▎ 摘　　要

NOVELTY - Preparation of metal oxide-graphene quantum dot composite material involves (S1) dissolving the graphene quantum dots in deionized water to form a graphene quantum dot dispersion, (S2) adding a soluble metal salt, an oxidant and a buffer into the dispersion, and performing hydrothermal reaction after the soluble metal salt is dissolved to obtain a metal oxide graphene quantum dot composite material. The metal soluble salt is a soluble salt of any one of metal manganese, vanadium and cobalt. USE - Preparation of metal oxide-graphene quantum dot composite material of positive electrode used in aqueous bimetallic ion battery such as zinc ion battery, magnesium ion battery or aluminum ion battery (claimed). ADVANTAGE - The preparation method is simple, and provides a universal and efficient method for material structure optimization. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) Positive electrode element; and (2) Aqueous bimetallic ion battery.