A new charge storage mechanism for electrochemical capacitors and charge storage density vs. crystalline structure of metal oxides
- Army Research Lab., Fort Monmouth, NJ (United States). Electronics and Power Sources Directorate
The hydrous ruthenium oxide (RuO{sub 2}{center_dot}xH{sub 2}O) powders with different contents of H{sub 2}O have been formed by a sol-gel process and have been annealed at different temperatures. It was found that the specific capacitance of RuO{sub 2}{center_dot}xH{sub 2}O is strongly dependent on the crystalline structure. The specific capacitance of over 720 F/g was obtained in an amorphous RuO{sub 2}{center_dot}xH{sub 2}O. This value is at least times greater than ever reported of this type of material. The specific capacitance dropped rapidly as the amorphous phase transforms into the crystalline phase at high temperatures. In contrast to the crystalline phase the specific capacitance of an amorphous RuO{sub 2}{center_dot}xH{sub 2}O was not dependent on the specific surface area. The charge storage mechanism in amorphous RuO{sub 2}{center_dot}xH{sub 2}O is different from that in the crystalline RuO{sub 2}. The current in the cyclic voltammetric curve of RuO{sub 2}{center_dot}xH{sub 2}O is nearly constant and is symmetrical with the potential in a range of 1 volts. The resistivity of pellets made from these powders is in the order of 10{sup {minus}3} {Omega}-cm.
- OSTI ID:
- 162946
- Report Number(s):
- CONF-950412--; ISBN 1-55899-296-0
- Country of Publication:
- United States
- Language:
- English
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