UYUNI, Bolivia—"Gray gold" may be the key to a future filled with hybrid or electric vehicles. That's because lithium is the most important ingredient in the batteries that power these cars. Even without many electric cars on the road today the lightest metal on Earth is more and more a mining target of multinational companies as lithium ion batteries power an increasing array of electronic gadgets.



Lithium is found in many places on the planet, but among all of them no deposit is richer than the vast salt flats of Salar de Uyuni in Bolivia, covering more than 10,000 square kilometers of the remote high plains. Lithium is found among these salts, mixed in with brine that lies beneath a saline crust, the residue of an ancient evaporated sea. That lithium-rich brine is the legacy of local volcanic activity transporting the metal to the surface where it could then be leached by infiltrating waters.



The U.S. Geological Survey estimates that this single salar (salt pan) contains 5.4 million metric tons of lithium. Harkening to a future of growing demand, landlocked Bolivia recently invested $5.7 million in a pilot plant to determine how best to process the salt, which may ultimately enable it to surpass its neighbor Chile in dominating the global market for the element.



But peasant salt harvesters still predominate in this part of the so-called Lithium Triangle—salt deserts perched atop the Andes at the junction of Argentina, Bolivia and Chile. The bulk of common table salt from the salar is still harvested by Aymara people, their faces sheathed by sheets or wooden masks to protect against the blinding sun, using hatchets or iron bars and often breaking through to the blue-green brine beneath the crust, rich in minerals ranging from boron to lithium.



Says Nestor Alconz, a salt harvester in the Salar de Coipasa: "Evo Morales, our president, came to the village last year. It was the first time a president ever came up to here. He told us about lithium but he said that it requires such high investments that it will take a lot of time until we can start that here. I don't think I will witness it, but I do hope our children will benefit from it."



Nevertheless, the Lithium Triangle salars are beginning to show the strains of increased lithium production: Evaporation ponds litter the barren landscape, and pumping the brine may lower the water table—a major threat in a desert area. Furthermore, large-scale extraction could destroy the unique salar ecosystem.



Although increasing demand has driven lithium prices from $350 to $3,000 per ton in the past five years, ultimately it will be the proliferation of electric cars that pushes consumption of the element to new heights. Whereas gadgets require roughly a few grams of lithium, a car battery requires as much as 30 kilograms.



And that's the hope of some Bolivians, that a lithium rush may enable them to escape poverty. "The discovery of lithium will allow Bolivia to become an industrialized country like others," says metallurgist Maritza Vallejos of the pilot plant in Rio Grande. "Thanks to the production of lithium batteries for electric cars, [we] will contribute to fighting global warming for the benefit of the entire Earth."

View slide show: "A Look at the Lithium Flats of Bolivia"