People want to use clean and green energy and live easy on earth’s
resources. Many are changing to hybrid cars and using solar panels side
by side with conventional sources of energy. But they hold a grudge.
How to store large amount of energy in batteries?
Hybrid
cars fit batteries for power storage. But this power is not enough to
last long distances and takes many undesirable hours to recharge. The
storage battery is not very helpful during acceleration. Solar and wind
also don’t provide us with power at constant rate. They give us energy
intermittently. Their storage devices also take lots of space and money
as well and yet they don’t seem promising for surge demand. Gary
Rubloff, who is the director of the University of Maryland’s NanoCenter
is also voicing a common consumer’s concern, “Renewable energy sources
like solar and wind provide time-varying, somewhat unpredictable energy
supply, which must be captured and stored as electrical energy until
demanded. Conventional devices to store and deliver electrical energy —
batteries and capacitors — cannot achieve the needed combination of
high energy density, high power, and fast recharge that are essential
for our energy future.”
Scientists at the Maryland NanoCenter at
the University of Maryland have produced new systems for storing
electrical energy derived from alternative sources that are, in some
cases, 10 times more efficient than what is commercially available.
Electrical
energy storage devices can be categorized into three groups. Each group
has its advantages and disadvantages. Batteries, mainly consisting of
lithium ion, accumulate large amounts of energy but cannot afford high
power or fast recharge. The second type is electrochemical capacitors
(ECCs). Their advantage is they can offer higher power at the price of
relatively lower energy density. The third storage device is
electrostatic capacitors (ESCs). They store charge on the surfaces of
two conductors. This way they are capable of high power and fast
recharge, but at the price of lower energy density.
Scientists
are using new processes to enhance the storage capacity of the devices.
They are banking upon millions of identical nanostructures having
peculiar shapes that will facilitate energy transport with the help of
electrons. Electrons will move to and fro and store energy at a very
large surface area. We all are familiar with the fact that materials
behave according to physical laws of nature. The Maryland researchers
are using this fact to their advantage. They are utilizing unusual
combinations of these behaviors to produce millions and in the end
billions of tiny, virtually indistinguishable nanostructures. These are
supposed to receive, store, and deliver electrical energy.
Scientists
are concentrating on self-assembly, self-limiting reaction, and
self-alignment behaviors of nanostructures. Rubloff clarifies further,
“The goal for electrical energy storage systems is to simultaneously
achieve high power and high energy density to enable the devices to
hold large amounts of energy, to deliver that energy at high power, and
to recharge rapidly (the complement to high power).”
The
Maryland research team is going for electrostatic nanocapacitors. They
significantly increase energy storage density of such devices - by a
factor of 10 over that of commercially available devices. This advance
puts electrostatic devices to a performance level competitive with
electrochemical capacitors.
The research team is right from the
beginning building up the technology for commercial purposes. Their
outward appearance would be like thin solar panels produced at
economical costs. Multiple storage devices can be staked one over the
other inside a car battery system. For the solar and wind energy
storage they dream about the fully integrated with storage devices in
manufacturing.
source
http://earthalternate.blogspot.com/2009/03/nanotech-batteries-new-energy-future.html
