Electric vehicles’ future relies on cobalt. It’s often mined by children and is soaring in price

The road to an imminent electric vehicle future has hit a speed bump — one made of cobalt.

An essential ingredient in lithium-ion batteries that power millions of smartphones as well as plug-in electric cars, cobalt is in heavy demand.

But just as the silverish-gray metal has established itself as a critical element in the growth of the market in electric vehicles, cobalt has also become a source of serious ethical and economic concerns.

Most notably, the majority of the world’s cobalt production is concentrated in the Democratic Republic of Congo, where in many cases children work in hazardous conditions mining the metal.

And once extracted, there are questions whether enough long-term supplies of cobalt can be established to fulfill the hopes of policymakers in places like California who want to transform the transportation system from gasoline-powered vehicles to EVs.