authors |
Fagg, DP; Kharton, VV; Frade, JR |
nationality |
International |
journal |
JOURNAL OF ELECTROCERAMICS |
author keywords |
gadolinia-doped ceria; solid electrolyte; sintering aid; transference number; hole conductivity |
keywords |
FUEL-CELLS; DOPED CE(GD)O2-DELTA; IONIC-CONDUCTION; CERIA; ELECTROLYTES |
abstract |
Small (2 mol%) additions of cobalt, iron and copper oxides into Ce0.8Gd0.2O2-delta considerably improve sinterability of ceria-gadolinia (CGO) solid electrolyte, making it possible to obtain ceramics with 95-99% density and sub-micron grain sizes at 1170-1370 K. The minor dopant additions have no essential effect on the total and ionic conductivity, whilst the p-type conduction in the transition metal-containing materials at 900-1200 K is 8-30 times higher than that in pure CGO. The oxygen ion transference numbers of the Co-, Fe- and Cu-doped ceramics, determined by the modified e.m.f. technique under oxygen/air gradient, are in the range 0.89-0.99. The electron-hole contribution to the total conductivity increases with temperature, as the activation energy for ionic conduction, 78 to 82 kJ/mol, is significantly lower than that for the p-type electronic transport (139-146 kJ/mol). The results show that CGO sintered with such additions can still be used as solid electrolytes for intermediate-temperature electrochemical applications, including solid oxide fuel cells (SOFCs) operating at 770-970 K, but that increasing operation temperature is undesirable due to performance loss. |
publisher |
SPRINGER |
issn |
1385-3449 |
year published |
2002 |
volume |
9 |
issue |
3 |
beginning page |
199 |
ending page |
207 |
digital object identifier (doi) |
10.1023/A:1023269326651 |
web of science category |
Materials Science, Ceramics |
subject category |
Materials Science |
unique article identifier |
WOS:000182098200007
|
ciceco authors
impact metrics
journal analysis (jcr 2019):
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journal impact factor |
2.588 |
5 year journal impact factor |
1.735 |
category normalized journal impact factor percentile |
76.786 |
dimensions (citation analysis):
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altmetrics (social interaction):
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