Braided Ion Sieve with Confined Photothermal Enhancement for Sustainable Lithium Extraction

The sustainable extraction of lithium from salt-water brines remains a critical challenge. Most lithium extraction strategies with ion-sieves are limited by sluggish adsorption kinetics and a poor regeneration capability. Here, we report a braided photothermal lithium sieve (BPL) that synergistically integrates solar-driven evaporation with selective ion adsorption to overcome the intrinsic limitations of conventional ion sieves. BPL utilizes photothermal energy to accelerate lithium adsorption via solar evaporation, boosting the extraction efficiency through enhanced ion enrichment and exchange. The fibrous substrate also provides a robust substrate for the stable operation and regenerative recycling of ion sieves. Hence, BPL achieves an outstanding lithium adsorption capacity of 73.1 g·m–3 and water evaporation rate of 1.46 kg·m–2·h–1 under 1 sun radiation. In salt-lake brines with complex competing ions, the BPL maintains exceptional morphology robustness, ion selectivity, and lithium extraction (96.9 g·m–3) during a 7 day practical regeneration–operation cycle. Overall, this work establishes a new paradigm for practical solar-powered mineral extraction, which can remarkably increase clean lithium production.