Aqueous Zinc-Sulfur Batteries From Sulfur Conversion to Device Integration.

Aqueous zinc-sulfur batteries combine sulfur's high theoretical specific capacity with the safety, resource abundance and manufacturing compatibility of aqueous zinc chemistry. However, their progression from high-capacity concepts to practical devices is hindered by the poor electronic conductivity of sulfur and zinc sulfide, sluggish solid-state conversion kinetics, large volume changes, water-induced parasitic reactions, redox-mediator failure and unstable zinc deposition. Because these processes interact across cell components, optimizing the cathode, electrolyte, separator, or anode in isolation often fails to achieve the ultimate goal of improving device performance. This Review presents a reaction-to-device framework for understanding recent advances in aqueous zinc-sulfur batteries. Cathode hosts and catalysts are evaluated according to their ability to integrate electronic conduction, species confinement, catalytic conversion and mechanical buffering; redox mediators and electrolyte formulations according to their control over conversion pathways, solvation structures, water activity and interfacial chemistry; and selective membranes and zinc-protective interfaces according to their regulation of ion transport and electrode compatibility. Flexible, stretchable, planar and pouch-cell configurations are further examined as tests of system-level integration. This reaction-to-device perspective establishes design and benchmarking principles for advancing zinc-sulfur batteries toward safe, economical and scalable energy-storage technologies.