Self-stabilized hybrid cathode for solid oxide fuel cell: A-site deficient perovskite coating as solid solution for Strontium diffusion
Self-stabilized hybrid cathode for solid oxide fuel cell: A-site deficient perovskite coating as solid solution for Strontium diffusion
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DOI：
10.1016/j.cej.2022.135446
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发表时间：
2022-02
影响因子：
15.1
通讯作者：
Jin Li;Xin Zhou;Congcong Wu;Li Zhao;Binghai Dong;Shimin Wang;B. Chi
中科院分区：
文献类型：
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作者：
Jin Li;Xin Zhou;Congcong Wu;Li Zhao;Binghai Dong;Shimin Wang;B. Chi
La0.6Sr0.4Co0.2Fe0.8O3-δ（LSCF）阴极由于表面锶（Sr）的富集，其长期稳定性一直是阻碍其在固体氧化物燃料电池（SOFC）中进一步发展和应用的最棘手的问题。为了提高LSCF基电极的耐久性和性能，我们提出了一种新的方法，通过在多孔LSCF支架表面引入高活性的A位缺陷La 0. 95 CoO 3-δ（LC 95）薄膜，同时作为Sr扩散的受体和电子传导的共形集电极。除了致密涂层的抑制作用外，涂层晶格中保留的A位缺陷使Sr扩散和偏析具有良好的稳定性。在700 °C下，La0.6Sr0.4Co0.2Fe0.8O3-δ@La0.95CoO3-δ（LSCF @ LC 95）混合阴极显示出0.28 Ω cm 2的极化电阻，远低于原始LSCF阴极的极化电阻（0.36 Ω cm 2）。除了较高的电化学活性外，具有LSCF @ LC 95阴极的单电池还表现出显著的长期稳定性，在120 h内没有可检测到的降解。
Challenged by the surface strontium (Sr) enrichment, long-term stability of the La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF) cathode remains to be the most intractable problem hindering its further development and application in solid oxide fuel cells (SOFCs). To enhance the durability and performance of LSCF-based electrodes, we propose a novel approach by introducing a highly active A-site deficient La0.95CoO3-δ(LC95) thin film onto the surface of the porous LSCF scaffold, simultaneously working as the accepter for Sr diffusion and conformal collector for electrons conduction. Besides the inhibiting effect from the dense coating, the A-site deficiencies reserved in coating lattice enable promising stabilization for Sr diffusion and segregation. At 700 °C, the La0.6Sr0.4Co0.2Fe0.8O3-δ@La0.95CoO3-δ(LSCF@LC95) hybrid cathode shows a polarization resistance of 0.28 Ωcm2, much lower than that for pristine LSCF cathode (0.36 Ωcm2). In addition to the higher electrochemical activity, single cell with LSCF@LC95 cathode exhibits remarkable long-term stability without detectable degradation over 120 h.