Power Generation Properties of Microtubular Solid Oxide Fuel Cell Bundle Under Pressurized Conditions

Abstract

A microtubular solid oxide fuel cell (SOFC) bundle was developed based on a new design. Anode-supported microtubular SOFCs with the cell configuration, La0.6Sr0.4Co0.2Fe0.8O3 (LSCF)-Ce0.9Gd0.1O1.95 (CGO) cathode/CGO electrolyte/Ni-CGO anode were fabricated and bundled in a porous LSCF current-collecting cube with sides of 1 cm. The power generation of the fabricated SOFC bundle was measured under pressurized conditions. Using humidified 30% H2/N2 mixture gas and air, the cubic power density of the bundle at 500°C under atmospheric pressure (0.1 MPa) was 0.47 W cm−3 at 0.4 A cm−2. With increasing operating pressure, the performance increased, and the cubic power density reached 0.66 W cm−3 at 0.6 MPa. The power enhancement brought about by pressurization was due to increased open circuit voltage and reduced polarization resistance. After comparing the power gain of the pressurized SOFC and the power consumption gain of the air compressor used for pressurization, it was found that pressurized cell operation exhibited the highest actual power gain at around 0.3 MPa.