Cathode mixture, all solid state battery, method for producing cathode mixture, and method for producing all solid state battery

Patent metadata

Field	Value
Publication number	US-11075375-B2
Application number	US-201916420418-A
Country	US
Kind code	B2
Filing date	May 23, 2019
Priority date	Jun 1, 2018
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

An object of the present disclosure is to produce a cathode mixture with less irreversible capacity. The present disclosure achieves the object by providing a cathode mixture comprising: a cathode active material including a S element; a sulfur containing compound including a P element and a S element; a conductive auxiliary material; and substantially no Li element; wherein when a diffraction intensity at 2θ=15.5° in an X-ray diffraction measurement using a CuKα ray is regarded as I 15.5 , a diffraction intensity at 2θ=25° is regarded as I 25 , and a diffraction intensity at 2θ=40° is regarded as I 40 , a standard value defined by the following formula is more than 1.2.

Standard value=( I 15.5 −I 40 )/( I 25 −I 40 )

First claim

What is claimed is:

1. A cathode mixture comprising:
a cathode active material including a S element;
a sulfur containing compound including a P element and a S element;
a conductive auxiliary material; and
substantially no Li element;
wherein in an X-ray diffraction measurement of the cathode mixture using a CuKα ray, a standard value defined by the following formula is more than 1.2:
Standard value=( I 15.5 −I 40 )/( I 25 −I 40 )

where:
I 15.5 is a diffraction intensity at 2θ=15.5°,
I 25 is a diffraction intensity at 2θ=25°, and
I 40 is a diffraction intensity at 2θ=40°.

2. The cathode mixture according to claim 1 , wherein a proportion of the Li element in the cathode mixture is 0 mol % or more and 20 mol % or less.

3. The cathode mixture according to claim 1 , wherein the standard value is 1.5 or more.

4. The cathode mixture according to claim 1 , wherein the standard value is 2.2 or less.

5. The cathode mixture according to claim 1 , wherein a molar ratio of the P element to the S element (P/S) in the cathode mixture is 0.12 or more and 0.27 or less.

6. The cathode mixture according to claim 1 , wherein a carbon material is included as the conductive auxiliary material.

7. An all solid state battery comprising a cathode layer, a solid electrolyte layer, and an anode layer in this order; wherein
the cathode layer comprises a cathode active material including a S element, a sulfur containing compound including a P element and a S element, a conductive auxiliary material, and substantially no Li element; and
in an X-ray diffraction measurement of the cathode layer using a CuKα ray, a standard value defined by the following formula is more than 1.2:
Standard value=( I 15.5 −I 40 )/( I 25 −I 40 )

where:
I 15.5 is a diffraction intensity at 2θ=15.5°,
I 25 is a diffraction intensity at 2θ=25°, and
I 40 is a diffraction intensity at 2θ=40°.

8. A method for producing a cathode mixture, the method comprising steps of:
a preparing step of preparing a raw material mixture containing a cathode active material including a S element, a sulfide including a P element and a S element, a conductive auxiliary material, and substantially no Li element; and
a mechanical milling step of conducting mechanical milling to the raw material mixture;
wherein in an X-ray diffraction measurement of the cathode mixture using a CuKα ray, a standard value defined by the following formula is more than 1.2:
Standard value=( I 15.5 −I 40 )/( I 25 −I 40 )

where:
I 15.5 is a diffraction intensity at 2θ=15.5°,
I 25 is a diffraction intensity at 2θ=25°, and
I 40 is a diffraction intensity at 2θ=40°.

9. A method for producing an all solid state battery, the method comprising steps of:
a layered body forming step of forming a layered body including a cathode layer, a solid electrolyte layer, and an anode layer in this order; and
an initial stage discharging step of initially discharging the layered body; wherein
in the layered body forming step, the cathode layer is formed using the cathode mixture according to claim 1 ; and
in the initial stage discharging step, discharging is carried out in an environment at a temperature of 60° C. or more.

10. The cathode mixture according to claim 1 , wherein a proportion of the Li element in the cathode mixture is 0 mol %.

11. The all solid state battery according to claim 7 , wherein a proportion of the Li element in the cathode layer is 0 mol %.

12. The method for producing a cathode mixture according to claim 8 , wherein a proportion of the Li element in the raw material mixture is 0 mol %.

13. The method for producing a cathode mixture according to claim 8 , wherein the mechanical milling is conducted for 48 hours or more.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nose Masafumi
• Takeuchi Kazuya
• Ikeda Yuki

Classifications

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M10/0562

  Solid materials · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M4/5805

  Phosphides · CPC title

• H01M4/364 Primary

  as mixtures · CPC title