Quasi-3D Modeling of Solid Oxide Fuel Cells for Combined Degradation Study

A quasi-3D model of a single solid oxide fuel cell (SOFC) considering degradation phenomena has been developed to investigate its macroscopic performance during long-term operation. Chromium poisoning, YSZ phase transformation, and interconnector oxidation are considered as the degradation modes. Chromium poisoning is modeled as a decrease in the active triple-phase boundary (TPB) length in the cathode caused by the deposition of chromia. YSZ phase transformation is modeled as a decrease in the ionic conductivity of the electrolyte depending on local temperature and oxygen partial pressure in the anode. Interconnector oxidation is modeled by Wagner’s theory considering the local temperature and oxygen partial pressure. The simulation results show that the electrochemically active area tends to avoid regions with a higher extent of degradation for all degradation phenomena. Combined degradation behavior is also investigated and discussed.