France is set to host a major solid-state battery production facility by ProLogium, a Taiwanese company, in Dunkerque, northern France. The investment is estimated at 5.2 billion euros, with around 3,000 direct jobs expected to be created in the long term. Construction of the factory began in February 2026 on the industrial area of the Grand Port maritime of Dunkerque. The site will occupy several dozen hectares and is expected to have an initial capacity of 0.8 GWh in 2028, increasing to 4 GWh by 2030 and 12 GWh by 2032. The site has been designed to potentially reach a maximum capacity of around 44 GWh if demand continues. ProLogium recently announced the mass production of its solid-state Gen 3.5 cell, which has a capacity of 185.4 Ah and achieves 381 Wh/kg and 903 Wh/l, verified by TÜV. These figures are significantly higher than the usual lithium-ion cells found in many electric vehicles, which range between 250 and 300 Wh/kg. The company's solid-state batteries use a ceramic-based solid electrolyte instead of a liquid electrolyte, aiming to increase energy storage and reduce fire risk. ProLogium's Gen 3.5 cell can charge from 5 to 80% in less than 10 minutes and offers better cold resistance and improved safety. However, the Dunkerque factory will produce the Gen 4 cell, designed for large-scale automotive production. The project faced delays, with ProLogium initially aiming for a faster production timeline in 2023 and later postponing the start to focus on the Gen 4 for the Dunkerque site. The French government supports the project with 1.4 billion euros in public aid. The site benefits from proximity to the Gravelines nuclear power plant and electrical connections provided by RTE. Dunkerque's port offers maritime, rail, and road access for the efficient transport of components and cells across Europe. ProLogium aims to produce batteries close to its future customers rather than shipping cells from the other side of the world. However, there are no series-produced electric cars currently announced to be equipped with this solid-state battery. ProLogium needs to clarify technical performance, battery prices, and contracts with automotive manufacturers. Dunkerque could become one of the first major European sites capable of producing solid-state batteries at an industrial scale. In 2028, it will be determined if this technology can move beyond the demonstration stage and be integrated into electric vehicles produced in hundreds of thousands.