A Review on System Design for Photothermal Lithium Extraction

The rapid development of electric vehicle batteries and large-scale grid energy storage systems has led to a substantial surge in global lithium (Li) demand. While abundant in brine and seawater, its extraction requires efficient and low-energy methods. Unlike established physicochemical or electrically-driven Li extraction processes, the emerging photothermal technology offers a cleaner and lower-cost alternative. This promising approach leverages abundant solar energy via photothermal materials to drive brine/seawater evaporation and concentrate Li⁺ for capture. Its core relies on synergistic coupling between photothermal units and Li extraction units. Crucially, systems design for photothermal Li extraction is of utmost importance for achieving high efficiency, selectivity, and stability. Unlike previous reviews focusing on extraction methods, this review reveals the impact of coupling interactions between photothermal units and Li extraction units on photothermal Li extraction performance. Based on the coupling interactions between the two functional units, this study defines integrated systems (where units are assembled within a single matrix) and non-integrated systems (where units exist in separate matrices). We further systematically summarize the synergistic enhancement effects of photothermal materials and Li extraction materials on Li extraction in each system. Finally, we present outlooks for the photothermal Li extraction system from four perspectives.