▎ 摘　　要

NOVELTY - Preparing porous silicon/graphene composite lithium ion battery anode material comprises e.g. (i) heating diatomite, carrying out natural cooling annealing treatment, removing organic matter, washing, carrying out acid leaching, and drying to obtain purified diatomite, (ii) mixing magnesium reduction agent and purified diatomite, heating under inert atmosphere, insulating, cooling, soaking in acid solution, washing and then drying to obtain porous silicon, and (iii) heating porous silicon under action of catalyst, cooling, and then carrying out deposition of pyrolytic carbon source. USE - The method is useful in preparing porous silicon/graphene composite lithium ion battery anode material (claimed). ADVANTAGE - The anode material has excellent electrochemical performance. DETAILED DESCRIPTION - Preparing porous silicon/graphene composite lithium ion battery anode material comprises (i) heating diatomite to 600-900 degrees C at a heating rate of 5-20 degrees C/minute under normal pressure, carrying out natural cooling annealing treatment for 1-4 hours, removing organic matter, washing using alkaline solution having concentration of 0.001-0.1 mol/l for 2.5-5 hours until it becomes neutral, carrying out acid leaching using 4-8 mol/l acid solution at 95 degrees C for 4-8 hours, then washing using deionized water, and drying at 80 degrees C to obtain purified diatomite, (ii) mixing magnesium reduction agent and purified diatomite in a mass ratio of 1:0.5-2, heating to 600-850 degrees C under inert atmosphere, insulating for 2-5 hours, cooling to room temperature, soaking in acid solution having concentration of 0.1-5 mol/l for 12-18 hours, washing and then drying to obtain porous silicon, and (iii) heating porous silicon (substrate) under action of catalyst and inert atmosphere in tubular furnace to 800-1100 degrees C at a heating rate of 5-10 degrees C/minute, naturally cooling and annealing for 5-10 minute, then carrying out deposition of pyrolytic carbon source to obtain final product, where deposition time is 10-30 minute, under inert atmosphere, flow rate is 100-400 sccm, cooling to room temperature at cooling rate of 20-50 degrees C/minute.