Cathodic overpotential of La0.6Sr0.4CoO3 and its composite cathodes LSC–LSGM on LaGaO3-based fuel cell

La0.6Sr0.4CoO3 (LSC) and its composites with La0.9Sr0.1Ga0.8Mg0.2O3 (LSGM) were tested as the possible cathode on LSGM electrolyte. The cathodic performance of LSC–LSGM composite electrodes did not improve from that of single-phase LSC electrode unlike La0.9Sr0.1MnO3 (LSM)–LSGM system shown in a previous study. One reason is little reduction in particle size for the composite electrodes. The other reason is that the mixed (electronic and ionic) conductivity of composite cathodes is not increasing from that of single-phase LSC since LSC has high mixed conductivity.