In this case, the average particle diameter of the particulate binder of the present invention 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 average particle diameter of the binder of the present invention can be measured in the same manner as the particle diameter of the inorganic solid electrolyte. The average particle diameter of the binder of the present invention can be adjusted, for example, by the type of dispersion medium, the composition of the polymer contained in the binder of the present invention, etc.

[0118] In the present invention, the solubility of the binder of the present invention in a dispersion medium can be appropriately imparted by the structure, composition (type and content of constituent components), weight average molecular weight, and further combination with the dispersion medium of the polymer (I) contained in the binder.

[0119] The inorganic solid electrolyte-containing composition of the present invention is preferably a slurry in which the inorganic solid electrolyte is dispersed in a dispersion medium. Furthermore, 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 is specifically a value measured by filtering through a 0.02 μm membrane filter and using Karl Fischer titration.

[0120] The inorganic solid electrolyte-containing composition of the present invention also includes an embodiment containing an active material and a conductive additive in addition to the inorganic solid electrolyte (the composition of this embodiment is referred to as an electrode composition). Hereinafter, the components contained in the inorganic solid electrolyte-containing composition of the present invention and the components that can be contained therein will be described.

[0121] <Binder> The binder contained in the inorganic solid electrolyte-containing composition of the present invention includes the binder of the present invention described above. The binder of the present invention contained in the inorganic solid electrolyte-containing composition of the present invention may be one type or two or more types. The content (solid content equivalent) of the binder of the present invention in the inorganic solid electrolyte-containing composition is not particularly limited, but is preferably 0.1 to 5.0 mass% in terms of the dispersion state of the solid particles and the resistance, more preferably 0.2 to 4.0 mass%, and even more preferably 0.3 to 2.0 mass%. Furthermore, for the same reasons, the content (solid content equivalent) of the polymer binder in 100 mass% 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%. In the present invention, at 100% by mass of solid content, the mass ratio of the total mass (total amount) of the inorganic solid electrolyte and the active material to the mass of the binder of the present invention [(mass of inorganic solid electrolyte + mass of active material) / (total mass of the binder of the present invention)] 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.

[0122] <Inorganic Solid Electrolyte> The inorganic solid electrolyte-containing composition of the present invention contains an inorganic solid electrolyte. In the present invention, the inorganic solid electrolyte refers to an inorganic solid electrolyte, and the solid electrolyte refers to a solid electrolyte capable of moving ions therein. Since it does not contain an organic substance as the main ion-conducting material, it is clearly distinguished from organic solid electrolytes (polymer electrolytes typified by polyethylene oxide (PEO) and the like, and organic electrolyte salts typified by lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and the like). In addition, since inorganic solid electrolytes are solid in a steady state, they are not usually dissociated or liberated into cations and anions. In this respect, inorganic electrolyte salts (LiPF ) that are dissociated or liberated into cations and anions in an electrolytic solution or a polymer are not easily dissociated or liberated into cations and anions. ６ , LiBF ４ , lithium bis(fluorosulfonyl)imide (LiFSI), LiCl, etc.). The inorganic solid electrolyte is not particularly limited as long as it has ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and 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 of lithium ions. The inorganic solid electrolyte can be appropriately selected from solid electrolyte materials commonly 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. The binder of the present invention can suppress deterioration and decomposition of the inorganic solid electrolyte during preparation of the inorganic solid electrolyte-containing composition, allowing the use of sulfide-based inorganic solid electrolytes, which are generally prone to deterioration and decomposition, and forming a better interface between the active material and the inorganic solid electrolyte, effectively suppressing an increase in interfacial resistance.

[0123] (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.

[0124] Examples of sulfide-based inorganic solid electrolytes include lithium ion conductive inorganic solid electrolytes having a composition represented by the following formula (S1): ａ１ M ｂ１ P ｃ１ S ｄ１ A ｅ１ (S1) In formula (S1), 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 of 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.

[0125] 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.

[0126] The sulfide-based inorganic solid electrolyte may be amorphous (glass) or crystallized (glass-ceramic), or may be only partially crystallized. For example, Li-P-S-based glass containing Li, P, and S, or Li-P-S-based glass-ceramic containing Li, P, and S can be used. The sulfide-based inorganic solid electrolyte may be, for example, lithium sulfide (Li ２ S), phosphorus sulfide (e.g., diphosphorus pentasulfide (P ２ S ５)), elemental phosphorus, elemental sulfur, sodium sulfide, hydrogen sulfide, lithium halides (e.g., LiI, LiBr, LiCl), and sulfides of the elements represented by M (e.g., SiS ２ , SnS, GeS ２ ) can be produced by reacting at least two or more raw materials.

[0127] Li in Li-P-S glass and Li-P-S glass ceramics ２ S and P ２ S ５ The ratio of Li ２ S:P ２ S ５ The molar ratio of Li is preferably 60:40 to 90:10, more preferably 68:32 to 78:22. ２ S and P ２ S ５ By setting the ratio to this range, the lithium ion conductivity can be made high. Specifically, the lithium ion conductivity is preferably set to 1×10 －４ S / cm or more, more preferably 1×10 －３ There is no particular upper limit, but it can be 1 × 10 －１ It is practical to have a viscosity of 200 S / cm or less.

[0128] As a specific example of a sulfide-based inorganic solid electrolyte, a combination of raw materials is shown below. For example, Li ２ S-P ２ S ５ , Li ２ S-P ２ S ５ -LiCl, Li ２ S-P ２ S ５ -H ２ S., Li. ２ S-P ２ S ５ -H ２ S-LiCl, Li ２ S-LiI-P ２ S ５ , Li ２ S-LiI-Li ２ O-P ２ S ５ , Li ２ S-LiBr-P２ S ５ 、Li ２ S-Li ２ O-P ２ S ５ 、Li ２ S-Li ３ PO ４ -P ２ S ５ 、Li ２ S-P ２ S ５ -P ２ O ５ 、Li ２ S-P ２ S ５ -SiS ２ 、Li ２ S-P ２ S ５ -SiS ２ -LiCl、Li ２ S-P ２ S ５ -SnS、Li ２ S-P ２ S ５ -Al ２ S ３ 、Li ２ S-GeS ２ 、Li ２ S-GeS ２ -ZnS、Li ２ S-Ga ２ S ３ 、Li ２ S-GeS ２ -Ga ２ S ３ 、Li ２ S-GeS ２ -P ２ S ５ 、Li ２ S-GeS ２ -Sb ２ S ５ 、Li ２ S-GeS ２ -Al ２ S ３ 、Li ２ S-SiS ２ 、Li ２ S-Al ２ S ３ 、Li ２ S-SiS ２ -Al ２S ３ , Li ２ S-SiS ２ -P ２ S ５ , Li ２ S-SiS ２ -P ２ S ５ - LiI, Li ２ S-SiS ２ - LiI, Li ２ S-SiS ２ -Li ４ SiO ４ , Li ２ S-SiS ２ -Li ３ P.O. ４ , Li １０ GeP ２ S 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.

[0129] (ii) Oxide-based inorganic solid electrolyte The oxide-based inorganic solid electrolyte preferably contains oxygen atoms, has the ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and has electronic insulation. The oxide-based inorganic solid electrolyte preferably has an ionic conductivity of 1×10 －６ S / cm or more, and 5×10 －６ S / cm or more is more preferable, and 1×10 －５ The upper limit is not particularly limited, but it is preferably 1 × 10 －１ It is practical to have a viscosity of 200 S / cm or less.

[0130] Specific examples of the compound include Li ｘａ La ｙａ TiO ３ [xa satisfies 0.3≦xa≦0.7, and ya satisfies 0.3≦ya≦0.7.] (LLT); Li ｘｂ La ｙｂ Zr ｚｂM 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 O ｎｄ (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 between 0 and 0.1, and M ｅｅ represents a divalent metal atom. 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); Li ３ BO ３ Li ３ BO ３ -Li ２ SO ４ Li ２ Alumni２ O ３ -P ２ O ５ Li ２ O—SiO ２ Li ６ BaLa ２ Ta ２ O １２ Li ３ P.O. （４－３／２ｗ） N ｗ (w is w<1); Li having a LISICON (Lithium super ionic conductor) type crystal structure ３．５ Zn ０．２５ GeO ４ La having a perovskite crystal structure ０．５５ Li ０．３５ TiO ３ LiTi having a NASICON (sodium super ionic conductor) type crystal structure ２ P ３ O １２ Li １＋ｘｈ＋ｙｈ (Al, Ga) ｘｈ (Ti, Ge) ２－ｘｈ Si ｙｈ P ３－ｙｈ O １２ (xh satisfies 0≦xh≦1, and yh satisfies 0≦yh≦1); Li having a garnet-type crystal structure ７ La ３ Zr ２ O １２ (LLZ), etc. Phosphorus compounds containing Li, P, and O are also desirable. For example, lithium phosphate (Li ３ P.O. ４ ) LiPON, in which part of the oxygen element of lithium phosphate is replaced with nitrogen element; 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. １ ON (A １ is one or more elements selected from Si, B, Ge, Al, C and Ga.) can also be preferably used.

[0131] (iii) Halide-based inorganic solid electrolyte The halide-based inorganic solid electrolyte is preferably a compound containing a halogen atom, having ionic conductivity of a metal belonging to Group 1 or Group 2 of the periodic table, and having electronic insulation. The halide-based inorganic solid electrolyte is not particularly limited, but examples thereof include LiCl, LiBr, LiI, and Li described in ADVANCED MATERIALS, 2018, 30, 1803075. ３ YBr ６ , Li ３ YCl ６ Among them, Li ３ YBr ６ , Li ３ YCl ６ is preferred.

[0132] (iv) Hydride-Based Inorganic Solid Electrolyte 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. The hydride-based inorganic solid electrolyte is not particularly limited, but examples thereof include LiBH ４ , Li ４ (BH ４ ) ３ I, 3LiBH ４ -LiCl, etc.

[0133] The inorganic solid electrolyte is preferably in the form of particles in the inorganic solid electrolyte-containing composition. In this case, the particle diameter (volume average particle diameter) 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 diameter of the inorganic solid electrolyte is measured by the following procedure. Particles of the inorganic solid electrolyte are diluted with water (heptane in the case of substances unstable in water) in a 20 mL sample bottle to prepare a 1 mass % dispersion. The diluted dispersion sample is irradiated with 1 kHz ultrasound for 10 minutes and used for testing immediately thereafter. Using this dispersion sample, data is acquired 50 times using a quartz measurement cell at a temperature of 25°C using a laser diffraction / scattering particle size distribution analyzer LA-920 (trade name, manufactured by HORIBA Corporation), to obtain the volume average particle diameter. For other detailed conditions, etc., refer to the description in Japanese Industrial Standards (JIS) Z 8828:2013 "Particle size analysis - dynamic light scattering method." Five samples are prepared for each level, and the average value is used.

[0134] The method for adjusting the particle size is not particularly limited, and known methods can be applied, such as a method using a conventional pulverizer or classifier. Suitable pulverizers or classifiers include, for example, a mortar, a ball mill, a sand mill, a vibration ball mill, a satellite ball mill, a planetary ball mill, a swirling airflow jet mill, or a sieve. Wet pulverization can be performed in the presence of a dispersion medium such as water or methanol. Classification is preferably performed to obtain the desired particle size. Classification is not particularly limited, and can be performed using a sieve, an air classifier, or the like. Both dry and wet classification methods can be used.

[0135] The inorganic solid electrolyte-containing composition may contain one or more inorganic solid electrolytes. The content of the inorganic solid electrolyte in the inorganic solid electrolyte-containing composition is not particularly limited, but in terms of the dispersion state of the solid particles and resistance, 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 is within the above range. In the present invention, the solid content (solid component) refers to components that do not volatilize or evaporate 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, it refers to components other than the dispersion medium described below.

[0136] <Dispersion medium> 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, specifically alcohol compounds, ether compounds, amide compounds, amine compounds, ketone compounds, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, nitrile compounds, ester compounds, etc. 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 terms of being able to exhibit excellent dispersibility. A non-polar dispersion medium generally refers to a medium that has low affinity for water, and in the present invention, examples thereof include ester compounds, ketone compounds, ether compounds, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, etc.

[0137] 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.

[0138] 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.).

[0139] 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.

[0140] Examples of amine compounds 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 hydrocarbon compounds include benzene, toluene, xylene, and perfluorotoluene. Examples of aliphatic hydrocarbon compounds include hexane, heptane, octane, nonane, decane, dodecane, cyclohexane, methylcyclohexane, ethylcyclohexane, cycloheptane, cyclooctane, decalin, paraffin, gasoline, naphtha, kerosene, and diesel. Examples of nitrile compounds 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.

[0141] In the present invention, among these, ether compounds, ketone compounds, aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, and ester compounds are preferred, and ester compounds, ketone compounds, aromatic hydrocarbon compounds, and ether compounds are more preferred.

[0142] 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.

[0143] The boiling point of the dispersion medium at normal pressure (1 atmosphere: 101,325 Pa) 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.

[0144] The inorganic solid electrolyte-containing composition may contain one or more dispersion media. Examples of dispersion media containing two or more dispersion media include xylene (a mixture of xylene isomers in which the molar ratio of the isomers is ortho-isomer:para-isomer:meta-isomer = 1:5:2), mixed xylenes (a mixture of o-xylene, p-xylene, m-xylene, and ethylbenzene), etc. 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%.

[0145] <Active Material> In one preferred embodiment, the inorganic solid electrolyte-containing composition of the present invention contains an active material capable of inserting and releasing ions of a metal belonging to Group 1 or Group 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).

[0146] (Positive electrode 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 Group 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 may be a transition metal oxide, or an element that can be composited with Li, such as an organic substance or sulfur. Among them, it is preferable to use a transition metal oxide as the positive electrode active material, and it is preferable to use a transition metal element M ａ A transition metal oxide containing one or more elements 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. ａ The amount of Li / M is preferably 0 to 30 mol % relative to the amount of Li / M (100 mol %). ａ More preferably, the transition metal oxides are synthesized by mixing them so that the molar ratio of the above is 0.3 to 2.2. Specific examples of the transition metal oxide include (MA) a transition metal oxide having a layered rock salt structure, (MB) a transition metal oxide having a spinel structure, (MC) a lithium-containing transition metal phosphate compound, (MD) a lithium-containing transition metal halide phosphate compound, and (ME) a ​​lithium-containing transition metal silicate compound.

[0147] (MA) Specific examples of transition metal oxides having a layered rock salt structure include LiCoO ２ (Lithium cobalt oxide [LCO]), LiNi ２ O ２ (lithium nickel oxide), LiNi ０．８５ Co ０．１０ Al ０．０５ O ２ (nickel cobalt lithium aluminum oxide [NCA]), LiNi １／３ Co １／３ Mn １／３ O ２ (Lithium nickel manganese cobalt oxide [NMC]) and LiNi ０．５ Mn ０．５ O ２ (Lithium manganese nickel oxide). (MB) Specific examples of transition metal oxides having a spinel structure include LiMn ２ O ４ (LMO), LiCoMnO ４ , Li ２ FeMn ３ O ８ , Li ２ CuMn ３ O ８ , Li ２ CrMn ３ O ８ and Li ２ NiMn ３ O ８Examples of the (MC) lithium-containing transition metal phosphate compound include LiFePO ４ and Li ３ Fe ２ (P.O. ４ ) ３ Olivine-type iron phosphate salts such as LiFeP ２ O ７ Iron pyrophosphates such as LiCoPO ４ Cobalt phosphates such as Li ３ V ２ (P.O. ４ ) ３ (MD) Examples of lithium-containing transition metal halide phosphate compounds include, for example, Li ２ FePO ４ Fluorophosphate iron salts such as F, Li ２ MnPO ４ Fluorophosphate manganese salts such as F and Li ２ CoPO ４ Examples of the (ME) lithium-containing transition metal silicate compound include cobalt fluoride phosphates such as Li ２ FeSiO ４ , Li ２ MnSiO ４ , Li ２ CoSiO ４ In the present invention, transition metal oxides having a layered rock salt structure (MA) are preferred, and LCO or NMC are more preferred.

[0148] The shape of the positive electrode active material is not particularly limited, but it is preferably particulate in the inorganic solid electrolyte-containing composition. When the positive electrode active material is 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 achieve the desired particle size, a conventional grinder or classifier is used, as with the inorganic solid electrolyte. The positive electrode active material obtained by the firing method may be used after washing with water, an acidic aqueous solution, an alkaline aqueous solution, or an organic solvent.

[0149] The inorganic solid electrolyte-containing composition may contain one or more positive electrode active materials. The content of the positive electrode active materials 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.

[0150] (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 reversibly insert and release lithium ions. The material is not particularly limited as long as it has the above 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. In terms of enabling a large capacity all-solid-state secondary battery, active materials that can be alloyed with lithium are preferred.

[0151] 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 or furfuryl alcohol resins. Further examples include various carbon fibers such as PAN-based carbon fibers, cellulose-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, dehydrated PVA (polyvinyl alcohol)-based carbon fibers, lignin carbon fibers, glassy carbon fibers, and activated carbon fibers, as well as mesophase microspheres, graphite whiskers, and flat graphite. These carbonaceous materials can also be divided into difficult-to-graphitize 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 or 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 having a coating layer described in JP-A-6-4516, etc. can also be used. As the carbonaceous material, hard carbon or graphite is preferably used, and graphite is more preferably used.

[0152] 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). Among these oxides, amorphous oxides are preferred, 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 that exhibits properties intermediate between metal elements and non-metalloid elements, and typically includes six elements: boron, silicon, germanium, arsenic, antimony, and tellurium, and three elements: selenium, polonium, and astatine. Furthermore, "amorphous" refers to an oxide having a broad scattering band with a peak in the 2θ range of 20° to 40° in an X-ray diffraction method using CuKα radiation, and may also have crystalline diffraction lines. The strongest intensity of the crystalline diffraction lines observed 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 a broad scattering band observed at 2θ values ​​of 20° to 40°, and it is particularly preferable that the crystal has no crystalline diffraction lines.

[0153] Among the compound group 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 element selected from Groups 13 (IIIB) to 15 (VB) of the periodic table (e.g., Al, Ga, Si, Sn, Ge, Pb, Sb, and Bi) alone or in combination of two or more elements thereof are particularly preferred. Specific examples of preferred amorphous oxides and chalcogenides include, for example, Ga ２ O ３ , GeO, PbO, PbO ２ , Pb ２ O ３ , Pb ２ O ４ , Pb ３ O ４ , Sb ２ O ３ , Sb ２ O ４ , Sb ２ O ８Bi ２ O ３ , Sb ２ O ８ Si ２ O ３ , Sb ２ O ５ , Bi ２ O ３ , Bi ２ O ４ , GeS, PbS, PbS ２ , Sb ２ S ３ or Sb ２ S ５ 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.

[0154] The oxides of metal or semi-metal elements, particularly the metal (composite) oxides and the chalcogenides, preferably contain at least one of titanium and lithium as a constituent component from the viewpoint of high current density charge / discharge characteristics. Examples of the lithium-containing metal composite oxide (lithium composite metal oxide) include composite oxides of lithium oxide and the metal (composite) oxides or the chalcogenides, more specifically, Li ２ SnO ２ The negative electrode active material, for example, a metal oxide, preferably contains titanium element (titanium oxide). Specifically, Li ４ Ti ５ O １２ Lithium titanate (LTO) is preferred because it has small volume fluctuations during absorption and desorption of lithium ions, has excellent rapid charge and discharge characteristics, suppresses electrode deterioration, and can improve the life of the lithium ion secondary battery.

[0155] 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.

[0156] The negative electrode active material capable of forming an alloy with lithium is not particularly limited as long as it is one that is commonly used as a negative electrode active material for secondary batteries. Examples of such active materials include (negative electrode) active materials (alloys, etc.) containing silicon or tin, and metals such as Al and In. A negative electrode active material containing silicon (silicon-containing active material) that enables higher battery capacity is preferred, and a silicon-containing active material having a silicon content of 50 mol% or more of the total constituent elements is more preferred. Generally, negative electrodes containing these negative electrode active materials (e.g., Si negative electrodes containing silicon-containing active materials, Sn negative electrodes containing tin-containing active materials, etc.) can absorb more Li ions than carbon negative electrodes (e.g., graphite and acetylene black). That is, the amount of Li ion absorption per unit mass increases. Therefore, the battery capacity (energy density) can be increased. As a result, there is an advantage in that the battery operating time can be extended. Examples of silicon-containing active materials include Si, SiO ｘ Silicon materials such as silicon (0<x≦1), as well as silicon-containing alloys containing titanium, vanadium, chromium, manganese, nickel, copper, lanthanum, etc. (e.g., LaSi ２ , VSi ２ , La—Si, Gd—Si, Ni—Si), or textured active materials (e.g., LaSi ２ / Si), and also SnSiO ３ , SnSiS ３ Examples of the active material include silicon and tin-containing active materials such as SiO ｘ can be used as an anode active material (semi-metal oxide) by itself, and can also be used as an anode active material (precursor material) that can be alloyed with lithium because it produces Si during operation of an all-solid-state secondary battery. Examples of anode active materials containing tin include Sn, SnO, and SnO ２ , SnS, SnS ２ and active materials containing the above silicon and tin elements. Also, composite oxides with lithium oxide, for example, Li ２ SnO ２ The following can also be mentioned.

[0157] 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.

[0158] 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.

[0159] The shape of the negative electrode active material is not particularly limited, but is preferably particulate in the inorganic solid electrolyte-containing composition. When the negative electrode active material is 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 inorganic solid electrolyte.

[0160] The inorganic solid electrolyte-containing composition may contain one or more negative electrode active materials. The content of the negative electrode active materials 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.

[0161] 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.

[0162] (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. ４ Ti ５ O １２ , Li ２ Ti ２ O ５ , LiTaO ３ , LiNbO ３ , LiAlO ２ , Li ２ ZrO ３ , Li ２ WO ４ , Li ２ TiO ３ , Li ２ B ４ O ７ , Li ３ P.O. ４ , Li ２ MoO ４ , Li ３ BO ３ , LiBO ２ , Li ２ CO ３ , Li ２ SiO ３ , SiO ２ , TiO ２ , ZrO ２ , Al ２ O ３ , B ２ O ３ 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 the negative electrode active material may be surface-treated with actinic rays or an active gas (plasma, etc.) before or after the surface coating.

[0163] <Conductive Aid> In one preferred embodiment, the inorganic solid electrolyte-containing composition of the present invention contains a conductive aid, and it is preferable to use the conductive aid in combination with the active material. For example, it is preferable to use the silicon atom-containing active material as the negative electrode active material in combination with the conductive aid. The conductive aid is not particularly limited, and a commonly known conductive aid can be used. For example, it may be an electron conductive material such as graphites such as natural graphite and artificial graphite, carbon blacks such as acetylene black, ketjen black, and furnace black, amorphous carbon such as needle coke, carbon fibers such as vapor-grown carbon fibers or carbon nanotubes, carbonaceous materials such as graphene or fullerene, metal powders or metal fibers such as copper and nickel, or conductive polymers such as polyaniline, polypyrrole, polythiophene, polyacetylene, and 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 undergo insertion and release of ions of a metal belonging to Group 1 or Group 2 of the periodic table (preferably Li ions) during charging and discharging of the battery 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 during charging and discharging of the battery is classified as an active material rather than a conductive additive. Whether or not a conductive additive functions as an active material during charging and discharging of the battery is not uniquely determined, but is determined by the combination with the active material.

[0164] The conductive assistant is preferably in particulate form in the inorganic solid electrolyte-containing composition. When the conductive assistant is particulate, the particle size (volume average particle size) of the conductive assistant is not particularly limited, but is preferably, for example, 0.02 to 1.0 μm. The particle size of the conductive assistant can be measured in the same manner as the particle size of the inorganic solid electrolyte. The inorganic solid electrolyte-containing composition may contain one or two types of conductive assistants. When the inorganic solid electrolyte-containing composition of the present invention contains a conductive assistant, the content of the conductive assistant in the inorganic solid electrolyte-containing composition is preferably 0 to 10 mass% based on 100 mass% of the solid content.

[0165] <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 typically used in this type of product, and is not particularly limited. For example, the lithium salts described in paragraphs 0082 to 0085 of JP 2015-088486 A 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, and more preferably 5 parts by mass or more, relative to 100 parts by mass of the solid electrolyte. The upper limit is preferably 50 parts by mass or less, and more preferably 20 parts by mass or less.

[0166] <Binders Other Than the Binder of the Present Invention> The inorganic solid electrolyte-containing composition of the present invention does not need to contain any binder other than the binder of the present invention because the binder of the present invention functions as a binder in the constituent layer. However, it may contain a binder other than the binder of the present invention to reinforce the function of the binder of the present invention. As such a binder, a binder normally used in all-solid-state secondary batteries can be appropriately selected and used. The inorganic solid electrolyte-containing composition of the present invention may contain one or more binders other than the binder of the present invention. When the inorganic solid electrolyte-containing composition of the present invention contains a binder other than the binder of the present invention, the content of the binder is appropriately determined and can be, for example, 3 mass% or less relative to 100 mass% of the solid content of the inorganic solid electrolyte-containing composition.

[0167] <Dispersant> The inorganic solid electrolyte-containing composition of the present invention does not need to contain any dispersants other than the binder of the present invention because the binder of the present invention also functions as a dispersant. However, it may contain other dispersants (referred to as other dispersants) to reinforce the dispersing function of the binder of the present invention. As the other dispersant, one that is commonly used in all-solid-state secondary batteries can be appropriately selected and used. Generally, compounds intended for particle adsorption and steric repulsion and / or electrostatic repulsion are preferably used. The inorganic solid electrolyte-containing composition of the present invention may contain one or more other dispersants. When the inorganic solid electrolyte-containing composition of the present invention contains other dispersants, the content of the other dispersants can be appropriately determined and can be, for example, 3 mass% or less based on 100 mass% of the solid content of the inorganic solid electrolyte-containing composition.

[0168] <Other Additives> The inorganic solid electrolyte-containing composition of the present invention may contain, as appropriate, as components other than the above-mentioned components, 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, an antioxidant, etc. The ionic liquid is contained to further improve ionic conductivity, and any known ionic liquid can be used without any particular limitation.

[0169] (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 binder of the present invention, a dispersion medium, preferably a conductive additive, and optionally a lithium salt and other components, for example, using various commonly used mixers. In the case of an electrode composition, an active material is further mixed. The mixing method is not particularly limited, and can be performed using known mixers such as a ball mill, bead mill, planetary mixer, blade mixer, roll mill, kneader, disk mill, planetary mixer, and narrow gap disperser. The components may be mixed all at once or sequentially. The mixing environment is not particularly limited, but examples include dry air (dew point -20°C or lower) and inert gas (e.g., argon gas, helium gas, nitrogen gas). The mixing conditions are also not particularly limited and can be set appropriately. For example, the mixing temperature can be 15 to 40°C. The rotation speed of the rotary mixer or the like can be set to 200 to 3,000 rpm. The binder of the present invention can suppress heat generation when mixed with solid particles such as an inorganic solid electrolyte. Therefore, the inorganic solid electrolyte-containing composition of the present invention can be prepared without excessive heat generation and suppressing an increase in the internal temperature of the mixed system, even without performing an unnecessary cooling operation. The internal temperature of the mixed system is not uniquely determined depending on the temperature of the dispersion medium, the amount mixed, etc., but can be suppressed to less than 45°C, for example, when mixed at room temperature.

[0170] [Sheet for All-Solid-State Secondary Battery] 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 (electrode sheet for an all-solid-state secondary battery), and the like. 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.

[0171] 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, the layer formed from the inorganic solid electrolyte-containing composition of the present invention is formed from components derived from the inorganic solid electrolyte-containing composition (excluding the dispersion medium), and typically, solid particles (inorganic solid electrolyte, conductive additive, and active material) are adhered (bound) together with the binder of the present invention in a mixed state. The sheet for an all-solid-state secondary battery can be incorporated into an all-solid-state secondary battery by peeling off the substrate as appropriate, or by incorporating the sheet directly into the all-solid-state secondary battery, thereby achieving a reduction in the resistance of the all-solid-state secondary battery (improvement of conductivity).

[0172] The solid electrolyte sheet for an all-solid-state secondary battery of the present invention may be any sheet having a solid electrolyte layer. It 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 such 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 preferably formed from the inorganic solid electrolyte-containing composition of the present invention. The content of each component in the 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 thickness of each layer constituting the solid electrolyte sheet for an all-solid-state secondary battery is the same as the thickness of each layer described in the all-solid-state secondary battery described below. The solid electrolyte sheet for an all-solid-state secondary battery of the present invention may be, for example, a sheet having, on a substrate, a layer composed of the inorganic solid electrolyte-containing composition of the present invention, a typical solid electrolyte layer, and a protective layer, in this order.

[0173] 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 in relation to 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.

[0174] 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 embodiments including a current collector, an active material layer, and a solid electrolyte layer in this order, as well as an electrode sheet having a current collector, an active material layer, a solid electrolyte layer, and an active material layer in this order, are also included. 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.

[0175] 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 low-resistance constituent layer in which solid particles containing an inorganic solid electrolyte are bound. By using this constituent layer as a constituent layer of an all-solid-state secondary battery, low resistance (high conductivity) of the all-solid-state secondary battery can be achieved.

[0176] [Method for Manufacturing Sheet for All-Solid-State Secondary Battery] The method for manufacturing the sheet for an all-solid-state secondary battery of the present invention is not particularly limited, and the sheet can be manufactured by forming each of the above-mentioned 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 a sheet for an all-solid-state secondary battery is produced by forming a film of the inorganic solid electrolyte-containing composition of the present invention on a current collector, 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.

[0177] 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 explained in the method for producing an all-solid-state secondary battery described below. In addition, in the method for producing a sheet for an all-solid-state secondary battery of the present invention, the substrate, the protective layer (particularly the release sheet), and the like can also be peeled off.

[0178] [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 its 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 to constitute a positive electrode. The negative electrode active material layer is preferably formed on a negative electrode current collector to constitute a negative electrode. In the present invention, each constituent layer (including the current collector, etc.) constituting the all-solid-state secondary battery may have a single-layer structure or a multi-layer structure.

[0179] It is preferred that at least one of the negative electrode active material layer, positive electrode active material layer, and solid electrolyte layer be formed from the inorganic solid electrolyte-containing composition of the present invention. Another preferred embodiment is that at least one of the negative electrode active material layer and the positive electrode active material layer be formed from the inorganic solid electrolyte-containing composition of the present invention. Another preferred embodiment of the present invention is that all layers be formed from the inorganic solid electrolyte-containing composition of the present invention. In the present invention, forming the constituent layers of an all-solid-state secondary battery from the inorganic solid electrolyte-containing composition of the present invention includes forming the constituent layers from the all-solid-state secondary battery sheet of the present invention (provided that, if a layer other than the layer formed from the inorganic solid electrolyte-containing composition of the present invention is present, the sheet is formed from this layer). The all-solid-state secondary battery of the present invention, in which at least one of the constituent layers is formed from the inorganic solid electrolyte-containing composition of the present invention, exhibits low resistance (high conductivity). Furthermore, since the all-solid-state secondary battery of the present invention exhibits low resistance and high ionic conductivity, it can also extract large currents. If the active material layer or solid electrolyte layer is not formed from the inorganic solid electrolyte-containing composition of the present invention, known materials can be used. In the present invention, each of the constituent layers (including the current collector and the like) constituting the all-solid-state secondary battery may have a single-layer structure or a multi-layer structure.

[0180] <Positive Electrode Active Material Layer, Solid Electrolyte Layer, Negative Electrode Active Material Layer> 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 content as those of the solid content of the inorganic solid electrolyte-containing composition of the present invention. The thicknesses of the negative electrode active material layer, solid electrolyte layer, and positive electrode active material layer are not particularly limited. Taking into account 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 even more 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.

[0181] <Current Collector> 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. 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 a current collector. Materials for forming the positive electrode current collector include aluminum, aluminum alloys, stainless steel, nickel, titanium, etc., as well as aluminum or stainless steel surfaces treated with carbon, nickel, titanium, or silver (thin films formed thereon), with aluminum and aluminum alloys being more preferred. Materials for forming the negative electrode current collector include aluminum, copper, copper alloys, stainless steel, nickel, titanium, etc., as well as aluminum, copper, copper alloys, or stainless steel surfaces treated with carbon, nickel, titanium, or silver, with aluminum, copper, copper alloys, and stainless steel being more preferred.

[0182] The current collector is usually in the form of a film sheet, but nets, punched materials, lath materials, porous materials, foamed materials, and molded fiber bodies can also be used. 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.

[0183] <Other Configurations> In the present invention, functional layers or members may be appropriately interposed or disposed between or on the outside of the negative electrode current collector, negative electrode active material layer, solid electrolyte layer, positive electrode active material layer, and positive electrode current collector.

[0184] <Housing> 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 housing to make it into a dry battery. The housing may be made of metal or resin (plastic). When a metal housing is used, examples include aluminum alloys and stainless steel. The metal housing is preferably divided into a positive electrode housing and a negative electrode housing, and is electrically connected to the positive electrode current collector and the negative electrode current collector, respectively. The positive electrode housing and the negative electrode housing are preferably joined and integrated via a gasket to prevent short circuits.

[0185] Hereinafter, an all-solid-state secondary battery according to a preferred embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited thereto.

[0186] FIG. 1 is a cross-sectional view schematically illustrating 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 discharge.

[0187] When an all-solid-state secondary battery having the layer structure shown in FIG. 1 is placed in a 2032-type coin case 11 (see, for example, FIG. 2 ), this all-solid-state secondary battery is referred to as a laminated body 12 for an all-solid-state secondary battery, and a battery produced by placing this laminated body 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.

[0188] (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 4, the solid electrolyte layer 3, and the negative electrode active material layer 2 are all formed from the inorganic solid electrolyte-containing composition of the present invention. The inorganic solid electrolytes and the binders of the present invention 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 each other. Furthermore, the conductive additives contained in the positive electrode active material layer 4 and the negative electrode active material layer 2 may be the same or different from each other. 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 the active material layer or the electrode active material layer. Furthermore, either the positive electrode active material or the negative electrode active material, or both together, may be simply referred to as the active material or the electrode active material.

[0189] The solid electrolyte layer contains an inorganic solid electrolyte having conductivity for metal ions belonging to Group 1 or 2 of the periodic table, the binder of the present invention, and the optional components described above within the scope 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 an inorganic solid electrolyte having conductivity for metal ions belonging to Group 1 or 2 of the periodic table, a positive electrode active material, the binder of the present invention, and the optional components described above within the scope ... 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.

[0190] In the present invention, when the constituent layers are formed from the inorganic solid electrolyte-containing composition of the present invention, a low-resistance all-solid-state secondary battery can be realized.

[0191] (Current Collector) The positive electrode current collector 5 and the negative electrode current collector 1 are as described above. When the all-solid-state secondary battery 10 has a constituent layer other than the constituent layer formed from the inorganic solid electrolyte-containing composition of the present invention, a layer formed from a known constituent layer-forming material can also be applied. Furthermore, each layer may be composed of a single layer or multiple layers.

[0192] [Manufacturing of All-Solid-State Secondary Battery] All-solid-state secondary batteries can be manufactured by conventional methods. Specifically, all-solid-state secondary batteries can be manufactured by forming the above-mentioned layers using the inorganic solid electrolyte-containing composition of the present invention. Specifically, all-solid-state secondary batteries can be manufactured by a method (method for manufacturing an all-solid-state secondary battery sheet of the present invention) that includes (intervenes) a step of applying the inorganic solid electrolyte-containing composition of the present invention to a suitable substrate (e.g., a metal foil serving as a current collector) and forming a coating film. More specifically, an inorganic solid electrolyte-containing composition containing a positive electrode active material is applied as a positive electrode material (positive electrode composition) to a metal foil serving as a positive electrode current collector and dried to form a positive electrode active material layer, thereby producing a positive electrode sheet for an all-solid-state secondary battery. Next, an inorganic solid electrolyte-containing composition for forming a solid electrolyte layer is applied and dried on this positive electrode active material layer to form a solid electrolyte layer. Furthermore, an inorganic solid electrolyte-containing composition containing a negative electrode active material is applied and dried on 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 can be obtained in which a solid electrolyte layer is sandwiched between a positive electrode active material layer and a negative electrode active material layer. This can also be enclosed in a case to form a desired all-solid-state secondary battery. Alternatively, the method of forming each layer can be reversed, and an all-solid-state secondary battery can be produced by forming a negative electrode active material layer, a solid electrolyte layer, and a positive electrode active material layer on the negative electrode current collector, and then overlaying the positive electrode current collector.

[0193] Another method includes the following. That is, a positive electrode sheet for an all-solid-state secondary battery is prepared 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) to a metal foil serving as a negative electrode current collector and dried to form a negative electrode active material layer, thereby preparing 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 manufactured. Another method includes the following. 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 from this, an inorganic solid electrolyte-containing composition is applied to a substrate and dried to prepare a solid electrolyte sheet for an all-solid-state secondary battery comprising a solid electrolyte layer. Furthermore, the solid electrolyte layer peeled from the substrate is sandwiched between the positive electrode sheet for an all-solid-state secondary battery and the negative electrode sheet for an all-solid-state secondary battery. In this way, an all-solid-state secondary battery can be manufactured.

[0194] Furthermore, a positive electrode sheet for an all-solid-state secondary battery 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 for an all-solid-state secondary battery 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 overlapped with each other in a state in which the positive electrode active material layer or the negative electrode active material layer is in contact with the solid electrolyte layer, and pressurized. In this way, the solid electrolyte layer is transferred to the positive electrode sheet for an all-solid-state secondary battery 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 overlapped with the negative electrode sheet for an all-solid-state secondary battery or the positive electrode sheet for an all-solid-state secondary battery (in a state in which the negative electrode active material layer or the positive electrode active material layer is 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 below can be applied.

[0195] The solid electrolyte layer or the like can also 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. In the above-mentioned manufacturing 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 can be used for either composition. When forming a solid electrolyte layer or an active material layer with a composition other than the inorganic solid electrolyte-containing composition of the present invention, examples of the material include commonly used compositions. Alternatively, instead of forming a negative electrode active material layer during the production of an all-solid-state secondary battery, the negative electrode active material layer can be formed by bonding ions of a metal belonging to Group 1 or Group 2 of the periodic table that have accumulated on the negative electrode current collector during initialization or charging during use, as described below, with electrons and depositing the metal on the negative electrode current collector or the like.

[0196] <Formation of Each Layer (Film Formation)> The coating method of the inorganic solid electrolyte-containing composition is not particularly limited and can be selected appropriately. Examples include coating (preferably wet coating), spray coating, spin coating, dip coating, slit coating, stripe coating, and bar coating. The coating temperature is not particularly limited and can be, for example, under unheated conditions, typically in the temperature range of about room temperature (e.g., 15 to 30°C). The coated inorganic solid electrolyte-containing composition is dried (heat treated). The drying treatment may be performed after coating each composition, or after coating multiple compositions in layers. 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 can remove the dispersion medium and create a solid state (coated, dried layer). Furthermore, it is preferable to avoid raising the temperature too high, as this avoids damaging the components of the all-solid-state secondary battery. This allows the all-solid-state secondary battery to exhibit excellent overall performance, and to obtain good binding properties and good ionic conductivity.

[0197] After coating and drying 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. It is also preferable to pressurize each layer in a laminated state. Examples of pressurizing methods include a hydraulic cylinder press. The pressure is not particularly limited and is generally in the range of 5 to 1500 MPa. The coated 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. It may also be pressed at a temperature higher than the glass transition temperature of the inorganic solid electrolyte. It may also be pressed at a temperature higher than the glass transition temperature of the polymer (I) contained in the binder of the present invention. However, the temperature is generally not higher than the melting point of this polymer (I). Pressing may be performed after the coating solvent or dispersion medium has been dried in advance, or may be performed while the solvent or dispersion medium remains. The compositions may be applied simultaneously, or coating, drying, and pressing may be performed simultaneously and / or sequentially. After coating on separate substrates, the compositions may be laminated by transfer.

[0198] The atmosphere in the film-forming method (coating, drying, and pressurization (under heating)) is not particularly limited, and may be any of the following: atmospheric air, dry air (dew point -20°C or lower), and inert gas (e.g., argon gas, helium gas, nitrogen gas). High pressure may be applied for a short period of time (e.g., within a few hours), or moderate pressure may be applied for a long period of time (one day or more). In the case of a sheet other than an all-solid-state secondary battery sheet, for example, an all-solid-state secondary battery, a restraining device for the all-solid-state secondary battery (e.g., screw tightening pressure) may be used to continuously apply moderate pressure. The pressing pressure may be uniform or may vary across the pressed portion, such as the sheet surface. The pressing pressure may be varied depending on the area or film thickness of the pressed portion. The same portion may also be subjected to different pressures in stages. The pressing surface may be smooth or roughened.

[0199] <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.

[0200] [Applications of All-Solid-State Secondary Battery] 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 movie players, 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 all-solid-state secondary battery can be used for various military and space applications. It can also be combined with solar cells.

[0201] 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.

[0202] Example 1: Polymer Synthesis and Preparation of Binder Solution or Dispersion Polymers shown in the following chemical formulas and in Tables 1-1 and 1-2 (collectively referred to as Table 1) were synthesized as follows, and binder solutions or dispersions were prepared. Synthesis Example S-1: Synthesis of Polymer S-1 and Preparation of Binder Solution S-1 First, dipentaerythritol hexakis(3-mercaptopropionate) (3.4 g), butyl butyrate (15.0 g), and nonafluorohexyl acrylate (5.6 g) were placed in a three-neck flask and heated to 80°C under a nitrogen stream. Subsequently, azo-based polymerization initiator V-601 (0.03 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the three-neck flask and stirred for 4 hours. Next, acrylamide (1.0 g) was added to the three-neck flask and dissolved, and then azo polymerization initiator V-601 (0.02 g) was added and stirred for 2 hours at 80° C. In this way, polymer S-1 was synthesized, and binder solution S-1 (concentration 67% by mass) composed of this polymer was obtained.

[0203] [Synthesis Examples S-2 to S-20: Synthesis of Polymers S-2 to S-20, and Preparation of Binder Solutions S-2 to S-20] Polymers S-2 to S-20 were synthesized in the same manner as in Synthesis Example S-1, except that compounds were used to induce each constituent component so that polymers S-2 to S-20 had the compositions (types and contents of constituent components) shown in Table 1, and the amount of polymerization initiator was adjusted so that the weight-average molecular weights would be as shown in Table 1, and binder solutions S-2 to S-20 composed of each polymer were obtained, respectively.

[0204] [Synthesis Example S-21: Synthesis of Polymer S-21 and Preparation of Polymer Dispersion S-21] Polymer S-21 was synthesized in the same manner as in Synthesis Example S-1, except that compounds were used to induce each constituent component so that polymer S-21 would have the composition (types and contents of constituent components) shown in Table 1, and the amount of polymerization initiator was adjusted so that the weight-average molecular weight would be as shown in Table 1. In this binder dispersion S-21, the particle size of polymer S-21 was measured by the same method as above for inorganic solid electrolytes, and was found to be 200 nm.

[0205] Synthesis Example S-22: Synthesis of Polymer S-22 and Preparation of Polymer Solution S-22 Polymer S-22 was synthesized in the same manner as in Synthesis Example S-1, except that in Synthesis Example S-1, dipentaerythritol hexakis(3-mercaptopropionate) and nonafluorohexyl acrylate were reacted in the content ratios shown in Table 1, with the amount of polymerization initiator adjusted so as to obtain the weight-average molecular weight shown in Table 1, and the reaction with acrylamide was not carried out. Binder solution S-22 composed of this polymer was obtained.

[0206] Synthesis Example S-23: Synthesis of Polymer S-23 and Preparation of Polymer Solution S-23 Polymer S-23 was synthesized in the same manner as in Synthesis Example S-20, except that in Synthesis Example S-20, dipentaerythritol hexakis(3-mercaptopropionate) and a compound having a polysiloxane structure (KF-2012: product number) were reacted in the content ratios shown in Table 1, with the amount of polymerization initiator adjusted so as to obtain the weight-average molecular weight shown in Table 1, and the reaction with acrylamide was not carried out. Thus, binder solution S-23 composed of this polymer was obtained.

[0207] Comparative Synthesis Example T-1: Synthesis of Polymer T-1 and Preparation of Binder Solution T-1 Polymer T-1 was synthesized in the same manner as in Synthesis Example S-1, except that compounds were used that lead to each component so that polymer T-1 had the composition shown in Table 1 (types and contents of components). A binder solution T-1 composed of this polymer was obtained.

[0208] Comparative Synthesis Example T-2: Synthesis of Polymer T-2 and Preparation of Binder Solution T-2 Acrylamide (2.5 g), nonafluorohexyl acrylate (47.5 g), and butyl butyrate (50.0 g) were charged into a three-necked flask and heated to 80°C under a nitrogen stream. Thereafter, azo-based polymerization initiator V-601 (0.1 g, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the three-necked flask and stirred for 4 hours. In this way, polymer T-2 was synthesized, and binder solution T-2 (concentration 50% by mass) composed of this polymer was obtained.

[0209] Comparative Synthesis Example T-3: Synthesis of Polymer T-3 and Preparation of Binder Dispersion T-3 Polymer T-3 was synthesized in the same manner as in Synthesis Example S-1, except that compounds were used that would lead to each constituent component so that Polymer T-3 would have the composition (types and contents of constituent components) shown in Table 1. The particle size of Polymer T-3 in this binder dispersion T-3 was measured by the same method as above for inorganic solid electrolytes, and was found to be 100 nm.

[0210] Comparative Synthesis Examples T-4 to T-5: Synthesis of Polymers T-4 to T-5, and Preparation of Binder Solutions T-4 to T-5 Polymers T-4 to T-5 were synthesized in the same manner as in Synthesis Example S-1, except that compounds were used that lead to the respective constituent components so that polymers T-4 and T-5 had the compositions (types and contents of constituent components) shown in Table 1, and binder solutions T-4 and T-5 composed of the respective polymers were obtained.

[0211] The chemical formula of each polymer synthesized is shown below. １ (A １１ ) and A ２ were all polymer chains. A in polymers S-6 to S-12, S-21, T-4 and T-5 １ The polymer chain corresponding to X is a polymer chain in which two types of components are randomly bonded. １ is a linking group, and X ２ is a substituent. In the following chemical formula, polymer chain A １ and A ２ The overall structure of each polymer is shown by specifying the bond positions of polymer chain A. １ and A ２ As long as the numbers (n and m) of the polymer chains A are the same, １ and A ２ The bonding position of the polymer chain A is not limited to the position specified by the following chemical formula. １ The two polymer chains shown in the figure are bonded to the left structural part of the central oxygen atom. １may be bonded to the right structural portion relative to the central oxygen atom.

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218] The acid value, base number, and weight average molecular weight of each synthesized polymer are shown in Table 1. The acid value, base number, and weight average molecular weight were measured by the above-mentioned methods. In addition, the "State" column in Table 1 shows the state of the binder in each composition described below, as determined by measuring the solubility in the dispersion medium by the above-mentioned method, and determining whether it is "dissolved" or "particles" (not dissolved but dispersed in particle form). Furthermore, in Table 1, "A ２ / A １ " column A １ A relative to the total content of ２ The ratio of the total content [A ２ Total content of / A １ The "content" shown in Table 1 is a value calculated from the charge ratio of each compound at the time of preparation. １ The total content of "A" is "2 / weight average molecular weight", but since these values ​​are small, １ "Total content of" and "A ２ / A １ The values ​​of " are not shown in Table 1. In Table 1, the units of acid number, base number and content are "mgKOH / g", "mgKOH / g" and "mass%, respectively, but these are omitted.

[0219]

[0220]

[0221] In the tables, "-" in the component column indicates that the corresponding component is not contained. １" refers to "-S-R" in the above formula (I). １ The following compounds from which "-S-" is derived are shown: DPMP: Dipentaerythritol hexakis(3-mercaptopropionate), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. PEMP: Pentaerythritol tetra(3-mercaptopropionate), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. TMMP: Trimethylolpropane tris(3-mercaptopropionate), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. "A" in the table is １ (A １１ ) in the above formula (I). １ "Amide-based components" refer to the following compounds that lead to components having an amide group, a sulfonamide group, or an imide group, and "other components" refer to compounds that lead to components that do not have an amide group, a sulfonamide group, or an imide group. １２ " is "A" in the above formula (I). １ " (A-1)" is a hydrogen atom corresponding to "A １２ " corresponds to "A" in the table. ２ " is "A" in the above formula (I). ２ " are shown below. Nonafluorohexyl acrylate: 3,3,4,4,5,5,6,6,6-nonafluorohexyl acrylate, manufactured by Tokyo Chemical Industry Co., Ltd. Heptafluorobutyl acrylate: 2,2,3,3,4,4,4-hexafluorobutyl acrylate, manufactured by Tokyo Chemical Industry Co., Ltd. X-22-174ASX (product number, manufactured by Shin-Etsu Chemical Co., Ltd.): compound having a polysiloxane structure (molecular weight 900) X-22-174BX: (product number, manufactured by Shin-Etsu Chemical Co., Ltd.): compound having a polysiloxane structure (molecular weight 2300) KF-2012: (product number, manufactured by Shin-Etsu Chemical Co., Ltd.): compound having a polysiloxane structure (molecular weight 4600)

[0222] [Example 2] 1. Synthesis of sulfide-based inorganic solid electrolyte [Synthesis Example A] A 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, lithium sulfide (Li ２ S, manufactured by Aldrich, purity >99.98%) 2.42 g and diphosphorus pentasulfide (P ２ S ５ 3.90 g of Li, manufactured by Aldrich, purity >99%) was weighed out and placed in an agate mortar and mixed for 5 minutes using an agate pestle. ２ S and P ２ S ５ The mixing ratio is Li in molar ratio. ２ S:P ２ S ５ = 75:25. Next, 66 g of zirconia beads having a diameter of 5 mm was added to a 45 mL zirconia container (manufactured by Fritsch), and the entire amount of the mixture of lithium sulfide and diphosphorus pentasulfide was added, and the container was completely sealed under an argon atmosphere. The container was set in a planetary ball mill P-7 (trade name, manufactured by Fritsch), and mechanical milling was performed for 20 hours at a temperature of 25 ° C. and a rotation speed of 510 rpm to obtain 6.20 g of a yellow powder sulfide-based inorganic solid electrolyte (Li-P-S-based glass, hereinafter sometimes referred to as LPS). The particle diameter of the Li-P-S-based glass was 15 μm.

[0223] 2. Each composition shown in Tables 2-1 to 2-4 (collectively referred to as Table 2) was prepared as follows. <Preparation of Inorganic Solid Electrolyte-Containing Compositions> 60 g of zirconia beads with a diameter of 5 mm was placed in a 45 mL zirconia container (manufactured by Fritsch), and 12.33 g of the LPS synthesized in Synthesis Example A above, 0.2 g (solid content by mass) of the binder solution or dispersion shown in Table 2-1 or Table 2-4, and 12.5 g (total amount) of butyl butyrate as a dispersion medium were then placed in the container. The container was then placed in a planetary ball mill P-7 (trade name). Mixing was performed for 10 minutes at an initial temperature of 25°C and a rotation speed of 150 rpm (temperature was not adjusted during mixing), to prepare inorganic solid electrolyte-containing compositions (slurries) K-1 to K-23 and Kc11 to Kc15, respectively.

[0224] <Preparation of Positive Electrode Composition> 60 g of zirconia beads having a diameter of 5 mm were placed in a 45 mL zirconia container (manufactured by Fritsch), and 4.8 g of the LPS synthesized in Synthesis Example A and 7.5 g (total amount) of butyl butyrate as a dispersion medium were placed in the container. The container was set in a planetary ball mill P-7 (trade name), and mixing was performed for 30 minutes at an initial temperature of 25°C and a rotation speed of 200 rpm (the temperature was not adjusted during mixing). Thereafter, 12.3 g of NMC (manufactured by Aldrich Chemical Co.) as a positive electrode active material, 0.33 g of acetylene black (AB) as a conductive additive, and 0.15 g (solid content by mass) of a binder solution or dispersion shown in Table 2-2 or Table 2-4 were added to the container, and the container was set in a planetary ball mill P-7 (trade name). Mixing was continued for 30 minutes at an initial temperature of 25°C and a rotation speed of 200 rpm (the temperature was not adjusted during mixing), to prepare positive electrode compositions (slurries) PK-1 to PK-23 and PKc21 to PKc25, respectively.

[0225] <Preparation of Negative Electrode Composition> 60 g of zirconia beads having a diameter of 5 mm were placed in a 45 mL zirconia container (manufactured by Fritsch), and 4.58 g of the LPS synthesized in Synthesis Example A, 0.1 g (solid content mass) of the binder solution or dispersion shown in Table 2-3 or Table 2-4, and 12 g (total amount) of butyl butyrate were placed in. This container was set in a planetary ball mill P-7 (trade name), and mixing was performed for 60 minutes at an initial temperature of 25°C and a rotation speed of 300 rpm (the temperature was not adjusted during mixing). Thereafter, 7.8 g of silicon (Si) was added as the negative electrode active material and 0.53 g of VGCF (manufactured by Showa Denko K.K.) as a conductive additive, and the container was similarly set in a planetary ball mill P-7 (trade name), followed by mixing for 10 minutes at an initial temperature of 25°C and a rotation speed of 100 rpm (the temperature was not adjusted during mixing), to prepare negative electrode compositions (slurries) NK-1 to NK-23 and NKc31 to NKc35, respectively.

[0226] 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 mass% of the solid content of the composition, and units are omitted in the table.

[0227] <Evaluation 1: Temperature measurement during composition preparation> The internal temperature of the mixture when each composition was prepared as described above was measured, and the amount of heat generated during mixing of the inorganic solid electrolyte and binder was evaluated based on which of the following evaluation criteria the maximum internal temperature fell within. In this test, the internal temperature of the mixture was evaluated as passing if it was rated as evaluation criterion "D" or higher. The results are shown in the "Heat generation test during dispersion" column in Table 2. - Evaluation criteria - A: Maximum internal temperature < 30°C B: 30°C ≦ Maximum internal temperature < 35°C C: 35°C ≦ Maximum internal temperature < 40°C D: 40°C ≦ Maximum internal temperature < 45°C E: 45°C ≦ Maximum internal temperature < 50°C F: 50°C ≦ Maximum internal temperature

[0228]

[0229]

[0230]

[0231]

[0232] LPS: LPS synthesized in Synthesis Example A NMC: LiNi １／３ Co １／３ Mn １／３ O ２ Si: Silicon (APS 1-5 μm, manufactured by Alfa Aesar) AB: Acetylene black VGCF: Carbon nanofiber

[0233] 3. Preparation of Solid Electrolyte Sheets for All-Solid-State Secondary Batteries <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 No." 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). Thereafter, using a heat press, the dried inorganic solid electrolyte-containing composition was heated and pressed at a temperature of 120°C and a pressure of 40 MPa for 10 seconds to prepare solid electrolyte sheets for all-solid-state secondary batteries (referred to as solid electrolyte sheets in Tables 3-1 and 3-4) 101 to 123 and c11 to c15, respectively. The film thickness of the solid electrolyte layer was 40 μm.

[0234] <Preparation of Positive Electrode Sheet for All-Solid State Secondary Battery> Each of the positive electrode compositions shown in the "Electrode Composition No." column in 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 further 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 prepare positive electrode sheets for all-solid state secondary batteries (referred to as positive electrode sheets in Tables 3-2 and 3-4) 201 to 223 and c21 to c25, respectively, having a positive electrode active material layer with a film thickness of 70 μm.

[0235] <Preparation of negative electrode sheets for all-solid-state secondary batteries> Each of the negative electrode compositions shown in the "Electrode composition No." column in Table 3-3 or Table 3-4 obtained above was applied to a copper foil having a thickness of 20 μm using a Baker-type applicator (product name: SA-201), heated at 80°C for 1 hour, and further heated at 110°C for 1 hour to dry the negative electrode composition (removing the dispersion medium). Thereafter, using a heat press, the dried negative electrode composition was pressed (10 MPa, 1 minute) at 25°C to prepare negative electrode sheets for all-solid-state secondary batteries (referred to as negative electrode sheets in Tables 3-3 and 3-4) 301 to 323 and c31 to c35, respectively, having a negative electrode active material layer with a film thickness of 60 μm.

[0236]

[0237]

[0238]

[0239]

[0240] 4. Production of All-Solid-State Secondary Battery 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, to be used in the production of an all-solid-state secondary battery.

[0241] - Preparation of cathode sheets for all solid state secondary batteries having solid electrolyte layer - On the cathode active material layer of each of the all solid state secondary battery cathode sheets shown in the "Electrode active material layer (sheet No.)" column of Tables 4-1 and 4-3, the solid electrolyte sheets prepared above and shown in the "Solid electrolyte layer (sheet No.)" column of Tables 4-1 and 4-3 were superimposed such that the solid electrolyte layer was in contact with the cathode active material layer, and the sheets were transferred (laminated) at 25°C and a pressure of 50 MPa using a press, and then pressed at 25°C and 600 MPa to prepare cathode sheets for all solid state secondary batteries Nos. 201 to 223 and c21 to c25 (cathode active material layer thickness 50 μm), each having a solid electrolyte layer with a thickness of 25 μm.

[0242] - Preparation of negative electrode sheets for all solid state secondary batteries having solid electrolyte layer - 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 Tables 4-2 and 4-3, the solid electrolyte sheet prepared above and shown in the "Solid electrolyte layer (sheet No.)" column of Tables 4-2 and 4-3 was superimposed such 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 a pressure of 50 MPa, followed by pressure at 25°C and 600 MPa to prepare negative electrode sheets for all solid state secondary batteries 301 to 323 and c31 to c35 each having a solid electrolyte layer with a thickness of 25 μm (negative electrode active material layer thickness of 40 μm).

[0243] All-solid-state secondary battery No. 401 having the layer structure shown in FIG. 1 was fabricated as follows. The all-solid-state secondary battery positive electrode sheet No. 201 (the aluminum foil of the solid electrolyte-containing sheet had already been peeled off) provided with the solid electrolyte layer obtained above 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 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 fabricate all-solid-state secondary battery No. 401 13 shown in FIG. 2 . The all-solid-state secondary battery fabricated in this manner had 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).

[0244] All solid state secondary batteries Nos. 402 to 423 and c101 to c105 were produced as follows. All solid state secondary batteries Nos. 402 to 423 and c101 to c105 were produced in the same manner as in the production of all solid state secondary battery No. 401, except that in the production of all solid state secondary battery No. 401, 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 Tables 4-1 and 4-3, were used instead of positive electrode sheet No. 201 for all solid state secondary batteries having a solid electrolyte layer. All solid state secondary batteries Nos. 402 to 423 and c101 to c105 were produced in the same manner as in the production of all solid state secondary battery No. 401.

[0245] All-solid-state secondary battery No. 501 having the layer structure shown in FIG. 1 was fabricated as follows. The solid electrolyte-containing negative electrode sheet No. 301 for all-solid-state secondary batteries obtained above (the aluminum foil of the solid electrolyte-containing sheet had already 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 to a diameter of 14.0 mm from the positive electrode sheet for all-solid-state secondary batteries fabricated below was placed on top of the solid electrolyte layer. A stainless steel foil (positive electrode current collector) was further placed on top of this 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 all-solid-state secondary battery No. 501 shown in FIG. 2 .

[0246] The positive electrode sheet for a solid secondary battery used in the production of all-solid-state secondary battery No. 501 was prepared as follows. - Preparation of positive electrode composition - 180 zirconia beads with a diameter of 5 mm were placed in a 45 mL zirconia container (manufactured by Fritsch), 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. This container was placed in a Fritsch planetary ball mill P-7 (trade name) and stirred at 25°C at 300 rpm for 60 minutes. Thereafter, LiNi was added as a positive electrode active material. １／３ Co １／３ Mn １／３ O ２7.0 g of (NMC) was added, and in the same manner, the container was set in a planetary ball mill P-7, and mixing was continued for 5 minutes at 25 ° C. and 100 rpm, to prepare a positive electrode composition. - Preparation of a positive electrode sheet for a solid secondary battery - The positive electrode composition obtained above was applied to a 20 μm thick aluminum foil (positive electrode current collector) using a Baker applicator (trade name: SA-201, manufactured by Tester Sangyo Co., Ltd.), heated at 100 ° C. for 2 hours, and the positive electrode composition was dried (dispersion medium removed). Thereafter, using a heat press, the dried positive electrode composition was pressurized (10 MPa, 1 minute) at 25 ° C. to prepare a positive electrode sheet for an all-solid-state secondary battery having a positive electrode active material layer with a film thickness of 80 μm.

[0247] All solid state secondary batteries Nos. 502 to 523 and c201 to c205 were produced as follows. All solid state secondary batteries Nos. 502 to 523 and c201 to c205 were produced in the same manner as in the production of all solid state secondary battery No. 501, except that in the production of all solid state secondary battery No. 501, 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 Tables 4-2 and 4-3, were used instead of negative electrode sheet No. 301 for all solid state secondary batteries having a solid electrolyte layer.

[0248] <Evaluation 2: Ionic Conductivity Measurement> The ionic conductivity of each of the manufactured all-solid-state secondary batteries was measured. Specifically, each all-solid-state secondary battery was used as a sample for ionic conductivity measurement, and AC impedance was measured at a voltage amplitude of 5 mV and a frequency of 1 MHz to 1 Hz using a 1255B FREQUENCY RESPONSE ANALYZER (trade name, manufactured by SOLARTRON) in a thermostatic bath at 25°C. The resistance in the layer thickness direction of the sample for ionic conductivity measurement was then determined, and the ionic conductivity was calculated using the following formula (C1). The results are shown in Tables 4-1 to 4-3 (collectively referred to as Table 4). Formula (C1): Ionic conductivity σ (mS / cm) = 1000 × sample layer thickness (cm) / [resistance (Ω) × sample area (cm)] ２) In formula (C1), the sample layer thickness is the value measured before placing the laminate 12 in the 2032-type coin case 11, and is the value obtained by subtracting the thickness of the current collector (total layer thickness of the solid electrolyte layer and the electrode active material layer). The sample area is the area of ​​a disk-shaped sheet with a diameter of 14.5 mm. It was determined whether the obtained ionic conductivity σ fell within any of the following evaluation criteria. In this test, an ionic conductivity σ of evaluation criterion "D" or higher is considered to be acceptable. - Evaluation Criteria - A: 0.30≦σ B: 0.25≦σ<0.30 C: 0.20≦σ<0.25 D: 0.15≦σ<0.20 E: 0.10≦σ<0.15 F: σ<0.10

[0249]

[0250]

[0251]

[0252] The results shown in Tables 1 to 4 reveal the following: When a comparative binder that does not contain a polymer represented by formula (I) and having an acid value of 3 mgKOH / g or less is used, it is not possible to suppress heat generation during preparation of the inorganic solid electrolyte-containing composition, and the resistance of the all-solid-state secondary battery increases. Specifically, when A in formula (I) is used, １ Polymers T-1 and T-3, which do not have the above formula (I), T-2, which is a linear polymer, and polymers T-4 and T-5, which have too high an acid value, all generate heat when mixed with solid particles such as an inorganic solid electrolyte. The inorganic solid electrolyte compositions of the comparative examples prepared by mixing in such a heat-generating state all produce high resistance in all-solid-state secondary batteries. In contrast, when the binder of the present invention containing a polymer represented by formula (I) and having an acid value of 3 mgKOH / g or less is used, heat generation during preparation of the inorganic solid electrolyte-containing composition can be suppressed, and an increase in the resistance of the all-solid-state secondary battery can be suppressed.

[0253] 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.

[0254] This application claims priority based on Japanese Patent Application No. 2023-108489 filed in Japan on June 30, 2023, and Japanese Patent Application No. 2023-220463 filed in Japan on December 27, 2023, the contents of which are incorporated herein by reference.

[0255] REFERENCE SIGNS LIST 1 negative electrode current collector 2 negative electrode active material layer 3 solid electrolyte layer 4 positive electrode active material layer 5 positive electrode current collector 6 operating part 10 all-solid-state secondary battery 11 2032-type coin case 12 laminate for all-solid-state secondary battery 13 coin-type all-solid-state secondary battery

Claims

1. A binder for an all-solid-state secondary battery, comprising a polymer represented by the following formula (I) and having an acid value of 3 mgKOH / g or less: In formula (I), R １ represents a (m+n)-valent linking group. １ represents a hydrogen atom, or a functional group or polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group. ２ represents a functional group or a polymer chain containing at least one of a fluorine atom and a polysiloxane structure, n is an integer of 1 to 8, and m is an integer of 1 to 9, provided that m+n is an integer of 2 to 10.

2. Section A above １ The binder for an all-solid-state secondary battery according to claim 1 , wherein represents a functional group or a polymer chain containing at least one of an amide group, a sulfonamide group, and an imide group.

3. Section A above ２ The binder for an all-solid-state secondary battery according to claim 1 , wherein the binder comprises a functional group or a polymer chain containing a polysiloxane structure.

4. The binder for an all-solid-state secondary battery according to claim 1, wherein the polymer has an acid value of 0.5 mg KOH / g or less and a base value of 0.5 mg KOH / g or less.

5. Section A above １ The binder for an all-solid-state secondary battery according to claim 1 , wherein the binder comprises a polymer chain of a (meth)acrylamide compound.

6. Section A above １ The binder for an all-solid-state secondary battery according to claim 1 , wherein the binder comprises a hydrogen atom and a polymer chain of a (meth)acrylamide compound.

7. The amount of A in the polymer １ The binder for all-solid-state secondary batteries according to claim 1, wherein the content of said binder is 1 to 30 mass%.

8. The binder for an all-solid-state secondary battery according to claim 1, wherein the weight average molecular weight of the polymer is 30,000 or less.

9. An inorganic solid electrolyte-containing composition comprising the binder for an all-solid-state secondary battery according to any one of claims 1 to 8, an inorganic solid electrolyte having ionic conductivity of a metal belonging to Group 1 or 2 of the periodic table, and a dispersion medium.

10. The inorganic solid electrolyte-containing composition according to claim 9, which contains an active material.

11. The inorganic solid electrolyte-containing composition according to claim 9, further comprising a conductive assistant.

12. A sheet for an all-solid-state secondary battery having a layer formed using the inorganic solid electrolyte-containing composition according to claim 9.

13. A sheet for an all-solid-state secondary battery having an active material layer formed using the inorganic solid electrolyte-containing composition according to claim 10.

14. 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, wherein at least one of the positive electrode active material layer, the solid electrolyte layer, and the negative electrode active material layer is formed using the inorganic solid electrolyte-containing composition according to claim 9.

15. 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, wherein at least one of the positive electrode active material layer and the negative electrode active material layer is an active material layer formed using the inorganic solid electrolyte-containing composition according to claim 10.

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