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High-performance gadolinia-doped ceria-based intermediate-temperature solid oxide fuel cells
| Content Provider | Semantic Scholar |
|---|---|
| Author | Liu, Qinglin |
| Copyright Year | 2007 |
| Abstract | Solid oxide fuel cells (SOFCs) are a highly efficient and environmentally benign device for power generation, which have drawn great attention in recent decades. However, the high operating temperature (~1000°C) of conventional SOFCs has imposed stringent materials and processing requirements and this has prevented SOFCs from commercialisation. Therefore, it is quite desirable to operate SOFCs at intermediate temperatures (500~800oC). The work presented in this thesis gives an in-depth investigation on the fabrication, characterisation and performance improvement of intermediate temperature SOFCs based on gadolinia-doped ceria (GDC) electrolyte material. The sintering behaviour and electrical properties of GDC electrolytes were studied using nanosized GDC powder with an average particle size of ~5 nm as the raw material. It was found that calcining the raw powder at 750°C would significantly improve the sinterability of the as-received GDC powder. The effect of microstructure on the ionic conductivity of GDC electrolytes was investigated with AC impedance spectroscopy. It was found that the grain interior conductivity is predominantly related to the relative density and insensitive to the grain size of the electrolyte, whereas the grain boundary conductivity is strongly related to both the relative density and the grain size of the electrolyte. The electrochemical properties of (La,Sr)(Co,Fe)O3 (LSCF) and LSCF-GDC cathodes on GDC electrolyte were evaluated. It was found that sintering temperature, microstructure and composition have great effects on the cathode performance. After sintering at 900°C for 2 h, the LSCF cathode produced an optimal polarisation resistance of 2.54 Ωcm at 600°C. The addition of 50 wt.% GDC to LSCF cathode generated a polarisation resistance of 0.26 Ωcm at 600°C, a reduction by a factor of 9. i ATTENTION: The Singapore Copyright Act applies to the use of this document. Nanyang Technological University Library |
| File Format | PDF HTM / HTML |
| DOI | 10.32657/10356/5253 |
| Alternate Webpage(s) | https://repository.ntu.edu.sg/bitstream/handle/10356/5253/MAE-THESES_1007.pdf;jsessionid=D6381FB220CF5A51907DE89CFDC7E534?sequence=1 |
| Alternate Webpage(s) | https://doi.org/10.32657/10356%2F5253 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
