Electrochemical properties of A-site deficient SOFC cathodes under Cr poisoning conditions

✍ Scribed by C.J. Fu; K.N. Sun; X.B. Chen; N.Q. Zhang; D.R. Zhou

• Book ID: 103827989
• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 746 KB
• Volume: 54
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/j.electacta.2009.07.055

✦ Synopsis

Under solid oxide fuel cells (SOFCs) operating atmosphere, volatile Cr species are generated over the chromia scale of chromia-forming alloy interconnects, poisoning the cathodes and causing the rapid degradation of the fuel cell performance. In this study, the influence of the cathode composition and Asite deficiency of Perovskite ABO 3 cathodes on their tolerance to Cr poisoning was investigated in detail through the electrochemical polarization and electrochemical impedance spectroscopy (EIS) analysis. Results showed that 5 mol% La-site deficient cathodes, La 0.75 Sr 0.2 BO 3-ı (B = Mn, Fe), presented a good performance in resistance to Cr poisoning and electrocatalytic activity to oxygen reduction reaction in the presence of alloy interconnects under a constant current density of 0.2 A cm -2 in oxygen at 1073 K. B-site atom of Perovskite ABO 3 cathodes has a strong influence on the mechanism of Cr deposition and cathodes performance, while proper A-site deficiency can greatly improve the cathodes electrochemical performance and slow down Cr deposition.