Structural Modification of V2O5 as High-Performance Aqueous Zinc-Ion Battery Cathode

We report the NH4+ intercalated V2O5, i.e. (NH4)2V10O25•8H2O, with excellent electrochemical performance as cathode in aqueous zinc-ion battery (ZIBs), as compared to V2O5, Na5V12O32 and K2V8O21. This work reveals that the ionic conductivity of Zn2+ can be enhanced by introducing cations into the V2O5 framework and the vanadium oxygen structural units will be rearranged. Compared to a single layer of vanadium pentoxide consisting solely of VO5 units, the electrochemical performance of the structural units rearranged vanadates shows a significant improvement. As a result, the obtained (NH4)2V10O25•8H2O delivers high discharge capacity (376 mA h g−1 at 0.5 A g−1), superior rate capability up to 10 A g−1, excellent cycling stability (a capacity retention over 93% for 1000 cycles) and high energy density (341 Wh kg−1).