PrGa_(1-x)Mg_xO_3作为燃料电池固体电解质的研究

A Study of PrGa_(1-x)Mg_xO_3 as the Electrolytes of SOFCs

用固相反应法合成了具有正交钙钛矿结构的 Pr Ga1-x Mgx O3( x=0 ,0 .0 5 ,0 .1 0 ,0 .1 5 ,0 .2 0 ,0 .2 5 ) .通过掺杂 ,样品的电导率显著提高 ,活化能降低 .所有样品均以离子导电为主 ,其中 Pr Ga0 .9Mg0 .1O3的氧离子电导率最高 ,在 80 0℃达到 0 .0 5 S/cm,Pr Ga0 .8Mg0 .2 O3的导电活化能最低 ,为 2 4 .1 9k J/mol.随着温度的升高 ,样品的离子迁移数增加 .Pr Ga0 .9Mg0 .1O3作为电解质的燃料电池在 94 0℃短路电流密度为 0 .4 5 A/cm2 ,最大功率密度达 0 .1 31 W/cm2 ,镁掺杂的 Pr Ga

PrGa 1- x Mg x O 3( x =0, 0.05, 0.10, 0.15, 0.20, 0.25) were synthesized by using a standard solid state technology. XRD results show that all samples are orthorhombic. Mg doping increases the oxygen ion conductivity and decreases the activation energy of the samples significantly. The conductivity of the samples is mainly ionic. PrGa 0.9 Mg 0.1 O 3 has the highest conductivity of 0.05 S/cm at 800 ℃, while PrGa 0.8 Mg 0.2 O 3 has the lowest activation energy of 24.19 kJ/mol in all the samples. The oxygen ion transport number of the samples increases with increasing temperature. SOFCs results show that PrGa 0.9 Mg 0.1 O 3 has the best properties, for which the power density of 0.131 W/cm 2 and the short circuit current density of 0.45 A/cm 2 were achieved at 940 ℃. This study reveals that Mg doped PrGaO 3 is a kind of solid electrolyte with superior properties.