Li+ intercalated V2O5·nH2O with enlarged layer spacing and fast ion diffusion as an aqueous zinc-ion battery cathode†
Aqueous zinc-ion batteries (ZIBs) show conspicuous potential in large-scale energy storage systems due to their cost-effectiveness and environmentally friendliness. Yet developmental cathodes in aqueous ZIBs suffer from sluggish Zn2+ diffusion kinetics. Herein, we introduce an effective strategy by the chemical intercalation of Li+ into the interlayer of V2O5·nH2O, i.e. LixV2O5·nH2O (LVO), with enlarged layer spacing and fast Zn2+ diffusion. As a cathode in aqueous ZIBs with a 2 M ZnSO4 electrolyte, the cotton-like LVO-250 demonstrates high rate capacities and excellent cycling performance (232 mA h g−1 after 500 cycles at 5 A g−1, and 192 mA h g−1 after 1000 cycles at 10 A g−1). The electrochemical reaction kinetics and zinc storage mechanism are investigated in detail.