Sulfide solid electrolyte material, lithium solid battery and method of preparing sulfide solid electrolyte material

1. A method of preparing a sulfide solid electrolyte material exhibiting a Li ion conductivity, wherein the sulfide solid electrolyte material comprises: (i) an organic compound having a molecular weight within a range of 30 to 300, (ii) S element, (iii) Li element, and (iv) at least one element selected from the group consisting of P, Si, Ge, Al, and B elements, the method comprising:

performing mechanical milling to a mixture of a raw material composition and the organic compound to convert the raw material composition to an amorphous state, thereby synthesizing a sulfide glass; and

drying the sulfide glass at a temperature in a range of from 110° C. to 140° C. such that an amount of the organic compound remaining in the sulfide solid electrolyte material is 0.40 wt % or more and 0.65 wt % or less, based on an amount of the sulfide solid electrolyte material.

2. The method according to claim 1 , wherein the sulfide solid electrolyte material further comprises a halogen element.

3. The method according to claim 1 , wherein the molecular weight of the organic compound is within a range of from 60 to 200.

4. The method according to claim 1 , wherein the organic compound is liquid at a temperature of 25° C.

5. The method according to claim 1 , wherein the organic compound is an aprotic organic compound.