Cover plate assembly and battery cell

Abstract

The application provides a cover plate assembly and a battery cell. The cover plate assembly comprises a cover plate, an insulating part and a pole, the pole is connected to the cover plate through the insulating part; the cover plate comprises a cover plate body and a first fixing part, the cover plate is provided with a mounting hole penetrating in a first direction, the cover plate body comprises a first surface and a second surface arranged oppositely in the first direction, and the first fixing part extends from the first surface to a direction away from the cover plate body; the first direction is the thickness direction of the cover plate body; the pole is at least partially arranged in the mounting hole, and the pole comprises a pole body and a protruding part arranged circumferentially along the outer wall of the pole body; at least one of the edge of the protruding part and the first fixing part is provided with a thinning structure; and the insulating part is connected at least between the first fixing part and the protruding part. The cover plate assembly and the battery cell provided by the application can help to reduce the material cost and the weight of the cover plate assembly.

Description

[0001] This application claims priority to Chinese Patent Application No. 202510596516.5, filed in China on May 9, 2025, entitled "Cover Assembly, Cell and Battery Pack", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a cover plate assembly and a battery cell. Background Technology

[0003] With increasingly fierce cost competition in the lithium battery industry, the cover plate assembly of the battery cell is a key component of lithium batteries, and its cost directly affects the overall cost of lithium batteries.

[0004] The cover plate assembly includes a cover plate body and a pole that penetrates and connects to the cover plate body. In order to ensure a reliable connection between the pole and the cover plate body and to have insulation and sealing performance that meets process requirements, a large number of components are set between the cover plate body and the pole. This not only leads to higher material costs for the cover plate assembly, but also has an adverse effect on assembly efficiency. Utility Model Content

[0005] In view of this, the purpose of this application is to provide a cover plate assembly and a battery cell to at least partially solve the problem of high cost of the cover plate assembly.

[0006] To achieve the above objectives, a first aspect of this application provides a cover plate assembly, comprising: a cover plate, an insulating portion, and a pole post, wherein the pole post is connected to the cover plate via the insulating portion; the cover plate includes a cover plate body and a first fixing portion, the cover plate having a through mounting hole along a first direction, the cover plate body including a first surface and a second surface disposed opposite to each other along the first direction, the first fixing portion extending from the first surface along the first direction in a direction away from the cover plate body; the first direction being the thickness direction of the cover plate body; the pole post at least partially passing through the mounting hole, the pole post including a pole post body and a protrusion disposed circumferentially along the outer wall of the pole post body; the edge of the protrusion and at least one of the first fixing portions having a thinning structure; the insulating portion being at least connected between the first fixing portion and the protrusion.

[0007] Optionally, the projections of the first fixing part and the protrusion along the first direction are spaced apart, and the minimum distance between the edge of the protrusion and the first fixing part is L1, where L1 ≥ 0.8 mm.

[0008] Optionally, along the first direction, the minimum distance between the first end and the protrusion is H3, where H3 ≥ 0.8; along the second direction, the minimum distance between the first end and the protrusion is L3, where L3 ≥ 0.2 mm; the second direction is perpendicular to the first direction.

[0009] Optionally, the thinning structure includes a chamfer, a rounded corner, or a stepped structure.

[0010] Optionally, the thinning structure includes a first thinning structure disposed at the edge of the protrusion; the first fixing part also extends in the direction of the central axis of the mounting hole, and the free end of the first fixing part is provided with a second thinning structure.

[0011] Optionally, the first thinning structure and the second thinning structure are arranged opposite to each other, and the minimum distance between them is L2, where L2 ≥ 0.8 mm.

[0012] Optionally, the first thinning structure has a dimension of H1 along the first direction, and the protrusion has a dimension of H2 along the first direction, with the ratio of H1 to H2 being 0.2 to 0.8.

[0013] Optionally, the cover plate further includes a second fixing portion, which extends from the second surface at least in the direction of the central axis of the mounting hole; along the first direction, the protrusion is located between the first fixing portion and the second fixing portion; the projections of the protrusion and the second fixing portion in the first direction overlap.

[0014] Optionally, along the first direction, a sealing portion is provided at least between the protrusion and the second fixing portion, and the insulating portion is connected to the sealing portion and fills the mounting hole.

[0015] Optionally, the insulating portion includes a first sub-portion, a second sub-portion, and a third sub-portion, wherein the second sub-portion is at least partially located between the first fixing portion and the second fixing portion, and the third sub-portion is at least partially located on the side of the first fixing portion away from the mounting hole, and the first sub-portion connects the second sub-portion and the third sub-portion; along the first direction, at least the portion of the first sub-portion near the pole body does not extend beyond the end of the pole body away from the second surface.

[0016] Based on the same inventive concept, a second aspect of this application also provides a battery cell, including a housing, an electrode assembly, and a cover plate assembly as described in the first aspect, wherein the cover plate assembly is connected to the housing, and the electrode assembly is disposed within the space formed by the cover plate assembly and the housing.

[0017] As can be seen from the above, the cover plate assembly and battery cell provided in this application, through the insulating portions connected to the first fixing portion and the protrusion respectively, enable the electrode post and the cover plate to achieve an insulated connection. This effectively reduces the number of parts in the cover plate assembly and the amount of metal material used, thereby reducing the material cost and weight of the cover plate assembly. Simultaneously, providing a thinning structure at least one of the edges of the protrusion and the first fixing portion reduces the number of right-angled edges in contact with the insulating portion, helping to reduce the risk of damage or even breakage of the insulating portion. Furthermore, it increases the space between the protrusion and the first fixing portion, helping to increase the thickness of the insulating portion between them, thereby improving the structural strength of the insulating portion and ensuring a reliable connection between the electrode post and the cover plate through the insulating portion. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a partial cross-sectional schematic diagram of the battery cell of the first structure according to an embodiment of this application; Figure 2 This is a partial top view of the cover plate assembly of the second structure according to an embodiment of this application; Figure 3 for Figure 2 Schematic diagram of the cross section AA in the middle; Figure 4 for Figure 3 Enlarged schematic diagram of part B; Figure 5 The cover plate assembly of the third structure in the embodiments of this application is in Figure 3 Enlarged schematic diagram of part B; Figure 5a for Figure 5 An enlarged schematic diagram of section C; Figure 6 The cover plate assembly of the fourth structure in the embodiments of this application is in Figure 3 Enlarged schematic diagram of part B; Figure 7 This is a partial schematic diagram of a battery cell with a second structure according to an embodiment of this application.

[0020] Explanation of reference numerals in the attached figures: 1000, Cover plate assembly; 100. Cover plate; 110. Cover plate body; 111. Mounting hole; 1111. First end; 1112. Second end; 112. First surface; 113. Second surface; 120. First fixing part; 121. First extension part; 122. Second extension part; 130. Second fixing part; 200, pole post; 210, pole post body; 220, protrusion; 300, lower insulating component; 400, upper insulating component; 500, riveting block; 600, sealing ring; 700. Sealing part; 800. Insulating part; 810. First sub-part; 820. Second sub-part; 830. Third sub-part; 900. Thinning structure; 910. First thinning structure; 920. Second thinning structure; 2000, housing; 2100, open end; 3000, Electrode assembly. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0022] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components described in these embodiments do not limit the scope of this application.

[0023] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0024] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0025] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] Figure 1 A partial cross-sectional schematic diagram of the first type of battery cell is shown.

[0027] like Figure 1 In some embodiments, the battery cell includes a cover assembly 1000 and a housing 2000. The cover assembly 1000 includes a cover body 110, which is provided with a portion along its thickness direction (e.g., ...). Figure 1 A mounting hole 111 (in the Z direction) is provided, and the cover plate body 110 is fitted and connected to the opening end 2100 of the housing 2000, so that the cover plate body 110 and the housing 2000 enclose a space for accommodating the electrode assembly 3000. A lower insulating member 300 is connected to the side of the cover plate body 110 near the electrode assembly 3000, and an upper insulating member 400 is connected to the side of the cover plate body 110 away from the electrode assembly 3000. The cover plate assembly 1000 also includes a pole post 200, which is fitted with a sealing ring 600 and passes through the lower insulating member 300, the cover plate body 110, and the upper insulating member 400. The end of the pole post 200 away from the electrode assembly 3000 extends out of the upper insulating member 400 and is riveted to the riveting block 500. The pole post 200 and the cover plate body 110 press the sealing ring 600 to seal the pole post 200 and the cover plate body 110 through the sealing ring 600, and to insulate the pole post 200 and the cover plate body 110 through the upper insulating member 400 and the lower insulating member 300.

[0028] As can be seen from the foregoing, in this embodiment, in order to achieve an insulated and sealed connection between the pole post 200 and the cover plate body 110, a sealing ring 600 needs to be fitted onto the pole post 200 and a riveting block 500 needs to be connected to the top of the pole post 200. Since the riveting block 500 needs to be made of metal, not only is the material cost high, but it also results in a large overall weight of the cover plate assembly 1000.

[0029] To address the aforementioned issues, embodiments of this application provide cover plate assemblies 1000 with alternative structures.

[0030] Figure 2 A partial top view of the cover plate assembly 1000 with the second structure is shown. Figure 3 Showing Figure 2 A schematic diagram of the cross-section AA in the middle. Figure 4 Showing Figure 3 Enlarged diagram of part B.

[0031] like Figure 2 , Figure 3 and Figure 4In some embodiments, the cover plate assembly 1000 includes: a cover plate 100, an insulating portion 800, and a terminal post 200, the terminal post 200 being connected to the cover plate 100 via the insulating portion 800; the cover plate 100 includes a cover plate body 110 and a first fixing portion 120, and the cover plate 100 is provided with a fixing portion 120 along a first direction (e.g., ...). Figure 4 The cover plate body 110 has a through mounting hole 111 in the Z direction. It includes a first surface 112 and a second surface 113 arranged opposite to each other in a first direction. The first fixing part 120 extends from the first surface 112 in a direction away from the cover plate body 110 in the first direction. The first direction is the thickness direction of the cover plate body 110. The pole post 200 is at least partially inserted through the mounting hole 111. The pole post 200 includes a pole post body 210 and a protrusion 220 arranged circumferentially along the outer wall of the pole post body 210. The edge of the protrusion 220 and at least one of the first fixing part 120 are provided with a thinning structure 900. The insulating part 800 is at least connected between the first fixing part 120 and the protrusion 220.

[0032] It should be noted that the outer wall of the pole body 210 surrounds the central axis of the pole 200 (e.g., Figure 4 (The dashed line in the middle) is set. The free end of the first fixing part 120 is the end of the first fixing part 120 that is away from the cover plate body 110.

[0033] For example, the free end of the first fixing part 120 forms the first end 1111 of the mounting hole 111.

[0034] For example, the pole body 210 can be a cylinder with a circular cross-section (unless otherwise specified, the cross-sections described below are all cross-sections perpendicular to the central axis of the pole 200), or it can be a cylinder with a polygonal cross-section.

[0035] For example, the outer contour shape of the cross-section of the protrusion 220 may be the same as or different from the cross-sectional shape of the pole body 210.

[0036] For example, along the first direction, the protrusion 220 may be disposed at the middle part of the pole body 210 or near the bottom end (the bottom end of the pole body 210 is near the second surface 113).

[0037] For example, along the first direction, the plate surface of the cover body 110 away from the first fixing part 120 may be connected to the lower insulating member 300.

[0038] For example, the bottom end of the electrode body 210 (i.e., the end near the second surface 113) is used for electrical connection with the tab of the electrode assembly 3000, and the top end is used for electrical connection with an external circuit (e.g., a busbar assembly or a switch).

[0039] For example, a sealing part 700 is connected between the pole post 200 and the cover plate 100.

[0040] For example, the first fixing part 120 and the cover plate body 110 can be connected by welding or integral molding.

[0041] When assembling the cover plate assembly 1000 of this embodiment, the assembled pole post 200 can be inserted into the mounting hole 111. After the pole post 200 moves to a preset position in the mounting hole 111 along the first direction, an insulating part 800 can be formed at least in the mounting hole 111 by injection molding. The protrusion 220 and the first fixing part 120 are connected through the insulating part 800 to achieve relative fixation of the pole post 200 and the cover plate 100, forming a reliable connection.

[0042] Compared to the first type of cover plate assembly 1000, the second type of cover plate assembly 1000 eliminates at least the riveting block 500. The insulating part 800, formed by injection molding, simultaneously achieves the functions of fixing the pole post 200 and insulating the pole post 200 from the cover plate 100. Eliminating the connection between the pole post 200 and the riveting block 500 reduces the overall metal material usage of the cover plate assembly 1000, lowering material costs and weight, which is beneficial for mass production.

[0043] As can be seen from the foregoing, the insulating part 800 is used to fix the pole post 200. If it breaks, especially the part of the insulating part 800 located between the protrusion 220 and the first fixing part 120, it may cause the connection between the pole post 200 and the cover plate 100 to fail. When the edges of the protrusion 220 and the first fixing part 120 are both right-angled edges, on the one hand, stress concentration may occur at the right-angled edges, and the insulating part 800 connected to multiple right-angled edges is prone to damage or even breakage under greater stress; on the other hand, the outward protruding right-angled edges may also lead to a smaller gap between the edge of the protrusion 220 and the first fixing part 120, and the thickness of the insulating part 800 located between the two is also correspondingly smaller, which is also prone to damage or even breakage.

[0044] To avoid the aforementioned problems, this embodiment provides a thinning structure 900 on at least one of the edges of the protrusion 220 and the first fixing portion 120. Compared to right-angled edges, providing the thinning structure 900 not only eliminates right-angled edges, but also forms a locally recessed structure on the edge of the protrusion 220 and / or the first fixing portion 120, increasing the distance between the edge of the protrusion 220 and the first fixing portion 120, thereby correspondingly increasing the thickness of the insulating portion 800 located between them.

[0045] The cover plate assembly 1000 provided in this embodiment, through the insulating portion 800 connected to the first fixing portion 120 and the protrusion 220 respectively, enables the pole post 200 and the cover plate 100 to achieve an insulated connection. This effectively reduces the number of parts in the cover plate assembly 1000 and the amount of metal material used, thereby reducing the material cost and weight of the cover plate assembly 1000. Simultaneously, by providing a thinning structure 900 at least one of the edges of the protrusion 220 and the first fixing portion 120, the number of right-angled edges in contact with the insulating portion 800 can be reduced, helping to reduce the risk of damage or even breakage of the insulating portion 800. Furthermore, it can increase the space between the protrusion 220 and the first fixing portion 120, helping to increase the thickness of the insulating portion 800 between the protrusion 220 and the first fixing portion 120, thereby improving the structural strength of the insulating portion 800 and ensuring that the pole post 200 and the cover plate 100 can form a reliable connection through the insulating portion 800.

[0046] like Figure 4 In some embodiments, the projections of the first fixing portion 120 and the protrusion 220 along the first direction are spaced apart, and the minimum distance between the edge of the protrusion 220 and the first fixing portion 120 is L1, where L1 ≥ 0.8 mm.

[0047] For example, L1 can be 0.8mm, 0.85mm, 0.9mm, 0.95mm or 1mm.

[0048] Understandably, for the projection of the pole post 200 along the first direction (hereinafter referred to as the pole post projection), the protrusion 220 is located on the outer periphery of the pole post body 210. The projection of the first fixing part 120 along the first direction (hereinafter referred to as the first fixing part projection) is separated from the projection of the protrusion 220 along the first direction. This means that the first fixing part projection is separated from the pole post projection, and the pole post 200 can pass through the inner hole formed by the first fixing part 120.

[0049] Before inserting the terminal post 200 into the mounting hole 111, the mounting hole 111 can be cleaned to ensure that there are no metal foreign objects inside. Then, the terminal post 200 is directly inserted into the mounting hole 111 through the inner hole formed by the first fixing part 120. Subsequently, the insulating part 800 completes the insulating and sealing connection between the terminal post 200 and the cover plate 100. This prevents the presence of metal foreign objects in the mounting hole 111, helps improve the electrical clearance and creepage distance between the cover plate 100 and the terminal post 200, and helps improve the insulation performance of the cover plate assembly 1000, thereby improving the safety performance of the battery cell using the cover plate assembly 1000 of this embodiment.

[0050] If L1 is too small, the gap between the protrusion 220 and the first fixing part 120 will be too small. When the insulating part 800 is formed by injection molding, even if the injection molding material fills the gap between the protrusion 220 and the first fixing part 120, the thickness of the insulating part 800 formed between them will still be insufficient, and the insulating part 800 at this position will still be at risk of breaking.

[0051] To avoid the above problems, in this embodiment, L1 is designed to be L1≥0.8mm, which can provide a sufficient gap between the protrusion 220 and the first fixing part 120. Correspondingly, the insulating part 800 formed in the above gap can also have a larger thickness. The structural strength of this insulating part 800 is greater, which helps to further reduce the risk of the insulating part 800 breaking.

[0052] like Figure 4 In some embodiments, along the second direction (e.g.) Figure 4 The minimum distance between the first end 1111 and the protrusion 220 is L3, where L3 ≥ 0.2 mm; the second direction is perpendicular to the first direction.

[0053] For example, L3 can be 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm or 0.5mm.

[0054] If L3 is too small, then along the second direction, the distance between the first end 1111 and the protrusion 220 will be too small, and the width of the portion of the insulating part 800 located between the two will be too small. During the assembly and use of the cover plate assembly 1000, the aforementioned portion of the insulating part 800 may break under the combined action of the first end 1111 and the protrusion 220.

[0055] To avoid the aforementioned problems, this embodiment designs L3 to be ≥ 0.2 mm, which helps reduce the risk of breakage in the insulation part 800 and helps ensure the insulation performance, sealing performance, and structural strength of the insulation part 800. It can also improve the electrical performance of the terminal 200 and reduce the risk of thermal runaway in the battery cell.

[0056] like Figure 4 In some embodiments, along the first direction, the minimum distance between the first end 1111 and the protrusion 220 is H3, where H3 ≥ 0.8.

[0057] For example, H3 can be 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm or 1.2mm.

[0058] The problems caused by H3 being too small are similar to those caused by L3 being too small. Furthermore, the beneficial effects of designing H3 to be H3≥0.8 are similar to the beneficial effects of designing L3 to be L3≥0.2mm, so they will not be elaborated here.

[0059] like Figure 4 In some embodiments, the thinning structure 900 includes a chamfer, a rounded corner, or a stepped structure.

[0060] The thinning structure 900 is set as a chamfered corner, rounded corner or stepped structure. The surface of the thinning structure 900 is more regular, which can effectively reduce the processing difficulty and make it easier to control the dimensional accuracy. It helps to ensure the structural strength of the insulating part 800 located between the protrusion 220 and the first fixed part 120.

[0061] Figure 5 The third type of cover plate assembly 1000 was demonstrated. Figure 3 Enlarged diagram of part B.

[0062] like Figure 5 In some embodiments, the thinning structure 900 includes a first thinning structure 910 disposed at the edge of the protrusion 220; the first fixing portion 120 also extends in the direction of the central axis of the mounting hole 111, and a second thinning structure 920 is disposed at the free end of the first fixing portion 120.

[0063] The portion of the first fixing part 120 near the cover plate body 110 (hereinafter referred to as the first extension 121) extends from the first surface 112 in a direction away from the cover plate body 110, and the portion of the first fixing part 120 near its free end (hereinafter referred to as the second extension 122) extends in a direction towards the central axis of the mounting hole 111.

[0064] For example, the first extension 121 may include a cylindrical structure, and the second extension 122 may include an annular plate structure.

[0065] For example, the connection between the first extension 121 and the second extension 122 can be welding or integral molding.

[0066] For example, the first thinning structure 910 can be formed by extruding or cutting the material of the protrusion 220. The second thinning structure 920 can be formed by extruding or cutting the material of the first fixing part 120. The structures of the second thinning structure 920 and the first thinning structure 910 can be the same or different.

[0067] by Figure 5The following explanation uses the structure and orientation shown as an example. The second extension 122 of the first fixing part 120 is at least used to limit the pole post 200 along the first direction by means of the insulating part 800. In order to ensure that a more reliable force can be provided to the protrusion 220, the second extension 122 needs to be positioned along the second direction (the second direction is perpendicular to the central axis of the mounting hole 111, such as...). Figure 5 (in the X direction) near the protrusion 220.

[0068] Since the first extension 121 is connected to the second extension 122, the first extension 121 will be closer to the pole body 210, which will limit the space between the first fixing part 120 and the protrusion 220 for accommodating the insulating part 800. To expand this space, this embodiment provides a second thinning structure 920 at the free end of the first fixing part 120. When the insulating part 800 is injection molded, more material for forming the insulating part 800 can be accommodated in this space, resulting in a larger material thickness for the insulating part 800 located between the protrusion 220 and the first fixing part 120, and a correspondingly greater structural strength. This can prevent the insulating part 800 from breaking and ensure a reliable connection between the pole 200 and the cover plate 100.

[0069] Meanwhile, the first thinning structure 910 at the edge of the protrusion 220 and the second thinning structure 920 at the free end of the first fixing part 120 can prevent the protrusion 220 and the part of the first fixing part 120 from forming right-angled edges when connected to the insulating part 800, which can further reduce the risk of the insulating part 800 breaking.

[0070] Figure 5a Showing Figure 5 An enlarged schematic diagram of section C.

[0071] like Figure 5 and Figure 5a In some embodiments, the first thinning structure 910 and the second thinning structure 920 are disposed opposite to each other, and the minimum distance between them is L2, where L2≥0.8mm.

[0072] For example, L2 can be 0.8mm, 0.85mm, 0.9mm, 0.95mm or 1mm.

[0073] If L2 is too small, the gap between the first thinning structure 910 and the second thinning structure 920 will be too small. When the insulating part 800 is formed by injection molding, even if the injection molding material fills the gap between the first thinning structure 910 and the second thinning structure 920, the thickness of the insulating part 800 formed between them will still be insufficient, and the insulating part 800 at this position will still be at risk of breakage.

[0074] To avoid the above problems, in this embodiment, L2 is designed to be L2≥0.8mm, which can provide a sufficient gap between the first thinning structure 910 and the second thinning structure 920. Correspondingly, the insulating part 800 formed in the above gap can also have a larger thickness, so that the structural strength of the insulating part 800 is greater, thereby further reducing the risk of breakage.

[0075] like Figure 5 and Figure 5a In some embodiments, the first thinning structure 910 has a dimension of H1 along the first direction, and the protrusion 220 has a dimension of H2 along the first direction, with the ratio of H1 to H2 being 0.2 to 0.8.

[0076] For example, the ratio of H1 to H2 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0077] If the ratio of H1 to H2 is too large, the thickness of the remaining material of the protrusion 220 in the first direction, excluding the first thinning structure 910, will be too small. This may result in low structural strength of the protrusion 220, making it prone to cracks or even breakage at the connection between the protrusion 220 and the electrode body 210. If the protrusion 220 separates from the electrode body 210, the electrode body 210 may detach from the mounting hole 111, leading to safety issues with the battery cell. If the ratio of H1 to H2 is too small, to ensure a sufficient gap between the first thinning structure 910 and the free end of the first fixing part 120, the outer diameter of the first fixing part 120 needs to be increased, or the height extending away from the cover body 110 needs to be increased. This would cause the cover body 110 to occupy too much space in the first direction, resulting in an excessively large overall size of the battery cell in the first direction. When assembling the battery pack, a single battery cell would occupy a large space within the battery pack, reducing the number of cells the battery pack can hold and resulting in a lower energy density.

[0078] To avoid the aforementioned problems, this embodiment designs the ratio of H1 to H2 to be between 0.2 and 0.8. This helps to improve the structural strength of the protrusion 220, ensuring a reliable connection between the protrusion 220 and the electrode body 210. It also helps to improve the connection reliability between the electrode 200 and the cover plate 100, preventing safety issues with the battery cell. Simultaneously, it helps to reduce the overall dimensions of the first fixing part 120, thereby minimizing the space occupied by the battery cell. When using this battery cell to assemble a battery pack, it helps to increase the energy density of the battery pack.

[0079] like Figure 5In some embodiments, the cover plate 100 further includes a second fixing portion 130, which extends from the second surface 113 at least toward the central axis of the mounting hole 111; along the first direction, a protrusion 220 is located between the first fixing portion 120 and the second fixing portion 130; the projections of the protrusion 220 and the second fixing portion 130 in the first direction overlap.

[0080] It should be noted that the free end of the second fixing part 130 forms the second end 1112 of the mounting hole 111.

[0081] For example, the second fixing part 130 and the cover plate body 110 can be connected by welding or integral molding; the connection method between the second fixing part 130 and the cover plate body 110 can be the same as or different from the connection method between the first fixing part 120 and the cover plate body 110.

[0082] In addition to the connection methods described above, the first fixing part 120 and the second fixing part 130 can be connected by welding or integral molding to form a structural component, which is connected to the cover plate body 110 by welding or integral molding.

[0083] like Figure 5 The portion of the second fixing part 130 near the cover plate body 110 extends from the second surface 113 in a direction away from the first surface 112, and the portion of the second fixing part 130 near its free end extends in the direction of the central axis of the mounting hole 111. At this time, the second fixing part 130 can protrude from the plate surface of the cover plate body 110 near the electrode assembly 3000.

[0084] Figure 6 The fourth type of cover assembly 1000 was demonstrated. Figure 3 Enlarged diagram of part B.

[0085] like Figure 6 In some embodiments, the second fixing part 130 extends entirely towards the central axis of the mounting hole 111. In this case, the second fixing part 130 can be flush with the plate surface of the cover plate body 110 near the electrode assembly 3000.

[0086] It should be noted that the shape of the outer contour of the cross section of the inner hole formed by the first fixing part 120, the inner hole formed by the second fixing part 130, and the pole body 210 can be circular or polygonal, and is not limited here.

[0087] Understandably, in this embodiment, the projections of the second fixing part 130 and the protrusion 220 overlap along the first direction, so the pole post 200 cannot pass through the inner hole formed by the second fixing part 130.

[0088] by Figure 5The structure and orientation shown are used as an example for explanation. After the pole post 200 is inserted into the mounting hole 111 from one side of the first fixing part 120, the protrusion 220 is located above the second fixing part 130. The protrusion 220 is blocked and limited by the second fixing part 130, so that at least a part of the pole post 200 is kept in the mounting hole 111. This can further reduce the risk of the pole post 200 coming out of the mounting hole 111 and help improve the connection reliability between the pole post 200 and the cover plate 100.

[0089] like Figure 5 and Figure 5a In some embodiments, a sealing portion 700 is provided at least between the protrusion 220 and the second fixing portion 130 along the first direction, and an insulating portion 800 is connected to the sealing portion 700 and fills the mounting hole 111.

[0090] For example, the sealing part 700 can be fitted onto the pole body.

[0091] It should be noted that after the pole post 200 is inserted into the mounting hole 111, the protrusion 220 and the second fixing part 130 cooperate to compress the sealing part 700, so that the sealing part 700 is deformed under pressure to achieve the sealing effect.

[0092] Combination Figure 5 and Figure 5a As can be seen, most of the pole post 200 is located inside the mounting hole 111. When the insulating part 800 and the sealing part 710 are connected and fill the mounting hole 111, a continuous insulating and sealing structure with a certain width (the dimension along the second direction) is formed between the pole post 200 and the inner wall of the mounting hole 111. This insulating and sealing structure has strong structural strength, which can ensure a stable and reliable connection between the pole post 200 and the cover plate 100. It also has insulation properties, which can reliably insulate between the pole post 200 and the cover plate 100. In addition, it fills the gaps in the mounting hole 111 so that the electrolyte in the cell cannot leak out through the mounting hole 111, thereby helping to improve the safety of the cell.

[0093] like Figure 5 In some embodiments, the insulating portion 800 includes a first sub-portion 810, a second sub-portion 820, and a third sub-portion 830. The second sub-portion 820 is at least partially located between the first fixing portion 120 and the second fixing portion 130, and the third sub-portion 830 is at least partially located on the side of the first fixing portion 120 away from the mounting hole 111. The first sub-portion 810 connects the second sub-portion 820 and the third sub-portion 830. Along a first direction, at least the portion of the first sub-portion 810 near the pole body 210 does not extend beyond the end of the pole body 210 away from the second surface 113.

[0094] For example, the end face of the first sub-part 810 away from the second surface 113 can be an annular plane, an annular curved surface, an annular inclined surface, or an annular surface with a recess or protrusion locally formed (annular surface includes an annular plane, an annular curved surface, or an annular inclined surface).

[0095] The insulating portion 800 covers at least the free end of the first fixing portion 120 through the first sub-portion 810, the second sub-portion 820, and the third sub-portion 830. On the one hand, this increases the contact area between the insulating portion 800 and the first fixing portion 120, which helps to improve the connection reliability between the insulating portion 800 and the first fixing portion 120. On the other hand, when the pole post 200 is connected to an external circuit, the insulating portion 800 can improve the insulation performance between the first fixing portion 120 and the external circuit, thereby improving the safety performance of the battery cell.

[0096] Meanwhile, since the first sub-part 810 is closest to the top of the pole body 210, designing the first sub-part 810 to not exceed the top of the pole body 210 can prevent the insulating part 800 from interfering with the external circuit, ensuring that the pole 200 can form a connection structure with the external circuit with good electrical performance. It can also prevent the insulating part 800 from being damaged by heat when the pole 200 is soldered to the external circuit, thus preventing the insulating part 800 from failing.

[0097] Based on the same inventive concept and in conjunction with the description of the cover plate assembly 1000 in the above embodiments, this embodiment provides a battery cell that has the corresponding technical effects of the cover plate assembly 1000 in the above embodiments, which will not be repeated here.

[0098] Figure 7 A schematic diagram of the second type of battery cell is shown.

[0099] like Figure 7 and Figure 4 The battery cell includes a housing 2000, an electrode assembly 3000, and a cover assembly 1000 as described in the above embodiments. The cover assembly 1000 is connected to the housing 2000, and the electrode assembly 3000 is disposed within the space formed by the cover assembly 1000 and the housing 2000.

[0100] It should be noted that the end of the pole post 200 of the cover plate assembly 1000 that is close to the electrode assembly 3000 can be exposed in the space where the electrode assembly 3000 is located, so that the pole post 200 and the tab of the electrode assembly 3000 can be electrically connected.

[0101] It should be noted that some embodiments of this application have been described above. Other embodiments are within the scope of the appended claims.

[0102] The various embodiments in this application are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0103] The description in this application is given for illustrative purposes and is not intended to be exhaustive or to limit the application to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical application of this application and to enable those skilled in the art to understand this application and design various embodiments with various modifications suitable for a particular purpose.

[0104] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application is limited to these examples; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0105] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications and variations of these embodiments will be apparent to those skilled in the art from the foregoing description.

[0106] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A cover plate assembly, characterized by include: A cover plate, an insulating part, and an electrode post, wherein the electrode post is connected to the cover plate through the insulating part; The cover plate includes a cover plate body and a first fixing part. The cover plate is provided with a mounting hole that runs through a first direction. The cover plate body includes a first surface and a second surface that are arranged opposite to each other along the first direction. The first fixing part extends from the first surface along the first direction in a direction away from the cover plate body. The first direction is the thickness direction of the cover plate body. The pole is at least partially inserted through the mounting hole. The pole includes a pole body and a protrusion disposed circumferentially along the outer wall of the pole body. The edge of the protrusion and at least one of the first fixing parts are provided with a thinning structure. The insulating portion is at least connected between the first fixing portion and the protrusion.

2. The cover plate assembly of claim 1, wherein, The projections of the first fixing part and the protrusion along the first direction are spaced apart, and the minimum distance between the edge of the protrusion and the first fixing part is L1, where L1 ≥ 0.8 mm.

3. The cover plate assembly of claim 1, wherein, The end of the first fixing part away from the cover plate body forms the first end of the mounting hole; along the first direction, the minimum distance between the first end and the protrusion is H3, H3≥0.8; along the second direction, the minimum distance between the first end and the protrusion is L3, L3≥0.2mm; the second direction is perpendicular to the first direction.

4. The cover plate assembly according to claim 1, characterized in that, The thinning structure includes chamfered corners, rounded corners, or stepped structures.

5. The cover plate assembly according to claim 1, characterized in that, The thinning structure includes a first thinning structure disposed at the edge of the protrusion; the first fixing part also extends in the direction of the central axis of the mounting hole, and a second thinning structure is disposed at the free end of the first fixing part.

6. The cover plate assembly of claim 5, wherein, The first thinning structure and the second thinning structure are arranged opposite to each other, and the minimum distance between them is L2, where L2 ≥ 0.8 mm.

7. The cover plate assembly of claim 6, wherein, The first thinning structure has a dimension of H1 along the first direction, and the protrusion has a dimension of H2 along the first direction. The ratio of H1 to H2 is 0.2 to 0.

8.

8. The cover plate assembly according to claim 7, characterized in that, The cover plate further includes a second fixing portion, which extends from the second surface at least in the direction of the central axis of the mounting hole; along the first direction, the protrusion is located between the first fixing portion and the second fixing portion; the projections of the protrusion and the second fixing portion in the first direction overlap.

9. The cover plate assembly of claim 8, wherein, Along the first direction, a sealing portion is provided at least between the protrusion and the second fixing portion, and the insulating portion is connected to the sealing portion and fills the mounting hole.

10. The cover plate assembly of claim 8, wherein, The insulating portion includes a first sub-part, a second sub-part, and a third sub-part, wherein the second sub-part is at least partially located between the first fixing portion and the second fixing portion, and the third sub-part is at least partially located on the side of the first fixing portion away from the mounting hole, and the first sub-part connects the second sub-part and the third sub-part; Along the first direction, at least the portion of the first sub-part close to the pole body does not extend beyond the end of the pole body away from the second surface.

11. An electric cell characterized by The electrode assembly is arranged in a space formed by the cover plate assembly and the shell.

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