This review presents a comprehensive analysis of recent advances in electrolyte design for AZSBs, offering detailed insights into reaction mechanisms, current challenges, and the corresponding strategies, while also outlining future directions for electrolyte development.

Aqueous Zn–S batteries (AZSBs) have emerged as a next-generation energy storage system, offering high energy density, cost-effectiveness, and enhanced safety. However, their widespread adoption is restricted by multiple challenges, including sluggish sulfur redox kinetics that lead to high polarization voltage and poor capacity retention of the sulfur cathode. Moreover, unwanted reactions and irregular zinc dendrite development on the anode severely compromise electrochemical performance, particularly in capacity retention and cycle life. Among the various strategies, electrolyte engineering has emerged as an effective approach to overcoming these bottlenecks by regulating sulfur conversion, stabilizing zinc plating/stripping, and expanding the electrochemical stability window. This review offers an in-depth exploration of recent innovations in electrolyte design for AZSBs, comprising discussions on the fundamental sulfur redox reaction mechanism, the challenges faced by AZSBs at both the cathode and anode, and the systematic strategies for enhancing battery performance through electrolyte modification. Finally, future research directions are proposed to optimize electrolyte formulations for achieving high-performance and long-lasting AZSBs, paving the way for their commercial viability.