A Durable Na0.56V2O5 Nanobelt Cathode Material Assisted by Hybrid Cationic Electrolyte for High-Performance Aqueous Zinc-Ion Batteries

Abstract

Rechargeable aqueous Zn‐ion batteries (ZIBs) show attractive potential in energy storage devices on account of high safety and eco‐friendliness. Yet the lack of suitable cathode materials prevented the practical application of ZIBs. In our work, a Na0.56V2O5 (NVO) nanobelt cathode material has been fabricated via a hydrothermal reaction. The prepared NVO samples reveal an expanded layer spacing, assisted by the chemical intercalation of Na+ into the V2O5. Particularly, a mild hybrid cationic electrolyte (0.5HCE, containing 3 M ZnSO4 and 0.5 M Na2SO4) was employed to replace the traditional ZnSO4 electrolyte (ZE) in the Zn//NVO system. Owing to the enlarged interlayer spacing and the protective effect of 0.5HCE, the NVO cathode delivers a preferable capacity and good cyclic stability. More specifically, the NVO cathode in 0.5HCE displays a high initial discharge capacity of 317 mAh g−1 at 0.1 A g−1, and exhibits a good stability after 1000 cycles at the current density of 1 A g−1. Besides, the Zn//NVO battery also presents a favorable rate capability and a high reversibility. This study could provide new directions for the development of low‐cost zinc ion batteries.