Electronics

Graphene-based supercapacitor a step closer to commerical reality

Graphene-based supercapacitor ...
Monash University researchers have created a compact electrode that uses a liquid electrolyte to maintain space between graphene sheets (Image: Shutterstock)
Monash University researchers have created a compact electrode that uses a liquid electrolyte to maintain space between graphene sheets (Image: Shutterstock)
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Monash University researchers have created a compact electrode that uses a liquid electrolyte to maintain space between graphene sheets (Image: Shutterstock)
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Monash University researchers have created a compact electrode that uses a liquid electrolyte to maintain space between graphene sheets (Image: Shutterstock)

Graphene-based supercapacitors have already proven the equal of conventional supercapacitors – in the lab. But now researchers at Melbourne’s Monash University claim to have developed of a new scalable and cost-effective technique to engineer graphene-based supercapacitors that brings them a step closer to commercial development.

With their almost indefinite lifespan and ability to recharge in seconds, supercapacitors have tremendous energy-storage potential for everything from portable electronics, to electric vehicles and even large-scale renewable energy plants. But the drawback of existing supercapacitors has been their low energy density of around 5 to 8 Wh/liter, which means they either have to be exceedingly large or recharged frequently.

Professor Dan Li and his team at Monash University’s Department of Materials Engineering has created a graphene-based supercapacitor with an energy density of 60 Wh/liter, which is around 12 times higher than that of commercially available supercapacitors and in the same league as lead-acid batteries. The device also lasts as long as a conventional battery.

To maximize the energy density, the team created a compact electrode from an adaptive graphene gel film they had previously developed. To control the spacing between graphene sheets on the sub-nanometer scale, the team used liquid electrolytes, which are generally used as the conductor in conventional supercapacitors.

Unlike conventional supercapacitors that are generally made of highly porous carbon with unnecessarily large pores and rely on a liquid electrolyte to transport the electrical charge, the liquid electrolyte in Li’s team’s supercapacitor plays a dual role of conducting electricity and also maintaining the minute space between the graphene sheets. This maximizes the density without compromising the supercapcitor’s porosity, they claim.

To create their compact electrode, the researchers used a technique similar to one used in traditional paper making, which they say makes the process cost-effective and easily scalable for industrial applications.

"We have created a macroscopic graphene material that is a step beyond what has been achieved previously. It is almost at the stage of moving from the lab to commercial development," Professor Li said.

The team’s research appears in the journal Science.

Source: Monash University

16 comments
asdf
Any information about how heavy these will be and how these compare with lithium batteries?
Majed Hosneddine
if the device has the same energy density and lifespan as that of Lead-Acid Battery. Then what is so special about this supercapacitor device?
Gary Bonney
Close to instant charge and discharge meaning they could buffer a cheaper low C rated battery pack to run say a car. Have a phone or laptop with a few second charge. The energy density is related to size not weight in the article, they would most likely be considerably lighter as there is no lead.
Mirmillion
Yes, this is the way forward, no question. Capacitors with sufficient energy density are, far and away, the most logical energy storage/release devices for the coming electric world. 5-second recharge times combined with relative safety, low weight and compact form factors is exactly what the real world is looking for. Much rather have low cost Capacitors than expensive, heavy and volatile L-ion or Lipo batteries.
Brian Maxwell
It charges in seconds not hours.
esecallum
These capacitors are extremely dangerous as anyone who has short circuited an ordinary electrolytic capacitor. All the energy released in about a millisecond would cause a massive explosion. People seem to forget the exponential discharge curve of capacitors making them useless as normal batteries.
Gildas Dubois
This is not for a car or motorbike. But the industrial implication for energy generation efficiency are tremendous.
Capt'nCrunch
What decays in a capacitor that would make it only last as long as a regular battery?
Capt'nCrunch
If these were used in an all-electric vehicle, could there be multiple alternators installed that would keep these constently charged when driving? Never need to refuel. That would be awesome.
JimRD
I need this development for my rc airplanes.