The archive · Hardware & Devices · Strategic decision · 2013–2026
Factorial lists at $1.3B, then Mercedes and Dodge put its solid-state cells on the road
Factorial's FEST cells drive a Mercedes EQS 1,205 km and a Dodge Charger Daytona test fleet — then the company SPACs onto Nasdaq at $1.3B in June 2026.
Factorial Energy
What the business is
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.
Starting capital：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).
How it started
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.
What happened
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.
How it ended up
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.
Background
Factorial's bet was that solid-state batteries would win by being manufacturable, not just by being better in the lab. Its FEST electrolyte is a quasi-solid polymer that runs on existing lithium-ion production lines with minor changes, and the company deliberately shipped cells to automakers for sampling while competitors were still doing fundamental research.
The strategy converted partners into owners: Mercedes-Benz and Stellantis co-led a $200M Series D in January 2022, and Hyundai and Kia joined as strategic investors. That money built a 200 MWh pilot plant near Boston, opened in October 2023 as the largest solid-state production line in the US.
Validation followed in the real world: 106+ Ah B-samples (391 Wh/kg) reached Mercedes in June 2024, all-solid Solstice A-samples reached 40 Ah with dry cathodes in December 2024, and in August 2025 a Mercedes EQS with FEST cells covered 1,205 km from Stuttgart to Malmö on a single charge. In June 2026 Stellantis started road-testing FEST cells in a Dodge Charger Daytona.
The payoff was a June 8, 2026 SPAC listing on Nasdaq (FAC) at a $1.3B equity value. The company is now pushing into drones, defense and data centers, but the original bet is not fully won: series production of solid-state cells has not started, and the automotive programs are still demonstrations, not production contracts.
What has to be true
- 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.
What can be applied
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.
Aftermath
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.
Sources
- How a Cornell startup scaled to $1.3 billion in battery tech
- Factorial Delivers B-Samples of Lithium-Metal Solid-State Battery Cells to Mercedes-Benz
- EQS with solid-state battery covers 1,205 km on a single charge
- Factorial Lists on Nasdaq, Bringing Solid-State Batteries From Validation to Scale
- Stellantis and Factorial begin solid-state road testing
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