Sodium-conducting solid electrolyte

• US 9,966,629 B2
• Filed: 04/28/2015
• Issued: 05/08/2018
• Est. Priority Date: 02/03/2015
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Massachusetts Institute of Technology, Samsung Electronics Co. Ltd.
• Inventors: Richards, William D., Ong, Shyue Ping, Mo, Yifei, Ceder, Gerbrand, Miara, Lincoln, Tsujimura, Tomoyuki, Wang, Yan, Ryu, Young-Gyoon, Suzuki, Naoki, Uechi, Ichiro
• Primary Examiner(s): Marks, Jacob
• Application Number:
  US14/698,691
• Publication Number:
  US 20160226095A1
• Time in Patent Office: 1,106 Days
• CPC Class Codes: C01B 25/14 Sulfur, selenium, or tellurium compounds of phosphorus
• CPC Class Codes: C01P 2002/30 Three-dimensional structures
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: H01M 10/05 Accumulators with non-aqueous electrolyte H01M10/39 takes precedence
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 4/381 Alkaline or alkaline earth metals elements H01M4/40 takes precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A sodium-conductive solid-state electrolyte material includes a compound of the composition Na₁₀MP₂S₁₂, wherein M is selected from Ge, Si, and Sn. The material may have a conductivity of at least 1.0×10⁻⁵ S/cm at a temperature of about 300K and may have a tetragonal microstructure, e.g., a skewed P1 crystallographic structure. Also provided are an electrochemical cell that includes the sodium-conductive solid-state electrolyte material and a method for producing the sodium-conductive solid electrolyte material via controlled thermal processing parameters.

Claims

1. A sodium-conductive solid-state electrolyte material comprising a compound of the composition Na₁₀MP₂S₁₂, wherein M is selected from Ge, Si, and Sn.

2. The electrolyte material of claim 1, wherein M is Ge.

3. The electrolyte material of claim 1, wherein M is Si.

4. The electrolyte material of claim 1, wherein M is Sn.

5. The electrolyte material of claim 1, having a conductivity of at least 1.0×

10<sup>−

5</sup> S/cm at a temperature of 300K.

6. The electrolyte material of claim 5, wherein the conductivity is at least 1.0×

10<sup>−

4</sup> S/cm at a temperature of 300K.

7. The electrolyte material of claim 1, having a peak in positions of within 0.50°

of 2θ

=18.18°

, 26.74°

, 33.88°

, 36.90°

, 38.07°

, 42.59°

, and/or 46.10°

as measured by X-ray diffraction using CuKα

radiation.

8. The electrolyte material of claim 1, having a tetragonal structure.

9. The electrolyte material of claim 8, wherein the tetragonal structure is a skewed P1 structure.

10. The electrolyte material of claim 1, consisting essentially of Na₁₀MP₂S₁₂, wherein M is selected from Ge, Si, and Sn.

11. An electrochemical cell comprising:

an anode layer containing an anode material;

a cathode layer containing a cathode material; and

an electrolyte layer between the anode and cathode layers,

wherein a solid-state, Na-conductive material is present in the cathode layer, the electrolyte layer, or both, the material comprising a compound of the composition Na₁₀MP₂S₁₂, M being selected from Ge, Si, and Sn.

12. The electrochemical cell of claim 11, wherein the cell is a solid-state cell.

13. The electrochemical cell of claim 11, wherein the cell is rechargeable.

14. A method for producing a sodium-conductive solid electrolyte material, comprising:

forming a raw material composition from elements Na, P, S, and M, wherein element M is selected from Ge, Si, and Sn;

heating the raw material composition to a temperature effective to form a solution; and

cooling the solution at a rate no greater than 1°

C. per minute to produce the electrolyte material,

wherein the electrolyte material exhibits an conductivity of at least 1.0×

10<sup>−

4</sup> S/cm at a temperature at 300K and the method is carried out within no more than 200 hours.

15. The method of claim 14, wherein the plurality of compounds includes Na₂S, P₂S₅, and MS₂, wherein M is selected from Ge, Si, and Sn.

16. The method of claim 14, further comprising heating the raw material composition to a melting temperature before cooling.

17. The method of claim 14, further comprising heating the raw material composition to a peak temperature of at least about 350°

C. for at least 2 hours.

18. The method of claim 17, further comprising heating the raw material composition to a peak temperature of at least 550°

C.

19. The method of claim 18, further comprising heating the raw material composition to 700°

C.

20. The method of claim 14, wherein the solution is cooled at a rate no greater than 0.5°

C. per minute.

21. The method of claim 14, wherein the solid-state solution is cooled at a rate no greater than 0.2°

C. per minute.

22. The method of claim 14, wherein the solid-state solution is cooled at a rate no greater than 0.1°

C. per minute.