Fabrication and Characterization of Microtubular SOFCs with Multilayered Electrolyte

Multilayered electrolytes for microtubular solid-oxide fuel cells (SOFCs) have been prepared and their electrochemical properties investigated. SC 2 O 3 -stabilized ZrO 2 (ScSZ) and Gd 2 O 3 -doped CeO 2 (GDC) were selected for the electrolyte materials; the multilayered electrolyte of GDC-ScSZ-GDC was successfully prepared on an anode tube (1.8 mm diameter) using multiple dip coating and a cofiring technique. The thickness of each electrolyte layer was about 3, 3, and 12 μm, respectively. The cell performance test showed an open-circuit voltage (OCV) of over 1 V at 600°C or higher temperature for the SOFC with a multilayered electrolyte, while a SOFC with a 12 μm thick GDC electrolyte showed an OCV of 0.84 V at 600°C. The cell performances of 0.35 W cm -2 at 0.7 V and 0.27 W cm -2 at 0.8 V were obtained for the SOFC with multilayered electrolyte at the operating temperature of 650°C.