As the demand for renewable-energy technologies skyrockets, so has the global search for their constituent materials, like lithium. Since Australia mines over half the worlds lithium, we have a responsibility to mine it in a sustainable way.
In this resource for Year 8, 9 and 10 Chemistry and Earth and Space students, you’ll learn more about lithium, the environmental challenges associated with mining it, and Australia’s roles and responsibilities in the ethical use of this resource.
Word Count / Video Length: 790 / 12:03 mins
Professor Rick Valenta, from the Sustainable Minerals Institute at the University of Queensland, and Dr 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, the panellists 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, Professor Alan Duffy.
Key terms
- Element – A chemical element is a substance that is made of only one type of atom. This means that all the atoms in this element have the same atomic number.
- Pegmatite – A pegmatite is an igneous rock, formed by slow crystallisation at high temperature and pressure at depth,
What is lithium?
Lithium is a chemical element that is abundant in the Earth’s crust. It is an alkali metal and is the lightest of all metals on the periodic table.
“It’s the 33rd most abundant element in the crust. So it’s quite abundant,” says Professor Rick Valenta.
Where does it come from?
Lithium is found mainly in volcanic rocks from melted sands, especially rocks called pegmatites, and evaporates from salt lakes. In Australia, lithium is mined from underground volcanic rocks.
Half of the lithium resources in the world are in a triangle between Bolivia, Chile, and Argentina. The rest are in countries such as Australia, USA, China and Canada.
“Argentina and Bolivia each have about 20% of the world’s lithium, and Chile has another 12%. And then USA, Australia, China and Canada, are around 10 to 5% each,” Professor Valenta explains.
“The total amount of lithium that we have (on Earth) is about 200 million tons that we know about now”
Australia mines and provides a large amount of the world’s useable lithium resources.
Why do we use lithium? Are there benefits to other energy sources?
Lithium is best known for its use in lithium-ion batteries. Lithium is the “ultimate choice” for batteries because they have the highest potential capacity and low electrochemical potential. This means that a lot of energy can be stored in small batteries and it can charge and discharge without causing my damage to the battery.
This makes it a very good, environmentally clean, rechargeable battery for use in things like electric cars, especially since only a very small amount of lithium is needed to make them.
“In a nutshell, I would say that, as opposed to what the name suggests, there is actually no lithium metal in lithium-ion battery.” says Dr Mahdokht Shaibani.
“We have a bit of lithium as a form of a compound in one of the electrodes, and a bit of lithium in the form of a salt in the electrolyte of the battery, the sum of which is no more than 2%.”
“But that would be a very important 2%”
Environmental challenges of lithium
Even though rechargeable lithium batteries provide a form of renewable, clean energy, mining for lithium from rocks has a large carbon footprint. Australia also sends the mined lithium overseas for processing, which increases the carbon footprint of manufacturing it.
“One of the main impacts (of rock mining) is the fact that it’s that you’re using a lot of energy.” says Professor Valenta, “You’re grinding that rock up, you’re also leaching the lithium out with sulfuric acid and other agents that are potentially contaminating.”
Similarly, getting lithium from salt lakes uses a huge amount of water which can also put stress on the land the water it is taken from.
“We were involved in a study of a whole range of commodities that are going to be required for the energy transition. And actually, lithium came out overall relatively low risk, except for the fact that in terms of water risk, it was off the scale.” Professor Valenta explains.
“For every tonne of lithium, you have to use up to about 250 cubic meters of freshwater.”
So, when making batteries, engineers and scientists need to consider how much damage to the environment will be caused to achieve renewable energies and technologies.
Australia’s role in lithium
Australia mines about 55% of the world’s usable lithium, but it gets processed, and manufactured into batteries, offshore.
One way to reduce the high carbon footprint from exporting it will be to move manufacturing to Australia. Here, we have many of the mineral elements that are needed to make lithium-ion battery electrodes, which would bring down the cost of manufacture. This could help because the cost and carbon footprint from aeroplanes and ships will be lower, and those extra elements don’t need to be shipped from other countries.
“The long term goal of Australia should be (to become) a sovereign battery supply chain, simply to bring security to the nation.”
Watch the full interview from the Cosmos briefing “Is Lithium the Answer?” here.
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Years: 8, 9, 10
Topics:
Chemical Sciences: Atoms, Particle Models
Earth and Space Sciences: Renewable/Non-renewable Resources, Rocks
Additional: Careers, Technology.
Concepts (South Australia):
Chemical Sciences: Properties of Matter, Change of Matter
Earth and Space Sciences: The Earth’s Surface
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