Factorial Inc. has agreed to merge with special purpose acquisition company Cartesian Growth Corporation III in a deal valuing the U.S.-based solid-state battery developer at about $1.1 billion, the companies said, positioning Factorial for a public listing in the United States.
Under the definitive business combination agreement, the merged company is expected to list on the Nasdaq under the ticker symbol FAC, with the transaction expected to close in mid-2026, subject to regulatory approvals and shareholder votes.
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The valuation is based on a pre-money, pre-merger equity value of approximately $1.1 billion. Cartesian III currently holds around $276 million in cash in trust, before redemptions. The transaction also includes $100 million in new private investment in public equity (PIPE) financing from institutional investors. Assuming no redemptions, the combined company would have a pro forma equity value of roughly $1.5 billion.
Factorial said its solid-state battery technology has been validated through testing with major automotive partners. In one demonstration, a modified Mercedes-Benz EQS equipped with Factorial’s 106 ampere-hour solid-state cells achieved more than 1,200 kilometres (745 miles) of driving range on a single charge. Separate laboratory testing with Stellantis confirmed performance of 77 Ah cells, including high energy density, fast charging capability and stable operation across a wide temperature range.
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Founded in Boston, Factorial develops two proprietary solid-state battery platforms: FEST® (Factorial Electrolyte System Technology), designed to improve safety and energy density, and Solstice™, which is intended to be compatible with existing lithium-ion manufacturing processes. The company says this approach could enable faster industrialisation compared with fully redesigned battery production lines.
While automotive remains a core focus, Factorial said it plans to expand into defence, aerospace and robotics markets, where high energy density, lightweight construction and performance in extreme environments are critical. Existing strategic partnerships include Hyundai Motor and Kia, alongside Mercedes-Benz and Stellantis.
See also: Stellantis, Factorial Test Solid-State Battery With Rapid 18-Minute Charge Capability
“This agreement marks a pivotal inflection point in our progression from proven technology to broad commercial deployment across multiple industries,” said Siyu Huang, co-founder and chief executive of Factorial.
Peter Yu, chairman and chief executive of Cartesian III, said the due diligence process highlighted opportunities for Factorial’s technology in national security applications, including unmanned aerial vehicles and other defence systems.
See also: Factorial Energy Scales Solstice Solid-State Battery to 40 Ah Capacity
Cantor Fitzgerald & Co. is acting as exclusive financial adviser and sole PIPE placement agent to Factorial, with legal advice provided by Goodwin Procter LLP. Cartesian III is advised by Greenberg Traurig LLP, while Thompson Coburn LLP is serving as legal counsel to Cantor. Early investors in Factorial include GVP Climate, in partnership with Gatemore Capital Management, and WAVE Equity Partners.
