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

Abstract

AbstractProducing battery‐grade Li2CO3 product from salt‐lake brine is a critical issue for meeting the growing demand of the lithium‐ion battery industry. Traditional procedures include Na2CO3 precipitation and multi‐stage crystallization for refining, resulting in significant lithium loss and undesired lithium product quality. Herein, we first proposed a bipolar membrane CO2 mineralization technique for directly producing battery‐grade Li2CO3 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 CO2 mineralization reaction, while prevent electro‐oxidating Cl− to Cl2 pollution. The obtained Li2CO3 production purity is above 99.75% with lithium recovery rate of 86%. Carbon dioxide was captured in the form of Li2CO3, with a capacity of 595 g of CO2 for1 kg of Li2CO3. The technology provides a sustainable and cost‐effective path for producing battery‐grade Li2CO3 from the lake brine.