Ce0.8Sm0.2O2-α ceramic prepared by sol-gel method at low temperature and its composite electrolyte in intermediate temperature fuel cells

doi:10.16085/j.issn.1000-6613.2016-2030

Abstract

Abstract: Ce_0.8Sm_0.2O_2-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 Ce_0.8Sm_0.2O_2-α(SDC) was determined by DSC-TGA. The XRD results showed that there was no reactions between Ce_0.8Sm_0.2O_2-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℃.

Key words: cerium oxide (CeO₂), composites, electrolytes, hydrogen, fuel cells, conductivity

摘要： 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Ce_0.8Sm_0.2O_2-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Ce_0.8Sm_0.2O_2-α的烧结温度。XRD结果表明，（Li/K）₂CO₃与Ce_0.8Sm_0.2O_2-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Ce_0.8Sm_0.2O_2-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。

关键词: 二氧化铈, 复合材料, 电解质, 氢, 燃料电池, 电导率

CLC Number:

GUAN Qingmei, WANG Hongtao. Ce_0.8Sm_0.2O_2-α ceramic prepared by sol-gel method at low temperature and its composite electrolyte in intermediate temperature fuel cells[J]. Chemical Industry and Engineering Progress, 2017, 36(09): 3395-3399.

管清梅, 王洪涛. 溶胶-凝胶法低温制备Ce_0.8Sm_0.2O_2-α及其复合电解质的中温燃料电池性能[J]. 化工进展, 2017, 36(09): 3395-3399.

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