Numerical evaluation of micro-structural parameters of porous supports in metal-supported solid oxide fuel cells

Abstract Metallic supported Solid Oxide Fuel Cells (SOFCs) are considered as a durable and cost effective alternative to the state-of-the-art ceramic supported cell designs. In order to understand the mass and charge transport in the metal-support of this new type of cell a novel technique involving X-ray tomography and micro-structural modelling is presented in this work. The simulation technique comprises a novel treatment of the boundary conditions, which leads to more accurate effective transport parameters compared to those, which can be achieved with the conventional homogenisation procedures. Furthermore, the porosity distribution in the metal-support was determined, which provided information about the inhomogeneous nature of the material. In addition to that, transport parameters for two identified, different dense layers of the metal-support are evaluated separately. The results of the evaluation show three significant findings. Firstly, that the effective transport parameters are up to a factor of 20 lower compared to other SOFC anodes. Secondly, that the micro-structure can have regions, which are much denser, especially the first 100 μm of the interface between gas-channel and support-structure. Thirdly, that the calculation of the transport parameters depends on the correct application of boundary conditions.