Princeton researchers have a theory that strings can be used as part of an efficient system to gather lithium, the hard-to-harvest material vital to powering most of our electronics.
Much research worldwide is focused on finding an alternative to the expensive battery component. This idea offers a solution that could make lithium — a proven power storer — easier and cheaper to supply.
If successful, the innovation could help to drive down the costs of electric vehicles and other technology.
“Our approach is cheap, easy to operate, and requires very little energy. It’s an environmentally friendly solution to a critical energy challenge,” Princeton professor and team lead Z. Jason Ren said in a university report.
It all starts with porous fibers that are spun into strings.
The experts laced the blue ropes, which resemble boot laces in size, with a “water-loving core and a water-repelling surface,” according to a Princeton report on the research. When dipped in briney water, the liquid moves up the rope. The hanging strings look sort of like wicks in an old-fashioned candle factory as the salts begin to gather.
When the water evaporates, sodium and lithium ions are left behind, forming crystals on the strings. Better yet, the lithium consistently crystalizes high on the string, away from the sodium crystals. This makes harvesting the lithium much easier, per Princeton.
It’s a powerful use of basic evaporation.
“We do not need to apply additional chemicals, as is the case with many other extraction technologies, and the process saves a lot of water,” Ren said in the tech report.
Euronews notes that it takes 2.2 million liters (about 581,000 gallons) of water to make a ton of lithium using common evaporation methods. The process can contaminate the land, air, and water, according to the report.
The Princeton string breakthrough could be used at existing lithium mines, in addition to opening up new sources, with clear benefits.
The researchers claim that the string approach could use 90% less land, producing lithium harvests within a month, which is up to 20 times faster. The strings could also be used at brine pits unsuitable for conventional lithium extraction, including old oil and gas wells. More research is being completed to see if the approach can gather lithium from seawater, all per Princeton.
There’s still some work to complete to take the concept from the lab to the industrial brine pits, but the team is optimistic that the low-cost string tech can be leveraged for great impact. To demonstrate the innovation, the researchers made an array of 100 strings that gathered lithium.
“We are very excited about this one … we think it has incredible potential to make a real impact on the world,” study co-author Sunxiang (Sean) Zheng said in the Princeton report.
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