Taiwanese battery developer ProLogium has begun mass production of its Gen 3.5 all-solid-state lithium ceramic battery, with a large-format cell achieving an energy density of 381 Wh/kg.
The company said its 185.4 Ah cell had reached a volumetric energy density of 903 Wh/l, according to third-party testing by TÜV. Production is taking place at ProLogium’s GWh-scale Taoke manufacturing facility in Taoyuan, Taiwan.
ProLogium has not disclosed the current production rate for the Gen 3.5 cells or announced a customer programme using them.
Separate testing by UL Solutions assessed the cells under the Chinese GB/T 43568-2026 standard. ProLogium said the cells lost less than 0.05% of their weight after six hours under vacuum at 120°C, compared with the standard’s maximum 0.5% threshold for classification as an all-solid-state battery.
The Gen 3.5 cell uses ProLogium’s Logithium architecture, which combines a ceramic separator with an edge-frame structure intended to provide additional separation, sealing and insulation around the electrode perimeter.
ProLogium developed the architecture in 2012 and began commercial production the following year, initially targeting applications including consumer electronics, medical devices and explosion-resistant equipment. It introduced roll-to-roll manufacturing in 2017 and opened its GWh-scale Taoke plant in 2024.
The company said it has shipped more than 2.4 million cells based on its lithium ceramic battery platform since 2013, including products and samples for consumer, specialist and automotive applications.
ProLogium is already developing its Gen 4 technology, which replaces the Gen 3.5 electrolyte with what the company describes as a fully inorganic “superfluidised” electrolyte system. It expects around 10% of the existing GWh-scale manufacturing equipment will need modification to produce the next-generation cells.
The company is targeting EVs as well as data centre, marine and aerospace applications with its solid-state technology.
ProLogium is also expanding production outside Taiwan. It broke ground on its Dunkirk gigafactory in northern France in February. The first phase is planned to reach 4 GWh of annual capacity progressively by 2030, while the site has a maximum planned capacity of 44 GWh.
The company said the French factory would manufacture its fourth-generation solid-state batteries. It also plans phased localisation of manufacturing in North America.
