Future Mercedes-Benz EVs May Get Solid-State Batteries With 80% More Range

Massachusetts-based Factorial has a new solid-state battery named Solstice. Factorial is backed by Mercedes-Benz, which led a $200 million funding round in the company in 2022. Mercedes-Benz is already working on bringing these batteries to market by the end of the decade.

Solid-state batteries are considered the next big thing in battery technology. Several automakers are already working with battery companies to develop solid-state cells, hoping to commercialize them in the future to eliminate range anxiety, improve battery safety and increase charging speeds.

One of the automakers investing in the tech is Mercedes-Benz. The German automaker entered a joint development agreement with Massachusetts-based Factorial Energy to develop next-generation batteries in 2021. Mercedes also led a $200 million funding round in 2022 and today Factorial announced a new solid-state battery named Solstice.

Factorial said the new battery has an energy density of 450-watt hours per kilogram. Tesla's 4680 nickel cobalt manganese cells installed on the Model Y have an estimated energy density of about 272-296 Wh/kg. The American battery start-up said this can potentially extend the range of an EV by 80% while also reducing the weight of the battery pack. 

Solid-state batteries basically use a solid electrolyte instead of the liquid or gel electrolytes found in traditional lithium-ion batteries. Key benefits include a higher energy density and far less flammability. Plus, they're faster charging. But so far, they have proven expensive to produce and no one has really figured out scalability.

Factorial said this battery uses a proprietary sulfide-based electrolyte that aims to have a high safety rating and operating temperatures of up to 90 degrees Celsius (194F). It also said there's potential to reduce cooling needs and reduce costs. It also incorporates a "dry coating" process that reduces the environmental impact of producing these batteries.

The announcement states that Mercedes-Benz is already working on integrating these batteries into its future EVs. Factorial would be Mercedes' second solid-state battery partner after it announced in 2022 that it was investing millions of dollars in Taiwanese solid-state battery maker ProLogium.

With that, the German automaker joins a growing list of brands investing in this tech, including Toyota which is developing solid-state batteries that can deliver over 600 miles of range starting in 2026.