All-solid-state battery and battery module

Abstract

An all-solid-state battery (10) comprises a positive electrode including a positive electrode active material layer (1), a solid electrolyte layer (5) including solid electrolyte particles (A), and a negative electrode including a negative electrode active material layer (2), the solid electrolyte particles (A) including solid electrolyte particles (A1) for which the average particle diameter d50 in a volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution measurement method is not less than 0.01 μm but less than 4.0 μm, and solid electrolyte particles (A2) for which the average particle diameter d50 in a volume-based particle size distribution measured using a laser diffraction / scattering particle size distribution measurement method is 4.0-30.0 μm.

Description

All-solid-state battery and battery module

[0001] The present invention relates to an all-solid-state battery and a battery module.

[0002] The all-solid-state battery includes, for example, a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order. Patent Document 1 describes a technique relating to the all-solid-state battery.

[0003] Patent Document 1 describes a solid electrolyte having a high ionic conductivity, the solid electrolyte including first particles made of a first solid electrolyte material and second particles made of a second solid electrolyte material, the first solid electrolyte material having a higher ionic conductivity than the second solid electrolyte material, and the second solid electrolyte material having a lower Young's modulus than the first solid electrolyte material.

[0004] International Publication No. 2020 / 100465

[0005] The present invention provides an all-solid-state battery with improved rate characteristics.

[0006] According to the study by the present inventors, the average particle diameter d in the volume-based particle size distribution measured by the laser diffraction scattering particle size distribution measurement method ５０ and a solid electrolyte particle (A1) having an average particle diameter d ５０ The present inventors have found that the rate characteristics of an all-solid-state battery can be improved by using solid electrolyte particles (A) containing solid electrolyte particles (A2) having a particle size of 4.0 μm or more and 30.0 μm or less, and have completed the present invention.

[0007] According to the present invention, the following all-solid-state battery and battery module are provided.

[0008] [1] A cathode including a cathode active material layer, a solid electrolyte layer including solid electrolyte particles (A), and a negative electrode including a negative electrode active material layer, wherein the solid electrolyte particles (A) have an average particle diameter d ５０and a solid electrolyte particle (A1) having an average particle diameter d ５０ [2] An all-solid-state battery comprising solid electrolyte particles (A2) having an average particle diameter d of 4.0 μm or more and 30.0 μm or less. ５０ [3] The all-solid-state battery according to [1], wherein the specific surface area of ​​the solid electrolyte particles (A1) measured by a nitrogen adsorption BET method is 5.0 m ２ / g or more 20.0m ２ [4] The all-solid-state battery according to [1] or [2], wherein the specific surface area of ​​the solid electrolyte particles (A2) measured by a nitrogen adsorption BET method is 0.1 m ２ / g or more 5.0m ２ [5] The all-solid-state battery according to any one of [1] to [3], wherein the specific surface area of ​​the solid electrolyte particles (A1) measured by a nitrogen adsorption BET method is less than X １ The specific surface area of ​​the solid electrolyte particles (A2) measured by the nitrogen adsorption BET method is X ２ When this is done, X １ and X ２ The ratio (X １ / X ２ [6] The all-solid-state battery according to any one of [1] to [4], wherein the particle diameter d of the solid electrolyte particles (A1) at which a cumulative volume reaches 10% in a volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is 1.0 or more and 200 or less. １０ [7] The all-solid-state battery according to any one of [1] to [5], wherein the particle diameter d of the solid electrolyte particles (A1) at which a cumulative volume is 95% in a volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is less than 1.0 μm. ９５ [8] The all-solid-state battery according to any one of [1] to [6], wherein the particle diameter d of the solid electrolyte particles (A2) at which a cumulative volume of 10% is obtained in a volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is less than 5.0 μm. １０[9] The all-solid-state battery according to any one of [1] to [7], wherein the particle diameter d of the solid electrolyte particles (A2) at which a cumulative volume is 95% in a volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is 1.0 μm or more. ９５

[10] The all-solid-state battery according to any one of [1] to [8], wherein the average particle diameter of the solid electrolyte particles (A1) in a volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is D １ The average particle diameter of the solid electrolyte particles (A2) in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is D ２ When this is done, D １ and D ２ The ratio (D １ / D ２ ) is 3.3 x 10 －４

[11] The all-solid-state battery according to any one of [1] to [9], wherein the solid electrolyte particles (A) comprise one or more electrolytes selected from the group consisting of sulfide-based solid electrolytes, oxide-based solid electrolytes, and polymer electrolytes.

[12] The all-solid-state battery according to any one of [1] to

[11] , wherein the content of the solid electrolyte particles (A) in the solid electrolyte layer is 50.0 parts by mass or more and 100.0 parts by mass or less, when the total content of the solid electrolyte layer is 100 parts by mass.

[13] The all-solid-state battery according to any one of [1] to

[12] , wherein the content of the solid electrolyte particles (A1) in the solid electrolyte particles (A) is 5.0 parts by mass or more and 95.0 parts by mass or less, and the content of the solid electrolyte particles (A2) in the solid electrolyte particles (A) is 5.0 parts by mass or more and 95.0 parts by mass or less, when the total content of the solid electrolyte particles (A) in the solid electrolyte layer is 100 parts by mass.

[14] The all-solid-state battery according to any one of [1] to

[13] , wherein the content of the binder resin in the solid electrolyte layer is 0.5 parts by mass or more when the entire solid electrolyte layer is taken as 100 parts by mass.

[15] A battery module comprising the all-solid-state battery according to any one of [1] to

[14] .

[0009] According to the present invention, an all-solid-state battery with improved rate characteristics can be provided.

[0010] FIG. 1 is a cross-sectional view showing an example of the structure of an all-solid-state battery according to an embodiment of the present invention.

[0011] The following describes an embodiment of the present invention. Note that the shapes, sizes, and layouts of the components in the drawings are merely schematic representations that allow the present invention to be understood, and are not to scale. Furthermore, unless otherwise specified, "to" in a numerical range indicates a range from above to below.

[0012] 1 is a cross-sectional view showing an example of the structure of an all-solid-state battery 10 of this embodiment. The all-solid-state battery 10 of this embodiment includes a positive electrode including a positive electrode active material layer 1, a solid electrolyte layer 5 including solid electrolyte particles (A), and a negative electrode including a negative electrode active material layer 2, and the solid electrolyte particles (A) have an average particle diameter d ５０ and a solid electrolyte particle (A1) having an average particle diameter d ５０ and solid electrolyte particles (A2) having a particle size of 4.0 μm or more and 30.0 μm or less.

[0013] As a result of the investigations by the present inventors, it was found that the average particle diameter d ５０ and a solid electrolyte particle (A1) having an average particle diameter d ５０ It has been revealed that the rate characteristics of an all-solid-state battery can be improved by using solid electrolyte particles (A) containing solid electrolyte particles (A2) having a particle size of 4.0 μm or more and 30.0 μm or less. That is, according to this embodiment, an all-solid-state battery having improved rate characteristics can be provided.

[0014] (Solid Electrolyte Layer) The solid electrolyte layer of the present embodiment contains solid electrolyte particles (A).

[0015] The solid electrolyte particles (A) of the present embodiment preferably contain one or more selected from the group consisting of a sulfide-based solid electrolyte, an oxide-based solid electrolyte, and a polymer electrolyte (hereinafter also referred to as a polymer-based solid electrolyte material), and more preferably contain a sulfide-based solid electrolyte.

[0016] The sulfide-based solid electrolyte is, for example, Li ２ S-P ２ S ５ Material, Li ２ S-SiS ２ Material, Li ２ S-GeS ２ Material, Li ２ S-Al ２ S ３ Material, Li ２ S-SiS ２ -Li ３ P.O. ４ Material, Li ２ S-P ２ S ５ -GeS ２ Material, Li ２ S-Li ２ O-P ２ S ５ -SiS ２ Material, Li ２ S-GeS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-SnS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-P ２ S ５ -Li ３ N material, Li ２ S ２＋Ｘ -P ４ S ３ Material, Li ２ S-P ２ S ５ -P ４ S ３ Material, LiPO ４ -Li ２ S-SiS material, Li ３ P.S. ４ , Li ３ P.O. ４ -Li ２ S-Si ２ S material, Li ３ P.O. ４ -Li ２ S-SiS ２Material, LiI-Li ２ S-B ２ S ３ Material, LiI-Li ２ S-SiS ２ Material, LiI-Li ２ S-P ２ S ５ Material, LiI-Li ２ S-P ２ O ５ Material, LiI-Li ３ P.O. ４ -P ２ S ５ Li ２ S-P ２ S ５ -LiCl material, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ I ｘ (where 0≦x≦2), Li １０ GeP ２ S １２ , and Li ３．２５ Ge ０．２５ P ０．７５ S ４ Preferably, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2) and Li ７－ｘ P.S. ６－ｘ I ｘ (where 0≦x≦2), more preferably Li ６ P.S. ５ Cl, Li ６ P.S. ５ Br and Li ６ P.S. ５ I, more preferably Li ６ P.S. ５ Contains Cl.

[0017] The oxide-based solid electrolyte is, for example, LiTi ２ (P.O. ４ ) ３ , LiZr ２ (P.O. ４ ) ３ , LiGe ２ (P.O. ４ ) ３ NASICON-type solid electrolyte materials such as (La ０．５＋ｘ Li ０．５－３ｘ ) TiO ３ Perovskite-type solid electrolyte materials such as Li ２ O-P ２ O ５ Material, Li ２ O-P ２ O ５ -Li ３ The material contains one or more selected from the group consisting of N materials and the like.

[0018] The polymer-based solid electrolyte material includes one or more selected from the group consisting of polyether-based electrolyte materials such as polyethylene oxide, polypropylene oxide, ethylene oxide-propylene copolymer, and dimethylsiloxane-ethylene oxide copolymer; gel polymer electrolyte materials such as polyacrylonitrile, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene polymer; and polymer solid electrolyte materials using hyperbranched polymers.

[0019] When the entire solid electrolyte layer is taken as 100 parts by mass, the content of the solid electrolyte particles (A) in the solid electrolyte layer of the present embodiment is, from the viewpoint of improving the rate characteristics of the all-solid-state battery, preferably 50.0 parts by mass or more and 100.0 parts by mass or less, more preferably 60.0 parts by mass or more and 99.9 parts by mass or less, even more preferably 70.0 parts by mass or more and 99.5 parts by mass or less, still more preferably 85.0 parts by mass or more and 99.5 parts by mass or less, still more preferably 90.0 parts by mass or more and 99.0 parts by mass or less, still more preferably 93.0 parts by mass or more and 98.0 parts by mass or less, still more preferably 93.5 parts by mass or more and 97.5 parts by mass or less, and still more preferably 94.0 parts by mass or more and 97.0 parts by mass or less.

[0020] The solid electrolyte particles (A) of this embodiment include solid electrolyte particles (A1) and solid electrolyte particles (A2).

[0021] The average particle diameter d of the solid electrolyte particles (A1) in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ５０ From the viewpoint of improving the rate characteristics of the all-solid-state battery, the thickness is 0.01 μm or more and less than 4.0 μm, preferably 0.05 μm or more and 3.0 μm or less, more preferably 0.10 μm or more and 2.0 μm or less, even more preferably 0.20 μm or more and 1.5 μm or less, even more preferably 0.30 μm or more and 1.2 μm or less, even more preferably 0.40 μm or more and 1.0 μm or less, and even more preferably 0.50 μm or more and 0.90 μm or less.

[0022] The particle diameter d of the solid electrolyte particles (A1) at which the cumulative volume is 10% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method １０ From the viewpoint of further improving the rate characteristics of the all-solid-state battery, is preferably 0.001 μm or more and less than 1.0 μm, more preferably 0.01 μm or more and 0.80 μm or less, even more preferably 0.02 μm or more and 0.60 μm or less, even more preferably 0.05 μm or more and 0.50 μm or less, even more preferably 0.10 μm or more and 0.50 μm or less, and even more preferably 0.20 μm or more and 0.50 μm or less.

[0023] The particle diameter d of the solid electrolyte particles (A1) at which the cumulative volume is 95% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ９５ From the viewpoint of further improving the rate characteristics of the all-solid-state battery, the thickness is preferably 0.05 μm or more and less than 5.0 μm, more preferably 0.10 μm or more and 4.0 μm or less, even more preferably 0.50 μm or more and 3.0 μm or less, even more preferably 1.0 μm or more and 2.5 μm or less, and even more preferably 1.5 μm or more and 2.0 μm or less.

[0024] The average particle diameter d of the solid electrolyte particles (A2) in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ５０From the viewpoint of improving the rate characteristics of the all-solid-state battery, the thickness is 4.0 μm or more and 30.0 μm or less, preferably 4.5 μm or more and 20.0 μm or less, more preferably 5.0 μm or more and 15.0 μm or less, even more preferably 5.5 μm or more and 10.0 μm or less, even more preferably 5.5 μm or more and 9.0 μm or less, even more preferably 5.5 μm or more and 8.0 μm or less, and even more preferably 5.8 μm or more and 7.0 μm or less.

[0025] The particle diameter d of the solid electrolyte particles (A2) at which the cumulative volume becomes 10% in the volume-based particle size distribution measured by the laser diffraction scattering particle size distribution measurement method １０ From the viewpoint of further improving the rate characteristics of the all-solid-state battery, the thickness is preferably 1.0 μm or more and 10 μm or less, more preferably 1.3 μm or more and 8.0 μm or less, even more preferably 1.5 μm or more and 5.0 μm or less, even more preferably 1.5 μm or more and 3.0 μm or less, and even more preferably 1.5 μm or more and 2.0 μm or less.

[0026] The particle diameter d of the solid electrolyte particles (A2) at which the cumulative volume is 95% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ９５ From the viewpoint of further improving the rate characteristics of the all-solid-state battery, the average particle diameter is preferably 5.0 μm or more and 50.0 μm or less, more preferably 7.5 μm or more and 30.0 μm or less, and even more preferably 10.0 μm or more and 20.0 μm or less.

[0027] The specific surface area of ​​the solid electrolyte particles (A1) as measured by the nitrogen adsorption BET method is preferably 5.0 m from the viewpoint of further improving the rate characteristics of the all-solid-state battery. ２ / g or more 20.0m ２ / g or less, more preferably 7.5m ２ / g or more 17.5m ２ / g or less, more preferably 10.0m ２ / g or more 15.0m ２ / g or less.

[0028] The specific surface area of ​​the solid electrolyte particles (A2) measured by the nitrogen adsorption BET method is preferably 0.1 m from the viewpoint of further improving the rate characteristics of the all-solid-state battery. ２ / g or more 5.0m ２ / g, more preferably less than 0.5m２ / g or more 4.0m ２ / g or less, more preferably 1.0m ２ / g or more 3.0m ２ / g or less.

[0029] The specific surface area of ​​the solid electrolyte particles (A1) measured by the nitrogen adsorption BET method is expressed as X １ The specific surface area of ​​the solid electrolyte particles (A2) measured by the nitrogen adsorption BET method is expressed as X ２ When this is done, X １ and X ２ The ratio (X １ / X ２ ) is preferably 1.0 or more and 200 or less, more preferably 1.5 or more and 100 or less, even more preferably 2.0 or more and 50 or less, even more preferably 3.0 or more and 25 or less, even more preferably 4.0 or more and 15 or less, and even more preferably 5.0 or more and 10 or less, from the viewpoint of further improving the rate characteristics of the all-solid-state battery.

[0030] The average particle diameter in the volume-based particle size distribution measured by the laser diffraction scattering particle size distribution measurement method is D １ , the average particle diameter in the volume-based particle size distribution measured by the laser diffraction scattering particle size distribution measurement method of the solid electrolyte particles (A2) is D ２ When this is done, D １ and D ２ The ratio (D １ / D ２ ) is preferably 3.3 × 10 from the viewpoint of further improving the rate characteristics of the all-solid-state battery. －４ or more and 1.0 or less, more preferably 0.01 or more and 0.50 or less, even more preferably 0.05 or more and 0.30 or less, and even more preferably 0.08 or more and 0.20 or less.

[0031] The solid electrolyte particles (A1) and the solid electrolyte particles (A2) can be prepared and obtained, for example, by subjecting commercially available solid electrolyte particles to a classification treatment using a sieve having an appropriate opening ratio and wire diameter.

[0032] When the content of the solid electrolyte particles (A) in the solid electrolyte layer of the present embodiment is taken as 100 parts by mass, the content of the solid electrolyte particles (A1) in the solid electrolyte particles (A) is preferably 5.0 parts by mass or more and 95.0 parts by mass or less, more preferably 10.0 parts by mass or more and 90.0 parts by mass or less, even more preferably 15.0 parts by mass or more and 80.0 parts by mass or less, still more preferably 15.0 parts by mass or more and 70.0 parts by mass or less, still more preferably 15.0 parts by mass or more and 60.0 parts by mass or less, and still more preferably 15.0 parts by mass or more and 50.0 parts by mass or less, from the viewpoint of further improving the rate characteristics of the all-solid-state battery.

[0033] When the content of the solid electrolyte particles (A) in the solid electrolyte layer of the present embodiment is taken as 100 parts by mass, the content of the solid electrolyte particles (A2) in the solid electrolyte particles (A) is preferably 5.0 parts by mass or more and 95.0 parts by mass or less, more preferably 10.0 parts by mass or more and 90.0 parts by mass or less, even more preferably 20.0 parts by mass or more and 85.0 parts by mass or less, still more preferably 30.0 parts by mass or more and 85.0 parts by mass or less, still more preferably 40.0 parts by mass or more and 85.0 parts by mass or less, and still more preferably 50.0 parts by mass or more and 85.0 parts by mass or less, from the viewpoint of further improving the rate characteristics of the all-solid-state battery.

[0034] The solid electrolyte layer of this embodiment may contain a binder resin. The binder resin for the solid electrolyte layer of this embodiment preferably contains one or more selected from the group consisting of fluorine-based binder resins, rubber-based binder resins, and acrylic binder resins. Such binder resins may be in the form of an emulsion. When water is used as a solvent, it is preferable to use an aqueous binder resin and a thickener such as CMC (carboxymethyl cellulose) in combination.

[0035] From the viewpoint of further improving the rate characteristics of the all-solid-state battery, the content of the binder resin in the solid electrolyte layer of the present embodiment is preferably 0.5 parts by mass or more and 15.0 parts by mass or less, more preferably 1.0 parts by mass or more and 10.0 parts by mass or less, even more preferably 1.5 parts by mass or more and 8.0 parts by mass or less, still more preferably 2.0 parts by mass or more and 7.0 parts by mass or less, still more preferably 2.5 parts by mass or more and 6.0 parts by mass or less, and still more preferably 3.0 parts by mass or more and 6.0 parts by mass or less, when the entire solid electrolyte layer is taken as 100 parts by mass.

[0036] The thickness of the solid electrolyte layer of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less.

[0037] The solid electrolyte layer of this embodiment can be formed on the surface of a negative electrode by, for example, applying a slurry of a solid electrolyte dispersed in an organic solvent to the surface of a negative electrode active material layer formed on a negative electrode current collector, followed by drying. The organic solvent may include, for example, one or more selected from the group consisting of acetonitrile, xylene, dimethoxyethane, dimethyl carbonate, triethylamine, and other tertiary amine solvents, heptane, hexane, tetrahydrofuran, toluene, N-methylpyrrolidone, as well as ether solvents, thiol solvents, and butyl butyrate, and it is preferable that all of the organic solvents have been dehydrated.

[0038] (Positive Electrode) The positive electrode of the present embodiment includes a positive electrode active material layer. The positive electrode active material layer of the present embodiment includes, for example, a positive electrode active material and may further include one or more selected from the group consisting of a positive electrode binder resin, a solid electrolyte, and a conductive additive.

[0039] The positive electrode active material of the present embodiment is not particularly limited, and examples thereof include composite oxides of lithium and transition metals such as lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-manganese composite oxide, lithium-nickel-manganese composite oxide, lithium-nickel-cobalt composite oxide, lithium-nickel-aluminum composite oxide, lithium-nickel-cobalt-aluminum composite oxide, lithium-nickel-cobalt-manganese composite oxide, lithium-nickel-manganese-aluminum composite oxide, and lithium-nickel-cobalt-manganese-aluminum composite oxide; TiS ２ , FeS, MoS ２ transition metal sulfides such as MnO, V ２ O ５ , V ６ O １３ , TiO ２ The lithium phosphate oxide preferably contains one or more elements selected from the group consisting of transition metal oxides such as those mentioned above and olivine-type lithium phosphate oxides, and from the viewpoint of improving working potential, capacity, durability, and energy density, the lithium phosphate oxide preferably contains a lithium composite oxide having a layered rock-salt crystal structure, more preferably one or more elements selected from the group consisting of lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-nickel-aluminum composite oxide, and lithium-nickel-cobalt-manganese composite oxide, and even more preferably lithium-nickel-cobalt-manganese composite oxide. Here, the olivine-type lithium phosphate oxide contains, for example, at least one element selected from the group consisting of Mn, Cr, Co, Cu, Ni, V, Mo, Ti, Zn, Al, Ga, Mg, B, Nb, and Fe, as well as lithium, phosphorus, and oxygen.

[0040] The average particle diameter d of the positive electrode active material of this embodiment ５０ is preferably 0.1 μm or more and 30 μm or less, more preferably 0.3 μm or more and 20 μm or less, even more preferably 0.5 μm or more and 15 μm or less, and even more preferably 1.0 μm or more and 10.0 μm or less. ５０ means the particle size at 50% of the integrated value in the particle size distribution (volume basis) determined by the laser diffraction scattering method.

[0041] When the entire cathode active material layer is taken as 100 parts by mass, from the viewpoint of further improving the capacity of the all-solid-state battery, the content of the cathode active material in the cathode active material layer of the present embodiment is preferably 50.0 parts by mass or more and 90.0 parts by mass or less, more preferably 55.0 parts by mass or more and 90.0 parts by mass or less, even more preferably 60.0 parts by mass or more and 90.0 parts by mass or less, still more preferably 65.0 parts by mass or more and 90.0 parts by mass or less, still more preferably 70.0 parts by mass or more and 88.0 parts by mass or less, and still more preferably 75.0 parts by mass or more and 85.0 parts by mass or less.

[0042] The positive electrode active material layer of this embodiment may contain one or more binder resins selected from the group consisting of fluorine-based binder resins, rubber-based binder resins, and acrylic binder resins. Such binder resins may be in the form of an emulsion. When water is used as the solvent, it is preferable to use an aqueous binder resin and a thickener such as CMC (carboxymethyl cellulose) in combination.

[0043] When the entire positive electrode active material layer is taken as 100 parts by mass, the content of the positive electrode binder resin in the positive electrode active material layer of the present embodiment is, from the viewpoint of further improving the performance balance between the capacity and the resistance value of the all-solid-state battery, preferably 0.5 parts by mass or more and 8.0 parts by mass or less, more preferably 0.8 parts by mass or more and 7.5 parts by mass or less, even more preferably 1.0 parts by mass or more and 7.0 parts by mass or less, and still more preferably 1.5 parts by mass or more and 6.5 parts by mass or less.

[0044] The solid electrolyte in the positive electrode active material layer of the present embodiment preferably includes one or more selected from the group consisting of a sulfide-based solid electrolyte, an oxide-based solid electrolyte, and a polymer electrolyte, and more preferably includes a sulfide-based solid electrolyte.

[0045] The oxide-based solid electrolyte is, for example, LiTi ２ (P.O. ４ ) ３ , LiZr ２ (P.O. ４ ) ３ , LiGe ２ (P.O. ４ ) ３ NASICON-type solid electrolyte materials such as (La ０．５＋ｘ Li０．５－３ｘ ) TiO ３ Perovskite-type solid electrolyte materials such as Li ２ O-P ２ O ５ Material, Li ２ O-P ２ O ５ -Li ３ The material contains one or more selected from the group consisting of N materials and the like.

[0046] The sulfide-based solid electrolyte is, for example, Li ２ S-P ２ S ５ Material, Li ２ S-SiS ２ Material, Li ２ S-GeS ２ Material, Li ２ S-Al ２ S ３ Material, Li ２ S-SiS ２ -Li ３ P.O. ４ Material, Li ２ S-P ２ S ５ -GeS ２ Material, Li ２ S-Li ２ O-P ２ S ５ -SiS ２ Material, Li ２ S-GeS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-SnS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-P ２ S ５ -Li ３ N material, Li ２ S ２＋Ｘ -P ４ S ３ Material, Li ２ S-P ２ S ５ -P ４ S ３ Material, LiPO ４ -Li２ S-SiS material, Li ３ P.S. ４ , Li ３ P.O. ４ -Li ２ S-Si ２ S material, Li ３ P.O. ４ -Li ２ S-SiS ２ Material, LiI-Li ２ S-B ２ S ３ Material, LiI-Li ２ S-SiS ２ Material, LiI-Li ２ S-P ２ S ５ Material, LiI-Li ２ S-P ２ O ５ Material, LiI-Li ３ P.O. ４ -P ２ S ５ Li ２ S-P ２ S ５ -LiCl material, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ I ｘ (where 0≦x≦2), Li １０ GeP ２ S １２ , and Li ３．２５ Ge ０．２５ P ０．７５ S ４ Preferably, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2) and Li ７－ｘ P.S. ６－ｘ I ｘ(where 0≦x≦2), more preferably Li ６ P.S. ５ Cl, Li ６ P.S. ５ Br and Li ６ P.S. ５ I, more preferably Li ６ P.S. ５ Contains Cl.

[0047] The polymer-based solid electrolyte material includes one or more selected from the group consisting of polyether-based electrolyte materials such as polyethylene oxide, polypropylene oxide, ethylene oxide-propylene copolymer, and dimethylsiloxane-ethylene oxide copolymer; gel polymer electrolyte materials such as polyacrylonitrile, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene polymer; and polymer solid electrolyte materials using hyperbranched polymers.

[0048] When the entire cathode active material layer is taken as 100 parts by mass, the content of the solid electrolyte in the cathode active material layer of the present embodiment is, from the viewpoint of further improving the performance balance between the capacity and the resistance value of the all-solid-state battery, preferably 5.0 parts by mass or more and 40.0 parts by mass or less, more preferably 8.0 parts by mass or more and 35.0 parts by mass or less, even more preferably 10.0 parts by mass or more and 33.0 parts by mass or less, even more preferably 12.0 parts by mass or more and 30.0 parts by mass or less, and still more preferably 14.0 parts by mass or more and 28.0 parts by mass or less.

[0049] The positive electrode active material layer of this embodiment preferably further contains a conductive additive, from the viewpoint of further reducing the resistance value of the all-solid-state battery. The conductive additive in the positive electrode active material layer of this embodiment preferably contains one or more selected from the group consisting of carbon black, activated carbon, graphite, mesoporous carbon, fullerenes, carbon nanotubes, carbon nanofibers, and carbon brushes, and more preferably contains carbon black, from the viewpoint of further reducing the resistance value of the all-solid-state battery.

[0050] When the entire positive electrode active material layer is taken as 100 parts by mass, the content of the conductive additive in the positive electrode active material layer of the present embodiment is, from the viewpoint of further improving the performance balance between the capacity and the resistance value of the all-solid-state battery, preferably 0.1 parts by mass or more and 10.0 parts by mass or less, more preferably 0.3 parts by mass or more and 5.0 parts by mass or less, even more preferably 0.5 parts by mass or more and 4.0 parts by mass or less, even more preferably 0.8 parts by mass or more and 3.0 parts by mass or less, and still more preferably 1.0 parts by mass or more and 2.0 parts by mass or less.

[0051] The density of the positive electrode active material layer of this embodiment is preferably 1.0 g / cm ３ 5.0g / cm or more ３ or less, more preferably 2.0 g / cm ３ 4.0g / cm or more ３ The following is the result.

[0052] The thickness of the positive electrode active material layer is not particularly limited, but is, for example, preferably from 1 μm to 150 μm, more preferably from 5 μm to 100 μm, and even more preferably from 10 μm to 80 μm.

[0053] The positive electrode of this embodiment may further include a positive electrode current collector 3. The positive electrode current collector includes, for example, one or more selected from the group consisting of aluminum, stainless steel, nickel, titanium, and alloys thereof. The positive electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh. The thickness of the positive electrode current collector is, for example, 1 μm or more and 50 μm or less.

[0054] The negative electrode of the present embodiment includes a negative electrode active material layer. The negative electrode active material layer of the present embodiment includes, for example, a negative electrode active material and may further include one or more selected from the group consisting of a negative electrode binder resin, a solid electrolyte, and a conductive additive.

[0055] The negative electrode active material of this embodiment is not particularly limited, and examples thereof include carbon materials such as graphite, amorphous carbon, diamond-like carbon, fullerene, carbon nanotubes, and carbon nanohorns; lithium-based metal materials such as metallic lithium and lithium alloys; Si, SiO ２ , SiO ｘ(0<x≦2), a Si-based material such as a Si-containing composite material; one or more selected from the group consisting of conductive polymers such as polyacene, polyacetylene, and polypyrrole, and more preferably a lithium-based metal material.

[0056] The content of the negative electrode active material in the negative electrode active material layer of this embodiment is preferably 70 parts by mass or more and 100 parts by mass or less, more preferably 80 parts by mass or more and 100 parts by mass or less, and even more preferably 90 parts by mass or more and 100 parts by mass or less, when the total amount of the negative electrode active material layer is 100 parts by mass.

[0057] The negative electrode active material layer of this embodiment may contain one or more binder resins selected from the group consisting of fluorine-based binder resins, rubber-based binder resins, and acrylic binder resins. Such binder resins may be in the form of an emulsion. When water is used as the solvent, it is preferable to use the aqueous binder resin in combination with a thickener such as CMC (carboxymethyl cellulose).

[0058] The content of the binder resin in the negative electrode active material layer of this embodiment may be, for example, 1 part by mass or more and 10 parts by mass or less, or 3 parts by mass or more and 6 parts by mass or less, when the total amount of the negative electrode active material layer is 100 parts by mass.

[0059] The solid electrolyte in the negative electrode active material layer of the present embodiment preferably includes one or more selected from the group consisting of a sulfide-based solid electrolyte, an oxide-based solid electrolyte, and a polymer electrolyte, and more preferably includes a sulfide-based solid electrolyte.

[0060] The oxide-based solid electrolyte is, for example, LiTi ２ (P.O. ４ ) ３ , LiZr ２ (P.O. ４ ) ３ , LiGe ２ (P.O. ４ ) ３ NASICON-type solid electrolyte materials such as (La ０．５＋ｘ Li ０．５－３ｘ ) TiO ３ Perovskite-type solid electrolyte materials such as Li ２ O-P ２ O５ Material, Li ２ O-P ２ O ５ -Li ３ The material contains one or more selected from the group consisting of N materials and the like.

[0061] The sulfide-based solid electrolyte is, for example, Li ２ S-P ２ S ５ Material, Li ２ S-SiS ２ Material, Li ２ S-GeS ２ Material, Li ２ S-Al ２ S ３ Material, Li ２ S-SiS ２ -Li ３ P.O. ４ Material, Li ２ S-P ２ S ５ -GeS ２ Material, Li ２ S-Li ２ O-P ２ S ５ -SiS ２ Material, Li ２ S-GeS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-SnS ２ -P ２ S ５ -SiS ２ Material, Li ２ S-P ２ S ５ -Li ３ N material, Li ２ S ２＋Ｘ -P ４ S ３ Material, Li ２ S-P ２ S ５ -P ４ S ３ Material, LiPO ４ -Li ２ S-SiS material, Li ３ P.S. ４ , Li ３ P.O. ４-Li ２ S-Si ２ S material, Li ３ P.O. ４ -Li ２ S-SiS ２ Material, LiI-Li ２ S-B ２ S ３ Material, LiI-Li ２ S-SiS ２ Material, LiI-Li ２ S-P ２ S ５ Material, LiI-Li ２ S-P ２ O ５ Material, LiI-Li ３ P.O. ４ -P ２ S ５ Li ２ S-P ２ S ５ -LiCl material, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ I ｘ (where 0≦x≦2), Li １０ GeP ２ S １２ , and Li ３．２５ Ge ０．２５ P ０．７５ S ４ Preferably, Li ７－ｘ P.S. ６－ｘ Cl ｘ (where 0≦x≦2), Li ７－ｘ P.S. ６－ｘ Br ｘ (where 0≦x≦2) and Li ７－ｘ P.S. ６－ｘ I ｘ (where 0≦x≦2), more preferably Li ６ P.S. ５ Cl, Li ６ P.S. ５ Br and Li６ P.S. ５ I, more preferably Li ６ P.S. ５ Contains Cl.

[0062] The polymer-based solid electrolyte material includes one or more selected from the group consisting of polyether-based electrolyte materials such as polyethylene oxide, polypropylene oxide, ethylene oxide-propylene copolymer, and dimethylsiloxane-ethylene oxide copolymer; gel polymer electrolyte materials such as polyacrylonitrile, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene polymer; and polymer solid electrolyte materials using hyperbranched polymers.

[0063] From the viewpoint of further reducing the resistance value of the all-solid-state battery, the conductive additive in the negative electrode active material layer of the present embodiment includes one or more selected from the group consisting of carbon black, activated carbon, graphite, mesoporous carbon, fullerenes, carbon nanotubes, carbon nanofibers, and carbon brushes, and more preferably includes carbon black.

[0064] The content of the conductive additive in the negative electrode active material layer of the present embodiment is 0.05 parts by mass or more and 10 parts by mass or less, preferably 0.5 parts by mass or more and 5.0 parts by mass or less, from the viewpoint of further improving the performance balance between the capacity and the resistance value of the all-solid-state battery, when the entire negative electrode active material layer is taken as 100 parts by mass.

[0065] In the negative electrode active material layer, electrode additives generally used for forming electrodes, such as thickeners, dispersants, and stabilizers, can be used as appropriate.

[0066] The density of the negative electrode active material layer of this embodiment is preferably 0.5 g / cm ３ 3.0g / cm or more ３ or less, more preferably 1.2 g / cm ３ 2.0g / cm or more ３ The following is the result.

[0067] The thickness of the negative electrode active material layer of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less.

[0068] The negative electrode of this embodiment may further include a negative electrode current collector 4. The negative electrode current collector includes, for example, one or more materials selected from the group consisting of copper, stainless steel, nickel, titanium, and alloys thereof. The negative electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh. The thickness of the negative electrode current collector is, for example, 1 μm or more and 50 μm or less.

[0069] (Optional Configuration of All-Solid-State Battery) The all-solid-state battery of this embodiment can further include exterior bodies 6 and 7. Examples of the exterior body include an aluminum laminate film, a strong aluminum can case, and a cylindrical aluminum exterior body.

[0070] The all-solid-state battery of this embodiment may further include a positive electrode terminal 9 and a negative electrode terminal 8. Examples of the positive electrode terminal include a terminal made of aluminum or an aluminum alloy. Examples of the negative electrode terminal include a terminal made of copper, a copper alloy, or a nickel-plated copper or copper alloy.

[0071] (Method for manufacturing all-solid-state battery) The method for manufacturing an all-solid-state battery is not particularly limited, and known methods can be applied. First, the preparation of the negative electrode will be described. The negative electrode can be prepared by known methods. Regardless of the method used to prepare the negative electrode, it is preferably prepared in a low-moisture environment under dew point control in order to suppress adsorption of moisture into the solid electrolyte.

[0072] When using a negative electrode having a negative electrode active material layer formed on a negative electrode current collector, a slurry prepared by dispersing a negative electrode active material, a solid electrolyte, and a binder resin in a dehydrated organic solvent is applied to a portion or all of the surface of a negative electrode current collector such as copper foil, followed by drying to obtain a negative electrode precursor sheet. The obtained negative electrode precursor sheet can be compressed using a press molding method such as a roll press, a uniaxial press, a rubber press, or an isostatic pressing (CIP, WIP) to obtain a negative electrode sheet. The organic solvent preferably includes one or more solvents selected from the group consisting of acetonitrile, xylene, dimethoxyethane, dimethyl carbonate, triethylamine, and other tertiary amine solvents, heptane, hexane, tetrahydrofuran, toluene, N-methylpyrrolidone, as well as ether solvents, thiol solvents, and butyl butyrate, all of which are preferably dehydrated.

[0073] The negative electrode can be obtained by disposing a metallic lithium layer (negative electrode active material layer) such as lithium foil on part or all of a negative electrode current collector such as stainless steel foil, and then adhering them together by rolling or the like.

[0074] Next, a solid electrolyte layer is formed on the surface of the negative electrode. When a sulfide-based solid electrolyte is used, it is preferably formed in a low-moisture environment under dew point control to prevent moisture adsorption.

[0075] The solid electrolyte layer can be formed on the surface of the negative electrode by, for example, applying a slurry of a solid electrolyte dispersed in an organic solvent to the surface of a negative electrode active material layer formed on a negative electrode current collector, followed by drying. The organic solvent may include, for example, one or more selected from the group consisting of acetonitrile, xylene, dimethoxyethane, dimethyl carbonate, triethylamine, and other tertiary amine solvents, heptane, hexane, tetrahydrofuran, toluene, N-methylpyrrolidone, as well as ether solvents, thiol solvents, and butyl butyrate, and it is preferable that all of them have been dehydrated.

[0076] Next, the stacked negative electrode and solid electrolyte layer are compressed using a press molding method such as a vacuum laminator, roll press, uniaxial press, rubber press, or isostatic pressing (CIP, WIP), to obtain a negative electrode-solid electrolyte layer laminate. When the solid electrolyte layer is stacked together with a substrate layer such as a polyester sheet and pressurized, the substrate layer is peeled off from the solid electrolyte layer. In this case, it is also preferable to use a substrate layer whose surface is coated with a release agent such as silicone, so that the substrate layer can be easily peeled off from the solid electrolyte layer.

[0077] Next, the fabrication of the positive electrode will be described. Regardless of the method used to fabricate the positive electrode, it is preferable to fabricate the positive electrode in a low moisture environment under dew point control in order to suppress moisture adsorption.

[0078] The positive electrode of this embodiment can be produced, for example, by dissolving or dispersing the components constituting the positive electrode active material layer in a solvent to produce a positive electrode slurry, applying the positive electrode slurry to at least one surface of a positive electrode current collector, drying, and rolling. Alternatively, the positive electrode of this embodiment can be produced, for example, by applying the positive electrode slurry to a support, drying it, peeling it from the support, and laminating the resulting film on the positive electrode current collector. The solvent preferably includes one or more solvents selected from the group consisting of tertiary amine solvents such as acetonitrile, xylene, dimethoxyethane, dimethyl carbonate, and triethylamine, heptane, hexane, tetrahydrofuran, toluene, N-methylpyrrolidone, ether solvents, thiol solvents, and butyl butyrate, and each of these solvents is preferably dehydrated.

[0079] A positive electrode is laminated on the negative electrode-solid electrolyte layer laminate to obtain an electrode laminate precursor. When a sulfide-based solid electrolyte is used as the solid electrolyte, the ionic conductivity of the solid electrolyte may decrease due to exposure to moisture. Therefore, after obtaining the electrode laminate precursor, it is preferable to compress the electrode laminate precursor using a vacuum laminator, roll press, uniaxial press, rubber press, isostatic pressing (CIP, WIP), or the like to obtain an electrode laminate.

[0080] The resulting electrode laminate is preferably quickly sealed in an exterior housing. One end of a rectangular metal plate serving as a negative electrode terminal is attached to the negative electrode current collector, and one end of a rectangular metal terminal serving as a positive electrode terminal is attached to the positive electrode current collector, and then the electrode laminate is housed in an aluminum exterior housing. A resin layer such as polyolefin is preferably formed on at least the surface of the inner surface of the exterior housing facing the electrode laminate. The resin layer is heated to melt the resin and solidify it again, and the electrode laminate is sealed in the aluminum exterior housing. At this time, the other end of the positive electrode terminal and the other end of the negative electrode terminal are positioned so as to extend outside the exterior housing. A layer of resin of the same type or a different type from the resin used in the resin layer on the interior surface of the exterior housing can be provided in the areas where the positive electrode terminal and the negative electrode terminal contact the resin layer on the interior surface of the exterior housing.

[0081] <Battery Module> The battery module of this embodiment includes the all-solid-state battery of this embodiment. The all-solid-state battery of this embodiment can improve the cycle characteristics, and therefore the battery module of this embodiment can improve the cycle characteristics.

[0082] The battery module of the present embodiment preferably includes two or more all-solid-state batteries of the present embodiment connected in series or in parallel. The battery module of the present embodiment more preferably includes a housing capable of accommodating two or more all-solid-state batteries of the present embodiment connected in series or in parallel. The battery module of the present embodiment further preferably includes one or more components selected from the group consisting of a protection circuit that protects the all-solid-state battery from an overcurrent, a balancing circuit that equalizes the voltage between the electrodes of the all-solid-state battery, a controller that controls the all-solid-state battery, a cooler that can cool the all-solid-state battery, and a heater that can heat the all-solid-state battery.

[0083] The battery module of this embodiment can be used in a battery system including a plurality of electrically connected battery modules and a battery control system. Examples of battery systems include battery packs, stationary storage battery systems, automotive power storage battery systems, automotive auxiliary storage battery systems, and emergency power storage battery systems.

[0084] The present invention is not limited to the above-described embodiment, and the present invention includes modifications and improvements within the scope of achieving the object of the present invention.

[0085] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0086] Example 1 An all-solid-state battery was fabricated by the following method.

[0087] [I] Preparation of a Negative Electrode-Solid Electrolyte Layer Laminate (1) A 20 μm-thick metallic lithium layer formed on the surface of a 10 μm-thick stainless steel negative electrode current collector was used as a negative electrode. (2) A slurry of solid electrolyte particles 1, solid electrolyte particles 2, and a binder resin dispersed in xylene was applied to the surface of a polyester film primarily composed of polyester, followed by drying to form a solid electrolyte layer on the polyester film. Solid electrolyte particles 1 and solid electrolyte particles 2 were mixed in the proportions (mass %) listed in Table 1. Next, the solid electrolyte layer was laminated on the negative electrode together with the polyester film so that the resulting solid electrolyte layer was in contact with the surface of the metallic lithium layer of the negative electrode, yielding a negative electrode-solid electrolyte layer laminate. (3) The negative electrode-solid electrolyte layer laminate obtained in (2) above was vacuum-sealed using a vacuum laminator and held at room temperature (25°C) under a pressure of 300 MPa for 1 minute. The negative electrode-solid electrolyte layer laminate was then removed from the vacuum laminator and compressed by isostatic pressing (CIP) to obtain a negative electrode-solid electrolyte layer laminate with a porosity of 7%. The size of the negative electrode-solid electrolyte layer laminate was 26 mm x 26 mm. (4) The polyester film was peeled off from the solid electrolyte layer to obtain a negative electrode-solid electrolyte layer laminate.

[0088] [II] Lamination of Positive Electrode and Negative Electrolyte Layer Laminates (1) A positive electrode active material, a solid electrolyte, a conductive additive, and a binder resin were dispersed in butyl butyrate to obtain a slurry. The obtained slurry was then applied to a 10 μm thick aluminum foil and dried to form a positive electrode active material layer, thereby obtaining a positive electrode. (2) The positive electrode obtained in (1) above was cut to 20 mm × 20 mm, and the positive electrode and the negative electrode-solid electrolyte layer laminate were laminated such that the positive electrode active material layer was in contact with the solid electrolyte layer of the negative electrode-solid electrolyte layer laminate prepared in [I] above, thereby obtaining an electrode laminate precursor. The number of layers of the positive electrode and the negative electrode-solid electrolyte layer laminate was one each.

[0089] [III] Preparation of Electrode Laminate The electrode laminate precursor obtained in [II] above was vacuum-sealed using a vacuum laminator and held at room temperature (25° C.) under a pressure of 300 MPa for 1 minute. The electrode laminate precursor was then removed from the vacuum laminator and compressed by a CIP method to obtain an electrode laminate having a porosity of 5% in the positive electrode active material layer.

[0090] [IV] Encapsulation in an exterior body The electrode laminate obtained in [III] above was enclosed in an aluminum exterior body (manufactured by Dai Nippon Printing Co., Ltd.) by the method described in the embodiment, and an all-solid-state battery in which the positive electrode terminal and the negative electrode terminal were extended to the outside of the exterior body was obtained.

[0091] <Rate Test> The all-solid-state battery obtained by the above method was repeatedly charged and discharged to evaluate its rate characteristics. The charge and discharge conditions were as follows: Charge: constant current-constant voltage method, rate = 0.1 C Discharge: constant current method, rate = 0.1 C, 0.2 C, 0.5 C, 1 C, 2 C In the rate test, the discharge capacity at 0.1 C was measured as C ０．１Ｃ , the discharge capacity at 1 C is C １Ｃ , discharge capacity at 2C is C ２Ｃ When the discharge capacity at each discharge rate is 0.1 C, the ratio of the discharge capacity at each discharge rate to the discharge capacity at 0.1 C (C １Ｃ / C ０．１Ｃ , C ２Ｃ / C ０．１Ｃ ) was used as the evaluation index. １Ｃ / C ０．１Ｃ , C ２Ｃ / C ０．１ＣThe larger the value of C, the better the rate characteristics of the battery. １Ｃ / C ０．１Ｃ , C ２Ｃ / C ０．１Ｃ The calculation results are shown in Table 1.

[0092] <Method for measuring particle diameters of solid electrolyte particles and positive electrode active material> The particle diameter d of the solid electrolyte particles at which the cumulative volume is 10% in the volume-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method １０ , the average particle diameter d in the volume-based particle size distribution ５０ and a particle diameter d at which the cumulative volume in the volume-based particle size distribution is 95%. ９５ were measured using a laser diffraction / scattering particle size distribution analyzer (MT3000, manufactured by Microtrac). ５０ was measured using a laser diffraction / scattering particle size distribution analyzer (MT3000, manufactured by Microtrac). Here, the solid electrolyte particles were measured after suspending the solid electrolyte particles in a dispersion medium and ultrasonically dispersing them. Furthermore, the positive electrode active material was measured after suspending the positive electrode active material in a dispersion medium and ultrasonically dispersing them. Each measurement was performed five times, and the average value was used.

[0093] <Method for Measuring Specific Surface Area of ​​Solid Electrolyte Particles> The specific surface area of ​​each solid electrolyte particle was determined by the nitrogen adsorption BET method using a QuantaSorb manufactured by Quantachrome Corporation.

[0094] (Examples 2 and 3 and Comparative Examples 1 and 2) All-solid-state batteries were fabricated and their battery characteristics were evaluated in the same manner as in Example 1, except that the ratio of solid electrolyte particles 1 to solid electrolyte particles 2 in the solid electrolyte layer was changed to the ratio (mass %) shown in Table 1. The obtained results are shown in Table 1.

[0095]

[0096] The raw materials for the all-solid-state batteries of Examples 1 to 3 and Comparative Examples 1 and 2 are as follows: <Positive electrode> Positive electrode active material: LiNi０．８ Co ０．１ Mn ０．１ O ２ (Average particle diameter d ５０ : 5 μm), content in positive electrode active material layer: 76 mass% Solid electrolyte: Li ６ P.S. ５ Cl (average particle diameter d ５０ : 6.5 μm), content in positive electrode active material layer: 19.5 mass% Conductive additive: CB (carbon black), content in positive electrode active material layer: 1.5 mass% Binder resin: SBR (styrene-butadiene rubber), content in positive electrode active material layer: 3 mass%

[0097] <Solid electrolyte layer> - Solid electrolyte particles 1: Li ６ P.S. ５ Cl d １０ :0.3μm Average particle diameter d ５０ : 0.6 μm d ９５ : 1.6μm Specific surface area: 14.2m ２ / g ・Solid electrolyte particle 2: Li ６ P.S. ５ Cl d １０ :1.8μm Average particle diameter d ５０ : 6.5 μm d ９５ : 16.5μm Specific surface area: 2.1m ２ / g Content of solid electrolyte particles 1 and solid electrolyte particles 2 in the solid electrolyte layer: 95% by mass Binder resin: SBR (styrene-butadiene rubber), content in the solid electrolyte layer: 5% by mass

[0098] This application claims priority based on Japanese Patent Application No. 2024-054237, filed March 28, 2024, the disclosure of which is incorporated herein in its entirety by reference.

[0099] 1 Positive electrode active material layer 2 Negative electrode active material layer 3 Positive electrode current collector 4 Negative electrode current collector 5 Solid electrolyte layer 6 Exterior body 7 Exterior body 8 Negative electrode terminal 9 Positive electrode terminal 10 All-solid-state battery

Claims

1. A cathode including a cathode active material layer, a solid electrolyte layer including solid electrolyte particles (A), and a negative electrode including a negative electrode active material layer, wherein the solid electrolyte particles (A) have an average particle diameter d ５０ and a solid electrolyte particle (A1) having an average particle diameter d ５０ and solid electrolyte particles (A2) having a particle size of 4.0 μm or more and 30.0 μm or less.

2. The average particle diameter d of the solid electrolyte particles (A2) ５０ The all-solid-state battery according to claim 1 , wherein the average particle diameter is 10.0 μm or less.

3. The solid electrolyte particles (A1) have a specific surface area of ​​5.0 m2 as measured by the nitrogen adsorption BET method. ２ / g or more 20.0m ２ The all-solid-state battery according to claim 1 or 2, wherein the surface area of ​​the all-solid-state battery is 1 / g or less.

4. The solid electrolyte particles (A2) have a specific surface area of ​​0.1 m2 as measured by the nitrogen adsorption BET method. ２ / g or more 5.0m ２ The all-solid-state battery according to any one of claims 1 to 3, wherein the average molecular weight is less than 1 / g.

5. The specific surface area of ​​the solid electrolyte particles (A1) measured by the nitrogen adsorption BET method is expressed as X １ The specific surface area of ​​the solid electrolyte particles (A2) measured by the nitrogen adsorption BET method is X ２ When this is done, X １ and X ２ The ratio (X １ / X ２ 5. The all-solid-state battery according to claim 1, wherein the value of (a) is 1.0 or more and 200 or less.

6. The particle diameter d of the solid electrolyte particles (A1) at which the cumulative volume is 10% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method １０ The all-solid-state battery according to any one of claims 1 to 5, wherein the thickness is less than 1.0 µm.

7. The particle diameter d of the solid electrolyte particles (A1) at which the cumulative volume is 95% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ９５ The all-solid-state battery according to any one of claims 1 to 6, wherein the thickness is less than 5.0 µm.

8. The particle diameter d of the solid electrolyte particles (A2) at which the cumulative volume is 10% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method １０ The all-solid-state battery according to any one of claims 1 to 7, wherein the thickness is 1.0 µm or more.

9. The particle diameter d of the solid electrolyte particles (A2) at which the cumulative volume is 95% in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method ９５ The all-solid-state battery according to any one of claims 1 to 8, wherein the thickness is 5.0 µm or more.

10. The average particle diameter of the solid electrolyte particles (A1) in the volume-based particle size distribution measured by a laser diffraction scattering particle size distribution measurement method is D １ The average particle diameter of the solid electrolyte particles (A2) in the volume-based particle size distribution measured by a laser diffraction / scattering particle size distribution measurement method is D ２ When this is done, D １ and D ２ The ratio (D １ / D ２ ) is 3.3 x 10 －４ The all-solid-state battery according to any one of claims 1 to 9, wherein the ρ is greater than or equal to 1.

0.

11. The all-solid-state battery according to any one of claims 1 to 10, wherein the solid electrolyte particles (A) contain one or more electrolytes selected from the group consisting of sulfide-based solid electrolytes, oxide-based solid electrolytes, and polymer electrolytes.

12. The all-solid-state battery according to any one of claims 1 to 11, wherein the content of the solid electrolyte particles (A) in the solid electrolyte layer is 50.0 parts by mass or more and 100.0 parts by mass or less, when the entire solid electrolyte layer is taken as 100 parts by mass.

13. The all-solid-state battery according to any one of claims 1 to 12, wherein, when the content of the solid electrolyte particles (A) in the solid electrolyte layer is taken as 100 parts by mass, the content of the solid electrolyte particles (A1) in the solid electrolyte particles (A) is 5.0 parts by mass or more and 95.0 parts by mass or less, and the content of the solid electrolyte particles (A2) in the solid electrolyte particles (A) is 5.0 parts by mass or more and 95.0 parts by mass or less.

14. The all-solid-state battery according to any one of claims 1 to 13, wherein the content of the binder resin in the solid electrolyte layer is 0.5 parts by mass or more when the entire solid electrolyte layer is taken as 100 parts by mass.

15. A battery module comprising the all-solid-state battery according to any one of claims 1 to 14.

Images