One-Step Solvometallurgical Process for Purification of Lithium Chloride to Battery Grade

Abstract

The use of lithium in manufacturing of lithium-ion batteries for hybrid and electric vehicles, along with stringent environmental regulations, have strongly increased the need for its sustainable production and recycling. The required purity of lithium compounds used for the production of battery components is very high (> 99.5%). In this work, a solvometallurgical process that exploits the differences in solubility between LiCl and other alkali and alkaline-earth chlorides and hydroxides in ethanolic solutions has been investigated for the purification of LiCl to battery grade at room temperature. A closed-loop flowsheet based on the green solvent ethanol is proposed for purification of LiCl, a precursor for battery-grade LiOH·H2O. High-purity LiCl solution (> 99.5% Li) could be obtained in a single-process step comprising the simultaneous selective dissolution of LiCl and the precipitation of Mg(OH)2 and Ca(OH)2 using LiOH·H2O in 95 vol% ethanol. However, the analogous process in aqueous solution resulted in impure LiCl (typically less than about 75%). Graphical Abstract: [Figure not available: see fulltext.].