Active material, battery and method for producing active material

Patent metadata

Field	Value
Publication number	US-11527750-B2
Application number	US-201916667982-A
Country	US
Kind code	B2
Filing date	Oct 30, 2019
Priority date	Nov 30, 2018
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A main object of the present disclosure is to provide an active material whose volume variation due to charge and discharge is small. The present disclosure achieves the object by providing an active material comprising a primary particle including at least one crystal phase of a Type I silicon clathrate and a Type II silicon clathrate, and the primary particle includes a void inside thereof.

First claim

What is claimed is:

1. An active material comprising a primary particle including a crystal phase of a Type I silicon clathrate as a main phase and optionally a crystal phase of a Type II silicon clathrate, and
the primary particle includes a void inside thereof, the void being observed with a SEM (scanning electron microscope), wherein
a void ratio inside the primary particle is in a range of from 4% to 40%.

2. The active material according to claim 1 , wherein the crystal phase of the Type I silicon clathrate has a peak at a position of 2θ=19.44°±1.00°, 21.32°±1.00°, 30.33°±1.00°, 31.60°±1.00°, 32.82°±1.00°, 36.29°±1.00°, 52.39°±1.00°, and 55.49°±1.00° in X-ray diffraction measurement using a CuKα ray.

3. The active material according to claim 1 , wherein the crystal phase of the Type II silicon clathrate is present in the active material and has a peak at a position of 2θ=20.09°±1.00°, 21.00°±1.00°, 26.51°±1.00°, 31.72°±1.00°, 36.26°±1.00°, and 53.01°±1.00° in X-ray diffraction measurement using a CuKα ray.

4. The active material according to claim 1 , wherein the void ratio inside the primary particle is in a range of from 10% to 38%.

5. A battery comprising a cathode layer, an electrolyte layer, and an anode layer, in this order, and
the anode layer includes the active material according to claim 1 .

6. A method for producing an active material according to claim 1 , the method comprising steps of:
a preparing step of preparing a precursor compound including at least a Na element and a Si element, and having at least a Zintl phase; and
a heat treating step of heat treating the precursor compound, and
the heat treating step includes a temperature rising treatment of rising a temperature to a first temperature at a rate of 100° C./min or more under reduced pressure, and after the temperature rising, a burning treatment of burning under reduced pressure.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kosaka Daichi
• Yoshida Jun
• Waseda Tetsuya
• Otomo Takamasa

Classifications

• H01M4/1395

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

• C01P2006/40

  Electric properties · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• H01M2004/027

  Negative electrodes · CPC title