Electrical Properties of Sr2+ and Gd3+ Codoped Ceria Electrolyte System for LT-SOFC

P. Koteswararao1,*, M. Buchi Suresh2, P. Varalaxmi3, B.N. Wani4 and P.V. Bhaskara Rao5

1Department of Physics, Geethanjali College of Engineering and Technology, Cheeryal (V), Keesara (M), Medchal District-501 301, India

2Center for Ceramic Processing, International Advanced Research Centre for Powder Metallurgy and New Materials, Hyderabad-500 005, India

3Department of Physics, Anurag Engineering College, Aushapur (V), Ghatkesar (M), Rangareddi District-501 301, India

4Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085, India

5Department of Physics, Wollega University, Nekemte, Ethiopia

*Corresponding author: E-mail: koteswarphysics@gmail.com

Abstract

This paper reports the effect of Sr2+ addition on electrical properties of Ce0.8Gd0.2O2-δ (GDC) electrolyte for low temperature solid oxide fuel cell application. The Sr2+ (0, 0.5, 1 and 2 mol %) doped GDC solid electrolytes have been prepared by solid state method. The sintered densities of the samples are around 95 %. Among all the compositions, the highest ionic conductivity is observed in the GDC sample with 0.5 mol % Sr addition. Nyquist plots resulted in multiple redoxation process such as grain and grain boundary conductions to the final conductivity. Estimated blocking factor is lower for the GDC electrolyte with 0.5 mol % Sr2+, indicating that Sr2+ addition promoted grain boundary conduction. Activation energies were calculated from Arrhenius plot and are found in the range of 0.80 to 1.25 eV, indicating oxygen ion conduction in the doped GDC electrolyte system of samples.

Keywords

Conductivity, GDC electrolyte, Impedance, Ionic conductivity, Activation energy.

   View Article PDF File Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.