Cover plate assembly and battery cell

Abstract

The present invention relates to the field of battery technology, and in particular to a cover assembly and a battery cell. The cover assembly includes a pole; a cover body, which is provided with a mounting hole for mounting the pole; a seal, which is arranged between the cover body and the pole; the size of the seal in the first direction is H, and the cover body is crimped with the seal in the first direction, so that the seal forms a first compression amount L1, and the first compression rate of the seal is K1=L1 / H, 15%≤K1≤55%. The present invention can avoid the situation where the sealing is poor and air leakage occurs due to insufficient pressing strength between the seal and the cover body, or avoid the situation where the seal is easily damaged when the battery cell is subjected to a preset pressure due to excessive pressing strength, resulting in sealing failure, thereby ensuring the effectiveness, sealing reliability and service life of the seal.

Description

Technical Field

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

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

[0003] The cover plate and the shell of the battery structure are sealed and connected to protect the bare battery cells in the shell. The cover plate includes a plain aluminum plate, a pole and a sealing ring. The sealing ring is pressed at the connection between the plain aluminum plate and the pole to isolate the inside and outside of the battery. Once the sealing ring fails, the sealing and insulation properties of the battery will be reduced. Therefore, the service life and reliability of the sealing ring can ensure the reliability of the internal seal of the battery and the cycle life of the battery. Since the sealing ring is an elastic part, it is easy to leak at the position where the sealing ring is set, resulting in failure of the inspection, affecting the quality and yield rate of the product. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a cover assembly and a battery cell to solve the problem that the sealing ring in the existing battery cover assembly is prone to failure, resulting in air leakage at the location where the sealing ring is set, causing failure of detection, and affecting the quality and yield rate of the product.

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

[0006] Pole;

[0007] The cover plate body is provided with a mounting hole for mounting the pole;

[0008] A seal is arranged between the cover body and the pole; the size of the seal in the first direction is H, and the cover body is crimped with the seal in the first direction, so that the seal forms a first compression amount L1, and the first compression rate of the seal is K1=L1 / H, 15%≤K1≤55%.

[0009] Preferably, in the first direction, a distance between an end of the cover plate body crimped with the seal and an end of the cover plate body away from the seal is X, and X≥0.7 mm.

[0010] Preferably, after the cover plate body is crimped with the sealing member, a dimension of the sealing member in contact with the cover plate body in the second direction is B, and 0.8 mm ≤ B ≤ 3 mm.

[0011] Preferably, the cover plate assembly further comprises:

[0012] The first insulating member at least partially covers the side wall of the pole in the circumferential direction, and part of the first insulating member extends into the mounting hole and abuts against the sealing member in the first direction, so that the sealing member forms a second compression amount L2, 0mm≤L2≤0.8mm.

[0013] Preferably, the second compression rate of the seal is K2=L2 / H, 0%≤K2≤50%.

[0014] Preferably, the cover plate assembly further comprises:

[0015] The support member is formed into an annular structure, and the support member is embedded between the first insulating member and the pole, and a part of the first insulating member is sandwiched between the support member and the cover plate body.

[0016] Preferably, the support member is a weldable member, and the support member is welded to the pole.

[0017] Preferably, a pressure relief hole is provided on the cover plate body; and the cover plate assembly further comprises:

[0018] A pressure relief component is installed on the pressure relief hole; the opening pressure of the pressure relief component is P, P≤1.2MPa.

[0019] Preferably, the side wall of the pole is formed with a protruding limiting boss;

[0020] In the first direction, the sealing member is sandwiched between the limiting boss and the cover plate body.

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

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

[0023] The cover assembly of the present invention limits the ratio of the first compression amount L1 caused by the cover body on the seal in the first direction to the dimension H of the seal in the first direction after the seal and the cover body are pressed together, that is, limits the range of the first compression rate K1, so as to avoid the situation where the press-fitting strength is insufficient, resulting in poor sealing between the seal and the cover body and easy leakage, or avoids the situation where the press-fitting strength is too high, resulting in damage to the seal when the battery cell is under a certain pressure, resulting in sealing failure, thereby ensuring the effectiveness and service life of the seal, and further improving the product quality and yield rate of the battery cell.

[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 cover plate assembly provided in an embodiment of the present invention;

[0027] Figure 2 A schematic structural diagram of a cover plate assembly provided by an embodiment of the present invention from another viewing angle;

[0028] Figure 3 A structural cross-sectional view of a cover plate assembly provided by an embodiment of the present invention;

[0029] Figure 4 for Figure 3 The enlarged structural diagram at A in the middle;

[0030] Figure 5 An exploded view of the structure of the cover plate assembly provided by an embodiment of the present invention;

[0031] Figure 6 A schematic diagram of a first structure of a pole in a cover plate assembly provided in an embodiment of the present invention;

[0032] Figure 7 A schematic diagram of a second structure of a pole in a cover plate assembly provided in an embodiment of the present invention;

[0033] Figure 8 A third structural schematic diagram of a pole in a cover plate assembly provided in an embodiment of the present invention;

[0034] Fig. 9 A schematic diagram of a first structure of a sealing member in a cover plate assembly provided in an embodiment of the present invention;

[0035] Fig.10 A schematic diagram of a second structure of a sealing member in a cover plate assembly provided in an embodiment of the present invention;

[0036] Fig.11 A third structural schematic diagram of a sealing member in a cover plate assembly provided in an embodiment of the present invention.

[0037] Icons: 10-pole; 11-limiting boss; 20-cover body; 21-mounting hole; 22-pressure relief hole; 23-liquid injection hole; 30-sealing member; 40-first insulating member; 50-second insulating member; 60-support member; 70-pressure relief member; 71-protective member; D1-first direction; D2-second direction. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] As used herein, the term "and / or" includes any one of the associated listed items and any combination of any two or more items.

[0042] 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 only used 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] According to a first aspect of the present invention, a cover plate assembly is provided, which specifically includes a pole 10 , a cover plate body 20 and a sealing member 30 .

[0048] Hereinafter, a specific structure of the cap plate assembly according to the present embodiment will be described.

[0049] In this embodiment, if Figures 1 to 3 and Figure 5 As shown, the cover body 20 is provided with a mounting hole 21, which is a through-hole structure penetrating the cover body 20, and the pole 10 is assembled with the cover via the mounting hole 21. The cover body 20 can be a sheet structure in a rectangular or circular shape, for example, the cover body 20 can be a rectangular plain aluminum sheet.

[0050] In this embodiment, as shown in 3 and Figure 4As shown, the seal 30 is assembled between the cover body 20 and the pole 10 to avoid the formation of a gap between the cover body 20 and the pole 10, so as to isolate the inside of the battery cell from the outside world and ensure the normal use of the battery cell. Specifically, in the thickness direction of the cover body 20, part of the seal 30 is sandwiched between the cover body 20 and the limiting boss 11 described below; the remaining part of the seal 30 extends toward the outside of the battery cell to be embedded in the area surrounded by the hole wall of the mounting hole 21 and the circumferential side wall of the pole 10. The seal 30 is an elastic member as a whole, such as a sealing ring. The seal 30 is formed into an annular structure to cover the circumferential side wall of the pole 10. The elasticity of the seal 30 itself can ensure that there is no gap between the seal 30 and the pole 10, and prevent the fluid from passing between the side wall of the pole 10 and the inner wall of the seal 30.

[0051] In this embodiment, if Figures 1 to 8 As shown, a protruding limiting boss 11 is formed on the side wall of the pole 10. In the first direction D1, the seal 30 is sandwiched between the limiting boss 11 and the cover body 20. The limiting boss 11 is preferably a closed annular structure and is arranged on the side of the pole 10 facing the inside of the battery cell in the axial direction.

[0052] It should be noted that the number of the poles 10 may be one or more, and the mounting holes 21 are arranged in a one-to-one correspondence with the poles 10. When the number of the poles 10 is set to one, the battery cell is installed with at least two cover plate assemblies; when the number of the poles 10 is multiple, at least some of the poles 10 in the multiple poles 10 are positive poles 10, and the remaining poles 10 are negative poles 10.

[0053] In an alternative embodiment, Figures 6 to 8 As shown, the pole 10 is formed into a block structure in a circular or rectangular shape, or a combination of a circular and rectangular block structure. However, the shape of the pole 10 is not limited thereto, and can also be an elliptical shape, as long as it can meet the function of conducting current of the battery cell.

[0054] Further, in an optional embodiment, as Figures 9 to 11 As shown, the seal 30 can be formed into an annular structure in a circular or rectangular shape. The shape of the seal 30 is preferably adapted to the outer wall of the pole 10 at the position where the seal 30 is set in the circumferential direction, that is, when the cross-section of the position of the pole 10 where the seal 30 is installed is circular in a direction perpendicular to the axial direction, a circular seal 30 is selected to cooperate with it, so as to ensure that the inner wall of the entire circle of the seal 30 can fit tightly with the side wall of the pole 10, thereby improving the sealing between the seal 30 and the pole 10.

[0055] It should be noted that if Fig.10 and Fig.11As shown, when the seal 30 is a polygonal structure, an arc-shaped chamfer can be set at the corner between two adjacent sides, as long as the sealing performance of the cover assembly is met. It should be further said that the shape of the seal 30 is not limited to this, but can also be a runway-shaped annular structure, as long as it can achieve reliable sealing with the pole 10.

[0056] In this embodiment, if Figure 3 and Figure 4 As shown; the dimension of the seal 30 in the first direction D1 is H, and the first direction D1 is the thickness direction of the cover body 20, that is, the first direction D1 is the axial direction of the pole 10; the cover body 20 is crimped with the seal 30 in the first direction D1, and the seal 30 is deformed when crimped with the cover body 20 due to its elasticity, so that the seal 30 forms a first compression amount L1 under the action of the extrusion of the cover body 20, and the first compression rate K1 of the seal 30 is L1 / H, and the preferred range of the first compression rate K1 is 15%≤K1≤55%. If the first compression amount is too small, it is impossible to ensure that the cover body The body 20 and the seal 30 are tightly and reliably assembled. Insufficient press-fitting strength between the cover body 20 and the seal 30 may easily lead to poor sealing between the seal 30 and the cover body 20, which may easily cause air leakage between the cover body 20 and the seal 30. If the first compression amount is too large, the pressure inside the battery cell will increase, which will cause the initial first compression amount K1 to increase, making the seal 30 prone to failure such as damage and cracking. As a result, the sealing and service life of the seal 30 are reduced due to the excessive press-fitting strength, which will cause the battery cell product to fail the helium inspection and have a low production yield.

[0057] In this embodiment, the first compression rate K1 is 15%≤K1≤55%. Under this condition, the problem of sealing failure caused by insufficient or excessive press-fitting strength between the cover plate body 20 and the seal 30 can be effectively avoided. Since the battery cell will also generate heat during operation, the following experiment is conducted to determine whether the first compression rate of 15%≤K1≤55% at different temperatures can ensure the effectiveness of the seal 30. The experimental parameters are shown in Tables 1 and 2 below:

[0058] Table 1

[0059]

[0060] Table 2

[0061]

[0062] Note: "Helium test NG" in Table 1 and Table 2 means the test failed, and "Helium test OK" means the test passed.

[0063] Referring to Table 1 and Table 2, it can be seen that, whether at room temperature (i.e., room temperature) or at a temperature of 120°C, in Examples 1-1 to 1-3 of Table 1 and Examples 2-1 to 2-3 of Table 2, the first compression amount K1 is less than 15%, so that the cover body 20 and the seal 30 are not tightly assembled. Insufficient press-fit strength between the cover body 20 and the seal 30 will directly lead to failure of the helium test, or leakage occurs at the position of the pole 10 when pressurized to a preset pressure, resulting in a decrease in the yield rate.

[0064] In Examples 1-13 to 1-16 in Table 1 and Examples 2-13 to 2-16 in Table 2, the first compression amount K1 is greater than 55%. Although the cover plate body 20 and the seal 30 are tightly and reliably assembled, by pressurizing the pole 10 with 1.2 MPa, baking at 85°C for 1000 hours, and applying 800N force to the pole 10 in the first direction D1 for 50,000 times to simulate the working conditions of the battery cell, when the battery cell is tested in this way, Examples 1-13 to 1-16 and Examples 2-13 to 2-16 in Tables 1 and 2 all fail the helium test and the sealing ring cracks after being baked at 85°C for 1000 hours or the pole 10 is subjected to 800N force 50,000 times in the first direction D1.

[0065] In Examples 1-4 to 1-12 in Table 1 and Examples 2-4 to 2-12 in Table 2, when the pole 10 was pressurized at 1.2 MPa, after being baked at 85°C for 1000 hours and the pole 10 was pressurized at 1.2 MPa, and when a force of 800 N was applied 50,000 times in the first direction D1 of the pole 10, no leakage occurred and the helium test was passed. Therefore, it is proved that the limiting condition of the first compression rate K1 being 15%≤K1≤55% can ensure the sealing effectiveness and reliability of the seal 30, thereby meeting the sealing requirements of the cover plate assembly for the battery cell shell and improving the yield rate of the battery cell.

[0066] Furthermore, if Figure 3 and Figure 4 As shown, after the cover body 20 and the seal 30 are crimped, the dimension of the seal 30 in contact with the cover body 20 in the second direction D2 is B. If the dimension B is too small, it will easily cause a decrease in the sealing reliability. If the dimension is too large, the corresponding dimension of the seal 30 in the second direction D2 will be thickened, which will increase the cost and weight. In a preferred embodiment, 0.8mm≤B≤3mm, wherein the second direction D2 is the length direction of the rectangular cover body 20.

[0067] In this embodiment, the second direction D2 is perpendicular to the first direction D1.

[0068] In order to verify whether the limiting condition of 0.8 mm ≤ B ≤ 3 mm can improve the sealing performance under the condition of the first compression rate K1 being 15% ≤ K1 ≤ 55%, an experiment is conducted below to determine whether the limiting condition of 0.8 mm ≤ B ≤ 3 mm can ensure the effectiveness of the sealing member 30. The experimental parameters are shown in Table 3 below:

[0069] Table 3

[0070]

[0071] Note: "Helium test NG" in Table 3 means the test failed, and "Helium test OK" means the test passed.

[0072] As shown in Table 3, in Examples 3-1 to 3-9 of Table 3, when the first compression rate K is 35%, the size of B in Example 3-1 of Table 3 is 0.5 mm, which is smaller than the preferred range of B ≥ 0.8 mm. Since the size of the contact between the seal 30 and the cover plate body 20 in the second direction D2 is too small, when the pole 10 is subjected to a high-intensity impact in the first direction D1, it is easy to cause sealing failure, thereby causing the helium test to fail. In Examples 3-2 to 3-9 of Table 3, the size of B is greater than or equal to 0.8 mm. m, since the sealing member 30 and the cover plate body 20 have a sufficient contact area in the second direction D2, the pole 10 can ensure effective sealing after being subjected to a force of 1200N for 10 times in the first direction D1 (under high-intensity impact conditions) and after being subjected to a force of 800N for 50,000 times (test conditions that meet the working environment and life requirements), and the helium test is qualified. However, although Examples 3-9 in Table 3 can ensure the helium test is qualified, the cost is significantly increased. Therefore, under the limited condition of 0.8mm≤B≤3mm, the requirements of sealing and economy can be met at the same time.

[0073] In addition, in this embodiment, Figure 3 and Figure 4 As shown, the portion of the cover body 20 used for crimping with the seal 30 in the first direction D1 can support the seal 30 in the first direction D1. In this embodiment, as shown in FIG. Figure 4 As shown, in the first direction D1, the distance between the end of the cover body 20 crimped with the seal 30 and the end of the cover body 20 away from the seal 30 is X, X≥0.7mm, that is, the thickness of the portion of the cover body 20 used for crimping with the seal 30 is not less than 0.7mm, thereby avoiding the situation where the sealing between the cover body 20 and the seal 30 is reduced due to deformation of the cover body 20, thereby further improving the sealing reliability between the cover body 20 and the seal 30.

[0074] Furthermore, in this embodiment, if Figures 1 to 5As shown, the cover assembly also includes a first insulating member 40, which at least partially covers the side wall of the pole 10 in the circumferential direction. The first insulating member 40 can be made of plastic material to play an insulating role. The first insulating member 40 is formed into an annular structure and is arranged on the side of the cover body 20 facing the outside of the battery cell. Part of the first insulating member 40 extends into the mounting hole 21 and abuts against the seal 30 in the first direction D1, so that the seal 30 forms a second compression amount L2, wherein 0mm≤L2≤0.8mm, so as to avoid the second compression amount being too large to affect the sealing between the seal 30 and the pole 10. It should be noted that when L2 is 0, that is, the seal 30 does not produce obvious deformation in the first direction D1.

[0075] In a preferred embodiment, the second compression rate of the seal 30 is K2=L2 / H, 0%≤K2≤50%. This avoids the situation where the pressure caused by the second compression rate being too large is too high and exceeds the tolerance strength of the first insulating member 40, thereby causing the first insulating member 40 to crack, or the problem of low sealing reliability caused by the first insulating member 40 not being in contact with the seal 30.

[0076] The following experiment is conducted on the effectiveness of the limiting condition of 0%≤K2≤50%. The experimental parameters are shown in Table 4 below:

[0077] Table 4

[0078]

[0079] Note: "Helium test NG" in Table 4 means the test failed, and "Helium test OK" means the test passed.

[0080] Referring to Table 4, it can be seen that in Examples 4-1 to 4-9, K1 is within the limiting condition of 15%≤K1≤55%, but in Examples 4-7 to 4-9, due to the excessively large parameter of K2, cracks occur in the first insulating member 40, and there is a risk of insulation failure, resulting in failure of the helium test; while in Examples 4-1 to 4-6 of Table 4, K2 is within the limiting condition of 0%≤K2≤50%, and there is no cracking in the first insulating member 40, so that the first insulating member 40 has good insulation, ensuring that the helium test is qualified.

[0081] Furthermore, in this embodiment, if Figures 1 to 3 and Figure 5 As shown, the cover assembly also includes a second insulating member 50, which is arranged on the side of the cover body 20 facing the interior of the battery cell. The second insulating member 50 is formed into a structure that is compatible with the shape of the cover body 20, and the second insulating member 50 is an insulating material such as plastic, thereby ensuring the insulation between the cover body 20 and the interior of the battery cell.

[0082] In addition, in this embodiment, Figures 1 to 5 As shown, the cover assembly also includes a support member 60 formed as a ring structure, the support member 60 is embedded between the first insulating member 40 and the pole 10, and part of the first insulating member 40 is clamped between the support member 60 and the cover body 20, so that the first insulating member 40 and the surface of the cover body 20 facing the outside of the battery cell are tightly fitted, thereby improving assembly reliability.

[0083] In a preferred embodiment, the support member 60 is a weldable member, that is, the support member 60 is formed of a weldable material, for example, the support member 60 may be made of aluminum alloy, copper or ceramic, so that the support member 60 can be welded to the pole 10 .

[0084] In this embodiment, if Figure 5 As shown, the cover body 20 is provided with a pressure relief hole 22, which is a through hole structure penetrating the cover body 20; the cover assembly also includes a pressure relief member 70 installed on the pressure relief hole 22. When an abnormal situation occurs in the battery cell, the pressure inside the battery cell will increase. When the pressure increases to a preset pressure, the pressure relief member 70 will open so that the inside of the battery cell is connected to the outside through the pressure relief hole 22, thereby releasing the pressure to avoid explosion and other dangers. In this embodiment, the opening pressure of the pressure relief member 70 is P, P≤1.2MPa, which meets the working requirements of the battery cell. The pressure relief member 70 can be an explosion-proof valve.

[0085] Furthermore, in this embodiment, if Figure 5 As shown, the cover assembly also includes a protective member 71, which is installed at the pressure relief hole 22 and is arranged on the side of the cover body 20 facing the outside of the battery cell to protect the pressure relief member 70 and prevent the components outside the battery cell from impacting the pressure relief member 70 and causing the pressure relief member 70 to open prematurely, thereby failing to effectively protect the battery cell.

[0086] In addition, in this embodiment, Figures 1 to 3 and Figure 5 As shown, the cover body 20 is also provided with a liquid injection hole 23, which is formed as a through-hole structure penetrating the cover body 20. After the cover body 20 and the shell of the battery cell are assembled, the electrolyte can be injected into the battery cell through the liquid injection hole 23. After the liquid injection is completed, the liquid injection hole 23 can be sealed with a sealing nail.

[0087] According to a cover assembly provided by the present invention, by limiting the ratio of a first compression amount L1 in a first direction caused by the cover body to the seal and a dimension H of the seal in the first direction after the seal and the cover body are pressed together, that is, limiting the range of the first compression rate K1, it is avoided that insufficient press-fitting strength leads to poor sealing between the seal and the cover body and easy leakage, or that excessive press-fitting strength leads to damage to the seal when the battery cell is subjected to a preset pressure, resulting in sealing failure, thereby ensuring the effectiveness and service life of the seal.

[0088] A battery cell provided according to the present invention includes the cover plate assembly as described above, and the seal can be reliably pressed into the cover plate body and will not be damaged under a preset pressure, thereby ensuring the effectiveness, sealing reliability and service life of the seal, thereby improving the product quality and yield rate of the battery cell.

[0089] 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 cover plate assembly, characterized in that: The cover plate assembly comprises: Pole; The cover plate body is provided with a mounting hole for mounting the pole; A seal is provided between the cover body and the pole; the seal has a dimension H in the first direction, the cover body is crimped with the seal in the first direction, so that the seal has a first compression amount L1, and a first compression rate K1=L1 / H of the seal, and at room temperature or at a temperature of 120°C, 15%≤K1≤55%; A first insulating member at least partially covers the side wall of the pole in the circumferential direction, a portion of the first insulating member extends into the mounting hole and abuts against the sealing member in the first direction, and a portion of the first insulating member covering the side wall of the pole in the circumferential direction abuts against the sealing member, so that the sealing member forms a second compression amount L2, 0mm≤L2≤0.8mm; a second compression rate K2=L2 / H, 0%≤K2≤50%; Before the sealing member is compressed, in the first direction, a portion of the sealing member abutted by the first insulating member and a portion of the sealing member pressed by the cover plate body are coplanar; A support member formed into an annular structure, the support member is embedded between the first insulating member and the pole, a portion of the first insulating member is sandwiched between the support member and the cover plate body, the support member is a weldable member, and the support member is welded to the pole; In the first direction, the distance between the end of the cover body crimped with the seal and the end of the cover body away from the seal is X, X≥0.7mm, the side of the cover body facing the inside of the battery cell is convex, so that part of the cover body extends beyond the surface of the seal abutting against the pole, X<the maximum thickness of the cover body; After the cover plate body is crimped with the sealing member, the contact dimension of the sealing member with the cover plate body in the second direction is B, and 0.8 mm≤B≤3 mm.

2. The cover plate assembly according to claim 1, characterized in that: The cover plate body is provided with a pressure relief hole; the cover plate assembly further comprises: A pressure relief component is installed on the pressure relief hole; the opening pressure of the pressure relief component is P, P≤1.2MPa.

3. The cover plate assembly according to claim 1, characterized in that: The side wall of the pole is formed with a protruding limiting boss; In the first direction, the sealing member is sandwiched between the limiting boss and the cover plate body.

4. A battery cell, characterized in that: The invention comprises the cover plate assembly according to any one of claims 1 to 3.

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