Formation of Mg–Li Alloy by Electro-Intercalation of Li⁺ Ions on a Solid Mg Cathode in a Eutectic LiCl–KCl Salt

Abstract

The electro-intercalation behavior of Li⁺ ions has been studied in a solid Mg cathode in LiCl–KCl molten salt. Cyclic voltammetry, chronoamperometry, and chronopotentiometry were employed to investigate the formation behavior of Mg–Li alloys via the electro-intercalation of Li⁺ ions. The electro-intercalation of Li⁺ ions into an Mg electrode occurred through underpotential deposition (UPD) to form Mg–Li alloys. The diffusion coefficient of Li⁺ ions at the Mg cathode was calculated by using Cottrell’s equation. The phase of the Mg–Li alloy was determined from the Li content of the alloy. The growth of the alloy layer by electro-intercalation was very fast compared to conventional solid-phase diffusion. The measured Li content of the Mg–Li alloy is similar to the theoretical value calculated on the basis of supplied charges.