Experiments and Modeling of Electrochemical Impedance Spectroscopy on Pressurized SOFC

Kurzfassung

For this contribution a combined experimental and modeling approach was used. Impedance measurements were performed on a five-cell anode-supported SOFC short stack at pressures between 1 and 8 bar. Each cell has an active area of 84 cm². Impedance spectra were taken at OCV and increasing current densities up to 25 A. The multi-scale model used for the simulations is based on an in-house software [4] and is representing the system including the electrochemical reactions on the surface of the electrodes, gas transport within the porous electrodes and in the gas channels on cell level and the thermal coupling of five cells to include temperature-related effects on stack level. The model was validated with current/voltage characteristics and impedance measurements in a wide range of operating conditions