US Patent 7209341 - Carbon nanohorn supercapacitor

http://www.freepatentsonline.com/7209341.html

While carbon nanotubes are by far the more common nanostructure, other carbon nanostructures such as carbon nanohorns may have some advantages in achieving higher surface area to volume ratios, which is particularly advantage in forming electrodes for supercapacitors. This patent from NEC claims:

1. A polarizing electrode composed of a carbon composite: wherein, as a carbon material of said carbon composite, a single-layer carbon nanohorn aggregate, which is made in such a manner that the single-layer carbon nanohorns are aggregated spherically, is used; and wherein said single-layer carbon nanohorn aggregate is supported by a carbon fiber or a carbon nanofiber.