Sulfide solid electrolyte

Patent metadata

Field	Value
Publication number	US-11387486-B2
Application number	US-201816637513-A
Country	US
Kind code	B2
Filing date	Aug 6, 2018
Priority date	Aug 10, 2017
Publication date	Jul 12, 2022
Grant date	Jul 12, 2022

Abstract

A sulfide solid electrolyte comprising lithium, phosphorus and sulfur, wherein the sulfide solid electrolyte has a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα rays, an area ratio of a peak derived from PS43− glass to the total area of peaks derived from glass observed in solid 31P-NMR measurement is 90% or more and 100% or less, and an area ratio of peaks derived from glass to the total area of all peaks at 60 to 120 ppm observed in solid 31P-NMR measurement is 1% or more and 45% or less.

First claim

The invention claimed is:

1. A sulfide solid electrolyte comprising lithium, phosphorus and sulfur,
wherein the sulfide solid electrolyte has a diffraction peak A at 2θ=25.2±0.5 deg and a diffraction peak B at 29.7±0.5 deg in powder X-ray diffraction using CuKα rays,
an area ratio of a peak derived from PS 4 3− glass to the total area of peaks derived from glass observed in solid 31 P-NMR measurement is 90% or more and 100% or less, and
an area ratio of peaks derived from glass to the total area of all peaks at 60 to 120 ppm observed in solid 31 P-NMR measurement is 1% or more and 40% or less.

2. The sulfide solid electrolyte according to claim 1 , wherein an intensity ratio (Ib/Ip) between a peak intensity Ip of the diffraction peak B and a diffraction intensity Ib of a high-angle-side low part of the diffraction peak B is 0.050 or more and 0.200 or less.

3. The sulfide solid electrolyte according to claim 1 , wherein a Si-relative half-value width of the diffractive peak B is 1.25 or more and 2.50 or less.

4. The sulfide solid electrolyte according to claim 1 , wherein a volume-based mean particle diameter measured by laser-diffraction particle size-distribution measurements is 0.1 μm or more and 10 μm or less.

5. The sulfide solid electrolyte according to claim 1 , further comprising halogen.

6. The sulfide solid electrolyte according to claim 5 , wherein a molar ratio of the lithium to the phosphorus, a (Li/P), a molar ratio of the sulfur to the phosphorus, b (S/P), and a molar ratio of the halogen to the phosphorus, c (X/P), satisfy the following 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 in the formulas, b>0 and c>0 are satisfied.

7. The sulfide solid electrolyte according to claim 5 , having a composition represented by the following formula (1):
Li a (P 1-α M α )S b X c   (1)

wherein in the formula, M is one or more elements selected from the group consisting of Si, Ge, Sn, Pb, B, Al, Ga, As, Sb and Bi, and X is one or more elements selected from the group consisting of F, Cl, Br and I; a to c satisfy the following 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 in the formulas, b>0 and c>0 are satisfied.

8. The sulfide solid electrolyte according to claim 5 , comprising chlorine (Cl).

9. The sulfide solid electrolyte according to claim 5 , comprising chlorine (Cl) and bromine (Br).

10. A method for producing a sulfide solid electrolyte, wherein the solid sulfide electrolyte (precursor) having an argyrodite-type crystal structure is treated by a media-less pulverizer.

11. The process for producing a sulfide solid electrolyte according to claim 10 , wherein the media-less pulverizer is an air flow type pulverizer or a thin film swirl type stirrer.

12. The process for producing a sulfide solid electrolyte according to claim 10 , wherein the media-less pulverizer is a jet mill.

13. The process for producing a sulfide solid electrolyte according to claim 10 , wherein the sulfide solid electrolyte having the argyrodite-type crystal structure is produced by heat treatment.

14. The process for producing a sulfide solid electrolyte according to claim 13 , wherein the heat treatment temperature is 350 to 480° C.

15. The process for producing a sulfide solid electrolyte according to claim 10 , wherein the heat treatment is not performed after the treatment by the media-less pulverizer.

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

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

18. A lithium ion battery comprising the electrode mix according to claim 16 .

19. The sulfide solid electrolyte according to claim 1 , wherein an intensity ratio (Ib/Ip) between a peak intensity Ip of the diffraction peak B and a diffraction intensity Ib of a high-angle-side low part of the diffraction peak B is 0.050 or more and 0.200 or less, and
a Si-relative half-value width of the diffractive peak B is 1.25 or more and 2.50 or less.

20. The sulfide solid electrolyte according to claim 1 , wherein an intensity ratio (Ib/Ip) between a peak intensity Ip of the diffraction peak B and a diffraction intensity Ib of a high-angle-side low part of the diffraction peak B is 0.050 or more and 0.200 or less, and
a volume-based mean particle diameter measured by laser-diffraction particle size-distribution measurements is 0.1 μm or more and 10 μm or less.

21. The sulfide solid electrolyte according to claim 1 , wherein the peak area ratio derived from PS 4 3 − glass is 100%.

Assignees

• Idemitsu Kosan Co

Inventors

• Utsuno Futoshi
• Tsuno Toshiaki
• Terai Kota
• Sato Atsushi

Classifications

• H01M10/484

  for measuring electrolyte level, electrolyte density or electrolyte conductivity · CPC title

• C01B25/14

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

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M4/62

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

• H01M2300/0068

  inorganic · CPC title