Battery cell cover plate assembly, battery cell, and battery pack

Abstract

The application 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 of a rectangular structure, the riveting block is provided with a pole mounting hole, the pole mounting hole is a stepped hole, the pole mounting hole comprises an assembly hole section and a riveting hole section, the assembly hole section and the riveting hole section are both runway-shaped holes, the riveting hole section is a tapered hole with a diameter gradually reduced towards the assembly hole section; the pole is riveted with the riveting block, the pole comprises an assembly column section and a riveting column section, the top of the riveting column section is provided with a concave riveting punch hole, the riveting punch hole is a tapered hole with a diameter gradually reduced towards the assembly hole section; in the axial section of the riveting hole section passing through the centers of the two end arcs, the taper angle of the riveting punch hole is alpha, the taper angle of the riveting hole section is beta, and a preset condition is met. The application can ensure that the arc edge of the pole is fully expanded, there is no gap between the pole and the riveting block, and the riveting strength and the thrust resistance of the battery cell cover plate assembly are ensured.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to cell cover assemblies, cells, and battery packs. Background Technology

[0002] In recent years, with the continuous advancement of battery technology and the expansion of its application scope, people's requirements for the overall performance and safety of batteries have gradually increased. As one of the important components of battery packaging, the assembly quality of each component in the cell cover assembly affects the overall performance and safety of the battery.

[0003] The battery cell cover assembly includes a cover body, terminals, and riveting blocks. The terminals are crucial for connecting to external circuits, while the cover body provides sealing and protection. During assembly, the terminals are fixed to the cover body using riveting blocks. When riveting the terminals and riveting blocks, vertical pressure is applied from the center axis of the terminal, causing the top of the terminal to expand and deform, thus achieving the riveting connection with the riveting block. Commonly used battery cell cover assemblies feature two types of terminals: circular terminals and oblong terminals (also commonly known as elliptical terminals).

[0004] The elongated oval pole includes a straight edge and a rounded edge. In the existing elongated oval pole cover plate structure, when riveting force is applied to the pole, there is a difference in material expansion during the riveting process between the rounded edge and the straight edge. That is, the material expansion capacity of the rounded edge of the pole is weaker than that of the straight edge, and the rounded edge of the pole may have insufficient material expansion. This will result in a gap between the pole and the riveting block, resulting in insufficient riveting strength of the cover plate body, failure to meet the design requirements for mechanical strength, poor thrust resistance, and affecting the reliability and safety of the battery cell. Summary of the Invention

[0005] In view of this, the present invention provides a cell cover assembly, a cell, and a battery pack to solve the problem that insufficient material expansion at the arc edge of the elliptical pole leads to insufficient riveting strength and poor thrust resistance of the cover body.

[0006] In a first aspect, the present invention provides a battery cell cover assembly, comprising a cover body, a riveting block, and a terminal post. The cover body has an assembly hole; the riveting block is rectangular in structure and has a terminal post mounting hole, which is a stepped hole including an assembly hole section and a riveting hole section. Both the assembly hole section and the riveting hole section are racetrack-shaped holes, and the riveting hole section is a tapered hole whose diameter gradually decreases towards the assembly hole section. The terminal post passes through the assembly hole and the terminal post mounting hole sequentially and is riveted to the riveting block. The terminal post includes an assembly post section and a riveting post section. The assembly post section mates with the assembly hole section, and the riveting post section fills the riveting hole section. The riveting post section is a tapered section, and a recessed riveting punch is formed at the top of the riveting post section. The riveting punch is a tapered hole whose diameter gradually decreases towards the assembly hole section. In the axial tangent plane passing through the center of the arcs at both ends of the riveting hole section, the cone angle of the riveting punch is α, and the cone angle of the riveting hole section is β, satisfying:

[0007] 5°≤β-α≤30°.

[0008] Beneficial effects: The battery cell cover assembly provided by the present invention has a differentiated cone angle β of the arc edge of the riveting hole section of the riveting block and the cone angle of the arc edge of the riveting punch of the pole, and the angle difference between the two cone angles is limited within the above range. This can ensure that the pole is fully expanded on the arc edge, there is no gap between the pole and the riveting block, the riveting strength of the battery cell cover assembly is guaranteed, its thrust resistance is guaranteed, and the welding quality between the pole and the riveting block is improved.

[0009] In one alternative implementation, the following condition is also met:

[0010] 30°≤α≤120°, 35°≤β≤150°.

[0011] In one optional embodiment, in the axial tangent plane perpendicular to its straight edge of the riveting hole segment, the cone angle of the riveting punch is γ, and the cone angle of the riveting hole segment is θ, satisfying:

[0012] 5°≤γ-θ≤30°.

[0013] In one alternative implementation, the following condition is also met:

[0014] 35°≤γ≤150°, 30°≤θ≤120°.

[0015] In one alternative implementation, the following condition is also met:

[0016] -0.5mm ≤ H - h ≤ 1.5mm

[0017] Where H is the depth of the riveting punch along the axial direction of the pole mounting hole, in mm;

[0018] h represents the depth of the riveting hole section along the axial direction of the pole mounting hole, in mm.

[0019] In one alternative implementation, the following condition is also met:

[0020]

[0021] Where T is the total thickness of the rivet block, in mm.

[0022] In one optional embodiment, the pole mounting hole further includes a welding countersunk platform located at the top of the riveting hole section. The inner diameter of the riveting hole section is smaller than the inner diameter of the welding countersunk platform along both the length and width directions of the cover plate body.

[0023] In one optional embodiment, a first insulating member is further included. The first insulating member has a receiving groove that mates with the riveting block. The first insulating member is disposed between the riveting block and the cover plate body, and the riveting block is disposed in the receiving groove.

[0024] Secondly, the present invention also provides a battery cell, including a housing, an electrode assembly, and a battery cell cover assembly as described above. The housing has a receiving cavity and an opening communicating with the receiving cavity; the electrode assembly is disposed in the receiving cavity of the housing; the battery cell cover assembly is disposed in the opening of the housing, encapsulating the electrode assembly within the housing.

[0025] Beneficial Effects: The cell cover assembly is used in battery cells to seal the openings 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 terminals of the cell cover assembly provide the path for current inflow and outflow, ensuring current conduction during the charging and discharging process of the cell. For the battery cell, the cell cover assembly not only serves as an electrical connection but also enhances the overall structural stability of the cell, making it an important component that ensures the robustness and safety of the cell during use.

[0026] Since the battery cell includes the battery cell cover assembly, it has all the technical effects of the battery cell cover assembly, so it will not be elaborated here.

[0027] Thirdly, the present invention also provides a battery pack including multiple battery cells from more than one technical solution, wherein the riveting blocks of adjacent battery cells are welded together by a busbar.

[0028] Beneficial effects: Since the battery pack includes the cells, it has all the technical benefits of the cells, which will not be elaborated here. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is an exploded view of the structure of a battery cell cover assembly according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 The top view of the assembled battery cell cover assembly shown;

[0032] Figure 3 For along Figure 2 Sectional view at point AA;

[0033] Figure 4for Figure 3 A magnified view of a section at point C;

[0034] Figure 5 For along Figure 2 Sectional view at point BB;

[0035] Figure 6 for Figure 1 The diagram shows the structure of the riveting block in the battery cell cover assembly.

[0036] Figure 7 for Figure 6 A top view of the riveted block shown;

[0037] Figure 8 For along Figure 7 Sectional view at point DD;

[0038] Figure 9 for Figure 8 A magnified view of a section at point F in the middle;

[0039] Figure 10 For along Figure 7 Sectional view at EE;

[0040] Figure 11 for Figure 1 The diagram shows the structure of the electrode post in the battery cell cover assembly.

[0041] Figure 12 for Figure 11 A top view of the pole shown;

[0042] Figure 13 For along Figure 12 Sectional view at point GG;

[0043] Figure 14 For along Figure 12 Cross-sectional view at HH.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Cover plate body; 101. Assembly hole; 2. Riveting block; 201. Pole post mounting hole; 2011. Assembly hole section; 2012. Riveting hole section; 2013. Welding countersunk platform; 3. Pole post; 301. Assembly post section; 302. Riveting post section; 303. Riveting punch; 304. Pole post base plate; 305. Pole post main body section; 4. First insulating component; 5. Second insulating component; 6. Sealing ring; 7. Explosion-proof valve; 8. Explosion-proof valve patch. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] In the cell cover assembly, the terminal post and the riveting block are riveted together. For elliptical terminal posts, the riveting process is more difficult when riveting along the arc edge of the elliptical terminal post than along the straight edge. After riveting, gaps are likely to appear between the arc edge of the terminal post and the riveting block, resulting in insufficient local riveting strength and poor thrust resistance. At the same time, excessively large gaps at the arc edge can also cause the riveting block and the terminal post to be unable to be welded.

[0048] Furthermore, the straight edge of the elliptical pole may experience excessive material expansion, causing the rivet block to expand and deform locally. This affects the fit between the rivet block and the external insulation component, resulting in dimensional deviations in both components and impacting the overall performance of the cell cover assembly.

[0049] This invention ensures sufficient material expansion of the electrode at the arc edge by reasonably limiting the cone angle of the riveting hole section of the riveting block and the cone angle of the riveting punch of the electrode post. This guarantees the riveting strength between the electrode post and the riveting block, ensures the thrust resistance performance of the cell cover assembly, and improves the welding quality between the riveting block and the electrode post. Furthermore, it avoids excessive material expansion of the electrode post at the straight edge, ensuring proper fit between the riveting block and the external insulation component, and ensuring the dimensional compliance of the riveting block and the external insulation component, thus guaranteeing the overall performance of the cell cover assembly.

[0050] The following is combined with Figures 1 to 14 The following describes embodiments of the present invention.

[0051] According to an embodiment of the present invention, in a first aspect, a battery cell cover assembly is provided, including a cover body 1, a riveting block 2, and a terminal post 3. The cover body 1 has an assembly hole 101; the riveting block 2 has a rectangular structure and a terminal post mounting hole 201, which is a stepped hole including an assembly hole section 2011 and a riveting hole section 2012. Both the assembly hole section 2011 and the riveting hole section 2012 are racetrack-shaped holes, and the riveting hole section 2012 is a tapered hole whose diameter gradually decreases towards the assembly hole section 2011; the terminal post 3 passes sequentially through the assembly hole 101 and the terminal post mounting hole 201 and is riveted to the riveting block 2, the terminal post 3 including an assembly post section. Assembly segment 301 and riveting segment 302 are assembled. Assembly segment 301 mates with assembly hole segment 2011. Riveting segment 302 fills riveting hole segment 2012. Riveting segment 302 is a tapered segment. The top of riveting segment 302 forms a recessed riveting punch 303. Riveting punch 303 is a tapered hole with a gradually decreasing diameter towards assembly hole segment 2011. In the axial tangent plane of riveting hole segment 2012 passing through the center of its two end arcs, the cone angle of riveting punch 303 is α, and the cone angle of riveting hole segment 2012 is β, satisfying:

[0052] 5°≤β-α≤30°.

[0053] Specifically, along the axial projection of the pole mounting hole 201, both the assembly hole section 2011 and the riveting hole section 2012 are racetrack-shaped holes, such as... Figure 7 As shown. Both the assembly hole section 2011 and the riveting hole section 2012 include two oppositely arranged arc edges and two oppositely arranged straight edges, as shown in the reference section. Figure 6 In the figure, S1 represents a straight edge, and S2 represents a rounded edge. That is, the two ends of the riveting hole section 2012 along the length of the cover plate body 1 are rounded edges, and the two ends of the riveting hole section 2012 along the width of the cover plate body 1 are straight edges. Wherein, as... Figure 2 As shown, the X direction is the length direction of the cover plate body 1, and the Y direction is the width direction of the cover plate body 1.

[0054] The riveting hole section 2012 is a tapered hole with a gradually decreasing diameter towards the assembly hole section 2011. That is, the sidewall of the riveting hole section 2012 is an inclined wall relative to the axis of the pole post mounting hole 201, and the mating structure between the pole post 3 and the riveting block 2 is an inclined riveting structure. The assembly hole section 2011 is a straight-walled hole, and its sidewall is parallel to the axis of the pole post mounting hole 201.

[0055] Since the riveting hole section 2012 is a tapered hole, the riveting post section 302 of the pole post 3 formed after riveting is a tapered section.

[0056] Specifically, under the punching pressure of the riveting punch, the pole post 3 expands and deforms towards the riveting hole section 2012, ultimately forming the riveting column section 302. A recessed riveting punch 303 is formed at the top of the riveting column section 302. The riveting punch 303 is a blind hole and also a tapered hole with a gradually decreasing diameter towards the assembly hole section 2011. The sidewall of the riveting punch 303 is an inclined wall relative to the axis of the pole post 3.

[0057] In the axial tangent plane passing through the centers of the arcs at both ends of the riveting hole segment 2012, the cone angle of the riveting punch 303 is α. Here, the axial tangent plane of the riveting hole segment 2012 refers to the section cut along the axis of the riveting hole segment 2012, that is, along... Figure 2 A section was cut at point AA, and the result was as follows: Figure 3 As shown, combined with Figure 4 The cone angle α of the riveting punch 303 is the included angle between the two opposite sidewalls of the riveting punch 303 at this time. For ease of description, it will be referred to as the cone angle α of the arc edge of the riveting punch 303 below. The cone angle β of the riveting hole segment 2012 is the included angle between the two opposite sidewalls of the riveting hole segment 2012 at this time. For ease of description, it will be referred to as the cone angle β of the arc edge of the riveting hole segment 2012 below.

[0058] Because the riveting column segment 302 formed by the pole post 3 under the riveting force is structurally compatible with the riveting hole segment 2012 of the riveting block 2, therefore, in the axial section of the riveting column segment 302 passing through the center of its two end arcs, that is, along Figure 12 The middle GG section was cut open, and the result was as follows: Figure 13 As shown, at this time, the included angle between the two opposite sidewalls of the riveted column segment 302 is also β.

[0059] Because the arc edge of the pole post 3 is difficult to expand and prone to insufficient expansion, the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 are differentiated, so that β is greater than α. Specifically, 5°≤β-α≤30°. The angle difference between the two cannot be too small. Otherwise, if the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 is determined, and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 is too large, it will cause excessive expansion of the arc edge of the pole post 3, resulting in insufficient expansion of the riveting block 2. Problems such as localized expansion and deformation, and out-of-tolerance dimensions exist. The angle difference between the two cannot be too large. Otherwise, if the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 is determined, and the cone angle α of the arc edge of the riveting punch 303 is too small, the volume of the riveting punch 303 will be small, the volume deformation of the pole post 3 under riveting pressure will be small, and the material feed of the arc edge of the pole post 3 will be insufficient, resulting in insufficient expansion of material. This will cause a gap between the pole post 3 and the riveting block 2, resulting in insufficient overall riveting strength of the battery cell cover assembly, and will also cause welding quality problems between the pole post 3 and the riveting block 2.

[0060] Therefore, the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 are set differently, and the angle difference between the two cone angles is limited to the above range. This ensures that the pole post 3 is fully expanded at the arc edge, there is no gap between the pole post 3 and the riveting block 2, the riveting strength of the cell cover assembly is guaranteed, its thrust resistance is guaranteed, and the welding quality between the pole post 3 and the riveting block 2 is improved. At the same time, it avoids excessive expansion of the arc edge of the pole post 3, and avoids problems such as local expansion deformation and dimensional deviation of the riveting block 2.

[0061] In some embodiments, the following are also satisfied:

[0062] 30°≤α≤120°, 35°≤β≤150°.

[0063] Limiting the cone angle α of the arc edge of the riveting punch 303 to the range of 30° to 120°, and limiting the cone angle β of the arc edge of the riveting hole section 2012 to the range of 35° to 150°, ensures that the pole post 3 expands sufficiently on the arc edge, effectively reducing the riveting gap between the pole post 3 and the riveting block 2, ensuring the tightness after assembly, thereby guaranteeing the riveting strength between the riveting column section 302 of the pole post 3 and the riveting hole section 2012 of the riveting block 2, and improving the thrust resistance performance of the entire cell cover assembly.

[0064] In some embodiments, in the axial tangent plane perpendicular to the straight edge of the riveting hole segment 2012, the cone angle of the riveting punch 303 is γ, and the cone angle of the riveting hole segment 2012 is θ, satisfying:

[0065] 5°≤γ-θ≤30°.

[0066] In the axial section perpendicular to the straight edge of the riveting hole segment 2012, the cone angle of the riveting punch is γ. Here, the axial section of the riveting hole segment 2012 refers to the cross-section cut along the axis of the riveting hole segment 2012, that is, along... Figure 2 A section was cut at point BB, and the result was as follows: Figure 5 As shown, the cone angle γ of the riveting punch 303 is the included angle between the two opposite sidewalls of the riveting punch 303 at this time. For ease of description, it will be referred to as the cone angle γ of the straight side of the riveting punch 303 below. The cone angle θ of the riveting hole segment 2012 is the included angle between the two opposite sidewalls of the riveting hole segment 2012 at this time. For ease of description, it will be referred to as the cone angle θ of the straight side of the riveting hole segment 2012 below.

[0067] Because the riveting post segment 302 formed by the pole post 3 under the riveting force is structurally compatible with the riveting hole segment 2012 of the riveting block 2, therefore, in the axial tangent plane perpendicular to its straight edge of the riveting post segment 302, that is, along Figure 12 The section was cut at point HH, and the result is as follows: Figure 14As shown, at this time, the included angle between the two opposite sidewalls of the riveted column segment 302 is also θ.

[0068] Because the straight edge of pole post 3 is more prone to material expansion than the arc edge, excessive material expansion is more likely to occur on the straight edge of pole post 3, causing localized expansion and deformation of riveting block 2 and external insulating parts, resulting in dimensional deviations. Therefore, in this embodiment, the cone angle θ of the straight edge of the riveting hole section 2012 of riveting block 2 and the cone angle γ of the straight edge of the riveting punch 303 of pole post 3 are set differently, so that γ is greater than θ. Specifically, 5°≤γ-θ≤30°. The angle difference between the two cannot be too small; otherwise, given a fixed cone angle θ of the straight edge of the riveting hole section 2012, the cone angle γ of the straight edge of the riveting punch 303 will be too small. This can lead to insufficient material expansion on the straight edge of pole post 3, resulting in a gap between the straight edge of pole post 3 and riveting block 2, which in turn leads to insufficient riveting strength of the entire cell cover assembly and welding quality problems between pole post 3 and riveting block 2. The angle difference between the two cannot be too large. Otherwise, if the cone angle θ of the straight edge of the riveting hole section 2012 is determined, and the cone angle γ of the straight edge of the riveting punch 303 is too large, the volume of the riveting punch 303 will be large, the volume deformation of pole post 3 under riveting pressure will be large, and the straight edge of pole post 3 will be excessively expanded, resulting in local expansion deformation of riveting block 2 and external insulation parts, leading to dimensional deviations.

[0069] Therefore, the cone angle θ of the straight edge of the riveting hole section 2012 of the riveting block 2 and the cone angle γ of the straight edge of the riveting punch 303 of the pole post 3 are set differently, and the angle difference between the two cone angles is limited to the above range. This ensures that the straight edge of the pole post 3 is fully riveted, avoids gaps between the straight edge of the pole post 3 and the riveting block 2, ensures the riveting strength of the cell cover assembly and the welding quality of the pole post 3 and the riveting block 2, and at the same time avoids excessive material expansion of the pole post 3 on the straight edge, ensuring a tight and good fit between the pole post 3 and the riveting block 2 and between the riveting block 2 and the external insulation component.

[0070] In some embodiments, the following are also satisfied:

[0071] 35°≤γ≤150°, 30°≤θ≤120°.

[0072] The cone angle γ of the straight edge of the riveting punch 303 is limited to the range of 35° to 150°, and the cone angle θ of the straight edge of the riveting hole section 2012 is limited to the range of 30° to 120°, so as to avoid excessive material expansion of the pole post 3 on the straight edge and ensure that the pole post 3 and the riveting block 2, as well as the riveting block 2 and the external insulating parts can fit tightly and well.

[0073] In some embodiments, the following are also satisfied:

[0074] -0.5mm ≤ H - h ≤ 1.5mm

[0075] Where H is the depth of the riveting punch 303 along the axial direction of the pole mounting hole 201, in mm;

[0076] h represents the depth of the riveting hole section 2012 along the axial direction of the pole mounting hole 201, in mm.

[0077] In this embodiment, the relationship between the riveting punch 303 and the riveting hole segment 2012 is further defined, so that the difference between the depth H of the riveting punch 303 and the depth h of the riveting hole segment 2012 is controlled between -0.5mm and 1.5mm. Otherwise, if H-h is lower than the lower limit, i.e., h-H≥0.5mm, that is, the depth of the riveting hole segment 2012 is too large, the volume of the riveting hole segment 2012 used to accommodate the expansion of the pole post 3 is large, and the expansion deformation volume of the arc edge of the pole post 3 is required to be large. For the arc edge where expansion is more difficult, it is easy to cause insufficient expansion of the pole post 3, resulting in a gap between the pole post 3 and the riveting block 2, affecting the welding of the two and easily causing explosions. If H-h is higher than the upper limit of 1.5mm, that is, the depth of the riveting punch 303 is too large, resulting in greater riveting difficulty.

[0078] In some embodiments, the following are also satisfied:

[0079]

[0080] Where T is the total thickness of the rivet block 2, in mm.

[0081] In this embodiment, the relationship between the riveting punch 303 and the riveting block 2 is further defined, so that the ratio of the depth H of the riveting punch 303 to the total thickness T of the riveting block 2 is controlled between 0.4 and 0.7. Otherwise, if the ratio is too small, below 0.4, the depth of the riveting punch 303 is small when the total thickness T of the riveting block 2 is fixed, resulting in a small deformation volume of the pole post 3 during the riveting process. For the arc edge where expansion is difficult, it is easy to cause insufficient expansion of the pole post 3, resulting in a gap between the pole post 3 and the riveting block 2, affecting the welding of the two and easily causing explosions. If the ratio is too large, above 0.7, the depth of the riveting punch 303 is too large when the total thickness T of the riveting block 2 is fixed, resulting in greater riveting difficulty.

[0082] In some embodiments, the pole mounting hole 201 further includes a welding countersunk 2013 disposed on the top of the riveting hole section 2012. Along the length and width directions of the cover plate body 1, the inner diameter of the riveting hole section 2012 is smaller than the inner diameter of the welding countersunk 2013.

[0083] The welding platform 2013 is used to accommodate the weld marks formed by welding the pole post 3 and the rivet block 2, so that the weld marks do not protrude from the top of the rivet block 2, thereby ensuring the welding quality of the busbar between adjacent cells.

[0084] To verify the technical solution and effects of the present invention, two sets of experimental data are provided below for the battery cell cover plate assembly with oblique riveting structure and straight riveting structure. Both include specific implementation cases and comparative cases, and thrust tests and appearance inspections of riveting and welding are performed on each case.

[0085] The thrust test was conducted using methods known to those skilled in the art. As an example, the specific content of the thrust test is as follows:

[0086] The testing equipment used is a universal testing machine.

[0087] Test method:

[0088] Randomly select test samples of battery cell cover assemblies that meet the specifications, ensuring that the sample surface is clean and free of scratches or pre-damage.

[0089] Calibrate the force and displacement sensors of the testing machine to ensure data accuracy.

[0090] The sampled cell cover plate assembly is placed in the fixture of the testing machine to ensure that the stress point is consistent with the design position, so as to ensure that the cell cover plate assembly does not shift or tilt during the test.

[0091] After confirming that the fixture is securely installed, set the loading pressure and apply a thrust to the cell cover assembly along the Z direction. The thrust should be directed towards the electrode post 3, and the electrode post 3 should be loaded vertically. Set the pressure loading speed.

[0092] Start the testing machine and apply a thrust to electrode 3 until the cell cover assembly fails (e.g., the cell cover assembly deforms, or electrode 3 falls off). The testing machine records the applied force value in real time. The thrust before the cell cover assembly fails is the maximum thrust value that the cell cover assembly can withstand. Record the maximum thrust value as F, in N.

[0093] The visual inspection of riveting and welding includes checking whether there are obvious deformations or gaps in the shape of each component in the battery cell cover assembly, and whether the dimensions are up to standard.

[0094] Group 1: The cone angle α of the arc edge of the riveting punch 303 of the pole post 3 is different from the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2; the rest of the designs are the same. See Table 1 and Table 2 for specific results.

[0095] Group 2: The cone angle γ of the straight edge of the riveting punch 303 and the cone angle θ of the straight edge of the riveting hole section 2012 are different, while the rest of the design is the same. See Tables 3 and 4 for specific results.

[0096] Table 1

[0097]

[0098] Table 2

[0099]

[0100] A comparison of Tables 1 and 2 shows that, in Examples 1 to 8, the difference between the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 is within the range of 5° to 30°. After testing, the thrust test of the cell cover assembly is greater than 1500N, which meets the requirements. After riveting, the components of the cell cover assembly have no deformation, dimensional deviation, or other problems. The welding between the pole post and the riveting block also has no welding problems such as explosions. The appearance and welding inspection are qualified.

[0101] In Comparative Examples 1 to 4, the difference between the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 is too small, less than 5°. The thrust test of the cell cover assembly is qualified, but there is local deformation in the length direction of the riveting block 2, and the length dimension of the riveting block is out of tolerance and does not meet the requirements. This is because the cone angle α of the arc edge of the riveting punch 303 is too small, which causes excessive material expansion in the arc edge of the pole post 3, resulting in local deformation in the length direction of the riveting block 2.

[0102] In Comparative Examples 5 to 8, the difference between the cone angle β of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle α of the arc edge of the riveting punch 303 of the pole post 3 is too large, exceeding 30°. This results in the failure of the thrust test of the cell cover assembly, an excessively large gap between the arc edge of the elliptical pole post and the riveting block 2, and a welding spall between the pole post 3 and the riveting block 2, failing to meet requirements. This is because the cone angle α of the arc edge of the riveting punch 303 is too small, leading to insufficient material expansion at the arc edge of the pole post 3, thus causing a gap between the arc edge of the pole post 3 and the riveting block.

[0103] Table 3

[0104]

[0105] Table 4

[0106]

[0107] A comparison of Tables 3 and 4 shows that in Examples 9 to 16, the difference between the cone angle γ of the straight edge of the riveting punch 303 and the cone angle θ of the straight edge of the riveting hole section 2012 is within the range of 5° to 30°. The thrust test of the battery cell cover assembly is qualified. After riveting, there are no problems with deformation or dimensional deviation of each component in the battery cell cover assembly. There are no problems with the welding between the pole and the riveting block. The appearance and welding inspection are qualified.

[0108] In Comparative Examples 9 to 12, the difference between the cone angle γ of the straight edge of the riveting punch 303 and the cone angle θ of the straight edge of the riveting hole section 2012 is too small, less than 5°. This results in the failure of the thrust test for the cell cover assembly, and the excessive gap between the straight edge of the elliptical pole and the riveting block 2, causing welding spalls and failing to meet requirements. This is because the cone angle γ of the straight edge of the riveting punch 303 is too small, leading to insufficient material expansion on the straight edge of the pole 3, thus causing a gap between the straight edge of the pole 3 and the riveting block 2.

[0109] In Comparative Examples 13 to 16, the difference between the cone angle γ of the straight edge of the riveting punch 303 and the cone angle θ of the straight edge of the riveting hole section 2012 is too large, exceeding 30°. Although the thrust test of the cell cover assembly is qualified, there is local deformation in the width direction of the riveting block, and the length dimension of the riveting block is out of tolerance, failing to meet the requirements. This is because the cone angle γ of the straight edge of the riveting punch 303 is too large, causing excessive expansion of the straight edge of the pole post 3, which in turn causes the riveting block 2 to expand and deform in the width direction.

[0110] In some embodiments, a first insulating member 4 is further included. The first insulating member 4 has a receiving groove that mates with the riveting block 2. The first insulating member 4 is disposed between the riveting block 2 and the cover plate body 1, and the riveting block 2 is disposed within the receiving groove. Specifically, in this embodiment, the first insulating member 4 is the aforementioned external insulating member. When the straight edge of the pole post 3 experiences excessive material expansion, it will cause local expansion and deformation of the riveting block 2 and the first insulating member 4, resulting in dimensional deviations.

[0111] In some embodiments, the pole post 3 further includes a pole post base plate 304, which is connected to the assembly column section 301. The pole post base plate 304 and the riveting block 2 are respectively disposed on the two side surfaces of the cover plate body 1. It also includes a second insulating member 5, which is disposed between the pole post base plate 304 and the cover plate body 1.

[0112] Specifically, in some embodiments, the first insulating member 4 and the second insulating member 5 are both plastic parts. The first insulating member 4 and the second insulating member 5 are used to ensure insulation between the cover plate body 1 and the riveting block 2, and between the cover plate body 1 and the electrode post 3, thereby preventing short circuits or leakage in the battery cell and improving the safety and reliability of the battery cell.

[0113] The cell cover assembly also includes an explosion-proof valve 7 and an explosion-proof valve patch 8. The cover body 1 has an explosion-proof valve mounting hole, and the explosion-proof valve 7 is located inside the explosion-proof valve mounting hole. The explosion-proof valve patch 8 is attached to the upper surface of the explosion-proof valve mounting hole, providing protection for the explosion-proof valve 7. The explosion-proof valve 7 is used to quickly open and release pressure in the event of thermal runaway of the cell, thereby ensuring the safety performance of the battery.

[0114] In some embodiments, the cell cover assembly further includes a sealing ring 6. The terminal post 3 also includes a terminal post body section 305 located between the assembly post section 301 and the terminal post base plate 304. The terminal post body section 305 mates with the assembly hole 101 of the cover body 1. The sealing ring 6 is sleeved on the terminal post body section 305. At least a portion of the sealing ring 6 is located between the terminal post body section 305 and the assembly hole 101 of the cover body 1, and at least a portion of the sealing ring 6 is located between the terminal post base plate 304 and the cover body 1. In this way, the sealing ring 6 can form a double seal between the terminal post 3 and the cover body 1 along the axial and radial directions of the terminal post, thereby improving the sealing performance, reliability, and safety of the cell.

[0115] According to an embodiment of the present invention, in a second aspect, a battery cell is also provided, including a housing, an electrode assembly, and a battery cell cover assembly as described in the above embodiments. The housing has a receiving cavity and an opening communicating with the receiving cavity; the electrode assembly is disposed in the receiving cavity of the housing; the battery cell cover assembly is disposed in the opening of the housing, encapsulating the electrode assembly within the housing.

[0116] The cell cover assembly is used in battery cells to seal the openings in the cell casing, serving to seal and protect the internal components of the battery, preventing chemical leakage and the impact of the external environment on the battery. The terminal post 3 of the cell cover assembly provides a path for current inflow and outflow, ensuring current conduction during the cell's charging and discharging processes. For the battery cell, the cell cover assembly not only provides electrical connections but also enhances the overall structural stability of the cell, making it a crucial component that ensures the cell's robustness and safety during use.

[0117] Since the battery cell includes the battery cell cover assembly, it has all the technical effects of the battery cell cover assembly, so it will not be elaborated here.

[0118] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, comprising a plurality of battery cells as described in the above embodiments, wherein the riveting blocks 2 of adjacent battery cells are welded together via a busbar.

[0119] Since the battery pack includes the battery cells and has all the technical benefits of the battery cells, it will not be elaborated here.

[0120] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell cover assembly, characterized in that, include: The cover plate body is provided with mounting holes; A riveting block, wherein the riveting block has a rectangular structure and is provided with a pole mounting hole, wherein the pole mounting hole is a stepped hole, including an assembly hole section and a riveting hole section, wherein both the assembly hole section and the riveting hole section are racetrack-shaped holes, and the riveting hole section is a tapered hole whose diameter gradually decreases toward the assembly hole section; The pole post passes through the assembly hole and the pole post mounting hole in sequence and is riveted to the riveting block. The pole post includes an assembly column section and a riveting column section. The assembly column section mates with the assembly hole section. The riveting column section fills the riveting hole section. The riveting column section is a tapered section. A recessed riveting punch is formed at the top of the riveting column section. The riveting punch is a tapered hole with a gradually decreasing diameter toward the assembly hole section. In the axial tangent plane passing through the centers of the arcs at both ends of the riveting hole segment, the cone angle of the riveting punch is α, and the cone angle of the riveting hole segment is β, satisfying: 5°≤β－α≤30°； In the axial tangent plane perpendicular to its straight side along the riveting hole segment, the cone angle of the riveting punch is γ, and the cone angle of the riveting hole segment is θ, satisfying: 5°≤γ-θ≤30°.

2. The cell cover assembly according to claim 1, characterized in that, Also satisfies: 30°≤α≤120°，35°≤β≤150°。 3. The cell cover assembly according to claim 1, characterized in that, Also satisfies: 35°≤γ≤150°, 30°≤θ≤120°.

4. The cell cover assembly according to any one of claims 1 to 3, characterized in that, Also satisfies: -0.5mm ≤ H - h ≤ 1.5mm Wherein, H is the axial direction along the pole mounting hole, and the depth of the riveting punch hole is in mm; h represents the depth of the riveting hole section along the axial direction of the pole mounting hole, in mm.

5. The cell cover assembly according to claim 4, characterized in that, Also satisfies: ， Where T is the total thickness of the riveting block, in mm.

6. The cell cover assembly according to any one of claims 1 to 3, characterized in that, The pole mounting hole also includes a welding countersunk platform located at the top of the riveting hole section. Along the length and width directions of the cover plate body, the inner diameter of the riveting hole section is smaller than the inner diameter of the welding countersunk platform.

7. The cell cover assembly according to any one of claims 1 to 3, characterized in that, It also includes a first insulating member, which has a receiving groove that mates with the rivet block. The first insulating member is located between the rivet block and the cover plate body, and the rivet block is located within the receiving groove.

8. A battery cell, characterized in that, include: A housing having a receiving cavity and an opening communicating with the receiving cavity; A pole assembly, wherein the pole assembly is disposed in the receiving cavity of the housing; The cell cover assembly according to any one of claims 1 to 7, wherein the cell cover assembly is disposed at the opening of the housing and encapsulates the electrode assembly within the housing.

9. A battery pack, characterized in that, The battery includes multiple battery cells as described in claim 8, wherein the riveting blocks of adjacent battery cells are welded together via a busbar.

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