Constructing Compact Hybrid Buffer Interface via Ion Agglomeration Zone Electrolyte for Stable Zn Metal Battery

Abstract The development of aqueous Zn batteries is plagued by longevity limited at practical condition, due to the unstable electrode‐electrolyte interface. Here, this work designs an extended‐scale ion agglomeration zone (EIAZ) electrolyte to obtain anion combined with cation structures and reduce water activity. The electrolyte nanostructure features nanometer‐scale depleted water zones in which ion pairs are densely packed together to form EIAZ, which facilitates compact hybrid buffer interface formed via a collective ion transmission process and ionic co‐opetition relationship. The convergence and densification models of buffer interface for Zn surface is the result of cations adaptive adsorption that mitigates the concentration polarization of interfacial Zn 2+ and prevents water contact with electrodes, constituting an indispensable premise for stabilizing both anode and cathode interface. Moreover, unique electrolyte nanostructure achieves Zn crystallographic optimization and fast interfacial reaction kinetics, generating ultralong cycling stability of 5500 h. Therefore, zinc‐organic batteries can exert outstanding stability for over 3000 cycles and 1000 cycles under high current (10 A g ‒1 ) and high mass loading (14 mg cm −2 ). Impressively, pouch cell shows an excellent capacity retention of 99.8% with 26.1 mAh after 250 cycles. This study offers a novel perspective for designing electrolyte nanostructures and electrode interfaces for high‐performance Zn batteries.