Lithium remains one of the world's most sought-after metals, especially as companies like Tesla continue to snatch up as much of the substance as possible. Researchers around the world are struggling to develop alternative ways to mine lithium safely and also keep up with the rising demand.
Desalinating seawater, however, would serve the dual purpose of both creating drinkable water and providing lithium, according to new research. From the outside it seems a convenient, and harmless, way of taking advantage of the full potential of desalinated water, given that lithium salts are a naturally occurring byproduct that could be produced through the process of obtaining drinking water.
One of the technologies that could offer support in both areas involves the use of metal-organic framework (MOF) membranes, touted as a greener and more energy efficient method, given the extremely high surface areas of the crystalline materials. They would offer an improved, and more selective, method of water filtration than the commonly used reverse osmosis membrane, which requires additional pumping to remove contaminants that the relatively porous membranes are not able to catch.
A team of researchers from Monash University in Australia, the Commonwealth Scientific and Industrial Research Organization (CSIRO), and the University of Texas at Austin have come up with the first membrane of its kind. Details about the membrane were shared in the study, titled "Ultrafast selective transport of alkali metal ions in metal organic frameworks with subnanometer pores," which was published in Science Advances on February 18th.
"We can use our findings to address the challenges of water desalination," says Huanting Wang, an author of the new study. "Instead of relying on the current costly and energy intensive processes, this research opens up the potential for removing salt ions from water in a far more energy efficient and environmentally sustainable way."
The membrane represents a true win-win, offering a more selective as well as energy-saving alternative.
Study author Huanting Wang, Department of Chemical Engineering Professor and Associate Dean (International) of the Faculty of Engineering at Monash University in Australia, made it very clear that their work should have an immediate impact in terms of the way that we look at maintaining lithium supplies:
“Lithium ions are abundant in seawater, so this has implications for the mining industry who currently use inefficient chemical treatments to extract lithium from rocks and brines," says Wang. "Global demand for lithium required for electronics and batteries is very high. These membranes offer the potential for a very effective way to extract lithium ions from seawater, a plentiful and easily accessible resource.”
It seems rather ironic that a process for providing life’s most essential basic necessity, drinkable water, is being considered among a process for mining what is arguably one of the world’s most basic raw materials necessities, the only difference of course being that in the case of lithium, in many cases its necessity has been cultivated and reinforced (How many among us can imagine an electronic product advertisement completely free of the mention of the word lithium).
Still, the debate about global lithium levels aside, the potential for the MOF membrane, if its use is carefully monitored and reported with transparency, can offer transformative benefits that could affect thousands worldwide.