Mercedes-Benz has gained priority access to ProLogium’s latest solid-state battery cells after signing a new agreement to test Gen4 Superfluidized Inorganic Lithium Ceramic Battery cells. Mercedes will evaluate the cells’ electrical and thermal performance and safety levels at specialized external testing institutes and at its own facilities.
The agreement represents a new stage in a relationship dating back to 2016. It began with the development of hybrid batteries combining solid-state and conventional technologies, then expanded to testing multiple formulations of lithium and ceramic cells, including pouch cells, next-generation prismatic cells, and ProLogium’s Bi-Polar technology.
What Do Gen4 Cells Offer?
ProLogium’s platform uses a nonflammable inorganic electrolyte, a ceramic separator, and a company-specific safety mechanism. The company says this design aims to address two major obstacles facing solid-state batteries: large-scale manufacturability and achieving a competitive cost structure.
According to figures announced by ProLogium, the energy density of Gen4 cells reaches 400 watt-hours per kilogram, with charging from 5% to 80% taking 6.4 minutes. The cells are also designed to provide high power and better performance at low temperatures. These figures remain the platform’s stated specifications, while the new testing aims to verify performance under practical conditions and at more advanced development stages.
From the Laboratory to Production
ProLogium opened Taiwan’s first gigawatt-hour battery plant in May 2024, and in February held a groundbreaking ceremony for its second plant in Dunkirk, France. The first phase of the French facility is expected to reach an annual production capacity of 4.0 gigawatt-hours, to be achieved gradually by 2030, while the site’s full capacity could reach 44 gigawatt-hours.
This month, the company announced that its third-and-a-half-generation Lithium Ceramic battery had entered mass production at its Taiwanese facility. A test report from TÜV also showed that a large 185.4 ampere-hour Gen3.5 cell achieved a gravimetric energy density of 381 watt-hours per kilogram. ProLogium says these steps are moving high-density solid-state battery technology from the laboratory and pilot projects into manufacturing.
Why Does This Matter?
The practical significance does not lie in granting Mercedes an immediate commercial priority right, but in linking the testing of fourth-generation cells to a manufacturing pathway expanding in Taiwan and France. The success of this stage will depend on ProLogium’s ability to maintain the stated performance as production increases and to pass safety and reliability tests, rather than on the results of individual cells alone.
Mercedes is simultaneously working with U.S.-based Factorial Energy on other solid-state batteries. Last September, it said that a modified EQS had traveled more than 745 miles, or 1,200 kilometers, on a single charge using 106 solid-state cells from Factorial. The company expects to launch its first production electric vehicle equipped with solid-state batteries by 2030, while other companies, including China’s BYD, plan to introduce vehicles of this type as early as 2027.
ProLogium is also attempting to support the commercialization phase through a business merger with Translational Development Acquisition Corp, a special purpose acquisition company, in preparation for listing its shares on Nasdaq under the symbol PRLG, which is expected to be completed by the end of 2026. However, the source does not specify which Mercedes model will use ProLogium cells or when actual commercial supply will begin.