Abstract: Disclosed is an all-solid-state lithium ion secondary battery being excellent in cycle characteristics. The all-solid-state lithium ion secondary battery may be an all-solid-state lithium ion secondary battery, wherein an anode comprises an anode active material, an electroconductive material and a solid electrolyte; wherein the anode active material comprises at least one active material selected from the group consisting of a metal that is able to form an alloy with Li, an oxide of the metal, and an alloy of the metal and Li; and wherein a bulk density of the solid electrolyte is 0.3 g/cm3 or more and 0.6 g/cm3 or less.

Abstract: Disclosed is a method for producing an all-solid-state lithium ion secondary battery being excellent in cycle characteristics. The production method may be a method for producing an all-solid-state lithium ion secondary battery, wherein the method comprises an anode mixture forming step of obtaining an anode mixture by drying a raw material for an anode mixture, which contains an anode active material, a solid electrolyte and an electroconductive material; and wherein, for the anode mixture after being dried in the anode mixture forming step, a voidage V of the inside of the anode mixture calculated by the following formula (1) is 43% or more and 54% or less: V=100?(D1/D0)×100??Formula (1).

Abstract: Provided is a method for producing sulfide-based solid electrolyte particles, which is configured to form the sulfide-based solid electrolyte particles into fine particles, while keeping the ion conductivity of the particles at a desired ion conductivity. Disclosed is a method for producing sulfide-based solid electrolyte particles, the method comprising: preparing a sulfide-based solid electrolyte material comprising lithium, phosphorus and sulfur; preparing a mixed solvent of a hydrocarbon-based compound and an ether-based compound; and forming the sulfide-based solid electrolyte material into fine particles by pulverizing the sulfide-based solid electrolyte material in the mixed solvent under an inert gas atmosphere, wherein a water concentration of the mixed solvent is 100 mass ppm or more and 200 mass ppm or less.

Abstract: Disclosed is an anode mixture configured to provide an all-solid-state lithium ion secondary battery being excellent in cycle characteristics when it is used in the battery, an anode including the anode mixture, and an all-solid-state lithium ion secondary battery including the anode. The anode mixture may be an anode mixture for an all-solid-state lithium ion secondary battery, wherein the anode mixture contains an anode active material, a solid electrolyte and an electroconductive material; and wherein a value obtained by multiplying, by a bulk density of the solid electrolyte, a volume percentage (%) of the electroconductive material when a volume of the anode mixture is determined as 100 volume %, is 0.53 or more and 3.0 or less.

Abstract: Disclosed is an all-solid-state lithium ion secondary battery including an anode that contains, as an anode active material, at least one selected from the group consisting of a metal that is able to form an alloy with Li, an oxide of the metal, and an alloy of the metal and Li, and being excellent in cycle characteristics. The all-solid-state lithium ion secondary battery may be an all-solid-state lithium ion secondary battery, wherein an anode comprises an anode active material, an electroconductive material and a solid electrolyte; wherein the anode active material comprises at least one active material selected from the group consisting of a metal that is able to form an alloy with Li, an oxide of the metal, and an alloy of the metal and Li; and wherein the solid electrolyte is particles with a BET specific surface area of from 1.8 m2/g to 19.7 m2/g.

Abstract: A method for efficiently producing sulfide solid electrolyte particles which are particles in spherical form and which have a small particle diameter. The method comprises: preparing a sulfide solid electrolyte material, grinding the sulfide solid electrolyte material by mechanical milling to obtain particles in flattened form (a first grinding step), and grinding the particles in flattened form by mechanical milling to obtain sulfide solid electrolyte particles in spherical form (a second grinding step), wherein a relationship A (J)>B (J) is satisfied, where A (J) is a kinetic energy (1/2(mv2)) per grinding medium used in the first grinding step, and B (J) is a kinetic energy (1/2(mv2)) per grinding medium used in the second grinding step.

Abstract: Disclosed is an anode mixture configured to provide an all-solid-state lithium ion secondary battery being excellent in cycle characteristics when it is used in the battery, an anode including the anode mixture, and an all-solid-state lithium ion secondary battery including the anode. The anode mixture may be an anode mixture for an all-solid-state lithium ion secondary battery, wherein the anode mixture contains an anode active material, a solid electrolyte and an electroconductive material; and wherein a value obtained by multiplying, by a bulk density of the solid electrolyte, a volume percentage (%) of the electroconductive material when a volume of the anode mixture is determined as 100 volume %, is 0.53 or more and 3.0 or less.

Abstract: Disclosed is a method for producing an all-solid-state lithium ion secondary battery being excellent in cycle characteristics.

Abstract: Disclosed is a method for producing an all-solid-state lithium ion secondary battery being excellent in cycle characteristics. The production method may be a method for producing an all-solid-state lithium ion secondary battery, wherein the method comprises: an anode mixture forming step of obtaining an anode mixture by drying a raw material for an anode mixture, which contains an anode active material, a solid electrolyte and an electroconductive material; and wherein, a value obtained by dividing a volume percentage (%) of the electroconductive material when the volume of the anode mixture is determined as 100 volume %, by a voidage V (%) of the inside of the anode mixture calculated by the following formula (1), is 2.3 or more and 16.

Abstract: Provided are an anode mixture configured to provide excellent cycle characteristics when used in an all-solid-state lithium ion secondary battery, an anode containing the anode mixture, and an all-solid-state lithium ion secondary battery containing the anode. Disclosed is an anode mixture for an all-solid-state lithium ion secondary battery, wherein the anode mixture contains an anode active material, a solid electrolyte and an electroconductive material; wherein the anode active material contains at least one active material selected from the group consisting of a metal that is able to form an alloy with Li and an oxide of the metal; and wherein a value obtained by dividing, by a BET specific surface area (m2/g) of the solid electrolyte, a volume percentage (%) of the electroconductive material when a volume of the anode mixture is determined as 100 volume %, is 0.09 or more and 1.61 or less.

Abstract: A composite active material including composite particles and a sulfide-based solid electrolyte is proposed. The composite particles contain active material particles and an oxide-based solid electrolyte. The active material particles contain at least any one of a cobalt element, a nickel element and a manganese element and further contain a lithium element and an oxygen element. The oxide-based solid electrolyte coats all or part of a surface of each of the active material particles. The sulfide-based solid electrolyte further coats 76.0% or more of a surface of each of the composite particles.

Abstract: A composite active material including composite particles and a sulfide-based solid electrolyte is proposed. The composite particles contain active material particles and an oxide-based solid electrolyte. The active material particles contain at least any one of a cobalt element, a nickel element and a manganese element and further contain a lithium element and an oxygen element. The oxide-based solid electrolyte coats all or part of a surface of each of the active material particles. The sulfide-based solid electrolyte further coats 76.0% or more of a surface of each of the composite particles.