Yttria-doped bismuth (YDB) and gadolinia-doped ceria (GDC) are investigated as a bilayer electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). LSM-YDB is used as a cathode material in order to improve the poor ionic conduction of LSM and the compatibility with the YDB electrolyte. The performance of the bilayer cell was measured under humidified H2 (3 % H2O) atmosphere and an operating temperature between 500 C and 650 C. The polarization resistance and ohmic resistance of the GDC-YDB bilayer cell were 0.189 cm2 and 0.227 cm2 at 650 C, respectively. The bilayer cell showed 0.527 Wcm-2 in the maximum power density at 650 C, which is about two times higher than the single-layer cell of 0.21 Wcm -2. The OCV of the bilayer cell was 0.89 V at 650 C, suggesting that the electronic conduction caused by the reduction of ceria was successfully suppressed by the YDB layer. The introduction of an YDB-GDC bilayer cell with LSM-YDB cathode thus appears to be a promising method for improving the performance of GDC-based SOFCs and reducing operating temperature.
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Acknowledgments This work was supported by the New & Renewable Energy (No. 20093021030021) and the Human Resources Development (No. 20104010100500) under the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korean Ministry of Knowledge Economy.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Mechanics of Materials
- Electrical and Electronic Engineering
- Materials Chemistry