Single-Chamber Mini-Solid Oxide Fuel Cells Operated at a Lower Temperature

The performance characteristics of a single-chamber solid oxide fuel cell (SOFCs) with micro-patterned electrode structures on the disc-type electrolyte were investigated. We selected Sm0.2Ce0.8O2-x (samarium doped ceria, or SDC) as an electrolyte, SDC-NiO cermat as an anode, and SDC-Sm0.5Sr0.5CoO3 (samarium strontium cobaltite) as a cathode for low operating temperatures (500-600 degrees C). To fabricate complex micro-patterned electrodes on electrolytes, we used microfluidic lithography. First, patterned NiO-SDC anode was sintered at 1350 degrees C for 4 hours, then SDC-SSC cathode was patterned and sintered at 1050 degrees C for 8 hours, resulting in a coplanar-type, single-chamber SOFC in which the interdigitated electrode has a 100-mu m line width and an anode-to-cathode distance of 100 mu m. A reduction condition was proposed below 350 degrees C using humidified hydrogen gas. The shape of electrode and microstructure was observed by scanning electron and optical microscopes. I-V characteristics of the SOFC were measured using a propane-air mixture gas by a DC source measure unit.