Img/2012/2/27/car-256.jpgWashington: Faster and more powerful electric cars may now be possible by tweaking capacitors, a kind of energy storage device like a battery, suggests a study.
Imagine an electric vehicle that can accelerate from zero to 60 miles per hour at the same rate as a fuel-powered sports car. There are no batteries that can power that type of acceleration because they release their energy too slowly.
Capacitors, however, could be up to the job - if they contained the right materials, such as polymers, the journal Physical Review Letters reported.
North Carolina State University physicist Vivek Ranjan had previously found that capacitors which contained the polymer polyvinylidene fluoride, or PVDF, in combination with another polymer called CTFE, were able to store up to seven times more energy than those currently in use.
"We knew that this material makes an efficient capacitor, but wanted to understand the mechanism behind its storage capabilities," said Ranjan, according to a university statement.
Ranjan with fellow physicist Jerzy Bernholc and Marco Buongiorno-Nardelli from the University of North Texas, did computer simulations to see how the atomic structure within the polymer changed when an electric field was applied.
They found that the atoms performed a synchronized dance, flipping from a non-polar to a polar state simultaneously, and requiring a very small electrical charge to do so.
"In the case of the PVDF mixture, the atoms change their state all at once, which means that you get a large amount of energy out of the system at very little cost in terms of what you need to put into it," said Ranjan.
"Hopefully these findings will bring us even closer to developing capacitors that will give electric vehicles the same acceleration capabilities as gasoline engines," concluded Ranjan.
First Published: Monday, February 27, 2012, 14:23