According to the US Geological Survey (USGS), Arkansas has lithium reserves that could be large enough to meet all of the world's electric vehicle battery needs.
It is estimated that there could be 5 to 19 million tons of lithium in southwest Arkansas. That would be enough to supply nine times the amount of key material needed for car batteries worldwide in 2030, according to the USGS.
Lithium is an important ingredient for rechargeable batteries used in electric vehicles and other devices. As the U.S. seeks to limit greenhouse gas emissions that cause climate change by encouraging the adoption of electric vehicles, the Biden administration has made building domestic supply chains for critical minerals, including lithium, a priority. A recent study shows that the U.S. may already have all of its lithium needs and more if companies can develop new technologies to tap into that need.
Enough to provide nine times the amount of key material needed worldwide
“Lithium is a critical mineral for the energy transition, and the potential for increased U.S. production to replace imports has implications for employment, production and supply chain resilience,” USGS Director David Applegate said in a press release yesterday.
Lithium laces the salty brine from the Smackover Formation, a geological formation of permeable limestone that extends across parts of Arkansas, Louisiana, Texas, Alabama, Mississippi and Florida. The formation is the result of an ancient sea and is also a historic site for oil and gas production.
Until recently, this lithium-rich brine was considered wastewater from oil and operations. Now companies are trying to develop technologies to extract the lithium in a cost-effective way.
ExxonMobil is reportedly ready to pounce. The company plans to begin production in 2027 and has already drilled exploratory wells in Arkansas. The New York Times Reports. The fossil fuel giant last year declared its ambitions to become a “leading” lithium supplier for electric vehicles after acquiring drilling rights to 120,000 acres of land in the Smackover Formation in Arkansas.
“We know we have an attractive resource. We are working to understand this cost equation and understand the supply and demand picture,” said Dan Ammann, president of ExxonMobil’s Low Carbon Solutions business The New York Times.
The company can use traditional oil and gas drilling techniques to reach lithium-rich saltwater trapped at depths of 10,000 feet. However, a new technology called direct lithium extraction (DLE) needs to be developed to separate lithium from water using chemical solvents or filters.
This is said to be a much faster method of extracting lithium than the traditional method of leaving the brine in ponds until the water evaporates. Another potential advantage of DLE is that it would be less energy intensive than traditional hard rock mining for lithium. Of course, there are still concerns about the environmental impact of all these methods, from the amount of land and water they use to what to do with the toxic waste left behind.
Shifting lithium production to the USA would also be a global game changer. Most lithium today comes from Australia and South America. Just 5 percent of global demand was met by US lithium producers in 2021. There is also a lot of lithium-rich brine in California's Salton Sea.
Arkansas' potential still depends on whether lithium reserves can be commercially produced, the USGS says. The agency used machine learning to work with the Arkansas Department of Energy and Environment's Office of the State Geologist to produce the first estimate of the amount of lithium available in brine from the Smackover Formation in southern Arkansas. They analyzed new brine samples in a laboratory and compared them with data from historical water samples from oil and gas production from the USGS produced waters database. A machine learning model used this data to predict lithium concentrations across the region.
“We have not estimated what is technically recoverable using newer methods of extracting lithium from brines,” Katherine Knierim, hydrologist and principal investigator of the study, said in the press release.