▎ 摘　　要

NOVELTY - Preparation of graphene-cobalt-iron-tin composite material, involves adding potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, adding natural graphite and deionized water to obtain pre-oxidized graphite, adding concentrated sulfuric acid, potassium permanganate and deionized water, stirring, adding hydrogen peroxide and deionized water to obtain graphite oxide, adding graphite oxide to ethanol, adding phosgene, iron(III) chloride and tin(II) chloride, adding sodium borohydride to obtain mixed solution, naturally cooling and vacuum drying. USE - Method for preparing graphene-cobalt-iron-tin composite material. ADVANTAGE - The method enables preparation of graphene-cobalt-iron-tin composite material with high electrochemical capacity, excellent rate performance and cycle stability. DETAILED DESCRIPTION - Method for preparing graphene-cobalt-iron-tin composite material, involves (1) adding potassium persulfate, phosphorus pentoxide and concentrated sulfuric acid, stirring at 100-200 rpm for 0.5-1 hours, then adding natural graphite, heating at 75-90 degrees C, continuously stirring for 1-8 hours, cooling to 30-50 degrees C, continuously stirring for 0.5-2 hours, then cooling to room temperature, adding appropriate amount of deionized water, leaving still for 10-24 hours, draining the supernatant and filtering to obtain pre-oxidized graphite, (2) adding pre-oxidized graphite to concentrated sulfuric acid, stirring at 100-200 rpm for 0.5-1 hour, adding potassium permanganate, heating at 20-40 degrees C, continuously stirring at 100-200 rpm for 0.5-1 hour, then adding deionized water, continuously stirring at 100-200 rpm for 0.5-1 hour, then adding hydrogen peroxide and deionized water, leaving still for 10-24 hours, draining the supernatant, filtering, washing with deionized water for 3-5 times, vacuum drying at 50-70 degrees C under oxidizing conditions for 20-30 hours to obtain graphite oxide, (3) adding graphite oxide to ethanol, ultrasonically treating for 3-10 hours, then adding phosgene, iron(III) chloride and tin(II) chloride in mixing ratio of 1:1:4, continuously stirring at 100-200 rpm for 5-10 hours, then slowly adding sodium borohydride, stirring to obtain mixed solution, (4) adding mixed solution to reaction vessel at 200-300 degrees C for 20-30 hours, naturally cooling, washing the resulting product with deionized water for 3-5 times and vacuum drying at 30-50 degrees C for 1-5 hours to obtain final product. The mass ratio of potassium persulfate, phosphorus pentoxide and natural graphite is 1-3:1-3:1-10.