▎ 摘　　要

NOVELTY - A graphene and ferrous disulfide composite positive electrode material preparing method involves preparing graphene dispersion liquid by using improved Hummer process, followed by using concentrated sulfuric acid and potassium permanganate in ice water, peeling graphite oxide to oxidized graphene ultrasonically to obtain an oxidized graphene colloid liquor. The oxidized graphene is reduced by a reducing agent in a water bath to obtain reduction product. The reduction product is etched using hydrofluoric acid aqueous solution and washed with water and ethanol. The washed product is dried. USE - Method for preparing graphene and ferrous disulfide composite positive electrode material. ADVANTAGE - The method enables preparing graphene and ferrous disulfide composite positive electrode material with high purity, high energy density, improved electric conductivity and improved ionic mobility. DETAILED DESCRIPTION - A graphene and ferrous disulfide composite positive electrode material preparing method involves preparing graphene dispersion liquid by using improved Hummer process, followed by using concentrated sulfuric acid and potassium permanganate in ice water, peeling graphite oxide to oxidized graphene ultrasonically to obtain an oxidized graphene colloid liquor. The oxidized graphene is reduced by a reducing agent in a water bath at 70-90 degrees C to obtain reduction product. The reduction product is etched using 25-30% hydrofluoric acid aqueous solution for 5-8 hours and washed with water and ethanol for 3-5 times. The washed product is dried to obtain graphene powder. The graphene powder is dispersed in acetone to obtain 10-15 g/l graphene dispersion liquid, followed by dissolving iron sulfate in mixed solution of acetone and water to prepare solution-A, and thiourea thiocarbamide and polyvinyl pyrrolidone in mixed solution of acetone and water to prepare solution-B. The solution-A is stirred with solution-B by adding sulfur powder, maintaining dosage of the (S) to be more than reaction rate to ensure oxidization reaction of iron ion (Fe 2+) into iron ion (Fe 3+) to obtain mixed solution. The mixed solution is transferred into reaction kettle, followed by adding acetone. The reaction kettle is sealed, followed by preserving temperature and reacting at 200-220 degrees C for 24-36 hours to obtain a reacted solution. The reacted solution is filtered to obtain black precipitate. The black precipitate is washed using carbon bisulfide, de-ionized water, organic solvent and diluted sulfuric acid to remove surplus sulfur (S) powder. The washed precipitate is dried and ground to obtain iron disulfide nano-crystal. The iron disulfide nano-crystal is stirred with the graphene dispersion liquid at a mass ratio of 100:35 mechanically for 3-6 hours to obtain mixed paste. The mixed paste is heated in helium gas protection at 120-135 degrees C for 6-10 hours and at 350-380 degrees C for 10-15 hours to obtain heated product. The heated product is cooled to room temperature, ball-milled and sieved to obtain a finished product, where the mass ratio of the iron sulfate, thiourea thiocarbamide and polyvinyl pyrrolidone is 1-2:2-3:1-2.