Long-term performance of anode-supported SOFC integrated with metal interconnect by joining process

Abstract

Using relatively simple and cheap joining process, anode-supported solid oxide fuel cell integrated with metal interconnect is fabricated and its impedance spectra are analyzed and compared with anode-supported cell at the operating temperature of 800 degrees C. The stable long-term performance is shown for about 800h at 800 degrees C under the constant current density of 300 mA cm(-2). The thermal cycle experiments from the operating temperature to the room temperature are also carried out in this study, while the maximum power density of 0.7W cm(-2) is indicated. The microstructures are analyzed using scanning electron microscope and energy dispersive X-ray spectra are analyzed for observing a diffusion of metal ions at the anode, adhesion layer and metal support. The diffusions of Fe and Cr from the adhesion layer to the inside of the anode occur during the operation and/or fabrication process, in which the diffused amount of Fe exceeds the value of Cr. It is considered that the undesired diffusions of Fe and Cr into the anode layer may cause the electrode degradation, but the anodic polarization decreases as the cell operation continues.(C) 2010 Published by Elsevier Ltd on behalf of Professor T. Nejat Veziroglu.