Negative electrode active material, negative electrode for secondary battery, and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-10826112-B2
Application number	US-201815974890-A
Country	US
Kind code	B2
Filing date	May 9, 2018
Priority date	Nov 10, 2015
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

A negative electrode active material includes a carbon material; a plurality of first particles including a first silicon oxide particle and a carbon layer and a plurality of second particles including a carbon particle and a second silicon oxide particle, and when a first mass of the first silicon oxide particle per gram of the negative electrode active material is referred to as M 1 gram, and a second mass of the second silicon oxide particle per gram of the negative electrode active material is referred to as M 2 grams, 0.40≤M 1 /(M 1 +M 2 )≤0.85 is satisfied, and when a first discharge capacity associated with the carbon material and the carbon particle is referred to as Cp C , and a second discharge capacity associated with the first silicon oxide particle and the second silicon oxide particle is referred to as Cp SO , 0.15≤Cp SO /(Cp C +Cp SO )≤0.5 is satisfied.

First claim

The invention claimed is:

1. A negative electrode for a secondary battery, comprising a negative electrode active material,
wherein the negative electrode active material includes a mixture of a carbon material, a plurality of first particles, and a plurality of second particles,
wherein the first particles include a first silicon oxide particle and a carbon layer covering a surface of the first silicon oxide particle,
wherein the second particles include a carbon particle and a second silicon oxide particle,
wherein when a first mass of the first silicon oxide particle per gram of the negative electrode active material is referred to as M 1 gram, and a second mass of the second silicon oxide particle per gram of the negative electrode active material is referred to as M 2 gram, the following is satisfied:
0.40≤ M 1 /( M 1 +M 2 )≤0.85; and

0.15≤ M 2 /( M 1 +M 2 )≤0.60, and

wherein when a first discharge capacity associated with the carbon material and the carbon particle of the second particles is referred to as Cp C , and a second discharge capacity associated with the first silicon oxide particle of the first particles and the second silicon oxide particle of the second particles is referred to as Cp SO , the following is satisfied:
0.5≤ Cp C /( Cp C +Cp SO )≤0.85; and

0.15≤ Cp SO /( Cp C +Cp SO )≤0.5.

2. The negative electrode for a secondary battery according to claim 1 , wherein
the first silicon oxide particle includes SiO X (where X≤2.5), and
the second silicon oxide particle includes SiO Y (Y≤2.5).

3. The negative electrode for a secondary battery according to claim 1 , wherein a particle size of the first silicon oxide particle in a major axis direction is from 1×10 −6 m to 1.5×10 −5 m.

4. The negative electrode for a secondary battery according to claim 1 , wherein the carbon particle of the second particles includes natural graphite.

5. The negative electrode for a secondary battery according to claim 4 , wherein
a particle size of the second silicon oxide particle in the major axis direction is from 3×10 −8 m to 1×10 −6 m, and
a particle size of the second particles is from 5×10 −6 m to 5×10 −5 m.

6. The negative electrode for a secondary battery according to claim 1 , wherein the carbon particle of the second particles includes non-graphitizable carbon.

7. The negative electrode for a secondary battery according to claim 6 , wherein
the second silicon oxide particle is disposed on a surface of the carbon particle of the second particle,
a particle size of the second silicon oxide particle in the major axis direction is from 3×10 −8 m to 1×10 −6 m, and
a particle size of the second particles is from 5×10 −6 m to 5×10 −5 m.

8. The negative electrode for a secondary battery according to claim 1 , wherein the second silicon oxide particle is provided on a surface of the carbon particle.

9. The negative electrode for a secondary battery according to claim 1 , wherein the second silicon oxide particle is provided in a layered space inside the carbon particle.

10. The negative electrode for a secondary battery according to claim 1 , wherein the second silicon oxide particle is provided on a surface of the carbon particle and in a layered space inside the carbon particle.

11. The negative electrode for a secondary battery according to claim 1 , wherein the carbon particle of the second particles includes spherical carbon material.

12. A lithium ion secondary battery comprising:
a negative electrode including a negative electrode active material;
a positive electrode;
a separator that separates the negative electrode from the positive electrode; and
a nonaqueous electrolytic solution,
wherein the negative electrode active material includes a mixture of a carbon material, a plurality of first particles, and a plurality of second particles,
wherein the first particles include a first silicon oxide particle and a carbon layer covering a surface of the first silicon oxide particle,
wherein the second particles include a carbon particle and a second silicon oxide particle,
wherein when a first mass of the first silicon oxide particle per gram of the negative electrode active material is referred to as M 1 gram, and a second mass of the second silicon oxide particle per gram of the negative electrode active material is referred to as M 2 gram, the following is satisfied:
0.40≤ M 1 /( M 1 +M 2 )≤0.85; and

0.15≤ M 2 /( M 1 +M 2 )≤0.60, and

wherein when a first discharge capacity associated with the carbon material and the carbon particle of the second particles is referred to as Cp C , and a second discharge capacity associated with the first silicon oxide particle of the first particles and the second silicon oxide particle of the second particles is referred to as Cp SO , the following is satisfied:
0.5≤ Cp C /( Cp C +Cp SO )≤0.85; and

0.15≤ Cp SO /( Cp C +Cp SO )≤0.5.

13. The lithium ion secondary battery according to claim 12 , wherein the second silicon oxide particle is provided on a surface of the carbon particle.

14. The lithium ion secondary battery according to claim 12 , wherein the second silicon oxide particle is provided in a layered space inside the carbon particle.

15. The lithium ion secondary battery according to claim 12 , wherein the second silicon oxide particle is provided on a surface of the carbon particle and in a layered space inside the carbon particle.

16. A negative electrode active material comprising:
a mixture of a carbon material, a plurality of first particles, and a plurality of second particles,
wherein the first particles include a first silicon oxide particle and a carbon layer covering a surface of the first silicon oxide particle,
wherein the second particles include a carbon particle and a second silicon oxide particle,
wherein when a first mass of the first silicon oxide particle per gram of the negative electrode active material is referred to as M 1 gram, and a second mass of the second silicon oxide particle per gram of the negative electrode active material is referred to as M 2 gram, the following is satisfied:
0.40≤ M 1 /( M 1 +M 2 )≤0.85; and

0.15≤ M 2 /( M 1 +M 2 )≤0.60, and

wherein when a first discharge capacity associated with the carbon material and the carbon particle of the second particles is referred to as Cp C , and a second discharge capacity associated with the first silicon oxide particle of the first particles and the second silicon oxide particle of the second particles is referred to as Cp SO , the following is satisfied:
0.5≤ Cp C /( Cp C +Cp SO )≤0.85; and

0.15≤ Cp SO /( Cp C +Cp SO )≤0.5.

Assignees

• Murata Manufacturing Co

Inventors

• Matsushita Tadashi
• Kuratsuka Masaki

Classifications

• H01M50/534

  characterised by the material of the leads or tabs · CPC title

• Y02P70/50

  Manufacturing or production processes characterised by the final manufactured product · CPC title

• H01M50/4295

  Natural cotton, cellulose or wood · CPC title

• H01M50/44

  Fibrous material · CPC title

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title