Sulfide solid electrolyte material, lithium solid-state battery, and method for producing sulfide solid electrolyte material
A sulfide solid electrolyte material contains glass ceramics that contains Li, A, X, and S, and has peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line. A is at least one kind of P, Si, Ge, Al, and B, and X is a halogen. A method for producing a sulfide solid electrolyte material includes amorphizing a raw material composition containing Li 2 S, a sulfide of A, and LiX to synthesize sulfide glass, and heating the sulfide glass at a heat treatment temperature equal to or more than a crystallization temperature thereof to synthesize glass ceramics having peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line, in which a ratio of the LiX contained in the raw material composition and the heat treatment temperature are controlled to obtain the glass ceramics.
1. A method for producing a sulfide solid electrolyte material comprising:
amorphizing a raw material composition containing Li 2 S, a sulfide of A, and LiX to synthesize sulfide glass; and
heating the sulfide glass at a heat treatment temperature equal to or more than a crystallization temperature of the sulfide glass to synthesize glass ceramics having peaks at 2θ=20.2° and 23.6° in X-ray diffraction measurement with CuKα line,
wherein:
A is at least one element selected from the group consisting of P, Si, Ge, Al and B,
X is a halogen, and
a ratio of the LiX contained in the raw material composition and the heat treatment temperature are controlled to obtain the glass ceramics.
2. The method according to claim 1 , wherein a ratio of a peak intensity at 2θ=20.2° to a peak intensity at 2θ=21.0° is 1 or more.
3. The method according to claim 1 , wherein the sulfide solid electrolyte material does not contain cross-linked sulfur.
4. The method according to claim 1 , wherein:
the ratio of the LiX contained in the raw material composition is in a range of about 14% by mole to about 30% by mole, and
an upper limit of the heat treatment temperature is a temperature that allows the synthesis of the glass ceramics of about 200° C.
5. The method according to claim 1 , wherein the ratio of the LiX contained in the raw material composition is 14% by mole or more and less than 30% by mole, and the heat treatment temperature is less than 200° C.
6. The method according to claim 1 , wherein the heat treatment temperature is 170° C. or more.
7. The method according to claim 1 , wherein the heat treatment temperature is 190° C. or less.