METHOD OF PRODUCING A SULFIDE SOLID ELECTROLYTE MATERIAL, SULFIDE SOLID ELECTROLYTE MATERIAL, AND LITHIUM BATTERY

• US 20120301796A1
• Filed: 12/15/2010
• Published: 11/29/2012
• Est. Priority Date: 12/16/2009
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Ohtomo, Takamasa, Kawamoto, Koji, Hama, Shigenori, Kato, Yuki
• Granted Patent: US 10,008,735 B2
• Time in Patent Office: Days
• US Class Current: 429/322
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A method of producing a sulfide solid electrolyte material includes: forming an intermediate having crosslinking sulfur but no Li₂S, by vitrifying, in a first vitrification process, a starting material composition obtained by mixing Li₂S and a sulfide of a group 14 or group 15 element such that a proportion of Li₂S with respect to the sum total of the Li₂S and the sulfide of a group 14 or group 15 element is smaller than a proportion of Li₂S required for the sulfide solid electrolyte material to obtain an ortho composition; and eliminating the crosslinking sulfur by vitrifying, in a second vitrification process, an intermediate-containing composition resulting from mixing a bond cleaving compound, which cleaves a bond of the crosslinking sulfur, with the intermediate.

Claims

1. A method of producing a sulfide solid electrolyte material, comprising:

forming an intermediate having crosslinking sulfur but no Li₂S, by vitrifying, in a first vitrification process, a starting material composition obtained by mixing Li₂S and a sulfide of a group 14 or group 15 element such that a proportion of Li₂S with respect to the sum total of the Li₂S and the sulfide of the group 14 or group 15 element is smaller than a proportion of Li₂S required for said sulfide solid electrolyte material to obtain an ortho composition; and

eliminating said crosslinking sulfur by vitrifying, in a second vitrification process, an intermediate-containing composition resulting from mixing a bond cleaving compound, which cleaves a bond of said crosslinking sulfur, with said intermediate.

2. The production method according to claim 1, wherein a proportion in which said bond cleaving compound is mixed with said intermediate is a proportion in which a sulfide solid electrolyte material substantially free of crosslinking sulfur is obtained.

3. The production method according to claim 1, wherein said bond cleaving compound is Li₂O.

4. The production method according to claim 1, wherein:

said sulfide of the group 14 or group 15 element is P₂S₅; and

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said P₂S₅ is smaller than 75%, on a molar basis.

5. The production method according to claim 3, wherein:

said sulfide of the group 14 or group 15 element is P₂S₅;

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said P₂S₅ is smaller than 75%, on a molar basis; and

in said intermediate-containing composition, the proportion of a sum total of said Li₂S and said Li₂O with respect to a sum total of said Li₂S, said P₂S₅ and said Li₂O is not smaller than 75%, on the molar basis.

6. The production method according to claim 1, wherein:

said sulfide of the group 14 or group 15 element is GeS₂; and

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said GeS₂ is smaller than 66.7%, on a molar basis.

7. The production method according to claim 3, wherein:

said sulfide of the group 14 or group 15 element is GeS₂;

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said GeS₂ is smaller than 66.7%, on a molar basis; and

in said intermediate-containing composition, the proportion of a sum total of said Li₂S and said Li₂O with respect to a sum total of said Li₂S, said GeS₂ and said Li₂O is not smaller than 66.7%, on the molar basis.

8. The production method according to claim 1, wherein:

said sulfide of the group 14 or group 15 element is SiS₂; and

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said SiS₂ is smaller than 66.7%, on a molar basis.

9. The production method according to claim 3, wherein:

said sulfide of the group 14 or group 15 element is SiS₂;

in said starting material composition, the proportion of said Li₂S with respect to the sum total of said Li₂S and said SiS₂ is smaller than 66.7%, on a molar basis; and

in said intermediate-containing composition, the proportion of a sum total of said Li₂S and said Li₂O with respect to a sum total of said Li₂S, said SiS₂ and said Li₂O is not smaller than 66.7%, on the molar basis.

10. The production method according to claim 1, wherein:

said first vitrification process is mechanical milling.

11. The production method according to claim 1, wherein:

said second vitrification process is mechanical milling.

12. A sulfide solid electrolyte material, comprising:

Li, a group 14 or group 15 element, O and S; and

the material being substantially free of crosslinking sulfur, wherein a Li₂S content is no greater than 1 mol %.

13. The sulfide solid electrolyte material according to claim 12, wherein said group 14 or group 15 element is P.

14. The sulfide solid electrolyte material according to claim 13, which is produced by vitrifying Li₂S, P₂S₅ and Li₂O.

15. The sulfide solid electrolyte material according to claim 14, wherein said Li₂O forms a phase.

16. A lithium battery, comprising:

a positive electrode active material layer containing a positive electrode active material;

a negative electrode active material layer containing a negative electrode active material; and

an electrolyte layer formed between said positive electrode active material layer and said negative electrode active material layer,

at least one from among said positive electrode active material layer, said negative electrode active material layer and said electrolyte layer containing the sulfide solid electrolyte material according to claim 12.