Battery cell cover plate and battery cell

Abstract

The utility model 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 cover plate main body, a liquid injection hole is formed in the cover plate main body, the radial size of the liquid injection hole is a sealing plug, the liquid injection hole is assembled in the liquid injection hole, and the radial size of the sealing plug is that the circumferential side wall of the sealing plug abuts against at least part of the hole wall of the liquid injection hole, so that an effective sealing area is formed in the contact part of the sealing plug and the liquid injection hole; the size of the effective sealing area in the thickness direction of the cover plate body is a, and a is larger than or equal to 0.3 mm. According to the utility model, the sealing plug and the liquid injection hole can be effectively assembled, the sealing effect is ensured, seepage or leakage of the battery cell is avoided, and the assembly yield of the sealing plug and the cover plate main body is ensured, so that the use performance and the service life of the battery cell are ensured.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a cell cover plate and a cell. Background Technology

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage, leading to increasingly stringent requirements for their performance and safety. A lithium-ion power battery generally consists of an internal structure and an external structure. The internal structure mainly includes the cell electrode assembly, while the external structure mainly includes the cell cover and cell casing. The cell casing provides space for the cell electrode assembly, and the cell cover and cell casing are welded together to fix the electrode assembly within the internal space. After assembly, electrolyte is injected into the cell through the injection port, which is then sealed with a rubber stopper. Finally, an aluminum cap is placed on top to form a complete lithium-ion battery structure. An explosion-proof valve is installed on the cell cover to prevent cell runaway. When the internal chemical reaction intensifies and produces gas, the valve breaks under pressure, releasing energy and mitigating the runaway.

[0003] In existing technologies, the assembly connection between the cell cover and the rubber stopper is not strong enough, and leakage is prone to occur at the seal between the cell cover and the rubber stopper. Especially when the battery generates gas during charging and discharging, the internal gas pressure will exert an outward pushing force on the rubber stopper. When the aluminum cover and the cover plate fail to seal, the poor sealing between the rubber stopper and the cell cover plate will cause the battery to leak out, affecting the function and life of the cell. In order to improve the assembly reliability of the cell cover and the rubber stopper, the size of the rubber stopper is usually increased, but this makes it difficult for the rubber stopper to be inserted into the liquid injection port or causes the rubber stopper to be crooked after insertion, resulting in a low assembly yield, increased production rework costs, and reduced production efficiency. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a cell cover and a cell to solve the problems that the existing cover and the rubber stopper are not firmly connected and the cell is prone to leakage or seepage. Increasing the size of the rubber stopper will make it difficult to insert the rubber stopper into the liquid injection port or cause the rubber stopper to be crooked after insertion, resulting in a low assembly yield, increased production rework costs, and reduced production efficiency.

[0005] The first aspect of this utility model provides a battery cell cover plate, wherein the battery cell cover plate comprises:

[0006] The cover plate body has an injection hole, the radial dimension of which is...

[0007] A sealing plug is fitted into the injection hole, and the radial dimension of the sealing plug is [missing information].

[0008] The circumferential sidewall of the sealing plug abuts against at least a portion of the wall of the injection hole to form an effective sealing area at the contact point between the sealing plug and the injection hole. The effective sealing area has a dimension a in the thickness direction of the cover plate body, where a ≥ 0.3 mm. The sealing plug can withstand an internal pressure P within the battery cell, where 1.2 MPa < P ≤ 2 MPa.

[0009] Preferably, the inner wall of the injection hole has a protruding boss, making the injection hole a stepped hole with a first step and a second step, wherein the radial dimension of the first step is larger than the radial dimension of the second step, and the sealing plug is fitted onto the second step. This is the radial dimension of the second step.

[0010] Preferably, the side of the second step facing the first step has a rounded corner, and the radius of the rounded corner is R1, where R1 ≥ 0.25 mm.

[0011] Preferably, at least a portion of the sidewall of the end of the sealing plug facing the inside of the cell is inclined to form a constricted portion, and the sidewall of the constricted portion forms an angle C with the bottom wall, where 30°≤C≤75°.

[0012] Preferably, at least a portion of the sidewall of the end of the sealing plug facing the inside of the battery cell is recessed inward, such that the sealing plug is formed as a boss-shaped structure with a protrusion, and the effective sealing area is formed on the sidewall of the protrusion.

[0013] Preferably, in the thickness direction of the cover plate body, the distance between the protrusion and the constricted portion is b, where b ≥ 1.5 mm.

[0014] Preferably, in the thickness direction of the cover plate body, the distance between the protrusion and the side of the injection hole facing the inside of the cell is k, where k ≥ 0.2 mm.

[0015] Preferably, the dimension of the second stepped portion in the thickness direction of the cover plate body is h, R1+a+k≤h≤H, in mm, where H is the thickness dimension of the cover plate body in mm.

[0016] Preferably, the cell cover further includes:

[0017] A cap is provided on the first stepped portion. The first stepped portion and the second stepped portion are arranged sequentially along the axial direction of the injection hole. The first stepped portion is provided at the end facing the outside of the cell, and the second stepped portion is provided at the end facing the inside of the cell.

[0018] The second aspect of this utility model provides a battery cell, including the battery cell cover plate described in any of the above technical solutions.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0020] The battery cell cover of this utility model has an injection hole in its main body, the radial dimension of which is [missing information]. This satisfies the requirements for internal vacuuming and electrolyte injection within the battery cell; the sealing plug is assembled inside the injection hole, and the radial dimension of the sealing plug is... This avoids the problem of the sealing plug being too large and difficult to insert into the injection hole, making it easier to insert the sealing plug. The sealing plug abuts against part of the wall of the injection hole on its circumferential sidewall, so as to form an effective sealing area at the contact point between the sealing plug and the injection hole. The dimension of the effective sealing area in the thickness direction of the cover plate body is 'a', where 'a' ≥ 0.3 mm. This ensures that the sealing plug and the injection hole are effectively assembled to guarantee the sealing effect, prevents leakage or seepage from the battery cell, and ensures the assembly yield of the sealing plug and the cover plate body, thereby guaranteeing the performance and lifespan of the battery cell.

[0021] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 An exploded view of the battery cell cover plate provided in an embodiment of this utility model;

[0024] Figure 2 This is a schematic diagram of the structure of the battery cell cover plate provided in an embodiment of the present utility model;

[0025] Figure 3 A cross-sectional view of the battery cell structure assembled into a battery cell according to an embodiment of this utility model;

[0026] Figure 4 for Figure 3 A magnified structural diagram of point A in the middle.

[0027] Icons: 10-Cover plate body; 11-Injection hole; 111-Boss; 101-First step; 102-Second step; 20-Sealing plug; 21-Narrowing part; 22-Protrusion; 30-Effective sealing area; 40-Cap; 41-Flanged part; 42-Groove. Detailed Implementation

[0028] The following detailed embodiments are provided to help the reader gain a comprehensive understanding of the methods, apparatus, and / or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatus, 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 illustrative and is not limited to the order set forth herein; changes that will be apparent after understanding the disclosure of this application are possible, except for operations that must occur in a specific order. Furthermore, for clarity and brevity, descriptions of features known in the art may be omitted.

[0029] The features described herein may be implemented in different forms and should not be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many feasible ways of implementing the methods, apparatus, and / or systems described herein that will be apparent upon understanding the disclosure of this application.

[0030] Throughout the specification, when an element (such as a layer, region, or substrate) is described as being "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, it may be directly "on" another element, "connected to" another element, "bonded to" another element, "on" another element, or "covering" another element, or there may be one or more other elements in between. In contrast, when an element is described as being "directly on" another element, "directly connected to" another element, "directly bonded to" another element, "directly on" another element, or "directly covering" another element, there may be no other elements in between.

[0031] As used herein, the term “and / or” includes any one of the relevant items listed and any combination of any two or more items.

[0032] Although terms such as “first,” “second,” and “third” may be used herein to describe individual components, assemblies, regions, layers, or parts, these components, assemblies, regions, layers, or parts are not limited by these terms. Rather, these terms are used only to distinguish one component, assembly, region, layer, or part from another. Therefore, without departing from the teachings of the examples described herein, the first component, assembly, region, layer, or part referred to as the second component, assembly, region, layer, or part may also be referred to as the second component, assembly, region, layer, or part.

[0033] For ease of description, spatial relation terms such as “above,” “upper,” “below,” and “lower” are used herein to describe the relationship between one element and another, as shown in the accompanying drawings. Such spatial relation terms are intended to include not only the orientation depicted in the drawings but also different orientations of the device during use or operation. For example, if the device in the drawings is flipped, an element described as being “above” or “upper” relative to another element will subsequently be “below” or “lower” relative to that 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 relation terms used herein will be interpreted accordingly.

[0034] The terminology used herein is for the purpose of describing various examples only and is not intended to limit this disclosure. Unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. The terms “comprising,” “including,” and “having” enumerate the stated features, quantities, operations, components, elements, and / or combinations thereof, but do not exclude the presence or addition of one or more other features, quantities, operations, components, elements, and / or combinations thereof.

[0035] Variations in the shapes shown in the accompanying drawings may occur due to manufacturing techniques and / or tolerances. Therefore, the examples described herein are not limited to the specific shapes shown in the accompanying drawings, but include changes in shape that may occur during manufacturing.

[0036] The features of the examples described herein can be combined in various ways that will be apparent upon understanding the disclosure of this application. Furthermore, although the examples described herein have a wide variety of constructions, other constructions are possible, as will be apparent upon understanding the disclosure of this application.

[0037] According to a first aspect of the present invention, a battery cell cover plate is provided, which specifically includes a cover plate body 10 and a sealing plug 20.

[0038] The specific structure of the cell cover plate according to this embodiment will be described below.

[0039] In this embodiment, as Figures 1 to 4 As shown, the cover plate body 10 is formed into a plate-like structure. Specifically, the cover plate body 10 can be formed into a rectangular or circular plate-like structure. An injection hole 11 is provided on the cover plate body 10. The injection hole 11 is formed as a through hole penetrating the cover plate body 10, allowing communication between the inside and outside of the battery cell. The injection hole 11 is formed into a circular hole-like structure, and the radial dimension of the injection hole 11 is... This satisfies the requirements for vacuuming the inside of the battery cell and injecting electrolyte.

[0040] In this embodiment, as Figures 1 to 4 As shown, the sealing plug 20 is assembled inside the injection hole 11. The sealing plug 20 is elastic and has a cylindrical structure. Before assembly, the radial dimension of the sealing plug 20 is... This avoids the situation where the sealing plug 20 is too large and makes it difficult to insert into the injection hole 11, and makes it easier to insert the sealing plug 20.

[0041] like Figure 3 As shown, the sidewall of the sealing plug 20 in the circumferential direction abuts against at least a portion of the wall of the injection hole 11, forming an effective sealing area 30 at the contact point between the sealing plug 20 and the injection hole 11. The sealing plug 20 is uniformly compressed in the effective sealing area 30. The pressure that the sealing plug 20 can withstand inside the battery cell is P, where P is greater than the opening pressure of the explosion-proof valve on the battery cell. Preferably, 1.2 MPa < P ≤ 2 MPa. The dimension of the effective sealing area 30 in the thickness direction of the cover plate body 10 is a, where a ≥ 0.3 mm. This ensures that the sealing plug 20 and the injection hole 11 are effectively assembled to guarantee the sealing effect, preventing leakage or seepage from the battery cell, ensuring the assembly yield of the sealing plug 20 and the cover plate body 10, and thus guaranteeing the performance and lifespan of the battery cell.

[0042] In this embodiment, as Figure 1 , Figure 3 and Figure 4 As shown, a protruding boss 111 is formed on the inner wall of the injection hole 11, making the injection hole 11 a stepped hole with a first stepped portion 101 and a second stepped portion 102. The radial dimension of the first stepped portion 101 is larger than the radial dimension of the second stepped portion 102. The sealing plug 20 is assembled into the second stepped portion 102. The radial dimension of the second step portion 102 is defined as follows: the effective sealing area 30 is formed by the second step portion 102 uniformly pressing the outer wall of the sealing plug 20.

[0043] Furthermore, such as Figure 3 and Figure 4As shown, the second step 102 has a rounded corner on the side facing the first step 101, with a radius of R1 ≥ 0.25 mm. This serves as a guide for the assembly of the sealing plug 20, facilitating its insertion into the cover plate body 10. It should be noted that the effective sealing area 30, as described above, is located below the rounded corner.

[0044] Furthermore, in this embodiment, as Figure 3 and Figure 4 As shown, at least a portion of the sidewall of the end of the sealing plug 20 facing the inside of the battery cell is inclined to form a constriction portion 21, so that the radial dimension of the end of the sealing plug 20 facing the inside of the battery cell is reduced compared to the size of the effective sealing area 30. An angle C is formed between the sidewall of the constriction portion 21 and the bottom wall of the sealing plug 20, where 30°≤C≤75°. This ensures sealing while facilitating the insertion of the sealing plug 20 into the cover plate body 10, avoiding the situation of the sealing plug 20 being skewed, improving the assembly yield, reducing production rework costs, and improving production efficiency.

[0045] In this embodiment, as Figure 3 and Figure 4 As shown, at least a portion of the sidewall of the end of the sealing plug 20 facing the inside of the cell is recessed inward, so that the sealing plug 20 is formed into a boss 111-shaped structure with a protrusion 22. The effective sealing area 30 is formed on the sidewall of the protrusion 22. This further facilitates the insertion of the sealing plug 20 into the liquid injection hole 11 and achieves the centered positioning of the sealing plug 20 relative to the liquid injection hole 11, avoiding the situation where the sealing plug 20 is skewed during the compression with the second step portion 102.

[0046] Furthermore, in this embodiment, as Figure 4 As shown, in the thickness direction of the cover plate body 10, the distance between the protrusion 22 and the constriction 21 is b, b≥1.5mm, so as to ensure that the sealing plug 20 is always centered during the process of being inserted into the injection hole 11, and to avoid the sealing plug 20 from being skewed.

[0047] In this embodiment, as Figure 4 As shown, in the thickness direction of the cover plate body 10, the distance between the protrusion 22 and the side of the injection hole 11 facing the inside of the cell is k, k≥0.2mm, thus preventing the sealing plug 20 from being scratched by the bottom of the injection hole 11. It should be noted that in this embodiment, the injection hole 11 is formed by a stamping process, which makes it impossible to chamfer the bottom of the injection hole 11. Therefore, the distance k is set to ensure that the sealing plug 20 is not affected.

[0048] Furthermore, the second step 102 has a dimension of h in the thickness direction of the cover plate body 10, in mm, R1+a+k≤h≤H, where H is the thickness dimension of the cover plate body 10 in mm, thus satisfying the stamping process requirements of the injection hole 11.

[0049] Furthermore, in this embodiment, such as Figures 1 to 4 As shown, the cell cover also includes a cap 40, which can be made of metal and is disposed on the first stepped portion 101. The first stepped portion 101 and the second stepped portion 102 are arranged sequentially along the axial direction of the injection hole 11. The first stepped portion 101 is disposed at the end facing the outside of the cell, and the second stepped portion 102 is disposed at the end facing the inside of the cell. This allows the cap 40 to seal the sealing plug 20 inside the cell. The cap 40 is welded to the first stepped portion 101 to ensure the connection strength between the cap 40 and the cover body 10.

[0050] Specifically, the circumferential sidewall of the cap 40 is folded outward to form a flange 41. This increases the weld penetration between the cap 40 and the cover plate body 10 without increasing the thickness of the cap 40, thus improving the connection strength between the cap 40 and the cover plate body 10. Furthermore, a groove 42 is formed on the side of the cap 40 facing the sealing plug 20 to allow the sealing plug 20 to extend beyond the second step portion 102, ensuring a tight fit between the sealing plug 20 and the injection hole 11.

[0051] The following describes the process after assembling the cover plate body 10 and the sealing plug 20, as described above. Measurements were taken of a, c, b, and R1, and a helium leak test was performed on the assembled cell cover plate. In this embodiment, the helium leak rate was less than 1×10⁻⁶. -7 pa·m 3 / s indicates that the test is qualified. Specific test parameters are shown in the table below:

[0052]

[0053]

[0054] Note: In the table, "NG" indicates that the helium leak detection test is unqualified, and "OK" indicates that the helium leak detection test is qualified.

[0055] As can be seen from the table above, in Examples 1 and 13, No size requirement Within the specified range, after the cover plate body 10 and sealing plug 20 are assembled, the helium leak detection rate does not meet the requirements; in Example 3, a = 0.28 mm, which is not within the limit of a ≥ 0.3 mm, and after the cover plate body 10 and sealing plug 20 are assembled, the helium leak detection rate does not meet the requirements; in Examples 4 and 12, C is not within the limit of 30° ≤ C ≤ 75°, and the sealing plug 20 is not installed properly; in Example 7, b = 1.43 mm, which is not within the limit of b ≥ 1.5 mm, and the sealing plug 20 is not installed properly; in Example 9, R1 = 0.24 mm, which is not within the limit of R1 ≥ 0.25 mm, and the sealing plug 20 is not installed properly; while in Examples 2, 5, 6, 8, 10, 11 and 14, a, c, b, and R1 are all within the limits specified above, and after the cover body 10 is attached to the sealing plug 20, the sealing plug 20 shows no signs of improper installation, and the helium leak detection rate meets the requirements.

[0056] Furthermore, in this embodiment, such as Figure 1 and Figure 2 As shown, the cell cover also includes poles and insulating components. The poles are installed on the cover body 10 and connected to the tabs on the pole group located inside the cell. The number of poles on the cover body 10 can be one or more. The insulating components are used to separate the cover body 10 from the inside of the cell or to separate the cover body 10 from the poles, so as to play an insulating role. The insulating components can be made of plastic.

[0057] According to the present invention, a battery cell cover plate has an injection hole in its main body, the radial dimension of which is [missing information]. This satisfies the requirements for internal vacuuming and electrolyte injection within the battery cell; the sealing plug is assembled inside the injection hole, and the radial dimension of the sealing plug is... This avoids the problem of the sealing plug being too large and difficult to insert into the injection hole, making it easier to insert the sealing plug. The sealing plug abuts against part of the wall of the injection hole on its circumferential sidewall, so as to form an effective sealing area at the contact point between the sealing plug and the injection hole. The dimension of the effective sealing area in the thickness direction of the cover plate body is 'a', where 'a' ≥ 0.3 mm. This ensures that the sealing plug and the injection hole are effectively assembled to guarantee the sealing effect, prevents leakage or seepage from the battery cell, and ensures the assembly yield of the sealing plug and the cover plate body, thereby guaranteeing the performance and lifespan of the battery cell.

[0058] According to the present invention, a battery cell includes a battery cell cover plate as described above. The assembly yield of the sealing plug and the cover plate body is improved, the rework cost of the battery cell production is reduced, the production efficiency of the battery cell is improved, and the performance and lifespan of the battery cell are guaranteed.

[0059] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the technical scope disclosed in this application. Such modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A battery cell cover plate, characterized in that, The cell cover plate includes: The cover plate body has an injection hole, the radial dimension of which is... A sealing plug is fitted into the injection hole, and the radial dimension of the sealing plug is [missing information]. The circumferential sidewall of the sealing plug abuts against at least a portion of the wall of the injection hole to form an effective sealing area at the contact point between the sealing plug and the injection hole. The effective sealing area has a dimension a in the thickness direction of the cover plate body, where a ≥ 0.3 mm. The sealing plug can withstand an internal pressure P within the battery cell, where 1.2 MPa < P ≤ 2 MPa.

2. The cell cover plate according to claim 1, characterized in that, The inner wall of the injection hole has a protruding boss, making the injection hole a stepped hole with a first step and a second step. The radial dimension of the first step is larger than the radial dimension of the second step. The sealing plug is fitted onto the second step. This is the radial dimension of the second step.

3. The cell cover plate according to claim 2, characterized in that, The second step has a rounded corner on the side facing the first step, and the radius of the rounded corner is R1, where R1 ≥ 0.25 mm.

4. The cell cover plate according to claim 3, characterized in that, At least a portion of the sidewall of the end of the sealing plug facing the inside of the cell is inclined to form a constricted portion, and the sidewall of the constricted portion forms an angle C with the bottom wall, where 30°≤C≤75°.

5. The cell cover plate according to claim 4, characterized in that, At least a portion of the sidewall of the end of the sealing plug facing the inside of the cell is recessed inward, such that the sealing plug is formed as a boss-shaped structure with a protrusion, and the effective sealing area is formed on the sidewall of the protrusion.

6. The cell cover plate according to claim 5, characterized in that, In the thickness direction of the cover plate body, the distance between the protrusion and the constricted portion is b, where b ≥ 1.5 mm.

7. The cell cover plate according to claim 5, characterized in that, In the thickness direction of the cover plate body, the distance between the protrusion and the side of the injection hole facing the inside of the cell is k, where k ≥ 0.2 mm.

8. The cell cover plate according to claim 7, characterized in that, The second stepped portion has a dimension of h in the thickness direction of the cover plate body, in mm, R1+a+k≤h≤H, where H is the thickness dimension of the cover plate body, in mm.

9. The cell cover plate according to claim 2, characterized in that, The cell cover plate also includes: A cap is provided on the first stepped portion. The first stepped portion and the second stepped portion are arranged sequentially along the axial direction of the injection hole. The first stepped portion is provided at the end facing the outside of the cell, and the second stepped portion is provided at the end facing the inside of the cell.

10. A battery cell, characterized in that, Includes the cell cover plate as described in any one of claims 1 to 9.

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