Modeling of Transport Mechanisms in SOFCs with Microstructure Reconstruction of Porous Electrodes

In this study, different mass and charge transport mechanisms for SOFCs are analyzed. Various reaction mechanisms are used on both anode and cathode with properties obtained from microstructure reconstruction of porous materials. Micro scale dynamics modeling of oxygen reduction on LSM/YSZ composite cathodes and detailed reaction mechanisms on anodes are incorporated in our simulation. To be more realistic, the microstructures of porous electrodes are reconstructed based on experimental observations, and the corresponding properties, e.g. specific interface area and porosity, are included in our simulation. With the validation of our full cell model by comparing with the results of other simulations and experiments, we predict the performances of SOFCs, e.g. concentrations, polarization, electrochemical impedance etc. Moreover, a parametric study is performed with the full cell model using different distributions of porosity. The resulting amplitude and frequency of impedance changing with the different porosity distributions are analyzed. The results obtained further better understanding of the processes that occur in SOFCs.