Sulfide-based solid electrolyte for lithium ion battery

Patent metadata

Field	Value
Publication number	US-9812734-B2
Application number	US-201414906706-A
Country	US
Kind code	B2
Filing date	Jun 23, 2014
Priority date	Jul 25, 2013
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

Provided is a solid electrolyte with which charge/discharge efficiency and cycle characteristics can be increased by reducing the electron conductivity of a compound which has a cubic crystal structure belonging to a space group F-43m, and is represented by Compositional Formula: Li 7-x PS 6-x Ha x (Ha is Cl or Br). Proposed is a sulfide-based solid electrolyte for a lithium ion battery, which includes a compound having a cubic crystal structure belonging to a space group F-43m, and being represented by Compositional Formula: Li 7-x PS 6-x Ha x (Ha is Cl or Br), in which x in the above Compositional Formula is 0.2 to 1.8, and the value of the lightness L* thereof in the L*a*b* color system is 60.0 or more.

First claim

The invention claimed is:

1. A sulfide-based solid electrolyte for a lithium ion battery comprising a compound which has a cubic crystal structure belonging to a space group F-43m and is represented by Compositional Formula: Li 7-x PS 6-x Ha x (Ha is Cl or Br), wherein x in the above Compositional Formula represents 0.2 to 1.8, and a value of lightness L* in a L*a*b* color system is 60.0 or more.

2. The sulfide-based solid electrolyte for a lithium ion battery according to claim 1 , wherein a transport number of lithium ion is 90% or more.

3. The sulfide-based solid electrolyte for a lithium ion battery according to claim 1 , wherein when Ha is Cl in the above Compositional Formula, x represents 0.2 to 1.8.

4. The sulfide-based solid electrolyte for a lithium ion battery according to claim 1 , wherein when Ha is Br in the above Compositional Formula, x represents 0.2 to 1.2.

5. The sulfide-based solid electrolyte for a lithium ion battery according to claim 1 , wherein the sulfide-based solid electrolyte for a lithium ion battery can be obtained by mixing a lithium sulfide (Li 2 S) powder, a phosphorus sulfide (P 2 S 5 ) powder, and a lithium chloride (LiCl) powder or a lithium bromide (LiBr) powder, and firing the mixture thus obtained at 350 to 500° C. under an inert atmosphere or firing the mixture thus obtained at 350 to 650° C. under an atmosphere including a hydrogen sulfide gas.

6. A lithium ion battery comprising the solid electrolyte according to claim 1 .

7. A lithium ion battery comprising the solid electrolyte according to claim 1 and a negative electrode active material including a carbon.

8. The sulfide-based solid electrolyte for a lithium ion battery according to claim 2 , wherein when Ha is Cl in the above Compositional Formula, x represents 0.2 to 1.8.

9. The sulfide-based solid electrolyte for a lithium ion battery according to claim 2 , wherein when Ha is Br in the above Compositional Formula, x represents 0.2 to 1.2.

10. The sulfide-based solid electrolyte for a lithium ion battery according to claim 2 , wherein the sulfide-based solid electrolyte for a lithium ion battery can be obtained by mixing a lithium sulfide (Li 2 S) powder, a phosphorus sulfide (P 2 S 5 ) powder, and a lithium chloride (LiCl) powder or a lithium bromide (LiBr) powder, and firing the mixture thus obtained at 350 to 500° C. under an inert atmosphere or firing the mixture thus obtained at 350 to 650° C. under an atmosphere including a hydrogen sulfide gas.

11. The sulfide-based solid electrolyte for a lithium ion battery according to claim 3 , wherein the sulfide-based solid electrolyte for a lithium ion battery can be obtained by mixing a lithium sulfide (Li 2 S) powder, a phosphorus sulfide (P 2 S 5 ) powder, and a lithium chloride (LiCl) powder or a lithium bromide (LiBr) powder, and firing the mixture thus obtained at 350 to 500° C. under an inert atmosphere or firing the mixture thus obtained at 350 to 650° C. under an atmosphere including a hydrogen sulfide gas.

12. The sulfide-based solid electrolyte for a lithium ion battery according to claim 4 , wherein the sulfide-based solid electrolyte for a lithium ion battery can be obtained by mixing a lithium sulfide (Li 2 S) powder, a phosphorus sulfide (P 2 S 5 ) powder, and a lithium chloride (LiCl) powder or a lithium bromide (LiBr) powder, and firing the mixture thus obtained at 350 to 500° C. under an inert atmosphere or firing the mixture thus obtained at 350 to 650° C. under an atmosphere including a hydrogen sulfide gas.

13. A lithium ion battery comprising the solid electrolyte according to claim 2 .

14. A lithium ion battery comprising the solid electrolyte according to claim 3 .

15. A lithium ion battery comprising the solid electrolyte according to claim 4 .

16. A lithium ion battery comprising the solid electrolyte according to claim 5 .

17. A lithium ion battery comprising the solid electrolyte according to claim 2 and a negative electrode active material including a carbon.

18. A lithium ion battery comprising the solid electrolyte according to claim 3 and a negative electrode active material including a carbon.

19. A lithium ion battery comprising the solid electrolyte according to claim 4 and a negative electrode active material including a carbon.

20. A lithium ion battery comprising the solid electrolyte according to claim 5 and a negative electrode active material including a carbon.

Assignees

• Mitsui Mining & Smelting Co

Inventors

• Miyashita Norihiko
• Chikumoto Takashi
• Matsushima Hideaki
• Matsuzaki Kenji

Classifications

• H01M2300/0068

  inorganic · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2220/30

  Batteries in portable systems, e.g. mobile phone, laptop · CPC title