The 185.4 Ah cell that cleared TÜV testing at 381 Wh/kg sits within a much wider LCB pouch format range
(Image courtesy of ProLogium Technology)
ProLogium Technology has begun mass production of its Gen 3.5 Lithium Ceramic Battery, with a third-party TÜV test placing the 185.4 Ah cell at 381 Wh/kg and 903 Wh/L, energy density figures above most conventional automotive lithium-ion cells. UL Solutions separately qualified the cell as all-solid-state under a new Chinese testing standard. The bigger test is how quickly that cell-level result scales into traction-battery volume for passenger EVs.
TÜV and UL testing validate the solid-state battery cell
A third-party TÜV test placed the 185.4 Ah cell at 381 Wh/kg gravimetric and 903 Wh/L volumetric energy density, ProLogium said. UL Solutions ran a second, independent test to verify the all-solid-state classification itself rather than the energy-density figures, holding the cell under vacuum at 120°C for six hours under China’s GB/T 43568-2026 methodology. ProLogium reported weight loss below 0.05%, comfortably inside the standard’s 0.5% threshold for all-solid-state classification. China has submitted GB/T 43568-2026 to the International Electrotechnical Commission as a reference for international standardisation, giving the classification a basis that extends beyond a single national test.
Mercedes-Benz and Chinese automakers are testing the platform
ProLogium has held a technology cooperation agreement with Mercedes-Benz since 2022, when the automaker took a board seat and made an investment in the company. At the time, Mercedes-Benz said it expected the first test vehicles equipped with ProLogium cells within the coming years, without specifying a model or production timeline. Chinese automakers Nio and Aiways have also worked with ProLogium on solid-state sample-vehicle projects.
Manufacturing scale set to expand from Taiwan to France
The Taoyuan facility ProLogium describes as Giga-level currently runs at an initial operational capacity of 0.5 GWh, equivalent to roughly 6,250 packs at 80 kWh, with plans to expand toward 1 to 2 GWh. The company is also developing a factory in Dunkirk, France, designed for an initial 4 GWh production phase and a maximum design capacity of 44 GWh, with the first phase expected to ramp progressively toward 2030.
Gen 4 widens the solid-state battery platform’s reach
ProLogium said its next-generation Gen 4 LCB will use a fully inorganic superfluidised electrolyte system while retaining the same Logithium cell architecture and manufacturing process, requiring modification to only about 10% of the existing Giga-level production line. The company added an Active Safety Mechanism intended to stabilise electrode materials at high temperature and reduce the risk of thermal runaway, alongside expected gains in low-temperature performance and manufacturing cost. ProLogium is targeting AI data centres, electric vehicles, maritime and aerospace applications for the new chemistry, extending the platform beyond the passenger-vehicle focus of earlier generations.
The immediate significance of Gen 3.5 is that ProLogium has moved a high-energy-density solid-state chemistry into mass production rather than pilot-line demonstration, a distinction the company has repeatedly pressed against rival programmes still confined to smaller-scale lines. The next phase to watch is the France facility’s ramp toward its 44 GWh design capacity, alongside how the Mercedes-Benz, Nio and Aiways partnerships progress from sample-vehicle projects toward production integration.
Stay ahead in the electrification revolution. Explore more breakthroughs from leading innovators in electric commercial transport – visit our news page.