Lithium Extraction from Molten LiOH by Using a Liquid Tin Cathode

Abstract Lithium is a critical metal with a wide range of applications in energy, electronics, and chemical industry. Currently, the industrial method for Li metal extraction relies on electrolysis of molten LiCl and suffers from various safety, cost, and environmental issues. In this work, we report electrochemical extraction of Li from molten LiOH by using a liquid tin (Sn) cathode. The use of liquid Sn cathode offers various advantages, such as lowering the dissociation potential of LiOH and easy collection of the metallic Li. Electrochemical and materials characterization results reveal that a plunge of electrolysis current occurs in the electrolyser without using a porous alumina membrane, due to the formation of a Li 2 O passivation layer at the cathode/electrolyte interface. In the electrolyser with a porous alumina membrane, continuous electrolysis has been achieved, and the side surface of the liquid Sn is identified to be the effective interface for Li electrodeposition. In addition, we demonstrate the use of the Li–Sn product for the synthesis of acetylene (C 2 H 2 ), a widely used fuel and chemical feedstock. Graphical Abstract