An innovative method uses atmospheric humidity to recover lithium quickly and efficiently, offering a new path for scalable direct lithium extraction.
A new pathway for direct lithium extraction
Today, direct lithium extraction relies mainly on two approaches depending on the type of deposit. Hard rock mining, typically from spodumene, requires energy-intensive blasting, crushing, and chemical processing.
Alternatively, lithium can be recovered from brines, highly saline fluids found beneath salt flats or as byproducts of oil and geothermal operations. These brines are estimated to hold about 78% of global lithium resources, but extraction becomes efficient only when lithium concentrations are high.
However, the presence of dissolved organic compounds and other impurities often requires combining multiple techniques or advanced pre-treatment processes. Existing direct lithium extraction technologies, including adsorption, ion exchange, solvent extraction, and membrane systems, still face major scalability challenges. In contrast, solar evaporation involves long processing times and significant water consumption.
This is where researchers from Princeton University introduce a new approach based on hygroscopic behavior.
Selective deliquescence enables 96% lithium recovery
The system developed by the research team leverages lithium chloride hydrate, a hygroscopic salt capable of absorbing moisture from the air. When added to brine waste and exposed to controlled humidity levels between 12% and 30%, the material absorbs water and forms a concentrated lithium solution, while other minerals and impurities remain solid.
This process, known as selective phase deliquescence, allows rapid solid-liquid separation without adding water, chemical reagents, or thermal energy.
According to the researchers, publishing in Nature Communications, the method achieves lithium recovery rates of up to 96%, with concentrations reaching 97,000 ppm, well above industrial requirements. The system has also been validated on complex mixtures and real waste samples under extraction conditions.
Extraction times are reduced dramatically, from months in traditional methods to just hours or even minutes.
Toward modular lithium production
As reported by Phys.org journalist Sanjukta Mondal, the team has already developed a modular prototype demonstrating the scalability of direct lithium extraction with hygroscopic salts.
The model is estimated to process between 3.65 and 8.01 kg of waste per day per meter of module height, outperforming several emerging lithium extraction technologies.
The study, titled Hygroscopicity-driven spontaneous sustainable direct lithium extraction, was published in 2026 and is currently under review.
