North Carolina State University physicists have recently deduced a way to improve high-energy-density capacitors so that they can store up to seven times as much energy per unit volume than the common capacitor.
High performance capacitors would enable hybrid and electric cars with much greater acceleration, better and faster steering of rockets and spacecraft, better regeneration of electricity when using brakes in electric cars, and improved lasers, among many other electrical applications.
A capacitor is an energy storage device. Electrical energy is stored by a difference in charge between two metal surfaces. Unlike a battery, capacitors are designed to release their energy very quickly. They are used in electric power systems, hybrid cars, and all kinds of electronics.
The amount of energy that a capacitor can store depends on the insulating material in between the metal surfaces, called a dielectric. A polymer called PVDF has interested physicists as a possible high-performance dielectric. It exists in two forms, polarized or unpolarized. In either case, its structure is mostly frozen-in and changes only slightly when a capacitor is charged up. Mixing a second polymer called CTFE with PVDF results in a material with regions that can change their structure, enabling it to store and release unprecedented amounts of energy.
The team, led by Vivek Ranjan, concluded that a more ordered arrangement of the material inside the capacitor could further increase the energy storage of new high-performance capacitors, which already store energy four times more densely than capacitors used in industry. Their predictions of higher energy density capacitors are encouraging, but have yet to be experimentally tested.
Citation: Vivek Ranjan, L. Yu, M. Nardelli and J. Bernholc, Physical Review Letters (forthcoming article)
Source: American Physical Society
Related stories:
Polymer electric storage, flexible and adaptable
(PhysOrg.com) -- The proliferation of solar, wind and even tidal electric generation and the rapid emergence of hybrid electric automobiles demands flexible and reliable methods of high-capacity electrical storage. Now a team of Penn State materials scientists is developing ferroelectric polymer-based capacitors that can deliver power more rapidly and are much lighter than conventional batteries.
Unique Material May Allow Capacitors to Store More Energy
Imagine an electric car with the same acceleration capability as a gas-powered sports car, or ultrafast rechargeable “batteries” that can be recharged a thousand times more than existing conventional batteries. According to physicists at North Carolina State University, all of these things are possible, thanks to their research on a polymer – or plastic material – that when used as a dielectric in capacitors may allow the capacitors to store up to seven times more energy than those currently in use.
New nanocomposite processing technique creates more powerful capacitors
A new technique for creating films of barium titanate (BaTiO
3) nanoparticles in a polymer matrix could allow fabrication of improved capacitors able to store twice as much energy as existing devices. The improved capacitors could be used in consumer devices such as cellular telephones – and in defense applications requiring both high energy storage and rapid current discharge.
From zero to a billion electron volts in 3.3 centimeters
In a precedent-shattering demonstration of the potential of laser-wakefield acceleration, scientists at the Department of Energy's Lawrence Berkeley National Laboratory, working with colleagues at the University of Oxford, have accelerated electron beams to energies exceeding a billion electron volts (1 GeV) in a distance of just 3.3 centimeters. The researchers report their results in the October issue of
Nature Physics.
Brown engineers build a better battery -- with plastic
Brown University engineers have created a new battery that uses plastic, not metal, to conduct electrical current. The hybrid device marries the power of a capacitor with the storage capacity of a battery. A description of the prototype is published in
Advanced Materials.
Nanoscientists fired up about battery alternative
Just about everything that runs on batteries - flashlights, cell phones, electric cars, missile-guidance systems - would be improved with a better energy supply. But traditional batteries haven't progressed far beyond the basic design developed by Alessandro Volta in the 19th century. Until now.
Nano World: Carbon nanotube capacitors
Carbon nanotubes could help release and hold electrical energy, for potential use in everything from microchips to hybrid cars, experts told UPI's Nano World.
Penn Theorists to Create Optical Circuit Elements
Engineers at the University of Pennsylvania have theorized a means of shrinking electronics so they could be run using light instead of electricity. In the search to create faster, smaller and more energy-efficient electronics, researchers have looked elsewhere in the electromagnetic spectrum, which ranges from the low-frequency energy used in everyday electronics to the high-frequency energy of gamma rays, to pass the limits of conventional technology.