CN219086203U

CN219086203U - Battery and battery pack

Info

Publication number: CN219086203U
Application number: CN202223316117.XU
Authority: CN
Inventors: ***; 齐彬伟; 张璐璐
Original assignee: China Lithium Battery Technology Co Ltd
Current assignee: China Lithium Battery Technology Co Ltd
Priority date: 2022-12-09
Filing date: 2022-12-09
Publication date: 2023-05-26
Anticipated expiration: 2032-12-09

Abstract

The utility model discloses a battery and a battery pack, wherein the battery comprises a battery core, two lug parts are arranged on the end surfaces of two sides of the battery core, the two lug parts are formed by bundling at least two single-piece lug parts, a lug insulating film is used for wrapping the outer surface of the lug part along the bundling direction of the single-piece lug parts in the lug parts, the lug parts are insulated with an external shell, the lug insulating film is simultaneously connected with the front end surface and the rear end surface of the battery core, the reliability of the connection between the lug insulating film and the lug parts is improved, meanwhile, the lug insulating film can be prevented from being scratched and damaged due to buckling and wrinkling of the lug parts, and the reliability of insulation between the lug parts and the external shell is effectively improved. The battery pack with the battery is characterized in that the lug insulation film is used for wrapping the lug along the bundling direction of the single lug and is connected with the front end face and the rear end face of the battery core, so that the lug is insulated from the outer shell, and the battery pack has more reliable internal insulation.

Description

Battery and battery pack

Technical Field

The utility model relates to the technical field of batteries, in particular to a battery and an electric battery pack.

Background

The lug part form of the battery core of the lithium ion battery mainly comprises a full lug and a multi-lug, and is commonly existing in soft-package and aluminum-shell batteries, in the assembly process, each single lug needs to be led out from two sides of the battery core by the battery core with a multi-lug structure, the lug part is formed by bundling and then is connected with a connecting sheet in a welding mode, the lug part is connected with a battery pole post by the connecting sheet, and meanwhile, the lug part is externally coated with a lug insulating film to realize insulation between the lug part and an external shell.

When the lug is wholly bent to the surface of the connecting sheet and welded with the connecting sheet, the lug is folded from one side of the connecting sheet, lamination is easy to occur between different single-sheet lugs, so that the lug is easy to warp and wrinkle, and the lug insulating film is made of flexible materials, so that the lug insulating film coated outside the lug is scratched and damaged due to the lug buckling and wrinkling, the insulating performance of the lug insulating film is reduced, the risk of insulation failure exists between the lug and an external shell, and the short-circuit risk of the battery is increased.

Disclosure of Invention

In order to overcome the technical problems described in the prior art, one of the purposes of the present utility model is to provide a battery, which can effectively reduce the risk of insulation failure between the tab and the battery case.

In order to overcome the above-mentioned problems of the prior art, a second object of the present utility model is to provide a battery pack having reliable internal insulation.

The technical scheme adopted by the utility model for achieving one of the purposes is as follows:

provided is a battery including:

the battery cell, the both sides terminal surface of the said battery cell has two polar lugs opposite in polarity;

the two lug parts are respectively formed by bundling at least two single lug pieces;

the electrode lug insulation film is used for wrapping the outer surface of the electrode lug along the bundling direction of the single-piece electrode lug and is connected with the front end face and the rear end face of the battery cell, the front end face and the rear end face are parallel to the leading-out end face of the electrode lug after being leveled, and the single-piece electrode lug with the same polarity is folded along the same direction.

The technical scheme has the following advantages or beneficial effects:

the utility model provides a battery, it is along the direction of closing in of monolithic utmost point ear through utmost point ear insulating film, and the surface of the utmost point ear of electricity core side terminal surface is located to the cladding, and simultaneously, utmost point ear insulating film is connected with the preceding terminal surface and the rear end face of electric core to it is insulating with outside casing to realize utmost point ear. Notably, the tab insulating film is arranged along the converging direction of the single tab, so that the tab insulating film coated on the outer surface of the tab is prevented from being scratched and damaged due to the buckling and wrinkling of the tab, and the tab insulating film is connected with the front end surface and the rear end surface of the battery core, so that the reliability of connection of the tab insulating film and the tab is improved, and the stability of insulation of the tab and an external shell is effectively improved, so that the risk of short circuit of the battery is reduced.

The second technical scheme adopted by the utility model for achieving the second purpose is as follows:

a battery pack is provided, wherein the battery pack comprises the above-described battery.

The technical scheme has the following advantages or beneficial effects:

the battery pack comprises the battery, the lug insulation film is wrapped on the outer surface of the lug part of the side end face of the battery core along the converging direction of the single lug, meanwhile, the lug insulation film is connected with the front end face and the rear end face of the battery core, the front end face and the rear end face are parallel to the leading-out end face of the lug after being leveled, and the single lug with the same polarity is folded along the same direction so as to realize insulation between the lug part and an external shell. Notably, the tab insulating film is arranged along the converging direction of the single tab, so that the tab insulating film coated on the outer surface of the tab is prevented from being scratched and damaged due to the buckling and wrinkling part of the tab, and the tab insulating film is connected with the front end surface and the rear end surface of the battery cell, so that the reliability of connection of the tab insulating film and the tab is improved, the stability of insulation between the tab and the outer shell is effectively improved, and the battery pack has reliable internal insulation.

Drawings

Fig. 1 is a partially exploded view of a battery provided in some embodiments.

Fig. 2 is a schematic structural view of a connecting piece according to some embodiments.

Fig. 3 is a bottom view of a battery provided in some embodiments.

Fig. 4 is a schematic view of an expanded structure of a tab insulating film according to some embodiments.

Wherein the reference numerals have the following meanings:

1-an electric core;

2-pole ear parts and 21-bending parts;

3-tab insulating film, 31-front end face connecting film, 32-tab connecting film, 33-back end face connecting film, 34-first bending film, 35-second bending film and 36-third bending film;

4-connecting piece, 41-tab connection.

Detailed Description

The technical solutions in the exemplary embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the exemplary embodiments of the present disclosure. The example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the present disclosure, and it is therefore to be understood that various modifications and changes may be made to the example embodiments without departing from the scope of the present disclosure.

In the description of the present disclosure, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying relative importance unless explicitly specified or limited otherwise; the term "plurality" refers to two or more than two; the term "and/or" includes any and all combinations of one or more of the associated listed items. In particular, references to "the/the" object or "an" object are likewise intended to mean one of a possible plurality of such objects.

Unless specified or indicated otherwise, the terms "connected," "fixed," and the like are to be construed broadly and are, for example, capable of being fixedly connected, detachably connected, or integrally connected, electrically connected, or signally connected; "coupled" may be directly coupled or indirectly coupled through intermediaries. The specific meaning of the terms in the present disclosure may be understood by those skilled in the art according to the specific circumstances.

Further, in the description of the present disclosure, it should be understood that the terms "upper", "lower", "inner", "outer", and the like, as described in the example embodiments of the present disclosure, are described with the angles shown in the drawings, and should not be construed as limiting the example embodiments of the present disclosure. It will also be understood that in the context of an element or feature being connected to another element(s) "upper," "lower," or "inner," "outer," it can be directly connected to the other element(s) "upper," "lower," or "inner," "outer," or indirectly connected to the other element(s) "upper," "lower," or "inner," "outer" via intervening elements.

Referring to fig. 1, an exemplary embodiment of the present utility model firstly provides a battery, which includes a battery core 1, two tab portions 2 and a tab insulating film 3, wherein the tab insulating film 3 is wrapped on an outer surface of the tab portion 2 disposed on a side end surface of the battery core 1 along a beam shrinking direction of a single tab, meanwhile, the tab insulating film 3 is connected with a front end surface and a rear end surface of the battery core 1, the front end surface and the rear end surface are parallel to an outgoing end surface of the tab after being leveled, the single tab portion with the same polarity is folded along the same direction to realize insulation between the tab portion 2 and an external housing, and notably, the tab insulating film 3 is disposed along the beam shrinking direction of the single tab portion, so that the tab insulating film 3 wrapped on an outer surface of the tab portion 2 is prevented from being scratched and damaged due to buckling and buckling of the tab portion 2, and the tab insulating film 3 is connected with the front end surface and the rear end surface of the battery core 1, reliability of connection between the tab insulating film 3 and the tab portion 2 is increased, insulation stability between the tab portion and an external housing is effectively improved, and risk of short circuit of the battery is reduced.

The front end face and the rear end face are parallel to the lead-out end face after the tabs are leveled, and the single tabs with the same polarity are folded along the same direction.

The battery as a minimum unit capable of performing electrochemical reactions such as charge/discharge, the battery provided in this embodiment includes a cell 1, wherein the cell 1 includes two tab portions 2 led out from both side end faces of the cell 1. It should be understood that the structure of the battery cell 1 in fig. 1 is schematically illustrated, and the specific structure thereof is not limited to the structure shown in fig. 1. Specifically, the battery cell 1 in the present embodiment is a laminated battery cell, and the stacked portion of the laminated battery cell includes a plurality of first electrode pieces, a separator, and a second electrode piece. Specifically, when the first electrode sheet is a positive electrode, the second electrode sheet is a negative electrode. Wherein the polarities of the first electrode sheet and the second electrode sheet are interchangeable. The side end face of each pole piece is led out of a single-piece pole lug, and it is to be noted that the end face of each side of the battery core 1 is folded by at least two single-piece pole lugs to form a pole lug part 2, and the single-piece pole lugs with the same polarity are folded along the same direction. The single tab is made of a metal foil having good electrical and thermal conductivity, such as aluminum, copper, or nickel.

Specifically, the electric core 1 is arranged in the battery shell, the end faces of two sides of the electric core 1 are provided with the positive electrode lug part 2 and the negative electrode lug part 2, and the positive electrode lug part 2 and the negative electrode lug part 2 can be respectively and electrically connected with the positive electrode post and the negative electrode post through the connecting sheet 4. The positive electrode tab portion 2 and the negative electrode tab portion 2 are led out from opposite end surfaces of the battery cell 1, and the tab portion 2 and the connection piece 4 on one side of the battery cell 1 are shown in fig. 1 as an example, and the tab portion 2 may be the positive electrode tab portion 2 or the negative electrode tab portion 2.

Referring to fig. 1 to 2, the battery in the present embodiment further includes a connecting piece 4, and the connecting piece 4 is bent into a first section and a second section. The first section is a pole connection part and is used for being electrically connected with a pole on the battery cover plate; the second section is a tab connection part 41, which is located at a side end surface of the battery cell 1, and further, the tab 2 formed by bundling single tabs is bent to one side of the tab connection part 41 to form a bending part 21, where the tab connection part 41 is away from the battery cell 1, and the inner side surface of the bending part 21 is at least partially attached to one side of the tab connection part 41 away from the battery cell 1 so as to be electrically connected. In some embodiments, when the tab connection portion 41 shown in fig. 2 is connected to the tab portion 2 shown in fig. 2, a connection manner of laser welding or ultrasonic welding may be adopted.

It should be noted that, in order to avoid the tab portion 2 from being warped and wrinkled due to serious dislocation after the entire tab portion 2 is folded and bent, the entire thickness of the tab portion 2 in this embodiment is set to be 0.5-5mm.

On the basis of the structure, the overall thickness of the lug part 2 should not exceed 5mm, if the thickness of the lug part 2 exceeds 5mm, the situation that buckling and wrinkling exist in the lug part 2 due to the fact that staggered layers easily occur after the lug part 2 is integrally folded and bent is caused, so that an insulating film is easily punctured, the risk of internal short circuit of a battery is caused, and the lug part 2 is too thick to cause untight folding and influence the lug to enter a shell.

The overall thickness of the tab portion 2 should not be less than 0.5mm either, and if the overall thickness of the tab portion 2 is less than 0.5mm, the entire thickness of the tab portion 2 will be too thin, so that the overall rigidity strength of the tab portion 2 cannot be ensured, and the tab portion 2 will be easily broken or worn during boxing, thereby affecting the normal operation of the battery.

Therefore, in the present embodiment, the thickness of the tab portion 2 should be set within the range of 0.5 to 5mm.

Referring to fig. 3, in the battery of the present embodiment, if the free end of the bending portion 21 of the tab portion 2 is too long along the side end face direction of the battery core 1, the risk of tearing occurs due to the larger stress of the connecting end of the bending portion 21; in addition, too long bending portion 21 may cause tab portion 2 to have to be further bent and bunched, resulting in more serious buckling and wrinkling of tab portion 2, and for this reason, in this embodiment, the width of bending portion 21 is smaller than the width of cell 1 along the side end face direction of cell 1. Further, along the side end face direction of the battery cell 1, the width of the bending portion 21 of the tab portion 2 in the present embodiment is smaller than the width of the tab connection portion 41, so that the bending length can be reduced to further reduce the tearing risk. It should be noted that, along the side end face direction of the battery cell 1, the width of the bending portion 21 cannot be too small, otherwise, the overcurrent area is small, the heat generated by the tab connection portion 41 is large, and a safety risk is caused. It should be understood that, in order to more clearly illustrate the connection and positional relationship of the tab portion 2 and the tab connection portion 41, the tab portion 2 is schematically illustrated in the form of lines in fig. 3.

Further, in the height direction of the battery cell 1, the coverage area of the tab insulating film 3 is larger than the projection area of the tab 2 on the battery cell 1.

On the basis of the structure, on the height direction of the battery cell 1, the coverage area of the lug insulation film 3 is larger than the projection area of the lug 2 on the battery cell, namely, the lug insulation film 3 can completely cover the lug 2 on the height direction, so that the risk of lap joint between the lug and the shell is effectively avoided, and a better insulation effect is realized.

Further, in the height direction of the battery cell, the distance between the bottom of the tab insulating film 3 and the bottom surface of the battery cell 1 is H1, and H1 is less than or equal to 3mm.

On the basis of the above structure, that is, the vertical distance between the bottom of the tab insulating film 3, which is close to the bottom surface of the battery cell 1 in the height direction, and the bottom surface of the battery cell 1 is less than 3mm. Because the bottom surface of electric core 1 is equipped with positive plate and negative plate generally to the bottom of electric core 1 is equipped with the diaphragm generally, and the diaphragm generally all sets up and surpasss positive and negative plate 3mm, so in order to prevent that the insulating film from spilling the diaphragm, the diaphragm damage leads to spilling positive and negative plate, and the positive and negative plate that leaks has taken place the electricity to be connected with the casing and has led to the battery short circuit, consequently the distance between insulating film and the electric core 1 bottom is less than or equal to 3mm, should wrap up a part of positive and negative plate at least.

Further, in order to prevent the risk of short circuit of the battery and the like caused by lithium precipitation of the negative electrode, which is caused by overlap joint of the lithium dendrite and the shell, the tab insulating film 3 should completely cover the negative electrode sheet, that is, the distance between the bottom of the tab insulating film 3 and the bottom surface of the battery cell 1 should be less than or equal to 1.5mm.

Further, the battery comprises a battery shell, the battery shell is provided with a cover plate, the cover plate can seal the battery shell, the battery cell 1 is arranged in the battery shell, the vertical distance between the edge of the tab insulating film 3 and the cover plate in the height direction of the battery cell 1 is H2, and the range of H2 is 0.2-1mm.

On the basis of the above structure, during the assembly process, the battery cell 1 is first placed inside the battery case, and then the cover plate of the battery case is covered and welded, thereby maintaining the battery case in a sealed state. If the edge of the tab insulating film 3 is too close to the cap plate, when the cap plate of the battery case is welded to close the battery case, the welding slag may abrade the tab insulating film 3, degrading the insulating performance.

If the edge of the tab insulating film 3 is too far from the height edge of the battery case, the height of the cladding of the tab insulating film 3 is small at this time, so that the tab insulating film 3 cannot fully cladding the tab 2 or the switching piece, and thus there is a short-circuit risk of instant breakdown under high current between the battery case and the switching piece.

The vertical distance H2 between the edge of the tab insulating film 3 and the height edge of the battery case should be in the range of 0.2-1mm.

In this embodiment, the tab insulating film 3 is bonded to the outer surface of the tab 2, and the front end surface and the rear end surface of the cell 1. The fixing of the shape surrounded by the lug insulating film 3 is realized in an adhesive mode, so that the complete coating of the lug part 2 of the battery cell 1 is realized. In addition, the front end face, the rear end face and the bottom face of the battery cell 1 are coated with battery cell 1 insulating films, and the battery cell 1 insulating films and the tab insulating films 3 are matched together so as to insulate the battery cell 1 from the battery shell. Therefore, in actual operation, the front end face, the rear end face and the bottom face of the battery cell 1 can be coated with the insulating film of the battery cell 1, then the tab 2 of the side end face of the battery cell 1 is coated with the adhesive tab insulating film 3, and meanwhile, the tab insulating film 3 covers part of the insulating films of the battery cell 1 on the front end face and the rear end face of the battery cell 1, so that the tab insulating film 3 and the insulating film of the battery cell 1 form a reliable connection relationship. In the embodiment of the utility model, the tab insulating film 3 with adhesiveness is matched with the insulating film of the battery core 1, so that the bare battery core 1 can be well coated without a hot melting process, thereby effectively avoiding the problems of hot melting wire drawing and poor welding caused by the hot melting process and being beneficial to improving the quality of the battery.

Still further, in some embodiments, the tab insulating film 3 may be disposed beyond the bottom surface and/or the top surface of the battery cell 1, and may be bent with respect to the bottom surface and/or the top surface of the battery cell 1 to further connect with the bottom surface and/or the top surface of the battery cell 1. Referring to fig. 4, fig. 4 is a schematic view showing an unfolding structure of a tab insulating film 3 in the present embodiment, which includes a main body film and a lower auxiliary film, wherein the main body film is divided into a front end surface connecting film 31, a tab connecting film 32 and a rear end surface connecting film 33, and the auxiliary film disposed at the bottom includes a first bending film 34, a second bending film 35 and a third bending film 36. The above-mentioned "bending" refers to folding the auxiliary film of the tab insulating film 3 when the tab insulating film 3 is coated on the outside of the tab portion 2, so that the auxiliary film is substantially attached to the bottom surface of the battery cell 1, and the shape surrounded by the tab insulating film 3 is fixed. Of course, the tab insulating film 3 provided in some other embodiments further includes an upper auxiliary film, which is not described herein.

The exemplary embodiment of the utility model also provides a battery pack, which comprises the battery provided in the technical scheme. The outer surface of the lug 2 arranged on the side end face of the battery cell 1 is coated by the lug insulation film 3 along the beam-collecting direction of the single lug, and meanwhile, the lug insulation film 3 is connected with the front end face and the rear end face of the battery cell 1 so as to realize insulation between the lug 2 and an external shell. Notably, the tab insulating film 3 is arranged along the beam converging direction of the single tab, so that the tab insulating film 3 coated on the outer surface of the tab 2 is prevented from being scratched and damaged due to the tab buckling and wrinkling part, the tab insulating film 3 is connected with the front end surface and the rear end surface of the battery cell 1, the reliability of connection between the tab insulating film 3 and the tab 2 is improved, the stability of insulation between the tab and the outer shell is effectively improved, and the battery pack has reliable internal insulation.

In a specific embodiment, the battery pack provided in the embodiment of the utility model is a battery module. The battery module includes a plurality of batteries, and a plurality of batteries can be fixed through end plate and curb plate.

In another specific embodiment, the battery pack provided in the embodiments of the present application is a battery pack. The battery pack comprises a plurality of batteries and a battery box body, wherein the battery box body is used for fixing the plurality of batteries. It should be noted that the battery pack includes a plurality of batteries, and a plurality of batteries are disposed in the case. Wherein, a plurality of batteries can form the battery module and install in the box after this moment, the battery module can include the end plate and the curb plate of fixed a plurality of batteries. Alternatively, the plurality of cells may be disposed directly in the case, i.e., without grouping the plurality of cells, at which time the end plates and side plates may be removed.

The technical means disclosed by the scheme of the utility model is not limited to the technical means disclosed by the embodiment, and also comprises the technical scheme formed by any combination of the technical features. It should be noted that modifications and adaptations to the utility model may occur to one skilled in the art without departing from the principles of the present utility model and are intended to be within the scope of the present utility model.

Claims

1. A battery, comprising:

the battery cell (1), the two side end surfaces of the battery cell (1) are provided with two pole lug parts (2) with opposite polarities; the two pole lugs (2) are respectively formed by at least two single pole lugs in a converging way,

the electrode lug insulation film (3), the electrode lug insulation film (3) is used for wrapping the outer surface of the electrode lug (2) along the bundling direction of the single-piece electrode lug, and is connected with the front end face and the rear end face of the battery cell (1), the front end face and the rear end face are parallel to the leading-out end face of the electrode lug after being leveled, and the single-piece electrode lug with the same polarity is folded along the same direction.

2. A battery according to claim 1, characterized in that the cells (1) are laminated cells.

3. A battery according to claim 1, characterized in that the overall thickness of the tab portion (2) is 0.5-5mm.

4. The battery according to claim 1, further comprising a connecting piece (4), wherein the connecting piece (4) comprises a tab connecting portion (41), and the tab (2) is bent to a side of the tab connecting portion (41) away from the battery cell (1) through an edge of one side of the tab connecting portion (41) to form a bending portion (21).

5. The battery according to claim 4, characterized in that the inner side of the bending part (21) is connected with at least part of the side of the tab connection part (41) facing away from the battery cell (1) in a fitting manner.

6. The battery according to claim 4, wherein the width of the bent portion (21) is smaller than the width of the cell (1) in the direction of the side end face of the cell (1).

7. The battery according to claim 6, wherein the width of the bent portion (21) is smaller than the width of the tab connection portion (41) in the direction of the side end face of the battery cell (1).

8. A battery according to any one of claims 1-7, characterized in that the cover area of the tab insulating film (3) is larger than the projected area of the tab portion (2) on the cell (1) in the height direction of the cell (1).

9. The battery according to any one of claims 1 to 7, wherein a distance between the bottom of the tab insulating film (3) and the bottom surface of the battery cell (1) in the height direction of the battery cell (1) is H1, and the H1 is not more than 3mm.

10. A battery according to any one of claims 1-7, characterized in that the battery comprises a battery housing provided with a cover plate for sealing the battery housing, the battery cell (1) being mounted in the battery housing, the vertical distance between the edge of the tab insulating film (3) and the cover plate being H2 in the height direction of the battery cell (1), the H2 being in the range of 0.2-1mm.

11. The battery according to claim 1, wherein the tab insulating film (3) is adhesively connected to the outer surface of the tab portion (2), the front end surface and the rear end surface of the battery cell (1), respectively.

12. A battery according to claim 1, characterized in that the tab insulating film (3) is arranged beyond the bottom and/or top surface of the cell (1) and is bendable relative to the bottom and/or top surface of the cell (1) to connect the bottom and/or top surface of the cell (1).

13. A battery comprising a battery as claimed in any one of claims 1 to 12.