Phase Stability of Perovskite Oxide Electrodes under Operating Condition in Solid Oxide Fuel Cell

• Published in: Chemistry of materials Vol. 36; no. 6; pp. 2933 - 2943
• Main Authors: Lee, Jinsil, Shin, Yonghun, Kim, Taeyun, Choi, Wooseon, Jung, Min-Hyoung, Kim, Young-Min, Yoon, Kyung Joong, Jeong, Hu Young, Lee, Donghwa, Joo, Jong Hoon
• Format: Journal Article
• Language: English
• Published: American Chemical Society 26.03.2024
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.3c03283

Perovskite-based materials are typically used as electrodes in solid oxide cells (SOCs) owing to their high catalytic activity in oxygen exchange reactions. The degradation of typical SOCs is a well-known phenomenon that is primarily attributed to the A-site cation redistribution within perovskite-based electrodes at elevated operating temperatures. To date, investigations of the degradation and stability of perovskite electrodes have predominantly focused on assessing thin-film electrodes under an open-circuit voltage. This study proposes a detailed degradation mechanism of electrodes based on bulk-dense materials under the operating conditions of an actual solid oxide fuel cell. Our findings revealed that La0.6Sr0.4Co0.2Fe0.8O3–δ is decomposed into SrO, spinel phase ((CoFe)3O4), and La-rich perovskite in the subsurface region under cathodic bias conditions. Additionally, the results of this study indicate that the phase decomposition associated with elements in the B-site must be considered to improve the enhancement of the stability and oxygen reduction reaction activity.