There is a tremendous demand for lithium, and although it is a plentiful resource, access and extraction is still challenging. New research, published in Proceedings of the National Academies of Sciences, may simplify the process of extracting lithium from aqueous brines. If successful, it will create a much larger supply and reduce costs of the element for batteries to power electric vehicles, electronics and a wide range of devices.
Lithium is commonly sourced from salt brines in South America via solar evaporation, a costly process that can take years and loses much of the resource along the way.
The research team from The University of Texas at Austin and University of California, Santa Barbara, designed membranes for precise separation of lithium over other ions, improving the efficiency of gathering it.
Wastewater generated in oil and gas production also contains lithium but remains untapped. One week’s worth of water from hydraulic fracturing in Texas’ Eagle Ford Shale, for example, could produce enough lithium for 300 electric vehicle batteries or 1.7 million smartphones, according to the researchers.
Central to the discovery is a novel polymer membrane the researchers created using crown ethers, which had not previously been applied or studied as integral parts of water treatment membranes. However, they can target specific molecules in water — a key ingredient for lithium extraction.
With most polymers, sodium travels through membranes faster than lithium. In these new materials, lithium travels faster than sodium, which is a common contaminant in lithium-containing brines. Researchers discovered that sodium ions bind with the crown ethers, slowing them down, while lithium ions remain unbound, enabling them to move more quickly through the polymer.
Original Release: Eureka Alert