Battery cell cover plate assembly, battery cell and power device

Abstract

The present application relates to the technical field of batteries. Disclosed are a battery cell cover plate assembly, a battery cell and a power device. The battery cell cover plate assembly comprises a cover plate body and a sealing bead. The cover plate body is provided with a liquid injection hole, and the inner diameter of the liquid injection hole is A. The sealing bead is provided in a compressed manner in the liquid injection hole and is used for sealing the liquid injection hole, and the diameter of the sealing bead is B. The compression ratio of the sealing bead to the liquid injection hole is K, satisfying: K=(B-A) / A, and 4%≤K≤40%. The battery cell cover plate assembly provided in the present application can ensure the effect of the sealing bead sealing the liquid injection hole. The present application provides a new liquid injection hole sealing structure, which is different from the traditional sealing structure using plastic plugs and aluminum rivets, and can effectively improve the sealing effect for liquid injection holes. In addition, in the present application, the liquid injection hole is sealed only by using the sealing bead, allowing for fewer structural members, thereby effectively reducing costs. During production, a sealing bead can simply be pressed into a liquid injection hole, thereby reducing processing procedures, accelerating the production cycle, and improving economic benefits.

Description

Battery cell cover plate assembly, battery cell and power device

[0001] Cross-reference to related applications

[0002] The present application claims priority to the Chinese patent application No. 202411006294.9, filed on July 25, 2024, and entitled "Battery cell cover plate assembly, battery cell and power device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of battery, in particular to a battery cell cover plate assembly, a battery cell and a power device. BACKGROUND

[0004] With the development and popularization of lithium batteries in the automobile power industry, higher requirements are put forward for the sealing performance of power batteries.

[0005] The traditional injection hole of the battery cover plate is sealed by glue nails and aluminum nails. First, the glue nails are punched into the injection hole, and then the aluminum nails and the cover plate body are welded to achieve the purpose of sealing.

[0006] In this way, the sealing performance of the injection hole depends on the welding quality. However, the unstable welding quality cannot guarantee the sealing performance of the injection hole. SUMMARY

[0007] Therefore, the present application provides a battery cell cover plate assembly, a battery cell and a power device to solve the problem of how to improve the sealing performance of the injection hole of the battery cell cover plate assembly.

[0008] In a first aspect, the present application provides a battery cell cover plate assembly, comprising a cover plate body and a sealing bead. The cover plate body is provided with an injection hole, and the inner diameter of the injection hole is A; the sealing bead is pressed into the injection hole and used to seal the injection hole, and the diameter of the sealing bead is B; the extrusion ratio of the sealing bead and the injection hole is K, which satisfies: K = (B-A) / A, 4%≤K≤40%.

[0009] Beneficial effects: the battery cell cover plate assembly provided by the present application sets the sealing bead in the injection hole and extrudes the sealing bead in the injection hole to seal the injection hole. By controlling the extrusion ratio K of the sealing bead and the injection hole within the range of 4%≤K≤40%, the sealing effect of the sealing bead on the injection hole can be ensured. The present application provides a new injection hole sealing structure, which is different from the traditional sealing structure of glue nails and aluminum nails, and can effectively improve the sealing effect of the injection hole. In addition, in the present application, the injection hole only needs to be sealed by the sealing bead, which has fewer structural parts and can effectively reduce the cost. When producing, the sealing bead is pressed into the injection hole, which reduces the processing procedures, speeds up the production rhythm and improves the economic benefits.

[0010] In an alternative embodiment, the hardness of the material of the sealing bead is greater than the hardness of the material of the cover plate body.

[0011] In an alternative embodiment, the inner surface of the cover plate body is provided with a groove recessed towards the outer surface of the cover plate body, and the liquid injection hole is arranged in the groove.

[0012] In an alternative embodiment, the thickness of the cover plate body is T, the depth of the recess of the groove relative to the inner surface of the cover plate body is T1, and the following condition is satisfied: 0 < T1 / T ≤ 0.5.

[0013] In an alternative embodiment, the bottom of the groove is provided with a convexity protruding towards the inner side of the cover plate body, and the liquid injection hole is arranged in the convexity.

[0014] In an alternative embodiment, the height of the convexity protruding from the inner surface of the cover plate body is T2, and the following condition is satisfied: 0 < T2 / T ≤ 0.5.

[0015] In an alternative embodiment, the liquid injection hole is provided with an outwardly expanded guide structure at one end close to the outer side of the cover plate body, and the maximum inner diameter of the guide structure is greater than the diameter of the sealing bead.

[0016] In an alternative embodiment, the outer side of the sealing bead and the periphery of the sealing bead in contact with the liquid injection hole are provided with sealing glue.

[0017] In a second aspect, the application further provides an electric core, comprising a shell, an electrode assembly, and the electric core cover plate assembly of any one of the above technical solutions. The shell has an open end; the electrode assembly is arranged in the shell; and the electric core cover plate assembly is arranged at the open end of the shell to encapsulate the electrode assembly in the shell.

[0018] Beneficial effects: Because the electric core comprises the electric core cover plate assembly, it has the same effects as the electric core cover plate assembly, which will not be described here.

[0019] In a third aspect, the application further provides a power device comprising the electric core of the above technical solution.

[0020] Beneficial effects: Because the power device comprises the electric core, it has the same effects as the electric core, which will not be described here. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the specific embodiments or prior art of the present application, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0022] Fig. 1 is a structural schematic diagram of an electric cell cover plate assembly according to an embodiment of the present application;

[0023] Fig. 2 is a top view of the electric cell cover plate assembly shown in Fig. 1;

[0024] Fig. 3 is a sectional view along A-A in Fig. 2;

[0025] Fig. 4 is an enlarged view of a portion of B in Fig. 3;

[0026] Fig. 5 is a structural schematic diagram of the inner side of the cover plate body in the electric cell cover plate assembly shown in Fig. 1;

[0027] Fig. 6 is an enlarged view of a portion of the liquid injection hole in Fig. 5.

[0028] Reference signs: 1, cover plate body; 2, liquid injection hole; 3, sealing bead; 4, groove; 5, convex bump; 6, guide structure. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in connection with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0030] The embodiments of the present application will be described below in connection with Figs. 1 to 6.

[0031] According to the embodiments of the present application, in a first aspect, an electric cell cover plate assembly is provided, which comprises a cover plate body 1 and a sealing bead 3. The cover plate body 1 is provided with a liquid injection hole 2, the inner diameter of the liquid injection hole 2 being A; the sealing bead 3 is pressed into the liquid injection hole 2 and used to seal the liquid injection hole 2, the diameter of the sealing bead 3 being B; the pressing ratio of the sealing bead 3 to the liquid injection hole 2 is K, which satisfies: K = (B-A) / A, 4%≤K≤40%.

[0032] The electric cell cover plate assembly provided by the embodiments of the present application realizes the sealing of the liquid injection hole 2 by setting the sealing bead 3 in the liquid injection hole 2 and pressing the sealing bead 3 into the liquid injection hole 2. By controlling the pressing ratio K of the sealing bead 3 to the liquid injection hole 2 within the range of 4%≤K≤40%, the sealing effect of the sealing bead 3 on the liquid injection hole 2 can be ensured. The present application provides a new liquid injection hole 2 sealing structure, which is different from the traditional sealing structure of glue nails and aluminum nails and can effectively improve the sealing effect of the liquid injection hole 2. In addition, in the present application, the liquid injection hole 2 only needs to be sealed by the sealing bead 3, so the number of structural parts is small and the cost can be effectively reduced. During production, the sealing bead 3 is simply pressed into the liquid injection hole 2, which reduces the processing procedures, speeds up the production rhythm and improves the economic benefits.

[0033] In some embodiments, the hardness of the material of the sealing bead 3 is greater than the hardness of the material of the cover plate body 1.

[0034] Compared with the material hardness of the cover plate body 1, the sealing bead 3 can ensure a strong hardness by using a material with a greater hardness, so as to ensure that the sealing bead 3 maintains an intact structure when being pressed into the liquid injection hole 2, thereby ensuring the sealing effect on the liquid injection hole 2. In some embodiments, the sealing bead 3 is a steel bead.

[0035] In some embodiments, in combination with FIGS. 4 and 6, the inner surface of the cover plate body 1 is provided with a groove 4 recessed toward the outer surface of the cover plate body 1, and the liquid injection hole 2 is arranged in the groove 4.

[0036] It should be noted that the inner surface of the cover plate body 1 refers to the side of the cover plate assembly facing the electrode assembly inside the shell of the battery cell after being assembled to the shell of the battery cell, and the surface of the cover plate body 1 facing the electrode assembly is the inner surface, and vice versa, the surface of the cover plate body 1 facing away from the electrode assembly is the outer surface.

[0037] By arranging the groove 4 on the inner surface of the cover plate body 1 and arranging the liquid injection hole 2 in the groove 4, the anti-deformation ability of the cover plate body 1 at the liquid injection hole 2 can be enhanced to resist the deformation force when the sealing bead 3 is pressed in.

[0038] In some embodiments, as shown in FIG. 4, the thickness of the cover plate body 1 is T, the depth of the groove 4 recessed relative to the inner surface of the cover plate body 1 is T1, and 0 < T1 / T ≤ 0.5 is satisfied.

[0039] By controlling the ratio of the depth T1 of the groove 4 to the thickness T of the cover plate body 1 within the range of less than 0.5, the processing difficulty of the groove 4 can be reduced.

[0040] In some embodiments, in combination with FIGS. 4 and 6, the bottom of the groove 4 is provided with a convexity 5 protruding toward the inner side of the cover plate body 1, and the liquid injection hole 2 is arranged in the convexity 5.

[0041] By arranging the convexity 5 on the bottom of the groove 4, the depth of the liquid injection hole 2 can be extended to provide sufficient installation space for the sealing bead 3 and improve the sealing effect, and at the same time, the convexity 5 can enhance the structural strength and anti-deformation ability of the cover plate body 1 at the liquid injection hole 2.

[0042] In some embodiments, as shown in FIG. 4, the height of the convexity 5 protruding from the inner surface of the cover plate body 1 is T2, and 0 < T2 / T ≤ 0.5 is satisfied.

[0043] By controlling the ratio of the height T2 of the convexity 5 protruding from the inner surface of the cover plate body 1 to the thickness T of the cover plate body 1 within the range of less than 0.5, the processing difficulty of the groove 4 can be reduced.

[0044] In some embodiments, as shown in FIG. 4, the injection hole 2 is provided with an outwardly expanded guide structure 6 at one end close to the outer side of the cover plate body 1, and the maximum inner diameter of the guide structure 6 is greater than the diameter of the sealing bead 3.

[0045] By providing the guide structure 6 at one end of the injection hole 2 close to the outer side of the cover plate body 1, since the guide structure 6 is an outwardly expanded structure and the maximum inner diameter of the guide structure 6 is greater than the diameter of the sealing bead 3, the guide structure 6 can play a guiding role in the process of pressing the sealing bead 3 into the injection hole 2, facilitating the assembly of the sealing bead 3.

[0046] Specifically, as viewed along the axial cross section of the injection hole 2, the guide structure 6 can be an oblique angle or a rounded angle.

[0047] In some embodiments, the outer side of the sealing bead 3 and the periphery where the sealing bead 3 contacts the injection hole 2 are provided with sealing glue.

[0048] After the sealing bead 3 is pressed into the injection hole 2, by applying sealing glue to the outer side of the sealing bead 3 and the periphery where the sealing bead 3 contacts the injection hole 2, the sealing performance at the injection hole 2 can be further enhanced.

[0049] The following provides sixteen specific experimental cases to illustrate the effects of the present application.

[0050] In the cases, except that the diameter A of the injection hole 2 and the diameter B of the sealing bead 3 are variables, the remaining parameters are the same.

[0051] The test results are shown in Table 1.

[0052] Table 1:

[0053] According to experimental case one, the extrusion ratio K is 2.5%, which is less than the lower limit value of 4%, and the helium leak detection at 1.2 MPa does not meet the sealing requirements of the injection hole 2.

[0054] According to experimental case twelve, the extrusion ratio K is 45%, which is greater than the upper limit value of 40%, although the helium leak detection at 1.2 MPa does not leak, which meets the sealing requirements, but since the size of the sealing bead 3 is too large, it is difficult to hit the sealing bead 3 into the injection hole 2, therefore, it is not recommended to use.

[0055] In the remaining experimental cases, the extrusion ratio K is between 4% and 40%, the helium leak detection at 1.2 MPa does not leak, which meets the sealing requirements of the injection hole 2, and the sealing bead 3 can normally hit the injection hole 2.

[0056] According to the embodiments of the present application, the second aspect also provides a battery cell, comprising a shell, an electrode assembly and the battery cell cover plate assembly of any one of the above embodiments. The shell has an open end; the electrode assembly is arranged in the shell; and the battery cell cover plate assembly is arranged at the open end of the shell to encapsulate the electrode assembly in the shell.

[0057] Since the battery cell comprises the battery cell cover plate assembly, it has the same effects as the battery cell cover plate assembly, which will not be repeated here.

[0058] The battery cell provided by the embodiments of the present application comprises the battery cell cover plate assembly in the above embodiments, the sealing bead 3 is arranged in the liquid injection hole 2, and the sealing bead 3 is extruded in the liquid injection hole 2 to seal the liquid injection hole 2. By controlling the extrusion ratio K of the sealing bead 3 and the liquid injection hole 2 in the range of 4%≤K≤40%, the sealing effect of the sealing bead 3 on the liquid injection hole 2 can be ensured. The present application provides a new liquid injection hole sealing structure, which is different from the traditional sealing structure of glue nails and aluminum nails, and can effectively improve the sealing effect of the liquid injection hole 2. In addition, in the present application, the liquid injection hole 2 only needs to be sealed by the sealing bead 3, and the structure is simple, which can effectively reduce the cost. When producing, the sealing bead 3 is pressed into the liquid injection hole 2, which reduces the processing procedure, speeds up the production rhythm and improves the economic benefit.

[0059] According to the embodiments of the present application, the third aspect also provides a power device comprising the battery cell in the above technical solutions.

[0060] Since the power device comprises the battery cell, it has the same effects as the battery cell, which will not be repeated here.

[0061] Although the embodiments of the present application are described in combination with the drawings, various modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An electrochemical cell cover plate assembly, comprising: The application relates to a sealing structure of a liquid injection hole of a battery cell cover plate. The sealing structure comprises: a cover plate body provided with a liquid injection hole, the inner diameter of the liquid injection hole being A; a sealing bead pressed into the liquid injection hole for sealing the liquid injection hole, the diameter of the sealing bead being B; the pressing ratio of the sealing bead and the liquid injection hole being K, wherein K=(B-A) / A, 4%<=K<=40%.

2. The cell cover plate assembly of claim 1, wherein, The hardness of the material of the sealing bead is greater than the hardness of the material of the cover plate body.

3. The cell cover plate assembly of claim 1 or 2, wherein, The inner surface of the cover plate body is provided with a groove recessed towards the outer surface of the cover plate body, and the liquid injection hole is arranged in the groove.

4. The cell cover plate assembly of claim 3, wherein, The thickness of the cover plate body is T, the depth of the groove recessed relative to the inner surface of the cover plate body is T1, and 0 5. The cell cover plate assembly of claim 3, wherein, The bottom of the groove is provided with a convexity protruding towards the inner side of the cover plate body, and the liquid injection hole is arranged in the convexity.

6. The cell cover plate assembly of claim 5, wherein, The height of the convexity protruding from the inner surface of the cover plate body is T2, and 0 7. The cell cover plate assembly of claim 1 or 2, wherein, The liquid injection hole is provided with an outwardly expanded guide structure at one end close to the outer side of the cover plate body, and the maximum inner diameter of the guide structure is greater than the diameter of the sealing bead.

8. The cell cover plate assembly of claim 7, wherein, The outer side of the sealing bead and the periphery of the sealing bead in contact with the liquid injection hole are provided with sealing glue.

9. An electric cell characterized by The application also relates to a battery cell. The battery cell comprises: a shell with an open end; an electrode assembly arranged in the shell; 10. A power plant characterized by the battery cell cover plate assembly of any one of claims 1 to 8 is arranged at the open end of the shell to encapsulate the electrode assembly in the shell. The application further relates to a battery cell comprising the battery cell of claim 9.

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