Sulfide solid electrolyte

Patent metadata

Field	Value
Publication number	US-10483587-B2
Application number	US-201916239140-A
Country	US
Kind code	B2
Filing date	Jan 3, 2019
Priority date	Sep 12, 2016
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A sulfide solid electrolyte containing lithium, phosphorus, sulfur, and two or more of elements X selected from halogen elements, where the sulfide solid electrolyte includes an argyrodite-type crystal structure, and a molar ratio of the sulfur to the phosphorus “b (S/P)” and a molar ratio of the element X to the phosphorus “c (X/P)” satisfy the following formula (1):

0.23< c/b< 0.57  (1).

First claim

The invention claimed is:

1. A sulfide solid electrolyte, comprising lithium, phosphorus, sulfur, and two or more of elements X selected from the group consisting of halogen elements,
wherein the sulfide solid electrolyte comprises an argyrodite-type crystal structure, and
wherein a molar ratio of the sulfur to the phosphorus, b (S/P), and a molar ratio of the elements X to the phosphorus, c (X/P), satisfy formula (1):
0.23< c/b< 0.57  (1).

2. The sulfide solid electrolyte according to claim 1 , wherein the molar ratio of the sulfur to the phosphorus, b (S/P),and the molar ratio of the elements X to the phosphorus, c (X/P), satisfy formula (1a):
0.25≤ c/b≤ 0.43  (1a).

3. The sulfide solid electrolyte according to claim 1 , wherein the molar ratio of the sulfur to the phosphorus, b (S/P), and the molar ratio of the elements X to the phosphorus, c (X/P), satisfy formula (1b):
0.30≤ c/b≤ 0.41  (1b).

4. The sulfide solid electrolyte according to claim 1 , wherein at least one of the elements X is chlorine.

5. The sulfide solid electrolyte according to claim 4 , satisfying formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X.

6. The sulfide solid electrolyte according to claim 4 ,
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X; and

wherein at least one of the elements X is bromine.

7. The sulfide solid electrolyte according to claim 4 ,
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X;

wherein at least one of the elements X is bromine; and
wherein a molar ratio of the lithium to the phosphorus, a (Li/P), the molar ratio of the sulfur to the phosphorus, b (S/P), and the molar ratio of the elements X to the phosphorus, c (X/P), satisfy formulas (A) to (C):
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

8. The sulfide solid electrolyte according to claim 4 ,
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X;

wherein at least one of the elements X is bromine; and
wherein the sulfide solid electrolyte comprises a composition represented by formula (3):
Li a (P 1-α M α )S b X c   (3)

wherein:
M is one or more of elements selected from the group consisting of Si, Ge,Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is two or more of elements selected from the group consisting of F, Cl, Br and I;
a to c satisfy formulas (A) to (C); and
α satisfies 0≤α≤0.3:
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

9. The sulfide solid electrolyte according to claim 4 ,
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X;

wherein diffraction peaks are measured at 2θ=25.2±0.5 deg and 29.7±0.5 deg in powder X-ray diffraction using CuKα rays; and
wherein, in powder X-ray diffraction using CuKα rays, the sulfide solid electrolyte does not have a diffraction peak derived from lithium halide, or if the sulfide solid electrolyte has a diffraction peak derived from lithium halide, said diffraction peak satisfies formula (4):
0< I A /I B <0.1  (4)

wherein I A represents an intensity of a diffraction peak of lithium halide, and I B represents an intensity of a diffraction peak at 2θ=25.2±0.5 deg.

10. The sulfide solid electrolyte according to claim 4 ,
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X;

wherein diffraction peaks are measured at 2θ=25.2±0.5 deg and 29.7±0.5 deg in powder X-ray diffraction using CuKα rays; and
wherein, in powder X-ray diffraction using CuKα rays, the sulfide solid electrolyte does not have a diffraction peak at 2θ=17.6±0.4 deg and 2θ=18.1±0.4 deg, or if the sulfide solid electrolyte has a diffraction peak at 2θ=17.6±0.4 deg and 2θ=18.1±0.4 deg, said diffraction peak satisfies formula (5):
0< I C /I D <0.05  (5)

wherein I C represents an intensity of a diffraction peak which is not a diffraction peak of an argyrodite-type crystal structure between the diffraction peaks at 2θ=17.6±0.4 deg and 2θ=18.1±0.4 deg, and I D represents an intensity of a diffraction peak at 2θ=29.7±0.5 deg.

11. The sulfide solid electrolyte according to claim 1 , wherein diffraction peaks are measured at 2θ=25.2±0.5 deg and 29.7±0.5 deg in powder X-ray diffraction using CuKα rays.

12. The sulfide solid electrolyte according to claim 1 , wherein at least one of the elements X is bromine.

13. The sulfide solid electrolyte according to claim 1 , wherein a molar ratio of the lithium to the phosphorus, a (Li/P), the molar ratio of the sulfur to the phosphorus, b (S/P), and the molar ratio of the elements X to the phosphorus, c (X/P), satisfy formulas (A) to (C):
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

14. The sulfide solid electrolyte according to claim 1 , comprising a composition represented by formula (3):
Li a (P 1-α M α )S b X c   (3)

wherein:
M is one or more of elements selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is two or more of elements selected from the group consisting of F, Cl, Br and I;
a to c satisfy formulas (A) to (C); and
a satisfies 0≤α≤0.3:
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

15. The sulfide solid electrolyte according to claim 1 , wherein:
at least one of the elements X is chlorine; and
at least one of the elements X is bromine.

16. The sulfide solid electrolyte according to claim 1 ,
wherein at least one of the elements X is chlorine;
wherein at least one of the elements X is bromine; and
wherein a molar ratio of the lithium to the phosphorus, a (Li/P), the molar ratio of the sulfur to the phosphorus, b (S/P), and the molar ratio of the elements X to the phosphorus, c (X/P), satisfy formulas (A) to (C):
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

17. The sulfide solid electrolyte according to claim 1 ,
wherein at least one of the elements X is bromine;
wherein the sulfide solid electrolyte satisfies formula (2):
0.25<X Cl <1  (2)

wherein X Cl represents a molar ratio of the chlorine to the elements X; and

wherein the sulfide solid electrolyte comprises a composition represented by formula (3):
Li a (P 1-α M α )S b X c   (3)

wherein:
M is one or more of elements selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is two or more of elements selected from the group consisting of F, Cl, Br and I;
a to c satisfy formulas (A) to (C); and
a satisfies 0≤α≤0.3:
5.0≤ a≤ 7.5  (A)

6.5≤ a+c≤ 7.5  (B)

0.5≤ a−b≤ 1.5  (C)

wherein b>0 and c>0 are satisfied.

18. An electrode mix, comprising the sulfide solid electrolyte according to claim 1 and an active material.

19. A lithium ion battery, comprising the electrode mix according to claim 18 .

20. A lithium ion battery, comprising the sulfide solid electrolyte according t

Assignees

• Idemitsu Kosan Co

Inventors

• Terai Kota
• Utsuno Futoshi
• Umeki Takashi
• Nakagawa Masaru
• Yamaguchi Hiroshi

Classifications

• C01B25/14

  Sulfur, selenium, or tellurium compounds of phosphorus · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M10/0525

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

• H01M2300/0068

  inorganic · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title