Engineers in Australia have created a new carbon-based material which allows supercapacitors to store as much energy as traditional lead-acid batteries and deliver charge much faster.
The new graphene materials are now being made in commercial quantities, says Dr Phillip Aitchison, chief technical officer of Monash University spinout Ionic Industries.
“We’re working with energy storage partners to bring this breakthrough to market-led applications – where both high energy and fast power delivery are essential.”
The need to improve and diversify energy storage technology is growing amid a global race to shift energy usage from fossil fuels to renewable sources of electricity.
Supercapacitors store charge electrostatically, rather than through chemical reactions as batteries do.
Much effort has gone into optimising the electrical conductivity and nanoscale architecture of high surface area carbons for this application. But only a small fraction of the material’s surface area has been accessible for storing energy, until now.
Professor Mainak Majumder, director of the ARC Research Hub for Advanced Manufacturing with 2D Materials (AM2D) at Monash says: “Our team has shown how to unlock much more of that surface area by simply changing the way the material is heat-treated.”
“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 rapid thermal annealing step turns graphite oxide into a new architecture – ‘multiscale reduced graphene oxide’ (M-rGO) – which the authors describe as “curved and tangled turbostratic crystallites interwoven into disordered domains”.
(A) Schematic highlighting the differences between different kinds of graphene supercapacitors. (B) High-resolution transmission electron micrographs of M-rGO showing numerous curved graphene crystallites. (C) Scanning electron micrograph of M-rGO particles. Credit: Jovanović et al 2025, Nature Communications https://doi.org/10.1038/s41467-025-63485-0.
This structure allows ions to move quickly and efficiently through the material, resulting in high energy and power density.
According to the researchers, the volumetric energy density of typical carbon-based and commercial supercapacitors is currently less than 10 watt-hours per litre (Wh/L), “far below even the first-generation lead-acid batteries (50-90 Wh/L)”.
Volumetric energy density measures the amount of energy stored in a system, substance or region of space. A higher value means that more energy is packed into less space.
When assembled into pouch cell devices, the supercapacitors delivered volumetric energy densities of up to 99.5 Wh/L in ionic liquid electrolytes and 49.2 Wh/L in organic electrolytes.
The supercapacitors were also capable of power densities as high as 69.2 kilowatts per litre (kW/L). Greater values mean more energy is transferred at a faster rate in a given volume.
According to Dr Petar Jovanović, a research fellow in AM2D, the supercapacitors also have “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.”
The findings have been published in Nature Communications.