Rechargeable Aqueous Zinc-Ion Batteries in MgSO(4)/ZnSO(4) Hybrid Electrolytes

MgSO(4) is chosen as an additive to address the capacity fading issue in the rechargeable zinc-ion battery system of Mg(x)V(2)O(5)·nH(2)O//ZnSO(4)//zinc. Electrolytes with different concentration ratios of ZnSO(4) and MgSO(4) are investigated. The batteries measured in the 1 M ZnSO(4)(−1) M MgSO(4) electrolyte outplay other competitors, which deliver a high specific capacity of 374 mAh g(−1) at a current density of 100 mA g(−1) and exhibit a competitive rate performance with the reversible capacity of 175 mAh g(−1) at 5 A g(−1). This study provides a promising route to improve the performance of vanadium-based cathodes for aqueous zinc-ion batteries with electrolyte optimization in cost-effective electrolytes. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40820-020-0385-7) contains supplementary material, which is available to authorized users.