Aluminum Electrodeposition in Dry Air Atmosphere: Comparative Study of an Acetamide–AlCl ₃ Deep Eutectic Solvent and a 1-Ethyl-3-Methylimidazolium Chloride–AlCl ₃ Ionic Liquid

Aluminum electrodeposition using ionic liquids or deep eutectic solvents has attracted significant interest for coating applications. Although Al electrodeposition is usually carried out in a nitrogen- or argon-filled glove box, there may be a potential for process cost reduction if the Al electrodeposition process could be carried out in a dry atmosphere. In this study, we examined two commonly used baths, namely a 1-ethyl-3-methylimidazolium chloride (EMImCl)–AlCl 3 ionic liquid and an acetamide (AcAm)–AlCl 3 deep eutectic solvent, to determine their respective feasibilities for the electrodeposition of a uniform Al film in dry air. Electrodeposition in dry air using the AcAm–AlCl 3 bath produced uniform Al films even after the bath had been used for more than 10 weeks, whereas electrodeposition in dry air using the EMImCl–AlCl 3 bath failed to produce an Al film covering the entire substrate. The current efficiency was almost 100% in the AcAm–AlCl 3 bath, whereas the value decreased to 50% in EMImCl–AlCl 3 bath in dry air. The findings of this study therefore reveal that AcAm–AlCl 3 is a suitable bath for Al electrodeposition in dry air.