Lithium Production Revolution: New ‘string’ technology for extracting lithium

Researchers have developed an innovative lithium extraction technique, to revolutionize lithium production, reducing time and land requirements, and meeting growing battery demand.

How is lithium production changing and why?

• 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.
• It is expected to grow to between two to three million tons in 2030, according to McKinsey.
• In 2015, 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.

Innovative Technique for Efficient Lithium Production

• Researchers have developed a technique that can drastically reduce the amount of land and time needed for production.
• This can improve production at existing lithium factories in the world while also unlocking sources that may have been too small or diluted to have been worthwhile in the past.
• Researchers used a set of porous fibres twisted into strings and engineered them to have a water-loving (hydrophilic) core and water-repelling surface.
• When one end is dipped in a salt-water solution, the water travels up the string because of capillary action.
• This is the same process used by trees to raise water from roots to leaves.
• Then, the water evaporates quickly from the string’s surface. This leaves behind salt ions such as sodium and lithium.
• The water will continue to evaporate like this as the salts become increasingly concentrated, eventually forming sodium chloride and lithium chloride crystals.
• This can be harvested relatively easily.

How the strings can fit into conventional lithium production methods?

• The strings themselves are not very hard to make.
• The raw strings were treated with chemicals to make them more hydrophilic inside and hydrophobic outside.
• Conventional methods of extraction rely on a series of massive evaporation ponds that concentrate lithium from saltwater reservoirs, and salt flats of underground aquifers.
• This means that operations are only commercially viable in a few locations around the world that meet some important criteria:
  • High starting lithium concentration,
  • Abundance of cheaply available land, and
  • Hot and dry climate to maximise evaporation.
• The new technique can remove some of these prerequisites by essentially “putting the pond on a string.”
• It can cut the amount of land required by 90 per cent while accelerating the evaporation technique by more than 20 times.
• This could mean that initial lithium harvest can happen in less than one month, compared to the months and even years it takes now.

Can this technology revolutionize lithium extraction methods?

• It will also allow us to look into new areas to extract lithium from.
  • For example, defunct oil and gas wells and geothermal brines that are currently considered too small or too diluted for lithium extraction could become viable sources.
• It might even open the doors to try extraction in humid climates.
• But the technology has currently only worked on a laboratory scale and the researchers are working on making it commercially viable.
• They are also investigating if it can be used to extract lithium from seawater.

Ref: Source