As the world races to electrify everything from vehicles to energy grids, demand for lithium—a key ingredient in lithium-ion batteries (LIB)—has exploded. Yet conventional lithium min-ing has long carried a heavy environmental toll, including mas-sive water usage, toxic chemical processes, and significant land disruption. Now, scientists and engineers across the globe are pioneering innovative direct lithium extraction (DLE) techniques, including electrochemical separation methods, that promise to supply lithium more efficiently and with far less environmental harm.
“There will be no energy transition without lithium,” said Alexandre Chagnes, professor of chemistry at the University of Lorraine in Nancy, France, and an expert in LIB chemistry. "We need ways to store energy, and today’s choice is lithium-ion batteries.”
To meet climate change mitigation goals, the annual demand for lithium is expected to increase by 15 times between 2020 and 2040, from 74 to 1160 kt (
Fig. 1)[
1]. Some forecasts suggest that existing lithium supplies may be insufficient to meet demand as early as 2029, even with the completion of numerous mining projects currently underway [
2]. Furthermore, under current pro-jections, the demand for the battery sector alone could exhaust 74% to 248% of existing lithium reserves by 2050, underscoring the need to secure sustainable sources of lithium [
3].
As for supply, the US Geological Survey estimates that global lithium reserves from known sources total around 105 million ton-nes, of which 28 million tonnes can be economically extracted with current technologies [
4]. However, the standard ways of obtaining lithium—largely from brine evaporation in South America’s "Lithium Triangle” of Argentina, Bolivia, and Chile and hard rock mining in Australia (
Fig. 2)—have proven increasingly problematic for environmental reasons [
5].
In brine extraction, lithium-rich water is pumped from under-ground caverns to the surface and into massive evaporation ponds (
Fig. 3), where it sits for up to two years [
5]. As the water evapo-rates, the lithium in it concentrates, eventually to be collected. This process requires vast quantities of water—more than 1.9 million liters per tonne of lithium produced [
6]—often in arid regions where water is scarce. It can also lead to groundwater contamina-tion and depletion of freshwater aquifers, adversely affecting local communities and biodiversity [
5]. While it can deliver lithium more quickly, hard rock mining requires blasting through tonnes of rock and processing ore with chemicals and heat. The process is carbon-intensive, land-destructive, and generates mine tailings that can leach toxins.
Due to concerns about environmental destruction, lawsuits against lithium mining companies have proliferated globally [
7]. People in Argentina and Chile have protested lithium mining citing water scarcity, land contamination, and the lack of informed con-sent from Indigenous groups [
8,
9].
Responding to these problems, the European Union has pro-posed new regulations requiring lithium imports to meet environ-mental and social standards [
10]. At the same time, the US Department of Energy has funded DLE projects with billions of USD as part of a push to expand domestic minerals production [
11]. Auto manufacturers, too, are supporting cleaner lithium extraction. Tesla (Austin, TX, USA), General Motors (Detroit, MI, USA), and Bavarian Motor Works (Munich, Germany) have all signed deals with companies that promise low-impact lithium pro-duction [
12-
14].
The same concerns, in addition to the looming increased demand, have driven research aimed at developing DLE technolo-gies. Unlike evaporation-based mining, DLE extracts lithium directly from brine using chemical processes, enabling faster and cleaner production. "With DLE, we do not have to wait a year for evaporation,” Chagnes said. "Instead, we use reagents to extract lithium directly from the brine.”
These reagents can include solid absorbents with a high affinity for lithium or solvents for liquid-liquid extraction. "With DLE, you are not heating anything. You use electricity to pump and process, which consumes far less energy,” Chagnes said. "And if you are in sunny regions like Argentina and Chile, you can use photovoltaic panels to generate that electricity.”
And unlike evaporation ponds, which leave behind enormous amounts of salt waste, DLE systems can reinject the lithium-depleted brine back into the ground. "You continuously pump, pro-cess, and reinject,” Chagnes said.
Possibly offering even greater environmental benefits are membrane-based and electrochemical methods at the cutting edge of DLE science. These technologies are not just greener; they are also faster. Such DLE processes can capture lithium in hours or days, making production more responsive to market demand.
One example comes from a lab at Stanford University (Palo Alto, CA, USA). The Stanford group has developed a high-selectivity membrane to separate lithium from other cations in the brine [
15]. The method uses electricity to move lithium through a solid-state electrolyte membrane from water with a low lithium concentration to a more concentrated, high-purity solution. Each of a series of cells increases the lithium concentration to a solution from which isolating the final chemical is relatively easy. The approach uses less than 10% of the electricity required by absorbent- and solvent-based brine extraction and has a lithium selectivity of nearly 100%, making it highly efficient.
According to Ge Zhang, a lab member and postdoctoral scholar in Stanford’s Department of Materials Science and Engineering, the system operates effectively in brines with high salinity, which is common in areas such as the Salton Sea in California, where the lithium concentration is lower compared to South America. "Many brines have a lower concentration of lithium, so they are not suit-able for evaporation methods,” Zhang said. "That is why alternative methods like ours are gaining attention.”
Saudi Arabia, too, is betting on DLE innovations. At King Abdul-lah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia, Zhiping Lai, professor of chemical engineering, and his team have developed a method to extract lithium even from ultra-low concentration sources, such as oil field wastewater and seawater [
16,
17]. In their method, iron phosphate electrodes selec-tively intercalate lithium from saltwater and then release it into freshwater. Charge balance is provided by silver oxidation and reduction at paired counter electrodes in each medium, keeping all other cations on the salt side. "We demonstrated our membrane technology using Red Sea water, which contains only 0.2 ppm lithium,” Lai said. "The beauty is that we add only an electrical field, not any chemicals—there is no impact to the local environment.”
While high-grade lithium sources are found in a few regions, low-grade resources such as geothermal fluids, oil field brine, and seawater are globally abundant. "The total amount of low-grade lithium is probably 100 or even 10 000 times higher than high-quality resources,” Lai said. "If we can extract lithium from those sources, we could essentially provide unlimited amounts of energy storage to support global needs.”
Lai’s startup, Lithium Infinity (Thuwal, Saudi Arabia), recently launched a pilot facility with a 6 million USD investment from Ma’aden (Saudi Arabian Mining Company; Riyadh, Saudi Arabia) and the KAUST innovation fund [
18]. "We identified oil field-produced water in Saudi Arabia that contains about 20 ppm of lithium. With our technology, we can produce up to 100 000 ton-nes of lithium carbonate per year,” Lai said. "That means we could build localized lithium supply chains in countries that lack high-quality brines.”
In another innovative research effort, a research team at Nan-jing University (China) was inspired by the ability of plants to selectively extract ion species during transpiration to develop a hierarchically structured solar transpirational evaporator [
19]. The device creates a pressure gradient that extracts lithium from brines through a silica ceramic membrane, capturing it in a vascu-lar storage layer. The researchers note that the process is inexpen-sive to operate because it works passively [
19].
Outside of the lab, several companies are moving to commer-cialize DLE. Backed with 145 million USD from Bill Gates’ Break-through Energy Ventures (Kirkland, WA, USA), Lilac Solutions (Oakland, CA, USA) has developed an ion-exchange technology that captures lithium using ceramic beads and returns the brine under-ground [
20]. Lilac’s pilot project at its Sydney, Australia-based lithium developer partner Lake Resources’ Kachi site in Argentina has yielded promising results, achieving lithium recovery rates of more than 80% in under three hours—a fraction of the year or more required using traditional evaporative methods [
21].
EnergyX (Austin, TX, USA), another American firm, uses a com-bination of technologies—adsorption, solvent extraction, and selec-tive membranes with both electrodialysis and selective bipolar electrodialysis—in its DLE system. The company claims its process can extract lithium with up to 94% efficiency while reducing costs by up to 50% and water usage by 90% compared to traditional evap-orative extraction [
22].
Despite their promise, the new extraction methods are not without challenges. Water consumption and residual waste remain problems that need better solutions, Chagnes said. "Even with DLE, you use water to recover the lithium from the reagent,” he said. "We need to develop ways to recycle and minimize water use.”
Reinjection of lithium-depleted brine into underground caverns also requires careful hydrological planning, Chagnes said. "If you do not reinject properly, you could change the water table—that could affect rivers, lakes, and local ecosystems.” Another issue is dilution. Reinjecting the waste brine into the wrong part of the basin could reduce the concentration of lithium in the area you want to extract from, Chagnes said. "You need a detailed three-dimensional (3D) understanding of the sedimentary basin.”
Even hard rock lithium mining is getting an eco-makeover. In Australia, where lithium is extracted from spodumene ore, compa-nies are turning to electric mining fleets, on-site solar power, and chemical process improvements to reduce emissions and waste. Pilbara Minerals (West Perth, WA, Australia), for instance, has part-nered with technology company Calix (San Jose, CA, USA) to trial a new kiln-based refining process. The method uses renewable energy to convert lithium ore to a more brittle and porous form that makes it easier to leach out lithium by heating the ore to a temperature of 900 °C. The companies say the process reduces CO2 emissions by 80% to 90% compared to conventional methods [
23]. Another company, Canada’s Snow Lake Lithium (Winnipeg, MB, Canada), is designing what it claims will be the world’s first all-electric lithium mine [
24]. The company says the site, located in Manitoba, will use hydropower, electric drilling equipment, and sustainable transportation to deliver lithium with a minimal carbon footprint.
New technologies are also transforming the way lithium depos-its are discovered. Exploration has long relied on costly, time-consuming geological surveys and drilling. However, startups like KoBold Metals (Berkeley, CA, USA)—another Breakthrough Energy Ventures-backed firm—aims to use artificial intelligence to identify promising lithium targets faster and with less environmental impact. The company claims its technology can identify unconven-tional lithium sources like geothermal brines, oilfield wastewater, and clay deposits by examining satellite imagery, soil samples, and historical records, thus minimizing invasive exploratory dril-ling [
25].
The lithium economy could also become increasingly circular. Recycling technologies are making progress, offering the prospect of turning end-of-life LIB into new raw materials [
26]. Companies like Redwood Materials (Carson City, NV, USA) have developed liq-uid-solid separation processes that recover lithium, cobalt, and nickel with about 95% efficiency. Redwood is currently building a processing center just east of Reno, NV, that will create battery cathode materials composed of 30% recycled nickel, 30% recycled lithium, and 100% recycled cobalt. The company says the center will eventually produce 20 GW h of cathode materials every year. Once it has built four more planned centers in the United States and European Union (EU) countries, the company anticipates its annual output will be 100 GW h, or enough to build batteries for an estimated 1.3 million electric vehicles [
27].
While only 5% of LIB are currently being recycled [
28], some experts believe that up to 50% of lithium demand could be met through recycling [
29]. But in the short term, mining remains cru-cial and making that extraction more efficient and cleaner is a key objective. "Lithium is everywhere,” Chagnes said. "We just have to be smarter about how we get it.”
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