Charge-tuning mediated rapid kinetics of zinc ions in aqueous Zn-ion battery

Vanadium oxides are considered to be one of the most promising cathode materials for rechargeable aqueous zinc-ion batteries. However, the sluggish kinetics of zinc-ion intercalation and unstable layered structure limit its further development. Herein, we use the interlayer charge-tuning strategy to fabricate a KBa0.45V6O16·2.2H2O nanowire by Ba2+ and K+ dual pre-intercalation. The dual ions intercalated cathode enables a discharge capacity of up to 563 mAh g−1 at 0.1 A g−1 and retains 98.5% capacity after 10,000 cycles at 5 A g−1. Experiments and theoretical calculations jointly reveal that charge-tuning reduces the electrostatic repulsion between zinc-ions and the host matrix, which realizes the rapid diffusion kinetics of zinc-ions and restrains the cathode dissolution effectively. Benefiting from its excellent flexibility and weather resistance, KBa0.45V6O16·2.2H2O nanowire-based Zn-ion battery also shows robust application in wearable electronic devices. The charge-tuning strategy provides new ideas to the design of high-performance cathode materials for aqueous Zn-ion batteries.