Abstract: The present invention relates to a sulfide-based solid electrolyte for an all-solid lithium secondary battery, and to a method for preparing the sulfide-based solid electrolyte. The present invention has an effect of providing a sulfide-based solid electrolyte that has excellent stability with respect to lithium metal and has excellent ion conductivity, while having high crystallinity. The present invention has an effect of providing a method for preparing a sulfide-based solid electrolyte that has excellent stability with respect to lithium metal and has excellent ion conductivity, while having high crystallinity even when heat-treated at a low temperature.

Abstract: A crystallized glass with negative coefficient of thermal expansion includes 38 wt % to 64 wt % of silica (SiO2); 30 wt % to 40 wt % of alumina (Al2O3); and 5 wt % to 12 wt % of lithium oxide (Li2O) as a basic component, and further includes more than one component selected from the group consisting of 0.5 wt % to 15 wt % of zirconia (ZrO2), 0.5 wt % to 6.5 wt % of titanium dioxide (TiO2), 0.5 wt % to 4 wt % of phosphorus pentoxide (P2O5), 2 wt % to 5 wt % of magnesium oxide (MgO), and 0 wt % to 5 wt % of magnesium fluoride (MgF2) in addition to the basic components. The crystallized glass may have a high negative coefficient of thermal expansion so that it has an advantage that it can be used as a thermal expansion compensation material according to the temperatures of all kinds of glasses and similar products thereof.