Stanford’s new method makes lithium extraction 40% cheaper, sustainable

Surging lithium demand across the globe

The transition towards renewable energy has resulted in a growing demand for lithium around the globe. The demand for lithium is going to reach 3−4 million metric tons by 2030, according to a report by McKinsey & Co.

To cater to this rising demand, there will be a need for more mining and to tap in more into the terrestrial resources. The metal is mined through salt-lake brines and high-grade ores via evaporation and chemical precipitation techniques.

The traditional extraction methods pose various challenges, such as their adaptability being limited due to the sensitivity of the geological structures of deposits and their dependence on specific climatic and weather conditions.

These challenges further drive up the extraction costs and also make the final product expensive.

Due to this, the direct lithium extraction techniques are gaining popularity for their environmental compatibility, efficiency, and more reasons. The prime contenders among these are those which are based on electrochemical processes such as ion pumping, electrodialysis, and electrolysis.

New technique proposed by Stanford University researchers

The new technique proposed by the Standford University researchers is a redox-couple electrodialysis (RCE) approach to realize sustainable Li extraction from salt-lake and oil-extraction brines.

It uses the same half-redox reaction which is the base of electrodialysis but it works in the opposite direction: hydrogen evolution reaction (HER) and the hydrogen oxidation reaction (HOR).

The method employs the use of a lithium-ion selective SSE membrane which ensures that only lithium ions can transport through the membrane from the brine to the receiving solution, according to the study.

It uses electricity to move lithium through a solid-state electrolyte membrane from water with a low lithium concentration to a more concentrated, high-purity solution.

“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 and a professor of materials science and engineering in the School of Engineering.

According to an article by Stanford Report, the research team estimates its approach costs $3,500 to $4,400 per ton of high-purity lithium hydroxide, which can be converted to battery-grade lithium carbonate inexpensively.

This is a huge cut when compared with costs of about $9,100 per ton for the dominant technology currently used for extracting lithium from brine. 

According to the researchers, this new approach uses less than 10% of the electricity required by current brine extraction technology and has a lithium selectivity of almost 100%, making it very efficient.

“The advantages displayed by our approach over conventional lithium extraction techniques enhance its feasibility in eco-friendly and cost-effective lithium production,” said co-lead author of the study, Rong Xu, a former postdoctoral researcher in Cui’s lab.