Advances in lithium and sodium separation techniques for brine lithium extraction processes

Abstract

The rapid development of lithium-ion (Li⁺) battery technology, coupled with its wide application in many fields have significantly increased the global demand for lithium (Li) resources. Li⁺ can be extracted from brines, but its chemical similarity to sodium ions (Na⁺) in solution poses significant challenges to the extraction process. Traditional methods such as evaporation ponds, ion exchange and precipitation have shown limitations in terms of separation efficiency and cost control. In order to overcome these challenges, researchers have developed several innovative techniques, including solvent extraction, adsorption, electrochemical insertion/de-insertion and membrane separation methods. The mechanism, effectiveness and improvement of these techniques for Li⁺ and Na⁺ separation was discussed. Moreover, the feasibility of industrial-scale applications and potential economic and environmental impacts were also been evaluated. In addition, the methods for concentrating Li⁺ after the Li⁺ and Na⁺ separation also been presented. This review comprehensively evaluates the separation of Li⁺ and Na⁺ during Li brine extraction, enabling the production of high-purity Li⁺ products and effective Li⁺ recovery.