掺入Al_2O_3对固体氧化物电解质材料YSZ性能影响的研究

Study on Influence of Doping YSZ with Small Amount of Al_2O_3

在立方相的钇稳定化氧化锆 [(ZrO2 ) 0 .92 (Y2 O3) 0 .0 8](YSZ)中 ,掺入少许不同量的Al2 O3,研究其对基体材料YSZ的烧结性能、机械强度和导电性能的影响 ,并对其机理进行了分析。实验结果表明 ,掺入Al2 O3能够明显降低电解质烧结温度 ,改善烧结性能。在 130 0℃烧结 1h后 ,少量掺杂Al2 O3的样品晶粒尺寸明显比纯YSZ样品的小 ;从阻抗谱图上可以看出 ,随着Al2 O3含量的增加 ,晶界电阻不断减小 ,在掺杂比例为 4 % (质量分数 )时 ,达到最小点。而后随着Al2 O3含量的增加 ,晶界电阻又呈上升趋势。用纯YSZ和掺 4 % (质量分数 )Al2 O3的材料制成SOFC ,得到伏安特性曲线 ,结果表明 ,掺 4 % (质量分数 )Al2 O3的性能比YSZ好。

Sintering,ionic conductive and mechanic properties were studied on YSZ [(ZrO 2) 0.92 (Y 2O 3) 0.08 ] doped with a small amount of Al 2O 3 and relative mechanism was analyzed.The experiments showed that doping Al 2O 3 could improve sintering property by decreasing the sintering temperature.After being sintered under 1300℃ for 1h,sample of YSZ doped with 4wt% Al 2O 3 (being abbreviated to 4A-YSZ) showed less grain size than pure YSZ notably and the least boundary resistance in all samples.Impedance spectra showed that boundary resistance decreased with increasing Al 2O 3 content between 0 and 4wt% and then it rose up,the minimum value was reached by 4A-YSZ sample too.Fuel cells with pure YSZ and 4A-YSZ electrolyte were fabricated and tested under the same experiment condition,the voltage-current curves showed that 4A-YSZ cell with a better property than pure YSZ.