Ni替代对钙钛矿氧化物LaNi_yFe_(1-y)O_(3-δ)电化学性能的影响

Influence ofthe Substitution of Ni on Electrochemical Properties of Perovskite-type Oxides LaNi_yFe_(1- y)O_(3- δ)

利用溶胶凝-胶法制备了LaNiyFe1-yO3-δ(y=0、0.1、0.2、0.3、0.4、0.5、0.6、0.7、0.8、0.9)系列储氢氧化物,采用FTIR、XRD对结构进行了表征,并对其不同温度下的电化学性能进行了研究。结果表明:常压298 K时,随着Ni含量的增加,电极的最大放电容量先增大后减小,其中LaNi0.2Fe0.8O3-δ效果最佳,其最大放电容量为128 mA·h/g,比未替代的LaFeO3提高了20 mA·h/g;经过30次充放电循环后的最大容量衰减率为14.84%,比LaFeO3下降了2.29%;温度升高,放电容量显著增大,333 K时达到最大值395.5 mA·h/g;与此同时,容量衰减率有所增加,但LaNi0.2Fe0.8O3-δ的衰减率明显低于同温度下的LaFeO3。

LaNiyFe1-yOs-δ（y =0,0. 1,0. 2,0. 3,0. 4 ides were synthesized by sol-gel method and investigated ,0. 5,0. 6,0. 7,0. 8,0. 9 ） series of hydrogen storage ox- by fourier transform infrared spectroscopy （FTIR） and X- ray diffraction（XRD）, electrochemical properties in different temperature were studied. The results shows that the maximum discharge capacity of electrode increases first and then decreases with the increasing of Ni content, and LaNi0.2Feo.803_8 shows the best hydrogen storage capacity. The maximum discharge capacity of LaNi0.2Fe0.3O3-δ is 128 mAh/g, 20 mAh/g higher than the unsubstituted LaFeO3. And the attenuation rate is 14. 84% which is 2. 29% lower than LaFeO3 after 30 charge/discharge cycles. The maximum discharge capacity increases abservably with the rising of the temperature, and it goes to the top 395.5 mAh/g when the temperature is 333 K. The increase of the attenuation rate of LaNi0. 2 Feo s 03-δ is significantly lower than the attenuation rate of LaFeO3 in the same tem- perature.