Scalable Fabrication of Si-Graphene Composite as Anode for Li-ion Batteries

Abstract

A facile and scalable method is reported to fabricate Si-graphene nanocomposite as anode material for Li-ion batteries (LIBs) with high capacity and capacity retention performance. The Si-graphene electrode showed an initial discharge capacity of 1307 mAh g−1 at a current rate of 0.1C. At the 25th cycle, the electrode retained a discharge capacity of 1270 mAh g−1, with an excellent capacity retention of 97%. At the 50th cycle, the electrode still retained high capacity retention of 89%. The improved capacity retention of Si-graphene anode compared with Si anode is attributed to the mechanical flexibility of graphene that compromises the volume expansion of Si during the lithiation/delithiation process. The electrochemical impedance measurement further confirms the enhanced electrical conductivity and the denser solid-electrolyte-interface of the Si-graphene electrode. This fabrication approach is cost-effective and easy to scale up compared to known techniques, making it a promising candidate for commercializing Si-based anode for LIBs.