Australian engineers hail new supercapacitor tech that may store enough energy to replace batteries

Engineers from Australia’s Monash University have reportedly made a significant breakthrough in supercapacitor technology that they say could pave the way for next-generation applications in electrified transport, grid stabilisation, and consumer electronics.

Supercapacitors are labelled as an emerging class of energy storage device that store charge electrostatically, rather than through chemical reactions such as those found in traditional batteries.

However, while offering fast charging, quick energy discharge, and a very long cycle life, supercapacitors have been limited by low energy density, storing less energy per volume or weight.

Conversely, lithium-ion batteries provide high energy density for a longer discharge, even though they charge slower, have a shorter lifespan, and lower power density.

The issue for supercapacitors has been that only a small fraction of the carbon material’s surface area was accessible for use.

But in a new study published in Nature Communications, a team of engineers from Monash University have created a new kind of carbon-based material that allows supercapacitors to store as much energy as traditional lead-acid batteries.

They say they can do this while still maintaining the benefits inherent in supercapacitor technology, such as delivering power far faster than conventional batteries can manage.

Specifically, by using a rapid thermal annealing process and a new material architecture synthesised from natural graphite – an abundant Australian resource – the Monash team was able to create multiscale reduced graphene oxide (M-rGO), a highly curved graphene structure with precise pathways for ions to move quickly and efficiently. 

The resulting material offers both high energy density and high power density – a combination that is rarely achieved in a single device.

“Our team has shown how to unlock much more of that surface area by simply changing the way the material is heat-treated,” said Professor Mainak Majumder, a member of the research team and Director of the ARC Research Hub for Advanced Manufacturing with 2D Materials (AM2D) at Monash.

“This discovery could allow us to build fast-charging supercapacitors that store enough energy to replace batteries in many applications and deliver it far more quickly.”

The research was supported by the Australian Research Council and the US Air Force Office of Sponsored Research and is part of the University’s wider commitment to developing advanced materials for a low-carbon energy future.

According to Dr Petar Jovanović, a research fellow in the ARC AM2D Hub and co-author of the study, say that – when assembled into pouch cell devices – the new supercapacitors can deliver volumetric energy densities of up to 99.5 Wh/L, power densities as high as 69.2 kW/L, and rapid charging capabilities with excellent cycle stability.

“These performance metrics are among the best ever reported for carbon-based supercapacitors, and crucially, the process is scalable and compatible with Australian raw materials,” said Dr Jovanović.

The supercapacitor is now being commercialised through a Monash University spinout company, Ionic Industries, which is working with energy storage partners to bring this breakthrough to market-led applications – where both high energy and fast power delivery are essential.