Nsutite-type VO2 microcrystals as highly durable cathode materials for aqueous zinc-Ion batteries

Aqueous Zn-ion batteries (ZIBs) have gained considerable interest because of cost-effectiveness, high safety, and high theoretical capacities. However, the shortage of high-performance cathode materials hinders their practical application on large scale. In this study, nsutite-type VO2 microcrystals that were prepared via a hydrothermal method and applied as cathode materials in ZIBs is reported. The nsutite-type VO2 microcrystal cathodes exhibited high specific capacity (314.4 mAh g−1 at 1 A g−1), excellent energy densities, and an ultrahigh capacity retention of 84% after 5000 cycles at 5 A g−1. Furthermore, by combining with various in-situ and ex-situ measurements, we found that VO2 nanotables that were formed in the electrochemical process contributed to enhancing the electrochemical performance. We believe that the facile synthetic method and excellent performances of the nsutite-type VO2 microcrystal cathodes can pave the way for the future improvements in the synthetic methodology of cathode materials in ZIBs.