CN218039729U

CN218039729U - Utmost point ear structure, electric core pole piece and lithium cell

Info

Publication number: CN218039729U
Application number: CN202222297200.0U
Authority: CN
Inventors: 吕鑫龙
Original assignee: Hefei Guoxuan High Tech Power Energy Co Ltd
Current assignee: Hefei Gotion High Tech Power Energy Co Ltd
Priority date: 2022-08-30
Filing date: 2022-08-30
Publication date: 2022-12-13
Anticipated expiration: 2032-08-30

Abstract

The utility model discloses a utmost point ear structure, electric core pole piece and lithium cell, distribute along pole piece length direction including a plurality of utmost point ears, utmost point ear divide into the N section along the pole piece to wherein utmost point ear stretches out pole piece length shortest section utmost point ear length and is the basis, all the other sections along keeping away from shortest section direction, utmost point ear stretches out pole piece length and increases in proper order, the shortest section in, the length that utmost point ear stretches out the pole piece equals. One end of the pole piece is provided with a non-pole lug section. After the battery core pole piece is wound, the pole lugs are welded together and are connected to the connecting piece together. The utility model discloses a predominant use is when utmost point ear twines into electric core, and utmost point ear demonstrates the echelonment because of the size difference, and after utmost point ear through ultrasonic bonding, every utmost point ear all links together, and utmost point ear top is parallel mutually, can not demonstrate the echelonment and arrange, also can not appear utmost point ear shelter from the connection piece and lap and carry out laser welding, reduces the welding degree of difficulty, produces the bad problem of welding when avoiding connection piece and apron to carry out laser welding simultaneously.

Description

Utmost point ear structure, electric core pole piece and lithium cell

Technical Field

The utility model relates to a lithium battery technology field, more specifically say, relate to a utmost point ear structure, electric core pole piece and lithium cell.

Background

Lithium batteries (lithium cells) refer to the most basic electrochemical unit containing lithium (including metallic lithium, lithium alloys, lithium ions and lithium polymers) in an electrochemical system, and are widely used in various industries due to the characteristics of high working voltage, long cycle life and good safety performance. With the increasing difficulty of environmental problems, energy conservation and emission reduction are increasingly concerned by people, so that the development of new energy automobiles is a necessary choice for economic transformation under the pressure of low carbon and emission reduction in China. The lithium battery serving as the heart of the new energy automobile is rapidly developed under the influence of the national policy and the great force for supporting the development of the new energy industry. The battery is divided into positive and negative electrodes, the tabs are metal conductors leading out the positive and negative electrodes from the battery core, the ears of the positive and negative electrodes of the battery are contact points during charging and discharging in a popular way, and the size and the number of the tabs influence the capacity and the multiplying power of the lithium battery.

With the development of the lithium battery industry, the problems of low rate and low capacity of common lithium batteries need to be solved urgently, and at the present stage, manufacturers are researching and developing high-capacity and high-rate lithium batteries in succession. However, as the capacity of lithium batteries increases, the volume of lithium batteries also gradually increases. In order to ensure that the cells can be welded and combined together, the size and the number of the lugs are increased. In the assembling process of the lithium battery, the tab and the connecting sheet are often required to be subjected to ultrasonic welding firstly, then the connecting sheet is welded on the cover plate through laser, the size and the number of the tab are increased to cause the tab to be arranged in a step shape after ultrasonic welding, the connecting sheet and the cover plate are influenced to be subjected to laser welding to cause poor welding, and the safety performance of the battery is seriously influenced. In the prior art, if the size of the tab is shortened or the number of the tabs is reduced, the distance between the tab and the connecting sheet is insufficient and the requirement of high multiplying power cannot be met.

Disclosure of Invention

1. Technical problem to be solved by the utility model

To the performance that exists among the prior art has large capacity, high rate and constantly increase utmost point ear size and quantity for realizing the lithium cell, lead to utmost point ear ultrasonic welding back to be the echelonment and arrange, influence connection piece and apron and carry out laser welding and lead to welding badly, seriously influence the problem of the security performance of lithium cell, the utility model provides a utmost point ear structure, electric core pole piece and lithium cell, it can realize when utmost point ear size and increase in quantity after utmost point ear ultrasonic welding welds, utmost point ear structure can not be the echelonment and arranges, and can not produce the problem of welding badly when connection piece and apron carry out laser welding.

2. Technical scheme

In order to achieve the above purpose, the utility model provides a technical scheme does:

the utility model provides a utmost point ear structure, a plurality of utmost point ears distribute along pole piece length direction, utmost point ear divide into N section along the pole piece to wherein utmost point ear stretches out pole piece length minimum section utmost point ear length as the basis, all the other sections along keeping away from minimum section direction, utmost point ear stretches out pole piece length and increases in proper order.

Furthermore, in the shortest section, the lengths of the pole lugs extending out of the pole pieces are equal.

Furthermore, the tab is divided into a first tab section, a second tab section and a third tab section, and the three sections are sequentially connected along the length direction of the pole piece.

Furthermore, the length of the pole piece extending out of the middle pole ear of the second pole ear section is smaller than that of the first pole ear section and that of the third pole ear section.

Furthermore, the lengths of the pole pieces extending out of the pole ears in the second pole ear section are equal.

Furthermore, an ultrasonic welding area is arranged on the tab, and after the tab is welded, the ultrasonic welding area is located on the same plane.

The utility model also provides an electricity core pole piece, pole piece surface set up to cover and scribble the district.

Furthermore, one end of the pole piece is provided with a non-pole ear section.

Furthermore, the first pole ear section, the second pole ear section and the third pole ear section are all arranged on the coating area.

The utility model also provides a lithium cell, after electric core pole piece convoluteed, utmost point ear welding is in the same place, is connected to the connection piece jointly.

3. Advantageous effects

Adopt the technical scheme provided by the utility model, compare with existing well-known technique, have following beneficial effect:

(1) The utility model provides a pair of utmost point ear structure, utmost point ear are based on in order to stretch out the shortest section utmost point ear of pole piece length, and all the other section utmost point ears increase in proper order with the pole piece length of keeping away from that the utmost point ear direction stretches out, can realize when utmost point ear twines into electric core, and utmost point ear demonstrates the echelonment because of the size difference. After the pole lugs are subjected to ultrasonic welding, each pole lug is connected together, the tops of the pole lugs are parallel to each other, stepped arrangement cannot be achieved, the pole lugs cannot shield the connecting pieces and the cover plate to be subjected to laser welding, and welding difficulty is reduced.

(2) The utility model provides a pair of electric core pole piece is provided with no utmost point ear section on it, first utmost point ear section, second utmost point ear section, third utmost point ear section, every utmost point ear section is provided with a plurality ofly utmost point ear, when a plurality of utmost point ear pole pieces twine into electric core, utmost point ear ultrasonic bonding back in the utmost point ear section is connected to on the connecting piece when, the top of utmost point ear is far away from the laser weld zone of connecting piece, can effectively avoid producing the bad problem of welding when connecting piece and apron carry out laser welding.

(3) The utility model provides a pair of lithium battery, this lithium battery can not be because of shortening utmost point ear size or reducing utmost point ear quantity, and the capacity that just leads to the lithium cell is little, the multiplying power is low. On the contrary, when the size and the number of the tabs are continuously increased, the lithium battery has the advantages of large capacity, high multiplying power and good safety performance.

Drawings

Fig. 1 is a schematic view of a tab structure of a pole piece before improvement;

fig. 2 is a schematic view of a novel tab structure of the improved pole piece of the present invention;

fig. 3 is a left side view of the battery cell after the winding of the tab structure of the present invention;

fig. 4 is an isometric view of the battery cell after the winding of the tab structure of the present invention;

FIG. 5 is a left side view of the wound cell tab and the connecting sheet after being welded;

fig. 6 is the utility model discloses positive triaxial mapping after coiling electric core utmost point ear and connection piece welding.

The reference numbers in the schematic drawings illustrate: 100. an electric core; 1. a coating area; 10. a first side; 11. no tab section; 12. a first tab section; 13. a second tab segment; 14. a third tab segment; 20. a tab; 201. an ultrasonic welding zone; 21. a first tab; 22. a second tab; 23. a third tab; 24. a first imaginary line; 25. a second imaginary line; 30. connecting sheets; 301. a laser welding area.

Detailed Description

For a further understanding of the present invention, reference will be made to the following detailed description taken in conjunction with the accompanying drawings and examples.

Examples

As shown in fig. 1, in order to improve the tab structure of the front pole piece, a plurality of tabs 20 are distributed along the length direction of the pole piece, and the length of each tab 20 is equal. In the actual production process, if a lithium battery with large capacity and high multiplying power is to be manufactured, the size and the number of the tabs 20 need to be increased continuously, but the tabs 20 are subjected to ultrasonic welding and then are arranged in a step shape, so that poor welding is caused when the subsequent connecting sheet and the cover plate are subjected to laser welding, and the service performance and the safety performance of the lithium battery are also influenced.

Specifically, in the present embodiment, a coating region 1 is disposed on a surface of a cell pole piece. One end of the pole piece is provided with a non-pole ear section 11, a first pole ear section 12, a second pole ear section 13 and a third pole ear section 14.

As shown in fig. 2, in the tab structure provided by this embodiment, a plurality of tabs 20 are distributed along the length direction of the pole piece, and the tabs 20 are divided into N sections along the pole piece, so that the tabs 20 extend out of the shortest section of the pole piece length, and the remaining sections are along the direction away from the shortest section, and the lengths of the tabs 20 extending out of the pole piece length are sequentially increased. Note that, in the shortest section of the tab 20 extending beyond the pole piece, the length of the tab 20 extending beyond the pole piece is equal.

In this embodiment, the tab section 11 is set as a start end and sequentially connected to the first tab section 12, the first tab section 12 is sequentially connected to the second tab section 13, and the second tab section 13 is sequentially connected to the third tab section 14. A first size tab 21 is provided on the first tab section 12, a second size tab 22 is provided on the second tab section 13, and a third size tab 23 is provided on the third tab section 14. The sizes of the lugs on the first lug section 12, the second lug section 13 and the third lug section 14 are different. Wherein, the length of each tab 20 on the second size tab 22 on the second tab segment 13 is equal, and the length of each tab 20 in the first size tab 21 on the first tab segment 12 and the third size tab 23 on the third tab segment 14 increases in sequence along the direction away from the second size tab 22 on the second tab segment 12 on the basis of the second size tab 22 on the second tab segment 12. This makes it possible to realize that the tab 20 is stepped due to the difference in size when the tab 20 is wound into a cell.

As shown in fig. 5 and 6, the tab 20 is located on the top of the battery cell 100, the connecting sheet 30 has a structure like a U-shape or an opening curve, and a laser welding area 301 is located at the non-opened end of the connecting sheet 30 in the middle.

After the plurality of tabs 20 on the tab segment are wound, the tab 20 on each tab segment has different sizes, so that the tab segment can be in a step shape when wound into the battery cell 100. As shown in fig. 3 and fig. 4, in the cell pole piece provided by this embodiment, when a plurality of tab pole pieces are wound into the battery cell 100, the plurality of tab pole pieces are continuously close to the first imaginary line 24 with the first imaginary line 24 as a reference line, the tab 20 at the first imaginary line 24 has the same length, and the height level is the second imaginary line 25. When the tab 20 extends to both ends, the length of the tab 20 at both ends is gradually higher than the second imaginary line 25, so that the tab piece will generate an inclined plane during the winding process.

After the tabs 20 are subjected to ultrasonic welding, the tabs and the ultrasonic welding area 201 are located in the same plane, and each tab 20 is bent due to different welding positions, so that the top of each tab 20 is aligned, and the tabs 20 are not arranged in a stepped manner after being welded. Therefore, the tab 20 does not shield the connecting sheet 30 from the cover plate for laser welding, and the welding difficulty can be effectively reduced.

After the tabs 20 are ultrasonically welded, each tab 20 is constantly close to the first imaginary line 24 by taking the first imaginary line 24 as a reference, and because the distance between the bottom of each tab 20 and the first imaginary line 24 is constantly increased, when the tab 20 is close to the first imaginary line 24, the length of the formed inclined plane needs to be correspondingly increased, at this time, in order to keep the top height of each tab 20 the same as the second imaginary line 25, the length of each tab 20 needs to be increased, therefore, in the embodiment, based on the second imaginary line 25, the height of the tab 20 which is farther from the first imaginary line 24 is larger than the height of the second imaginary line 25, so that the top alignment of each tab 20 is completed.

The ultrasonic welding region 201 of the tab 20 is connected to one end of the connection piece 30. After the tab 20 is in a welded state, it is connected to one end of the connecting plate 30, and then the tab 20 and the connecting plate 30 are subjected to ultrasonic welding at an ultrasonic welding region 201. At this time, the top of the tab 20 is far from the laser welding area 301 of the connection piece 30, so that the connection piece 30 and the cover plate are not interfered with laser welding, and the problem of poor laser welding of the cover plate is effectively avoided.

This embodiment still provides a lithium cell, adopts foretell utmost point ear structure and electric core pole piece, can realize when the size and the quantity of utmost point ear 20 constantly increase, the capacity increase of this lithium cell, and the multiplying power improves to can guarantee the security performance of lithium cell.

The present invention and its embodiments have been described above schematically, and the description is not limited thereto, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching of the present invention, without departing from the inventive spirit of the present invention, the person skilled in the art should also design the similar structural modes and embodiments without creativity to the technical solution, and all shall fall within the protection scope of the present invention.

Claims

1. The utility model provides a utmost point ear structure, a plurality of utmost point ears (20) distribute along pole piece length direction, its characterized in that, utmost point ear (20) divide into the N section along the pole piece to wherein utmost point ear (20) stretch out pole piece length shortest section utmost point ear (20) length and be the basis, all the other sections are along keeping away from shortest section direction, utmost point ear (20) stretch out pole piece length and increase in proper order.

2. A tab construction according to claim 1, wherein the tabs (20) extend from the pole pieces in the shortest sections by equal lengths.

3. The pole lug structure as claimed in claim 2, wherein the pole lug (20) is divided into a first pole lug section (12), a second pole lug section (13) and a third pole lug section (14), and the three sections are connected in sequence along the length direction of the pole pieces.

4. A tab structure according to claim 3, wherein the tab (20) of the second tab section (13) extends beyond the pole piece by a length less than the first tab section (12) and the third tab section (14).

5. A tab structure as claimed in claim 4, wherein the tabs (20) of the second tab section (13) extend out of the tab section by the same length.

6. A tab structure as claimed in any one of claims 1 to 5, wherein the tab (20) is provided with an ultrasonic welding region (201), and after the tab (20) is welded, the ultrasonic welding region (201) is located on the same plane.

7. A battery cell pole piece comprising a tab structure according to any one of claims 1 to 6, wherein the surface of the pole piece is provided with a coating region (1).

8. The cell pole piece according to claim 7, characterized in that one end of the pole piece is provided with a tab-free section (11).

9. The cell pole piece according to claim 8, characterized in that the first tab section (12), the second tab section (13) and the third tab section (14) are disposed on the coating region (1).

10. A lithium battery comprising a cell pole piece according to any of claims 7 to 9, wherein after winding the cell pole piece, the tabs (20) are welded together and connected together to the connecting tab (30).