Electrochemical Solvometallurgy Pathway for the Sustainable Recovery of Bulk Metallic Lithium

Due to the wide range of potential applications of metallic Li and other active metals, the development of simple and cost-effective electrochemical methods for extracting these metals from their salts is greatly important. Accordingly, herein, an electrochemical solvometallurgy technology pathway is proposed to realize the recovery of metallic Li at room temperature. A low-cost aprotic polar molecular liquid, dimethylformamide (DMF), was selected for electrowinning of Li with abundant LiCl as the raw material. Subsequently, the electrolyte structure of the optimized binary DMF/LiCl system (0.7 M LiCl) was analyzed using 7Li nuclear magnetic resonance spectroscopy, Fourier-transform infrared spectroscopy, and theoretical calculations. Electrochemical reaction mechanisms were elucidated through cyclic voltammetry and ultraviolet–visible absorption spectrometry. Finally, the Li coating was successfully obtained using potentiostatic deposition on a high-purity In substrate in the form of nanoalloy sheets. To realize the transformation of electrodeposited materials from the “thin film” to the “bulk”, a continuous, direct smelting electrodeposited film short-process technique was proposed to achieve recovery of stable metallic Li in the form of a bulk Li–In intermediate alloy. This low-energy, low-carbon, and sustainable strategy can be applied for the low-temperature electrochemical recovery of reactive (Li, Mg, Al, and Ti) and rare-earth metals.