The device you are reading this on probably uses a lithium-based battery. So does the iPhone 15 series that launched yesterday. So do all modern batteries, including the ones found in electric vehicles. For something that is to a clean future, Lithium production is an extremely resource-intensive and time-consuming process. Princeton engineers have developed a new string-based technology that could change that.
A large majority of the lithium produced in the world is extracted from “brine reservoirs” located in salt flats. This method of production can require hundreds of square kilometres, and it often takes months or even years to produce lithium that can be used in batteries.
The total demand for lithium was 500,000 metric tons of lithium carbonate equivalent in 2021 and it is expected to grow to between two to three million tons in 2030, according to McKinsey. In 2015, not all that long ago, less than 30 per cent of the demand was for batteries, with the rest split between ceramics and glasses, greases, metallurgical powders, polymers and other uses. By 2030, batteries will account for 95 per cent of the demand, growing with the penetration of electric vehicles and energy storage devices.
In addition to concentrating the salts, the technique causes lithium and sodium to crystallize at distinct locations along the string due to their different physical properties. Sodium, with low solubility, crystallizes on the lower part of the string, while the highly soluble lithium salts crystallize near the top. The natural separation allowed the team to collect lithium and sodium individually, a feat that typically requires the use of additional chemicals.
The string technique is far more compact and can begin producing lithium much more quickly. Although the researchers caution that it will take additional work to scale their technology from the lab to an industrial scale, they estimate it can cut the amount of land needed by more than 90% compared to current operations and can accelerate the evaporation process by more than 20 times compared to traditional evaporation ponds, potentially yielding initial lithium harvests in less than one month.
Compact, low-cost, rapid operations could expand access to include new sources of lithium, such as disused oil and gas wells and geothermal brines, that are currently too small or too dilute for lithium extraction. The researchers said the accelerated evaporation rate could also allow for operation in more humid climates. They are even investigating whether the technology would allow for lithium extraction from seawater.