Flux XII is a Madison-based energy storage company commercializing high-performance, tunable organic chemistries for aqueous flow batteries. Its technology platform integrates low-cost, abundant feedstocks into electrolytes and membranes that can be manufactured through simple industrial processes and deployed at megawatt scale by commercial hardware suppliers. The company claims its approach can cut the capital expenditures of flow battery systems by 50 % at the 100 MW scale, enabling economical long-duration storage to support data centers, electric vehicles and broader grid electrification. With the fresh seed capital, Flux XII has already scaled electrolyte and membrane production in industrial facilities and is testing multiple kilowatt-scale prototypes. In 2026 it plans to validate a minimum viable product module and design a containerized battery energy storage system, followed by pilot deployments with a utility-led consortium in 2027. Financially, the firm secured a $3.95 million seed round and had previously attracted non-dilutive and early backing from Activate Fellowship, Third Derivative, Gigascale Capital, The Collaborative Fund, Safar Partners and LiquidMetal Ventures. No revenue or user figures were disclosed, but investor interest underscores confidence in the company’s materials-integration strategy and cost-reduction potential.

Total raised

$4M

Funding rounds

1

Latest round

Seed

Latest activity

Nov 2025