A team led by researchers from West Virginia University studied 15 middle-Devonian sedimentary rock samples from the Appalachian basin in the US and found plenty of lithium in pyrite minerals in shale.

“This is unheard of,” Shailee Bhattacharya, a sedimentary geochemist who is presenting these findings during the European Geosciences Union (EGU) General Assembly 2024 in Vienna, said in a media statement.

Though the geologic literature lacked information on the intersection between lithium and sulphur-rich pyrite, the electrochemical and engineering world has already begun to look at how lithium-sulphur batteries could replace lithium-ion ones.

“I am trying to understand how lithium and pyrite could be associated with one another,” Bhattacharya said.

As it turns out, organic-rich shale may show potential for higher lithium recovery as a result of a curious interaction between lithium and pyrite.

The researchers made this discovery in their quest to explore whether previous industrial operations, like mine tailings or drill cuttings, could serve as a source of additional lithium without generating new waste materials.

Even though they are aware that primary sources for lithium like pegmatites and volcanic clays are well understood and exploited to a certain extent, they believe that finding other stores that are safe and economical to develop would be helpful.

They do caution that, at the moment, the observations in their research can’t be extrapolated beyond the samples from the current study site.

“This is a well-specific study,” Bhattacharya said. Yet, she is convinced that this work is promising because it hints at the possibility that certain shales could be a lithium source that doesn’t require new mines.

“We can talk about sustainable energy without using a lot of energy resources,” the scientist noted.