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

We report theNH₄⁺ 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). [ABSTRACT FROM AUTHOR]