Encapsulating V₂O₃ Nanoparticles in Hierarchical Porous Carbon Nanosheets via C–O–V Bonds for Fast and Durable Potassium-Ion Storage

Vanadium oxide (V2O3) has been considered as a promising anode material for potassium-ion batteries (PIBs), but challenging as well for the low electron/ion conductivity and poor structural stability. To tackle these issues, herein, a novel sheetlike hybrid nanoarchitecture constructed by uniformly encapsulating V2O3 nanoparticles in amorphous carbon nanosheets (V2O3@C) with the generation of C–O–V bonding is presented. Such a subtle architecture effectively facilitates the infiltration of electrolyte, relieves the mechanical strain, and reduces the potassium-ion diffusion distance during the repetitive charging/discharging processes. The generated C–O–V bonding not only accelerated charge transfer across the carbon–V2O3 interface but also strengthened the structural stability. Benefiting from the synergistic effects, the as-prepared V2O3@C nanosheets display fast and durable potassium storage behaviors with a reversible capacity of 116.6 mAh g–1 delivered at 5 A g–1, and a specific capacity of 147.9 mAh g–1 retained after 1800 cycles at a high current density of 2 A g–1. Moreover, the insertion/extraction mechanism of V2O3@C nanosheets in potassium-ion storage is systematically demonstrated by electrochemical analysis and ex situ technologies. This study will shed light on the fabricating of other metal oxides anodes for high-performance PIBs and beyond.