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 comprises a riveting block body, the riveting block body is provided with a pole mounting hole, the pole mounting hole is a stepped hole comprising a first hole section and a second hole section, the first hole section and the second hole section are both runway-shaped holes in the axial projection of the pole mounting hole; the pole before riveting comprises a pole body, the pole body passes through the assembly hole and the pole mounting hole in sequence, the pole body is riveted with the riveting block, and the pole body comprises a first column section and a second column section after riveting; recessed structures are arranged at the corresponding positions of the two side edges of the riveting block and the straight edges of the pole mounting hole to form deformation compensation zones; the size of the deformation compensation zone of the riveting block is designed to meet preset conditions. The application can guarantee the width of the riveting block, and improve the production yield and safety of the battery cell cover plate assembly.

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] Lithium-ion batteries are widely used in various fields such as transportation power supply, power storage, new energy storage power supply, aerospace and military industry due to their advantages such as large capacity, high operating voltage, strong charge retention capability and long cycle life.

[0003] A battery cell is the smallest unit of a lithium battery pack. A battery cell typically consists of electrode assemblies, electrolyte, bare cell insulating sheets, cover assembly, and casing. The cover assembly includes terminals, riveting blocks, the cover body, insulating components, and sealing rings. Terminals include round terminals and oblong terminals (commonly known as elliptical terminals). The terminals and riveting blocks are riveted together and then welded.

[0004] The elongated oval pole has both straight and curved edges. During the riveting process, there is a difference in material expansion between the straight and curved edges of the elongated oval pole. Generally, the straight edge of the elongated oval pole expands more easily than the curved edge. Therefore, in order to ensure good riveting strength between the pole and the riveting block, gaps between the curved edge of the pole and the riveting block should be avoided. In this case, the straight edge of the pole is prone to excessive expansion, which can cause local expansion and deformation of the riveting block and its external insulation components near the pole. This can lead to dimensional deviations, insulation deformation, and cracking risks, affecting the overall safety performance of the cell cover assembly. Summary of the Invention

[0005] In view of this, the present invention provides a cell cover plate assembly, a cell, and a battery pack to solve the problems of excessive material expansion on the straight edges of the elongated oval pole and the riveting block after riveting, and the out-of-tolerance width dimensions of the riveting block and its external insulation components.

[0006] In a first aspect, the present invention provides a battery cell cover assembly, including a cover body, a riveting block, and a terminal post. The cover body has an assembly hole; the riveting block includes a riveting block body, which has a terminal post mounting hole, the terminal post mounting hole being a stepped hole, including a first hole segment and a second hole segment arranged sequentially along a direction away from the cover body, and both the first hole segment and the second hole segment being racetrack-shaped holes along the axial projection of the terminal post mounting hole; the terminal post before riveting includes a terminal post body, the terminal post body sequentially passing through the assembly hole and the terminal post mounting hole, the terminal post body and the riveting block being riveted together, and the terminal post body after riveting including a first post segment that mates with the first hole segment and a second post segment that mates with the second hole segment. The second column segment mates with the hole segment; both sides of the riveting block and the corresponding straight edges of the pole mounting holes are provided with recessed structures to form deformation compensation zones; along the X direction, the inner dimension of the second hole segment is L0 (mm); along the X direction, the length of the deformation compensation zone is L (mm); along the Y direction, the distance between the midpoint of the straight edge of the second hole segment and the edge of the deformation compensation zone is W0 (mm); along the Y direction, the recess depth of the deformation compensation zone relative to the side edge of the riveting block body is W (mm); satisfying:

[0007] 1.0≤L / L0≤1.5,

[0008] 0.05≤W / W0≤0.1.

[0009] Beneficial effects: Because elliptical poles are more prone to material expansion on their straight edges, excessive material expansion can easily occur, causing the riveting block to deform along its width near the pole. To ensure the width dimension of the riveting block is within acceptable limits, this invention pre-compensates the riveting block with a compensation structure. Deformation compensation zones are set on both sides of the riveting block in the width direction, corresponding to the straight edges of the pole. These deformation compensation zones are recessed into the side edges (length direction) of the riveting block body. Thus, during pole riveting, excessive material expansion occurs on the straight edges of the pole, squeezing the deformation compensation zones on both sides of the riveting block. After being squeezed, the deformation compensation zones expand outward, compensating for the recess of the deformation compensation zones relative to the side edges of the riveting block body. As a result, after riveting, the recess depth of the deformation compensation zones is reduced, or the side edges of the deformation compensation zones are flush with or slightly exceed the side edges of the riveting block body. This ensures that the width dimension of the riveting block body at the pole position is within acceptable limits, and also ensures that the dimensions of the external insulating components of the riveting block are within acceptable limits, thereby improving the product yield and safety performance of the cell cover assembly.

[0010] This invention limits the dimensional parameters of the deformation compensation zone in both length and width directions. The ratio of the length L of the deformation compensation zone to the inner dimension L0 of the second hole segment is controlled within the range of 1.0 to 1.5. The ratio of the recess depth W of the deformation compensation zone relative to the side of the riveting block body to the distance W0 between the midpoint of the straight edge of the second hole segment and the edge of the deformation compensation zone is controlled within the range of 0.05 to 0.1. This ensures that the deformation compensation zone compensates for the dimensional deformation of the riveting block during riveting, while also ensuring that the width of the riveting block near the electrode post is within acceptable limits. This avoids excessive material expansion at the straight edge of the electrode post, which could lead to out-of-tolerance width dimensions of the riveting block. Furthermore, because the width of the riveting block is normal, it will not squeeze the external insulating component, ensuring that the width of the insulating component is also within acceptable limits. This significantly improves the production yield and safety of the battery cell cover assembly, achieving cost reduction and efficiency improvement while ensuring product quality.

[0011] In one alternative implementation, the following condition is also met:

[0012] 8.5mm≤L≤20mm

[0013] 0.1mm≤W≤0.25mm

[0014] 8mm≤L0≤15mm,

[0015] 2mm≤W0≤3mm.

[0016] In one alternative implementation, the deformation compensation area is arc-shaped, and the depth of the deformation compensation area recessed into the side of the rivet block body decreases from the middle to both ends.

[0017] In one optional embodiment, the pole body is provided with a pre-riveting hole, which is a racetrack-shaped hole projected along the axial direction of the pole body.

[0018] In one optional embodiment, the wall thickness of the pole body on the straight edge of the pre-riveting hole is T1 (in mm), and the wall thickness of the pole body on the center of the arc edge along the X direction passing through the pre-riveting hole is T2 (in mm), satisfying:

[0019] 1.0mm≤T1≤1.5mm

[0020] 2.0mm≤T2≤3mm

[0021] T1 < T2.

[0022] In one optional implementation, the depth of the pre-riveting hole along the axial direction of the pole body is h, in mm, satisfying:

[0023] 1.2mm≤h≤1.7mm.

[0024] In one optional embodiment, the pole post further includes a pole post base plate, which is connected to the pole post body. The pre-riveting hole is a tapered hole with its internal dimensions gradually decreasing towards the pole post base plate. The angle between the inner wall of the pre-riveting hole and the axis of the pre-riveting hole is γ, satisfying the following:

[0025] 5°≤γ≤15°.

[0026] In one alternative embodiment, the riveting block includes a first step and a second step, and both the first step and the second step are provided with deformation compensation zones along the Z direction.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] Thirdly, the present invention also provides a battery pack comprising multiple battery cells from more than one technical solution, wherein adjacent battery cells are electrically connected via a busbar.

[0031] 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

[0032] 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.

[0033] Figure 1 This is a schematic diagram of a battery cell cover assembly from a first-view perspective according to an embodiment of the present invention;

[0034] Figure 2 for Figure 1 The diagram shown is a structural schematic of the battery cell cover assembly from a second-view perspective.

[0035] Figure 3 for Figure 1 A top view of the battery cell cover assembly shown;

[0036] Figure 4 For along Figure 3 Sectional view at point AA;

[0037] Figure 5 for Figure 4 A sectional view of the middle cover plate body;

[0038] Figure 6 for Figure 1 The diagram shows the structure of the riveting block in the battery cell cover assembly before riveting.

[0039] Figure 7 for Figure 6 A top view of the riveted block shown;

[0040] Figure 8 for Figure 6 The front view of the riveting block shown;

[0041] Figure 9 for Figure 4 A cross-sectional view of the riveted block after riveting;

[0042] Figure 10 This is a schematic diagram of the pole before riveting;

[0043] Figure 11 for Figure 10 A top view of the pole before riveting;

[0044] Figure 12 For along Figure 11 Sectional view at CC;

[0045] Figure 13 For along Figure 11 Sectional view at point BB;

[0046] Figure 14 for Figure 4 A cross-sectional view of the pole after riveting.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1. Cover plate body; 101. Assembly hole; 2. Riveting block; 201. Riveting block body; 2011. Pole post mounting hole; 20111. First hole section; 20112. Second hole section; 20113. Welding countersunk platform; 202. Deformation compensation zone; 203. First step; 204. Second step; 3. Pole post; 301. Pole post body; 3011. First post section; 3012. Second post section; 3013. Third post section; 302. Pre-riveting hole; 303. Pole post base plate; 304. Riveting hole; 4. First insulating component; 5. Second insulating component; 6. Sealing ring; 7. Injection hole. Detailed Implementation

[0049] 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.

[0050] In related technologies, a battery cell generally consists of an electrode assembly (also called an electrode group), electrolyte, bare cell insulating sheet, cover plate assembly (usually integrating structural components such as terminals, injection holes, and explosion-proof valves), and a housing. The housing and cover plate are fixedly connected by welding, forming a closed space to accommodate the electrode assembly; the bare cell insulating sheet wraps around the outside of the electrode group, serving to provide electrical insulation and protect the electrode group from damage by the housing welds.

[0051] A cover plate assembly typically consists of terminals, riveting blocks, aluminum sheets, upper plastic, lower plastic, and sealing rings. The terminals are usually cylindrical, and the cover plate assembly is achieved by riveting the terminals to the riveting blocks and then welding them together. Currently, to improve the overall energy density of battery packs, individual cells are increasingly adopting a "blade" structure, with a very small cell cross-section and a narrow cover plate width. Simultaneously, to meet fast charging requirements, the terminals need a large current-carrying cross-sectional area, which a single terminal cannot provide. Therefore, many blade cell cover plate assemblies currently employ a dual (or multiple) cylindrical terminal design, inevitably leading to a significant increase in production costs.

[0052] To meet cost reduction requirements, some technologies have adopted a single elongated oval (or racetrack-shaped) pole structure instead of dual circular poles to maintain the same current-carrying cross-sectional area. However, compared to circular pole cover assemblies, racetrack-shaped pole cover assemblies are more difficult to control during assembly and riveting, especially in balancing the straight and curved edges. When the dimensions of the straight and curved edges of the pole are not properly designed, the riveting block often experiences significant expansion along the width direction at the pole position after riveting. This leads to the riveting block and its external insulation components exceeding their dimensions, posing a risk of cracking and severely impacting the production yield of the cell cover assembly.

[0053] To address the common problems of racetrack-shaped single pole structure, this invention provides a cell cover assembly that ensures the strength of the riveting structure of the pole and the riveting block, while avoiding deformation of the riveting block along the width direction at the pole position after riveting. This ensures that the dimensions of the riveting block and its external insulation parts are qualified, greatly improving the yield of cover production.

[0054] The following is combined Figures 1 to 14 The following describes embodiments of the present invention.

[0055] 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 includes a riveting block body 201, which has a terminal post mounting hole 2011. The terminal post mounting hole 2011 is a stepped hole, including a first hole segment 20111 and a second hole segment 20112 sequentially arranged along a direction away from the cover body 1. Projected axially along the terminal post mounting hole 2011, both the first hole segment 20111 and the second hole segment 20112 are racetrack-shaped holes; the terminal post 3 before riveting includes a terminal post body 301, which sequentially passes through the assembly hole 101 and the terminal post mounting hole 2011. The terminal post body 301 and the riveting block 2 are riveted together. After riveting, the terminal post body 301 includes a first hole segment 20111 and a second hole segment 20112 arranged sequentially along a direction away from the cover body 1. The first column segment 3011 mates with the second column segment 20112; the two sides of the riveting block 2 are provided with recessed structures corresponding to the straight edges of the pole mounting holes 2011 to form deformation compensation areas 202; along the X direction, the inner dimension of the hole of the second column segment 20112 is L0 (mm); along the X direction, the length of the deformation compensation area 202 is L (mm); along the Y direction, the distance between the midpoint of the straight edge of the second column segment 20112 and the edge of the deformation compensation area 202 is W0 (mm); along the Y direction, the recess depth of the deformation compensation area 202 relative to the side of the riveting block body 201 is W (mm); satisfying:

[0056] 1.0≤L / L0≤1.5,

[0057] 0.05≤W / W0≤0.1.

[0058] Specifically, the inner diameter of the assembly hole 101 of the cover plate body 1 is larger than the inner diameter of the pole mounting hole 2011 of the riveting block 2. Before riveting, the pole body 301 passes through the assembly hole 101 and the pole mounting hole 2011 in sequence before riveting. The pole 3 undergoes a shape change before and after riveting. The inner diameter of the second hole segment 20112 of the pole mounting hole 2011 is larger than the inner diameter of the first hole segment 20111. Before riveting, there is an annular gap between the pole body 301 and the second hole segment 20112 of the pole mounting hole 2011, which constitutes the expansion filling area. During the riveting process, the pole 3 is subjected to riveting force, and the upper part of the pole body 301 expands and deforms towards the expansion filling area. After riveting, the top of the pole body 301 forms the second column segment 3012, which fills the expansion filling area, thus realizing the riveting connection between the pole body 301 and the riveting block 2.

[0059] Along the axial projection of the pole mounting hole 2011 of the riveting block 2, both the first hole segment 20111 and the second hole segment 20112 are racetrack-shaped holes, including straight edges and rounded edges, as shown in the reference. Figure 7 S1 refers to the straight edge, and S2 refers to the rounded edge. After riveting and forming, the projection of the first column segment 3011 and the second column segment 3012 of the pole post 3 that are adapted to it along its axial direction is also an waist-shaped circle, similar to a racetrack shape.

[0060] Because elliptical poles are more prone to material expansion on their straight edges, excessive material expansion can easily occur, causing the riveting block 2 to deform along its width near the pole 3. To ensure the width dimension of the riveting block 2 is within acceptable limits, this invention pre-compensates for the riveting block 2 by providing deformation compensation areas 202 on both sides of its width direction, corresponding to the straight edges of the pole 3. The deformation compensation areas 202 are recessed into the sides (length direction sides) of the riveting block body 201. Thus, during the riveting process of the pole 3, excessive material expansion occurs on the straight edges of the pole 3, compressing the deformation compensation areas 202 on both sides of the riveting block 2. 2. After being subjected to compression, the deformation compensation area 202 undergoes outward deformation to compensate for the depression of the deformation compensation area 202 relative to the side of the riveting block body 201. As a result, after riveting, the depression depth of the deformation compensation area 202 becomes smaller, or the side of the deformation compensation area 202 is flush with the side of the riveting block body 201, or slightly exceeds the side of the riveting block body 201. This ensures that the width dimension of the riveting block body 201 at the pole post 3 position is qualified, and ensures that the dimensions of the insulation parts outside the riveting block 2 are qualified, thereby improving the product yield and safety performance of the cell cover assembly.

[0061] Furthermore, along the X direction, the length of the deformation compensation zone 202 at least covers the length of the pole mounting hole 2011. Figure 6 or Figure 7In the diagram, the X direction is also the length direction of the rivet block 2, and the Y direction is also the width direction of the rivet block 2. Since both the rivet block 2 and the cover plate body 1 are narrow and long structures, the pole mounting hole 2011 of the rivet block 2 and the assembly hole 101 of the cover plate body 1 are set in the same direction and coaxially. Therefore, the X direction is also the length direction of the cover plate body 1, and the Y direction is also the length direction of the cover plate body 1.

[0062] Furthermore, this embodiment of the invention limits the dimensional parameters of the deformation compensation area 202 in both length and width directions. The ratio of the length L of the deformation compensation area 202 to the inner dimension L0 of the second hole segment 20112 is controlled within the range of 1.0 to 1.5. The ratio of the recess depth W of the deformation compensation area 202 relative to the side of the riveting block body 201 to the distance W0 between the midpoint of the straight edge of the second hole segment 20112 and the edge of the deformation compensation area 202 is controlled within the range of 0.05 to 0.1. If the value of L / L0 is too small or the value of W / W0 is too small, the width dimension of the riveting block 2 will exceed its upper tolerance limit. If the value of L / L0 is too large or the value of W / W0 is too large, the width dimension of the riveting block 2 will exceed its lower tolerance limit. All four of these situations will result in poor deformation compensation effect of the riveting block 2 near the pole post 3, and the width dimension of the riveting block 2 will still exceed the tolerance. Therefore, by limiting the values ​​of L / L0 and W / W0 within the aforementioned ranges, while ensuring that the deformation compensation zone 202 compensates for the dimensional deformation of the riveting block 2 during the riveting process, the width of the riveting block 2 near the pole post 3 is guaranteed to be within acceptable limits. This avoids excessive material expansion at the straight edge of the pole post 3, which could lead to the width of the riveting block 2 exceeding tolerances. At the same time, since the width of the riveting block 2 is normal, it will not squeeze the external insulating component, ensuring that the width of the insulating component is also within acceptable limits. This greatly improves the production yield and safety of the cell cover assembly, achieving cost reduction and efficiency improvement while ensuring product quality.

[0063] In some embodiments, the following are also satisfied:

[0064] 8.5mm≤L≤20mm

[0065] 0.1mm≤W≤0.25mm;

[0066] 8mm≤L0≤15mm,

[0067] 2mm≤W0≤3mm.

[0068] Furthermore, in this embodiment of the invention, L, W, L0 and W0 are controlled within the above-mentioned limits, which can adapt to various specifications of long oval pole structure battery cell cover assemblies on the market, ensuring that the deformation compensation area 202 can compensate for the width dimension of the riveting block 2 during the straight edge expansion process, so that the width dimension of the riveting block 2 and its external insulating parts are qualified.

[0069] In some embodiments, the deformation compensation area 202 is arc-shaped, and the depth of the deformation compensation area 202 recessed into the side of the rivet block body 201 decreases from the middle to both ends.

[0070] Specifically, along the Y direction, the closer the deformation compensation area 202 is to the center, the greater the depth of its recess into the side of the rivet block body 201; the closer the two ends of the deformation compensation area 202 are to the rivet block body 201, the smaller the depth of its recess into the side of the rivet block body 201, and the two ends of the deformation compensation area 202 are as smoothly connected to the rivet block body 201 as possible. This ensures that after the pole post 3 is riveted, the side of the rivet block 2 can form a relatively smooth side surface.

[0071] In some embodiments, the pole body 301 is provided with a pre-riveting hole 302, which is a racetrack-shaped hole when projected along the axial direction of the pole body 301.

[0072] Because riveting elliptical poles is difficult due to material expansion, especially the rounded edges, a pre-riveting hole 302 is provided on the pole body 301 before riveting. This constitutes a riveting compensation structure for the pole 3. The pre-riveting hole 302 is a blind hole, as shown in the reference diagram. Figures 10 to 13 By setting pre-riveting holes 302 on the electrode body 301, the difficulty of material expansion during the riveting process of the electrode body 301 can be reduced, ensuring that the arc edge of the electrode 3 is fully expanded, avoiding gaps between the arc edge of the electrode 3 and the riveting block 2, ensuring that the cell cover assembly has good riveting strength and thrust resistance, and also avoiding welding quality problems such as pinholes, craters, and pits between the electrode 3 and the riveting block 2, thus ensuring the welding yield between the electrode 3 and the riveting block 2.

[0073] In some embodiments, the wall thickness of the pole post body 301 on the straight edge of the pre-riveting hole 302 is T1, in mm, and the wall thickness of the pole post body 301 at the center of the arc edge along the X direction and passing through the pre-riveting hole 302 is T2, in mm, satisfying:

[0074] 1.0mm≤T1≤1.5mm

[0075] 2.0mm≤T2≤3mm

[0076] T1 < T2.

[0077] Furthermore, in this embodiment, by controlling the wall thickness T1 of the pole body 301 on the straight edge of the pre-riveting hole 302 within the range of 1.0mm≤T1≤1.5mm, and controlling the wall thickness T2 of the pole body 301 on the arc edge along the X direction and passing through the center of the arc edge of the pre-riveting hole 302 within the range of 2.0mm≤T2≤3mm, it can be ensured that the pole 3 is fully expanded on the arc edge, avoiding gaps between the arc edge of the pole 3 and the riveting block 2; at the same time, it can be ensured that the pole 3 is not excessively expanded on the straight edge, avoiding the width dimension of the riveting block 2 from exceeding the tolerance. Since the straight edge of the pole post 3 is more prone to material expansion than the arc edge, in order to avoid excessive material expansion on the straight edge of the pole post 3 and affecting the width dimension of the riveting block 2, the wall thickness T1 of the pole post body 301 on the straight edge of the pre-riveting hole 302 is less than the wall thickness T2 of the pole post body 301 on the arc edge along the X direction and passing through the center of the pre-riveting hole 302, that is, T1 < T2.

[0078] In some embodiments, along the axial direction of the pole body 301, the depth of the pre-riveting hole 302 is h, in mm, satisfying:

[0079] 1.2mm≤h≤1.7mm.

[0080] Furthermore, in this embodiment of the invention, the depth h of the pre-riveting hole 302 is limited to the range of 1.2mm ≤ h ≤ 1.7mm. If the depth h of the pre-riveting hole 302 is too small, below 1.2mm, it will provide limited assistance to the riveting expansion of the arc edge of the pole post 3, and a gap will still exist between the arc of the pole post 3 and the riveting block 2 after riveting. If the depth h of the pre-riveting hole 302 is too large, above 1.7mm, it is easy to cause over-compensation, resulting in excessive expansion of the straight edge of the pole post 3, which will affect the width dimension of the riveting block 2.

[0081] In some embodiments, the pole post 3 further includes a pole post base plate 303, which is connected to the pole post body 301. The pre-riveting hole 302 is a tapered hole with its internal dimensions gradually decreasing towards the pole post base plate 303. The angle between the inner wall of the pre-riveting hole 302 and the axis of the pre-riveting hole 302 is γ, satisfying:

[0082] 5°≤γ≤15°.

[0083] Specifically, refer to Figure 12 and Figure 13 In this embodiment, the structure of the pre-riveting hole 302 is further defined. The pre-riveting hole 302 is set as a tapered hole, and the included angle γ between the sidewall of the pre-riveting hole 302 and the pre-riveting hole 302 is limited to within the range of 5°≤γ≤15°. If γ is too small, the compensation effect for the riveting expansion of the arc edge of the pole post 3 will be poor; if γ is too large, the straight edge of the pole post 3 will be more prone to excessive expansion, affecting the width dimension of the riveting block 2.

[0084] After riveting, the pre-riveting hole 302 at the top of the pole post 3 becomes the riveting hole 304 under the pressing action of the riveting punch, such as Figure 14 As shown.

[0085] In some embodiments, the riveting block 2 includes a first step 203 and a second step 204, and along the Z direction, both the first step 203 and the second step 204 are provided with a deformation compensation area 202.

[0086] Specifically, refer to Figure 8 , combined Figure 4 By setting the riveting block 2 as a stepped structure including a first step 203 and a second step 204, a limiting end face is formed between the first step 203 and the second step 204. At the same time, the insulating part set outside the riveting block 2 is set with a matching limiting end face. The two can be well positioned and assembled, ensuring the assembly effect. However, the straight edge of the pole post 3 will expand excessively compared with the arc edge during the riveting process, causing the riveting block 2 to deform outward along the width direction. The first step 203 and the second step 204 of the riveting block 2 will both deform outward near the pole post 3. Therefore, deformation compensation areas 202 are set at the positions of the first step 203 and the second step 204 of the riveting block 2 corresponding to the pole post 3. In this way, the riveting block 2 and the insulating part located outside it will not squeeze the insulating part, whether it is the first step 203 or the second step 204, thus ensuring that the width dimensions of the riveting block 2 and the insulating part outside it are qualified.

[0087] In some embodiments, the cell cover assembly further includes a first insulating member 4 and a second insulating member 5. The first insulating member 4 is disposed between the riveting block 2 and the cover body 1, and the second insulating member 5 is disposed between the electrode base plate 303 and the cover body 1. The first surface of the riveting block 2 and the cover body 1 are insulated from each other by the first insulating member 4, and the second surface of the electrode base plate 303 and the cover body 1 are insulated from each other by the second insulating member 5.

[0088] In this embodiment, the insulating component located outside the riveting block 2 is the first insulating component 4.

[0089] Furthermore, in some embodiments, both the first insulating member 4 and the second insulating member 5 are made of plastic. 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.

[0090] In some embodiments, the pole mounting hole 2011 further includes a welding countersunk platform 20113 disposed on the top of the second hole section 20112.

[0091] Specifically, in this embodiment, the pole mounting hole 2011 of the riveting block 2 is further provided with a welding countersunk 20113, which is used to accommodate the weld marks of the welding of the riveting block 2 and the pole 3.

[0092] To verify the technical effect of the present invention, different cases were arranged for riveting verification, including the embodiments and comparative examples. After riveting and expansion, the width dimensions of the riveting block 2 and the first insulating member 4 were measured in each case. The results are shown in Table 1.

[0093] Table 1

[0094]

[0095] As can be seen from Table 1:

[0096] In Examples 1 to 15, the following conditions are met: 1.0≤L / L0≤1.5 and 0.05≤W / W0≤0.1. The verification results show that the widths of the riveting block 2 and the first insulating component 4 are both qualified, and there are no obvious defects in the weld appearance between the riveting block 2 and the pole post 3.

[0097] In Comparative Example 1, the value of W / W0 is too large, exceeding 0.1, that is, the width of the deformation compensation zone 202 is too large, the compensation is excessive, and after the riveting and expansion, the width of the riveting block 2 exceeds its lower tolerance limit. Furthermore, there are pinholes and blast points in the welding between the riveting block 2 and the pole post 3.

[0098] In Comparative Examples 2 and 3, the value of W / W0 is too small, exceeding 0.05. That is, the width of the deformation compensation zone 202 is too small, and the compensation is insufficient. After the material is stretched by riveting, the width of the first insulating part 4 exceeds its tolerance limit.

[0099] In Comparative Example 4, the value of L / L0 is too small, exceeding 1.0, which means that the length of the deformation compensation zone 202 is too small and the compensation is insufficient. After the material is stretched by riveting, the width of the first insulating part 4 exceeds its tolerance limit in some areas.

[0100] In Comparative Example 5, the value of L / L0 is too large, exceeding 1.5, that is, the length of the deformation compensation zone 202 is too large, the compensation is excessive, and after the material is stretched by riveting, the first insulating part 4 has a local width exceeding the lower limit of its tolerance, and there are pinholes and blast points in the welding between the riveting block 2 and the pole post 3.

[0101] It is evident that when the design of the riveting block 2 meets the above requirements, after the cover plate is assembled and riveted, the arc edge of the pole post 3 overlaps well with the riveting block 2, the surface fit is seamless, and the welding yield is high. At the corresponding straight edge position of the pole post 3, the riveting block 2 will not squeeze the first insulating component 4, and the overall width of the riveting block 2 and the first insulating component 4 meets the design requirements. Conversely, if the compensation amount of the deformation compensation area 202 is insufficient, the riveting block 2 or the first insulating component 4 will still have local width exceeding the standard after riveting; when the compensation amount of the deformation compensation area 202 is too large, the width of the riveting block 2 or the first insulating component 4 will be too low after riveting.

[0102] In some embodiments, the pole body 301 further includes a third pole segment 3013, which is connected between the first pole segment 3011 and the pole base plate 303. The third pole segment 3013 is adapted to the mounting hole 101 of the cover plate body 1.

[0103] The cell cover assembly also includes a sealing ring 6. The sealing ring 6 is sleeved on the third post 3013 of the pole post 3. At least a portion of the sealing ring 6 is located between the third post 3013 and the mounting hole 101 of the cover body 1, and at least a portion of the sealing ring 6 is located between the pole post base plate 303 and the cover body 1. In this way, the sealing ring 6 can form a double seal between the pole post 3 and the cover body 1 along the axial and radial directions of the pole post 3, thereby improving the sealing performance, reliability and safety of the cell.

[0104] In some embodiments, the cell cover assembly further includes an injection hole 7. Electrolyte is injected into the cell through the injection hole 7.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] In some embodiments, the battery cell includes a blade cell.

[0109] 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 adjacent battery cells are electrically connected via a busbar.

[0110] Specifically, in some embodiments, the riveting blocks 2 of adjacent cells are welded via busbars.

[0111] Since the battery pack includes the battery cells and has all the technical benefits of the battery cells, it will not be elaborated here.

[0112] 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, comprising a riveting block body, the riveting block body having a pole mounting hole, the pole mounting hole being a stepped hole, comprising a first hole segment and a second hole segment arranged sequentially along the direction away from the cover plate body, the first hole segment and the second hole segment being racetrack-shaped holes along the axial projection of the pole mounting hole; The pole post, before riveting, includes a pole post body, which passes through the assembly hole and the pole post mounting hole in sequence. The pole post body and the riveting block are riveted together. After riveting, the pole post body includes a first post segment that mates with the first hole segment and a second post segment that mates with the second hole segment. The two sides of the rivet block along the Y direction are provided with recessed structures corresponding to the straight edges of the pole mounting holes to form deformation compensation areas. Along the X direction, the internal dimension of the second hole segment is L0, in mm; Along the X direction, the length of the deformation compensation zone is L, in mm; Along the Y direction, the distance between the midpoint of the straight edge of the second hole segment and the edge of the deformation compensation area is W0, in mm; Along the Y direction, the recess depth of the deformation compensation area relative to the side of the riveting block body is W, in mm; satisfy: 1.0≤L / L0≤1.5, 0.05≤W / W0≤0.1; 8.5mm≤L≤20mm 0.1mm≤W≤0.25mm; 8mm≤L0≤15mm, 2mm≤W0≤3mm.

2. The cell cover assembly according to claim 1, characterized in that, The deformation compensation area is arc-shaped, and the depth of the deformation compensation area recessed into the side of the rivet block body decreases from the middle to both ends.

3. The cell cover assembly according to claim 1, characterized in that, The pole body is provided with a pre-riveting hole, which is a racetrack-shaped hole projected along the axial direction of the pole body.

4. The cell cover assembly according to claim 3, characterized in that, The wall thickness of the pole post body on the straight edge of the pre-riveting hole is T1, in mm, and the wall thickness of the pole post body on the arc edge along the X direction passing through the pre-riveting hole is T2, in mm, satisfying: 1.0mm≤T1≤1.5mm 2.0mm≤T2≤3mm T1 < T2.

5. The cell cover assembly according to claim 4, characterized in that, Along the axial direction of the pole body, the depth of the pre-riveting hole is h, in mm, and satisfies: 1.2mm≤h≤1.7mm.

6. The cell cover assembly according to claim 4, characterized in that, The pole post also includes a pole post base plate, which is connected to the pole post body. The pre-riveting hole is a tapered hole with its internal dimensions gradually decreasing towards the pole post base plate. The angle between the inner wall of the pre-riveting hole and the axis of the pre-riveting hole is γ, satisfying the following: 5°≤γ≤15°.

7. The cell cover assembly according to claim 1, characterized in that, The riveting block includes a first step and a second step along the Z direction, and both the first step and the second step are provided with the deformation compensation area.

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, It includes multiple battery cells as described in claim 8, with adjacent battery cells being electrically connected via a busbar.

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