Ce0.8Sm0.2O1.9-BaCe0.8Sm0.2O2.9复合电解质的成分对其电化学性能的影响

采用一步溶胶凝胶法制备摩尔比分别为9∶1、7∶3、5∶5和3∶7的复合电解质Ce0.8Sm0.2O1.9(SDC)-BaCe0.8Sm0.2O2.9(BCS)粉末,研究复合电解质SDC-BCS的相成分对电导率及其电化学性能的影响.结果表明:随着SDC含量的增加,复合电解质SDC-BCS的晶粒尺寸增大、电导率提高;复合电解质的晶界电导率均高于单相SDC的晶界电导率.不同成分的复合电解质制备的NiO-SDC-BCS|SDC-BCS|LSCF-SDC-BCS单电池的功率密度随着SDC含量的增加而提高.当SDC∶BCS的摩尔比为9∶1时,其单电池700 ℃的最大功率密度为550 mW/cm2,是单电池NiO-SDC|SDC|LSCF-SDC最大功率密度的3倍.

Effect of Composition on Electrochemical Performance of Ce0.8Sm0.2O1.9-BaCe0.8Sm0.2O2.9 Composite Electrolytes

The composite electrolytes Ce0.8Sm0.2O1.9-BaCe0.8Sm0.2O2.9(SDC-BCS, molar ratio 9∶1, 7∶3, 5∶5 and 3∶7) were synthesized by one-step citric acid-nitrate gel combustion method.In this work, the effect of SDC-BCS composition on the conductivity and electrochemical performance were studied.The results indicate that grain size and electrical conductivity of SDC-BCS increase with increasing of SDC content in SDC-BCS.Compared to electrolyte SDC, the grain-boundary conductivity of composite electrolytes is much higher.The power density of the single cell NiO-SDC-BCS|SDC-BCS|LSCF-SDC-BCS which was prepared by composite electrolytes with different phase compositions increases with increasing SDC content.When the molar ratio of SDC∶ BCS gets 9∶1,the peak power density of the single cell is 550 mW/cm2 at temperature 700 ℃, which is 3 times higher than that of NiO-SDC|SDC|LSCF-SDC single cell.