Abstract
Super capacitors
also known as Electric double-layer capacitors, or electrochemical double layer
capacitors (EDLCs), or ultracapacitors, are electrochemical capacitors that
have an unusually high energy density when compared to common capacitors,
typically on the order of thousands of times greater than a high capacity
electrolytic capacitor. For instance, a typical electrolytic capacitor will
have a capacitance in the range of tens of millifarads. The same size super
capacitor would have a capacitance of several farads, an improvement of about
two or three orders of magnitude in capacitance but usually at a lower working
voltage. Larger, commercial electric doublelayer capacitors have capacities as
high as 5,000farads.
Super capacitor
technology is based the electric double layer phenomenon that has been
understood for over a hundred years. However, it has only been exploited by
commercial applications for about ten years. As in a conventional capacitor, in
an ultracapacitor two conductors and a dielectric generate an electric field
where energy is stored. The double layer is created at a solid electrode-solution
interface - it is, then, essentially a charge separation that occurs at the
interface between the solid and the electrolyte. Two charge layers are formed,
with an excess of electrons on one side and an excess of positive ions on the
other side. The polar molecules that reside in between form the dielectric. In
most ultracapacitors, the electrode is carbon combined with an electrolyte.
Consumer Electronics
Super capacitors can be
used in PC Cards, flash photography devices in digital cameras, flashlights,
portable media players, solar power calculator, electronic toy, internet
equipments and in automated meter reading, particularly where extremely fast
charging is desirable.
Fuel Cell Vehicles
In the future the
combustion engine mechanical energy obtained from the fuel combustion could be
replaced electrical engine supplied by electricity produced by a fuel cell. The
promise of fuel cell technology has had a recent resurgence due to new
advancements not in fuel cells, but in the double-layer capacitors. Indeed,
high power energy storage is required in all types of fuel cell applications
and double-layer capacitors are ideally suited to provide it. These
improvements open up opportunities for the development of new power train and subsystem
architectures utilizing both double-layer capacitors and fuel cells which can
improve performance, efficiency, and cleanliness in electric and hybrid vehicle
technology.
Introduction
This paper offers a
concise review on the use of a super capacitor in various energy storage
applications. Super capacitor is also known as Electric/electrochemical double
layer capacitor (EDLC) is a unique electrical storage device, which can store
much more energy than conventional capacitors and offer much higher power
density than batteries. Electric double-layer capacitor would have a
capacitance of several farads, an improvement of about two or three orders of
magnitude in capacitance, but usually at a lower working voltage.
Conclusion
In this paper the use
of super capacitor for various energy storage applications is described. They
would have a capacitance of several farads, an improvement of about two or
three orders of magnitude in capacitance, but usually at a lower working voltage.
The specific Power of the super capacitors and its lifetime (1 million of
Cycles) is very high. These peculiarities make it very attractive for various
energy storage applications and the startup of the automobiles etc.
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