Novel aluminum vanadate as a cathode material for high-performance aqueous zinc-ion batteries

Abstract

Rechargeable aqueous zinc-ion batteries (AZIBs) have garnered widespread attention as a new large-scale energy storage candidate owing to their low cost and high theoretical capacity. Because of the unique divalent state of Zn2+ and the existence of a strong electrostatic repulsion phenomenon, researchers are currently focusing on how to prepare high-performance cathode materials. In this study, we synthesized aluminum vanadate (AlV3O9) as a cathode material for AZIBs using a solvothermal method. Al3+ acted as a pillar in the resultant structure and stabilized it. Furthermore, this large interlayer spacing enhanced the ion diffusion coefficient and accelerated the ion transport process. Because of these advantages, the AlV3O9 (AVO) cathode exhibited excellent electrochemical performance, including a high capacity of 421.0 mA h g−1 at 0.1 A g−1 and a stable rate capability of 348.2 mA h g−1 at 1 A g−1. Moreover, it exhibited a specific capacity of 202 mA h g−1 even at a high current density of 3 A g−1 (the capacity retention rate reached 84.38% after 1600 cycles). The prepared ZIBs presented a high power density of 366.6 W kg−1 at an energy density of 286 W h kg−1. These extraordinary results indicate the great application potential of AVO as a cathode material for AZIBs.