Interface engineering toward self-corrosion inhibited alkaline aluminum-air battery via optimized electrolyte system

In this manuscript, an introduced ionic liquids-ethylene glycol-KOH electrolyte system is proposed. Theoretical calculations and experiments show that ionic liquids with stronger hydrophobicity provide better corrosion inhibition for their spontaneous adsorption behavior and water molecule segregation. In this process, the imidazole ring cations play a major role. The electrolyte system reconstructs the Al/electrolyte interface with poor H2O, thus has lower self-corrosion rate for [BMIM]PF6 and contributes to the uniform dissolution of Al anode. Additionally, discharge performance of the full-cell feature same trend, endowing an outstanding capacity of 1971 mAh g−1 and anode utilization of 66.2% in alkaline [BMIM]PF6-ethylene glycol electrolyte. In terms of maintaining the activity of the Al-6061 anode whilst keeping low corrosion rate level, the proposed electrolyte system seems to be potential alternative. [Display omitted] •An aluminum-ionic liquid-alkaline electrolyte interface is constructed for Al-air batteries.•Al-molecular H2O-poor interface significantly suppresses the self-corrosion via the initiative adsorption of ionic liquid.•Imidazole ring of studied ionic liquids plays a dominant role in the adsorption behavior.