Thermal modeling of a small anode supported solid oxide fuel cell

A combined thermal and simple kinetic model is applied to a small single solid oxide fuel cell (SOFC, 20 cm2 square cell of anode supported electrolyte with 1 cm2 active area). The aim was to compute the temperature field to analyze the operating conditions of the active area of the cell. The cell is simulated in the conditions used for electrochemical characterization, i.e. at negligible fuel utilization and thermally non-adiabatic. Though using a very simple kinetic model, the simulated polarization curves fit the experimental results at high current density where the curve slope tends to decrease. The simulated temperature field shows clearly that this aspect of the curve is explained by a local temperature increase (of 30 K at 1 A/cm2). The temperature of the active area can be plotted versus the current and this result fits previous measurements. Finally, the temperature profile simulated shows that, with the usual temperature measurement used in standard electrochemical testing, a few millimeters away from the active surface, does not detect the effective cell temperature. In a stack modeling perspective, the quality of the kinetic model used is essential. This model, combined with a parameter estimation tool, allows using experimental results to end, from routine measurements, with an accurate and up-to-date kinetic model.