▎ 摘　　要

NOVELTY - Preparing porous silicon/graphene composite material comprises (i) mixing calcium hydroxide suspension with the porous silica, and passing the reaction gas to obtain porous silica/calcium carbonate composites, and (ii) mixing the porous silica/calcium carbonate composite obtained in step (i) with reducing agent, and carrying out thermal reduction reaction to obtain final product. USE - The porous silicon/graphene composite material is useful for preparing cathode of lithium-ion battery. ADVANTAGE - The porous silicon/graphene composite material has first capacity high primary Coulomb efficiency and good cycle performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for porous silicon/graphene composite material obtained by above method, where the composite material is composed of porous silicon and graphene embedded in pores and surfaces of the porous silicon in situ.