For years, supercapacitors have occupied an awkward middle ground in energy storage. They can charge and discharge in seconds, survive far more cycles than most batteries and deliver huge bursts of power, but they have usually fallen short on the one metric that matters most for many real-world devices: how much energy they can actually hold. That is why they have excelled in niche roles such as regenerative braking and power smoothing, while lithium-ion batteries have continued to dominate electric cars, consumer electronics and grid storage.
Now that balance may be starting to shift. In a paper published in Nature Communications, researchers at Monash University in Australia describe a graphene-based electrode architecture that pushes carbon supercapacitors to stack-level volumetric energy densities of up to 99.5 watt-hours per litre in ionic-liquid electrolytes, while also delivering power densities as high as 69.2 kilowatts per litre in pouch-cell devices. Those figures bring the devices into the range of lead-acid batteries for energy density, while preserving the characteristic fast charging and high-power delivery that make supercapacitors attractive in the first place.
The underlying idea is that supercapacitors store charge electrostatically on surfaces rather than through slower chemical reactions in bulk materials, so their performance depends heavily on how much surface area ions can actually reach, and how quickly they can move once they get there. Graphene has long looked like an ideal material because it is conductive, mechanically robust and has a theoretically enormous surface area, but in practice those atom-thin sheets tend to restack and clump together, making much of that area inaccessible. Reviews of the field have repeatedly identified restacking, pore accessibility and large-scale manufacturability as central barriers to graphene supercapacitors moving beyond the laboratory.
The Monash group’s advance lies in making graphene hard to pack too neatly. Using a rapid thermal annealing step on a graphite-oxide precursor, the team created what it calls multiscale reduced graphene oxide, or M-rGO: a carbon structure made up of unusually curved, turbostratic graphene crystallites embedded within more disordered domains. According to the paper, this architecture creates more accessible pathways for ions and enables fast ion transport through both the curved crystallites and the disordered regions, while also improving pore–ion matching. In other words, the researchers have re-shaped graphene into a more crumpled, three-dimensional maze that is much harder for the sheets to collapse back into an unusable stack.
That matters because the long-standing trade-off in this field has been between energy density and power density. Thin, open structures can let ions race through quickly, boosting power, but often sacrifice packing density and therefore total stored energy. Dense structures can store more charge per unit volume, but transport becomes sluggish. The Monash devices appear to narrow that trade-off substantially, which is why the work has attracted attention outside the immediate supercapacitor community. Monash says the materials are already being produced at commercial quantities by its spinout Ionic Industries, suggesting that this is not merely an elegant materials paper but a bid to bridge the gap between university performance metrics and industrial deployment.
Supercapacitors and lithium-ion batteries: Complimentary energy supply?
Supercapacitors, even improved ones, are not about to eliminate lithium-ion batteries. The basic physics is still different: batteries store energy in the bulk of electrode materials through electrochemical reactions, which gives them higher energy density, whereas supercapacitors store charge mainly at or near surfaces, which limits how much energy they can hold even as it lets them charge and discharge extremely quickly. Graphene-based devices are therefore more likely to complement batteries than replace them outright, especially in transport and grid systems where short bursts of power, rapid recovery and long cycle life are especially valuable.
That complementarity may, however, become more important in an electrifying world. A supercapacitor that approaches lead-acid battery energy density while charging dramatically faster could help in buses, delivery vehicles and rail systems that repeatedly brake and accelerate, in grid infrastructure that has to absorb and release power spikes, and in consumer electronics that increasingly demand fast charging without a severe penalty in lifetime. The same logic applies to data centres and industrial motors, where power quality and rapid response are often as important as bulk energy storage. Carbon-based supercapacitors also avoid some of the material constraints associated with more exotic battery chemistries, although electrolytes, device packaging and manufacturing cost still matter enormously for any eventual commercial success.
There is also a broader scientific pattern here. Recent papers in Nature Communications have highlighted other routes to improving supercapacitors, including highly disordered nanoporous carbons that enhance ion adsorption capacity and even all-water devices based on 1-nanometre clay channels. Together, these studies suggest that the field is moving away from simply maximising surface area and towards a subtler strategy: engineering disorder, confinement and transport pathways so that ions can move rapidly through dense materials without losing access to storage sites. The Monash work fits neatly into that trend by showing that the “shape” of graphene at multiple length scales can be as important as its chemical identity.
How can Canada benefit?
Canada, interestingly, may be well placed to benefit from exactly this kind of shift. Ottawa’s Critical Minerals Strategy explicitly treats graphite as part of the value chain needed for the green and digital economy, and recent federal support has focused on building more domestic processing capacity rather than exporting raw material alone. In March 2026, Natural Resources Canada highlighted a project led by Green Graphite Technologies to demonstrate a low-greenhouse-gas route to battery-grade graphite with purity above 99.95 per cent, aimed at strengthening Canada’s domestic battery supply chain. That is not the same as making supercapacitors, but it is the sort of upstream capability that advanced carbon devices depend on.
The Canadian graphite picture is also becoming more strategic. In March 2026, Nouveau Monde Graphite said it had executed an updated binding framework with the Government of Canada covering a 30,000-tonne-per-year purchase commitment for flake graphite concentrate from its planned Matawinie mine in Quebec over seven years, while the company continues to move the project toward a final investment decision. That sort of offtake arrangement points to something larger than a single mining project: a governmental effort to secure domestic graphite flows for energy storage and advanced manufacturing. If graphene-rich supercapacitors or hybrid battery-capacitor systems become commercially important, reliable graphite supply will be part of the story.
Canada is also pushing on the downstream materials side. Montreal-based NanoXplore launched a 99.8 per cent purity graphene powder in May 2026 aimed at highly conductive applications including energy storage and advanced electronics, and the company has reported progress on a dry-process production line designed to manufacture hundreds of tonnes per year. The same company also received up to C$2.75 million from the federal government in late 2025 to help develop ultra-high-power cylindrical lithium-ion cells, underscoring that Canada’s strategy is not solely about mining but about capturing value in higher-performance electrochemical devices. Meanwhile, the University of Waterloo’s Ontario Battery and Electrochemistry Research Centre is positioning itself as a national hub for translating electrochemical materials research into real cells and manufacturable systems.
What makes the Monash result of interest, then, is not just the impressive performance number. It is that the work addresses a stubborn materials problem in a way that looks scalable, dovetails with a broader shift in supercapacitor science and lands at a moment when countries are racing to build graphite, graphene and advanced energy-storage supply chains of their own. Whether these curved-carbon supercapacitors become ubiquitous in cars or gadgets remains uncertain. But they do make one thing clearer: the old boundary between “battery” and “capacitor” is beginning to blur, and that could have consequences well beyond the lab bench.