Electrochemistry of Gallium in the Lewis Acidic Aluminum Chloride‐1‐Methyl‐3‐ethylimidazolium Chloride Room‐Temperature Molten Salt

The electrochemistry of gallium at tungsten and glassy carbon was investigated in the 60.0/40.0 mol % aluminum chloride‐1‐methyl‐3‐ethylimidazolium chloride molten salt. The electrodissolution of gallium produces a gallium(I) solution, which can be electrochemically oxidized to Ga(III). The formal potential for the Ga(III)/Ga(I) and Ga(I)/Ga(0) couples are 0.655 and 0.437 V, respectively. The Ga(I)/Ga(III) electrode reaction exhibits slow‐charge transfer kinetics with an anodic transfer coefficient and a standard heterogeneous rate constant of 0.24 and , respectively, at tungsten, and 0.14 and , respectively, at glassy carbon. The electrodeposition of gallium at glassy carbon from solutions of Ga(I) exhibits instantaneous three‐dimensional nucleation with diffusion‐controlled growth of the nuclei. The Ga(III) species can react with gallium metal to form Ga(I). The diffusion coefficients for Ga(III) and Ga(I) species are and , respectively. © 1999 The Electrochemical Society. All rights reserved.