Producing battery grade lithium carbonate from salt‐lake brine via bipolar membrane carbon dioxide mineralization

Abstract Producing battery‐grade Li 2 CO 3 product from salt‐lake brine is a critical issue for meeting the growing demand of the lithium‐ion battery industry. Traditional procedures include Na 2 CO 3 precipitation and multi‐stage crystallization for refining, resulting in significant lithium loss and undesired lithium product quality. Herein, we first proposed a bipolar membrane CO 2 mineralization technique for directly producing battery‐grade Li 2 CO 3 from lake brine that enriches alkali metals (Na + , K + ). Results indicate the process can successfully separate Li + from contaminants and present a selectivity above 900 for Li + through the CO 2 mineralization reaction, while prevent electro‐oxidating Cl − to Cl 2 pollution. The obtained Li 2 CO 3 production purity is above 99.75% with lithium recovery rate of 86%. Carbon dioxide was captured in the form of Li 2 CO 3 , with a capacity of 595 g of CO 2 for1 kg of Li 2 CO 3 . The technology provides a sustainable and cost‐effective path for producing battery‐grade Li 2 CO 3 from the lake brine.