Cover plate assembly and battery

Abstract

The application relates to the technical field of power batteries, and provides a cover plate assembly and a battery. The cover plate assembly comprises a cover plate body with a liquid injection hole, a sealing plug and a sealing cover; the inner side and the outer side of the cover plate body are respectively formed with a first groove and a second groove, the first groove and the second groove are located at the two ends of the liquid injection hole, and the first groove and the second groove are in communication with the liquid injection hole; the sealing plug is provided with a main body portion in interference fit in the liquid injection hole, and a first limiting portion and a second limiting portion arranged on the main body portion, one end of the sealing plug penetrates through the liquid injection hole, and the first limiting portion and the second limiting portion are respectively limited in the first groove and the second groove; the sealing cover is sealed above the sealing plug and is welded to the cover plate body. The cover plate assembly can realize bidirectional positioning of the sealing plug, can form multiple sealing barriers, can improve the reliability of the sealing plug installation, and can improve the sealing performance at the liquid injection hole.

Description

Technical Field

[0001] This application relates to the field of power battery technology, and in particular to a cover plate assembly. This application also relates to a battery equipped with the aforementioned cover plate assembly. Background Technology

[0002] During the manufacturing process of lithium batteries, after the secondary electrolyte filling is completed, the electrolyte filling hole of the battery casing needs to be sealed to prevent subsequent leakage. In traditional structures, a sealing pin (i.e., a sealing plug) and a sealing cap are usually used to seal the electrolyte filling hole. The sealing pin is inserted into the electrolyte filling hole and makes an interference fit with the inner wall of the hole, and the sealing cap is welded to the cell cover plate to achieve the seal.

[0003] However, the structure of the sealing pin typically only includes a main body that fits into the inner wall of the injection hole. This design makes it prone to over-insertion of the sealing pin into the injection hole during assembly due to excessive driving force. Furthermore, during battery use, the gas pressure generated inside the battery can push the sealing pin, causing it to shift outwards along the cover plate. All these factors affect the sealing of the injection hole, thus necessitating improvements to the sealing structure at the injection hole. Utility Model Content

[0004] In view of this, this application aims to provide a cover plate assembly that can improve the sealing performance at the injection hole.

[0005] To achieve the above objectives, the technical solution of this application is implemented as follows:

[0006] A cover plate assembly includes a cover plate body having an injection hole, a sealing plug, and a sealing cap;

[0007] The inner and outer sides of the cover plate body are respectively formed with a first groove and a second groove. The first groove and the second groove are respectively located at both ends of the injection hole, and both the first groove and the second groove are connected to the injection hole.

[0008] The sealing plug has a main body portion that is interference-fitted into the injection hole, and a first limiting portion and a second limiting portion provided on the main body portion. One end of the sealing plug passes through the injection hole, and the first limiting portion and the second limiting portion are respectively limited in the first groove and the second groove.

[0009] The sealing cap is placed above the sealing plug and is welded to the cover plate body.

[0010] Further, the sealing plug has an insertion portion connected to the main body portion, the radial dimension of the insertion portion is larger than the radial dimension of the main body portion; the first limiting portion is disposed at an end of the insertion portion close to the main body portion, and the first limiting portion can abut against the bottom wall of the first groove to restrict the movement of the sealing plug in the direction pointing to the outer side of the cover plate body.

[0011] Further, in the insertion direction, the radial dimension of the insertion portion is arranged to gradually decrease.

[0012] Further, the second limiting portion includes a limiting flange disposed at the end of the main body portion;

[0013] The limiting flange protrudes radially outward along the main body portion, and the limiting flange can be clamped on the bottom wall of the second groove to restrict the movement of the sealing plug in the insertion direction.

[0014] Further, the sealing cap has a cap main body covering above the sealing plug, a buffer portion disposed in the circumferential direction of the cap main body, and a welding portion disposed in the circumferential direction of the buffer portion; the welding portion is in interference fit with the side wall of the second groove.

[0015] Further, a liquid blocking flange disposed around the liquid injection hole in the circumferential direction is provided in the second groove; the liquid blocking flange extends from the bottom wall of the second groove to the outer side of the cover plate body, and the liquid blocking flange divides the second groove into a first part and a second part;

[0016] The first part is in communication with the liquid injection hole, and the second part is used for installing the sealing cap.

[0017] Further, on the longitudinal section of the liquid injection hole, the sealing cap is in a shape of "several", and has a cap body main body covering the liquid blocking flange, and a connecting edge disposed in the circumferential direction of the cap body main body; the connecting edge abuts against the second part, and the connecting edge is welded and connected to the cover plate body.

[0018] Compared with the related art, the present application has the following advantages:

[0019] (1) In the cover plate assembly according to the present application, through the first groove and the second groove disposed on the inner side and the outer side of the cover plate body respectively, as well as the first limiting portion and the second limiting portion disposed on the sealing plug, both the first groove and the second groove are communicated with the liquid injection hole, the main body portion of the sealing plug is in interference fit in the liquid injection hole, and the first limiting portion and the second limiting portion are limited in the first groove and the second groove respectively. This structural form can realize two-way positioning of the sealing plug, and improve the installation reliability of the sealing plug on the cover plate body.

[0020] Furthermore, based on the interference fit between the main body and the injection hole, the limiting fit between the first limiting part and the first groove, as well as the limiting fit between the second limiting part and the second groove, can form multiple sealing barriers to improve the sealing performance at the injection hole. Simultaneously, the sealing cap is positioned above the injection hole and welded to the cover plate body, further enhancing the sealing reliability at the injection hole and effectively preventing leakage of electrolyte from inside the battery.

[0021] (2) The insert portion provided on the sealing plug is such that the radial dimension of the insert portion is greater than the radial dimension of the main body portion, and the first limiting portion is located at the end of the insert portion near the main body portion. This facilitates the arrangement of the first limiting portion, and by utilizing the cooperation between the first limiting portion and the bottom wall of the first groove, the sealing plug is restricted from moving to the outside of the cover plate, ensuring that the main body of the sealing plug and the injection hole always maintain a good sealing effect.

[0022] (3) The radial dimension of the insert is set to gradually decrease, so that a conical guide surface can be formed on the outer circumferential surface of the insert, which facilitates the insertion of the sealing plug into the injection hole.

[0023] (4) The second limiting part includes a limiting protrusion located at the end of the main body, which can be engaged on the bottom wall of the second groove. Its structure is relatively simple, easy to manufacture and mold, and can effectively limit the movement of the sealing plug along the sealing plug insertion direction. Moreover, the cooperation between the limiting protrusion and the first limiting part can also effectively position the sealing plug in both directions, so that the sealing plug and the injection hole are always in an interference fit state. At the same time, the setting of the second limiting part is also conducive to increasing the contact area with the nailing device, ensuring that the sealing plug is subjected to more balanced force during the sealing plug insertion process, and better interference fit with the injection hole.

[0024] (5) The sealing cover has a cover body, a buffer part and a welding part, and the welding part is interference fit with the side wall of the second groove. On the one hand, the interference fit between the welding part and the side wall of the second groove can make the contact between the sealing cover and the cover plate body tighter, which is conducive to ensuring the assembly position and welding quality of the sealing cover. On the other hand, the buffer part can prevent the weld from cracking due to thermal expansion and contraction when the sealing cover is welded to the cover plate body.

[0025] (6) A liquid-blocking protrusion is provided in the second groove, and the liquid-blocking protrusion divides the second groove into a first part and a second part. The first part is connected to the liquid injection hole, which can effectively prevent the electrolyte from overflowing to the outer surface of the cover plate body during liquid injection. The second part is used to install the sealing cover. In this way, the isolation of the liquid-blocking platform can also prevent the electrolyte from contacting the second part and causing poor welding of the sealing cover.

[0026] (7) The sealing cover has a several-shaped structure on the longitudinal section of the liquid injection hole, which on the one hand facilitates molding and preparation, and on the other hand provides an accommodating space for the liquid-retaining convex edge, so that it can better cooperate with the liquid-retaining convex edge. Moreover, the design of the several-shaped structure can also improve the structural strength of the sealing cover, and at the same time make the connecting edge abut against the second part, so that the welding area is far away from the area in contact with the electrolyte, ensuring the stability of the welding quality.

[0027] Another object of the present application is to propose a battery, wherein the battery is provided with the cover plate assembly as described above.

[0028] The battery described in the present application, by adopting the above-mentioned cover plate assembly, can realize the two-way positioning of the sealing plug, and can form multiple sealing barriers, improve the installation reliability of the sealing plug and the sealing performance at the liquid injection hole, thereby improving the quality of the battery. Brief Description of the Drawings

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present application, and the illustrative embodiments of the present application and the descriptions thereof are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0030] Figure 1 is a schematic structural view of a first perspective of the application state of the cover plate assembly according to the embodiment of the present application;

[0031] Figure 2 is a schematic structural view of a second perspective of the application state of the cover plate assembly according to the embodiment of the present application;

[0032] Figure 3 is a schematic structural view of a third perspective of the application state of the cover plate assembly according to the embodiment of the present application;

[0033] Figure 4 is Figure 3 a cross-sectional view along the A-A viewing direction in the drawing;

[0034] Figure 5 is a schematic partial structural view of the cover plate body according to the embodiment of the present application;

[0035] Figure 6 is a perspective view of the sealing plug according to the embodiment of the present application;

[0036] Figure 7 is a cross-sectional view of the sealing plug according to the embodiment of the present application;

[0037] Figure 8 is a schematic structural view of the sealing cover according to the embodiment of the present application;

[0038] Figure 9 is another schematic structural view of the cooperation between the cover plate body and the sealing cover according to the embodiment of the present application;

[0039] Figure 10 This is a schematic diagram of another partial structure of the cover plate body described in an embodiment of this application;

[0040] Explanation of reference numerals in the attached figures:

[0041] 1. Cover plate body; 2. Battery casing; 3. Sealing plug; 4. Sealing cover;

[0042] 11. Positive terminal; 12. Negative terminal; 13. Explosion-proof valve; 14. Lower plastic part; 30. Main body; 31. Insertion part; 311. First limiting part; 32. Second limiting part; 101. Liquid-blocking flange; 401. Cover body; 402. Buffer part; 403. Welding part; 404. Cover body; 405. Connecting edge;

[0043] 10. Injection hole; 20. First groove; 300. Second groove; 30a. First part; 30b. Second part. Detailed Implementation

[0044] 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.

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] An embodiment of the first aspect of this application provides a cover plate assembly that improves the sealing performance at the injection hole by optimizing the sealing structure at the injection hole.

[0051] In related technologies, after the secondary electrolyte filling of a lithium battery is completed, the electrolyte filling hole of the battery casing needs to be sealed to prevent subsequent leakage. In traditional structures, a sealing pin (i.e., a sealing plug) is usually used in conjunction with a sealing cap to achieve a seal at the electrolyte filling hole. The sealing pin is inserted into the electrolyte filling hole and makes an interference fit with the inner wall of the hole, and the sealing cap is welded to the cell cover plate to achieve a seal.

[0052] However, the structure of the sealing pin typically only includes a main body that fits into the inner wall of the injection hole. This design makes it prone to excessive insertion of the sealing pin into the injection hole during assembly due to excessive driving force. Furthermore, during battery use, the gas pressure generated inside the battery can push the sealing pin, causing it to shift outwards along the cover plate. All these factors affect the sealing of the injection hole, thus necessitating improvements to the sealing structure at the injection hole.

[0053] In view of this, in order to overcome the shortcomings of the related technology, the cover plate assembly of this embodiment combines... Figures 1 to 10 As shown, the overall design includes a cover body 1 with an injection hole 10, a sealing plug 3, and a sealing cap 4.

[0054] The inner and outer sides of the cover plate body 1 are respectively formed with a first groove 20 and a second groove 300. The first groove 20 and the second groove 300 are located at both ends of the injection hole 10, and both the first groove 20 and the second groove 300 are connected to the injection hole 10.

[0055] The sealing plug 3 has a main body 30 that is interference-fitted into the injection hole 10, and a first limiting part 311 and a second limiting part 32 provided on the main body 30. One end of the sealing plug 3 passes through the injection hole 10, and the first limiting part 311 and the second limiting part 32 are respectively limited in the first groove 20 and the second groove 300. The sealing cap 4 seals the top of the sealing plug 3 and is welded to the cap plate body 1.

[0056] At this time, in the above structure, the first groove 20 and the second groove 300 on the inner and outer surfaces of the cover plate body 1 are connected to the injection hole 10, and the structure of the sealing plug 3 is optimized so that the main body 30 of the sealing plug 3 is interference-fitted in the injection hole 10, and the first limiting part 311 and the second limiting part 32 of the sealing plug 3 are respectively limited in the first groove 20 and the second groove 300.

[0057] This structural design enables bidirectional positioning of the sealing plug 3, improving the reliability of its installation on the cover plate body 1. Furthermore, based on the interference fit between the main body 30 and the injection hole 10, the limiting fit between the first limiting part 311 and the first groove 20, and the limiting fit between the second limiting part 32 and the second groove 300, can form multiple sealing barriers, enhancing the sealing performance at the injection hole 10.

[0058] At the same time, the sealing cap 4 is sealed above the sealing cap 4 and welded to the cover plate body 1, which can further improve the sealing reliability at the injection hole 10 and effectively prevent the leakage of electrolyte inside the battery.

[0059] It should be noted that the sealing plug 3, also known as the sealing pin, is made of an elastic material that does not react with the electrolyte, such as preferably fluororubber.

[0060] Based on the above overall introduction, specifically, combined with Figures 1 to 3 As shown, the structure of the battery will be roughly described here. The battery is rectangular in shape, and can be, for example, a square battery or a blade battery. Typically, a battery includes a battery casing 2 with an opening, an electrode assembly housed within the battery casing 2, and a cover assembly that seals the opening.

[0061] The cover assembly includes a cover body 1, a lower plastic part 14, a positive electrode post 11, a negative electrode post 12, and an explosion-proof valve 13. An injection hole 10 is formed on the cover body 1, which is used to inject electrolyte into the battery casing 2.

[0062] Reference Figure 5 and Figure 10As shown in the figure, in this embodiment, a first groove 20 and a second groove 300 are respectively formed on the inner and outer surfaces of the cover plate body 1. The first groove 20 and the second groove 300 are respectively located at both ends of the injection hole 10, and both the first groove 20 and the second groove 300 are connected to the injection hole 10.

[0063] Combination Figure 4 , Figure 6 , Figure 7 and Figure 9 and Figure 10 As shown, in some exemplary embodiments, for example, the sealing plug 3 has an insertion portion 31 connected to the main body 30, the radial dimension of the insertion portion 31 being larger than the radial dimension of the main body 30. A first limiting portion 311 is provided at one end of the insertion portion 31 near the main body 30, and the first limiting portion 311 can abut against the bottom wall of the first groove 20 to restrict the movement of the sealing plug 3 along the direction of the cover plate body 1 outward.

[0064] Specifically, the radial dimension of the insertion part 31 is larger than the radial dimension of the main body part 30. In this case, a limiting end face is formed at the end of the insertion part 31 that is connected to the main body part 30, and this limiting end face constitutes the first limiting part 311. Furthermore, after the insertion part 31 passes through the injection hole 10, the limiting end face can abut against the bottom wall of the first groove 20, thereby restricting the movement of the sealing plug 3 in the direction pointing outward from the cover plate body 1.

[0065] At this time, the insertion part 31 provided on the sealing plug 3 has a radial dimension larger than that of the main body part 30, so that the first limiting part 311 is provided at the end of the insertion part 31 near the main body part 30. This facilitates the arrangement of the first limiting part 311, and by using the first limiting part 311 to cooperate with the bottom wall of the first groove 20, the sealing plug 3 is restricted from moving to the outside of the cover plate, ensuring that the main body of the sealing plug 3 and the injection hole 10 always maintain a good sealing effect.

[0066] Continue to combine Figure 4 , Figure 6 , Figure 7 and Figure 9 and Figure 10 As shown, in some exemplary embodiments, for example, the radial dimension of the insertion portion 31 is gradually reduced in the insertion direction, that is, the outer peripheral surface of the insertion portion 31 is tapered, thereby guiding the sealing plug 3 into the injection hole 10, making the assembly of the sealing plug 3 smoother.

[0067] Furthermore, as a further preferred embodiment, reference is still made to... Figure 4 , Figure 6 , Figure 7 and Figure 9 and Figure 10As shown, a chamfer or rounded corner structure is also formed at the end of the insertion part 31 to further facilitate the insertion of the sealing plug 3 into the injection hole 10.

[0068] Combined Figure 4 , Figure 6 , Figure 7 and Figure 9 and Figure 10 As shown, in some exemplary embodiments, the second limiting portion 32 includes, for example, a limiting flange located at the end of the main body portion 30. This limiting flange protrudes radially outward from the main body portion 30 and can engage with the bottom wall of the second groove 300 to restrict the movement of the sealing plug 3 along the insertion direction.

[0069] Here, the second limiting part 32 adopts a limiting flange structure, which allows the limiting flange to be engaged on the bottom wall of the second groove 300. Its structure is relatively simple, easy to manufacture, and effectively restricts the movement of the sealing plug 3 along the insertion direction. Furthermore, the cooperation between the limiting flange and the first limiting part 311 also provides good bidirectional positioning of the sealing plug 3, ensuring that the sealing plug 3 and the injection hole 10 always maintain an interference fit. Simultaneously, the second limiting part 32 also increases the contact area with the nailing device, ensuring more balanced force on the sealing plug 3 during insertion, better interference fit with the injection hole 10, and improved insertion quality.

[0070] In this embodiment, combined with Figure 4 and Figure 8 As shown, in one exemplary embodiment, the sealing cap 4 has, for example, a cap body 401 covering the sealing plug 3, a buffer portion 402 circumferentially disposed on the cap body 401, and a welding portion 403 circumferentially disposed on the buffer portion 402. The welding portion 403 is interference-fitted with the sidewall of the second groove 300, and the sealing cap 4 is welded to the cap body by welding the welding portion 403 to the edge of the second groove 300.

[0071] In terms of specific structure, the cover body 401 is a flat plate shape, and the buffer part 402 includes a buffer groove formed on the circumference of the cover body 401, located on one side of the cover body 401. The groove wall of the second groove 300 is inclined, and the welding part 403 is disposed on the circumference of the buffer part 402, that is, on the outer circumferential surface of the buffer groove. The welding part 403 is interference-fitted into the second groove 300. In specific implementation, the outer side of the cover body 401 is lower than the outer side of the cover plate body, or flush with the outer side of the cover plate body, to ensure the overall appearance quality of the battery cell.

[0072] In the above embodiment, the sealing cover 4 has a cover body 401, a buffer part 402, and a welding part 403, and the welding part 403 is interference-fitted with the side wall of the second groove 300. In this way, not only can the interference fit between the welding part 403 and the side wall of the second groove 300 make the contact between the sealing cover 4 and the cover plate body 1 tighter, which is conducive to ensuring the assembly position and welding quality of the sealing cover 4, but the buffer part 402 can also prevent the weld from cracking due to thermal expansion and contraction when the sealing cover 4 is welded to the cover plate body 1.

[0073] Reference Figure 9 and Figure 10 As shown, in another exemplary embodiment, a liquid-blocking protrusion 101 is provided in the second groove 300, circumferentially surrounding the injection hole 10. This liquid-blocking protrusion 101 extends from the bottom wall of the second groove 300 towards the outer side of the cover body 1, and divides the second groove 300 into a first portion 30a and a second portion 30b. The first portion 30a communicates with the injection hole 10, and the second portion 30b is used to install the sealing cap 4.

[0074] Specifically, the sidewalls of the second groove 300 are designed to be flat, rather than... Figure 5 The inclined arrangement is shown in the figure. The liquid-blocking protrusion 101 extends from the bottom wall of the second groove 300 to the outside of the cover plate body 1 and surrounds the circumference of the injection hole 10. At this time, under the dividing action of the liquid-blocking protrusion 101, the second groove 300 is divided into a first part 30a that communicates with the injection hole 10 and a second part 30b for installing the sealing cap 4.

[0075] With the liquid-blocking protrusion 101 in place, during electrolyte injection, the electrolyte flows along the first part 30a, the injection hole 10, and the first groove 20 into the battery casing 2, effectively preventing electrolyte from overflowing onto the outer surface of the cover plate body 1. Furthermore, the liquid-blocking platform also prevents electrolyte from contacting the second part 30b and causing poor welding of the sealing cover 4.

[0076] Based on the provision of the liquid-blocking protrusion 101, continue to combine Figure 9 and Figure 10 As shown, in some exemplary embodiments, in the longitudinal section of the injection hole 10, the sealing cap 4 is, for example, U-shaped, and has a cap body 404 with a sealing and liquid-blocking protrusion 101, and a connecting edge 405 provided circumferentially on the cap body 404. The connecting edge 405 specifically abuts against the second part 30b, and the connecting edge 405 is welded to the cover plate body 1, thereby realizing the welded connection between the sealing cap 4 and the cover plate body 1.

[0077] In the structure described above, the sealing cover 4 has a several-shaped structure on the longitudinal section of the liquid injection hole 10. On the one hand, it is convenient for molding and preparation, and on the other hand, it provides an accommodating space for the liquid-retaining convex edge 101, enabling better cooperation with the liquid-retaining convex edge 101. Moreover, the design of the several-shaped structure can also improve the structural strength of the sealing cover 4, and at the same time make the connecting edge 405 abut against the second portion 30b, so that the welding area is far away from the area in contact with the electrolyte, ensuring the stability of welding quality.

[0078] It is worth noting that, for the cover plate assembly of this embodiment, based on the above exemplary implementation forms, in specific implementation, as a preferred embodiment, it still consists of Figures 1 to 10 as shown, which may for example include a cover plate body 1, a sealing plug 3 and a sealing cover 4. A first groove 20 and a second groove 300 are respectively formed on the inner side surface and the outer side surface of the cover plate body 1. The first groove 20 and the second groove 300 are respectively located at two ends of the liquid injection hole 10 on the cover plate body 1, and both the first groove 20 and the second groove 300 are in communication with the liquid injection hole 10.

[0079] The sealing plug 3 has a main body portion 30, and a first limiting portion 311 and a second limiting portion 32 disposed on the main body portion 30. The main body portion 30 is interference-fitted in the liquid injection hole 10. One end of the sealing plug 3 passes through the liquid injection hole 10, and the first limiting portion 311 and the second limiting portion 32 are respectively limited in the first groove 20 and the second groove 300. The sealing cover 4 is sealed above the sealing plug 3, and the sealing cover 4 is welded to the cover plate body 1.

[0080] The sealing plug 3 has a plug-in portion 31 connected to the main body portion 30, and the radial dimension of the plug-in portion 31 is larger than the radial dimension of the main body portion 30. The first limiting portion 311 is disposed at the end of the plug-in portion 31 close to the main body portion 30, and the first limiting portion 311 can abut against the bottom wall of the first groove 20, so as to limit the movement of the sealing plug 3 in the direction pointing to the outer side of the cover plate body 1. Moreover, in the plug-in direction, the radial dimension of the plug-in portion 31 is set to gradually decrease.

[0081] The second limiting portion 32 includes a limiting convex edge disposed at the end of the main body portion 30, the limiting convex edge protrudes radially outward along the main body portion 30, and the limiting convex edge can be clamped on the bottom wall of the second groove 300, so as to limit the movement of the sealing plug 3 in the plug-in direction.

[0082] The sealing cover 4 has a cover main body 401 covering above the sealing plug 3, a buffer portion 402 disposed in the circumferential direction of the cover main body 401, and a welding portion 403 disposed in the circumferential direction of the buffer portion 402, and the welding portion 403 is interference-fitted with the side wall of the second groove 300.

[0083] Alternatively, a liquid-retaining protruding rim 101 arranged circumferentially around the liquid injection hole 10 is provided in the second groove 300. The liquid-retaining protruding rim 101 extends from the bottom wall of the second groove 300 toward the outer side of the cover plate body 1, and the liquid-retaining protruding rim 101 divides the second groove 300 into a first portion 30a and a second portion 30b. The first portion 30a is in communication with the liquid injection hole 10, and the second portion 30b is used for installing the sealing cover 4.

[0084] On the basis that the liquid-retaining protruding rim 101 is provided, the sealing cover 4 has a shape of the Chinese character "几" on the longitudinal section of the liquid injection hole 10, and has a cover body main part 404 that encloses the liquid-retaining protruding rim 101, and a connecting rim 405 arranged in the circumferential direction of the cover body main part 404. The connecting rim 405 abuts against the second portion 30b, and the connecting rim 405 is welded to the cover plate body 1.

[0085] In the above preferred embodiments of the cover plate assembly, the specific arrangement and layout of the cover plate body 1, the sealing plug 3, the sealing cover 4, the fitting structure between the sealing plug 3 and the cover plate body 1, the connection structure between the sealing cover 4 and the cover plate body 1, and the like can still refer to the records in the above exemplary embodiments. Moreover, in this preferred embodiment, the beneficial effects brought by the design of the cover plate body 1, the sealing plug 3, the sealing cover 4, the fitting structure between the sealing plug 3 and the cover plate body 1, the connection structure between the sealing cover 4 and the cover plate body 1, and the like can also refer to the records in the above exemplary embodiments.

[0086] With the above design, the cover plate assembly of this embodiment can realize bidirectional positioning of the sealing plug 3, form multiple sealing barriers, improve the installation reliability of the sealing plug 3, and thus can improve the sealing performance at the liquid injection hole 10.

[0087] Embodiments of the second aspect of the present application provide a battery, as Figures 1 to 10 shown, the battery is provided with the cover plate assembly as described above.

[0088] For the battery of this embodiment, by adopting the above cover plate assembly, bidirectional positioning of the sealing plug 3 can be realized, multiple sealing barriers can be formed, the installation reliability of the sealing plug 3 and the sealing performance at the liquid injection hole 10 can be improved, so that the quality of the battery can be enhanced.

[0089] The foregoing descriptions are only some embodiments of the present application, and are not intended to limit the present application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined as required to form other specific technical solutions. Those skilled in the art can make various modifications and variations to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall all be included in the protection scope of the claims of the present application.

Claims

1. A cover plate assembly, characterized in that: comprises a cover plate body with a liquid injection hole, as well as a sealing plug and a sealing cover; a first groove and a second groove are respectively formed on the inner side surface and the outer side surface of the cover plate body, the first groove and the second groove are respectively located at two ends of the liquid injection hole, and both the first groove and the second groove are in communication with the liquid injection hole; the sealing plug has a main body part in interference fit with the liquid injection hole, and a first limiting part and a second limiting part arranged on the main body part, one end of the sealing plug passes through the liquid injection hole, and the first limiting part and the second limiting part are respectively limited in the first groove and the second groove; the sealing cover is sealed above the sealing plug and is welded to the cover plate body.

2. The cover plate assembly according to claim 1, characterized in that: the sealing plug has an insertion part connected to the main body part, and the radial dimension of the insertion part is larger than the radial dimension of the main body part; the first limiting part is arranged at one end of the insertion part close to the main body part, and the first limiting part can abut against the bottom wall of the first groove to limit the movement of the sealing plug in the direction pointing to the outer side of the cover plate body.

3. The cover plate assembly according to claim 2, characterized in that: in the insertion direction, the radial dimension of the insertion part is arranged to be gradually reduced.

4. The cover plate assembly according to claim 1, characterized in that: the second limiting part comprises a limiting flange arranged at the end of the main body part; the limiting flange protrudes radially outward along the main body part, and the limiting flange can be clamped on the bottom wall of the second groove to limit the movement of the sealing plug in the insertion direction.

5. The cover plate assembly according to claim 1, characterized in that: the sealing cover has a cover main body covering above the sealing plug, a buffer part arranged in the circumferential direction of the cover main body, and a welding part arranged in the circumferential direction of the buffer part; the welding part is in interference fit with the side wall of the second groove.

6. The cover plate assembly according to claim 1, characterized in that: a liquid retaining flange arranged around the circumference of the liquid injection hole is arranged in the second groove; the liquid retaining flange extends from the bottom wall of the second groove to the outer side of the cover plate body, and the liquid retaining flange divides the second groove into a first part and a second part; the first part is in communication with the liquid injection hole, and the second part is used for installing the sealing cover.

7. The cover plate assembly according to claim 6, characterized in that: on the longitudinal section of the liquid injection hole, the sealing cover is in a shape of "π", and has a cover main body enclosing the liquid retaining flange, and a connecting edge arranged in the circumferential direction of the cover main body; the connecting edge abuts against the second part, and the connecting edge is welded to the cover plate body.

8. A battery, characterized in that: the battery is provided with the cover plate assembly according to any one of claims 1 to 7.

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