In a groundbreaking advancement for electric vehicles, Mercedes-Benz has announced the launch of the world’s first solid-state battery-powered EV from a global OEM. The German automaker revealed that a prototype EQS, featuring a solid-state battery developed with US startup Factorial Energy, has entered real-world testing.
“Mercedes-Benz engineers from the road and racetrack and Factorial cell engineers have worked together on delivering an all-new solid-state battery test program, which has brought the first car powered by a lithium-metal solid-state battery to the road,” the company stated. This marks a crucial milestone in transitioning from lab research to practical EV applications.
Initial laboratory testing for the prototype EQS was conducted in Stuttgart in late 2024, with road tests beginning in February 2025. The vehicle boasts an impressive WLTP range of 620 miles (1,000 km), a 25% increase over the current EQS 450+. Even under the stricter EPA standard, the expected range is 527 miles, rivaling high-range EVs like the Lucid Air.
This technological leap is credited to Factorial Energy’s solid-state battery, which replaces the traditional liquid electrolyte with a solid one. This innovation increases energy density, enhances safety, and reduces weight. Mercedes-Benz claims that the new battery offers 25% more range within the same size and weight parameters as current lithium-ion packs. Further improvements, including passive cooling, could boost range by 40% in future models.
While semi-solid-state batteries are already in some Chinese EVs, Mercedes-Benz’s breakthrough could redefine industry standards. This advancement not only promises longer ranges but also a future where solid-state technology accelerates the transition to sustainable mobility.
