KINETICS AND MECHANISM OF THE MAGNESIUM ELECTRODE-REACTION IN MOLTEN MAGNESIUM-CHLORIDE

Using electrochemical impedance spectroscopy (EIS) and relaxation meth od with galvanostatic perturbation (RM) the kinetics and mechanism of the magnesium electrode reaction in pure molten MgCl2 have been determ ined at several temperatures. A three-step electrode process has been found, the high frequency process being pure charge transfer with the low frequency process showing mixed charge transfer-diffusion characte r. The low frequency step has also been treated as a preceding chemica l reaction followed by charge transfer. On the basis of the correspond ing exchange current densities and Warburg diffusion impedance, a mech anism of the overall electrode reaction in this melt is proposed.