New solvent method extracts lithium faster from low-grade brines

Researchers at Columbia Engineering have developed a novel solvent-based method called switchable solvent selective extraction (S3E) to extract lithium more quickly and cleanly from low-grade brines, which are traditionally difficult to process due to low lithium concentrations and high contamination. Unlike conventional solar evaporation ponds that are slow, water-intensive, and limited to specific climates, S3E uses a temperature-sensitive solvent that selectively absorbs lithium ions and water at room temperature and releases purified lithium upon heating, allowing the solvent to be reused. This process also effectively removes magnesium, a common contaminant, enhancing lithium selectivity by up to 10 times over sodium and 12 times over potassium. Lab tests simulating brines from California’s Salton Sea—a region with lithium reserves sufficient for over 375 million electric vehicle batteries—showed that S3E could recover nearly 40% of lithium over multiple cycles using the same solvent batch. The method can operate continuously and be powered by low-grade heat from waste or solar sources,