Licube is positioning itself as a crucial supplier of lithium-6, a rare isotope essential for fueling fusion power plants, by leveraging technology licensed from Japan’s Hirosaki University. Fusion reactors primarily operate on deuterium and tritium, with tritium being scarce in nature. To overcome this, fusion facilities plan to breed tritium on-site using lithium blankets that react with neutrons emitted during fusion. Lithium-6 is significantly more effective for this neutron capture, but it comprises only about 7.5% of natural lithium, making its extraction and purification a key bottleneck for scaling fusion energy.

The startup’s proprietary technology uses a ceramic membrane and electrolyzer to accelerate the separation of lithium-6 from lithium-7, aiming to enrich lithium-6 concentration to nearly 99.995%. This process could supply the necessary fuel breeding materials for fusion plants, which are forecasted to create a $50 billion market by 2040 if fusion power becomes commercially viable. While fusion reactors remain years away from widespread deployment, Licube is also applying its lithium purification method to other industries, including semiconductors, pharmaceuticals, fission reactors, and aerospace.

CEO and co-founder Yohei Kiguchi was motivated to launch Licube after visiting the ITER fusion project in France and realizing the immense future energy potential fusion holds. He sees fusion as the next major energy revolution but acknowledges possible delays in its commercialization. Until fusion plants become operational at scale, Licube plans to sustain its business by addressing lithium purification needs across sectors, positioning itself at the intersection of emerging fusion energy and broader technology markets.

Licube is among 20 startups taking the stage at TechCrunch Disrupt 2026 in San Francisco, showcasing innovations that could shape the future of energy and technology. The company exemplifies how startups are preparing critical infrastructure in promising but still-developing fields like fusion power, underlining the complex supply chain challenges fusion faces beyond just developing the reactors themselves. As fusion startups continue to secure significant investments, companies like Licube aim to ensure that fuel availability does not become a limiting factor.