Solid-state batteries are an encouraging technology in electric mobility. The use of a solid electrolyte instead of liquid enhances cell safety and allows for the use of new anodes such as lithium-metal, significantly outperforming conventional lithium-ion cells and enabling higher energy densities. The solid-state technology reduces battery weight and has the potential to increase the gravimetric energy density for vehicle batteries up to 450 Wh/kg at the cell level, thereby increasing electric range. [Gravimetric energy density refers to the amount of energy stored in a battery cell per unit mass and is fundamental for evaluating the efficiency and performance of battery cells, especially in electric vehicles where weight is a critical factor.]

After intensive testing on various test benches, the prototype solid-state battery was integrated into a Mercedes-Benz EQS Sedan at the end of 2024. The vehicle was slightly modified to fit the solid-state battery and equipped with all accessories to operate it. The first laboratory vehicle tests were conducted in Stuttgart at the end of 2024 to prepare for the road tests that started in February 2025.