SOLID ELECTROLYTE AND METHOD FOR PRODUCING SAME

A method of production of a solid electrolyte having an Argyrodite-type crystal structure, including steps of mixing raw materials such that lithium (Li), phosphorus (P), sulfur (S), oxygen (O), and halogen (X) satisfy the following formulas (11) to (14) to obtain a mixture; and heating the mixture: 4.8 ≦ Li/P ≦ 5 .3 3.8 ≦ S/P ≦ 4 .4 0 < O/P ≦ 0 .8 1.0 < X/P ≦ 2 .0 wherein the formula (11) represents a molar ratio of Li to P, the formula (12) represents a molar ratio of S to P, the formula (13) represents a molar ratio of O to P, and the formula (14) represents a molar ratio of halogen (X) to P.