▎ 摘　　要

NOVELTY - A lithium battery diaphragm comprises base film, and composite material layer formed on one side or two sides of the base film. The composite material layer comprises graphene, inorganic material and auxiliary agent. USE - A lithium battery diaphragm. ADVANTAGE - The lithium battery membrane has excellent tensile strength and puncture strength, and can obviously improve the safety and electrochemical performance of the lithium battery. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) preparing the lithium battery diaphragm comprising mixing graphene with a solvent to obtain a graphene mixed liquid; mixing an inorganic material precursor with a solvent to obtain an inorganic material precursor mixed solution; mixing the graphene mixed liquid with the inorganic material precursor mixed liquid and performing heat treatment to obtain a graphene-grafted inorganic composite material; mixing the graphene-grafted inorganic composite material with a solvent and an auxiliary agent to obtain a coating slurry; and applying the coating slurry to one or both sides of a base film; and (2) lithium battery comprising positive electrode, negative electrode and the lithium battery diaphragm.