Room-Temperature Electrodeposition of Mg Metal from Amide Salts Dissolved in Glyme-Ionic Liquid Mixture

The electrodeposition of Mg metal from an ionic liquid–glyme mixture was investigated at room temperature. The mixture contains a glyme, a simple amide salt Mg(Tf 2 N) 2 (Tf = SO 2 CF 3 ), and a quaternary-ammonium Tf 2 N ionic liquid. Using the mixture bath, substantial cathodic electrodeposition of Mg at a large current density (∼10 mA cm −2 ) was observed, suggesting a change in coordination geometry around Mg 2+ cation together with improved conductivity. By mixing diglyme, the conductivity increased by an order of magnitude (2.5 – 2.6 mS cm −1 ) compared to the glyme-free ionic liquid (0.35 mS cm −1 ) and the viscosity became as low as that of pure glyme. Additionally, potentiostatic electrolysis resulted in a non-dendritic thin film of elemental Mg with metallic luster.