Sealing top cover capable of circularly injecting liquid and battery
By setting a combination structure of a fusible plug and a pressure relief groove on the top cover of the lithium-ion battery, the problems of electrolyte loss and irreversible sealing are solved, enabling multiple electrolyte injections and safe pressure relief of the battery, thus improving the battery's performance and safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HUIZHOU KEDALI PRECISION IND CO LTD
- Filing Date
- 2025-04-10
- Publication Date
- 2026-05-08
AI Technical Summary
Existing lithium-ion batteries suffer from electrolyte loss during charge-discharge cycles, leading to performance degradation. Furthermore, the irreversible welding and sealing of the injection hole prevents secondary electrolyte injection, which may damage the electrode or separator, affecting battery quality and safety.
The system combines a fusible plug with a functional hole, which is fastened by threads. A diversion and pressure relief groove is set below the functional hole to achieve buffering and diversion of electrolyte. In the event of battery thermal runaway, the fusible plug melts to relieve pressure, integrating electrolyte injection and pressure relief functions.
This technology enables multiple electrolyte injections into the battery, improving its gradient recycling and safety, preventing battery casing cracking or explosion, and enhancing electrolyte wetting efficiency and overall battery performance.
Smart Images
Figure CN224217570U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of battery technology, specifically to a recyclable liquid-filled sealed top cover and battery. Background Technology
[0002] During use, the capacity of a lithium-ion battery gradually decreases with each charge and discharge cycle, and the electrolyte inside the battery is depleted, affecting the battery's performance.
[0003] The top cover of a battery typically has an electrolyte injection port and an explosion-proof valve. The explosion-proof valve is used to release pressure from the battery cell, and its structure is usually quite complex and difficult to manufacture. The electrolyte injection port is used to inject electrolyte into the battery. Currently, after injecting electrolyte into a square battery, a sealing pin is usually inserted into the injection port and welded to seal the battery. However, since the welded seal is irreversible, there is no way to inject electrolyte a second time. The decrease in the amount of electrolyte inside the battery will continuously affect the battery's performance. In addition, since the electrolyte has a certain flow rate and pressure during injection, if it directly impacts the inside of the battery, it may damage the electrodes or separator, affecting the battery quality. Utility Model Content
[0004] In view of this, the purpose of this utility model is to provide a recyclable liquid-filled sealed top cover and battery.
[0005] A recyclable liquid-filling sealed top cover is installed on a battery. It includes a cover plate body, a fusible plug, and a connecting plate. The cover plate body has a functional hole with threads on its sidewall. The fusible plug has threads on its sidewall that mate with the functional hole. The fusible plug includes a torsion block at its top and two flat portions on opposite sides. The connecting plate is installed on the bottom surface of the cover plate body and has a pressure relief groove. The bottom of the pressure relief groove has multiple first through holes. The thread gaps of the fusible plug are coated with sealant, and the fusible plug is threadedly bonded to the functional hole, thus sealing the functional hole.
[0006] In the above technical solution, the fusible plug and the functional hole are fastened together by threads. The threads on the outside of the fusible plug are coated with sealant, which can enhance the stability of the connection and prevent loosening during use. At the same time, the sealant can fill the gaps in the threads to enhance the sealing performance. The fusible plug has a twisting block on top. During installation, the flat parts on both sides of the twisting block can be clamped with an installation tool to screw the fusible plug into the functional hole. The operation is simple and convenient. When the battery needs to be refilled with electrolyte, the fusible plug can be removed with the installation tool, and then electrolyte can be injected into the battery through the functional hole. The shunt pressure relief groove is located below the functional hole. When the electrolyte is injected from the functional hole, it first falls into the shunt pressure relief groove, and then flows into the battery through the first through hole at the bottom of the shunt pressure relief groove. In addition, the fusible plug is made of a specific temperature-resistant material, which melts when the temperature rises to its melting point. When the battery experiences thermal runaway, when its internal temperature reaches the melting point of the fusible plug, the fusible plug melts, making the functional hole connected to the outside. At this time, the functional hole is equivalent to the battery's pressure relief hole. The high-temperature and high-pressure gas inside the battery can be discharged from the functional hole, achieving the effect of pressure relief. This effectively prevents the battery casing from cracking or exploding, improving safety.
[0007] It should be noted that, since the electrolyte has a certain flow rate and pressure during injection, direct impact on the battery interior may damage the electrodes or separator. Therefore, a flow diversion and pressure relief groove is set below the functional hole. The flow diversion and pressure relief groove can act as a buffer to slow down the flow rate of the electrolyte. At the same time, the multiple first through holes on the flow diversion and pressure relief groove can act as a guide to ensure that the electrolyte penetrates the battery evenly, avoiding uneven wetting or electrolyte accumulation and improving wetting efficiency. In addition, it is worth mentioning that in the event of battery thermal runaway, the gas inside the battery is discharged to the outside of the battery through the flow diversion and pressure relief groove and the functional hole.
[0008] Optionally, in one embodiment, the fusible plug is a rubber plug.
[0009] In the above technical solution, the fusible plug is made of rubber, which can melt at a certain temperature to allow the high-temperature and high-pressure gas inside the battery to flow out.
[0010] Optionally, in one embodiment, a protrusion is provided on the top surface of the cover plate body, and the functional hole passes through the protrusion in the vertical direction.
[0011] In the above technical solution, the protrusion can ensure that the installation tool is always at a certain distance from the top surface of the cover plate body when installing and removing the fusible plug, so as to prevent the installation tool from scratching the surface of the cover plate body.
[0012] Optionally, in one embodiment, the first through hole is offset from the functional hole in the vertical direction.
[0013] In the above technical solution, the functional hole and the first through hole are staggered, so that when the electrolyte is injected from the functional hole, it first falls on the bottom surface of the diversion and pressure relief tank, and then is discharged through the first through hole, thus avoiding the electrolyte directly impacting the internal structure of the battery.
[0014] Optionally, in one embodiment, the connecting plate is provided with a support groove that mates with the functional hole, and the diversion and pressure relief groove passes through the support groove.
[0015] In the above technical solution, the length of the fusible plug is usually longer than the functional hole. After it is screwed into the functional hole, the part longer than the functional hole falls into the support groove. After it is installed in place, the bottom end of the fusible plug abuts against the bottom surface of the support groove. In other words, the support groove can also play a positioning role, indicating to the installer that the fusible plug has been screwed in. In addition, since the functional hole and the support groove are directly connected, the diversion and pressure relief groove needs to pass through the support groove to ensure the connection with the functional hole.
[0016] Optionally, in one embodiment, the sidewall of the diversion and pressure relief groove has a plurality of second through holes.
[0017] In the above technical solution, the second through hole is used to further improve the conductivity of the electrolyte, so that the electrolyte can penetrate into the battery more evenly.
[0018] Optionally, in one embodiment, the connecting plate has connecting portions on both sides for connecting to the battery.
[0019] In the above technical solution, the connecting plate is connected to the battery through the connecting parts on both sides, so that the sealed top cover is firmly installed on the battery.
[0020] Optionally, in one embodiment, the sealing top cover further includes two poles, which are installed through the cover body and the connecting plate.
[0021] In the above technical solution, the two terminals are the positive and negative terminals of the battery, respectively, used to guide the current inside the battery to the outside.
[0022] Another objective of this invention is to provide a battery with the aforementioned sealed top cover, which allows for multiple electrolyte fillings, facilitates gradient cycle use, and effectively prevents the battery casing from exploding or cracking under high temperature and pressure.
[0023] Compared with the prior art, the beneficial effects of this utility model are as follows:
[0024] This invention uses a fusible rubber plug for sealing. Compared with sealing nail welding, the fusible rubber plug is inexpensive and can be disassembled and replaced at any time. The battery can be refilled multiple times during use, which is beneficial for the gradual recycling of the battery. In addition, in the event of battery thermal runaway, the fusible rubber plug can melt itself, allowing the gas inside the battery to be discharged, thereby achieving automatic pressure relief, reducing the risk of battery casing cracking and explosion, and effectively improving the safety of battery use.
[0025] This invention features a toggle block at the top of the fusible plug, which facilitates the installation of the fusible plug and makes installation quicker and more convenient.
[0026] This utility model integrates the functions of an injection hole and a pressure relief hole, requiring only one functional hole to realize the battery's injection and pressure relief functions, making the overall structure of the sealed top cover simpler. Below the functional hole, a diversion and pressure relief groove is provided, which can act as a buffer to slow down the flow rate of the electrolyte and avoid excessive injection impact that could damage the battery's internal structure. At the same time, the diversion and pressure relief groove can also guide the electrolyte, allowing it to penetrate the battery evenly, avoiding uneven wetting or electrolyte accumulation, and improving wetting efficiency. Attached Figure Description
[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a perspective view of the sealing top cover of Example 1.
[0029] Figure 2 An exploded view of the sealed top cover.
[0030] Figure 3 for Figure 2 A magnified view of area A in the middle.
[0031] Figure 4 Bottom view of the sealed top cover.
[0032] Figure 5 This is a three-dimensional view of a fusible plug.
[0033] Explanation of the reference numerals in the figure:
[0034] 1-Cover plate body; 11-Functional hole; 12-Protrusion; 13-Pole post; 2-Meltable plug; 21-Twist block; 211-Flat surface; 3-Connecting plate; 31-Diverting pressure relief groove; 311-First through hole; 312-Second through hole; 32-Support groove; 33-Connecting part. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0036] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Example 1
[0038] Please refer to Figures 1 to 5 This embodiment provides a sealing top cover installed on a battery, which includes a cover body 1, a fusible plug 2, and a connecting plate 3. The cover body 1 has a functional hole 11, and the side wall of the functional hole 11 has threads. The side wall of the fusible plug 2 has threads that cooperate with the functional hole 11. The fusible plug 2 includes a twist block 21 at the top, and the twist block 21 includes two flat parts 211 opposite to each other on both sides. The connecting plate 3 is installed on the bottom surface of the cover body 1, and the connecting plate 3 has a diversion and pressure relief groove 31. The bottom of the diversion and pressure relief groove 31 has a plurality of first through holes 311. The thread gap of the fusible plug 2 is coated with sealant, and the fusible plug 2 is threadedly bonded to the functional hole 11 to seal the functional hole 11.
[0039] Specifically, the fusible plug 2 and the functional hole 11 are fastened together by threads. Before installation, sealant is applied to the thread gap on the outside of the fusible plug 2, and then the fusible plug 2 is screwed into the functional hole. The sealant can greatly enhance the stability of the connection between the fusible plug 2 and the functional hole 11, prevent the fusible plug 2 from loosening during use, and at the same time, the sealant can fill the gap in the threads to enhance the overall sealing performance. The top of the fusible plug 2 is provided with a twist block 21, and both sides of the twist block 21 are provided with flat parts 211. During installation, the flat parts 211 on both sides of the twist block 21 can be clamped by a specific installation tool, and the fusible plug 2 can be screwed into the functional hole 11. The twist block 21 makes the installation operation easier. When the battery needs to be refilled, the fusible plug 2 can be removed using the installation tool, and then the battery can be filled with electrolyte through the functional hole 11. The shunt pressure relief groove 31 is located below the functional hole 11. When the electrolyte is injected from the functional hole 11, it first falls into the shunt pressure relief groove. Inside the pressure groove 31, the gas is then guided into the battery through the first through hole 311 at the bottom of the pressure relief groove 31. In addition, the fusible plug 2 is made of a specific heat-resistant material and will melt when the temperature rises to its melting point. When the battery experiences thermal runaway, its internal temperature reaches the melting point of the fusible plug 2, causing the fusible plug 2 to melt and connect the functional hole 11 to the outside. At this time, the functional hole 11 is equivalent to the battery's pressure relief hole, and the high-temperature and high-pressure gas inside the battery can be discharged from the functional hole 11 to achieve the effect of pressure relief, effectively preventing the battery casing from cracking or exploding and improving the safety of use.
[0040] It should be noted that since the electrolyte has a certain flow rate and pressure during injection, direct impact on the battery interior may damage the electrodes or separator. Therefore, the diversion and pressure relief groove 31 provided below the functional hole 11 can act as a buffer to slow down the flow rate of the electrolyte. At the same time, the multiple first through holes 311 provided on the diversion and pressure relief groove 31 can act as a guide to ensure that the electrolyte penetrates the battery evenly, avoid uneven local wetting or electrolyte accumulation, and improve wetting efficiency.
[0041] Preferably, such as Figure 3 As shown, the bottom of the diversion pressure relief groove 31 protrudes from the bottom surface of the connecting plate 3. The purpose is to increase the depth of the diversion pressure relief groove 31 without increasing the thickness of the connecting plate 3, so as to ensure the buffering effect.
[0042] Furthermore, multiple second through holes 312 are opened on both sides of the pressure relief groove 31. The second through holes 312 can further improve the flow of electrolyte, so that the electrolyte can penetrate into the battery more evenly.
[0043] It is understandable that the first through hole 311 and the second through hole 312 on the shunt pressure relief groove 31 are used not only for the electrolyte to pass through, but also for the gas inside the battery to pass through. When the battery thermally runs away, the fusible plug 2 melts, and the gas inside the battery passes through the shunt pressure relief groove 31 and the functional hole 11 in sequence and is discharged to the outside of the battery.
[0044] Preferably, the first through hole 311 is offset from the functional hole 11 in the vertical direction, so that when the electrolyte is injected from the functional hole 11, it first falls on the bottom surface of the middle part of the diversion and pressure relief groove 31, and then is discharged through the first through holes 311 on both sides, avoiding the electrolyte from directly impacting the inside of the battery and effectively protecting the internal structure of the battery.
[0045] Because rubber has high hardness, good airtightness, and properties such as heat resistance, aging resistance, and corrosion resistance, as well as shock absorption and electrical insulation properties, the fusible plug 2 is made of rubber material, which can effectively ensure the sealing performance of the functional hole 11. Preferably, in this embodiment, rubber material with a melting point of 120°C is selected to adapt to the temperature during battery thermal runaway, ensuring that the plug can melt normally to allow the high-temperature and high-pressure gas inside the battery to flow out.
[0046] In other embodiments, since the types and models of batteries are different, the temperature at which thermal runaway occurs is also different, usually ranging from 80°C to 200°C. Based on the temperature at which the battery thermally runs away, a rubber material with a suitable melting point can be selected to make the fusible plug 2.
[0047] Please refer to Figure 1 and Figure 2 In this embodiment, an annular protrusion 12 is provided on the top surface of the cover plate body 1, and the functional hole 11 passes through the protrusion 12 in the vertical direction. After the fusible plug 2 is installed, the twist block 21 at its top is located above the protrusion 12. The protrusion 12 is provided so that the installation tool can always maintain a certain distance from the top surface of the cover plate body 1 when the fusible plug 2 is installed and removed, so as to prevent the installation tool from scratching the surface of the cover plate body 1.
[0048] Please refer to Figures 2 to 4 In this embodiment, the connecting plate 3 is provided with a support groove 32 that cooperates with the functional hole 11. Preferably, the depth of the support groove 32 is less than the depth of the diversion and pressure relief groove 31. The diversion and pressure relief groove 31 passes through and penetrates the support groove 32, dividing the support groove 32 into left and right parts. Normally, the length of the fusible plug 2 is longer than the functional hole 11. After it is screwed into the functional hole 11, the part longer than the functional hole 11 will fall into the support groove 32. After it is installed in place, the bottom end face of the fusible plug 2 abuts against the bottom surface of the support groove 32. In other words, the support groove 32 can also play a positioning role, indicating to the installer that the fusible plug 2 has been screwed in.
[0049] Please refer toFigure 2 and Figure 4 In this embodiment, the connecting plate 3 has connecting parts 33 on both sides for connecting with the battery. The connecting plate 3 is connected to the battery through the connecting parts 33 on both sides, so that the sealing top cover is securely installed on the battery.
[0050] Please refer to Figure 1 , Figure 2 and Figure 4 In this embodiment, the sealed top cover also includes two terminals 13, which are installed through the cover body 1 and the connecting plate 3, and are the positive and negative terminals of the battery, respectively, to conduct the current inside the battery to the outside. Example 2
[0051] This embodiment provides a battery, which includes the sealed top cover described in Embodiment 1, as well as a battery cell and a housing. The sealed top cover is installed on the opening of the housing to seal the battery cell inside the housing. By removing the fusible plug 2 on the sealed top cover, the battery can be repeatedly injected with electrolyte, which is beneficial for the graded cycle use of the battery. In the event of thermal runaway of the battery cell, the fusible plug 2 will melt on its own, and the gas inside the housing can be discharged through the functional hole 11 on the sealed top cover to achieve pressure relief and effectively prevent the battery housing from exploding and cracking under high temperature and high pressure.
[0052] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.
[0053] In the description of this utility model, it should be understood that terms such as "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, 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. Therefore, they should not be construed as limitations on this utility model.
[0054] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0055] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., 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 utility model according to the specific circumstances.
Claims
1. A recyclable liquid-fillable sealed top cover, disposed on a battery, characterized in that, include: The cover plate body has a functional hole, and the side wall of the functional hole has a thread; A fusible plug, wherein the sidewall of the fusible plug is provided with threads that mate with the functional hole, and the fusible plug includes a torsion block at the top end, the torsion block including two planar portions disposed opposite each other on both sides; A connecting plate is installed on the bottom surface of the cover plate body. The connecting plate is provided with a diversion and pressure relief groove, and the bottom of the diversion and pressure relief groove has multiple first through holes. The fusible plug is coated with sealant in the threaded gap, and the fusible plug is bonded to the threaded functional hole to seal the functional hole.
2. The sealing top cover according to claim 1, characterized in that, The fusible plug is a rubber plug.
3. The sealing top cover according to claim 1, characterized in that, The top surface of the cover plate body is provided with a protrusion, and the functional hole passes through the protrusion in the vertical direction.
4. The sealing top cover according to claim 1, characterized in that, The first through hole is offset from the functional hole in the vertical direction.
5. The sealing top cover according to claim 1, characterized in that, The connecting plate is provided with a support groove that matches the functional hole, and the diversion and pressure relief groove passes through the support groove.
6. The sealing top cover according to claim 1, characterized in that, The sidewall of the diversion and pressure relief groove has multiple second through holes.
7. The sealing top cover according to claim 1, characterized in that, The connecting plate has connecting parts on both sides for connecting to the battery.
8. The sealing top cover according to claim 1, characterized in that, The sealed top cover also includes two pole posts, which are installed through the cover plate body and the connecting plate.
9. A battery, characterized in that, Includes the sealing top cover as described in any one of claims 1-8.