SOLID ELECTROLYTE, AND ELECTRODE MIXTURE AND BATTERY CONTAINING THE SAME

1 . A solid electrolyte comprising a lithium (Li) element, a phosphorus (P) element, a sulfur (S) element, and an X element, where X represents at least one element selected from the group consisting of a chlorine (Cl) element, a bromine (Br) element, and an iodine (I) element,

wherein the solid electrolyte has a peak attributed to a fluorine (F) element in surface analysis based on X-ray photoelectron spectroscopy.

2 . The solid electrolyte according to claim 1 , comprising a fluoride solvent.

3 . The solid electrolyte according to claim 1 ,

wherein the ratio (quantitative value of F1s/quantitative value of P2p) of quantitative value of F1s (atom %) and quantitative value of P2p (atom %), calculated based on X-ray photoelectron spectroscopy with the total amount of Li1s, C1s, O1s, F1s, P2p, S2p, Cl2p, and Br3d being set to 100%, is 0.01 or more and 0.34 or less.

4 . The solid electrolyte according to claim 1 , comprising a crystal phase of an argyrodite-type crystal structure.

5 . An electrode material mixture comprising:

the solid electrolyte according to claim 1 ; and

an active material.

6 . A battery comprising:

a positive electrode layer;

a negative electrode layer; and

a solid electrolyte layer provided between the positive electrode layer and the negative electrode layer,

wherein the battery contains the solid electrolyte according to claim 1 .