▎ 摘　　要

NOVELTY - Preparation of layered nano silicon-graphene anode material, involves performing delithiation of lithium-silicon alloy in anhydrous ethanol, ultrasonically vibrating in anhydrous ethanol-containing graphene oxide, wrapping graphene oxide on the surface of silicon nanosheets and reducing graphene oxide to graphene layer. The specific preparation involves dispersing silicon-lithium alloy powder in absolute ethanol, magnetically stirring under argon, performing delithiation of lithium-silicon alloy in anhydrous ethanol to form lamellar silicon nanosheets, adding to anhydrous ethanol in which graphene oxide is dispersed, ultrasonically oscillating, spontaneously wrapping graphene oxide on the surface of silicon nanosheets and uniformly dispersing in anhydrous ethanol to prepare dispersion, sealing the dispersion, filtering and drying to obtain precursor of negative electrode material, heating the precursor under the protection of argon gas and reducing graphene oxide to a graphene layer. USE - Method for preparing layered nano silicon-graphene anode material for lithium ion battery (all claimed). ADVANTAGE - The method enables simple, controllable and mass preparation of layered nano silicon-graphene anode material with improved stability, and alleviates the volume deformation of the two-dimensional layered nano-silicon wafer during lithium ion deintercalation process. DETAILED DESCRIPTION - Method for preparing layered nano silicon-graphene anode material, involves performing delithiation of lithium-silicon alloy in anhydrous ethanol to form lamellar silicon nanosheets, ultrasonically vibrating in anhydrous ethanol-containing graphene oxide, spontaneously wrapping graphene oxide on the surface of silicon nanosheets due to excessive specific surface area, reducing graphene oxide to graphene layer by high-temperature heat treatment, improving adhesion of graphene layer to silicon nanosheet layer. The specific preparation involves (1) dispersing silicon-lithium alloy powder in absolute ethanol, magnetically stirring under argon for 2-3 hours, performing delithiation of lithium-silicon alloy in anhydrous ethanol to form lamellar silicon nanosheets, adding to anhydrous ethanol in which graphene oxide is dispersed, ultrasonically oscillating for 8-12 minutes, spontaneously wrapping graphene oxide on the surface of silicon nanosheets and uniformly dispersing in anhydrous ethanol to prepare dispersion, (2) sealing the dispersion for 20-30 hours, filtering and drying to obtain precursor of negative electrode material, (3) rapidly heating the precursor at 800-1000 degrees C under the protection of argon gas for 1-3 minutes and reducing graphene oxide to a graphene layer.