▎ 摘　　要

NOVELTY - A sheet-type composite material comprises a single-layer structure sheet-type graphene, a multi-layer structure sheet-type graphene, and oxide-based solid electrolyte particles. The single-layer structure sheet-type graphene has a sheet length of 1-500 mu m, and a sheet width of 1-500 mu m. The multi-layer structure sheet-type graphene has length of 1-500 mu m, and width of 1-500 mu m. The ratio of a particle size of the oxide-based solid electrolyte particles with respect to the sheet length of the single-layer structure sheet-type graphene or the multi-layer structure sheet-type graphene is 0. 001-1. The oxide-based solid electrolyte particles are supported in contact with the front surface and the back surface of the single-layer structure sheet-type graphene and the front surface and the back surface of the multi-layer structure sheet-type graphene. The content of both the single-layer structure sheet-type graphene and the multi-layer structure sheet-type graphene is 0.5-10 %mass. USE - Sheet-type composite material used for slurry for active material for positive electrode for lithium-ion secondary battery (all claimed) used as power source for portable electronic device such as mobile phone and notebook personal computer, and electric vehicle. ADVANTAGE - The sheet-type composite material provides lithium-ion secondary battery having improved lithium-ion conductivity and electroconductivity. The graphene has excellent property such as high thermal and chemical stability, high strength, high conductivity, high thermal conductivity, and high specific surface area. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) production of the composite material, which involves applying ultrasonic waves to a dispersion liquid (d1) in which graphite oxide containing layered crystals comprising graphene oxide and oxide-based solid electrolyte particles are dispersed, exfoliating the layers of the layered crystals to form the single-layer structure sheet-type graphene oxide and the multi-layer structure sheet-type graphene oxide, generating electric charge on the surface of the oxide-based solid electrolyte particles, the front surface and the back surface of the single layer structure sheet-type graphene oxide, and the front surface and the back surface of the multi-layer structure sheet-type graphene oxide, contacting several oxide-based solid electrolyte particles with the front surface and the back surface of the single layer structure sheet-type graphene oxide, and the front surface and the back surface of the multi-layer structure sheet-type graphene oxide, reducing the single-layer structure sheet-type graphene oxide and the multi-layer structure sheet-type graphene oxide to the single-layer structure sheet-type graphene and the multi-layer structure sheet-type graphene; (2) a slurry, which comprises composite material and a positive electrode active material; and (3) a lithium-ion secondary battery, which comprises a positive electrode layer containing the composite material, the positive electrode active material, a positive electrode provided with a positive electrode current collector, a negative electrode, a separator, and a non-aqueous electrolyte.