Synthesis of LSM-YSZ-GDC dual composite SOFC cathodes for high-performance power-generation systems

Abstract

This article investigates a method in further improvement of a (La-0.8,Sr-0.2)MnO3 (LSM)-Yttria-stabilized zirconia (YSZ) dual composite cathode by adding material with high ionic conductivity such as gadolinia-doped ceria (GDC). A nano-porous composite cathode containing LSM, YSZ, and GDC was prepared by a two-step polymerizable complex (PC) method which minimizes the formation of YSZ-GDC solid solution. The structure of the resulting LSM/GDC-YSZ dual composite cathode was such that the LSM and GDC phases were present on the YSZ core particles without formation of the La2Zr2O7, SrZrO3, and GDC-YSZ solid solution. At 800 A degrees C, the electrode polarization resistance of the LSM/GDC-YSZ dual composite cathode decreased to 0.266 a"broken vertical bar cm(2), compared with 0.385 a"broken vertical bar cm(2) for the LSM/YSZ-YSZ dual composite cathode. In addition, the Ni-YSZ anode-supported single cell using a LSM/GDC-YSZ dual composite cathode with H-2 as the fuel achieved a maximum power density of 0.65 W cm(-2) at 800 A degrees C.