Battery sealing structure

Abstract

The utility model relates to battery sealing technical field provides a kind of battery sealing structure. Battery sealing structure includes battery top cover, hole plug and hole cover, the surface of battery top cover is provided with liquid injection hole;Hole plug is set in the liquid injection hole;Hole cover is covered in the outside of the liquid injection hole, the inner surface of the hole is provided with accommodating cavity, the accommodating cavity has easy broken part, and the accommodating cavity is used to store detection gas. The utility model provides a kind of battery sealing structure, to solve the defect that hole plug is extruded and is easy to lead to air bag breakage in prior art, the battery sealing structure provided by the utility model, by accommodating cavity is integrated in the inner surface of hole cover, detection gas can be separated from the physical contact of hole plug, thereby reduce the extrusion risk of hole plug interference fit deformation to air bag.

Description

Technical Field

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

[0002] In lithium-ion battery production, the injection port is typically sealed using a double-sealing structure of a plug and a cap. In existing technology, the plug is generally made of rubber and is pressed into the injection port via an interference fit. A cylindrical placement hole is formed at its end, and an air bladder filled with helium is directly embedded in this hole to test the seal between the cap and the top cover. The cap covers the plug and is fixed to the top cover via laser welding.

[0003] However, during the process of pressing the plug into the injection hole, the plug undergoes elastic deformation due to the interference fit, which causes the inner wall of the placement hole to shrink. The air bladder is located inside the placement hole of the plug. The rubber plug deforms under radial compression, and the inner wall of the placement hole directly applies pressure to the air bladder. This continuous compression can easily lead to air bladder rupture or premature helium leakage. After the air bladder ruptures, the helium supply is insufficient or it is released prematurely, which will lead to a decrease in the sensitivity of helium detection and make it impossible to accurately identify welding defects in the cap. Utility Model Content

[0004] This invention provides a battery sealing structure to solve the defect in the prior art where the pressure of the plug can easily cause the airbag to break. In the battery sealing structure provided by this invention, by integrating the receiving cavity into the inner surface of the cover, the physical contact between the gas and the plug can be detected, thereby reducing the risk of the airbag being squeezed by the interference fit deformation of the plug.

[0005] The battery sealing structure provided by this utility model includes: The battery top cover has liquid injection holes on its surface; A plug is disposed inside the injection hole; A cap is provided on the outside of the injection hole, and a receiving cavity is provided on the inner surface of the hole. The receiving cavity has a fragile part and is used to store the detection gas.

[0006] According to the battery sealing structure provided by this utility model, the inner surface of the hole cover is provided with a receiving groove, and a patch is sealed at the opening of the receiving groove. The receiving groove and the patch together restrict the receiving cavity, and the patch is used to form the fragile part.

[0007] According to the battery sealing structure provided by this utility model, the inner surface of the hole cover is provided with an annular protrusion, and the annular protrusion and the hole cover together restrict the receiving groove.

[0008] According to the battery sealing structure provided by this utility model, a guide blind hole is provided at one end of the plug facing the hole cover, and a gas guide groove is provided on the inner wall of the guide blind hole. The annular protrusion is at least partially located in the guide blind hole. In the event of the patch breakage, the gas guide groove is used to guide the detection gas out of the receiving cavity.

[0009] According to the battery sealing structure provided by this utility model, a first preset gap is provided between the annular protrusion and the plug.

[0010] According to the battery sealing structure provided by this utility model, the plug is provided with a first limiting shoulder, which is disposed on the side surface of the plug and is used to abut against the inner surface of the battery top cover.

[0011] According to the battery sealing structure provided by this utility model, a second preset gap is provided between the first limiting shoulder and the inner surface of the battery top cover, and the second preset gap is less than or equal to the first preset gap.

[0012] According to the battery sealing structure provided by this utility model, the plug is further provided with a second limiting shoulder, which is located on the side surface of the plug and is used to abut against the outer surface of the battery top cover.

[0013] According to the battery sealing structure provided by this utility model, the hole cover includes: The first cover wall, wherein the receiving cavity is disposed on the inner surface of the first cover wall; The second cover wall is disposed around the first cover wall on the side of the first cover wall facing the battery top cover, and a flange is provided at the end of the second cover wall away from the first cover wall. The flange is used for welding to the battery top cover.

[0014] According to the battery sealing structure provided by this utility model, the outer surface of the first cover wall is provided with at least one of a groove and a protrusion, and / or the inner surface of the first cover wall is provided with at least one of a groove and a protrusion.

[0015] In the battery sealing structure provided by this utility model, by integrating the receiving cavity into the inner surface of the orifice cap, the detection gas can be prevented from physically contacting the orifice plug, thereby reducing the risk of compression of the airbag due to the interference fit deformation of the orifice plug. Compared with the prior art solution of embedding the airbag into the orifice plug placement hole, this utility model can improve the situation where the airbag is damaged or helium leaks prematurely due to rubber shrinkage, ensuring the complete storage of detection gas. At the same time, the integrated design of the receiving cavity simplifies the assembly process, eliminating the need for rear-mounted airbag operation and improving production efficiency. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is an exploded structural diagram of the battery sealing structure provided in this embodiment of the utility model.

[0018] Figure 2 This is a partial cross-sectional structural diagram of the battery sealing structure provided in this embodiment of the utility model.

[0019] Figure 3 This is a partial cross-sectional view of another battery sealing structure provided in this embodiment of the utility model.

[0020] Figure 4 This is an axial side view of the plug provided in an embodiment of the present invention.

[0021] Figure 5 This is a top view of the plug provided in this embodiment of the utility model.

[0022] Figure label: 100: Battery top cover; 110: Liquid injection hole; 200: Hole plug; 210: Guide blind hole; 220: Gas guide groove; 230: First limiting shoulder; 240: Second limiting shoulder; 300: Hole cover; 310: Receiving cavity; 320: Fragile part; 330: Annular protrusion; 340: First cover wall; 350: Second cover wall. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0024] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0025] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0027] Figure 1 This is an exploded structural diagram of the battery sealing structure provided in this embodiment of the utility model; Figure 2 This is a partial cross-sectional structural diagram of the battery sealing structure provided in this embodiment of the utility model.

[0028] See Figure 1 and Figure 2 This utility model provides a battery sealing structure, which includes a battery top cover 100, a plug 200, and a cover 300. The surface of the battery top cover 100 is provided with an injection hole 110, and the plug 200 is interference-fitted into the injection hole 110 to achieve a primary seal. The cover 300 covers the outside of the injection hole 110, and its inner surface is provided with a receiving cavity 310 for storing a detection gas (such as helium). The surface of the receiving cavity 310 is provided with a fragile part 320.

[0029] Specifically, the receiving cavity 310 on the inner surface of the cap 300 is a recessed groove structure, and the fragile part 320 can be designed as an encapsulation structure (e.g., a PC film) at the opening of the receiving cavity 310, or a thinned area on the sidewall of the receiving cavity 310. In one optional embodiment, the receiving cavity 310 is a cylindrical groove, and a circular PC film is adhered to its opening as the fragile part 320. In another optional embodiment, the receiving cavity 310 is a rectangular groove, and its top surface is thinned, with the thinned area constituting the fragile part 320.

[0030] During the helium gas sealing test, the welded cap 300 is placed in a negative pressure environment. If there is a defect (such as a burst point) at the laser welding position between the cap 300 and the top cover, the external vacuum negative pressure seeps into the inner space of the cap 300 through the welding defect. When the pressure difference between the inside and outside of the containment cavity 310 exceeds a preset threshold, the fragile part 320 ruptures and releases the detection gas; the helium gas escapes through the welding defect channel to the external vacuum environment and is captured by the helium mass spectrometer, thereby identifying the sealing failure point.

[0031] See Figure 1 and Figure 2 It is understood that in the battery sealing structure provided by this utility model embodiment, by integrating the receiving cavity 310 into the inner surface of the hole cover 300, the detection gas can be separated from the physical contact with the hole plug 200, thereby reducing the risk of compression of the airbag due to the interference fit deformation of the hole plug 200. Compared with the prior art solution of embedding the airbag into the hole plug 200 placement hole, this utility model embodiment can improve the situation where the airbag is damaged or helium leaks prematurely due to rubber shrinkage, ensuring the complete storage of detection gas. At the same time, the integrated design of the receiving cavity 310 can simplify the assembly process, eliminating the need for rear-mounted airbag operation and improving production efficiency.

[0032] Continue reading Figure 1 and Figure 2 In an optional embodiment of this utility model, a receiving groove is provided on the inner surface of the orifice cover 300. The opening of the receiving groove is sealed by a patch, thereby forming a sealed receiving cavity 310. The patch constitutes the fragile part 320 of the receiving cavity 310. Specifically, the receiving groove is a structure recessed into the body of the orifice cover 300, and its opening edge and the patch can be fixed by hot melt bonding, laser sealing, or adhesive. The patch is made of a plastic deformation material, and its thickness direction can be set with a weak area as the fragile part 320.

[0033] In one optional embodiment, the receiving groove is a cylindrical groove, with a circular PET film covering the groove opening. A micron-level cross-shaped indentation is pre-pressed into the center of the film as a fragile section 320. In another optional embodiment, the receiving groove is a rectangular groove, with a PP film heat-sealed at the groove opening. An annular weakening groove is provided at the edge of the film to form the fragile section 320.

[0034] When the battery is placed in a helium detection negative pressure environment, if there is a defect at the welding interface between the hole cover 300 and the battery top cover 100, the external negative pressure will penetrate into the inner space of the hole cover 300 through the defect channel. The detection gas pressure inside the receiving cavity 310 will create a pressure difference with the external vacuum, and this pressure difference will act on the surface of the patch. When the pressure difference exceeds the patch's bearing limit, the weak area will rupture, and the detection gas will escape along the welding defect channel and be captured by the external helium mass spectrometer.

[0035] See Figure 1 and Figure 2 It is understood that, compared to the prior art solution of embedding the airbag into the rubber plug 200, the battery sealing structure provided by this utility model, through the structure of the patch-encapsulated receiving groove, confines the detection gas inside the rigid plug 300, thereby reducing the risk of compression caused by the deformation of the plug 200. Secondly, the patch in this utility model is fixed to the metal plug 300, and its deformation only responds to pressure difference changes, unaffected by the assembly process. Furthermore, the directional weakening design of the fragile part 320 makes the rupture behavior controllable, ensuring the helium release location and improving detection accuracy. Simultaneously, the patch pre-encapsulation process simplifies the production process and avoids the operational difficulties of a rear-mounted airbag.

[0036] Continue reading Figure 1 and Figure 2 In an optional embodiment of this utility model, an annular protrusion 330 is provided on the inner surface of the hole cover 300, and the annular protrusion 330 and the hole cover 300 body together form a receiving groove. Specifically, the annular protrusion 330 extends vertically from the inner surface of the hole cover 300, and its inner sidewall and the inner surface of the hole cover 300 define an annular groove space. The top of the annular protrusion 330 is provided with a flat support surface, and a patch covers the support surface and the opening of the receiving groove. In an optional embodiment, the annular protrusion 330 is a continuous circular ring structure, integrally stamped with the hole cover 300 using aluminum alloy, and the receiving groove is a circular groove.

[0037] See Figure 1 and Figure 2 It is understood that in the battery sealing structure provided by this embodiment of the present invention, when the plug 200 moves upward under the action of the internal gas pressure of the battery, the annular protrusion 330 can block the plug 200 from squeezing the patch, thereby avoiding accidental breakage caused by mechanical squeezing. Secondly, the annular protrusion 330 can form a suspended membrane structure in the middle area of ​​the patch, so that the pressure difference is concentrated on the suspended area, causing the fragile part 320 to break in a directional manner and release the detection gas.

[0038] Compared to the unprotected airbag structure in the prior art, this embodiment of the invention establishes a protective barrier through a rigid annular protrusion 330, reducing the risk of accidental damage during assembly and use. Simultaneously, the integration of the protrusion with the cover 300 enhances the overall structural integrity and avoids assembly errors inherent in separate parts.

[0039] Figure 3 This is another partial cross-sectional view of the battery sealing structure provided in this embodiment of the utility model; Figure 4 This is an axial side view of the plug provided in an embodiment of the present invention; Figure 5 This is a top view of the plug provided in this embodiment of the utility model.

[0040] See Figure 3 , Figure 4 and Figure 5 In an optional embodiment of this utility model, a guide blind hole 210 is machined at the end of the plug 200 facing the cover 300. A gas guide groove 220 is formed on the inner wall of the guide blind hole 210, and the annular protrusion 330 extends at least partially into the guide blind hole 210. When the patch breaks and releases the detection gas, the gas guide groove 220 provides a gas escape channel. Specifically, the guide blind hole 210 is a cylindrical cavity with a depth greater than the height of the annular protrusion 330. The gas guide groove 220 extends axially along the inner wall of the blind hole, and the outer diameter of the annular protrusion 330 is smaller than the inner diameter of the guide blind hole 210, forming a clearance fit.

[0041] In one optional embodiment, four straight air guide grooves 220 are symmetrically arranged on the inner wall of the guide blind hole 210, and the grooves extend through the bottom of the blind hole to the end face of the plug 200. In another optional embodiment, the air guide grooves 220 have a spiral structure and extend continuously from the bottom of the blind hole to the opening end.

[0042] See Figure 3 , Figure 4 and Figure 5 It is understood that in the battery sealing structure provided by this utility model embodiment, the clearance fit between the annular protrusion 330 and the guide blind hole 210 can achieve radial alignment of the hole cover 300 and the hole plug 200; furthermore, when the hole plug 200 is affected by the internal air pressure of the battery and moves axially, the guide blind hole 210 can cooperate with the annular protrusion 330 to guide the movement of the hole plug 200 and limit the movement trajectory of the hole plug 200. In this way, the coaxiality of the assembly of the hole cover 300 and the hole plug 200 can be improved through mechanical nesting, avoiding sealing failure caused by misalignment.

[0043] On the other hand, after the patch breaks, the detection gas enters the gap space between the annular protrusion 330 and the guide blind hole 210, and flows directionally along the gas guide groove 220 to the welding interface of the hole cover 300-battery top cover 100. The detection gas escapes to the external vacuum environment through the welding defect and is captured by the detection equipment. In this way, a directional gas channel can be established, so that the detection gas can be quickly gathered to the welding defect area, thereby improving the detection efficiency.

[0044] Continue reading Figure 2 In an optional embodiment of the present invention, a first preset gap H1 is provided between the annular protrusion 330 and the plug 200. The first preset gap is specifically the vertical distance between the outer wall of the annular protrusion 330 and the corresponding surface of the plug 200.

[0045] See Figure 2 It is understood that in the battery sealing structure provided in this utility model embodiment, during use, the internal air pressure of the battery may increase due to environmental factors, such as temperature or air pressure, which will push the plug 200 upward, that is, move it away from the battery.

[0046] During this process, the first preset gap allows the plug 200 to have reasonable room for movement. Specifically, the first preset gap can form a buffer isolation zone. The first preset gap absorbs the spatial displacement of the plug 200, which can prevent the annular protrusion 330 and the patch from directly and rigidly abutting against the plug 200. Secondly, the space of the first preset gap can serve as a channel for the detection gas to escape from the cavity 310. After the patch breaks, the detection gas flows quickly to the welding interface through the space of the first preset gap, which can prevent the plug 200 and the annular protrusion 330 from directly abutting against each other and obstructing the escape of the detection gas, thereby ensuring the accuracy of the sealing test.

[0047] Continue reading Figure 2 In an optional embodiment of this utility model, the plug 200 is provided with a first limiting shoulder 230. The first limiting shoulder 230 is disposed on the side surface of the plug 200 and is adapted to abut against the inner surface of the battery top cover 100. The first limiting shoulder 230 is an annular flange or a split protrusion surrounding the side wall of the plug 200, and its outer diameter is slightly larger than the inner diameter of the injection hole 110. After installation, it can abut against the inner wall of the top cover inside the injection hole 110, forming an upward movement limit for the plug 200. In an optional embodiment of this utility model, the first limiting shoulder 230 can be replaced by multiple evenly distributed elastic claws. After the claws are compressed and contracted, they pass through the injection hole 110 and then unfold to abut against the inner wall of the top cover.

[0048] See Figure 2It is understood that in the battery sealing structure provided by this utility model embodiment, the first limiting shoulder 230 can constrain the upward movement of the plug 200, thus improving the dynamic sealing guarantee. Specifically, when the plug 200 is pressed into the injection hole 110, the first limiting shoulder 230 stops moving after contacting the inner surface of the battery top cover 100, which can ensure that the main body of the plug 200 is at the designed depth; if the internal air pressure increases during battery use, the plug 200 is subjected to an upward thrust, and the first limiting shoulder 230 abuts against the inner wall of the battery top cover 100 to prevent upward movement, thus maintaining the stability of the sealing interface.

[0049] Continue reading Figure 2 In an optional embodiment of this utility model, a second preset gap H2 is provided between the first limiting shoulder 230 and the inner surface of the battery top cover 100. The size of the second preset gap is less than or equal to the first preset gap, that is, it satisfies the relationship: the second preset gap ≤ the first preset gap. The second preset gap and the first preset gap can jointly construct a buffer space to adapt to the internal air pressure fluctuations of the battery.

[0050] In an optional embodiment, after the plug 200 is installed into the injection hole 110, the plug 200 can be pressed further into the injection hole 110 until it reaches a preset position. At this time, there is a gap between the plug 200 and the annular protrusion 330, which is the first preset gap. There is also a certain gap between the first limiting shoulder 230 and the inner surface of the battery top cover 100, which is the second preset gap. The second preset gap is equal to the first preset gap.

[0051] During use, the internal air pressure of the battery may increase due to environmental factors such as temperature or air pressure, which will push the plug 200 upward, that is, move it away from the battery. During this process, the first preset gap and the second preset gap allow the plug 200 to have reasonable room for movement, and the displacement of the plug 200 is absorbed by the first preset gap and the second preset gap.

[0052] When the plug 200 moves upward to the point where the first limiting shoulder 230 abuts against the inner surface of the battery top cover 100, the first preset gap and the second preset gap disappear simultaneously. At this time, the plug 200 abuts against the annular protrusion 330, thus forming a double limiting structure where the plug 200 abuts against the annular protrusion 330 and the first limiting shoulder 230 abuts against the battery top cover 100. When the internal air pressure of the battery is restored, the plug 200 will move downward under the attraction of the negative pressure inside the battery until the first preset gap and the second preset gap reappear completely.

[0053] See Figure 2 and Figure 3It is understood that the battery sealing structure provided in this utility model embodiment can achieve dynamic sealing optimization through a dual-gap linkage mechanism. Specifically, when the internal air pressure of the battery increases, the second preset gap and the first preset gap decrease synchronously during the upward movement of the plug 200 until the first limiting shoulder 230 abuts against the inner surface of the battery top cover 100 and the plug 200 abuts against the annular protrusion 330, forming a double rigid limit. When the air pressure recovers, the plug 200 automatically resets under negative pressure attraction, and the dual gaps return to their initial state. This mechanism of simultaneous disappearance of dual gaps triggering limit can provide mechanical stop protection under extreme air pressure, and the dual-gap design allows the battery to adaptively stabilize the internal pressure to avoid the impact of excessive or insufficient internal pressure on battery stability, thereby effectively improving the safety and stability of the battery.

[0054] Continue reading Figure 2 and Figure 3 In an optional embodiment of this utility model, the plug 200 is further provided with a second limiting shoulder 240, which is disposed on the side surface of the plug 200 and is used to abut against the outer surface of the battery top cover 100. Specifically, the second limiting shoulder 240 is an annular flange surrounding the side wall of the plug 200, and its outer diameter is larger than the diameter of the injection hole 110, so as to ensure that the second limiting shoulder 240 is locked onto the outer surface of the battery top cover 100 when the plug 200 is pressed in.

[0055] Optionally, multiple variations can be constructed through structural fine-tuning during implementation. Variation 1: The second limiting shoulder 240 is a continuous annular plane, making full contact with the surface of the battery top cover 100 (e.g., Figure 2 and Figure 3 (As shown); Variation 2: The second limiting shoulder 240 is replaced with multiple evenly distributed arc-shaped protrusions, forming ventilation gaps between the protrusions to reduce assembly resistance.

[0056] When a first preset gap is provided, the first preset gap is provided between the outer surface of the second limiting shoulder 240 and the annular protrusion 330; when a first limiting shoulder 230 is provided, the second limiting shoulder 240 and the first limiting shoulder 230 respectively form the upper and lower limiting mechanisms of the plug 200.

[0057] See Figure 2 and Figure 3 It is understood that in the battery sealing structure provided in this utility model embodiment, when the plug 200 is pressed into the injection hole 110, the second limiting shoulder 240 stops pressing when it contacts the outer surface of the battery top cover 100. When the gas pressure inside the battery changes and generates negative pressure, the plug 200 moves down under negative pressure. The second limiting shoulder 240 abuts against the battery top cover 100 to prevent displacement, thereby reducing the impact of the negative gas pressure inside the battery on the plug 200.

[0058] Continue reading Figure 2 and Figure 3 In an optional embodiment of this utility model, the hole cover 300 structure includes a first cover wall 340 and a second cover wall 350. The first cover wall 340 serves as the main body, and an annular protrusion 330 is disposed on the first cover wall 340. The second cover wall 350 is disposed circumferentially along the first cover wall 340 on the side of the first cover wall 340 facing the battery top cover 100, and the end of the second cover wall 350 away from the first cover wall 340 is provided with a flange, which is used for sealing connection with the battery top cover 100 by laser welding.

[0059] The cover wall design forms a bent transition structure, wherein the included angle between the first cover wall 340 and the second cover wall 350 can be set adaptively, preferably 90°, and the flange width can be set adaptively to provide sufficient welding contact surface.

[0060] During assembly, the patch is first encapsulated on the surface of the annular protrusion 330 of the first cover wall 340; then the hole cap 300 is placed over the injection hole 110, so that the flange of the second cover wall 350 fits against the surface of the battery top cover 100; a sealing ring is formed by welding along the circumferential direction of the flange using a laser beam. During the welding process, the bending structure of the first cover wall 340 and the second cover wall 350 disperses thermal stress, which can reduce deformation in the weld area.

[0061] See Figure 2 and Figure 3 It is understood that in the battery sealing structure provided by this utility model embodiment, the structure of the bent cover wall optimizes the welding reliability and stress distribution. Specifically, the angle design between the first cover wall 340 and the second cover wall 350 can disperse the thermal stress of laser welding and reduce the risk of explosion caused by direct welding of the flat hole cover 300. Secondly, the flange can provide a wide welding surface, which can effectively improve the uniformity of weld penetration. The bending structure at the flange can also disperse the thermal stress of laser welding and reduce the risk of explosion caused by direct welding of the hole cover 300. In addition, compared with the rigid flat cover body, which is prone to false welding due to unevenness, the bending structure can also compensate for the flatness tolerance of the battery top cover 100 and ensure that the flange fits the entire circumference.

[0062] Continue reading Figure 2 and Figure 3 In an optional embodiment of this invention, the outer surface of the first cover wall 340 is provided with at least one of a groove and a protrusion, and / or the inner surface of the first cover wall 340 is provided with at least one of a groove and a protrusion. A groove is a regular recessed pit extending inward from the cover wall surface; a protrusion is a reinforcing rib protruding outward from the cover wall surface (for example, in an optional case, an annular protrusion 330 can serve as the protrusion here). These structures can optimize mechanical properties by changing the local stiffness of the cover wall.

[0063] Optionally, multiple variations can be constructed in combination with the morphology of the cap wall during implementation, as in Example 1 ( Figure 2 As shown): The outer surface of the first cover wall 340 has an annular groove, and the inner surface has an annular protrusion 330; Embodiment 2: The inner surface of the first cover wall 340 has a cross-shaped protrusion, and the intersection forms a groove, and the outer surface is smooth; Variation: The groove and the protrusion can be combined to form a wave pattern, covering the entire surface of the first cover wall 340.

[0064] See Figure 2 and Figure 3 It is understood that in the battery sealing structure provided by this utility model embodiment, during laser welding, the groove and protrusion structures can disperse thermal stress: the groove accommodates the thermal expansion deformation of the material, reducing micro-cracks in the flat cover caused by thermal stress; the protrusion provides additional support points to suppress cover wall warping and improve the cover's pressure resistance. Secondly, if the internal air pressure rises abnormally during battery use, the protrusion structure can also enhance the bending strength of the cover wall of the hole cover 300, while the groove can absorb local deformation energy.

[0065] It should be noted that the technical solutions in the various embodiments of this utility model can be combined with each other, but the basis for such combination is that they can be implemented by those skilled in the art. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist, that is, it is not within the protection scope of this utility model.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A battery sealing structure, characterized in that, include: The battery top cover has liquid injection holes on its surface; A plug is disposed inside the injection hole; A cap is provided on the outside of the injection hole, and a receiving cavity is provided on the inner surface of the hole. The receiving cavity has a fragile part and is used to store the detection gas.

2. The battery sealing structure according to claim 1, characterized in that, The inner surface of the cap is provided with a receiving groove, and a patch is sealed at the opening of the receiving groove. The receiving groove and the patch together define the receiving cavity, and the patch is used to form the fragile part.

3. The battery sealing structure according to claim 2, characterized in that, The inner surface of the hole cover is provided with an annular protrusion, and the annular protrusion and the hole cover together restrict the receiving groove.

4. The battery sealing structure according to claim 3, characterized in that, The end of the plug facing the cover is provided with a guide blind hole, and the inner wall of the guide blind hole is provided with a gas guide groove. The annular protrusion is at least partially located in the guide blind hole. In the event of the patch breakage, the gas guide groove is used to guide the detection gas out of the receiving cavity.

5. The battery sealing structure according to claim 3, characterized in that, A first preset gap is provided between the annular protrusion and the plug.

6. The battery sealing structure according to claim 5, characterized in that, The plug is provided with a first limiting shoulder, which is disposed on the side surface of the plug and is used to abut against the inner surface of the battery top cover.

7. The battery sealing structure according to claim 6, characterized in that, A second preset gap is provided between the first limiting shoulder and the inner surface of the battery top cover, and the second preset gap is less than or equal to the first preset gap.

8. The battery sealing structure according to claim 6, characterized in that, The plug is also provided with a second limiting shoulder, which is located on the side surface of the plug and is used to abut against the outer surface of the battery top cover.

9. The battery sealing structure according to any one of claims 1 to 8, characterized in that, The orifice cover includes: The first cover wall, wherein the receiving cavity is disposed on the inner surface of the first cover wall; The second cover wall is disposed around the first cover wall on the side of the first cover wall facing the battery top cover, and a flange is provided at the end of the second cover wall away from the first cover wall. The flange is used for welding to the battery top cover.

10. The battery sealing structure according to claim 9, characterized in that, The outer surface of the first cover wall is provided with at least one of a groove and a protrusion, and / or the inner surface of the first cover wall is provided with at least one of a groove and a protrusion.

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