Fusion energy startups face an enormous challenge as they strive to achieve what physicists and engineers have dreamed of for decades—a reactor that provides more energy than it consumes. Beyond proving the feasibility of their groundbreaking technology, scaling it, and convincing investors of profitability, these companies encounter an often overlooked yet critical dilemma: obtaining a reliable source of fusion fuel.
Today, startups engaged in fusion research commonly assert they intend to produce their own fuel internally, a technically accurate but somewhat incomplete response. Tritium, a pivotal component required for fusion reactions, does not occur naturally in significant quantities. To generate it, reactors must first utilize lithium-6, an isotope of lithium currently available in only limited supply.
This subtle but pressing reality struck Charlie Jerrott several years ago while employed at fusion startup Focused Energy. “It occurred to me then that nobody had addressed the fuel sourcing,” Jerrott said. “You have this entire ecosystem developing fusion technology and infrastructure, yet there is no dedicated supplier creating the fuel that these companies will inevitably need.”
Realizing the opportunity, Jerrott teamed up with colleague Jacob Peterson to form Hexium, a company devised to tackle the fuel supply problem directly. After operating in stealth mode, Hexium publicly announced its launch this week, backed by an $8 million seed investment from a consortium led by MaC Venture Capital and Refactor, with participation from Humba Ventures, Julian Capital, Overture VC, and R7 Partners.
At the heart of Hexium’s innovation lies Atomic Vapor Laser Isotope Separation (AVLIS), a technology first developed and validated by the U.S. Department of Energy in the 1980s. AVLIS was initially conceived to separate uranium isotopes for nuclear fuel production. However, following the Cold War and the sudden abundance of uranium recycled from Soviet-era weaponry, the technology was set aside. Now, Hexium has revitalized AVLIS and adapted it specifically to produce lithium-6 at scale.
To execute isotope separation, Hexium leverages precision-tuned lasers calibrated to a remarkable picometer accuracy—using relatively modest energy inputs comparable to those employed for tattoo removal. Crucially, these lasers are fine-tuned to interact exclusively with lithium-6 atoms while passing harmlessly by atoms of lithium-7.
The AVLIS method involves vaporizing metallic lithium into an atomic cloud. When the laser beam passes through this cloud, interactions selectively ionize lithium-6 atoms, enabling charged plates to attract them electrostatically and condense them into a purified liquid form. The end product can then be reliably packaged and supplied directly to fusion energy developers.
In addition to providing fusion ventures with lithium-6, the process neatly yields lithium-7 as a secondary output—a resource with significant commercial value as an additive protecting traditional nuclear reactors from corrosion during operation.
With its seed funding secured, Hexium’s next-phase plans focus on constructing and operating a pilot facility to demonstrate industrial viability. Provided this initial step succeeds, the firm intends to replicate its system using modular units capable of collectively generating tens or hundreds of kilograms of lithium-6 annually.
Importantly, Hexium claims its approach allows economical lithium isotope separation without demanding large-scale plants. “We don’t need to build sprawling factories—our economics easily work at small, local scales,” said Peterson. “We envision compact facilities roughly the size of a Starbucks location, which we can easily replicate wherever demand arises.”
Hexium’s strategy, if successful, might significantly boost the fusion industry’s confidence by removing one of its critical, least-discussed uncertainties—the availability of fusion fuel.
