Positive electrode layer, positive electrode and solid-state battery

Abstract

To provide a positive electrode layer, a positive electrode including the positive electrode layer, and a solid-state battery including the positive electrode, which are capable of reducing the rate of increase in resistance of a solid-state battery.SOLUTION: A positive electrode layer or the like includes a sulfide solid electrolyte containing lithium atoms, sulfur atoms, and halogen atoms, and the sulfide solid electrolyte includes a coating layer on a surface thereof, the coating layer including at least one selected from a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of the compound represented by the following general formula (1), a polymer of the compound represented by the following general formula (2), and a polymer of the compound represented by the following general formula (1) and the compound represented by the following general formula (2).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a positive electrode layer, a positive electrode, and a solid-state battery. [Background technology]

[0002] With the recent rapid spread of information-related and communication devices such as personal computers, video cameras, and mobile phones, the development of batteries to be used as their power sources has become increasingly important. Among these, lithium-ion batteries have attracted attention due to their high energy density and excellent safety.

[0003] Conventionally, batteries used for such applications have used electrolytes containing flammable organic solvents, which necessitates the installation of safety devices to suppress temperature rises during short circuits, as well as improvements in the structure and materials to prevent short circuits.In response to this, batteries that use solid electrolytes instead of flammable organic solvents and solidify the battery can be developed, which eliminates the need for flammable organic solvents in the battery, simplifies the safety devices, and is superior in terms of manufacturing cost and productivity.

[0004] Patent Document 1 describes a solid electrolyte having a BET specific surface area of ​​10 m as the solid electrolyte to be contained in the solid electrolyte layer. 2 / g or more, and the solid electrolyte contains a sulfide solid electrolyte containing lithium atoms, sulfur atoms, phosphorus atoms, and halogen atoms, and an epoxy compound, and the infrared absorption spectrum by FT-IR analysis (ATR method) has a peak density of 2800 to 3000 cm -1 A modified sulfide solid electrolyte having a peak at [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 158458 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, the resistance of solid-state batteries tends to increase with repeated charging and discharging, and an increase in the rate of increase in resistance means that the deterioration of the battery caused by charging and discharging the battery increases. The present inventors have now discovered that the modified sulfide solid electrolyte disclosed in Patent Document 1 may further increase the rate of increase in resistance when contained in an anode layer or a solid electrolyte layer, and that some of the modified sulfide solid electrolytes disclosed in Patent Document 1 may further increase the rate of increase in resistance even when contained in a cathode layer.

[0007] One embodiment of the present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a positive electrode layer, a positive electrode including the positive electrode layer, and a solid-state battery including the positive electrode, which are capable of reducing the rate of increase in resistance of a solid-state battery. [Means for solving the problem]

[0008] The means for solving the above problems include the following embodiments. <1> A sulfide solid electrolyte containing lithium atoms, sulfur atoms, and halogen atoms is included. A positive electrode layer in which the sulfide solid electrolyte has, on the surface thereof, a coating layer containing at least one selected from a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a polymer of a compound represented by the following general formula (2):

[0009] [ka]

[0010] (In formula (1), R 1 ~R 3 are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 1 ~R 3at least one of R is a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group; 1 ~R 3 At least one of them has an ether structure. In formula (2), R 11 ~R 14 are each independently a hydrogen atom, a halogen atom, a monovalent silyl ether group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 11 ~R 14 At least one of the groups is a silyl ether group. <2> the coating layer contains at least one of a compound represented by general formula (1) and a polymer of a compound represented by general formula (1), R 1 ~R 3 any two of the above are hydrogen atoms and one is a monovalent hydrocarbon group having an ether structure. <1> The positive electrode layer according to claim 1. <3> the coating layer contains at least one of a compound represented by general formula (2) and a polymer of a compound represented by general formula (2), R 11 ~R 14 three of which are monovalent silyl ether groups and one of which is a monovalent hydrocarbon group, <1> or <2> The positive electrode layer according to claim 1. <4> The coating layer contains at least one compound selected from the group consisting of a compound represented by the following chemical formula and a polymer containing at least one compound represented by the following chemical formula: <1> ~ <3> 10. The positive electrode layer according to any one of the above items.

[0011] [ka]

[0012] <5> The compound represented by the general formula (1), the compound represented by the general formula (2), the polymer of the compound represented by the general formula (1), the polymer of the compound represented by the general formula (2), or the polymer of the compound represented by the general formula (1) and the compound represented by the general formula (2) has a molecular weight or a weight average molecular weight of 60 or more. <1> ~ <4> 10. The positive electrode layer according to any one of the above items. <6> the sum of the contents of the compound represented by general formula (1), the compound represented by general formula (2), the polymer of the compound represented by general formula (1), the polymer of the compound represented by general formula (2), and the polymer of the compound represented by general formula (1) and the compound represented by general formula (2) is 0.1 parts by mass to 20 parts by mass when the content of the sulfide solid electrolyte contained in the positive electrode layer is taken as 100 parts by mass; <1> ~ <5> 10. The positive electrode layer according to any one of the above items. <7> a positive electrode current collector and the above <1> ~ <6> and a positive electrode layer according to any one of the above. <8> the above <7> a cathode according to claim 1, an electrolyte layer, and an anode including an anode layer and an anode current collector. <9> the electrolyte layer does not contain a solid electrolyte having a coating layer on its surface containing at least one selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), or contains a solid electrolyte having the coating layer, and the content of the solid electrolyte having the coating layer relative to the total mass of the electrolyte layer is 1 mass% or less; and the negative electrode layer does not contain a solid electrolyte having a coating layer on its surface, the coating layer containing at least one selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), or a solid electrolyte having the coating layer, and the content of the solid electrolyte having the coating layer relative to the total mass of the negative electrode layer is 1 mass% or less; <8> The solid-state battery according to claim 1.

[0013] [ka]

[0014] (In formula (1), R 1 ~R 3 are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 1 ~R 3 at least one of R is a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group; 1 ~R 3 At least one of them has an ether structure. In formula (2), R 11 ~R 14 are each independently a hydrogen atom, a halogen atom, a monovalent silyl ether group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 11 ~R 14 At least one of the groups is a silyl ether group. [Effects of the Invention]

[0015] According to one embodiment of the present disclosure, it is possible to provide a positive electrode layer, a positive electrode including the positive electrode layer, and a solid-state battery including the positive electrode, which can reduce the rate of increase in resistance of a solid-state battery. [Brief explanation of the drawings]

[0016] [Figure 1]FIG. 1 is a schematic cross-sectional view showing one embodiment of the solid electrolyte of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0017] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In the numerical ranges described in this disclosure, the upper or lower limit value described in a certain numerical range may be replaced with the value shown in the examples. In the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In the present disclosure, when there are multiple substances corresponding to each component, the amount of each component means the total amount of the multiple substances unless otherwise specified. In this disclosure, "solid electrolyte" means an electrolyte that remains solid at 25°C under a nitrogen atmosphere. In the present disclosure, the term "sulfide solid electrolyte" includes both a crystalline sulfide solid electrolyte having a crystalline structure and an amorphous sulfide solid electrolyte. In the present disclosure, a crystalline sulfide solid electrolyte is a solid electrolyte in which peaks derived from the solid electrolyte are observed in the X-ray diffraction pattern in powder X-ray diffraction (XRD) measurement, regardless of whether or not peaks derived from the raw materials of the solid electrolyte are present. That is, a crystalline sulfide solid electrolyte includes a crystalline structure derived from the solid electrolyte, and the crystalline structure may be partially or entirely derived from the solid electrolyte. Furthermore, as long as the crystalline sulfide solid electrolyte has the X-ray diffraction pattern described above, it may also include an amorphous sulfide solid electrolyte (also referred to as a "glass component") as a part of it. Therefore, the crystalline sulfide solid electrolyte includes so-called glass ceramics obtained by heating an amorphous solid electrolyte (glass component) above its crystallization temperature. In the present disclosure, the amorphous sulfide solid electrolyte (glass component) refers to a solid electrolyte in which the X-ray diffraction pattern in powder X-ray diffraction (XRD) measurement is a halo pattern in which no peaks other than those derived from the material are observed, and it does not matter whether or not there are peaks derived from the raw materials of the solid electrolyte.

[0018] [Positive electrode layer] The positive electrode layer of the present disclosure contains a sulfide solid electrolyte containing lithium atoms, sulfur atoms, and halogen atoms (hereinafter also referred to as a "specific sulfide solid electrolyte"). The sulfide solid electrolyte has, on its surface, a coating layer containing at least one selected from a compound represented by the following general formula (1), a compound represented by the following general formula (2) (hereinafter, the compound represented by the following general formula (1) and the compound represented by the following general formula (2) will also be referred to as "specific compounds"), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2) (hereinafter, the polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2) will also be referred to as "specific polymer").

[0019] [ka]

[0020] In formula (1), R 1 ~R 3 are each independently a hydrogen atom, a halogen atom, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 1 ~R 3 at least one of R is a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group; 1 ~R 3 At least one of them has an ether structure. In formula (2), R 11 ~R 14are each independently a hydrogen atom, a halogen atom, a monovalent silyl ether group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R 11 ~R 14 At least one of the groups is a silyl ether group.

[0021] The positive electrode layer of the present disclosure can reduce the rate of increase in resistance of a solid-state battery. The reason why this effect is achieved is not clear, but is presumed to be as follows. A sulfide solid electrolyte without a coating layer deteriorates during charge and discharge due to electrons being extracted by carbon fibers, etc. It is presumed that the sulfide solid electrolyte having a coating layer can suppress this deterioration and reduce the rate of increase in resistance of the solid-state battery. Furthermore, oxygen is released from the deteriorated sulfide solid electrolyte, which reacts with the sulfide solid electrolyte, leading to further deterioration. However, it is presumed that the sulfide solid electrolyte has a coating layer that can suppress the reaction with oxygen, thereby reducing the rate of increase in resistance of the solid-state battery. Furthermore, the positive electrode layer may contain a conductive additive. In this case, it is presumed that the reaction between the conductive additive and the sulfide solid electrolyte can be suppressed, thereby reducing the rate of increase in resistance of the solid-state battery.

[0022] (Sulfide solid electrolyte) The sulfide solid electrolyte contains lithium atoms, sulfur atoms, and halogen atoms. The sulfide solid electrolyte may be amorphous or crystalline.

[0023] In one embodiment, the composition of the sulfide solid electrolyte is expressed, for example, as xLiS·(100−x)P2S5 (70≦x≦80), yLiI·zLiBr·(100−yz)(xLiS·(1−x)P2S5) (0.7≦x≦0.8, 0≦y≦30, 0≦z≦30), or the like. The sulfide solid electrolyte may have a composition represented by the following general formula (1). Li 4-x Ge 1-x P xS4(0 < x < 1) ··· Equation (1) In Equation (1), at least a part of Ge may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. Also, at least a part of P may be substituted with at least one selected from the group consisting of Sb, Si, Sn, B, Al, Ga, In, Ti, Zr, V, and Nb. A part of Li may be substituted with at least one selected from the group consisting of Na, K, Mg, Ca, and Zn. A part of S may be substituted with a halogen. The halogen is at least one of F, Cl, Br, and I.

[0024] Examples of the amorphous sulfide solid electrolyte include solid electrolytes composed of lithium sulfide, phosphorus sulfide, and lithium halide, such as Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-LiI-LiBr, etc.; and solid electrolytes containing other atoms such as oxygen atoms and silicon atoms, such as Li2S-P2S5-Li2O-LiI, Li2S-SiS2-P2S5-LiI, etc. From the perspective of obtaining higher ionic conductivity, solid electrolytes composed of lithium sulfide, phosphorus sulfide, and lithium halide, such as Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-LiI-LiBr, etc., are preferably mentioned. The types of atoms constituting the amorphous sulfide solid electrolyte can be confirmed, for example, by an ICP emission spectroscopic analyzer. The crystalline sulfide solid electrolyte may be a so-called glass ceramic obtained by heating the amorphous solid electrolyte above the crystallization temperature. Its crystal structure includes Li3PS4 crystal structure, Li4P2S6 crystal structure, Li7PS6 crystal structure, Li7P3S 11 Crystal structure, crystal structure having peaks in the vicinity of 2θ = 20.2° and 23.6° (for example, JP-A-2013-16423), etc. Also, Li 4-x Ge 1-x P xS4-type thio-LISICON Region II crystal structure (Kanno et al., Journal of the Electrochemical Society, 148(7)A742-746(2001)), Li 4-x Ge 1-x P x Examples include a crystal structure similar to the S4-type thio-LISICON Region II type (see Solid State Ionics, 177 (2006), 2721-2725).

[0025] The shape of the sulfide solid electrolyte is not particularly limited, but may be, for example, particulate. The average particle diameter (D 50 ) can be, for example, in the range of 0.01 μm to 500 μm, or 0.1 to 200 μm.

[0026] The content of the sulfide solid electrolyte relative to the total mass of the positive electrode layer is preferably 10 mass % to 50 mass %, and more preferably 11 mass % to 20 mass %.

[0027] -Coating layer- The specific sulfide solid electrolyte has a coating layer containing at least one selected from a specific compound and a specific polymer. The coating layer may be provided on the entire surface of the specific sulfide solid electrolyte, or may be provided on only a portion of the surface.

[0028] Hereinafter, one of the specific compounds, the compound represented by general formula (1), will be described. Examples of the halogen atom include fluorine, chlorine, bromine, and iodine, with fluorine, chlorine, and bromine being preferred, and fluorine being more preferred.

[0029] From the viewpoint of reducing the rate of increase in resistance of a solid-state battery, the monovalent hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and even more preferably 5 to 10 carbon atoms. The monovalent hydrocarbon group may be any of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group, preferably an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and more preferably an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched, preferably branched. Examples of the aliphatic hydrocarbon group include an alkyl group and an alkenyl group, with an alkyl group being preferred. Examples of the alicyclic hydrocarbon group include a cycloalkyl group and a cycloalkenyl group. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenyl group, a diphenylmethyl group, a trityl group, an anthranyl group, a perylenyl group, and a pyrenyl group. The aromatic hydrocarbon group may be partially substituted with a hydroxyl group, the above-mentioned monovalent aliphatic hydrocarbon group (e.g., an alkyl group, an alkenyl group), etc. For example, a benzyl group is also included in the aromatic hydrocarbon group in the present disclosure. The monovalent hydrocarbon group may contain an ether structure.

[0030] The monovalent halogenated hydrocarbon group includes the above-mentioned monovalent hydrocarbon groups partially substituted with halogen atoms. Preferred halogen atoms are fluorine, chlorine, and bromine, with fluorine being more preferred.

[0031] From the viewpoint of reducing the resistance increase rate of the solid-state battery, in general formula (1), R 1 ~R 3 Preferably, any two of R are hydrogen atoms and one is a monovalent hydrocarbon group having an ether structure or a monovalent halogenated hydrocarbon group, 1 ~R 3 It is more preferable that any two of the groups be hydrogen atoms and one be a monovalent hydrocarbon group having an ether structure.

[0032] Examples of compounds that satisfy the general formula (1) include the following compounds: However, compounds that satisfy the general formula (1) are not limited to these.

[0033] [ka]

[0034] The coating layer may contain a polymer of the compound represented by general formula (1). The polymer of the compound represented by general formula (1) may be composed solely of the compound represented by general formula (1), or may be a polymer copolymerized with other monomers, etc., within a range that does not significantly impair the effects of the present disclosure. In the present disclosure, a polymer of a compound represented by general formula (1) refers to a compound in which two or more compounds represented by general formula (1) are polymerized. Furthermore, the presence of the polymer of the compound represented by general formula (1) in the coating layer is confirmed by GC-MS.

[0035] The compound represented by general formula (2), which is one of the specific compounds, will be described below. Note that the halogen atoms, monovalent hydrocarbon groups, and monovalent halogenated hydrocarbon groups are the same as those in general formula (1), so descriptions thereof will be omitted here. The monovalent silyl ether group is *-O-Si-(R 20 In the above group, R 20 are each independently a hydrogen atom or a monovalent hydrocarbon group, and R 20 At least one of R is a monovalent hydrocarbon group. 20 is preferably a monovalent hydrocarbon group, preferably an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, more preferably an aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear or branched, preferably branched. The monovalent hydrocarbon group here is also the same as in general formula (1), and therefore will not be described here. In the above groups, * represents the bond to Si in general formula (2).

[0036] From the viewpoint of reducing the resistance increase rate of the solid-state battery, in general formula (2), R 11 ~R 14Among these, it is preferable that at least two are monovalent silyl ether groups, more preferable that at least three are monovalent silyl ether groups, and even more preferable that three are monovalent silyl ether groups and one is a monovalent hydrocarbon group.

[0037] Examples of compounds that satisfy the general formula (2) include the following compounds: However, compounds that satisfy the general formula (2) are not limited to these.

[0038] [ka]

[0039] The coating layer may contain a polymer of the compound represented by general formula (2). The polymer of the compound represented by general formula (2) may be composed solely of the compound represented by general formula (2), or may be a polymer copolymerized with other monomers, etc., within a range that does not significantly impair the effects of the present disclosure. In the present disclosure, a polymer of a compound represented by general formula (2) refers to a compound in which two or more compounds represented by general formula (2) are polymerized.

[0040] The coating layer may contain a polymer of the compound represented by general formula (1) and the compound represented by general formula (2). The polymer may be composed only of the compound represented by general formula (1) and the compound represented by general formula (2), or may be a polymer copolymerized with other monomers, etc., within a range that does not significantly impair the effects of the present disclosure. In the present disclosure, a polymer of a compound represented by general formula (1) and a polymer of a compound represented by general formula (2) refers to a compound in which one or more compounds represented by general formula (1) and one or more compounds represented by general formula (2) are polymerized. Furthermore, the presence of the polymer of the compound represented by general formula (2) and the polymer of the compound represented by general formula (1) and the compound represented by general formula (2) in the coating layer is confirmed by GC-MS.

[0041] From the viewpoint of reducing the resistance increase rate of the solid-state battery, the molecular weight of the specific compound is preferably 60 or more, more preferably 60 to 10,000, and even more preferably 300 to 5,000. The positive electrode layer may contain a specific polymer, in which case the weight-average molecular weight of the specific polymer is preferably 60 to 10,000, and more preferably 300 to 5,000. The "weight average molecular weight" is determined by gel permeation chromatography (GPC) in terms of polystyrene.

[0042] When the content of the sulfide solid electrolyte contained in the positive electrode layer is taken as 100 parts by mass, the sum of the contents of the specific compound and the specific polymer is preferably 0.1 parts by mass to 20 parts by mass, more preferably 1 part by mass to 10 parts by mass, and even more preferably 3 parts by mass to 7 parts by mass, from the viewpoint of reducing the resistance increase rate of the solid battery. From the viewpoint of reducing the resistance increase rate of the solid-state battery, the sum of the contents of the specific compound and the specific polymer relative to the total mass of the positive electrode layer is preferably 0.01% by mass to 4% by mass, and more preferably 0.1% by mass to 2% by mass.

[0043] The specific sulfide solid electrolyte having a coating layer on the surface of the sulfide solid electrolyte can be produced by mixing the sulfide solid electrolyte, the specific compound, and an organic solvent, and then removing the organic solvent. Examples of organic solvents include hexane, pentane, 2-ethylhexane, toluene, dimethyl ether, diethyl ether, tert-butyl methyl ether, dimethoxymethane, dimethoxyethane, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate; methyl propionate, ethylenediamine, diaminopropane, dimethylethylenediamine, and diethylethylenediamine. The sulfide solid electrolyte to be used may be one produced by a conventionally known method, or may be a commercially available one.

[0044] (Cathode active material) The positive electrode layer of the present disclosure may contain a positive electrode active material. The positive electrode active material can be any material that can promote a battery chemical reaction involving the movement of lithium ions due to atoms, preferably lithium atoms, that are used as atoms that exhibit ionic conductivity in relation to the negative electrode active material. Examples of such positive electrode active materials that can insert and extract lithium ions include oxide-based positive electrode active materials and sulfide-based positive electrode active materials. Preferred examples of oxide-based positive electrode active materials include lithium-containing transition metal composite oxides such as LMO (lithium manganese oxide), LCO (lithium cobalt oxide), NMC (lithium nickel manganese cobalt oxide), NCA (lithium nickel cobalt aluminate), LNCO (lithium nickel cobalt oxide), and olivine-type compounds (LiMeNPO4, Me=Fe, Co, Ni, Mn). Examples of sulfide-based positive electrode active materials include titanium sulfide (TiS2), molybdenum sulfide (MoS2), iron sulfide (FeS, FeS2), copper sulfide (CuS), nickel sulfide (Ni3S2), etc. In addition to the above positive electrode active materials, niobium selenide (NbSe3) and the like can also be used. The positive electrode active material can be used alone or in combination of two or more kinds.

[0045] The positive electrode active material may have a crystal structure belonging to at least one space group selected from the space groups R-3m, Immm, and P63-mmc (also referred to as P63mc or P6 / mmc). The positive electrode active material may also have an O2-type structure in which the transition metal, oxygen, and lithium are primarily arranged. Examples of positive electrode active materials having a crystal structure belonging to R-3m include Li x Me y O α X β(Me represents at least one selected from the group consisting of Mn, Co, Ni, Fe, Al, Cu, V, Nb, Mo, Ti, Cr, Zr, Zn, Na, K, Ca, Mg, Pt, Au, Ag, Ru, W, B, Si, and P, and X represents at least one selected from the group consisting of F, Cl, N, S, Br, and I, satisfying 0.5≦x≦1.5, 0.5≦y≦1.0, 1≦α<2, and 0<β≦1.) Compounds represented thereby are exemplified. As the positive electrode active material having a crystal structure belonging to Immm, for example, Li x1 M 1 A 1 2 (satisfying 1.5≦x1≦2.3, M 1 contains at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, and A 1 contains at least oxygen, and the ratio of oxygen in A 1 is 85 atomic% or more.) Composite oxides represented thereby (specific example: Li2NiO2), Li x1 M 1A 1-x2 M 1B x2 O 2-y A 2 y (0≦x2≦0.5, 0≦y≦0.3, and at least one of x2 and y is not 0, M 1A represents at least one selected from the group consisting of Ni, Co, Mn, Cu, and Fe, M 1B represents at least one selected from the group consisting of Al, Mg, Sc, Ti, Cr, V, Zn, Ga, Zr, Mo, Nb, Ta, and W, and A2 represents at least one selected from the group consisting of F, Cl, Br, S, and P.) Composite oxides represented thereby are exemplified. As the positive electrode active material having a crystal structure belonging to P63-mmc, for example, M1 x M2 y O2 (M1 represents an alkali metal (preferably at least one of Na and K), M2 represents a transition metal (preferably at least one selected from the group consisting of Mn, Ni, Co, and Fe), and x + y satisfies 0<x + y≦2.) Composite oxides represented thereby are exemplified. As the positive electrode active material having an O2-type structure, for example, Lix [Li α (Mn a Co b M c ) 1-α O2 (where 0.5 < x < 1.1, 0.1 < α < 0.33, 0.17 < a < 0.93, 0.03 < b < 0.50, 0.04 < c < 0.33, and M represents at least one selected from the group consisting of Ni, Mg, Ti, Fe, Sn, Zr, Nb, Mo, W, and Bi). Examples of the composite oxide include Li 0.744 [Li 0.145 Mn 0.625 Co 0.115 Ni 0.115 O2 and the like.

[0046] The content rate of the positive electrode active material with respect to the total mass of the positive electrode layer is preferably 65% by mass to 95% by mass, and more preferably 80% by mass to 90% by mass.

[0047] (Conductive aid) The positive electrode layer of the present disclosure may contain a conductive aid. Examples of the conductive aid include carbon-based materials such as artificial graphite, graphite carbon fiber, resin-fired carbon, thermally decomposed vapor-phase grown carbon, coke, mesocarbon microbeads, furfuryl alcohol resin-fired carbon, polyacene, pitch-based carbon fiber, vapor-phase grown carbon fiber, natural graphite, and non-graphitizable carbon.

[0048] The content rate of the conductive aid with respect to the total mass of the positive electrode layer is preferably 1% by mass to 5% by mass, and more preferably 1% by mass to 2% by mass.

[0049] (Binder) The positive electrode layer of the present disclosure may contain a binder. Examples of the binder include fluorine-based polymers such as polytetrafluoroethylene and polyvinylidene fluoride, thermoplastic elastomers such as butylene rubber and styrene-butadiene rubber, and various resins such as acrylic resin, acrylic polyol resin, polyvinyl acetal resin, polyvinyl butyral resin, and silicone resin.

[0050] The content of the binder relative to the total mass of the positive electrode layer is preferably 0.1 mass % to 10 mass %, and more preferably 0.2 mass % to 0.8 mass %.

[0051] (Other ingredients) The positive electrode layer of the present disclosure may contain components other than the above-described components (hereinafter also referred to as "other components"). Examples of the other components include solid electrolytes other than sulfide solid electrolytes. Examples of solid electrolytes other than sulfide solid electrolytes include oxide solid electrolytes and halogenated solid electrolytes. The oxide solid electrolyte preferably contains oxygen (O) as the main anion element, and may contain, for example, Li, Q element (Q represents at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W, and S), and O. Examples of the oxide solid electrolyte include garnet-type solid electrolytes, perovskite-type solid electrolytes, Nasicon-type solid electrolytes, Li-PO-based solid electrolytes, and Li-BO-based solid electrolytes. Examples of the garnet-type solid electrolyte include Li7La3Zr2O 12 , Li 7-x La3(Zr 2-x Nb x )O 12 (0≦x≦2), Li5La3Nb2O 12 Examples of perovskite-type solid electrolytes include (Li,La)TiO3, (Li,La)NbO3, (Li,Sr)(Ta,Zr)O3, etc. Examples of Nasicon-type solid electrolytes include Li(Al,Ti)(PO4)3, Li(Al,Ga)(PO4)3, etc. Examples of Li-PO-based solid electrolytes include Li3PO4 and LIPON (a compound in which part of the O in Li3PO4 is substituted with N), and examples of Li-BO-based solid electrolytes include Li3BO3 and a compound in which part of the O in Li3BO3 is substituted with C, etc. As the halide solid electrolyte, a solid electrolyte containing Li, M, and X (M represents at least one of Ti, Al, and Y, and X represents F, Cl, or Br) is suitable. 6-3z Y zX6 (where X represents Cl or Br, and z satisfies 0 < z < 2), Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≤ 1.5) is preferred. Li 6-3z Y z Among X6, Li3YX6 (where X represents Cl or Br) is more preferred in terms of excellent lithium ion conductivity, and further Li3YCl6 is preferred. Also, Li 6-(4-x)b (Ti 1-x Al x ) b F6 (0 < x < 1, 0 < b ≤ 1.5) is preferably included together with a solid electrolyte such as a sulfide solid electrolyte, for example, from the viewpoint of suppressing oxidative decomposition of the sulfide solid electrolyte, and more preferably covers at least a part of the surface of the solid electrolyte such as a sulfide solid electrolyte. Thereby, the lithium ion conductivity becomes better.

[0052] (Use) The positive electrode layer of the present disclosure can be suitably used as a material constituting the positive electrode of a solid battery.

[0053] [Positive Electrode] The positive electrode of the present disclosure includes a positive electrode current collector and the positive electrode layer formed on at least one surface of the positive electrode current collector. Since the positive electrode layer has been described above, the description is omitted here.

[0054] (Positive Electrode Current Collector) As the positive electrode current collector, conventionally known ones can be used. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, carbon, etc., and an aluminum alloy foil or an aluminum foil is preferred. The aluminum alloy foil and the aluminum foil may be manufactured using powder. The shape of the positive electrode current collector is, for example, foil-shaped or mesh-shaped.

[0055] The thickness of the positive electrode current collector is not particularly limited, and can be, for example, 1 to 100 μm. The thickness of the positive electrode layer is not particularly limited, and can be, for example, 1 to 200 μm.

[0056] The positive electrode of the present disclosure can be produced by applying an electrode composition containing a specific sulfide solid electrolyte and the like to the surface of a positive electrode current collector and drying it.

[0057] (Application) The positive electrode of the present disclosure can be suitably used as a positive electrode for a solid-state battery.

[0058] [Solid battery] The solid-state battery of the present disclosure includes the above-described positive electrode, an electrolyte layer, and a negative electrode. The positive electrode has been described above, so a description thereof will be omitted here. The solid-state battery of the present disclosure is preferably a lithium-ion battery.

[0059] A schematic cross-sectional view showing one embodiment of a solid state battery is shown in Figure 1. As shown in Figure 1, an anode layer A, an electrolyte layer B, and a cathode layer C are laminated. In FIG. 1, the negative electrode active material is indicated by reference numeral 101, the positive electrode active material by reference numeral 103, the conductive additives by reference numerals 105 and 107, the binders by reference numerals 109 and 111, the negative electrode current collector by reference numeral 113, and the positive electrode current collector by reference numeral 115. The solid-state battery may have a structure in which the stacking end faces (side faces) of the stacked structure of the positive electrode / solid electrolyte layer / negative electrode are sealed with a resin. The positive electrode current collector and the negative electrode current collector may have a buffer layer, an elastic layer, or a PTC (Positive Temperature Coefficient) thermistor layer disposed on their surfaces. The electrolyte layer may also have a two-layer structure as shown in FIG.

[0060] (electrolyte layer) The electrolyte layer contains a solid electrolyte. The solid electrolyte layer may have a single layer structure or a multilayer structure of two or more layers. As the solid electrolyte, a conventionally known solid electrolyte that can be used for the electrolyte layer of a solid-state battery can be used, and an example of the solid electrolyte is a sulfide solid electrolyte. From the viewpoint of reducing the rate of increase in resistance of the solid-state battery, it is preferable that the electrolyte layer does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 1 mass% or less; it is more preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 0.5 mass% or less; it is even more preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 0.1 mass% or less; and it is particularly preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer.

[0061] The electrolyte layer may contain a binder, such as a rubber-based binder such as styrene butadiene rubber, or a fluoride-based binder such as polyvinylidene fluoride (PVDF).

[0062] The electrolyte layer may be one produced by a conventionally known method, or may be a commercially available one.

[0063] The thickness of the electrolyte layer is not particularly limited, and can be, for example, 1 μm to 100 μm.

[0064] (Negative electrode) The negative electrode includes a negative electrode current collector and the negative electrode layer formed on at least one surface of the negative electrode current collector.

[0065] -Negative electrode current collector- The negative electrode current collector can be made of any of the above-mentioned metal foils, and nickel foil is preferred. The thickness of the negative electrode current collector is not particularly limited, and can be, for example, 10 μm to 100 μm.

[0066] -Anode layer- The negative electrode layer may contain a solid electrolyte. As the solid electrolyte, a conventionally known solid electrolyte that can be used for the negative electrode layer of a solid-state battery may be used, and an example of the solid electrolyte is a sulfide solid electrolyte. From the viewpoint of reducing the rate of increase in resistance of the solid-state battery, it is preferable that the negative electrode layer does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 1% by mass or less; it is more preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 0.5% by mass or less; it is even more preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, or that it contains a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer, and the content of the solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer relative to the total mass of the electrolyte layer is 0.1% by mass or less; and it is particularly preferable that it does not contain a solid electrolyte having a coating layer containing at least one of a specific compound and a specific polymer.

[0067] The negative electrode layer may contain a negative electrode active material. Examples of the negative electrode active material include silicon, silicon alloys, and silicon oxides. Furthermore, the negative electrode active material may include metal lithium, metal indium, metal aluminum, metal silicon, metal tin, or other metals capable of forming alloys with metal lithium, oxides of these metals, and alloys of these metals with metal lithium.

[0068] The content of the negative electrode active material relative to the total mass of the negative electrode layer is not particularly limited, and can be, for example, 40 mass % to 75 mass %.

[0069] The thickness of the negative electrode layer is not particularly limited, and can be, for example, 1 μm to 100 μm.

[0070] The negative electrode layer may contain the above-mentioned conductive material, binder, and the like.

[0071] The negative electrode to be used may be one produced by a conventionally known method, or may be a commercially available one. [Example]

[0072] The present disclosure will be described in more detail below with reference to examples, but the invention of the present disclosure is not limited to these examples.

[0073] Example 1 (Formation of positive electrode layer and preparation of positive electrode) A Schlenk flask (volume: 100 mL) equipped with a stir bar was charged with 0.59 g of lithium sulfide, 0.95 g of diphosphorus pentasulfide, 0.19 g of lithium bromide, and 0.28 g of lithium iodide under a nitrogen atmosphere. After rotating the stir bar, 20 mL of the complexing agent tetramethylethylenediamine (TMEDA) was added, and stirring was continued for 12 hours. The resulting complex was dried under vacuum (room temperature: 23°C) to obtain a powdered complex. The complex powder was then heated under vacuum at 120°C for 2 hours to obtain an amorphous sulfide solid electrolyte. The amorphous sulfide solid electrolyte was then heated under vacuum at 140°C for 2 hours to obtain a crystalline sulfide solid electrolyte A (the heating temperature (140°C in this example) to obtain a crystalline sulfide solid electrolyte is sometimes referred to as the "crystallization temperature").

[0074] In a Schlenk flask (volume: 100 mL) equipped with a stirrer, 3 g of the crystalline sulfide solid electrolyte A obtained as described above was weighed out and added under a nitrogen atmosphere, followed by the addition of 22 g of toluene and stirring to obtain a slurry-like fluid. 0.16 g (5 parts by mass relative to 100 parts by mass of the crystalline sulfide solid electrolyte) of a specific compound shown in Table 1 was further added to the slurry-like fluid, and after stirring for 10 minutes, the toluene was distilled off by vacuum drying to obtain a specific sulfide solid electrolyte A having a coating layer on its surface. The specific sulfide solid electrolyte A was observed using an EDS-equipped scanning electron microscope (SEM-EDS, magnification 30,000x), and then the polysiloxane-derived Si was mapped using EDS. Image analysis was performed using ImageJ to confirm that the specific sulfide solid electrolyte A had a coating layer. Furthermore, GC-MS confirmed that this coating layer contained a polymer of the specific compound. The same method was used to confirm these findings in the following examples and comparative examples.

[0075] 80.0 g of (LiNi1 / 3Co1 / 3Mn1 / 3O2) was used as the positive electrode active material, 9.51 g of the specific sulfide solid electrolyte obtained as described above, and 2.5 g of carbon fiber (VGCF, Showa Denko K.K.) as a conductive additive were placed in a FILMICS container. A solution containing styrene butadiene rubber as a binder (the binder concentration in the solution was 5% by mass relative to the total solution) and 32.21 g of tetralin as a solvent were then added to the FILMICS container to obtain a positive electrode raw material composition with a solids concentration of 69% by mass. Using a FILMICS kneading device, the positive electrode raw material composition was kneaded at a peripheral speed of 25 m / s to obtain a positive electrode composition. A high-shear PC wheel was used for the FILMICS. The electrode composition for the positive electrode was applied in the form of a film to the surface of a positive electrode current collector (aluminum foil) by a blade coating method using an applicator, and the film-like electrode composition was heated at 100°C for 30 minutes to form a positive electrode layer on the surface of the positive electrode current collector, thereby obtaining a positive electrode comprising a positive electrode current collector and a positive electrode layer.

[0076] (Formation of negative electrode layer and production of negative electrode) A solution containing 18.6 g of elemental silicon as the negative electrode active material, 8.69 g of sulfide solid electrolyte A, a styrene-butadiene rubber binder (the binder concentration in the solution was 5% by mass relative to the total solution), and diisobutyl ketone solvent were added to a FILMICS container to obtain a negative electrode raw material composition with a solids concentration of 43% by mass. A FILMICS was used as a kneading device, and the negative electrode raw material composition was kneaded at a peripheral speed of 5 m / s to 30 m / s to obtain an electrode composition for the negative electrode. A high-shear PC wheel was used for the FILMICS. The electrode composition for the negative electrode was applied in the form of a film to the surface of a negative electrode current collector (nickel foil) using a blade coating method with an applicator, and the film-like electrode composition was heated at 100°C for 30 minutes to form a negative electrode layer on the surface of the negative electrode current collector, thereby obtaining a negative electrode comprising a negative electrode current collector and a negative electrode layer.

[0077] (Preparation of solid electrolyte layer) 40 g of sulfide solid electrolyte A, 8.00 g of a solution containing acrylate butadiene rubber and hexane (the concentration of the acrylate butadiene rubber in the solution was 5% by mass relative to the total solution), 25.62 g of heptane, and 8.00 g of dibutyl ether were mixed and kneaded with an ultrasonic homogenizer to obtain a solid electrolyte layer composition. The solid electrolyte layer composition was applied to the surface of aluminum foil in the form of a film by a blade coating method using an applicator, and the film-like solid electrolyte layer composition was heated at 100°C for 30 minutes to form a solid electrolyte layer.

[0078] (Solid-state battery manufacturing) A solid electrolyte layer and a positive electrode were transferred in this order to both sides of the obtained negative electrode using a pressure of 20 kN. The obtained laminate was pressed using a roll press to obtain a solid-state battery. The press linear pressure was 4 ton / cm. The gap between the rolls was 200 μm.

[0079] <Examples 2 and 3> A solid-state battery was produced in the same manner as in Example 1, except that the specific compound was changed to the specific compound shown in Table 1. The specific sulfide solid electrolyte used in Example 2 is specific sulfide solid electrolyte B, and the specific sulfide solid electrolyte used in Example 3 is specific sulfide solid electrolyte C.

[0080] <Comparative Examples 1 to 3> (Formation of positive electrode layer and preparation of positive electrode) A positive electrode was produced in the same manner as in Example 1, except that the specific sulfide solid electrolyte A was changed to a sulfide solid electrolyte A having no coating layer.

[0081] (Formation of negative electrode layer and production of negative electrode) A negative electrode was produced in the same manner as in Example 1, except that the sulfide solid electrolyte A not having a coating layer was changed to the specific sulfide solid electrolyte shown in Table 1.

[0082] (Fabrication of solid electrolyte layer and manufacturing of solid state battery) In the same manner as in Example 1, a solid electrolyte layer was prepared and a solid battery was manufactured.

[0083] <Comparative Examples 4 to 6> (Formation of positive electrode layer and preparation of positive electrode) A positive electrode was produced in the same manner as in Example 1, except that the specific sulfide solid electrolyte A was changed to a sulfide solid electrolyte A having no coating layer.

[0084] (Formation of negative electrode layer and production of negative electrode) A negative electrode was prepared in the same manner as in Example 1.

[0085] (Preparation of solid electrolyte layer) A solid electrolyte layer was produced in the same manner as in Example 1, except that the sulfide solid electrolyte A having no coating layer was changed to the specific sulfide solid electrolyte shown in Table 1.

[0086] (Solid-state battery manufacturing) A solid-state battery was produced in the same manner as in Example 1.

[0087] <Comparative Example 7> (Formation of positive electrode layer and preparation of positive electrode) A positive electrode was produced in the same manner as in Example 1, except that the specific sulfide solid electrolyte A was changed to a sulfide solid electrolyte A having no coating layer.

[0088] (Formation of negative electrode layer and production of negative electrode) A negative electrode was prepared in the same manner as in Example 1.

[0089] (Preparation of solid electrolyte layer) A negative electrode was prepared in the same manner as in Example 1.

[0090] (Solid-state battery manufacturing) A solid-state battery was produced in the same manner as in Example 1.

[0091] <Comparative Examples 8 and 9> (Formation of positive electrode layer and preparation of positive electrode) A solid state battery was produced in the same manner as in Example 1, except that the compound used in the coating layer of the sulfide solid electrolyte was changed to the compound shown in Table 1. The sulfide solid electrolytes used in Comparative Examples 8 and 9 have a coating layer, but the compound contained therein is not a specific compound. The sulfide solid electrolyte used in Comparative Example 8 is sulfide solid electrolyte x, and the sulfide solid electrolyte used in Comparative Example 9 is sulfide solid electrolyte y.

[0092] (Formation of negative electrode layer and production of negative electrode) A negative electrode was prepared in the same manner as in Example 1.

[0093] (Preparation of solid electrolyte layer) A negative electrode was prepared in the same manner as in Example 1.

[0094] (Solid-state battery manufacturing) A solid-state battery was produced in the same manner as in Example 1.

[0095] <Comparative Examples 10 to 11> (Formation of positive electrode layer and preparation of positive electrode) A positive electrode was produced in the same manner as in Example 1, except that the specific sulfide solid electrolyte A was changed to a sulfide solid electrolyte A having no coating layer.

[0096] (Formation of negative electrode layer and production of negative electrode) A negative electrode was produced in the same manner as in Example 1, except that the sulfide solid electrolyte A having no coating layer was changed to a sulfide solid electrolyte shown in Table 1.

[0097] (Fabrication of solid electrolyte layer and manufacturing of solid state battery) In the same manner as in Example 1, a solid electrolyte layer was prepared and a solid battery was manufactured.

[0098] <Comparative Examples 12 and 13> (Formation of positive electrode layer and preparation of positive electrode) A positive electrode was produced in the same manner as in Example 1, except that the specific sulfide solid electrolyte A was changed to a sulfide solid electrolyte A having no coating layer.

[0099] (Formation of negative electrode layer and production of negative electrode) A negative electrode was prepared in the same manner as in Example 1.

[0100] (Preparation of solid electrolyte layer) A solid electrolyte layer was produced in the same manner as in Example 1, except that the sulfide solid electrolyte A having no coating layer was changed to a sulfide solid electrolyte shown in Table 1.

[0101] (Solid-state battery manufacturing) A solid-state battery was produced in the same manner as in Example 1.

[0102] [Drag increase rate evaluation] Using the solid-state batteries obtained in the examples and comparative examples, CCCV charge / discharge was performed 1000 cycles at 0.1 C with an upper limit voltage of 4.55 V and a lower limit voltage of 2.5 V. The design capacity of the solid-state battery was 0.3 Ah. From the obtained results, the battery resistance increase rate was calculated based on the following formula and summarized in Table 1. The initial resistance was the resistance after 3 cycles. Resistance increase rate (%) = ((battery resistance after 1000 cycles - initial resistance) / initial resistance) x 100

[0103] [Table 1]

[0104] The results in Table 1 show that the solid state batteries of the Examples in which the specific sulfide solid electrolyte was contained in the positive electrode layer had a reduced rate of increase in resistance compared to the solid state batteries of the Comparative Examples. [Explanation of symbols]

[0105] A: negative electrode layer, B: electrolyte layer, C: positive electrode layer, 101: negative electrode active material, 103: positive electrode active material, 105 and 107: conductive additive, 109 and 111: binder, 113: negative electrode current collector, 115: positive electrode current collector

Claims

1. A positive electrode current collector; A sulfide solid electrolyte containing lithium atoms, sulfur atoms, and halogen atoms is included. a positive electrode comprising a positive electrode layer in which the sulfide solid electrolyte has, on a surface thereof, a coating layer containing at least one selected from a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a polymer of a compound represented by the following general formula (2); an electrolyte layer; a negative electrode including a negative electrode layer and a negative electrode current collector; A solid-state battery in which the electrolyte layer and the negative electrode layer do not include a solid electrolyte having the coating layer. 【Chemistry 1】 (In formula (1), R １ ~R ３ At least one of the groups is a monovalent hydrocarbon group having an ether structure or a monovalent halogenated hydrocarbon group having an ether structure. In formula (2), R １１ ~R １４ are each independently a hydrogen atom, a halogen atom, a monovalent silyl ether group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R １１ ~R １４ At least one of is a silyl ether group.

2. the coating layer contains at least one of a compound represented by general formula (1) and a polymer of a compound represented by general formula (1), R １ ~R ３ 2. The solid-state battery according to claim 1, wherein any two of the groups are hydrogen atoms and one is a monovalent hydrocarbon group having an ether structure.

3. the coating layer contains at least one of a compound represented by general formula (2) and a polymer of a compound represented by general formula (2), R １１ ~R １４ 3. The solid state battery according to claim 1, wherein three of the groups are monovalent silyl ether groups and one is a monovalent hydrocarbon group.

4. 3. The solid-state battery according to claim 1, wherein the coating layer comprises at least one selected from the group consisting of compounds represented by the following chemical formulas and polymers containing at least one of the compounds represented by the following chemical formulas: 【Chemistry 2】

5. 3. The solid-state battery according to claim 1, wherein the molecular weight or weight average molecular weight of the compound represented by the general formula (1), the compound represented by the general formula (2), the polymer of the compound represented by the general formula (1), the polymer of the compound represented by the general formula (2), or the polymer of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 60 or more.

6. 3. The solid state battery according to claim 1, wherein, when the content of the sulfide solid electrolyte contained in the positive electrode layer is taken as 100 parts by mass, the sum of the contents of the compound represented by the general formula (1), the compound represented by the general formula (2), the polymer of the compound represented by the general formula (1), the polymer of the compound represented by the general formula (2), and the polymer of the compound represented by the general formula (1) and the compound represented by the general formula (2) is 0.1 parts by mass to 20 parts by mass.

7. the electrolyte layer does not contain a solid electrolyte having a coating layer on its surface, the coating layer containing at least one selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), or a solid electrolyte having the coating layer, and the content of the solid electrolyte having the coating layer relative to the total mass of the electrolyte layer is 1 mass% or less; and the negative electrode layer does not contain a solid electrolyte having a coating layer on its surface, the coating layer containing at least one selected from the group consisting of a compound represented by the following general formula (1), a compound represented by the following general formula (2), a polymer of a compound represented by the following general formula (1), a polymer of a compound represented by the following general formula (2), and a polymer of a compound represented by the following general formula (1) and a compound represented by the following general formula (2), or a solid electrolyte having the coating layer, and the ratio of the above to the total mass of the negative electrode layer is 2. The solid state battery according to claim 1, wherein the content of the solid electrolyte having the coating layer is 1 mass % or less. 【Transformation 3】 In formula (1), R １ ~R ３ At least one of the groups is a monovalent hydrocarbon group having an ether structure or a monovalent halogenated hydrocarbon group having an ether structure. In formula (2), R １１ ~R １４ are each independently a hydrogen atom, a halogen atom, a monovalent silyl ether group, a monovalent hydrocarbon group, or a monovalent halogenated hydrocarbon group, and R １１ ~R １４ At least one of is a silyl ether group.

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