Unlocking vast lithium stores: Faster, cleaner method extracts critical mineral from low-grade brines

Demand for lithium is skyrocketing as factories across the world churn out electric vehicles and the massive batteries that make wind turbines and solar panels reliable sources of energy. Unfortunately, current methods for producing lithium are slow and require high-quality feedstocks that are found in relatively few locations on the planet. Ironically, the environmental costs are also significant: refining the mineral behind clean energy requires large amounts of land and pollutes water supplies that local communities depend on.

In a new paper, researchers from Columbia Engineering describe a new method for extracting lithium that could dramatically shorten processing time, unlock reserves that existing methods can't tap, and reduce environmental impact. Their technique uses a temperature-sensitive solvent to extract lithium directly from the brines found in deposits across the world. Unlike current technologies, this approach can efficiently extract lithium even when the mineral is found in very low concentrations and contaminated with similar materials.

The results, detailed in a paper published today in Joule, show that the innovation, called switchable solvent selective extraction, S³E (pronounced S three E), can extract lithium with strong selectivity: up to 10 times higher than for sodium, and 12 times higher than for potassium. The process also excludes magnesium, a common contaminant in lithium brines, by triggering a chemical precipitation step that separates it out.

Improving on solar evaporation

Roughly 40% of lithium production begins with a salty brine that's found in large reservoirs that form under deserts. Nearly all of that lithium is extracted using a technique called solar evaporation, where the brine is pumped into sprawling ponds that bake under the desert sun—for up to two years—until enough water evaporates. This is only feasible in dry, flat regions with vast amounts of land, such as Chile's Atacama Desert or parts of Nevada. It also consumes large volumes of water in places that can scarcely afford it.

"There's no way solar evaporation alone can match future demand," said Ngai Yin Yip, La Von Duddleson Krumb Associate Professor of Earth and Environmental Engineering at Columbia University. "And there are promising lithium-rich brines, like those in California's Salton Sea, where this method simply can't be used at all."

Unlike conventional lithium recovery methods, S³E doesn't rely on binding chemicals or extensive postprocessing. Instead, the process exploits the way lithium ions interact with water molecules in a solvent system that changes its behavior based on temperature. At room temperature, the solvent pulls lithium and water from the brine. When heated, it releases the lithium, along with water, into a purified stream and regenerates itself for reuse.

An approach with tremendous potential

In lab tests using synthetic brines modeled on the Salton Sea, a geothermal region in Southern California estimated to hold enough lithium to supply more than 375 million EV batteries, the system recovered nearly 40% of the lithium over just four cycles with the same solvent batch. That suggests a viable path toward continuous operation.

"This is a new way to do direct lithium extraction," said Yip. "It's fast, selective, and easy to scale. And it can be powered by low-grade heat from waste sources or solar collectors."

The team emphasized that this is a proof-of-concept study. The system hasn't yet been optimized for yield or efficiency. But even in this early form, S³E appears promising enough to offer an alternative to evaporation ponds and hard-rock mining, the two approaches that dominate the lithium supply chain today and come with steep tradeoffs.

As the global clean energy transition picks up speed, technologies like S³E could play a crucial role in keeping it on track—by making it possible to extract lithium faster, more cleanly, and from more places than ever before.

"We talk about green energy all the time," said Yip. "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."