Battery cell cover plate assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack. The battery cell cover plate assembly comprises a cover plate body, a riveting block and a pole, the cover plate body is provided with an assembly hole; the riveting block is provided with a pole mounting hole; the riveting block is of a narrow and long structure, reverse pre-deformation structures are arranged from the central axis of the pole mounting hole to the two ends of the riveting block in the length direction of the riveting block, each reverse pre-deformation structure is of a bent structure formed by the riveting block deviating from a first plane, the first plane is perpendicular to the central axis of the pole mounting hole, the thickness of the riveting block is T, and T is larger than T; the maximum vertical distance between the reverse pre-deformation structure and the first plane is H, and H is larger than T; the pole comprises a pole assembly section matched with the pole mounting hole, the pole assembly section sequentially penetrates through the assembly hole and the pole mounting hole and then is riveted with the riveting block, and the reverse pre-deformation structure deforms in the direction away from the cover plate body and reduces the flatness of the riveted riveting block. According to the invention, the flatness of the riveting block after riveting can be improved.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery cover assembly, a battery cell and a battery pack. Background Art

[0002] With the rapid development of new energy technologies, the performance and safety of power batteries, a core component of electric vehicles, have attracted widespread attention. As a new type of power battery structure, battery cells are highly sought after for their high energy density, safety, and space efficiency. During the battery cell manufacturing process, the connection between the terminal and the rivet block in the cell cover is crucial, directly impacting the overall performance and reliability of the cell.

[0003] Existing battery cells utilize a narrow, long cover plate design. To meet current requirements, the rivet block is also designed to be narrow and long, and is connected to the terminal through riveting. During riveting, vertical pressure is applied from top to bottom, centering on the terminal, to ensure a tight fit between the rivet block and the terminal.

[0004] Because the area of ​​the rivet block near the center of the pole is subjected to greater force, the riveting effect is better. However, the area away from the center of the pole is prone to warping due to uneven force. That is, the ends of the narrow and long rivet block are prone to warping and deformation after riveting. This deformation will cause the flatness value of the rivet block to increase, thereby affecting the dimensional accuracy of the total height of the battery cell. Furthermore, dimensional deviations may cause quality problems such as cold welds in the welding of the rivet block to the busbar, reducing the reliability and consistency of the battery and failing to fully meet the requirements of high-performance power batteries. Summary of the Invention

[0005] In view of this, the present invention provides a battery cover assembly, a battery cell and a battery pack to solve the problem that the rivet block is prone to warping and deformation at both ends after riveting, resulting in an increase in the flatness value of the rivet block, thereby affecting the dimensional accuracy of the total height of the battery cell and causing quality problems such as cold welding when welding the rivet block and the busbar.

[0006] In a first aspect, the present invention provides a battery cell cover assembly, comprising a cover body, a rivet block, and a pole. The cover body is provided with an assembly hole; the rivet block is provided with a pole mounting hole; the rivet block is a narrow and long structure, and along the length direction of the rivet block, from the central axis of the pole mounting hole to both ends of the rivet block, a reverse pre-deformation structure is provided, the reverse pre-deformation structure is a curved structure formed by the rivet block away from a first plane, the first plane being perpendicular to the central axis of the pole mounting hole and parallel to the surface of the cover body, the thickness of the rivet block is T, in mm, the maximum vertical distance from the surface of the reverse pre-deformation structure close to the cover body to the first plane is H, in mm, and H>T; the pole includes a pole assembly section adapted to the pole mounting hole, the pole assembly section sequentially passing through the assembly hole and the pole mounting hole, and then riveted to the rivet block, the reverse pre-deformation structure deforming in a direction away from the cover body and reducing the flatness of the riveted rivet block after riveting.

[0007] Beneficial Effects: By pre-setting reverse pre-deformation structures on both sides of the rivet block, i.e., pre-setting the rivet block as a curved structure away from the first plane, the present invention allows the reverse pre-deformation structure to deform in a direction away from the cover plate body during the riveting process, thereby offsetting the positive deformation generated during riveting, i.e., warping deformation away from the riveting direction. This reduces the flatness deviation of the rivet block after riveting, that is, improves the flatness of the rivet block after riveting, thereby ensuring the dimensional accuracy of the total height of the battery cell. Furthermore, due to the improved flatness of the rivet block after riveting, the welding quality between the rivet block and the busbar can be improved, ensuring the reliability and consistency of the battery.

[0008] In an optional embodiment, along the length direction of the riveted block, from the central axis of the pole mounting hole to the first end of the riveted block is a first reverse pre-deformation structure, and the maximum vertical distance between the surface of the first reverse pre-deformation structure close to the cover body and the first plane is H1, satisfying:

[0009]

[0010] Wherein, L1 is the distance from the central axis of the pole mounting hole to the first end of the riveted block along the length direction of the riveted block, in mm, and K1 is the compensation coefficient, 100≤K1≤250;

[0011] The second reverse pre-deformation structure is formed from the central axis of the pole mounting hole to the second end of the rivet block. The maximum vertical distance from the surface of the second reverse pre-deformation structure close to the cover body to the first plane is H2, which satisfies:

[0012]

[0013] Wherein, L2 is the distance from the central axis of the pole mounting hole to the second end of the riveted block along the length direction of the riveted block, in mm, and K2 is the compensation coefficient, 100≤K2≤250.

[0014] In an optional embodiment, 4mm≤L1≤35mm; 4mm≤L2≤35mm.

[0015] In an optional embodiment, K1=K2.

[0016] In an optional embodiment, the thickness T of the riveting block satisfies: 1.5 mm ≤ T ≤ 4.5 mm.

[0017] In an optional embodiment, the pole mounting hole is a waist-shaped hole, and the straight edge of the waist-shaped hole is arranged along the length direction of the riveting block;

[0018] Or the pole mounting hole is a circular hole.

[0019] In an optional embodiment, the center of the pole mounting hole is arranged at the center of the riveting block along its length direction;

[0020] Alternatively, the center of the pole mounting hole is arranged on a side deviating from the center of the riveting block along the length direction thereof.

[0021] In an optional embodiment, the pole also includes a pole base plate, the pole assembly section is arranged on the pole base plate, the pole base plate and the rivet block are respectively arranged on both sides of the cover plate body, and after the pole assembly section is riveted to the pole mounting hole of the rivet block, the top of the pole assembly section forms a rivet portion perpendicular to the central axis of the pole assembly section, and the top surface of the rivet portion is not higher than the top surface of the rivet block; the pole mounting hole is a stepped hole, and the stepped hole includes a rivet hole section for forming the rivet portion of the pole, and the rivet hole section is a cylindrical hole or a conical hole.

[0022] In the second aspect, the present invention also provides a battery cell, comprising a shell, a pole group and the battery cell cover assembly in the above technical solution, the shell having a accommodating cavity and an opening connected to the accommodating cavity; the pole group is arranged in the accommodating cavity of the shell; the battery cell cover assembly is arranged in the opening of the shell to encapsulate the pole group in the shell.

[0023] Beneficial Effects: The cell cover assembly is applied to the battery cell to seal the opening of the cell housing, sealing and protecting the internal components of the battery, preventing chemical leakage and the impact of the external environment on the battery. The poles of the cell cover assembly provide a path for the flow of current in and out, ensuring the current conduction during the battery cell's charging and discharging process. The cell cover assembly not only serves as an electrical connection for the battery cell, but also enhances the overall structural stability of the battery cell. It is an important component of the battery cell, ensuring the durability and safety of the battery cell during use.

[0024] Because the battery cell includes a battery cell cover plate assembly and has all the technical effects of the battery cell cover plate assembly, it will not be repeated here.

[0025] In a third aspect, the present invention further provides a battery pack comprising a plurality of battery cells according to the above technical solution, wherein the riveted blocks of adjacent battery cells are welded via a busbar.

[0026] Beneficial effects: Since the battery pack includes battery cells, it has all the technical effects of battery cells and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 An exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 The front view of the cell cover assembly after assembly is shown;

[0030] Figure 3 A top view of a battery cell cover assembly in the prior art;

[0031] Figure 4 This is a schematic diagram of the structure of the riveted block of the battery cell cover assembly in the prior art warping after riveting;

[0032] Figure 5 for Figure 4 A partial enlarged view of the middle D area;

[0033] Figure 6 for Figure 1 The front view of the rivet block in the battery cover assembly shown;

[0034] Figure 7 for Figure 1 A top view of the rivet block in the cell cover assembly shown;

[0035] Figure 8 For the Figure 7 Cross-sectional view at the middle BB;

[0036] Figure 9 A cross-sectional view of a rivet block in another battery cell cover assembly according to an embodiment of the present invention;

[0037] Figure 10 for Figure 1 A cross-sectional view of a pole in the cell cover assembly shown;

[0038] Figure 11 for Figure 1The cell cover assembly shown is along Figure 3 Cross-sectional view at AA in the middle;

[0039] Figure 12 for Figure 11 A partial enlarged view of point E in the middle;

[0040] Figure 13 The figure shows the schematic diagram of the measuring points when measuring flatness.

[0041] Description of reference numerals:

[0042] 1. Cover plate body; 101. Assembly hole; 2. Rivet block; 201. Pole mounting hole; 3. Pole; 301. Pole assembly section; 302. Pole base plate; 303. Riveted portion; 4. First insulating member; 5. Second insulating member; 6. Sealing ring; 7. Explosion-proof valve; 8. Explosion-proof valve patch. DETAILED DESCRIPTION

[0043] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0044] The following combination Figures 1 to 13 , describing embodiments of the present invention.

[0045] According to an embodiment of the present invention, in a first aspect, a cell cover assembly is provided, comprising a cover body 1 , a rivet block 2 and a pole 3 . The cover body 1 is provided with an assembly hole 101; the rivet block 2 is provided with a pole mounting hole 201; the rivet block 2 is a narrow and long structure, and along the length direction of the rivet block 2, a reverse pre-deformation structure is provided from the central axis of the pole mounting hole 201 to both ends of the rivet block 2. The reverse pre-deformation structure is a curved structure formed by the rivet block 2 away from the first plane. The first plane is perpendicular to the central axis of the pole mounting hole 201 and parallel to the surface of the cover body 1. The thickness of the rivet block 2 is T, in mm. The maximum vertical distance from the surface of the reverse pre-deformation structure close to the cover body 1 to the first plane is H, in mm, and H>T; the pole 3 includes a pole assembly section 301 adapted to the pole mounting hole 201. After the pole assembly section 301 passes through the assembly hole 101 and the pole mounting hole 201 in sequence, it is riveted to the rivet block 2. The reverse pre-deformation structure deforms in a direction away from the cover body 1 and reduces the flatness of the rivet block 2 after riveting.

[0046] The riveting block 2 and the pole 3 are riveted together. During this process, vertical pressure is applied from top to bottom with the pole 3 as the center. Figure 4 The middle riveting force F1 makes the riveting block 2 fit tightly with the pole 3. Since the area of ​​the riveting block 2 close to the center of the pole 3 is subjected to greater force, the riveting effect is better, while the area far from the center of the pole 3 is prone to warping due to uneven force, as shown in FIG. Figures 3 to 5 As shown, especially for the narrow and long riveting block 2, the warping and deformation of its two ends after riveting are more obvious.

[0047] To address the aforementioned issues with the narrow, elongated rivet block 2, the present invention pre-sets a reverse pre-deformation structure on both sides of the rivet block 2. This pre-sets the rivet block 2 as a curved structure that deviates from the first plane. This allows the reverse pre-deformation structure to deform in a direction away from the cover plate body 1 during the riveting process, thereby offsetting the positive deformation generated during riveting, i.e., the warping deformation away from the riveting direction. This reduces the flatness deviation of the rivet block 2 after riveting, improving the flatness of the rivet block 2 after riveting, thereby ensuring the dimensional accuracy of the total height of the battery cell. Furthermore, the improved flatness of the rivet block 2 after riveting can improve the welding quality between the rivet block 2 and the busbar, ensuring the reliability and consistency of the battery.

[0048] The length direction of the riveting block 2 is Figure 6 The X direction shown in is also the length direction of the cover body 1; Figure 6 The Z direction shown in FIG is the thickness direction of the riveting block 2 , and is also the thickness direction of the cover plate body 1 .

[0049] And, the first plane is as Figure 8 or Figure 9 The first plane is perpendicular to the axis of the central hole of the pole 3 of the riveting block 2 and parallel to the surface of the cover body 1. Specifically, Figure 8 In the embodiment, the first plane is the XY plane passing through the highest point of the top of the riveted block. Figure 8 The figure also illustrates a second plane P2-P2, which is the XY plane passing through the lowest point of the bottom of the riveted block. The second plane is parallel to the first plane. After riveting, the second plane P2-P2 aligns with the upper surface of the cover body 1. The maximum vertical distance H between the surface of the reverse pre-deformed structure closest to the cover body 1 and the first plane is the vertical distance between the first and second planes.

[0050] Since the present invention is a reverse pre-deformation structure designed to avoid the situation where the two ends of the riveting block 2 are warped after riveting, it is easy to understand that the direction in which the reverse pre-deformation structure deviates from the first plane is opposite to the direction in which the riveting block 2 warps during the riveting process.

[0051] The riveting block 2 can be formed into a reverse pre-deformed structure by punching. By designing a die of a specific shape, the riveting block 2 is punched on a punching device to form the required reverse pre-deformed structure.

[0052] The selection of the punching equipment and the design of the die for forming the riveting block 2 can be achieved by using techniques well known to those skilled in the art. The following is an example.

[0053] Mold material selection: The mold material should have high hardness, wear resistance and heat resistance. Commonly used mold materials include tool steel (such as H13, Cr12MoV) and cemented carbide.

[0054] Mold shape design: According to the required reverse pre-deformation shape, the geometric parameters of the mold are accurately calculated so that the mold cavity is the forming shape of the riveted block, that is, the riveted block is provided with a reverse pre-deformation structure.

[0055] Positioning accuracy control: Positioning pins or guide holes are set on the mold to ensure that the riveting block 2 is accurately positioned during the stamping process.

[0056] Stamping Equipment Selection: Select the appropriate press capacity based on the material thickness of the rivet block 2 and the desired degree of deformation. For example, if the rivet block 2 is made of pure aluminum AL1060 and the thickness T of the rivet block 2 is between 1.5mm and 4.5mm, a press with a capacity of 20 tons or more can be used.

[0057] Process parameter control: The process parameters (such as punching speed) are determined according to the material thickness and mechanical properties (such as yield strength and elastic modulus) of the riveting block 2.

[0058] Dimension inspection: After stamping is completed, the reverse pre-deformed structure of the riveted block 2 needs to be dimensionally inspected to ensure that it meets the design requirements.

[0059] In some embodiments, the stamping die is made into a shape corresponding to the structure of the riveting block 2 before riveting, and the shape is directly stamped by the stamping die. The size of H can be adjusted by trimming the die.

[0060] Flatness, as a geometric tolerance indicator, is used to assess the degree of deviation between an actual surface and an ideal plane. Simply put, it describes the flatness of a surface. The smaller the flatness value, the closer the surface is to an ideal plane—in other words, the flatter it is.

[0061] The thickness T of the riveting block 2 , that is, the wall thickness of the material of the riveting block 2 , does not change before and after the pre-deformation.

[0062] The maximum vertical distance from the surface of the reverse pre-deformation structure close to the cover body 1 to the first plane is H. Since the rivet block 2 is provided with a reverse pre-deformation structure, before riveting, the two surfaces of the rivet block 2 along its thickness direction are non-planar. Therefore, in the case of 8 or Figure 9 In the orientation shown, H is the dimension along the Z direction between the highest point of the upper surface and the lowest point of the lower surface of the rivet block 2.

[0063] It is understandable that before riveting, H>T of the riveted block 2. However, after riveting, due to the riveting force, the reverse pre-deformation structure deforms in a direction away from the cover plate body 1, making the surface of the riveted block 2 flat. At this time, the smaller the flatness, the closer H is to T. In an ideal state, the flatness is 0, and H=T.

[0064] By optimizing the shape and size of the riveted block 2, the present invention designs a reverse pre-deformation structure for the riveted block 2, ensuring that H>T (i.e., the maximum dimension of the reverse pre-deformation structure along the thickness direction of the riveted block 2 is greater than the thickness of the riveted block 2). This allows for deformation compensation during the riveting process, thereby reducing the degree of warping at both ends of the riveted block 2 after riveting, and thus reducing the flatness of the riveted block 2. Specifically, the present invention can achieve a flatness of less than or equal to 0.25 mm after riveting.

[0065] In some embodiments, along the length direction of the riveted block 2, a first reverse pre-deformation structure is formed from the central axis of the pole mounting hole 201 to the first end of the riveted block 2. The maximum vertical distance from the surface of the first reverse pre-deformation structure close to the cover body 1 to the first plane is H1, satisfying:

[0066]

[0067] Wherein, L1 is the distance from the central axis of the pole mounting hole 201 to the first end of the riveted block 2 along the length direction of the riveted block 2, in mm, and K1 is the compensation coefficient, 100≤K1≤250;

[0068] The second reverse pre-deformation structure is formed from the central axis of the pole mounting hole 201 to the second end of the rivet block 2. The maximum vertical distance from the surface of the second reverse pre-deformation structure close to the cover body 1 to the first plane is H2, which satisfies:

[0069]

[0070] Wherein, L2 is the distance from the central axis of the pole mounting hole 201 to the second end of the riveted block 2 along the length direction of the riveted block 2, in mm, and K2 is the compensation coefficient, 100≤K2≤250.

[0071] After research, the applicant found that since the riveting force is applied vertically from the position of the pole 3, the closer to the pole mounting hole 201, the smaller the deformation of the riveted block 2 after riveting, and the farther away from the pole mounting hole 201, especially at the two end positions of the riveted block 2, the more obvious the warping deformation. Therefore, the maximum dimension H occupied by the reverse pre-deformation structure along the thickness direction of the riveted block 2 is related to the distance between the end of the riveted block 2 and the pole mounting hole 201. Therefore, taking the central axis of the pole mounting hole 201 as the starting point and the end of the reverse pre-deformation structure as the end point, the distance L between the two is determined, and multiplied by the coefficient 1 / K, the compensation amount of the reverse pre-deformation can be obtained. The maximum dimension H occupied by the reverse pre-deformation structure along the thickness direction of the riveted block 2 is the sum of the thickness of the riveted block 2 and the compensation amount of the reverse pre-deformation.

[0072] For a narrow, elongated riveted block 2, two reverse pre-deformation structures are provided on either side of its length. The distance from the end of the first reverse pre-deformation structure to the center axis of the pole mounting hole 201 is L1. Substituting this into the above formula yields the maximum dimension H1 of the first reverse pre-deformation structure along the thickness direction of the riveted block 2. Similarly, for the second reverse pre-deformation structure, substituting L2 yields H2. The coefficient K ranges from 100 to 250. When applied to the riveted block 2, the calculated H consistently ensures a flatness of less than 0.25 mm, or even less, after riveting.

[0073] The compensation coefficient K1 or K2 takes a value within the above range, for example, 100, 120, 130, 150, 160, 180, 200, 220, 230, 250.

[0074] In some embodiments, 4 mm ≤ L1 ≤ 35 mm; 4 mm ≤ L2 ≤ 35 mm.

[0075] To prevent localized expansion and deformation of the rivet block 2 after the pole 3 is riveted, the distance between the central axis of the pole mounting hole 201 and the end of the rivet block 2 must be kept constant. Therefore, L1 and L2 must be limited to a minimum of 4 mm. However, if this distance is too large, the rivet block 2 will occupy too much space in the cover body 1 and affect the layout of other structural components, such as preventing the explosion-proof valve 7 and the injection port from being located. Therefore, the maximum distance between L1 and L2 must not exceed 35 mm.

[0076] L1 or L2 takes values ​​within the above range, for example, 4mm, 6mm, 8mm, 10mm, 12mm, 13mm, 15mm, 16mm, 18mm, 20mm, 22mm, 23mm, 25mm, 26mm, 28mm, 30mm, 32mm, 33mm, 35mm.

[0077] It is understood that along the length of the rivet block 2, when the central axis of the pole mounting hole 201 coincides with the center of the rivet block 2, L1 = L2, and when K1 = K2, H1 = H2. Correspondingly, when L1 ≠ L2, the central axis of the pole mounting hole 201 is eccentric with respect to the rivet block 2.

[0078] In some embodiments, K1 = K2.

[0079] When calculating H for two reverse pre-deformed structures, the value of K can be the same or different.

[0080] When K1=K2, that is, the compensation coefficients of the two reverse pre-deformation structures take the same value, and the calculated H1 and H2 are applied to the riveted block 2. After the riveted block 2 is riveted, the two reverse pre-deformation structures undergo compensatory deformation consistency under the action of the riveting force, thereby ensuring better overall flatness of the riveted block 2.

[0081] In some embodiments, the thickness T of the riveting block 2 satisfies: 1.5 mm ≤ T ≤ 4.5 mm.

[0082] To ensure sufficient riveting processing and strength of the pole 3, it is also necessary to limit 1.5≤T≤4.5mm. If the thickness of the rivet block 2 is too small, the pole 3 will be deformed after riveting and seriously affect the flatness. If the rivet block 2 is too thick, the riveting will be too difficult, the pole 3 will not expand well, and the riveting strength of the cover body 1 will be affected.

[0083] The thickness T of the rivet block 2 is within the above range, for example, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3.0 mm, 3.2 mm, 3.5 mm, 3.8 mm, 4.0 mm, 4.2 mm, and 4.5 mm.

[0084] In some embodiments, the pole mounting hole 201 is a waist-shaped hole, and the straight edge of the waist-shaped hole is arranged along the length direction of the riveting block 2; or the pole mounting hole 201 is a circular hole.

[0085] The cell cover plate assembly provided by the present invention is applicable to both elliptical and circular poles. For narrow, elongated riveted blocks 2, the prior art riveted blocks 2 will warp at both ends after being riveted to the pole 3 (whether elliptical or cylindrical). By adopting the technical solution of the present invention, a reverse pre-deformation structure is provided on both sides of the pole mounting hole 201 of the riveted block 2, which can effectively improve the flatness of the riveted block 2 after riveting. In particular, by using the above formula to calculate H and designing a reverse pre-deformation structure, the flatness of the riveted block 2 after riveting can be controlled to within 0.25 mm or even lower.

[0086] In some embodiments, the pole 3 also includes a pole base plate 302, the pole assembly section 301 is provided on the pole base plate 302, the pole base plate 302 and the rivet block 2 are respectively provided on both sides of the cover body 1, and after the pole assembly section 301 is riveted to the pole mounting hole 201 of the rivet block 2, the top of the pole assembly section 301 forms a rivet portion 303 perpendicular to the central axis of the pole assembly section 301, and the top surface of the rivet portion 303 is not higher than the top surface of the rivet block 2; the pole mounting hole 201 is a stepped hole, and the stepped hole includes a rivet hole section for forming the rivet portion 303 of the pole 3, and the rivet hole section is a cylindrical hole or a conical hole.

[0087] Specifically, the pole bottom plate 302 is provided on the lower surface of the cover body 1, and the pole assembly section 301 passes through the assembly hole 101 of the cover body 1 and the pole mounting hole 201 of the rivet block 2 in sequence. The pole assembly section 301 cooperates with the pole mounting hole 201 of the rivet block 2 and is riveted. After riveting, a riveted portion 303 is formed on the top of the pole assembly section 301. The riveted portion 303 is perpendicular to the central axis of the pole assembly section 301, so that the pole 3, the rivet block 2 and the cover body 1 are tightly and firmly connected.

[0088] In the present invention, the shape of the pole base plate 302 is not limited. The shape of the pole assembly section 301 is also not limited. The shape of the pole assembly section 301 is adapted to the shape of the pole mounting hole 201 of the rivet block 2. In other words, the shape of the pole mounting hole 201 of the rivet block 2 is also not limited, and includes a straight rivet structure (where the rivet hole section is a cylindrical hole) and an oblique rivet structure (where the rivet hole section is a tapered hole).

[0089] In some embodiments, the center of the pole mounting hole 201 is located at the center of the riveting block 2 along its length; or, the center of the pole mounting hole 201 is located on a side away from the center of the riveting block 2 along its length.

[0090] Regarding the position of the pole mounting hole 201, the rivet block 2 includes two situations: one is that the center of the pole mounting hole 201 is located at the center of the rivet block 2 along its length direction, in which case L1=L2; the other is that the center of the pole mounting hole 201 is located on one side deviated from the center of the rivet block 2 along its length direction, in which case L1≠L2.

[0091] In some embodiments, a first insulating member 4 and a second insulating member 5 are further included. The first surface of the cover body 1 and the rivet block 2 are insulated and connected via the first insulating member 4 , and the second surface of the cover body 1 and the pole 3 are insulated and connected via the second insulating member 5 .

[0092] By providing the first insulating member 4 and the second insulating member 5, the cover body 1, the rivet block 2 and the pole 3 can be insulated and connected, thereby achieving electrical isolation between the cover body 1 and the rivet block 2 and between the cover body 1 and the pole 3, which can effectively avoid the occurrence of short circuit or leakage and improve the overall safety of the battery.

[0093] Specifically, in some embodiments, the first insulating member 4 and the second insulating member 5 are plastic members. Each of the first insulating member 4 and the second insulating member 5 is provided with a through hole for the assembly section of the pole 3 to pass through. The first insulating member 4 has a groove adapted to the rivet block 2, which is disposed in the groove of the first insulating member 4.

[0094] In order to verify the technical solution and technical effect of the present invention, specific embodiments and comparative examples are provided below, and the flatness of each case is measured. Specifically, the flatness of the riveted block 2 after riveting is ≤0.25mm, which is qualified. The flatness measurement method can adopt the test method known to those skilled in the art. As an example, after riveting, the present invention selects 8-12 points on the entire plane of the riveted block 2 within a range of 5mm inward along each edge of the riveted block 2, measures the height of each point, and calculates the maximum height difference from the highest point to the lowest point, which is the flatness. The schematic diagram of the measurement points is shown in FIG. Figure 13 , where the shaded area indicated by G is the selected area of ​​the measurement points, and the points indicated by M are the measurement points, a total of 12.

[0095] The following flatness measurement is performed on the riveted cases of the elliptical pole and the riveted block 2. The riveted block 2 in each case adopts the same specifications.

[0096] For the first group of cases, the pole mounting hole 201 of the riveting block 2 is centered, as shown in FIG. Figure 8 As shown, L1 = L2. Therefore, it is sufficient to measure and record the distance L from either end of the rivet block 2 to the central axis of the pole mounting hole 201, calculate H, and use this to perform reverse pre-deformation design on the rivet block 2. The measured results are shown in Table 1.

[0097] For the second group of cases, the pole mounting hole 201 of the riveting block 2 is eccentrically arranged, such as Figure 9 As shown, L1≠L2, therefore, it is necessary to measure the distances from both ends of the riveted block 2 to the central axis of the pole mounting hole 201, calculate the corresponding H1 and H2, and perform reverse pre-deformation design on the riveted block 2. The measured results are shown in Table 2.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, along the length direction of the riveted block 2, the pole mounting hole 201 is arranged in the center relative to the riveted block 2, as shown in FIG. Figure 8As shown, in Examples 1 to 6, before the pole 3 is riveted, a reverse pre-deformation structure is provided on the riveted block 2, that is, the deformation compensation amount is designed for the riveted block 2. After riveting, the flatness of the riveted block 2 is good, less than 0.25mm, and all are qualified. However, in Comparative Examples 1 to 6, since the riveted block 2 is not provided with a reverse pre-deformation structure, warping deformation occurs at both ends of the riveted block 2 after riveting, resulting in a surface flatness exceeding 0.25mm, which does not meet the requirements. Therefore, using the technical solution of the present invention, a reverse pre-deformation structure is provided in advance on the riveted block 2, so that H>T, which can compensate for the warping deformation of the riveted block 2 caused by the riveting force, ensuring that the flatness of the riveted block 2 after riveting is ≤0.25mm, meeting the flatness requirements of the riveted block 2.

[0101] Table 2

[0102]

[0103] As can be seen from Table 2, along the length direction of the riveted block 2, the pole mounting hole 201 is arranged eccentrically relative to the riveted block 2, as shown in FIG. Figure 9 As shown, in Examples 7 to 12, before the pole 3 is riveted, a reverse pre-deformation structure is provided on the riveted block 2, that is, the deformation compensation amount is designed for the riveted block 2. After riveting, the flatness of the riveted block 2 is good, less than 0.25mm, and all are qualified. However, in Comparative Examples 7 to 12, since the riveted block 2 is not provided with a reverse pre-deformation structure, warping deformation occurs at both ends of the riveted block 2 after riveting, resulting in a surface flatness exceeding 0.25mm, which does not meet the requirements. Therefore, using the technical solution of the present invention, a reverse pre-deformation structure is provided in advance on the riveted block 2, so that H>T, which can compensate for the warping deformation of the riveted block 2 caused by the riveting force, ensuring that the flatness of the riveted block 2 after riveting is ≤0.25mm, meeting the flatness requirements of the riveted block 2.

[0104] To verify the technical benefits of the H calculation formula provided by the present invention, a third set of examples is provided below. For example, when T = 2.5 mm, the terminal mounting hole 201 is centered relative to the rivet block 2, L1 = L2 = 23 mm, and K is between 100 and 250, the value of H calculated using the above formula is between 2.592 mm and 2.73 mm. See Table 3 for details.

[0105] Table 3

[0106]

[0107] As shown in Table 3, in Examples 13 to 17, the compensation coefficient K is set between 100 and 250, and the corresponding H is calculated. Based on this value, the reverse pre-deformation structure of the riveted block 2 is designed. After riveting, the flatness of the riveted block 2 is good and is significantly lower than 0.25 mm.

[0108] In Comparative Examples 13 and 14, the compensation coefficient K is lower than its specified lower limit value. The actual measured flatness of the riveted block 2 after riveting is greater than 0.25 mm, which does not meet the flatness requirement of the riveted block 2. The main reason is that the actual compensation amount is too large, that is, H is too large, which makes riveting difficult. In fact, it is not completely riveted in place and is slightly loose, which does not meet the requirements.

[0109] In Comparative Examples 15 and 16, the compensation coefficient K exceeds its upper limit value. The actual measured flatness of the riveted block 2 after riveting is greater than 0.25 mm, which does not meet the flatness requirements of the riveted block 2. The main reason is that the actual compensation amount is insufficient, resulting in the warping problem after riveting, and therefore the flatness is unqualified.

[0110] It can be seen from this that by limiting the compensation coefficient K to the range of 100 to 250, H is calculated. The reverse pre-deformation structure of the riveted block 2 is designed according to H, which can properly compensate for the riveting deformation of the riveted block 2 and effectively improve the flatness of the riveted block 2 after riveting, thereby ensuring the welding area and welding quality between the riveted block 2 and the busbar, and improving the overall safety performance of the battery.

[0111] In some embodiments, the battery cell cover assembly further includes an explosion-proof valve 7 and an explosion-proof valve patch 8. The cover body 1 is provided with an explosion-proof valve mounting hole, within which the explosion-proof valve 7 is disposed. The explosion-proof valve patch 8 is attached to the upper surface of the explosion-proof valve mounting hole to protect the explosion-proof valve 7. The explosion-proof valve 7 is designed to rapidly explode and release pressure in the event of thermal runaway in the battery cell, thereby ensuring battery safety.

[0112] In some embodiments, the battery cell cover assembly also includes a sealing ring 6, which is sleeved on the pole assembly section 301, and at least a portion of the sealing ring 6 is disposed between the pole assembly section 301 and the assembly hole 101 of the cover body 1, and at least a portion of the sealing ring 6 is disposed between the pole base plate 302 and the cover body 1. In this way, the sealing ring 6 can form a seal between the pole 3 and the cover body 1 along the Z direction and the XY plane, thereby improving the sealing, reliability and safety of the battery cell.

[0113] According to an embodiment of the present invention, in a second aspect, a battery cell is further provided, comprising a shell, a pole group and the battery cell cover assembly of the above embodiment, wherein the shell has a accommodating cavity and an opening connected to the accommodating cavity; the pole group is arranged in the accommodating cavity of the shell; the battery cell cover assembly is arranged in the opening of the shell to encapsulate the pole group in the shell.

[0114] The cell cover assembly is used to seal the opening of the cell casing, sealing and protecting the internal components of the battery, preventing chemical leakage and the impact of the external environment on the battery. The poles of the cell cover assembly provide a path for the flow of current in and out, ensuring the current conduction during the charging and discharging process of the battery cell. The cell cover assembly not only serves as an electrical connection for the battery cell, but also enhances the overall structural stability of the battery cell. It is an important component of the battery cell, ensuring the durability and safety of the battery cell during use.

[0115] Because the battery cell includes a battery cell cover plate assembly and has all the technical effects of the battery cell cover plate assembly, it will not be repeated here.

[0116] In some embodiments, the battery cell comprises a blade cell.

[0117] According to an embodiment of the present invention, in a third aspect, a battery pack is further provided, comprising a plurality of battery cells according to the above embodiments, wherein the rivet blocks 2 of adjacent battery cells are welded via a busbar.

[0118] Because the battery pack includes battery cells and has all the technical effects of battery cells, they will not be described here.

[0119] Although the embodiments of the present invention have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention. Such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A battery cover assembly, characterized in that: include: A cover plate body, wherein the cover plate body is provided with an assembly hole; A rivet block, wherein the rivet block is provided with a pole mounting hole; the rivet block is a narrow and long structure, and a reverse pre-deformation structure is provided along the length direction of the rivet block, from the central axis of the pole mounting hole to both ends of the rivet block. The reverse pre-deformation structure is a curved structure of the rivet block formed away from a first plane, the first plane being perpendicular to the central axis of the pole mounting hole and parallel to the surface of the cover plate body. The thickness of the rivet block is T, in mm, and the maximum vertical distance from the surface of the reverse pre-deformation structure close to the cover plate body to the first plane is H, in mm, where H>T; The pole includes a pole assembly section adapted to the pole mounting hole. The pole assembly section passes through the assembly hole and the pole mounting hole in sequence and is riveted to the rivet block. The reverse pre-deformation structure deforms in a direction away from the cover body and reduces the flatness of the rivet block after riveting.

2. The battery cover assembly according to claim 1, characterized in that: Along the length direction of the rivet block, a first reverse pre-deformation structure is formed from the central axis of the pole mounting hole to the first end of the rivet block. The maximum vertical distance from the surface of the first reverse pre-deformation structure close to the cover body to the first plane is H1, satisfying: Wherein, L1 is the distance from the central axis of the pole mounting hole to the first end of the riveted block along the length direction of the riveted block, in mm, and K1 is the compensation coefficient, 100≤K1≤250; A second reverse pre-deformation structure is formed from the central axis of the pole mounting hole to the second end of the rivet block. The maximum vertical distance from the surface of the second reverse pre-deformation structure close to the cover body to the first plane is H2, satisfying: Wherein, L2 is the distance from the central axis of the pole mounting hole to the second end of the rivet block along the length direction of the rivet block, in mm, and K2 is the compensation coefficient, 100≤K2≤250.

3. The battery cover assembly according to claim 2, characterized in that: 4mm≤L1≤35mm;4mm≤L2≤35mm.

4. The battery cover assembly according to claim 2 or 3, characterized in that: K1=K2.

5. The battery cell cover assembly according to any one of claims 1 to 3, characterized in that: The thickness T of the riveting block satisfies: 1.5 mm ≤ T ≤ 4.5 mm.

6. The battery cell cover assembly according to any one of claims 1 to 3, characterized in that: The pole mounting hole is a waist-shaped hole, and the straight edge of the waist-shaped hole is arranged along the length direction of the riveting block; Or the pole mounting hole is a circular hole.

7. The battery cell cover assembly according to any one of claims 1 to 3, characterized in that: The center of the pole mounting hole is set at the center of the riveting block along its length direction; Alternatively, the center of the pole mounting hole is arranged on a side deviating from the center of the rivet block along the length direction thereof.

8. The battery cell cover assembly according to any one of claims 1 to 3, characterized in that: The pole further comprises a pole bottom plate, the pole assembly section is provided on the pole bottom plate, the pole bottom plate and the rivet block are respectively provided on both sides of the cover plate body, after the pole assembly section is riveted to the pole mounting hole of the rivet block, a riveted portion perpendicular to the central axis of the pole assembly section is formed on the top of the pole assembly section, and the top surface of the riveted portion is not higher than the top surface of the rivet block; The pole mounting hole is a stepped hole, and the stepped hole includes a riveting hole section for forming a riveted portion of the pole, and the riveting hole section is a cylindrical hole or a tapered hole.

9. A battery cell, characterized in that: include: a housing, the housing comprising a receiving cavity and an opening communicating with the receiving cavity; a pole group, the pole group being arranged in the accommodating cavity of the shell; The battery cell cover plate assembly according to any one of claims 1 to 8, wherein the battery cell cover plate assembly is arranged at the opening of the shell, and the electrode group is encapsulated in the shell.

10. A battery pack, characterized in that: The invention comprises a plurality of battery cells according to claim 9, wherein the rivet blocks of adjacent battery cells are welded by a busbar.

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