Stellantis N.V. and Factorial Energy have validated Factorial’s automotive-sized FEST® solid-state battery cells, a major milestone for next-generation electric vehicle (EV) batteries. The breakthrough positions Stellantis and Factorial to advance EV performance with lighter, more efficient batteries.

“Reaching this level of performance reflects the strengths of our collaboration with Factorial.

“This breakthrough puts us at the forefront of the solid-state revolution, but we are not stopping there. We continue working together to push the boundaries and deliver even more advanced solutions, bringing us closer to lighter, more efficient batteries that reduce costs for our customers,” said Ned Curic, Stellanti’s Chief Engineering and Technology Officer.

The 77Ah FEST® cells achieved an energy density of 375Wh/kg, supporting over 600 cycles toward automotive qualification. Unlike lithium-ion batteries, these solid-state cells charge from 15% to over 90% in 18 minutes at room temperature and deliver high power with discharge rates up to 4C. Factorial’s AI-driven electrolyte formulation enables performance in temperatures from -30°C to 45°C (-22°F to 113°F), overcoming previous solid-state limitations.

“Battery development is about compromise. While optimizing one feature is simple, balancing high energy density, cycle life, fast charging, and safety in an automotive-sized battery with OEM validation is a breakthrough,” said Siyu Huang, CEO of Factorial Energy. “This achievement with Stellantis is bringing next-generation battery technology from research to reality.”

The collaboration optimizes battery pack design for reduced weight and improved efficiency, enhancing vehicle range and affordability. Stellantis invested $75 million in Factorial in 2021 and plans to integrate these batteries into a demonstration fleet by 2026. This fleet will validate the technology’s real-world performance, a critical step toward commercialization.

The milestone aligns with Stellantis’ push for sustainable EV solutions, leveraging Factorial’s disruptive technology to meet the rising demand for high-performance batteries. As the companies refine pack architecture, the validated cells promise faster charging and greater efficiency, potentially reshaping the EV market. With the demonstration fleet on the horizon, Stellantis and Factorial are poised to lead the solid-state battery push, delivering cost-effective, high-range EVs to consumers.