This paper describes general characteristics and the frequency response of an energy storage device, called ultracapacitor. The device has a specific capacitance of 0.8 up to 5 F/sq cm, combined with very high energy density (greater than 6 J/g) and power density (greater than 70 W/g). By its operating principle, the ultracapacitor can be classified as a double-layer capacitor. However, in contrast to the supercapacitors, which are based on porous carbon electrodes, the ultracapacitor's electrodes consist of a thinner but extremely porous (120 sq m/g) conductive ceramic over a metallic substrate, resulting in a power density higher than those of supercapacitors by more than one order of magnitude. Double-layer charging was established as the major charge storage mechanism.
33rd International Power Sources Symposium
- Pub Date:
- Electric Energy Storage;
- Electrical Impedance;
- Frequency Response;
- Glass Fibers;
- Electronics and Electrical Engineering