Date of Thesis
Solid oxide fuel cells (SOFCs) present an opportunity to explore clean and efficient energy sources. Modeling efforts in the area of SOFC electrodes have focused largely on the infiltrate phase, while neglecting the impact of various formulation parameters on the porous and ceramic phases. As the porous and ceramic phases are critical to the function of an SOFC electrode, their performance may place additional constraints on formulation parameters. This work aims to expand an existing model to consider the porous and ceramic phases, using measurements of conductivity and the underlying physical structure to derive insights into the differing behaviors of the phases. A simplified, two-phase, non-infiltrated model found that the porous phase is more able than the ceramic phase to form direct paths through the electrode. An extension to the full three-phase system determined that the infiltrate phase is yet more able to form direct paths through the electrode, when compared to the porous and ceramic phases. It was found that, while consideration of the porous phase conductivity sets an upper bound on infiltrate loadings that produce operational electrodes, increasing the ceramic:infiltrate particle diameter ratio expands the range of allowable loadings. Likewise, increasing the post-sintering porosity of the cell expands this range. These results are presented such that they can be used to guide further modeling and experimental work exploring SOFC properties.
mathematical modeling, solid oxide fuel cells, percolation theory, conductivity, electrochemical devices
Honors Thesis (Bucknell Access Only)
Bachelor of Science in Chemical Engineering
Ryan C. Snyder
Yappert, Ryan Davis, "Modeling Competing Diffusion and Conductivity Effects in Infiltrated Solid Oxide Fuel Cells" (2016). Honors Theses. 374.