Journal of Applied Electrochemistry, Vol.39, No.8, 1297-1303, 2009
Electrodeposition of Al, Mn, and Al-Mn Alloy on aluminum electrodes from molten salt (AlCl3-NaCl-KCl)
Electrochemical deposition of aluminum and manganese from basic and acidic molten AlCl3-NaCl-KCl mixture on an aluminum electrode at 180 A degrees C was studied by the methods of voltammetry, and potential and current transient. The deposition of aluminum was found to proceed via a nucleation/growth mechanism in basic melt, while the deposition of manganese was found to be diffusion controlled in basic melt. The diffusion coefficient of Mn2+ ions in basic melt, as derived by voltammetry was in agreement with the deductions of transient methods. Analysis of the chronoamperograms indicates that the deposition of manganese on Al was controlled by 3D diffusion controlled nucleation and growth. The processes are manifested as peaks on a decaying chronoamperogram. Non-linear fitting methods were applied to obtain the kinetic parameters from theoretical formulae proposed to describe this system. It is also found that under more cathodic potentials, the saturation number density of the manganese nuclei and also the efficiency of use of the available surface nucleation sites increased.