The effect of different annealing temperatures on the electrochemical performance of potassium ammonium vanadate (KNVO) was investigated, and the annealed KNVO regained H 2 O from the aqueous electrolyte to achieve an optimal structural water content during activation. In addition, the accompanying oxygen vacancies further promoted Zn 2+ diffusion kinetics of the KNVO cathode in AZIBs and achieved excellent rate performance (344 mA h g -1 at 10 A g -1 ).