▎ 摘　　要

NOVELTY - Preparation of carbon-coated tin-cobalt/graphene microsphere anode material involves preparing nano intermediate by adding soluble tin salt and soluble cobalt salt in deionized water, dissolving, adding graphene solution and surface modifier, ultrasonically dispersing, adding reducing agent, reacting, filtering, washing solid material and drying, preparing intermediate composite microspheres by dissolving nano intermediate in deionized water, adding binder and spray-drying, dissolving petroleum bitumen in kerosene, adding intermediate composite microspheres, heating and carbonizing. USE - Preparation of carbon-coated tin-cobalt/graphene microsphere anode material used for lithium ion battery. ADVANTAGE - The method enables simple preparation of carbon-coated tin-cobalt/graphene microsphere anode material. The lithium ion battery obtained using the carbon-coated tin-cobalt/graphene microsphere anode material has high capacity, coulomb efficiency, cycle durability and filling density. DETAILED DESCRIPTION - Preparation of carbon-coated tin-cobalt/graphene microsphere anode material involves preparing nano intermediate by adding soluble tin salt and soluble cobalt salt in deionized water, dissolving, adding graphene solution and surface modifier, ultrasonically dispersing for 5-10 minutes, adding reducing agent for 10-20 minutes, reacting, depositing tin-cobalt alloy on graphene nano surface, filtering, washing solid material and drying, preparing intermediate composite microspheres by dissolving nano intermediate in deionized water, stirring, adding binder, stirring into slurry, spray-drying and obtaining micron sized intermediate composite microspheres large particles, dissolving petroleum bitumen in kerosene, adding intermediate composite microspheres, heating, drying, and carbonizing in inert atmosphere. The graphene is formed oxidation and hydrazine hydrate reduction of natural graphite flakes by Hummer law. The soluble tin salt is tin(IV) chloride, tin(II) sulfate, sodium stannate or tin phosphate. The soluble cobalt salt is cobalt sulfate or cobalt nitrate. The reducing agent is 0.1-1 mol/L sodium borohydride ethanol solution or potassium borohydride in water. The surface modifier is sodium lauryl sulfate or sodium dodecyl sulfate.