Engineering news
A team of researchers from University of Central Florida has developed a new process for creating flexible supercapacitors that can store more energy and be recharged more than 30,000 times without degrading.
The method from the University of Central Florida's (UCF) NanoScience Technology Centre said it could improve technology 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.
Scientists have been studying the use of nanomaterials to improve supercapacitors that could enhance or even replace batteries in electronic devices. However, a supercapacitor that held as much energy as a lithium-ion battery would have to be much bigger.
The team at UCF has experimented with applying newly discovered two-dimensional materials only a few atoms thick to supercapacitors. Other researchers have also tried formulations with graphene and other two-dimensional materials, but with limited success.
Principal investigator Yeonwoong "Eric" Jung, an assistant professor with joint appointments to the NanoScience Technology Center and the Materials Science & Engineering department, said: "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.”
Using this process, Jung's team has developed supercapacitors composed of millions of nanometer-thick wires coated with shells of two-dimensional materials. A highly conductive core facilitates fast electron transfer for fast charging and discharging. And uniformly coated shells of two-dimensional materials yield high energy and power densities.
This process for integrating two-dimensional materials means that it is capable of surpassing conventional materials typically used for small electronic devices not only in terms of energy density, but also power density and cyclic stability – this defines how many times it can be charged, drained and recharged before beginning to degrade. A lithium-ion battery typically 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.
Jung is working with UCF's Office of Technology Transfer to patent the process.
The UCF team said that supercapacitors that use the new materials could be used in phones and other electronic gadgets, and electric vehicles that could benefit from sudden bursts of power and speed. Due to their flexibility they could also provide “significant advancement” in wearable technology.
"It's not ready for commercialisation," Jung said. "But this is a proof-of-concept demonstration, and our studies show there are very high impacts for many technologies."