▎ 摘　　要

NOVELTY - The preparation method of transition metal oxide/graphene composite material involves (A) dissolving transition metal salt in deionized water, and uniformly stirring to obtain soaking liquid, and dispersing three-dimensional reduced graphene oxide in soaking liquid to prepare mixed liquid, (B) vacuum freezing and drying the mixed liquid, and placing in water for complete sublimation to obtain solid mixture, and (C) pre-decomposing the solid mixture at 160-200 degrees C in air for 1-4 hours to obtain reaction precursor, and calcining reaction precursor at 300-350 degrees C in air for 10-30 hours. USE - Preparation method of transition metal oxide/graphene composite material for cathode of lithium ion battery (all claimed). ADVANTAGE - The method enables preparation of transition metal oxide/graphene composite material with high capacity, prolonged service life, and excellent performance, by economical process.