CN220710378U

CN220710378U - Lithium ion battery cell and battery pack

Info

Publication number: CN220710378U
Application number: CN202322322440.6U
Authority: CN
Inventors: 张丽洁
Original assignee: Envision Power Technology Jiangsu Co Ltd; Envision Ruitai Power Technology Shanghai Co Ltd
Current assignee: Envision Power Technology Jiangsu Co Ltd; Envision Ruitai Power Technology Shanghai Co Ltd
Priority date: 2023-08-28
Filing date: 2023-08-28
Publication date: 2024-04-02
Anticipated expiration: 2033-08-28

Abstract

The utility model provides a lithium ion battery cell and a battery pack, wherein the battery cell comprises: the laminated body comprises a plurality of layers of positive plates, a plurality of layers of diaphragms and a plurality of layers of negative plates which are alternately laminated; the electrode lug comprises an anode lug and a cathode lug which are respectively connected with the anode plate and the cathode plate, wherein the electrode lug is provided with a first state and a second state, the electrode lug comprises a positioning area and an electrode lug area in the first state, the positioning area is provided with a positioning hole, and a plurality of layers of anode plates and a plurality of layers of cathode plates are respectively positioned through the positioning holes; in the second state, the tab includes only the tab region. The utility model can realize positioning the pole piece when the positive pole piece and the negative pole piece are stacked, prevent the pole piece from shifting, set a cutting mark between the positioning area and the pole ear area, cut and remove the positioning area along the cutting mark after welding the pole ear, so that the pole ear only comprises the pole ear area, thereby avoiding influencing the cell structure.

Description

Lithium ion battery cell and battery pack

Technical Field

The utility model belongs to the technical field of lithium batteries, and particularly relates to a lithium ion battery cell and a battery pack.

Background

The winding process and the lamination process are two production modes of the current bare cell of the lithium battery, and have the characteristics of the bare cell. As the application of the soft-pack battery in the power market increases, the solution of the winding process in the soft-pack power battery field tends to be mature, and the application of the winding process in the power soft-pack market is increased in the next two years. However, for the power battery, the lamination process can better control the yield of the battery core, the lamination process is more excellent in improving the battery performance and the energy density, but the bare battery core prepared by the lamination process has the risk of dislocation of the pole pieces because the edges of the pole pieces are not limited effectively and the lamination body is deviated.

Disclosure of Invention

In view of the above drawbacks of the prior art, the present utility model aims to provide a lithium ion battery cell and a battery pack, so as to improve the problem that the lamination body is offset and there is a risk of dislocation of the pole pieces due to no effective limit on the edge of the pole pieces of the existing bare battery cell prepared by lamination process.

To achieve the above and other related objects, the present utility model provides a lithium ion battery cell, comprising:

the laminated body comprises a plurality of layers of positive plates, a plurality of layers of diaphragms and a plurality of layers of negative plates which are alternately laminated;

the electrode lug comprises an anode lug and a cathode lug which are respectively connected with the anode plate and the cathode plate, wherein the electrode lug is provided with a first state and a second state, the electrode lug comprises a positioning area and an electrode lug area in the first state, the positioning area is provided with a positioning hole, and a plurality of layers of anode plates and a plurality of layers of cathode plates are respectively positioned through the positioning holes; in the second state, the tab includes only the tab region.

In one embodiment of the utility model, the positive tab and the negative tab are located at both ends of the laminate body.

In one embodiment of the present utility model, the thickness of the battery cell is D1, the width of the battery cell is W1, and the length of the battery cell is L1, wherein d1= (1% -10%) L1, w1= (10% -50%) L1.

In one embodiment of the utility model, the positive tab and the negative tab are located on top of the laminate body.

In one embodiment of the present utility model, the thickness of the cell is D2, the width of the cell is W2, and the length of the cell is L2, where d2= (10% -40%) L2, w2= (50% -90%) L2.

In one embodiment of the present utility model, a cutting mark for cutting off the positioning area in the second state is prefabricated between the positioning area and the tab area.

In one embodiment of the utility model, the distance between the cutting mark and the end of the tab away from the lamination body is less than 20% of the tab length.

In one embodiment of the utility model, the diameter of the positioning hole is set between 1mm and 5 mm.

In one embodiment of the utility model, the positioning hole is provided with a buckle, and the plurality of layers of positive plates and the plurality of layers of negative plates are respectively fixed through the buckle.

The utility model also provides a battery pack comprising the lithium ion battery cell according to any one of the above embodiments.

The utility model provides a lithium ion battery cell and a battery pack, wherein a tab is arranged to comprise a positioning area and a tab area, and a positioning hole is designed on the positioning area so as to position a tab when a positive electrode tab and a negative electrode tab are stacked and prevent the tab from shifting. In addition, set up the cutting mark between location area and utmost point ear district, cut out the removal with the location area along this cutting mark after the utmost point ear welding to make the utmost point ear only include utmost point ear district, thereby avoid producing the influence to electric core structure.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a battery cell according to an embodiment of the utility model.

Fig. 2 is a schematic structural diagram of a laminated body according to an embodiment of the present utility model.

Fig. 3 is a schematic structural diagram of a positive electrode sheet according to an embodiment of the utility model.

Fig. 4 is a schematic structural diagram of a negative plate according to an embodiment of the utility model.

Fig. 5 is an enlarged schematic view at a in fig. 2.

Fig. 6 is an enlarged schematic view at B in fig. 2.

Fig. 7 is a schematic diagram of the present utility model in a first state in an embodiment.

Fig. 8 is a schematic view illustrating tab welding according to an embodiment of the utility model.

Fig. 9 is a schematic diagram of the present utility model in a second state in an embodiment.

Fig. 10 is a schematic structural diagram of a battery cell according to another embodiment of the utility model.

Fig. 11 is a schematic structural view of a positive electrode sheet according to another embodiment of the present utility model.

Fig. 12 is a schematic structural view of a negative electrode sheet according to another embodiment of the present utility model.

Fig. 13 is a schematic view of the present utility model in a first state in another embodiment.

Fig. 14 is a schematic view illustrating tab welding according to another embodiment of the utility model.

Fig. 15 is a schematic view of the present utility model in a second state in another embodiment.

Fig. 16 is a schematic structural view of an annular buckle in an embodiment of the present utility model.

Fig. 17 is a schematic structural view of an annular buckle in another embodiment of the present utility model.

Description of the reference numerals:

100. a battery cell; 101. a housing; 10. stacking sheets; 102. a pole; 103. an explosion-proof valve; 11. a positive plate; 12. a diaphragm; 13. a negative electrode sheet; 21. a positive electrode tab; 22. a negative electrode ear; 201. a positioning area; 202. a tab region; 2011. positioning holes; 2012. a buckle; 203. cutting marks.

Detailed Description

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model.

It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present utility model by way of illustration, and only the components related to the present utility model are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complex.

Referring to fig. 1 to 15, the present utility model proposes a lithium ion battery cell and a battery pack to improve the problem that the lamination body is offset and there is a dislocation risk of the pole pieces due to the fact that the edge of the pole pieces is not limited effectively in the existing bare battery cell prepared by lamination process. The battery cell 100 comprises a shell 101, a laminated body 10 and a tab, wherein the laminated body 10 is installed in the shell 101, a pole column 102 and an explosion-proof valve 103 are arranged on the shell 101, the pole column 102 is electrically connected with the tab, the laminated body 10 comprises a plurality of layers of positive plates 11, a plurality of layers of diaphragms 12 and a plurality of layers of negative plates 13, and the positive plates 11, the diaphragms 12 and the negative plates 13 are alternately laminated together according to the sequence of the positive plates 11, the diaphragms 12, the negative plates 13, the diaphragms 12 and the positive plates 11. In some other embodiments, the explosion-proof valve 103 may be disposed on one side of the housing 101 where the pole 102 is disposed, i.e., the explosion-proof valve 103 and the pole 102 are located on the same side of the housing 101, although the explosion-proof valve 103 may also be disposed on other sides of the housing 101, i.e., the explosion-proof valve 103 and the pole 102 are located on different sides of the housing 101, such that the explosion-proof valve 103 and the pole 102 are separated so as to be in different planes to achieve thermoelectric separation.

Referring to fig. 1, in the present embodiment, the tab includes a positive tab 21 and a negative tab 22, and the positive tab 21 and the negative tab 22 are connected to the positive tab 11 and the negative tab 13, respectively. In this embodiment, the positive electrode tab 21 and the positive electrode tab 11 are integrally formed, the negative electrode tab 22 and the negative electrode tab 13 are integrally formed, and the connection between the positive electrode tab 21 and the positive electrode tab 11 and the connection between the negative electrode tab 22 and the negative electrode tab 13 are designed as chamfer angles, i.e. the connection between the positive electrode tab 21 and the positive electrode tab 11 and the connection between the negative electrode tab 22 and the negative electrode tab 13 are arc-shaped transitional connections, so as to avoid breakage or damage of the tab caused by stress concentration.

Referring to fig. 1 to 4 and fig. 10 to 12, in this embodiment, the positive electrode tab 21 and the negative electrode tab 22 may be disposed at opposite ends of the laminated body 10, that is, the tabs of the battery cell 100 are led out from two sides thereof; of course, the positive tab 21 and the negative tab 22 may be disposed on top of the laminated body 10, that is, the tabs of the battery cells 100 are led out from the top thereof. In this embodiment, the width W3 of the tab is set, for example, between 35mm and 45mm, preferably 40mm. In this embodiment, when the positive electrode tab 21 and the negative electrode tab 22 are located at opposite ends of the laminated body 10, the electrode posts 102 are located at opposite ends of the housing 101 to be electrically connected to the positive electrode tab 21 and the negative electrode tab 22, respectively, and the explosion-proof valve 103 is disposed at both ends of the housing 101 where the electrode posts 102 are disposed, and the thickness of the battery cell is D1, the width of the battery cell is W1, and the length of the battery cell is L1, wherein d1= (1% -10%) L1, w1= (10% -50%) L1; when the positive electrode tab 21 and the negative electrode tab 22 are located at the top of the laminated body 10, the electrode post 102 is located at the top of the casing 101, so as to be electrically connected with the positive electrode tab 21 and the negative electrode tab 22 respectively, and the explosion-proof valve 103 is located at the top of the casing 101, and the thickness of the battery cell is D2, the width of the battery cell is W2, the length of the battery cell is L2, wherein d2= (10% -40%) L2, w2= (50% -90%) L2, i.e., the whole battery cell is designed as a long and thin battery cell or a square and thin battery cell, so as to increase the heat dissipation performance of the battery cell and improve the safety capability of the battery cell.

Referring to fig. 1 to 17, in the present embodiment, the structures of the positive electrode tab 21 and the negative electrode tab 22 are identical, and the following embodiment is described by taking the positive electrode tab 21 as an example: the positive tab 21 is provided with a positioning area 201 and a tab area 202, the tab area 202 is connected with the positive tab 11, the positioning area 201 is located on one side of the tab area 202 away from the positive tab 11 and is in an integrated structure with the tab area 202, a positioning hole 2011 is formed in the positioning area 201, and when the positive tab 11, the diaphragm 12 and the negative tab 13 are alternately stacked, the positive tab 11 is positioned through the positioning hole 2011 in the positive tab 11, and the negative tab 13 is positioned through the positioning hole 2011 in the negative tab 13. Further, a buckle 2012 is further provided on the positioning hole 2011, when the positive electrode plate 11, the separator 12 and the negative electrode plate 13 are alternately stacked, the positive electrode plate 11 and the negative electrode plate 13 pass through the positioning holes 2011 and 2011 on the positioning holes 2011 and 22 on the positive electrode lug 21 respectively in sequence through the buckle 2012 to fix, thereby limiting the positive electrode plate 11 and the negative electrode plate 13 and preventing the stacked body from dislocation. In this embodiment, the latch 2012 is an annular latch.

Referring to fig. 5 and 6, in the present embodiment, a cutting mark 203 is disposed between the positioning area 201 and the tab area 202, and the cutting mark 203 is used for cutting the tab after welding to remove the positioning area 201, so that only the tab area 202 is reserved for the positive tab 21 and the negative tab 22, thereby avoiding influencing the cell structure. In this embodiment, the cutting mark 203 may be made by laser marking. In this embodiment, the distance H between the cutting mark 203 and the end of the positive tab 21 away from the positive tab 11 in the laminated body 10 is less than 20% of the length L3 of the positive tab 21, so as to avoid wasting materials. Further, the distance H between the cutting mark 203 and the end of the positive tab 21 away from the positive plate 11 is greater than the diameter of the positioning hole 2011, so as to avoid that the width of the positioning area 201 is too small to design the positioning hole 2011. The diameter of the positioning hole 2011 is set between 1mm and 5 mm.

Referring to fig. 7 to 8 and fig. 13 to 15, in this embodiment, the tab is designed with a first state and a second state, in the first state, the positive tab 21 on the positive tab 11 and the negative tab 22 in the negative tab 13 each include a positioning area 201 and a tab area 202, in the first state, multiple layers of the positive tab 11, multiple layers of the separator 12 and multiple layers of the negative tab 13 are stacked alternately in the order of the positive tab 11, the separator 12, the negative tab 13, the separator 12 and the positive tab 11, the positioning hole 2011 on the positive tab 21 and the negative tab 22 is fixed by a buckle 2012, i.e. the positive tab 21 and the negative tab 22 are fixed in advance, so as to avoid dislocation, then the multiple positive tabs 21 and the multiple negative tabs 22 in the laminated body 10 are respectively pre-welded, the welding areas are located on the tab area 202, finally the cut tabs 21 and the cut tabs 22 are cut out along the cutting edges 203 on the positive tab 21 and the negative tab 22, so as to avoid influence on the second tab 201 and the second battery cell to be in the second state, and the second battery cell is positioned in the second state, so that the battery cell is not affected.

Referring to fig. 1 to 15, the present utility model further provides a battery pack including the lithium ion battery cell described in the above embodiment, and the description thereof is omitted herein for avoiding repetition.

It should be appreciated that reference throughout this specification to "one embodiment," "an embodiment," or "a particular embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present utility model and not necessarily in all embodiments. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present utility model may be combined in any suitable manner with one or more other embodiments. It will be appreciated that other variations and modifications of the embodiments of the utility model described and illustrated herein are possible in light of the teachings herein and are to be considered as part of the spirit and scope of the utility model.

It will also be appreciated that one or more of the elements shown in the figures may also be implemented in a more separated or integrated manner, or even removed because of inoperability in certain circumstances or provided because it may be useful depending on the particular application.

The foregoing description is only illustrative of the preferred embodiments of the present application and the technical principles employed, and it should be understood by those skilled in the art that the scope of the present application is not limited to the specific combination of the above technical features, but encompasses other technical features which may be combined with any combination of the above technical features or their equivalents without departing from the inventive concept, such as the technical features disclosed in the present application (but not limited to) and the technical features having similar functions are substituted for each other.

Other technical features besides those described in the specification are known to those skilled in the art, and are not described herein in detail to highlight the innovative features of the present utility model.

Claims

1. A lithium ion cell, comprising:

2. The lithium ion cell of claim 1, wherein the positive tab and the negative tab are located at two ends of the laminate body.

3. The lithium-ion battery cell of claim 2, wherein the thickness of the battery cell is D1, the width of the battery cell is W1, and the length of the battery cell is L1, wherein d1= (1% -10%) L1, w1= (10% -50%) L1.

4. The lithium ion cell of claim 1, wherein the positive tab and the negative tab are located on top of the laminate body.

5. The lithium ion battery cell of claim 4, wherein the thickness of the battery cell is D2, the width of the battery cell is W2, and the length of the battery cell is L2, wherein d2= (10% -40%) L2, w2= (50% -90%) L2.

6. The lithium ion battery cell of claim 1, wherein a cutting mark for cutting out the positioning area in the second state is prefabricated between the positioning area and the tab area.

7. The lithium ion battery cell of claim 6, wherein a distance between the cut-out and an end of the tab remote from the stack of sheets is less than 20% of a length of the tab.

8. The lithium ion cell of claim 1, wherein the positioning hole is provided with a diameter between 1mm and 5 mm.

9. The lithium ion battery cell according to claim 1, wherein the positioning hole is provided with a buckle, and the plurality of positive electrode sheets and the plurality of negative electrode sheets are respectively fixed by the buckle.

10. A battery pack comprising a lithium-ion cell according to any one of claims 1 to 9.