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it home reported on august 29 that lithium batteries are widely used in electric vehicles and various electronic devices, but the production process of lithium has a serious impact on the environment, which makes lithium batteries not really "green". scientists at stanford university have developed a new lithium extraction method that is more efficient, half the price, and more environmentally friendly than traditional methods.

image source: tesla

this research is of great significance. with the popularity of electric vehicles and renewable energy storage systems, the demand for lithium will increase significantly in the future, and traditional lithium extraction methods require a lot of resources, including energy, land and water. currently, it takes about 500,000 liters of water to extract one ton of lithium. in addition, traditional methods require deep mining in the earth's crust, and this precious resource is concentrated in a few places, such as chile and bolivia.

according to it home, the vast majority of lithium currently comes from hard rock mining in salt lake areas, such as the atacama salt flats in chile. it takes about 18 months to extract lithium from these sources because the mineral-rich brine needs to be mined and extracted first and pumped into evaporation ponds covering an area of ​​26 square kilometers. solar radiation evaporates the brine, which is constantly pumped from one pool to another, with increasing concentrations, and then the brine is collected and refined into lithium. the lithium recovery rate of traditional methods is typically 40%.

the research team led by yi cui, a professor of materials science and engineering at the stanford university school of engineering, has developed a method called "redox galvanic electrodialysis" (rce). its working principle is to use electricity to pass through a solid electrolyte membrane to transfer lithium from water with a lower metal concentration to a solution with a higher concentration. through a series of units, the lithium concentration is gradually increased until the metal is easily separated.

the rce approach has many advantages:

only one-tenth of the electricity required by traditional extraction methods.

the lithium selectivity is close to 100% and the efficiency is extremely high.

it typically costs about $9,100 to extract a ton of lithium from brine, while the rce method costs about $3,500-4,400.

the method does not require large evaporation ponds, could significantly reduce the environmental impact of lithium extraction and expand the global source of available lithium brines.

salt water in the united states, canada, and europe is more difficult to treat because it contains a lot of toxic materials and has a higher boiling point, but the rce method can make it economically viable in these areas.

efficient direct lithium extraction (dle) methods have been studied since the 1970s, and some have been commercialized. cnbc notes that 7% of lithium comes from relatively sustainable dle methods. the stanford team's rce method appears to be the most promising, with nearly 100% efficiency, lower electricity requirements, and lower operating costs.

what remains to be seen is how the rce process can be scaled up to meet demand, how it can be optimized for rapid and safe extraction, and whether it can be applied to seawater containing lithium salts. given that demand for lithium is expected to increase in the coming years, this new technology has the potential to help meet our growing need for lithium.

the team's research results were published in the journal matter.