Reversible K0.54V2O5 Nanorods for High-Performance Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) have advantages of nontoxicity and low cost, but the Zn2+ storage mechanism still requires further investigation, giving rise to difficulty in designing a reasonable structure to improve battery performance. Here, K+-inserted layered vanadium oxide (K0.54V2O5) with a nanorod shape is demonstrated as a promising cathode material for ZIBs, and the storage mechanism of zinc ions is explored. This material displays an excellent electrochemical performance, with a capacity of 176 mA h g–1 over 2400 cycles at 5 A g–1, corresponding to a capacity retention of 97%. The attractive performance is due to the layered structure and ions embedded, which improve the gallery spacing and ion diffusion rate. More importantly, this study advances the development of vanadium-based oxides for ZIBs.