Anisotropic oxide ion conduction in melilite intermediate temperature electrolytes

作者：Wei Fengxia; Gasparyan Hripsime; Keenan Philip J; Gutmann Matthias; Fang Yanan; Baikie Tom; Claridge John B; Slater Peter R; Kloc Christian L; White Tim J^*

来源：Journal of Materials Chemistry A, 2015, 3(6): 3091-3096.

DOI：10.1039/c4ta05132g

Electrolytes with oxide ion conductivities higher than 10(-2) S cm(-1) at moderate temperatures (similar to 500-900 degrees C) offer the possibility for solid oxide fuel cells to operate with less maintenance. This study of [A(1+x)B(1-x)](2)[Ga](2)[Ga2O7+x/2](2) (0 <= x <= 0.5) (A = La, Nd; B = Ca, Sr) layered-melilite found that in large single crystals intralayer oxide ion conduction is dominant. This anisotropic behavior arises by relaxation about the interstitial oxygen through changes in the interlayer A and Ga coordination, and at 850 degrees C conductivities are similar to 0.008 S cm(-1) along the c direction and similar to 0.036 S cm(-1) perpendicular to the c axis. It is found that the ionic conductivity can be optimized by increasing the number of interstitial oxygen and reducing the size of interlayer cations.

• 出版日期2015
• 单位南阳理工学院