▎ 摘　　要

NOVELTY - A carbon-coated silicon/graphene composite is prepared by mixing graphene oxide, hexadecyl trimethyl ammonium bromide, sodium hydroxide and water, slowly adding ethyl orthosilicate, stirring, hydrothermal reacting, centrifuging reaction liquid, washing by water, filtering, drying, calcining to obtain silicon dioxide/graphene composite, mixing with magnesium powder and molten-salt, putting into sealed stainless reactor, high temperature reacting, etching reaction product with hydrofluoric acid, filtering, water washing, vacuum drying to obtain graphene/silicon mixture, adding with tripolyphosphazene and 4,4-dihydroxydiphenyl sulfone in absolute ethanol, adding triethylamine, ultrasonically processing, centrifugally separating, washing with ethanol, vacuum drying to obtain polyphosphazene-coated silicon/graphene composite, carbonizing, and cooling. USE - Method for preparing carbon-coated silicon/graphene composite used as cathode material of lithium ion battery (claimed). ADVANTAGE - The composite has high-viscosity characteristic, realizes uniform coating and ultra-thin load, removes polyphosphazene heteroatom, and forms uniformly loaded porous carbon film. DETAILED DESCRIPTION - A carbon-coated silicon/graphene composite is prepared by mixing graphene oxide, hexadecyl trimethyl ammonium bromide, sodium hydroxide and water to form mixed solution, slowly adding ethyl orthosilicate, stirring, hydrothermal reacting, centrifuging reaction liquid, washing by water, filtering, drying, calcining to obtain silicon dioxide/graphene composite, mixing with magnesium powder and molten-salt, putting into sealed stainless reactor, high temperature reacting under inert gas atmosphere protection, etching reaction product with hydrofluoric acid, filtering, water washing, vacuum drying to obtain graphene/silicon mixture, adding with tripolyphosphazene and 4,4-dihydroxydiphenyl sulfone in absolute ethanol, adding triethylamine, constant temperature ultrasonically processing for 4 hours, centrifugally separating, washing with ethanol, vacuum drying to obtain polyphosphazene-coated silicon/graphene composite, high temperature carbonizing under inert gas atmosphere, and cooling to room temperature.