Mercedes-Benz and Factorial have detailed their joint solid-state battery testing program, following the announcement of their partnership around the technology last year. At the core of the program is a new concept vehicle powered by a lithium-metal solid state battery that will be tested on the road.
Together, Mercedes AMG High Performance Powertrains (HPP), the OEM’s subsidiary specializing in Formula 1 technologies, and the Mercedes-Benz Center of Competence for Battery Systems designed and developed a new innovative battery system. While detailing its performance on the track, Mercedes-Benz similarly highlighted HPP’s capability of transferring F1 technologies and expertise into high-performance automotive projects.
Following an intensive testing period conducted across various test benches, the solid-state battery prototype was integrated into the OEM’s EQS model towards the end of 2024. The EV was modified so it could fit the battery and was equipped with the necessary accessories to operate it. The first laboratory vehicle tests were already conducted in Stuttgart at the end of 2024 to prepare for the road tests that started in February 2025.
Working alongside HPP, the Mercedes-Benz Center of Competence for Battery Systems developed a prototype solid-state battery using Factorial’s cells that can be integrated into a car for on-road testing. This battery utilizes an innovative floating cell carrier that sees its materials expand while charging and contract as its power decreases. To support the cells during these volume changes, the battery is equipped with pneumatic actuators that interact with the cell volume change during charging and discharging, benefitting the battery’s performance and lifespan.
Overall, Mercedes-Benz says the solid-state battery featured in the EQS-based vehicle enabled an up to 25% increase in range against the corresponding, standard, EQS battery. Through the unit’s passive battery cooling capabilities, further weight and energy efficiencies have been achieved, with the development EV itself expected to have a range in excess of 620 miles (1000 km). Over the next few months, Mercedes-Benz will further test the solid-state battery and its overall performance in an electric vehicle with extensive laboratory and road tests.
