Oxygen chemical potential variation in ceria-based solid oxide fuel cells determined by Raman spectroscopy

Citation
A. Mineshige et al., Oxygen chemical potential variation in ceria-based solid oxide fuel cells determined by Raman spectroscopy, SOL ST ION, 135(1-4), 2000, pp. 481-485
Citations number
16
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
SOLID STATE IONICS
ISSN journal
01672738 → ACNP
Volume
135
Issue
1-4
Year of publication
2000
Pages
481 - 485
Database
ISI
SICI code
0167-2738(200011)135:1-4<481:OCPVIC>2.0.ZU;2-#
Abstract
The profile of oxygen chemical potential in 20 mol% Sm-doped ceria Ce0.8Sm0 .2O2-delta (SDC) at 1273 K under the open-circuit conditions of solid oxide fuel cells was determined using Raman spectroscopy. SDC pellets were annea led in various atmospheres, and a peak intensity of a Raman band of SDC in the range 540-600 cm(-1), which has been assigned to a band that originates in the oxygen vacancies, increased with decreasing oxygen partial pressure [P(O-2)] upon annealing. A clear relationship between the peak area of the oxygen-vacancy band and P(O-2) upon annealing was obtained. This relations hip was used to determine the profile of oxygen partial pressure, P(O-2), i n SDC located between fuel and air. The experimental profile was in good ag reement with that obtained theoretically. The profile revealed that most pa rt of SDC was mixed conductive and only a thin layer adjacent to the air si de remained purely ionic conductive under the open-circuit conditions of SO FCs. (C) 2000 Elsevier Science B.V. All rights reserved.