Research Fellow at Australia’s Monash University, Mahdokht Shaibani has, alongside colleagues Mainak Majumder, Matthew Hill and Meysam Sharifzadeh, developed what many believe to be the world’s most efficient lithium-sulfur battery.
The ultra-high capacity Li-S battery was created through a collaboration with Fraunhofer Institute for Material and Beam Technology, Technische Universität Dresden, CSIRO, and Université de Liège and has been partially funded by industry and the government.
The battery will be revolutionary for many applications, including mobile phones, grid systems and, of course, electric vehicles.
“While portable electronics such as phones are one of the targeted applications and there has been interest from global manufacturers keen to harness the technology, our priority is to test our batteries in electric vehicles and grids,” Shaibani explains.
“This is because we need radical new and clean energy storage technologies to fight climate change in Australia where sustained climate change could have drastic effects on not only the ecosystems but also people’s lives.”
Since June last year, Shaibani and her team have initiated a government-funded programme to test Li-S batteries in EVs and new renewable energy platforms that will help develop better storage batteries for grids.
So, what makes it better than lithium-ion?
Shaibani says that the redox reaction-based storage mechanism in the Li-S system, which is a chemical reaction that involves a transfer of electrons between two species, is completely different from the typical process found with lithium-ion.
As that’s about as far as my ‘expert’ knowledge goes, I’ll let Shaibani explain the rest.
“In the lithium-ion system, the lithium ions shuttle between the positive electrode intercalation host and the graphite negative electrode. In the Li-S system, a sulfur/carbon composite serves as the positive electrode and a lithium metal serves as the negative electrode. When the two fully react to form Li2S, the delivered specific capacity is the highest of any commercial intercalation materials.”
In simple words, sulfur offers lots of capacity for holding lithium. What’s more, it also relieves the strain on the already scarce material supply of rare-earth metals needed for lithium-ion batteries.
“Cost-effectiveness and environmental friendliness is where the Li-S system could really shine,” she continues. “The three ingredients of a sulfur electrode are sulfur, carbon, and a binder. No heavy metals or rare-earth elements involved.
Cobalt Vs Sulfur
By 2030, EV cobalt requirements could reach as high as 81% of production, meaning that the industry will soon experience a serious shortage of the material. Recycling may be one answer to supply problems, although it is unlikely to be very effective due to the lack of EVs being scrapped.
However, by replacing it with sulfur, the industry will see a much lower acquisition cost and a much larger supply cushion.
“As opposed to cobalt, sulfur has been historically very cheap to acquire and is in significant abundant, with an annual production of about 70 million tons per year,” says Shaibani.
“As for the binder and carbon, I use the very same materials that have been used in the manufacturing of lithium-ion battery electrodes for decades now and the electrode processing is completely water-based, no toxic solvent involved.”
By using a water-based process, it allows manufacturers to reduce their carbon footprint when producing EVs, whilst also being cheaper and more obtainable than its soon-to-be predecessor.
Long-range EVs on the horizon
The number one problem potential EV buyers experience around the world is, by far, range anxiety. Of course, this is quickly changing, as modern EVs regularly achieve 200-300 miles per charge. However, for people who are used to driving internal combustion engine vehicles, it’s still a worry for them.
But they’re in luck as, according to Shaibani, lithium-sulfur offers up to a five-fold increase in energy efficiency compared to Lithium-ion.
“From a practical point of view, and considering the breakthrough of our research group and the advancements of other research institutions and companies, you can expect to see around a two-fold increase at the battery pack level when first introduced to the market.”
The Tesla Model S achieves a class-leading range of around 373 miles (600 km), which is impressive by today’s standard. However, according to Shaibani, the next generation of lithium batteries should allow for 1000km and more.
This huge increase in battery efficiency will definitely have a significant impact on the global EV adoption levels.
Australia’s Auto Revival
Australia has never really had much of a presence of the global automotive market. In fact, it all but shut down around three years ago, when Holden and Toyota finally closed their doors.
However, it just so happens that the country has a shedload of lithium and sulfur. So we could see, much like China has seen in recent times, the development of highly-efficient batteries in a rapidly growing EV market help grow Australia’s automotive presence on the global stage.
“Being a leading global exporter of lithium, we think that it is a natural fit to make these batteries in Australia,” says Shaibani. “And more than anything, the Li-S battery technology should boost the Australian lithium market.”
Looking forward, she hopes that Australia will be the first country to introduce Li-S battery-driven cars to the world and at highly competitive price points.
Australia’s lithium value chain is estimated at $213 billion. Let that sink in.