Chelation-Driven Electrolyte Design for Enhanced Interface and Electrochemical Window in Aqueous Aluminum Batteries.

Aqueous aluminum-ion batteries have garnered significant attention owing to the abundance of aluminum resources, high theoretical specific capacity, and excellent safety. However, challenges such as electrolyte-induced water decomposition, aluminum anode corrosion, and electrode material compatibility continue to constrain their performance. In this study, we restructured the solvation environment using the chelating reagent Bis(2-methoxyethyl)amine (BMEA), achieving an expanded electrochemical window of 2.2 V and mitigating hydrogen evolution side reactions. Advanced atom probe tomography analysis confirmed that BMEA actively participates in the formation of the solid-electrolyte interphase (SEI), effectively preventing aluminum surface corrosion and extending the cycle life of the aluminum anode. Employed as a BMEA-containing electrolyte in aluminum-organic batteries, the resulting Al||Tetrachloro-1,4-benzoquinone (TCB) battery delivered a high capacity of 218.0 mAh g and demonstrated stable cycling over 300 cycles. This study highlights the potential of chelating agents as additives in advancing high-performance aluminum batteries.