Engineering crystal water in potassium ammonium vanadate for fast Zn-ion storage

The effect of different annealing temperatures on the electrochemical performance of potassium ammonium vanadate (KNVO) was investigated, and the annealed KNVO regained H2O from the aqueous electrolyte to achieve an optimal structural water content during activation. In addition, the accompanying oxygen vacancies further promoted Zn2+ diffusion kinetics of the KNVO cathode in AZIBs and achieved excellent rate performance (344 mA h g-1 at 10 A g-1).