Electrodeposition of Aluminium from Ionic Liquids: a study on combined deposition parameters Effect

Since their discovery, ionic liquids (ILs) have attracted a wide interest for their potential use as medium for many chemical processes such as extraction, catalysis, organic synthesis and electrochemistry , just to name a few. Regarding the latter the use as electrolytes of ILs characterized by very large electrochemical window allowed the electrodeposition of cations that are impossible to reduce in aqueous solution such as Al, Si, Hf, Nb etc. In particular, from chloroaluminated ILs resulted relatively simple the deposition of Aluminium from his chloride salt. Despite the discovery of this process in the nineties, nowadays aluminium electrodeposition from Chloroaluminate ILs still maintains a number of open issues both on the side of fundamental science and technological aspects. The present research, part of the “SCAIL-Up” European Project, aims to both shed some light on the aluminium electrodeposition process as concerns the effect of deposition parameters, and to assess the best deposition parameters for the process scaling up. Thick Al-coatings (20 µm) were deposited on brass substrate combining the most relevant operating parameters; i.e.temperature and agitation [1]. The samples obtained in different conditions were characterized by means of scanning electron microscopy (SEM) and x-ray powder diffraction (XRD) to asses their morphology and texture. Roughness measures were also performed to assess the best deposition conditions to achieve smooth and homogeneous deposits that constitute the target for industrial applications. These experimental studies were theoretically supported and validate by means of COMSOL simulations. Finally, a newly designed Rotating Hull Cylinder Cell (RHC), suitable for application in aggressive environments was tested to study the deposit growth rate at different current densities.