(CN) – Every time you fire up your iPad, Prius or bicycle headlamp, you're probably using the chemistry of lithium. And a new study published Wednesday by Stanford University reveals how to help make America lithium independent – by harvesting lithium from supervolcanoes.
The world depends on stored battery electricity, whether it's for headlamps or cars. And in this age of reducing greenhouse gas emissions, more lithium will be needed to make the batteries that help power the world. Awareness of human-caused greenhouse gas emissions has led to the development of sustainable energy technology, the researchers said, and this has required developing unconventional ore resources that are strategic to clean energy and geopolitical supply.
Lithium is classified as an energy-critical element by several governments due to increasing demand for lithium-ion batteries, the researchers wrote. Lithium-ion batteries have a high-power density and relatively low cost that makes them optimal for energy storage in portable electronic devices, the electrical power grid, and the growing fleet of hybrid and electric vehicles.
Authors of the study, which was published Wednesday by Nature Communications, are Thomas R. Benson, Matthew A. Coble, James J. Rytuba and Gail A. Mahood.
The lithium study came a bit by accident. Mahood said the study was an outgrowth of her team's long-term research aimed at understanding the birth of the Yellowstone hotspot and its association with eruptions of huge volumes of basaltic lava that cover much of the northwestern United States, known as the Columbia River flood basalts. She said Stanford for the last 10 years has been studying the earliest explosive, rhyolitic volcanism associated with these flood basalts, which occur in southeastern Oregon and northern Nevada.
Although current annual consumption of lithium is small compared to the estimated world extractable lithium reserve, the researchers said lithium demand will likely become critical by 2030.
Much of the world supply of lithium currently is from deposits in Chile and Australia.
“The presence of lithium-ion batteries in mobile electronics and hybrid and electric vehicles necessitates discovery of new lithium resources to meet rising demand and to diversify the global lithium supply chain,” researchers said. The study set out to demonstrate that lake sediments preserved within volcanic calderas have the potential to host large lithium clay deposits.
The Stanford University study addressed lithium from a scientific and cultural standpoint. “From a scientific standpoint, we wanted to understand what kinds of magmas and in which kinds of tectonic settings have the largest endowments of lithium,” Mahood said. “From a practical standpoint, we want to understand how lithium gets mobilized from magmas and volcanic rocks and concentrated into mineable deposits.”
Supervolcanoes – like the one that sits under Yellowstone National Park – produce lithium in abundance, but in varying degrees. The researchers studied trace elements found in various magma samples to determine how they correlated to lithium concentrations. They discovered a correlation among the elements and lithium that could make it easier to identify supervolcanoes for lithium exploration.
Researchers found that in areas with low amounts of zirconium there is a high probability that high amounts of lithium would not be present. But where there is abundant rubidium around a supervolcano, you'll likely find abundant lithium.
The researchers compared lithium concentrations of magmas formed in a variety of tectonic settings. They found that cenozoic calderas in western North America and in other intracontinental zones are “promising new targets for lithium exploration” because lithium leached from the eruptive products by meteoric and hydrothermal fluids becomes concentrated in clays within caldera lake sediments to potentially economically extractable levels. Cenozoic calderas in western North America and in other intracontinental settings that generated certain magmas are promising new targets for lithium exploration, the researchers wrote, because lithium leached from the eruptive byproducts becomes concentrated within caldera lake sediments.
Mining those lithium deposits out of the land is another issue, since volcanoes tend to be on federal or state land. But the energy production associated with the costs of mining may outweigh the negative aspects of mining. “Our research suggests those reserves are greater than appreciated and may extend to other supervolcanoes of the western United States,” Mahood said. “Most of the prospective areas would be federal lands. For example, most of the areas we have been working in in southeastern Oregon and northern Nevada are administered by the Bureau of Land Management and U.S. Fish and Wildlife Service.”
Mahood said the total lithium reserves in North America “may need to be reassessed upward given the results of our research. Even if the number is greatly increased, the amount that is easily recoverable won’t match that available in Chile, Australia, and elsewhere internationally.
“But the important point is that when it comes to strategic minerals like lithium and the rare earth elements that are critical for clean-energy technology and electronic devices, you want to make sure that you have an adequate domestic supply so that you aren’t subject to the vagaries of international politics.”
The research team collected volcanic field samples during their work that preserved bits of magma as it would have been prior an eruption. The team analyzed the samples in the laboratory at Stanford using a high-resolution ion microprobe, a $2 million instrument jointly funded by the U.S. Geological Survey and Stanford, Mahood said.
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