A repeatable injection battery top cover structure

Abstract

This utility model discloses a refillable battery top cover structure, relating to the field of lithium battery technology, including a top cover sheet, a welding piece for the injection hole, and a rubber stopper. The top cover sheet has an annular protrusion at the injection hole, into which a EPDM rubber stopper is fitted. The stopper has an initially closed elastic sealing channel at its center, and an annular protrusion on its inner wall. The welding piece for the injection hole presses against the rubber stopper and is welded to the top cover sheet, with a through hole at its center for inserting an injection needle. During injection, the injection needle opens the elastic sealing channel, and the annular protrusion ensures a tight seal. After the needle is removed, the channel self-seales due to its elasticity. The structure also includes an explosion-proof valve and positive and negative terminals. The explosion-proof valve can release pressure, and the positive and negative terminals are assembled via a sealed and insulating assembly. This structure enables secondary and multiple electrolyte replenishment, provides reliable sealing, and ensures structural stability, improving battery safety and practicality.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a refillable battery top cover structure. Background Technology

[0002] With the rapid development of my country's power lithium battery industry, the market's requirements for battery performance and safety are becoming increasingly stringent. As the core component of power lithium batteries, the safety and stability of the battery cell directly depend on the structural design of the battery top cover.

[0003] Current traditional battery top cover structures have significant shortcomings in the electrolyte filling process. Most top covers only support a single electrolyte filling, and the sealing structure is fixed after the filling is completed, which cannot meet the needs of subsequent secondary or multiple electrolyte replenishment. In addition, the sealing structure of some top covers is poorly designed, and the seal is prone to failure after the electrolyte filling operation, resulting in electrolyte leakage, which not only affects battery performance but may also cause safety hazards.

[0004] To improve the stability, sealing reliability, and maintainability of the battery top cover structure, and thus ensure the overall safety and service life of the power lithium battery, it is necessary to innovate and optimize the existing battery top cover structure. Utility Model Content

[0005] To address the technical problems existing in the background art, this utility model proposes a refillable liquid-filled battery top cover structure.

[0006] This utility model proposes a refillable battery top cover structure, including a top cover plate, an injection hole welding plate, and a rubber stopper. The top cover plate has an injection hole with an annular boss at the injection hole. The rubber stopper is assembled inside the annular boss. The injection hole welding plate presses down on the rubber stopper and is welded to the top cover plate. The injection hole welding plate has a through hole at its center. The rubber stopper has a columnar structure with an elastic sealing channel along its center for inserting an injection needle. The elastic sealing channel is initially closed. When the injection needle is inserted, the elastic sealing channel is opened. After the injection needle is removed, the elastic sealing channel recovers its closure due to its own elasticity to achieve self-sealing.

[0007] Preferably, the inner wall of the elastic sealing channel of the rubber stopper is provided with an annular protrusion, which is distributed circumferentially along the elastic sealing channel to enhance the sealing effect after the injection needle is pulled out.

[0008] Preferably, it also includes an explosion-proof valve, which is welded to the corresponding hole of the top cover plate.

[0009] Preferably, the assembly further includes a positive electrode post, a negative electrode post, a sealing ring, a lower plastic sheet, an upper plastic sheet, and a welding block. The positive electrode post and the negative electrode post pass through the sealing ring, the lower plastic sheet, the top cover sheet, and the upper plastic sheet in sequence, respectively, and then cooperate with the welding block. The assembly is pressed down by a tooling fixture and welded to form a fixed battery top cover assembly.

[0010] Preferably, it also includes an explosion-proof patch, which is affixed to the top cover structure for physical protection.

[0011] Preferably, the rubber stopper is made of EPDM (ethylene propylene diene monomer).

[0012] Preferably, it further includes a stop bracket, which is disposed within the top cover structure.

[0013] Preferably, it further includes a positive electrode connecting piece and a negative electrode connecting piece, which are respectively matched with the corresponding positive electrode post and negative electrode post.

[0014] The refillable battery top cover structure proposed in this invention has the following beneficial effects:

[0015] 1. Enables repeated electrolyte filling: Through the design of the elastic sealing channel of the rubber stopper, combined with the cooperation of the electrolyte filling hole welding piece, the battery can support secondary and multiple electrolyte fillings, which solves the problem that the traditional battery top cover can only be filled once, making it easier for battery maintenance and performance optimization in the later stage.

[0016] 2. Excellent sealing performance: The rubber stopper is made of EPDM material, combined with an elastic sealing channel and annular protrusion on the inner wall. It can not only fit tightly with the injection needle during the injection process, but also automatically seal after injection. At the same time, the fixing and compression of the rubber stopper by the annular protrusion and the injection hole welding plate further improve the overall sealing reliability and effectively prevent electrolyte leakage.

[0017] 3. The explosion-proof valve can promptly release pressure when the internal pressure of the battery is too high. Explosion-proof patches provide physical protection for core components, and the stop bracket ensures the stability of internal components. The coordinated action of all components significantly improves the structural stability and safety of the battery top cover. The connection methods for each component are mainly welding and precision assembly. The assembly process can be assisted by tooling fixtures to ensure assembly accuracy. At the same time, the welding fixing method can ensure the firmness of the component connection and extend the service life of the top cover structure.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] Figure 1 This is an exploded view of the present invention;

[0020] Figure 2 This is a schematic diagram of the structure of this utility model;

[0021] Figure 3 This is a schematic diagram of the bottom structure of this utility model;

[0022] Figure 4 This is a cross-sectional view of the injection hole portion of this utility model;

[0023] Figure 5 This is a cross-sectional view of the top cover plate of this utility model.

[0024] The labels in the diagram are as follows: 1. Welding block; 2. Top plastic; 3. Annular boss; 4. Explosion-proof patch; 5. Injection hole welding piece; 6. Rubber stop; 7. Top cover piece; 8. Explosion-proof valve; 9. Stop bracket; 10. Sealing ring; 11. Negative electrode post; 12. Positive electrode post; 13. Negative electrode connecting piece; 14. Positive electrode connecting piece; Detailed Implementation

[0025] The embodiments of this utility model are described in detail below. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar symbols denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0026] like Figures 1-5 The above illustrates a refillable electrolyte battery top cover structure:

[0027] The refillable battery top cover structure includes a top cover plate 7, a filling hole welding plate 5, a rubber stopper 6, an explosion-proof valve 8, a positive terminal post 12, a negative terminal post 11, a sealing ring 10, a lower plastic piece, an upper plastic piece 2, a welding block 1, an explosion-proof patch 4, a stop bracket 9, a positive terminal connecting piece 14, and a negative terminal connecting piece 13. These components work together to achieve both the refillable battery function and ensure the overall structural stability and safety of the top cover.

[0028] Top cover plate 7: As the basic load-bearing component of the top cover structure, it has an injection hole for electrolyte injection, and an annular boss 3 is integrally formed at the edge of the injection hole. The annular boss 3 is arranged around the circumference of the injection hole, which can provide precise assembly positioning space for the rubber stopper 6, while enhancing the structural strength around the injection hole and preventing deformation of the top cover plate 7 during the injection and sealing process.

[0029] Rubber stopper 6: It adopts a columnar structure design and is assembled in the annular protrusion 3 of the top cover plate 7. Its material is EPDM. EPDM has excellent elasticity, corrosion resistance and aging resistance, and can adapt to the electrolyte environment inside the battery for a long time, ensuring the stability of the sealing performance.

[0030] The rubber stopper 6 has an axially oriented elastic sealing channel at its center. Initially closed, this channel opens when the injection needle is inserted, allowing electrolyte to be injected into the battery. After injection, the needle is removed, and the channel quickly closes due to the elastic recovery force of the EPDM material, achieving self-sealing and effectively preventing electrolyte leakage. Furthermore, the inner wall of the elastic sealing channel features circumferentially distributed annular protrusions. These protrusions fit tightly against the needle body during injection, enhancing sealing. After the needle is removed, the compression between the protrusions further improves the sealing effect after closure, preventing a decline in sealing performance due to prolonged use.

[0031] The injection hole welding piece 5 has a sheet-like structure and covers the top of the rubber stopper 6. Its edge is welded and fixed to the top cover piece 7. During the welding process, a certain pressure is applied to the rubber stopper 6, causing it to be slightly compressed. This design can firmly fix the rubber stopper 6 within the annular boss 3, preventing displacement of the rubber stopper 6 during battery use. On the other hand, the compressed state of the rubber stopper 6 can further enhance the fit and seal between it and the annular boss 3 and the injection hole welding piece 5. The injection hole welding piece 5 has a through hole in its center. The diameter of the through hole matches the outer diameter of the injection needle, providing a channel for the injection needle to be inserted into the elastic sealing channel, ensuring smooth injection operation.

[0032] Explosion-proof valve 8: It is fixed to the corresponding preset hole of the top cover plate 7 by welding. When the internal pressure of the battery is too high due to a fault, the explosion-proof valve 8 will automatically rupture and release pressure to prevent the battery from exploding and ensure the safety of battery use.

[0033] Positive and negative terminals 11 and insulating sealing assembly: The positive terminal 12 and negative terminal 11 serve as the battery current output and input components, respectively. Both pass sequentially through the sealing ring 10, lower plastic, top cover plate 7, and upper plastic 2 before correspondingly engaging with the welding block 1. The sealing ring 10, made of an elastic material resistant to electrolyte corrosion, is fitted around the outside of the positive and negative terminals 11, filling the gaps between the terminals and the lower plastic and top cover plate 7 to prevent electrolyte leakage from the mating point. The lower and upper plastic 2 are respectively positioned below and above the top cover plate 7, providing insulation and preventing short circuits between the positive and negative terminals 11 and the top cover plate 7. During assembly, pressure is applied to the positive and negative terminals 11 and welding block 1 using specialized tooling fixtures to ensure tight fit between the components. Subsequently, welding is used to fix the terminals and welding block 1 together, forming a structurally stable battery top cover assembly.

[0034] Explosion-proof patch 4: Made of insulating material with a certain strength, it is attached to the outer surface of the top cover after the core components of the top cover structure are assembled. Its main function is to provide physical protection for components such as the explosion-proof valve 8 and the injection hole welding plate 5, preventing external dust and impurities from entering or external impacts from damaging the components, while also preventing personnel from directly contacting live parts, thus improving safety during use.

[0035] Stop bracket 9: Located inside the top cover structure, it works in conjunction with the top cover plate 7, lower plastic and other components to further limit and fix the position of components such as positive and negative terminals 11 and sealing ring 10, preventing internal components from shifting under conditions such as vibration and impact, and ensuring the overall stability of the top cover structure.

[0036] Positive and negative electrode connecting pieces 13: One end of the positive electrode connecting piece 14 is fixedly connected to the positive electrode post 12, and the other end is used to connect to the positive current collector of the battery cell; one end of the negative electrode connecting piece 13 is fixedly connected to the negative electrode post 11, and the other end is used to connect to the negative current collector of the battery cell. Through the positive and negative electrode connecting pieces 13, current conduction between the battery cell and the posts is achieved, ensuring the battery can output electrical energy normally.

[0037] In this embodiment, during operation:

[0038] When the battery needs to be filled with electrolyte, including the first filling, the second or multiple replenishments, the filling needle is inserted into the elastic sealing channel of the rubber stopper 6 through the through hole in the center of the filling hole welding piece 5.

[0039] Since the elastic sealing channel is initially closed, the inner wall of the channel will be opened when the injection needle is inserted. The annular protrusion on the inner wall of the channel fits tightly with the outer wall of the injection needle to prevent electrolyte leakage during the injection process.

[0040] The electrolyte is injected into the battery cell through the injection needle, sequentially passing through the through hole of the injection hole welding piece 5, the elastic sealing channel of the rubber stopper 6, and the injection hole of the top cover piece 7. After injection, the injection needle is pulled out directly. The elastic sealing channel of the rubber stopper 6 closes quickly under the elastic restoring force of the EPDM material. The annular protrusions on the inner wall of the channel squeeze each other, further enhancing the sealing effect and ensuring that the electrolyte will not leak from the channel. This allows for secondary and multiple electrolyte replenishment operations, and maintains reliable sealing performance after each injection.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A refillable electrolyte-filled battery top cover structure, characterized in that, Includes a top cover plate (7), a liquid injection hole welding plate (5), and a rubber stopper (6). The top cover plate (7) is provided with a liquid injection hole, and an annular boss (3) is provided at the liquid injection hole. The rubber stopper (6) is assembled in the annular boss (3). The liquid injection hole welding plate (5) presses against the rubber stopper (6) and is welded to the top cover plate (7). The center of the liquid injection hole welding plate (5) is provided with a through hole. The rubber stopper (6) has a columnar structure with an elastic sealing channel for inserting a liquid injection needle along its center along the axial direction. The elastic sealing channel is initially closed. When the liquid injection needle is inserted, the elastic sealing channel is opened. After the liquid injection needle is pulled out, the elastic sealing channel recovers its closure by its own elasticity to achieve self-sealing.

2. The refillable electrolyte-fillable battery top cover structure according to claim 1, characterized in that, The inner wall of the elastic sealing channel of the rubber stopper (6) is provided with an annular protrusion, which is distributed along the circumference of the elastic sealing channel to enhance the sealing effect after the injection needle is pulled out.

3. The refillable electrolyte-fillable battery top cover structure according to claim 1, characterized in that, It also includes an explosion-proof valve (8), which is welded to the corresponding hole of the top cover plate (7).

4. The refillable battery top cover structure according to claim 1, characterized in that, It also includes a positive electrode post (12), a negative electrode post (11), a sealing ring (10), a lower plastic, an upper plastic (2), and a welding block (1). The positive electrode post (12) and the negative electrode post (11) pass through the sealing ring (10), the lower plastic, the top cover plate (7), and the upper plastic (2) in sequence, respectively, and then cooperate with the welding block (1). They are pressed by a tooling fixture and welded to form a fixed battery top cover assembly.

5. The refillable electrolyte-fillable battery top cover structure according to claim 1, characterized in that, It also includes an explosion-proof patch (4), which is attached to the top cover structure for physical protection.

6. The refillable electrolyte-filled battery top cover structure according to claim 1, characterized in that, The rubber stopper (6) is made of EPDM.

7. The refillable electrolyte-fillable battery top cover structure according to claim 4, characterized in that, It also includes a positive electrode connector (14) and a negative electrode connector (13), which are respectively matched with the corresponding positive electrode post (12) and negative electrode post (11).

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