对称固体氧化物燃料电池电极材料Sm_(0.9)Pr_(0.1)FeO_(3-δ)的制备及性能研究

Preparation and properties of Sm_(0.9)Pr_(0.1)FeO_(3-δ) electrode materials for symmetrical solid oxide fuel cells

采用柠檬酸-硝酸盐自蔓延燃烧法合成了Sm_(0.9)Pr_(0.1)FeO_(3-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|YSZ|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|YSZ|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 15.80 Ω·cm^2, respectively. The maximum power density of SPF symmetrical cell was 168 mW/cm^2 at 850 ℃ with humidified hydrogen (3%H 2O) as fuel and ambient air as oxidant. The results indicate that SPF is a promising electrode material for symmetrical solid oxide fuel cells.