Reducing the Cathode Losses by Optimization of IT-SOFC Cathode Microstructure

Abstract

In order to reduce the cathode losses, studies were carried out to optimize the LSM-based cathode microstructure. First, the current collector coatings were prepared with LSM sintered at different temperatures. The sample sintered at 1150°C exhibited the best performance in terms of microstructure and the electrical conductivity. Second, composite cathode materials with different LSM contents were prepared. When three-dimensional LSM network was formed, the conduction of the composite cathode was dominated by LSM phase, resulting in higher conductivity and lower activation energy. When the YSZ network formed, the composite exhibited a lower polarization resistance. Results from electrochemical impedance spectroscopy showed that the composite cathode with 50 wt% LSM displayed the lowest R p value of 0.26 Ω·cm 2 at 750°C.