Carbon nanotubes could boost cellphone battery capacity tenfold

Stuart Corner
Tuesday, 29 June 2010 10:22

Business IT - Technology

Researchers at MIT have raised the prospect of increasing the capacity of cellphone batteries tenfold by using carbon nanotubes as one of a battery's electrodes.

The researchers found that using carbon nanotubes for one of the battery's electrodes produced a significant increase - up to tenfold - in the amount of power it could deliver from a given weight of material, compared to a conventional lithium-ion battery.

In the new battery electrode, according to an MIT press release,  "carbon nanotubes - a form of pure carbon in which sheets of carbon atoms are rolled up into tiny tubes '” 'self-assemble' into a tightly bound structure that is porous at the nanometre scale (billionths of a metre).

"In addition, the carbon nanotubes have many oxygen groups on their surfaces, which can store a large number of lithium ions; this enables carbon nanotubes for the first time to serve as the positive electrode in lithium batteries, instead of just the negative electrode.

The findings, by a team led by associate professor of mechanical engineering and materials science and engineering yang Shao-Horn, in collaboration with Bayer chair professor of chemical engineering Paula Hammond, are reported in a paper published June 20 in the journal Nature Nanotechnology. The lead authors are chemical engineering student Seung Woo Lee and postdoctoral researcher Naoaki Yabuuchi.

According to Hammond, this 'electrostatic self-assembly" process is important because ordinarily carbon nanotubes on a surface tend to clump together in bundles, leaving fewer exposed surfaces to undergo reactions. By incorporating organic molecules on the nanotubes, they assemble in a way that "has a high degree of porosity while having a great number of nanotubes present," she said.

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