Preparation and Characteristics of High Performance Cathode for Anode-Supported Solid Oxide Fuel Cell

Anode-supported solid oxide fuel cell (SOFC) was investigated to increase the cell power density at intermediate temperature through control of the cathode structure. The anode-supported SOFC cell were fabricated by wet process, in which the electrolyte of 8 mol% Y2O3-stabilized ZrO2 (YSZ) was coated on the surface of anode support of Ni/YSZ and then the cathode was coated. The cathode has two- or three-layered structure composed of (La0.85Sr0.15)(0.9)MnO3-x(LSM), LSM/YSZ composite (LY), and La0.6Sr0.4Co0.2Fe0.8O3(LSCF) with different thickness. Their single cells with different cathode structures were characterized by measuring the cell performance and ac impedance in the temperature range of 600 to 800 degrees C in humidified hydrogen with 3% water and air. The cell with LY 9 mu m/LSM 9 mu m/LSCF 17 mu m showed best performance of 590 mW/cm(2), which was attributed to low polarization resistance due to LY and to low interfacial resistance due to LSCF.