Preconstructed Electrolyte Interphase Enables Stable Commercial V2O5 Cathodes for Aqueous Zinc-Ion Batteries

Abstract Aqueous zinc-ion batteries (AZIBs) show great potential for large-scale energy storage on account of their exceptional safety, low cost, and environmental friendliness. As a representative cathode for AZIBs, commercial vanadium pentoxide (c-V2O5) still suffers from critical bottlenecks including severe vanadium dissolution, sluggish Zn2+ diffusion, and intensive interfacial side reactions in aqueous electrolytes. Herein, a novel electrochemical pretreatment strategy is developed to in-situ construct a uniform, compact ∼3 nm amorphous electrolyte interfacial layer (EIL) with an organic–inorganic composite structure on the surface of c-V2O5 in an organic lithium-ion battery system, which breaks through the limitations of unstable and inhomogeneous interfacial layers formed in conventional aqueous systems. The EIL exerts multifunctional effects by suppressing vanadium dissolution, accelerating ion diffusion, and inhibiting side reactions, endowing the modified electrode with a high initial Coulombic efficiency of 98.3%, outstanding cycling stability (180 mAh g–1 after 5000 cycles at a current density of 1 A g–1), and enhanced rate capability. This work could provide guidance for optimizing cathode materials of AZIBs through rational electrolyte interface engineering in the future.