Ce_(0.8)Sm_(0.2)O_(1.9)-BaCe_(0.8)Sm_(0.2)O_(2.9)复合电解质的晶界电导

Grain-boundary Conductivity of Ce_(0.8)Sm_(0.2)O_(1.9)-BaCe_(0.8)Sm_(0.2)O_(2.9) Composite Electrolytes

分别采用机械混合法和一步溶胶-凝胶法制备摩尔比为1:1的Ce_(0.8)Sm_(0.2)O_(1.9)(SDC)-BaCe_(0.8)Sm_(0.2)O_(2.9)(BCS)复合电解质,研究了不同制备方法对复合电解质SDC-BCS的显微结构以及电化学性能的影响。结果表明:相比于机械混合法,一步溶胶-凝胶法制得的复合电解质中的SDC和BCS两相的分布更加均匀;且与单相电解质SDC相比,复合电解质中SDC和BCS的相界能够为质子和氧离子提供传输通道,有利于晶界电导率的提高。另外,一步溶胶-凝胶法制备的复合电解质制作的单电池,具有较高的开路电压和最大功率密度,在700℃时分别达到0.914 V和0.281 W/cm^2。

Ce0.8Sm0.201.9-BaCe0.8Sm0.2O2.9 （SDC-BCS, molar ratio 1：1） composite electrolytes were prepared via mechanically- mixing method and one-step citric acid-nitrate gel combustion method. The SDC-BCS pellets were sintered in air at 1 550 ℃ for 5 h. The microstructure and electrochemical properties of SDC-BCS composite electrolyte prepared by different methods were investigated. The results show that phase distribution of SDC-BCS composite electrolyte via one-step method is more uniform than that of mechanically-mixing method. The phase boundary of SDC-BCS composite can provide the transfer channel for protons and oxygen ions, which is benefit to the improvement of the grain-boundary conductivity. The open circuit voltage and the peak power density of the single cell with SDC-BCS composite electrolyte via one-step method are higher than that of SDC-BCS composite electrolyte via mechanically-mixing method.