Carbon nanotubes dramatically increase lithium battery capacity @ Massachusetts Institute of Technology

Author(s):

Yang Shao-Horn (MIT MRSEC, IRG-I) and Paula Hammond (MIT MRSEC, IRG-II)

Shao-Horn and Hammond of the MIT MRSEC have found that using carbon nanotubes to fabricate a lithium battery’s electrodes produced a significant increase in the amount of power it could deliver, compared to a conventional lithium-ion battery.

To produce the powerful new electrode material, the team used a layer-by-layer fabrication method, in which a base material is alternately dipped in solutions containing carbon nanotubes — a form of pure carbon in which sheets of carbon atoms are rolled up into tiny tubes.
Lithium batteries with the new material demonstrate energy output that is five times greater than for conventional capacitors, and a total power delivery rate 10 times that of lithium-ion batteries. In addition to their high power output, the carbon-nanotube electrodes showed very good stability over time. After 1,000 cycles of charging and discharging a test battery, there was no detectable change in the material’s performance.

In its present form, the material might have applications for small, portable electronic devices, but if the reported high-power capability were demonstrated in a much thicker form, it might eventually be suitable for other applications such as hybrid cars.

Image: TEM image of a layer-by-layer MWNT electrode slice, showing pore sizes on the order of ~20 nm.

Related publication(s):

1. S.W. Lee, N. Yabuuchi, B.M. Gallant, S. Chen, B.-S, Kim, P.T. Hammond, and Y. Shao-Horn. High-power lithium batteries from functionalized carbon-nanotube electrodes. Nature Nanotechnology 5, 531-537 (20 June 2010) doi:10.1038/nnano.2010.116 Article