Battery cover plate structure and lithium ion battery

Abstract

The utility model relates to a battery cover plate structure and a lithium ion battery. The battery cover plate structure comprises a base plate and a stop frame matched with the base plate, the terminal assembly comprises an external conductive port and a connecting port located below the external conductive port, the substrate is provided with a first through hole for the connecting port to pass through, and the area of the exposed top surface of the external conductive port is larger than the area of the bottom surface of the connecting port; a gap is formed between the connecting port and the first through hole; the connecting piece is located below the connecting port and used for being welded to the connecting port. The sealing piece comprises an embedding and extruding part, and the embedding and extruding part is embedded and extruded in the gap. According to the utility model, the contact area between the upper surface of the external conductive port and the external connecting piece is increased, the electron transmission path can be shortened, the interface impedance between the terminal and the external connecting piece is reduced, and the charging and discharging efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of power battery technology, specifically to a battery cover structure and a lithium-ion battery. Background Technology

[0002] With increasingly severe environmental problems and growing public concern for energy conservation and emission reduction, the country is vigorously developing the new energy market, and lithium batteries are being widely used in new energy vehicles and energy storage devices. However, without protective measures for lithium batteries, considerable dangers can occur. Lithium batteries require protection because their materials dictate that they cannot be overcharged, over-discharged, over-currented, short-circuited, or subjected to excessively high temperatures during charging and discharging. Therefore, the battery cover is a core component of lithium batteries; it protects the battery chips, preventing short circuits and other problems, and also prevents battery explosions, greatly contributing to battery stability and safety.

[0003] Authorization Announcement No.: CN212659600 U, Application Date: 2020.06.30, Utility Model Title: Cell Cover Plate, Cell, Module, and Battery Pack for Power Batteries. This utility model discloses a cell cover plate, cell, module, and battery pack for a power battery. The cell cover plate includes a light aluminum sheet, a terminal post, and a sealing ring. The terminal post passes through a terminal post hole in the light aluminum sheet. The peripheral surface and lower surface of the terminal post have an edge portion with a first width that is insulated from the light aluminum sheet by a lower insulating plastic ring, and the upper surface has an edge portion with a second width that is insulated from the light aluminum sheet by an upper insulating plastic ring. This utility model, by improving the structural form of the terminal post, can eliminate the riveted aluminum block, significantly reduce the height of the terminal post, and simplify the assembly process.

[0004] The aforementioned prior art requires laser welding of the outer peripheral wall of the bottom support ring to the aluminum sheet, and ultrasonic welding of the contact area between the upper insulating plastic ring and the aluminum sheet, in order to form a space to accommodate the pole post, within which the pole post is prone to rotation.

[0005] In addition, the cover plate may shift due to vibration during transportation or use, causing the battery core and tabs to fail to connect securely to the terminals. Utility Model Content

[0006] In view of the defects in the above-mentioned prior art, such as the need to form the electrode holder space by two welding processes and the electrode being prone to rotation, the purpose of this utility model is to provide a battery cover structure.

[0007] The technical solution provided by this utility model is as follows:

[0008] A battery cover structure includes a substrate and a stop frame adapted to the substrate; it also includes:

[0009] A terminal assembly includes an external conductive port and a connection port located below the external conductive port. The substrate has a first through hole through which the connection port passes. The exposed top surface area of ​​the external conductive port is larger than the bottom surface area of ​​the connection port. There is a gap between the connection port and the first through hole.

[0010] A connector located below the connection port for soldering to the connection port;

[0011] A seal comprising an insert portion that is inserted into the gap.

[0012] The stop bracket is used to fix the battery core and the tabs, and the stop bracket and the base plate are interlocked to form a preliminary assembly; in addition, the contact area between the exposed upper surface of the external conductive port and the external connector is increased, which improves the charging and discharging efficiency.

[0013] Furthermore, the seal also includes a base, with the interlocking portion disposed above the base; the base is hollow and located between the substrate and the connector. The seal is interference-fitted with the side of the connection port, effectively preventing rotation of the terminal assembly.

[0014] Furthermore, the substrate includes a first surface and a second surface along its thickness direction, the first surface facing away from the stop frame and the second surface facing the stop frame; the interlocking portion divides the upper surface of the base into a first plane and a second plane; wherein the first plane and the second surface are pressed together, and the second plane is pressed together with the connection port; the lower surface of the base is pressed together with the connector. The seal fills the tiny gap between the cover plate and the housing through compression deformation, forming a physical barrier. The seal is made of an elastic material and can buffer internal vibrations or external impacts of the battery.

[0015] Furthermore, the integral molding of the interlocking part and the base can enhance the overall strength of the seal and extend its service life.

[0016] Furthermore, the seal has a T-shaped cross-section.

[0017] Furthermore, the stop bracket is provided with a second through hole, which corresponds to the first through hole, and the size of the second through hole is larger than that of the first through hole. The second through hole can accommodate a seal and a connector.

[0018] Furthermore, the second surface of the substrate is provided with a first groove, which is coaxial with the first through hole, and the first through hole is located inside the first groove. The stop bracket is provided with a protrusion adapted to the first groove. The protrusion is hollow and coaxial with the second through hole. The inner side of the protrusion extends into the second through hole and hangs above the second through hole. The inner diameter of the protrusion is smaller than the inner diameter of the second through hole. The initial assembly of the substrate and the stop bracket is achieved by the interlocking of the protrusion and the first groove.

[0019] Furthermore, the portion of the protrusion suspended above the second through hole forms a second groove together with the second through hole, and the connector is adapted to the second groove. By limiting the connector through the second groove, not only can the welding of the connector and the connection port be better realized, but also after welding, the terminal assembly and the connector can tightly press the substrate and the stop bracket together.

[0020] Furthermore, the terminal assembly also includes an injection-molded component that surrounds the outer ring of the external conductive port. The injection-molded component serves to insulate the external conductive port from the substrate.

[0021] A lithium-ion battery includes a battery cell, the top of which is connected to the aforementioned battery cover structure.

[0022] Compared with the prior art, the technical solution provided by this utility model has the following advantages:

[0023] This invention first inserts a T-shaped seal into the gap between the connection port and the first through hole. The flexible filling of the seal prevents the terminal assembly from rotating. Then, the connection port is welded to the connector to further ensure that the terminal assembly does not rotate.

[0024] The increased contact area between the upper surface of the external conductive port and the external connector of this invention shortens the electron transmission path, reduces the interface impedance between the terminal and the external connector, and improves the charging and discharging efficiency.

[0025] The external conductive port of this invention provides a larger contact area on its upper surface, thus making the mechanical connection more stable and reducing the risk of terminal loosening or breakage due to vibration; at the same time, the enlarged terminal surface facilitates the use of processes such as laser welding, improving connection strength and sealing performance. Attached Figure Description

[0026] Figure 1 This is an exploded view of the battery cover structure in one embodiment of this application;

[0027] Figure 2 This is a schematic diagram of the terminal assembly structure in one embodiment of this application;

[0028] Figure 3This is a cross-sectional view of the battery cover structure in one embodiment of this application;

[0029] Figure 4 As one embodiment of this application Figure 3 A magnified view of a portion of node A;

[0030] Figure 5 This is a schematic diagram of the sealing element structure in one embodiment of this application;

[0031] Figure 6 This is a cross-sectional view of the seal in one embodiment of this application;

[0032] Figure 7 This is a schematic diagram of the terminal body structure in one embodiment of this application;

[0033] Figure 8 This is a schematic diagram of a connection port in one embodiment of this application;

[0034] Figure 9 This is a schematic diagram of a connector in one embodiment of this application;

[0035] Figure 10 This is a schematic diagram of the first groove in one embodiment of this application;

[0036] Figure 11 This is a schematic diagram of the protrusion and the second groove in one embodiment of this application;

[0037] Figure 12 This is an exploded view of a battery cover structure with the welding ring removed in one embodiment of this application;

[0038] Figure 13 This is a cross-sectional view of the terminal body and injection molded part in one embodiment of this application;

[0039] Figure 14 As one embodiment of this application Figure 13 A magnified view of a portion of node B;

[0040] Figure 15 This is a schematic diagram of an external conductive port in one embodiment of this application;

[0041] Figure 16 This is a schematic diagram showing the relative positional relationship between the external conductive port and the connection port in one embodiment of this application.

[0042] Explanation of the labels in the diagram:

[0043] Substrate 1, first groove 11;

[0044] Stop 2, protrusion 21, second groove 22;

[0045] Terminal assembly 3, connection port 31, external conductive port 32, injection molded part 33;

[0046] Connector 4, welding ring 41, connecting piece 42;

[0047] Seal 5, interlocking part 51, base 52. Detailed Implementation

[0048] To further understand the content of this utility model, a detailed description of this utility model will be provided in conjunction with the accompanying drawings and embodiments.

[0049] The structures, proportions, and sizes illustrated in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art in understanding and reading the invention. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this utility model. Furthermore, terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity and not intended to limit the scope of implementation. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0050] Example 1

[0051] This application discloses a battery cover structure, including a substrate 1, a stop frame 2, a terminal assembly 3, a connector 4, and a sealing element 5. The substrate 1 is used to fix and support the terminal assembly 3 and provide it with an electrical connection and heat dissipation path. The substrate 1 is made of conductive material. The terminal assembly 3 and the connector 4 are connected by welding to form a conductive channel from the battery cell to the external circuit. The stop frame 2 serves a physical fixing and protection function, used to fix the battery core and tabs, preventing the core from directly contacting the cover due to vibration or displacement during manufacturing, transportation, and use, thus avoiding the risk of separator damage or short circuit. At the same time, the stop frame 2 limits the connector 4 through a positioning structure and isolates the positive and negative connectors 4.

[0052] More specifically, the substrate 1 includes a first surface and a second surface along the thickness direction. The first surface is away from the stop frame 2, and the second surface is opposite to the stop frame 2. The second surface is provided with a first groove 11, and the stop frame 2 is provided with a protrusion 21 that matches the first groove 11. Therefore, the stop frame 2 and the substrate 1 can be engaged with each other to achieve preliminary assembly.

[0053] The substrate 1 has a first through hole through which the terminal assembly 3 passes. The first groove 11 is coaxial with the first through hole, and the first through hole is located inside the first groove 11. The stop bracket 2 has a second through hole, which corresponds to the position of the first through hole, and the size of the second through hole is larger than the size of the first through hole.

[0054] The protrusion 21 is hollow and coaxial with the second through hole. The outer side of the protrusion 21 rests on the stop bracket 2, and the inner side extends into the second through hole and is suspended above the second through hole. Therefore, the inner diameter of the protrusion 21 is smaller than the inner diameter of the second through hole. The advantage of this design is that the part of the protrusion 21 suspended above the second through hole forms the second groove 22 together with the second through hole. The connector 4 is designed to match the second groove 22. By limiting the connector 4, not only can the welding of the connector 4 and the terminal assembly 3 be better realized, but after the welding is completed, the terminal assembly 3 and the connector 4 can tightly press the substrate 1 and the stop bracket 2 together.

[0055] Terminal assembly 3 includes a terminal body and an injection molded part 33. The terminal body includes an external conductive port 32 and a connection port 31 located below the external conductive port 32. The connection port 31 and the external conductive port 32 are preferably integrally molded to enhance the overall performance of the terminal body. The outer diameter of the external conductive port 32 is larger than the outer diameter of the connection port 31, and the outer diameter of the external conductive port 32 is larger than the outer diameter of the first through hole. The outer diameter of the connection port 31 is smaller than the outer diameter of the first through hole, and there is a gap between the connection port 31 and the first through hole.

[0056] Therefore, the external conductive port 32 is located above the first through hole, and the connection port 31 passes through the first through hole and is welded to the connector 4. The injection molded part 33 is wrapped around the outer ring of the external conductive port 32, and the bottom surface of the injection molded part 33 is in contact with the first surface of the substrate 1.

[0057] The exposed top surface area of ​​the external conductive port 32 is larger than the bottom surface area of ​​the connection port 31. The advantage of this design is that the contact area between the exposed upper surface of the external conductive port 32 and the external connector is increased, which can shorten the electronic transmission path, reduce the interface impedance between the terminal and the external connector, and improve the charging and discharging efficiency.

[0058] Meanwhile, the exposed upper surface of the external conductive port 32 provides a larger contact area, thus making the mechanical connection more stable and reducing the risk of terminal loosening or breakage due to vibration; at the same time, the enlarged terminal surface facilitates the use of processes such as laser welding, improving connection strength and sealing.

[0059] The seal 5 includes an insert portion 51, which is inserted into the gap between the connection port 31 and the first through hole, and the top of the insert portion 51 abuts against the bottom of the injection molded part 33. The insert portion 51, through its own elasticity, fixes the connection port 31 in the first through hole, effectively preventing the connection port 31 from rotating.

[0060] It is worth noting that both the injection molded part 33 and the sealing part 5 are insulating materials. Since the terminal body is covered or isolated in all directions, the terminal body and the substrate 1 are insulated from each other. At the same time, the injection molded part 33 and the sealing part 5 can absorb the vibration and impact of the battery during transportation or use, reduce the mechanical stress between the terminal body and the substrate 1, and prevent the terminal body from loosening or breaking.

[0061] The sealing member 5 also includes a base 52, with an interlocking portion 51 disposed above the base 52, and the base 52 is hollow. Relative to the thickness direction of the substrate, the base 52 is located between the substrate 1 and the connector 4. The interlocking portion 51 divides the upper surface of the base 52 into a first plane 521 and a second plane 522. The first plane 521 is pressed against the second surface of the substrate 1, the second plane 52 is pressed against the connection port 31, and the lower surface of the base 52 is pressed against the connector 4.

[0062] It is worth noting that after the connector 4 and the terminal assembly 3 are welded together, the seal 5 is in a compressed state. The cross-section of the seal 5 is preferably T-shaped, and the embedded part 51 and the base 52 are integrally formed.

[0063] The connector 4 is located below the connection port 31 in the terminal body. The connector 4 includes a welding ring 41 and a connecting piece 42. The connecting piece 42 is used to connect the winding core and the tab inside the battery. The welding ring 41 has a stepped cross-section. The bottom step of the welding ring 41 is circumferentially adapted to the second groove 22 of the stop frame 2. The upper step of the welding ring 41 is hollow and is relatively far away from the protrusion 21 provided on the stop frame 2. This hollow cavity is used to accommodate the connecting piece 42 so that the connecting piece 42 contacts the connection port 31 in the terminal body.

[0064] It is worth noting that the base 52 on the seal 5 and the upper step of the welding ring 41 are both located in the central through hole inside the protrusion 21, and the base 52 is relatively close to the protrusion 21. After the cover plate structure is installed, the base 52 is in a compressed state. Because it is a flexible material, the base 52 can fill the gap between the protrusion 21 and the upper step of the welding ring 41.

[0065] The substrate 1 preferably has two first through holes for placing positive and negative electrode components, respectively. Similarly, the stop bracket 2 has two second through holes and two protrusions 21. Correspondingly, the terminal assembly 3 includes a positive terminal assembly and a negative terminal assembly, and the connector 4 is also divided into a positive connector and a negative connector. The positive terminal assembly is assembled with the positive connector, and the negative terminal assembly is assembled with the negative connector.

[0066] A lithium-ion battery in this embodiment includes a battery cell, the top of which is connected to the battery cover structure described above.

[0067] Example 2

[0068] This embodiment presents a battery cover structure, the basic structure of which is the same as that of Embodiment 1. The difference is that the cross-section of the connection port 31 on the terminal body is stepped, so that the lower surface of the base 52 is flush with the lower surface of the connection port 31. In this embodiment, the connector 4 omits the welding ring 41 and only includes a connecting piece 42. The upper surface of the connecting piece 42 is a smooth plane and fits against the connection port 31 to facilitate welding.

[0069] In this application, laser welding is preferred, and welding of the connection port 31 to the connection piece 42 has the following significant advantages over riveting:

[0070] The connection strength is higher; welding achieves atomic-level bonding through material melting, resulting in a connection point strength far exceeding that of riveting's mechanical interlocking. Laser welding ensures uniform and robust weld points, reducing the risk of loosening due to vibration or long-term use. The weld point has lower resistance, effectively reducing battery internal resistance and improving current transmission efficiency.

[0071] The structure is compact and lightweight, and welding does not require additional riveting parts (such as rivets or rivet blocks), saving space and reducing overall weight.

[0072] Laser welding offers better sealing, enabling seamless connections that effectively prevent electrolyte leakage and improve battery safety and lifespan. Riveting, on the other hand, can lead to leakage risks due to complex sealing designs or assembly errors.

[0073] In this application, the connector 4 is limited by the second groove 22 so that the connector 4 does not occupy too much internal space of the battery cell, and the connector 4 can also press the stop frame 2.

[0074] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A battery cover structure, comprising a substrate (1) and a stop frame (2) adapted to the substrate (1). Its features are, Also includes: Terminal assembly (3) includes an external conductive port (32) and a connection port (31) located below the external conductive port (32). The substrate (1) has a first through hole through which the connection port (31) passes. The exposed top surface area of ​​the external conductive port (32) is larger than the bottom surface area of ​​the connection port (31). There is a gap between the connection port (31) and the first through hole. Connector (4), which is located below the connection port (31) and is used to weld to the connection port (31); The seal (5) includes an insert (51) that is inserted into the gap.

2. The battery cover structure according to claim 1, characterized in that: The sealing element (5) also includes a base (52), and the interlocking part (51) is disposed above the base (52); the base (52) is hollow and located between the substrate (1) and the connector (4).

3. The battery cover structure according to claim 2, characterized in that: The substrate (1) includes a first surface and a second surface along the thickness direction, the first surface being away from the stop frame (2) and the second surface being facing the stop frame (2). The interlocking portion (51) divides the upper surface of the base (52) into a first plane (521) and a second plane (522). The first plane (521) is pressed against the second surface, the second plane (522) is pressed against the connection port (31), and the lower surface of the base (52) is pressed against the connector (4).

4. The battery cover structure according to claim 3, characterized in that: The interlocking part (51) and the base (52) are integrally formed.

5. The battery cover structure according to claim 1, characterized in that: The seal (5) has a T-shaped cross section.

6. The battery cover structure according to claim 1, characterized in that: The stop bracket (2) is provided with a second through hole, which corresponds to the first through hole, and the size of the second through hole is larger than that of the first through hole.

7. A battery cover structure according to claim 6, characterized in that: The second surface of the substrate (1) is provided with a first groove (11), the first groove (11) is coaxial with the first through hole, and the first through hole is located inside the first groove (11); The stop bracket (2) is provided with a protrusion (21) that is adapted to the first groove (11). The protrusion (21) is hollow and coaxial with the second through hole. The inner side of the protrusion (21) extends into the second through hole and is suspended above the second through hole. The inner diameter of the protrusion (21) is smaller than the inner diameter of the second through hole.

8. The battery cover structure according to claim 7, characterized in that: The portion of the protrusion (21) suspended above the second through hole forms a second groove (22) together with the second through hole, and the connector (4) is adapted to the second groove (22).

9. A battery cover structure according to claim 1, characterized in that: The terminal assembly (3) further includes an injection molded part (33) which is wrapped around the outer ring of the external conductive port (32); the injection molded part (33) is used to prevent the external conductive port (32) from contacting the substrate (1).

10. A lithium-ion battery, comprising a single battery cell, characterized in that: The top of this battery cell is connected to a battery cover structure as described in any one of claims 1-9.

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