1000-kilometer battery: Mercedes tests solid-state battery on British roads
In February 2025, Mercedes-Benz began real-world road testing of a modified EQS equipped with a lithium-metal solid-state battery for the first time. The goal is to achieve a range of over 1,000 kilometers – a milestone in the race for more efficient electromobility.
The technology
The battery in question is based on a sulfide-based solid electrolyte, allowing the use of a lithium-metal anode. This combination increases the gravimetric energy density to up to 450 Wh/kg at the cell level and enables around 25% more range at the same weight compared to conventional lithium-ion batteries.
The cells come from Factorial Energy, which developed the battery pack together with Mercedes-AMG High-Performance Powertrains (HPP). Mercedes stresses that this is a true integration into a vehicle prototype based on experience from racing technology and battery cell expertise.
Testing and production readiness
Following initial lab tests in Stuttgart at the end of 2024, road testing has been underway since February 2025, according to Automotive Testing Technology International. Mercedes plans to implement the technology in production vehicles before the end of the decade.
Strong competition
The test comes amid a global race for the next generation of batteries in which Mercedes is far from alone. Volkswagen, BMW, Toyota and Chinese manufacturers such as BYD and CATL are also working on solid-state or quasi-solid-state batteries. This development highlights the importance of increasing range through new cell chemistry.
Outlook
The real-world road tests of the Mercedes solid-state battery mark a significant step toward market launch. Challenges such as production scaling, costs and series integration remain, but this milestone demonstrates that efficient electromobility is within reach.
