Over the last decade, smartphones have got better in almost every conceivable way. But while consumers have seen vast improvements in screen resolution, processing power and camera quality, battery development has stalled.
Now a team of American scientists think nanotechnology holds the key to a revolution in energy storage, and they’ve proved it.
Dominic Lipinski/PA Archive
A study published in ACS Nano has revealed a new process for creating flexible super-capacitors which take seconds to charge, provide power for more than a week and can be recharged more than 30,000 times. A conventional lithium-ion battery yields just 1,500 charges.
“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 post doctoral associate at the University of Central Florida (UCF).
The super-capacitors are comprised of millions of nanometer-think wires coated with shells of two-dimensional materials. The core facilitates rapid electron transfer for charing and discharging, while the shells pack in huge amounts of energy into a minuscule space.
“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 lead investigator Yeonwoong “Eric” Jung, an assistant professor at UCF.
Jung said the super-capacitors aren’t yet ready for commercialisation, but that they could soon be used to enhance or replace batteries in a range of electronic gadgets, and even electric vehicles.
“This is a proof-of-concept demonstration, and our studies show there are very high impacts for many technologies.”
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A phone that charges in seconds? Scientists bring it closer to reality
November 21, 2016
A thin, flexible supercapacitor developed at the University of Central Florida boasts high energy and power densities. Credit: University of Central Florida
A team of UCF scientists 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 novel method from the University of Central Florida's NanoScience Technology Center could eventually revolutionize technology as varied as mobile phones and 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.
Anyone with a smartphone knows the problem: After 18 months or so, it holds a charge for less and less time as the battery begins to degrade.
Scientists have been studying the use of nanomaterials to improve supercapacitors that could enhance or even replace batteries in electronic devices. It's a stubborn problem, because a supercapacitor that held as much energy as a lithium-ion battery would have to be much, much larger.
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.
"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 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.
Illustration represents the novel design of the supercapacitor developed at the University of Central Florida. Credit: University of Central Florida
Scientists already knew two-dimensional materials held great promise for energy storage applications. But until the UCF-developed process for integrating those materials, there was no way to realize that potential, Jung said.
"For small electronic devices, our materials are surpassing the conventional ones worldwide in terms of energy density, power density and cyclic stability," Choudhary said.
Cyclic stability defines how many times it can be charged, drained and recharged before beginning to degrade. For example, 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.
Jung is working with UCF's Office of Technology Transfer to patent the new process.
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. And because they're flexible, it could mean a significant advancement in wearable tech, as well.
"It's not ready for commercialization," Jung said. "But this is a proof-of-concept demonstration, and our studies show there are very high impacts for many technologies."
In addition to Choudhary and Jung, the research team included Chao Li, Julian Moore and Associate Professor Jayan Thomas, all of the UCF NanoScience Technology Center; and Hee-Suk Chung of Korea Basic Science Institute in Jeonju, South Korea.
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Fast-charging everlasting battery power from graphene
July 19, 2016 by Han Lin
Swinburne University researchers have invented a new, flexible energy-storage technology that could soon replace the batteries in our cars, phones and more.
Han Lin's new super battery (actually, a supercapacitor) can store as much energy per kilogram as a lithium battery, but charges in minutes, or even seconds, and uses carbon instead of expensive lithium.
The majority of batteries used in Australia are lead-acid batteries. These have three main disadvantages: they can take hours to charge, they have a limited lifespan for charging and discharging, and they're bad for the environment, therefore requiring special, expensive disposal processes.
Han's supercapacitor charges extremely fast, can be charged and discharged millions of time, and is environmentally friendly.
Previously, a major problem with supercapacitors has been their low capacity to store energy. But Han has overcome this problem by using sheets of a form of carbon known as graphene, which has a very large surface area available to store energy.
Large scale production of the graphene that would be needed to produce these supercapacitors was once unachievable, but using a 3-D printer, Han is able to produce graphene at a low cost.
And because the technology is extremely flexible and thin (as thin as ordinary printing paper) the new super batteries could be potentially be built into clothing, or worn as a watch strap, to achieve a wearable power supply.
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