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nanotimes
10-02 :: February 2010
News in Brief
Energy //
New Storage Devices out of Paper and Cloth
E
ngineer Yi Cui and his team from Stanford University have manufactured new energy storage devices out
of paper and cloth, with a range of potential applications. With an extremely simple “dipping and drying”
process using single-walled carbon nanotube (SWNT) ink, they produced highly conductive textiles with
conductivity of 125 S cm
−1
and sheet resistance less than 1 Ω/sq.
Such conductive textiles show outstanding flexibility and stretchability and demonstrate strong adhesion bet-
ween the SWNTs and the textiles of interest. Super-
capacitors made from these conductive textiles show
high areal capacitance, up to 0.48F/cm
2
.
The findings hold promise for the development of
rechargeable lithium batteries offering a longer life
cycle and higher energy capacity than their contem-
poraries.
“These nanomaterials are special,” Cui said. “They‘re
a one-dimensional structure with very small diame-
ters.” The small diameter helps the nanomaterial ink
stick strongly to the fibrous paper, making the battery
and supercapacitor very durable. The paper super-
capacitor may last through 40,000 charge-discharge
cycles – at least an order of magnitude more than
lithium batteries. The nanomaterials also make ideal
conductors because they move electricity along much
more efficiently than ordinary conductors, Cui said.
“This technology has potential to be commer-
cialized within a short time,“ said Peidong Yang,
professor of chemistry at the University of California-
Berkeley. “I don‘t think it will be limited to just ener-
gy storage devices,” he said.