Simultaneous regulation of cations and anions in an electrolyte for high-capacity, high-stability aqueous zinc–vanadium batteries

Safe,inexpensive aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices.However,they still face issues,including dissolution and collapse of the cathode as well as H_(2)evolution and the growth of Zn dendrites on the Zn anode.Herein,we simultaneously regulate the cations and anions in the electrolyte for high-capacity,high-stability aqueous zinc–vanadium(Zn–V)batteries based on a bimetallic cation-doped Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O cathode.We demonstrate that Na^(+) cations suppress cathode dissolution and restrain Zn dendrite growth on the anode via an electrostatic shield effect.We also illustrate that ClO_(4)^(-) anions participate in energy storage at the cathode and are reduced to Cl^(-),generating a protective layer on the Zn anode surface and providing a stable interface to decrease Zn dendrites and H_(2)evolution during long-term cycling.When Na^(+) and ClO_(4)^(-) are introduced into an aqueous ZnSO_(4) electrolyte,a Zn/Zn symmetric cell shows durable and reversible Zn stripping/plating for 1500 h at a current density of 1 mA cm^(-2) and with an area capacity of 1 mAh cm^(-2).Zn/Na_(0.33)K_(0.1)V_(2)O_(5)·nH_(2)O full batteries exhibit a high capacity of 600 mAh g^(-1)at 0.1 A g^(-1) and long-term cycling performance for 5000 cycles,with a capacity of 200 mAh g^(-1) at 20 Ag^(-1).