Liquid injection hole sealing structure and battery

Abstract

This invention provides a sealing structure for an electrolyte injection port and a battery. The electrolyte injection port sealing structure provided by this invention is disposed on the top cover of a battery and includes an injection channel, a protrusion, and a sealing assembly. The injection channel includes a first injection port near the upper surface of the battery top cover and a second injection port near the lower surface of the battery top cover. The central axes of the first and second injection ports coincide, and the walls of the first and second injection ports are connected by a slope that is higher around the perimeter and lower in the middle. The protrusion includes an annular protrusion disposed on the upper surface of the battery top cover, surrounding the injection port of the injection channel. If electrolyte overflow occurs during injection, the overflowing electrolyte will be confined within the annular protrusion and guided back into the battery through the slope, preventing the overflow from spreading to the surface of the battery top cover and causing corrosion damage. This reduces the cost of overflow treatment and eliminates the safety hazards of metal corrosion and insulation degradation caused by electrolyte diffusion.

Description

Technical Field

[0001] This utility model relates to the field of new energy batteries, and in particular to a liquid injection hole sealing structure and a battery. Background Technology

[0002] In lithium-ion battery manufacturing, the overflow of electrolyte into the injection hole during the electrolyte filling process seriously affects cell quality and production efficiency. Currently, the mainstream cell top cover injection hole has a planar structure, making it easy for the electrolyte to spread along the top cover during injection, leading to three risks: first, corrosion of the top cover metal components, shortening cell lifespan; second, reduced insulation performance, increasing the risk of short circuits; and third, contamination of the sealing surface, causing subsequent sealing difficulties or failures. Existing technologies often use an adsorbent material layer around the injection hole to absorb overflow, but the adsorption capacity of the adsorbent material is limited and it needs to be replaced regularly, which increases manufacturing costs and process complexity. In addition, the adsorbent material may release harmful substances under high temperature conditions, creating safety hazards. Utility Model Content

[0003] The purpose of this invention is to provide a sealing structure for the injection hole and a battery to solve the technical problems of high cost and safety hazards in handling overflow in the prior art.

[0004] The technical solution of this utility model is as follows: a liquid injection hole sealing structure is provided on the top cover of a battery, including a liquid injection channel, a protrusion, and a sealing assembly; the liquid injection channel includes a first liquid injection hole near the upper surface of the top cover of the battery and a second liquid injection hole near the lower surface of the top cover of the battery; the central axes of the first liquid injection hole and the second liquid injection hole coincide, and the hole walls of the first liquid injection hole and the second liquid injection hole are connected by a slope that is high around the perimeter and low in the middle; the protrusion includes an annular protrusion disposed on the upper surface of the top cover of the battery, and the annular protrusion is disposed around the liquid injection port of the liquid injection channel; the sealing assembly includes a sealing plug that forms an interference fit with the liquid injection channel.

[0005] Preferably, the inclination angle of the inclined plane is in the range of [15°, 30°].

[0006] Preferably, the distance between the inner side of the bottom end of the annular protrusion and the injection port of the injection channel is 1.2 mm.

[0007] Preferably, a guide groove is provided between the inner side of the bottom end of the annular protrusion and the injection port of the injection channel, and the width range of the guide groove is [0.3mm, 0.8mm].

[0008] Preferably, the ratio of the height of the annular protrusion to the diameter of the second injection hole is in the range of [0.2, 0.4].

[0009] Preferably, the annular protrusion has a height of 0.8 mm, a top width of 0.5 mm, and a bottom width of 0.5 mm.

[0010] Preferably, the diameter of the second injection hole is 2.5 mm.

[0011] Preferably, there are multiple annular protrusions, and the multiple annular protrusions are distributed in a stepped manner.

[0012] Preferably, the liquid injection channel and the protrusion are integrally formed with the battery top cover.

[0013] This utility model also provides a battery, including the liquid injection hole sealing structure as described in any of the above technical solutions.

[0014] The beneficial effects of this invention are as follows: if overflow occurs during electrolyte injection, the overflowing electrolyte will be confined within the annular protrusion and guided back into the battery by the inclined surface, preventing the overflow from spreading to the surface of the battery top cover and causing corrosion damage. Overflow can be handled without the need for absorbent materials, reducing the cost of overflow treatment and eliminating the safety hazards of metal corrosion and insulation degradation caused by electrolyte diffusion. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of the liquid injection hole sealing structure according to an embodiment of the present utility model.

[0016] Figure 2 This is a top view schematic diagram of the overall structure of the injection hole sealing structure according to an embodiment of the present utility model.

[0017] Figure 3 This is a top view of a portion of the sealing structure of the injection hole in an embodiment of this utility model.

[0018] Reference numerals: 100-Battery top cover; 200-Injection channel; 210-First injection hole; 220-Second injection hole; 300-Protrusion; 400-Sealing assembly; 500-Sloping surface; 600-Guide groove. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of them. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] Figure 1 This is a schematic cross-sectional view of the injection hole sealing structure according to an embodiment of the present invention. Figure 2 This is a top view schematic diagram of the overall structure of the injection hole sealing structure according to an embodiment of the present invention. It should be noted that if substantially the same result is achieved, the embodiment of the present invention is not necessarily identical. Figure 1 and Figure 2 The structures shown are limited. For example... Figure 1 and Figure 2 As shown, the liquid injection hole sealing structure is provided on the battery top cover 100, including a liquid injection channel 200, a protrusion 300, and a sealing assembly 400. The liquid injection channel 200 includes a first liquid injection hole 210 near the upper surface of the battery top cover 100 and a second liquid injection hole 220 near the lower surface of the battery top cover 100. The central axes of the first liquid injection hole 210 and the second liquid injection hole 220 coincide, and the hole walls of the first liquid injection hole 210 and the second liquid injection hole 220 are connected by a slope 500 that is high around the perimeter and low in the middle. The protrusion 300 includes an annular protrusion provided on the upper surface of the battery top cover 100, and the annular protrusion is arranged around the liquid injection port of the liquid injection channel 200. The sealing assembly 400 includes a sealing plug that forms an interference fit with the liquid injection channel 200.

[0022] In this embodiment, the annular protrusion of the protrusion 300 surrounds the injection port of the injection channel 200, forming a physical baffle. If overflow occurs during injection, the overflowing electrolyte will be confined within the annular protrusion and guided back into the battery via the inclined surface 500, preventing the overflow from spreading to the surface of the battery top cover 100 and causing corrosion damage. After injection, the sealing plug of the sealing assembly 400 forms an interference fit with the injection channel 200, sealing the injection channel 200 and preventing contamination of the sealing surface due to seal failure. The injection port sealing structure of this embodiment eliminates the need for absorbent materials to handle overflow, reducing the cost of overflow treatment and preventing safety hazards such as metal corrosion and insulation degradation caused by electrolyte diffusion.

[0023] Furthermore, the liquid injection hole sealing structure of this embodiment only makes local adjustments to the surrounding structure of the liquid injection hole of the existing top cover, without changing the basic structure and installation dimensions of the battery top cover 100. It can be directly compatible with existing production lines without replacing production equipment, which greatly reduces the technical transformation costs and mass production implementation difficulties for enterprises.

[0024] In some embodiments, the inclination angle of the inclined plane 500 is in the range of [15°, 30°].

[0025] In this embodiment, the core function of the inclined surface 500 is to guide the overflow in the annular protrusion back to the injection hole (inside the battery). The inclination angle of [15°, 30°] is the key to achieving efficient flow guidance and no residue.

[0026] Electrolytes often have a certain viscosity. If the inclination angle is too small and the slope of the inclined plane 500 is gentle, the component of gravity of the electrolyte along the inclined plane 500 is insufficient, and it is easy to adhere to the surface of the inclined plane 500 to form liquid accumulation. Not only will it not be able to flow back quickly, but it may also cause corrosion risks. When the inclination angle is in the range of [15°, 30°], the slope is sufficient to allow the electrolyte to flow naturally under the action of gravity, while avoiding splashing caused by excessive flow rate.

[0027] In some embodiments, the distance between the inner side of the bottom end of the annular protrusion and the upper end of the injection channel 200 is 1.2 mm.

[0028] In this embodiment, the longer the distance between the inner bottom of the annular protrusion and the upper end of the injection channel 200, the larger the accommodating space formed by the annular protrusion, and the greater the capacity to hold overflowing electrolyte. However, a larger distance requires more material to process the annular protrusion and the guide groove 600. A 1.2mm spacing minimizes material usage while ensuring functionality. Especially for the battery top cover 100 in mass production, this slight dimensional optimization can significantly reduce overall material costs. In this embodiment, setting the distance between the inner bottom of the annular protrusion and the upper end of the injection channel 200 to 1.2mm is a better choice after comprehensively considering the capacity and cost of the electrolyte.

[0029] Figure 3 This is a top view schematic diagram of a portion of the liquid injection hole sealing structure according to an embodiment of the present invention, as shown below. Figure 3 As shown, in some embodiments, a guide groove 600 is provided between the inner side of the bottom end of the annular protrusion and the injection port of the injection channel 200, and the width range of the guide groove 600 is [0.3mm, 0.8mm].

[0030] In this embodiment, the guide channel 600 is formed by excavating between the inner side of the bottom of the annular protrusion and the injection port of the injection channel 200. The core function of the guide channel 600 is to guide the overflow in the annular protrusion to the inclined surface 500. The number and relative position of the guide channels 600 can be set according to actual needs. A preferred option is to set two opposite guide channels 600.

[0031] In this embodiment, the width range of the guide groove 600 is [0.3mm, 0.8mm]. If the width of the guide groove 600 is too small, the viscosity of the electrolyte may cause liquid residue to remain in the groove, which may corrode the guide groove 600 or spread to the sealing surface in the long term. If the width is too large, it will occupy too much of the space inside the annular protrusion, causing the annular protrusion to be unable to effectively block the overflow. The range of [0.3mm, 0.8mm] can find a balance between the guiding efficiency and the edge strength.

[0032] In some embodiments, the ratio of the height of the annular protrusion to the diameter of the second injection hole 220 is in the range of [0.2, 0.4].

[0033] In this embodiment, the core function of the annular protrusion is to form a physical baffle to prevent electrolyte from overflowing onto the top cover surface during electrolyte injection. The diameter of the second injection hole 220 is a fundamental parameter for battery injection efficiency and channel strength. An excessively large diameter can lead to structural weakness, while an excessively small diameter will affect the injection speed. The ratio between the two is limited to [0.2, 0.4], which essentially establishes a balance between "sufficient baffle height to intercept overflow" and "height that does not damage the top cover structure".

[0034] If the ratio is less than 0.2, meaning the annular protrusion is too low, the electrolyte may overflow onto the top cover surface during injection, leading to corrosion of the top cover's metal substrate and insulation failure, potentially causing battery leakage and short circuits. If the ratio is greater than 0.4, meaning the annular protrusion is too high, the excessive protrusion increases the amount of material used in the top cover, potentially causing stress concentration at the base of the protrusion. In the vibration environment of battery assembly, transportation, or charging and discharging, the protrusion is prone to cracking, leading to seal failure. Furthermore, an excessively high protrusion may exceed the original top cover's outline, causing spatial interference with the battery's top cover, terminals, and other components, making it incompatible with existing production line fixtures and assembly processes, necessitating equipment replacement.

[0035] The ratio of the height of the annular protrusion to the diameter of the second injection hole 220 is set within the range of [0.2, 0.4]. This ensures the protrusion height is within a reasonable range, neither exceeding the original dimensions of the top cover nor increasing local structural stress. It is directly compatible with existing production line processing and assembly processes, requiring no equipment adjustments and significantly reducing the difficulty of mass production implementation for enterprises. The protrusion height is typically 0.5-1.5mm.

[0036] In some embodiments, the annular protrusion has a height of 0.8 mm, a top width of 0.5 mm, and a bottom width of 0.5 mm.

[0037] In this embodiment, the conventional overflow height during electrolyte injection is typically <0.5mm, with a height of 0.8mm providing ample safety margin. This ensures a sufficient "edge barrier" to prevent the electrolyte from overflowing the protrusion during injection. The width of the annular protrusion directly determines the interception capability of the edge itself; a width of 0.5mm is sufficient to form a "continuous and complete edge," maintaining structural integrity and preventing failure even under long-term slight corrosion from the electrolyte.

[0038] In some embodiments, the diameter of the second injection hole 220 is 2.5 mm.

[0039] In this embodiment, the core function of the second injection hole 220 is to allow the electrolyte to be injected into the battery efficiently and stably. The diameter directly determines the injection flow rate. If the diameter is too small, the injection flow rate will be significantly reduced, resulting in a longer injection time for a single battery, which directly affects the mass production efficiency of the production line, especially in large-scale power battery production, and will cause a production capacity bottleneck. If the diameter is too large, such as >3mm, although the injection speed is increased, the electrolyte is prone to overflow from the injection channel 200 due to the excessive flow rate and impact force during the injection process. Even with the anti-overflow design of the annular protrusion and the guide groove 600, the amount of overflow will increase, exceeding the backflow bearing capacity of the guide structure, which will increase the risk of corrosion. In this embodiment, the 2.5mm diameter strikes a balance between efficient liquid injection and controllable overflow. It meets the requirements of the mass production line for liquid injection speed while keeping the overflow within the range of the annular protrusion. Combined with the 15°-30° inclined surface 500 and the 0.3-0.8mm wide guide groove 600, a small amount of overflow can be quickly returned to the battery interior to prevent diffusion.

[0040] In some embodiments, the number of the annular protrusions is multiple, and the multiple annular protrusions are distributed in a stepped manner.

[0041] In this embodiment, compared to a single annular protrusion, multiple stepped annular protrusions form multiple baffles, which can cope with more complex liquid injection scenarios. The inner annular protrusions near the liquid injection channel 200 can intercept a small amount of overflow during normal liquid injection, and quickly return it in conjunction with the inner guide channel 600. The outer annular protrusions away from the liquid injection channel 200 serve as redundant protection. When the liquid injection speed is too fast and the overflow volume exceeds the inner layer's bearing capacity, they can intercept the overflowing electrolyte a second time, preventing it from spreading to the top cover surface and minimizing the risk of overflow control failure.

[0042] In some embodiments, the liquid injection channel 200 and the protrusion 300 are integrally formed with the battery top cover 100.

[0043] In this embodiment, battery manufacturing has extremely high capacity requirements. The one-piece molding process can simplify the process, shorten the cycle, and directly solve the problem of low efficiency in traditional processing.

[0044] This utility model also provides a battery, including the liquid injection hole sealing structure as described in any of the above technical solutions.

[0045] The beneficial effects of this utility model are as follows: The annular protrusion of the protrusion 300 surrounds the injection port of the injection channel 200, forming a physical baffle. If leakage occurs during injection, the overflowing electrolyte will be confined within the annular protrusion and guided back into the battery through the inclined surface 500, preventing the overflow from spreading to the surface of the battery top cover 100 and causing corrosion damage. After injection, the sealing plug of the sealing component 400 forms an interference fit with the injection channel 200 to seal the injection channel 200, which can avoid contamination of the sealing surface caused by sealing failure. The injection hole sealing structure of this embodiment can handle the overflow problem without the need for absorbent material, reducing the cost of overflow handling and eliminating the safety hazards of metal corrosion and insulation degradation caused by electrolyte diffusion.

[0046] The above description is merely an embodiment of the present utility model. It should be noted that those skilled in the art can make improvements without departing from the inventive concept of the present utility model, but these improvements all fall within the protection scope of the present utility model.

Claims

1. A liquid injection hole sealing structure, disposed on the top cover of a battery, characterized in that, Includes the injection channel, the protrusion, and the sealing assembly; The liquid injection channel includes a first liquid injection hole near the upper surface of the battery top cover and a second liquid injection hole near the lower surface of the battery top cover; the central axes of the first liquid injection hole and the second liquid injection hole coincide, and the hole walls of the first liquid injection hole and the second liquid injection hole are connected by a slope that is high around the perimeter and low in the middle. The protrusion includes an annular protrusion disposed on the upper surface of the battery top cover, the annular protrusion being disposed around the injection port of the injection channel; The sealing assembly includes a sealing plug that forms an interference fit with the injection channel.

2. The injection hole sealing structure according to claim 1, characterized in that, The angle of inclination of the inclined plane is in the range of [15°, 30°].

3. The injection hole sealing structure according to claim 1, characterized in that, The distance between the inner side of the bottom end of the annular protrusion and the injection port of the injection channel is 1.2 mm.

4. The injection hole sealing structure according to claim 1, characterized in that, A guide groove is provided between the inner side of the bottom end of the annular protrusion and the injection port of the injection channel, and the width range of the guide groove is [0.3mm, 0.8mm].

5. The injection hole sealing structure according to claim 1, characterized in that, The ratio of the height of the annular protrusion to the diameter of the second injection hole is in the range of [0.2, 0.4].

6. The injection hole sealing structure according to claim 1, characterized in that, The annular protrusion has a height of 0.8 mm, a top width of 0.5 mm, and a bottom width of 0.5 mm.

7. The injection hole sealing structure according to claim 1, characterized in that, The diameter of the second injection hole is 2.5 mm.

8. The injection hole sealing structure according to claim 1, characterized in that, The number of annular protrusions is multiple, and the multiple annular protrusions are distributed in a stepped manner.

9. The injection hole sealing structure according to claim 1, characterized in that, The liquid injection channel and the protrusion are integrally formed with the battery top cover.

10. A battery, characterized in that, The injection hole sealing structure includes any one of claims 1-9.

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