Simulation of aluminium electrodeposition on complex geometry: Influence of input parameters and electrodeposition conditions

It is necessary to improve the current efficiency and thickness distribution of the electrodeposition of Al coatings on a Mg alloy from ionic liquids. To accomplish this, finite element method is presented here to help experimental processes to refine various electrodeposition conditions for improving efficiency and economy. However, the simulation of Al deposition from ionic liquids is hindered by the lack of initial parameters in existing works. In this paper, the initial kinetic parameters used in the model were obtained precisely using Tafel plots and cyclic voltammograms. The cathodic and anodic transfer coefficients were calculated to be 0.136 and 0.864 at 318.15 K. The exchange current density for Al₂Cl₇⁻/AlCl₄⁻ redox process was calculated as 4.6A/m² at 318.15 K. Subsequently, the multiphysics model in this work combined secondary current distribution, laminar flow, and transport of diluted species. The results of the Al coating thicknesses from finite element method agree well with the experimental method. Hence, the finite element model can precisely predict the Al coating thickness, which provides a positive outlook to analyze the thickness of Al coating and promotes its utilization in industry.