Silicon@carbon-graphene-based flexible composite material and preparation method thereof and lithium battery

The invention provides a silicon@carbon-graphene-based flexible composite material and a preparation method thereof and a lithium battery. The flexible composite material is prepared from graphene nanosheets and silicon@carbon particles inlaid in the graphene nanosheets, wherein the graphene nanosheets are irregularly arranged and served as a basic skeleton of the flexible composite material; thesilicon@carbon particles take a silicon particle as a core and comprise a double-carbon layer coating the surface of the silicon particle. The method comprises the following steps: adding silicon intoa solution with oxidability, washing and drying; then adding polydiallyl dimethyl ammonium chloride, stirring and drying; mixing with graphene oxide, and regulating pH; performing suction filtrationto form a film; performing freeze drying on the film; sintering to obtain the flexible composite material. With the double-carbon layer structure on the silicon surface, the flexible composite material provided by the invention