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Performance and impedance studies of thin, porous molybdenum and tungsten electrodes for the alkali metal thermoelectric converterColumnar, porous, magnetron-sputtered molybdenum and tungsten films show optimum performance as alkali metal thermoelectric converter electrodes at thicknesses less than 1.0 micron when used with molybdenum or nickel current collector grids. Power densities of 0.40 W/sq cm for 0.5-micron molybdenum films at 1200 K and 0.35 W/sq cm for 0.5-micron tungsten films at 1180 K were obtained at electrode maturity after 40-90 h. Sheet resistances of magnetron sputter deposited films on sodium beta-double-prime-alumina solid electrolyte (BASE) substrates were found to increase very steeply as thickness is decreased below about 0.3-double-prime 0.4-micron. The ac impedance data for these electrodes have been interpreted in terms of contributions from the bulk BASE and the porous electrode/BASE interface. Voltage profiles of operating electrodes show that the total electrode area, of electrodes with thickness less than 2.0 microns, is not utilized efficiently unless a fairly fine (about 1 x 1 mm) current collector grid is employed.
Document ID
19890025248
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Wheeler, B. L. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Williams, R. M. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Jeffries-Nakamura, B. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Lamb, J. L. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Loveland, M. E. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Bankston, C. P. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Cole, T. (California Institute of Technology Jet Propulsion Laboratory, Pasadena, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1988
Publication Information
Publication: Journal of Applied Electrochemistry
Volume: 18
ISSN: 0021-891X
Subject Category
ELECTRONICS AND ELECTRICAL ENGINEERING
Distribution Limits
Public
Copyright
Other