Electrowinning of Lithium from Molten Salt Containing LiOH for Hydrogen Storage and Transportation

Abstract

Investigation on electrowinning of lithium from molten salt containing LiOH was conducted in order to develop a system of storage and transportation for hydrogen by using LiH as a storage medium. Electrolysis of LiOH in molten LiOH-42 mol% LiCl was tried, but lithium metal was not obtained. A chemical potential diagram for Li-O-H system was then constructed from thermochemical data for the analysis of side reactions, and a possibility of reaction between lithium metal and LiOH in the bath was revealed. Electrolysis of LiOH in molten LiCl-42 mol% KCl was tried by charging LiOH in an anode compartment comprised of a porous magnesia diaphragm in order to prevent the side reaction of lithium metal with LiOH, and lithium metal was successfully obtained.