| abstract |
A method of manufacturing a high surface area per unit weight carbon electrode includes providing a substrate, depositing a carbon-rich material on the substrate to form a film, and after the depositing, activating the carbon-rich material to increase the surface area of the film of carbon-rich material. Due to the activation process being after deposition, this method enables use of low cost carbon-rich material to form a carbon electrode in the capacitor. The electrode may be used in capacitors, ultracapacitors and lithium ion batteries. The substrate may be part of the electrode, or it may be sacrificial - being consumed during the activation process. The carbon-rich material may include any of carbonized material, carbon aerogel and metal oxides, such as manganese and ruthenium oxide. The activation may include exposing the carbon-rich material to carbon dioxide at elevated temperature, in the range of 300 to 900 degrees centigrade. This method may be used to make both symmetric and asymmetric ultracapacitors. |