Electrochemical characterization and modeling of anode supported solid oxide fuel cell

A commercial 100 cm² anode supported SOFC operated with hydrogen has been characterized under power generation using polarization and impedance measurements as well as modeling approaches. Both the experiments and simulations were made with three different flow rates and currents between 0 and 60 A at constant cell temperature of 750°C. The cell voltage was 0.85 V at 60 A in the case where the fuel and oxidant utilizations were 50%. Impedance measurements were used to determine the ionic conductivity of the electrolyte, which was 1.2 S m⁻¹. Impedance measurements also revealed that the anode is the main contributor in the mass transfer limitations of the cell. The SOFC model presented here includes the electrochemical and adsorption reactions, gas phase mass transfer at the anode and cathode, and ionic conductance in the electrodes and electrolyte. The model had eight unknown variables describing the electrochemical activity of the cell, and the parameters could be fitted to correspond to the results well. The most sensitive parameter in the simulations appeared to be the electrochemical mass transfer coefficient of the anode.