Mercedes-Benz Testing Prototype Solid-State Battery Cells
Mercedes-Benz has recently announced the commencement of real-world testing of prototype solid-state battery cells provided by the U.S. company Factorial. These cells have been integrated into a Mercedes-Benz EQS sedan since late 2024 and have undergone extensive laboratory testing. The automaker now states that the EQS is prepared for on-road testing and could potentially achieve a remarkable range of up to 621 miles (1,000 km) on an unconfirmed drive cycle with the implementation of solid-state cells.
Mercedes-Benz EQS solid-state battery prototype
The enhanced range is primarily attributed to the increased energy density of the solid-state cells. Mercedes asserts that these cells offer 25% more energy and range within the same weight and dimensions as the standard EQS battery pack. Additionally, the utilization of passive battery cooling, similar to the approach used in the Mercedes EQXX engineering concept, will contribute to weight reduction and improved efficiency.
The development of the EQS test vehicle’s battery pack involved Mercedes’ Formula 1 powertrain unit, incorporating a novel floating cell carrier with pneumatic actuators to accommodate cell expansion and contraction during charging and discharging.
Mercedes-Benz EQS solid-state battery prototype
The collaboration between Mercedes and Factorial dates back to 2021, with Factorial supplying test cells to Mercedes and Stellantis starting in 2022. By 2024, Factorial expressed confidence in enhancing Mercedes EV range by up to 80% with its cells. The battery firm, based in Massachusetts, has established what it claims to be the largest U.S. EV solid-state battery plant in a Boston suburb, aiming to produce up to 200 gigawatt-hours of batteries annually in the future.
Mercedes plans to continue testing the solid-state cells both in the laboratory and on the road in the coming months, potentially leading to their integration into production vehicles. If commercialized, Mercedes is also developing a new micro-converter and innovative cooling systems to enable the coexistence of solid-state cells with other cell types within the same EV battery pack.