Sr- and Ni-doped LaCaO3 and LaFeO3 perovskites -: New cathode materials for solid-oxide fuel cells
Sr- and Ni-doped LaCaO3 and LaFeO3 perovskites -: New cathode materials for solid-oxide fuel cells
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DOI：
10.1149/1.1838789
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发表时间：
1998-09-01
影响因子：
3.9
通讯作者：
Goodenough, JB
中科院分区：
文献类型：
--
作者：
Huang, K;Lee, HY;Goodenough, JB
用于固体氧化物燃料电池的改进的阴极材料将是混合的电子和氧化物离子导体，其在大于或等于700 ℃的操作温度T-op下具有良好的氧还原催化活性，并且热膨胀与电解质和互连体的热膨胀相匹配。我们报告的适当的关系Sr和Ni掺杂的LaCoO 3和LaFeO 3钙钛矿，满足这些标准。单相区域由X-射线衍射确定，并使用热重分析测量来获得氧损失的温度以上，因此氧化物离子电导率，发生。电导率和Seebeck测量表明，由于Ni-III/Ni 2+氧化还原对与低自旋/中自旋Co-IV/Co-III和高自旋Fe 4 +/Fe 3+氧化还原对的重叠，p型和n型极化电荷载流子共存。动态双折射率Δ H-m = 0.03、0.02和0.08 eV。分别对Ni ~（2+）、Co ~（4+）和Fe ~（4+）极化子进行了估算。最佳组合物在掺杂剂之间具有渗滤路径。与传统阴极材料La 1-xSrxCoO 3-delta和La 1-xSrx MnO 3的传输数据的比较表明，可以预期具有上级阴极性能。
An improved cathode material for a solid-oxide fuel cell would be a mixed electronic and oxide-ion conductor with a good catalytic activity for oxygen reduction at an operating temperature T-op greater than or equal to 700 degrees C and a thermal expansion matched to that of the electrolyte and interconnect. We report on the proper ties of Sr- and Ni-doped LaCoO3 and LaFeO3 perovskites that meet these criteria. Single-phase regions were determined by X-ray diffraction, and thermogravimetric analysis measurements were used to obtain the temperatures above which oxygen loss, and hence oxide-ion conductivity, occurs. The conductivity and Seebeck measurements indicate the coexistence of both p-type and n-type polaronic charge carriers resulting from an overlap of the Ni-III/Ni2+ redox couple with the low-spin/intermediate-spin Co-IV/Co-III and high-spin Fe4+/Fe3+ redox couples. Motional enthalpies Delta H-m = 0.03, 0.02, and 0.08 eV. respectively, were estimated for Ni2+, Co-IV, and Fe4+ polarons. Optimal compositions have percolation pathways between dopants. Comparisons with transport data for the conventional cathode materials La1-xSrxCoO3-delta and La1-xSrx MnO3 indicate superior cathode performance can be expected.