Novel hybrid Si film/highly branched graphene nanosheets for anode materials in lithium-ion batteries

Abstract

Silicon anodes have the highest theoretical capacity in lithium-ion battreries, which, however, suffer from huge volume expansion with poor cyclic performance. To achieve good cyclic perfomrance, in this study, silicon film/highly branched graphene nanosheets (HBGNs) hybrid materials have been prepared via plasma-enhanced chemical vapor deposition of HBGNs, followed by low vacuum chemical vapor deposition of Si. The HBGNs, with 3D-conductive graphene networks, provide a large surface area for Si loading and the densely packed vertical graphene structure offers void space for large volume expansion of Si. Therefore, the Si/HBGN anode exhibits a high capacity and good cyclic performance, emerging as a promissing binder- and conductive additive-free Si/C composite anode for lithium-ion batteries.