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-2019372107-A1
Application number	US-201916420418-A
Country	US
Kind code	A1
Filing date	May 23, 2019
Priority date	Jun 1, 2018
Publication date	Dec 5, 2019
Grant date	—

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 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 )

2 . The cathode mixture according to claim 1 , wherein a proportion of the Li element 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) 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 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 )

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 the cathode mixture, 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 )

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.

Assignees

• Toyota Motor Co Ltd

Inventors

• Nose Masafumi
• Takeuchi Kazuya
• Ikeda Yuki

Classifications

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/38

  of elements or alloys · CPC title

• C01B25/14

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