Electrochemical Characterization of Air Plasma Sprayed LSM/YSZ Composite Cathodes on Metallic Interconnects

Abstract

Porous composite cathodes composed of (La0.8Sr0.2)0.98MnO3-y (LSM) and yttria stabilized zirconia (YSZ) have been produced by axial air plasma spraying on porous metal interconnect substrates and characterized by scanning electron microscopy (SEM). Cathodes with different microstructures were produced by varying the input parameters of the APS process to determine the effect of this variation on cathode microstructure and performance. Symmetrical double-cathode cells with YSZ electrolytes produced by plasma spraying were also fabricated for comparison of electrochemical performance at temperatures ranging from 650{degree sign}C to 900{degree sign}C, using electrochemical impedance spectroscopy (EIS) to correlate the microstructural quality with the cathode polarization resistance. Values of the APS process parameters most suitable for the deposition of LSM/YSZ composite cathodes were identified, and post-testing analysis of the symmetrical cells was carried out to examine the degradation of the metal substrate and cathodes.