Key Takeaways
1. Mercedes-Benz is testing a modified EQS with a lithium-metal solid-state battery aiming for over 1,000 kilometers of range.
2. The battery features a sulfide-based solid electrolyte and a lithium-metal anode, boosting energy density to 450 Wh/kg and increasing range by 25% without added weight.
3. Cells are produced by Factorial Energy in collaboration with Mercedes-AMG High-Performance Powertrains, leveraging racing technology expertise.
4. Real-world testing began in February 2025 after initial lab tests in Stuttgart, with plans for production vehicle incorporation by the end of the decade.
5. The testing is part of a global competition in battery development, with other major companies like Volkswagen, BMW, and Toyota also pursuing similar technologies.
In February 2025, Mercedes-Benz started to test a modified EQS on the road for the first time, featuring a lithium-metal solid-state battery. This testing aims to reach a range of more than 1,000 kilometers, marking a key achievement in the quest for better electric mobility.
Battery Details
The battery utilizes a sulfide-based solid electrolyte, which enables the use of a lithium-metal anode. This unique pairing boosts the gravimetric energy density to as much as 450 Wh/kg at the cell level and provides roughly 25% more range without increasing weight compared to standard lithium-ion batteries.
The cells used are produced by Factorial Energy, which collaborated with Mercedes-AMG High-Performance Powertrains (HPP) to develop the battery pack. Mercedes emphasizes that this is a genuine integration into a vehicle prototype, drawing on knowledge from racing technologies and expertise in battery cells.
Testing Phases
After initial laboratory tests conducted in Stuttgart at the end of 2024, the real-world road testing began in February 2025, as reported by Automotive Testing Technology International. Mercedes aims to incorporate this technology into production vehicles by the decade’s end.
This testing occurs in the context of a worldwide competition for the next generation of batteries, and Mercedes is not the only player. Competitors like Volkswagen, BMW, Toyota, and Chinese firms including BYD and CATL are also developing solid-state or near-solid-state batteries. This evolution underscores the significance of enhancing range through innovative cell chemistry.
Future Possibilities
The road tests of the Mercedes solid-state battery represent a major progress toward a market introduction. While challenges such as scaling production, managing costs, and integrating into series production persist, this achievement indicates that efficient electric mobility is achievable.
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