Battery cell cover plate and battery cell

Abstract

The present application relates to the technical field of batteries, and in particular to a battery cell cover plate and a battery cell. The battery cell cover plate comprises: a riveting member, a riveting hole on the riveting member being provided with a first step portion and a second step portion, and the size d1 of the first step portion in the first direction is less than the size d2 of the second step portion in the first direction; and a pole, a riveting portion on the pole being riveted to the second step portion so as to form, on the side wall of the pole, a bulged portion protruding in a direction perpendicular to the second direction, the size of the riveting portion in the first direction being d3, and the ratio of the projection area of the bulged portion on the riveting member to the cross-sectional area of the riveting portion being S1 / S2=0.2-0.4, wherein S1=π(d2 2-d1 2) / 4, and S2=πd3 2 / 4. In the present invention, reliable riveting between a pole and a riveting member can be ensured, so that the riveting member can withstand a pulling force that meets the structural strength requirements of a battery cell cover plate, thereby avoiding abnormal flatness of the riveting member, improving the yield of the battery cell cover plate and a battery cell, and ensuring the use safety of the battery cell.

Description

Cell cover and cell

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202510180604.7, filed on February 19, 2025, entitled "Cell Cover and Cell", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a cell cover and a cell. Background Technology

[0004] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage, and the requirements for the performance and safety of lithium-ion batteries are becoming increasingly stringent.

[0005] The lithium battery cover is a key component in lithium-ion batteries. Its functions include welding with the casing to form a sealed cavity, leading out the positive and negative electrodes, and serving as an assembly carrier. Traditional covers consist of a riveting block, upper plastic, terminal posts, a top cover plate, lower plastic, and a sealing ring. The terminal posts pass through the sealing ring, lower plastic, top cover plate, and upper plastic, finally passing through the hole in the riveting block. The terminal posts are then riveted together, forcing the top of the post against the countersunk surface of the riveting block to complete the assembly. Insufficient material application from the terminal posts to the riveting block results in insufficient tensile strength, failing to meet the structural strength requirements of the cover. Conversely, excessive material application from the terminal posts to the riveting block leads to poor flatness of the assembled riveting block, affecting the appearance of the cover.

[0006] Public content

[0007] In view of this, the purpose of this application is to provide a cell cover and a cell to solve the problems of insufficient material extrusion from the pole to the rivet block in the existing cell cover assembly, which results in insufficient tensile strength of the rivet block and fails to meet the structural strength requirements of the cover, or excessive material extrusion from the pole to the rivet block, which results in poor flatness of the rivet block after assembly, thus affecting the appearance of the cell cover.

[0008] In a first aspect, this application provides a battery cell cover plate, wherein the battery cell cover plate comprises:

[0009] A riveting component having a riveting hole, the riveting hole being formed as a stepped structure having a first step portion and a second step portion, the first step portion having a dimension of d1 in a first direction, the second step portion having a dimension of d2 in a first direction, d1 < d2.

[0010] The pole post has riveting portions that extend sequentially into the first step portion and the second step portion. The riveting portions are riveted to the second step portion to form a material expansion portion protruding perpendicular to the second direction on the side wall of the pole post. Before riveting, the dimension of the riveting portions in the first direction is d3.

[0011] The projected area of ​​the expansion portion on the riveting member in the second direction is S1, and the cross-sectional area of ​​the riveting portion perpendicular to the second direction is S2, where S1 = π(d2) / 2. 2 -d1 2 ) / 4, S2=πd3 2 / 4, S1 / S2=0.2~0.4.

[0012] Beneficial effects: By limiting the ratio of the projected area of ​​the rising part in the second direction on the riveting part to the cross-sectional area of ​​the riveting part in the direction perpendicular to the second direction, the reliable riveting of the pole post and the riveting part is ensured, so that the riveting part can withstand the pull force that meets the structural strength requirements of the cell cover plate, and the abnormal flatness of the riveting part is avoided, thereby improving the yield of the cell cover plate and the cell, and ensuring the safety of the cell in use.

[0013] In some embodiments, the riveted portion is clearance-fitted with the first stepped portion.

[0014] In some embodiments, d1-d3 = 0.03mm ~ 0.15mm.

[0015] In some embodiments, the flatness of the side of the riveting member facing the outside of the battery cell is ≤0.25mm.

[0016] In some embodiments, the pull-out force F borne by the riveted member is ≥800N.

[0017] In some embodiments, the expansion portion is formed as a closed annular structure, wherein the inner and outer rings of the annular structure are coaxially arranged.

[0018] In some embodiments, the riveting hole further has a third stepped portion, the second stepped portion being disposed between the first stepped portion and the third stepped portion, and the dimension of the third stepped portion in a first direction being greater than the dimension of the second stepped portion in the first direction.

[0019] In some embodiments, the cell cover plate further includes:

[0020] The cover plate body has mounting holes for the pole post to pass through;

[0021] A first insulating element is sandwiched between the cover plate body and the riveting member, and a portion of the first insulating element covers the circumferential sidewall of the riveting member.

[0022] In some embodiments, the cell cover plate further includes:

[0023] A sealing element has a protruding base plate on the side of the electrode facing the inside of the cell. The sealing element is sandwiched between the base plate and the main body of the cover plate, and a portion of the sealing element extends into the mounting hole and the side wall of the electrode.

[0024] The second insulating element is disposed on the side of the cover plate body opposite to the first insulating element.

[0025] Secondly, this application provides a battery cell, including the battery cell cover plate described in any of the above technical solutions. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 is a schematic diagram of the structure of the battery cell cover plate provided in an embodiment of this application;

[0028] Figure 2 is an exploded view of the battery cell cover plate provided in an embodiment of this application;

[0029] Figure 3 is a structural schematic diagram of the cell cover plate provided in an embodiment of this application from another perspective;

[0030] Figure 4 is a cross-sectional view taken along point AA in Figure 3;

[0031] Figure 5 is a cross-sectional view of the riveting component in the battery cell cover provided in an embodiment of this application;

[0032] Figure 6 is a cross-sectional view of the electrode post in the cell cover provided in the embodiment of this application.

[0033] Icons: 10-Riveting part; 11-Riveting hole; 111-First step; 112-Second step; 113-Third step; 20-Pole post; 21-Riveting part; 22-Expansion part; 23-Base plate; 30-Cover plate body; 31-Mounting hole; 40-Sealing element; 51-First insulating element; 52-Second insulating element; D1-First direction; D2-Second direction. Embodiments of the present invention

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0035] In the description of this application, it should be understood that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of this application, "multiple" means two or more, and "at least one" can refer to one, two, or more, unless otherwise explicitly specified. The terms "first," "second," and "third," etc., are only for the convenience of description and are used to name parts or embodiments by number, and do not imply any order of importance between the parts or embodiments.

[0036] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0037] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0038] According to a first aspect of the present invention, a battery cell cover plate is provided, which specifically includes a riveting member 10 and a terminal post 20.

[0039] The specific structure of the cell cover plate according to this embodiment will be described below.

[0040] In this embodiment, as shown in Figures 1 to 6, the riveting member 10 is formed as a block structure, such as a rectangular or circular block structure. The riveting member 10 has a riveting hole 11, which is a through hole structure that penetrates the main body of the riveting member 10. Specifically, the riveting hole 11 is formed as a stepped structure with a first step portion 111 and a second step portion 112. The first step portion 111 has a dimension of d1 in the first direction D1, and the second step portion 112 has a dimension of d2 in the first direction D1, where d1 < d2.

[0041] The pole post 20 has riveting portions 21 that extend sequentially into the first step portion 111 and the second step portion 112. The riveting portions 21 are riveted to the second step portion 112 to form a material expansion portion 22 protruding perpendicular to the second direction D2 (i.e., protruding outward along the direction perpendicular to the central axis of the pole post 20) on the side wall of the pole post 20. That is, the riveting process reduces the height dimension of the riveting portion 21 in the second direction D2 to squeeze material into the circumferential side wall of the riveting portion 21, thereby forming the protruding material expansion portion 22. Before riveting, the dimension of the riveting portion 21 in the first direction D1 is d3; the projected area of ​​the material expansion portion 22 on the riveting member 10 in the second direction D2 is S1, and the cross-sectional area of ​​the riveting portion 21 in the direction perpendicular to the second direction D2 is S2, where S1 = π(d2) / 2. 2 -d1 2 ) / 4, S2=πd3 2 / 4, under the condition of S1 / S2=0.2~0.4, the riveting of the rivet 10 and the pole post 20 can be reliably riveted, so that the rivet 10 can withstand the pull force that meets the structural strength requirements of the cell cover plate, and avoid the abnormal flatness of the rivet 10, thereby improving the yield of the cell cover plate and the cell.

[0042] Preferably, the flatness of the side of the riveting member 10 facing the outside of the battery cell is ≤0.25mm, thus meeting the appearance requirements of the battery cell cover. In a preferred embodiment, the pull-out force F borne by the riveting member 10 is ≥800N, thus meeting the structural strength requirements of the battery cell cover.

[0043] The following tests were conducted under the condition that S1 / S2 = 0.2~0.4 to verify that the riveted part 10 can withstand the pull-out force of the battery cell cover and avoid abnormal flatness of the riveted part 10 under this condition. The test results are shown in Test 1 to Test 3 below.

[0044] Experiment 1: d1=6.1, d3=6. By setting different d2 dimensions, the expansion area of ​​the riveting part 21 in the second step part 112 was adjusted to conduct multiple tests. The assembled riveted part 10 was tested for the pull-out force it could withstand and its flatness. The test results are shown in Table 1 below:

[0045] Table 1

[0046]

[0047] Experiment 2: d1=7.1, d3=7. By setting different d2 dimensions, the expansion area of ​​the riveting part 21 in the second step part 112 was adjusted to conduct multiple tests. The assembled riveted part 10 was tested for the pull-out force it could withstand and its flatness. The test results are shown in Table 2 below:

[0048] Table 2

[0049]

[0050] Experiment 3: d1=7.6, d3=7.5. By setting different d2 dimensions, the expansion area of ​​the riveting part 21 in the second step part 112 was adjusted to conduct multiple tests. The assembled riveted part 10 was tested for the pull-out force it could withstand and its flatness. The test results are shown in Table 3 below:

[0051] Table 3

[0052]

[0053] Referring to Tables 1 to 3 above, in Examples 1-4 to 1-9, Examples 2-3 to 2-8, and Examples 3-4 to 3-9, S1 / S2 is within the limiting range of 0.2 to 0.4. The pull-out force F of the riveting part 10 is greater than 800N and the flatness of the riveting part 10 is less than 0.25mm. Therefore, the limiting condition of S1 / S2 = 0.2 to 0.4 can ensure that the riveting part 10 can withstand the pull-out force required for the battery cell cover and avoid abnormal flatness of the riveting part 10. However, in Examples 1-1 to 1-3, Examples 2-1 and 2-2, and Examples 3-1 to 3-3, S1 / S2 is less than 0.2, which means that the riveting part 10 can withstand a pull force of less than 800N to meet the structural strength requirements of the battery cell cover. In embodiments 1-10 to 1-12, 2-9 to 2-12 and 3-10 to 3-12, S1 / S2 is greater than 0.4, which means that the flatness of the riveting part 10 is greater than 0.25mm. Poor flatness affects the appearance of the battery cell cover.

[0054] Furthermore, in this embodiment, the riveting part 21 and the first stepped part 111 are fitted with a clearance. Preferably, d1-d3=0.03mm~0.15mm, thus ensuring that the riveting part 21 passes smoothly through the riveting hole 11.

[0055] In this embodiment, as shown in FIG6, the expansion part 22 is formed as a closed ring structure. The inner ring and the outer ring of the ring structure are coaxially arranged, so that the distance between the inner ring and the outer ring of the expansion part 22 in the circumferential direction is equal. This ensures that the riveting connection between the riveting part 10 and the pole post 20 is uniformly stressed, thereby improving the assembly reliability between the riveting part 10 and the pole post 20.

[0056] In this embodiment, as shown in FIG5, the riveting hole 11 also has a third step portion 113, and a second step portion 112 is disposed between the first step portion 111 and the third step portion 113. The dimension of the third step portion 113 in the first direction D1 is larger than the dimension of the second step portion 112 in the first direction D1. This makes the dimensions of the first step portion 111, the second step portion 112 and the third step portion 113 increase sequentially in the first direction D1, thereby providing more space for riveting the riveting member 10 and the pole post 20, which is beneficial to improving the flatness of the riveting member 10.

[0057] Furthermore, in this embodiment, as shown in Figures 1 to 4, the cell cover plate also includes a cover plate body 30 and a first insulating member 51. The cover plate body 30 is formed as a rectangular or circular sheet structure, and the cover plate body 30 has a mounting hole 31 for the electrode post 20 to pass through. The first insulating member 51 is sandwiched between the cover plate body 30 and the riveting member 10. Part of the first insulating member 51 covers the side wall of the riveting member 10 in the circumferential direction. In addition, part of the first insulating member 51 extends into the space between the cover plate body 30 and the electrode post 20 to separate the electrode post 20 and the cover plate body 30, thereby ensuring the insulation of the cover plate body 30.

[0058] In this embodiment, the first direction D1 is perpendicular to the second direction D2; the second direction D2 is the axial direction of the pole post 20, i.e. the thickness direction of the cover plate body 30. When the cover plate body 30 is rectangular, the first direction D1 can be the length direction of the cover plate body 30.

[0059] Furthermore, in this embodiment, as shown in Figures 1 to 4, the cell cover also includes a sealing element 40 and a second insulating element 52. The sealing element 40 can be an elastic sealing ring, and it covers part of the circumferential sidewall of the electrode post 20. The side of the electrode post 20 facing the inside of the cell has a protruding bottom plate 23. The sealing element 40 is sandwiched between the bottom plate 23 and the cover body 30, and part of the sealing element 40 extends between the mounting hole 31 and the sidewall of the electrode post 20 to improve the assembly sealing between the cover body 30 and the electrode post 20. The second insulating element 52 is disposed on the side of the cover body 30 away from the first insulating element 51, and part of it extends between the bottom plate 23 and the cover body 30 to form insulation protection on the other side of the cover body 30. Both the first insulating element 51 and the second insulating element 52 can be made of plastic material. In this embodiment, the first insulating element 51 is disposed on the side of the cell cover facing the outside of the cell, and the second insulating element 52 is disposed on the side of the cell cover facing the outside of the cell.

[0060] According to the present invention, a battery cell cover plate has a riveting hole on a riveting member formed into a stepped structure having a first stepped portion and a second stepped portion. The first stepped portion has a dimension of d1 in a first direction, and the second stepped portion has a dimension of d2 in the first direction, where d1 < d2. A terminal post has riveting portions that sequentially extend into the first stepped portion and the second stepped portion. The riveting portions are riveted to the second stepped portion to form an outwardly protruding expansion portion on the sidewall of the terminal post. The dimension of the riveting portion in the first direction is d3. The ratio of the projected area of ​​the expansion portion in the second direction on the riveting member to the cross-sectional area of ​​the riveting portion perpendicular to the second direction is defined as S1 / S2 = 0.2~0.4, where S1 = π(d2 / d2). 2 -d1 2 ) / 4, S2=πd3 2 / 4, ensuring reliable riveting between the riveting parts and the pole post, enabling the riveting parts to withstand the pull-out force required to meet the structural strength requirements of the cell cover plate, and avoiding abnormal flatness of the riveting parts, thereby improving the yield rate of the cell cover plate.

[0061] According to the present invention, a battery cell includes a battery cell cover as described above. The riveting component can withstand the pull-out force that meets the structural strength requirements of the battery cell cover and avoids abnormal flatness of the riveting component, thereby improving the yield of the battery cell cover and the battery cell and ensuring the safety of the battery cell in use.

[0062] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims. Industrial applicability

[0063] The battery cell cover provided in this application has a riveting hole on the riveting member formed into a stepped structure with a first step and a second step. The dimension of the first step in the first direction is d1, and the dimension of the second step in the first direction is d2, where d1 < d2. The electrode post has a riveting part that extends sequentially into the first step and the second step. The riveting part is riveted to the second step to form an outwardly protruding expansion part on the side wall of the electrode post. The dimension of the riveting part in the first direction is d3. The ratio of the projected area of ​​the expansion part in the second direction on the riveting member to the cross-sectional area of ​​the riveting part perpendicular to the second direction is defined as S1 / S2 = 0.2~0.4, where S1 = π(d2 / d2). 2 -d1 2 ) / 4, S2=πd3 2 / 4, ensuring reliable riveting between the pole and the riveting component, enabling the riveting component to withstand the pull-out force required to meet the structural strength requirements of the cell cover plate, and avoiding abnormal flatness of the riveting component, thereby improving the yield rate of the cell cover plate and the cell, and ensuring the safety of the cell in use.

Claims

1. An electrode cover plate, characterized by, The electric cell cover plate comprises: a riveting piece formed with a riveting hole, the riveting hole is formed in a stepped structure with a first step portion and a second step portion, the first step portion has a size d1 in the first direction, the second step portion has a size d2 in the first direction, d1 < d2; a pole formed with a riveting portion sequentially extending into the first step portion and the second step portion, the riveting portion is riveted with the second step portion to form a bulging portion on the side wall of the pole, the size of the riveting portion in the first direction before riveting is d3; The projected area of the swelling part on the riveting part in the second direction is S1, the cross-sectional area of the riveting part perpendicular to the second direction is S2, S1=π(d2 2 -d1 2 ) / 4, S2=πd3 2 / 4, S1 / S2=0.2~0.

4.

2. The cell cover plate of claim 1, wherein, the riveting portion is clearance fit with the first step portion.

3. The cell cover plate of claim 2, wherein, d1-d3=0.03mm ~0.15mm.

4. The cell cover plate of claim 1, wherein, the flatness of the side of the riveting piece facing the outside of the electric cell is ≤0.25mm.

5. The cell cover plate of claim 1, wherein, the pulling force F borne by the riveting piece is ≥800N.

6. The cell cover plate of claim 1, wherein, the bulging portion is formed in a closed ring structure, the inner ring and the outer ring of the ring structure are coaxially arranged.

7. The cell cover plate of claim 1, wherein, the riveting hole further has a third step portion, the second step portion is arranged between the first step portion and the third step portion, the size of the third step portion in the first direction is greater than the size of the second step portion in the first direction.

8. The cell cover plate of claim 1, wherein, The electric cell cover plate further comprises: a cover plate body formed with a mounting hole for the pole to pass through; a first insulating piece clamped between the cover plate body and the riveting piece, part of the first insulating piece is wrapped around the side wall of the riveting piece in the circumferential direction.

9. The cell cover plate of claim 8, wherein, The electric cell cover plate further comprises: a sealing piece, the side of the pole facing the inside of the electric cell has a protruding bottom plate, the sealing piece is clamped between the bottom plate and the cover plate body, part of the sealing piece extends between the mounting hole and the side wall of the pole; a second insulating piece arranged on the side of the cover plate body away from the first insulating piece.

10. An electric cell characterized by The electric cell cover plate comprises: the electric cell cover plate comprises: the electric cell cover plate comprises: the electric cell cover plate comprises:

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