Blocking Sr-segregation in perovskite cathodes for solid oxide cells by Mn co-doping
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Author(s)
Type
Journal Article
Abstract
State-of-the-art electrodes for the oxygen reduction/oxidation reaction typically present durability issues due to the appearance of (surface) precipitates during operation at high temperature. In this work, we employ a combinatorial approach to study the effect of B-site co-doping on the thermal degradation of the La0.8Sr0.2MnxCoyFe1-x-yO3±δ family. A continuous library of materials was fabricated in a single process by means of combinatorial pulsed-laser deposition, followed by an annealing at 800 °C for a period of 100 h. The library was then characterized by advanced techniques, involving surface microstructural and chemical analysis and cation profiling throughout the range of compositions. Remarkable stability of Mn-doped materials (and of the parent La0.8Sr0.2MnO3-δ compound) was observed regarding the appearance of segregated surface strontium species, particularly sulfates. This result was correlated with a drastic reduction of the degradation of the Mn-containing La0.8Sr0.2MnxCoyFe1-x-yO3 ± δ films during midterm electrochemical performance studies. Complementary density functional theory calculations reveal a direct correlation between cation reducibility (i.e., the O 2p band center position) and surface Sr enrichment. These results indicate that the addition of Mn to La0.8Sr0.2MnxCoyFe1-x-yO3 electrodes plays a substantial role in the stabilization of strontium segregation phenomena and suggest a general strategy for enhancing perovskite stability based on co-doping and band engineering.
Date Issued
2025-05-26
Date Acceptance
2025-05-07
Citation
ACS Applied Energy Materials, 2025
ISSN
2574-0962
Publisher
American Chemical Society
Journal / Book Title
ACS Applied Energy Materials
Copyright Statement
© 2025 American Chemical Society. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
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Publication Status
Published online
Date Publish Online
2025-05-26