Fabrication and evaluation of electrolyte films and high performance electrode materials with metallic catalysts for low-temperature operating SOFC in the next generation

本研究针对可在800℃以下运行的低温运行固体氧化物燃料电池开展了以下两个方面的工作：（1）高氧离子导电电解质陶瓷膜的制备;（2）高活性电极材料的制备。对于第一个研究项目，提出了一种基于电泳沉积（EPD）的新方法来制备由多孔基底支撑的电解质膜，该电解质膜可用作电池中的电极。该工艺使我们能够在非导电多孔基底上精确地存款陶瓷粉末。致密的氧化钇稳定的氧化锆（YSZ）薄膜的厚度约为。采用该工艺在多孔NiO-YSZ衬底上成功制备了5μm的纳米晶。以La（Sr）Co（Fe）O_3为阴极，在800℃时，YSZ薄膜的最大输出功率密度为2.01W/cm^2。该工艺也用于制备YSZ和Sm_2O_3掺杂CeO_2（SDC）双层电解质薄膜。这种双层电解质膜是通过沉积YSZ，然后在没有任何热处理的情况下沉积SDC，然后与基板共烧而形成的。在700 ℃时，由约1000 μ m/g的钙钛矿组成的双层电解质膜的最大功率密度大于0.6 W/cm ^2。4μm，约1μ m厚的SDC薄膜。在电极材料的研究中，研究了（Sr，Ce）MnO_3钙钛矿化合物。虽然在化合物中获得了高的电导率，但很明显，它们的催化性能不足以应用于低温操作的SOFC中的电极。

In this research, the following two projects were carried out for low-temperature operating solid oxide fuel cell which can be operated below or at 800℃ : (1) fabrication of ceramic films of highly oxide ion conducting electrolyte ; (2) preparation of electrode materials with high activities.For the first research project, a new process based on electrophoretic deposition (EPD) was proposed to fabricate electrolyte films supported by porous substrates which can be used as an electrode in the cell. The process enabled us to electrophoretically deposit ceramic powders onto non-conducting porous substrates. Dense yttria-stabilized zirconia (YSZ) films with a thickness of ca. 5μm were successfully fabricated on porous NiO-YSZ substrates by the process proposed. The ~5μm thick dense YSZ films showed maximum output power density of 2.01W/cm^2 at 800℃ with La(Sr)Co(Fe)O_3 cathode. The process was also used to fabricate bilayered YSZ and Sm_2O_3-doped CeO_2 (SDC) electrolyte films. Such bilayered electrolyte films were formed by depositing YSZ followed by SDC without any heat treatment, and then co-fired with substrates. Maximum power densities greater than 0.6 W/cm^2 were obtained at 700 ℃ for the bilayered electrolyte films consisting of ca. 4μm and ca. 1μm-thick SDC films.In the research on electrode materials, (Sr, Ce)MnO_3 perovskite compounds were studied. Although high electrical conductivities were obtained in the compounds, it became apparent that their catalytic properties were not sufficient for application to an electrode in low-temperature operating SOFC.