Al2 O3掺杂对Ce0.8 Gd0.15 Y0.05 O2-δ固体电解质的微结构与电性能的影响

采用溶胶-凝胶法制备了AlO1.5掺杂浓度为0.5%,1.0%,2.0%的AlO1.5/Ce0.8Gd0.15Y0.05O2-δ固体电解质材料,利用X射线衍射（XRD）、扫描电子显微镜（SEM）和交流阻抗谱研究了Al2O3掺杂对Ce0.8Gd0.15Y0.05O2-δ微观结构及电性能的影响,结果表明：800℃焙烧的所有粉末样品均为单相立方萤石结构,在所有样品中,AlO1.5掺杂量为0.5%的样品晶粒均匀,较致密,交流阻抗谱测试表明掺杂AlO1.5（x=0.5%）使Ce0.8Gd0.15Y0.05O2-δ晶界电阻减小,晶界电导率增高;当AlO1.5掺杂量x≥1%时,Al2O3对晶界的阻塞作用使晶界电导率降低,在所有样品中Ce0.8Gd0.15Y0.05O2-δ/0.5%AlO1.5晶界电导率最高（σ700℃=8.12×10-3S/cm）,说明在Ce0.8Gd0.15Y0.05O2-δ少量掺杂AlO1.5（x=0.5%）具有烧结助剂和晶界清除剂的作用.

Effect of Al2 O3 Dopant on Microstructure and Electrical Properties of Ce0. 8 Gd0. 15 Y0. 05 O2-δ Solid Electrolytes

AlO1.5/Ce0.8Gd0.15Y0.05O2-δ solid electrolytes,with AlO1.5 concentrations ranging from 0. 5% to 2%were prepared by sol-gel method. The effects of AlO1. 5 doping on the microstructure and conductivity were discussed by means of X-ray diffraction （ XRD ） , scanning electron microscopy （ SEM ） and AC impedance spectroscopy. The results show that all powders calcined at 800℃ are crystallized in a single cubic fluorite structure. The sample doping with 0. 5% AlO1. 5 is more uniform and relative dense. AC impedance spectra analysis suggests that AlO1.5（x=0. 5%）make the grain boundary resistance of Ce0.8Gd0.15Y0.05O2-δdecrease and the grain boundary conductivity increase. When AlO1. 5 dopant concentration is over 1%, the grain boundary conductivity begins to reduce because of blocking effect of AlO1. 5 particles at grain boundaries in all samples. The grain boundary conductivity of AlO1. 5/ Ce0. 8 Gd0. 15 Y0. 05 O2-δ reaches the maximum,σ700℃ =8. 12 ×10-3 S/cm, which suggests that doping with a little AlO1.5（x=0. 5%）in Ce0.8Gd0.15Y0.05O2-δhave the effective sintering aids and grain boundary scavengers.