Start-up Factorial Energy has raised $200 million to help fund further development and commercialization of its advanced solid-state battery for EVs.
Automakers Stellantis NV and Daimler AG's Mercedes-Benz led the round for three-year-old Factorial, based outside Boston in Woburn, Massachusetts.
Factorial is one of several U.S. battery start-ups attempting to commercialize solid-state technology, which promises to reduce the risk of battery fires and extend driving range.
Potential competitors include QuantumScape, a 12-year-old Silicon Valley start-up that went public in 2020, and 10-year-old Solid Power, based in Louisville, Colorado, which went public in December.
QuantumScape has been funded by Volkswagen AG, while Solid Power has backing from BMW, Ford Motor and Hyundai Motor.
Other companies, notably Toyota Motor, are developing solid-state batteries in house.
Most of those batteries use a solid-state electrolyte in place of liquid solutions that are potentially more flammable.
Stellantis Chief Executive Carlos Tavares last year said the company aims to begin installing solid-state batteries in its electric vehicles by 2026.
Factorial said it has development partnerships with Mercedes, Stellantis, Hyundai and Kia Motors.