Origin of cathodic degradation and new phase formation at the La0.9Sr0.1MnO3/YSZ interface

✍ Scribed by Hee Y. Lee; Seung M. Oh

• Book ID: 104296322
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 660 KB
• Volume: 90
• Category: Article
• ISSN: 0167-2738
• DOI: 10.1016/s0167-2738(96)00408-0

✦ Synopsis

New phase formation at the La,,,Sr,,,MnO,/YSZ interface and its effects on the cathodic performances were studied at 900°C in air. The resistance caused by the interfacial product layer kept increasing with time to reach up to 40% of the total resistance after 500 h. The interfacial product was identified as La,Zr,O, by XRD measurement. The electrical conductivity of La,Zr,O, (2.4 X 10-a S cm-' at lOOO"C), measured by AC impedance and current interruption methods, was 4 to 7 orders of magnitude smaller than those of La,,,Sr,,MnO, electrode or YSZ electrolyte. Either the electronic conductivity or the electrochemical 0, reduction activity of La,Zr,O, was negligible. Combining these results, a conclusion was made that the cathodic degradation comes mainly from the growth of interfacial product layer and its contribution to the cell resistance increment is ohmic in nature.