As the demand for renewable-energy technologies skyrockets, we need to think about how to source their constituent materials without further damaging the world we’re trying to save, according to yesterday’s Cosmos Briefing.
Rick Valenta, from the Sustainable Minerals Institute at the University of Queensland, and Mahdokht Shaibani, a research fellow at Melbourne’s Monash University, discussed the future of lithium – a key component of batteries. With 55% of the world’s lithium supply currently coming from Australia, they highlight our nation’s responsibility to mine it in a sustainable way.
The session was hosted by the Royal Institution of Australia’s lead scientist, Alan Duffy.
According to Shaibani, lithium metal is the “ultimate choice” for use in a battery, with “the highest theoretical capacity and the lowest electrochemical potential”. This means that it stores a large amount of energy for its weight, and it also can cycle – charge and discharge – several hundred times with a very small degradation in the battery’s capacity.
But there’s surprisingly very little lithium metal itself in any lithium-ion battery – just 2%, as it works more effectively as a composite. Small percentages add up, however, resulting in a huge ongoing effort around the world to source this valuable metal.
So where do we find it?
According to Valenta, although Australia currently supplies a large chunk of the world’s lithium, more than half of the world’s reserves are in the “Lithium Triangle”: Chile, Argentina and Bolivia.
“The total amount of lithium that [Australia has] is about 200 million tonnes – that we know about now,” Valenta adds. “That’s an important distinction, because we’ve hardly started looking for it.”
He points out that the process of lithium mining poses many challenges, from intensive energy use, to potentially contaminating chemicals, to high water usage.
While lithium derived from hard-rock mining has a larger carbon footprint, lithium derived from salt brines – the main source of the large South American reserves – requires a large amount of water for processing, which may have social ramifications for regions already under severe water stress.
“We [in Australia] are better equipped to deal with those sorts of challenges than most other jurisdictions would be,” says Valenta, both in terms of technology and environmental regulations.
Right now, Australia exports its lithium overseas for refining, but there may be great value in bringing more of the battery supply chain onto home soil, as we have all of the 10 mineral elements that are required to make lithium-ion battery electrodes.
“Like any other supply chain, the least value is within mining,” Shaibani says, “and the largest profit is within the final products – so unfortunately, we’re not benefiting that much from this … massive market.”
She suggests we could not only refine lithium here but also manufacture batteries, which would significantly bring down their cost.
“That’s probably when we will be able to see the mass adoption of renewable energies by residentials,” Shaibani says – such as batteries connected to rooftop solar panels.
“The critical thing is that there are a whole range of commodities or elements that you need in order to accomplish the energy transition,” Valenta says. “We’ve really got two ambitious things in front of us: the energy transition and the achievement of sustainable development goals – bringing the other 7 billion or so people closer to the standard [of living] that we enjoy.”
Valenta says that unlike other elements needed for the energy transition, such as cobalt, lithium will not become critically scarce anytime soon.
“We’ve got a lot, so we really have the luxury of being able to choose the sources that have the least environmental social footprint,” he concludes.
The Royal Institution of Australia has an Education resource based on this briefing. You can access it here.