Metal-organic frameworks derived flower-like V2O3/C/N for high‐performance sodium storage

Abstract

Vanadium oxide is a promising anode material for sodium-ion batteries due to its high theoretical capacity. However, its electrochemical performance is limited by its low electron transport capacity. To address this issue, we synthesized V2O3/C/N materials with a flower-like structure composed of ultra-thin nanosheets using V-MOFs as a template. The flower-like structure composed of nanosheets shortens the diffusion distance of sodium ions. Additionally, N doping regulates the electronic structure of the carbon layer and introduces defects, improving conductivity and generating more active sites. Consequently, V2O3/C/N-550 demonstrates outstanding electrochemical performance. It achieves an initial coulombic efficiency (ICE) of 90.5% at 0.1 A/g, with the highest capacity reaching 332.4 mAh/g. Even after 300 cycles, the capacity remains at 107.6% of its initial value. Additionally, it exhibits a discharge capacity of 190.7 mAh/g at 2 A/g. CV and GITT analyses confirm that V2O3/C/N-550 has a higher pseudocapacitance contribution and sodium ion diffusion kinetics. This can be attributed to its higher crystallinity, the flower-like structure composed of nanosheets, and the synergistic effect of N-doped carbon. Overall, this study provides valuable insights for the development of high-performance sodium-ion anode materials.