Determination of Diffusion Coefficients of Mg2+ Ions from Molten LiCl-KCl-MgCl2

Abstract

The diffusion coefficients of Mg 2+ ions at molybdenum electrode in molten LiCl-KCl-MgCl2 at 670 ºC were determined using the cyclic voltammetry, chronoamperometry and chronopotentiometry, which were calculated to be 1.47 × 10-6 , 1.23 × 10-6 and 1.67 × 10-6 cm 2 /s, respectively. The activation energy for the diffusion process of Mg 2+ ions was found to be 106.3 kJ/mol. The underpotential deposition (UPD) of Li + ions on the pre-deposited Mg and the codeposition of Mg 2+ and Li + ions led a formation of liquid Mg-Li solution at a more positive potential than a potential for Li deposition.