New lithium extraction method promises cleaner energy output

The study published in the journal Nature Water reveals an elegant and straightforward technique. They've developed porous fibers twisted into strings with a water-attracting core and a water-repelling surface. The technology mimics nature, employing capillary action—similar to how trees draw water from their roots to their leaves.

Lithium is an important component of #EV batteries, but it also takes a vast amount of land and time to extract lithium from briny water. Now, Princeton researchers have developed a workaround: https://t.co/dLxZ9NxDa1

— Princeton Engineering (@EPrinceton) September 8, 2023

When these strings are submerged in saltwater, the water ascends and then evaporates, leaving behind concentrated salts like sodium and lithium. As the water evaporates, these salts crystallize on the string, making them easy to harvest.

Significantly, the method separates lithium and sodium naturally, eliminating the need for additional chemicals. "We aimed to utilize evaporation and capillary action to concentrate, separate, and harvest lithium. Our approach is cheap, easy to operate, and environmentally friendly," said Z. Jason Ren, the study's leader and professor at Princeton.

Tackling a resource crunch

The scarcity of lithium has been a stumbling block in the clean energy transition. However, this innovative technique could make lithium production accessible and efficient, overcoming the limitations of the present extraction methods.

In traditional methods, huge evaporation ponds concentrate lithium from salt flats, requiring several months or even years to yield usable lithium. But this string technique drastically trims down the production timeline and land requirements. "Our process is like putting an evaporation pond on a string," said Sunxiang (Sean) Zheng, the study's coauthor.

Scalability and future prospects

While the researchers warn that scaling from lab to industrial levels requires additional work, the potential is staggering. They anticipate a land reduction of more than 90% and an acceleration of the evaporation process by over 20 times compared to traditional methods. This method could yield initial lithium yields in under a month and open new avenues for lithium sources, including disused oil wells and geothermal brines.

Researchers are even exploring the possibility of extracting lithium from seawater, potentially a game-changer for lithium accessibility globally.

The research has already started making waves in the business world. Zheng is spearheading a startup, PureLi Inc., aiming to refine and commercialize this groundbreaking technology. Meanwhile, the Princeton team has also collaborated with the University of Maryland to optimize material efficiency.

This breakthrough could be a critical turning point as the race to renewable energy grows. It's not just about lithium or batteries; it's about making clean energy a viable, sustainable option. In a world of climate change and limited natural resources, such innovations might be the catalyst we've been waiting for.

The study was published in the journal Nature Water

Study Abstract

Limited lithium supply is hindering the global transformation towards electrification and decarbonization. Current lithium mining can be energy, chemical and land intensive. Here we present an efficient and self-concentrating crystallization method for the selective extraction of lithium from both brine and seawater. The sequential and separable crystallization of cation species with different concentrations and solubilities was enabled by a twisted and slender 3D porous natural cellulose fibre structure via capillary and evaporative flows. The process exhibited an evaporation rate as high as 9.8 kg m−2 h−1, and it selectively concentrated lithium by orders of magnitude. The composition and spatial distribution of crystals were characterized, and a transport model deciphered the ion re-distribution process in situ. We also demonstrated system scalability via a 100-crystallizer array.