Ionic Conduction in Ba_(0.9)La_(0.1)Ce_(0.9)Nd_(0.1)O_(3-α) Ceramic

Proton-conducting Ba0.9La0.1Ce0.9Nd0.1O3-α ceramic was prepared by high temperature solid-state reaction.X-ray powder diffraction pattern(XRD) shows that the material is of a single orthorhombic phase of perovskite-type BaCeO3.Ionic conduction in the material under different gas atmospheres was studied by using gas concentration cell and ac impendence spectroscopy methods in the temperature range of 500~900 ℃,respectively,and compared with that of Ba0.9Ca0.1Ce0.9Nd0.1O3-α.The results indicate that Ba0.9La0.1Ce0.9Nd0.1O3-α is a pure protonic conductor with the protonic transport number of 1 in wet hydrogen in the range 500~900 ℃.In dry air,Ba0.9La0.1Ce0.9Nd0.1O3-α is a mixed conductor of oxide ion and electronic hole.The oxide ionic transport numbers are 0.295~0.081.The oxide ionic conductivity of the material is higher than that of Ba0.9Ca0.1Ce0.9Nd0.1O3-α.In wet air,Ba0.9La0.1Ce0.9Nd0.1O3-α is a mixed conductor of proton,oxide ion and electronic hole.The protonic transport numbers are 0.151~0.009,and the oxide ionic transport numbers are 0.300~0.107.The protonic conductivity of the material is lower than that of Ba0.9Ca0.1Ce0.9Nd0.1O3-α.In hydrogen-air fuel cell,Ba0.9La0.1Ce0.9Nd0.1O3-α is a mixed conductor of proton,oxide ion and electron.The ionic transport numbers are 0.964~0.853.The ionic conductivity of the material is close to that of Ba0.9Ca0.1Ce0.9Nd0.1O3-α.