Characterization of Anode-Supported Solid Oxide Fuel Cells with Composite LSM-YSZ and LSM-GDC Cathodes

The anode-supported solid oxide fuel cells (SOFCs) with an yttria-stabilized zirconia (YSZ) electrolyte have been successfully prepared by the sequential steps of fabricating technique including tape casting, spin coating, and screen-printing. Two types of the SOFCs are manufactured and their cell performances are characterized via the detail analysis of the electrochemical impedance spectroscopy (EIS). The maximum power densities are 411 and 289 mW/cm(2) for the high and low performance cells at 800 degrees C, respectively. According to the EIS analysis, the electrochemical performance of the poor cell is dominated by the anodic noncharge-transfer resistance, which is mainly resulted by the gas diffusion polarization due to the low porosity of the anode. The high performance cell is controlled by the simultaneous contributions of the ohmic resistance (Ro), the anodic polarization (R-AP), and the cathodic polarization (R-CP) at the operation temperature of 800 degrees C. However, the R-CP will dominate the performance of the cell as the temperature is lowered down to 700 degrees C. (C) 2010 The Electrochemical Society. [DOI:10.1149/1.3527985] All rights reserved.