The Recent Progress of Photothermal Evaporation for Lithium Extraction

Abstract Over the past few decades, the demand for lithium resources has increased significantly with the rapid development and extensive application of lithium‐ion batteries. Extracting lithium from salt‐lake brine is of significance because of its abundance in brines. Common methods for directly extracting lithium from salt lakes include precipitation, electrodialysis, and photothermal evaporation. Among these methods, lithium extraction using photothermal evaporation is considered an efficient and clean approach to addressing lithium shortages. In recent years, a lot of progress is made regarding lithium extraction with photothermal evaporation, so it is urgent to review the mechanistic basis and application of lithium extraction with photothermal evaporation. In this review, first, the mechanism of lithium extraction with photothermal evaporation is fully summarized, involving membrane separation, lithium‐ion sieves, and separated crystallization. Second, a series of strategies for designing various evaporators with highly efficient lithium adsorption characteristics based on photothermal materials are further discussed in detail. Finally, recommendations and perspectives on the larger‐scale development of lithium adsorbents by photothermal evaporation are proposed. Overall, this review not only offers in‐depth insight into lithium extraction from brines with low Li⁺ concentration, but also inspires the development and design of next‐generation lithium extraction evaporators with unprecedented properties.