Characterization of Electrochemical Properties of Micro-Tubular SOFCs

Micro-tubular Solid Oxide Fuel Cells (SOFCs) are fabricated and tested for analysis of electrochemical properties. The impedance spectra from individual 1.8 mm diameter, 1.2 cm length micro-tubular SOFCs are obtained for the intermediate temperature range of 450–550°C. The micro-tubular SOFC used is anode supported, consisting of a NiO and Gd_0.2Ce_0.8O_2−x (GDC) cermet anode, thin GDC electrolyte, and a La_0.6Sr_0.4Co_0.2Fe_0.8O_3−y (LSCF) and GDC composite cathode. The impedance information gained at cell operating temperatures of 450, 500, and 550°C yielded power density losses of 0.8, 2.3, and 4.6% respectively. Within the operating temperature range of 450–550 °C, the ceria based 1.8 mm micro-tubular SOFCs were found to have a power densities ranging between 180–740 mW/cm².