镧改性镍基阳极固体氧化物燃料电池

Lanthanum modified nickel-based anode of SOFCs

研究了镧改性镍基阳极的组成与结构及其电化学性能.XRD结果显示,镧可以与氧化镍反应生成LaNiO3,在复合阳极中可以与氧化锆反应生成La2Zr2O7.SEM结果显示,当镧含量为10%(摩尔比)时,复合阳极的颗粒较小,分布均匀;添加镧可以较好地阻止镍与氧化钇稳定的氧化锆(YSZ)的烧结长大,而且很好地改善镍与YSZ的界面接触;镧改性阳极的微结构得到了明显的改善,大大降低了电池的极化电阻,提高了电池性能,电池在800℃时的最大功率密度由添加前的1.33W/cm2提高到1.61W/cm2.但当添加过量的镧(20%摩尔比)时,因较多的La2Zr2O7生成,使电池的欧姆和极化电阻明显增加,电池性能降低.

The effects of adding lanthanum to the nickel-based anode on the cell performances were studied.Because lanthanum can react with nickel and zirconium,it can hinder the sintering of nickel and yttrium stabilized zirconium（YSZ） and improve the interfacial contact between Ni and YSZ on the anode.When 10%（mol） lanthanum was added to the anode,the particles in the anode became smaller and better interfacial contact and the distribution was more uniform than Ni-YSZ anode,which led to a great decrease of the polarization resistance and a great increase of the activity for electrochemical oxidation of hydrogen.When the content of lanthanum added to NiO was 10 mol %,the cell maximum power density increased to 1.61W/cm^2 from 1.33 W/cm^2 of the Ni-YSZ anode cell at 800 oC.When the lanthanum content increased to 20%（mol）,a large amount of La2Zr2O7 was formed,which led to both the decrease of the electronic conductivity of anode and the decrease of the cell performance.