Abstract: Perovskitetype oxide Ba0.6Sr0.4Co0.9Nb0.1O3δ (BSCN) was synthesized by the solid state reaction and investigated as a cathode for intermediatetemperature solidoxide fuel cells (ITSOFCs). XRD pattern indicated that BSCN crystallized in a singlephase perovskite with a cubic perovskite structure (Pm3m) and no evident reaction happened after the mixture of BSCN cathode and GDC electrolyte was sintered at 1 000 ℃ for 10 h. During the operating temperature of SOFCs (600~800 ℃), the electrical conductivity of BSCN reaches 21~27 S/cm. The thermal expansion coefficient value of 17.0 × 10-6/K has been measured for BSCN sample, which is much lower than that of SrCo0.9Nb0.1O3δ(SCN). This result indicated that Ba doping in SCN has a better thermal match to GDC electrolyte. Symmetrical cell with the configuration of BSCN/GDC/BSCN was used for the impedance measurements. The polarization resistance of BSCN cathode on GDC electrolyte is 0.026 Ω·cm2 at 750 ℃. With BSCN cathode, NiOCe0.8Sm0.2O1.9 anode and 300 μm thick GDC electrolyte, the maximum power density of single cell achieved 782 mW/cm2 at 800 ℃. All these results indicate that the BSCN oxide is a promising cathode candidate material for ITSOFCs.

Key words: Intermediatetemperature solidoxide fuel cells , Cathode, Electrical conductivity , Polarization resistance , Maximum power density

摘要： 采用固相反应法合成了中温固体氧化物燃料电池(IT灢SOFCs)阴极材料Ba0.6Sr0.4Co0.9Nb0.1O3灢毮
(BSCN)。利用XRD对该材料的结构进行了表征。研究表明,室温下阴极材料BSCN 成立方相结构(Pm灢3m);将该
阴极材料与电解质Ce0.9Gd0.1O1.95(GDC)混合,并在1000曟煅烧10h后,它们之间无化学反应发生。在SOFCs的
操作温度(600~800曟)下,BSCN阴极的电导率可达21~27S/cm。热膨胀测试表明,BSCN 的热膨胀系数为17.0
暳10-6/K,明显低于SrCo0.9Nb0.1O3灢毮(SCN)的热膨胀系数,这有利于提高阴极与电解质GDC间的热匹配性。以
BSCN作电极,GDC作电解质,制备对称电池BSCN/GDC/BSCN,研究电极与电解质间的极化阻抗。750 曟时,极化
阻抗仅为0.026毟·cm2。以BSCN作阴极,NiO灢SDC(NiO灢Ce0.8Sm0.2O1.9)作阳极,300毺m 厚的GDC作电解质,制
备单电池BSCN/GDC/NiO灢SDC。800曟时,单电池的最大功率密度可达782mW/cm2。以上结果表明,BSCN 有望
成为中温固体氧化物燃料电池阴极的候选材料。

关键词: 中温固体氧化物燃料电池 , 阴极 , 电导率 , 极化阻抗 , 最大功率密度