Solid-state batteries: ProLogium makes a major breakthrough ahead of its arrival in Dunkirk

ProLogium claims to have started mass production in Taiwan of solid electrolyte cells for electric vehicles. Backed by Mercedes, the company promises outstanding performance from its future batteries. This advancement is intended to prepare for its next manufacturing facility in Dunkirk.

ProLogium produces its first solid-state batteries

Long considered a laboratory technology, solid-state batteries are gradually making their way to the market. ProLogium now announces that it is producing its first high-capacity cells on its facility in Taoyuan, Taiwan. This is an important step, although the production volumes are still far behind those of battery industry giants.

The Gen 3.5 cell developed by the Taiwanese company has a capacity of 185.4 Ah. According to tests conducted by Germany’s TÜV, it achieves an energy density of 381 Wh/kg and 903 Wh/liter. For comparison, the best NMC cells currently used in electric vehicles are around 300 Wh/kg.

This technology relies on a composite solid electrolyte combined with a ceramic separator. ProLogium also claims improved resistance to high temperatures, punctures, and overcharging conditions. These are promising advancements for enhancing battery safety, though they will need to be verified once the cells are integrated into mass-produced electric vehicles.

ProLogium discusses mass production, but its factory in Taiwan currently has a capacity of only 0.5 GWh per year. This would theoretically allow for equipping around 6,000 cars with 80 kWh batteries. We are still far from the dozens of GWh produced annually by large lithium-ion cell factories.

Coming to Dunkerque soon?

The next step relates directly to France. ProLogium began construction of a factory in Dunkerque in 2026. The facility is set to start production by the end of 2028 with a capacity of 0.8 GWh, rising to 4 GWh by 2030 and then to 12 GWh by 2032. In the long term, ProLogium mentions a potential capacity of 44 GWh.

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Solid-state batteries: Where is ProLogium’s project in northern France?

Beyond technical performance, the Dunkirk factory represents a major industrial project for France. With Mercedes’ support, ProLogium will invest 5.2 billion euros in the facility and initially planned to create 3,000 direct jobs, with an additional 12,000 indirect jobs possible. The French government is also authorized to support its research program with 1.5 billion euros.

This facility is intended to further strengthen the position of the “battery valley” in Hauts-de-France, where ACC is already located near Lens, AESC in Douai, and Verkor in Dunkirk. However, after several delays and a revision of the planned capacity, the focus now is on meeting the new industrial timeline.