The Electric: Mercedes Goes to Advanced Tests of Factorial’s Solid State Batteries
Mercedes-Benz, aiming to introduce next-generation solid state batteries into its electric vehicles by 2026, said it has moved into advanced tests of a battery developed by Massachusetts-based Factorial Energy. The move comes amid increasing industry and investor skepticism about the mass-market potential of most next-gen EV batteries.
In the most recent sign of industry turmoil, Ionic Materials, another startup solid-state battery maker, on Tuesday let go all of its staff and closed its doors, as we reported. Sherwood Partners, a California-based receivership firm, this week began selling off Ionic’s intellectual property, laboratory equipment and other assets, according to a former Ionic employee. Sherwood and Ionic did not respond to emails.
Many in the EV industry have seen solid state batteries as a sort of holy grail propulsion system for EVs because they theoretically could deliver about 500 miles of driving range, charge fast, cost less than conventional lithium-ion batteries, and pose a lower fire risk because they eliminate flammable liquid as the electrolyte. But commercial solid state batteries seem unlikely to be ready until late this decade, and they are threatened by the improving performance and lower cost of conventional EV batteries. As we have written, as long as current “good enough” batteries deliver satisfactory performance, most automakers are unlikely to risk commercializing an untried technology such as solid state, even if such batteries might work better. The solid state players also face competition from next-gen silicon anode makers such as Sila Nanotechnologies and Enevate, which are in or near commercial EV production and deliver similar energy density and driving range as solid state designs.
Factorial CEO Siyu Huang told me she hopes the company’s batteries are in commercial EVs in 2027 or 2028. On Wednesday, Factorial said it had shipped “B Samples” of its 106 ampere-hour battery—20 times the charge capacity of a smartphone battery—to Mercedes. Few experimental batteries such as Factorial’s reach B Samples, which means its batteries have passed Mercedes’ lab tests and are ready to be tailored for the automaker’s qualification vehicles, where they will face around 18 months of further punishing tests. If they pass muster, Mercedes could ask Factorial for “C Sample” versions of its battery, which would be tailored yet again to fit a specific EV.
Factorial also has batteries in the earlier A Sample stage with Stellantis, with which it has a joint development agreement. At a conference last year, Stellantis CEO Carlos Tavares highlighted the automaker’s work with Factorial, and suggested the carmaker would have a solid state battery powering an EV in 2026. Mercedes and Stellantis led Factorial’s $200 million Series D funding in 2022.
Huang, the Factorial CEO, argued that solid state batteries using lithium metal will compete well with conventional batteries because they allow EV makers to reduce the weight of the vehicles by up to 30%. Greater energy density means Factorial’s batteries can be smaller and lighter than conventional EV batteries, allowing EV designers to eliminate supporting steel and aluminum framing in the vehicle itself, she said. “That’s a huge amount of cost reduction,” she said.
In April, SES AI—which like Factorial uses lithium metal as the anode, but employs a liquid electrolyte—moved into the B Sample stage with Hyundai Motor, as we reported, putting it arguably ahead of Factorial. Another Factorial rival, California lithium-metal battery developer QuantumScape, has said it hopes to move into B Samples with undisclosed customers later this year.