Mercedes-Benz and Factorial Energy
Mercedes-Benz has taken a key step in electric mobility by successfully road-testing the first vehicle powered by a lithium-metal solid-state battery. Developed in collaboration with Factorial Energy, this technology represents progress in battery efficiency, safety, and range, setting a new standard in the industry.
This development follows years of research and engineering between Mercedes-Benz’s AMG High Performance Powertrains (HPP) and the Center of Competence for Battery Systems. Leveraging Formula 1-derived expertise, the team has successfully adapted high-performance racing innovations for application in electric vehicles (EVs).
Advancements in Battery Technology
Solid-state batteries are widely regarded as a future advancement in electric mobility due to their higher energy density and improved safety profile compared to conventional lithium-ion batteries. Unlike traditional batteries that use liquid electrolytes, solid-state batteries incorporate a solid electrolyte, enabling the use of advanced materials like lithium metal anodes. This results in increased gravimetric energy density—up to 450 Wh/kg—allowing for extended driving ranges while simultaneously reducing battery weight.
The solid-state battery developed for Mercedes-Benz features a significantly higher energy storage capacity than conventional lithium-ion cells, allowing for greater range without increasing the battery's physical size. By utilizing lithium-metal anodes, the battery reduces internal resistance, which improves charging speed and enhances energy retention over time. Additionally, the absence of liquid electrolytes eliminates the risk of leakage and reduces thermal instability, making the battery more resilient under extreme operating conditions.
For the first prototype, engineers integrated the solid-state battery into a modified Mercedes-Benz EQS. Following extensive test bench evaluations, the vehicle underwent real-world trials starting in February 2025. Early results indicate that the technology delivers a 25% increase in driving range compared to conventional lithium-ion batteries of the same weight and size. Passive battery cooling has further improved energy efficiency, reducing the need for active cooling systems and contributing to overall weight reduction.
Extended Range and Efficiency
One of the most significant outcomes of the solid-state battery integration is the enhanced driving range. The prototype EQS, fitted with the new battery, is expected to achieve a range exceeding 1,000 km (620 miles) on a single charge—surpassing the standard EQS model, which currently offers a range of approximately 800 km (497 miles) with a 118 kWh battery. This improvement means fewer charging stops for long-distance travel, making electric vehicles more practical for a wider range of consumers and reducing reliance on charging infrastructure.
Furthermore, the increased energy density of the solid-state battery allows for a more compact and lightweight design without compromising performance. The vehicle benefits from improved aerodynamics and overall efficiency, which in turn enhances its real-world energy consumption. The reduction in battery weight also contributes to better handling and acceleration characteristics, ensuring that performance is not sacrificed for efficiency.
Key Benefits of Solid-State Batteries
The introduction of solid-state battery technology has several potential advantages:
According to Markus Sch?fer, Member of the Board of Management of Mercedes-Benz Group AG and Chief Technology Officer for Development & Procurement:
“Developing an automotive-scale solid-state battery underlines our commitment to innovation and sustainability. We’re therefore excited to announce that we’ve started road testing with a prototype vehicle equipped with this advanced technology. We will gain crucial insights into possible series integration of this cutting-edge battery technology.”
Moving Towards Mass Adoption
The test program with Factorial Energy marks a step in the transition from laboratory research to real-world applications. In 2024, Factorial delivered its proprietary FEST? (Factorial Electrolyte System Technology) lithium-metal solid-state battery cells to Mercedes-Benz, enabling large-scale feasibility testing.
Siyu Huang, CEO and Co-Founder of Factorial Energy, highlighted the significance of this achievement:
“Being the first to successfully integrate lithium metal solid-state batteries into a production vehicle platform is an important step for electric mobility. This milestone demonstrates that solid-state battery technology is advancing beyond the laboratory and into real-world applications. Our collaboration with Mercedes-Benz confirms that the future of electric vehicles is actively being developed today.”
Next Steps for Mercedes-Benz’s Solid-State Battery Program
In the coming months, Mercedes-Benz will conduct further testing of the solid-state battery system under various real-world conditions. Engineers will analyze the battery’s durability, efficiency, and overall integration into EV platforms. The goal is to refine the technology for potential mass-market production, making solid-state batteries a feasible option for future Mercedes-Benz electric models.
With initial test results already showing improvements in range and efficiency, the prospect of a commercialized solid-state battery EV from Mercedes-Benz is progressing. If successful, this technology could enhance the capabilities of electric vehicles, reinforcing Mercedes-Benz’s position as a leader in automotive innovation.
Towards a More Sustainable Future
As the automotive industry continues its transition toward electrification, advancements like this solid-state battery prototype contribute to overcoming existing challenges related to range and safety. Mercedes-Benz’s investment in this field reflects its commitment to sustainability and innovation.
With road tests underway, the industry is closely watching how this technology develops. If proven successful, solid-state batteries could play a pivotal role in the next generation of electric vehicles, making them more efficient and practical for widespread adoption.