采用溶胶-凝胶法合成中低温固体氧化物燃料电池（IT-SOFC）阴极材料La_1.5Ba_0.1Sr_0.4CoMO_5+δ（M为Co、Cu、Fe、Ni）（LBSCM），通过X射线衍射（XRD）、热膨胀系数（TEC）测试、扫描电镜（FESEM）、直流四电极法对材料的微观结构及电性能进行研究。XRD分析结果表明，溶胶-凝胶法制备的LBSCM均为双钙钛矿结构，阴极粉体颗粒大小较均匀、致密度较高。利用直流四电极法测试了阴极材料LBSCM的电导率，结果表明，在测试温度400~800℃下，LBSCM（M=Fe）导电机制符合小极化子导电理论，而LBSCM（M为Co、Cu、CuFe）电导率随着测试温度的升高逐渐减小，表现为类金属导电机理，其中电导率最大的是LBSCM（M=Co），在400℃达到了1 204 S/cm。热膨胀系数研究结果表明，掺杂Cu、Fe、Ni的LBSCM阴极材料热膨胀系数均明显降低。

La_1.5Ba_0.1Sr_0.4CoMO_5+δ(LBSCM,M=Co,Cu,Fe and Ni) cathode materials for medium and low temperature solid oxide fuel cell (IT-SOFC) are synthesized via sol-gel method.The microstructure and electrical properties of the materials are studied by means of X-ray diffraction (XRD),thermal expansion coefficient (TEC),scanning electron microscope (FESEM) and DC four-electrode method.XRD results show that LBSCM prepared via sol-gel method possesses double perovskite structure,and the cathode powder made from LBSCM has uniform particle size and high density.The results by DC four-electrode method show that the conductivity mechanism of LBSCM (M=Fe) in the test temperature range of 400-800℃ accords with the theory of small polaron conductivity,while the conductivity of LBSCM (M=Co,Cu or CuFe) decreases with the increase of test temperature,showing a metal-like conduction mechanism.Among which LBSCM (M=Co) shows the largest conductivity,reaching 1,204 S·cm^-1 at 400℃.The results by TEC study indicates that thermal expansion coefficients of LBSCM cathode materials doped with Cu,Fe and Ni decreases obviously.

程旭(1984-),男,硕士研究生,研究方向为固体氧化物燃料电池阴极材料,360451955@qq.com