Production of lithium hydroxide by electrodialysis with bipolar membranes

Abstract

In conventional lithium extraction processes, highly purified lithium sulfate is generated as an intermediate, which is transformed into lithium hydroxide for lithium-ion battery applications. This study illustrates the technical feasibility of converting the pre-purified lithium sulfate (Li2SO4) into lithium hydroxide (LiOH) and sulfuric acid (H2SO4) using an electrodialysis with bipolar membrane (EDBM) process. A feed solution of 1.5 mol/L Li2SO4 is converted into 2.2 mol/L LiOH and 1.3 mol/L H2SO4 with a specific energy consumption of less than 10 kWh/kg LiOH produced. Due to the increased acid and base volume caused by electroosmosis, both acid and base concentrations are lower than that..