Threatened by possible shortages of lithium for electric car batteries, automakers are racing to lock in supplies of the once-obscure “white gold” in a politically and environmentally fraught competition from China to Nevada to Chile.

General Motors Co. and the parent company of China’s BYD Auto Ltd. went straight to the source and bought stakes in lithium miners, a rare step in an industry that relies on outside vendors for copper and other raw materials. Others are investing in lithium refining or ventures to recycle the silvery-white metal from used batteries.

A shortfall in lithium supplies would be an obstacle for plans to ramp up sales to tens of millions of electric vehicles a year. It is fueling political conflict over resources and complaints about the environmental cost of extracting them.

“We already have that risk” of not being able to get enough, GM’s chief financial officer, Paul A. Jacobson, said at a Deutsche Bank conference in mid-June.

“We’ve got to have partnerships with people that can get us the lithium in the form that we need,” Jacobson said.

Ford Motor Co. has signed contracts stretching up to 11 years into the future with lithium suppliers on two continents. Volkswagen AG and Honda Motor Co. are trying to reduce their need for freshly mined ore by forming recycling ventures.

Global lithium output is on track to triple this decade, but sales of electric SUVs, sports cars and sedans that rose 55% last year threaten to outrun that. Each battery requires about 17 pounds of lithium, plus cobalt, nickel and other metals.

“There will be a shortage of EV battery supplies,” said Joshua Cobb, senior auto analyst for BMI.

Adding to uncertainty, lithium has emerged as another conflict in strained U.S.-Chinese relations.

Beijing, Washington and other governments see metal supplies for electric vehicles as a strategic issue and are tightening controls on access. Canada ordered three Chinese companies last year to sell lithium mining assets on security grounds.