Hydrogenated V2O5 with fast Zn-ion migration kinetics as high-performance cathode material for aqueous zinc-ion batteries

The scarce inventory of cathode materials with mild interaction between Zn2+ and cathode lattice is the main obstacle to the development for aqueous rechargeable Zinc-ion batteries. In this paper, based on the first -principles calculations, we show that the insertion of protons in V2O5 effectively reduces the electrostatic interaction and the Zn-ion diffusion energy barrier in V2O5 substantially decreases after hydrogenation. Hence, the hydrogenated V2O5 (HV2O5) nanospheres are first proposed as a high capacity cathode for aqueous rechargeable Zinc-ion batteries by microwave-assisted chemical precipitation synthesis. It is demonstrated to exhibit high peak capacities of 602 mAh g-1 at 0.1 A g-1, high rate capacity as well an excellent cycle lifespan with a capacity retention of 86% after 5000 cycles at 10 A g-1. The mechanism of ions-diffusion in different charge and discharge states is also studied, and it proves dual-ion energy storage mechanism that HV2O5 can attract Zn ions and H ions at discharging.

Automated summary

Based on first-principles calculations, this paper proposes hydrogenated V2O5 (HV2O5) nanospheres as a high capacity cathode for aqueous rechargeable Zinc-ion batteries. The electrostatic interaction and Zn-ion diffusion energy barrier in V2O5 are effectively reduced after hydrogenation. The experimental results demonstrate that HV2O5 exhibits high peak capacities, high rate capacity, and excellent cycle lifespan. Furthermore, the mechanism of ions-diffusion in different charge and discharge states is studied, indicating the dual-ion energy storage mechanism of HV2O5 attracting both Zn ions and H ions during discharging.