A sealing piece of a hole structure, a sealing assembly, a cover plate and a battery cell

Abstract

The utility model discloses a kind of sealing element of hole structure, sealing assembly, cover plate and electric core, sealing element of hole structure includes: first convex part, include the first sealing surface for horizontal sealing;Second convex part, include the second sealing surface for in longitudinal sealing and the third sealing surface for in oblique sealing, oblique with the extension direction of third sealing surface vertical, the extension direction of third sealing surface is intersected into obtuse angle with longitudinal direction;Connecting portion, between first convex part and second convex part, include the fourth sealing surface for radial sealing, first sealing surface, fourth sealing surface, third sealing surface, second sealing surface meet and form sealing area.This application breaks through the single barrier of existing sealing structure, and different direction sealing structure is mutually restrained, effectively improve the sealing performance of sealing element to hole structure.In addition, the utility model also provides a kind of sealing assembly, a kind of cover plate and a kind of electric core.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and in particular to a sealing element, sealing assembly, cover plate and battery cell with a hole structure. Background Technology

[0002] The casing of a lithium-ion battery cell contains electrolyte. During cell manufacturing, the electrolyte needs to be injected into the cell through an injection hole on the cell cover, and then the injection hole is sealed with a sealing nail. Commonly used sealing nails are cylindrical in shape and are directly inserted into the injection hole. The outer wall of the sealing nail and the inner wall of the injection hole are press-fitted together to achieve a seal. However, this type of sealing nail has a simple sealing structure. Once the seal is broken, the electrolyte will leak out along the gap between the outer wall of the sealing nail and the wall of the injection hole, causing electrolyte leakage. Utility Model Content

[0003] The purpose of this invention is to solve the problem that existing hole-structured seals have a single sealing structure and insufficient sealing performance.

[0004] To solve the above-mentioned technical problems, this utility model discloses a sealing element with a hole structure for installation in a hole structure, comprising:

[0005] The first protrusion includes a first sealing surface for longitudinal sealing;

[0006] The second protrusion includes a second sealing surface for radial sealing and a third sealing surface for oblique sealing, the oblique direction being perpendicular to the extending direction of the third sealing surface and intersecting the longitudinal direction at an acute angle.

[0007] The connecting portion is disposed between the first protrusion and the second protrusion, and includes a fourth sealing surface for radial sealing. The first sealing surface, the fourth sealing surface, the third sealing surface, and the second sealing surface are in contact to form a sealing area.

[0008] Using the above technical solution, the seal utilizes a sealing area formed by interconnected first, fourth, third, and second sealing surfaces. This sealing area can seal both radially and longitudinally within the hole structure. Specifically, the first sealing surface seals longitudinally within the hole structure, the fourth and second sealing surfaces seal radially, and the third sealing surface seals obliquely. Compared to existing seals, this application overcomes the limitation of a single sealing structure, and the sealing structures in different directions mutually restrain each other, effectively improving the sealing performance of the seal on the hole structure. Applied to the use of sealing the electrolyte filling hole in lithium batteries, the seal provided by this application can seal radially, longitudinally, and obliquely within the filling hole, improving the sealing performance of the seal and effectively preventing electrolyte leakage from the lithium battery's filling hole, thereby enhancing the safety of the lithium battery.

[0009] The aforementioned third sealing surface extends at an obtuse angle to the longitudinal direction (that is, the oblique direction perpendicular to the extension direction of the third sealing surface intersects the longitudinal direction at an acute angle), which not only forms an outwardly protruding second protrusion, giving the second protrusion a draft angle to facilitate the processing and forming of the second protrusion structure, but also increases the sealing surface between the seal and the hole structure, improving the sealing performance of the seal for the injection hole.

[0010] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a sealing member with a hole structure, wherein the first protrusion, the second protrusion, and the connecting part are cylindrical or prismatic structures.

[0011] By adopting the above technical solution, the application environment of the seal can be broadened, and different seals can be used for different hole structures.

[0012] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a sealing element with a hole structure, wherein the first sealing surface includes a horizontal surface and an inclined surface, the inclined surface is in contact with the fourth sealing surface, the inclined surface intersects the first sealing surface at an obtuse angle, and the inclined surface intersects the fourth sealing surface at an obtuse angle.

[0013] Using the above technical solution, because the height of the fourth sealing surface is less than the depth of the hole structure in the longitudinal direction, the seal is installed in the hole structure, and there is a longitudinal interference fit between the first and third sealing surfaces. To ensure that the first protrusion does not interfere with the second protrusion's engagement in the groove on the hole wall when the seal is inserted into the hole structure, an inclined surface is provided at the position of the first sealing surface. This allows the seal to continue to be pressed down even when the edge of the hole structure abuts against the inclined surface, until the second protrusion is fully inserted into the groove on the hole wall. At this point, the horizontal surface abuts against the top surface of the hole structure, forming a radial sealing structure. In other words, this inclined surface design increases the longitudinal extension of the seal during installation, reducing the difficulty of installation.

[0014] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a sealing element with a hole structure, which further includes a guide surface extending along a second direction, the guide surface being connected to the second sealing surface, and the second direction intersecting the extension direction of the third sealing surface at an acute angle.

[0015] By adopting the above technical solution, by setting a tapered guide surface at the bottom of the seal, the guiding nature of the seal being installed into the hole structure is increased, and the difficulty of making the second protrusion pass through the narrower area of ​​the hole structure is reduced.

[0016] The present invention also discloses a sealing assembly based on the aforementioned hole structure, comprising:

[0017] A seal with a hole structure as described above;

[0018] The top cover has a groove at its bottom, and the first protrusion is received within the groove.

[0019] By using the above solution, the top cover is fixed to the top of the aforementioned sealing element, and then the top cover is welded to the surface of the part where the hole structure is located. This can further improve the sealing of the hole structure. Even if liquid leaks from the hole structure, the leaked liquid will be sealed inside the part by the top cover and will not overflow onto the surface of the part where the hole structure is located.

[0020] It is feasible to use the aforementioned part as a cover plate for a lithium battery cell, and to use this sealing assembly to seal the injection hole on the cover plate for injecting electrolyte into the cell, so that the electrolyte in the cell will not leak onto the surface of the cover plate.

[0021] According to another specific embodiment of the present invention, a sealing assembly is disclosed, wherein the top surface of the first protrusion and the top surface of the groove are spaced apart along the longitudinal direction.

[0022] By adopting the above technical solution, the top surface of the first protrusion of the sealing element is spaced apart from the top wall of the groove on the top cover. When the sealing element protrudes outward under the pressure inside the battery cell, the gap can accommodate the height of the protrusion of the sealing element, thus avoiding the top cover being subjected to an outward lifting force when the sealing element protrudes outward or protrudes too high, which would affect the firmness of the welded part between the top cover and the cover plate surface.

[0023] The present invention also discloses a cover plate based on the aforementioned sealing assembly, comprising:

[0024] The sealing assembly as described in any of the foregoing embodiments;

[0025] The mounting section includes mounting grooves and injection holes distributed sequentially along the longitudinal direction. The periphery of the top cover is welded to the side wall of the mounting groove, and the bottom wall of the mounting groove is longitudinally sealed to the first sealing surface. The injection hole includes a first mounting area and a second mounting area. The first mounting area is radially sealed to the fourth sealing surface, the second mounting area is radially sealed to the second sealing surface, and the second mounting area is obliquely sealed to the third sealing surface.

[0026] Using the above technical solution, the cover plate is used on the cell of a lithium battery. It includes a mounting groove for accommodating the top cover of the aforementioned sealing assembly, and the sidewall of the mounting groove is welded to the circumferential edge of the top cover. An injection hole for sealing connection with the aforementioned sealing element is provided in the mounting groove. Specifically, the fourth sealing surface of the connecting portion of the sealing element is sealed to the first mounting area of ​​the injection hole, the second sealing surface on the second protrusion of the sealing element radially seals the second mounting area of ​​the injection hole, and the third sealing surface on the second protrusion obliquely seals the second area of ​​the injection hole. This achieves longitudinal, radial, and oblique sealing between the sealing element and the injection hole, improving the sealing performance of the sealing element on the injection hole of the cover plate. This effectively prevents electrolyte leakage from the injection hole of the lithium battery, thereby improving the safety of the lithium battery.

[0027] According to another specific embodiment of the present invention, a cover plate is disclosed, wherein the first mounting area includes a first mounting surface, and the first mounting surface is sealed to the fourth sealing surface; the second mounting area includes a second mounting surface and a third mounting surface, the second mounting surface is sealed to the second sealing surface, and the third mounting surface is sealed to the third sealing surface.

[0028] The above technical solution includes a first mounting area extending longitudinally and a second mounting area recessed relative to the first mounting area, which are respectively sealed to the connecting part and the second protrusion of the sealing element. The upper surface of the injection hole is sealed to the first sealing surface. The fourth sealing surface and the second sealing surface provide radial sealing in the hole structure, and the third sealing surface provides oblique sealing in the hole structure. This solution breaks through the barrier of the existing single sealing structure, and the sealing structures in different directions restrain each other, effectively improving the sealing performance of the sealing element for the injection hole. This can effectively prevent the electrolyte from overflowing from the injection hole of the lithium battery, thereby improving the safety of the lithium battery.

[0029] According to another specific embodiment of the present invention, an embodiment of the present invention discloses a cover plate, the cover plate further comprising a chamfer structure disposed between the first mounting surface and the third mounting surface.

[0030] By adopting the above technical solution, the chamfered structure not only facilitates the insertion of the seal into the injection hole on the cover plate, but also facilitates the removal of the seal from the injection hole. Its main function is to guide, reduce the difficulty of inserting the seal into the injection hole, and also reduce the difficulty of removing the seal from the injection hole.

[0031] The present invention also discloses a battery cell based on the aforementioned cover plate, comprising: a cover plate as described in any of the preceding embodiments, wherein the cover plate further comprises a positive electrode post or a negative electrode post.

[0032] By adopting the above technical solution, this battery cell improves the sealing performance of the cover plate compared to existing technologies, which can effectively prevent the electrolyte from overflowing from the filling hole of the lithium battery, thereby improving the safety of the lithium battery. Attached Figure Description

[0033] Figure 1 A cross-sectional view of an existing sealant nail mounting structure is shown;

[0034] Figure 2 A front view of a seal according to this application is shown;

[0035] Figure 3 A front view of another seal in an embodiment of this application is shown;

[0036] Figure 4 A cross-sectional view of the sealing assembly in an embodiment of this application is shown;

[0037] Figure 5 A cross-sectional view showing the sealing assembly provided in the embodiments of this application installed in a cover plate;

[0038] Figure 6 A front view of the cover plate of the battery cell in an embodiment of this application is shown;

[0039] Figure 7 A cross-sectional view of the mounting portion of the cover plate in an embodiment of this application is shown;

[0040] Figure 8 Show Figure 7 Enlarged schematic diagram of the chamfered structure.

[0041] Figure label:

[0042] First protrusion 10; First sealing surface 11; 111: Horizontal surface; 112: Inclined surface;

[0043] Second protrusion 20; Second sealing surface 21; Third sealing surface 22;

[0044] Connecting part 30; Fourth sealing surface 31;

[0045] Guide surface 40;

[0046] Top cover 50; Groove 51;

[0047] Mounting slot 61;

[0048] Injection hole 62; First mounting area 621; Second mounting area 622; Chamfered structure 623;

[0049] First mounting surface 6211; Second mounting surface 6221; Third mounting surface 6222;

[0050] Radial X; Longitudinal Y; Extension direction of the third sealing surface A; Second direction B; Oblique direction C. Detailed Implementation

[0051] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0052] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0053] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the convenience of describing the utility model 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. Therefore, they should not be construed as limitations on the utility model.

[0054] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0055] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0056] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0057] The casing of a lithium battery cell contains electrolyte. During cell manufacturing, the electrolyte needs to be injected into the cell through an injection hole on the cell cover, and then the injection hole is sealed with sealant pins. For example... Figure 1 As shown, commonly used sealing nails have a cylindrical structure that is directly inserted into the injection hole. The outer wall of the sealing nail and the inner wall of the injection hole are press-fitted together to seal the hole. However, this type of sealing nail has a simple sealing structure. Once the seal is broken, the electrolyte will leak out along the gap between the outer wall of the sealing nail and the wall of the injection hole, causing electrolyte leakage and seriously affecting the safety of the battery cell. Therefore, existing sealing nails suffer from a simple sealing structure and insufficient sealing performance.

[0058] For ease of subsequent description, the embodiments of this application exemplarily define the following directions: such as Figure 2 As shown, the X direction represents the radial direction of the seal, and the Y direction represents the longitudinal direction of the seal; as Figure 2 As shown, direction A represents the extension direction of the third sealing surface 22, direction C represents the oblique direction, which is perpendicular to direction A, and direction B represents the second direction (i.e., the extension direction of the guide surface 40).

[0059] This utility model embodiment discloses a battery cell, which includes cover plates at both ends. The cover plates are provided with a positive electrode post or a negative electrode post, and an injection hole 62 for injecting electrolyte into the battery cell. The injection hole 62 is sealed by a sealing component.

[0060] By adopting the above technical solution, this battery cell improves the sealing performance of the cover plate compared to existing technologies, which can effectively prevent the electrolyte from overflowing from the filling hole of the lithium battery, thereby improving the safety of the lithium battery.

[0061] The present invention discloses a cover plate including a mounting part and a sealing assembly that is sealed to the mounting part.

[0062] The cover plate in this application can effectively prevent electrolyte from overflowing from the filling hole of the lithium battery, thereby improving the safety of the lithium battery.

[0063] This utility model discloses a sealing assembly including a sealing element and a top cover 50 disposed on the sealing element. In the application of sealing the electrolyte filling hole 62 of a lithium battery, after inserting the sealing element into the electrolyte filling hole 62, the top cover 50 is welded to the surface of the cover plate where the electrolyte filling hole 62 is located. This further enhances the sealing of the electrolyte filling hole 62. Even if electrolyte leaks from the electrolyte filling hole 62, the leaked electrolyte will be sealed inside the cover plate by the top cover 50 and will not overflow onto the surface of the cover plate.

[0064] For example, such as Figure 2As shown, the aforementioned sealing member includes a first protrusion 10, a second protrusion 20, and a connecting portion 30, wherein the first protrusion 10 is included in the longitudinal Y (i.e., Figure 2 The first sealing surface 11 shown is sealed in the Y direction; the second protrusion 20 is contained in the radial X (i.e., Figure 2 The second sealing surface 21 (shown in the X direction) and the oblique C (i.e. Figure 2 The third sealing surface 22 (shown in direction C) is sealed; the connecting part 30 is disposed between the first protrusion 10 and the second protrusion 20, and is included in the radial X (i.e. Figure 2 The fourth sealing surface 31 (shown in the X direction) is sealed, and the first sealing surface 11, the fourth sealing surface 31, the third sealing surface 22, and the second sealing surface 21 are connected to form a sealing area.

[0065] like Figure 2 As shown, the seal includes a first protrusion 10 (corresponding to...) Figure 2 The part circled by the dotted box at the upper left of the middle) and the second protrusion 20 (corresponding to Figure 2 (The part circled by the dashed box at the lower left of the middle) A connecting part 30 is provided between the first protrusion 10 and the second protrusion 20, and the aforementioned sealing area is sealed and connected to the inner wall of the hole structure.

[0066] Specifically, from top to bottom, the first sealing surface 11, the fourth sealing surface 31, the third sealing surface 22, and the second sealing surface 21 on the seal are interconnected to form a sealing area. The first sealing surface 11 extends radially (X), the fourth sealing surface 31 and the second sealing surface 21 extend longitudinally (Y), and the third sealing surface 22 extends along direction A. The first sealing surface 11 provides longitudinal sealing of the hole structure, the fourth sealing surface 31 and the second sealing surface 21 provide radial sealing of the hole structure, and the third sealing surface 22 provides oblique sealing of the hole structure. The structure of the first sealing surface 11 and the second sealing surface 21 allows for compression in the longitudinal (Y) direction of the seal. Furthermore, the second sealing surface 21 and the fourth sealing surface 31 provide compression in the radial (X) direction of the seal, enabling the seal to seal the hole structure both radially (X) and longitudinally (Y). Simultaneously, compression also exists in the direction perpendicular to the extension direction A of the third sealing surface 22, allowing the seal to seal obliquely (C). Compared to existing seals, this application overcomes the limitation of a single sealing structure, and the multi-directional sealing structures mutually restrain each other, effectively improving the sealing performance of the seal for the hole structure. Applied to the use of sealing the electrolyte filling hole in lithium batteries, the seal provided in this application can seal the electrolyte filling hole 62 in both the radial (X) and longitudinal (Y) directions, improving the sealing performance of the seal for the electrolyte filling hole 62. This effectively prevents electrolyte leakage from the electrolyte filling hole of the lithium battery, thereby improving the safety of the lithium battery.

[0067] In addition, the sealing element in this embodiment includes a first sealing surface 11, a fourth sealing surface 31, a third sealing surface 22, and a second sealing surface 21, which enriches the sealing structure of the sealing element. Even if the sealing structure of the fourth sealing surface 31 is damaged due to hardening or other reasons, the second sealing surface 21 and the third sealing surface 22 can still effectively seal the hole structure, preventing the liquid inside the hole structure from leaking, thereby improving the sealing performance of the sealing element on the hole structure.

[0068] It should be noted that, Figure 2 The image shown is a front view of the seal provided in this application. Its three-dimensional structure matches the three-dimensional structure of the hole. The overall structure of the seal can be a cylindrical structure or a prism, such as a square prism, pentagonal prism, hexagonal prism, etc. This application does not impose specific limitations on the number of edges of the prism structure seal. In practice, a seal matching the cross-sectional shape of the actual hole structure can be produced, or a seal with a different structure can be selected according to the actual usage environment.

[0069] In addition, the aforementioned first protrusion 10 is used not only to seal the top wall of the hole structure in the radial X direction, but also to limit the excessive insertion of the connecting part 30 into the hole structure. In the use of the liquid injection hole seal of the lithium battery, it can prevent the seal from falling into the cell under the cover plate and affecting the safety of the cell.

[0070] For example, the extending direction A of the aforementioned third sealing surface 22 intersects the longitudinal direction Y at an obtuse angle (i.e., Figure 2 (The α shown is an obtuse angle), for example, α is 120°, 150°, etc.

[0071] By adopting the above technical solution, such as Figure 2 As shown, the third sealing surface 22 in the second protrusion 20 and the fourth sealing surface 31 of the connecting part 30 form an obtuse angle α, which not only constitutes the second protrusion 20 protruding outward from the fourth sealing surface 31, giving the second protrusion 20 a draft angle to facilitate the processing and forming of the structure of the second protrusion 20, but also increases the sealing surface between the seal and the hole structure, and improves the sealing performance of the seal for the injection hole.

[0072] Reference Figure 3 As shown, in another embodiment of this application, the aforementioned first sealing surface 11 includes a horizontal surface 111 and an inclined surface 112. The inclined surface 112 is in contact with the fourth sealing surface 31, and the inclined surface 112 intersects the first sealing surface 11 at an obtuse angle (i.e., Figure 3 The β mentioned is an obtuse angle, for example, β is 120° or 150°, and the inclined surface 112 intersects the fourth sealing surface 31 at an obtuse angle (i.e., Figure 3 The γ mentioned is an obtuse angle, for example, β is 120° or 150°.

[0073] refer to Figure 4and Figure 7 As shown, because in the longitudinal direction Y, the total height of the fourth sealing surface 31, the third sealing surface 22, and the second sealing surface 21 is less than the hole depth of the hole structure (i.e., Figure 4 h1 is less than Figure 7 (h2 in the text), so the seal is installed in the hole structure. There is an interference fit in the longitudinal Y direction between the first sealing surface 11 and the third sealing surface 22. In order to ensure that the first protrusion 10 does not affect the second protrusion 20 being stuck in the second mounting area 622 on the hole wall of the hole structure when the seal is inserted into the hole structure, refer to Figure 3 As shown, by providing an inclined surface 112 at the position of the first sealing surface 11, the seal can be pressed down further even when the edge of the hole structure abuts against the inclined surface 112 during installation, until the second protrusion 20 is fully inserted into the second installation area 622 on the hole wall. That is, the design of the inclined surface 112 increases the extensibility of the seal along the longitudinal direction Y during installation, reducing the difficulty of installing the seal.

[0074] The difference between the first sealing surface 11 in this embodiment and the first sealing surface 11 in the previous embodiment is the addition of an inclined surface 112, which provides a significant advantage in the installation of the seal in the later embodiment. This application does not specifically limit the size of the angles α, β, and γ involved in these two embodiments; they can be adaptively adjusted according to the actual diameter of the second protrusion 20 and the diameter of the connecting portion 30, or other relevant dimensions.

[0075] In this embodiment, when the seal is in use, if the second protrusion 20 fills the second mounting area 622 on the bore wall, the horizontal surface 111 abuts against the top surface of the bore structure, the fourth sealing surface 31 seals the area on the bore wall other than the second mounting area 622, and the second sealing surface 21 and the third sealing surface 22 seal the second mounting surface 6221 and the third mounting surface 6222 on the bore wall of the second mounting area 622, respectively. Furthermore, after the seal is installed, the second protrusion 20 and the first protrusion 10 restrict the seal's movement along the longitudinal direction Y. Even if the pressure below the bore structure increases, the seal will not move along the longitudinal direction Y, further enhancing the sealing stability of the seal.

[0076] For example, the aforementioned seal also includes a guide surface 40 extending along a second direction B, which intersects the extension of the third sealing surface 22 at an acute angle (i.e., Figure 2 Angle a is shown in the figure.

[0077] Reference Figure 2 As shown, by providing a tapered guide surface 40 at the bottom of the seal, which is connected to the second sealing surface 21, the tapered guide surface 40 increases the guiding nature of the seal as it is installed into the hole structure, reducing the difficulty of passing the second protrusion 20 through a narrower area in the hole structure.

[0078] It should be noted that in this utility model, the specific included angle α between the second direction B and the extension direction A of the third sealing surface 22 can be 30° or 20°. This embodiment does not make a specific limitation on this, and it can be adapted in actual processing.

[0079] For example, the material of the aforementioned seal can be: an elastomer made of high-rigidity, high-gloss homopolymer polypropylene and metallocene-catalyzed polyolefin in a 50% ratio, or ethylene propylene diene monomer (EPDM) rubber, or silicone rubber or fluororubber.

[0080] In this embodiment of the present invention, the aforementioned sealing assembly includes a sealing member and a top cover 50, wherein the bottom of the top cover 50 includes a groove 51, and the first protrusion 10 of the sealing member is accommodated in the groove 51.

[0081] Reference Figure 4 As shown, the sealing assembly includes the aforementioned seal and a top cover 50 fixed to the first protrusion 10 of the aforementioned seal. In one application, the aforementioned seal is first installed in the hole structure, and then the top cover 50 is placed over the first protrusion 10 and welded to the surface of the part containing the hole structure. Mapped to the use of sealing the electrolyte filling hole of a lithium battery, after inserting the seal into the electrolyte filling hole 62, the top cover 50 is welded to the surface of the cover plate containing the electrolyte filling hole 62. This sealing assembly can further improve the sealing performance of the electrolyte filling hole; even if electrolyte leaks from the electrolyte filling hole 62, the leaked electrolyte will be sealed inside the cover plate by the top cover 50 and will not overflow onto the surface of the cover plate.

[0082] In this sealing assembly, the first sealing surface 11 of the seal contacts the surface of the hole structure to achieve sealing in the longitudinal direction Y of the hole structure, the fourth sealing surface 31 and the second sealing surface 21 seal in the radial direction X of the hole structure, and the third sealing surface 22 seals in the oblique direction C of the hole structure. Compared with existing sealing assemblies, this application effectively improves the sealing performance of the hole structure.

[0083] It should be noted that the top surface of the aforementioned first protrusion 10 and the top surface of the groove 51 include a gap that is spaced along the longitudinal direction Y.

[0084] Using the above technical solution, taking the injection hole 62 on the cell cover as an example, the above technical solution is explained as follows: By controlling the top surface of the first protrusion 10 of the seal to be spaced apart from the top wall of the groove 51 on the top cover 50, when the internal pressure of the cell increases, the seal may partially protrude outward under the action of the internal pressure of the cell. This gap can accommodate the height of the seal protrusion, and avoid the top cover 50 being subjected to an outward lifting force when the seal protrudes outward or the height of the outward protrusion is too high, which may affect the firmness of the welding between the top cover 50 and the cover plate surface.

[0085] It should be noted that the specific parameters for the aforementioned interval setting in this application can be 1mm or 1.2mm, and this application embodiment does not impose specific limitations.

[0086] In this embodiment of the invention, the aforementioned cover plate includes a mounting portion and a sealing assembly that is sealed to the mounting portion. The mounting portion includes mounting grooves 61 and injection holes 62 arranged sequentially along the longitudinal direction Y. The periphery of the top cover 50 in the sealing assembly is welded to the side wall of the mounting groove 61, and the bottom wall of the mounting groove 61 is longitudinally sealed to the first sealing surface 11. The injection hole 62 and the sealing element are located radially X (i.e., Figure 2 The X direction shown), and the longitudinal Y direction (i.e. Figure 2 The sealing connection shown in the Y direction and the oblique C direction (i.e., C direction) improves the sealing performance of the sealant on the liquid injection hole 62 on the cover plate, which can effectively prevent the electrolyte inside the liquid injection hole 62 of the lithium battery from overflowing, thereby improving the safety of the lithium battery.

[0087] Specific reference Figure 5 , Figure 7 as well as Figure 6 As shown, the position on the cover plate for injecting electrolyte into the cell first includes a mounting groove 61 for accommodating the top cover 50 of the sealing assembly. In the middle of the mounting groove 61, there is an injection hole 62 extending in the thickness direction of the cover plate. After the aforementioned sealing member is sealed and connected to the injection hole, the top cover 50 is covered on the top of the sealing member, and the circumferential edge area of ​​the top cover 50 is welded to the side wall of the mounting groove 61.

[0088] For example, the aforementioned injection hole 62 includes a first mounting area 621 and a second mounting area 622. The first mounting area 621 is radially sealed to the fourth sealing surface 31, the second mounting area 622 is radially sealed to the second sealing surface 21, and the second mounting area 622 is obliquely sealed to the third sealing surface 22. This achieves a seal between the sealing element and the injection hole 62 in the longitudinal direction Y, the radial direction X, and the oblique direction C, improving the sealing performance of the sealing element on the injection hole 62 on the cover plate. This can effectively prevent the electrolyte inside the injection hole of the lithium battery from overflowing, thereby improving the safety of the lithium battery.

[0089] Specifically, the first mounting area 621 includes a first mounting surface 6211, which is sealed to the fourth sealing surface 31; the second mounting area 622 includes a second mounting surface 6221 and a third mounting surface 6222, which is sealed to the second sealing surface 21, and the third mounting surface 6222 is sealed to the third sealing surface 22.

[0090] Reference Figure 7As shown, the injection hole 62 includes a first mounting area 621 extending longitudinally along the Y direction and a second mounting area 622 located at the lower end of the first mounting area 621. The mounting range of the second mounting area 622 is larger than that of the first mounting area 621. This mounting range refers to the diameter of the second mounting area 622 and the diameter of the first mounting area 621, forming a receiving space for accommodating the second protrusion 20. Specifically, the first mounting area 621 is radially sealed to the fourth sealing surface 31 of the seal, the second mounting area 622 is radially sealed to the second sealing surface 21, and the second mounting area 622 is obliquely sealed to the third sealing surface 22. The upper surface of the injection hole 62 is longitudinally sealed to the first sealing surface 11, thereby achieving a seal between the seal and the injection hole 62 in the longitudinal Y, radial X, and oblique C directions.

[0091] In this embodiment of the application, in the longitudinal direction Y, under the action of the first protrusion 10 and the second protrusion 20, the seal and the injection hole 62 are press-fitted in the longitudinal direction Y, that is, the total height of the fourth sealing surface 31, the third sealing surface 22 and the second sealing surface 21 is less than the total height of the first mounting surface 6211 and the second mounting surface 6221 of the injection hole 62 (i.e. Figure 4 h1 is less than Figure 7 (h2 in the figure), and simultaneously, the first sealing surface 11 is sealed to the upper surface of the injection hole 62, thereby forming a longitudinal Y-shaped seal. In the radial X direction, the diameter of the fourth sealing surface 31 is larger than the diameter of the first mounting surface 6211 of the injection hole 62, and the diameter of the second sealing surface 21 is larger than the diameter of the second mounting surface 6221 of the injection hole 62, so that the seal and the injection hole 62 are interference-fitted in the radial X direction, thereby achieving a radial X-shaped seal. That is, the seal of this utility model embodiment can seal the injection hole 62 in both the radial X and longitudinal Y directions; at the same time, the third sealing surface 22, which is inclined relative to the longitudinal Y direction, allows the seal and the injection hole 62 to seal in the oblique C direction perpendicular to the third sealing surface 22. This breaks through the barrier of the single sealing structure in the existing system. Moreover, the sealing structures in different directions restrain each other, effectively improving the sealing performance of the seal on the injection hole 62, which can effectively prevent the electrolyte inside the injection hole 62 of the lithium battery from overflowing, thereby improving the safety of the lithium battery.

[0092] It should be noted that the interference fit between the aforementioned injection hole 62 and the seal in the radial direction X is greater than the interference fit in the longitudinal direction Y. First, the interference fit in the radial direction X is the difference between the diameter of the fourth sealing surface 31 and the inner diameter of the first mounting surface 6211 of the injection hole 62; the interference fit in the longitudinal direction Y is that the total height of the fourth sealing surface 31, the third sealing surface 22, and the second sealing surface 21 is less than the difference between the total height of the first mounting surface 6211 and the second mounting surface 6221 of the injection hole 62. This design can prevent the injection hole 62 from excessively compressing the first protrusion 10 and the second protrusion 20, thereby affecting the firmness of the connection between the first protrusion 10, the second protrusion 20, and the connecting part 30.

[0093] According to another specific embodiment of the present invention, a chamfer structure 623 is further provided between the first mounting surface 6211 and the third mounting surface 6222 (i.e., Figure 8 (623).

[0094] Reference Figure 8 As shown, the chamfered structure 623 provided at the transition position between the first mounting surface 6211 and the second mounting surface 6221 on the injection hole 62 not only facilitates the insertion of the seal into the injection hole 62 on the cover plate, but also facilitates the removal of the seal from the injection hole 62. Its main function is to guide, reduce the difficulty of inserting the seal into the injection hole 62, and also reduce the difficulty of removing the seal from the injection hole 62.

[0095] For example, the chamfer dimension of the chamfer structure 623 is C0.2, which facilitates the removal of the seal from the injection hole 62.

[0096] In the application of sealing the liquid injection hole of lithium batteries, taking an injection hole 62 of a certain size as an example, the actual design parameters of the seal in this utility model will be explained.

[0097] On the cover plate, the diameter of the first mounting area 621 of the injection hole 62 is 3.5±0.05mm, corresponding to the diameter of the fourth sealing surface 31 on the seal, which is 3.6±0.05mm, meaning the seal is compressed by 0.1-0.2mm in the radial direction X. On the cover plate, the diameter of the second mounting area 622 of the injection hole 62 is 3.7±0.05mm, corresponding to the diameter of the second protrusion 20 on the seal, which is 3.8±0.05mm, meaning the second protrusion 20 of the seal is compressed by 0.1-0.2mm in the radial direction X. On the cover plate, the depth of the injection hole 62 (i.e., the sum of the heights of the aforementioned first mounting area 621 and second mounting area 622) is 3.6±0.05mm, corresponding to the height between the edge of the first sealing surface 11 and the edge of the second protrusion 20 on the seal, which is 3.5±0.05mm, meaning the seal is compressed by 0.05-0.1mm in the longitudinal direction Y. That is, the compression of the seal in the longitudinal Y direction is set to be less than the compression in the radial X direction, so that the seal can be more easily inserted into the insertion cover plate.

[0098] The above example, taking the sealing of the liquid injection hole on the cover plate of a battery cell as an example, illustrates the structure and sealing fit of the aforementioned sealing element, sealing assembly, and cover plate with specific parameters. Of course, the specific parameters need to be adjusted according to the actual specifications of the battery cell, the cover plate, etc., and this embodiment does not impose specific limitations on them.

[0099] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A sealing element with a hole structure for installation in a hole structure, characterized in that, include: The first protrusion includes a first sealing surface for longitudinal sealing; The second protrusion includes a second sealing surface for radial sealing and a third sealing surface for oblique sealing, the oblique direction being perpendicular to the extending direction of the third sealing surface and intersecting the longitudinal direction at an acute angle. The connecting portion is disposed between the first protrusion and the second protrusion, and includes a fourth sealing surface for radial sealing. The first sealing surface, the fourth sealing surface, the third sealing surface, and the second sealing surface are in contact to form a sealing area.

2. The sealing element with a hole structure as described in claim 1, characterized in that, The first protrusion, the second protrusion, and the connecting part are cylindrical or prismatic structures.

3. The sealing element with the hole structure as described in claim 2, characterized in that, The first sealing surface includes a horizontal surface and an inclined surface. The inclined surface is in contact with the fourth sealing surface. The inclined surface intersects the first sealing surface at an obtuse angle. The inclined surface intersects the fourth sealing surface at an obtuse angle.

4. The sealing element with the hole structure as described in claim 2, characterized in that, It also includes a guide surface extending along a second direction, the guide surface being connected to the second sealing surface, the second direction intersecting the extension direction of the third sealing surface at an acute angle.

5. A sealing assembly, characterized in that, include: A sealing element with a hole structure as described in any one of claims 1 to 4; The top cover has a groove at its bottom, and the first protrusion is received within the groove.

6. The sealing assembly as claimed in claim 5, characterized in that, The top surface of the first protrusion and the top surface of the groove are spaced apart along the longitudinal direction.

7. A cover plate, characterized in that, include: The sealing assembly as described in claim 5 or 6; The mounting part includes mounting grooves and injection holes distributed sequentially along the longitudinal direction. The periphery of the top cover is welded to the side wall of the mounting groove, and the bottom wall of the mounting groove is longitudinally sealed to the first sealing surface. The injection hole includes a first mounting area and a second mounting area. The first mounting area is radially sealed to the fourth sealing surface, the second mounting area is radially sealed to the second sealing surface, and the second mounting area is obliquely sealed to the third sealing surface.

8. The cover plate as described in claim 7, characterized in that, The first mounting area includes a first mounting surface, which is sealed to the fourth sealing surface; the second mounting area includes a second mounting surface and a third mounting surface, which are sealed to the second sealing surface and the third mounting surface is sealed to the third sealing surface.

9. The cover plate as described in claim 8, characterized in that, The cover plate also includes a chamfered structure disposed between the first mounting surface and the third mounting surface.

10. A battery cell, characterized in that, include: The cover plate as described in any one of claims 7 to 9 further includes a positive electrode post or a negative electrode post.

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