Sealing plug, sealing structure and battery

Abstract

The application relates to the battery technical field and provides a sealing plug, a sealing structure and a battery. The sealing plug comprises a sealing plug body capable of being inserted into a liquid injection hole, a first limiting part and a plurality of first protruding parts which protrude outward from the sealing plug body along a direction perpendicular to the insertion direction of the sealing plug body; the first limiting part can abut against a first side of the edge of the liquid injection hole and limit the insertion depth of the sealing plug body in the liquid injection hole; the plurality of first protruding parts are arranged at intervals along the insertion direction of the sealing plug body and are located on the same side of the first limiting part; each first protruding part is an annular structure arranged circumferentially around the sealing plug body, and at least part of the first protruding parts can abut against the side wall of the liquid injection hole in the state that the sealing plug body is inserted into the liquid injection hole. The sealing plug disclosed by the application is convenient and fast to install, can better seal the liquid injection hole, can better prevent electrolyte leakage, and can improve the safety and reliability of battery application.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a sealing plug. This application also relates to a sealing structure including the sealing plug, and a battery including the sealing structure. Background Technology

[0002] A battery is composed of multiple battery cells connected in series and parallel. During the battery production process, electrolyte injection holes need to be reserved on the battery casing. After the electrode assembly is assembled into the battery casing, electrolyte needs to be injected into the battery casing through the injection holes, and then the injection holes are sealed by a sealing structure.

[0003] Existing sealing structures have problems with poor sealing of the injection hole due to structural design limitations. If the injection hole is not properly sealed, electrolyte leakage may lead to risks such as battery explosion, affecting the safety of battery use. Utility Model Content

[0004] In view of this, the present application aims to provide a sealing plug that is easy to install and has good sealing performance.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows: A sealing plug for sealing a liquid injection hole on a battery casing includes a sealing plug body that can be inserted into the liquid injection hole, and a first limiting portion and a plurality of first protrusions that protrude outward from the sealing plug body in a direction orthogonal to the insertion direction of the sealing plug body. The first limiting portion can abut against a first side of the edge of the injection hole, thereby limiting the insertion depth of the sealing plug body in the injection hole; Multiple first protrusions are arranged at intervals along the insertion direction of the sealing plug body and are located on the same side of the first limiting portion; each first protrusion is an annular ring arranged around the circumference of the sealing plug body, and when the sealing plug body is inserted into the injection hole, at least a portion of the first protrusions can abut against the side wall of the injection hole.

[0006] Furthermore, from the end of the sealing plug body that is first inserted into the injection hole to the other end, the dimensions of the sealing plug body gradually increase in the direction orthogonal to its own insertion direction; or, From the moment the sealing plug body is inserted into one end of the injection hole to the other end, the dimensions of the sealing plug body in the direction orthogonal to its own insertion remain unchanged.

[0007] Furthermore, from the end of the first protrusion that is inserted into the injection hole to the other end, the dimension of the first protrusion remains unchanged in the direction orthogonal to its own insertion direction; or, From the end of the first protrusion that is first inserted into the injection hole to the other end, the size of the first protrusion gradually increases in the direction orthogonal to its own insertion direction.

[0008] Furthermore, there are multiple first limiting portions, which are arranged at intervals along the insertion direction of the sealing plug body, and each first limiting portion is an annular ring surrounding the sealing plug body; and / or, The first side is provided with a first recessed portion that is recessed towards the insertion direction, and the first limiting portion has an embedding portion that can be embedded in the first recessed portion.

[0009] Furthermore, the sealing plug body has a groove at one end where the first limiting part is located, and a sealing part is provided at the opening of the groove to seal the opening, and the gas to be tested is sealed in the groove.

[0010] Furthermore, the sealing plug body is provided with a second limiting portion, which can abut against a second side of the edge of the injection hole, thereby preventing the sealing plug body from dislodging from the injection hole; and / or, The end of the sealing plug body that is first inserted into the injection hole is provided with a guide portion, which can guide the sealing plug body into the injection hole.

[0011] Furthermore, the end of the sealing plug body that is first inserted into the injection hole is provided with a second protrusion. The second protrusion protrudes from the sealing plug body along the insertion direction of the sealing plug body and is used to press against the lower plastic.

[0012] Compared with related technologies, this application has the following advantages: (1) The sealing plug described in this application, by providing a first limiting part on the sealing plug body, can abut against the first side of the edge of the injection hole during the process of inserting the sealing plug into the injection hole, thereby limiting the insertion depth of the sealing plug body in the injection hole. This makes it convenient for operators to judge whether the sealing plug is installed in the injection hole. The installation is convenient and quick. The first limiting part fits against the first side, which can also better ensure the sealing effect of the injection hole. By providing multiple first protrusions, after the sealing plug is inserted into the injection hole, some of the first protrusions abut against the side wall of the injection hole, which can further improve the sealing effect of the injection hole, thereby improving the sealing quality of the injection hole. This can better prevent electrolyte leakage and improve the safety and reliability of battery applications.

[0013] (2) From the first end of the sealing plug body inserted into the injection hole to the other end, the dimensions of the sealing plug body orthogonal to its own insertion direction gradually increase. During the insertion of the sealing plug into the injection hole, the interference dimension between the two gradually increases, which facilitates the smooth insertion of the sealing plug into the injection hole and can better ensure the sealing effect. From the first end of the sealing plug body inserted into the injection hole to the other end, the dimensions of the sealing plug body orthogonal to its own insertion direction remain unchanged. Through the design of reasonable interference dimension, the sealing performance of the sealing plug body to the injection hole can also be better guaranteed.

[0014] (3) From the first end of the first protrusion inserted into the injection hole to the other end, the size of the first protrusion in the direction orthogonal to its own insertion remains unchanged, which is convenient to process. Through the design of reasonable interference size, the sealing performance of the sealing plug body to the injection hole can be well guaranteed. From the first end of the first protrusion inserted into the injection hole to the other end, the size of the first protrusion in the direction orthogonal to its own insertion gradually increases. During the process of the sealing plug being inserted into the injection hole, the interference size between the two gradually increases, which is conducive to the smooth insertion of the sealing plug into the injection hole and can better guarantee the sealing effect.

[0015] (4) By setting multiple first limiting parts and arranging them at intervals along the insertion direction of the sealing plug body, the limiting effect can be better guaranteed. Multiple first limiting parts can form a multi-stage limiting structure, which can improve the reliability of the limiting during the insertion of the sealing plug into the injection hole. A first recess is provided on the first side, and the first limiting part is partially embedded in the first recess. The embedded part of the first limiting part embedded in the first recess and the unembedded part not embedded in the first recess can also form a two-stage limiting structure, which can improve the reliability of the limiting during the insertion of the sealing plug into the injection hole.

[0016] (5) A groove is provided on the main body of the sealing plug. By sealing the sealing part at the opening of the groove and sealing the detection gas in the groove, the sealing quality of the sealing structure can be judged by detecting the detection gas, which is beneficial to improving the quality of the produced batteries.

[0017] (6) The second limiting part can abut against the second side of the edge of the injection hole, preventing the sealing plug body from falling out of the injection hole. This improves the reliability of the sealing plug body's seal on the injection hole and better prevents the sealing plug from falling out due to increased pressure inside the battery casing, thus ensuring the reliability of the injection hole seal. The guide part provides clear insertion direction guidance for the sealing plug body. During the sealing plug assembly process, the operator does not need to spend extra time accurately aligning the injection hole. They only need to bring the guide part roughly close to the injection hole, and the guide part will automatically guide the sealing plug body into the correct position, which can significantly shorten the assembly time and improve the assembly efficiency.

[0018] (7) A second protrusion is provided on the sealing plug body. The second protrusion abuts against the lower plastic, which can also limit the insertion position of the sealing plug body and improve the installation accuracy of the sealing plug body. At the same time, it is also helpful for the operator to judge whether the sealing plug is installed in the injection hole.

[0019] Another object of this application is to provide a sealing structure, including a sealing plug as described above, and a sealing cap covering the sealing plug to block the injection hole.

[0020] Furthermore, the cover plate in the battery casing includes a cover plate body and a blocking portion disposed on the cover plate body, the blocking portion surrounding the circumference of the injection hole and protruding from the first side in a direction away from the first side. The sealing cap has a surrounding portion around the outer periphery of the blocking portion, and the sealing cap is connected to the cover plate body or the blocking portion through the surrounding portion.

[0021] The sealing structure described in this application, by using the sealing plug as described above, makes it easy for operators to determine whether the sealing plug is properly installed in the injection hole. The installation is convenient and quick, and it can better ensure the sealing effect of the injection hole, better prevent electrolyte leakage, and improve the safety and reliability of battery applications.

[0022] In addition, a blocking part is provided on the cover plate body. During the electrolyte filling process, the blocking part can effectively prevent the electrolyte from overflowing outside the blocking part and will not contaminate the area around the blocking part. This can reduce or eliminate the cleaning process. Moreover, during the welding process between the sealing cap and the cover plate, it helps to ensure the welding quality between the sealing cap and the cover plate, thereby improving the reliability of the sealing cap's seal on the injection hole.

[0023] Meanwhile, another objective of this application is to provide a battery that is sealed by the sealing structure described above.

[0024] The battery described in this application, through the application of the above-mentioned sealing structure, has a high assembly effect, good consistency in the installation of sealing plugs, and a good sealing effect, which can effectively prevent electrolyte leakage, thereby improving the safety and reliability of battery application, and thus helping to improve the safety and reliability of electrical equipment using this battery. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is an exemplary structural diagram of the battery described in an embodiment of this application; Figure 2 for Figure 1A structural diagram from another perspective; Figure 3 For along Figure 2 Sectional view of line AA in the middle; Figure 4 for Figure 3 Enlarged view of section B; Figure 5 This is an exemplary structural diagram of the sealing plug described in an embodiment of this application; Figure 6 This is a structural schematic diagram of another sealing plug in the application state described in the embodiments of this application; Figure 7 for Figure 6 The diagram shows an exemplary structural schematic of a sealing plug; Figure 8 This is a structural schematic diagram of another sealing plug in the application state described in the embodiments of this application; Figure 9 This is a structural schematic diagram of the sealing plug in the application state as described in the embodiments of this application; Figure 10 for Figure 9 Enlarged view of section C; Figure 11 for Figure 10 The diagram shows an exemplary structural schematic of a sealing plug; Figure 12 This is a structural schematic diagram of another sealing plug in the application state described in the embodiments of this application; Figure 13 This is a structural schematic diagram of the application state of the additional sealing plug described in the embodiments of this application.

[0026] Explanation of reference numerals in the attached figures: 1. Battery casing; 101. Cover plate; 102. Main body of the housing; 103. Electrode assembly; 104. Lower plastic; 1011. Cover plate body; 1012. Blocking part; 10111, Injection hole; 10112, First recess; 10113, Second recess; 1011a, First side; 1011b, Second side; 1011c, First injection hole; 1011d, Second injection hole; 2. Sealing plug; 201. Sealing plug body; 202. First limiting part; 203. First protrusion; 204. Groove; 205. Sealing part; 206. Second limiting part; 207. Second protrusion; 2011, Guiding Department; 3. Sealing cap; 301. Sealing cap body; 302. Surrounding part; 3021, First flip-edge; 3022, Second flip-edge. Detailed Implementation

[0027] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0028] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0029] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0031] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0033] An embodiment of the first aspect of this application provides a sealing plug, which, by improving its own structure, enables a casting device (a device that presses the sealing plug into the injection hole) to quickly insert the sealing plug into the injection hole, while the sealing plug can better seal the injection hole.

[0034] In related technologies, a battery is composed of multiple battery cells connected in series and parallel. During the battery production process, electrolyte injection holes need to be pre-drilled in the battery casing. After the electrode assembly is assembled into the battery casing, electrolyte needs to be injected into the battery casing through the injection holes, and then the injection holes are sealed by a sealing structure.

[0035] Existing sealing structures have problems with poor sealing of the injection hole due to structural design limitations. If the injection hole is not properly sealed, electrolyte leakage may lead to risks such as battery explosion, affecting the safety of battery use.

[0036] Specifically, in typical battery designs, a sealing plug and a sealing cap are often used to seal the liquid injection hole. The sealing plug is inserted into the liquid injection hole, and the sealing cap is welded to the cover plate to achieve a seal at the liquid injection hole on the battery casing.

[0037] To improve the sealing effect, specifically to enhance the sealing effect of the sealing plug on the injection hole, the design often increases the diameter of the rod (the diameter of the sealing plug body) at the point where it mates with the injection hole. This achieves a tight fit between the sealing plug and the cover plate, resulting in a better seal. However, with the increase in the sealing plug rod diameter, there is a problem that driving equipment may have difficulty inserting the larger diameter sealing plug into the injection hole. In view of this, in order to overcome the shortcomings of the relevant technologies, such as Figures 1 to 5 As shown, in the sealing plug 2 of this embodiment, the overall design of the sealing plug 2 is to seal the liquid injection hole 10111 on the battery housing 1, and the sealing plug 2 includes a sealing plug body 201 that can be inserted into the liquid injection hole 10111, and a first limiting part 202 and a plurality of first protrusions 203 that protrude outward from the sealing plug body 201 in a direction orthogonal to the insertion direction of the sealing plug body 201.

[0038] Specifically, the first limiting portion 202 can abut against the first side 1011a of the edge of the injection hole 10111, specifically referring to the first side 1011a of the second injection hole 1011d described below, thereby limiting the insertion depth of the sealing plug body 201 in the injection hole 10111. A plurality of first protrusions 203 are arranged at intervals along the insertion direction of the sealing plug body 201 and are located on the same side of the first limiting portion 202; each first protrusion 203 is an annular ring surrounding the sealing plug body 201, and when the sealing plug body 201 is inserted into the injection hole 10111, at least a portion of the first protrusions 203 can abut against the sidewall of the injection hole 10111.

[0039] To better understand the sealing plug 2 in this embodiment, the structure of the battery housing 1 will be briefly described first. The battery housing 1 mainly includes a housing body 102 with a receiving cavity and a cover plate assembly.

[0040] The main body 102 of the battery casing has an open side, and the cover assembly is placed over the open side, forming a sealed cavity together with the main body 102 of the battery casing. The electrode assembly 103 is installed inside the cavity. The cover assembly includes a cover 101 and a lower plastic 104 located on the side of the cover 101 facing the cavity. The liquid injection hole 10111 on the battery casing 1 is specifically located on the cover 101.

[0041] In one example, still refer to Figures 1 to 5 As shown, the injection port 10111 includes a first injection port 1011c and a second injection port 1011d, which are interconnected. The first injection port 1011c is located on the side of the cover plate 101 facing the outside of the battery casing 1. Figure 4 In the state shown, the side of the cover plate 101 facing the outside of the battery housing 1 is the side opposite to the insertion direction, and the second liquid injection hole 1011d is provided on the side of the cover plate 101 facing the internal cavity of the battery housing 1. The side of the cover plate 101 facing the internal cavity of the battery housing 1 is the same as the insertion direction of the cover plate 101.

[0042] The sealing plug 2 of this application has a first limiting part 202 on the sealing plug body 201. During the process of inserting the sealing plug 2 into the injection hole 10111, the first limiting part 202 can abut against the first side 1011a of the edge of the injection hole 10111, thereby limiting the insertion depth of the sealing plug body 201 in the injection hole 10111. This makes it easier for the operator to judge whether the sealing plug 2 is installed in the injection hole 10111, and can better prevent the sealing plug 2 from being over-pressed. The installation is convenient and quick. The first limiting part 202 fits against the first side 1011a, which can also better ensure the sealing effect of the injection hole 10111.

[0043] Furthermore, by providing multiple first protrusions 203, after the sealing plug 2 is inserted into the injection hole 10111, the first protrusions 203 abut against the side wall of the injection hole 10111, which can further improve the sealing effect of the injection hole 10111, thereby improving the sealing quality of the injection hole 10111, better preventing electrolyte leakage, and improving the safety and reliability of battery applications.

[0044] To achieve a better sealing effect, such as Figure 4 and Figure 5As shown, in some exemplary embodiments, from the end of the sealing plug body 201 that is first inserted into the injection hole 10111 to the other end, the dimensions of the sealing plug body 201 gradually increase in the direction orthogonal to its own insertion direction.

[0045] In a preferred example, the sealing plug body 201 is frustum-shaped, and the included angle between the outer wall of the sealing plug body 201 and the axial center line is between 5° and 15°, such as 5°, 8°, 10°, 12°, 15°, etc., so as to take into account both the ease of insertion and the sealing effect.

[0046] In a preferred example, along the radial direction of the sealing plug body 201, the protrusion dimensions of each first protrusion 203 protruding outward from the outer wall of the sealing plug body 201 are the same, so that from the end of the sealing plug body 201 first inserted into the injection hole 10111 to the other end, the diameter of the multiple first protrusions 203 decreases sequentially, thereby further achieving the effect of balancing the ease of insertion and the sealing quality.

[0047] In a preferred embodiment, along the insertion direction of the sealing plug body 201, the thickness between each first protrusion 203 is between 0.05mm and 0.2mm, such as 0.05mm, 0.1mm, 0.15mm, 0.2mm, etc., and the distance between adjacent first protrusions 203 is between 0.05mm and 0.2mm, such as 0.05mm, 0.1mm, 0.15mm, 0.2mm, etc., which can take into account both the ease of processing and sealing performance.

[0048] In the above implementation, the sealing plug body 201 is first inserted into one end of the injection hole 10111 and then into the other end, so that the size of the sealing plug body 201 gradually increases in the direction orthogonal to its own insertion. During the process of the sealing plug 2 being inserted into the injection hole 10111, the interference size between the two gradually increases, which is conducive to the smooth insertion of the sealing plug 2 into the injection hole 10111 and can better ensure the sealing effect.

[0049] It should be understood that, in addition to being truncated cone-shaped, the sealing plug body 201 can also be configured in other shapes. In some exemplary embodiments, from the end into which the sealing plug body 201 is first inserted into the injection hole 10111 to the other end, the dimensions of the sealing plug body 201 orthogonal to its own insertion direction remain unchanged. Such a sealing plug body 201 can also be cylindrical. The dimensions and arrangement of each first protrusion 203 are still as described above and will not be detailed here.

[0050] In this embodiment, the sealing plug body 201 is inserted from one end of the injection hole 10111 to the other end. The dimensions of the sealing plug body 201 in the direction orthogonal to its own insertion direction remain unchanged. The sealing performance of the sealing plug body 201 to the injection hole 10111 can also be better guaranteed by the design of reasonable interference dimensions.

[0051] Still refer to Figures 4 to 5 As shown, in some of the exemplary embodiments, from the end of the first protrusion 203 that is first inserted into the injection hole 10111 to the other end, the size of the first protrusion 203 in orthogonal to its own insertion direction remains unchanged, which here refers to the outer diameter of the first protrusion 203 on the sealing plug body 201.

[0052] Here, from one end of the first protrusion 203 inserted into the injection hole 10111 to the other end, the size of the first protrusion 203 remains unchanged in the direction orthogonal to its own insertion direction, which is convenient to process. Through the design of reasonable interference size, the sealing performance of the sealing plug body 201 to the injection hole 10111 can be well guaranteed.

[0053] It should be noted that, in addition to this, the outer diameter of the first protrusion 203 on the sealing plug body 201 can also be varied, for example... Figure 6 and Figure 7 In some exemplary embodiments of the structure shown, from one end of the first protrusion 203 that is first inserted into the injection hole 10111 to the other end, the size of the first protrusion 203 gradually increases in the direction orthogonal to its own insertion direction.

[0054] As described above, the first protrusion 203 is shaped like a serrated edge. During the nailing process (when the sealing insert is inserted into the injection hole 10111 using equipment), the serrated edge structure formed by the first protrusion 203 has a guiding effect, which facilitates the nailing operation and improves the nailing yield. In one example, the angle between the outer wall of the first protrusion 203 and the axial centerline of the sealing plug body 201 is between 5° and 20°, such as 5°, 8°, 10°, 12°, 17°, 20°, etc., to balance the ease of insertion and the sealing effect.

[0055] As shown above, the first protrusion 203 is inserted from one end of the injection hole 10111 to the other end. The size of the first protrusion 203 gradually increases in the direction orthogonal to its own insertion direction. During the process of inserting the sealing plug 2 into the injection hole 10111, the interference size between the two gradually increases, which facilitates the smooth insertion of the sealing plug 2 into the injection hole 10111 and can better ensure the sealing effect.

[0056] like Figure 12As shown, in order to improve the efficiency and quality of nailing, in some exemplary embodiments, there are multiple first limiting portions 202, which are arranged at intervals along the insertion direction of the sealing plug body 201, and each first limiting portion 202 is an annular ring arranged around the sealing plug body 201.

[0057] For example Figure 12 In the middle, there are two first limiting parts 202. A gap is provided between the two first limiting parts 202 in the axial direction of the sealing plug body 201. In addition, the number of first limiting parts 202 can be other numbers, such as three or four.

[0058] In this exemplary embodiment, multiple first limiting parts 202 are provided and arranged at intervals along the insertion direction of the sealing plug body 201, which can better ensure the limiting effect. Multiple first limiting parts 202 can form a multi-stage limiting structure, which can improve the reliability of the limiting of the sealing plug 2 during the insertion process in the injection hole 10111, thereby improving the efficiency and quality of nailing.

[0059] In a preferred example, still refer to Figure 12 As shown, the first injection hole 1011c of the cover plate body 1011 adopts a stepped hole to form a double-step structure, which facilitates the installation of the sealing cover 3 described below, so that the second flange 3022 of the sealing cover 3 described below is coplanar with the outer surface of the cover plate body 1011, which facilitates the welding connection between the sealing cover 3 and the cover plate body 1011.

[0060] like Figure 13 As shown, in order to improve the efficiency and quality of nailing, in some exemplary embodiments, the first side 1011a is provided with a first recess 10112 recessed towards the insertion direction, and the first limiting part 202 has an inserting part that can be inserted into the first recess 10112.

[0061] Here, by making the first limiting part 202 have an embedded portion, on the longitudinal section of the sealing plug body 201, for example, refer to Figure 13 In the state shown, the first limiting part 202 is stepped. By providing the first recess 10112, the embedding part can be embedded in the first recess 10112, and the shapes of the sealing plug body 201 and the cover plate 101 are adapted.

[0062] Here, a recess is provided on the first side 1011a, and the first limiting part 202 is partially embedded in the first recess 10112. The embedded part of the first limiting part 202 embedded in the first recess 10112 and the unembedded part not embedded in the first recess 10112 can also form a two-level limiting structure, which can improve the reliability of the limiting of the sealing plug 2 during the insertion of the sealing plug 2 into the injection hole 10111, thereby improving the efficiency and quality of nailing.

[0063] In typical battery designs, a sealing plug 2 and a sealing cap 3 are often used to seal the liquid injection hole 10111 on the battery casing 1. After the sealing plug 2 is inserted into the liquid injection hole 10111 by the equipment, the sealing cap 3 is assembled with the cover plate 101 and laser welded to achieve the sealing effect of the entire battery.

[0064] To inspect the welding effect between the sealing cap 3 and the cover plate 101, helium testing and other methods are often used. However, due to the interference fit between the sealing plug 2 and the injection hole 10111, it may be impossible to effectively detect the welding sealing effect between the sealing cap 3 and the cover plate 101.

[0065] To improve the accuracy of sealing tests at the welding position between the sealing cap 3 and the cover plate 101, in some exemplary embodiments, such as Figures 9 to 11 As shown, the sealing plug body 201 has a groove 204 at one end with a first limiting part 202, and a sealing part 205 is provided at the opening of the groove 204 to seal the opening, and the gas to be tested is sealed in the groove 204.

[0066] In some examples, the gas to be detected is preferably an inert gas, such as helium or nitrogen. It should be understood that other gases may also be used.

[0067] In some examples, the sealing portion 205 is, for example, a patch that can be adhered to the opening. More specifically, the sealing portion 205 is, for example, made of a thin plastic material that can encapsulate the gas to be detected within the groove 204.

[0068] In one example, along the axial direction of the injection hole 10111, the distance between the outer surface of the sealing portion 205 and the sealing cap 3 is between 5mm and 6mm, for example, 5mm, 5.25mm, 5.8mm, 6mm, etc. Furthermore, for example... Figure 10 As shown, after the sealing cover 3 and the cover plate 101 are welded, the theoretical installation position of the sealing cover 3 can ensure that there is a gap between the sealing cover 3 and the sealing plug 2 for the gas to be tested to overflow.

[0069] Thus, during the detection of the gas to be detected, if there is a weld gap at the welded part of the sealing cap 3 and the cover plate 101, the gas to be detected can overflow through the gap between the sealing cap 3 and the sealing plug 2, and the gap between the sealing cap 3 and the cover plate 101.

[0070] In detail, when there are problems such as weld defects or missing welds in the welding between the sealing cap 3 and the cover plate 101, a helium sampling negative pressure test is performed on the battery. At this time, the negative pressure will enter the gap between the sealing cap 3 and the sealing plug 2 through the weld defects. The negative pressure will absorb the sealing part 205, and the sealing part 205 will fail. The gas to be tested in the groove 204 can flow out through the weld defects, thereby detecting welding quality problems.

[0071] In the above implementation, a groove 204 is provided on the sealing plug body 201. By sealing the plugging part 205 at the opening of the groove 204, and simultaneously sealing the detection gas in the groove 204, the sealing quality of the sealing structure can be judged by detecting the sealed detection gas, which is beneficial to improving the quality of the produced batteries.

[0072] like Figure 12 and Figure 13 As shown, in some exemplary embodiments, the sealing plug body 201 is provided with a second limiting portion 206, which can abut against the second side 1011b of the edge of the injection hole 10111, thereby preventing the sealing plug body 201 from being dislodged from the injection hole 10111.

[0073] In some examples, the second limiting portion 206 protrudes outward from the outer wall of the sealing plug body 201 radially along the sealing plug body 201, and may be, for example, annular, or a plurality of such portions arranged circumferentially around the sealing plug body 201.

[0074] Here, the second limiting part 206 can abut against the second side 1011b of the edge of the injection hole 10111, thereby preventing the sealing plug body 201 from coming out of the injection hole 10111. This can improve the reliability of the sealing plug body 201 to the injection hole 10111 and better prevent the sealing plug 2 from coming out due to the increased pressure inside the battery housing 1, thus better ensuring the reliability of the sealing of the injection hole 10111.

[0075] Still refer to Figure 12 and Figure 13 As shown, in some exemplary embodiments, the end of the sealing plug body 201 that is first inserted into the injection hole 10111 is provided with a guide portion 2011, which can guide the sealing plug body 201 into the injection hole 10111.

[0076] Here, the guide portion 2011 can be, for example, a chamfer or a rounded corner. By providing the guide portion 2011 on the sealing plug body 201, the sealing plug body 201 can be easily and smoothly inserted into the injection hole 10111, which helps to improve assembly efficiency. The guide portion 2011 provides clear insertion direction guidance for the sealing plug body 201.

[0077] During the assembly process, the operator does not need to spend extra time precisely aligning the injection hole 10111. The operator only needs to bring the guide part 2011 approximately close to the injection hole 10111. The shape of the guide part 2011, such as a cone or arc, will automatically guide the sealing plug body 201 to slide into the correct position, significantly shortening the assembly time of the sealing plug 2.

[0078] like Figure 10 As shown, in some exemplary embodiments, the end of the sealing plug body 201 that is first inserted into the injection hole 10111 is provided with a second protrusion 207. The second protrusion 207 protrudes from the sealing plug body 201 along the insertion direction of the sealing plug body 201 and is used to press against the lower plastic 104.

[0079] The second protrusion 207 can be one or multiple protrusions arranged at intervals. The cross-sectional shape of the second protrusion 207 can be, for example, circular, triangular, square, etc. Here, by providing the second protrusion 207 on the sealing plug body 201, the second protrusion 207 can press against the lower plastic 104, which can also limit the insertion position of the sealing plug body 201, thereby improving the installation accuracy of the sealing plug body 201. At the same time, it also helps the operator to judge whether the sealing plug 2 is properly installed in the injection hole 10111.

[0080] In a preferred embodiment, the sealing plug 2 is made of fluororubber, which effectively balances structural strength and sealing performance. The sealing cap 3 is made of metal, as detailed in relevant technical specifications.

[0081] It should be noted that the various embodiments of the sealing plug 2 described above can be combined arbitrarily as needed, for example... Figure 12 A second protrusion 207 can also be provided in the middle.

[0082] The second aspect of this application provides a sealing structure, including the sealing plug 2 as described above, and a sealing cap 3 covering the sealing plug 2 and sealing the injection hole 10111, forming a two-stage sealing structure. It should be noted that the first seal is achieved by the sealing plug 2, and after the sealing cap 3 and the cover plate 101 are assembled, they are welded together to form a single structure, achieving a second seal for the battery.

[0083] The sealing structure described in this application, by using the sealing plug 2 as described above, makes it convenient for operators to judge whether the sealing plug 2 is properly installed in the injection hole 10111. The installation is convenient and quick, and can better ensure the sealing effect of the injection hole 10111, better prevent electrolyte leakage, and improve the safety and reliability of battery application.

[0084] During the filling of the battery with electrolyte, electrolyte often overflows and contaminates the surface of the cover plate 101 and related surfaces. Before welding the sealing cap 3 to the cover plate 101, a laser cleaning operation is required, which affects production efficiency. Even after cleaning, it is difficult to ensure that the electrolyte is thoroughly cleaned. In the subsequent laser welding, the presence of residual electrolyte often affects the welding yield.

[0085] In some preferred embodiments, the cover plate 101 of this embodiment includes a cover plate body 1011 and a blocking portion 1012 provided on the cover plate body 1011. The blocking portion 1012 surrounds the circumference of the injection hole 10111 and protrudes from the first side 1011a in a direction away from the first side 1011a.

[0086] In some preferred embodiments, the blocking portion 1012 is annular. The sealing cover 3 of this embodiment has a surrounding portion 302 that surrounds the outer periphery of the blocking portion 1012, and the sealing cover 3 is connected to the cover body 1011 or the blocking portion 1012 through the surrounding portion 302.

[0087] In one example, along the radial direction of the sealing cap 3, that is, in the direction orthogonal to the axial direction of the injection hole 10111, the wall thickness of the blocking part 1012 is between 0.3mm and 1mm, for example, it can be 0.3mm, 0.5mm, 0.7mm, 0.85mm, 1mm, etc.

[0088] In one example, along the axial direction of the injection hole 10111, the height of the blocking portion 1012 protruding from the first side 1011a in a direction away from the first side 1011a is between 0.2mm and 2mm, for example, it can be 0.2mm, 0.5mm, 1mm, 1.5mm, 2mm, etc.

[0089] In one example, the sealing cap 3 is a cap-shaped structure, and there is a mating structure between the sealing cap 3 and the cover plate 101. The sealing cap 3 and the cover plate 101 are laser-welded to achieve a seal for the entire injection port.

[0090] In detail, the sealing cap 3 includes a sealing cap body 301, which is a circular plate-like structure, with a surrounding portion 302 at the edge of the sealing cap body 301. In a preferred embodiment, the surrounding portion 302 includes a first flange 3021 disposed at the edge of the sealing body and bent toward the cover plate 101, and a second flange 3022 extending radially outward from the first flange 3021 along the sealing cap body 301. The sealing cap 3 is welded to the cover plate body 1011 via the second flange 3022, and the second flange 3022 is embedded within the cover plate 101.

[0091] In some examples, the outer periphery of the blocking portion 1012 is provided with a second recess 10113, and the aforementioned second flange 3022 is embedded in the second recess 10113. The recess depth of the second recess 10113 is between 0.1mm and 0.5mm, for example, it can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, etc.

[0092] In some examples, the thickness of the sealing cap body 301 is between 0.3mm and 1mm, for example, it can be 0.3mm, 0.5mm, 0.7mm, 0.85mm, 1mm, etc.

[0093] In addition, the sealing cover 3 may not include the second flange 3022, in which case the sealing cover 3 is welded to the blocking part 1012 via the first flange 3021.

[0094] In addition, a blocking part 1012 is provided on the cover plate body 1011. During the electrolyte filling process, the blocking part 1012 can effectively prevent the electrolyte from overflowing outside the blocking part 1012 and will not contaminate the area around the blocking part 1012. This can reduce or eliminate the cleaning process. Furthermore, during the welding process between the sealing cap 3 and the cover plate 101, it is beneficial to ensure the welding quality between the sealing cap 3 and the cover plate 101, thereby improving the reliability of the sealing cap 3 in sealing the injection hole 10111.

[0095] Meanwhile, embodiments of the third aspect of this application relate to a battery that is sealed by the sealing structure described above.

[0096] The battery of this application, by applying the above-mentioned sealing structure, has a high assembly effect, good installation consistency of the sealing plug 2, and a good sealing effect, which can effectively prevent electrolyte leakage, thereby improving the safety and reliability of battery application, and thus helping to improve the safety and reliability of electrical equipment using this battery.

[0097] The above descriptions are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.

Claims

1. A sealing plug for sealing a liquid injection hole on a battery casing, characterized in that: It includes a sealing plug body that can be inserted into the injection hole, and a first limiting part and a plurality of first protrusions that protrude outward from the sealing plug body in a direction orthogonal to the insertion direction of the sealing plug body; The first limiting portion can abut against a first side of the edge of the injection hole, thereby limiting the insertion depth of the sealing plug body in the injection hole; Multiple first protrusions are arranged at intervals along the insertion direction of the sealing plug body and are located on the same side of the first limiting portion; each first protrusion is an annular ring arranged around the circumference of the sealing plug body, and when the sealing plug body is inserted into the injection hole, at least a portion of the first protrusions can abut against the side wall of the injection hole.

2. The sealing plug according to claim 1, characterized in that: From the end of the sealing plug body that is first inserted into the injection hole to the other end, the dimensions of the sealing plug body gradually increase in a direction orthogonal to its own insertion direction; or... From the moment the sealing plug body is inserted into one end of the injection hole to the other end, the dimensions of the sealing plug body in the direction orthogonal to its own insertion remain unchanged.

3. The sealing plug according to claim 1, characterized in that: From the end of the first protrusion that is first inserted into the injection hole to the other end, the size of the first protrusion remains unchanged in the direction orthogonal to its own insertion direction; or, From the end of the first protrusion that is first inserted into the injection hole to the other end, the size of the first protrusion gradually increases in the direction orthogonal to its own insertion direction.

4. The sealing plug according to claim 1, characterized in that: There are multiple first limiting portions, which are arranged at intervals along the insertion direction of the sealing plug body, and each first limiting portion is an annular ring surrounding the sealing plug body; and / or, The first side is provided with a first recessed portion that is recessed towards the insertion direction, and the first limiting portion has an embedding portion that can be embedded in the first recessed portion.

5. The sealing plug according to claim 1, characterized in that: The sealing plug body has a groove at one end where the first limiting part is located, and a sealing part is provided at the opening of the groove to seal the opening, and the gas to be tested is sealed in the groove.

6. The sealing plug according to claim 1, characterized in that: The sealing plug body is provided with a second limiting part, which can abut against a second side of the edge of the injection hole, thereby preventing the sealing plug body from falling out of the injection hole; and / or, The end of the sealing plug body that is first inserted into the injection hole is provided with a guide portion, which can guide the sealing plug body into the injection hole.

7. The sealing plug according to claim 1, characterized in that: The end of the sealing plug body that is first inserted into the injection hole is provided with a second protrusion. The second protrusion protrudes from the sealing plug body along the insertion direction of the sealing plug body and is used to press against the lower plastic.

8. A sealing structure, characterized in that: The sealing plug, as described in any one of claims 1-7, further includes a sealing cap covering the sealing plug and sealing the injection hole.

9. The sealing structure according to claim 8, characterized in that: The cover plate in the battery casing includes a cover plate body and a blocking portion provided on the cover plate body. The blocking portion surrounds the circumference of the injection hole and protrudes from the first side in a direction away from the first side. The sealing cap has a surrounding portion that surrounds the outer periphery of the blocking portion, and the sealing cap is connected to the cover plate body or the blocking portion through the surrounding portion.

10. A battery, characterized in that: The battery is sealed by the sealing structure as described in claim 8 or 9.

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