Defect-repaired reduced graphene oxide caging silicon nanoparticles for lithium-ion anodes with enhanced reversible capacity and cyclic performance

Abstract

Combining nanoscale silicon with reduced graphene oxide (RGO) is a transformative approach to assembling high capacity silicon-based anodes for lithium-ion batteries (LIBs). However, preparation of RGO via conventional reduction methods always causes abundant structural defects. The crystalline structure and electronic conductivity of the resultant RGO are seriously damaged. Herein defect-repaired RGO (DRGO) building blocks to support silicon nanoparticles (SiNPs) are prepared, showing enhanced reversible capacity and cyclic performance. Specifically, RGO is engineered to produce a cage-shaped shell, enwrapping SiNPs with reserved interspace. Glucose is used to repair the defects in the graphene oxide (GO) to generate lower-defect RGO. The as-prepared SiNPs embedded in defect-repaired RGO cages (Si@DRGOC) deliver the gravimetric capacity of 2678.4 mA h g−1 at 100 mA g−1 with high coulombic efficiency over 98% as an anode for LIBs. The Si@DRGOC electrode also delivers reasonable rate capacity of 1284.5 mA h g−1 at 2 A g−1, and 2002.7 mA h g−1 as the current density cycling back to 100 mA g−1. This well-engineered structure may provide a promising strategy for fabrication of high-performance LIBs anode materials.