Argonne and University of Chicago researchers have developed a new membrane technology that efficiently extracts lithium from water, offering a potential domestic solution as demand for lithium continues to rise in support of electric vehicles (EVs), electronics, and defense systems.
Lithium is abundant in seawater and underground saltwater reservoirs, but extracting it from these sources has traditionally been costly and inefficient. Most lithium today is sourced from a few countries through hard-rock mining and evaporation ponds, leaving supply chains vulnerable to disruption.
To address this, researchers at Argonne National Laboratory and the University of Chicago’s Pritzker School of Molecular Engineering created a membrane made from vermiculite, a low-cost, naturally occurring clay.
By separating the clay into atomically thin layers and reinforcing them with aluminum oxide pillars, the team stabilized the material in water and tailored its electrochemical properties.
The membrane’s positively charged surface repels highly charged ions, such as magnesium, while allowing lithium ions to pass. Additional sodium ions were used to fine-tune the membrane’s pore size, improving selectivity by filtering based on\ ion size and charge.
Because the membrane is made from low-cost materials and is scalable, it offers a potentially viable method for lithium extraction from previously untapped domestic sources like geothermal brines and oilfield wastewater. These resources are abundant in the US but under-used due to technical barriers. This could strengthen national supply chains while reducing environmental impacts compared to conventional mining.
This approach could open new sources of lithium from brines and seawater, reducing dependence on foreign supply. It may also be adapted to recover other critical minerals or remove contaminants from water supplies.
This research was funded by AMEWS, an Energy Frontier Research Center funded by the DOE Office of Basic Energy Sciences. The findings first appeared in the journal Advanced Materials.
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