Secondary battery and manufacturing method of the same

Patent metadata

Field	Value
Publication number	US-2016126541-A1
Application number	US-201514921126-A
Country	US
Kind code	A1
Filing date	Oct 23, 2015
Priority date	Oct 24, 2014
Publication date	May 5, 2016
Grant date	—

Abstract

A negative electrode and a secondary battery including the negative electrode are provided. A plurality of projections and depressions are provided in a negative electrode active material layer and a negative electrode current collector. The plurality of projections and depressions in the negative electrode active material layer absorb expansion of the negative electrode active material and suppress deformation thereof. The plurality of projections and depressions in the negative electrode current collector suppress deformation of the negative electrode current collector caused by expansion and contraction of the negative electrode active material.

First claim

What is claimed is:

1 . A secondary battery comprising:
a negative electrode; a positive electrode; an electrolyte solution; and a separator, wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer includes a compound containing silicon, wherein the negative electrode active material layer includes a first projection and depression and a second projection and depression, wherein the negative electrode current collector includes a third projection and depression and a fourth projection and depression, wherein the first projection and depression and the third projection and depression overlap with each other, and wherein the second projection and depression and the fourth projection and depression overlap with each other.

2 . The secondary battery according to claim 1 , wherein the negative electrode current collector is exposed at a bottom of a depression of the first projection and depression.

3 . The secondary battery according to claim 1 , wherein SiO y (0.95≦y≦1.05) is used as the compound containing silicon.

4 . The secondary battery according to claim 1 , further comprising a graphene on a surface of the negative electrode active material layer.

5 . The secondary battery according to claim 1 , wherein the compound containing silicon includes a SiO particle.

6 . The secondary battery according to claim 5 , wherein a silicon particle with a particle size of less than or equal to 10 μm is dispersed in the SiO particle.

7 . A negative electrode comprising:
a negative electrode current collector; and a negative electrode active material layer, wherein the negative electrode active material layer includes a compound containing silicon, wherein the negative electrode active material layer includes a first depression and a second depression, wherein the negative electrode current collector includes a third depression and a fourth depression, wherein the first depression and the third depression overlap with each other, wherein the second depression and the fourth depression overlap with each other, wherein a long side of the third depression and a long side of the fourth depression are parallel to a short side of the negative electrode current collector, and wherein a length of the long side of the third depression and a length of the long side of the fourth depression are 80% or more and 100% or less of a length of the short side of the negative electrode current collector.

8 . The negative electrode according to claim 7 , wherein the negative electrode current collector is exposed at a bottom of the first depression.

9 . The negative electrode according to claim 7 , wherein SiO y (0.95≦y≦1.05) is used as the compound containing silicon.

10 . The negative electrode according to claim 7 , further comprising a graphene on a surface of the negative electrode active material layer.

11 . The negative electrode according to claim 7 , wherein the compound containing silicon includes a SiO particle.

12 . The negative electrode according to claim 11 , wherein a silicon particle with a particle size of less than or equal to 10 μm is dispersed in the SiO particle.

13 . A method for manufacturing a secondary battery comprising the step of:
performing a first charging and discharging while pressure is applied in a thickness direction of the secondary battery, wherein the secondary battery includes: a negative electrode; a positive electrode; an electrolyte solution; and a separator, wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer includes a compound containing silicon, wherein the negative electrode active material layer includes a first projection and depression and a second projection and depression, wherein the negative electrode current collector includes a third projection and depression and a fourth projection and depression, wherein the first projection and depression and the third projection and depression overlap with each other, and wherein the second projection and depression and the fourth projection and depression overlap with each other.

14 . The method according to claim 13 , wherein the first projection and depression, the second projection and depression, the third projection and depression, and the fourth projection and depression are formed using a cutter knife.

15 . The method according to claim 13 , wherein the pressure is applied at 10 MPa.

16 . The method according to claim 13 , wherein the negative electrode current collector is exposed at a bottom of a depression of the first projection and depression.

17 . The method according to claim 13 , wherein SiO y (0.95≦y≦1.05) is used as the compound containing silicon.

18 . The method according to claim 13 , further comprising a graphene on a surface of the negative electrode active material layer.

19 . The method according to claim 13 , wherein the compound containing silicon includes a SiO particle.

20 . The method according to claim 19 , wherein a silicon particle with a particle size of less than or equal to 10 μm is dispersed in the SiO particle.

Assignees

• Semiconductor Energy Lab

Inventors

• Goto Junya
• Motoyoshi Mako
• Sato Yuika
• Kawakami Takahiro

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/058

  Construction or manufacture · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/70

  characterised by shape or form · CPC title