Molten Salt Solutions (MSS) has closed an oversubscribed $7m seed funding round to transition its proprietary technology from laboratory validation to pilot-scale production of nuclear-grade enriched lithium isotopes. The round was led by Dolby Family Ventures with participation from Vanedge Capital Partners, Alumni Ventures, Gaingels, True Ventures, and Future Ventures.

This round brings the company’s cumulative funding to over $15m, following a $3m pre-seed and more than $5m in grant funding, including support through New Mexico’s Advanced Energy Award. The capital injection specifically targets the domestic supply chain for two distinct next-generation energy pathways rather than conventional battery manufacturing;

  • Lithium-6: crucial for commercial fusion systems, where it acts as a key material in the fuel cycle required to breed tritium and sustain fusion reactions; and
  • Lithium-7: deployed in advanced fission molten salt reactors to stabilise pH or serve within the reactor’s molten salt coolant medium.

The United States currently lacks commercial-scale domestic enrichment production for either isotope, leaving developers reliant on limited or geopolitically sensitive foreign supply chains.

MSS, founded by isotope enrichment specialists from the Los Alamos National Laboratory (LANL), is based on a High-Speed Counter-Current Chromatography (HSCCC) platform. The company claims this method is 100 times more efficient than legacy chemical enrichment approaches. This uses counter-rotating bobbins and immiscible liquid phases to achieve high-efficiency lithium isotope separation without solid support phases.

The company has secured strategic customer agreements to deliver kilogram-scale test quantities beginning in 2027, scaling toward commercial multi-tonne supplies in the 2030s. The seed capital will fund the scale-up needed to fulfil non-binding strategic supply agreements already signed with next-generation reactor developers including Type One Energy and Gauss Fusion in March, and Fissionaire in June.

MSS has structured its delivery timelines across two distinct frameworks to match the development phases of its initial customers, moving from initial test-scale quantities to multi-tonne commercial supply. The framework agreements with Type One Energy and Gauss Fusion focus on supplying lithium-6 for tritium breeding fuel cycles.

Delivery of initial kilogram-scale quantities designated strictly for materials testing and laboratory validation is set for 2027. Early- to Mid-2030s will see expansion to several hundred tonnes annually to support pilot plant deployments and the commercial rollout of the startups’ first power plants.

The commercial agreement executed with Fissionaire focuses on supplying lithium-7 to stabilise molten salt reactor coolants. Delivery of early test-scale quantities for initial systems testing is targeted for 2028. This will be followed by scaling up to multi-tonne levels as Fissionaire advances through larger-scale testing and moves toward full commercial reactor deployment.

“Fusion and small modular fission reactors are racing toward commercialisation and are necessary to meet growing global power demands. Both depend on a secure domestic supply of enriched lithium. MSS meets this need,” said MSS CEO John Elling. “This investment enables us to scale our technology and production capability to meet the demands of advanced reactors today and in the future.”