Gallium Ion Pre-Insertion Protocol to (NH4)2V10O25<middle dot>8H2O Cathode Materials for Reversible Aqueous Zn Battery

Vanadate is one of the promising cathode materials for aqueous zinc ion batteries (AZIBs) due to its abundant resources and various valence states. However, the further development is restricted by their sluggish reaction kinetics between zinc ions and the host materials. In this work, several kinds of gallium ions pre-intercalated vanadate electrode materials through a simple hydrothermal strategy are designed. Ga-NHVO-0.5 sample achieves a specific capacity of 438.23 mAh g(-1) at current density of 0.2 A g(-1). At the same time, it delivers an energy density of 250.34 Wh kg(-1) at a power density of 55 W kg(-1). The assembled button cells retain 83.84% of its initial capacity after 4000 times cycling, revealing their promising applications in portable power devices. Moreover, the devices still possess a favorable stability under different bending conditions.