Graphene Enhances Li Storage Capacity of Porous Single-Crystalline Silicon Nanowires

We demonstrated that graphene significantly enhances the reversible capacity of porous silicon nanowires used as the anode in Li-ion batteries. We prepared our experimental nanomaterials, viz., graphene and porous single crystalline silicon nanowires,: respectively, using a liquid phase graphite exfoliation method and an electroless HF/AgNO3 etching process. The Si porous nanowlre/graphene electrode realized a charge capacity of 2470 mAh g(-1) that is much higher than the 1256 mAh g of porous Si nanowire/C-black electrode and 6.6 times the theoretical capacity of commercial graphite. This relatively high capacity could originate from the favorable charge transportation characteristics of the combination of graphene with the porous Si 1D nanostructure.