In a move that tightens the link between German engineering and Taiwanese battery innovation, Mercedes-Benz has signed a joint testing agreement with ProLogium Holding Inc. The pact, announced on September 24, 2026, gives the automaker priority access to evaluate ProLogium’s fourth-generation solid-state battery cells, known as the Gen4 Superfluidized Inorganic Next-Generation Lithium Ceramic Battery. The agreement builds on almost a decade of cooperation, during which Mercedes-Benz invested in ProLogium and participated in early hybrid-solid-state projects.
Under the new framework, the Gen4 modules will undergo intensive electrical, thermal and safety assessments at Mercedes-Benz’s dedicated test facilities as well as at accredited third-party labs. The results will determine whether the technology can be integrated into future electric vehicles. According to Jörg Burzer, Member of the Board of Management and Chief Technology Officer at Mercedes-Benz, “Our long-standing partnership with ProLogium is a strong example of how we bring the best expertise together to advance next-generation battery technologies.” He added that the collaboration reflects the brand’s commitment to shaping electric mobility through technological leadership and innovation.
Gen4 battery architecture and its European rollout
ProLogium’s Gen4 platform claims five core advantages: intrinsic safety, high energy density, rapid charging capability, scalable manufacturing, and a cost structure that can compete with traditional lithium-ion cells. The safety envelope is built around a non-flammable inorganic electrolyte and a ceramic separator, complemented by an active safety mechanism proprietary to ProLogium. These features enable fast charging, high power output, and reliable performance even at low temperatures.
Beyond the laboratory, ProLogium is preparing a massive production hub in Dunkirk, France. The planned gigafactory will eventually reach a design capacity of up to 44 GWh, providing a localized supply chain for European automakers. Vincent Yang, Founder and CEO of ProLogium, emphasized that the French government and the European Union are supporting the project, which will allow the company to serve global markets from Europe once the first phase—targeted at 4 GWh—comes online.
Parallel testing with Factorial Energy’s lithium-metal cells
Mercedes-Benz is not limiting its battery exploration to ProLogium. The brand is also evaluating lithium-metal cells produced by U.S. firm Factorial Energy. A recent endurance test with a Mercedes-Benz EQS equipped with a Factorial solid-state pack logged a single-charge distance of 748.8 miles (1,205 km). The vehicle still displayed an estimated remaining range of 85 miles (137 km) when the test concluded, underscoring the high energy density of the new chemistry.
This dual-track strategy—testing both ceramic-based solid-state solutions from ProLogium and lithium-metal technology from Factorial Energy—places Mercedes-Benz among a select group of manufacturers, including BYD, Toyota, Nissan and Honda, that are actively probing the next wave of battery tech. While commercial rollout timelines remain fluid, several industry insiders suggest that viable solid-state packs could appear in production models within the next twelve months.
