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

As a new large-scale energy storage candidate owing to their low cost and high theoretical capacity, rechargeable aqueous zinc-ion batteries (AZIBs) have garnered widespread attention. However, the unique divalent state of Zn2+ and the existence of a strong electrostatic repulsion phenomenon has prompted increased research on high-performance cathode materials is currently attracting considerable attention. In this study, we synthesized aluminum vanadate (AlV3O9) as a cathode material for AZIBs using a solvothermal method. Al3+ acts as a pillar in the result of the proposition and plays a role in stabilizing the structure. Furthermore, this large interlayer spacing also 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-1even at a high current density of 3 A g-1 (the capacity retention rate reached 84.38% after 1600 cycles). Moreover, the prepared ZIBs present a high power density of 286.0 W kg-1 at an energy density of 366.6 W h kg-1. These extraordinary results indicate the great application potential of AVO as a cathode material for AZIBs.