MIT Energy Storage Using Carbon Nanotubes
Posted on February 8, 2006 Comments (1)
Image / Michael Ströck, Images of different types of carbon nanotubes. Carbon nanotubes are key to MIT researchers’ efforts to improve on an energy storage device called an ultracapacitor. Larger image
The LEES ultracapacitor has the capacity to overcome this energy limitation by using vertically aligned, single-wall carbon nanotubes — one thirty-thousandth the diameter of a human hair and 100,000 times as long as they are wide. How does it work? Storage capacity in an ultracapacitor is proportional to the surface area of the electrodes. Today’s ultracapacitors use electrodes made of activated carbon, which is extremely porous and therefore has a very large surface area. However, the pores in the carbon are irregular in size and shape, which reduces efficiency. The vertically aligned nanotubes in the LEES ultracapacitor have a regular shape, and a size that is only several atomic diameters in width. The result is a significantly more effective surface area, which equates to significantly increased storage capacity.