Processing of perovskite La0.9Sr0.1Ga0.8Mg0.2O3-δ electrolyte by glycine-nitrate combustion method

• DOI: 10.1016/j.ijhydene.2021.07.003
• Publication Date: 2021-07-28T05:05:57Z
• Authors: Q. Zhang; W.J. Liu; J. Wang; D. Liu; Z.H.C. Sun
• Keywords: 01 natural sciences; 0104 chemical sciences; 3. Good health

Abstract The doped LaGaO3 is a well-known intermediate-temperature electrolyte due to its high ionic conductivity and negligible electronic conductivity. However, the phase pure La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM 9182) compound is not easy to be prepared because of its sensitive character with preparing process. In this work, the influence of evaporating temperature (glycine-nitrate combustion method) on the phase formation and physical property of LSGM 9182 is investigated systematically. The samples with different evaporating temperature 80 °C ≤ T ˂ 84 °C, 84 °C ≤ T ˂ 88 °C, 88 °C ≤ T ˂ 92 °C and T ≥ 92 °C was named as compound A, B, C and D. XRD results show that the phase pure compound can only be synthesized with the evaporating temperature 80 °C ≤ T ˂ 84 °C, the higher evaporating temperature, the higher content of LaSrGaO4 or LaSrGa3O7 impurity. Due to the slight change in composition, shoulders and splitting of some XRD reflections in phase pure compound A disappear for compound D, representing an transition from low-symmetry orthorhombic lattice to high-symmetry cubic lattice. Owing to the competiting contribution between crystal symmetry and impurity, the conductivity of compound D does not decrease almostly at low temperature, however, the influence of low conductive LaSrGaO4 prevails at high temperature, consequently, the conductivity of compound D decreases to a large degree at 800 °C. Above results suggest that evaporating temperature is an important parameter to prepare high quality LSGM electrolyte, suitable evaporating temperature supplies proper energy for chemical reaction and produce single perovskite phase compound finally.