中溫氧化物燃料電池陰極材料Sm0.5Sr0.5Co0.8M0.2O3-δ在B-site 摻雜（M = Fe, Mn, Cu）其性質影響

Effect of B-site Doping on Sm0.5Sr0.5Co0.8M0.2O3-δ Properties for IT-SOFC Cathode Material (M=Fe, Mn, Cu)

李建宏(Jian-Hong Li) ； 傅彥培(Yen-Pei Fu)

《臺灣鑛業》 63卷3期 (2011/09) Pp. 47-57

https://doi.org/10.30014/TMI.201109.0006

摘要

本研究以固態反應法製備Sm0.5Sr0.5Co0.8M0.2O3-δ（M = Fe, Mn, Cu）等陰極材料，希望藉由金屬離子之摻雜和梯度陰極的方式，以提升Sm0.5Sr0.5CoO3-δ陰極觸媒之電催化活性。實驗以XRD、SEM 分析其結構與表面形貌之變化，再進行試片導電率與交流阻抗之量測，探討電子導電率、極化阻值與交換電流密度，隨溫度變化之情形。結果顯示，燒結後之試片皆為結晶良好之Sm0.5Sr0.5CoO3-δ相，以及微量之Sr2Co2O5相。摻雜Fe之Sm0.5Sr0.5Co0.8Fe0.2O3-δ有較大的晶粒尺寸且其導電率最為優異，最大值約在650℃為2.026×10^3 S/cm，並探討其導電機制，討論氧空孔與氧化B-site 陽離子數目對電子導電率的影響，氧空孔增加，電子導電率則降低。比較Sm0.5Sr0.5CoO3-δ（SSC）和Sm0.5Sr0.5Co0.8M0.2O3-δ （M = Fe, Mn, Cu）分別搭接Sm0.2Ce0.8O1.9（SDC）進行阻抗分析，經由其交換電流密度值（exchange current density，i0）中，可知Sm0.5Sr0.5 Co0.8Cu0.2O3-δ 擁有較低之極化阻值，以及較好的電催化活性。

關鍵字

釤鍶鈷氧陰極 ； 導電率 ； 極化阻值 ； 交換電流密度

並列摘要

Sm0.5Sr0.5Co0.8M0.2O3-δ (M=Fe,Mn,Cu) cathodes has been successfully prepared by solid-statereaction method in this research. In order to improved the electrocatalytic properties of Sm0.5Sr0.5CoO3-δ (SSC), the different metal ions doped on the B-site of SSC. The structure and surface morphology were examined by XRD and SEM. The electrochemical properties were characterized by electrochemical impedance spectroscopy (EIS) technique. The electrical conductivity results showed that Sm0.5Sr0.5Co0.8Fe0.2O3-δ had a maximum electronic conductivity, which value is 2.026×10^3 S/cm at 650°C among all specimens. According to the relation between the electronic conductivity and the oxygen vacancies of B-site, it was found that with the increase in the oxygen vacancies, the electrical conductivity was decreased. The electrochemical properties revealed that Sm0.5Sr0.5Co0.8Cu0.2O3-δ possessed the highest exchange current density (i0), the lowest polarization resistance among all specimens due to their high electrocatalytic properties.

並列關鍵字

Cathode materials ； Conductivity ； Polarization resistance Exchange current density