Thermo-mechanical stability of multi-scale-architectured thin-film-based solid oxide fuel cells assessed by thermal cycling tests

The thermo-mechanical stability of a thin-film and nanostructure-based SOFC (TF-SOFC) is assessed by thermal cycling tests. An ultrathin bi-layer electrolyte composed of 150-nm-thick yttria-stabilized zirconia (YSZ) and 450-nm-thick gadolinia-doped ceria (GDC) is successfully built on a NiO-YSZ anode support the microstructure scale of which changes from mu m to nm (multi-scale architecture). The concept of multi-scale architecture in the TF-SOFC not only enables the reliable implementation of thin-film electrolytes and nanostructured electrodes to improve the critical low-temperature performance of the SOFC but also secures the thermo-mechanical stability of TF-SOFC. Competent cell performance is obtained, including a peak power density about 1.4 W cm-2 at 600 degree C. The TF-SOFC survives 50 thermal cycle tests between 600 and 400 degree C over 124 h without suffering a drastic failure. Although some cell output degradation is observed after the thermal cycling tests, the cell sustains a peak power density over 1 W cm-2 at 600 degree C, which indicates the superior thermo-mechanical stability of the multi-scale-architectured TF-SOFC.