▎ 摘　　要

NOVELTY - A low-expansion silicon carbon cathode material has a core-shell structure, with nano-silicon as core, porous carbon material as middle layer (5-30 wt.%), and boron-doped graphene sponge as outermost layer (1-10 wt.%). USE - Low-expansion silicon carbon cathode material for lithium ion battery. ADVANTAGE - The low-expansion silicon carbon cathode material has excellent lithium storage active point, electroconductivity and liquid-retaining performance, and improved power and cycle performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the low-expansion silicon carbon cathode material, which involves using asphalt, potassium hydroxide, deionized water, porous carbon, organic solution, nano silicon material, hydrogen peroxide, graphene oxide solution, hydrazine hydrate, and boron chloride. The mass ratio of graphene sponge and silicon carbon precursor is (1-5):100.