Polyol-mediated synthesis of La0.9Sr0.1Ga0.8Mg0.2O2.85-Ce0.85Sm0.15O1.925 composite electrolyte for IT-SOFCs

Abstract

The Sr- and Mg-doped LaGaO3 (La0.9Sr0.1Ga0.8Mg0.2O2.85; LSGM) and Sm-doped CeO2 (Ce0.8Sm0.2O1.9; SDC) were synthesized by polyol assisted synthesis route. The composite of LSGM & SDC was prepared by their mixing in the weight ratio of 9:1, respectively. Its suitability as solid electrolyte was examined for electrochemical applications like solid oxide fuel cells (SOFCs). The structural, microstructural and most important electrical properties of the composite (LSGM-SDC) was studied by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Impedance spectroscopic (EIS) techniques. It was observed that the sintered LSGM-SDC composite comprises perovskite cubic LSGM phase mostly, with a minor SDC phase, as perceived by X-ray diffraction study. The LSGM-SDC composite electrolyte possess a small grain boundary and bulk resistance as compared to LSGM and SDC samples. In the measured temperature range, i.e. 500–700 °C, LSGM-SDC composite shows the highest conductivity as compare to LSGM and SDC systems. Thus, the composite processing of LSGM & SDC may result as an attractive approach for the preparation of solid electrolyte material for IT-SOFCs. © 2020 Elsevier Ltd. All rights reserved.