Battery cell cover plate and battery cell

Abstract

The invention relates to the technical field of batteries, in particular to a battery cell cover plate and a battery cell. The battery cell cover plate comprises a pole assembled on a cover plate main body; the first insulating part and the second insulating part are arranged on the two sides of the cover plate body in the thickness direction. The sealing piece is arranged on the pole in a sleeving manner, a first convex part on the sealing piece is clamped between the circumferential side wall of the pole and the hole wall of the mounting hole, a second convex part is clamped between the cover plate main body and the pole, part of the first insulating piece extends into a groove between the first convex part and the second convex part, and the second convex part is compressed by the pole and the cover plate main body; the amount of compression of the second protrusion n3 = (H3-h3) / H3, 20% < = n3 < = 40%. According to the invention, the cover plate main body, the first insulating part and the second insulating part are used for simultaneously applying pressure to the sealing part, so that effective compression of the sealing part is realized, and the condition of electrolyte leakage or seepage after the battery cell is assembled is avoided, thereby improving the use safety of the battery cell while ensuring the performance of the battery cell.

Description

Technical Field

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

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries, as power batteries, are widely used in electric vehicles and energy storage fields, and the requirements for the use performance and safety of lithium-ion batteries are increasing day by day. A lithium-ion battery includes a cover plate, a housing, and an electrode assembly. The cover plate and the housing are connected by laser welding to form a sealed space that protects the electrode assembly and has a certain strength. Traditional cover plates include structures such as riveting blocks, upper plastics, electrode posts, top cover sheets, lower plastics, sealing rings, etc. The electrode posts pass through the sealing rings, lower plastics, top cover sheets, upper plastics respectively, and finally pass through the holes of the riveting blocks, and the electrode posts are riveted so that the top of the electrode posts extrudes materials towards the sinking platforms of the riveting blocks to complete the assembly. Existing top cover sheets are usually made of aluminum. In order to improve the stability and safety performance of battery monomers, top cover sheets and housings made of steel have been gradually developed. On the basis of ensuring the strength of the structure, the thickness of the steel top cover sheet is smaller than that of the aluminum top cover sheet. In this way, after the cover plate is assembled, the compression amount of the sealing ring is likely to be insufficient, resulting in reduced sealing performance and easy occurrence of electrolyte leakage or seepage, affecting the performance of the cell. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a cell cover plate and a cell to solve the problem that the compression amount of the sealing ring by the steel top cover sheet in the existing cell cover plate is insufficient, resulting in reduced sealing performance of the cell cover plate and easy occurrence of electrolyte seepage or leakage in the cell, affecting the performance of the cell.

[0004] The first aspect of the present invention provides a cell cover plate, wherein the cell cover plate includes: A cover plate main body, provided with an installation hole; An electrode post, passing through the installation hole; An insulating assembly, including a first insulating member and a second insulating member, the first insulating member and the second insulating member are respectively arranged on both sides in the thickness direction of the cover plate main body; A sealing member, sleeved on the electrode post, the sealing member is formed with protruding first, second, and third convex portions, the first convex portion is clamped between the circumferential side wall of the electrode post and the hole wall of the installation hole, the second convex portion is clamped between the cover plate main body and the electrode post, and a part of the first insulating member extends into the groove between the first convex portion and the second convex portion; The second convex portion is compressed by the electrode post and the cover plate main body, and the compression amount n3 of the second convex portion = (H3 - h3) / H3, 20% ≤ n3 ≤ 40%; Wherein, H3 is the distance between the end of the second convex portion abutted against one end of the cover plate body and the end of the seal member abutted against the pole column in the thickness direction of the cover plate body before compression, and 1 mm ≤ H3 ≤ 2 mm; h3 is the distance between the end of the second convex portion abutted against one end of the cover plate body and the end of the seal member abutted against the pole column in the thickness direction of the cover plate body after compression, and the unit is mm.

[0005] Preferably, the first convex portion and the second convex portion are arranged on the side of the seal member facing the cover plate body, and the protruding height of the first convex portion is greater than that of the second convex portion; The third convex portion is clamped between the second insulating member and the pole column, and the third convex portion is arranged on the side of the seal member facing away from the cover plate body.

[0006] Preferably, the first convex portion, the second convex portion and the third convex portion are all formed into an annular structure and are nested layer by layer in sequence from inside to outside; a crimping portion is formed on the side of the second convex portion facing away from the groove, and at least part of the crimping portion is clamped between the pole column and the second insulating member. The compression amount n4 of the crimping portion = (H4 - h4) / H4, and 15% ≤ n4 ≤ 30%, wherein H4 is the dimension of the crimping portion in the thickness direction of the cover plate body before compression, 0.5 mm ≤ H4 ≤ 1 mm, and h4 is the dimension of the crimping portion in the thickness direction of the cover plate body after compression, and the unit is mm.

[0007] Preferably, in the length direction or the width direction of the cover plate body, the dimension of the first convex portion is L1, L1 ≥ 0.5 mm, and / or the dimension of the groove is L2, L2 ≥ 0.5 mm, and / or the dimension of the second convex portion is L3, L3 ≥ 1 mm, and / or the dimension of the crimping portion is L4, L4 ≥ 1 mm.

[0008] Preferably, it further includes: A connecting member, arranged on the side of the cover plate body facing the outside of the battery cell and connected to the pole column, and the first insulating member is clamped between the connecting member and the cover plate body.

[0009] Preferably, in the thickness direction of the cover plate body, the first convex portion is clamped between the connecting member and the pole column, and the compression amount n1 of the first convex portion = (H1 - h1) / H1, where 5% ≤ n1 ≤ 15%. Here, H1 is the distance between the end of the first convex portion abutting against the connecting member and the end of the seal abutting against the pole column in the thickness direction of the cover plate body before compression, and 2 mm ≤ H1 ≤ 3 mm; h1 is the distance between the end of the first convex portion abutting against the connecting member and the end of the seal abutting against the pole column in the thickness direction of the cover plate body after the first convex portion is compressed, with the unit being mm.

[0010] Preferably, the cover plate body is formed with a sealing boss protruding towards the connecting member, and a recessed sealing groove is formed on the side of the connecting member facing the cover plate body. A part of the first insulating member is bent and arranged in the gap surrounded by the sealing boss and the sealing groove.

[0011] Preferably, the bottom of the groove is compressed by the first insulating member and the pole column, and the compression amount n2 of the groove = (H2 - h2) / H2, where 15% ≤ n2 ≤ 30%. Among them, H2 is the dimension between the bottom of the groove and the end of the seal abutting against the pole column in the thickness direction of the cover plate body before compression, and 0.7 mm ≤ H2 ≤ 1.5 mm; h2 is the distance between the end of the groove abutting against the first insulating member and the end of the seal abutting against the pole column in the thickness direction of the cover plate body after the groove is compressed, with the unit being mm.

[0012] Preferably, the cover plate body is a steel piece; And / or, the pole column includes a first connecting portion, a first column portion, a second column portion, and a second connecting portion arranged in sequence along the axial direction. The first convex portion surrounds the circumferential side wall of the second column portion, and the third convex portion surrounds the circumferential side wall of the second connecting portion; the first connecting portion is arranged outside the battery cell, and the second connecting portion is arranged inside the battery cell.

[0013] In a second aspect of the present invention, a battery cell is provided, including the battery cell cover plate according to any one of the above technical solutions.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: For the cell cover plate of the present invention, the first convex part of the seal is clamped between the circumferential side wall of the pole post and the hole wall of the mounting hole, and the second convex part is clamped between the cover plate main body and the pole post. A part of the first insulating part extends into the groove between the first convex part and the second convex part. In this way, the cover plate main body, the first insulating part and the second insulating part simultaneously apply pressure to the seal, realizing effective compression of the seal. The compression amount n3 of the second convex part = (H3 - h3) / H3, and 20% ≤ n3 ≤ 40%. This ensures that the second convex part has sufficient compression amount after the cell cover plate is assembled and will not be over-compressed to affect the service life of the seal. Thus, while ensuring the strength of the cell cover plate, the sealing performance of the cell cover plate is improved, avoiding the situation of electrolyte leakage or seepage after the cell is assembled, and further enhancing the use safety of the cell while ensuring the cell performance.

[0015] To make the above objects, features and advantages of the present application more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a schematic structural diagram of the cell cover plate provided by the embodiment of the present invention; Figure 2 It is an exploded structural diagram of the cell cover plate provided by the embodiment of the present invention; Figure 3 It is a schematic structural diagram of the cell cover plate provided by the embodiment of the present invention from another perspective; Figure 4 It is along Figure 3 The cross-sectional view taken along the A-A position in Figure 5 It is along Figure 4 The enlarged structural diagram at position B in Figure 6 It is a schematic structural diagram of the seal in the cell cover plate provided by the embodiment of the present invention; Figure 7 It is a schematic structural diagram of the seal in the cell cover plate provided by the embodiment of the present invention from another perspective.

[0018] Icons: 10 - Cover body; 11 - Mounting hole; 12 - Sealing boss; 20 - Terminal post; 21 - First connecting part; 22 - First cylindrical part; 23 - Second cylindrical part; 24 - Second connecting part; 31 - First insulating part; 32 - Second insulating part; 40 - Sealing part; 41 - First convex part; 42 - Second convex part; 43 - Third convex part; 44 - Groove; 45 - Crimping part; 50 - Connecting part; 51 - Riveting hole; 511 - First stepped section; 512 - Second stepped section; 513 - Third stepped section; 52 - Sealing groove; 53 - Limiting boss. Detailed implementation manners

[0019] The following detailed implementation manners are provided to assist the reader in obtaining a comprehensive understanding of the methods, devices, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, devices, and / or systems described herein will be apparent after understanding the disclosure of this application. For example, the order of operations described herein is merely exemplary and is not limited to the order set forth herein. Rather, changes that will be apparent after understanding the disclosure of this application can be made, except for operations that must occur in a specific order. In addition, descriptions of features known in the art may be omitted for the sake of clarity and conciseness.

[0020] The features described herein may be implemented in different forms and should not be construed as limited to the examples described herein. Rather, the examples described herein are 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 this application.

[0021] Throughout the specification, when an element (such as a layer, region, or substrate) is described as "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, it can be directly "on" another element, "connected to" another element, "bonded to" another element, "above" another element, or "covering" another element, or there can be one or more other elements between them. In contrast, when an element is described as "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly above" another element, or "directly covering" another element, there can be no other elements between them.

[0022] As used herein, the term "and / or" includes any one of the listed related items and any combination of any two or more of them.

[0023] Although terms such as "first", "second", and "third" may be used herein to describe various components, elements, regions, layers, or sections, these components, elements, regions, layers, or sections are not limited by these terms. Rather, these terms are only used to distinguish one component, element, region, layer, or section from another. Thus, a first component, element, region, layer, or section as referred to in the examples described herein may also be referred to as a second component, element, region, layer, or section without departing from the teachings of the examples.

[0024] For ease of description, spatial relationship terms such as "above", "upper", "below", and "lower" may be used herein to describe the relationship of one element to another as shown in the figures. Such spatial relationship terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, an element described as "above" or "upper" relative to another element will then be "below" or "lower" relative to the other element. Thus, the term "above" includes both the orientation of "above" and "below" 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 relationship terms used herein will be interpreted accordingly.

[0025] The terms used herein are for the purpose of describing various examples only and are not intended to limit the disclosure. Unless the context clearly dictates otherwise, the singular forms are also intended to include the plural forms. The terms "comprises", "comprising", and "having" list the stated features, quantities, operations, components, elements, and / or combinations thereof that exist, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0026] Due to manufacturing techniques and / or tolerances, variations in the shapes shown in the figures may occur. Thus, the examples described herein are not limited to the specific shapes shown in the figures but include changes in shape that occur during manufacturing.

[0027] 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 a variety of configurations, other configurations are possible as will be apparent after understanding the disclosure of the present application.

[0028] According to a first aspect of the present invention, a battery cell cover plate is provided, which specifically includes a cover plate body 10, a pole column 20, an insulating assembly, and a seal 40.

[0029] In the following, the specific structure of the cell cover plate according to the present embodiment will be described as above.

[0030] In the present embodiment, as Figures 1 to 5 shown, the cover plate body 10 is formed into a plate-like structure, and an installation hole 11 is formed in the cover plate body 10. The installation hole 11 is a through-hole structure penetrating the cover plate body 10. In a preferred embodiment, the cover plate body 10 is a steel member, that is, the cover plate body 10 is made of steel, so as to effectively improve the structural strength of the cell cover plate of the present application relative to the cell cover plate made of aluminum, and the thickness dimension can be relatively reduced, which helps to increase the cell capacity.

[0031] In the present embodiment, as Figures 1 to 5 shown, the pole column 20 is inserted through the installation hole 11. Specifically, the pole column 20 includes a first connection portion 21, a first column portion 22, a second column portion 23, and a second connection portion 24 arranged in sequence along the axial direction. The first connection portion 21 is arranged outside the cover plate body 10, and the second connection portion 24 is arranged inside the cover plate body 10.

[0032] Specifically, as Figure 2 shown, the first connection portion 21, the first column portion 22, and the second column portion 23 are all formed into columnar structures. The first connection portion 21 is used to connect the bus bar, the electrical equipment, or the power supply equipment. The second connection portion 24 is formed into a plate-like structure, and the second connection portion 24 is used to connect the pole group inside the cell. In the present embodiment, as Figures 1 to 5 shown, the insulation assembly includes a first insulation member 31 and a second insulation member 32. The first insulation member 31 and the second insulation member 32 are respectively arranged on both sides of the cover plate body 10 in the thickness direction to form insulation protection for the cover plate body 10 to prevent short circuit caused by metal lap. In an alternative embodiment, the first insulation member 31 can be made of PPS material, and the second insulation member 32 can be made of PP material.

[0033] In the present embodiment, as Figures 1 to 7As shown, the seal 40 is formed as an annular structure sleeved on the terminal post 20. The seal 40 can be an O-ring made of fluororubber. Specifically, the seal 40 is formed with protruding first convex portion 41, second convex portion 42 and third convex portion 43. The first convex portion 41 is clamped between the circumferential side wall of the terminal post 20 and the hole wall of the mounting hole 11. More specifically, the first convex portion 41 surrounds the circumferential side wall of the second cylindrical portion 23. In the thickness direction of the cover plate body 10, the second convex portion 42 is clamped between the cover plate body 10 and the terminal post 20. A part of the first insulating member 31 extends into the groove 44 between the first convex portion 41 and the second convex portion 42. The third convex portion 43 is clamped between the second insulating member 32 and the terminal post 20. Specifically, the third convex portion 43 surrounds the circumferential side wall of the second connecting portion 24. In this way, the cover plate body 10, the first insulating member 31 and the second insulating member 32 simultaneously apply pressure to the seal 40.

[0034] The second convex portion 42 is compressed by the second connecting portion 24 on the terminal post 20 and the cover plate body 10. The compression amount n3 of the second convex portion 42 = (H3 - h3) / H3, where 20% ≤ n3 ≤ 40%. Here, H3 is the distance between the end of the second convex portion 42 abutted against the cover plate body 10 and the end of the seal 40 abutted against the terminal post 20 (i.e., the end of the seal 40 abutted against the second connecting portion 24) in the thickness direction of the cover plate body 10 before compression, and 1mm ≤ H3 ≤ 2mm. h3 is the distance between the end of the second convex portion 42 abutted against the cover plate body 10 and the end of the seal 40 abutted against the terminal post 20 in the thickness direction of the cover plate body 10 after the second convex portion 42 is compressed, with the unit of mm. This ensures that the second convex portion 42 has sufficient compression amount after the cell cover plate is assembled and will not be over-compressed to affect the service life of the seal 40, thereby realizing the effective compression of the seal 40, improving the sealing performance of the cell cover plate while ensuring the strength of the cell cover plate, and avoiding the situation of electrolyte leakage or seepage after assembly.

[0035] Further, in this embodiment, as Figure 5 and Figure 6As shown, a crimping portion 45 is formed on the side of the second convex portion 42 facing away from the groove 44. The third convex portion 43 is disposed on the side of the crimping portion 45 facing the inside of the battery cell and is spaced from the second convex portion 42 in the length or width direction of the cover plate body 10. At least a part of the crimping portion 45 is clamped between the pole 20 and the second insulating member 32 (that is, at least a part of the crimping portion 45 is clamped between the second connecting portion 24 and the second insulating member 32). The compression amount n4 of the crimping portion 45 = (H4 - h4) / H4, where 15% ≤ n4 ≤ 30%. Here, H4 is the dimension of the crimping portion 45 in the thickness direction of the cover plate body before the seal 40 is compressed, and 0.5 mm ≤ H4 ≤ 1 mm. h4 is the dimension of the crimping portion in the thickness direction of the cover plate body after compression, with the unit being mm. In this way, through the combined compression of the cover plate body 10 and the second insulating member 32 on the seal 40, it is ensured that the crimping portion 45 also has sufficient compression amount after the battery cell cover plate is assembled and will not be over-compressed to affect the service life of the seal 40, thereby further achieving effective compression of the seal 40 and improving the sealing performance of the battery cell cover plate.

[0036] In addition, preferably, as Figure 4 and Figure 5 shown, the second insulating member 32 clamped between the cover plate body 10 and the second connecting portion 24 surrounds the circumferential side wall of the second convex portion 42, and the first insulating member 31 extends into the groove 44 between the first convex portion 41 and the second convex portion 42, so that a meandering structure with multiple bends is formed between the first insulating member 31, the second insulating member 32, and the seal 40, thereby ensuring the sealing reliability of the battery cell cover plate.

[0037] In a preferred embodiment, as Figure 4 and Figure 5 shown, the bottom of the groove 44 is compressed by the first insulating member 31 and the second connecting portion 24 on the pole 20. The compression amount n2 of the groove 44 = (H2 - h2) / H2, where 15% ≤ n2 ≤ 30%. Here, H2 is the dimension between the bottom of the groove 44 and the end of the seal 40 abutted against the pole 20 (that is, the end of the seal 40 abutted against the second connecting portion 24) in the thickness direction of the cover plate body 10 before compression, and 0.7 mm ≤ H2 ≤ 1.5 mm. h2 is the distance between the end of the groove 44 abutted against the first insulating member 31 and the end of the seal 40 abutted against the pole 20 in the thickness direction of the cover plate body 10 after the groove 44 is compressed, with the unit being mm. In this way, the compression effect of the first insulating member 31 on the seal 40 is increased, and further effective compression of the seal 40 is achieved, improving the sealing performance of the battery cell cover plate.

[0038] Specifically, in this embodiment, as Figures 2 to 7As shown, the first convex portion 41 and the second convex portion 42 are provided on the side of the seal 40 facing the cover plate body 10. The protruding height of the first convex portion 41 is greater than that of the second convex portion 42, so as to ensure the effective covering of the first convex portion 41 on the second cylindrical portion 23 and be able to be crimped with the riveted part described below to improve the sealing performance. The third convex portion 43 is provided on the side of the seal 40 facing away from the cover plate body 10. The third convex portion 43 is arranged around the circumference of the second connecting portion 24, so as to further improve the sealing performance of the seal 40.

[0039] More specifically, in this embodiment, as Figure 2 , Figure 6 and Figure 7 shown, the first convex portion 41, the second convex portion 42 and the third convex portion 43 are all formed into an annular structure and are nested layer by layer in sequence from the inside to the outside, that is, the first convex portion 41, the second convex portion 42 and the third convex portion 43 are coaxially arranged. The radial dimension of the second convex portion 42 is greater than that of the first convex portion 41, and the radial dimension of the third convex portion 43 is greater than that of the second convex portion 42, so as to ensure that the cover plate body 10, the first insulating member 31 and the second insulating member 32 apply force on the seal 40 evenly and ensure that the compression amount of the seal 40 meets the sealing requirements of the battery cell cover plate.

[0040] In addition, in this embodiment, as Figures 1 to 5 shown, the battery cell cover plate further includes a connecting member 50. The connecting member 50 is provided on the side of the cover plate body 10 facing the outside of the battery cell and is connected to the pole 20 to realize the fixed assembly of the battery cell cover plate. The first insulating member 31 is clamped between the connecting member 50 and the cover plate body 10 to separate the cover plate body 10 from the connecting member 50, thereby forming insulation protection. In an alternative embodiment, the connection method between the connecting member 50 and the pole 20 can be a riveting connection, a welding connection, or a connection of first riveting and then welding. However, the method of fixing the pole 20 on the cover plate body 10 is not limited to this, as long as the fixed assembly of the battery cell cover plate is ensured.

[0041] Specifically, the connecting member 50 is formed into a block structure. A riveting hole 51 is formed in the connecting member 50. The riveting hole 51 is formed into a stepped hole structure having a first stepped section 511, a second stepped section 512, and a third stepped section 513 arranged in sequence along the axial direction. The radial dimension of the first stepped section 511 > the radial dimension of the second stepped section 512 > the radial dimension of the third stepped section 513. The third stepped section 513 is arranged on the side close to the cover plate main body 10. Before riveting, the radial dimension of the first connecting portion 21 is the same as that of the first columnar body and smaller than the radial dimension of the second columnar body portion 23. After riveting, the circumferential side wall of the first connecting portion 21 expands outward to form a clearance fit with the second stepped section 512, and the first connecting portion 21 has a clearance fit with the third stepped section 513. One side of the connecting member 50 facing the cover plate main body 10 is clamped on the step between the first columnar body portion 22 and the second columnar body portion 23.

[0042] It should be noted that after riveting, the pole column 20 and the connecting member 50 are welded together to form a weld mark between the first connecting portion 21 and the second stepped section 512. The first stepped section 511 is used to avoid the weld mark and prevent the flatness of the side of the connecting member 50 facing away from the cover plate main body 10 from increasing after welding.

[0043] In a preferred embodiment, as Figure 4 and Figure 5 shown, the first convex portion 41 is crimped with the connecting member 50. That is, in the thickness direction of the cover plate main body 10, the first convex portion 41 is clamped between the connecting member 50 and the second connecting portion 24 of the pole column 20. In this way, the compression effect of the connecting member 50 on the seal 40 is increased to further effectively compress the seal 40 and improve the sealing performance of the battery cell cover plate. Specifically, the compression amount n1 of the first convex portion 41 = (H1 - h1) / H1, 5% ≤ n1 ≤ 15%, where H1 is the distance between the end of the first convex portion 41 abutting against the connecting member 50 and the end of the seal 40 abutting against the pole column 20 (i.e., the end of the seal 40 abutting against the second connecting portion 24) in the thickness direction of the cover plate main body 10 before compression, 2 mm ≤ H1 ≤ 3 mm; h1 is the distance between the end of the first convex portion 41 abutting against the connecting member 50 and the end of the seal 40 abutting against the pole column 20 in the thickness direction of the cover plate main body 10 after the first convex portion 41 is compressed, and the unit is mm.

[0044] In a preferred embodiment, after the battery cell cover plate is assembled, the first convex portion 41, the second convex portion 42, the groove 44, and the crimping portion 45 all deform, so as to ensure to the greatest extent that the compression amount of the seal 40 meets the sealing requirements of the battery cell cover plate.

[0045] Next, the sealing performance and pressure resistance performance of the battery cell cover plates with different compression amounts are detected. Specifically, a helium mass spectrometer is used to detect the sealing performance of the battery cell cover plates. The detection standard is that the helium leak rate is lower than 1×10 -7Pa·m 3 / s indicates that the test is qualified. The withstand voltage performance test is to detect whether the pole 20 can withstand 30s without leakage under 1.2MPa pressure from inside to outside along its axial direction (or ensure that the withstand voltage value is greater than 1.2MPa). The test results are shown in Tables 1 and 2.

[0046] Table 1

[0047] Table 2

[0048] Referring to the embodiments in Table 1 and the comparative examples in Table 2, it can be seen that in Examples 1 to 12 in Table 1, n1, n2, n3 and n4 are all within the limited range as described above, and the sealing performance test and the pressure resistance performance test are both qualified, while in Comparative Examples 1 to 4 in Table 2, the parameter of n1 is not within the range of 5% to 15%, the parameter of n2 is not within the range of 15% to 30%, the parameter of n3 is not within the range of 20% to 40% in Comparative Examples 9 to 12, and the parameter of n4 is not within the range of 15% to 30% in Comparative Examples 13 to 16, resulting in a helium leak detection rate higher than 1×10 -7 Pa·m 3 / s and / or the withstand voltage value is less than 1.2Mpa, which cannot meet the requirements for the use of the battery cover.

[0049] It should be noted that in the present application, H1, H2, H3 and H4 are actually the design heights of the seal 40, and the specific values ​​can be obtained by actual measurement of the real object. h1, h2, h3 and h4 are the dimensions of various positions on the compressed seal 40, which can be obtained by cutting the assembled battery cell cover plate with the axis passing through the pole as the cross-section.

[0050] In addition, in the present embodiment, the cover body 10 is formed as a rectangular plate-like structure. In the length direction or width direction of the cover body 10, the size of the first protrusion 41 is L1, L1≥0.5mm, and / or the size of the groove 44 is L2, L2≥0.5mm, and / or the size of the second protrusion 42 is L3, L3≥1mm, and / or the size of the crimping portion 45 is L4, L4≥1mm, thereby ensuring that the seal 40 has sufficient compression area to ensure the sealing performance of the battery cover.

[0051] In this embodiment, if Figure 2 and Figure 4As shown, the cover plate body 10 is formed with a sealing boss 12 protruding towards the connecting member 50. The sealing boss 12 can be formed by stamping, so that one side of the cover plate body 10 facing the inside of the battery cell is recessed. One side of the connecting member 50 facing the cover plate body 10 is formed with a recessed sealing groove 52. Specifically, in the thickness direction of the cover plate body 10, the sealing groove 52 and the sealing boss 12 are arranged up and down, and the opening of the sealing groove 52 faces the sealing boss 12. Part of the first insulating member 31 is bent in the gap formed by the sealing boss 12 and the sealing groove 52, which can prevent the sealing member 40 from rotating around the pole column 20, thus further improving the assembly sealing performance of the battery cell cover plate.

[0052] In an optional embodiment, a plurality of sealing bosses 12 are provided, and the plurality of sealing bosses 12 are arranged at intervals around the circumference of the mounting hole 11, and the sealing grooves 52 are arranged in one-to-one correspondence with the sealing bosses 12.

[0053] In this embodiment, as Figure 2 and Figure 4 shown, a limiting boss 53 is formed on the circumferential side wall of the connecting member 50. The limiting boss 53 is arranged on the side of the connecting member 50 facing away from the cover plate body 10. Part of the first insulating member 31 extends towards the limiting boss 53 to surround the circumferential side wall of the connecting member 50, so as to improve the insulating protection effect of the first insulating member 31.

[0054] According to a battery cell cover plate provided by the present invention, the first convex portion of the sealing member is clamped between the circumferential side wall of the pole column and the hole wall of the mounting hole, the second convex portion is clamped between the cover plate body and the pole column, part of the first insulating member extends into the groove between the first convex portion and the second convex portion, and the third convex portion is clamped between the second insulating member and the pole column. In this way, the cover plate body, the first insulating member and the second insulating member simultaneously apply pressure to the sealing member, realizing effective compression of the sealing member, improving the sealing performance of the battery cell cover plate while ensuring the strength of the battery cell cover plate, avoiding the leakage or seepage of electrolyte after assembly, and making the battery cell cover plate have both reliable strength and good sealing performance.

[0055] According to a battery cell provided by the present invention, it includes the battery cell cover plate as described above. The battery cell cover plate has good sealing performance, avoiding the leakage or seepage of electrolyte after the battery cell is assembled, thereby improving the use safety of the battery cell while ensuring the performance of the battery cell.

[0056] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present application, which are used to illustrate the technical solutions of the present application, rather than limiting it. The protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any person skilled in the art within the technical scope disclosed by the present application can still modify the technical solutions described in the foregoing embodiments or can easily think of changes, or perform equivalent replacements on some of the technical features; 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 all be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A battery cell cover, characterized in that: The battery cover plate comprises: The cover plate body is provided with a mounting hole; A pole, passing through the mounting hole; An insulating assembly, comprising a first insulating member and a second insulating member, wherein the first insulating member and the second insulating member are respectively arranged on two sides of the cover plate body in a thickness direction; A sealing member, sleeved on the pole, the sealing member is formed with a first protruding portion, a second protruding portion and a third protruding portion, the first protruding portion is sandwiched between the circumferential side wall of the pole and the hole wall of the mounting hole, the second protruding portion is sandwiched between the cover plate body and the pole, and a portion of the first insulating member extends into a groove between the first protruding portion and the second protruding portion; The second protrusion is compressed by the pole and the cover plate body, and the compression amount of the second protrusion is n3=(H3-h3) / H3, 20%≤n3≤40%; Among them, H3 is the distance between one end of the second protrusion abutting against the cover plate body and one end of the seal abutting against the pole in the thickness direction of the cover plate body before compression, 1mm≤H3≤2mm; h3 is the distance between one end of the second protrusion abutting against the cover plate body and one end of the seal abutting against the pole in the thickness direction of the cover plate body after the second protrusion is compressed, and the unit is mm.

2. The cell cover plate according to claim 1, characterized in that: The first convex portion and the second convex portion are arranged on a side of the sealing member facing the cover plate body, and a protruding height of the first convex portion is greater than a protruding height of the second convex portion; The third protrusion is sandwiched between the second insulating member and the pole, and the third protrusion is arranged on a side of the sealing member facing away from the cover plate body.

3. The cell cover plate according to claim 1, characterized in that: The first protrusion, the second protrusion and the third protrusion are all formed into an annular structure, and are nested in layers from the inside to the outside; the second protrusion forms a crimping portion on the side facing away from the groove, and at least part of the crimping portion is clamped between the pole and the second insulating member, and the compression amount of the crimping portion n4=(H4-h4) / H4, 15%≤n4≤30%, wherein H4 is the size of the crimping portion in the thickness direction of the cover plate body before compression, 0.5mm≤H4≤1mm; h4 is the size of the crimping portion in the thickness direction of the cover plate body after compression, and the unit is mm.

4. The cell cover plate according to claim 3, characterized in that: In the length direction or width direction of the cover plate body, the size of the first protrusion is L1, L1≥0.5mm, and / or the size of the groove is L2, L2≥0.5mm, and / or the size of the second protrusion is L3, L3≥1mm, and / or the size of the crimping portion is L4, L4≥1mm.

5. The cell cover plate according to claim 1, characterized in that: Also includes: The connecting piece is arranged on a side of the cover body facing the outside of the battery cell and is connected to the pole. The first insulating piece is sandwiched between the connecting piece and the cover body.

6. The cell cover plate according to claim 5, characterized in that: In the thickness direction of the cover plate body, the first protrusion is clamped between the connecting piece and the pole, and the compression amount of the first protrusion n1=(H1-h1) / H1, 5%≤n1≤15%, wherein H1 is the distance between one end of the first protrusion abutting against the connecting piece and one end of the sealing piece abutting against the pole in the thickness direction of the cover plate body before compression, 2mm≤H1≤3mm; h1 is the distance between one end of the first protrusion abutting against the connecting piece and one end of the sealing piece abutting against the pole in the thickness direction of the cover plate body after the first protrusion is compressed, and the unit is mm.

7. The cell cover plate according to claim 5, characterized in that: The cover plate body is formed with a sealing boss protruding toward the connecting member, and a concave sealing groove is formed on a side of the connecting member facing the cover plate body. Part of the first insulating member is bent in a gap enclosed by the sealing boss and the sealing groove.

8. The cell cover plate according to claim 1, characterized in that: The bottom of the groove is compressed by the first insulating member and the pole, and the compression amount of the groove is n2=(H2-h2) / H2, 15%≤n2≤30%; Among them, H2 is the dimension between the bottom of the groove and the end of the seal abutting against the pole in the thickness direction of the cover plate body before compression, 0.7mm≤H2≤1.5mm; h2 is the distance between the end of the groove abutting against the first insulating member and the end of the seal abutting against the pole in the thickness direction of the cover plate body after the groove is compressed, and the unit is mm.

9. The cell cover plate according to claim 1, characterized in that: The cover plate body is a steel part; And / or, the pole includes a first connecting portion, a first columnar portion, a second columnar portion and a second connecting portion arranged in sequence along the axial direction, the first protrusion is arranged around the circumferential side wall of the second columnar portion, and the third protrusion is arranged around the circumferential side wall of the second connecting portion; the first connecting portion is arranged on the outer side of the cover plate body, and the second connecting portion is arranged on the inner side of the cover plate body.

10. A battery cell, characterized in that: The invention comprises a cell cover plate as described in any one of claims 1 to 9.

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