Surface exchange properties of Ce{sub 0.9}Gd{sub 0.1}O{sub 2{minus}x} coated with La{sub 1{minus}x}Sr{sub x}Fe{sub y}Co{sub 1{minus}y}O{sub 3{minus}{delta}}
- Imperial Coll. of Science, Technology and Medicine, London (United Kingdom). Dept. of Materials
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.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 404647
- Journal Information:
- Journal of the Electrochemical Society, Vol. 143, Issue 10; Other Information: PBD: Oct 1996
- Country of Publication:
- United States
- Language:
- English
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