▎ 摘　　要

NOVELTY - A composite material comprises 60-95 %mass preferably 80-95 %mass cobalt carbonate and graphene. USE - Composite material for negative electrode of sodium ion batteries (claimed). ADVANTAGE - The composite material has uniform size and provides batteries with good electrochemical performance, rate performance, cycle stability, strong operability, good reproducibility and stable product quality. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the composite material.