Form Energy raises $750 million for iron-air battery production

Form Energy, a U.S.-based long-duration energy storage startup, has secured $750 million in a Series G funding round to expand its iron-air battery manufacturing in West Virginia. The round was led by T. Rowe Price, with participation from Sequoia Capital, Janus Henderson, Franklin Templeton, and others.

Unlike conventional lithium-ion batteries that discharge over a few hours, Form Energy’s technology utilizes a reversible oxidation process—converting iron to rust during discharge and reversing the reaction to charge. This method allows for electricity supply of up to 100 hours, helping to mitigate the intermittency of renewable energy sources. The company aims to reduce reliance on expensive minerals like lithium, cobalt, and nickel.

The company has already secured significant commercial interest. Google is constructing a data center in Minnesota that will be partially powered by a 300 megawatt/30 gigawatt-hour Form battery system, with deliveries expected by 2028. Additionally, AI infrastructure specialist Crusoe has announced plans to purchase 12 gigawatt-hours of Form’s systems starting in 2027. CEO Mateo Jaramillo noted that the company is not dependent on China for its supply chain, as approximately 80 percent of components are sourced from the United States.