Mercedes-Benz And Factorial Achieve Solid-State Battery Breakthrough

Mercedes-Benz has made a giant leap in electric vehicle (EV) technology with the start of road tests of its first EV with a lithium-metal solid-state battery. The milestone, worked on in collaboration with Factorial Energy, has enabled the test vehicle, on the EQS model, to cover a distance of 1,000 kilometers (620 miles) on a single charge. This is a groundbreaking achievement in battery efficiency, energy density, and safety, solidifying the automaker's commitment to innovation and sustainable mobility.

The creation of this new-generation battery system has been spearheaded by Mercedes AMG High Performance Powertrains (HPP) and the Mercedes-Benz Center of Competence for Battery Systems. In contrast to traditional lithium-ion batteries, the new solid-state battery uses a solid electrolyte instead of liquid electrolytes, which substantially enhances energy density and overall safety. The new battery offers 25% more range than a similar EQS battery of identical weight and size, and it has the potential to transform the EV market.

Mercedes-Benz stressed the benefits of the solid-state battery, pointing out that the technology provides superior safety, lightness, and more efficient driving. Perhaps one of the highlights of the new system is that it has high gravimetric energy density, which can amount to as much as 450 Wh/kg on a cell basis. This capability means that a vehicle can enjoy an extended range while driving without additional weight or size in batteries. In addition, the solid-state chemistry also prevents the necessity of active battery cooling, further minimizing the vehicle's energy inefficiencies and eliminating unneeded weight.

The quest for this breakthrough started in 2021, when Mercedes-Benz collaborated with Factorial Energy to create next-generation battery technology. In 2024, Factorial had already supplied its initial lithium-metal solid-state battery cells for testing using Mercedes-Benz's FEST® (Factorial Electrolyte System Technology) platform. After rigorous laboratory tests, the manufacturer was able to successfully incorporate the battery into an EQS prototype by the close of 2024. The initial tests, which were carried out in Stuttgart, yielded encouraging results, prompting the start of on-road testing in February 2025.

Markus Schäfer, Mercedes-Benz Group AG Chief Technology Officer, noted the importance of the innovation, citing that the automotive-scale solid-state battery reaffirms the company's commitment to innovation and sustainability. He was thrilled about the road testing stage, pointing out that the information collected would be vital in establishing the viability of large-scale production and inclusion in future Mercedes-Benz EVs.

Factorial Energy CEO Siyu Huang was no less enthusiastic than Schäfer, calling the feat historic. Huang underlined that it was the first ever integration of lithium-metal solid-state batteries into a mass-production car platform, proving that the tech had passed lab experiments and stepped into usable, real-world practical applications. According to Huang, the achievement had raised a new bar for the entire auto sector, demonstrating that the future of electric mobility ceased to be some sort of future promise but turned into an in-the-moment reality.

The solid-state battery version of the EQS prototype is even better than the range of the current EQS 450+, which manages 800 kilometers (497 miles) on its 118 kWh lithium-ion battery. Being able to drive over 1,000 kilometers on a single charge not only increases the desirability of electric cars but also alleviates one of the main concerns of would-be EV buyers—range anxiety.

Mercedes-Benz will press on with strenuous testing throughout the coming months, targeting how the battery functions in everyday use. The focus is to attain reliability, efficiency, and security before it pursues large-scale production and future model integration. If it achieves this, it could create a new benchmark industry standard, setting Mercedes-Benz well ahead of other companies when it comes to solid-state battery innovation.

The innovations achieved through partnership with Factorial Energy are a significant milestone in the history of EV technology. With enhanced range, efficiency, and safety, the lithium-metal solid-state battery has the potential to change the future of electric mobility. As road testing continues, the industry will be keenly observing, waiting for the next development toward making this innovative technology a reality in commercial electric vehicles.