that can deliver a strong surge of electrical power
could be manufactured from carbon nanotubes using a
technique developed by researchers at UC Davis.
Supercapacitors are electrical
storage devices that can deliver a huge amount of
energy in a short time. Hybrid-electric and fuel-cell
powered vehicles need such a surge of energy to start,
more than can be provided by regular batteries. Supercapacitors
are also needed in a wide range of electronic and
engineering applications, wherever a large, rapid
pulse of energy is required.
Ning Pan, a professor of textiles
in the Department of Biological and Agricultural Engineering
and the Nanomaterials in the Environment, Agriculture
and Technology (NEAT) center at UC Davis, postdoctoral
researcher Chunsheng Du and Jeff Yeh of Mytitek Inc.
of Davis prepared suspensions of carbon nanotubes
-- tiny rolled-up cylinders of carbon just a few atoms
across. They developed a method to deposit the nanotubes
on nickel foil so that the nanotubes were aligned
and packed closely together.
Conventional, or "Faraday"
capacitors, store electrical charges between a series
of interleaved conducting plates. Because of their
small size, the nanotubes provide a huge surface area
on which to store and release energy, Pan said.
The new devices can produce
a power density of 30 kilowatts per kilogram (kW/kg),
compared with 4 kW/kg for the most advanced devices
currently available commercially, Pan said. Other
researchers have described laboratory supercapacitors
capable of up to 20 kW/kg, he said.
The work is published in the
Feb. 1 issue of the journal Nanotechnology.
Free access to the journal: http://www.iop.org/EJ/journal/Nano
• Ning Pan, Nanophases in the Environment, Agriculture
and Technology, (530) 752-6232, firstname.lastname@example.org
• Andy Fell, UC Davis News Service, (530) 752-4533,