CN213483918U

CN213483918U - Pole piece and battery cell

Info

Publication number: CN213483918U
Application number: CN202022714065.6U
Authority: CN
Inventors: 金虎权; 李根雨; 孙俊吉; 孙威; 曹启飞; 周滢杰; 郭恒志; 王春阳; 刘胜南; 刘盼盼
Original assignee: Sichuan Xinminya Battery Technology Co Ltd; Suzhou Lingwei New Energy Technology Co Ltd; Hunan Lingpai New Energy Technology Co Ltd
Current assignee: Hunan Lingpai Energy Storage Technology Co ltd; Hunan Lingpai New Energy Research Institute Co ltd; Suzhou Lingpai New Energy Technology Co ltd; Hunan Lingpai New Energy Technology Co Ltd; Hengyang Lingpai New Energy Technology Co Ltd; Hunan Lead Power Dazhi Technology Inc
Priority date: 2020-11-20
Filing date: 2020-11-20
Publication date: 2021-06-18
Anticipated expiration: 2030-11-20

Abstract

The application provides a pole piece and electric core, electric core includes: a plurality of stacked pole pieces, said pole pieces comprising: a coating zone; a tab comprising a first portion connected to a first edge of the coated region and a second portion protruding beyond a second edge of the coated region, the first edge directly intersecting the second edge; a connecting structure, one end of the connecting structure being connected to the second portion. This application pole piece and electric core, the pole piece piles up the thickness direction of direction and battery the same, with the main position of generating heat towards the battery bottom, gives the heat dissipation mechanism of battery package through heat-conduction with the heat transfer, can improve the radiating efficiency of battery to improve the battery thermal safety nature.

Description

Pole piece and battery cell

Technical Field

The application relates to the technical field of lithium ion batteries, in particular to a pole piece and a battery cell.

Background

With the rapid development of electric vehicles, the thermal safety of the ion battery is becoming more stringent. Therefore, the problem of improving the heat dissipation of the lithium ion battery will become important. In order to improve the thermal safety of the lithium ion battery, the structure of the battery can be optimized from the aspect of the structure of the battery, and the heat dissipation efficiency of the lithium ion battery is improved.

In some existing square lithium ion battery structures, two pole column ends face upwards, and pole pieces in an electric core are parallel to the height direction of a battery regardless of a winding or lamination electric core. There are the following problems: because the heat conducting structure of the common battery pack is arranged at the lower part of the battery module, the heat conducting structure is contacted with the bottom of the battery to dissipate heat, and the heat dissipating effect is poor; when the battery thickness is large, the welding with the connecting sheet is difficult along with the increase of the layer number of the pole lugs.

Therefore, there is a need to provide more efficient and reliable solutions.

SUMMERY OF THE UTILITY MODEL

The application provides a pole piece and electric core, can improve the radiating efficiency of battery to improve the battery thermal safety nature.

One aspect of the present application provides a pole piece, comprising: a coating zone; a tab comprising a first portion connected to the first edge of the coating region and a second portion protruding beyond the second edge of the coating region, the first edge directly intersecting the second edge.

In some embodiments of the present application, the tab is a right trapezoid, the first side is parallel to one leg of the right trapezoid, and the second side is parallel to the other leg of the right trapezoid.

In some embodiments of the present application, the second portion has a width of 5 mm to 20 mm.

In some embodiments of the present application, the tab has a width of 10 mm to 30 mm.

Another aspect of the present application also provides a battery cell, including: a plurality of stacked pole pieces, said pole pieces comprising: a coating zone; a tab comprising a first portion connected to a first edge of the coated region and a second portion protruding beyond a second edge of the coated region, the first edge directly intersecting the second edge; a connecting structure, one end of the connecting structure being connected to the second portion.

In some embodiments of the present application, the connection structure is perpendicular to the first edge of the tab.

In some embodiments of the present application, the tab stack on the number of pole pieces has a thickness of less than 500 microns.

In some embodiments of the present application, the second portion is connected to the connecting structure by welding, and the total welding area is 1 mm to 500 mm.

In some embodiments of the present application, an end of the connecting structure distal from the second portion comprises a bent structure.

In some embodiments of the present application, the bend structure is parallel to the pole piece.

In some embodiments of the present application, the thickness of the connection structure is 0.5 mm to 3 mm.

This application pole piece and electric core, the pole piece piles up the thickness direction of direction and battery the same, with the main position of generating heat towards the battery bottom, gives the heat dissipation mechanism of battery package through heat-conduction with the heat transfer, can improve the radiating efficiency of battery to improve the battery thermal safety nature.

Drawings

The following drawings describe in detail exemplary embodiments disclosed in the present application. Wherein like reference numerals represent similar structures throughout the several views of the drawings. Those of ordinary skill in the art will understand that the present embodiments are non-limiting, exemplary embodiments, and that the accompanying drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of the present application, as other embodiments may equally accomplish the utility model intent of the present application. It should be understood that the drawings are not to scale. Wherein:

FIG. 1 is a schematic diagram of a pole piece according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram illustrating cutting of a pole piece according to an embodiment of the present disclosure;

fig. 3 is a front view of a battery cell according to an embodiment of the present application;

fig. 4 is a top view of a battery cell according to an embodiment of the present disclosure;

fig. 5 is a side view of a cell according to an embodiment of the present disclosure;

fig. 6 is a partially developed view of a battery cell according to an embodiment of the present application.

Detailed Description

The following description is presented to enable any person skilled in the art to make and use the present disclosure, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Thus, the present application is not limited to the embodiments shown, but is to be accorded the widest scope consistent with the claims.

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings.

Fig. 1 is a schematic diagram of a pole piece according to an embodiment of the present application.

An embodiment of the present application provides a pole piece 100, and referring to fig. 1, the pole piece 100 includes: a coating zone 110; a tab 120, the tab 120 comprising a first portion 121 and a second portion 122, the first portion 121 being connected to the first edge 111 of the coating region 110, the second portion 122 protruding beyond the second edge 112 of the coating region 110, the first edge 111 directly intersecting the second edge 112.

The application the pole piece, the pole piece pile up and form electric core after, utilize second part 122 comes the welding with utmost point ear 120 and the connection structure of the outside electricity intercommunication of battery, the pole piece is piled up the direction and is the same with the thickness direction of battery, with the main position of generating heat towards the battery bottom, gives the heat dissipation mechanism of battery package with the heat transfer through heat-conduction, can improve the radiating efficiency of battery to improve the thermal safety nature of battery.

In some embodiments of the present application, the surface of the coating region 110 is coated with the prepared electrode slurry.

In some embodiments of the present application, the tab 120 is a right trapezoid, and the first side 111 is parallel to one leg of the right trapezoid, and the second side 112 is parallel to the other leg of the right trapezoid. The right trapezoid shape can minimize the area of the tab 120, reduce the area and weight of the pole piece, and improve the cell capacity.

In other embodiments of the present application, the tab 120 may have other shapes, such as a rectangular shape or other irregular shapes. As long as the tab 120 is connected to the coating region 110 and includes a second portion protruding from the coating region 110 by the second pass 112.

In some embodiments of the present application, the width w of the second portion 122 is 5 mm to 20 mm, such as 8 mm, 10 mm, or 15 mm. The width of the second portion 122 cannot be too small, otherwise the subsequent welding with the connecting structure is not good; the width of the second portion 122 also does not need to be too large, otherwise the area and weight of the pole piece are increased, and the cell capacity is reduced.

In some embodiments of the present application, the width d of the tab 120 is 10 mm to 30 mm, for example, 15 mm, 20 mm or 25 mm.

Fig. 2 is a schematic cutting diagram of a pole piece according to an embodiment of the present application.

Referring to fig. 2, a method of forming the pole piece 100 may include: forming a plurality of coating regions 110 on the foil 130; cutting the foil 130 forms a number of discrete pole pieces 100, the pole pieces 100 including the coated areas 110 and the tabs 120.

In order to illustrate the structure of the battery cell more clearly, the embodiment of the present application provides three views of the battery cell 200. Fig. 3 is a front view of a battery cell according to an embodiment of the present application; fig. 4 is a top view of a battery cell according to an embodiment of the present disclosure; fig. 5 is a side view of a battery cell according to an embodiment of the present application. When the structure of the battery cell is described, reference may be made to fig. 3, fig. 4, and fig. 5 at the same time.

Referring to fig. 3, 4, and 5, the battery cell 200 includes: a cell body 210, the cell body 210 including a plurality of stacked pole pieces 100 (the cell body 210 is formed by stacking a plurality of pole pieces 100), the pole pieces 100 including: a coating zone; a tab comprising a first portion connected to the first edge of the coating region and a second portion protruding beyond the second edge of the coating region, the first edge directly intersecting the second edge.

The structure of the pole piece 100 has been described in detail above, and is not described herein again. It should be understood that the cell body 210 may be formed by laminating the pole pieces 100, and the cell body 210 may also be formed by winding the pole pieces 100.

Fig. 6 is a partially developed view of a battery cell according to an embodiment of the present application. Referring to fig. 6, the battery cell 200 further includes a connection structure 220, and one end of the connection structure 220 is connected to the second portion of the tab 120. It should be noted that fig. 6 is a top view, and thus although only one pole piece is shown in fig. 6, it should be understood that the pole piece is stacked together to form the cell main body 210. In addition, fig. 6 is a partially developed view of the battery cell 200 (specifically, a structure in which the connection structure 220 is developed), and is not a complete structure shown in fig. 3, 5, and 6. The purpose of this is to more clearly illustrate how the connection structure 220 is connected to the cell body 210.

In some embodiments of the present application, the connection structure 220 is perpendicular to the first side of the tab.

In some embodiments of the present application, the stack of tabs 120 on the number of pole pieces has a thickness of less than 500 microns. The stacking thickness of the battery core tabs 120 cannot be too large, otherwise, the welding quality is affected, the redundant space on the side surface of the square-shell battery is too small, the connection structure and the shell are short-circuited, and the safety problem occurs.

In some embodiments of the present application, the second portion of the tab 120 is connected to the connection structure 220 by welding, and the total welding area is 1 mm to 500 mm.

In some embodiments of the present application, an end of the connection structure 220 remote from the second portion of the tab 120 includes a bent structure 221.

In some embodiments of the present application, the thickness of the connecting structure 220 is 0.5 mm to 3 mm.

With continued reference to fig. 3, 4, and 5, the connection structure 220 in the structure of connecting the connection structure 220 shown in fig. 6 and the cell main body 210 together is bent 180 degrees along the boundary of the first portion and the second portion of the tab toward the direction close to the pole piece; and then bending the connecting structure 220 and the tab 120 by 90 degrees along the first edge toward the coating region, so that the connecting structure 220 stands up and is perpendicular to the cell main body 210.

In some embodiments of the present application, the bending structure 221 is parallel to several pole pieces in the cell body 210.

In some embodiments of the present application, the tabs 120 of the cell body 210 are welded together before the connecting structure 220 is bent. After welding, the tabs may be gathered at the center of the thickness of the cell main body 210, or may be gathered at one side of the thickness direction of the cell main body 210.

In the battery electric core, the pole piece stacking direction is the same as the pole column direction, so that the pole piece is tightly attached to the bottom of the battery shell in parallel, and heat is conducted to the bottom of the battery shell.

In some embodiments of the present application, a single battery cell may be packaged to form a battery, the length of the connecting structure 220 may be extended to make the space between the bending structure 221 and the cell main body 210 larger, and then a plurality of (e.g., 2 or 3) battery cells are packaged together to form a battery.

In view of the above, it will be apparent to those skilled in the art upon reading the present application that the foregoing application content may be presented by way of example only, and may not be limiting. Those skilled in the art will appreciate that the present application is intended to cover various reasonable variations, adaptations, and modifications of the embodiments described herein, although not explicitly described herein. Such alterations, modifications, and variations are intended to be within the spirit and scope of the exemplary embodiments of this application.

It is to be understood that the term "and/or" as used herein in this embodiment includes any and all combinations of one or more of the associated listed items. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present.

It will be understood that the terms "comprises," "comprising," "includes" or "including," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It will be further understood that, although the terms first, second, third, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element in some embodiments may be termed a second element in other embodiments without departing from the teachings of the present application. The same reference numerals or the same reference characters denote the same elements throughout the specification.

Further, the present specification describes example embodiments with reference to idealized example cross-sectional and/or plan and/or perspective views. Accordingly, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of exemplary embodiments.

Claims

1. A pole piece, comprising:

a coating zone;

a tab comprising a first portion connected to the first edge of the coating region and a second portion protruding beyond the second edge of the coating region, the first edge directly intersecting the second edge.

2. The pole piece of claim 1 wherein said tab is a right trapezoid, said first side being parallel to one leg of said right trapezoid and said second side being parallel to the other leg of said right trapezoid.

3. The pole piece of claim 1, wherein the width of the second portion is 5 mm to 20 mm.

4. The pole piece of claim 1 wherein the tab has a width of 10 mm to 30 mm.

5. A battery cell, comprising:

a plurality of stacked pole pieces, said pole pieces comprising:

a coating zone;

a tab comprising a first portion connected to a first edge of the coated region and a second portion protruding beyond a second edge of the coated region, the first edge directly intersecting the second edge;

a connecting structure, one end of the connecting structure being connected to the second portion.

6. The cell of claim 5, wherein the connection structure is perpendicular to the first edge of the tab.

7. The cell of claim 5, wherein a thickness of the tab stack on the plurality of pole pieces is less than 500 microns.

8. The electrical core of claim 5, wherein the second portion is attached to the connection structure by a weld having a total weld area of 1 to 500 square millimeters.

9. The cell of claim 5, wherein an end of the connection structure distal from the second portion comprises a bent structure.

10. The cell of claim 9, wherein the bend structure is parallel to the pole piece.

11. The cell of claim 5, wherein the connection structure has a thickness of 0.5 mm to 3 mm.