Electrochemical Performance and Stability of LSM-ESB Cathode

Abstract

Among (La0.8Sr0.2)0.95MnO3-δ (LSM) based cathodes LSM-(Er0.2Bi0.8)2O3 (LSM-ESB) composite shows promising performance and is one of potential cathodes for low temperature solid oxide fuel cells (LT-SOFCs). The high conductivity ESB exhibits oxygen-ordering at temperatures ≤600°C, resulting in an ordered super-lattice with low oxygen mobility. Here the electrochemical performance of LSM-ESB was investigated using electrochemical impedance spectroscopy (EIS). The cathode area specific resistance (ASR) of LSM-ESB is a function of LSM/ESB ratio, suggesting that the importance of co-existence of electronic and ionic conducting phases. Under cathodic polarization, ASR of cell decreases as a function of bias while ASR remains almost the same under anodic polarization. Also, the high temperature reactivity between LSM and ESB solid phases is studied. Our finding shows that A site deficiency of LSM ABO3 perovskite structure is important to prevent the formation of strontium bismuth oxide.