In recent years, the demand for lithium has surged as lithium-ion batteries become integral to our world. Despite abundant lithium resources in places like the U.S., Europe, and Australia, China dominates the global lithium refining market. The biggest hurdle to tapping into lithium from the U.S. and Australia is the extraction from hard rock minerals. Current methods are energy-intensive and generate significant waste, making them far more expensive than extracting lithium from brine. Traditional hard rock extraction involves baking the rock at over 1,000 degrees Celsius and chemically leaching it, discarding the remaining rock.
Now, a team of researchers from MIT and other institutions has developed a low-temperature process for extracting battery-grade lithium from the most common lithium-bearing mineral. This process uses a liquid reagent to dissolve the rock into useful components: not just battery-ready lithium salts but also smelter-grade alumina and cement-grade silica. Once extracted, the solvent and reagent can be recovered and reused, keeping waste levels near zero. The researchers estimate this closed-loop process costs half as much as traditional hard rock lithium extraction and could make it competitive with brine extraction. A paper detailing this process was published in Science, and the team has begun commercializing the technology through an MIT spinout, Rock Zero.
"By 2040, we need to quadruple lithium production globally, which amounts to hundreds of new lithium-producing assets," says author Camden Hunt. The research began with a bathroom renovation, where a glass etching cream inspired the team to develop a method to chemically break apart the abundant lithium-bearing mineral, spodumene. Using a mixture of water and ammonium fluoride, the researchers were able to dissolve spodumene rock at room temperature, marking a breakthrough over traditional methods.
The team isolated lithium fluoride, lithium hydroxide, and lithium carbonate, ensuring they met the purity specifications for battery-grade lithium salts. By developing processes to reuse ammonium fluoride and water, they successfully processed 17 different spodumene sources, demonstrating its wide applicability.
The team also evaluated the commercial feasibility of their new system, calculating if there is enough spodumene in the world to supply 100 terawatt-hours of battery production. They believe this approach is the lowest-energy, lowest-cost method for extracting lithium, enabling the energy transition. This work was supported by the Department of Energy Advanced Research Projects Agency-Energy (ARPA-E), the MIT Climate Grant Challenges program, and the National Science Foundation, utilizing MIT.nano facilities.
Blogger's Review: This research represents a significant breakthrough not only in technology but also in reshaping the global lithium supply chain. By reducing energy consumption and costs, MIT's new process could fundamentally alter the dynamics of the lithium market, accelerating the development of sustainable energy. The key challenge ahead will be further commercializing and optimizing this process for widespread use.