Electrochemical studies of aluminum deposition in ionic liquids at ambient temperatures

Ionic liquids are low melting salts used as potential non-aqueous electrolytes for the electrodeposition of aluminum. In the present study, an ionic liquid based on a mixture of AlCl3 and 1-methyl-3-butylimidazolium chloride was used as an electrolyte for the electrodeposition of aluminum at ambient temperatures. Electrochemical studies were carried out using cyclic voltammetry (CV) and chronoamperometry (CA) techniques. Electrodeposition of aluminum was carried out in the above-mentioned ionic liquid on copper as cathode. The process of electrodeposition was found to be quasi-reversible and the kinetic mechanism was identified as instantaneous nucleation followed by diffusion controlled three-dimensional growth. Kinetic parameters such as charge transfer coefficient (a) and diffusion coefficient (DO) of the species Al2Cl7- were obtained from the CV and CA data, which compared well with those available in the literature for aluminum deposition.