Date of Thesis

2016

Description

Fuel cell technology is a viable alternative energy source to the classic combustion of fossil fuels that will raise efficiencies and lower emissions. Solid oxide fuel cells in particular can use a variety of fuels with extremely high efficiencies and cleanliness. A key limitation to the deployment of solid oxide fuel cells are the high operating temperatures which causes lower system stability, higher system complexities, and raises costs. Infiltrated solid oxide fuel cell electrodes help avert this problem, however not much is known about how input variables affect electrode performance. This thesis will investigate how two specific input variables affect electrode performance; particle morphology and partial electron conductivity in the oxygen conducting phase.

In this investigation, a mechanistic model is used to simulate the creation process for solid oxide fuel cell electrodes. The impetus behind using a model is that developing solid oxide fuel cell electrodes is expensive and time consuming. A model will allow the scientific community to direct their experiments such that they are more cost and time efficient. The results from the model show that macro scale morphology changes (such as spheres to plates) boost certain performance parameters while not affecting others. Furthermore, micro scale morphology changes (such as surface area to volume ratio) affect performance parameters to a greater extent. The results also show that adding partial electron conductivity to the oxygen ion conducting phase boosts electron conductivity. The magnitude of this boost depends on the amount of electron conductivity added to the oxygen ion conducting phase and this amount is nonlinear with the amount of electron conductivity added.

Keywords

sofc, solid oxide fuel cells, modeling, tpb density, three phase boundary density, electrical conductivity, effective electrical conductivity, percolation threshold, matlab, fortran, morphology, partial electron conductivity, alternative energy, fossil fuels, ysz, oxidation of fossil fuels

Access Type

Masters Thesis (Bucknell Access Only)

Degree Type

Master of Science in Chemical Engineering

Major

Chemical Engineering

First Advisor

Ryan C. Snyder

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