Improved performance of La0.85Sr0.15MnO3 cathodes by sol-gel coatings

Abstract

Sol-gel coating technique has been applied to deposit films of yttria-stabilized zirconia (YSZ) or samaria-doped ceria (SDC) within tile pores of La0.85Sr0.15MnO3 (LSM) cathodes. The composite cathodes have potential advantages as the new electrode has stable and individual paths for electrons and ions due to the formation of YSZ or SDC films between electrode/electrolyte interface at low sintering temperature (<800 degreesC). For the LSM cathodes modified by sol-gel coating, percolation problems and resistive compounds, such as La2Zr2O7 and SrZrO3, were not observed. The R, of the LSM cathode modified with SDC sol was only 0.12 Omegacm(2) at 750degreesC and air atmosphere. The result implied that deposition of YSZ or SDC in the pore surface of cathode increased the area of triple phase boundary between air, LSM cathode and YSZ electrolyte, resulting in the improved cathode performance for applications in reduced-temperature solid oxide fuel cells.