Mercedes-backed ProLogium begins mass-producing solid-state batteries in Taiwan

ProLogium Technology, the Taiwanese battery maker backed by Mercedes-Benz, has started mass-producing all-solid-state battery cells at its facility in Taoyuan, Taiwan, marking what the company says is a milestone for the long-promised technology's path to commercialization.

A 30% Leap in Energy Density

The company announced on September 2 that its Generation 3.5 Lithium Ceramic Battery has entered mass production on the Taoke assembly line at its Giga-level industrial platform. The large-format 185.4 ampere-hour pouch cell delivers a gravimetric energy density of 381 Wh/kg and a volumetric energy density of 903 Wh/L, according to testing by Germany's TÜV. That represents roughly a 30% improvement over the mainstream nickel-manganese-cobalt cells powering most electric vehicles in the United States today, which typically top out around 300 Wh/kg at the cell level.news.metal+1

ProLogium says its Gen 3.5 cell can fast-charge from 5% to 80% state of charge in under 10 minutes. The cell uses a composite solid electrolyte and a ceramic separator with a proprietary edge-frame structure designed to isolate potential burrs while providing sealing and insulation.insideevs+1

Certified All-Solid-State

UL Solutions tested the cell under China's new GB/T 43568-2026 methodology, introduced in July to better distinguish all-solid-state cells from those still using some liquid electrolyte. During testing, the cell was held in a vacuum at 120°C for six hours, recording a weight loss of less than 0.05% — well below the 0.5% threshold required for the all-solid-state designation.ua+1

Scaling Up

The Taoyuan facility's initial production capacity stands at 0.5 GWh per year, enough for roughly 6,000 to 14,000 EV battery packs depending on pack size. ProLogium plans to double that capacity by 2030. A second facility in Dunkirk, France, designed for an initial output of 4 GWh and a maximum of 44 GWh, is expected to come online in 2028.news.metal+2

ProLogium has also signaled that a Gen 4 cell, featuring a fully inorganic superfluidized electrolyte system promising faster charging and better low-temperature performance, is in development. Factories producing Gen 3.5 cells would need to upgrade just 10% of their line equipment to begin assembling the next-generation cells.insideevs