Mitigating cathodic dissolution through interfacial water masking to enhance the longevity of aqueous zinc–ion batteries

Abstract

Aqueous zinc-ion batteries (AZIBs) hold vast potential for large-scale energy storage applications due to their intrinsic safety features. Vanadium-based cathodes, known for their high specific capacity, face dissolution issues primarily due to water activity at the cathode–electrolyte interface. Herein, we introduce an innovative strategy that mitigates cathode dissolution through the use of an interfacial water-masking agent (IWMA). Taking isosorbide dimethyl ether (IDE) as a subject, it preferentially adsorbs onto the cathode interface, effectively displacing surface-active water. Simultaneously, its strong hydrogen bonding with water reduces the number of active bound water molecules in the solvation structure of Zn²⁺. These merits substantially strengthen the structural stability of the cathode, thereby improving both its reversible capacity and cycle stability. Impressively, this IWMA avoids involvement in the solvation structure and effectively reduces the desolvation energy of hydrated Zn²⁺, resulting in excellent rate performance for V₂O₅·nH₂O and Zn_0.25V₂O₅·nH₂O cathodes, with remarkable longevity exceeding 2500 and 4000 cycles at a rate of 5 A g⁻¹, respectively. This groundbreaking achievement marks a substantial stride in surmounting a formidable challenge in the realm of AZIBs.