Can a Huge Arkansas Lithium Deposit Be a Game Changer?

A significant new source of lithium has been discovered in Arkansas, potentially altering the burgeoning battery supply chain over the next 15 years.

According to a new study from the U.S. Geological Survey (USGS), there are between 5 million and 19 million tons of lithium in southwestern Arkansas. Researchers used a combination of water testing and machine learning to locate the deposits. Before automakers or battery makers get too excited, it remains to be seen if extracting the earth metal will be cost-effective.

The amount of lithium could potentially supply EV production in the U.S. at least out to 2040.

These lithium reserves are present in brines located in a geological location known as the Smackover Formation, the USGS says. The brines are high-salinity waters associated with deep salt deposits that can be traced back millions of years.

We estimate there is enough dissolved lithium present in that region to replace U.S. imports of lithium and more,” said Katherine Knierim, a hydrologist and the study’s principal researcher. “It is important to caution that these estimates are an in-place assessment. We have not estimated what is technically recoverable based on newer methods to extract lithium from brines.”

ExxonMobil is reportedly already working on tapping the massive lithium deposits buried 10,000 feet (3 km) under Arkansas. The energy giant purchased drilling rights across 120,000 acres (48,560 ha) within the Smackover Formation.

The lithium used in battery-electric vehicles sold in the U.S. primarily comes from overseas sources. Most of the supply is currently imported from countries such as Australia, Chile and Argentina, which are part of the “Lithium Triangle” and major producers of lithium. Australian hard-rock lithium and Chilean brine deposits are especially dominant in global exports.

Although some lithium is mined domestically – like at the Silver Peak mine in Nevada – the U.S. remains heavily reliant on foreign imports. Even after mining, much of the refining and battery production is concentrated in China, which controls about 72% of global lithium refining capacity. This makes China a critical supplier, despite efforts by automakers and governments to diversify supply chains.

Silver Peak is currently the only active lithium-producing mine in the U.S. It extracts lithium from underground brine pools, which are pumped to the surface and evaporated to concentrate the lithium. This mine has been in operation since the 1960s. Production from Kings Mountain, NC, is also under development.

Producing 30 million BEVs annually would require a substantial amount of lithium. On average, each EV battery needs about 8 kg (17.6 lbs.) of lithium. This means manufacturing 30 million vehicles would demand approximately 240,000 metric tons of lithium annually, according to McKinsey.

Given that lithium supply chains are currently under pressure, meeting this level of demand poses significant challenges. The global lithium supply in 2020 was about 82,000 metric tons, highlighting the need for substantial scaling of mining and refining operations to meet future demand. Industry forecasts suggest that lithium demand will exceed 2 million tons by 2030, driven by both BEVs and other energy storage applications.