Active material, anode layer, battery, and methods for producing these

Patent metadata

Field	Value
Publication number	US-2021391576-A1
Application number	US-202117210746-A
Country	US
Kind code	A1
Filing date	Mar 24, 2021
Priority date	Mar 27, 2020
Publication date	Dec 16, 2021
Grant date	—

Abstract

A main object of the present disclosure is to provide an active material wherein a volume variation due to charge/discharge is small. The present disclosure achieves the object by providing an active material comprising a silicon clathrate II type crystal phase, and having a composition represented by Na x Si 136 , wherein 1.98<x<2.54.

First claim

What is claimed is:

1 . An active material comprising a silicon clathrate II type crystal phase, and
having a composition represented by Na x Si 136 , wherein 1.98<x<2.54.

2 . The active material according to claim 1 , wherein the “x” satisfies 2.30≤x≤2.50.

3 . The active material according to claim 1 , wherein the active material includes a void inside a primary particle.

4 . The active material according to claim 1 , wherein, as peaks of the silicon clathrate II type crystal phase, peak “A” at a position of 2θ=20.09°±0.50° and peak “B” at a position of 2θ=31.72°±0.50° are observed in X-ray diffraction measurement using a CuKα ray, and
when an intensity of the peak “A” is regarded as I A , an intensity of the peak “B” is regarded as I B , and a maximum intensity in 2θ=22° to 23° is regarded as I M , I A /I M and I B /I M are respectively more than 1.

5 . The active material according to claim 4 , wherein the I A /I M satisfies 1.02<I A /I M and the I B /I M satisfies 1.03<I B /I M .

6 . An anode layer comprising the active material according to claim 1 .

7 . A battery comprising a cathode layer, an anode layer, and an electrolyte layer formed between the cathode layer and the anode layer, and
the anode layer is the anode layer according to claim 6 .

8 . A method for producing an active material, the method comprising:
a preparing step of preparing an intermediate including a silicon clathrate II type crystal phase and having a composition represented by Na y Si 136 , wherein 8≤y≤21, an alloying step of obtaining an alloy compound by alloying the intermediate and a Li based material, a Li removing step of removing Li from the alloy compound and obtaining a porous compound including a void inside a primary particle, and a Na removing step of removing Na from the porous compound.

9 . A method for producing an anode layer, the method comprising:
an active material producing step of producing an active material by the method for producing an active material according to claim 8 , and an anode layer forming step of forming an anode layer by using the active material.

10 . A method for producing a battery, the method comprising:
an active material producing step of producing an active material by the method for producing an active material according to claim 8 , and an anode layer forming step of forming an anode layer by using the active material.

Assignees

• Toyota Motor Co Ltd

Inventors

• Otaki Mitsutoshi
• Yoshida Jun
• Suzuki Kazuhiro
• Harata Masanori

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M2004/021

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

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• C01B33/021 Primary

  Preparation (chemical coating from the vapour phase C23C16/00) · CPC title