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

Abstract

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 Zn 2+ 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 (AlV 3 O 9 ) as a cathode material for AZIBs using a solvothermal method. Al 3+ 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 AlV 3 O 9 (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.