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 of a rectangular structure, the riveting block is provided with a pole mounting hole, the pole mounting hole is a stepped hole and comprises an assembling hole section and a riveting hole section, the assembling hole section and the riveting hole section are kidney-shaped holes, and the riveting hole section is a conical hole with the caliber gradually reduced towards the assembling hole section; the terminal post is riveted with the riveting block, the terminal post comprises an assembling post section and a riveting post section, the assembling post section is matched with the assembling hole section, the riveting hole section is filled with the riveting post section, and the riveting post section is a conical section; the taper angle of the arc edge of the riveting hole section is alpha; the taper angle beta of the arc edge of the riveting column section is larger than or equal to-10 degrees and smaller than or equal to 15 degrees. According to the invention, no gap is ensured between the pole and the riveting block after riveting, the overall riveting strength of the battery cell cover plate assembly is improved, the thrust resistance meets the requirements, and the reliability and safety of the battery cell are ensured.

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 body, a pole and a rivet block. Among them, the pole is a key part for connecting to the external circuit, while the cover plate body plays a role of sealing and protection. During the assembly process, the pole and the cover plate body 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 body 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 will cause a gap between the pole and the rivet block, resulting in insufficient riveting strength of the cover body, mechanical strength unable to meet design requirements, 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 battery cover assembly, a battery cell and a battery pack to solve the problems of insufficient riveting strength of the cover body and poor thrust resistance due to insufficient expansion of the arc edge of the elliptical pole.

[0006] In a first aspect, the present invention provides a 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 a rectangular structure, and is provided with a pole mounting hole. The pole mounting hole is a stepped hole, comprising an assembly hole section and a rivet hole section. Both the assembly hole section and the rivet hole section are waist-shaped holes, and the rivet hole section is a tapered hole with a diameter gradually decreasing toward the assembly hole section. After the pole passes through the assembly hole and the pole mounting hole in sequence, it is riveted with the rivet block. The pole comprises an assembly column section and a rivet column section. The assembly column section cooperates with the assembly hole section, and the rivet column section fills the rivet hole section. The rivet column section is a tapered section. In the axial section of the rivet hole section passing through the center of the circular arc at its two ends, the cone angle of the rivet hole section is α; in the axial section of the rivet column section passing through the center of the circular arc at its two ends, the cone angle of the rivet column section is β, satisfying: -10°≤α-β≤15°.

[0007] Beneficial effects: The battery cell cover plate assembly provided by the present invention limits the angle difference between the cone angle α of the arc edge of the riveted hole section of the riveted block and the cone angle β of the arc edge of the riveted column section of the pole within the range of -10° to 15°, thereby limiting the structure of the pole after riveting and expansion, which can effectively solve the problem of insufficient expansion of the arc edge of the elliptical pole, and ensure that after the pole is riveted, the riveted column section of the pole and the riveted hole section of the riveted block are tightly matched, and there is no gap between the pole and the riveted block, thereby improving the overall riveting strength of the battery cell cover plate assembly, so that its mechanical strength meets the design requirements, and its thrust resistance performance meets the requirements, thereby ensuring the reliability and safety of the battery cell. At the same time, there is no gap between the pole and the riveted block, which can ensure the welding quality between the pole and the riveted block, further improving the reliability and safety of the battery. In addition, it can also prevent the arc edge of the elliptical pole from excessive expansion, which would cause local deformation of the riveted block along the X direction, ensuring that the riveted block and the external insulating part fit properly and have no dimensional deviations, thus achieving precise design of the riveted fitting structure between the pole and the riveted block, which helps to ensure production consistency and reduce the defective product rate.

[0008] In some optional embodiments, the following conditions are also met:

[0009] 40°≤α≤130°, 40°≤β≤145°.

[0010] In some alternative embodiments, α=β.

[0011] In some optional embodiments, when -10°≤α-β≤0°, the following condition is also satisfied: h≥t; when 0°<α-β≤15°, the following condition is also satisfied: th≤0.3mm; wherein h is the height of the riveted column section along the axial direction of the pole mounting hole, in mm; and t is the depth of the riveted hole section along the axial direction of the pole mounting hole, in mm.

[0012] In some optional embodiments, the following conditions are also met:

[0013]

[0014] 0.55mm≤t≤1.8mm,

[0015] 1.5mm≤T≤3.5mm,

[0016] Wherein, T is the total thickness of the riveting block along the axial direction of the pole mounting hole, in mm.

[0017] In some optional embodiments, the following conditions are also met:

[0018]

[0019] 0.6mm≤h≤1.85mm,

[0020] 1.4mm≤H≤3mm,

[0021] Where H is the sum of the heights of the assembly column section and the riveted column section along the axial direction of the pole mounting hole, in mm.

[0022] In some optional embodiments, the following conditions are also met:

[0023]

[0024] in,

[0025] L1 is the inner diameter of the first end of the riveting hole segment along the Z direction, passing through the center of the arc at both ends of the riveting hole segment, in mm;

[0026] L2 is the inner diameter of the second end of the riveting hole segment along the Z direction passing through the center of the arc at both ends thereof, in mm.

[0027] In some optional embodiments, the pole mounting hole further includes a welding sink provided on the top of the riveting hole section, and the welding sink is a waist-shaped hole;

[0028] Also meets:

[0029]

[0030] Wherein, L3 is the inner diameter of the welding sink along the X direction and passing through the center of the arc at both ends thereof, in mm.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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

[0036] 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.

[0037] Figure 1 This is an exploded view of the structure of a battery cover assembly according to an embodiment of the present invention;

[0038] Figure 2 for Figure 1 A top view of the assembled cell cover assembly is shown;

[0039] Figure 3 For the Figure 2 Cross-sectional view at AA in the middle;

[0040] Figure 4 For the Figure 2 Cross-sectional view at the middle BB;

[0041] Figure 5 for Figure 1 A top view of the rivet block in the cell cover assembly shown;

[0042] Figure 6 For the Figure 5 Cross-sectional view at CC;

[0043] Figure 7 for Figure 6 A partial enlarged view of point E in the middle;

[0044] Figure 8 for Figure 1 A top view of the pole in the cell cover assembly shown;

[0045] Figure 9 for Figure 8 The front view of the pole shown;

[0046] Figure 10 for Figure 8 Cross-sectional view along DD.

[0047] Description of reference numerals:

[0048] 1. Cover plate body; 101. Assembly hole; 2. Riveted block; 201. Pole mounting hole; 2011. Assembly hole section; 2012. Riveted hole section; 2013. Welding sinker; 3. Pole; 301. Assembly column section; 302. Riveted column section; 303. Riveted punching hole; 304. Pole base plate; 305. Pole main section; 4. First insulating member; 5. Second insulating member; 6. Sealing ring; 7. Explosion-proof valve; 8. Explosion-proof valve patch. DETAILED DESCRIPTION

[0049] 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.

[0050] In the cell cover assembly, the pole and rivet block are riveted together. For elliptical poles, riveting along the arc edge of the pole is more difficult than expanding along the straight edge. This can easily create a gap between the arc edge of the pole and the rivet block after riveting, resulting in insufficient localized riveting strength and poor thrust resistance. Furthermore, excessive gaps in the arc can prevent the rivet block and pole from being welded.

[0051] Therefore, the present invention ensures the riveting strength of the pole and the rivet block by designing the matching structure of the arc edge of the pole and the arc edge of the pole mounting hole of the rivet block, ensures the thrust resistance performance of the battery cover assembly, and improves the welding quality between the rivet block and the pole.

[0052] The following combination Figures 1 to 10 , 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 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 a rectangular structure, and the rivet block 2 is provided with a pole mounting hole 201. The pole mounting hole 201 is a stepped hole, comprising an assembly hole section 2011 and a rivet hole section 2012. Both the assembly hole section 2011 and the rivet hole section 2012 are waist-shaped holes, and the rivet hole section 2012 is a tapered hole with a diameter gradually decreasing toward the assembly hole section 2011. After the pole 3 passes through the assembly hole 101 and the pole mounting hole 201 in sequence, it is riveted to the rivet block 2. 3 includes an assembly column segment 301 and a riveted column segment 302. The assembly column segment 301 cooperates with the assembly hole segment 2011, and the riveted column segment 302 fills the riveted hole segment 2012. The riveted column segment 302 is a tapered segment. In an axial section of the riveted hole segment 2012 passing through the center of the circular arcs at its two ends, the tapered angle of the riveted hole segment 2012 is α. In an axial section of the riveted column segment 302 passing through the center of the circular arcs at its two ends, the tapered angle of the riveted column segment 302 is β, satisfying the following: -10°≤α-β≤15°.

[0054] Specifically, along the axial projection of the pole mounting hole 201, the shapes of the assembly hole section 2011 and the riveting hole section 2012 are both waist-shaped holes, such as Figure 5 As shown. The assembly hole section 2011 and the riveting hole section 2012 each include two oppositely disposed arc edges and two oppositely disposed straight edges. Figure 5 In the figure, S1 refers to a straight edge, and S2 refers to an arc edge, that is, the two ends of the riveting hole section 2012 along the width direction of the cover plate body 1 are straight edges, and the two ends of the riveting hole section 2012 along the length direction of the cover plate body 1 are arc edges. Figure 2 As shown, the X direction is the length direction of the cover body 1 , and the Y direction is the width direction of the cover body 1 .

[0055] The rivet hole section 2012 is a tapered hole with a diameter that tapers toward the assembly hole section 2011. That is, the sidewalls of the rivet hole section 2012 are inclined relative to the axis of the pole mounting hole 201, and the mating structure between the pole 3 and the rivet block 2 is an oblique rivet structure. The assembly hole section 2011 is a straight hole, with its sidewalls parallel to the axis of the pole mounting hole 201.

[0056] Since the riveting hole section 2012 is a tapered hole, the riveted column section 302 of the pole 3 formed after riveting is a tapered section.

[0057] In the axial section of the riveting hole segment 2012 passing through the center of the arcs at both ends, the cone angle of the riveting hole segment 2012 is α, wherein the axial section of the riveting hole segment 2012 refers to the section cut along the axis of the riveting hole segment 2012, that is, along Figure 5 The results are as follows: Figure 6 and Figure 7 As shown, in the axial section of the riveted hole segment 2012 passing through the center of the arc at its two ends, the taper angle α of the riveted hole segment 2012 is the angle between the two side walls of the riveted hole segment 2012 at this time. For ease of description, it is hereinafter referred to as the taper angle α of the arc edge of the riveted hole segment 2012.

[0058] In the axial section of the riveted column segment 302 passing through the center of the arcs at both ends, the cone angle of the riveted column segment 302 is β, wherein the axial section of the riveted column segment 302 refers to the cross section cut along the axis of the riveted column segment 302, that is, along Figure 8 The results are shown in Figure 2. Figure 10 As shown, or with reference to Figure 9 In the axial section of the riveted column segment 302 passing through the center of the arc at its two ends, the taper angle β of the riveted column segment 302 is the angle between the two side walls of the riveted column segment 302 at that time. For ease of description, it is hereinafter referred to as the taper angle β of the arc edge of the riveted column segment 302.

[0059] Specifically, under the punching force of the riveting punch, the pole 3 expands and deforms toward the riveting hole segment 2012, ultimately forming a riveted column segment 302. A riveted punch hole 303 is formed at the top of the riveted column segment 302. The taper angle β of the arc edge of the riveted column segment 302 can be controlled by riveting process parameters such as the shape, depth, and volume of the riveted punch hole 303, so that the angle difference between the taper angle β of the arc edge of the riveted column segment 302 and the taper angle α of the arc edge of the riveted hole segment 2012 meets the above requirements.

[0060] In the present invention, the riveted column section 302 of the pole 3 is formed by the pole 3 expanding and deforming under the action of the riveting force. The cone angle β of the arc edge of the riveted column section 302 of the pole 3 is related to the riveting process. The riveted column section 302 is adapted to the riveted hole section 2012, but an angle difference between the two cone angles is allowed. It can be α>β, α<β, or α=β. However, the angle difference between the two must meet the following conditions: -10°≤α-β≤15°. Otherwise, if the value of α-β is too large, exceeding 15°, then after riveting, the gap between the arc edge of the pole 3 and the riveted block 2 is too large, resulting in insufficient riveting strength of the overall battery cover assembly and quality problems such as cracking points in the weld between the pole 3 and the riveted block 2. If the value of α-β is too small, exceeding -10°, the arc edge of the pole 3 will expand too much, the riveted block 2 will be locally deformed in the X direction, and the length of the riveted block 2 will be out of tolerance.

[0061] The battery cell cover plate assembly provided by the present invention limits the angle difference between the cone angle α of the arc edge of the riveting hole section 2012 of the riveting block 2 and the cone angle β of the arc edge of the riveting column section 302 of the pole 3 to within the range of -10° to 15°, thereby limiting the structure of the pole 3 after riveting and material expansion. This can effectively solve the problem of insufficient material expansion on the arc edge of the elliptical pole, ensure that after riveting, the riveting column section 302 of the pole 3 and the riveting hole section 2012 of the riveting block 2 are tightly matched, and there is no gap between the pole 3 and the riveting block 2. This improves the overall riveting strength of the battery cell cover plate assembly, ensures that its mechanical strength meets the design requirements, and meets the thrust resistance requirements, thereby ensuring the reliability and safety of the battery cell. At the same time, there is no gap between the pole 3 and the riveting block 2, which can ensure the welding quality between the pole 3 and the riveting block 2, further improving the reliability and safety of the battery. In addition, it can also avoid excessive expansion of the arc edge of the elliptical pole, which may cause local deformation of the riveted block 2 along the X direction, ensuring normal cooperation between the riveted block 2 and the external insulating part, without dimensional deviation, and realizing precise design of the riveted cooperation structure between the pole 3 and the riveted block 2, which helps to ensure production consistency and reduce the defective product rate.

[0062] In some embodiments, the following conditions are also met:

[0063] 40°≤α≤130°, 40°≤β≤145°.

[0064] Limiting the cone angle α of the arc edge of the riveted hole segment 2012 within the range of 40° to 130°, and limiting the cone angle β of the arc edge of the riveted column segment 302 of the pole 3 within the range of 40° to 145°, can effectively reduce the riveting gap between the pole 3 and the riveted block 2, ensure the tightness after assembly, thereby ensuring the riveting strength between the riveted column segment 302 of the pole 3 and the riveted hole segment 2012 of the riveted block 2, and improving the thrust resistance performance of the entire battery cover assembly.

[0065] In some embodiments, α=β.

[0066] When the taper angle α of the arc edge of the rivet hole segment 2012 and the taper angle β of the arc edge of the rivet post segment 302 of the pole 3 are equal, the rivet post segment 302 of the pole 3 and the rivet hole segment 2012 of the rivet block 2 can achieve a relatively perfect geometric match. The rivet post segment 302 of the pole 3 can precisely fill the rivet hole segment 2012, virtually eliminating the riveting gap, improving the overall riveting strength of the battery cell cover assembly, and achieving excellent thrust resistance. At the same time, the weld quality between the pole 3 and the rivet block 2 is guaranteed. Furthermore, the equal taper angles simplify the design of the rivet block 2 and the pole 3, which helps improve the consistency of battery cell products.

[0067] The present invention only limits the cone angle of the arc edge of the riveting hole section 2012 to solve the problem of insufficient expansion of the arc edge of the pole 3, and does not limit the cone angle of the straight edge of the riveting hole section 2012, that is, along the Figure 2 The taper angle of the straight side of the riveted hole section 2012 obtained by sectioning at the middle BB is not limited. The taper angle of the straight side of the riveted column section 302 of the pole 3 is similarly not limited.

[0068] In some embodiments, when -10°≤α-β≤0°, the following applies: h≥t; when 0°<α-β≤15°, the following applies: th≤0.3mm; wherein h is the height of the riveted column segment 302 along the axial direction of the pole mounting hole 201, in mm; and t is the depth of the riveted hole segment 2012 along the axial direction of the pole mounting hole 201, in mm.

[0069] When -10°≤α-β≤0°, that is, the cone angle α of the arc edge of the riveted hole segment 2012 is smaller than the cone angle β of the arc edge of the riveted column segment 302 of the pole 3, at this time, the height h of the riveted column segment 302 needs to be greater than or equal to the depth t of the riveted hole segment 2012, so as to avoid assembly interference between the riveted column segment 302 and the riveted hole segment 2012, resulting in riveting failure.

[0070] When 0°<α-β≤15°, that is, the cone angle α of the arc edge of the riveted hole segment 2012 is greater than the cone angle β of the arc edge of the riveted post segment 302 of the pole 3, at this time, the height h of the riveted post segment 302 and the depth t of the riveted hole segment 2012 must satisfy: th≤0.3mm. This ensures that there is no interference between the riveted post segment 302 and the riveted hole segment 2012, ensures a reasonable fitting clearance, and allows the pole 3 to be riveted in place, with the pole 3 and the riveted block 2 to fit tightly together.

[0071] In some embodiments, the following conditions are also met:

[0072]

[0073] 0.55mm≤t≤1.8mm,

[0074] 1.5mm≤T≤3.5mm,

[0075] Wherein, T is the total thickness of the riveting block 2 along the axial direction of the pole mounting hole 201 , in mm.

[0076] In this embodiment, the relationship between the depth t of the rivet hole segment 2012 and the total thickness T of the rivet block 2 is further defined so that the ratio of t to T is within the range of 0.35 to 0.6. Otherwise, If it is less than 0.35, t is too small, and the volume of the riveting hole section 2012 of the riveting block 2 is too small, which affects the riveting assembly of the riveting block 2 and the pole 3. There is a possibility of interference between the riveting block 2 and the pole 3, making riveting difficult or causing the pole 3 to expand and deform due to riveting. If it is greater than 0.6, t is too large. When T is constant, the depth of the assembly hole section 2011 is too small. The assembly hole section 2011 plays a supporting role in the riveting process between the pole 3 and the riveting block 2. If the depth of the assembly hole section 2011 is too small, the structural strength of the assembly hole section 2011 is low, and the riveting block 2 is easily deformed under the action of the riveting force, affecting the normal fit between the riveting block 2 and its external insulating parts, resulting in dimensional deviation.

[0077] t takes values ​​in the range of 0.55mm to 1.8mm, including 0.55mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.5mm, and 1.8mm.

[0078] T takes values ​​in the range of 1.5mm to 3.5mm, including 1.5mm, 1.8mm, 2.0mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm, 3.2mm, and 3.5mm.

[0079] In some embodiments, the following conditions are also met:

[0080]

[0081] 0.6mm≤h≤1.85mm,

[0082] 1.4mm≤H≤3mm,

[0083] Wherein, H is the sum of the heights of the assembly column section 301 and the riveted column section 302 along the axial direction of the pole mounting hole 201 , in mm.

[0084] In this embodiment, the relationship between the height h of the riveted column section 302 and the sum of the heights H of the assembly column section 301 and the riveted column section 302 is further limited so that the ratio of h to H is within the range of 0.35 to 0.65. Otherwise, If h is less than 0.35, it will cause insufficient expansion of the riveted material of the pole 3, resulting in a local gap between the pole 3 and the riveted block 2, resulting in insufficient riveting strength of the battery cover assembly, and affecting the welding quality between the riveted block 2 and the pole 3, resulting in cold welding; If it is greater than 0.65, h is too large, and there is a possibility of interference between the pole 3 and the riveted block 2 during assembly, which will affect the fit between the pole 3 and the riveted block 2 .

[0085] In some embodiments, the following conditions are also met:

[0086]

[0087] in,

[0088] L1 is the inner diameter of the first end of the riveting hole segment 2012 along the Z direction, passing through the center of the arc at both ends thereof, in mm;

[0089] L2 is the inner diameter of the second end of the riveting hole segment 2012 along the Z direction passing through the center of the arc at both ends thereof, in mm.

[0090] The riveting hole section 2012 is a tapered hole. Figure 7 From the perspective of , the top has the largest diameter, and the diameter becomes smaller as it goes down. L2 is the inner diameter of the upper end of the riveting hole section 2012 passing through the center of the arc at both ends along the Z direction, which is also the inner diameter of the assembly hole section 2011 in the same direction.

[0091] In this embodiment, further, The value of is controlled in the range of 0.1 to 0.2. If the depth t of the rivet hole section 2012 is determined, the cone angle α of the arc edge of the rivet hole section 2012 will be too small; If the angle is greater than 0.2, when the depth t of the rivet hole section 2012 is determined, the cone angle α of the arc edge of the rivet hole section 2012 will be too large, which is not conducive to ensuring the riveting assembly accuracy between the rivet block 2 and the pole 3, resulting in insufficient riveting material expansion of the pole 3, a gap between the rivet block 2 and the pole 3, or excessive expansion of the pole 3, causing deformation of the rivet block 2, affecting the normal cooperation between the rivet block 2 and its external insulating parts, and causing dimensional deviation.

[0092] In addition, The value is controlled within the range of 0.1 to 0.2, which can also ensure that the riveted hole segment 2012 has certain dimensional stability and structural strength during the manufacturing and riveting process. At the same time, the force distribution of the riveted hole segment 2012 can be optimized, thereby improving the fatigue resistance and service life of the product.

[0093] In some embodiments, the pole mounting hole 201 further includes a welding sink 2013 provided on the top of the riveting hole section 2012, and the welding sink 2013 is a waist-shaped hole;

[0094] Also meets:

[0095]

[0096] Wherein, L3 is the inner diameter of the welding sink 2013 along the X direction and passing through the center of the arc at both ends thereof, and the unit is mm.

[0097] Specifically, in this embodiment, the pole mounting hole 201 of the riveting block 2 is further provided with a welding sink 2013, which is used to accommodate the weld marks of the riveting block 2 and the pole 3. The welding sink 2013 needs to have a sufficient size to accommodate the weld marks.

[0098] Reference Figure 7 , cut along the axial direction of the pole mounting hole 201 at the center of the arc edge passing through the pole mounting hole 201, The single side width of the welding sink 2013 from the riveting hole section 2012 along the length direction of the cover body 1 should be controlled within the range of 0.3mm to 1.5mm. Otherwise, If it is less than 0.3 mm, the width of the welding sink 2013 is too small, which will cause the welding mark of the pole 3 and the rivet block 2 to exceed the pole mounting hole 201; If it is greater than 1.5 mm, the width of the welding sink 2013 is too large, which will result in too little material remaining on the edge of the rivet block 2 after removing the pole mounting hole 201, resulting in insufficient strength of the rivet block 2 and easy deformation during the riveting process.

[0099] In some embodiments, the pole 3 further includes a pole bottom plate 304 , which is connected to the assembly column section 301 of the pole 3 . The pole bottom plate 304 and the riveting block 2 are respectively provided on both side surfaces of the cover body 1 .

[0100] 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 .

[0101] In this embodiment, the first insulating member 4 is the aforementioned insulating member located outside the riveted block 2. This invention prevents excessive expansion of the arc edge of the elliptical pole, which could cause localized deformation of the riveted block 2 along the X-direction, thereby ensuring proper fit between the riveted block 2 and the first insulating member 4 and consistent dimensional tolerances.

[0102] 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 body 1 and the rivet block 2, and between the cover body 1 and the terminal 3, thereby preventing short circuits or leakage in the battery cell and improving the safety and reliability of the battery cell.

[0103] To verify the technical effects of the present invention, specific experimental cases are provided below, including examples and comparative examples. Each case is subjected to a thrust test, a welding quality test of the pole 3 and the riveted block 2, and an appearance test of the pole 3 and the riveted block 2 after riveting.

[0104] First, the thrust test is performed using methods known to those skilled in the art. As an example, the thrust test is as follows:

[0105] The testing equipment is a universal material testing machine.

[0106] Test method:

[0107] 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.

[0108] Calibrate the force and displacement sensors of the testing machine to ensure data accuracy.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] Second, the welding quality of the pole 3 and the riveted block 2 is inspected. Specifically, the welding quality is inspected to see if there is any cold welding, i.e., the welding is not firm, the contact is poor, or there are holes. Inspection methods known to those skilled in the art can be used. For example, the following inspection methods can be used:

[0113] Method 1: Visual inspection: Observe the solder joints with the naked eye or a magnifying glass to check for the following characteristics: surface roughness, cracks, or oxidation; shorts or bridges between solder joints; and insufficient contact area between the solder joint and the pad / pin. Advantages: Simple, low-cost, and quick to detect obvious defects. Disadvantages: Relying on operator experience, it cannot detect minor cold solder joints or internal defects (such as voids within BGA solder balls).

[0114] Method 2: Resistance Test: Use a multimeter or precision resistance tester to measure the resistance between solder joints. A normal solder joint should have very low resistance (microohms). If the resistance is significantly elevated (e.g., over 10 milliohms), it may indicate a poor solder joint. Advantages: Directly reflects conductivity and is suitable for single-point testing. Disadvantages: Requires contact with the test point, which may interfere with delicate solder joints.

[0115] Method 3: Destructive Testing—Tensile Testing—applies tension to the solder joint to test its mechanical strength. Weak solder joints tend to fall off easily. Advantages: Accurate results and quantifiable weld strength. Disadvantages: Destructive to the sample, suitable only for spot checks.

[0116] Here, method 1 is used to test the welding quality of each case.

[0117] Third, 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.

[0118] The test results require that the thrust F>1500N, the riveted block 2 has no obvious deformation after riveting, the size of the riveted block 2 is qualified, and the welding between the riveted block 2 and the pole 3 has no quality problems such as explosion points and cold welding.

[0119] The test results are detailed in Tables 1 and 2.

[0120] Table 1

[0121]

[0122] Table 2

[0123]

[0124] By comparing Table 1 and Table 2, it can be seen that in Examples 1 to 8, after the pole and the rivet block are riveted, the thrust test is qualified, that is, the overall riveting strength of the battery cover assembly meets the requirements. And the size of the rivet block along the X direction is qualified. The value of α-β is controlled within the range of -10° to 15°, which can ensure that the pole is sufficiently expanded at the arc edge and not excessive. Among them, in Examples 4 and 5, the thrust test is qualified, the pole is sufficiently expanded at the arc edge, the rivet block is not deformed or out of size, and there is no hot spot or cold welding between the pole and the rivet block, which meets the requirements, that is, α=β is preferred.

[0125] In Comparative Examples 1 to 4, the values ​​of α-β are all lower than the lower limit, exceeding -10°. As a result, the pole expands too much on the arc edge. Although the thrust test is qualified, the rivet block is obviously deformed along the X direction, and the length dimension of the rivet block is out of tolerance and does not meet the requirements.

[0126] In Comparative Examples 5 to 8, the values ​​of α-β are all higher than the upper limit, exceeding 15°. As a result, the pole has too little material expansion at the arc edge. After riveting, the gap between the arc edge of the pole and the rivet block is too large, resulting in the thrust test of the battery cell cover assembly failing, that is, the overall riveting strength of the battery cell change assembly is insufficient, and the gap between the arc edge of the pole and the rivet block also causes explosion points in the welding of the two. The welding quality test fails and does not meet the requirements.

[0127] In some embodiments, the 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 affixed 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 cell, thereby ensuring battery safety.

[0128] In some embodiments, the cell cover assembly further includes a sealing ring 6. The pole 3 further includes a pole main section 305 located between the assembly column section 301 and the pole bottom plate 304. The pole main section 305 cooperates with the assembly hole 101 of the cover body 1. The sealing ring 6 is sleeved on the pole main section 305. At least a portion of the sealing ring 6 is located between the pole main 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 pole bottom plate 304 and the cover body 1. In this way, the sealing ring 6 can form a double seal between the pole 3 and the cover body 1 along the axial and radial directions of the pole, thereby improving the sealing, reliability, and safety of the battery cell.

[0129] 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 embodiment. The housing has a receiving cavity and an opening communicating with the receiving cavity; the pole group is disposed in the receiving cavity of the housing; and the cell cover assembly is disposed in the opening of the housing, encapsulating the pole group within the housing.

[0130] 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 current to flow in and out, ensuring 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.

[0131] In some embodiments, the battery cell comprises a blade cell.

[0132] 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.

[0133] 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.

[0134] Because the battery pack includes battery cells and has all the technical effects of battery cells, they will not be described here.

[0135] 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 riveting block, the riveting block having a rectangular structure, the riveting block being provided with a pole mounting hole, the pole mounting hole being a stepped hole, comprising an assembly hole section and a riveting hole section, both the assembly hole section and the riveting hole section being waist-shaped holes, the riveting hole section being a tapered hole whose diameter gradually decreases toward the assembly hole section; A pole, wherein the pole passes through the assembly hole and the pole mounting hole in sequence and is then riveted to the riveting block. The pole comprises an assembly column section and a riveted column section. The assembly column section cooperates with the assembly hole section, and the riveted column section fills the riveted hole section. The riveted column section is a tapered section. In the axial section of the riveted hole segment passing through the center of the circular arcs at both ends thereof, the cone angle of the riveted hole segment is α; In the axial section of the riveted column segment passing through the center of the circular arcs at both ends thereof, the cone angle of the riveted column segment is β; satisfy: -10°≤α-β≤15°。 2. The battery cover assembly according to claim 1, characterized in that: Also meets: 40°≤α≤130°，40°≤β≤145°。 3. The battery cover assembly according to claim 2, characterized in that: α＝β。 4. The battery cover assembly according to claim 1 or 2, characterized in that: When -10°≤α-β≤0°, it also satisfies: h≥t; When 0°<α-β≤15°, the following conditions must also be met: th≤0.3mm; in, h is the height of the riveted column section along the axial direction of the pole mounting hole, in mm; t is the depth of the riveting hole section along the axial direction of the pole mounting hole, in mm.

5. The battery cover assembly according to claim 4, characterized in that: Also meets: 0.55mm≤t≤1.8mm, 1.5mm≤T≤3.5mm, Wherein, T is the total thickness of the rivet block along the axial direction of the pole mounting hole, in mm.

6. The battery cover assembly according to claim 4, characterized in that: Also meets: 0.6mm≤h≤1.85mm, 1.4mm≤H≤3mm, Wherein, H is the sum of the heights of the assembly column section and the riveted column section along the axial direction of the pole mounting hole, in mm.

7. The battery cover assembly according to claim 1 or 2, characterized in that: Also meets: in, L1 is the inner diameter of the first end of the riveting hole segment along the Z direction, passing through the center of the arc at both ends thereof, in mm; L2 is the inner diameter of the second end of the riveting hole segment along the Z direction passing through the center of the arc at both ends thereof, in mm.

8. The battery cover assembly according to claim 1 or 2, characterized in that: The pole mounting hole further comprises a welding sink provided on the top of the riveting hole section, wherein the welding sink is a waist-shaped hole; Also meets: Wherein, L3 is the inner diameter of the welding sink along the X direction and passing through the center of the arc at both ends thereof, and the unit is mm.

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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