Stellantis takes a major step towards solid-state battery: an electric revolution?

Electromobility is undeniably one of the main pathways for the future of the automotive industry. Driven by increasingly strict environmental regulations, such as the CAFE (Corporate Average Fuel Economy) standards in Europe which impose ever lower CO2 emission thresholds, electric cars are set to play a predominant role on our roads in the coming years. However, despite growing adoption, electric vehicles still face significant obstacles to widespread development. The main concerns for consumers remain vehicle range and the time required for charging, as well as the available infrastructure.

To overcome these challenges and accelerate the transition, car manufacturers are investing massively in the research and development of new battery technologies. Among the most promising avenues are solid-state batteries, considered the "Holy Grail" of electromobility due to their potential to offer higher energy density, faster charging, and increased safety compared to current lithium-ion batteries. In this race for innovation, the Stellantis group, parent company of our favorite brand, is today taking a significant new step by announcing, in collaboration with Factorial Energy, the successful validation of automotive-size solid-state battery cells and the initiation of tests in a pilot vehicle fleet starting in 2026. This announcement is of great importance and positions Stellantis among the fastest players in the concrete experimentation of this future technology.

Promises of ultra-fast charging to remove barriers to electromobility

The fundamental question that constantly arises regarding electric cars is that of range and charging capability. It is on these crucial points that the solid-state battery technology developed by Factorial Energy, named FEST® (Factorial Electrolyte System Technology), in collaboration with Stellantis, brings exciting prospects. One of the most notable advancements announced is the validated cells' ability to allow for fast charging from 15% to 90% in just 18 minutes. Such a charging time, if confirmed in real-world conditions and over a wide range of temperatures, could significantly reduce charging anxiety during long journeys and make the electric car experience more comparable to refueling a conventional vehicle.

This charging speed is made possible by the intrinsic characteristics of solid-state technology, which uses a solid electrolyte instead of liquid, potentially allowing for faster and safer ion transfers. By taking this important step towards commercialization with the validation of automotive-size cells and the announcement of concrete tests starting in 2026, Stellantis is clearly positioning itself as a pioneer in the integration of these disruptive technologies. The group thus demonstrates its willingness to be at the forefront of solutions that can remove the main barriers to the massive adoption of electric vehicles and thus accelerate the achievement of its electrification goals set out in its Dare Forward 2030 strategic plan.

Promising technical characteristics and conclusive tests

Beyond the promise of fast charging, the technical characteristics of the FEST® battery cells validated by Stellantis and Factorial Energy are particularly encouraging. These 77Ah cells have demonstrated an impressive energy density of 375 Wh/kg. Although the announcement does not provide a specific range figure associated with this density, higher energy density potentially means more kilometers driven for a given battery weight, or a lighter battery for an equivalent range, which has a positive impact on overall vehicle efficiency. The cells have also achieved over 600 cycles of charge/discharge, which is an important step towards automotive qualification, indicating a certain level of durability.

Another crucial point is the ability of these batteries to operate over a wide temperature range, from -30°C to 45°C, with potential for further extension. This characteristic is essential to ensure the performance and reliability of electric vehicles in different climates and surpasses the temperature limitations often encountered with previous generations of solid-state batteries under development. Furthermore, the cells offer high power output with discharge rates up to 4C, meeting the increased performance requirements for modern electric vehicles. Ned Curic, Stellantis Chief Engineering and Technology Officer, highlighted the importance of this step: "Achieving this level of performance reflects the strength of our collaboration with Factorial. This advancement puts us at the forefront of the solid-state battery revolution, and we are going even further. Together, we are pushing boundaries to develop ever more performing solutions: lighter, more efficient, more affordable batteries for our customers." On his part, Siyu Huang, Factorial Energy CEO, emphasized the delicate balance achieved: "Battery development is a matter of compromises. Optimizing a single characteristic is relatively simple, but successfully balancing high energy density, long cycle life, fast charging, and safety in an automotive-size battery with OEM validation constitutes a true breakthrough. This achievement with Stellantis moves next-generation battery technology from research to reality." The collaboration goes beyond the cell itself, including the optimization of battery packs and vehicle integration to maximize efficiency and potentially reduce costs.

Towards a more serene electric future, despite remaining challenges

The automotive industry is at a turning point, and electric cars, despite their undeniable potential to reduce polluting emissions, still face many obstacles to their mass development. Fears related to real-world range under varied conditions and the time spent at charging stations are significant psychological and practical barriers for many motorists. The announcement from Stellantis and Factorial Energy regarding the validation of these solid-state batteries represents a significant technological advancement and should eventually help to overcome these barriers by offering more performant solutions.

However, it is important to remain measured. While solid-state technology promises much, particularly in terms of energy density (which should translate into better range, even if the group is not communicating specific figures at this stage), the announcement of charging from 15% to 90% in 18 minutes, while fast, is actually quite similar to what is already possible with certain 800-volt fast-charging architectures found on current high-end electric vehicles. The true revolution of solid-state batteries will lie in their ability to combine significantly higher energy density (offering range well beyond current standards) and ultra-short charging times, while also being affordable and durable in the long term. The fleet test planned for 2026 is a crucial step to validate these promises under real-world conditions. This collaboration strengthens Stellantis's strategic investment in Factorial Energy and confirms that the group is actively working on tomorrow's technologies to make its future electric vehicles, including Citroën models, increasingly attractive and adapted to customer expectations. The hope for a more serene electric future, with fewer constraints related to range and charging, is partly based on advancements like this one.