Electrode assembly and secondary battery

Patent metadata

Field	Value
Publication number	US-2020220140-A1
Application number	US-202016818635-A
Country	US
Kind code	A1
Filing date	Mar 13, 2020
Priority date	Dec 22, 2018
Publication date	Jul 9, 2020
Grant date	—

Abstract

The present disclosure provides an electrode assembly and a secondary battery. The electrode assembly includes a first electrode plate, a second electrode plate and a separator. The first electrode plate, the second electrode plate and the separator are wound to a flat structure, and the flat structure comprises a main region and corner regions, the corner regions are provided at two ends of the main region along a width direction of the main region. The first electrode plate and the second electrode plate each are wound to turns. A gap is provided between two adjacent turns of the first electrode plate, the gap includes a first gap and a second gap. The first gap corresponds to the corner region in position, the second gap corresponds to the main region in position, and a dimension of the first gap is larger than a dimension of the second gap.

First claim

What is claimed is:

1 . An electrode assembly, comprising a first electrode plate, a second electrode plate and a separator, the separator separating the first electrode plate and the second electrode plate;
the first electrode plate, the second electrode plate and the separator being wound to a flat structure, and the flat structure comprising a main region and a corner region, the corner region being provided at an end of the main region along a width direction of the main region; the first electrode plate and the second electrode plate each being wound to turns; a gap being provided between two adjacent turns of the first electrode plate, the gap comprising a first gap and a second gap; the first gap corresponding to the corner region in position, the second gap corresponding to the main region in position, a dimension of the first gap being larger than a dimension of the second gap.

2 . The electrode assembly according to claim 1 , wherein
a ratio of the dimension of the first gap to the dimension of the second gap is less than 16.

3 . The electrode assembly according to claim 2 , wherein the dimension of the first gap is 20 μm-80 μm, the dimension of the second gap is 5 μm-20 μm.

4 . The electrode assembly according to claim 1 , wherein
the second electrode plate is provided with a first protrusion and a second protrusion, the first protrusion corresponds to the corner region in position, the second protrusion corresponds to the main region in position, the first protrusion and the second protrusion protrude toward the same side of the second electrode plate; a height of the first protrusion is larger than a height of the second protrusion.

5 . The electrode assembly according to claim 4 , wherein
the separator comprises a first separator and a second separator, the first separator and the second separator are respectively positioned at two sides of the second electrode plate; the first protrusion and the second protrusion protrude toward the first separator; in the corner region, a third gap is kept between the second electrode plate and the first separator, and a dimension of the third gap is equal to the height of the first protrusion; in the main region, a fourth gap is kept between the second electrode plate and the first separator, and a dimension of the fourth gap is equal to the height of the second protrusion.

6 . The electrode assembly according to claim 4 , wherein
the second electrode plate comprises a first region and a second region, the first region corresponds to the corner region in position, the second region extends from an end of the first region and corresponds to the main region in position; the first region is provided with the first protrusions, and a ratio of a total area of the first protrusions to an area of the first region is 50%-90%; the second region is provided with the second protrusions, and a ratio of a total area of the second protrusions to an area of the second region is 50%-90%.

7 . The electrode assembly according to claim 4 , wherein the first electrode plate is a negative electrode plate, the second electrode plate is a positive electrode plate.

8 . The electrode assembly according to claim 4 , wherein a recess is formed at an inner side of the first protrusion and a recess is formed at an inner side of the second protrusion.

9 . The electrode assembly according to claim 1 , wherein a ratio of a width of the main region to a thickness of the main region is 5-20.

10 . The electrode assembly according to claim 1 , wherein in the main region, the number of layers of the first electrode plate is even, the number of layers of the second electrode plate is even.

11 . The electrode assembly according to claim 1 , wherein
in the corner region, the first electrode plate and the second electrode plate each are divided into a plurality of layers; each layer of the first electrode plate in the corner region is in the shape of circular arc, each layer of the second electrode plate in the corner region is in the shape of circular arc.

12 . A secondary battery, comprising a case, a cap assembly and an electrode assembly;
the case comprising an accommodating cavity, the electrode assembly being accommodated in the accommodating cavity, the cap assembly being connected with the case; the electrode assembly comprising a first electrode plate, a second electrode plate and a separator, the separator separating the first electrode plate and the second electrode plate; the first electrode plate, the second electrode plate and the separator being wound to a flat structure, and the flat structure comprising a main region and a corner region, the corner region being provided at an end of the main region along a width direction of the main region; the first electrode plate and the second electrode plate each being wound to turns; a gap being provided between two adjacent turns of the first electrode plate, the gap comprising a first gap and a second gap; the first gap corresponding to the corner region in position, the second gap corresponding to the main region in position, a dimension of the first gap being larger than a dimension of the second gap.

13 . The secondary battery according to claim 12 , wherein
a ratio of the dimension of the first gap to the dimension of the second gap is less than 16.

14 . The secondary battery according to claim 13 , wherein the dimension of the first gap is 20 μm-80 μm, the dimension of the second gap is 5 μm-20 μm.

15 . The secondary battery according to claim 12 , wherein
the second electrode plate is provided with a first protrusion and a second protrusion, the first protrusion corresponds to the corner region in position, the second protrusion corresponds to the main region in position, the first protrusion and the second protrusion protrude toward the same side of the second electrode plate; a height of the first protrusion is larger than a height of the second protrusion.

16 . The secondary battery according to claim 15 , wherein
the separator comprises a first separator and a second separator, the first separator and the second separator are respectively positioned at two sides of the second electrode plate; the first protrusion and the second protrusion protrude toward the first separator; in the corner region, a third gap is kept between the second electrode plate and the first separator, and a dimension of the third gap is equal to the height of the first protrusion; in the main region, a fourth gap is kept between the second electrode plate and the first separator, and a dimension of the fourth gap is equal to the height of the second protrusion.

17 . The secondary battery according to claim 15 , wherein
the second electrode plate comprises a first region and a second region, the first region corresponds to the corner region in position, the second region extends from an end of the first region and corresponds to the main region in position; the first region is provided with the first protrusions, and a ratio of a total area of the first protrusions to an area of the first region is 50%-90%; the second region is provided with the second protrusions, and a ratio of a total area of the second protrusions to an area of the second region is 50%-90%.

18 . The secondary battery according to claim 12 , wherein the first electrode plate is a negative electrode plate, the second electrode plate is a positive electrode plate.

19 . The secondary battery according to claim 12 , wherein a ratio of a widt

Assignees

• Jiangsu Contemporary Amperex Tech Ltd

Inventors

• Xu Hu
• Wu Kai
• Ren Miaomiao
• Yang Rui
• Xu Long
• Lai Youlei
• Lin Yongshou

Classifications

• H01M50/54

  Connection of several leads or tabs of plate-like electrode stacks, e.g. electrode pole straps or bridges · CPC title

• Y02P70/50

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

• H01M50/46 Primary

  Separators, membranes or diaphragms characterised by their combination with electrodes · CPC title

• H01M10/0587 Primary

  of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title