"Dual- Engineering" Strategy to Regulate NH V O as Cathodes for High-Performance Aqueous Zinc Ion Batteries.

Aqueous zinc ion batteries (AZIBs) have attracted attention as a promising candidate for secondary battery energy storage due to their safety and environmental benefits. However, the vanadium-based cathode material NH V O has the problem of structural instability. In this paper, it is found by density functional theory calculation that excessive NH located in the interlayer will repel the Zn during the process of Zn insertion. This results in the distortion of the layered structure, further affects the diffusion of Zn and reduces the reaction kinetics. Therefore, part of the NH is removed by heat treatment. In addition, the introduction of Al into the material by hydrothermal method is able to further enhance its zinc storage properties. This dual-engineering strategy shows excellent electrochemical performance (578.2 mAh g at 0.2 A g ). This study provides valuable insights for the development of high performance AZIBs cathode materials.