▎ 摘　　要

NOVELTY - A porous silicon/graphene composite material preparing method involves selecting rice husk, washing, filtering and drying the rice hush to remove alkali metal oxide impurities through pyrolysis. The precursor salt solution is added to husk under catalytic carbonizing reaction to obtain carbonized product. The carbonized product is subjected to aerobic oxidation condition to obtain oxidation product, followed by adding metal oxide mixture with oxidation product to obtain reduction product, washing the reduction product with water and drying to obtain finished product. USE - Method for preparing porous silicon/graphene composite material that is utilized in lithium ion battery. ADVANTAGE - The method enables preparing composite material with high density capacity, high efficiency and good circulation property. DETAILED DESCRIPTION - A porous silicon/graphene composite material preparing method involves selecting rice husk, washing, filtering and drying the rice hush to remove alkali metal oxide impurities through pyrolysis under absence of oxygen or low oxygen condition. The obtained rice husk after pyrolysis process is according to liquid-solid ratio of 20-80:1 ml/g. The precursor salt solution is added to husk at 700-1000 degrees C for 1-5 hours under high temperature catalytic carbonizing reaction to obtain carbonized product. The carbonized product is subjected to aerobic low temperature oxidation condition at 300-600 degrees C for 0.1-4 hours to obtain oxidation product, followed by adding metal oxide mixture with oxidation product under low oxygen condition to obtain reduction product, washing the reduction product with water and drying to obtain a porous silicon/graphene composite material, where the precursor salt solution is a transition metal salt, the solvent is water, ethanol or acetone.