The influence of the glass additive Li2O-B2O3-SiO2 on the phase composition, conductivity, and microstructure of the Li7La3Zr2O12

An influence of the lithium boron-silicate glass 65Li(2)O center dot 27B(2)O(3)center dot 8SiO(2) on the phase composition, conductivity and microstructure of the Li7La3Zr2O12 with cubic configuration was investigated. A series of the Li7La3Zr2O12 - x wt% 65Li(2)O center dot 27B(2)O(3)center dot 8SiO(2) composite electrolytes (x = 1-10) was prepared (during annealing) for 1 h at 1150 degrees C. The samples were characterized by the X-ray diffraction, Raman spectroscopy, scanning electron microscopy and differential scanning calorimetry. According to the XRD and Raman spectroscopy, the obtained composites with x < 7 had no impurities. It was established by the DSC and Raman spectroscopy that the 65Li(2)O center dot 27B(2)O(3)center dot 8SiO(2) additive was in the glassy state for all studied composites and predominantly located in the intergrain area. A glass addition of 1 wt% leads to the conductivity growth from 1.5 x 10(-4) to 3.1 x 10(-4) S cm(-1) at 25 degrees C. With further addition of the glass, the total conductivity of electrolyte decreased whereas the activation energy increased. In view of the high activation energy, the composite electrolytes have higher total conductivity values than the Li7La3Zr2O12 with cubic structure at temperatures above 100 degrees C. Thus, the obtained composites can be used as solid electrolytes in the high-energy power sources. (C) 2018 Elsevier B.V. All rights reserved.