A multi-shelled V2O3/C composite with an overall coupled carbon scaffold enabling ultrafast and stable lithium/sodium storage

Designing multi-shelled structures is an efficient way to improve the rate performance and cycle stability of transition metal oxides for lithium and sodium storage. However, the sluggish electron transport kinetics caused by the lack of overall conductive networks especially for the inner shells drastically restricts their high-power ability. Herein, a novel multi-shelled V2O3/C composite with an in-built overall carbon scaffold coupled on each of the porous V2O3 thin shells was developed through a simple solvothermal process followed by thermal treatment based on a sequential self-template mechanism. This novel structure simultaneously enables outstanding electrical conductivity, fast ion transport kinetics, and excellent structural stability. As expected, the composite shows a remarkably fast lithium storage ability of 427 mA h g(-1) at 5000 mA g(-1) and extraordinary cycle stability with 96% retention after 600 cycles, which is one of the best performances among the reported vanadium oxide/carbon composites. Moreover, it also exhibits an excellent sodium storage ability of 173 mA h g(-1) after 2000 cycles at 1000 mA g(-1). We believe that this work would broaden the avenue for designing advanced electrode materials for energy storage and conversion.