中文摘要：

采用柠檬酸自蔓延燃烧法合成了 Sr0.95Ti0.05Co0.95O3？δ（STC）阴极粉体和 Sm0.2Ce0.8O1.9（SDC）电解质粉体,将 STC 与SDC 粉体按质量比7：3混合得到复合阴极。通过 X 射线衍射（XRD）、直流四端子法和热膨胀仪表征了样品的化学相容性、电导率和热膨胀系数。XRD 表明，STC 在900℃能够得到立方纯钙钛矿结构，复合阴极 STC？SDC 在工作温度区间内具有很好的化学相容性；在650℃空气气氛下 STC？SDC 与 SDC 之间的界面极化阻抗仅为0.05Ω·cm2。制备了阳极支持型（NiO-SDC│SDC│STC？SDC）单电池,在450～650℃范围内以湿润的 H2（3%水蒸汽）为燃料气，空气为氧化剂测试了单电池的性能。结果表明：阳极支撑的单电池共烧1350℃可以得到致密的电解质层和多孔的电极,而且650℃时单电池开路电压0.82 V，最大输出功率为721 mW/cm2。结果预示，在以 SDC 为电解质的中低温固体氧化物燃料电池（IT-SOFC）中，STC-SDC 是一个很有前途的复合阴极材料。

英文摘要：

A cathode powder of Sr0.95Ti0.05Co0.95O3-δ（STC） and an electrolyte powder of Sm0.2Ce0.8O1.9 （SDC） were synthesized by a citric acid-nitrates self-propagating combustion method. The composite-cathode was obtained by mixing the STC and SDC powders in a mass ratio of 7：3. The chemical compatibility, electrical conductivity and thermal expansion coefficient of the composite cathode were characterized by X-ray diffraction（XRD）, direct current four-terminal method and thermal dilatometer, respectively. The XRD results show that a pure cubic STC perovskite phase can be obtained at 900 and℃ no second phase is formed in the composite cathode at the operating temperature. The polarization resistance of the electrode is only 0.05 Ω·cm2 at 650 ℃. The anode-supported solid oxide fuel cells of NiO-SDC│SDC│STC-SDC were fabricated. The electrochemical performances were examined at 450-650 ℃ with humidified hydrogen （about 3% H2O） as a fuel and air as an oxidant. It is demonstrated that the anode-supported half cells can be sintered at 1 350 with a dense electrolyte layer and porous℃ electrodes, and the single cell with an open circuit voltage of 0.82 V and the maximum power density of 721 mW/cm2 at 650 ℃ can be obtained. These results indicate that STC-SDC is a promising composite cathode candidate for IT-SOFC with SDC electrolyte.