Abstract
Degradation phenomena of La0.58Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathodes were investigated via post-mortem analyses of an experimental solid oxide fuel cell (SOFC) stack tested at 700 °C for 2000 h using advanced electron microscopy (SEM-EDS, HR-TEM-EDS) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Similar studies were carried out on non-tested reference cells for comparison. The analysis focused on the LSCF/CGO cathode and the CGO barrier layer, as the cathode degradation can be a major contributor to the overall degradation in this type of SOFC. SEM-EDS and TOF-SIMS were used to investigate inter-diffusion across the barrier layer - electrolyte interface and the barrier layer - cathode interface. In addition, TOF-SIMS data were employed to investigate impurity distribution before and after testing. HR-TEM-EDS was used to investigate possible phase segregation in the LSCF and to look for reaction between the phases. The results show that phase separation and inter-diffusion across the cathode-barrier layer interface and the barrier layer-electrolyte interface happened mainly during sintering and cathode firing, and to a very little degree during the test period.
Original language | English |
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Journal | Journal of Power Sources |
Volume | 283 |
Pages (from-to) | 151-161 |
ISSN | 0378-7753 |
DOIs | |
Publication status | Published - 2015 |
Keywords
- Cathode degradation
- LSCF
- SEM
- SOFC
- TEM
- TOF-SIMS
- Cathodes
- Diffusion barriers
- Electrodes
- Electrolytes
- Fuel cells
- Mass spectrometry
- Organic polymers
- Phase separation
- Scanning electron microscopy
- Secondary ion mass spectrometry
- Sintering
- Solid oxide fuel cells (SOFC)
- Transmission electron microscopy
- Cathode degradations
- Electrolyte interfaces
- Impurity distribution
- Phase segregations
- Post mortem analysis
- Time of flight secondary ion mass spectrometry
- ToF SIMS
- Solid electrolytes