K掺杂的SrSiO_(3-δ)基电解质材料的制备与性能研究

Preparation and properties of K-doped SrSiO_(3-δ)-based electrolyte materials

采用固相法制备了固体氧化物燃料电池(SOFC)电解质材料Sr_(1-x)K_(x)SiO_(3-δ)(x=0.00、0.05、0.10、0.15、0.20、0.25、0.30、0.35)。通过红外光谱、X射线衍射、扫描电镜、交流阻抗等对试样进行表征分析。结果表明:用固相法经950℃煅烧所得粉体呈立方钙钛矿结构。Sr_(1-x)K_(x)SiO_(3-δ)的烧结活性较好,在1200℃烧结的电解质陶瓷相对密度均大于98%,平均晶粒尺寸为7~15μm;中温条件下该系列电解质材料的离子电导率较高、电导活化能较低。其中800℃时Sr_(0.90)K_(0.10)SiO_(2).95的离子电导率最高(8.66×10^(-2)S/cm),电导活化能最低(1.27 eV)。

The electrolyte material Sr_(1-x)K_(x)SiO_(3-δ)(x=0.00,0.05,0.10,0.15,0.20,0.25,0.30,0.35)for solid oxide fuel cell(SOFC)was prepared by solid phase method.The samples were characterized by infrared spectrum,X-ray diffraction,scanning electron microscopy and AC impedance.The results show that the powder obtained by solid phase calcination at 950℃has cubic perovskite structure.The sintering activity of Sr_(1-x)K_(x)SiO_(3-δ)is better,the relative density of electrolytic ceramics sintered at 1200℃is greater than 98%,and the average grain size is 7-15μm.The electrolytes have higher ionic conductivity and lower activation energy at medium temperature.At 800℃,the ionic conductivity of Sr_(0.90)K_(0.10)SiO_(2).95 is the highest(8.66×10^(-2)S/cm),and the activation energy is the lowest(1.27 eV).