Effect of High-Temperature Exposure on Degradation of La0.6Sr0.4CoO3 Coated Metallic Interconnects for ITSOFC and SOEC

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 23; no. 3; pp. 1 - 7
• Main Authors: Korb, Matias de Angelis, Tarragó, Diego Pereira, Krischer, Cesar Augusto, Duluard, Sandrine, Ansart, Florence, Malfatti, Célia de Fraga
• Format: Journal Article
• Language: English; Portuguese
• Published: Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol) 01.01.2020; ABM, ABC, ABPol
• Subjects: coating; Engineering Sciences; ENGINEERING, CHEMICAL; impedance spectroscopy; lanthanum cobaltite; Materials; MATERIALS SCIENCE, MULTIDISCIPLINARY; METALLURGY & METALLURGICAL ENGINEERING; steel intreconnect; Coating; Impedance spectroscopy; Steel intreconnect; Lanthanum cobaltite; lanthanum cobaltite; impedance spectroscopy; steel intreconnect; coating
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/1980-5373-mr-2020-0084

Previous studies showed the formation of new phases affecting the electrical properties of LSC thin films deposited on stainless steel substrates, which are commonly tested for ITSOFC and SOEC interconnects. A 4.3 μm thick La0.6Sr0.4CoO3 coating was deposited on AISI430 steel by spray pyrolysis, followed by heat treatment (800°C/2h) and an oxidation in air (800°C/96h). The La0.6Sr0.4CoO3 phase interacted with the metallic substrate and formed SrCrO4, causing degradation of the perovskite into La0.9Sr0.1CoO3. An EDS mapping showed Sr and Cr enrichment in the coating/substrate interface. TG analysis indicated a lower mass gain for the coated substrate. The total ASR at 800°C of the interconnect before and after oxidation was 3.23 Ω.cm2 and 3.98 Ω.cm2, respectively. The Ea underwent very small variation, remaining around 0.24 eV (T≤300°C) and 0.65 eV (T≥400°C). The reaction of Cr from the substrate and Sr from LSC seems to have impaired the performance of the interconnect.