▎ 摘　　要

NOVELTY - Graphite oxide is dispersed in deionized water in volume ratio of 1 g:300-500 ml, sonicated for 15-20 hours and processed to obtain graphite oxide nanosheets. The graphite oxide nanosheet is dispersed in water dispersed system. A hydrazine hydrate as reducing agent is added such that the molar amount of hydrazine hydrate is 2-3 times of graphite oxide, stirred under reflux, filtered, washed with deionized water and acetone and dried, to obtain pure nano graphene. 20-35 wt.% Pure nano graphene is milled, to obtain silicon alloy-graphene composite negative electrode material. USE - Preparation of silicon alloy-graphene composite negative electrode material used for lithium-ion battery. ADVANTAGE - The method enables preparation of silicon alloy-graphene composite negative electrode material having excellent electroconductivity and cycling stability. The lithium-ion battery containing the silicon alloy-graphene composite negative electrode material has high capacity and excellent durability. DETAILED DESCRIPTION - A predetermined ratio of silicon, cobalt, manganese, zinc and magnesium are milled in jar mill filled with pure nitrogen, sealed and processed at 600-750 rpm for 10-20 hours, to obtain silicon alloy (Si2.05Co0.15Mn0.23Zn0.56Mg0.22). 1 g Graphite is dispersed in 30-40 mL concentrated sulfuric acid having concentration of 70 wt.% under ice-cooling and stirred. The amount of graphite powder dispersed in concentrated sulfuric acid is 70 wt.%. Potassium permanganate with content of 3.5-4 times the mass of graphite is added and heated at 10 degrees C or less for 1-2 hours and processed in oil bath. Deionized water with content of 30-40 times of graphite is added and mixed at 80-90 degrees C. Hydrogen peroxide having concentration of 30 %mass, and potassium permanganate is added. The reaction mixture is centrifuged, and washed with hydrochloric acid solution having concentration of 5 %mass, deionized water and acetone and dried, to obtain graphite oxide. Graphite oxide is dispersed in deionized water in volume ratio of 1 g:300-500 ml, sonicated for 15-20 hours and processed to obtain graphite oxide nanosheets. The graphite oxide nanosheet is dispersed in water dispersed system. A hydrazine hydrate as reducing agent is added such that the molar amount of hydrazine hydrate is 2-3 times of graphite oxide, stirred under reflux at 80-90 degrees C for 10-20 hours, filtered, washed with deionized water and acetone and dried, to obtain pure nano graphene. 20-35 wt.% Pure nano graphene is milled at 500-600 rpm for 6-10 hours, to obtain silicon alloy-graphene composite negative electrode material.