Graphite is an ideal conductor for battery anodes, and with the increasing popularity of lithium-ion batteries, the World Bank estimates that demand for this critical mineral will increase by 500% between 2018 and 2050 [ref].
The process of extracting graphite from the ground and getting it ready for use in batteries is a long and complex one.
The graphite has to be mined, concentrated, shaped and sized into small balls in a process known as spheronisation, purified, and then finally carbon coated.
Currently, the global value chain for graphite is quite disjointed, with many unconnected companies providing single services along the value chain.
But as demand for graphite continues to grow, more companies are looking to do more in-house; expanding their services along the value chain and creating value-added products from their graphite ore.
“CSIRO is one of the very few research organisations with capabilities and skills spanning across the entire value chain for natural graphite battery anodes,” says Dr Joanne Loh, Senior Research Scientist with CSIRO Mineral Resources.
“In conjunction with CSIRO Manufacturing, we can provide real continuity - from the fundamental science that provides a solid evidence base for work, through to demonstrating impact and outcomes for clients within industry. In effect, we are a one-stop shop for graphite processing.”
Diversifying sources of graphite
In order to meet the expected demand for graphite in an environmentally sustainable way, there are a number of challenges that need to be overcome.
CSIRO has been collaborating with the Australian mineral industry to find the best way forward.
One of the key challenges for the industry is that battery grade graphite needs to be very high purity and traditionally the only process for achieving this is a highly toxic one.
“For use in battery anodes, the graphite needs to be ultra-high purity,” says Mr Karl Bunney, an Experimental Scientist with CSIRO Mineral Resources.
“Not quite as stringent as nuclear grade, but we’d be looking for a purity of 99.95% or more, compared to around 95% for things like pencils and lubricants.
The only source for purified graphite to date has been China, where it’s processed using hydrofluoric acid.
It's an enormously toxic process and has huge impacts on health and the environment.”
With the large-scale use of hydrofluoric acid banned in most countries, Australian companies are seeking alternative methods that will still allow them to value-add and produce battery grade graphite, without such serious environmental costs.
That’s where CSIRO’s broad range of expertise and multidisciplinary approach has now come into play.
An exciting industry collaboration with Mineral Commodities
In 2019, CSIRO began a partnership with Mineral Commodities (MRC) - a global mining and development company with a primary focus on the production of high-grade mineral sands and natural flake graphite.
MRC own and operate a graphite mine at Skaland in Norway. They also have a graphite development project at Munglinup in Western Australia, which has been classified as a critical minerals project by the Federal Government.
For the last two years, CSIRO and MRC have been working together through a Cooperative Research Centre Project (CRC-P), supported by the Federal Government. The focus of the CRC-P was to develop an environmentally friendly and commercially viable method for purifying graphite.
This initial project, which ended in March 2022, was a resounding success, with battery grade purification achieved for both Skaland and Munglinup samples.
The CSIRO-developed purification process achieved the same results as the traditional purification process, but avoids the use of environmentally-unfriendly hydrofluoric acid.
“We’re really pleased with the results,” says Dr Surinder Ghag, Chief Technology Officer with MRC.
“It’s been brilliant working with Karl and the team at CSIRO, and to collaborate with researchers who are such highly-skilled experts in their field. Now we’re excited to move onto the next phase of the work.”
Real world impact
In April 2022, MRC were awarded a $3.94 million Critical Minerals Acceleration Initiative (CMAI) grant, that will allow the collaboration with CSIRO to continue and expand.
While the initial project involved working with samples of 1 kilogram at a time, the CMAI project will scale up to running 20-kilogram samples.
“The big challenge for us with the new pilot will be scaling up,” says Mr Bunney.
“Running at 20 kilograms per batch puts us about halfway between [the order of magnitude of] a laboratory pilot and an industrial scale operation. At this point it becomes less of a science problem and more of an engineering one.
“We know the chemistry works – but if you take a part of the process like stirring, we need to find out if that works as well in a 20 cubic foot tank as it does in a little beaker in my laboratory.”
For MRC, scaling up brings a number of advantages. Firstly, they will be able to provide larger samples to their own customers for qualification and feedback.
But a larger pilot project will also take them a step closer to commercialisation.
“This is a big step up,” says Dr Ghag.
“It will provide us with data for the engineering design for a commercial scale plant, and it will allow us to update our feasibility study for the Munglinup deposit and downstream activities.
"If we achieve everything we’re hoping for with this stage, we’ll be ready for a vertically integrated mine to anode materials development.
“Obviously, there will still be work to do on the financing, but this helps to de-risk that step.”
Industry collaborations such as this one will become more crucial than ever as Australia moves towards net zero emissions, and the demand for low emissions technologies continues to grow.
And for researchers like Karl Bunney, it’s enormously rewarding work.
“Clients working with CSIRO benefit from that multidisciplinary approach that moves you from fundamental science all the way through to real world impact,” he says.
“We take companies from where they are to where they want to be – and because we are close enough to industry, we actually see that difference.
“All research hopefully leads to a positive difference or change in the world. We actually see it. It’s fantastic.”