Novel Room Temperature Molten Salts for Aluminium Electrodeposition

Abstract

This work describes novel room temperature molten salts which can be used for aluminium electrodeposition. We have characterised the conductivity as a function of the bath composition and shown that the changes in conductivity occur because of an equilibrium between [Al₂Cl₇] and [AlCl₂ The voltammetry of the optimum melt is analysed together with the mechanism of nucleation. Hull cell tests were performed and the morphology of the deposits was analysed using scanning electron microscopy. These room temperature molten salts have a number of advantages over those described in the literature including lower water sensitivity, greater ease of purification and greatly reduced cost. The electrodeposition of adherent, dull aluminium is demonstrated. It is also shown that soluble aluminium anodes can be used. These novel baths form a viable alternative to conventional methods of depositing aluminium.