VO2 (A) nanostructures with controllable feature sizes and giant aspect ratios: one-step hydrothermal synthesis and lithium-ion battery performance

Abstract

In this paper, uniform 1D VO₂ (A) nanostructures with controllable morphologies were prepared via an easy one-step hydrothermal method for the first time. Aspect ratios are tunable from 10 : 1 to 1000 : 1 by changing the synthesis parameters such as the concentration of vanadium source and the reaction time. The mechanism of morphology evolution was investigated and discussed based on the nucleation and growth process of VO₂ (A) particles. Electrochemical analyses of VO₂ (A) nanostructures were performed, and the results showed a capacity of 277 mAh g⁻¹ for a Li-ion battery using these nanostructures as cathode materials. This shows a significant improvement compared with other vanadium oxides such as VO₂ (B) (approximately 180 mAh g⁻¹) and V₂O₅ (approximately 230 mAh g⁻¹). Unfortunately, the VO₂ (A) nanostructures exhibit high initial irreversible loss due to the formation of an intermediate layer after electrochemical reactions.