中低温固体氧化物燃料电池功能梯度阴极的合成

分别以Sr(NO3)2,Co(NO3)2·6H2O和Sm(NO3)3·6H2O,Ce(NO3)3·6H2O为原料,采用氨基乙酸法和固相合成法制备了Sm0.5Sr0.5CoO3(SSC)和Sm0.2Ce0.8O1.9(SDC)粉体,采用旋涂法在Al2O3基板上制备出了中低温固体氧化物燃料电池复合阴极层,并用X射线衍射仪、能谱仪和扫描电镜对梯度阴极的材料成分和微观结构等进行了分析。结果表明:复合浆料旋涂结合热处理可以有效地在基板表面制备出复合阴极层,且制备的阴极层与基板结合良好;通过使用氨基乙酸法和固相合成法制备的粉末,实现了阴极中晶粒尺度的调控;通过控制浆料中SSC和SDC相对含量获得了组分梯度;控制造孔剂含量有效地实现了孔隙度的调控,从而获得梯度化的固体氧化物燃料电池阴极。

SYNTHESIS OF FUNCTIONALLY GRADED CATHODES FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS

Sm_(0.5)Sr_(0.5)CoO_3 (SSC) and Sm_(0.5)Ce_(0.8)O_(1.9) (SDC) were prepared with Sr(NO_3)_2, Co(NO_3)_2·6H_2O and Sm(NO_3)_3·6H_2O, Ce(NO_3)_3·6H_2O as raw materials by a glycine-nitrates process(GNP) and a solid reaction method. Spin-coating was used to prepare the SSC and the SDC composite cathodes lays on the Al_2O_3 substrate. The composition and the microstructure of the graded cathode were characterized by X-ray diffraction, energy dispersive spectrometry and scanning electronic microscopy. The results show that the method of spin-coating combined with calcining can prepare the composite cathodes lays effectively. The lays have a good combina tion with the substrate. The powders prepared by the GNP and solid reaction method could be used to obtain the grain gradient. In the slurry, the relative contents of the SSC and the SDC can be controlled to obtain the composition gradient. The different contents of the pore-making agent can achieve the pore gradient. Therefore, the gradient composite cathodes lays were obtained.