喷雾裂解制备球形LSM阴极材料用于SOFC电池

LSM Composite Powder Preparation for SOFC Cathode by Ultrasonic Spray Pyrolysis

采用超声喷雾裂解技术(UPS)在800℃合成固体氧化物燃料电池(SOFC)阴极材料La0.7Sr0.3MnO3(LSM)。采用XRD、SEM研究了LSM的物相和晶型结构。结果表明:该方法合成产物为钙钛矿结构La0.7Sr0.3MnO3,合成的LSM粉末粒度在1~10μm之间,比表面为3.9m2/g-1。合成的颗粒具有高比表面的球形中空结构,球形颗粒表面排列许多凸起条纹。按照YSZ∶LSM之间的比例为3∶7时合成的LSM浆料,用作SOFC燃料电池阴极,最大电流为1900 mA·cm-2,比固相法合成阴极材料高800 mA·cm-2。通过电化学阻抗研究表明,喷雾裂解制备的LSM粉体具比固相法合成的粉体有更低的电阻(10Ω·cm2),可以提高氧气吸附反应的三相界面,提高燃料电池的性能。

La0.7Sr0.30MnO3(LSM) powders of SOFC cathode with pure perovskite structure and uniform particle size were synthesized by ultrasonic spray pyrolysis method at 800 ℃. The morphological features, crystallinity and the phases of the synthesized powders were characterized by scanning electron microscopy(SEM), and X-ray diffraction(XRD). The powders are almost spherical with a diameter in the range of 1~5 μm and their BET specific areas are around 3.9m2/g. According the mass ratio between YSZ∶LSM 3∶7, cathode materials were formed and used for SOFC. The polarization resistances of such cathodes are investigated as function of the polarization resistance was reduced by to 10 Ω·cm2 at 750 ℃, leading to a peak current density of 1900 mA·cm-2, which is 800 mA·cm-2higher than that of the solid LSM cathode in an anode-supported cell. LSM powder prepared by the spray pyrolysis reaction of adsorbed oxygen can be increased three-phase boundary and improve the fuel cell performance.