Researchers at Columbia University’s School of Engineering and Applied Science, led by Ngai Yin Yip, associate professor of earth and environmental engineering, have proposed a new method for extracting lithium that could address several long-standing limitations in how the critical mineral is currently produced. The approach, demonstrated at laboratory scale, offers a faster route to recovery from low-grade brines while reducing land use and water loss associated with conventional extraction methods.
Dach, E., Marston, J., Abu-Obaid, S., Peng, A., & Yip, N. Y. (2026). A novel approach for direct lithium extraction from alkali metal cations in brine mixtures using thermally switchable solvents. Joule, 102265. https://doi.org/10.1016/j.joule.2025.102265
Global demand for lithium continues to rise as electric vehicles, grid-scale batteries, and renewable energy systems expand. Much of today’s lithium supply comes either from hard-rock mining or from saline brines concentrated through solar evaporation. The latter method dominates production in regions such as South America’s salt flats, where brine is pumped into large ponds and left to evaporate over periods that can extend beyond a year. While effective in specific climates, the process requires large areas of land, consumes significant water resources, and is not viable for many lithium-bearing brines with lower concentrations or high levels of chemical contaminants.
Ngai Yin Yip from Columbia University stated,
“We talk about green energy all the time. But we rarely talk about how dirty some of the supply chains are. If we want a truly sustainable transition, we need cleaner ways to get the materials it depends on. This is one step in that direction.”
The Columbia-led team focused on a category of resources that remain largely untapped: low-grade and chemically complex brines found in geothermal reservoirs, oilfield waters, and inland saline aquifers. These sources are widespread, including well-studied deposits such as California’s Salton Sea, but have proven difficult to exploit using existing technologies. Traditional direct lithium extraction methods rely on solid sorbents or membranes that struggle with selectivity, fouling, and regeneration when exposed to mixed-ion environments.
The new technique, referred to as switchable solvent selective extraction, uses a temperature-responsive solvent system to separate lithium ions directly from brine. At lower temperatures, the solvent selectively associates with lithium and water molecules, leaving most competing ions behind. When heated, the solvent releases the lithium into a purified aqueous stream and regenerates itself for reuse. This eliminates several intermediate processing steps common in other extraction approaches.
Laboratory tests using synthetic brines representative of real-world geothermal compositions showed strong selectivity for lithium over more abundant alkali metals such as sodium and potassium, while effectively excluding magnesium, one of the most problematic contaminants in lithium recovery. Over multiple extraction cycles using the same solvent batch, the system recovered a substantial fraction of the available lithium, suggesting the potential for continuous operation rather than batch processing.
Beyond performance metrics, the researchers emphasize the broader systems implications of the method. Because the solvent switching is driven by moderate temperature changes, the process could be powered using low-grade heat from industrial waste streams or solar thermal collectors. This contrasts with evaporation ponds, which depend on specific climate conditions, and hard-rock mining, which requires energy-intensive crushing and chemical treatment.
Independent analyses of lithium supply chains have repeatedly identified extraction as one of the most environmentally burdensome stages of battery production. Water depletion, land disruption, and chemical waste have raised concerns among regulators and local communities, particularly in arid regions. By shortening processing times and enabling lithium recovery from brines previously considered uneconomic, solvent-based extraction methods like S3E could diversify supply while reducing pressure on a small number of high-impact production sites.
The researchers note that the work remains at a proof-of-concept stage. Further optimization will be required to improve yields, assess long-term solvent stability, and evaluate performance with real brines under industrial conditions. Scale-up challenges, including solvent management and system integration, will also need to be addressed before commercial deployment can be considered.
Even so, the study contributes to a growing body of research aimed at rethinking how critical materials are sourced for the energy transition. As lithium demand continues to outpace current production capacity, engineering solutions that enable faster, cleaner, and more flexible extraction could play an important role in stabilizing supply chains. Rather than replacing existing methods outright, approaches such as switchable solvent extraction may complement them by unlocking resources that have so far remained out of reach.
Adrian graduated with a Masters Degree (1st Class Honours) in Chemical Engineering from Chester University along with Harris. His master’s research aimed to develop a standardadised clean water oxygenation transfer procedure to test bubble diffusers that are currently used in the wastewater industry commercial market. He has also undergone placments in both US and China primarely focused within the R&D department and is an associate member of the Institute of Chemical Engineers (IChemE).
