Synergetic vanadium oxide nanocomposite cathode material with high specific capacity and long life for advanced aqueous zinc-ion batteries

Abstract

Based on their high safety, low cost, and environmental friendliness aqueous zinc-ion batteries (AZIBs) are considered one of the most attractive candidates for large-scale energy storage applications. Vanadium-based compounds with high theoretical specific capacity are promising cathode materials for AZIBs. However, it is a great challenge for modified vanadium oxygen compounds to gain excellent zinc storage performance due to the strong electrostatic interaction between Zn2+ and V, O. Here, we present a one-step hydrothermal method and subsequent calcination to gain an advanced V2O5/VO2 nanocomposite as the cathode of highly stable AZIBs. The obtained composite has a synergistic effect, and the introduction of VO2 enhances the composites' general characteristics. Therefore, this composite structure not only accelerates the intercalation dynamics of Zn2+, but also further consolidates the stability during cycling. As a result, the as-synthesized cathode provides a high specific capacity of 453.2 mA h g−1 at 1 A g−1 and excellent cycle stability, with a high capacity maintained (200 mA h g−1) over 80 % after 2000 cycles at 10 A g−1. This work provides a new perspective for the development of viable insertion materials for AZIBs.