Electrochemical Stability of Magnesium Battery Current Collectors in a Grignard Reagent-Based Electrolyte

The electrochemical stabilities of several electrodes were investigated by cyclic voltammetry and chronoamperometry in a tetrahydrofuran solution containing phenylmagnesium chloride and aluminum chloride. The existence of chloride ions in the electrolyte caused pitting of affordable, non-noble metal electrodes at high potentials and crucially lowered their corrosion resistance. In contrast, Pt and glassy carbon electrodes exhibited high corrosion resistance. Since Pt is expensive and bulk glassy carbon is not flexible, these two materials are not suitable current collectors in commercial batteries. A considerable improvement in corrosion resistance was confirmed when glassy carbon coatings were formed on the affordable electrodes by plasma carburization, which can be one solution to this corrosion problem.