Measurement of phenomenological coefficients for modeling of the coupled heat and mass transfer in 10Sc1CeSZ solid oxide ceramics

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This follow-up proposal refers to an overall project that aims at modelling oxide ceramic fuel cells and electrolyzers based on the phenomenological theory of irreversible processes (TIP). This modelling aims at locally resolved temperature-, concentration and potential fields, which can then be compared with results from conventional models with monocausal transport approaches. In the current project, the phenomenological coefficients necessary for modelling the coupled transport processes in the electrolyte of a SOFC, i.e. the ion conductivity at a constant temperature, the thermal conductivity at constant electrochemical potential and the coupling coefficients between ion flow and temperature gradients, are determined experimentally. With these coefficients, first calculations on temperature and potential profiles in the electrolyte of a SOFC under different load conditions could be carried out, based on the TiP approach, and compared with the conventional model approaches. Since these initial comparisons have already revealed significant deviations in the calculated temperature profiles normal to the electrode area, which also affect the local temperature distribution at the anode and cathode, this TiP modelling shall be validated experimentally for an entire cell in the follow-up project and also be extended to oxide ceramic electrolysis. To calculate the temperature curves, the radiative energy transport and the electrochemical reactions within the electrodes on the cathode and anode side, which were previously excluded, must also be taken into account in the TiP model approach. The model will then be validated through extensive experiments.