Cover plate assembly for battery, battery, battery pack and vehicle

Abstract

A vehicle (3000), the vehicle (3000) comprising a battery pack (2000). The battery pack (2000) comprises a battery (1000). The battery (1000) comprises a cover plate assembly (100) for the battery (1000). The cover plate assembly (100) comprises a cover plate (10), a sealing cover (20) and a welding seam part (30). A through hole (11) is formed in the cover plate (10). The sealing cover (20) is arranged on the cover plate (10) to block the through hole (11). The welding seam part (30) is arranged between the sealing cover (20) and the cover plate (10), so as to achieve sealed connection between the sealing cover (20) and the cover plate (10). The welding seam part (30) is provided with a welding seam surface (31), the end of the welding seam surface (31) far away from the through hole (11) being connected to the cover plate (10), and the end of the welding seam surface (31) close to the through hole (11) being connected to the sealing cover (20). In the thickness direction of the cover plate assembly (100), the end of the welding seam surface (31) away from the center line of the sealing cover (20) is higher than the end of the welding seam surface (31) close to the center line of the sealing cover (20).

Description

Cover assembly for battery, battery, battery pack and vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 1, 2023, with application number 202322954041.1 and entitled “Cover assembly for battery, battery, battery pack and vehicle”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a cover assembly for a battery, a battery, a battery pack, and a vehicle. Background Art

[0004] In the existing battery cover assembly structure, a sealing cover is welded to the battery base to seal the liquid injection hole. The sealing cover can absorb some of the stress generated during welding and provide a certain buffering effect. However, the weld strength between the sealing cover and the cover plate is relatively low, affecting the sealing performance of the cover plate assembly.

[0005] Public content

[0006] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the first object of the present application is to provide a cover plate assembly for a battery, which can improve the structural strength and sealing performance of the cover plate assembly.

[0007] The second object of the present application is to provide a battery, comprising the cover plate assembly for the battery in the above embodiment.

[0008] The third object of the present application is to provide a battery pack comprising the battery in the above embodiment.

[0009] The fourth object of the present application is to provide a vehicle comprising the battery pack in the above embodiment.

[0010] According to the embodiment of the first aspect of the present application, a cover plate assembly for a battery includes: a cover plate, wherein a through hole is formed on the cover plate; a sealing cover, wherein the sealing cover is arranged on the cover plate to seal the through hole; and a weld portion, wherein the weld portion is arranged between the sealing cover and the cover plate to achieve a sealed connection between the sealing cover and the cover plate, the weld portion having a weld surface facing away from the cover plate, an end of the weld surface away from the center line of the sealing cover is connected to the cover plate, and an end of the weld surface close to the center line of the sealing cover is connected to the sealing cover, and in the thickness direction of the cover plate assembly, the end of the weld surface away from the center line of the sealing cover is higher than the end of the weld surface close to the center line of the sealing cover.

[0011] According to the cover plate assembly of the embodiment of the present application, the cover plate and the sealing cover are connected by welding. During the welding process, a weld portion is formed between the cover plate and the sealing cover, which can enhance the connection strength between the cover plate and the sealing cover, reduce the operational difficulty of welding between the cover plate and the sealing cover, and improve the assembly stability between the sealing cover and the cover plate. The setting of the weld surface increases the contact area between the weld portion and the air, which can enhance the sealing performance and reliability between the sealing cover and the cover plate, and improve the helium inspection yield of the battery using the cover plate assembly.

[0012] In some embodiments, the weld surface is an arc-shaped surface.

[0013] In some embodiments, the through hole includes a first hole segment and a second hole segment connected to each other along the thickness direction of the cover plate, the sealing cover is arranged in the first hole segment, and the weld portion is located between the outer periphery of the sealing cover and the inner wall of the cover plate forming the first hole segment.

[0014] In some embodiments, the depth of the first hole segment is h, the thickness of the sealing cover is t, and h and t satisfy: 1.8≤h / t≤2.5.

[0015] In some embodiments, a groove is formed on a surface of the sealing cover away from the through hole, and the groove is located at an edge of the sealing cover.

[0016] In some embodiments, the depth of the groove is H, the depth of the first hole segment is h, and the thickness of the sealing cover is t, and H, h, and t satisfy: H=ht.

[0017] In some embodiments, a protrusion is provided on the sealing cover, at least part of the orthographic projection of the protrusion in the thickness direction of the cover plate overlaps with the orthographic projection of the second hole segment in the thickness direction of the cover plate, and protrudes in a direction away from the second hole segment.

[0018] In some embodiments, the sealing cover includes an overlapping portion, the raised portion includes a first bending portion, the raised portion protrudes in a direction away from the second hole segment through the first bending portion, the sealing cover includes a second bending portion, the second bending portion is located at the edge of the sealing cover, connected end to end and in a ring shape, the second bending portion is connected to the cover plate, and the shape of the second bending portion corresponds to the inner wall of the cover plate in the first hole segment, and the first bending portion, the overlapping portion, and the second bending portion are arranged to form the groove.

[0019] In some embodiments, the cover plate forms a step portion between the first hole segment and the second hole segment, and the overlapping portion overlaps the step portion.

[0020] In some embodiments, the angle between the surface of the first bent portion away from the second hole segment and the surface of the overlapping portion away from the step portion is β, the angle between the surface of the second bent portion connected to the cover plate in the radial direction of the sealing cover and the central axis of the through hole is γ / 2, the width of the overlapping portion is L, and the minimum distance between the side surface of the weld portion adjacent to the central axis of the sealing cover and the side surface of the groove adjacent to the central axis of the sealing cover is N1, and L, N1, β, and γ satisfy: 0.5t≤L≤N1=(h-t)×tan(γ / 2)+L+(v-t)×tan(β).

[0021] In some embodiments, the distance between one end of the second bend portion adjacent to the central axis of the sealing cover and the central axis of the sealing cover is a1, and the distance between one end of the second bend portion away from the central axis of the sealing cover and the central axis of the sealing cover is a2, and a1 and a2 satisfy: 1mm≤h×tan(γ / 2)+a1≤20mm.

[0022] In some embodiments, L, N1, a1, and a2 satisfy: 0 mm ≤ (N1 - (a2 - a1) × (ht) / hL) / tan (β) ≤ 4 mm.

[0023] In some embodiments, a minimum distance between an end of the weld portion close to the step portion and the step portion is N2, and N2 satisfies: 0.5t≤N2≤t.

[0024] In some embodiments, the minimum straight-line distance between the end of the weld surface of the weld portion away from the center line of the sealing cover and the end of the weld surface close to the through hole is T, the thickness of the sealing cover is t, and T and t satisfy: t≤T≤4t.

[0025] In some embodiments, the maximum distance from one end of the weld portion close to the step portion to the weld surface is W, the thickness of the sealing cover is t, and W and t satisfy: 0.5t≤W≤2t.

[0026] In some embodiments, the cross-section of the sealing cover along the plane parallel to the cover plate is elliptical, the major semi-axis length of the sealing cover is a, and the minor semi-axis length is b, and a and b satisfy: 1mm≤a≤20mm, 1mm≤b≤20mm, and 1<a / b≤2.

[0027] According to the second embodiment of the present application, the battery includes: a shell, the shell is formed with an opening; a cover assembly, the cover assembly is engaged at the opening, the cover assembly and the shell define a accommodating cavity, the cover assembly is the cover assembly for the battery described in any one of the above embodiments; and a battery cell, the battery cell is arranged in the accommodating cavity.

[0028] The battery pack according to the third embodiment of the present application includes the battery according to the above-mentioned second embodiment of the present application.

[0029] The vehicle according to the fourth embodiment of the present application includes a battery pack according to the third embodiment of the present application.

[0030] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0032] FIG1 is a schematic diagram of a cover plate assembly according to an embodiment of the present application.

[0033] FIG2 is an enlarged schematic diagram of the P region in FIG1 .

[0034] FIG3 is a schematic diagram of the cooperation between the sealing cover and the cover plate according to an embodiment of the present application.

[0035] FIG4 is a schematic diagram of a sealing cover according to an embodiment of the present application.

[0036] FIG5 is a schematic diagram of the sealing cover from another perspective according to an embodiment of the present application.

[0037] FIG6 is a schematic block diagram of a battery according to an embodiment of the present application.

[0038] FIG7 is a schematic block diagram of a battery pack according to an embodiment of the present application.

[0039] FIG8 is a schematic block diagram of a vehicle according to an embodiment of the present application.

[0040] Reference numerals:

[0041] 3000 vehicles,

[0042] Battery 1000, Battery Pack 2000,

[0043] Cover assembly 100, housing 200, opening 201, accommodating cavity 202, battery cell 203,

[0044] Cover plate 10, through hole 11, first hole section 12, second hole section 13, step portion 14,

[0045] Sealing cover 20, overlapping portion 21, groove 22, raised portion 23, first bent portion 24, second bent portion 25,

[0046] Weld portion 30 and weld surface 31 . DETAILED DESCRIPTION

[0047] The following describes in detail embodiments of the present application, and the embodiments described with reference to the accompanying drawings are exemplary.

[0048] 1 to 5 , a cap plate assembly 100 for a battery according to an embodiment of the present application will be described. The cap plate assembly 100 includes a cap plate 10, a sealing cover 20, and a weld portion 30. The cap plate 10 has a thickness direction A.

[0049] Specifically, as shown in Figures 1 to 5, a through hole 11 is formed in the cover plate 10, and a sealing cover 20 is provided on the cover plate 10 to seal the through hole 11. A weld portion 30 is provided between the sealing cover 20 and the cover plate 10 to achieve a sealed connection between the sealing cover 20 and the cover plate 10. The weld portion 30 has a weld surface 31 facing away from the cover plate 10. The end of the weld surface 31 away from the centerline of the sealing cover 20 is connected to the cover plate 10, and the end of the weld surface 31 closer to the centerline of the sealing cover 20 is connected to the sealing cover 20. In the thickness direction A of the cover plate assembly 100, the end of the weld surface 31 away from the centerline of the sealing cover 20 is higher than the end closer to the centerline of the sealing cover 20.

[0050] 1-3 , the through hole 11 penetrates the cover plate 10 along the thickness direction A of the cover plate 10. The sealing cover 20 and the through hole 11 are opposite each other along the thickness direction A of the cover plate 10. The weld portion 30 is provided between the sidewall on the outer periphery of the sealing cover 20 and the sidewall on the inner periphery of the through hole 11 to connect the sealing cover 20 to the cover plate 10 and seal the sealing cover 20. The outer periphery of the sealing cover 20 is annular, and the inner wall of the through hole 11 on the cover plate 10 is adapted to the outer periphery of the sealing cover 20. The sealing cover 20, with its annular outer periphery, coincides with the center of the through hole 11. The sealing cover 20 is provided at the through hole 11 and is arranged concentrically therewith.

[0051] The weld portion 30 is provided between the outer periphery of the sealing cover 20 and the inner wall of the through hole 11. The weld portion 30 is provided with a weld surface 31 on the side away from the through hole 11 along the thickness direction A of the cover plate 10. One end of the weld surface 31 overlaps the cover plate 10, and the other end of the weld surface 31 overlaps the sealing cover 20. The weld surface 31 is away from the cover plate 10 and the sealing cover 20 along the thickness direction A of the cover plate 10 and is exposed to the external atmosphere. That is, the weld surface 31 is located on one side surface of the cover plate 10 in the thickness direction A.

[0052] According to the cover plate assembly 100 of the embodiment of the present application, the cover plate 10 and the sealing cover 20 are connected by welding. During the welding process, a weld portion 30 is formed between the cover plate 10 and the sealing cover 20, which can enhance the connection strength between the cover plate 10 and the sealing cover 20, reduce the operational difficulty of welding between the cover plate 10 and the sealing cover 20, and improve the assembly stability between the sealing cover 20 and the cover plate 10. The provision of the weld surface 31 increases the contact area between the weld portion 30 and the air, which can enhance the sealing performance and reliability between the sealing cover 20 and the cover plate 10, and improve the helium inspection yield of the battery using the cover plate assembly 100.

[0053] According to some embodiments of the present application, as shown in FIG2 , the weld surface 31 is an arc-shaped surface. The weld surface 31 is an arc-shaped surface, which can form an edge weld, and the edge weld has a wider weld width margin. The weld width refers to the lateral width of the molten metal of the welding wire or welding rod during the welding process, that is, the width of the joint melted on the two workpieces during the welding process, which can make the weld width between the sealing cover 20 and the cover plate 10 larger, and can increase the reliability of the welding seal between the sealing cover 20 and the cover plate 10. Therefore, the weld surface 31 is an arc-shaped surface, which is conducive to improving the reliability of the welding seal between the sealing cover 20 and the cover plate 10, and can also make the appearance of the cover plate assembly 100 more simple and beautiful.

[0054] According to some embodiments of the present application, as shown in FIG3 , the through hole 11 includes a first hole segment 12 and a second hole segment 13 connected to each other along the thickness direction A of the cover plate 10. The sealing cover 20 is disposed within the first hole segment 12, and the weld portion 30 is located between the outer peripheral edge of the sealing cover 20 and the inner wall of the cover plate 10 forming the first hole segment 12. The first hole segment 12 and the second hole segment 13 are coaxially arranged, and one end of the first hole segment 12 along the thickness direction A of the cover plate 10 is connected to an end of the second hole segment 13 along the thickness direction A of the cover plate 10 adjacent to the sealing cover 20. The cross-sectional area of ​​the first hole segment 12 along the thickness direction A of the cover plate 10 is greater than the cross-sectional area of ​​the second hole segment 13 along the thickness direction A of the cover plate 10.

[0055] Therefore, the setting of the first hole section 12 facilitates the installation of the sealing cover 20, and the weld portion 30 is provided between the outer periphery of the sealing cover 20 and the inner wall of the first hole section 12, so as to facilitate the fixed connection between the sealing cover 20 and the first hole section 12. The first hole section 12 can play a certain limiting role on the sealing cover 20. The setting of the second hole section 13 facilitates the connection between the first hole section 12 and the interior of the cover plate assembly 100. The setting of the first hole section 12 and the second hole section 13 can improve the positioning accuracy of the sealing cover 20, thereby enhancing the installation accuracy of the cover plate assembly 100.

[0056] According to some embodiments of the present application, as shown in FIG3 , the depth of the first hole section 12 is h, the thickness of the sealing cover 20 is t, and h and t satisfy the following relationship: 1.8 ≤ h / t ≤ 2.5. If h / t is less than 1.8, the depth of the first hole section 12 will be too small, and the space for accommodating the sealing cover 20 will be too small, which will increase the difficulty of assembling the sealing cover 20 with the first hole section 12, and may easily cause the sealing cover 20 to protrude from the upper surface of the cover plate 10, affecting the installation of the cover plate assembly 100. A thicker sealing cover 20 will increase the difficulty of producing the sealing cover 20, resulting in higher production costs for the sealing cover 20 and waste of production materials.

[0057] If h / t is greater than 2.5, the depth of the first hole section 12 will be too large, and the space required to accommodate the sealing cover 20 will be too large, which is not conducive to improving the space utilization inside the cover plate 10. The thickness of the sealing cover 20 will be too thin, resulting in a low structural strength of the sealing cover 20. For example, h / t = 2.

[0058] Thus, defining the relationship between the depth of the first hole section 12 and the thickness of the sealing cover 20 ensures that the first hole section 12 has sufficient space to accommodate the sealing cover 20, thereby ensuring the structural strength of the sealing cover 20, improving the positioning accuracy of the sealing cover 20 installed in the first hole section 12, and enhancing the assembly stability of the cover plate assembly 100. Furthermore, the depth of the first hole section 12 being twice the thickness of the sealing cover 20 leaves sufficient space for welding the sealing cover 20, preventing welding through the sealing cover 20 and ensuring the sealing effect of the sealing cover 20.

[0059] According to some embodiments of the present application, as shown in FIG4 , a groove 22 is formed on the side surface of the sealing cover 20 away from the through hole 11. The groove 22 is located at the edge of the sealing cover 20. The groove 22 is formed by a portion of the side surface of the sealing cover 20 away from the through hole 11 along the thickness direction A of the cover plate 10, which is recessed in the direction toward the through hole 11. The groove 22 extends along the circumference of the through hole 11. The shape of the groove 22 corresponds to the outer periphery of the sealing cover 20. The groove 22 is opposite to the overlapping portion 21 of the sealing cover 20 along the thickness direction A of the cover plate 10, so that the groove 22 can more comprehensively release welding stress. Therefore, the provision of the groove 22 on the sealing cover 20 can release the welding stress generated when the sealing cover 20 is welded to the cover plate 10 through the groove 22, thereby preventing the sealing cover 20 from cracking the weld portion 30 due to excessive welding stress. The provision of the groove 22 ensures the yield and reliability of the weld portion 30, which is conducive to reducing the production cost of the cover plate assembly 100.

[0060] According to some embodiments of the present application, as shown in Figures 3 and 4 , the depth of the groove 22 is H, the depth of the first hole section 12 is h, and the thickness of the sealing cover 20 is t, where H, h, and t satisfy the following relationship: H = ht. Thus, by defining the depth of the groove 22 by the depth of the first hole section 12 and the thickness of the sealing cover 20, the welding stress generated during welding of the sealing cover 20 can be released to the greatest extent, facilitating complete release of welding stress and further improving the yield and reliability of the weld portion 30.

[0061] According to some embodiments of the present application, as shown in Figures 3 and 4, a raised portion 23 is provided on the sealing cover 20. At least a portion of the orthographic projection of the raised portion 23 in the thickness direction A of the cover plate 10 overlaps with the orthographic projection of the second hole segment 13 in the thickness direction A of the cover plate 10, and the raised portion 23 protrudes in a direction away from the second hole segment 13. The raised portion 23 is provided in the center of the sealing cover 20, and the raised portion 23 and the second hole segment 13 are arranged opposite each other along the thickness direction A of the cover plate 10. The raised portion 23 is formed by a portion of the center of the sealing cover 20 protruding along the thickness direction A of the cover plate 10 in a direction away from the second hole segment 13. A certain distance exists between the raised portion 23 and the second hole segment 13 on the side adjacent to the second hole segment 13 along the thickness direction A of the cover plate 10. The space between the raised portion 23 and the second hole segment 13 forms a relief portion. The relief portion is parallel to the side of the cover plate 10 away from the through hole 11 along the thickness direction A of the cover plate 10. The groove 22 surrounds the raised portion 23. Thus, the provision of the raised portion 23 creates a certain distance between the sealing cover 20 and the second hole segment 13, providing more space for heat dissipation in the sealing cover 20. This facilitates heat dissipation during welding and reduces welding difficulty.

[0062] According to some embodiments of the present application, as shown in Figures 3 and 4, the sealing cover 20 includes a lap portion 21, the raised portion 23 includes a first bent portion 24, the raised portion 23 protrudes in a direction away from the second hole segment 13 through the first bent portion 24, the sealing cover 20 includes a second bent portion 25, the second bent portion 25 is located at the edge of the sealing cover 20, connected end to end and in a ring shape, the second bent portion 25 is connected to the cover plate 10, and the shape of the second bent portion 25 corresponds to the inner wall of the cover plate 10 in the first hole segment 12, the first bent portion 24, the lap portion 21, and the second bent portion 25 are arranged to form a groove 22. The first bent portion 24 connects the raised portion 23 and the overlapping portion 21. The first bent portion 24 is located at the edge of the raised portion 23, connected end to end, and is annular. The second bent portion 25 is connected to the overlapping portion 21. The second bent portion 25 is disposed opposite the inner wall of the first hole section 12, and the weld portion 30 is located between the second bent portion 25 and the inner wall of the first hole section 12. The raised portion 23, the first bent portion 24, the overlapping portion 21, and the second bent portion 25 have equal thickness.

[0063] Therefore, the sealing cover 20 can buffer the stress generated during welding by setting the raised portion 23, the first bent portion 24, the overlapping portion 21 and the second bent portion 25, thereby absorbing and releasing the stress generated during welding and achieving a better buffering effect. The structure of the sealing cover 20 is easier to stamp and form, which can reduce the difficulty of stamping and improve the efficiency of forming. After forming, the stress on the sealing cover 20 is dispersed rather than concentrated, so that the stress will not cause the weld portion 30 to crack, making the fatigue resistance of the cover plate assembly 100 better, ensuring the quality of the weld portion 30 and the sealing reliability of the cover plate assembly 100.

[0064] According to some embodiments of the present application, as shown in Figures 3 and 4, the cover plate 10 forms a step portion 14 between the first hole section 12 and the second hole section 13, and the overlapping portion 21 overlaps the step portion 14. The step portion 14 is located at one end of the first hole section 12 adjacent to the second hole section 13 along the thickness direction A of the cover plate 10. The step portion 14 extends along the circumference of the through hole 11. The step portion 14 is arranged opposite to the sealing cover 20 along the thickness direction A of the cover plate 10. The overlapping portion 21 of the sealing cover 20 is located on a side of the sealing cover 20 adjacent to the second hole section 13 along the thickness direction A of the cover plate 10. When the sealing cover 20 is installed in the first hole section 12, the overlapping portion 21 of the sealing cover 20 abuts against the step portion 14. Therefore, the setting of the step portion 14 can enable the through hole 11 to limit the sealing cover 20 in the thickness direction A of the cover plate 10, and the overlap portion 21 and the step portion 14 can increase the contact area between the sealing cover 20 and the step portion 14, so that the sealing cover 20 is installed more tightly in the through hole 11, thereby improving the connection strength and installation stability of the sealing cover 20.

[0065] According to some embodiments of the present application, as shown in Figures 2 to 4, the angle between the surface of the first bend portion 24 away from the second hole section 13 and the surface of the overlapping portion 21 away from the step portion 14 is β, the angle between the surface of the second bend portion 25 connected to the cover plate 10 in the radial direction of the sealing cover 20 and the central axis of the through hole 11 is γ / 2, the width of the overlapping portion 21 is L, and the minimum distance between the side surface of the weld portion 30 adjacent to the central axis of the sealing cover 20 and the side surface of the groove 22 adjacent to the central axis of the sealing cover 20 is N1, and L, N1, β, and γ satisfy: t / 2≤L≤N1=(h-t)×tan(γ / 2)+L+(v-t)×tan(β).

[0066] The angle between the side surface of the first bent portion 24 away from the second hole section 13 and the side surface of the overlapping portion 21 away from the step portion 14 along the thickness direction A of the cover plate 10 is β, the angle between the side surface of the second bent portion 25 opposite to the inner wall of the cover plate 10 and the central axis of the through hole 11 is γ, and the width L of the overlapping portion 21 is the distance from the connection position of the side surface of the overlapping portion 21 away from the step portion 14 along the thickness direction A of the cover plate 10 and the first bent portion 24 to the connection position of the overlapping portion 21 and the second bent portion 25. If L, N1, β, and γ do not satisfy t / 2≤L≤N1=(h-t)×tan(γ / 2)+L+(v-t)×tan(β), the welding effect between the sealing cover 20 and the cover plate 10 will be affected, and the sealing effect of the weld portion 30 will be deteriorated. Therefore, by limiting the values ​​of L, N1, β, and γ and the relationship between L, N1, β, and γ, the welding process of the sealing cover 20 can be ensured, and the heat of the weld 30 can be prevented from burning the raised portion 23 of the sealing cover 20 and affecting the sealing performance of the sealing cover 20.

[0067] According to some embodiments of the present application, as shown in Figures 2 to 4, the distance between one end of the second bend portion 25 adjacent to the central axis of the sealing cover 20 and the central axis of the sealing cover 20 is a1, and the distance between one end of the second bend portion 25 away from the central axis of the sealing cover 20 and the central axis of the sealing cover 20 is a2, and a1 and a2 satisfy: 1mm≤h×tan(γ / 2)+a1≤20mm.

[0068] The second bent portion 25 is obliquely arranged at the edge of the sealing cover 20, one end of the second bent portion 25 is connected to the overlapping portion 21, and the other end of the second bent portion 25 extends obliquely along the thickness direction A of the cover plate 10 toward a direction away from the overlapping portion 21 and away from the central axis of the sealing cover 20. The distance between the end of the second bent portion 25 adjacent to the central axis of the sealing cover 20, that is, the end of the outer peripheral side wall of the sealing cover 20 adjacent to the step portion 14 along the thickness direction A of the cover plate 10 and the central axis of the sealing cover 20 is a1, and the distance between the end of the second bent portion 25 away from the central axis of the sealing cover 20, that is, the end of the outer peripheral side wall of the sealing cover 20 away from the step portion 14 along the thickness direction A of the cover plate 10 and the central axis of the sealing cover 20 is a2.

[0069] Therefore, by limiting the values ​​of a1 and a2 and the relationship between a1, a2, h, and γ, the distance between the second bend portion 25 and the central axis of the sealing cover 20 can be limited, thereby improving the production accuracy of the sealing cover 20 and further improving the position accuracy of the weld portion 30, thereby achieving a better welding effect between the sealing cover 20 and the cover plate 10.

[0070] According to some embodiments of the present application, as shown in Figures 2-4, L, N1, a1, and a2 satisfy the following: 0mm≤(N1-(a2-a1)×(ht) / hL) / tan(β)≤4mm. Therefore, by defining the values ​​of L, N1, a1, and a2, as well as the relationship between L, N1, a1, and a2, the inclination angle of the second bend portion 25 relative to the overlap portion 21 can be defined, effectively improving the welding effect of the sealing cover 20 and the cover plate 10, thereby improving the welding strength and sealing performance of the weld portion 30, and enhancing the overall structural strength and sealing performance of the cover plate assembly 100.

[0071] According to some embodiments of the present application, as shown in FIG2 , the minimum distance N2 between the end of the weld portion 30 near the step portion 14 and the step portion 14 satisfies the following: 0.5t ≤ N2 ≤ t. If the minimum distance N2 between the end of the weld portion 30 near the step portion 14 and the step portion 14 is less than 0.5t, the thickness of the weld portion 30 along the thickness direction A of the cover plate 10 is too large, increasing the difficulty of welding and easily causing the sealing cover 20 to be welded through. If the minimum distance N2 between the end of the weld portion 30 near the step portion 14 and the step portion 14 is greater than t, the thickness of the weld portion 30 along the thickness direction A of the cover plate 10 is too small, easily causing the weld between the sealing cover 20 and the cover plate 10 to be weak, resulting in a low structural strength of the cover plate assembly 100. For example, N2 = 0.75t. Thus, the minimum distance between the end of the weld portion 30 close to the step portion 14 and the step portion 14 is limited, which reduces the welding difficulty and improves the structural strength of the cover plate assembly 100 while ensuring the connection strength between the sealing cover 20 and the cover plate 10.

[0072] According to some embodiments of the present application, as shown in Figures 2 and 3, the minimum straight-line distance between the weld surface 31 of the weld portion 30 away from the centerline of the sealing cover 20 and the end closest to the through-hole 11 is T, the thickness of the sealing cover 20 is t, and T and t satisfy: t≤T≤4t. That is, the weld width of the weld portion 30 is T, the thickness of the sealing cover 20 is t, and T and t satisfy: t≤T≤4t. If the weld width T of the weld portion 30 is less than t, the weld width of the weld portion 30 is too small, resulting in insufficient weld strength between the sealing cover 20 and the cover plate 10, affecting the assembly strength of the cover plate assembly 100. If the weld width T of the weld portion 30 is greater than 4t, the weld width of the weld portion 30 is too large, and the weld may penetrate the side wall of the sealing cover 20 during welding, causing damage to the sealing cover 20 and prolonging the welding time. This can result in excessive heat generation, causing burning of the central portion of the sealing cover 20, and affecting the performance of the sealing cover 20. For example, T = t. Therefore, limiting the weld width of the weld portion 30 can effectively ensure the welding effect between the sealing cover 20 and the cover plate 10 , enhance the connection strength between the sealing cover 20 and the cover plate 10 , and improve the sealing performance of the weld portion 30 .

[0073] According to some embodiments of the present application, as shown in Figures 2 and 3 , the maximum distance from the end of the weld 30 adjacent to the step 14 to the weld surface 31 is W. That is, the penetration depth of the weld 30 in the thickness direction A of the cover plate 10 is W, and the thickness of the sealing cover 20 is t, where W and t satisfy t / 2 ≤ W ≤ 2t. If the penetration depth W of the weld 30 in the thickness direction A of the cover plate 10 is less than t / 2, the penetration depth of the weld 30 in the thickness direction A of the cover plate 10 is too small, resulting in a weak connection between the sealing cover 20 and the cover plate 10 and reducing the structural strength of the cover plate assembly 100. If the penetration depth W of the weld 30 in the thickness direction A of the cover plate 10 is greater than 2t, the penetration depth of the weld 30 in the thickness direction A of the cover plate 10 is too large, increasing the difficulty of welding and hindering the production cost of the cover plate assembly 100. For example, W = 1t. Thus, by limiting the penetration depth of the weld portion 30 in the thickness direction A of the cover plate 10, the connection strength between the sealing cover 20 and the cover plate 10 can be ensured, the sealing performance of the weld portion 30 can be enhanced, the difficulty of welding between the sealing cover 20 and the cover plate 10 can be reduced, and the production cost of the cover plate assembly 100 can be reduced.

[0074] According to some embodiments of the present application, as shown in FIG5 , the cross-section of the sealing cover 20 along a plane parallel to the cover plate 10 is elliptical, with the semi-major axis length of the sealing cover 20 being a and the semi-minor axis length being b, where a and b satisfy the following conditions: 1 mm ≤ a ≤ 20 mm, 1 mm ≤ b ≤ 20 mm, and 1 ≤ a / b ≤ 2. When a / b = 1, the sealing cover 20 is circular. When a / b is less than 1 or greater than 2, the sealing cover 20 is elliptical, and the sealing cover 20 is a relatively flat elliptical shape. The elliptical shape of the sealing cover 20 is not conducive to uniform distribution of welding stress when welded to the cover plate 10, and the stress generated during welding is easily concentrated at the two ends of the ellipse, causing cracks in the weld seams 30 at both ends of the sealing cover 20, thereby affecting the sealing performance of the sealing cover 20.

[0075] Thus, by limiting the length of the semi-axial length of the long side and the short side of the sealing cover 20, the shape of the sealing cover 20 can be limited, so that the sealing cover 20 and the cover plate 10 can be adapted to each other. Limiting the length relationship between the semi-axial length of the long side and the short side of the sealing cover 20 facilitates defining the shape of the sealing cover 20, improves the processing accuracy of the sealing cover 20, reduces the welding difficulty between the sealing cover 20 and the cover plate 10, and enhances the strength and sealing performance of the weld portion 30 between the sealing cover 20 and the cover plate 10.

[0076] According to the battery 1000 of the embodiment of the second aspect of the present application, as shown in FIG6 , the battery 1000 includes: a housing 200, a cover assembly 100, and a battery cell 203. The housing 200 is formed with an opening 201, and the cover assembly 100 is fitted at the opening 201. The cover assembly 100 and the housing 200 define a receiving cavity 202. The cover assembly 100 is the cover assembly 100 for a battery in any of the above embodiments, and the battery cell 203 is disposed in the receiving cavity 202. That is, one end of the housing 200 is open to form the opening 201, and the battery cell 203 is disposed in the housing 200 through the opening 201. The cover assembly 100 cooperates with the housing 200 at the opening 201 to form a seal on the housing 200, so that the battery cell 203 is placed in the closed receiving cavity 202.

[0077] According to the battery 1000 of the embodiment of the present application, by using the cover plate assembly 100 in the above embodiment, the welding slag generated by the cover plate assembly 100 during welding can be prevented from falling into the interior of the battery through the through hole 11 on the cover plate 10 due to vibration or other reasons during the process of the battery cell 203 or use, thereby effectively improving the sealing performance and structural strength of the cover plate assembly 100, thereby improving the overall performance of the battery 1000 and improving the safety of the battery 1000.

[0078] The battery pack 2000 according to the third embodiment of the present application includes the battery 1000 in the above embodiment, as shown in FIG7 .

[0079] According to the battery pack 2000 of the embodiment of the present application, by using the battery 1000 in the above embodiment, the yield and reliability of the battery pack 2000 in the production process can be improved, which is beneficial to reducing the manufacturing cost of the battery pack 2000, effectively improving the comprehensive performance and safety of the battery pack 2000, reducing the production cost of the battery pack 2000, and extending the service life of the battery pack 2000.

[0080] The vehicle 3000 according to the fourth embodiment of the present application includes the battery pack 2000 in the above embodiment, as shown in FIG8 .

[0081] According to the vehicle 3000 of the embodiment of the present application, by using the battery pack 2000 of the above embodiment, the service life of the battery pack 2000 can be extended and thus the service life of the vehicle 3000 can be extended, the comprehensive performance and safety performance of the vehicle 3000 can be improved, and the after-sales cost of the vehicle 3000 can be reduced.

[0082] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application 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, and therefore should not be understood as a limitation on the present application.

[0083] In the description of the present application, "first feature" and "second feature" may include one or more of the features. In the description of the present application, "plurality" means two or more. In the description of the present application, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through another feature between them. In the description of the present application, the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature.

[0084] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "example," "specific example," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment or example of the present application. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0085] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and intent of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A cover plate assembly (100) for a battery, characterized in that: include: A cover plate (10), wherein a through hole (11) is formed on the cover plate (10); a sealing cover (20), the sealing cover (20) being arranged on the cover plate (10) to seal the through hole (11); and A weld portion (30), the weld portion (30) being arranged between the sealing cover (20) and the cover plate (10) to achieve a sealed connection between the sealing cover (20) and the cover plate (10), the weld portion (30) having a weld surface (31) facing away from the cover plate (10), an end of the weld surface (31) away from the center line of the sealing cover (20) being connected to the cover plate (10), and an end of the weld surface (31) close to the center line of the sealing cover (20) being connected to the sealing cover (20), and in the thickness direction of the cover plate assembly (100), an end of the weld surface (31) away from the center line of the sealing cover (20) is higher than an end of the weld surface (31) close to the center line of the sealing cover (20).

2. The cover plate assembly (100) for a battery according to claim 1, characterized in that: The weld surface (31) is an arc-shaped surface.

3. The cover plate assembly (100) for a battery according to claim 1 or 2, characterized in that: The through hole (11) comprises a first hole section (12) and a second hole section (13) which are connected to each other along the thickness direction of the cover plate (10); the sealing cover (20) is arranged in the first hole section (12); and the welding seam portion (30) is located between the outer peripheral edge of the sealing cover (20) and the inner wall of the cover plate (10) forming the first hole section (12).

4. The cover plate assembly (100) for a battery according to claim 3, characterized in that: The depth of the first hole section (12) is h, the thickness of the sealing cover (20) is t, and h and t satisfy: 1.8≤h / t≤2.

5.

5. The cover plate assembly (100) for a battery according to claim 3, characterized in that: A groove (22) is formed on a surface of one side of the sealing cover (20) away from the through hole (11), and the groove (22) is located at the edge of the sealing cover (20).

6. The cover plate assembly (100) for a battery according to claim 5, characterized in that: The depth of the groove (22) is H, the depth of the first hole section (12) is h, the thickness of the sealing cover (20) is t, and H, h, and t satisfy: H=ht.

7. The cover plate assembly (100) for a battery according to claim 5, characterized in that: The sealing cover (20) is provided with a protrusion (23), wherein at least part of the orthographic projection of the protrusion (23) in the thickness direction of the cover plate (10) overlaps with the orthographic projection of the second hole section (13) in the thickness direction of the cover plate (10), and protrudes in a direction away from the second hole section (13).

8. The cover plate assembly (100) for a battery according to claim 7, characterized in that: The sealing cover (20) comprises an overlapping portion (21); The protruding portion (23) comprises a first bending portion (24), and the protruding portion (23) protrudes in a direction away from the second hole section (13) through the first bending portion (24); The sealing cover (20) comprises a second bent portion (25), the second bent portion (25) being located at the edge of the sealing cover (20), connected end to end and in a ring shape, the second bent portion (25) being connected to the cover plate (10), and the shape of the second bent portion (25) corresponding to the inner wall of the cover plate (10) in the first hole section (12), and the first bent portion (24), the overlapping portion (21) and the second bent portion (25) being arranged to form the groove (22).

9. The cover plate assembly (100) for a battery according to claim 8, characterized in that: The cover plate (10) forms a step portion (14) between the first hole section (12) and the second hole section (13), and the overlapping portion (21) overlaps the step portion (14).

10. The cover plate assembly (100) for a battery according to claim 9, characterized in that: The angle between the surface of the first bent portion (24) away from the second hole section (13) and the surface of the overlapping portion (21) away from the step portion (14) is β; The angle between the surface of the second bent portion (25) connected to the cover plate (10) in the radial direction of the sealing cover (20) and the central axis of the through hole (11) is γ / 2; The width of the overlapping portion (21) is L; The minimum distance between a side surface of the weld portion (30) adjacent to the central axis of the sealing cover (20) and a side surface of the groove (22) adjacent to the central axis of the sealing cover (20) is N1; The L, N1, β, and γ satisfy: 0.5t≤L≤N1=(h-t)×tan(γ / 2)+L+(v-t)×tan(β).

11. The cover plate assembly (100) for a battery according to claim 10, characterized in that: The distance between one end of the second bent portion (25) adjacent to the central axis of the sealing cover (20) and the central axis of the sealing cover (20) is a1, and the distance between one end of the second bent portion (25) away from the central axis of the sealing cover (20) and the central axis of the sealing cover (20) is a2, and a1 and a2 satisfy: 1mm≤h×tan(γ / 2)+a1≤20mm.

12. The cover plate assembly (100) for a battery according to claim 11, characterized in that: The L, N1, a1, and a2 satisfy: 0mm≤(N1-(a2-a1)×(ht) / hL) / tan(β)≤4mm.

13. The cover plate assembly (100) for a battery according to any one of claims 9 to 12, characterized in that: The minimum distance between one end of the weld portion (30) close to the step portion (14) and the step portion (14) is N2, and N2 satisfies: 0.5t≤N2≤t.

14. The cover plate assembly (100) for a battery according to any one of claims 1 to 13, characterized in that: The minimum straight-line distance between an end of the weld surface (31) of the weld portion (30) away from the center line of the sealing cover (20) and an end of the weld surface (31) close to the through hole (11) is T, the thickness of the sealing cover (20) is t, and T and t satisfy: t≤T≤4t.

15. The cover plate assembly (100) for a battery according to any one of claims 9 to 13, characterized in that: The maximum distance from one end of the weld portion (30) close to the step portion (14) to the weld surface (31) is W, the thickness of the sealing cover (20) is t, and W and t satisfy: 0.5t≤W≤2t.

16. The cover plate assembly (100) for a battery according to any one of claims 1 to 15, characterized in that: The cross section of the sealing cover (20) along a plane parallel to the cover plate (10) is elliptical, the major semi-axis length of the sealing cover (20) is a, and the minor semi-axis length is b, and a and b satisfy: 1 ​​mm ≤ a ≤ 20 mm, 1 mm ≤ b ≤ 20 mm, and 1 < a / b ≤ 2.

17. A battery (1000), characterized in that: include: A housing (200), wherein the housing (200) is formed with an opening (201); A cover plate assembly (100), the cover plate assembly (100) being fitted at the opening (201), the cover plate assembly (100) and the housing (200) defining a receiving cavity (202), the cover plate assembly (100) being the cover plate assembly (100) for a battery according to any one of claims 1 to 16; and A battery core (203), wherein the battery core (203) is arranged in the accommodating cavity (202).

18. A battery pack (2000), characterized in that: Comprising a battery (1000) according to claim 17.

19. A vehicle (3000), characterized in that: Comprising the battery pack (2000) according to claim 18.

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