Nanotech Energy Storage with Ultracapacitors
Nanotechnology has much to offer in the field of energy storage. While much of the research is focused on improvements in batteries and fuel cells, some of the most exciting might be with ultracapacitors, because they have a much longer life than a traditional battery.
Capacitors are like batteries in that they store electrical energy. They simply store electrons on one electrode. Because like charges repel, these electrons push electrons away from any adjacent electrode. These stored electrons can then be used to power electronic gadgets.
One option being explored is making ultracapacitors with nanotubes. Capacitors have one advantage over batteries in that they can be recharged much more quickly. However, capacitors and ultracapacitors do not have as high a power density as batteries. Researchers at MIT are planning to change that by using carbon nanotubes to increase the surface area of the electrodes, thus increasing the number of electrons that can be stored.
The MIT researchers are projecting that they can produce ultracapacitors not only with a power density as great as batteries but also with a much longer lifetime than batteries, up to the lifetime of a car. These ultracapacitors could be recharged in the time it currently takes to fill up your gas tank.
If the power density of ultracapacitors does increase sufficiently to allow them to power electric cars or back up the public electricity grid, their longer lifetime (perhaps decades) would make them a better option than batteries that have to be replaced every few years.