Abstract Double perovskite La1.8Sr0.2CoFeO5+δ (DP-LSCF) is prepared by a modified sol-gel method and investigated as a cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs, 600–850 °C). The compound is characterised by a variety of techniques, including TG/DTA, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and SEM-EDS. The formation of the double perovskite structure with rhombohedral symmetry after its calcination at 1000 °C for 6 h is revealed by X-ray diffraction. Excellent chemical compatibility with a Ce0.9Gd0.1O1.95 (GDC) electrolyte is found. The double perovskite structure is confirmed by Raman and X-ray photoelectron spectroscopy. The partial substitution of Fe cations at the Co site affects the physical-chemical properties of DP-LSCF. Compared with other double perovskite materials based on Co, DP-LSCF shows a lower thermal expansion coefficient (19.4×10-6 K-1). The compound exhibits semiconductor behaviour and an area specific resistance of 0.42 Ω·cm2 at 800 oC when GDC is employed as the electrolyte. These results suggest that DP-LSCF is a promising cathode material for IT-SOFC applications.

中文翻译：

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双钙钛矿La1.8Sr0.2CoFeO5+δ作为中温固体氧化物燃料电池正极材料

摘要 双钙钛矿 La1.8Sr0.2CoFeO5+δ (DP-LSCF) 通过改进的溶胶-凝胶法制备，并被研究作为中温固体氧化物燃料电池（IT-SOFCs，600-850 °C）的阴极材料。该化合物通过多种技术进行表征，包括 TG/DTA、X 射线衍射、拉曼光谱、X 射线光电子能谱和 SEM-EDS。X射线衍射揭示了在1000°C下煅烧6小时后形成的具有菱面体对称性的双钙钛矿结构。发现与 Ce0.9Gd0.1O1.95 (GDC) 电解质具有出色的化学相容性。双钙钛矿结构由拉曼和 X 射线光电子能谱证实。Co 位点 Fe 阳离子的部分取代影响了 DP-LSCF 的物理化学性质。与其他基于 Co 的双钙钛矿材料相比，DP-LSCF 显示出较低的热膨胀系数（19.4×10-6 K-1）。当使用 GDC 作为电解质时，该化合物在 800 oC 下表现出半导体行为和 0.42 Ω·cm2 的面积电阻率。这些结果表明 DP-LSCF 是一种用于 IT-SOFC 应用的有前途的正极材料。