Low-Temperature Operating Micro Solid Oxide Fuel Cells with Perovskite-type Proton Conductors

ABSTRACTMicro-solid oxide fuel cells (Micro-SOFCs) with yttrium-doped barium zirconate (BZY) and strontium and cobalt-doped lanthanum scandate (LSScCo) electrolytes were fabricated for low-temperature operation at 300 °C. The micro-SOFC with a BZY electrolyte could operate at 300 °C with an open circuit voltage (OCV) of 1.08 V and a maximum power density of 2.8 mW/cm2. The micro-SOFC with a LSScCo electrolyte could operate at 370 °C; its OCV was about 0.8 V, and its maximum power density was 0.6 mW/cm2. Electrochemical impedance spectroscopy revealed that the electrolyte resistance in both the micro-SOFCs was lower than 0.1 Ωcm2, and almost all of the resistance was due to anode and cathode reactions. Although the obtained maximum power density was not sufficient for practical applications, improvement of electrodes will make these micro-SOFCs promising candidates for power sources of mobile electronic devices.