Co元素掺杂对CeO_2基固态电解质导电行为的影响

分别采用晶格固溶(Solid Solution,SS)和晶界择优偏聚(Grain Boundary Segregation,GBS)两种方式将Co元素添加至Gd掺杂的CeO_2粉末(GDC)内,研究两种添加方式对GDC电导行为的影响。首先采用共沉淀法制备10%Gd(摩尔分数,下同)掺杂的GDC粉末(10GDC),再分别通过以上两种方式将1%Co元素添加至10GDC粉末中,得到10GDC-1Co(SS)和10GDC-1Co(GBS)粉末样品。上述粉末样品中只含有CeO_2固溶体相,晶粒尺寸范围为10.1~12nm。将Co掺杂前后粉末样品在1000℃下烧结1h,分别得到10GDC,10GDC-1Co(SS)和10GDC-1Co(GBS)片状陶瓷样品。烧结后所有陶瓷样品中均只含有CeO_2固溶体相,晶粒尺寸范围为44.5~59.7nm。10GDC-1Co(SS)和10GDC-1Co(GBS)样品的电导率均高于10GDC样品的电导率,当测试温度低于430℃时,10GDC-1Co(GBS)样品的电导率高于10GDC-1Co(SS)样品;当测试温度高于430℃时,10GDC-1Co(SS)样品的电导率高于10GDC-1Co(GBS)样品。

Effects of Co-dopings on Electrical Behaviors of CeO2-based Solid Electrolyte

Co element was added into Gd-doped ceria(GDC)powders by two methods namely lattice solution and preferred grain boundary segregation,respectively.The 10%(mole fraction,the same below)Gd-doped ceria(10GDC)solid solution powders were co-precipitated and then doped with 1% Co by the means of the two ways.These powders were named as 10GDC-1Co(SS)and 10GDC-1Co (GBS),respectively.Then the powders above were sintered at 1000°C for 1h to obtain 10GDC, 10GDC-1Co(SS)and 10GDC-1Co(GBS)ceramic samples.All the synthesized powders and sintered samples only consist of the CeO2 solid solution phase,and their grain sizes are 10.1-12nm and 59.8-112nm,respectively.The conductivities of 10GDC-1Co(SS)and 10GDC-1Co(GBS)samples are higher than that of 10GDC samples.When the test temperature is lower than 430℃,the conductivi-ties of 10GDC-1Co(GBS)samples are higher than that of 10GDC-1Co(SS)samples,but as the test temperature increases,the conductivities of 10GDC-1Co(GBS)samples are lower than that of 10GDC-1Co(SS)samples.