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 highperformance PIBs and beyond.

Automated summary

A novel sheetlike hybrid nanoarchitecture consisting of V2O3 nanoparticles uniformly encapsulated in amorphous carbon nanosheets (V2O3@C) with the generation of C-O-V bonding is presented. This architecture effectively facilitates electrolyte infiltration, relieves mechanical strain, and reduces potassium-ion diffusion distance, leading to fast and durable potassium storage behaviors. The insertion/extraction mechanism of V2O3@C nanosheets in potassium-ion storage is systematically demonstrated, shedding light on the fabricating of high-performance metal oxides anodes for PIBs.