Battery

Patent metadata

Field	Value
Publication number	US-9698397-B2
Application number	US-201114356458-A
Country	US
Kind code	B2
Filing date	Nov 10, 2011
Priority date	Nov 10, 2011
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A battery includes a flat wound electrode body formed by winding a positive electrode sheet and a negative electrode sheet with a separator interposed therebetween into a flat shape. The separator has an outer edge adjacent portion adjacent to either an outer edge of a positive electrode active material layer or an outer edge of a negative electrode active material layer. In a curve positioned portion disposed at least in a curved portion of the flat wound electrode body, the outer edge adjacent portion has a suppression portion for suppressing the occurrence or development of a crack.

First claim

The invention claimed is:

1. A battery provided with a flat wound electrode body including a positive electrode sheet having a positive active material layer and a negative electrode sheet having a negative active material layer, the positive electrode sheet and the negative electrode sheet being wound together with a separator in a flat shape,
wherein the separator includes an edge adjacent portion close to any one of an edge of the positive active material layer in an axial direction along a winding axis of the flat wound electrode body and an edge of the negative active material layer in the axial direction, and
the edge adjacent portion includes a curve positioned portion placed in a curved portion of the flat wound electrode body,
the separator includes a plurality of suppression portions configured to suppress occurrence of a crack or growth of a crack, the suppression portions being placed only in an edge portion extending along an edge of the separator in the axial direction and including the edge adjacent portion and in at least the curve positioned portion of the edge adjacent portion, and arranged in a separated relationship at spaced intervals from each other in a winding circumferential direction of the flat wound electrode body.

2. The battery according to claim 1 , wherein the separator made of a porous resin material with a polymer oriented in a predetermined direction, and
the suppression portion is made so that an orientation state of the polymer in the suppression portion is different from an orientation state of the polymer in other portions.

3. The battery according to claim 2 , wherein
the separator has an orientation that the polymer is oriented in the predetermined direction, and
the suppression portion has an orientation of the polymer that is lower than an orientation of the polymer in the other portions.

4. The battery according to claim 3 , wherein the predetermined direction is a winding circumferential direction of the flat winding electrode body.

5. The battery according to claim 4 , wherein the suppression portion is a press-heated portion made of the resin material forming the separator pressed by a heated member in a thickness direction so that the press-heated portion has a thickness thinner than a thickness of a portion surrounding the press-heated portion.

6. The battery according to claim 1 , wherein the suppression portion is configured to extend outward from the edge adjacent portion of the separator in a width direction of the separator and reach an edge of the separator.

7. The battery according to claim 1 ,
wherein the separator includes:
a first separator located on a radial outside of the positive electrode sheet in the flat wound electrode body; and
a second separator located on the radial outside of the negative electrode sheet in the flat wound electrode body,

wherein the flat wound electrode body is configured such that
the positive electrode sheet, the first separator, the negative electrode sheet, and the second separator are wound,
in each of the first separator and the second separator, the edge adjacent portion located at each side in an axial direction along a winding axis of the flat wound electrode body includes the suppression portion in at least the curve positioned portion.

8. The battery according to claim 1 , wherein the separator is formed with the suppression portion in the edge adjacent portion throughout the winding circumferential direction.

9. The battery according to claim 2 , wherein the suppression portion is configured to extend outward from the edge adjacent portion of the separator in a width direction of the separator and reach an edge of the separator.

10. The battery according to claim 3 , wherein the suppression portion is configured to extend outward from the edge adjacent portion of the separator in a width direction of the separator and reach an edge of the separator.

11. The battery according to claim 4 , wherein the suppression portion is configured to extend outward from the edge adjacent portion of the separator in a width direction of the separator and reach an edge of the separator.

12. The battery according to claim 5 , wherein the suppression portion is configured to extend outward from the edge adjacent portion of the separator in a width direction of the separator and reach an edge of the separator.

Assignees

• Ueki Tomoyoshi
• Shimamura Harunari
• Fukumoto Yusuke
• Toyota Motor Co Ltd

Inventors

• Ueki Tomoyoshi
• Shimamura Harunari
• Fukumoto Yusuke

Classifications

• H01M10/0431 Primary

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title

• H01M50/593

  Spacers; Insulating plates · CPC title

• H01M50/586

  inside the batteries, e.g. incorrect connections of electrodes · CPC title

• H01M50/417

  Polyolefins · CPC title

• H01M2/18

  Electricity · mapped topic