Thursday, June 03, 2021

How to produce lithium, responsibly

As the boom in electric cars, and all things clean- and high-tech, continues apace, the issue of green lithium has come to centre stage. 

Lithium is, for now at least, an essential ingredient in battery technology (along with nickel, cadmium and graphite), whether that be for cellphones, vehicles or mass power storage, and it is considered an essential part of our short-term green future. Traditional methods of lithium mining, though, are fraught with environmental problems. 

Traditional lithium production involves hard-rock mining, breaking it down with acids and then baking it, all of which uses large quantities of both water and energy, and leaves behind a decimated landscape and large piles of tailings, tainted with many other much less desirable minerals.

In some places, lithium is naturally found in subterranean brine or geothermal pools, already naturally separated from the bedrock. But it still needs to be kept in huge evaporation ponds for many months, using vast quantities of fresh water, and then subjected to the usual high-temperature isolation processes.

But it doesn't have to be that way. Canadian start-up Summit Nanotech is starting to extract lithium in Chile (with later plans for Canadian production) using a much more environmentally-friendly brine-based extraction process (go to minute 18:20 in the audio) compressing the raw materials down to a much smaller volume using very selective chemical sponges or "sorbents". This way, the lithium is isolated without the need for large amounts of water and land, or noxious gas emissions. On top of that, this new method is apparently much cheaper, and at least doubles the yield compared to traditional brine production. What's not to like?

Quebec company Lithion Recycling goes about the problem in a different way, by recycling lithium from old batteries (go to minute 24:40 in the audio). Lithium is now so valuable that it is already quite economical to recycle batteries to extract their lithium, and then re-use it in new batteries, a process that can apparently be repeated again and again (in theory, when there are enough batteries in production, this method could be applied to substantially cut down on the amount of new lithium that needs to be extracted from the ground). Using hydrometallurgy, Lithion's process can recover 95% of lithium-ion battery components and generate high-purity ingredients for new battery production, closing, as they say, the loop of battery life-cycle.

I'm sure these are just two (Canadian) examples among many of the kind of industrial innovation that the clean-tech industry will need in the years ahead. Kind of makes me feel good.

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