Researchers at ETH Zurich, Texas A&M University, Hamad Bin Khalifa University, Canadian Light Source Inc., and the Paul Scherrer Institute are winners of the 2025 Gizmodo Science Fair for safely and sustainably extracting lithium-6—a key fuel for nuclear fusion.
The question
Can electrochemical processes help clean water polluted from fracking? And could the same setup be used to extract lithium-6 from oil field wastewater?
The result
A project led by ETH Zurich suggests we can. The system, which the researchers say is “like a battery in reverse,” works by powering a cell loaded with water, where a negatively charged zeta vanadium oxide electrode bonds with and traps lithium-6 ions. Heavier lithium-7 ions, on the other hand, slip right through the tunnel. This process could compile enough lithium-6 for fueling nuclear fusion within 25 four-hour cycles, according to the paper on this technology, published March 20 in Chem.
Why they did it
Lithium-6 is a rare yet key ingredient in producing tritium, an even rarer isotope of hydrogen used for fusion reactions. Currently, the United States sources its lithium-6 from an old stockpile produced during the Cold War, using a now-banned method to extract it from toxic mercury. Needless to say, we’re just counting the days before we run out.
Sarbajit Banerjee, a chemical engineer at ETH Zurich in Switzerland, has a knack for coming up with creative electrochemical solutions to tricky separation problems. For this particular project, he and his team discovered that an electrochemical cell they set up to separate lithium from contaminated water was so efficient that they began to wonder if this mechanism could be applied elsewhere—like plucking some precious lithium isotopes from dirty water.
“Our initial focus was just removing lithium from [contaminated] water, because of the immense challenges in the lithium supply chain for batteries,” said Andy Ezazi, study co-author and now CEO of Quiddity Products, a startup hoping to scale this technology for commercial use. The idea to extend the cell’s use for extracting lithium-6 arose rather organically, as the team was pondering the various uses of lithium across industries.
The team eventually figured it out—but it took a lot of trial and error to get there. So what started as a project seeking to clean up polluted water evolved into a technique for sourcing precious lithium-6. “We got through so many leaky pipes and pumps that prop up every few days… Sometimes you’re a nuclear scientist. Sometimes you’re a plumber,” Banerjee joked.
... continue reading