Lithium isotope effect accompanying electrochemical insertion of lithium into gallium

Abstract

Lithium has been electrochemically inserted from a 1:2 (v/v) mixed solution of ethylene carbonate (EC) and methylethyl carbonate (MEC) containing 1 M LiClO 4 or from dimethyl sulfoxide (DMSO) containing 1 M LiCl into gallium, and the lithium isotope fractionation accompanying the insertion has been observed. The lighter isotope was preferentially fractionated into gallium, which was in accordance with the theory of the equilibrium isotope fractionation arising from molecular vibrational quantum effects. The single-stage lithium isotope separation factor ranged from 1.015 to 1.025 at 25 °C. It was independent both of the kind of electrolyte solution and of the chemical composition of the Li–Ga alloys formed within the experimental range studied and within experimental uncertainty.