▎ 摘　　要

Silicon (Si) anode materials have received much attentionon accountof their unparalleled theoretical specific capacity, but they sufferfrom huge volumetric expansion and particle pulverization, which leadsto rapid capacity fading and poor electrical conductivity as well.In this work, a quaternary silicon/carbon (Si/C) composite anode materialis proposed which combines the advantages of both graphene and thethree-dimensional carbon framework through rational structural designand simple synthesis methods. Nanosilicon/carbon nanofibers/pyrolyticcarbon (SCC) composite particles are first synthesized by spray dryingand pyrolysis, which are then wrapped by graphene nanosheets througha second spray drying and pyrolysis process to obtain the final product(SGCC). In this composite, a 3D carbon skeleton composed of carbonnanofibers and pyrolytic carbon serves as an electric conductive matrixthat supports and stabilizes Si nanoparticles, while graphene nanosheetswrapped on the surface further improve the conductivity and structurestability of the composite particles, and isolate the particles fromdirect contact with electrolytes. Meanwhile, the rich pores of thecomposite particles can effectively provide space for the volume expansionof Si during lithiation. As a consequence, the as-prepared SGCC compositeshows a high initial Coulomb efficiency of 84.7%, a high reversiblecapacity of 2150.8 mA h g(-1), and a good capacityretention rate of 83.75% after 100 cycles.