Factorial lists at $1.3B, then Mercedes and Dodge put its solid-state cells on the road

Factorial Energy develops solid-state battery cells (quasi-solid FEST and all-solid Solstice platforms) for EVs, drones, defense and energy storage, with Mercedes-Benz, Stellantis, Hyundai and Kia as strategic investors.

Solid-state cells can be made on existing lithium-ion lines — so partner with automakers early, ship A/B samples, and let road tests carry the technology to production.

Series D of $200M led by Mercedes-Benz and Stellantis (Jan 2022, per Nasdaq release); June 2026 SPAC close brought over $100M gross proceeds at a $1.3B equity value (Factorial IR).

Lionano, Factorial's predecessor, was founded in 2013 at Cornell by Siyu Huang, Alex Yu and professor Héctor Abruña. After a 2019 meeting with ex-Panasonic boss Joe Taylor — who told them cathodes were a commodity but solid-state had potential — the company rebranded as Factorial in April 2021 and, by the end of that year, had 40 Ah room-temperature solid-state cells and joint development agreements with three top-10 automakers.

The January 2022 $200M Series D funded a 200 MWh pilot plant near Boston — opened October 2023 as the largest solid-state line in the US. B-samples of 106+ Ah cells (391 Wh/kg) went to Mercedes in June 2024, and all-solid Solstice cells hit 40 Ah with dry cathodes in December 2024. In August 2025 a Mercedes EQS with FEST cells drove 1,205 km from Stuttgart to Malmö without recharging, and in June 2026 Stellantis began road-testing FEST cells in a Dodge Charger Daytona — the first automotive solid-state integration in North America.

Public since June 8, 2026 (Nasdaq: FAC) at a $1.3B equity value after a SPAC close. Road-testing programs with Mercedes and Stellantis are running, and the company is expanding into drones, defense and data centers — but series production of solid-state cells is still ahead.

Drop-in compatibility with existing lithium-ion production lines removed the biggest objection automakers have to solid-state: retooling cost.

Three OEM investors (Mercedes, Stellantis, Hyundai-Kia) became customers and test fleets, spreading validation cost and de-risking demand.

Road tests beat press releases: a 1,205 km EQS drive and a Dodge Charger Daytona fleet are evidence no slide deck can match.

The dual-platform strategy (quasi-solid FEST now, all-solid Solstice next) gave short-term bankability and a long-term upgrade path.

Put the cells in real vehicles before you have a factory: Mercedes and Dodge carried validation costs, and the drop-in manufacturing story made automakers investors as much as customers.

As of 2026-09-02, Factorial Energy Inc. (Nasdaq: FAC) is public after a June 8, 2026 SPAC close at about a $1.3B equity value with over $100M gross proceeds. It is road-testing FEST cells in a Dodge Charger Daytona with Stellantis, working with Mercedes on Solstice A-samples, and expanding into drones (KULR, Tulip Tech, JRES), defense (In-Q-Tel investment) and hyperscale data centers; Karma Automotive announced the first US passenger-vehicle solid-state production program with Factorial in Q1 2026. Actual series production of solid-state cells is still not in place.