STRUCTURE AND PERFORMANCE OF La_(0.6)Sr_(0.38)MnO_(3-z)-YSZ COMPOSITE CATHODE

摘要

The composite cathode of La_(0.6)Sr_(0.38)MnO_(3-z) and YSZ was found to yield lower cathodic overpotential than non-composite one. The structure of the composite cathode has been studied to further decrease the cathodic overpotential. The dependence of the overpotential on the electrode thickness has been studied. The powder size of 1.25 μm, and the electrode thickness of about 20 μm were optimum within the range studied. The reason for giving optimum values is discussed in terms of the triple phase boundary and the oxygen mass transport flux in gas phase. It was found that the electrode structure where oxygen is transported sufficiently at high current density plays an important role in decreasing the overpotential.