Cover plate assembly and cylindrical lithium battery

Abstract

The present application proposes a cover plate assembly and a cylindrical lithium battery. The cover plate assembly includes a cover plate, an upper plastic part, and a pole. By constructing a first protrusion and a first recess on the cover plate, and constructing a second protrusion, a second recess, a third protrusion, and a third recess on the upper plastic part, and by constructing a fourth protrusion and a fourth recess on the pole, after the three are assembled, the first protrusion is nested with the first recess, the second protrusion is nested with the second recess, the third protrusion is nested with the third recess, and the fourth protrusion is nested with the fourth recess, and they are combined together to form an anti-twisting structure. When the lithium battery including the above-mentioned cover plate assembly is used for a long time or used under harsh working conditions, due to the strong torsional strength between the cover plate, the upper plastic part and the pole, the upper plastic part and the pole are not easy to twist, thereby improving the reliability and safety of the lithium battery.

Description

Technical Field

[0001] The present application relates to the technical field of lithium-ion batteries, and in particular to a cover plate assembly and a cylindrical lithium battery. Background Art

[0002] In the related art, a pole riveting structure can be constructed on the top cover as the positive electrode of a cylindrical lithium battery. The pole riveting structure generally includes a pole made of a metal material and an upper plastic part made of a plastic material, wherein the pole is sealed and fixed by the riveting force between the flange of the pole and the upper plastic part. However, since the hardness and strength of the upper plastic part are much smaller than those of the pole, the pole frequently shakes during long-term use, resulting in riveting failure, and the pole twists relative to the upper plastic part, causing the lithium battery to fail. Furthermore, the shaking of the pole can also cause the upper plastic part to deform, which in turn causes the upper plastic part to loosen and twist. If the pole twists along with the upper plastic part, the lithium battery will fail. In particular, for lithium batteries used in harsh working conditions such as power tools, this problem is particularly prominent because the lithium battery will be under long-term vibration conditions. Summary of the Invention

[0003] The embodiments of the present application provide a cover plate assembly and a cylindrical lithium battery to at least solve the technical problem that the pole and the upper plastic part in the existing cover plate assembly are prone to twisting during long-term use and under harsh working conditions.

[0004] A first embodiment of the present application provides a cover plate assembly, comprising:

[0005] A cover plate, wherein the cover plate is provided with a first mounting hole extending therethrough, wherein a hole wall of the first mounting hole is circumferentially configured with alternating first convex portions and first concave portions;

[0006] An upper plastic part, comprising a flange extending through the first mounting hole, the upper plastic part being provided with a second mounting hole extending through the flange, the outer wall of the flange being circumferentially configured with alternating second protrusions and second recesses, and the hole wall of the second mounting hole being circumferentially configured with alternating third protrusions and third recesses;

[0007] The pole comprises a connecting portion passing through the second mounting hole, wherein the outer wall of the connecting portion is circumferentially configured with alternating fourth protrusions and fourth recesses;

[0008] The first protrusions are nested in the second recesses in a one-to-one correspondence, and the second protrusions are nested in the first recesses in a one-to-one correspondence, so as to limit the rotation of the upper plastic part relative to the cover plate. The third protrusions are nested in the fourth recesses in a one-to-one correspondence, and the fourth protrusions are nested in the third recesses in a one-to-one correspondence, so as to limit the rotation of the pole relative to the upper plastic part.

[0009] The cover plate assembly according to the embodiment of the present application has at least the following beneficial effects:

[0010] In the cover plate assembly of the embodiment of the present application, the first protrusion and the first recess constructed on the cover plate and the second protrusion and the second recess constructed on the upper plastic part together constitute an anti-twist structure. Due to the limiting effect of the anti-twist structure, relative rotation is not easy to occur between the upper plastic part and the cover plate. At the same time, the third protrusion and the third recess constructed on the upper plastic part and the fourth protrusion and the fourth recess constructed on the pole together constitute an anti-twist structure. Due to the limiting effect of the anti-twist structure, relative rotation is not easy to occur between the pole and the upper plastic part. Therefore, when the lithium battery including the above-mentioned cover plate assembly is used for a long time or used under harsh working conditions, the torsional strength between the cover plate, the upper plastic part and the pole is strong, and the upper plastic part and the pole are not easy to twist, thereby improving the reliability and safety of the lithium battery.

[0011] In one possible embodiment, the first mounting hole has a ridge circumferentially formed at the top of the hole wall, and the outer wall of the flange has a circumferentially formed positioning groove that cooperates with the ridge. The ridge is enclosed in the positioning groove to restrict axial movement of the upper plastic component along the first mounting hole. By providing the positioning groove and the ridge enclosing therein, axial movement of the upper plastic component along the first mounting hole can be restricted, thereby preventing the upper plastic component from moving axially along the first mounting hole.

[0012] In one possible embodiment, the ridge is elastically deformed and squeezed into the positioning groove by the downward pressure applied to the flange and the ridge. The downward pressure is provided by riveting the terminal. This assembly method is quick and convenient, greatly improving the efficiency of the connection between the ridge and the positioning groove. Furthermore, by utilizing the riveting process on the terminal to provide downward pressure, the cover plate and the upper plastic component are directly connected by riveting, eliminating the need for additional tools and steps. This is very convenient.

[0013] In one possible embodiment, the ridges are only located at the first recesses, and the positioning grooves are only located at the second protrusions. By properly positioning the ridges and positioning grooves, the manufacturing difficulty and cost of the upper plastic part and cover can be reduced, as well as the impact on the strength of the upper plastic part.

[0014] In one possible embodiment, the thickness of the cover plate is H, and the height of the ridge is H1, satisfying the following: H1 / H = 20% to 50%. By properly designing the ridge height, the upper plastic part can be effectively locked axially while also improving the assembly processability and connection stability of the cover plate and the upper plastic part.

[0015] In one possible embodiment, the rib is disposed at the top of the wall of the first mounting hole, and the top surface of the rib smoothly transitions to the top surface of the cover plate. By disposing the rib at the top of the wall of the first mounting hole and ensuring a smooth transition between the top surface of the rib and the top surface of the cover plate, the rib can be used to initially position the flange without additional assembly steps, thereby facilitating downward pressure in the subsequent riveting process to engage the rib in the positioning groove, which is very convenient.

[0016] In one possible embodiment, the top surface of the rib is radially inclined toward the interior of the first mounting hole. By radially inclining the top surface of the rib toward the interior of the first mounting hole, the flange can be guided, thereby smoothly compressing and deforming toward the center of the first mounting hole, thereby improving assembly efficiency and quality.

[0017] In a possible embodiment, the top surface of the ridge has an inclination angle α, which satisfies 20°≤α≤50°. By properly designing the inclination angle of the top surface of the ridge, the assembly efficiency is improved while the limiting effect is ensured.

[0018] In one possible embodiment, the second protrusion, the second recess, the third protrusion, and the third recess are formed by the flange wall extending in alternating zigzags along the radial and circumferential directions of the second mounting hole. By arranging the flange wall to extend in alternating zigzags along the circumferential and radial directions to form the second protrusion, the second recess, the third protrusion, and the third recess, the upper plastic component has a compact and simple structure, is easy to process, and has advantages such as being lightweight and easy to assemble.

[0019] A second embodiment of the present application provides a cylindrical lithium battery, comprising a cover plate assembly according to the first embodiment.

[0020] The cylindrical lithium battery according to the embodiment of the present application has at least the following beneficial effects:

[0021] The cylindrical lithium battery of the embodiment of the present application is not easily twisted when used for a long time or under harsh working conditions because the torsional strength between the cover plate, the upper plastic part and the terminal is strong, so the cylindrical lithium battery has the characteristics of high reliability and safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0023] Figure 1 is a cross-sectional schematic diagram of a cover plate assembly provided in an embodiment of the present application;

[0024] Figure 2 yes Figure 1 An exploded diagram of the cover plate assembly, the upper plastic part and the pole;

[0025] Figure 3 yes Figure 1 A cross-sectional schematic diagram of a cover plate in a cover plate assembly;

[0026] Figure 4 yes Figure 3 A partial schematic diagram of the middle part;

[0027] Figure 5 yes Figure 1 A schematic structural diagram of the top of the upper plastic part in the cover assembly;

[0028] Figure 6 yes Figure 1 A schematic structural diagram of the bottom of the upper plastic part in the cover assembly;

[0029] Figure 7 yes Figure 1 A schematic diagram of the structure of the pole in the cover assembly;

[0030] Figures 8a to 8d 1 is a schematic diagram of the process of the method for axially positioning the upper plastic component 20 in the cover assembly of the embodiment of the present application.

[0031] Reference numerals:

[0032] 10-cover plate, 11-first mounting hole, 111-first convex portion, 112-first concave portion, 113-convex ridge;

[0033] 20 - upper plastic part, 21 - flange, 211 - second protrusion, 212 - second recess, 213 - positioning groove, 21a - first wall, 21b - second wall, 21c - third wall, 22 - second mounting hole, 221 - third protrusion, 222 - third recess, 23 - body;

[0034] 30-pole, 31-connecting portion, 311-fourth protrusion, 312-fourth recess, 313-gap, 32-end portion, 321-flanged edge, 33-support portion;

[0035] 40-housing;

[0036] 50- lower plastic parts;

[0037] 60-Sealing ring. DETAILED DESCRIPTION

[0038] Examples of the present embodiment are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present embodiment and are not to be construed as limiting the present embodiment.

[0039] In the description of this embodiment, it should be understood that descriptions involving orientation, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on this embodiment.

[0040] In the description of this embodiment, "several" means one or more, "many" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and is not to be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0041] In the description of this embodiment, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this embodiment based on the specific content of the technical solution.

[0042] The following combination Figures 1 to 7 The cover plate assembly according to the embodiment of the present application is described in detail.

[0043] like Figure 1 and Figure 2As shown, the cover assembly includes a cover 10, an upper plastic part 20 and a pole 30. The cover assembly can be used for various types of lithium batteries, such as cylindrical lithium batteries, to form the positive or negative electrode of the lithium battery. The cover assembly of the embodiment of the present application is constructed by constructing a first protrusion 111 and a first recess 112 on the cover 10, constructing a second protrusion 211, a second recess 212, a third protrusion 221, and a third recess 222 on the upper plastic part 20, and constructing a fourth protrusion 311 and a fourth recess 312 on the pole 30. After the three are assembled, the first protrusion 111 is nested with the first recess 112, the second protrusion 211 is nested with the second recess 212, the third protrusion 221 is nested with the fourth recess 312, and the fourth protrusion 311 is nested with the third recess 222. The two recesses 212 are combined to form an anti-twist structure, thereby effectively preventing the upper plastic part 20 from rotating relative to the cover plate 10. The third protrusion 221, the third recess 222, the fourth protrusion 311 and the fourth recess 312 are combined to form another anti-twist structure, thereby effectively preventing the pole 30 from rotating relative to the upper plastic part 20. Therefore, when the lithium battery including the above-mentioned cover plate assembly is used for a long time or used under harsh working conditions, due to the strong torsional strength between the cover plate 10, the upper plastic part 20 and the pole 30, neither the upper plastic part 20 nor the pole 30 is easily twisted, thereby improving the reliability and safety of the lithium battery.

[0044] It is understood that the cover plate assembly includes a cover plate 10, which is made of metal. It is understood that the cover plate 10 is the installation base for components such as the upper plastic part 20 and the terminal 30. Moreover, when the cover plate assembly is assembled into a lithium battery, the cover plate 10 is connected to the housing 40 of the lithium battery. Figure 1 and Figure 2 As shown, taking the application of the cover plate assembly to a cylindrical lithium battery as an example, the cylindrical lithium battery includes a cylindrical shell 40, and the cover plate 10 is located on the top of the shell 40 as the top cover of the cylindrical lithium battery, and the cover plate 10 and the shell 40 are integrally formed. In this way, the process of separately welding the cover plate 10 on the shell 40 can be omitted, which can save processes and costs. Of course, it is not limited to this. The cover plate 10 can also be an independent component such as a metal sheet, which is subsequently connected to the shell 40 through a welding process. Furthermore, the cover plate 10 is the top cover of the cylindrical lithium battery, so the cover plate 10 is circular as a whole, but it is not limited to this. For example, the shape of the cover plate 10 can also be rectangular for use in square lithium batteries.

[0045] like Figure 1 and Figure 3As shown, it can be understood that the cover plate 10 has a top surface and a bottom surface relative to each other. For a lithium battery, the top surface of the cover plate 10 is located outside the lithium battery, and the bottom surface of the cover plate 10 is located inside the lithium battery. The cover plate 10 is provided with a first circular mounting hole 11 that penetrates the cover plate 10 in the thickness direction (the vertical direction in the figure), so that the first mounting hole 11 connects the top and bottom surfaces of the cover plate 10. The first mounting hole 11 is used for the upper plastic part 20 to pass through it, thereby achieving insulation isolation of the terminal 30 passing through the upper plastic part 20.

[0046] like Figure 2 and Figure 3 As shown, the hole wall of the cover plate 10 is constructed with alternating first protrusions 111 and first recesses 112 along the circumferential direction. It can be understood that the alternation of first protrusions 111 and first recesses 112 described here means that a first recess 112 is provided between two first protrusions 111, and correspondingly, a first protrusion 111 is provided between two first recesses 112. In this way, alternating first protrusions 111 and first recesses 112 are formed in the circumferential direction of the hole wall of the first mounting hole 11. Therefore, in the anti-torsion structure, the first protrusion 111, the first recess 112, the second recess 212, and the second protrusion 211 are evenly distributed along the 360° circumferential range, the force is relatively balanced, and the anti-torsion structure is safe and reliable.

[0047] Specifically, the first protrusion 111 is formed by the hole wall of the first mounting hole 11 protruding toward the center of the first mounting hole 11, and a first recess 112 is defined between two adjacent first protrusions 111. In this case, the surfaces of all the first protrusions 111 and all the first recesses 112 together constitute the hole wall of the first mounting hole 11. That is, the first protrusions 111 and the first recesses 112 also penetrate the cover plate 10 as a whole and are connected to the top and bottom surfaces of the cover plate 10. Of course, this is not limited to this, and the first protrusions 111 and the first recesses 112 can also be formed in any suitable manner.

[0048] It can be understood that, therefore, when the upper plastic part 20 is operated to perform assembly movement from top to bottom in a direction close to the top surface of the cover plate 10, each first protrusion 111 can be embedded in each second recess 212 on the upper plastic part 20, and each second protrusion 211 can be embedded in each first recess 112. That is, the nesting movement of the first protrusion 111 and the second recess 212, and the nesting movement of the second protrusion 211 and the first recess 112, are achieved synchronously with the assembly movement of the upper plastic part 20 from top to bottom in a direction close to the top surface of the cover plate 10. Therefore, after the upper plastic part 20 and the cover plate 10 are assembled, each first protrusion 111 is nested in each second recess 212 in a one-to-one correspondence, and each second protrusion 211 is nested in each first recess 112 in a one-to-one correspondence. The first protrusions 111, the first recess 112, the second protrusions 211, and the second recess 212 together form an anti-twist structure to limit the upper plastic part 20 from rotating relative to the cover plate 10.

[0049] like Figure 2 As shown, it can be understood that the shape, size, and number of the first protrusion 111 and the second recess 212 match, and the shape, size, and number of the first recess 112 match those of the second protrusion 211. Taking the shapes of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 as an example for explanation, for example, the projections of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 on the bottom surface of the cover plate 10 are all fan-shaped; taking the number of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 as an example for explanation, for example, the number of the first protrusion 111 and the first recess 112 are both four, and accordingly, the number of the second protrusion 211 and the second recess 212 on the upper plastic part 20 that matches them is also four.

[0050] It is understandable that during the long-term use of the lithium battery or when used under harsh working conditions, as the riveting force of the pole 30 weakens, the upper plastic part 20 may not only be twisted relative to the cover plate 10, but may also be displaced up and down relative to the cover plate 10. Therefore, in some embodiments, the hole wall of the first mounting hole 11 is circumferentially configured with a ridge 113, and the outer wall of the flange 21 is circumferentially configured with a positioning groove 213 that cooperates with the ridge 113. The ridge 113 is enclosed in the positioning groove 213 to limit the axial movement of the upper plastic part 20 along the first mounting hole 11.

[0051] In some embodiments, as Figure 3 and Figure 4 As shown, combined with Figure 2The rib 113 is formed by a protrusion from the wall of the first mounting hole 11, extending toward the center of the first mounting hole 11. The positioning groove 213 is formed by a recessed portion of the outer wall of the flange 21, extending toward the center of the second mounting hole 22. This allows for a snap-fit ​​connection between the cover 10 and the upper plastic component 20, creating an axial constraint between them to prevent displacement of the upper plastic component 20 along the axial direction of the first mounting hole 11. For example, the rib 113 can be elastically deformed by the downward pressure of the flange 21 and the compression of the rib 113, forcing it into the positioning groove 213. Among them, the rib 113 formed on the cover plate 10 plays a limiting function, and the flange 21 formed on the upper plastic part 20 plays a locking function. The flange 21 deforms during the assembly process. When the rib 113 is inserted into the positioning groove 213, the flange 21 returns to its original position, thereby locking with the cover plate 10 and providing retention force. This assembly method is quick and convenient, and can greatly improve the efficiency of the connection between the rib 113 and the positioning groove 213.

[0052] Specifically, the upper plastic component 20 is assembled from the top side of the cover plate 10, and during this process, its flange 21 is inserted into the first mounting hole 11. Therefore, when the upper plastic component 20 is assembled from the top to the bottom, toward the top of the cover plate 10, after the flange 21 contacts the rib 113, continued downward pressure is applied to the upper plastic component 20, causing the flange 21 to deform and continue to move downward. When the flange 21 deforms to a certain extent, the rib 113 snaps into the positioning groove 213. At this point, since the flange 21 is no longer squeezed by the rib 113, it returns to its original position, and its outer wall is in good contact with the wall of the first mounting hole 11.

[0053] It is understandable that after the pole 30 is inserted into the second mounting hole 22, a riveting process is finally performed to connect the cover plate 10, the upper plastic part 20 and other components through the pole 30. In some embodiments, the purpose of snapping the ridge 113 into the positioning groove 213 is achieved by applying downward pressure when riveting the pole 30. That is, the flange 21 is now positioned at the top of the ridge 113, and after the pole 30 is inserted into the second mounting hole 22, the pole 30 is riveted, so that the upper plastic part 20 is subjected to the downward pressure applied by the pole 30, causing the ridge 113 to snap into the positioning groove 213, thereby simultaneously achieving a snap connection with the cover plate 10. In this way, the snap connection between the cover plate 10 and the upper plastic part 20 is directly achieved by the riveting process without adding additional tools and processes, which is very convenient.

[0054] It should be noted that the surfaces of the aforementioned first protrusion 111 and the first recess 112 together constitute the hole wall of the first mounting hole 11. Therefore, in this embodiment, the rib 113 is provided on the hole wall of the first mounting hole 11, which also means that the rib 113 is provided on the surface of the first protrusion 111 and the first recess 112. It is understandable that the positions of the rib 113 and the positioning groove 213 are provided corresponding to each other, and the rib 113 and the positioning groove 213 can be provided in sections or completely within a 360° circumference, which is not limited here. For the purpose of facilitating processing and not affecting the structural strength of the flange 21, as shown in FIG. Figure 2 and Figure 3 As shown, in some embodiments, the ridges 113 are formed only at each first recess 112, and the positioning grooves 213 are formed only at each second protrusion 211. This prevents the ridges 113 from encroaching upon the center area of ​​the first mounting hole 11, thereby reducing manufacturing difficulty and cost. Similarly, when the positioning grooves 213 are formed only at each second protrusion 211, the structural strength of the flange 21 is not weakened, and the structure is simple, making it easier to manufacture.

[0055] like Figures 2 to 4 As shown, the rib 113 is positioned at the top of the wall of the first mounting hole 11, and the top surface of the rib 113 smoothly transitions to the top surface of the cover plate 10. Accordingly, the positioning groove 213 is also positioned at a corresponding height on the flange 21. This allows for initial positioning of the flange 21 via the rib 113 without requiring additional assembly steps, allowing for the subsequent riveting process to provide downward pressure and snap the rib 113 into the positioning groove 213, a very convenient process. Of course, this is not limiting; the heights of the rib 113 and positioning groove 213 can be flexibly adjusted, such as being positioned in the middle of the first mounting hole 11.

[0056] Further, if Figure 4 As shown, in some embodiments, the thickness of the cover plate 10 is H, and the height of the rib 113 is H1, satisfying: H1 / H = 20% to 50%. It is understandable that if the height of the rib 113 is too small, it will be difficult to machine a guiding slope on the top of the rib 113, which is not conducive to the flange 21 being snapped into the first mounting hole 11, and the rib 113 itself is also easily damaged and fails; conversely, if the height of the rib 113 is too large, the effective fitting height between the hole wall of the first mounting hole 11 and the outer wall of the flange 21 is too small, resulting in an unstable connection between the two. When the riveting force of the pole 30 is weakened, the upper plastic part 20 is prone to shifting up and down and shaking. Therefore, by rationally designing the height of the rib 113, it can effectively achieve the purpose of axial locking with the upper plastic part 20, and also improve the assembly processability and connection stability of the two.

[0057] Furthermore, in some embodiments, the top surface of the rib 113 is configured to be inclined radially toward the interior of the first mounting hole 11. By configuring the top surface of the rib 113 to be inclined radially toward the interior of the first mounting hole 11, it can serve as a guide for the flange 21, so that when downward pressure is applied to the flange 21, it is smoothly compressed and deformed toward the center of the first mounting hole 11, thereby improving assembly efficiency and quality.

[0058] Furthermore, in some embodiments, the top surface of the rib 113 has an inclination angle α, satisfying 20°≤α≤50°. It is understood that if the inclination angle of the top surface of the rib 113 is too small, the guiding effect on the assembly of the flange 21 will be insignificant, increasing the difficulty of the rib 113 being inserted into the positioning groove 213 and even damaging the rib 113 or the flange 21. Conversely, if the inclination angle of the top surface of the rib 113 is too large, it will be difficult to ensure the locking effect of the rib 113 in the positioning groove 213, and the upper plastic part 20 will not be effectively limited in the axial direction. Therefore, by rationally designing the inclination angle of the top surface of the rib 113, on the one hand, assembly efficiency is improved, and on the other hand, the limiting effect is ensured.

[0059] It will be appreciated that the cover plate assembly includes an upper plastic member 20, which serves to insulate the terminal 30 from the cover plate 10. In this embodiment, the upper plastic member 20 is made of plastic and is an independent component, such as one formed by injection molding. It is connected to the cover plate 10 through a certain assembly motion and is pressed against the top surface of the cover plate 10 by the riveting force generated by the terminal 30. Ultimately, the upper plastic member 20, the cover plate 10, the terminal 30, and other components form a cover plate assembly.

[0060] like Figure 5 and Figure 6 As shown, in some embodiments, the upper plastic part 20 includes a flange 21 and a body 23 located on the top of the flange 21. The flange 21 is cylindrical. The upper plastic part 20 is provided with a second mounting hole 22 that passes through the body 23 and the flange 21. That is, the second mounting hole 22 passes through the upper plastic part 20 along the thickness direction (the up and down direction in the figure), so that the second mounting hole 22 connects the top surface of the body 23 and the bottom surface of the flange 21. The second mounting hole 22 is used for the pole 30 to pass through it, so as to achieve insulation isolation between the cover plate 10 and the pole 30.

[0061] Specifically, the outer dimensions of the body 23 are larger than the diameter of the first mounting hole 11, while the outer dimensions of the flange 21 match the inner diameter of the first mounting hole 11. Therefore, during operation, when the plastic component 20 is assembled from top to bottom toward the top surface of the cover plate 10, the flange 21 can penetrate into the first mounting hole 11, and its outer surface can be well aligned with the inner wall surface of the first mounting hole 11. The body 23 can be restrained by the top surface of the cover plate 10, thereby preventing the entire upper plastic component 20 from falling into and passing through the first mounting hole 11. It will be understood that in the assembled cover plate assembly, the body 23 is pressed against the top surface of the cover plate 10 by the riveting force of the terminal 30.

[0062] like Figure 5 and Figure 6 As shown, the outer wall of the flange 21 is circumferentially configured with alternating second protrusions 211 and second recesses 212, and the hole wall of the second mounting hole 22 is circumferentially configured with alternating third protrusions 221 and third recesses 222. It will be understood that the alternation of second protrusions 211 and second recesses 212 described herein means that a second recess 212 is provided between two second protrusions 211, and correspondingly, a second protrusion 211 is provided between two second recesses 212, and the same applies to the third protrusions 221 and third recesses 222. In this way, in the anti-torsion structure formed by the nesting of the second convex portion 211, the second concave portion 212, the first concave portion 112, and the first convex portion 111, the second convex portion 211, the second concave portion 212, the first concave portion 112, and the first convex portion 111 are evenly distributed along the circumferential range of 360°, the force is relatively balanced, and the anti-torsion structure is safe and reliable. At the same time, in the anti-torsion structure formed by the nesting of the third convex portion 221, the third concave portion 222, the fourth convex portion 311, and the fourth concave portion 312, the third convex portion 221, the third concave portion 222, the fourth convex portion 311, and the fourth concave portion 312 are evenly distributed along the circumferential range of 360°, the force is relatively balanced, and the anti-torsion structure is safe and reliable.

[0063] In some embodiments, the second protrusion 211, the second recess 212, the third protrusion 221, and the third recess 222 are formed by the wall of the flange 21, which alternately zigzags along the radial and circumferential directions of the second mounting hole 22. Specifically, the wall of the flange 21 includes a first wall portion 21a located on the outer circumference and extending along the circumference, a second wall portion 21b located on the inner circumference and extending along the circumference, and a third wall portion 21c extending along the radial direction. The third wall portion 21c connects the first wall portion 21a and the second wall portion 21b. The first wall portion 21a and the outer walls of the third wall portions 21c on either side together form the second protrusion 211, the second wall portion 21b and the outer walls of the third wall portions 21c on either side together form the second recess 212, the first wall portion 21a and the inner walls of the third wall portions 21c on either side together form the third recess 222, and the second wall portion 21b and the inner walls of the third wall portions 21c on either side together form the third protrusion 221. In this case, the surfaces of all the second protrusions 211 and all the second recesses 212 together constitute the outer wall surface of the flange 21, and the surfaces of all the third protrusions 221 and all the third recesses 222 together constitute the inner surface of the flange 21, that is, the hole wall of the second mounting hole 22.

[0064] It will be appreciated that the second protrusion 211, the second recess 212, the third protrusion 221, and the third recess 222 are formed by the wall portion of the flange 21, which alternately zigzags along the radial and circumferential directions of the second mounting hole 22. This creates a compact and simple structure. These structures can be directly molded from the upper plastic component 20 through integral injection molding, which is very convenient and offers advantages such as light weight and ease of assembly. Of course, this is not limiting, and the second protrusion 211, the second recess 212, the third protrusion 221, and the third recess 222 may have any other suitable configuration.

[0065] It can be understood that when the upper plastic part 20 is operated to perform assembly movement from top to bottom in a direction close to the top surface of the cover plate 10, each second protrusion 211 can be embedded in each first recess 112 of the cover plate 10, and at the same time, each first protrusion 111 of the cover plate 10 can be embedded in each second recess 212, that is, the nesting movement of the first protrusion 111 and the second recess 212, and the nesting movement of the second protrusion 211 and the first recess 112, are achieved synchronously with the assembly movement of the upper plastic part 20 from top to bottom in a direction close to the top surface of the cover plate 10. Therefore, when the assembly is completed, each first protrusion 111 is nested in each second recess 212 in a one-to-one correspondence, and each second protrusion 211 is nested in each first recess 112 in a one-to-one correspondence. The first protrusions 111, the first recess 112, the second protrusions 211, and the second recess 212 together form an anti-twist structure to limit the upper plastic component 20 from rotating relative to the cover 10.

[0066] It can also be understood that when the operating pole 30 is assembled in a direction from bottom to top toward the bottom surface of the flange 21, the third protrusion 221 can be embedded in each fourth recess 312 on the pole 30, and each fourth protrusion 311 on the pole 30 can be embedded in each third recess 222. That is, the nesting movement of the third protrusion 221 and the fourth recess 312, and the nesting movement of the fourth protrusion 311 and the third recess 222, are achieved synchronously with the assembly movement of the operating pole 30 in a direction from bottom to top toward the bottom surface of the flange 21. Therefore, when assembly is complete, each third protrusion 221 is nested in each fourth recess 312 in a one-to-one correspondence, and each fourth protrusion 311 is nested in each third recess 222 in a one-to-one correspondence. The third protrusions 221, the third recess 222, the fourth protrusions 311, and the fourth recess 312 together form an anti-twist structure to restrict the pole 30 from rotating relative to the upper plastic component 20.

[0067] like Figure 5 and Figure 6 As shown, it can be understood that the second protrusion 211 matches the shape, size, and number of the first recess 112, and the second recess 212 matches the shape, size, and number of the first protrusion 111. Taking the shapes of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 as an example for explanation, for example, the projections of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 on the bottom surface of the cover 10 are all fan-shaped; taking the number of the first protrusion 111, the first recess 112, the second protrusion 211, and the second recess 212 as an example for explanation, for example, the number of the first protrusion 111 and the first recess 112 are both four, and accordingly, the number of the second protrusion 211 and the second recess 212 on the upper plastic part 20 that matches them is also four. The third convex portion 221 , the third concave portion 222 , the fourth convex portion 311 and the fourth concave portion 312 are similar and are not described herein in detail.

[0068] In some embodiments, a rib 113 is circumferentially formed on the wall of the first mounting hole 11, and a positioning groove 213 is circumferentially formed on the outer wall of the flange 21 to cooperate with the rib 113. The rib 113 is enclosed in the positioning groove 213 to restrict the axial movement of the upper plastic part 20 along the first mounting hole 11. The positioning groove 213 is formed by the second protrusion 211 of the flange 21 being recessed inwardly toward the center of the second mounting hole 22. Specifically, the positioning groove 213 is formed at the top of the second protrusion 211, i.e., the top of the first wall 21a. Positioning the positioning groove 213 in this position facilitates processing and assembly, and facilitates a snap-fit ​​connection between the positioning groove 213 and the rib 113.

[0069] As will be understood, the cover plate assembly includes a terminal post 30. When assembled into a lithium battery, the terminal post 30 electrically connects to the internal wound electrode group of the lithium battery, serving as an electrical contact for connecting external electrical devices to the lithium battery. As will be understood, the terminal post 30 is made of a metal, such as aluminum, which has good electrical conductivity and facilitates the riveting of the upper plastic component 20 to the top surface of the cover plate 10.

[0070] like Figure 7 As shown, the terminal 30 includes a central connecting portion 31, a terminal portion 32 at the top of the connecting portion 31, and a support portion 33 at the bottom of the connecting portion 31. The connecting portion 31 is inserted into the second mounting hole 22, the support portion 33 is located at the bottom of the cover 10, and the terminal portion 32 is exposed at the top of the body 23 of the upper plastic component 20 for electrical connection to external devices. Furthermore, the terminal portion 32 includes a flange 321 at the periphery. This flange 321 is deformed by riveting the terminal 30, thereby pressing the body 23 against the top surface of the cover 10.

[0071] The outer wall of the connecting portion 31 is circumferentially configured with alternating fourth protrusions 311 and fourth recesses 312. It should be understood that the alternating fourth protrusions 311 and fourth recesses 312 described herein refer to a fourth recess 312 being provided between two fourth protrusions 311, and correspondingly, a fourth protrusion 311 being provided between two fourth recesses 312. Thus, the anti-torsion structure formed by the nested fourth protrusions 311, fourth recesses 312, and the aforementioned third recesses 222 and third protrusions 221 is evenly distributed along the circumferential direction, resulting in a relatively balanced force distribution and a safe and reliable anti-torsion structure.

[0072] Specifically, the fourth protrusion 311 is formed by the outer wall of the connecting portion 31 protruding in a direction away from the center of the second mounting hole 22, and a fourth recess 312 is defined between two adjacent fourth protrusions 311. Of course, the present invention is not limited to this, and the fourth protrusion 311 and the fourth recess 312 can also be formed in any suitable manner.

[0073] When the operating pole 30 is assembled from bottom to top, toward the bottom surface of the flange 21, each fourth protrusion 311 can be embedded in each third recess 222, and each third protrusion 221 can also be embedded in each fourth recess 312. That is, the nesting movement of the fourth protrusion 311 and the third recess 222, and the nesting movement of the third protrusion 221 and the fourth recess 312 are achieved simultaneously as the operating pole 30 is assembled from bottom to top, toward the bottom surface of the flange 21. Therefore, when assembly is completed, each third protrusion 221 is nested in each fourth recess 312, and each fourth protrusion 311 is nested in each third recess 222. The third protrusions 221, the third recess 222, the fourth protrusion 311, and the fourth recess 312 together form an anti-twist structure to prevent the pole 30 from rotating relative to the upper plastic component 20.

[0074] like Figure 7 As shown, combined with Figure 2 It can be understood that the shape, size, and number of the fourth protrusion 311 match those of the third recess 222, and the shape, size, and number of the fourth recess 312 match those of the third protrusion 221. Taking the shapes of the fourth protrusion 311, the fourth recess 312, the third protrusion 221, and the third recess 222 as an example, for example, the projections of the fourth protrusion 311, the fourth recess 312, the third protrusion 221, and the third recess 222 on the bottom surface of the cover plate 10 are all fan-shaped. Furthermore, taking the number of the fourth protrusion 311, the fourth recess 312, the third protrusion 221, and the third recess 222 as an example, for example, the number of the fourth protrusion 311 and the fourth recess 312 are both four. Accordingly, the number of the third recess 222 and the number of the third protrusion 221 on the upper plastic part 20 that match them is also four.

[0075] Furthermore, in some embodiments, a gap 313 is provided between the bottom surface of the fourth protrusion 311 and the top surface of the support portion 33. This gap 313 is used to accommodate the sealing ring 60 described below. It is understood that the height of the gap 313 can be set to be the same as the thickness of the sealing ring 60, so that the bottom surface of the fourth protrusion 311 is coplanar with the bottom surface of the cover plate 10, thereby improving the sealing effect.

[0076] Of course, if Figure 1 As shown, the cover assembly includes, in addition to the cover 10 , upper plastic part 20 and pole 30 mentioned above, a lower plastic part 50 and a sealing ring 60 located on one side of the bottom surface of the cover 10 .

[0077] The present application will be further described below with reference to examples and comparative examples. The following examples and comparative examples of the present application are designed with reference to conventional 4680 cylindrical lithium batteries.

[0078] Example 1:

[0079] Embodiment 1 provides a cover plate assembly, comprising a cover plate 10, an upper plastic part 20, and a pole 30. The cover plate 10 is provided with a first mounting hole 11 having a circular outline and extending therethrough. The hole wall of the first mounting hole 11 is provided with four spaced first protrusions 111 protruding toward the center of the first mounting hole 11. A first recess 112 is defined between two adjacent first protrusions 111. In addition, a ridge 113 is laterally provided on the top of each first recess 112. The top surface of the ridge 113 is inclined radially toward the interior of the first mounting hole 11. The upper plastic component 20 includes a main body 23 located at the top of the cover plate 10 and a cylindrical flange 21 extending through the first mounting hole 11. The upper plastic component 20 is provided with a second mounting hole 22 extending through the flange 21. The wall portion of the flange 21 includes a first wall portion 21a located on the outer ring and extending along the circumferential direction, a second wall portion 21b located on the inner ring and extending along the circumferential direction, and a third wall portion 21c extending along the radial direction. The third wall portion 21c connects the first wall portion 21a and the second wall portion 21b. Among them, the first wall portion 21a and the outer walls of the third wall portions 21c on both sides together constitute the second convex portion 211, the second wall portion 21b and the outer walls of the third wall portions 21c on both sides together constitute the second concave portion 212, and the first wall portion 21a and the inner walls of the third wall portions 21c on both sides together constitute the third concave portion 222, and the second wall portion 21b and the inner walls of the third wall portions 21c on both sides together constitute the third convex portion 221. In addition, the outer wall of the flange 21 is circumferentially constructed with a positioning groove 213 that cooperates with the convex ridge 113. The pole 30 includes a connecting portion 31 located in the middle, a terminal portion 32 located at the top of the connecting portion 31, and a support portion 33 located at the bottom of the connecting portion 31. The connecting portion 31 is inserted into the second mounting hole 22, and the terminal portion 32 is exposed at the top of the body 23 of the upper plastic part 20. In addition, the terminal portion 32 includes a flange 321 located at the periphery, which presses the body 23 against the top surface of the cover plate 10. The outer wall of the connecting portion 31 protrudes outward to form four spaced fourth protrusions 311, and a fourth recess 312 is defined between two adjacent fourth protrusions 311. After the cover 10, the upper plastic part 20, and the terminal 30 are assembled, the first protrusion 111 is nested with the first recess 112, the second protrusion 211 is nested with the second recess 212, the third protrusion 221 is nested with the fourth recess 312, and the fourth protrusion 311 is nested with the third recess 222, together forming an anti-twist structure. The ridge 113 is enclosed in the positioning groove 213, so that the upper plastic part 20 is axially limited by the ridge 113.

[0080] The thickness of the cover plate 10 is H, the height of the ridge 113 is H1, and the inclination angle of the top surface of the ridge 113 is α, which satisfies: H1 / H=40%, α=30°.

[0081] Comparative Example 1:

[0082] Comparative Example 1 provides a cover plate assembly, which differs from Example 1 in that: α=15°.

[0083] Comparative Example 2:

[0084] Comparative Example 2 provides a cover plate assembly, which differs from Example 1 in that: H1 / H=10%.

[0085] Comparative Example 3:

[0086] Comparative Example 3 provides a cover plate assembly, which differs from Example 1 in that: H1 / H=10%, α=15°.

[0087] Table 1 below evaluates the axial limiting effect of the upper plastic part 20 on the cover assembly made in the above-mentioned embodiment and comparative example. The specific test method is: place the cover assembly on the thrust test equipment, use the tooling on the workbench to clamp the cover assembly in the width direction, so that the surface of the terminal part 32 in the pole 30 is suspended downward, the surface of the support part 33 is facing upward, and the center position of the surface of the support part 33 is placed vertically directly below the thrust pusher. Set the parameters on the equipment, and use thrusts of different gradients of 1100N to 1350N to perform thrust tests on different cover assemblies. After testing one cover assembly with one thrust value, perform an airtightness test. The same cover assembly cannot be repeatedly tested with different thrusts. Move the thrust pusher to 2mm above the surface of the support part 33 as the origin position to start the test. According to the thrusts of different gradients, move the different cover assemblies down 3mm in turn, and after holding for 10s, the pusher rises back to the origin position.

[0088] After the thrust test, the cover assembly is placed in a helium detector for air tightness test and the leak rate is recorded. -7 Pa·m 3 / s is the airtightness qualification judgment standard.

[0089] Table 1

[0090] example 1100N 1150N 1200N 1250N 1300N 1350N Example 1 qualified qualified qualified qualified qualified qualified Comparative Example 1 qualified qualified qualified qualified qualified Unqualified Comparative Example 2 qualified qualified qualified qualified Unqualified / Comparative Example 3 qualified qualified qualified Unqualified / /

[0091] As can be seen from Table 1, when the height of the rib 113 is constant, that is, when H1 / H is at a certain value, when the inclination angle α decreases, the length of the rib 113 in the radial direction of the first mounting hole 11 correspondingly decreases, and its limiting effect on the upper plastic part 20 becomes worse. When the thrust reaches a certain value, the upper plastic part 20 shifts, that is, the rib 113 fails to axially limit the upper plastic part 20, and the air tightness test fails.

[0092] When the H1 / H ratio decreases, the height of the ridge 113 becomes smaller, that is, the ridge 113 becomes thinner, resulting in a decrease in its structural strength. When the thrust reaches a certain level, the ridge 113 will deform and the upper plastic part 20 will shift. That is, the axial limit of the ridge 113 on the upper plastic part 20 will fail, and the air tightness test will fail.

[0093] When H1 / H=10% and α=15°, the length of the rib 113 in the radial direction of the first mounting hole 11 is too small, and the height of the rib 113 is also too small, resulting in a low structural strength of the rib 113. After the upper plastic part 20 and the cover plate 10 are fully assembled, the rib 113 is easily deformed by the thrust during the thrust test due to its insufficient structural strength, and thus fails the airtightness test.

[0094] The following combination Figures 8a to 8d The method for axially positioning the upper plastic component 20 in the cover assembly of this embodiment is described.

[0095] First, if Figure 8a As shown, prepare the cover 10 and the upper plastic part 20, keep the top surface of the cover 10 facing upward, place the upper plastic part 20 on the top surface of the cover 10, and make the bottom surface of the flange 21 of the upper plastic part 20 contact the top surface of the ridge 113, so that the flange 21 is initially positioned by the top of the ridge 113.

[0096] Then, if Figure 8b As shown, the pole 30 , the lower plastic part 50 and the sealing ring 60 are prepared, and the pole 30 , the lower plastic part 50 and the sealing ring 60 are assembled to form an assembly.

[0097] Then, if Figure 8c As shown, the assembly consisting of the pole 30, the lower plastic part 50 and the sealing ring 60 is assembled from the bottom side of the cover 10, so that the top of the pole 30 passes through the first mounting hole 11 and the second mounting hole 22 and extends to the top of the upper plastic part 20.

[0098] Finally, if Figure 8d As shown, by riveting the pole 30, the top of the pole 30 undergoes plastic deformation to form a flange 321. The riveting force of the flange 321 presses the upper plastic part 20 downward, so that the ridge 113 is inserted into the positioning groove 213. In addition, the flange 321 presses the body 23 in the upper plastic part 20 against the top surface of the cover 10.

[0099] The present application also provides a cylindrical lithium battery comprising the cover plate assembly of the above embodiment. Due to the cover plate assembly of the above embodiment, the cylindrical lithium battery of this embodiment is less susceptible to twisting of the upper plastic part 20 and the terminal 30 during prolonged use or under harsh operating conditions due to the strong torsional strength between the cover plate 10, the upper plastic part 20, and the terminal 30. Consequently, the cylindrical lithium battery exhibits high reliability and safety.

[0100] like Figures 1 to 3 As shown, in some embodiments, the cover plate 10 is the top cover of a cylindrical lithium battery, which includes a cylindrical shell 40 and the cover plate 10 located on top of the shell 40, and the shell 40 and the cover plate 10 are integrally formed. In this way, the process of separately welding the cover plate assembly to the shell 40 can be omitted, which can save process steps and costs.

[0101] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present embodiment. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0102] Although examples of the present embodiment have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and intent of the present embodiment, and the scope of the present embodiment is defined by the claims and their equivalents.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate (10) is provided with a first mounting hole (11) extending therethrough, the first mounting hole (11) being circular, the hole wall of the first mounting hole (11) being circumferentially configured with alternating first convex portions (111) and first concave portions (112), the first convex portion (111) being formed by the hole wall of the first mounting hole (11) protruding in a direction toward the center of the first mounting hole (11), and the first concave portion (112) being defined between two adjacent first convex portions (111); An upper plastic part (20) comprises a flange (21) passing through the first mounting hole (11), the flange (21) being cylindrical, the upper plastic part (20) being provided with a second mounting hole (22) passing through the flange (21), the outer wall of the flange (21) being circumferentially configured with alternating second convex portions (211) and second concave portions (212), and the hole wall of the second mounting hole (22) being circumferentially configured with alternating third convex portions (221) and third concave portions (222), the second convex portion (211), the second concave portion (212), the third convex portion (221) and the third concave portion (222) being formed by the wall portion of the flange (21) extending in a zigzag manner along the radial direction and the circumferential direction of the second mounting hole (22); A pole (30) comprising a connecting portion (31) passing through the second mounting hole (22), wherein the outer wall of the connecting portion (31) is circumferentially configured with alternating fourth protrusions (311) and fourth recesses (312); wherein each of the first protrusions (111) is nested in each of the second recesses (212) in a one-to-one correspondence, and each of the second protrusions (211) is nested in each of the first recesses (112) in a one-to-one correspondence, so as to limit the upper plastic part (20) from rotating relative to the cover plate (10); each of the third protrusions (221) is nested in each of the fourth recesses (312) in a one-to-one correspondence, and each of the fourth protrusions (311) is nested in each of the third recesses (222) in a one-to-one correspondence, so as to limit the pole (30) from rotating relative to the upper plastic part (20); The hole wall of the first mounting hole (11) is circumferentially configured with a rib (113), and the outer wall of the flange (21) is circumferentially configured with a positioning groove (213) that matches the rib (113). The rib (113) is covered in the positioning groove (213) to limit the upper plastic part (20) from moving in the axial direction of the first mounting hole (11). The rib (113) is elastically deformed and squeezed into the positioning groove (213) by the downward pressure applied by the flange (21) and the rib (113). The downward pressure is provided by the riveting action on the pole (30).

2. The cover plate assembly according to claim 1, wherein: The ridge (113) is only constructed at each of the first recesses (112), and the positioning groove (213) is only constructed at each of the second protrusions (211).

3. The cover plate assembly according to claim 1 or 2, characterized in that: The thickness of the cover plate is H, and the height of the ridge (113) is H1, which satisfies the following relationship: H1 / H=20% to 50%.

4. The cover plate assembly according to claim 1 or 2, characterized in that: The ridge (113) is arranged at the top of the hole wall of the first mounting hole (11), and the top surface of the ridge (113) is smoothly transitionally connected to the top surface of the cover plate (10).

5. The cover plate assembly according to claim 3, wherein: The top surface of the ridge (113) is arranged to be inclined in a radial direction toward the inside of the first mounting hole (11).

6. The cover plate assembly according to claim 5, wherein: The inclination angle of the top surface of the ridge (113) is α, which satisfies 20°≤α≤50°.

7. A cylindrical lithium battery, characterized in that: The invention comprises the cover plate assembly according to any one of claims 1 to 6.

Images