Mercedes-Benz and Formula 1 engineers team up for solid-state battery road tests

Mercedes-Benz, in collaboration with Mercedes AMG High Performance Powertrains (HPP) and Factorial Energy, has begun real-world road testing of an advanced solid-state battery in a prototype EQS. This marks the first time a lithium-metal solid-state battery has been integrated into a production vehicle platform, setting a major milestone in electric vehicle (EV) development. The project combines Formula 1 engineering expertise with cutting-edge battery technology to deliver safer, lighter, and more efficient EV batteries.

Solid-state batteries replace the liquid electrolyte found in conventional lithium-ion batteries with a solid electrolyte, enabling the use of a lithium-metal anode. This significantly increases energy density, enhances safety, and reduces battery weight, leading to greater efficiency and extended driving range. Mercedes-Benz’s new solid-state battery offers up to 25% more range while maintaining the same size and weight as traditional EQS battery packs.

The prototype test vehicle is expected to achieve a range of over 1,000 km on a single charge—an improvement over the 800 km range of the current EQS 450+, which has a 118 kWh lithium-ion battery. Solid-state technology has the potential to reach 450 Wh/kg in gravimetric energy density, allowing for more energy storage without increasing weight. This breakthrough could revolutionize EV performance, making long-distance travel more practical.

Mercedes-Benz engineers have also introduced a floating cell carrier system, which accommodates the expansion and contraction of battery materials during charging and discharging. The battery’s innovative pneumatic actuators adjust to these volume changes, improving overall battery lifespan and reliability. Additionally, the passive cooling system eliminates the need for heavy, complex liquid cooling, further improving vehicle efficiency.

The development of this solid-state battery system was made possible through expertise from Mercedes AMG HPP, a division specializing in Formula 1 hybrid powertrains. Known for rapidly transferring race-proven technologies to road cars, HPP played a key role in designing and integrating the new battery system into the EQS. Siyu Huang, CEO and Co-Founder of Factorial Energy, emphasized that this development proves solid-state technology is ready for real-world application and no longer confined to laboratory testing.

Mercedes-Benz first partnered with Factorial Energy in 2021 to develop next-generation battery technology. By mid-2024, Factorial delivered B-sample lithium-metal solid-state battery cells to Mercedes-Benz, marking a crucial step toward commercialization. After intensive lab and test bench evaluations, the battery was integrated into a modified EQS prototype in late 2024. The first on-road tests began in February 2025, with extensive trials planned in the coming months.

This milestone aligns with Mercedes-Benz’s commitment to innovation and sustainability, as highlighted by Markus Schäfer, Chief Technology Officer. The company aims to assess the feasibility of series production integration, using data from these road tests to refine battery performance, durability, and efficiency. If successful, this project could pave the way for mass adoption of solid-state EV batteries.

As testing progresses, Mercedes-Benz is positioning itself as a leader in next-generation EV technology. With Formula 1 expertise, cutting-edge materials, and a revolutionary design, the company is demonstrating that solid-state batteries are not just a future concept—they are rapidly becoming a real-world solution for electric mobility.