Cell configuration for performance evaluation in planar solid oxide fuel cells

Cell configurations with asymmetric and symmetric electrode geometries and different reference electrode positions were investigated on 50 mm x 50 mm planar solid oxide fuel cells (SOFC). The reliability and accuracy of the polarization performance of individual electrodes were studied with respect to the electrode geometry and the reference electrode position. The results indicate that a centrally located reference electrode creates inactive electrolyte regions in the center of the cell, pushing the equipotential lines close to the electrode-electrolyte interface region and thus introducing error in the measurement of polarization performance. The potential of reference electrodes located at the corner of the electrode coating was not stable due to the steam build-up in the reference electrode region. Cells with a symmetric electrode geometry arrangement and reference electrodes located at the side of the working electrodes, away from the receiving end of the fuel and oxidant gases, were found to be suitable for performance evaluation in planar SOFC.