Extracting lithium from brines, such as those in the lithium triangle of South America, at the tri-border intersection of Argentina, Bolivia, and Chile, can be like "looking for a needle in a haystack."
Thus, Sibani Lisa Biswal, professor of chemical and biomolecular engineering at Rice University in the American city of Houston, describes for the BBC in Serbian the current process of processing the precious metal for humanity's transition to renewable energy sources.
"The concentration of lithium in these solutions is very low, generally less than 0,01 percent, which is far less than other ions like magnesium, potassium, calcium or sodium in these solutions," he explains.
That's why, in 2021, she and a team of researchers began working on inventing an innovative electrochemical reactor.
Study results published in November in the Proceedings of the National Academy of Sciences of the United States of America could be a "game-changer" in lithium mining, says Biswal.
A reactor is a device or facility in which an electrochemical reaction occurs, in this case the decomposition of metals under the influence of electricity.
Unlike conventional two-chamber reactors, the Houston scientists designed a three-chamber system with a ceramic membrane that almost exclusively lets lithium ions through, while retaining others.
"Such a system allows us to retain and separate lithium from other ions."
"But also to prevent lithium from coming into contact with reactions with other ions, which is often harmful to the end product," says the American scientist who led the research group.
- New rebellion against lithium in Serbia
- Dossier South America: An Introduction to the Lithium Triangle
- Lithium mine in Serbia is not among EU's 'strategic projects', Vučić announces it will be soon
Although lithium is one of the most important metals in the world's efforts to transition to a greener economy - due to its applications in battery production and the automotive industry - its exploitation, paradoxically, can be harmful to the environment.
This is the reason why dozens of protests have been organized across Serbia in recent years, and there have also been demonstrations in Bosnia and Herzegovina, Portugal, and South American countries.
Everything you need to know about lithium - watch the video from our YouTube channel
https://www.youtube.com/watch?v=NtGPCivX8-E
Another team of scientists at Rice University has been working on the invention for months. "faster and greener" methods for recycling lithium-ion batteries, which are used, among other things, to power electric cars or operate smartphones.
Instead of acids, which can harm the environment, they use organic solutions.
Instead of the usual heating of the solution at high temperatures, the scientists use the principle of a microwave oven, says Sohini Bhattacharya, a member of the team, for BBC Serbian.
"We quickly realized that the lithium extraction ability is also extremely good - in just 30 seconds we can extract about 50 percent of the lithium from discarded batteries, in 15 minutes that percentage goes up to 87 percent, and in half an hour to 100 percent," explains the researcher in postdoctoral studies at Rice University.
This is a significant improvement over previous methods, which save less than five percent of lithium through recycling, mostly due to contamination of the metal during the process, according to the Rice University website.
'Milestone' in lithium production
In the previous practice of extracting lithium from salt solutions, electrochemical reactors with two chambers were used, which did not prove to be sufficiently efficient.
This got scientists at the University of Houston thinking.
"They had side reactions going on, such as chloride reactions, which can produce very harmful gases and harm the end product, in this case lithium."
"In addition, the selectivity, or efficiency, in separating lithium has been quite low so far," explains Haotan Wang, one of the researchers, to BBC Serbian.
They came up with the idea of adding another chamber to the device, to physically separate these chemical reactions from the lithium compounds they wanted to obtain.
"The solution is passed through the middle chamber, while electrolysis (decomposition under the influence of electric current) takes place in the other two."
"In that case, there are no byproducts and the chloride reactions do not come into contact with lithium," Wang adds.
A team of about a dozen Rice University researchers faced a new task - they had to devise a way to isolate only lithium in the middle chamber.
They found the solution in a ceramic membrane, which allows lithium to pass through and other ions to be retained with great efficiency, explains Sibani's Lisa Biswal.
"The most exciting moment of the research was when one of our researchers tested the ceramic membrane, because up until that point we were not sure how we would achieve high selectivity."
"Once we overcame that challenge, we realized the method would work," the scientist explains.
- Rio Tinto in Serbia: "I would support the same project in my country," the German state secretary told the BBC
- At least three lithium projects developed in Germany, geologist says
- Ruling coalition in Serbia rejects opposition proposal to ban lithium mining
Recycling microwave batteries
Used lithium-ion batteries and their recycling still cause headaches for scientists, who are searching for a sufficiently efficient, cost-effective and environmentally friendly way to carry out this process.
Andrew Abbott previously spoke about this for the BBC., Professor of Physical Chemistry at the University of Leicester.
To avoid the use of aggressive acids, scientists from Houston decided to use so-called deep eutectic solution (DES), with low melting points, which is "completely organic," says Sohini Bhattacharya.
"When we started our research, we realized that metals decompose much more slowly in such solutions than in acids, and it took a lot of work to make improvements in efficiency," explains Bhattacharya.
Then they figured out that in the same way they quickly heat food, they could raise the temperature of the solution.
The solution was a microwave oven.
"We wondered what would happen if we microwaved the solution, but at that point we weren't aware that it would improve the selectivity for lithium, we just wanted to speed up the process," says Bhattacharya.
Reducing the process time could go some way to solving the bottleneck problem in the production of lithium-ion batteries.
"When batteries are recycled with acids, the process takes three hours and in the end you get mixed lithium, cobalt, nickel and other metals."
"If we use a deep eutectic solvent, in three to six hours we will get a product with about 80 percent lithium, but the remaining 20 percent will be cobalt and nickel," explains Salma Alhashim, a doctoral student at Rice University.
"When we apply the microwave method to that, in five minutes we get 85 percent of the lithium, and less than five percent of the nickel and cobalt," he adds.
How do new methods protect the environment?
Salma Alhashim believes that an innovative method of battery recycling could reduce negative environmental impacts on multiple levels.
"When you use green solutions, you don't do any damage like the harsh acids that are used now."
"It also reduces the energy used to heat solvents to high temperatures during recycling."
"Now, with a small amount of energy input, we can achieve that warming in the short term, which is great for the environment," explains the Rice University doctoral student.
- Lithium mining in Serbia: "An opportunity not to be missed", agree Vučić and Šolc
- Everything you need to know about pine, a companion of lithium in the Jadra Valley
- Artificial intelligence finds new substance - a replacement for lithium
How can science get out of the laboratory?
In addition to environmental benefits, the innovative recycling method could also bring economic benefits to companies and countries, Alhashim adds.
"By recycling lithium-ion batteries in this way, we could consequently reduce the costs of lithium mining, because we would obtain lithium in this faster, more efficient and sustainable way."
"Recycling would ultimately reduce the final price of the lithium battery," the researcher emphasizes.
Global lithium production increased almost tenfold between 2010 and 2024, reaching 240.000 tonnes, data from the German statistical agency Statista.
"Many countries do not have deposits of lithium, cobalt and nickel, which are used to produce batteries, but are located in specific areas of the planet, which is why we often have problems in the supply chain," says Sohini Bhattacharya.
But after years of using electric vehicles and other technology, many countries have large stocks of discarded batteries, he adds.
"If we can recycle them quickly and efficiently, and without harming the environment, it will also be economically significant," Bhattacharya believes.
Laboratory research that proved the functionality of their method has been completed and the results have been published in scientific journal Advanced Functional Materials last year.
There is already interest "from across industries" to take the innovative recycling method out of the lab and into manufacturing plants, says Bhattacharya.
"If someone decides to implement it, we will need to conduct additional, different research and see what happens," he adds.
There is also interest in the industry for another invention by Rice University scientists.
"We have been contacted by companies from the energy sector and various startups, who are willing to test the readiness of our technology for commercial use," says Sibani's Lisa Biswal.
While they await feedback from the industry, they expect to continue developing the technology for "at least another two or three years," adds Haotian Wang.
"We have a long way to go, but I believe in our method and look forward to its potential use in industry," Wang concludes.
- The most important question about lithium and batteries that we don't have an answer to
- Lithium in the spotlight: China develops huge deposit in Bolivia
- Battle for lithium: China and America squabble over South American wealth
BBC is in Serbian from now on and on YouTube, follow us HERE.
Follow us on Facebook, Twitter, Instagram, YouTube i Viber. If you have a topic suggestion for us, please contact bbcnasrpskom@bbc.co.uk
Bonus video:
