Solid electrolyte and lithium battery including the same

• US 10,446,872 B2
• Filed: 08/02/2016
• Issued: 10/15/2019
• Est. Priority Date: 08/04/2015
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Ceder, Gerbrand, Kim, Jaechul, Miara, Lincoln, Richards, William, Tsujimura, Tomoyuki, Wang, Yan, Suzuki, Naoki
• Primary Examiner(s): Carrico, Robert S
• Application Number:
  US15/226,179
• Publication Number:
  US 20170040637A1
• Time in Patent Office: 1,169 Days
• Field of Search: None
• CPC Class Codes: C01B 17/22 Alkali metal sulfides or polysulfides
• CPC Class Codes: C01B 25/14 Sulfur, selenium, or tellurium compounds of phosphorus
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2300/0065 Solid electrolytes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A solid electrolyte material represented by Formula 1:
L_1+2x(M1)_1−x(M2)(M3)₄  Formula 1
wherein 0.25<x<1, L is at least one element selected from a Group 1 element, M1 is at least one element selected from a Group 2 element, a Group 3 element, a Group 12 element, and a Group 13 element, M2 is at least one element selected from a Group 5 element, a Group 14 element, and a Group 15 element, and M3 is at least one element selected from a Group 16 element, and wherein the solid electrolyte material has an I-4 crystal structure.

Claims

1. A solid electrolyte material represented by Formula 1:

Li_1+2xZn<sub>1−

x</sub>PS₄ 

 

Formula 1

wherein 0.05≤

x<

1,

wherein the solid electrolyte material has an I-4 crystal structure, and

wherein the solid electrolyte material has a peak at about 18°

two-theta, when analyzed by X-ray diffraction using CuKα

radiation.

2. The solid electrolyte material of claim 1, wherein x of Formula 1 satisfies 0.625≤

x≤

0.8.

3. The solid electrolyte material of claim 1, wherein the solid electrolyte material does not comprise a disulfide bond.

4. The solid electrolyte material of claim 1, wherein the solid electrolyte material has an ionic conductivity of greater than 2.9×

10<sup>−

8</sup> Siemen per centimeter as measured at room temperature.

5. A method of preparing a solid electrolyte, the method comprising:

contacting LiZnPS₄ and amorphous Li₃PS₄ to obtain a mixture; and

heat-treating the mixture to obtain the solid electrolyte of claim 1.

6. The method of claim 5, wherein the LiZnPS₄ is prepared by:

providing a mixture of Li₂S, ZnS, and P₂S₅; and

heat-treating the mixture to obtain the LiZnPS₄.

7. The method of claim 6, wherein Li₂S, ZnS, and P₂S₅ are contained in the mixture at a molar ratio of 1:

2;

1.

8. The method of claim 5, wherein the amorphous Li₃PS₄ is prepared by mixing Li₂S and P₂S₅ at a molar ratio of 3:

1.

9. The method of claim 5, wherein the LiZnPS₄ and the amorphous Li₃PS₄ are contained in the mixture at a molar ratio of 1:

3.

10. The method of claim 6, wherein the heat-treating of the mixture of Li₂S, ZnS, and P₂S₅ comprises heat-treating at a temperature in a range of about 200°

C. to about 500°

C.

11. The method of claim 5, wherein the heat-treating of the LiZnPS₄ and the Li₃PS₄ comprises heat-treating at a temperature in a range of about 200°

C. to about 230°

C.

12. A secondary battery comprising:

a positive electrode comprising a positive active material;

a negative electrode comprising a negative active material; and

a solid electrolyte layer between the positive electrode and the negative electrode, the solid electrolyte layer comprising the solid electrolyte material of claim 1.

13. The solid electrolyte material of claim 1, wherein the solid electrolyte material has peaks at about 29.5°

two-theta, about 34°

two-theta, about 35.5°

two-theta, about 43.5°

two-theta, about 46.5°

two-theta, about 52°

two-theta, and about 54°

two-theta, when analyzed by X-ray diffraction using CuKα

radiation.

14. The solid electrolyte material of claim 1, wherein x of Formula 1 satisfies 0.25≤

x<

1.

15. The solid electrolyte material of claim 1, wherein a structure of the solid electrolyte material comprises a body centered cubic anion sublattice.

16. The solid electrolyte material of claim 15, wherein the structure of the solid electrolyte material comprises adjacent tetrahedral lithium sites.

17. The solid electrolyte material of claim 1, wherein [P₂S₆]⁴⁻

and (P₂S₇)⁴⁻

are absent based on Raman analysis for peaks at 380 inverse centimeters and 400 inverse centimeters, respectively.

18. The solid electrolyte material of claim 1, wherein the solid electrolyte material has a peak at position of about 17.8°

two-theta to about 18.4°

two-theta, when analyzed by X-ray diffraction using CuKα

radiation.

19. The solid electrolyte material of claim 1, wherein the solid electrolyte material has peaks at about 29.4°

two-theta to about 29.8°

two-theta, about 33.9°

two-theta to about 34.2°

two-theta, about 35.4°

two-theta to about 36.3°

two-theta, about 43.2°

two-theta to about 44.4°

two-theta, about 46.3°

two-theta to about 46.8°

two-theta, about 51.9°

two-theta to about 52.10 two-theta, and about 53.3°

two-theta to about 54.4°

two-theta, when analyzed by X-ray diffraction using CuKα

radiation.

20. A solid electrolyte material represented by Formula 1:

Li_1+2xZn<sub>1−

x</sub>PS₄ 

 

Formula 1

wherein 0.05≤

x<

1, and

wherein [PS₄]³⁻

anions of the solid electrolyte define a body centered cubic sublattice.

21. The solid electrolyte material of claim 20 wherein x of Formula 1 satisfies 0.25≤

x<

1.

22. The solid electrolyte material of claim 20, wherein the solid electrolyte material has peak at about 18°

two-theta, when analyzed by X-ray diffraction using CuKα

radiation.

23. The solid electrolyte material of claim 22, wherein a structure of the solid electrolyte comprises adjacent tetrahedral lithium sites.

24. A solid electrolyte material prepared by:

contacting Li₂S, ZnS, and P₂S₅ to obtain LiZnPS₄; and

combining the LiZnPS₄ and amorphous Li₃PS₄ to form the solid electrolyte material,

wherein the solid electrolyte material has an I-4 crystal structure,

wherein the solid electrolyte material has an ionic conductivity of greater than 2×

10<sup>−

4</sup> Siemen per centimeter, and

wherein the solid electrolyte material has a peak at position of about 18°

±

0.50 two-theta, when analyzed by X-ray diffraction using CuKα

radiation.