Characterization of La0.5Sr0.5Co0.5Ti0.5O3−δ as symmetrical electrode material for intermediate-temperature solid-oxide fuel cells
Characterization of La0.5Sr0.5Co0.5Ti0.5O3−δ as symmetrical electrode material for intermediate-temperature solid-oxide fuel cells
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DOI：
10.1016/j.ijhydene.2012.09.033
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发表时间：
2012-12
影响因子：
7.2
通讯作者：
R. Martínez-Coronado;A. Aguadero;D. Pérez-Coll;L. Troncoso;J. Alonso;M. Fernández-Díaz
中科院分区：
文献类型：
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作者：
R. Martínez-Coronado;A. Aguadero;D. Pérez-Coll;L. Troncoso;J. Alonso;M. Fernández-Díaz
La0.5Sr0.5Co0.5Ti0.5O3−δ钙钛矿氧化物已制备为多晶粉末，表征并测试了固体氧化物燃料电池的阴极和阳极材料。氧化的材料被认为是从“原位”中子粉末衍射（NPD）实验中呈现混合离子-电子电导率（MIEC），并补充了传输测量;足够高的氧缺乏的存在，氧原子的大位移因子表明大的不稳定性和迁移率与类似超导体的行为相结合，在T = 850 °C时最大电导率为29 S cm− 1。一个完全可逆的还原-氧化过程已被观察到，其中还原的Pm-3 m钙钛矿与La 0.5Sr 0.5Co 0.5Ti 0.5O 2.64组成已获得由拓扑氧去除没有突变的热膨胀。氧化后的材料作为阴极与LSGM电解质一起工作时表现出良好的性能，在850 °C下产生接近500 mW/cm 2的输出功率密度。在中等温度（800 °C）下，它可以用作阴极或阳极，分别产生220和170 mW/cm 2的功率密度。当同时用作阴极和阳极时，获得了110 mW/cm 2的最大功率密度。因此，我们提出La0.5Sr0.5Co0.5Ti0.5O3−δ组合物作为中温SOFC对称电极的有希望的候选者。
La0.5Sr0.5Co0.5Ti0.5O3−δperovskite oxide has been prepared as polycrystalline powder, characterized and tested as cathode and anode material for solid-oxide fuel cells. The oxidized material is suggested to present mixed ionic-electronic conductivity (MIEC) from “in-situ” neutron powder diffraction (NPD) experiments, complemented with transport measurements; the presence of a sufficiently high oxygen deficiency, with large displacement factors for oxygen atoms suggest a large lability and mobility combined with a semiconductor-like behaviour with a maximum conductivity of 29 S cm−1at T = 850 °C. A complete reversibility towards reduction–oxidation processes has been observed, where the reduced Pm-3m perovskite with La0.5Sr0.5Co0.5Ti0.5O2.64composition has been obtained by topotactical oxygen removal without abrupt changes in the thermal expansion. The oxidized material shows good performance working as a cathode with LSGM electrolyte, yielding output power densities close to 500 mW/cm2at 850 °C. At intermediate temperatures (800 °C) it may be used as a cathode or as an anode, yielding power densities of 220 and 170 mW/cm2, respectively. When used simultaneously as cathode and anode a maximum power density of 110 mW/cm2was obtained. Therefore, we propose the La0.5Sr0.5Co0.5Ti0.5O3−δcomposition as a promising candidate for symmetrical electrode in intermediate-temperature SOFC.