CRITICAL MINERALSA More Efficient Way to Extract Lithium from Mining Sites, Oil Fields, Used Batteries
Lithium is a lightweight metal commonly used in energy-dense and rechargeable batteries. Electric vehicles, which are needed to achieve net-zero emissions by 2050, rely on lithium-ion batteries. Chemists have invented a more efficient way to extract lithium from waste liquids leached from mining sites, oil fields and used batteries.
Chemists at the Department of Energy’s Oak Ridge National Laboratory have invented a more efficient way to extract lithium from waste liquids leached from mining sites, oil fields and used batteries. They demonstrated that a common mineral can adsorb at least five times more lithium than can be collected using previously developed adsorbent materials.
“It’s a low-cost high-lithium-uptake process,” said Parans Paranthaman, an ORNL Corporate Fellow and National Academy of Inventors Fellow with 58 issued patents. He led the proof-of concept experiment with Jayanthi Kumar, an ORNL materials chemist with expertise in the design, synthesis and characterization of layered materials.
“The key advantage is that it works in a wider pH range of 5 to 11 compared to other direct lithium extraction methods,” Paranthaman said. The acid-free extraction process takes place at 140 degrees Celsius, compared to traditional methods that roast mined minerals at 250 degrees Celsius with acid or 800 to 1000 degrees Celsius without acid.
The team has applied for a patent for the invention.
Lithium is a lightweight metal commonly used in energy-dense and rechargeable batteries. Electric vehicles, which are needed to achieve net-zero emissions by 2050, rely on lithium-ion batteries. Industrially, lithium is extracted from brines, rocks and clays. The ORNL innovation may help meet rising demand for lithium by making domestic sources commercially viable.
The research reveals a route away from the status quo: a linear economy in which materials from mining, refining or recycling are made into products that, at the end of their lives, are discarded as waste. The work moves toward a circular economy in which materials are kept in circulation as long as possible to reduce consumption of virgin resources and generation of waste.
The ORNL invention relies on aluminum hydroxide, a mineral that is abundant in Earth’s crust. The scientists used aluminum hydroxide as a sorbent, which is a material that takes up another material — in this case, lithium sulfate — and holds it.
In a process called lithiation, an aluminum hydroxide powder extracts lithium ions from a solvent to form a stable layered double hydroxide, or LDH, phase. Then in delithiation, treatment with hot water causes the LDH to relinquish lithium ions and regenerate the sorbent. During relithiation, the sorbent is reused to extract more lithium. “This is the basis for a circular economy,” Paranthaman said.
