Energy storage in miniaturized capacitors may boost green energy technology

Jan 17, 2014
The photograph shows clearly the large grains closely packed together and separated by well-defined grain boundaries. The density of the CCTO ceramic is 94 percent of the maximum theoretical density, indicating the superior nature of the samples. Credit: R.Pandey/Texas State

"Supercapacitors" take the energy-storing abilities of capacitors (which store electrical charge that can be quickly dumped to power devices) a step further, storing a far greater charge in a much smaller package. In AIP Advances, researchers describe the possibility of fabricating a new class of high heat-tolerant electronics that would employ supercapacitors made from a material called calcium-copper-titanate, or CCTO, which the researchers have identified for the first time as a practical energy-storage material.

The capacitors of electronic circuits function something like batteries – storing that can be quickly dumped to like camera flashes. So-called "supercapacitors" take the energy-storing abilities of capacitors a step further, storing a far greater charge in a much smaller package.

In a paper published in the journal AIP Advances researchers describe the possibility of fabricating a new class of high heat-tolerant electronics that would employ supercapacitors made from a material called calcium-copper-titanate, or CCTO, which the researchers have identified for the first time as a practical energy-storage material.

Devices using CCTO supercapacitors could compete with similar devices currently in use and could operate at much higher temperatures than standard silicon circuits, "more like the temperature in an engine," says William Stapleton, an assistant professor of at Texas State University (TSU) in San Marcos, Texas. CCTO had been identified as a promising supercapacitor material before, but its development for practical applications faced unexpected hurdles.

The lead author Raghvendra Pandey, Ingram Professor of electrical engineering at Texas State University, San Marcos, TX along with Stapleton and other collaborators, showed that in CCTO two properties of fundamental importance for the efficiency of a capacitor device are tightly linked. The first property, called permittivity, is the physical property of the capacitor material that allows it to store energy– with higher permittivity values representing a better capacitor.

The second property, called loss tangent "has to do with how efficiently energy can be moved into and out of the capacitor, that is, how much is lost in the process to inefficiency," Stapleton said.

"When the loss tangent is high," explain Pandey, "the capacitor is 'leaky' and it cannot hold a stored charge for more than a few seconds."

Researchers found that permittivity and loss tangent increased or decreased in tandem in CCTO. Efforts to simultaneously retain the high permittivity while minimizing the loss tangent might not succeed unless a new approach is taken for processing the material. While the work could help explain why researchers have had trouble producing ideal CCTO material in the past, Pandey and his research team have demonstrated that CCTO supercapacitors should be capable of achieving high permittivity while maintaining low loss tangent, which would make them suitable for storing energy at the desired levels for many industrial applications.

"Efficient, high-speed, high-density energy storage is important to many fields, and offer this," Stapleton said. "Fields such as 'green' energy and electric vehicles could benefit immediately from the use of these ."

Explore further: New capacitors to improve electric vehicles

More information: The article, "Applications of CCTO supercapacitor in energy storage and electronics" by R. K. Pandey, W. A. Stapleton, J.Tate, A. K. Bandyopadhyay, I. Sutanto, S. Sprissler and S. Lin appears in the journal AIP Advances: dx.doi.org/10.1063/1.4812709

Related Stories

New capacitors to improve electric vehicles

Aug 02, 2013

Scientists from the National Physical Laboratory (NPL) have developed a new lead-free, high temperature ceramic capacitor that could improve the efficiency and reliability of electric and hybrid vehicles.

New material holds big energy hope

Jul 01, 2013

(Phys.org) —A new material that can store large amounts of energy with very little energy loss has been developed by researchers at the Australian National University.

Recommended for you

Could 'Jedi Putter' be the force golfers need?

Apr 18, 2014

Putting is arguably the most important skill in golf; in fact, it's been described as a game within a game. Now a team of Rice engineering students has devised a training putter that offers golfers audio, ...

Better thermal-imaging lens from waste sulfur

Apr 17, 2014

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

dan42day
3.7 / 5 (3) Jan 18, 2014
Perhaps they could build a handheld directed energy weapon that would use energy stored in a half dozen small copper colored capacitor cartridges contained in a cylinder that revolved to bring a new cartridge into position for each shot.
Whydening Gyre
1 / 5 (1) Jan 18, 2014
Perhaps they could build a handheld directed energy weapon that would use energy stored in a half dozen small copper colored capacitor cartridges contained in a cylinder that revolved to bring a new cartridge into position for each shot.

Now THAT was funny...
goracle
1 / 5 (1) Jan 19, 2014
Perhaps they could build a handheld directed energy weapon that would use energy stored in a half dozen small copper colored capacitor cartridges contained in a cylinder that revolved to bring a new cartridge into position for each shot.

If they did, the Powers That Be in the firearms establishment would have them martyred for refusing to recant their belief that the capacitors revolve around the axis.
FrankTrades
1 / 5 (1) Jan 21, 2014
Green energy has been a financial flop. Are there other applications?
hinesdarrel
not rated yet Feb 14, 2014
Hey its a great post. Capacitors are mainly used to store energy for a limited period of time, which can be used later. The time for which the capacitor holds energy defined the capacity of the capacitor.
http://www.analog...ler.html

More news stories

Easter morning delivery for space station

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.