Engineering the interplanar spacing of ammonium vanadates as a high-performance aqueous zinc-ion battery cathode

We report the engineering of the interplanar spacing of ammonium vanadates to achieve the optimal electrochemical performance as cathodes for aqueous zinc-ion batteries (ZIBs) and provide insights into the origin of the enhanced electrochemical behaviors. The NH 4 V 4 O 10 compound, with the largest interplanar spacing (9.8 Å) and high diffusion coefficient, exhibits high energy density (374.3 W h kg −1 ) and power density (9000 W kg −1 ) as well as superior long-term cycling performance (a discharge capacity of 255.5 mA h g −1 can be maintained after 1000 cycles at 10 A g −1 ). With the merits of impressive energy density and long cycle life, the NH 4 V 4 O 10 might be a new promising cathode for aqueous ZIBs for grid energy storage applications. This work provides a direction for choosing or designing the ideal high-performance cathode for aqueous ZIBs and other advanced battery systems.