Lithium ion conducting sulfide based crystallized glass and method for production thereof

1. A lithium-ion-conducting sulfide-based crystallized glass comprising: lithium (Li), phosphorus (P), and sulfur (S) elements in a molar ratio of Li 2 S:P 2 S 5 of from 68 to 74:26 to 32 in terms of Li 2 S and P 2 S 5 ,

wherein the crystallized glass has diffraction peaks at 2θ=17.8±0.3 deg, 18.2±0.3 deg, 19.8±0.3deg, 21.8±0.3 deg, 23.8±0.3 deg, 25.9±0.3 deg, 29.5±0.3 deg and 30.0±0.3 deg in X-ray diffraction, wherein CuKα: λ=1.5418 Å.

2. A solid electrolyte for a lithium rechargeable battery comprising the lithium-ion-conducting sulfide-based crystallized glass according to claim 1 as a material.

3. An all-solid battery comprising the solid electrolyte according to claim 2 .

4. The lithium-ion-conducting sulfide-based crystallized glass according to claim 1 , which is prepared by a heat-treatment of a glass formed from a raw material comprising from 68 to 74 mol % of Li 2 S and from 26 to 32 mol % of P 2 S 5 .

5. The lithium-ion-conducting sulfide-based crystallized glass according to claim 1 , which is prepared by a heat-treatment of a glass formed from a raw material comprising from 68 to 73 mol % of Li 2 S and from 27 to 32 mol % of P 2 S 5 .

6. The lithium-ion-conducting sulfide-based crystallized glass according to claim 1 , wherein the molar ratio of Li 2 S:P 2 S 5 is from 68 to 73 to 27 to 32 in terms of Li 2 S and P 2 S 5 .

7. The lithium-ion-conducting sulfide-based crystallized glass according to claim 1 , wherein the diffraction peaks at 2θ=17.8±0.3 deg, 18.2±0.3 deg, 19.8±0.3 deg, 21.8±0.3 deg, 23.8±0.3 deg, 25.9±0.3 deg, 29.5±0.3 deg and 30.0±0.3 deg in X-ray diffraction show that the crystallized glass has a crystal phase different from crystal phases of Li 7 PS 6 , Li 4 P 2 S 6 and Li 3 PS 4 .

8. A method of producing a lithium-ion-conducting sulfide-based crystallized glass, the method comprising:

preparing a mixture comprising 68 to 74 mol % of Li 2 S and 26 to 32 mol % of P 2 S 5 and forming a sulfide-based glass from the mixture, and heat-treating the sulfide-based glass at 230 to 360° C., thereby producing the crystallized glass.

9. The method according to claim 8 , wherein the Li 2 S is prepared by reacting lithium hydroxide with hydrogen sulfide in an aprotic organic solvent to produce crude Li 2 S and purifying the crude Li 2 S by cleaning with an organic solvent at 100° C. or more.

10. The method according to claim 8 , wherein the total amount of sulfur oxides contained in the Li 2 S is 0.15 mass % or less and the amount of lithium N-methylaminobutyrate (LMAB) is 0.1 mass % or less.

11. The method according to claim 8 , wherein phosphorus (P) and sulfur (S) at a molar ratio corresponding to P 2 S 5 are used instead of the P 2 S 5 .

12. A lithium-ion-conducting sulfide-based crystallized glass produced by the method according to claim 11 .

13. The method according to claim 8 , wherein the sulfide-based glass is produced from Li 2 S and P 2 S 5 or phosphorus (P) and sulfur (S) by a mechanical milling process.

14. A lithium-ion-conducting sulfide-based crystallized glass produced by the method according to claim 8 .

15. A solid electrolyte for a lithium rechargeable battery comprising the lithium-ion-conducting sulfide-based crystallized glass according to claim 14 as a material.

16. An all-solid battery comprising the solid electrolyte according to claim 15 .

17. A lithium-ion-conducting sulfide-based crystallized glass comprising: lithium (Li), phosphorus (P), and sulfur (S) elements in a molar ratio of Li 2 S:P 2 S 5 of from 68 to 74:26 to 32 in terms of Li 2 S and P 2 S 5 ,

wherein the crystallized glass has diffraction peaks at 2θ=17.8±0.3 deg, 18.2±0.3 deg, 19.8±0.3 deg, 21.8±0.3 deg, 23.8±0.3 deg, 25.9+0.3 deg, 29.5±0.3 deg and 30.0±0.3 deg in X-ray diffraction, wherein CuKα: λ=1.5418 Å,

wherein the crystallized glass is obtained a method comprising heat-treating the sulfide-based glass at a temperature in a range from 230 to 360° C., wherein the heat-treating temperature is equal or higher than the crystallization temperature of the sulfide-based glass, thereby producing the crystallized glass.

18. The lithium-ion-conducting sulfide-based crystallized glass according to claim 17 , wherein the diffraction peaks at 2θ=17.8+0.3 deg, 18.2±0.3 deg, 19.8±0.3 deg, 21.8±0.3 deg, 23.8±0.3 deg, 25.9±0.3 deg, 29.5±0.3 deg and 30.0±0.3 deg in X-ray diffraction show that the crystallized glass has a crystal phase different from crystal phases of Li 7 PS 6 , Li 4 P 2 S 6 and Li 3 PS 4 .