对称固体氧化物燃料电池电极材料Sm0.9Pr0.1FeO3-δ的制备及性能研究

摘要

采用柠檬酸-硝酸盐自蔓延燃烧法合成了Sm0.9Pr0.1FeO3-δ (SPF)粉体.以YSZ为电解质, SPF同时作为阴极和阳极, 构建了对称固体氧化物燃料电池SPF|Y|YSZ|S|SPF.利用X射线衍射法研究材料的成相以及相互间的化学稳定性, 交流阻抗法记录界面极化行为, 热膨胀仪评估材料的热膨胀系数, 用扫描电子显微镜观察电池的断面微观结构, 用自组装的测试系统评价电池输出性能.结果表明, 合成的SPF粉体呈钙钛矿结构, 且在还原条件下仍保持不变, 与电解质YSZ间有良好的化学及热稳定性;800℃时空气及氢气气氛下的电解质|电|电极间的极化阻抗分别为0.15和15.80Ω·cm2;以加湿H2 (含体积分数3％的水蒸气)为燃料气, 空气为氧化气时, 单电池SPF|Y|YSZ|S|SPF输出功率密度为168mW/cm2.结果显示SPF是对称固体氧化物燃料电池良好的候选电极材料.%Sm0.9Pr0.1FeO3-δ (SPF) powders were synthesized by a citric acid-nitrates self-propagating combustion method.The YSZ-supported symmetrical solid oxide fuel cell based on the configuration of SPF│YSZ│SPF was fabricated.The phase structure, chemical compatibility, polarization resistance, cross-section microstructure and the cell performance were investigated by X-ray diffraction (XRD), electrochemical impedance spectra, thermal dilatometer, scanning electron microscope (SEM) and self-assembly SOFC test system, respectively.The XRD results indicate that the synthesized SPF powder exhibited a single perovskite structure and was chemically and thermally compatible with YSZ electrolyte.The area specific resistances (ASR) of SPF│YSZ in air and hydrogen atmosphere at 800℃ were 0.15 and 15.80Ω·cm2, respectively.The maximum power density of SPF symmetrical cell was 168mW/cm2 at 850℃ with humidified hydrogen (3％H2O) as fuel and ambient air as oxidant.The results indicate that SPF is a promising electrode material for symmetrical solid oxide fuel cells.