Improvement of Micro Tubular SOFCs using Multi-Layered Electrolyte

Fabrication technology of multi-layered electrolyte for micro tubular SOFCs has been developed. Sc2O3 stabilized ZrO2(ScSZ) and Gd2O3-doped CeO2 (GDC) was selected for the electrolyte materials and a GDC-ScSZ-GDC multi-layered electrolyte was successfully prepared using multiple dip coating and co-firing technique. The thickness of each layer for the electrolyte was about 3, 3, and 12 micron, respectively. The cell performance test showed the open circuit voltage (OCV) of over 1 V at 600oC or higher, while a SOFC with 10 micron thick GDC electrolyte showed the OCV of 0.78 V at 600oC. The cell performance of 0.35 Wcm-2 @ 0.7 V was obtained at the operating temperature of 650 oC.