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, a riveting block and a pole. The riveting block is provided with a pole mounting hole and comprises an assembly hole section and a riveting hole section, and the assembly hole section and the riveting hole section are runway-shaped holes; the terminal post before riveting comprises a terminal post main body, an annular gap is formed between the terminal post main body and a riveting hole section to form a thrust bearing area, the terminal post main body after riveting forms an assembly post section and a riveting post section, the thrust bearing area is filled with the riveting post section, and a riveting punched hole is formed in the top of the riveting post section under riveting force; and a preset condition is met between the pole and the riveting block. According to the invention, the material expansion difference between the arc edge and the straight edge of the long circular pole can be effectively reduced, the close fit between the pole and the riveting block is ensured, the thrust resistance of the battery cell cover plate assembly is improved, the welding quality is improved, and the reliability and the safety of the battery are 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] In recent years, with the continuous advancement of battery technology and the expansion of its application scope, people's requirements for overall battery performance and safety have gradually increased. As one of the key components of battery packaging, the assembly quality of the cell cover assembly affects the overall performance and safety of the battery.

[0003] The battery cell cover plate assembly includes a cover plate, a pole and a rivet block. Among them, the pole is a key part for connecting to the external circuit, while the cover plate plays a role of sealing and protection. During the assembly process, the pole and the cover plate are fixed by a rivet block. When the pole and the rivet block are riveted, vertical pressure is applied to the pole from the center axis position of the pole, causing the top of the pole to swell and deform, thereby achieving riveting with the rivet block. In commonly used battery cell cover plate assemblies, the pole is divided into two structures, one is a circular pole and the other is an oblong pole (also commonly known as an elliptical pole). The oblong pole includes a straight edge and an arc edge. In the existing oblong pole cover plate structure, when the riveting force is applied to the pole, there is a problem of difference in material expansion during the riveting process of the arc edge and the straight edge, that is, the arc edge of the pole has weaker material expansion ability than the straight edge of the pole, and the arc edge of the pole has insufficient material expansion.

[0004] This difference in material expansion can cause a gap between the terminal and the rivet block, resulting in insufficient cover plate riveting strength, mechanical strength that fails to meet design requirements, and poor thrust resistance, affecting the reliability and safety of the battery cell. Furthermore, the gap between the terminal and the rivet block can affect welding quality, further reducing the reliability and safety of the battery. Therefore, the inconsistent material expansion between the straight and arc edges of the oblong terminal after riveting poses a potential threat to the overall performance and safety of the battery. 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 of insufficient riveting strength of the cover and poor thrust resistance due to inconsistent material expansion between the arc edge and the straight edge of the elliptical pole.

[0006] In the first aspect, the present invention provides a battery cell cover plate assembly, including a cover plate, a rivet block and a pole. The cover plate is provided with an assembly hole; the rivet block is a rectangular structure, and the rivet block is provided with a pole mounting hole, and the pole mounting hole is a stepped hole, including an assembly hole section and a rivet hole section, and both the assembly hole section and the rivet hole section are runway-shaped holes; the pole before riveting includes a pole body, the pole body is passed through the pole mounting hole, and an annular gap is provided between the pole body and the rivet hole section to form a thrust support area, the pole body is riveted to the rivet block, and the pole body after riveting includes an assembly column section that cooperates with the assembly hole section and a rivet column section that cooperates with the rivet hole section, the rivet column section fills the thrust support area, and the top of the rivet column section is formed with a concave rivet punching by the riveting force; the pole and the rivet block meet the following conditions:

[0007]

[0008] in,

[0009] V1 is the volume of the riveting punching hole, in mm 3 ,

[0010] V2 is the volume of the thrust bearing area, in mm 3 .

[0011] Beneficial Effects: The present invention limits the ratio of the volume V1 of the riveted punching hole to the volume V2 of the thrust support area, controlling it within the range of 1.0 to 1.3. This can effectively reduce the difference in material expansion between the arc edge and the straight edge of the oblong pole, ensuring consistent material expansion on both sides. In particular, the arc edge of the pole can be fully expanded, which can improve the mechanical strength and thrust resistance of the battery cover assembly and enhance the safety performance of the battery cell. At the same time, the close fit between the pole and the riveted block and the seamless gap between the pole and the riveted block significantly improve the welding quality and enhance the reliability and safety of the battery.

[0012] In an optional embodiment, the riveting hole section is a tapered hole, the diameter of the riveting hole section decreases toward the assembly hole section, and the side wall of the riveting hole section is directly connected to the side wall of the assembly hole section.

[0013] In an optional embodiment, the following conditions are met:

[0014]

[0015] In an optional embodiment, the side wall of the riveting hole segment is parallel to the central axis of the pole mounting hole, and the riveting hole segment is connected to the assembly hole segment via an annular step surface.

[0016] In an optional embodiment, the following conditions are met:

[0017]

[0018] In an optional embodiment, the following is also satisfied: 6mm 3 ≤V1≤95mm 3 , 5.5mm 3 ≤V2≤75mm 3 .

[0019] In an optional embodiment, the pole mounting hole also includes a welding sinker provided on the top of the riveted hole section. The size of the welding sinker is larger than the size of the riveted hole section along the X direction and the Y direction, and the top surface of the riveted column section is lower than the welding sinker.

[0020] In an optional embodiment, the riveting punching hole is a tapered hole, and the diameter of the riveting punching hole decreases along the riveting direction.

[0021] In a second aspect, the present invention further provides a battery cell comprising a housing, a pole group, and the cell cover assembly described in the above technical solution. The housing has a receiving cavity and an opening communicating with the receiving cavity; the pole group is disposed in the housing cavity; and the cell cover assembly is disposed in the opening of the housing, encapsulating the pole group within the housing.

[0022] 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 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 a crucial component of the battery cell and ensures the durability and safety of the battery cell during use.

[0023] 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.

[0024] 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.

[0025] 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

[0026] 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.

[0027] Figure 1This is a structural schematic diagram of a riveted block in a battery cell cover assembly according to an embodiment of the present invention;

[0028] Figure 2 for Figure 1 a cross-sectional view of the riveting block shown;

[0029] Figure 3 For Figure 1 A cross-sectional view of a pole mated with a rivet block shown before riveting;

[0030] Figure 4 for Figure 3 The schematic diagram of the structure of the pole after riveting is shown;

[0031] Figure 5 An exploded view of a battery cell cover assembly according to an embodiment of the present invention;

[0032] Figure 6 for Figure 5 The top view of the cell cover assembly before the pole is riveted;

[0033] Figure 7 for Figure 5 The cell cover assembly shown is at the front edge of the pole riveting Figure 6 Cross-sectional view at AA in the middle;

[0034] Figure 8 for Figure 7 A partial enlarged view of point B in the middle;

[0035] Figure 9 for Figure 5 The battery cover assembly shown is at the rear edge of the pole riveting Figure 6 Cross-sectional view at AA in the middle;

[0036] Figure 10 for Figure 9 A partial enlarged view of point C in the middle;

[0037] Figure 11 for Figure 5 The battery cover assembly shown is at the rear edge of the pole riveting Figure 6 Cross-sectional view of middle GG;

[0038] Figure 12 This is a structural schematic diagram of a rivet block in another battery cover assembly according to an embodiment of the present invention;

[0039] Figure 13 for Figure 12 a cross-sectional view of the riveting block shown;

[0040] Figure 14 For Figure 12 The schematic diagram of the structure of the pole after riveting with the riveted block shown;

[0041] Figure 15 An exploded view of another battery cell cover assembly according to an embodiment of the present invention;

[0042] Figure 16 for Figure 15 A top view of the cell cover assembly shown;

[0043] Figure 17 for Figure 15 The cell cover assembly shown is at the front edge of the pole riveting Figure 16 Cross-sectional view at FF;

[0044] Figure 18 for Figure 17 A partial enlarged view of point D in the middle;

[0045] Figure 19 for Figure 15 The battery cover assembly shown is at the rear edge of the pole riveting Figure 16 Cross-sectional view at FF;

[0046] Figure 20 for Figure 19 A partial enlarged view of point E in the middle;

[0047] Figure 21 for Figure 15 The structure diagram of the battery cover assembly after assembly is shown;

[0048] Figure 22 for Figure 21 The half-section structure diagram of the battery cell cover assembly is shown.

[0049] Description of reference numerals:

[0050] 1. Cover plate; 101. Assembly hole; 2. Riveted block; 201. Pole mounting hole; 2011. Assembly hole section; 2012. Riveted hole section; 2013. Welding sinker; 2014. Thrust bearing area; 3. Pole; 301. Pole body; 3011. Assembly column section; 3012. Riveted column section; 3013. Riveted punching hole; 302. Pole base plate; 4. First insulating member; 5. Second insulating member; 6. Sealing ring; 7. Explosion-proof valve; 8. Explosion-proof valve patch. DETAILED DESCRIPTION

[0051] 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.

[0052] The following combination Figures 1 to 22 , describing embodiments of the present invention.

[0053] According to an embodiment of the present invention, in a first aspect, a cell cover assembly is provided, comprising a cover 1, a rivet block 2, and a pole 3. The cover 1 is provided with an assembly hole 101; the rivet block 2 is a rectangular structure, and the rivet block 2 is provided with a pole mounting hole 201, which is a stepped hole, comprising an assembly hole section 2011 and a rivet hole section 2012, both of which are runway-shaped holes; the pole 3 before riveting comprises a pole body 301, which is provided through the pole mounting hole 201, and has a hole section 2012 between the pole body 301 and the rivet hole section 2012. The annular gap forms a thrust bearing area 2014. The pole body 301 is riveted to the riveting block 2. After riveting, the pole body 301 includes an assembly column segment 3011 that cooperates with the assembly hole segment 2011 and a riveted column segment 3012 that cooperates with the riveted hole segment 2012. The riveted column segment 3012 fills the thrust bearing area 2014. The top of the riveted column segment 3012 is formed with a concave riveted punch 3013 due to the riveting force. The following conditions are met between the pole 3 and the riveted block 2:

[0054]

[0055] in,

[0056] V1 is the volume of the riveted punching hole 3013, in mm 3 ,

[0057] V2 is the volume of the thrust bearing area 2014, in mm 3 .

[0058] Specifically, the riveting punching hole 3013 is a blind hole, and the volume V1 of the riveting punching hole 3013 is as follows: Figure 10 The volume of the area shown by the black shaded block in the figure. The volume V2 of the thrust bearing area 2014 is as follows: Figure 8 or Figure 18 The volume of the area indicated by the black shaded block.

[0059] In the cell cover assembly provided by the present invention, the structure of the pole 3 changes before and after riveting. Because both the assembly hole section 2011 and the riveting hole section 2012 are racetrack-shaped holes, the cross-section of the pole body 301 that fits into the assembly hole section 2011 along the radial direction is a waist-shaped circle, i.e., an oblong pole, also commonly known as an elliptical pole.

[0060] There is an annular gap between the pole body 301 and the riveted hole section 2012, which constitutes the thrust support area 2014. During the riveting process between the pole 3 and the riveted block 2, the upper end of the pole body 301 will expand and deform toward the thrust support area 2014 under the action of the riveting force until the entire thrust support area 2014 is filled. At this time, the pole body 301 is divided into two parts. The undeformed portion still cooperates with the assembly hole section 2011 of the pole mounting hole 201 to form the assembly column section 3011, and the expanded and deformed portion adapts to the riveted hole section 2012 of the pole mounting hole 201 to form the riveted column section 3012. The thrust support area 2014 is used to support and accommodate the expanded portion of the pole 3 to form the riveted column section 3012, thereby achieving the connection between the cover plate 1, the riveted block 2, and the pole 3. Specifically, after the pole 3 and the rivet block 2 are riveted, the pole 3 expands to form a riveted column section 3012 that fills the thrust support area 2014. This structure is used to withstand the thrust load exerted on the cell cover assembly in the battery pack and is a very important structure in the cell cover assembly.

[0061] Due to the difference in material expansion between the arc edge and the straight edge of the oblong pole, in order to solve this technical problem, the present invention limits the ratio of the volume V1 of the riveted punch hole 3013 to the volume V2 of the thrust support area 2014, controlling it within the range of 1.0 to 1.3. This can effectively reduce the difference in material expansion between the arc edge and the straight edge of the oblong pole, ensuring that the material expansion on both sides is consistent, especially the arc edge of the pole 3 can be fully expanded, which can improve the mechanical strength and thrust resistance of the battery cover assembly and enhance the safety performance of the battery cell. At the same time, the close fit between the pole 3 and the riveted block 2, and the seamless gap between the pole 3 and the riveted block 2, significantly improve the welding quality and enhance the reliability and safety of the battery.

[0062] Specifically, based on the principle of equal volume flow in material expansion theory, in related art cell cover plate assemblies, the volume V1 of the riveted punch hole 3013 is typically equal to the volume V2 of the thrust support area 2014, without taking into account the differential material expansion between the arc-shaped and straight sides of the oblong pole. In particular, the longer or wider the oblong pole, the more difficult it is to rivet and expand the material, resulting in a greater shortage of material in the pole 3, and the more pronounced the differential material expansion between the arc-shaped and straight sides.

[0063] The present invention enlarges the volume V1 of the riveting punching hole 3013, so that That is, the volume V1 of the riveted punching hole 3013 is greater than the volume V2 of the thrust support area 2014. In this way, it can be ensured that the arc edge of the oblong pole can fully expand the material and fill the thrust support area 2014. The arc edge of the formed riveted column section 3012 is closely fitted with the arc edge of the riveted hole section 2012, ensuring that the thrust resistance performance of the pole 3 meets the requirements; at the same time, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 is controlled not to be too large, so that It can avoid excessive expansion of the pole 3 and cause local deformation of the rivet block 2, ensure that the rivet block 2 and the external insulating part can be assembled normally, and can achieve precise control of the volume of the expanded pole 3 during the riveting process, which helps to ensure production consistency and reduce the defective product rate.

[0064] In some embodiments, the rivet hole segment 2012 is a tapered hole, the diameter of which decreases toward the assembly hole segment 2011 , and the side wall of the rivet hole segment 2012 is directly connected to the side wall of the assembly hole segment 2011 .

[0065] In this embodiment, the riveting hole section 2012 is a tapered hole, that is, an oblique riveting structure is adopted between the pole 3 and the riveting block 2. Figures 1 to 11 The riveted column segment 3012 formed by the rear pole 3 after riveting is also a tapered columnar structure.

[0066] Since the rivet hole section 2012 is a tapered hole and its diameter decreases toward the assembly hole section 2011, that is, the side wall of the rivet hole section 2012 is inclined and is set at an acute angle to the central axis of the pole mounting hole 201, the pole 3 can be more fully expanded and deformed during the riveting process, thereby improving the connection strength of the rivet block 2, the pole 3 and the cover plate 1, as well as the welding quality of the rivet block 2 and the pole 3, and improving the overall connection strength of the battery cell cover plate assembly.

[0067] In some embodiments, the following conditions are met:

[0068]

[0069] In this embodiment, according to the expansion characteristics of the pole 3 in the oblique riveting structure, the ratio of the volume V1 of the riveting punching hole 3013 to the volume V2 of the thrust bearing area 2014 is further optimized and limited.

[0070] Since the oblique riveting structure is adopted between the riveting block 2 and the pole 3, the expansion effect of the pole 3 along the X direction and the Y direction is relatively sufficient. The upper limit value can be reduced to 1.2, so that the straight edge of the oblong pole can be further prevented from excessive expansion and local deformation of the riveting block 2, ensuring that the riveting block 2 and the external insulating part can be assembled normally, and the volume of the expanded material of the pole 3 during the riveting process can be accurately controlled, which helps to ensure production consistency and reduce the defective product rate.

[0071] In some embodiments, the side wall of the riveting hole section 2012 is parallel to the central axis of the pole mounting hole 201 , and the riveting hole section 2012 is connected to the assembly hole section 2011 via an annular step surface.

[0072] In this embodiment, the side wall of the rivet hole section 2012 is parallel to the central axis of the pole mounting hole 201, and the step surface is perpendicular to the central axis of the pole mounting hole 201, that is, the rivet hole section 2012 is a straight wall hole, and a straight rivet structure is adopted between the rivet block 2 and the pole 3. Figures 12 to 22 The riveted column segment 3012 formed by the rear pole 3 after riveting is also a cylindrical structure.

[0073] In some embodiments, the following conditions are met:

[0074]

[0075] This embodiment further optimizes and limits the ratio of the volume V1 of the riveting punching hole 3013 to the volume V2 of the thrust support area 2014 in view of the expansion characteristics of the pole 3 in the straight riveting structure. Compared with the oblique riveting structure, in the straight riveting structure, the pole 3 will also partially expand in the Z direction, resulting in insufficient expansion of the pole 3 in the X and Y directions, especially at the arc edge. Therefore, The lower limit value is increased to 1.1, which can further ensure that in the straight riveting structure, the oblong pole is fully expanded at the arc edge, ensuring that the arc edge of the oblong pole can be fully expanded to fill the thrust support area 2014, and the arc edge of the formed riveted column section 3012 is tightly fitted with the arc edge of the riveted hole section 2012, ensuring that the thrust resistance performance of the pole 3 meets the requirements.

[0076] In the straight riveting structure and the oblique riveting structure, the structure of the pole 3 before riveting can be the same, as shown in FIG. Figure 3 After riveting, the structure of the riveted column section 3012 of the pole 3 changes with the shape of the riveted hole section 2012 of the pole mounting hole 201 .

[0077] In some embodiments, the following conditions are also met: 6 mm 3 ≤V1≤95mm 3 , 5.5mm 3 ≤V2≤75mm 3 .

[0078] Control the volume V1 of the riveted punch hole 3013 to 6mm 3 Up to 95mm 3 and the volume V2 of the thrust bearing area 2014 is controlled within 5.5mm 3 Up to 75mm 3The range of V1 and V2 is applicable to most specifications of battery cell cover assemblies. In addition, by limiting the range of V1 and V2 and combining it with the ratio relationship in the above embodiment, it can ensure that the pole 3 has sufficient volume of material expansion and deformation to fill the thrust support area 2014, so that it has sufficient bearing capacity under external thrust loads and prevents damage to the battery cell cover assembly due to excessive local stress; at the same time, it can prevent the pole 3 from expanding too much and causing the rivet block 2 to expand and deform outward, ensuring the normal assembly of the various components in the battery cell cover assembly, thereby improving the durability, reliability and consistency of the battery cell cover assembly.

[0079] V1 at 6mm 3 Up to 95mm 3 The range of values ​​is 6mm, including 3 , 8mm 3 , 10mm 3 , 15mm 3 , 20mm 3 , 25mm 3 , 30mm 3 , 35mm 3 , 40mm 3 , 45mm 3 , 50mm 3 , 55mm 3 , 60mm 3 , 65mm 3 , 70mm 3 , 75mm 3 , 80mm 3 , 85mm 3 , 90mm 3 , 95mm 3 .

[0080] V2 at 5.5mm 3 Up to 75mm 3 Pinch value range, including 5.5mm 3 , 6mm 3 , 8mm 3 , 10mm 3 , 15mm 3 , 20mm 3 , 25mm 3 , 30mm 3 , 35mm 3 , 40mm 3 , 45mm 3 , 50mm 3 , 55mm 3 , 60mm 3 , 65mm 3 , 70mm 3 , 75mm3 .

[0081] In some embodiments, the pole mounting hole 201 also includes a welding sink 2013 provided on the top of the riveted hole section 2012. Along the X direction and along the Y direction, the size of the welding sink 2013 is larger than the size of the riveted hole section 2012, and the top surface of the riveted column section 3012 is lower than the welding sink 2013.

[0082] In this embodiment, the welding sink 2013 is provided to accommodate the welding mark of the electrode 3 and the riveted block 2 after riveting, ensuring that the welding mark does not protrude from the surface of the riveted block 2, thereby ensuring the overall high dimensional accuracy of the battery cell.

[0083] In some embodiments, the riveting punching hole 3013 is a tapered hole, and the diameter of the riveting punching hole 3013 decreases along the riveting direction.

[0084] In this embodiment, since the riveting punch 3013 is conical and the diameter decreases along the riveting direction, the corresponding riveting punch is also a conical column structure. In this way, there is a larger contact area between the riveting punch and the pole 3, which can guide the volume flow of the pole 3 during the riveting process, further improving the expansion effect of the arc edge of the oblong pole, so that it can more fully fill the thrust support area 2014.

[0085] Specifically, the structure of the riveting punch 3013 is determined by the riveting punch pin. Therefore, after the structure and volume of the riveting punch 3013 are determined, the structure and size of the riveting punch pin are designed accordingly.

[0086] In order to verify the technical solution and technical effects of the present invention, two sets of experimental data are provided below for battery cell cover plate assemblies using oblique rivet structures and straight rivet structures. Both include specific implementation cases and comparative cases, and thrust tests and appearance inspections of riveting and welding are performed on each case.

[0087] The thrust test is performed using a method known to those skilled in the art. As an example, the thrust test is as follows:

[0088] The testing equipment is a universal material testing machine.

[0089] Test method:

[0090] Randomly select test samples of cell cover assemblies that meet the specifications to ensure that the sample surface is clean and free of scratches or pre-damage.

[0091] Calibrate the force and displacement sensors of the testing machine to ensure data accuracy.

[0092] Place the sampled cell cover assembly in the fixture of the testing machine to ensure that the force point is consistent with the designed position and that the cell cover assembly does not move or tilt during the test.

[0093] Confirm that the fixture is firmly installed, set the loading pressure, and apply thrust to the battery cover assembly along the Z direction, with the thrust directed towards pole 3, and load pole 3 vertically. Set the pressure loading speed.

[0094] Start the tester and apply a thrust to the terminal 3 until the cell cover assembly fails (e.g., the cell cover assembly deforms, or the terminal 3 falls off). The tester records the applied force in real time. The thrust before the cell cover assembly fails is the maximum thrust the cell cover assembly can withstand. Record the maximum thrust value, denoted as F, in Newtons.

[0095] Among them, the appearance inspection of riveting and welding includes checking whether there is obvious deformation or gap in the appearance of each component in the battery cover assembly, and whether the size is qualified.

[0096] Group 1: The pole 3 and the riveted block 2 use an oblique riveting structure. That is, the riveted hole section 2012 in the pole mounting hole 201 of the riveted block 2 is a tapered hole. See Table 1 for specific results.

[0097] Group 2: The pole 3 and the riveting block 2 use a straight riveting structure. That is, the riveting hole section 2012 in the pole mounting hole 201 of the riveting block 2 is a straight-walled hole. See Table 2 for specific results.

[0098] Table 1

[0099]

[0100] As shown in Table 1, for the cell cover plate assembly riveted using an oblique rivet structure, in Examples 1 to 7, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 ranged from 1.00 to 1.30, and the thrust test results all met the requirements, satisfying the use requirements of the cell cover plate assembly. Specifically, in Examples 1 to 5, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 ranged from 1.00 to 1.20, not only meeting the thrust test requirements, but also ensuring good riveting and weld appearance, meeting the use requirements of the cell cover plate assembly while exhibiting superior performance.

[0101] In Comparative Examples 1 and 2, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 is too small, both lower than 1.00. After riveting, the battery cell cover assembly has insufficient material expansion of the pole 3, resulting in low riveting strength of the battery cell cover assembly that does not meet the requirements.

[0102] In Comparative Examples 3 and 4, the ratio of the volume V1 of the riveted punch 3013 to the volume V2 of the thrust support area 2014 is too large, both higher than 1.30, and the riveted block 2 is locally deformed and bulged with an excessive width. The cover plate 1 is also locally deformed and bulged, affecting the fit and welding between the battery cell shell and the battery cell cover plate assembly, and does not meet the battery cell requirements.

[0103] Table 2

[0104]

[0105] As shown in Table 2, for the cell cover plate assemblies riveted using a direct rivet structure, in Examples 8 to 14, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 ranged from 1.00 to 1.30, and the thrust test results all met the requirements, satisfying the use requirements of the cell cover plate assembly. Specifically, in Examples 10 to 14, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 ranged from 1.10 to 1.30, not only meeting the thrust test requirements, but also ensuring good riveting and weld appearance, meeting the use requirements of the cell cover plate assembly while exhibiting superior performance.

[0106] In Comparative Examples 5 and 6, the ratio of the volume V1 of the riveted punching hole 3013 to the volume V2 of the thrust support area 2014 is too small, both lower than 1.00. After riveting, the battery cell cover assembly has insufficient material expansion of the pole 3, resulting in low riveting strength of the battery cell cover assembly that does not meet the requirements.

[0107] In Comparative Examples 7 and 8, the ratio of the volume V1 of the riveted punch 3013 to the volume V2 of the thrust support area 2014 is too large, both higher than 1.30, and the riveted block 2 is locally deformed and bulged with an excessive width. The cover plate 1 is also locally deformed and bulged, affecting the fit and welding between the battery cell shell and the battery cell cover plate assembly, and does not meet the battery cell requirements.

[0108] Therefore, the cell cover plate assembly provided by the present invention can effectively reduce the difference in material expansion between the arc edge and the straight edge of the oblong pole by controlling the ratio of the volume V1 of the riveted punch hole 3013 to the volume V2 of the thrust support area 2014 within the range of 1.0 to 1.3, so that the material expansion on both sides is consistent, especially the arc edge of the pole 3 can be fully expanded, which can improve the mechanical strength and thrust resistance of the cell cover plate assembly and improve the safety performance of the battery cell. At the same time, the close fit between the pole 3 and the riveted block 2 and the seamless gap between the pole 3 and the riveted block 2 significantly improve the welding quality and enhance the reliability and safety of the battery.

[0109] In some embodiments, a first insulating member 4 and a second insulating member 5 are further included. The first surface of the cover plate 1 and the rivet block 2 are insulated and connected via the first insulating member 4 , and the second surface of the cover plate 1 and the pole 3 are insulated and connected via the second insulating member 5 .

[0110] Specifically, in some embodiments, the first insulating member 4 and the second insulating member 5 are both plastic members. The first insulating member 4 and the second insulating member 5 are used to ensure insulation between the cover plate 1 and the rivet block 2, and between the cover plate 1 and the pole 3, thereby preventing short circuits or leakage in the battery cell and improving the safety and reliability of the battery cell.

[0111] The battery cover assembly also includes an explosion-proof valve 7 and an explosion-proof valve patch 8. The cover 1 has an explosion-proof valve mounting hole, in which the explosion-proof valve 7 is located. 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 quickly explode and release pressure in the event of thermal runaway in the battery cell, thereby ensuring the safety of the battery.

[0112] In some embodiments, the battery cell cover plate assembly also includes a sealing ring 6, which is sleeved on the pole body 301, and at least part of the sealing ring 6 is arranged between the pole body 301 and the assembly hole 101 of the cover plate 1, and at least part of the sealing ring 6 is arranged between the pole base plate 302 and the cover plate 1. In this way, the sealing ring 6 can form a seal between the pole 3 and the cover plate 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 provided, comprising a housing, a pole group, and the cell cover assembly of the above technical solution. The housing has a receiving cavity and an opening communicating with the receiving cavity; the pole group is disposed in the housing cavity; and the cell cover assembly is disposed in the opening of the housing, encapsulating the pole group within the housing.

[0114] 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 pole 3 of the cell cover assembly provides 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 constitutes a vital component of the battery cell and ensures 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] 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 technical solution, wherein the rivet blocks 2 of adjacent battery cells are welded via a busbar.

[0117] Because the battery pack includes battery cells and has all the technical effects of battery cells, they will not be described here.

[0118] 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, wherein the cover plate is provided with an assembly hole; A riveting block, the riveting block is a rectangular structure, the riveting block is provided with a pole mounting hole, the pole mounting hole is a stepped hole, including an assembly hole section and a riveting hole section, and the assembly hole section and the riveting hole section are both runway-shaped holes; The pole, before riveting, comprises a pole body, the pole body being passed through the pole mounting hole, an annular gap being provided between the pole body and the riveted hole section to form a thrust bearing area, the pole body being riveted to the riveted block, and the pole body after riveting comprising an assembly column section cooperating with the assembly hole section and a riveted column section cooperating with the riveted hole section, the riveted column section filling the thrust bearing area, and a concave riveted punching hole being formed on the top of the riveted column section by the riveting force; The following conditions are met between the pole and the riveting block: in, V1 is the volume of the riveting punch, in mm 3 , V2 is the volume of the thrust bearing area, in mm 3 .

2. The battery cover assembly according to claim 1, characterized in that: The rivet hole section is a tapered hole, the diameter of which decreases toward the assembly hole section, and the side wall of the rivet hole section is directly connected to the side wall of the assembly hole section.

3. The battery cover assembly according to claim 2, characterized in that: satisfy:

4. The battery cover assembly according to claim 1, characterized in that: The side wall of the riveting hole section is parallel to the central axis of the pole mounting hole, and the riveting hole section is connected to the assembly hole section via an annular step surface.

5. The battery cover assembly according to claim 4, characterized in that: satisfy:

6. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: Also meets: 6mm 3 ≤V1≤95mm 3 , 5.5mm 3 ≤V2≤75mm 3 。 7. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: The pole mounting hole further includes a welding sinker provided on the top of the riveted hole section. The size of the welding sinker is larger than that of the riveted hole section along the X direction and the Y direction, and the top surface of the riveted column section is lower than the welding sinker.

8. The battery cell cover assembly according to any one of claims 1 to 5, characterized in that: The riveting punching hole is a tapered hole, and the diameter of the riveting punching hole decreases along the riveting direction.

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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