Hydrogenated V2O5 Nanosheets for Superior Lithium Storage Properties

Abstract

V2O5 is a promising cathode material for lithium ion batteries boasting a large energy density due to its high capacity as well as abundant source and low cost. However, the poor chemical diffusion of Li+, low conductivity, and poor cycling stability limit its practical application. Herein, oxygen‐deficient V2O5 nanosheets prepared by hydrogenation at 200 °C with superior lithium storage properties are described. The hydrogenated V2O5 (H‐V2O5) nanosheets deliver an initial discharge capacity as high as 259 mAh g−1 and it remains 55% when the current density is increased 20 times from 0.1 to 2 A g−1. The H‐V2O5 electrode has excellent cycling stability with only 0.05% capacity decay per cycle after stabilization. The effects of oxygen defects mainly at bridging O(II) sites on Li+ diffusion and overall electrochemical lithium storage performance are revealed. The results reveal here a simple and effective strategy to improve the capacity, rate capability, and cycling stability of V2O5 materials which have large potential in energy storage and conversion applications.