Battery cover and battery

Abstract

The present invention relates to the technical field of batteries, and in particular to a cell cover plate and a cell. The cell cover plate includes: the riveting hole on the riveting part has a first step portion and a second step portion, and the dimension d1 of the first step portion in the first direction is smaller than the dimension d2 of the second step portion in the first direction; the riveting part on the pole column is riveted to the second step portion to form a bulging part protruding perpendicular to the second direction on the side wall of the pole column, and the dimension of the riveting part in the first direction is d3; the ratio of the projected area of the bulging part on the riveting part to the cross-sectional area of the riveting part is S1 / S2 = 0.2~0.4, S1 = π(d2 2 -d1 2 ) / 4, S2 = πd3 2 / 4. The present invention can ensure reliable riveting between the pole column and the riveting part, enable the riveting part to withstand the pulling force meeting the structural strength requirements of the cell cover plate, avoid the abnormal flatness of the riveting part, thereby improving the yield rate of the cell cover plate and the cell, and ensuring the safe use of the cell.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery cover and a battery. Background Art

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields, and the requirements for the performance and safety of lithium-ion batteries are increasing.

[0003] The lithium battery cover is a key component in lithium-ion batteries. Its functions are to weld with the shell to form a sealed cavity, lead out the positive and negative electrodes of the electrode group, and serve as an assembly carrier. The traditional cover includes a rivet block, an upper plastic, a pole, a top cover sheet, a lower plastic, a sealing ring and other structures. The pole passes through the sealing ring, the lower plastic, the top cover sheet, the upper plastic, and finally through the rivet block hole. The pole is riveted so that the top of the pole is squeezed toward the sink of the rivet block to complete the assembly. Insufficient material extruded from the pole to the rivet block results in insufficient tensile force on the rivet block, which does not meet the structural strength requirements of the cover, or too much material from the pole to the rivet block results in poor flatness of the assembled rivet block, affecting the appearance of the cover. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a battery cell cover and a battery cell to solve the problem that the riveted assembly of the rivet block and the pole on the existing battery cell cover is insufficient in the material extruded from the pole to the rivet block, resulting in insufficient tensile force on the rivet block, which does not meet the structural strength requirements of the cover, or too much material is extruded from the pole to the rivet block, resulting in poor flatness of the rivet block after assembly, thereby affecting the appearance of the battery cell cover.

[0005] A first aspect of the present invention provides a cell cover, wherein the cell cover comprises:

[0006] A rivet part is formed with a rivet hole, wherein the rivet hole is formed into a stepped structure having a first step portion and a second step portion, wherein the dimension of the first step portion in the first direction is d 1 , the dimension of the second step portion in the first direction is d 2 , d 1 <d 2 ;

[0007] The pole is formed with a riveted portion that sequentially extends into the first step portion and the second step portion, the riveted portion is riveted with the second step portion to form a bulging portion protruding perpendicular to the second direction on the side wall of the pole, and the dimension of the riveted portion in the first direction before riveting is d 3 ;

[0008] The projection area of ​​the swelling portion on the riveted part in the second direction is S1, and the cross-sectional area of ​​the riveted portion perpendicular to the second direction is S2, S1=π(d2 2 -d 1 2 ) / 4,S2=πd 3 2 / 4, S1 / S2=0.2~0.4.

[0009] Preferably, the riveted portion is clearance-fitted with the first step portion.

[0010] Preferably, d 1 -d 3 =0.03mm ~0.15mm.

[0011] Preferably, the flatness of a side of the rivet facing the outside of the battery core is ≤0.25 mm.

[0012] Preferably, the pull-out force F ≥ 800N borne by the rivet.

[0013] Preferably, the expanding portion is formed as a closed annular structure, and the inner ring and outer ring of the annular structure are coaxially arranged.

[0014] Preferably, the rivet hole further has a third step portion, the second step portion is arranged between the first step portion and the third step portion, and a dimension of the third step portion in the first direction is greater than a dimension of the second step portion in the first direction.

[0015] Preferably, the cell cover plate further comprises:

[0016] The cover plate body is formed with a mounting hole for the pole to pass through;

[0017] The first insulating member is sandwiched between the cover plate body and the riveted member, and a portion of the first insulating member covers the side wall of the riveted member in the circumferential direction.

[0018] Preferably, the cell cover plate further comprises:

[0019] A sealing member, wherein the side of the pole facing the inside of the battery cell has a protruding bottom plate, the sealing member is sandwiched between the bottom plate and the cover plate body, and a portion of the sealing member extends between the mounting hole and the side wall of the pole;

[0020] The second insulating member is arranged on a side of the cover plate body facing away from the first insulating member.

[0021] A second aspect of the present invention provides a battery cell, comprising the battery cell cover plate described in any of the above technical solutions.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The cell cover of the present invention has a rivet hole on the rivet piece formed into a stepped structure having a first step portion and a second step portion, and the dimension of the first step portion in the first direction is d 1 The dimension of the second step portion in the first direction is d 2 , d 1 <d 2 The pole is formed with a riveted portion that sequentially extends into the first step portion and the second step portion, the riveted portion is riveted with the second step portion to form an outwardly protruding material portion on the side wall of the pole, and the dimension of the riveted portion in the first direction is d 3 ; By limiting the ratio of the projection area of ​​the rising part on the riveted part in the second direction to the cross-sectional area of ​​the riveted part perpendicular to the second direction, that is, S1 / S2=0.2~0.4, S1=π(d 2 2 -d 1 2 ) / 4,S2=πd 3 2 / 4, ensure reliable riveting between the pole and the rivet, so that the rivet can withstand the pulling force that meets the structural strength requirements of the battery cover, and avoid abnormal flatness of the rivet, thereby improving the yield rate of the battery cover and the battery, and ensuring the safety of the battery.

[0024] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A schematic diagram of the structure of a cell cover plate provided in an embodiment of the present invention;

[0027] Figure 2 An exploded view of the structure of a cell cover provided by an embodiment of the present invention;

[0028] Figure 3 A schematic structural diagram of a cell cover provided by an embodiment of the present invention from another perspective;

[0029] Figure 4 For along Figure 3 The cross-section taken at AA in the middle;

[0030] Figure 5A structural cross-sectional view of a riveted part in a cell cover provided by an embodiment of the present invention;

[0031] Figure 6 A structural cross-sectional view of a pole in a cell cover provided by an embodiment of the present invention.

[0032] Icons: 10- rivet; 11- rivet hole; 111- first step portion; 112- second step portion; 113- third step portion; 20- pole; 21- rivet portion; 22- expansion portion; 23- bottom plate; 30- cover plate body; 31- mounting hole; 40- seal; 51- first insulating member; 52- second insulating member; D1- first direction; D2- second direction. DETAILED DESCRIPTION

[0033] The following specific embodiments are provided to help the reader obtain a comprehensive understanding of the methods, devices and / or systems described herein. However, after understanding the disclosure of the present application, various changes, modifications and equivalents of the methods, devices and / or systems described herein will be apparent. For example, the order of operations described herein is merely an example, and is not limited to the order set forth herein, but in addition to the operations that must occur in a particular order, changes that will be apparent after understanding the disclosure of the present application may be made. In addition, in order to improve clarity and brevity, descriptions of features known in the art may be omitted.

[0034] The features described herein may be implemented in different forms and should not be interpreted as being limited to the examples described herein. Rather, the examples described herein have been provided only to illustrate some of the many possible ways of implementing the methods, devices and / or systems described herein that will be apparent after understanding the disclosure of the present application.

[0035] Throughout the specification, when an element (such as a layer, a region, or a substrate) is described as being “on”, “connected to”, “bound to”, “over”, or “covering” another element, it may be directly “on”, “connected to”, “bound to”, “over”, or “covering” another element, or one or more other elements may be present between them. In contrast, when an element is described as being “directly on”, “directly connected to”, “directly bound to”, “directly over”, or “directly covering” another element, there may be no other elements present between them.

[0036] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0037] Although terms such as "first," "second," and "third" may be used herein to describe various members, components, regions, layers, or portions, these members, components, regions, layers, or portions are not limited by these terms. Rather, these terms are used only to distinguish one member, component, region, layer, or portion from another member, component, region, layer, or portion. Therefore, without departing from the teachings of the examples described herein, the first member, component, region, layer, or portion referred to may also be referred to as the second member, component, region, layer, or portion.

[0038] For ease of description, spatial relational terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another element as shown in the accompanying drawings. Such spatial relational terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. For example, if the device in the accompanying drawings is turned over, an element described as being "above" or "upper" relative to another element will subsequently be "below" or "lower" relative to the other element. Therefore, the term "above" includes both "above" and "below" orientations depending on the spatial orientation of the device. The device may also be positioned in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relational terms used herein will be interpreted accordingly.

[0039] The terms used herein are only used to describe various examples and are not used to limit the present disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms "include", "comprise" and "have" list the stated features, quantities, operations, components, elements and / or their combinations that exist, but do not exclude the existence or addition of one or more other features, quantities, operations, components, elements and / or their combinations.

[0040] Variations in the shapes shown in the 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 drawings but include variations in shapes that occur during manufacturing.

[0041] The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of the present application. In addition, although the examples described herein have various configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0042] According to a first aspect of the present invention, a cell cover is provided, which specifically includes a rivet 10 and a pole 20 .

[0043] Hereinafter, the specific structure of the cell cover plate as described above according to this embodiment will be described.

[0044] In this embodiment, if Figures 1 to 6 As shown, the rivet 10 is formed into a block structure, such as a rectangular or circular block structure, and the rivet 10 is formed with a rivet hole 11, which is a through hole structure that penetrates the main body of the rivet 10. Specifically, the rivet hole 11 is formed into a stepped structure having a first step portion 111 and a second step portion 112, wherein the size of the first step portion 111 in the first direction D1 is d 1 The dimension of the second step portion 112 in the first direction D1 is d 2 , d 1 <d 2 .

[0045] The pole 20 is formed with a riveted portion 21 that sequentially extends into the first step portion 111 and the second step portion 112. The riveted portion 21 is riveted with the second step portion 112 to form a bulging portion 22 that protrudes perpendicularly to the second direction D2 (i.e., protrudes outward in a direction perpendicular to the central axis of the pole 20) on the side wall of the pole 20. That is, the riveting process reduces the height dimension of the riveted portion 21 in the second direction D2 to squeeze material toward the circumferential side wall of the riveted portion 21, thereby forming a bulging portion 22. Before riveting, the dimension of the riveted portion 21 in the first direction D1 is d 3 The projection area of ​​the rising material portion 22 on the rivet 10 in the second direction D2 is S1, and the cross-sectional area of ​​the rivet portion 21 perpendicular to the second direction D2 is S2, S1=π(d 2 2 -d 1 2 ) / 4,S2=πd 3 2 / 4, under the condition of S1 / S2=0.2~0.4, the rivet 10 and the pole 20 can be reliably riveted, so that the rivet 10 can withstand the pulling force that meets the structural strength requirements of the battery cover and avoid the abnormal flatness of the rivet 10, thereby improving the yield rate of the battery cover and the battery.

[0046] Preferably, the flatness of the side of the rivet 10 facing the outside of the battery cell is ≤0.25 mm, thus meeting the appearance setting requirements of the battery cover. In a preferred embodiment, the pull-out force F ≥ 800N of the rivet 10 meets the structural strength requirements of the battery cover.

[0047] The following test is conducted on the limiting condition of S1 / S2=0.2~0.4 to verify that under this limiting condition, the rivet 10 can withstand the pull-out force of the battery cover and avoid the abnormal flatness of the rivet 10. The test results are shown in the following tests 1 to 3.

[0048] Test 1: d 1 =6.1, d 3 =6, by setting different d 2 The size of the riveted part 21 is adjusted in the second step part 112 to carry out multiple tests, and the assembled riveted part 10 is tested for the pull-out force and flatness that it can withstand. The test results are shown in Table 1 below:

[0049] Table 1

[0050]

[0051] Test 2: d 1 =7.1, d 3 =7, by setting different d 2 The size of the riveted part 21 is adjusted in the second step part 112 to carry out multiple tests, and the assembled riveted part 10 is tested for the pull-out force and flatness that it can withstand. The test results are shown in Table 2 below:

[0052] Table 2

[0053]

[0054] Test 3: d 1 =7.6, d 3 =7.5, by setting different d 2 The size of the rivet 21 is adjusted in the second step 112 to carry out multiple tests, and the assembled rivet 10 is tested for the pull-out force and flatness that it can withstand. The test results are shown in Table 3 below:

[0055] Table 3

[0056]

[0057] Referring to Tables 1 to 3 above, it can be seen that in Examples 1-4 to 1-9, Examples 2-3 to 2-8, and Examples 3-4 to 3-9, S1 / S2 are all within the limiting condition range of 0.2~0.4, the parameters of the pull-out force F of the rivet 10 are all greater than 800N and the flatness of the rivet 10 is less than 0.25mm, so the limiting condition of S1 / S2=0.2~0.4 can be ensured so that the rivet 10 can withstand the pull-out force that satisfies the battery cover and avoid the situation where the flatness of the rivet 10 is abnormal; and in Examples 1-1 to 1-3, Examples 2-1 and 2-2, and Examples 3-1 to 3-3, S1 / S2 S2 is less than 0.2, resulting in the rivet 10 being able to withstand a pull-out force of less than 800N to meet the cell cover, and thus failing to meet the structural strength requirements of the cell cover; whereas in Examples 1-10 to 1-12, 2-9 to 2-12, and 3-10 to 3-12, S1 / S2 is greater than 0.4, resulting in the flatness of the rivet 10 being greater than 0.25mm, and poor flatness affects the appearance of the cell cover.

[0058] Furthermore, in this embodiment, the riveted portion 21 is clearance-matched with the first step portion 111. 1 -d 3 =0.03mm ~0.15mm, thus ensuring that the riveted portion 21 passes through the riveted hole 11 smoothly.

[0059] In this embodiment, if Figure 6 As shown, the expansion portion 22 is formed into a closed annular structure, and the inner ring and outer ring of the annular structure are coaxially arranged, so that the distance between the inner ring and the outer ring of the expansion portion 22 at each location in the circumferential direction is equal, thereby ensuring that the riveted connection between the rivet 10 and the pole 20 is evenly stressed, thereby improving the assembly reliability between the rivet 10 and the pole 20.

[0060] In this embodiment, if Figure 5 As shown, the riveting hole 11 also has a third step portion 113, the second step portion 112 is arranged between the first step portion 111 and the third step portion 113, and the size of the third step portion 113 in the first direction D1 is greater than the size of the second step portion 112 in the first direction D1, so that the sizes of the first step portion 111, the second step portion 112 and the third step portion 113 in the first direction D1 increase sequentially, thereby providing more space for riveting the rivet 10 and the pole 20, which is beneficial to improving the flatness of the rivet 10.

[0061] In addition, in this embodiment, if Figures 1 to 4As shown, the cell cover also includes a cover body 30 and a first insulating member 51. The cover body 30 is formed into a rectangular or circular sheet structure, and the cover body 30 is formed with a mounting hole 31 for the pole 20 to pass through; the first insulating member 51 is clamped between the cover body 30 and the rivet 10, and part of the first insulating member 51 is covered on the side wall of the rivet 10 in the circumferential direction. In addition, part of the first insulating member 51 extends between the cover body 30 and the pole 20 to separate the pole 20 and the cover body 30, thereby ensuring the insulation of the cover body 30.

[0062] 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 20 , that is, the thickness direction of the cover body 30 . When the cover body 30 is rectangular, the first direction D1 may be the length direction of the cover body 30 .

[0063] In addition, in this embodiment, if Figures 1 to 4 As shown, the cell cover also includes a seal 40 and a second insulating member 52. The seal 40 can be an elastic sealing ring. The seal 40 is coated on the circumferential side wall of part of the pole 20. The pole 20 has a protruding bottom plate 23 on the side facing the inside of the cell. The seal 40 is sandwiched between the bottom plate 23 and the cover body 30. Part of the seal 40 extends between the mounting hole 31 and the side wall of the pole 20 to improve the assembly sealing of the cover body 30 and the pole 20. The second insulating member 52 is arranged on the side of the cover body 30 facing away from the first insulating member 51, and part of the second extends between the bottom plate 23 and the cover body 30 to form insulation protection on the other side of the cover body 30. The first insulating member 51 and the second insulating member 52 can be formed of plastic materials. In this embodiment, the first insulating member 51 is arranged on the side of the cell cover facing the outside of the cell, and the second insulating member 52 is arranged on the side of the cell cover facing the outside of the cell.

[0064] According to a cell cover provided by the present invention, the rivet hole on the rivet is formed into a stepped structure having a first step portion and a second step portion, and the dimension of the first step portion in the first direction is d 1 The dimension of the second step portion in the first direction is d 2 , d 1 <d 2 The pole is formed with a riveted portion that sequentially extends into the first step portion and the second step portion, the riveted portion is riveted with the second step portion to form an outwardly protruding material portion on the side wall of the pole, and the dimension of the riveted portion in the first direction is d 3 ; By limiting the ratio of the projection area of ​​the rising part on the riveted part in the second direction to the cross-sectional area of ​​the riveted part perpendicular to the second direction, that is, S1 / S2=0.2~0.4, S1=π(d 2 2 -d 12 ) / 4,S2=πd 3 2 / 4, ensure reliable riveting between the rivet and the pole, so that the rivet can withstand the pulling force that meets the structural strength requirements of the battery cover, and avoid abnormal flatness of the rivet, thereby improving the yield rate of the battery cover.

[0065] A battery cell provided by the present invention includes the battery cell cover as described above. The rivet parts can withstand the pulling force that meets the structural strength requirements of the battery cell cover and avoid abnormal flatness of the rivet parts, thereby improving the yield of the battery cell cover and the battery cell and ensuring the safety of the battery cell.

[0066] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-described embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-described embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A battery cell cover, characterized in that: The battery cover plate comprises: A rivet part is formed with a rivet hole, wherein the rivet hole is formed into a stepped structure having a first step portion and a second step portion, wherein the first step portion has a size d1 in the first direction, and the second step portion has a size d2 in the first direction, and d1<d2; A pole, formed with a riveted portion extending into the first step portion and the second step portion in sequence, the riveted portion and the second step portion are riveted to form a bulging portion protruding perpendicular to the second direction on the side wall of the pole, and the dimension of the riveted portion in the first direction before riveting is d3; The projection area of ​​the swelling portion on the riveted part in the second direction is S1, and the cross-sectional area of ​​the riveted portion perpendicular to the second direction is S2, S1=π(d2 2 -d1 2 ) / 4,S2=πd3 2 / 4, S1 / S2=0.2~0.4; The riveted portion and the first step portion are clearance-matched; d1-d3=0.03mm~0.15mm.

2. The cell cover plate according to claim 1, characterized in that: The flatness of the side of the rivet facing the outside of the battery core is ≤0.25 mm.

3. The cell cover plate according to claim 1, characterized in that: The pull-out force F ≥ 800N borne by the riveted part.

4. The cell cover plate according to claim 1, characterized in that: The swelling portion is formed into a closed annular structure, and the inner ring and the outer ring of the annular structure are coaxially arranged.

5. The cell cover plate according to claim 1, characterized in that: The rivet hole further has a third step portion, the second step portion is disposed between the first step portion and the third step portion, and a dimension of the third step portion in the first direction is greater than a dimension of the second step portion in the first direction.

6. The cell cover plate according to claim 1, characterized in that: The battery cover plate also includes: The cover plate body is formed with a mounting hole for the pole to pass through; The first insulating member is sandwiched between the cover plate body and the riveted member, and a portion of the first insulating member covers the side wall of the riveted member in the circumferential direction.

7. The cell cover plate according to claim 6, characterized in that: The battery cover plate also includes: A sealing member, wherein the side of the pole facing the inside of the battery cell has a protruding bottom plate, the sealing member is sandwiched between the bottom plate and the cover plate body, and a portion of the sealing member extends between the mounting hole and the side wall of the pole; The second insulating member is arranged on a side of the cover plate body facing away from the first insulating member.

8. A battery cell, characterized in that: The invention comprises a battery cell cover as described in any one of claims 1 to 7.

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