Hostname: page-component-7bb8b95d7b-dvmhs Total loading time: 0 Render date: 2024-10-04T15:31:03.876Z Has data issue: false hasContentIssue false

A New Charge Storage Mechanism for Electrochemical Capacitors and Charge Storage Density Vs. Crystalline Structure of Metal Oxides

Published online by Cambridge University Press:  15 February 2011

JP. Zheng
Affiliation:
Army Research Laboratory, Electronics and Power Sources Directorate, Mail Stop: AMSRL-EP-PB, Fort Monmouth, NJ 07703-5601
T.R. Jow
Affiliation:
Army Research Laboratory, Electronics and Power Sources Directorate, Mail Stop: AMSRL-EP-PB, Fort Monmouth, NJ 07703-5601
Get access

Abstract

The hydrous ruthenium oxide (RuO2.xH2O) powders with different contents of H20 have been formed by a sol-gel process and have been annealed at different temperatures. It was found that the specific capacitance of RuO2.xH2O is strongly dependent on the crystalline structure. The specific capacitance of over 720 F/g was obtained in an amorphous RuO2.xH2O. This value is at least two 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 RuO2.xH2O was not dependent on the specific surface area. The charge storage mechanism in amorphous RuO2.xH2O is different from that in the crystalline RuO2. The current in the cyclic voltammetric curve of RuO2.xH2O 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 10−3 Ω-cm.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Raistrick, I.D., in The Electrochemistry of Semiconductors and Electronics-Processes and Devices, edited by McHardy, J. and Luduig, F., (Noyes, New Jersey, 1992), p. 297.Google Scholar
2 Conway, B.E., in Proceeding of The Second International Seminar on Double Layer Capacitors and Similar Energy Storage Devices, (Beerfield Beach, Florida, December 7-9,1992).Google Scholar
3 Trasatti, S. and Lodi, G., in Electrodes of Conductive Metallic Oxides-Part A, edited by Trasatti, S., (Elsevier, New York, 1980), p. 301.Google Scholar
4 CRC Handbook of Chemistry and Physics, 71sf ed. edited by Lide, D.R..Google Scholar
5 Hadzi-Jordanov, S., Angerstein-Kozlowska, H., Vukovic, M. and Conway, B.E., J. Electrochem. Soc., Vol. 125, 1471 (1978).Google Scholar
6 Sierra Alcazar, H.B., KA, Kern, Mason, G.E., and Tong, R., in Proceedings of the 33rd Power Source Symposium, (Cherry Hill, NJ, June 13-16, 1988, The Electrochemical Society, Inc. 1988), p. 607.Google Scholar
7 Doblhofer, K., Metikos, M., Ognmi, Z., Gerischer, H. and Bunsenges, Ber., Phys. Chem., 82, 1046 (1978).Google Scholar
8 Trasatti, S. and Buzzanca, G., J. Electroanal Chem, 29, 1 (1971).Google Scholar
9 Sarangapani, S., Forchione, J., Griffith, A. and LaConti, A., in Proceeding of The Second International Seminar on Double Layer Capacitors and Similar Energy Storage Devices, (Beerfield Beach, Florida, December 9-11, 1991).Google Scholar
10 Kokoulina, D.V., Ivanova, T.V., Kroasovitskaya, Y.I., Kudryartseva, Z.I. and Krishtalik, L.I., Electrokhimiya, 13, 1511 (1977).Google Scholar
11 Sommerfeld, J.T. and Parravano, G., J. Phys. Chem. 69, 102 (1965).Google Scholar
12 Burk, L.D., Murphy, O.J., O’Neill, J.F. and Venkatesan, S., Faraday I, J.C.S. 23, 1659 (1977).Google Scholar
13 Kozawa, A., Extended Abstracts, Electrochemical Society Meeting, p. N29, Boston (1973).Google Scholar
14 Burke, L.D. and Whelan, D.P., J. Electroanal. Chem., 103, 179 (1979).Google Scholar
15 McBreen, J., Power Sources, ed. Collins, D.H., Academic Press, London, 5, 525 (1975).Google Scholar
16 Sato, K., Noguchi, M., Demachi, A., Oki, N. and Endo, M., Science, Vol 264, 556 (1994).Google Scholar