Abstract: Methods and apparatus for an electrochemical double-layer capacitor using nanotube structures. An electrochemical double-layer capacitor includes a first carbon nanotube-based electrode and a second carbon nanotube-based electrode mixed with an electrolyte, the carbon nanotubes comprising multiwall carbon nanotubes (MWNT) fabricated on one of a plurality of substrates using chemical vapor deposition (CVD), and a separator disposed between the first carbon nanotube-based electrode and the second carbon nanotube-based electrode.

Abstract: Engineered structure for charge storage. An electrolyte is disposed between two electrically conducting plates, each plate serving as a base for an aligned array of electrically conducting nanostructures extending from the surface of each plate into the electrolyte. The nanostructures have diameter and spacing comparable to the dimension of an ion of the electrolyte. An electrically insulating separator is disposed between the two plates. A CVD process (or other processes yielding similar results) is used to make the aligned array of electrically conducting nanostructures.