In-situ prepared of quadrilateral flake Zn 0.25 (NH 4 ) V 2 O 5 ·H 2 O as a cathode for aqueous rechargeable Zn-ion batteries

Aqueous zinc ion batteries (AZIBs) have great potential in the large-scale energy storage as its low price, safety, efficiency and environmental friendliness. In this work, a novel cathode of quadrilateral flake Zn 0.25 (NH 4 )V 2 O 5 ·H 2 O is prepared in-situ by electrochemical induction, in which NH 4 + and hydrated zinc ions are co-embedded in VO framework. Specifically, the Zn 0.25 (NH 4 )V 2 O 5 ·H 2 O electrode displays a largest discharge specific capacity of 355 mA h g -1 at 0.1 A g -1 in 2 M Zn(CF 3 SO 3 ) 2 , and shows an excellent cycle lifespan of 84.6% capacity retention at 1 A g −1 . Furthermore, the Zn//Zn 0.25 (NH 4 ) V 2 O 5 ·H 2 O cell is evaluated its practicability by driving a motor fan. In addition, we adopt ex-situ XRD and XPS to investigate the electrochemical induction process and energy storage mechanism of the Zn 0.25 (NH 4 )V 2 O 5 ·H 2 O electrode, and Zn 0.25 (NH 4 )V 2 O 5 ·H 2 O electrode follows a typical reversible zinc ion intercalation/deintercalation mechanism. Finally, this electrochemical induction method will promote further in-depth research on vanadium-based material cathode for AZIBs.