Isosorbide dimethyl ether enables interfacial regulation to boost the aqueous zinc-sulfur battery performance

Abstract

Aqueous zinc-sulfur batteries (AZSBs) offer high theoretical capacity, intrinsic safety, and low cost, but suffer from unstable interfaces, hydrogen evolution, and sluggish sulfur kinetics due to parasitic water activity and poor solvation structure. In this work, isosorbide dimethyl ether (ID) is introduced as a multifunctional co-solvent into a 2M Zn(OTF) 2 aqueous electrolyte (IDW). ID restructures the Zn 2+ solvation shell and adsorbs onto the Zn anode via its ether groups, forming a twodimensionally aligned, water-deficient interface that suppresses hydrogen evolution and enables uniform Zn deposition.Simultaneously, ID's electron-donating ability enhances interaction with iodine, promoting the formation of soluble I 3 - species and establishing an efficient I 3 -/I -redox mediation that accelerates sulfur conversion and mitigates active material loss. As a result, Zn∥Zn cells with IDW exhibit over ninefold longer lifespan (~1340 h) compared to the baseline aqueous electrolyte at 1 mA cm -2 and 1 mAh cm -2 . The full AZSB delivers high capacity, excellent rate performance, and maintains 70% capacity retention after 200 cycles. This work demonstrates a dual-interfacial regulation strategy through rational electrolyte design, provides a promising pathway toward high-performance, long-cycle-life AZSBs.