Automaker Stellantis said it would invest more than $100-million in California's Controlled Thermal Resources, its latest bet on the direct lithium extraction (DLE) sector amid the global hunt for new sources of the electric vehicle battery metal.

The investment by the Chrysler and Jeep parent announced on Thursday comes as the green energy transition and US Inflation Reduction Act have fueled concerns that supplies of lithium and other materials may fall short of strong demand forecasts.

DLE technologies vary, but each aims to mechanically filter lithium from salty brine deposits and thus avoid the need for open pit mines or large evaporation ponds, the two most common but environmentally challenging ways to extract the battery metal.

Stellantis, which has said half of its fleet will be electric by 2030, also agreed to nearly triple the amount of lithium it will buy from Controlled Thermal, boosting a previous order to 65 000 metric tons annually for at least 10 years, starting in 2027.

"This is a significant investment and goes a long way toward developing this key project," Controlled Thermal CEO Rod Colwell said in an interview.

The company plans to spend more than $1-billion to separate lithium from superhot geothermal brines extracted from beneath California's Salton Sea after flashing steam off those brines to spin turbines that will produce electricity starting next year.

That renewable power is expected to cut the amount of carbon emitted during lithium production.

Rival Berkshire Hathaway BRKa.N has struggled to produce lithium from the same area given large concentrations of silica in the brine that can form glass when cooled, clogging pipes.

Colwell said a $65-million facility recently installed by Controlled Thermal can remove that silica and other unwanted metals. DLE equipment licensed from Koch Industries would then remove the lithium.

"We're very happy with the equipment," he said. "We're going to deliver. There's just no doubt about it."

Stellantis CEO Carlos Tavares called the Controlled Thermal partnership "an important step in our care for our customers and our planet as we work to provide clean, safe and affordable mobility."

Both companies declined to provide the specific investment amount.

Controlled Thermal aims to obtain final permits by October and start construction of a commercial lithium plant soon thereafter, Colwell said. Goldman Sachs GS.N is leading the search for additional debt and equity financing, he added.

Controlled Thermal had separately agreed to supply lithium to General Motors till 2024, but that goal has been pushed to 2025, Colwell said.

GM said it has a "close working relationship" with Controlled Thermal but deferred comment on technical questions to its junior partner. GM added it believes it has enough raw material supply to reach its target of producing one-million EVs by 2025.

Stellantis also has an investment in Vulcan Energy Resources, which is developing a German DLE project.