Using an AlCl3/Urea Ionic Liquid Analog Electrolyte for Improving the Lifetime of Aluminum‐Sulfur Batteries

Abstract Aluminum‐sulfur (Al−S) chemistry is attractive for the development of next‐generation rechargeable battery systems. However, only a few reversible Al−S cells have been reported until now. This paper demonstrates that the use of an AlCl 3 /urea electrolyte in Al−S cells is a promising approach to improve the cycle life and reach a high discharge voltage plateau of ∼1.6–2.0 V. In contrast to the instability of sulfur in the conventional AlCl 3 /EMIC electrolyte, sulfur is chemically stable in the AlCl 3 /urea electrolyte, which allows better cell cycling stability. The Al−S cell delivers an initial capacity of ∼700 mAh g s −1 and maintains a capacity of up to ∼500 mAh g s −1 after 100 cycles.