Solid-state batteries find their way onto the road

19.03.2025

Solid-state batteries: The future of electromobility?

Together with its partners, Mercedes wants to take the lead in the field of solid-state batteries. In collaboration with the American company Factorial Energy, Mercedes-Benz has developed a vehicle prototype with a lithium-metal solid-state battery and carried out the first road tests as early as February 2025. The battery was designed by Mercedes AMG High Performance Powertrains (HPP) and the competence centre for battery systems. The EQS, in which the battery was integrated, was selected as the test model.

A milestone for battery research 

The main difference between solid-state batteries and today's rechargeable batteries lies in the electrolyte: instead of a liquid substance, a solid electrolyte is used. The electrolyte plays a central role in every battery as it enables the transport of ions between the anode and cathode. The main difference in the solid-state battery is the use of a lithium metal anode, as it offers a significantly higher energy density compared to conventional anode materials. 

The new technology could make it possible for electric cars to achieve a gravimetric energy density of up to 450 Wh/kg in the future, which would result in a significantly greater range. The new type of battery is also considered to be much safer: while the liquid electrolyte, like petrol, burns easily and quickly, its solid counterpart is almost impossible to set on fire. 

Innovative tests and a patent

After numerous test bench tests, the solid-state battery was installed in a Mercedes EQS at the end of 2024, followed by laboratory tests in Stuttgart. Road tests have been underway since February 2025.

According to the press release, the solid-state battery from Mercedes-Benz has an innovative cell carrier with floating storage, which has now also been patented. The battery cells change their volume during charging and discharging, which is equalised by pneumatic actuators. The new technology is intended to significantly improve the service life and performance of the battery.

Future prospects for electromobility

The solid-state battery tested apparently enables a range increase of up to 25 per cent compared to the current EQS range of 821 kilometres. The next, solid battery generations could even generate up to 80 per cent more range without significantly affecting the size or weight of the battery. In addition, passive cooling ensures improved energy efficiency. Initial forecasts assume a range of over 1,000 kilometres. At the same time, the charging time should be reduced.

Mercedes-Benz is setting new standards in electromobility with this innovative prototype. The upcoming tests will show whether this technology will fulfil the requirements of series production. Nevertheless, material scarcity and price fluctuations also play a role and will result in different battery variants on the market. Which battery will ultimately be offered in which vehicle will probably depend on the requirements and the customers' willingness to pay. However, if the new solid-state battery proves its worth, it could change the electric vehicle industry forever, as a new level of efficiency will be achieved.

Image: Aditya Panchal on Unsplash 

Sources: futurezone.at, 21.02.2025

elektronikpraxis.de, Dipl.-Ing. (FH) Michael Richter, 27.02.2025

adac.de, 03.03.2025

auto-motor-und-sport.de, Gerd Stegmaier and Markus Schönfeld, 17.03.2025