Cover plate assembly, battery cell and battery

Abstract

The invention provides a cover plate assembly, a battery cell and a battery, the cover plate assembly comprises a cover plate body, an electrode terminal, a first connecting piece, a second connecting piece and a protection piece, and the cover plate body is provided with a mounting hole penetrating through the thickness direction of the cover plate body; the electrode terminal is mounted to the mounting hole; the first connecting piece is sleeved on the electrode terminal around the mounting hole and is connected with the electrode terminal; the second connecting piece is arranged on the surface of the first connecting piece and covers the electrode terminal and at least part of the first connecting piece; and the protection piece is pressed between the electrode terminal and the second connecting piece, and the protection piece at least covers a gap at the connecting position of the first connecting piece and the electrode terminal. Therefore, the protection piece in the cover plate assembly is pressed between the electrode terminal and the second connecting piece, and the protection piece at least covers the gap at the connecting position of the first connecting piece and the electrode terminal. Therefore, the protection piece and the second connecting piece are matched to separate the electrode terminal at the gap and the first connecting piece from external air, and the situation that the internal resistance of the electrode terminal is increased to cause negative effects can be prevented.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular, to a cover plate assembly, an electric core, and a battery. Background Art

[0002] With the increasing development of electronic products, batteries are used more and more widely. As an important part of the battery, the battery cover plate has the most complex structure. In order to reduce costs, the negative electrode post on the negative terminal side often uses pure copper material. The welding block of the negative terminal and the aluminum material have different materials. The two are often fixedly connected by riveting + welding. There is a potential difference between the two. When both are exposed, electrochemical corrosion will occur between copper and aluminum, preferentially corroding the aluminum material with a lower potential, which will increase the internal resistance between the welding block and the negative terminal. In severe cases, the electrode post may fall off, resulting in adverse consequences.

[0003] Therefore, how to solve the problem of increased internal resistance of the electrode terminal is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] In view of this, this application provides a cover plate assembly, an electric core, and a battery, which can solve the technical problem of increased internal resistance of the electrode terminal.

[0005] In order to achieve the above object, this application provides the following technical solutions:

[0006] A cover plate assembly includes:

[0007] A cover plate body having an installation hole penetrating in its thickness direction;

[0008] An electrode terminal passing through the installation hole;

[0009] A first connecting member disposed on one side of the cover plate body, sleeved around the installation hole on the electrode terminal and connected to the electrode terminal;

[0010] A second connecting member disposed on the surface of the first connecting member and covering the electrode terminal and at least part of the first connecting member;

[0011] A protection member pressed between the electrode terminal and the second connecting member, and the protection member at least covers the gap at the connection position between the first connecting member and the electrode terminal.

[0012] Optionally, in the above cover plate assembly, along the axial direction of the electrode terminal, the protection member covers the surface of the electrode terminal and the gap.

[0013] Optionally, in the above-mentioned cover plate assembly, the first connecting member is provided with a groove, which is recessed in the side surface of the first connecting member facing the second connecting member and surrounds the electrode terminal. At least a part of the protective member is accommodated in the groove, and the depth of the groove is less than the thickness of the protective member before being compressed.

[0014] Optionally, in the above-mentioned cover plate assembly, the thickness of the protective member before being compressed is a, satisfying 0.2≤a≤2mm.

[0015] Optionally, in the above-mentioned cover plate assembly, the compression rate of the protective member along its axial direction is greater than or equal to 10% and less than or equal to 50%.

[0016] Optionally, in the above-mentioned cover plate assembly, along the radial direction of the protective member, the length of the edge of the protective member exceeding the gap is c, satisfying 0.5mm≤c≤2mm.

[0017] Optionally, in the above-mentioned cover plate assembly, the second connecting member is provided with a positioning hole, which corresponds to the electrode terminal along the axial direction of the electrode terminal.

[0018] Optionally, in the above-mentioned cover plate assembly, the material of the protective member includes fluororubber or a composite material of polypropylene and ethylene propylene diene monomer.

[0019] A battery cell includes the above-mentioned cover plate assembly.

[0020] A battery includes a plurality of the above-mentioned battery cells, and the electrode terminals of two adjacent battery cells are electrically connected through a second connecting member.

[0021] In the cover plate assembly provided by the present application, the protective member is pressed between the electrode terminal and the second connecting member, and the protective member at least covers the gap at the connection position between the first connecting member and the electrode terminal. Thus, the protective member and the second connecting member cooperate to separate the electrode terminal and the first connecting member at the gap from the external air, and can prevent the occurrence of adverse consequences caused by the increase in the internal resistance of the electrode terminal. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0023] Figure 1 It is an exploded view of a partial cover plate assembly provided by an embodiment of the present application;

[0024] Figure 2Exploded view of the cover assembly provided by the embodiment of the present application;

[0025] Figure 3 Schematic structural diagram of the cover assembly provided by the embodiment of the present application;

[0026] Figure 4 Top view of the cover assembly provided by the embodiment of the present application;

[0027] Figure 5 is Figure 4 A - A sectional view in

[0028] Figure 6 is Figure 5 Partial enlarged view in

[0029] Figure 7 Schematic structural diagram of the battery provided by the embodiment of the present application.

[0030] Wherein:

[0031] 1. Cover body; 11. Mounting hole;

[0032] 2. Electrode terminal; 3. First connecting member; 31. Groove;

[0033] 4. Second connecting member; 41. Positioning hole; 5. Protective member; 6. First insulating member; 7. Second insulating member; 8. Sealing member. Detailed implementation manners

[0034] The present application provides a cover assembly.

[0035] Next, the technical solutions in the embodiments of the present application will be described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0036] As Figures 1-7 shown, the embodiment of the present application provides a cover assembly, which can solve the technical problem of the increased internal resistance of the electrode terminal 2.

[0037] First, as Figures 1-2As shown in the figure, the cover plate assembly includes a cover plate body 1, an electrode terminal 2, a first connecting member 3, a second connecting member 4, and a protection member 5. Among them, the cover plate body 1 has a mounting hole 11 penetrating through its thickness direction; the electrode terminal 2 is sleeved in the mounting hole 11; the first connecting member 3 is arranged on one side of the cover plate body 1, and is sleeved around the mounting hole 11 on the electrode terminal 2 and connected to the electrode terminal 2; the second connecting member 4 is arranged on the surface of the first connecting member 3 and covers the electrode terminal 2 and at least part of the first connecting member 3; the protection member 5 is pressed between the electrode terminal 2 and the second connecting member 4, and the protection member 5 at least covers the gap at the connection position between the first connecting member 3 and the electrode terminal 2. The protection member 5 is pressed between the electrode terminal 2 and the second connecting member 4 and at least covers the gap at the connection position between the first connecting member 3 and the electrode terminal 2. In some embodiments, the shape of the protection member 5 is adapted to the cross-section of the electrode terminal 2 and can accurately cover the gap. The first connecting member 3 is used to fix the electrode terminal 2 to components such as the cover plate body 1, the seal 8, the first insulating member 6, and the second insulating member 7, and can also be used for electrical connection with external components.

[0038] In some embodiments, the protection member 5 can be a structural member that can deform under a certain pressure.

[0039] In some embodiments, when the electrode terminal 2 is the negative electrode, its material is usually copper, and the material of the first connecting member 3 is aluminum. There is a potential difference between the two materials (the potential difference of aluminum is lower than that of copper, the electrode potential of copper is +0.34V, and that of aluminum is -1.66V). If the electrode terminal 2 and the first connecting member 3 are simultaneously exposed to the air and form an electric couple (primary battery), it will cause an increase in the internal resistance of the electrode terminal 2, which may lead to a decline in the structural stability and then cause adverse consequences. At the same time, it will cause the first connecting member 3 to oxidize and corrode quickly, resulting in the situation that the electrode terminal 2 falls off from the first connecting member 3. Therefore, setting the protection member 5 can seal the gap at the connection position between the electrode terminal 2 and the first connecting member 3, avoiding air leakage when the second connecting member 4 is connected to the first connecting member 3, resulting in the gap at the connection position between the electrode terminal 2 and the first connecting member 3 coming into contact with the external air, thereby causing the electrode terminal 2 to oxidize. At the same time, it also avoids the situation that the protection member 5 at the gap position forms an electric couple with the first connecting member 3. It should be noted that the material of the electrode terminal 2 is not limited to copper, and the material of the first connecting member 3 is not limited to aluminum. The materials of the electrode terminal 2 and the first connecting member 3 can also be the same material. And the connection between the first connecting member 3 and the electrode terminal 2 includes but is not limited to welding or riveting; the connection between the first connecting member 3 and the second connecting member 4 includes but is not limited to welding or riveting.

[0040] It can be seen that the protective member 5 in the cover plate assembly provided by the embodiments of the present application is pressed between the electrode terminal 2 and the second connecting member 4, and the protective member 5 at least covers the gap at the connection position between the first connecting member 3 and the electrode terminal 2. Thus, the cooperation between the protective member 5 and the second connecting member 4 separates the electrode terminal 2 and the first connecting member 3 at the gap from the external air, and can prevent the occurrence of adverse consequences caused by the increase in the internal resistance of the electrode terminal.

[0041] The protective member 5 cooperating with the second connecting member 4 can separate the electrode terminal 2 and the first connecting member 3 at the gap from the external air, and can also separate the end face of the electrode terminal 2 from the external air, which can reduce the oxidation of the electrode terminal 2 and prevent the occurrence of adverse consequences caused by the increase in the internal resistance of the electrode terminal 2.

[0042] During specific implementation, along the axial direction of the electrode terminal 2, the protective member 5 covers the surface of the electrode terminal 2 and the gap at the connection position between the first connecting member 3 and the electrode terminal 2. That is, the protective member 5 covers both the gap and the surface of the electrode terminal 2, and the protective member 5 can separate the end face of the electrode terminal 2 from the external air, which can reduce the oxidation of the electrode terminal 2. In this embodiment, the protective member 5 can be a solid member to improve the sealing performance of the protective member 5.

[0043] During specific implementation, the first connecting member 3 is provided with a groove 31. The groove 31 is formed by concave inward on the side of the first connecting member 3 facing the second connecting member 4, and the groove 31 surrounds the electrode terminal 2. At least part of the protective member 5 is accommodated in the groove 31. The groove 31 provides a specific installation space for the protective member 5, which helps the precise positioning of the protective member 5. And the depth of the groove 31 is less than the thickness of the protective member 5 before being compressed. This design makes the protective member 5 in a certain compressed state after installation. The compressed state can make the protective member 5 fit tightly with components such as the groove 31 and the electrode terminal 2, enhancing the sealing effect, providing sufficient compression rate for the protective member 5, and avoiding the situation of poor sealing effect of the protective member 5. At the same time, the depth of the groove 31 cannot be much less than the thickness of the protective member 5 before being compressed, to avoid too large a compression rate of the protective member 5 and the situation of the sealing performance failure of the protective member 5 after aging.

[0044] During specific implementation, as Figure 6 shown, the thickness of the protective member 5 before being compressed is a, satisfying 0.2 ≤ a ≤ 2 mm. It should be noted that a can be any one of 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.5 mm, 2.0 mm.

[0045] The test results of the specific effects that the specific value of the thickness a of the protective member 5 before being compressed can achieve in the cover plate assembly are shown in Table 1:

[0046] Table 1

[0047]

[0048] As can be seen from Table 1, controlling the size of a can not only avoid the difficult injection molding caused by too small thickness, and when assembling the cover plate assembly, the protection part 5 is easily deformed when clamped and is not easy to be positioned, but also avoid the situation that the height space occupied is too large due to too large thickness, which is not conducive to the improvement of battery capacity.

[0049] During specific implementation, as Figure 6 shown, the compression rate of the protection part 5 along its axial direction is greater than or equal to 10% and less than or equal to 50%. The thickness of the protection part 5 after compression is b, and the compression rate is satisfies It should be noted that the compression rate of the protection part 5 can be any one of 10%, 15%, 20%, 25%, 26%, 27%, 28%, 29%, 30%, 35%, 40%, 45%, 50%.

[0050] For the specific values of the thickness a of the protection part 5 before compression, the specific value of the thickness b after compression, the specific value of the compression rate at a specific thickness, and the test results of its sealing performance, please refer to Table 2:

[0051] Table 2

[0052]

[0053]

[0054] As can be seen from Table 2, controlling the thickness and compression rate of the protection part 5 can not only avoid the situation that the sealing performance is poor due to too small compression rate of the protection part 5, but also avoid the situation that the sealing performance fails after the protection part 5 ages due to too large compression rate of the protection part 5.

[0055] During specific implementation, as Figure 6 shown, along the radial direction of the protection part 5, the length of the edge of the protection part 5 exceeding the gap at the connection position of the first connecting part 3 and the electrode terminal 2 is c, which satisfies 0.5mm ≤ c ≤ 2mm. It should be noted that c can be any one of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.5mm, 2.0mm.

[0056] For the specific value of c and the test results of the sealing performance of the protection part 5, please refer to Table 3:

[0057] Table 3

[0058]

[0059] As can be seen from Table 3, controlling the size of c can not only avoid the failure of sealing due to too small size, but also avoid the situation that the width space is occupied too much and the size of the structural member is easily limited due to too large size.

[0060] In specific implementation, the second connecting member 4 is provided with a positioning hole 41, and along the axial direction of the electrode terminal 2, the positioning hole 41 corresponds to the electrode terminal 2. The setting of the positioning hole 41 provides an accurate positioning reference for the installation of the second connecting member 4, enabling the second connecting member 4 to be accurately installed at the predetermined position, ensuring the fitting accuracy between it and the electrode terminal 2 and the first connecting member 3. This helps to improve the assembly efficiency of the entire cover plate assembly and reduce the performance degradation or fault problems caused by installation deviation. At the same time, the accurate positioning is also beneficial to ensuring the good electrical connection performance between the second connecting member 4 and the electrode terminal 2, further enhancing the stability and reliability of the assembly. It should be noted that when the second connecting member 4 is provided with the positioning hole 41, the protective member 5 needs to be able to cover the gap at the connection position of the electrode terminal 2 and the first connecting member 3, and also needs to cover the end face of the electrode terminal 2. At the same time, it is also necessary to ensure that the protective member 5 can completely cover the positioning hole 41 of the second connecting member 4. When the second connecting member 4 is not provided with the positioning hole 41, the protective member 5 can be set to only cover the gap at the connection position of the electrode terminal 2 and the first connecting member 3 (i.e., the protective member 5 is an annular member); or, the protective member 5 covers both the gap at the connection position of the electrode terminal 2 and the first connecting member 3 and the end face of the electrode terminal 2. When the protective member 5 is an annular member, the length by which the edge of the protective member 5 extends beyond the gap at the connection position of the first connecting member 3 and the electrode terminal 2 is c, which is understood to mean that both the outer edge and the inner edge of the protective member 5 extend beyond the gap at the connection position of the first connecting member 3 and the electrode terminal 2 by a length of c.

[0061] In specific implementation, the material of the protective member 5 includes fluororubber (FKM) or a composite material of polypropylene (PP) and ethylene propylene diene monomer (EPDM). Fluororubber has excellent high-temperature resistance, oil resistance, chemical corrosion resistance and aging resistance, and can be used for a long time under relatively harsh environmental conditions, effectively protecting the connection part of the electrode terminal 2 and the first connecting member 3. The composite material of polypropylene and ethylene propylene diene monomer combines the rigidity and chemical resistance of polypropylene and the elasticity, weather resistance and insulation performance of ethylene propylene diene monomer. It can not only provide good sealing and insulation effects, but also has a certain flexibility, enabling it to better adapt to the deformation and stress during the installation process and ensuring the close fit between the protective member 5 and each component. However, it is not limited to this. The material of the protective member 5, as long as it can achieve its sealing performance, those skilled in the art can make specific designs according to actual needs.

[0062] In a specific implementation, the cover assembly further includes a first insulating member 6, a second insulating member 7 and a sealing member 8, wherein the first insulating member 6 is disposed between the first connecting member 3 and the cover body 1, and is used to insulate the cover body 1 and the first connecting member 3. The second insulating member 7 is disposed on the surface of the cover body 1 away from the first insulating member 6, and is used to insulate the electrode terminal 2 and the cover body 1. The sealing member 8 is disposed in the mounting hole 11 and is sleeved on the outer side of the electrode terminal in the circumferential direction, so that part of the sealing member 8 is located between the outer wall of the electrode terminal 2 and the hole wall of the mounting hole 11 of the cover body 1, and part of the sealing member 8 is pressed between the bottom plate of the electrode terminal 2 and the cover body 1 along its axial direction, and is used to insulate the electrode terminal 2 and the cover body 1, so as to improve the insulation and sealing performance of the cover assembly 1.

[0063] The present application also provides a battery cell, including the above-mentioned cover plate assembly. Therefore, based on the above-mentioned cover plate assembly embodiment, the battery cell of the present application embodiment at least has all the beneficial effects brought by the technical solution of the above-mentioned cover plate assembly embodiment. Figure 7 As shown, the embodiment of the present application also provides a battery, including the above-mentioned battery cell, and the electrode terminals 2 of two adjacent battery cells are electrically connected through the second connecting member 4 (that is, the second connecting member 4 is used to be welded to the first connecting member 3 and serves to connect different battery cells in the battery). It also has at least all the beneficial effects brought by the technical solution of the above-mentioned cover plate assembly embodiment.

[0064] The basic principles of the present application are described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, effects, etc. mentioned in the present application are only examples and not limitations, and it cannot be considered that these advantages, strengths, effects, etc. are required by each embodiment of the present application. In addition, the specific details disclosed above are only for the purpose of illustration and ease of understanding, not for limitation, and the above details do not limit the present application to being implemented by adopting the above specific details.

[0065] The block diagrams of the devices, apparatuses, equipment, and systems involved in this application are only illustrative examples and are not intended to require or imply that they must be connected, arranged, and configured in the manner shown in the block diagram. As will be appreciated by those skilled in the art, these devices, apparatuses, equipment, and systems can be connected, arranged, and configured in any manner. Words such as "including", "comprising", "having", etc. are open words, referring to "including but not limited to", and can be used interchangeably with them. The words "or" and "and" used here refer to the words "and / or" and can be used interchangeably with them, unless the context clearly indicates otherwise. The words "such as" used here refer to the phrase "such as but not limited to", and can be used interchangeably with them.

[0066] It should also be noted that in the devices, equipment and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations shall be regarded as equivalent solutions of the present application.

[0067] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0068] It should be understood that the qualifiers "first", "second", "third", "fourth", "fifth" and "sixth" used in the description of the embodiments of the present application are only for more clearly elaborating the technical solutions and cannot be used to limit the protection scope of the present application.

[0069] The above description has been presented for purposes of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the form disclosed herein. Although several example aspects and embodiments have been discussed above, those skilled in the art will recognize some of their variations, modifications, alterations, additions, and subcombinations.

Claims

1. A cover plate assembly, characterized in that, Comprising: A cover body (1) having a mounting hole (11) penetrating through its thickness direction; An electrode terminal (2) inserted through the mounting hole (11); A first connecting member (3) disposed on one side of the cover body (1), sleeved around the mounting hole (11) and connected to the electrode terminal (2); A second connecting member (4) disposed on the surface of the first connecting member (3) and covering the electrode terminal (2) and at least part of the first connecting member (3); A protection member (5) pressed between the electrode terminal (2) and the second connecting member (4), and the protection member (5) at least covers the gap at the connection position between the first connecting member (3) and the electrode terminal (2).

2. The cover plate assembly according to claim 1, characterized in that, Along the axial direction of the electrode terminal (2), the protection member (5) covers the surface of the electrode terminal (2) and the gap.

3. The cover plate assembly according to claim 2, wherein, The first connecting member (3) is provided with a groove (31), the groove (31) is recessed in the side surface of the first connecting member (3) facing the second connecting member (4), and the groove (31) surrounds the electrode terminal (2). At least part of the protection member (5) is received in the groove (31), and the depth of the groove (31) is less than the thickness of the protection member (5) before being compressed.

4. The cover plate assembly according to claim 1, characterized in that, The thickness of the protection member (5) before being compressed is a, satisfying 0.2 ≤ a ≤ 2 mm.

5. The cover plate assembly according to any one of claims 1 to 4, characterized in that The compression ratio of the protection member (5) along its axial direction is greater than or equal to 10% and less than or equal to 50%.

6. The cover plate assembly according to claim 1, characterized in that, Along the radial direction of the protection member (5), the length by which the edge of the protection member (5) extends beyond the gap is c, satisfying 0.5 mm ≤ c ≤ 2 mm.

7. The cover plate assembly according to claim 2, characterized in that, The second connecting member (4) is provided with a positioning hole (41), and along the axial direction of the electrode terminal (2), the positioning hole (41) corresponds to the electrode terminal (2).

8. The cover plate assembly according to claim 1, wherein The material of the protection member (5) includes fluororubber or a composite material of polypropylene and ethylene propylene diene monomer rubber.

9. A battery cell, characterized in that, Comprising the cover assembly according to any one of claims 1 - 8.

10. A battery, characterized in that, Comprising a plurality of battery cells according to claim 9, and the electrode terminals (2) of two adjacent battery cells are electrically connected through the second connecting member (4).

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