Reduced graphene oxide as a dual-functional enhancer wrapped over silicon/porous carbon nanofibers for high-performance lithium-ion battery anodes

Abstract

Silicon/porous carbon nanofibers wrapped by reduced graphene oxide (Si/P-CNFs@rGO) are innovatively synthesized via a convenient preparation process consisting of a simple electrospinning method followed by a carbonization process and a sequent electrodeposition. Experimental results show that silicon nanoparticles (Si NPs) are anchored on the carbon fiber with rGO tightly wrapped on the fiber surface. This rGO protective layer acting as a dual-functional enhancer could not only accommodate the volume expansion of Si but also enhance the electrical conductivity, leading to an improved electrochemical performance. The as-obtained Si/P-CNFs@rGO electrode exhibits an excellent performance, with a high reversible capacity of 1851.3 mAh g⁻¹ at a current density of 0.2 A g⁻¹ with almost no capacity fading up to 50th cycle, a high reversible capacity of 1217.8 mAh g⁻¹ with an excellent coulombic efficiency (CE) of 99.0% at 0.53 A g⁻¹ after 300 cycles, and a high discharge specific capacity of 421.5 mAh g⁻¹ even at a high current density of 4 A g⁻¹.