Investigation of Cathode Kinetics in SOFC: Model Thin Film SrTi_(1-x)Fe_xO_(3-δ) Mixed Conducting Oxides
- Creators
- Jung, WooChul
- Tuller, Harry L.
- Others:
- Singhal, S.
- Eguchi, K.
Abstract
To understand the kinetics controlling the SOFC cathode processes, a model mixed conducting perovskite materials system, SrTi_(1-x)Fe_xO_(3-δ), was selected, offering the ability to systematically control both the levels of electronic and ionic electrical conductivity as well as the energy band structure. This, in combination with considerably simplified electrode geometry, served to demonstrate that the rate of oxygen exchange at the surface of SrTi_(1-x)Fe_xO_(3-δ) is only weakly correlated with either high electronic or ionic conductivity, in apparent contradiction with common expectations. On the other hand, evidence was found suggesting the importance of minority electronic species in determining the rate of oxygen exchange. Furthermore, the enrichment of Sr to the surface of the electrodes was found to reduce the oxygen exchange rate constant; this effect becoming more evident with increasing values of x. The observed trends are discussed in relation to the cathodic behavior of MIEC electrodes.
Additional Information
© 2011 The Electrochemical Society. This work was initially supported by the Ceramics Program, Division of Materials Research Directorate for Mathematical & Physical Sciences, National Science Foundation under award DMR-0243993 and continued under the Materials Science and Engineering Division, Office of Basic Energy Sciences, Department of Energy under award DE SC0002633. W.J. Thanks the Samsung Foundation for fellowship support. The authors thank Dr. R.A. De Souza and Dr. J. Fleig for helpful discussions. The x-ray, XPS and AFM facilities of the Center for Materials Science and Engineering, an NSF MRSEC funded facility, were used in this study.Attached Files
Published - ISI000300770104015Proceedings.pdf
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Additional details
- Eprint ID
- 30070
- Resolver ID
- CaltechAUTHORS:20120412-134556825
- DMR-0243993
- NSF
- DE SC0002633
- Department of Energy (DOE) Materials Science and Engineering Division
- Samsung Foundation
- Created
-
2012-04-17Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field
- Series Name
- ECS Transactions
- Series Volume or Issue Number
- 35