Top cover assembly and secondary battery

Abstract

This invention discloses a top cover assembly and a secondary battery. The top cover assembly includes terminals, a cover plate, and an insulating plate. The cover plate has a first surface and a second surface facing each other. A first through hole is formed through the first and second surfaces of the cover plate. The insulating plate is fitted to the second surface of the cover plate. One end of the terminal passes through the first through hole and connects to the insulating plate. A first protrusion is provided on the side of the insulating plate near the cover plate. A mounting groove is recessed around the periphery of the first protrusion on the insulating plate. A sealing ring protrudes from the end of the terminal that connects to the insulating plate, and the sealing ring abuts against the inside of the mounting groove. This top cover assembly structure, with its sealing ring on the terminal and abutting against the inside of the mounting groove, ensures a tight fit between the cover plate and the insulating plate, eliminating assembly gaps and improving battery safety. Furthermore, the sealing ring and the internal clamping force of the mounting groove secure the terminal to the insulating plate, facilitating assembly and resulting in a stable structure.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a top cover assembly and a secondary battery comprising such a top cover assembly. Background Technology

[0002] The top cover assembly is a crucial component of the battery, sealing off the opening in the battery casing. Traditional top cover assemblies consist of terminals, a top cover plate, and a lower plastic layer. The terminals protrude from the top cover plate, while the lower plastic layer lies beneath it, isolating the tabs of the battery pack from the top cover plate. However, this type of top cover assembly has the following drawbacks: a zero-gap cannot be guaranteed between the lower plastic layer and the top cover plate during assembly. Electrolyte from inside the battery pack can seep into the gap between the lower plastic layer and the top cover plate. When metal particles are introduced into this gap, the metal particles and electrolyte shorten the safe distance between the tabs and the top cover plate, making it highly susceptible to high-voltage breakdown and arcing. This causes a sudden increase in the internal temperature of the battery, posing a significant safety risk to its use.

[0003] To improve the safety of the top cover assembly, manufacturers currently mainly use the following two methods:

[0004] 1. Add an insulating ring between the lower plastic sheet and the top cover to increase the safe distance between the electrode tab and the top cover;

[0005] 2. By pressing the electrical connector to compress the lower plastic, the lower plastic is deformed, thereby increasing the isolation effect between the electrode tab and the top cover plate.

[0006] However, the former increases the number of parts, making assembly more complicated, and the lower plastic is prone to falling off. By adopting the latter design, although the lower plastic is not easy to fall off, the strength required to compress the lower plastic is greater, the electrical connector is at risk of deformation, and the assembly is more difficult. Summary of the Invention

[0007] The purpose of this invention is to provide a top cover assembly and a secondary battery, wherein the top cover assembly has the characteristics of high safety and easy assembly.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] On one hand, a top cover assembly is provided, including a terminal, a cover plate, and an insulating plate. The cover plate has a first surface and a second surface facing each other. A first through hole is formed in the cover plate through the first surface and the second surface. The insulating plate is attached to the second surface of the cover plate. One end of the terminal passes through the first through hole and is connected to the insulating plate. A first protrusion is provided on the side of the insulating plate near the cover plate. A mounting groove is recessed around the periphery of the first protrusion in the insulating plate. A sealing ring is provided at the end of the terminal that is connected to the insulating plate. The sealing ring abuts against the inside of the mounting groove.

[0010] As a preferred embodiment of the top cover assembly, the depth of the mounting groove is less than the height of the sealing ring protruding from the terminal.

[0011] As a preferred embodiment of the top cover assembly, the terminal includes a terminal body, a sealing ring, and an insulating layer disposed on the outside of the terminal body. The terminal body is electrically connected to the tab of the core package. The insulating layer abuts against the inner wall of the first through hole. The sealing ring is fixedly disposed between the terminal body and the insulating layer. The sealing ring partially protrudes from the terminal body near the end of the core package, forming the sealing protrusion ring.

[0012] As a preferred embodiment of the top cover assembly, the side of the terminal body is provided with a first snap-fit ​​protrusion, and the non-end of the sealing ring is provided with a first snap-fit ​​groove, and the first snap-fit ​​protrusion is snapped into the first snap-fit ​​groove.

[0013] As a preferred embodiment of the top cover assembly, the opening size of the mounting groove is larger than the bottom size.

[0014] As a preferred embodiment of the top cover assembly, it further includes an electrical connector having a second protrusion. The first protrusion has a second through hole through it. The second protrusion is inserted into the second through hole. The center line of the second through hole coincides with the center line of the first through hole. The outer side wall of the second protrusion abuts against the inner side wall of the second through hole. The end face of the second protrusion away from the electrical connector abuts against the terminal body.

[0015] As a preferred embodiment of the top cover assembly, the inner wall of the second through hole is inclined toward the centerline of the second through hole, and the outer wall of the second through hole has a mating surface that abuts against the sealing convex ring. The mating surface is connected to the bottom of the mounting groove and is parallel to the centerline of the second through hole.

[0016] As a preferred embodiment of the top cover assembly, it also includes a retaining ring, wherein the first boss is provided with a second through hole, and the retaining ring abuts against the inner sidewall of the second through hole.

[0017] As a preferred embodiment of the top cover assembly, the fixing ring includes a first fixing member and a second fixing member. The first fixing member and the second fixing member are connected at an angle. The first boss is provided with a second through hole. The center line of the second through hole is the same as the center line of the first through hole. The first fixing member abuts against the inner wall of the second through hole. The second fixing member is close to the terminal body. One end of the terminal body inserted into the second through hole is provided with a limiting groove. The second fixing member abuts against the limiting groove.

[0018] On the other hand, a secondary battery is also provided, including a top cover assembly with any of the above-mentioned structures.

[0019] As a preferred option for the top cover assembly.

[0020] The beneficial effects of this invention are as follows: The top cover assembly of this structure features a sealing ring on the terminal. This sealing ring abuts against the inside of the mounting groove, ensuring a tight fit between the cover plate and the insulating plate, eliminating assembly gaps between them, and improving battery safety. Furthermore, the sealing ring's internal clamping force within the mounting groove secures the terminal to the insulating plate, facilitating assembly and resulting in a robust structure. Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0022] Figure 1 This is an exploded view of the top cover assembly according to an embodiment of the present invention.

[0023] Figure 2 This is an overall structural diagram of the top cover assembly according to an embodiment of the present invention.

[0024] Figure 3 for Figure 2 A partial view of AA.

[0025] Figure 4 for Figure 3 Enlarged view of point C in the middle.

[0026] Figure 5 This is an exploded view of the top cover assembly according to another embodiment of the present invention.

[0027] Figure 6 This is an overall structural diagram of the top cover assembly according to another embodiment of the present invention.

[0028] Figure 7 for Figure 6 Partial sectional view of BB.

[0029] Figure 8 for Figure 7 Enlarged view of point D in the middle.

[0030] Figure 9 This is a partial cross-sectional view of the insulating plate described in the embodiment.

[0031] Figure 10 for Figure 9 Enlarged view of point E in the middle.

[0032] Figure 11 This is a structural diagram of the terminal described in an embodiment of the present invention.

[0033] Figure 12This is a partial view of the insulating plate described in an embodiment of the present invention.

[0034] Figure 13 This is a structural diagram of the electrical connector sheet according to an embodiment of the present invention.

[0035] In the picture:

[0036] 1. Cover plate; 11. First through hole;

[0037] 2. Insulating board; 21. Second through hole; 22. Mounting groove; 23. First boss; 231. Abutting surface; 232. Clearance notch;

[0038] 3. Terminal; 31. Terminal body; 311. Conductive protrusion; 312. First snap-fit ​​protrusion; 32. Insulating layer; 321. Third snap-fit ​​protrusion; 33. Sealing ring; 331. Sealing ring;

[0039] 4. Electrical connector; 41. Second boss; 411. Chamfered corner structure;

[0040] 5. Fixing ring; 51. First fixing component; 52. Second fixing component. Detailed Implementation

[0041] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] Reference Figures 1 to 4 , Figure 9 , Figure 11 and Figure 12This invention provides a top cover assembly, including a terminal 3, a cover plate 1, and an insulating plate 2. The cover plate 1 has a first surface and a second surface facing each other. A first through hole 11 is formed through the first surface and the second surface of the cover plate 1. The insulating plate 2 is fitted to the second surface of the cover plate 1. One end of the terminal 3 passes through the first through hole 11 and connects to the insulating plate 2. A first protrusion 23 is provided on the side of the insulating plate 2 near the cover plate 1. A mounting groove 22 is recessed around the periphery of the first protrusion 23. A sealing ring 331 protrudes from the end of the terminal 3 that connects to the insulating plate 2. The sealing ring 331 abuts against the interior of the mounting groove 22. This top cover assembly, with the sealing ring 331 on the terminal 3, ensures a tight fit between the cover plate 1 and the insulating plate 2 by abutting against the interior of the mounting groove 22, eliminating assembly gaps between the cover plate 1 and the insulating plate 2 and improving battery safety. In addition, the internal clamping force between the sealing ring 331 and the mounting groove 22 is used to fix the terminal 3 and the insulating plate 2, which is easy to assemble and has a stable structure.

[0044] Specifically, the sealing ring 331 is an elastic insulating ring. During assembly, the sealing ring 331 can be inserted into the mounting groove 22 by external force to achieve good sealing and insulation.

[0045] To prevent the insulating plate 2 from falling off, the depth of the mounting groove 22 is less than the height of the sealing ring 331 protruding from the terminal 3. During specific assembly, external force is used to cause the sealing ring 331 to undergo elastic deformation, so that the sealing ring 331 can fill the mounting groove 22, making it difficult for the sealing ring 331 to fall off in the mounting groove 22, thus achieving reliable connection between the sealing ring 331 and the insulating plate 2.

[0046] Among them, reference Figure 3 , Figure 4 and Figure 11The terminal 3 includes a terminal body 31, a sealing ring 33, and an insulating layer 32 disposed on the outside of the terminal body 31. The terminal body 31 is electrically connected to the tab of the core package. The insulating layer 32 abuts against the inner wall of the first through hole 11. The sealing ring 33 is fixedly disposed between the terminal body 31 and the insulating layer 32. The sealing ring 33 partially protrudes from the terminal body 31 near the end of the core package, forming the sealing protrusion ring 331. The insulating layer 32 is disposed on the outside of the terminal body 31. By abutting against the inner wall of the first through hole 11, the terminal 3 is fixed to the cover plate 1, and the terminal 3 is insulated from the cover plate 1. In this embodiment, the sealing ring 33 is embedded between the insulating layer 32 and the terminal body 31, and no other components are needed to fix the sealing ring 33. In other embodiments, the sealing ring 33 can also be fixed by adhesive layers or connecting screws, etc. No specific limitation is made to the fixing method of the sealing ring 33 here.

[0047] The terminal body 31 has a first snap-fit ​​protrusion 312 protruding from its side, and the sealing ring 33 has a first snap-fit ​​groove recessed at its non-end portion. The first snap-fit ​​protrusion 312 snaps into the first snap-fit ​​groove. The protrusion 312 on the side of the terminal body 31 creates a T-shaped structure. During terminal assembly, the first snap-fit ​​protrusion 312 snaps into the first snap-fit ​​groove, positioning the sealing ring 33 on the terminal body 31, which facilitates assembly. Furthermore, the engagement of the first snap-fit ​​protrusion 312 with the first snap-fit ​​groove prevents the sealing ring 33 from detaching from the terminal body 31 after assembly, resulting in a more airtight structure. In actual production, the insulating layer 32 can be injection molded.

[0048] Specifically, the inner wall of the first through hole 11 is provided with a third snap-fit ​​groove at one end near the insulating plate 2, and the insulating layer 32 is provided with a third snap-fit ​​protrusion 321 on the side away from the terminal body 31. The third snap-fit ​​protrusion 321 is snapped into the third snap-fit ​​groove. In actual assembly, the third snap-fit ​​protrusion 321 is snapped into the third snap-fit ​​groove. Even if an external force pulls the terminal 3 toward the side away from the core package, the terminal 3 will not come off from the first through hole 11.

[0049] Preferably, the groove opening of the mounting groove 22 is larger than the bottom opening, and the larger groove opening is more conducive to placing the sealing ring 331.

[0050] In one embodiment, reference is made to Figures 1 to 4 as well as Figure 13The top cover assembly also includes an electrical connector 4, which has a second protrusion 41. A second through hole 21 is provided through the first protrusion 23. The second protrusion 41 is inserted into the second through hole 21. The center line of the second through hole 21 coincides with the center line of the first through hole 11. The outer side wall of the second protrusion 41 abuts against the inner side wall of the second through hole 21. The end face of the second protrusion 41 away from the electrical connector 4 abuts against the terminal body 31. By abutting the outer side wall of the second protrusion 41 against the inner side wall of the second through hole 21, the electrical connector 4 is fixed to the insulating plate 2. The end face of the second protrusion 41 away from the electrical connector 4 abuts against the terminal body 31, making the structure between the electrical connector 4, the insulating plate 2, and the terminal 3 more compact. Electrical connection between the electrical connector 4 and the terminal 3 can be achieved without the need for additional conductive components.

[0051] Among them, reference Figure 3 and Figure 4 The inner wall of the second through hole 21 is inclined toward the center line of the second through hole 21, and the outer wall of the second through hole 21 has a mating surface 231 that abuts against the sealing protrusion 331. The mating surface 231 is connected to the bottom of the mounting groove 22. The mating surface 231 is parallel to the center line of the second through hole 21, so that the side wall of the second through hole 21 gradually thickens from the bottom of the mounting groove 22 toward the cover plate 1. Since the end of the mating surface 231 connected to the bottom of the mounting groove 22 is thinner, when the second protrusion 41 is pushed in the second through hole 21 toward the terminal 3, the hole wall of the second through hole 21 will rotate toward the mounting groove 22 with the connection between the mating surface and the bottom of the mounting groove 22 as the center, thus pressing the sealing protrusion 331 inside the mounting groove 22 from the side, increasing the radial sealing performance, and making the assembled top cover assembly structure stable. Furthermore, the inner wall of the second through hole 21 is inclined towards the center line of the second through hole 21, making the end of the second through hole 21 smaller than the end closer to the terminal 3 and larger than the end farther from the terminal 3. This structure of the second through hole 21 makes it easier for the second boss 41 to contact the end of the terminal body 31, preventing poor soldering between the electrical connector 4 and the terminal 3, and also reducing the requirements for the electrical connector 4. It should be noted that, in this specification, the outer wall of the second through hole 21 refers to the side of the side wall of the second through hole 21 that is away from the center line of the second through hole 21 (i.e., the outer surface of the first boss 23), and the outer wall of the second through hole 21 refers to the side of the side wall of the second through hole 21 that is close to the center line of the second through hole 21.

[0052] Specifically, the outer side of the first boss 23 near the terminal 3 is provided with a clearance notch 232, which prevents the first boss 23 from scratching the terminal body 31 during the assembly process.

[0053] Furthermore, a chamfered structure 411 is provided at the connection between the side wall and the end face of the second boss 41. Since the surface of the chamfered structure 411 is smoothly transitioned, when the second boss 41 is inserted into the second through hole 21, the sharp edges on the second boss 41 are prevented from scratching the inner side wall of the second through hole 21.

[0054] In another embodiment, refer to Figures 5 to 8 The top cover assembly also includes a retaining ring 5. The first boss 23 is provided with a second through hole 21. The retaining ring 5 abuts against the inner wall of the second through hole 21. The retaining ring 5 provides pressure to the second through hole 21, pressing the hole wall of the second through hole 21 to squeeze the sealing ring 331, so that the sealing ring 331 is clamped between the insulating layer 32 and the first boss 23.

[0055] The fixing ring 5 includes a first fixing member 51 and a second fixing member 52. The first fixing member 51 and the second fixing member 52 are connected at an angle. The first boss 23 has a second through hole 21. The center line of the second through hole 21 is the same as the center line of the first through hole 11. The first fixing member 51 abuts against the inner wall of the second through hole 21. The second fixing member 52 is close to the terminal body 31. One end of the terminal body 31 inserted into the second through hole 21 is provided with a limiting groove. The second fixing member 52 abuts against the limiting groove. This design allows the fixing ring 5 to abut against both the insulating plate 2 and the terminal 3, preventing the insulating plate 2 from falling off and improving the compactness of the structure in the top cover assembly.

[0056] Preferably, the inner wall of the second through hole 21 is inclined toward the center line of the second through hole 21, and the first fixing member 51 is parallel to the inner wall of the second through hole 21, so that the first fixing member 51 can provide both lateral extrusion force and vertical extrusion force for the first boss 23, making the structure more compact and less likely to fall off.

[0057] In this embodiment, the fixing ring 5 is made of aluminum alloy, copper alloy, or other metal materials. In actual design, to prevent the fixing ring 5 from scratching the core package, the side of the fixing ring 5 closest to the core package does not protrude from the insulating plate 2.

[0058] To reduce the overall thickness of the top cover assembly, the tabs of the core package are directly welded to the retaining ring 5. This replaces the electrical connecting piece 4 in the traditional top cover assembly, allowing the retaining ring 5 to provide both a fixing function for the insulating plate 2 and an electrical connection function for the terminal body 31 and the tabs of the core package.

[0059] Continue to refer to Figures 5 to 8In another embodiment, the top cover assembly adds an electrical connecting piece 4 to the fixing ring 5. The electrical connecting piece 4 has a second protrusion 41, and the terminal body 31 protrudes towards the electrical connecting piece 4 with a conductive protrusion. The upper end of the second protrusion 41 passes through the fixing ring 5 and abuts against the conductive protrusion 311. Through the contact between the second protrusion 41 and the conductive protrusion 311, the electrical connection between the electrical connecting piece 4 and the terminal 3 is achieved. By simultaneously providing the fixing ring 5 and the electrical connecting piece 4 in the top cover assembly, the insulating plate 2 and the sealing protrusion 331 are fixed using the fixing ring 5, while the electrical connecting piece 4 is electrically connected to the terminal body 31, thus reducing the requirements for the electrical connecting piece 4.

[0060] In another embodiment, a secondary battery is provided, which includes any of the top cover components described above. This secondary battery has the characteristics of high safety and easy assembly.

[0061] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings, and are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used merely for descriptive distinction and have no special meaning.

[0062] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0064] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A top cover assembly, characterized in that, The device includes a terminal, a cover plate, and an insulating plate. The cover plate has a first surface and a second surface facing each other. A first through hole is formed in the cover plate through the first surface and the second surface. The insulating plate is attached to the second surface of the cover plate. One end of the terminal passes through the first through hole and is connected to the insulating plate. A first protrusion is provided on the side of the insulating plate near the cover plate. A mounting groove is recessed around the periphery of the first protrusion in the insulating plate. A sealing ring protrudes from the end of the terminal that is connected to the insulating plate. The sealing ring abuts against the inside of the mounting groove. The terminal includes a terminal body, a sealing ring, and an insulating layer disposed on the outside of the terminal body. The terminal body is electrically connected to the tab of the core package. The insulating layer abuts against the inner wall of the first through hole. The sealing ring is fixedly disposed between the terminal body and the insulating layer. The sealing ring protrudes from the terminal body near the end of the core package to form the sealing protrusion ring. The side of the terminal body is provided with a first snap-fit ​​protrusion, and the non-end of the sealing ring is provided with a first snap-fit ​​groove, and the first snap-fit ​​protrusion is snapped into the first snap-fit ​​groove. The first boss has a second through hole through it; The inner wall of the second through hole is inclined toward the center line of the second through hole, and the outer wall of the second through hole has a mating surface that abuts against the sealing convex ring. The mating surface is connected to the bottom of the mounting groove and is parallel to the center line of the second through hole.

2. The top cover assembly according to claim 1, characterized in that, The depth of the mounting groove is less than the height of the sealing ring protruding from the terminal.

3. The top cover assembly according to any one of claims 1-2, characterized in that, The opening size of the mounting groove is larger than the bottom size.

4. The top cover assembly according to claim 1, characterized in that, It also includes an electrical connector piece having a second protrusion inserted into a second through hole. The center line of the second through hole coincides with the center line of the first through hole. The outer side wall of the second protrusion abuts against the inner side wall of the second through hole. The end face of the second protrusion away from the electrical connector piece abuts against the terminal body.

5. The top cover assembly according to claim 1, characterized in that, It also includes a retaining ring, wherein the first boss has a second through hole through which the retaining ring abuts against the inner wall of the second through hole.

6. The top cover assembly according to claim 5, characterized in that, The fixing ring includes a first fixing member and a second fixing member. The first fixing member and the second fixing member are connected at an angle. The first boss is provided with a second through hole. The center line of the second through hole coincides with the center line of the first through hole. The first fixing member abuts against the inner side wall of the second through hole. The second fixing member is close to the terminal body. The end of the terminal body inserted into the second through hole is provided with a limiting groove. The second fixing member abuts against the limiting groove.

7. A secondary battery, characterized in that, Includes the top cover assembly as described in any one of claims 1 to 6.

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