Multifunctional Electrolyte toward Long‐Life Zinc‐Ion Batteries: Synchronous Regulation of Solvation, Cathode and Anode Interfaces

Abstract Rechargeable aqueous zinc‐ion batteries (ZIBs) are threatened by the cathode dissolution and anode corrosion/dendrites, resulting in poor reversibility. Here, a multifunctional electrolyte is developed to regulate the cathode, anode interface, and solvation by introducing a low‐cost diethylene glycol monomethyl ether (DGME). The DGME can modulate the primary solvation sheath (PSS) of the hydrated Zn²⁺ and destroy the original hydrogen bond network of water, while the electric double layer (EDL) interface is reconstructed by the adsorption of DGME, which guides the uniform deposition of Zn²⁺ on the (002) crystal plane. Simultaneously, the DGME also effectively inhibits the dissolution of VO₂ and enhances the reaction kinetics. As a proof of concept, the Zn//Cu cells deliver 2000 cycles with an ultrahigh coulombic efficiency (CE) of 99.6%. Additionally, the multifunctional electrolyte significantly improves the multiple performance of Zn//VO₂ full cells. The low‐cost and multifunctional electrolyte can be readily applied to ZIBs, demonstrating its practical versatility.