Characterization of Sr-doped LaMnO{sub 3} and LaCoO{sub 3} as cathode materials for a doped LaGaO{sub 3} ceramic fuel cell
- Univ. of Texas, Austin, TX (United States). Center for Material Science and Engineering
Energy dispersive spectrometry line scan and ac impedance spectroscopy were used in this study to investigate the chemical reactions between two cathode materials, La{sub 0.84}Sr{sub 0.16} MnO{sub 3} (LSM), La{sub 0.5}Sr{sub 0.5}CoO{sub 3{minus}{delta}} (LSC), and the electrolyte La{sub 0.9}Sr{sub 0.1}Ga{sub 0.8}Mg{sub 0.2}O{sub 2.85} (LSGM). Significant interdiffusions of Co into LSGM and Ga into LSC were found at an LSC/LSGM interface even at relatively low fabrication temperatures. In contrast, only small interdiffusion of Mn into LSGM and Ga into LSM were detected at the LSM/LSGM interface even though it was fired at 1,470 C. The ac impedance spectra of the electrolyte LSGM with LSM, LSC, and Pt electrodes indicate a grain-boundary contribution to the total conductivity in the intermediate frequency range and a diffusion-controlled impedance in the low-frequency range. Irrespective of chemical reactions and a larger thermal expansion coefficient, LSC has the lowest dc resistance of all three electrodes investigated. Considering both the small interdiffusion reactions between LSM and LSGM and their similar thermal expansion coefficients, LSM could be an appropriate cathode material for LSGM-based fuel cells.
- Sponsoring Organization:
- Electric Power Research Inst., Palo Alto, CA (United States)
- OSTI ID:
- 428170
- Journal Information:
- Journal of the Electrochemical Society, Vol. 143, Issue 11; Other Information: PBD: Nov 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells
Materials System for Intermediate Temperature Solid Oxide Fuel Cell