Si nanoparticles veiled with ultrathin rGO film reduced directly by precoated Ni template: Fabrication and electrochemical performance

Si/graphene composite has been considered as a promising structure to limit the volume expansion and improve poor conductivity of silicon anode. Herein, a novel method to prepare Si/reduced graphene oxide (Si/rGO) composite anode was proposed. With this approach, nickel shell was pre-coated on Si particles via electroless deposition before used as a template to in-situ reduce GO. During the reduction process, the nickel template can as well promote the self-assembly of graphene sheets on the surface of Si nanoparticles. Following these facile and convenient processes, a Si/rGO hybrid-structure can be directly fabricated. Compared with pure Si anode, this Si/rGO composite displays a greatly improved electrochemical performance in both cycling stability and rate capability. It delivers a reversible capacity as high as 975 mA h g −1 and 717 mA h g −1 after 300 cycles under the current densities of 1 A g −1 and 3 A g −1 , respectively. Meanwhile, its capacity can still maintain at 602 mA h g −1 even at a rather higher current of 5 A g −1 .