▎ 摘　　要

NOVELTY - Sheet-shaped positive electrode composite material comprises sheet-like graphene having a length of 5-500 micrometer and a width of 5-500 micrometer. A multiple of lithium transition metal oxide particles having a ratio of the diameter to the length of the sheet graphene (diameter / length) of 0.001 or more and 0.05 or less. The multiple of lithium transition metal oxide particles adjacent to each other carry the multiple of lithium transition metal oxide particles in contact with each other on the front and back surfaces of the sheet-like graphene. USE - Sheet-shaped positive electrode composite material used for a lithium ion secondary battery, which further used for lithium ion secondary battery (claimed). ADVANTAGE - The sheet-shaped positive electrode composite material capable of improving discharge capacity and high output characteristics. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for producing a sheet-shaped positive electrode composite material for a lithium ion secondary battery, which involves preparing a mixed dispersion by mixing a multiple of lithium transition metal oxide particles in a dispersion of graphite oxide; applying ultrasonic waves to the mixed dispersion solution to separate the layered crystal of the graphite oxide to form a sheet-like graphene oxide; generating charges of different polarities on the multiple of lithium transition metal oxide particles surface and the front and back surfaces of the sheet-like graphene oxide; adsorbing the multiple of lithium transition metal oxide particles on the front and back surfaces of the sheet-like graphene oxide to form a composite material by carrying the particles; and freeze-drying the composite material, converting the sheet-like graphene oxide into sheet-like graphene by performing a heat treatment under a reducing atmosphere, where the sheet-like graphene oxide includes length is 5 micrometer or more and 500 micrometer or less, the width is 5 micrometer or more and 500 micrometer or less; and (2) a lithium ion secondary battery comprising a positive electrode, a negative electrode, a separator and a non-aqueous electrolyte comprising the sheet-shaped positive electrode composite material for a lithium ion secondary battery.