A solid electrolyte glass at least including: at least one alkali metal element; a phosphorus (P) element; a sulfur (S) element; and one or more halogen elements selected from I, Cl, Br and F; wherein the solid electrolyte glass has two exothermic peaks that are separated from each other in a temperature range of 150 C. to 350 C. as determined by differential scanning calorimetry (in a dry nitrogen atmosphere at a temperature-elevating speed of 10 C./min from 20 to 600 C.).

A solid electrolyte glass at least including: at least one alkali metal element; a phosphorus (P) element; a sulfur (S) element; and one or more halogen elements selected from I, Cl, Br and F; wherein the solid electrolyte glass has two exothermic peaks that are separated from each other in a temperature range of 150 C. to 350 C. as determined by differential scanning calorimetry (in a dry nitrogen atmosphere at a temperature-elevating speed of 10 C./min from 20 to 600 C.).

A solid electrolyte glass at least including: at least one alkali metal element; a phosphorus (P) element; a sulfur (S) element; and one or more halogen elements selected from I, Cl, Br and F; wherein the solid electrolyte glass has two exothermic peaks that are separated from each other in a temperature range of 150 C. to 350 C. as determined by differential scanning calorimetry (in a dry nitrogen atmosphere at a temperature-elevating speed of 10 C./min from 20 to 600 C.).