以三氧化二钐、浓硝酸、硝酸铈铵、柠檬酸为原料,采用溶胶-凝胶法低温(900℃)制备Ce0.8Sm0.2O2–α(SDC),低于通常高温烧结温度(1400℃),并与(Li/K)2CO3共熔体进行复合.采用DSC-TGA确定制备Ce0.8Sm0.2O2–α的烧结温度.XRD结果表明,(Li/K)2CO3与Ce0.8Sm0.2O2–α复合后没有发生化学反应.SEM图像表明,SDC粒径均匀一致,(Li/K)2CO3作为SDC颗粒黏结剂均匀覆盖SDC颗粒表面.采用电化学工作站研究了复合电解质在400～600℃下干燥氮气气氛中的电导率.结果表明,温度为600℃时,复合电解质在干燥氮气气氛中的电导率达到最大值3.3×10-2S/cm,高于单一二氧化铈材料在相同条件下的电导率.氧分压与电导率关系曲线表明,复合电解质具有良好的氧离子导电性.H2/O2燃料电池性能测试表明复合电解质Ce0.8Sm0.2O2–α-(Li/K)2CO3(SDC-SG-LK)在600℃开路条件下的电解质阻抗、极化阻抗分别为3.13Ω·cm2、0.81Ω·cm2,最大输出功率密度为130mW/cm2.%Ce0.8Sm0.2O2–α was synthesized by sol-gel method at 900℃ using Sm2O3,HNO3, (NH4)2Ce(NO3)6,citric acid as raw materials and then compounded with (Li/K)2CO3. The preparation temperature(900℃)is much lower than conventional sintering temperature(1400℃). The sintering temperature of Ce0.8Sm0.2O2–α(SDC) was determined by DSC-TGA. The XRD results showed that there was no reactions between Ce0.8Sm0.2O2–α and(Li/K)2CO3. The SEM examinations revealed that the SDC particle size is uniform,and the surface is uniformly covered by (Li/K)2CO3 that act as the SDC particle binder. The conductivity of the composite electrolyte in dry nitrogen was measured using electrochemical analyzer. The highest conductivity was 3.3×10–2S/cm at 600℃,which is higher than that of single CeO2 material. The H2/O2 fuel cell by the composite electrolyte showed that the electrolyte impedance and polarization impedance under open-circuit condition were 3.13Ω·cm2 and 0.81Ω·cm2,respectively,and generated the maximum power density of 130mW/cm2 at 600℃.
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