When John Goodenough created the first lithium-ion rechargeable battery at Oxford in 1980, he needed some cobalt. Experiments had already established that the metal is energy-dense, perfect for small batteries that need a lot of power.1 So Goodenough made the cobalt himself, heating the precursors at very high temperatures.

Today, cobalt appears in most commercial lithium-ion batteries—but it comes at a price. The silvery metal is expensive, yes. But it also has a darker cost: a long history of human rights violations, including child mining, associated with production in the Democratic Republic of the Congo. Electronics devices and electric car companies don’t want to pay big bucks and connect themselves with these atrocities, so they have tried to cut down on the amount of cobalt their batteries use. Panasonic, Tesla’s battery supplier, announced at the end of last month that they are developing batteries that don’t need cobalt. And they have some help: Goodenough and other researchers have also developed rechargeable batteries that don’t need cobalt.

A miner works at Tilwizembe, a former industrial copper-cobalt mine, outside of Kolwezi, the capital city of Lualaba Province in the south of the Democratic Republic of the Congo on June 11, 2016. Kenny Katombe/Reuters

Batteries have a positive end, usually graphite, and a cathode, the negative end—a combination of lithium, cobalt, and oxygen in the device you are probably reading this story on. In electric cars, the cathode is usually more nickel-heavy than in smaller devices—which lessens the strain on the cobalt supply chain, but has higher processing costs and is slightly more likely to catch fire in airplanes a la the infamous Samsung Galaxy Note 7. The electrons on the outer orbit of the cobalt atom are paired up, which means it’s small, dense, and forms layers easily.

But a new wave of battery researchers, including Goodenough, are moving to materials like manganese and iron. Instead of layers, these elements come together into a “rocksalt” structure, so called for its resemblance to our favorite tableside seasoning. The rocksalt cathodes are already in use in some devices, but they don’t yet have the same high energy density as cobalt or nickel.

Researchers and companies are ready for the alternatives. “Cobalt’s expensive and people will do their best not to use it,” says Goodenough, who still works as an engineering professor at the University of Texas. Over the past two years, the price of cobalt has quadrupled, and while portable electronic devices currently use the lion’s share of cobalt, batteries for electric cars will require nearly 1,000 times more cobalt than a phone. What with anthropogenic climate change, more and more people are trading in combustion motors for an electric model. And while these trends might be better for the planet, they drive up the price of cobalt.