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

摘要

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 nanowire/ graphene electrode realized a charge capacity of 2470 mAh g ' that is much higher than the 1256 mAh g~(-1) 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 ! D nanostructure.