▎ 摘　　要

NOVELTY - A positive electrode active material (301) is manufactured by forming mixture by mixing reaction product and graphene oxide, and calcining mixture to form positive electrode active material containing graphene having angle of 0-3 degrees with respect to surface of positive electrode active material in which reaction product is formed from raw material, and graphene is formed by calcining graphene oxide. USE - Manufacture of positive electrode active material for energy storage device (claimed) used for electric vehicle. ADVANTAGE - Weight of battery is reduced to increase capacity of battery. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a positive electrode active material (301) comprising material capable of injection and extraction of lithium ions, and graphene which coats surface of material. DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the lithium-ion secondary battery. Positive electrode active material (301) Positive electrode (302) Current collector (305) Negative electrode active material (306) Negative electrode (307)