甘氨酸-硝酸盐法合成La_(1-x)Sr_xCr_(1-y)Mn_yO_(3-δ)阳极材料及性能研究(英文)

Synthesis and Properties of La_(1-x)Sr_xCr_(1-y)Mn_yO_(3-δ) Anode Material by Glycine-Nitrate Process

用甘氨酸-硝酸盐法合成了La0.7Sr0.3Cr0.5Mn0.5O3-δ(LSCM7355)阳极材料。LSCM7355前驱体在1200℃下烧结5h后得到了单一钙钛矿型材料,材料中各元素摩尔比例与设计值吻合较好。1000℃和1200℃烧结5h后,LSCM7355粉体分别为纳米和微米结构。在250～850℃范围内,空气气氛下,LSCM7355的电导率符合小极化子绝热导电机理,其在850℃时为25S/cm。LSCM7355材料在还原气氛下电导率比氧化气氛下低。

Thermogravimetric analysis （TGA） and differential scanning calorimetric （DSC） method was adopted to characterize the reaction process of La0.7 Sr0. 3 Cr0. 5 Mn0. 5 O3-δ （ LSCM7355 ） anode material by glycine nitrate process. The microstructure and features of LSCM7355 were tested by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, direct current four-electrode and temperature process reduction （TPR） techniques. XRD patterns indicates that perovskite phase existed after the precursor was sintered at 1 000 ℃ for 5 h, and LSCM7355 material with single perovskite phase was obtained after sintering at 1 200 ℃ for 5 h. The molar ratio of the elements in LSCM7355 material agrees well with the designed value. The powders have nanometer and micrometer size after sintering at 1 000 ℃ and 1 200 ℃, respectively. The total conductivity of LSCM7355 increases linearly with temperature at air and reaches 25 S/cm at 850 ℃, which wholly becomes smaller in the pure hydrogen and methane.