What could be called a significant breakthrough in the sphere of electric vehicles, Mercedes-Benz claims to have unveiled the “world’s first solid-state battery vehicle from a global OEM.”
The German carmaker has unveiled that a prototype EQS, equipped with a solid-state battery developed in collaboration with US startup Factorial Energy, has begun real-world testing.
“Mercedes-Benz engineers from the road and racetrack and Factorial cell engineers have worked together on delivering an all-new solid-state battery test programme, which has brought the first car powered by a lithium-metal solid-state battery to the road,” said the company in a press release.
Over the next few months, Mercedes-Benz will further test the solid-state battery and its overall performance. Image: Mercedes-Benz.
This is a big milestone in the transition from laboratory experiments to practical applications.
“The first laboratory vehicle tests were already conducted in Stuttgart at the end of 2024 to prepare for the road tests that started in February 2025,” added the press release.
Significant range improvement
The prototype EQS is projected to deliver an impressive 1,000km of range, based on WLTP testing. This represents a more than 25% improvement over the current EQS 450+ model.
While WLTP figures typically exceed EPA estimates, the vehicle is still expected to achieve a remarkable 850km under EPA standards, which easily rivals the range of the Lucid Air.
This extended range is attributed to Factorial Energy’s innovative solid-state battery technology, which replaces the traditional liquid electrolyte with a solid one.
This allows for higher energy density and enhanced safety, while also promising significant weight reductions.
Mercedes-Benz states that the solid-state pack delivers 25% more range within the same size and weight parameters as current lithium-ion batteries.
“Further weight and energy efficiency is achieved through passive battery cooling,” said Mercedes.
The company states the solid-state battery pack has the potential for a 40% range increase in future iterations.
Using Factorial’s advanced ASSB
The battery being tested in the EQS is the first step toward incorporating Factorial’s more advanced 'Solstice' all-solid-state battery.
It features a lithium-metal anode, which stores more energy than conventional graphite anodes, and a 'floating cell carrier'.
To manage the material’s expansion and contraction during charging and discharging, the battery incorporates pneumatic actuators designed by Mercedes’ Formula 1 engineers at their motorsport headquarters in Brixworth, UK.
“Being the first to successfully integrate lithium metal solid-state batteries into a production vehicle platform marks a historic achievement in electric mobility,” said Siyu Huang, CEO and co-founder of Factorial Energy.
Advances in solid-state batteries
This development signifies a crucial advancement over semi-solid-state batteries, which use a gel-like electrolyte and are already being deployed in some Chinese EVs.
While semi-solid batteries offer a faster path to scalability, true solid-state batteries promise a more substantial leap in performance and safety.
This breakthrough could pave the way for a new generation of electric vehicles with significantly enhanced range and performance, accelerating the transition to sustainable transportation.
“This breakthrough demonstrates that solid-state battery technology has moved beyond the laboratory and into real-world application, setting a new benchmark for the entire automotive industry,” concluded Huang.
Separately, Toyota has reportedly worked on a new type of cathode material for all-solid-state batteries. This solid-state battery cathode, according to the company, is expected to have twice as much energy density than lithium-ion batteries.