Abstract
Aqueous rechargeable zinc-ion batteries (ZIBs) have garnered
considerable attention due to their safety, cost-effectiveness, and
eco-friendliness. There is a growing interest in finding suitable
cathode materials for ZIBs. Layered vanadium oxide has emerged as a
promising option due to its ability to store zinc ions with high
capacity. However, the advancement of high-performance ZIBs encounters
obstacles such as sluggish diffusion of zinc ions resulting from the
high energy barrier between V2O5 layers, degradation of electrode
structure over time and consequently lower capacity than the theoretical
value. In this study, we investigated the pre-doping of different
cations (including , , and ) into V2O5 to enhance the overall charge
storage performance. Our findings indicate that the presence of V4+
enhances the charge storage performance, while the introduction of into
V2O5 (NH4-V2O5) not only increases the interlayer distance (d(001) =
15.99 Å), but also significantly increases the V4+/V5+ redox couple
(atomic concentration ratio increased from 0.14 to 1.08), resulting in
the highest electrochemical performance. The NH4-V2O5 cathode exhibited
a high specific capacity (310.8 mAh g-1 at 100 mA g-1), improved cycling
stability, and a significantly reduced charge transfer resistance
compared to pristine V2O5.