Abstract
Porous ceramic materials can be used for the construction of supported solid oxide fuel cells (SOFC), namely the porous support and the porous electrode. The relation between the microstructure of electrode porous support and gas diffusion is investigated.
A steady-state diffusion cell technique is employed for the measurement of effective diffusion coefficients of binary gaseous mixtures relevant to SOFC operation. Using the results obtained from the diffusion measurements and an appropriate diffusion model, a range of tortuosities is estimated. Data on the porosity and the pore size for two porous ceramic support materials are also presented. A one-dimensional model is used to relate these effective parameters to the transport of gases to and from the fuel cell anode. Therefore, losses arising from the diffusion process are quantified. The influence of change in the design specifications on the concentration polarisation of the anode is analysed and the implications of these results on the design and operation of supported SOFCs are discussed. In addition, improved microstructures for the porous supports are recommended.
A steady-state diffusion cell technique is employed for the measurement of effective diffusion coefficients of binary gaseous mixtures relevant to SOFC operation. Using the results obtained from the diffusion measurements and an appropriate diffusion model, a range of tortuosities is estimated. Data on the porosity and the pore size for two porous ceramic support materials are also presented. A one-dimensional model is used to relate these effective parameters to the transport of gases to and from the fuel cell anode. Therefore, losses arising from the diffusion process are quantified. The influence of change in the design specifications on the concentration polarisation of the anode is analysed and the implications of these results on the design and operation of supported SOFCs are discussed. In addition, improved microstructures for the porous supports are recommended.
| Original language | English |
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| Number of pages | 17 |
| Publication status | Published - 7 Oct 2004 |
| Event | Fuel Cells Science and Technology 2004 - Scientific Advances in Fuel Cell Systems - Munich, Germany, Munich, Germany Duration: 6 Oct 2004 → 7 Oct 2004 |
Conference
| Conference | Fuel Cells Science and Technology 2004 - Scientific Advances in Fuel Cell Systems |
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| Country/Territory | Germany |
| City | Munich |
| Period | 6/10/04 → 7/10/04 |
Keywords
- Supported solid oxide fuel cell, Gas-phase diffusion, Tortuosity, Concentration polarisation