Structural and electrical properties of Gd and W co-doped La2Mo2O9 as electrolyte for IT-SOFCs

Abstract

In this study, a modified sol-gel method was employed to synthesize Gd and W co-doped La2Mo2O9 (LMX). The impact of Gd and W co-doping on the pristine LMX lattice was examined using X-Ray diffraction, and the local structural parameters were analyzed through Rietveld refinement. The findings indicate that both the pure and co-doped LMX samples possess a cubic structure with a P213 space group. To investigate the electrical performance of the lanthanum molybdate (La2Mo2O9) both in its pure form and when co-doped with Gd and W, electrochemical impedance spectroscopy was conducted. The results demonstrated that co-doping enhances the conductivity of oxy-ions compared to pure LMX. Specifically, La1.7Gd0.3Mo1.7W0.3O9 (LMXG3) exhibited a higher ionic conductivity of approximately 2 x 10−2 Scm−1 at a temperature of 650 °C, surpassing the conductivity of the pure LMX sample and other co-doped LMX samples. This investigation highlights the potential of the Gd and W co-doped LMX system as a solid electrolyte for intermediate-temperature solid oxide fuel cells (IT-SOFCs).