George Washington University's Micro-Propulsion and Nanotechnology Laboratory researchers have constructed an ultracapacitor from a synthesised compound of grapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. flakes and single-walled carbon nanotubes, yielding better energy storage and cost savings.
The device, described in the Journal of Applied Physics, capitalizes on the synergy brought about by utilising two carbon nanostructures with complementary properties.
Single-walled carbon nanotubes and grapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. have excellent electronic, thermal, and mechanical properties that make them attractive materials for designing new ultracapacitorsUnconventional internal design yields a larger capacitanceThat property of a system of conductors and dielectrics which permits the storage of electricity when potential difference exists between the conductors. Its value is expressed as the ratio of a quantity of electricity to a potential difference. A capacitance value is always positive. per unit volume than other types. Valuable for high-current and low frequencyThe number of complete cycles or vibrations per unit of time. Rate of alternation in an AC current. Expressed in cycles per second or hertz (Hz). electrical circuits, power supply filters, etc. Applications are similar to those of rechargeable batteries., said Jian Li, first author on the paper. Many groups had explored the use of the two materials separately, but few had looked at combining them.
"In our lab we developed an approach by which we can obtain both single-walled carbon nanotubes and grapheneGraphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice., so we came up with the idea to take advantage of the two promising carbon nanomaterials together," added Michael Keidar, a professor in the Department of Mechanical and Aerospace Engineering in the School of Engineering and Applied Science at GW, and director of the Micro-propulsion and Nanotechnology Laboratory.
