Towards high-performance aqueous zinc-ion battery via cesium ion intercalated vanadium oxide nanorods

Layered vanadium oxide cathode materials have attracted extensive attentions in rechargeable aqueous zinc-ion batteries (ZIBs) owing to its large interlayer distance and high capacity. Unfortunately, it suffers from fast capacity decay during long-term cycle due to severe structural collapse. Herein, we intercalate cesium ion (Cs+) into hydrated vanadium pentoxide (V2O5 center dot nH(2)O) to obtain a reinforce layered structure, which forms strong Cs-O bond with the built-in oxygen atom and enhances the interaction between the layers to avoid the structure collapse. As a result, the Cs+ intercalated material (CsVO) presents an enhanced specific capacity (404.9 mAh g(-1) at current density of 0.1 A g(-1), 189.9 mAh g(-1) at 20 A g(-1)) and excellent long-term cycle stability (the capacity retention of 89% over 10,000 cycles even at 20 A g(-1)), that is obviously superior to the bare V2O5 center dot & nbsp;nH(2)O electrode. Furthermore, Zn2+/H+ co-insertion mechanism in aqueous ZIBs is demonstrated by ex-situ XRD and XPS characterizations.

Automated summary

Layered vanadium oxide cathode materials have been extensively studied in rechargeable aqueous zinc-ion batteries due to their large interlayer distance and high capacity. However, these materials suffer from fast capacity decay during long-term cycles. In this study, cesium ions were intercalated into hydrated vanadium pentoxide to reinforce the layered structure and enhance the interaction between layers, resulting in improved specific capacity and excellent long-term cycle stability.