Flexible supercapacitor could mean smartphones that charge in seconds

Scientists at the University of Central Florida have devised a new process for making flexible supercapacitors. These supercapacitors can store more energy than previous flexible supercapacitors and can be recharged over 30,000 times without degrading. The scientists think that the new approach could one day revolutionize technology ranging from mobile phones to electric vehicles.

"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 much of the research published recently in the academic journal ACS Nano.

Much research is being performed into supercapacitors to improve them to the point where they could replace batteries in electronics. The challenge today is that most supercapacitors need to be much larger than a lithium battery to store the same amount of energy. The new technique that the scientists are working on in Florida uses supercapacitors made up of millions of nanometer-thick wires that are coated with shells of two-dimensional materials.

The supercapacitors also have a highly conductive core that allows for fast electron transfer for faster charging and discharging. The shells of the two-dimensional materials yield high energy and power densities. The supercapacitors created with the new process yields a device that can be charged 30,000 times with no degradation compared to only about 1,5000 charge cycles for lithium batteries. Supercapacitors using the new process aren't ready for the commercial market and there is no timeframe on when they will be.

"There have been problems in the way people incorporate these two-dimensional materials into the existing systems – that's been a bottleneck in the field. We developed a simple chemical synthesis approach so we can very nicely integrate the existing materials with the two-dimensional materials," said principal investigator Yeonwoong "Eric" Jung, an assistant professor with joint appointments to the NanoScience Technology Center and the Materials Science & Engineering Department.