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Author Sirman, J. D. ♦ Kilner, J. A.
Sponsorship USDOE
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword DIRECT ENERGY CONVERSION ♦ MATERIALS SCIENCE ♦ CERIUM OXIDES ♦ SURFACE PROPERTIES ♦ ELECTRICAL PROPERTIES ♦ GADOLINIUM OXIDES ♦ SOLID ELECTROLYTE FUEL CELLS ♦ SOLID ELECTROLYTES ♦ LANTHANUM OXIDES ♦ STRONTIUM OXIDES ♦ IRON OXIDES ♦ COBALT OXIDES ♦ SURFACE COATING
Abstract Gadolinia-doped ceria (CGO) has potential use as an electrolyte in an intermediate temperature (500--650 C) solid oxide fuel cell (SOFC) and an oxygen separator due to its high ionic and low electronic conductivity in this temperature range. The oxygen surface exchange coefficient (k) and the self-diffusion coefficient (D*) of Ce{sub 0.9}Gd{sub 0.1}O{sub 2{minus}x} (CGO) have been measured using the isotopic exchange, depth profiling (IEDP) method using a secondary ion mass spectrometer (SIMS). At 486 C, D* was of the order of 10{sup {minus}10} cm{sup 2}/s and k was 10{sup {minus}10} cm/s. This D* is comparable with values calculated from ac impedance spectroscopy data. La{sub 1{minus}x}Sr{sub x}Fe{sub y}Co{sub 1{minus}y}O{sub 3{minus}{delta}} particles on the surface of the CGO give rise to a 100-fold increase in k at 500 C. A comparison of impedance spectroscopy results on CGO with platinum electrodes and LSFC electrodes is given, and the different electrical responses are discussed.
ISSN 00134651
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-10-01
Publisher Place United States
Journal Journal of the Electrochemical Society
Volume Number 143
Issue Number 10


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