La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3–δ)–Sm_(0.2)Ce_(0.8)O_(1.9)复合阴极的制备及性能表征  

PREPARATION AND CHARACTERIZATION OF La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)-Sm_(0.2)Ce_(0.8)O_(1.9) COMPOSITE CATHODES

作　　者：石平[1] 程继贵[2] 董洁[2] 何海根[2] 

机构地区：[1]安徽工程大学机械与汽车工程学院,安徽芜湖241000 [2]合肥工业大学材料科学与工程学院,合肥230009

出　　处：《硅酸盐学报》2010年第10期1857-1861,共5页Journal of The Chinese Ceramic Society

基　　金：安徽工程科技学院青年基金(2007YQ028)资助项目

摘　　要：分别采用凝胶浇注法和甘氨酸–硝酸盐法制备La0.6Sr0.4Co0.2Fe0.8O3–δ(LSCF)粉体与Sm0.2Ce0.8O1.9(SDC)粉体,随后制备出不同比例的LSCF–SDC复合阴极。用X射线衍射分析粉体的化学稳定性,用扫描电子显微镜观察复合阴极的微观结构,在500～800℃范围内测量其热膨胀系数和电导率。采用丝网印刷法将LSCF–SDC涂覆在SDC电解质片上,在1100℃烧结4h。用交流阻抗法在600～800℃范围内测量不同成分的LSCF–SDC复合阴极和SDC电解质的交流阻抗谱。结果表明:LSCF和SDC粉体具有良好的化学相容性,烧结体具有多孔结构,LSCF–SDC复合阴极与SDC电解质可形成良好的接触界面。SDC的加入在降低阴极材料的热膨胀系数的同时还保持了其本身较高的电导率,在中温范围内,电导率达到500S/cm以上。复合阴极的极化电阻随着SDC的含量增加而减小,当SDC含量为30%时,复合阴极的极化电阻最小,在700℃空气中测试得到的界面电阻为0.32Ω·cm2。La0.6Sr0.4Co0.2Fe0.8O3-δ（LSCF） and Sm0.2Ce0.8O1.9（SDC） powders were synthesized by the gel-casting process and glycline-nitrate process,respectively.LSCF-SDC composite cathodes were prepared with different content of SDC.The chemical stability of the powders was investigated by X-ray diffraction.Microstructure of the sintered LSCF-SDC samples was observed by the scanning electron microscopy.Electrical conductivity and thermal expansion coefficient were also measured at 500-800 ℃.Symmetrical cathods of LSCF-SDC were coated on SDC electrolyte by the screen-printing process and sintered at 1 100 ℃ for 4 h.The electrochemical properties of the interfaces between LSCF-SDC cathodes and SDC electrolyte were investigated using alternating current impedance spectroscopy.It shows that LSCF has no reaction with SDC.The composite cathodes formed good contact with SDC electrolyte.The electrical conductivity of LSCF-SDC composite cathodes is higher than 500 S/cm at 500-800 ℃.Its polarization resistance decreases with the increase of SDC content.The interfacial resistance of LSCF-SDC with 30% in mass SDC is 0.34 Ω·cm2 at 700 ℃.

关 键 词：固体氧化物燃料电池 掺杂钴酸镧 复合阴极 交流阻抗 界面阻抗 

分 类 号：TM911.4[电气工程—电力电子与电力传动]