Flexible Supercapitors Can Charge Devices and EVs in Seconds

Flexible supercapacitors developed by researchers at the University of Central Florida pave the way for fast-charging mobile devices, EVs

Allowing mobile devices to charge within minutes remains a Holy Grail of sorts for energy storage researchers. Now a team of scientists at the University of Central Florida (UCF) is that much closer to achieving this milestone with the development of flexible supercapacitors that can store more energy than typical batteries and be charged tens of thousands of times without degrading.

A team of scientists at the University of Central Florida has developed a flexible supercapacitor that can store more energy than typical batteries and be charged more than 30,0000 times without losing its energy-storage properties. (Image source: University of Central Florida)

The team from the university’s NanoScience Technology Center advocates one day replacing typical mobile device and electric vehicle (EV) batteries with highly optimized supercapacitors to achieve an ultra-fast charging capability.

In tests, the supercapacitor was charged more than 30,0000 times without losing its energy-storage properties, which would solve the problem of normal degradation that causes lithium-ion batteries to hold a charge for less time after about 18 months. Additionally, supercapacitors can recharge more quickly than typical batteries.

“If they were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,” said Nitin Choudhary, a postdoctoral associate who conducted the bulk of the research. He and the team published a paper on their work in the journal ACS Nano .

Key to the technology developed by Choudhary and his colleagues are nanomaterials they used to reduce the size of the supercapacitor, which generally would have to be far larger than a typical lithium-ion battery to hold a similar amount of energy.

Specifically, the team experimented with applying newly-discovered, two-dimensional materials only a few atoms thick to supercapacitors, developing a simple chemical synthesis approach to integrate existing materials with these new ones, they said.

The result is a supercapacitor with a highly conductive core that consist of millions of nanometer-thick wires coated with shells of two-dimensional materials. The core allows for fast electron transfer for speedy charging and discharging, while uniformly coated shells of two-dimensional materials yield high energy and power densities, researchers said.

The work is the first demonstration of the potential that two-dimensional materials hold for energy storage applications.“For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability,” Choudhary said.

Yeonwoong “Eric” Jung, an assistant professor in UFC's NanoScience Technology Center and the Materials Science and Engineering Department, was the principal investigator on the research and now is working with UCF’s Office of Technology Transfer to patent the new process the team developed. While the work is more a proof of concept than something that’s ready for commercialization, he said, it does hold great promise in the future for applications such as mobile devices and EVs, among others.

Elizabeth Montalbano is a freelance writer who has written about technology and culture for more than 15 years. She has lived and worked as a professional journalist in Phoenix, San Francisco and


There does remain the serious problem with super capacitors, as with ALL capacitors, which is that, unlike batteries, the voltage constantly drops as charge is consumed. That is intrinsic with capacitors. So it is more challenging to utilize the last half of the stored energy in the capacitors.

There is an interesting question as well, which is how to handle that charging current. Delivering 50 or 75 kilowatt-hours in just a few minutes means a quite high current. That is rather inescapable. It would be VERY INTERESTING to know how the researchers get around that challenge.

There are some interesting problems for the electrical supply grid presented with a system that requires this sort of charge current. One possible solution may be to use conventional batteries at charge stations to provide DC to charge the vehicle. These could be charged over a longer period of time, perhaps dynamically to level grid demand or indeed supply from renewables. The batteries in this case could have a "relaxed / benign" charge/discharge regime with a commensurate increase in life.

How/why does not parallelizing (serial-parallelizing, almost certainly) the supercaps not help with the high current issue?

Yes supercapacitors can charge very quickly. But they hold power in the form of high voltage and very little current. Current is what drives electric motors. The article does not divulge the discharge time for these supercapacitors, but the longest discharging supercapacitors I've found last only a few minutes. EVs need to operate for hours. This is a major challenge before supercapitors can replace batteries in EVs.

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