South SFV Today

A new technology has been developed to extract lithium from brines at an estimated cost of under 40% of today's dominant extraction method, according to a study published in Matter by Stanford University researchers. The new approach is said to be more reliable and sustainable in its use of water, chemicals, and land.

Global demand for lithium has surged due to the rise of electric vehicles and renewable energy storage. Currently, the dominant method relies on evaporating brines in large ponds under the sun for over a year, followed by heavy use of potentially toxic chemicals. This process is both financially and environmentally costly.

Many scientists are searching for less expensive and more efficient lithium extraction methods. The new study focuses on "redox-couple electrodialysis" (RCE) as a promising alternative. "The benefits to efficiency and cost innate to our approach make it a promising alternative to current extraction techniques and a potential game changer for the lithium supply chain," said Yi Cui, senior author of the study.

The research team estimates their approach costs $3,500 to $4,400 per ton of high-purity lithium hydroxide, compared with about $9,100 per ton for current methods. The market price for battery-grade lithium carbonate is nearly $15,000 per ton but reached $80,000 during a shortage in late 2022.

Demand for lithium is expected to rise significantly by 2030 due to electric vehicles and renewable energy storage systems. Traditional rock mining methods are even more expensive and environmentally damaging than brine extraction.

The RCE method uses electricity to move lithium through a solid-state electrolyte membrane from low-concentration water to a high-purity solution. This process requires less than 10% of the electricity used by current technologies and achieves nearly 100% selectivity.

"The advantages displayed by our approach over conventional lithium extraction techniques enhance its feasibility in eco-friendly and cost-effective lithium production," said Rong Xu, co-lead author of the study.

A techno-economic analysis within the study suggests that RCE's lower capital costs make it relatively inexpensive. It avoids large-scale solar evaporation ponds' extensive land use and water consumption.

The RCE method works with various saline waters, including those with different concentrations of lithium, sodium, and potassium. Experiments showed that this technology could extract lithium from wastewater resulting from oil production or potentially seawater.

"Direct lithium extraction techniques like ours have been in development for a while," said Ge Zhang, co-author of the study. "Our method seems to have none of these drawbacks."

The scalability of RCE also appears promising; experiments scaling up fourfold maintained high energy efficiency and selectivity. However, further research is needed on optimizing device design for faster extraction rates without degrading membranes over time.

"In principle, our method is applicable for seawater as well," Zhang noted despite not demonstrating this in their current study.

Optimism remains high among researchers about moving this technology from laboratory settings to industrial applications soon.

Other contributors include Xin Xiao (now at Zhejiang University), Yusheng Ye, Pu Zhang, Yufei Yang, Sanzeeda Baig Shuchi (all at Stanford), with funding from Stanford’s Precourt Institute for Energy's StorageX Initiative.

For media inquiries:

Mark Golden

Precourt Institute for Energy

(650) 724-1629

mark.golden@stanford.edu

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