Sulfur is an important electrode material in metal−sulfur batteries. It is usually coupled with metal anodes and undergoes electrochemical reduction to form metal sulfides. Herein, we demonstrate, for the first time, the reversible sulfur oxidation process in AlCl3/carbamide ionic liquid, where sulfur is electrochemically oxidized by AlCl4− to form AlSCl7. The sulfur oxidation is: 1) highly reversible with an efficiency of ~94%; and 2) workable within a wide range of high potentials. As a result, the Al−S battery based on sulfur oxidation can be cycled steadily around ~1.8 V, which is the highest operation voltage in Al−S batteries. The study of sulfur oxidation process benefits the understanding of sulfur chemistry and provides a valuable inspiration for the design of other high-voltage metal−sulfur batteries, not limited to Al−S configurations.

Changing the solvation sheath of hydrated Zn ions is an effective strategy to stabilize Zn anodes to obtain a practical aqueous Zn‐ion battery. However, key points related to the rational design remain unclear including how the properties of the solvent molecules intrinsically regulate the solvated structure of the Zn ions. This study proposes the use of a stability constant (K), namely, the equilibrium constant of the complexation reaction, as a universal standard to make an accurate selection of ligands in the electrolyte to improve the anode stability. It is found that K greatly impacts the corrosion current density and nucleation overpotential. Following this, ethylene diamine tetraacetic acid with a superhigh K effectively suppresses Zn corrosion and induces uniform Zn‐ion deposition. As a result, the anode has an excellent stability of over 3000 h. This work presents a general principle to stabilize anodes by regulating the solvation chemistry, guiding the development of novel electrolytes for sustainable aqueous batteries.