Nanomaterials create flexible supercapacitors

November 23, 2016 // By Nick Flaherty
Researchers at the University of Central Florida have developed a new process for creating flexible supercapacitors that can store more energy and be recharged more than 30,000 times without degrading.

The team at UCF's NanoScience Technology Center has experimented with applying newly discovered two-dimensional materials only a few atoms thick to supercapacitors.

"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.

Jung's team has developed supercapacitors composed of millions of nanometer-thick wires coated with shells of two-dimensional transition-metal dichalcogenide (TMD) material. A highly conductive core provides fast electron transfer for fast charging and discharging and the uniformly coated shells of two-dimensional materials yield high energy and power densities. 

By combining an array of one-dimensional (1D) nanowires with the conformal 2D TMD layers, the supercapacitor components possess “one-body” geometry with atomically sharp and structurally robust core/shell interfaces. These outperform previously developed stand-alone 2D TMD-based supercapacitors, particularly with the charge retention.

1D and 2D structures create a flexible supercapcitor
The team at Forida used 1D nanowires coated in 2D structures to create a flexible supercapacitor

"For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability," said Nitin Choudhary, a postdoctoral associate on the team. "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."

A lithium-ion battery can be recharged fewer than 1,500 times without significant failure. Recent formulations of supercapacitors with two-dimensional materials can be recharged a few thousand times. By comparison, the new process created at UCF yields a supercapacitor that doesn't degrade even after it's been recharged 30,000 times.

"It's not ready for commercialization," said Jung, who is working with UCF's Office of Technology Transfer to patent the new