Supervolcanoes could become vital source of lithium for batteries
Scientists at Stanford University have developed a simple method for detecting levels of lithium in the holes in the ground created when supervolcanoes erupted, known as calderas. The team extracted tiny blobs of magma from volcanic lakes created by the now dormant supervolcanoes and analysed the zirconium levels, knowing if they were high, the lithium concentration would be low – and vice versa. The results suggested dormant supervolcanoes around the world could provide rich sources of lithium for the batteries used in electric vehicles.
The Stanford team has come up with a new technique to detect lithium in volcanic lakes that have appeared in calderas – holes in the ground that were created when supervolcanoes erupted, displacing huge quantities of lava.

Lithium, found in the volcanic deposits, has been drawn out into the lake over thousands of years, and gathered as a clay in the lake. But some lakes are more lithium-rich than others, depending on the original magma content, and the key is being able to identify which ones.

“Because lithium is a very volatile element, it is extremely difficult to measure,” Tom Benson, lead author of the study, says. “You can't simply measure the whole-rock chemical composition of a volcanic rock, like volcanologists typically do.”

Instead, the team worked out a way to identify how much lithium was in the lake. By extracting tiny blobs of magma that had been trapped in crystals, heating them up and quenching them, Benson could identify the lithium content in the magma.

The process was fiddly and time-consuming, but it helped reveal a simpler way to find lithium. “What this research shows is that the zirconium content of the magmas show a nearly linear relationship with lithium,” says Benson. “When the lithium content of the magma is high, the zirconium content is low, and vice-versa.” And zirconium is much easier to measure because it is non-volatile.

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The study was based in the US, but the whole world will be facing similar challenges in the future. For example, in the UK, “the grid-connected energy storage market is expected to expand from total installed capacity of 3 GW at the end of 2016 to 28 GW by 2022,” Marek Kubik, a market director for energy storage systems at AES, says.

“It’s a neat study and very interesting,” adds professor Stephen Piercey, from the Memorial University of Newfoundland, who was not involved in the study. “Their use of micro chemical methods provide a means of documenting what types of volcanoes may have been enriched in lithium, and by association what supervolcanic environments might have the potential for lithium redistribution... as potential sources for lithium extraction.”

People living around volcanoes, in places like Iceland, have been harnessing their energy for over a hundred years, using steam from geothermal vents to drive turbines. However, this only works around active volcanoes.

“The lithium deposits I discuss in this manuscript only occur in old, dormant volcanoes where the caldera lake has drained and exposed the old lake sediments,” says Benson.

“Geothermal is used to provide the energy, and lithium can store the energy; they are not in competition and can actually really complement each other,” he adds. “I think it is important to use both volcanic resources as we strive to develop a global clean energy portfolio.”

The research is published in Nature Communications.