Anode performance control of micro-tubular SOFC via wet coating method

A cathode-supported micro SOFC was prepared via co-sintering technique of a scandia-stabilized zirconia (ScSZ) electrolyte layer and a micro-tubular (La,Sr)_xMnO_3−δ (LSM) support, and subsequent deposition of various anode layers by dip-coating method. The micro-tubular SOFCs were electrochemically evaluated in a humidified H₂ (3% H₂O) atmosphere. An LSM-Ce_0.9Gd_0.1O_1.95 activation layer was also introduced between the cathode tube and the electrolyte layer in order to improve the catalytic activation at the cathode side. The micro SOFCs exhibited a stable open circuit voltage above 1.05 V at 650 °C, and the cells with the anode film thicknesses of 8, 30 and 50 μm generated a maximum power density of 36, 49 and 126 mW/cm², respectively. And, the cell with 50 μm thick anode layer showed about 10 times higher exchange current density than the others, which indicates that the anode performance on the cathode-supported micro SOFC was greatly affected by the thickness of the anode coating layer.     

Fabrication and characterization of a cathode-support solid oxide fuel cell by tape casting and lamination

(La_0.8Sr_0.2)_0.95MnO₃ (LSM95) cathode supported Zr_0.89Sc_0.1Ce_0.01O_2−x (SSZ) electrolytes with LSM-SSZ active cathode layers were fabricated using the tape-casting, lamination and co-sintering techniques. The loadings of pore-formers in the cathode support layers and the active cathode layers were optimized through impedance measurement on symmetrical cathode fuel cells. The pore size distribution and porosity of cathode-support substrates were measured using the mercury intrusion porosimetry. The open circuit voltage and maximum power density of cathode-support solid oxide fuel cells with NiO/SSZ cermet anodes were 1.10 V and 0.325 W cm⁻² at 750 °C with H₂ as fuels and air as oxidants.