Sealing structure, cover body assembly and battery

Abstract

The utility model provides a sealing structure, a cover body assembly and a battery, and aims to improve the sealing reliability of a liquid injection hole. The sealing structure is used for being arranged on a top cover, a liquid injection hole is formed in the top cover in a penetrating mode and comprises a first hole section and a second hole section, the second hole section and the first hole section are sequentially distributed in the liquid injection direction, the hole diameters of the second hole section and the first hole section become smaller, and a step face is formed between the first hole section and the second hole section. The sealing piece comprises a first sealing part, a second sealing part and a third sealing part which are integrally arranged, the first sealing part, the second sealing part and the third sealing part are sequentially distributed in the axial direction of the sealing piece, the radial sizes of the first sealing part, the second sealing part and the third sealing part are sequentially increased, the sealing piece is used for being installed in the liquid injection hole, and the first sealing part is used for being matched with the first hole section. The second sealing part is used for extending into the second hole section and abutting against the step face, and the third sealing part is used for being welded to the surface of the top cover.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a sealing structure, a cover assembly and a battery. Background Art

[0002] During the lithium battery production and assembly process, the battery cell is first installed in a housing with an opening at one end. The housing opening is then sealed with a top cover. The top cover has a pre-reserved injection hole, through which electrolyte is injected into the housing to saturate the battery cell. The injection hole needs to be sealed to maintain the pressure environment inside the housing and prevent external air and moisture from entering the battery cell.

[0003] Related technologies use a combination of sealing aluminum sheets and rubber particles to seal the injection hole on the top cover. To seal the injection hole, the rubber particles are first installed in the hole and pressed down, and then the aluminum sheet is welded to the top cover. However, this sealing method suffers from low sealing reliability, primarily due to the small contact area between the aluminum sheet and the top cover, which can lead to poor welding. Furthermore, when pressing down on the rubber particles, overpressure can easily cause them to enter the battery cell. Utility Model Content

[0004] The embodiments of the present application provide a sealing structure, a cover assembly, and a battery, which can improve the technical problem of insufficient sealing reliability of the liquid injection hole.

[0005] In the first aspect, an embodiment of the present application provides a sealing structure for being arranged on a top cover, wherein a liquid injection hole is provided through the top cover, and the liquid injection hole includes a first hole segment and a second hole segment. Along the liquid injection direction, the second hole segment and the first hole segment are distributed in sequence and the aperture becomes smaller, and a step surface is formed between the first hole segment and the second hole segment. The sealing structure includes a sealing member, and the sealing member includes a first sealing portion, a second sealing portion and a third sealing portion which are integrally arranged. Along the axial direction of the sealing member, the first sealing portion, the second sealing portion and the third sealing portion are distributed in sequence and the radial dimensions increase in sequence. The sealing member is used to be installed in the liquid injection hole, the first sealing portion is used to cooperate with the first hole segment, the second sealing portion is used to extend into the second hole segment and abut the step surface, and the third sealing portion is used to be welded to the surface of the top cover.

[0006] In one embodiment, at least the third sealing portion is a metal structure.

[0007] In one embodiment, the first sealing portion is a plastic structure; and / or the second sealing portion is a metal structure; and / or the second sealing portion is used to cooperate with the second hole segment.

[0008] In one embodiment, the sealing structure further includes a metal pressing block, which is used to be arranged on the surface of the top cover. The metal pressing block includes an integrally arranged main body portion and a welding portion. The welding portion is arranged around the main body portion along the edge of the main body portion. The welding portion is used to be welded to the top cover. A receiving groove is provided on the main body portion, and the receiving groove is used to accommodate the third sealing portion.

[0009] In one embodiment, the thickness of the welding portion is smaller than the thickness of the main body portion; and / or the main body portion is used to abut the third sealing portion; and / or the third sealing portion is adapted to the receiving groove.

[0010] In the second aspect, an embodiment of the present application provides a cover body assembly, including a top cover and the above-mentioned sealing structure, wherein a liquid injection hole is provided through the top cover, and the liquid injection hole includes a first hole segment and a second hole segment. Along the liquid injection direction, the second hole segment and the first hole segment are distributed in sequence and the hole diameter becomes smaller. A step surface is formed between the first hole segment and the second hole segment. The seal is installed in the liquid injection hole, the first sealing part cooperates with the first hole segment, the second sealing part extends into the second hole segment and abuts the step surface, and the third sealing part is welded to the surface of the top cover.

[0011] In one embodiment, the first sealing portion is interference fit with the first hole segment.

[0012] In one embodiment, the second sealing portion cooperates with the second hole section.

[0013] In one embodiment, the top cover includes a first layer and a second layer that are stacked, the first layer is welded to the third sealing portion, and at least the first layer is a metal layer.

[0014] In a third aspect, an embodiment of the present application provides a battery, comprising a shell, a battery cell and the above-mentioned cover assembly, wherein the battery cell is located in the shell, and the cover assembly is covered on the shell to seal the shell.

[0015] Beneficial effects of the embodiments of the present application:

[0016] In an embodiment of the present application, a sealing structure is used to be arranged on a top cover, and a stepped sealing member in the sealing structure can be used to cooperate with a stepped injection hole on the top cover to seal the injection hole. Specifically, along the injection direction, the injection hole includes a second hole segment and a first hole segment that are sequentially distributed and whose apertures become smaller in sequence, and a step surface is also formed between the first hole segment and the second hole segment. The sealing member includes a first sealing portion, a second sealing portion, and a third sealing portion that are integrally arranged. The first sealing portion and the second sealing portion are used to extend into the injection hole, wherein the first sealing portion cooperates with the first hole segment to achieve a first sealing of the injection hole in the injection hole, the second sealing portion abuts the step surface to achieve a second sealing of the injection hole in the injection hole, and the third sealing portion is welded to the surface of the top cover to achieve a third sealing of the injection hole at the opening of the injection hole.

[0017] The sealing structure provided in the embodiment of the present application can effectively improve the reliability of the sealing of the liquid injection hole by performing multiple sealing on the liquid injection hole, and reduce the risk of external water vapor entering the shell through the liquid injection hole and contacting the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 This is a three-dimensional schematic diagram of a sealing structure provided by an embodiment of the present application at a certain viewing angle;

[0020] Figure 2 is a three-dimensional schematic diagram of a sealing structure provided by an embodiment of the present application from another perspective;

[0021] Figure 3 is a schematic top view of a sealing structure provided by another embodiment of the present application;

[0022] Figure 4 yes Figure 3 Schematic diagram of the cross-sectional structure along the AA direction;

[0023] Figure 5 This is a schematic diagram of the main structure of a sealing structure provided by another embodiment of the present application;

[0024] Figure 6 This is a three-dimensional schematic diagram of a sealing structure provided by another embodiment of the present application at one viewing angle;

[0025] Figure 7 is a three-dimensional schematic diagram of a sealing structure provided by another embodiment of the present application from another perspective;

[0026] Figure 8 1 is a schematic top view of a metal pressing block in a sealing structure provided by another embodiment of the present application;

[0027] Figure 9 yes Figure 8 Schematic diagram of the cross-sectional structure along the BB direction;

[0028] Figure 10 This is a three-dimensional schematic diagram of a metal pressing block in a sealing structure provided by another embodiment of the present application at one viewing angle;

[0029] Figure 11 is a three-dimensional schematic diagram of a metal pressing block in a sealing structure provided by another embodiment of the present application from another perspective;

[0030] Figure 12 This is a three-dimensional schematic diagram of a cover assembly provided by an embodiment of the present application at a certain viewing angle;

[0031] Figure 13 is a three-dimensional schematic diagram of a cover assembly provided by an embodiment of the present application from another perspective;

[0032] Figure 14 This is a schematic top view of the cover assembly provided in one embodiment of the present application;

[0033] Figure 15 yes Figure 14 Schematic diagram of the cross-sectional structure in the CC direction;

[0034] Figure 16 yes Figure 15 Enlarged view of part D in the middle;

[0035] Figure 17 This is a three-dimensional schematic diagram of a top cover provided by an embodiment of the present application at a certain viewing angle;

[0036] Figure 18 yes Figure 17 Enlarged view of part E in the middle;

[0037] Figure 19 Schematic diagram of the cross-sectional structure of a battery provided in one embodiment of the present application.

[0038] Reference numerals:

[0039] 10. Sealing structure;

[0040] 1. Seals;

[0041] 11. First sealing portion;

[0042] 12. Second sealing portion;

[0043] 13. Third sealing part;

[0044] 2. Metal briquetting;

[0045] 21. Main body; 22. Welding portion; 23. Accommodation groove;

[0046] 20. Cover assembly;

[0047] 3. Top cover; 3a. First surface; 3b. Second surface; 31. First layer; 32. Second layer;

[0048] 4. Liquid injection hole; 41. First hole section; 42. Second hole section; 43. Step surface;

[0049] 5. Pole;

[0050] 100, battery; 30, casing; 40, battery cell. DETAILED DESCRIPTION

[0051] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0052] Furthermore, it should be understood that the specific embodiments described herein are intended only to illustrate and explain the present application and are not intended to limit the present application. In this application, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0055] The terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0056] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0057] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0058] Embodiments of the present application provide a sealing structure, a cover assembly, and a battery.

[0059] First, see Figures 1 to 19 The present embodiment provides a sealing structure 10 for sealing a liquid injection hole 4. The liquid injection hole 4 is provided on the top cover 3. The top cover 3 is used to cover the housing 30 of the battery 100. The housing 30 accommodates the battery cell 40. When assembling the battery 100, the battery cell 40 is first loaded into the housing 30 and then the top cover 3 is placed on the housing 30. The electrolyte is injected into the housing 30 through the liquid injection hole 4 on the top cover 3 to infiltrate the battery cell 40. Finally, the sealing structure 10 is used to seal the liquid injection hole 4 to prevent external moisture from entering the housing 30 and contacting the battery cell 40.

[0060] Specifically, the sealing structure 10 includes a stepped sealing member 1, which includes an integrally arranged first sealing portion 11, a second sealing portion 12 and a third sealing portion 13. Along the axial direction of the sealing member 1, the first sealing portion 11, the second sealing portion 12 and the third sealing portion 13 are distributed in sequence and their radial dimensions increase in sequence.

[0061] The above-mentioned sealing structure 10 is used to be arranged on the top cover 3, wherein the stepped sealing member 1 can be used to cooperate with the stepped injection hole 4 on the top cover 3 to seal the injection hole 4. In detail, the injection hole 4 is set through the top cover 3, and the injection hole 4 includes a first hole segment 41 and a second hole segment 42, and the first hole segment 41 is connected to the second hole segment 42. Along the injection direction, the second hole segment 42 and the first hole segment 41 are distributed in sequence. It can be understood that when the electrolyte is injected into the injection hole 4, the electrolyte first flows through the second hole segment 42 and then flows through the first hole segment 41. Here, the injection direction refers to the flow direction of the electrolyte in the injection hole 4. Along the injection direction, the aperture of the injection hole 4 becomes smaller. Specifically, the aperture of the second hole segment 42 is larger than the aperture of the first hole segment 41, and a step surface 43 is formed between the first hole segment 41 and the second hole segment 42. In more detail, the seal 1 is used to be installed in the liquid injection hole 4, wherein the first sealing portion 11 is used to cooperate with the first hole section 41 to achieve a first sealing of the liquid injection hole 4, the second sealing portion 12 is used to extend into the second hole section 42 and abut the step surface 43 to achieve a second sealing of the liquid injection hole 4, and the third sealing portion 13 is used to be welded to the surface of the top cover 3 to achieve a third sealing of the liquid injection hole 4 at the opening of the liquid injection hole 4.

[0062] The sealing structure 10 provided in the embodiment of the present application can effectively improve the sealing reliability of the liquid injection hole 4 by performing multiple sealing on the liquid injection hole 4, and reduce the risk of external water vapor entering the shell 30 through the liquid injection hole 4 and contacting the battery cell 40.

[0063] In some embodiments, the second sealing portion 12 is further configured to cooperate with the second hole section 42. The cooperation here may be a clearance fit or an interference fit.

[0064] In the sealing member 1 , the first sealing portion 11 , the second sealing portion 12 and the third sealing portion 13 are integrally provided. As an example, the sealing member 1 may be obtained by welding, bonding or integral molding.

[0065] In some embodiments, at least the third sealing portion 13 is a metal structure, which facilitates welding the third sealing portion 13 and the top cover 3 together.

[0066] As an example, the seal 1 is a metal part, that is, the first sealing part 11, the second sealing part 12, and the third sealing part 13 are all metal structures. The seal 1 can be integrally formed, that is, the first sealing part 11, the second sealing part 12, and the third sealing part 13 are integrally formed. As an example, the seal 1 can be directly prepared by a stamping process.

[0067] As an example, only the third sealing portion 13 is a metal structure, while the first sealing portion 11 and the second sealing portion 12 are plastic structures. The first sealing portion 11 and the second sealing portion 12 can be integrally injection molded and then bonded to the third sealing portion 13 by bonding or hot pressing. Optionally, the plastic structure includes at least one of a silicone structure, a rubber structure, and a silicone rubber structure. Such a plastic structure has excellent elastic deformation capability, so that the first sealing portion 11 and the second sealing portion 12 can be respectively interference-fitted with the first hole section 41 and the second hole section 42 of the liquid injection hole 4, thereby improving the sealing effect.

[0068] As an example, only the first sealing portion 11 is made of plastic, while the second and third sealing portions 12, 13 are both made of metal. The second and third sealing portions 12, 13 can be integrally stamped and then bonded to the first sealing portion 11 by bonding or hot pressing. This not only improves the strength of the seal 1, but also allows the second and third sealing portions 12, 13 to be welded to the top cover 3, while the first sealing portion 11 can be interference-fitted with the first hole section 41 of the liquid injection hole 4, improving the sealing effect.

[0069] In some embodiments, see Figure 1 and Figure 2 , the first sealing part 11 is cylindrical, the second sealing part 12 is disc-shaped, and the third sealing part 13 is square-shaped. In other embodiments, the first sealing part 11 may be prismatic, the second sealing part 12 may be square-shaped, and the third sealing part 13 may be disc-shaped, which is not limited here. Optionally, the first sealing part 11 is adapted to the first hole section 41 of the injection hole 4, and the second sealing part 12 is adapted to the second hole section 42 of the injection hole 4, and the shapes of the first sealing part 11 and the second sealing part 12 are related to the shapes of the first hole section 41 and the second hole section 42 of the injection hole 4. Optionally, the first sealing part 11, the second sealing part 12 and the third sealing part 13 are concentrically arranged, that is, the center lines of the first sealing part 11, the second sealing part 12 and the third sealing part 13 are collinear. Along the centerline of the first sealing portion 11, the first sealing portion 11 has two opposing surfaces. The second sealing portion 12 is located on one side of the first sealing portion 11, and the third sealing portion 13 is located on one side of the second sealing portion 12 and away from the first sealing portion 11. The diameter of the first sealing portion 11 is smaller than that of the second sealing portion 12, and the diameter of the second sealing portion 12 is smaller than the side length of the third sealing portion 13. Along the centerline of the first sealing portion 11, the projection of the second sealing portion 12 is within the projection of the third sealing portion 13, and the projection of the first sealing portion 11 is within the projection of the second sealing portion 12. It can be understood that the seal 1 has a stepped shape.

[0070] In some embodiments, the sealing structure 10 also includes a metal pressing block 2, which includes an integrally arranged main body portion 21 and a welding portion 22. The welding portion 22 is arranged around the main body portion 21 along the edge of the main body portion 21. A receiving groove 23 is opened on the main body portion 21, and the receiving groove 23 is used to accommodate the third sealing portion 13.

[0071] The metal pressing block 2 is used to be arranged on the surface of the top cover 3, wherein the welding portion 22 of the metal pressing block 2 is used to be welded together with the top cover 3, and the welding portion 22 is arranged around the main body portion 21, and a receiving groove 23 is opened on the main body portion 21, and the receiving groove 23 is used to accommodate the third sealing portion 13, so that the metal pressing block 2 can seal the third sealing portion 13 near the opening of the injection hole 4, which is equivalent to the fourth sealing of the injection hole 4, further improving the sealing reliability of the injection hole 4 and reducing the risk of sealing failure of the injection hole 4.

[0072] In some embodiments, the metal pressing block 2 and the sealing member 1 are independently provided, that is, there is no connection between the two, which facilitates welding of the sealing member 1 and the top cover 3. Of course, in some embodiments, the metal pressing block 2 and the sealing member 1 can also be connected.

[0073] In some embodiments, the thickness of the welding portion 22 is thinner than that of the main body 21. A receiving groove 23 is provided on the main body 21. Specifically, the receiving groove 23 is formed by a partial inward depression on one side of the main body 21. This prevents the main body 21 from being too thin, as the receiving groove 23 would be too shallow to accommodate the third sealing portion 13. By making the welding portion 22 thinner than the main body 21, it is easier to weld the welding portion 22 to the top cover 3, particularly by laser welding.

[0074] In some embodiments, the main body 21 is used to press against the third sealing portion 13. The main body 21 is used to press against the side of the third sealing portion 13 facing away from the second sealing portion 12. The thickness of the third sealing portion 13 can be equal to or slightly greater than the depth of the accommodating groove 23 so that the main body 21 presses against the third sealing portion 13, or the main body 21 can be partially raised toward the third sealing portion 13 to achieve the pressing against the third sealing portion 13. By using the main body 21 to press against the third sealing portion 13, the third sealing portion 13 is brought closer to the surface of the top cover 3 and the second sealing portion 12 is brought closer to the step surface 43, thereby improving the sealing effect of the seal 1 on the liquid injection hole 4. In addition, since the pressure in the shell 30 will increase during the operation of the battery 100, the seal 1 will be under pressure to a certain extent. By using the main body 21 to press against the third sealing portion 13, the risk of the seal 1 detaching from the liquid injection hole 4 is reduced.

[0075] In some embodiments, the third sealing portion 13 is adapted to the receiving groove 23. This allows the third sealing portion 13 to be positioned so that when the pressure in the housing 30 increases, even if the welding between the third sealing portion 13 and the top cover 3 fails, the seal 1 is not easily displaced.

[0076] Second, see Figures 12 to 18 The embodiment of the present application also provides a cover assembly 20, which includes a top cover 3 and a sealing structure 10. A liquid injection hole 4 is provided through the top cover 3, and the liquid injection hole 4 includes a first hole segment 41 and a second hole segment 42. Along the liquid injection direction, the second hole segment 42 and the first hole segment 41 are distributed in sequence and the aperture becomes smaller. A step surface 43 is formed between the first hole segment 41 and the second hole segment 42. The sealing member 1 is installed in the liquid injection hole 4, the first sealing portion 11 cooperates with the first hole segment 41, the second sealing portion 12 extends into the second hole segment 42 and abuts the step surface 43, and the third sealing portion 13 is welded to the surface of the top cover 3.

[0077] Optionally, the sealing structure 10 is the sealing structure 10 provided in the first aspect.

[0078] Along the thickness direction of the top cover 3, the top cover 3 has two opposite surfaces, namely a first surface 3a and a second surface 3b. When the top cover 3 is placed on the shell 30, the first surface 3a faces the outside of the shell 30, and the second surface 3b faces the inside of the shell 30. A liquid injection hole 4 is provided through the top cover 3, with the openings at both ends of the liquid injection hole 4 located on the first surface 3a and the second surface 3b, respectively. The liquid injection hole 4 includes a first hole segment 41 and a second hole segment 42. Along the injection direction, the second hole segment 42 and the first hole segment 41 are arranged in sequence. It can be understood that when electrolyte is injected into the liquid injection hole 4, the electrolyte first flows through the second hole segment 42 and then flows through the first hole segment 41. Here, the injection direction refers to the flow direction of the electrolyte in the liquid injection hole 4. Along the injection direction, the aperture of the liquid injection hole 4 decreases. Specifically, the aperture of the first hole segment 41 is smaller than the aperture of the second hole segment 42. Typically, electrolyte is injected into the housing 30 from outside the top cover 3. Along the injection direction, the first hole segment 41 is close to the second surface 3b, and the second hole segment 42 is close to the first surface 3a. It can be understood that the injection hole 4 is a stepped hole, with a stepped surface 43 formed between the first hole segment 41 and the second hole segment 42, that is, the stepped surface 43 connects the first hole segment 41 and the second hole segment 42. Optionally, the stepped surface 43 is a flat surface.

[0079] The seal 1 is installed in the injection hole 4, with the first sealing portion 11 and the second sealing portion 12 of the seal 1 both located within the injection hole 4 and corresponding to the first hole section 41 and the second hole section 42, respectively. Specifically, the first sealing portion 11 cooperates with the first hole section 41, which can be a clearance fit or an interference fit. The second sealing portion 12 extends into the second hole section 42 and abuts the stepped surface 43. The third sealing portion 13 of the seal 1 is located outside the injection hole 4 and abuts against a surface of the top cover 3, specifically the first surface 3a, and is welded to the top cover 3.

[0080] In the embodiment of the present application, the seal 1 includes an integrally arranged first sealing portion 11, a second sealing portion 12, and a third sealing portion 13. The first sealing portion 11 and the second sealing portion 12 extend into the injection hole 4, wherein the first sealing portion 11 cooperates with the first hole section 41 and the second sealing portion 12 abuts the stepped surface 43, thereby achieving a double seal of the injection hole 4 within the injection hole 4. The third sealing portion 13 is welded to the surface of the top cover 3 to achieve a third seal of the injection hole 4 at the opening of the injection hole 4. By using the sealing structure 10 to achieve multiple seals on the injection hole 4, the reliability of the sealing of the injection hole 4 can be effectively improved.

[0081] In some embodiments, the first sealing portion 11 is interference-fitted with the first hole section 41. By utilizing the interference fit between the first sealing portion 11 and the first hole section 41, not only can the sealing member 1 seal the liquid injection hole 4, but the wall of the liquid injection hole 4 can also fix the sealing member 1. In this way, when the pressure in the housing 30 increases, the strength of the weld between the third sealing portion 13 and the top cover 3 can be reduced, thereby reducing the risk of separation of the sealing member 1 and the top cover 3.

[0082] In some embodiments, the first sealing portion 11 and the first hole section 41 are gap-fitted, and a first adhesive layer (not shown) is further disposed between the first sealing portion 11 and the first hole section 41. Specifically, the first sealing portion 11 and the first hole section 41 are bonded together, and the first adhesive layer seals the gap between the first sealing portion 11 and the first hole section 41, thereby improving the sealing effect and reducing the difficulty of assembly. During assembly, liquid adhesive can be first applied to the first sealing portion 11, and then the first sealing portion 11 can be installed in the first hole section 41. After the liquid adhesive solidifies, the first adhesive layer is obtained.

[0083] In some embodiments, the second sealing portion 12 and the second hole segment 42 may be fitted with each other in a clearance fit or in an interference fit. As an example, the second sealing portion 12 and the second hole segment 42 may be fitted with each other in a clearance fit, and a second adhesive layer (not shown) may be provided between the clearance fit of the second sealing portion 12 and the second hole segment 42. The second adhesive layer seals the gap between the second sealing portion 12 and the second hole segment 42, thereby improving the sealing effect and reducing the difficulty of assembly.

[0084] In some embodiments, when the sealing structure 10 further includes a metal pressing block 2 , the metal pressing block 2 is disposed on the first surface 3 a of the top cover 3 , and the welding portion 22 of the metal pressing block 2 is welded to the top cover 3 .

[0085] In some embodiments, the top cover 3 includes a first layer 31 and a second layer 32 that are stacked, at least the first layer 31 is a metal layer, and the first layer 31 is welded to the third sealing portion 13 .

[0086] The first layer 31 is the surface layer of the top cover 3, and the second layer 32 is the inner layer of the top cover 3. When the top cover 3 is placed on the housing 30, the first layer 31 is away from the housing 30, while the second layer 32 is closer to the housing 30. The surface of the first layer 31 is the first surface 3a, and the surface of the second layer 32 is the second surface 3b. At least the first layer 31 is a metal layer, which facilitates welding to the third sealing portion 13. As an example, the first layer 31 is a plain aluminum sheet. As an example, the second layer 32 is a plastic component.

[0087] In some embodiments, the first layer 31 is a metal layer, the third sealing portion 13 is a metal structure, and the sealing structure 10 further includes a metal pressing block 2. Optionally, the first layer 31, the third sealing portion 13, and the metal pressing block 2 are made of the same metal. For example, the first layer 31, the third sealing portion 13, and the metal pressing block 2 are all made of aluminum. Since the first layer 31 is welded to the third sealing portion 13 and the metal pressing block 2, by using the same metal, the melting points are consistent, which improves the welding effect.

[0088] In some embodiments, the cover assembly 20 further includes a pole 5 , which is disposed through the top cover 3 , and one end of the pole 5 is used to connect to the battery cell 40 .

[0089] Thirdly, see Figure 19 The embodiment of the present application further provides a battery 100 , comprising a shell 30 , a battery cell 40 and a cover assembly 20 , wherein the battery cell 40 is located in the shell 30 , and the cover assembly 20 is covered on the shell 30 to seal the shell 30 .

[0090] The battery 100 provided in the embodiment of the present application has a good sealing effect, and the safety and reliability of the battery 100 are improved.

[0091] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A sealing structure, for installation on a top cover, wherein the top cover is provided with a liquid injection hole, wherein the liquid injection hole comprises a first hole segment and a second hole segment, wherein the second hole segment and the first hole segment are sequentially distributed and the hole diameters become smaller along the liquid injection direction, and a step surface is formed between the first hole segment and the second hole segment, wherein: The sealing structure includes a sealing member, which includes a first sealing portion, a second sealing portion and a third sealing portion that are integrally arranged. Along the axial direction of the sealing member, the first sealing portion, the second sealing portion and the third sealing portion are distributed in sequence and their radial dimensions increase in sequence. The sealing member is used to be installed in the injection hole, the first sealing portion is used to cooperate with the first hole section, the second sealing portion is used to extend into the second hole section and abut the step surface, and the third sealing portion is used to be welded to the surface of the top cover.

2. The sealing structure according to claim 1, wherein: At least the third sealing portion is a metal structure.

3. The sealing structure according to claim 2, characterized in that: The first sealing portion is a plastic structure; and / or the second sealing portion is a metal structure; and / or the second sealing portion is used to cooperate with the second hole segment.

4. The sealing structure according to any one of claims 1 to 3, characterized in that: The sealing structure also includes a metal pressing block, which is used to be arranged on the surface of the top cover. The metal pressing block includes a main body portion and a welding portion that are integrally arranged. The welding portion is arranged around the main body portion along the edge of the main body portion. The welding portion is used to be welded to the top cover. A receiving groove is opened on the main body portion, and the receiving groove is used to accommodate the third sealing portion.

5. The sealing structure according to claim 4, characterized in that: The thickness of the welding portion is smaller than the thickness of the main body portion; and / or the main body portion is used to abut the third sealing portion; and / or the third sealing portion is adapted to the accommodating groove.

6. A cover assembly, characterized in that: It includes a top cover and a sealing structure according to any one of claims 1 to 5, wherein a liquid injection hole is provided through the top cover, and the liquid injection hole includes a first hole segment and a second hole segment. Along the liquid injection direction, the second hole segment and the first hole segment are distributed in sequence and the hole diameter becomes smaller, and a step surface is formed between the first hole segment and the second hole segment. The sealing member is installed in the liquid injection hole, the first sealing portion cooperates with the first hole segment, the second sealing portion extends into the second hole segment and abuts the step surface, and the third sealing portion is welded to the surface of the top cover.

7. The cover assembly according to claim 6, wherein: The first sealing portion is interference fit with the first hole segment.

8. The cover assembly according to claim 6, wherein: The second sealing portion cooperates with the second hole section.

9. The cover assembly according to any one of claims 6 to 8, wherein: The top cover includes a first layer and a second layer which are stacked together. The first layer is welded to the third sealing portion, and at least the first layer is a metal layer.

10. A battery, characterized in that: The battery cell comprises a shell, a battery cell and a cover assembly according to any one of claims 6 to 9, wherein the battery cell is located in the shell, and the cover assembly is disposed on the shell to seal the shell.

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