Sealing nail, battery cover plate and battery

Abstract

The present application relates to the technical field of batteries. Specifically, disclosed are a sealing nail, a battery cover plate and a battery. The sealing nail comprises a sealing portion for sealing a liquid injection hole, and a gas injection portion. In a pre-installation state, a gas injection channel is formed between a first matching face of the gas injection portion and an inner wall of the liquid injection hole, the gas injection channel can be used for evacuation or gas injection, the end of a second matching face of the gas injection portion that is away from the sealing portion is inclined towards the central axis of the gas injection portion, and at least part of the second matching face can be in interference fit with the inner wall of the liquid injection hole, thereby having the function of temporarily fixing the sealing nail; in addition, the sealing nail does not easily fall out of the liquid injection hole, thereby facilitating evacuation or gas injection work; moreover, the second matching face has a guiding function when the sealing nail is inserted into the liquid injection hole, thereby facilitating the insertion of the sealing nail. When the sealing portion of the sealing nail is completely inserted into the liquid injection hole, the liquid injection hole can be sealed by means of the sealing portion, thereby achieving a good sealing effect. The battery cover plate and the battery each comprise the sealing nail.

Description

A sealing nail, a battery cover and a battery

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202410509824.5, filed on April 26, 2024, entitled "A Sealing Nail, Battery Cover and Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a sealing nail, a battery cover, and a battery. Background Technology

[0004] Generally, a battery consists of a top-open casing and a battery cover. The battery cover is located at the top of the casing and connected to it, creating a relatively sealed space. The battery cover has an injection hole through which electrolyte can be injected into the casing. After injection, to ensure a good seal, the casing needs to be evacuated to a negative pressure and filled with helium before installing the sealing pins. This allows for a helium test after the sealing pins are installed into the injection hole, ensuring a good seal and preventing leaks.

[0005] However, existing sealing pins can only be filled with helium before installation; after installation, helium cannot be added to the casing. This means that some of the helium already inside the casing may leak out during the installation process, resulting in material waste and a decrease in the helium content inside the casing, affecting the accuracy of subsequent helium testing. Furthermore, for sealing pins made of flexible materials, compression during installation, long-term use, and handling may cause them to rebound due to recovery deformation, causing them to pop out of the injection hole. This leads to seal failure, electrolyte leakage inside the casing, and potential battery safety hazards.

[0006] Application content

[0007] In view of this, the purpose of this application is to provide a sealing nail that, after being pre-installed into the injection hole, can still be filled with helium into the housing, making operation more convenient and alleviating the problem of helium diffusion outward, thereby improving the accuracy of detection.

[0008] In a first aspect, this application provides a sealing nail, including a sealing part and an air injection part connected to each other, wherein the sealing part is used to block the liquid injection hole;

[0009] The gas injection section includes a first mating surface and a second mating surface. The first mating surface is transitionally connected to the sealing section, and a gas injection channel is formed between the first mating surface and the inner wall of the injection hole. The gas injection channel is used for vacuuming or gas injection. One end of the second mating surface is transitionally connected to the sealing section, and the other end of the second mating surface is inclined toward the central axis of the gas injection section. At least a portion of the second mating surface is interference-fitted with the inner wall of the injection hole.

[0010] The second mating surface and the axial direction of the gas injection part have an included angle α, and the included angle α ranges from 0.01° to 30°.

[0011] Beneficial effects: This sealing pin includes a sealing part and an injection part for sealing the injection hole, and has elastic deformation capability. The injection part includes a first mating surface and a second mating surface that transitionally connect with the sealing part. When the sealing pin is in a pre-installed state, an injection channel is formed between the first mating surface and the inner wall of the injection hole. This channel can be used for vacuuming or injection. The end of the second mating surface away from the sealing part is inclined towards the central axis of the injection part, and at least a portion of the second mating surface can be press-fitted with the inner wall of the injection hole. On one hand, the second mating surface temporarily fixes the sealing pin, facilitating vacuuming or injection; on the other hand, it also acts as a guide, facilitating the insertion of the sealing pin into the injection hole. When the sealing part of the sealing pin also enters the injection hole, the sealing pin is installed, and the injection hole is sealed through the sealing part, providing a good sealing effect, and the sealing pin is not easily dislodged from the injection hole.

[0012] In one optional embodiment, the length of the gas injection section is L1, the length of the liquid injection hole is L2, and the length of the gas injection section L1 satisfies: 0.5mm≤L1≤3.0mm.

[0013] In one optional embodiment, the width of the end of the second mating surface connected to the sealing part is d1, the width of the end of the second mating surface away from the sealing part is d2, and the width of the second mating surface is d3 at the middle position of the length of the air injection part.

[0014] Where, d3 = 1 / 2(d1 + d2);

[0015] The width d3 of the second mating surface satisfies: 0.2mm≤d3≤1.0mm.

[0016] In one optional embodiment, the number of the first mating surfaces and the second mating surfaces are the same and there are multiple of each, and the first mating surfaces and the second mating surfaces are alternately arranged along the circumferential direction of the gas injection part.

[0017] In one alternative embodiment, the second mating surface is a conical arc surface, and all the second mating surfaces are located on the same conical surface.

[0018] In one optional embodiment, the interference fit between the second mating surface and the inner wall of the injection hole is 0.05 mm to 0.2 mm.

[0019] The sealing part has a sealing surface in the circumferential direction. The sealing surface is transitionally connected to the first mating surface and the second mating surface, and the sealing surface is interference-fitted with the inner wall of the injection hole. The interference between the sealing surface and the inner wall of the injection hole is 0.1mm to 0.25mm.

[0020] In one optional embodiment, the sealing nail further includes a guide portion connected to the air injection portion. The guide portion has a guide surface, which is transitionally connected to the first mating surface and the second mating surface of the air injection portion. One end of the guide surface away from the air injection portion is inclined toward the central axis of the guide portion. The guide surface and the axial direction of the guide portion have an included angle β, which is greater than the included angle α. The included angle β ranges from 10° to 80°.

[0021] In one alternative embodiment, a boss is provided at the end of the sealing portion away from the air injection portion.

[0022] Secondly, this application provides a battery cover plate, including a cover plate body and a sealing pin as described in any of the above solutions, wherein the cover plate body is provided with an injection hole and the sealing pin is disposed in the injection hole.

[0023] Beneficial effects: The battery cover includes a cover body and the aforementioned sealing pin. The cover body has a liquid injection hole, and the sealing pin is disposed within the liquid injection hole. By using the aforementioned sealing pin, it is convenient to perform vacuuming and gas injection during the pre-installation process of the sealing pin through the gas injection channel formed between the sealing pin and the inner wall of the liquid injection hole. This makes the operation more convenient and ensures the accuracy of subsequent helium testing. Furthermore, once the sealing pin is fully installed in the liquid injection hole, it is not easily dislodged, resulting in a more reliable seal.

[0024] Thirdly, this application provides a battery, including a housing, a battery cell, and a battery cover plate as described above. One end of the housing is provided with an opening, the battery cell is disposed inside the housing through the opening, and the battery cover plate is connected to the housing and is used to seal the opening.

[0025] Beneficial effects: The battery includes a casing, a battery cell, and the aforementioned battery cover. One end of the casing has an opening through which the battery cell is housed. The battery cover is welded to the casing and seals the opening. By using the aforementioned battery cover to seal the casing opening, on the one hand, the battery cover provides a good seal, resulting in high helium detection accuracy, reduced electrolyte leakage, and lower safety risks; on the other hand, the battery cover is relatively thin, and the sealing pins on the cover are less likely to interfere with the battery cell, which helps to reduce the overall height of the battery and improve space utilization. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0027] Figure 1 is a schematic diagram of the sealing nail provided in the embodiment of this application in the pre-installation state;

[0028] Figure 2 is a structural schematic diagram of the sealing nail provided in the embodiment of this application from a first perspective;

[0029] Figure 3 is a schematic diagram of the sealing nail provided in the embodiment of this application from a second perspective;

[0030] Figure 4 is a front view of the sealing nail provided in the embodiment of this application;

[0031] Figure 5 is a top view of the sealing nail provided in the embodiment of this application;

[0032] Figure 6 is a right view of the sealing nail provided in the embodiment of this application;

[0033] Figure 7 is a partial structural schematic diagram of the battery cover plate provided in the embodiment of this application.

[0034] Numbering in the diagram: 100-Sealing pin; 110-Sealing part; 1101-Sealing surface; 1102-Transition surface; 1103-Boss; 120-Gas injection part; 1201-First mating surface; 1202-Second mating surface; 130-Guide part; 1301-Guide surface; 200-Battery cover; 201-Injection hole. 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, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0036] This embodiment provides a sealing pin 100 made of a flexible material, which has a certain elastic deformation capability. The sealing pin 100 can be inserted into the liquid injection hole 201 on the battery cover 200 along the first direction shown in FIG. 1, thereby sealing the liquid injection hole 201. For example, the sealing pin 100 can be made of materials such as fluororubber or EPDM.

[0037] Specifically, referring to Figures 2-4, the sealing pin 100 includes a sealing portion 110 and an air injection portion 120 arranged sequentially along a first direction, wherein the sealing portion 110 is used to block the injection hole 201. The air injection portion 120 includes a first mating surface 1201 and a second mating surface 1202, the first mating surface 1201 being transitionally connected to the sealing portion 110. One end of the second mating surface 1202 is transitionally connected to the sealing portion 110, and the other end of the second mating surface 1202 is inclined towards the central axis of the air injection portion 120. At least a portion of the second mating surface 1202 of the sealing pin 100 can be interference-fitted with the inner wall of the injection hole 201.

[0038] Referring again to Figures 1 and 4, when installing the sealing pin 100, the gas injection part 120 of the sealing pin 100 can first be inserted into the liquid injection hole 201 on the battery cover 200. The sealing part 110 is located on the side of the battery cover 200 away from the battery cell. At this time, the sealing pin 100 is in a pre-installed state. A gas injection channel is formed between the first mating surface 1201 of the sealing pin 100 and the inner wall of the liquid injection hole 201. The gas injection channel can be used for vacuuming or gas injection. For example, helium can be injected into the battery through the gas injection channel. Of course, other protective gases can also be injected into the battery through the gas injection channel. At least a portion of the second mating surface 1202 of the sealing pin 100 is interference-fitted with the inner wall of the injection hole 201, so that the sealing pin 100 can be temporarily fixed in the injection hole 201 and maintain its positional relationship with the injection hole 201, which facilitates vacuuming or gas injection. After the vacuuming and gas injection at the injection hole 201 are completed, the sealing part 110 of the sealing pin 100 is pushed towards the battery cover plate 200 so that the sealing part 110 is also fully inserted into the injection hole 201. At this time, the sealing pin 100 is installed and the injection hole 201 can be sealed by the sealing part 110, thus achieving a sealing effect.

[0039] During the installation process described above, by spaced apart from the inner wall of the injection hole 201, the first mating surface 1201 of the gas injection section 120 forms a gas injection channel with flow function between the first mating surface 1201 and the inner wall of the injection hole 201, thereby facilitating vacuuming or gas injection. Furthermore, the interference fit between at least a portion of the second mating surface 1202 and the inner wall of the injection hole 201 allows the sealing pin 100 to be temporarily fixed within the injection hole 201, ensuring that the sealing pin 100 remains in a pre-installed state, facilitating vacuuming or gas injection operations. Furthermore, the other end of the second mating surface 1202 is inclined toward the central axis of the gas injection section 120. On the one hand, when the sealing pin 100 is inserted into the liquid injection hole 201, the second mating surface 1202 can play a certain guiding role to facilitate insertion. On the other hand, through this setting, the sealing pin 100 will not be ejected from the liquid injection hole 201 because the force of its recovery deformation is greater than the friction between the second mating surface 1202 and the inner wall of the liquid injection hole 201, thereby improving the process yield.

[0040] As an optional solution, the second mating surface 1202 and the axial direction of the air injection section 120 have an included angle α, where the axial direction of the air injection section 120 is the extension direction of the central axis of the air injection section 120, which is the same as the first direction shown in Figures 1 and 4. The included angle α ranges from 0.01° to 30°. For example, the included angle α can be 0.01°, 1°, 3°, 5°, 10°, 15°, 20°, 25°, or 30°, etc., and can be any value within this range. Of course, the included angle α should not be too large. If the included angle α is too large, it will reduce the contact area between the second mating surface 1202 and the inner wall of the injection hole 201, resulting in a decrease in the friction between the two, and the sealing pin 100 will easily fall out of the injection hole 201.

[0041] Furthermore, the length of the gas injection section 120 is L1, which satisfies the condition: 0.5mm ≤ L1 ≤ 3.0mm. For example, if the depth of the injection hole 201 is L2, and the depth L2 = 1.5mm, the length L1 of the gas injection section 120 can be 0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, or 3.0mm, etc., as long as the interference fit between the second mating surface 1202 on the gas injection section 120 and the inner wall of the injection hole 201 extends into the injection hole 201. It is important to note that the length of the gas injection section 120 should not be too short. Otherwise, the contact area between the second mating surface 1202 and the inner wall of the injection hole 201 will be small, resulting in a decrease in the friction between them. The sealing pin 100 will not be able to be temporarily fixed in the pre-installation position in the injection hole 201 and will easily come out of the injection hole 201. Of course, the length of the gas injection section 120 should not be too long either. Otherwise, when the sealing pin 100 is fully pressed into the injection hole 201, the end of it extending into the inner side of the battery cover plate 200 will exceed the inner end face of the battery cover plate 200 by too much, which may interfere with the battery cell and is not conducive to reasonable space arrangement.

[0042] Referring to Figure 5, since there is an angle α between the second mating surface 1202 and the axial direction (i.e., the first direction) of the air injection section 120, the width of the end of the second mating surface 1202 connected to the sealing section 110 is smaller than the width of the end of the second mating surface 1202 away from the sealing section 110. In other words, the second mating surface 1202 gradually widens from the end connected to the sealing section 110 to the end away from the sealing section 110. For ease of explanation, the width of the end of the second mating surface 1202 connected to the sealing section 110 is denoted as d1, the width of the end of the second mating surface 1202 away from the sealing section 110 is denoted as d2, and the width of the second mating surface 1202 at the midpoint of the length of the air injection section 120 is d3; where d3 = 1 / 2(d1 + d2). To ensure a sufficiently large contact area between the second mating surface 1202 and the inner wall of the injection hole 201, thus providing sufficient friction between the sealing pin 100 and the injection hole 201, and simultaneously ensuring a sufficiently large venting channel between the first mating surface 1201 and the inner wall of the injection hole 201, the width d3 of the second mating surface 1202 at the midpoint of the length of the air injection section 120 must satisfy: 0.2mm ≤ d3 ≤ 1.0mm. For example, the value of d3 can be 0.2mm, 0.4mm, 0.6mm, 0.8mm, or 1.0mm, etc., and any value within this range is acceptable.

[0043] Furthermore, the number of first mating surfaces 1201 and second mating surfaces 1202 is the same, and multiple of each are provided. The first mating surfaces 1201 and second mating surfaces 1202 are alternately arranged along the circumferential direction of the air injection section 120. By adopting the above arrangement, the force on the sealing pin 100 in the injection hole 201 can be more evenly distributed. For example, referring to Figure 6, in this embodiment, there are three first mating surfaces 1201 and three second mating surfaces 1202, and the three first mating surfaces 1201 and three second mating surfaces 1202 are alternately arranged. Of course, in other embodiments, the number of first mating surfaces 1201 and second mating surfaces 1202 can also be set to other numbers, which can be selected as needed and are not limited here.

[0044] In some embodiments, if the injection hole 201 is a circular hole, the second mating surface 1202 can be configured as a conical arc surface. All the second mating surfaces 1202 are located on the same conical surface, and the second mating surface 1202 smoothly transitions with the first mating surface 1201, thereby making the second mating surface 1202 fit more tightly with the inner wall of the injection hole 201. Exemplarily, the first mating surface 1201 can be a plane, or it can be a concave or convex arc surface, which is not limited here.

[0045] Of course, in some embodiments, if the injection hole 201 is other irregular shapes, such as a square hole or other regular polygonal hole, the second mating surface 1202 can also be set as a plane so that the second mating surface 1202 fits more tightly with the inner wall of the injection hole 201.

[0046] Further, referring to Figures 2 and 5, to ensure that the sealing pin 100 is securely fixed within the injection hole 201 in the pre-installed state, the second mating surface 1202 located at the midpoint of the length of the air injection section 120 can be press-fitted with the inner wall of the injection hole 201, that is, the second mating surface 1202 at a width of d3 can be press-fitted with the inner wall of the injection hole 201. Optionally, the interference fit between the second mating surface 1202 and the inner wall of the injection hole 201 at this location is 0.05mm to 0.2mm. That is, the difference between the diameter D3 of the circle containing the second mating surface 1202 and the inner diameter of the injection hole 201 is 0.05mm to 0.2mm, and D3 is greater than the inner diameter of the injection hole 201. For example, the interference fit between the second mating surface 1202 and the inner wall of the injection hole 201 can be 0.05mm, 0.1mm, 0.15mm or 0.2mm, etc., and will not be listed here.

[0047] Optionally, in this embodiment, the sealing part 110 is cylindrical, and the sealing part 110 has a sealing surface 1101 in its circumferential direction. The sealing surface 1101 is the circumferential sidewall of the cylindrical sealing part 110. The sealing surface 1101 and the first mating surface 1201 are connected by a transition surface 1102, and the sealing surface 1101 and the second mating surface 1202 are directly connected. The diameter of the sealing part 110 is equal to the diameter D1 of the circle containing the second mating surface 1202 at a width of d1. The sealing surface 1101 is press-fitted with the inner wall of the injection hole 201, and the press-fit amount between the sealing surface 1101 and the injection hole 201 is greater than the press-fit amount between the second mating surface 1202 at a width of d3 and the inner wall of the injection hole 201. For example, the press-fit amount between the sealing surface 1101 and the inner wall of the injection hole 201 is 0.1 mm to 0.25 mm. That is, the difference between the diameter of the sealing part 110 and the inner diameter of the injection hole 201 is 0.1mm to 0.25mm, and the diameter of the sealing part 110 is larger than the inner diameter of the injection hole 201. For example, the interference between the sealing surface 1101 and the inner wall of the injection hole 201 can be 0.1mm, 0.15mm, 0.2mm or 0.25mm, etc., which will not be listed here.

[0048] Referring again to Figures 3 and 4, the sealing pin 100 also includes a guide portion 130 connected to the gas injection portion 120. The guide portion 130 is located at the end where the sealing pin 100 first inserts into the injection hole 201. The guide portion 130 provides a good guiding effect when the sealing pin 100 is inserted into the injection hole 201, making it easier for the sealing pin 100 to be inserted into the injection hole 201.

[0049] Exemplarily, the guide portion 130 can be configured as a cone or a frustum. To save space, the guide portion 130 in this embodiment is configured as a frustum. The guide portion 130 has a guide surface 1301, which is a part of a cone surface. The guide surface 1301 is smoothly connected to the first mating surface 1201 and the second mating surface 1202 of the air injection portion 120. The end of the guide surface 1301 away from the air injection portion 120 is inclined towards the central axis of the guide portion 130. The axial direction of the guide portion 130 is the extension direction of the central axis of the guide portion 130, which is the same as the axial direction of the air injection portion 120. An angle β is formed between the guide surface 1301 and the axial direction of the guide portion 130, and the angle β is greater than the angle α. The value of the angle β ranges from 10° to 80°. For example, the included angle β can be 10°, 20°, 30°, 40°, 50°, 60°, 70° or 80°, etc., and can be any value within this range.

[0050] In this embodiment, the sealing part 110, the air injection part 120, and the guide part 130 are integrally injection molded. A boss 1103 is provided at the end of the sealing part 110 away from the air injection part 120. By providing the boss 1103, burrs and flash can be avoided at the sealing part 110 of the sealing nail 100 during demolding, which helps to improve the manufacturing yield of the sealing nail 100 product.

[0051] The following pre-assembly experiments were conducted multiple times on sealing pins 100 and battery cover plates 200 of the same size and specifications to obtain the pre-compression yield of the assembly of sealing pins 100 and battery cover plates 200 of the same size and specifications. Then, the size and specifications of sealing pins 100 were changed, and pre-assembly experiments were conducted multiple times on sealing pins 100 and battery cover plates 200 of different sizes and specifications to obtain the pre-compression yield of the assembly of sealing pins 100 and battery cover plates 200 of different sizes and specifications. The specific experimental data are shown in Table 1 below:

[0052] Table 1

[0053] Among the samples 1#, 2#, 3#, 4#, and 5#, when the included angles α, β, and L1 of the sealing nail 100 are all within the range required by the aforementioned dimensions of the sealing nail 100, the final assembly pre-compression yield is above 98.0%. At this point, the assembly result between the sealing nail 100 and the liquid injection hole 201 of the battery cover 200 is better, with good and reliable sealing. Samples 1#, 2#, 3#, 4#, and 5# are qualified.

[0054] Comparing samples 6#, 7#, and 8#, the values ​​of included angles α, β, and L1 are close to the highest value within the range required by the dimensional specifications. At this point, the pre-compression yield begins to decline, approximately between 80.0% and 90.0%. Some sealing pins 100 exhibit poor assembly when assembling with the electrolyte injection hole 201 of the battery cover 200; however, the vast majority of sealing pins 100 remain well-sealed and reliable. Samples 6#, 7#, and 8# are qualified.

[0055] Comparing samples 9# and 10#, their included angle α exceeded the range of 0.01° to 30°, while included angles β and L1 were within the dimensional specifications. However, the pre-compression yield dropped sharply, approximately 10.0%-20.0%. The vast majority of sealing pins 100 failed to assemble properly with the electrolyte injection holes 201 of the battery cover 200. In this case, most sealing pins 100 could not meet the assembly and sealing requirements. Samples 9# and 10# were therefore defective.

[0056] Comparing samples 11# and 12#, their included angle β both exceeded the 10°–80° range required by the aforementioned dimensional specifications. Specifically, the included angle β of sample 11# was less than 10°, while that of sample 12# was greater than 80°. The included angles α and L1 were within the dimensional specifications, but the pre-compression yield also dropped sharply, approximately 10.0%–30.0%. The vast majority of sealing pins 100 failed to assemble properly with the electrolyte injection holes 201 of the battery cover 200, meaning that most of the sealing pins 100 could not meet the sealing requirements. Samples 11# and 12# were therefore defective.

[0057] Comparing samples 13# and 14#, the L1 of samples 13# and 14# is outside the dimensional specification range of 0.5mm≤L1≤3.0mm, while the other included angles α and β meet the dimensional specification requirements. For sample 13#, L1 < 0.5mm, resulting in a sharp drop in the pre-pressurization yield, even below 10.0%. The assembly of the sealing pin 100 with the electrolyte injection hole 201 of the battery cover 200 is essentially unqualified; only a very small number of sealing pins 100 can meet the sealing requirements. Sample 13# is unqualified. For sample 14#, L1 > 3.0mm. Due to the excessive length of the sealing pin 100, interference with the battery cell inside the casing occurs after the sealing pin 100 is fully pressed into the electrolyte injection hole 201. Therefore, all samples 14# are unqualified.

[0058] In summary, when the dimensions of the sealing pin 100 meet the required values ​​of the included angles α, β and L1, it can be basically guaranteed that the sealing pin 100 can be properly pressed into the liquid injection hole 201 on the battery cover plate 200, thus meeting the needs of assembly and subsequent sealing.

[0059] Referring to Figure 7, this embodiment provides a battery cover 200, including a cover body and the aforementioned sealing pin 100. The cover body has an injection hole 201, and the sealing pin 100 is disposed within the injection hole 201. By employing the aforementioned sealing pin 100, it is convenient to perform vacuuming and gas injection during the pre-installation process through the gas injection channel formed between the sealing pin 100 and the inner wall of the injection hole 201. This operation is relatively convenient and ensures the accuracy of subsequent helium testing. Furthermore, during the pre-installation process, the sealing pin 100 is well positioned with respect to the injection hole 201, making it difficult for it to pop out of the injection hole 201. In addition, after the sealing pin 100 is fully installed in the injection hole 201, the seal is relatively reliable, and it is not easy for it to detach from the injection hole 201.

[0060] This embodiment also provides a battery, including a casing, a battery cell, and the aforementioned battery cover 200. One end of the casing has an opening, through which the battery cell is disposed within the casing. The battery cover 200 is welded to the casing and used to seal the opening. By using the aforementioned battery cover 200 to seal the opening in the casing, on the one hand, the battery cover 200 provides a good seal, high helium detection accuracy, and reduces the likelihood of electrolyte leakage, thus minimizing safety hazards; on the other hand, the battery cover 200 is relatively thin overall, and the sealing pins 100 on the battery cover 200 are less likely to interfere with the battery cell, which helps to reduce the overall height of the battery and improve space utilization.

[0061] Although embodiments of this application have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of this application, and all such modifications and variations fall within the scope defined by the appended claims. Industrial applicability

[0062] This application provides a sealing pin, including a sealing portion and an injection portion for sealing an injection hole, the sealing pin having elastic deformation capability. The injection portion includes a first mating surface and a second mating surface that transitionally connect with the sealing portion. When the sealing pin is in a pre-installed state, an injection channel is formed between the first mating surface and the inner wall of the injection hole, which can be used for vacuuming or injection. The end of the second mating surface away from the sealing portion is inclined towards the central axis of the injection portion, and at least a portion of the second mating surface can be interference-fitted with the inner wall of the injection hole. On one hand, the second mating surface temporarily fixes the sealing pin, facilitating vacuuming or injection; on the other hand, the second mating surface also provides a certain guiding effect, facilitating the insertion of the sealing pin into the injection hole. When the sealing portion of the sealing pin also enters the injection hole, the sealing pin is installed, and the injection hole can be sealed through the sealing portion, providing a good sealing effect, and the sealing pin is not easily dislodged from the injection hole.

[0063] The sealing pin ensures the airtightness of the liquid injection hole on the battery cover, resulting in high reliability.

[0064] By using the battery cover described above, leakage of electrolyte inside the casing can be minimized, thus reducing safety risks.

Claims

1. A sealing nail, characterized in that, It includes a sealing part and an air injection part that are connected to each other, wherein the sealing part is used to seal the injection hole; The gas injection section includes a first mating surface and a second mating surface. The first mating surface is transitionally connected to the sealing section, and a gas injection channel is formed between the first mating surface and the inner wall of the injection hole. The gas injection channel is used for vacuuming or gas injection. One end of the second mating surface is transitionally connected to the sealing section, and the other end of the second mating surface is inclined toward the central axis of the gas injection section. At least a portion of the second mating surface is interference-fitted with the inner wall of the injection hole. The second mating surface and the axial direction of the gas injection part have an included angle α, and the included angle α ranges from 0.01° to 30°.

2. The sealing nail according to claim 1, characterized in that, The length of the gas injection section is L1, and the length of the gas injection section L1 satisfies: 0.5mm≤L1≤3.0mm.

3. The sealing nail according to claim 1, characterized in that, The width of the second mating surface at the end connected to the sealing part is d1, the width of the second mating surface at the end away from the sealing part is d2, and the width of the second mating surface at the middle position of the length of the air injection part is d3. Where, d3 = 1 / 2(d1 + d2); The width d3 of the second mating surface satisfies: 0.2mm≤d3≤1.0mm.

4. The sealing nail according to claim 1, characterized in that, The number of the first mating surfaces and the second mating surfaces are the same, and multiple of each are provided. The first mating surfaces and the second mating surfaces are alternately arranged along the circumferential direction of the gas injection part.

5. The sealing nail according to claim 4, characterized in that, The second mating surface is a conical arc surface, and all the second mating surfaces are located on the same conical surface.

6. The sealing nail according to claim 1, characterized in that, The interference fit between the second mating surface and the inner wall of the injection hole is 0.05 mm to 0.2 mm. The sealing part has a sealing surface in the circumferential direction. The sealing surface is transitionally connected to the first mating surface and the second mating surface, and the sealing surface is interference-fitted with the inner wall of the injection hole. The interference between the sealing surface and the inner wall of the injection hole is 0.1mm to 0.25mm.

7. The sealing nail according to claim 1, characterized in that, The sealing nail further includes a guide portion connected to the air injection portion. The guide portion has a guide surface, which is transitionally connected to the first mating surface and the second mating surface of the air injection portion. The end of the guide surface away from the air injection portion is inclined toward the central axis of the guide portion. There is an included angle β between the guide surface and the axial direction of the guide portion. The included angle β is greater than the included angle α, and the value of the included angle β ranges from 10° to 80°.

8. The sealing nail according to claim 1, characterized in that, The sealing part has a boss at the end away from the gas injection part.

9. A battery cover, characterized in that, It includes a cover plate body and a sealing pin as described in any one of claims 1-8, wherein the cover plate body is provided with an injection hole and the sealing pin is disposed in the injection hole.

10. A battery, characterized in that, The device includes a housing, a battery cell, and a battery cover as described in claim 9. One end of the housing has an opening, the battery cell is disposed inside the housing through the opening, and the battery cover is connected to the housing and is used to seal the opening.

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