Effect of angstrom-level oxide overcoat on Sr segregation behavior of LSM electrodes
Effect of angstrom-level oxide overcoat on Sr segregation behavior of LSM electrodes
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DOI：
10.1016/j.ijhydene.2022.07.200
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发表时间：
2022-09-08
影响因子：
7.2
通讯作者：
Lee, Min Hwan
中科院分区：
文献类型：
--
作者：
Li, Haoyu;Kang, Hung-Sen;Lee, Min Hwan
固体氧化物燃料电池中钙钛矿（ABO（3））基阴极的长期耐久性在很大程度上受到A位掺杂剂的表面偏析和热团聚的限制。由于原子级薄的氧化物的沉积已被证明在抑制电极团聚方面是高度有效的，因此用相同的方法成功地抑制掺杂剂偏析将通过一石二鸟而显著地增强阴极的耐久性。在这份报告中，我们证明，原子尺度的涂层与2-3埃的标称厚度确实是一个有效的方法，调整Sr偏析行为在La 0.8Sr 0.2MnO 3（LSM），如果一个适当的选择的涂层材料。涂层的二进制氧化物与多价阳离子（CeO 2和TiO 2）desegregates Sr物种到晶格的LSM，而大衣与单价阳离子（ZrO 2和Y2 O3）表现出对Sr偏析的影响不大。基于一系列的X射线光电子能谱和电化学分析，对该行为进行了机理解释。(c)2022作者（S）由Elsevier Ltd代表Hydrogen Energy Publications LLC出版。这是CC BY许可下的开放获取文章（http：//creativecommons.org/licenses/by/4.0/）。
Long-term durability of perovskite (ABO(3))-based cathodes in solid oxide fuel cells has been largely limited by surface segregation of A-site dopant and thermal agglomeration. Since a deposition of an atomically thin oxide has proven to be highly effective in suppressing electrode agglomeration, a successful suppression of dopant segregation with the same approach will enhance the durability of cathodes significantly by killing two birds with one stone. In this report, we demonstrate that an atomic-scale overcoat with a nominal thickness of 2-3 angstrom is indeed an effective approach of tuning Sr segregation behavior in La0.8Sr0.2MnO3 (LSM) if a proper choice of the overcoat material is made. Coating of a binary oxide with multi-valent cations (CeO2 and TiO2) desegregates Sr species into the lattice of LSM while an overcoat with single valent cations (ZrO2 and Y2O3) exhibits little effect on Sr segregation. A mechanistic interpretation of the behavior is also presented based upon a series of X- ray photoelectron spectroscopy and electrochemical analyses. (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Hydrogen Energy Publications LLC. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).