The development of micro-tubular solid oxide fuel cells (SOFCs) has received more and more attention recently due to a number of advantages of this configuration, such as high volumetric power output and rapid start-up/shut-down. Previously, the fabrication of micro-tubular SOFC was achieved through multiple-step processes, which involves at least one sintering in each step, making the cell fabrication time consuming and costly. For a more economical fabrication of micro-tubular SOFC with more reliability and flexibility in quality control, an advanced dry-jet wet extrusion technique, i.e. a phase inversion-based co-extrusion process, followed by co-sintering and reduction processes has been developed and systematically investigated in this thesis. At the beginning of the study, a dual-layer hollow fibre which consists of a ceriumgadolinium oxide (CGO) electrolyte outer layer of approximately 80 μm supported by an asymmetric nickel (Ni)-CGO anode inner layer, is successfully fabricated using this technique. The resultant cell of the corresponding dual-layer hollow fibre produces the maximum power density of 0.34-0.68 W cm-2 at 550-600 oC. Improvement on the structure of the dual-layer hollow fibres is performed by reducing the electrolyte layer thickness to as thin as 10 μm and the maximum power density of the corresponding cell increases to about 1.11 W cm-2 at 600 oC. However, the value of power density is still slightly lower than what have been previously reported in the literature. One of the major reasons for such lower power output is the less effective porosity in the anode layer of hollow fibres. Therefore, the optimisation on anode porosity of the dual-layer HF is carried out and resulting in the outstanding power output of about 2.32 W cm-2 at 600 oC. This result indeed highlights the advantage of co-extrusion/co-sintering as a fabrication technique in developing high quality micro-tubular SOFC.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:555892 |
| Date | January 2011 |
| Creators | Othman, Mohd Hafiz Dzarfan Bin |
| Contributors | Li, Kang |
| Publisher | Imperial College London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/10044/1/9572 |
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