Pole, battery cell and battery pack

Abstract

This invention relates to the field of battery technology, disclosing an electrode post, a battery cell, and a battery pack. The electrode post includes an electrode post base plate and an electrode post body. The electrode post body includes a first segment connected to the electrode post base plate and a second segment connected to the first segment. The sidewalls of both the first and second segments are designed as inclined walls for easy demolding. The angle between the sidewall of the first segment and the electrode post base plate is a first demolding angle, which is 90°–θ1, satisfying: 0.1°≤θ1≤2°. The angle between the sidewall of the second segment and the electrode post base plate is a second demolding angle, which is 90°–θ2, satisfying: 0.1°≤θ2≤2°. This invention optimizes the structural design of the electrode post body by providing demolding angles on the sidewalls of both the first and second segments, allowing the electrode post to be more smoothly ejected from the mold after pressing, thereby significantly improving production efficiency, enhancing product dimensional consistency, and improving the overall performance of the electrode post.

Description

Technical Field

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

[0002] Lithium-ion batteries are the core power source for modern electric vehicles and energy storage systems, and their performance and safety directly affect the reliability and market competitiveness of end products. The cover plate assembly, a key structural component of lithium-ion batteries, integrates terminals, insulators, sealing rings, and explosion-proof valves, undertaking multiple functions such as sealing the battery cavity, conducting electrode current, and safely relieving pressure. Among these, the terminals, as the core conductive component of the cover plate assembly, have a significant impact on the battery's electrical performance, sealing performance, and production efficiency due to the optimization of their structural design and manufacturing process.

[0003] Currently, the pole section in the industry typically adopts a racetrack-shaped or cylindrical structure, with both ends having the same dimensions. This design faces significant technical bottlenecks in the pressing and forming process:

[0004] High demolding resistance: Due to the symmetrical cross-sectional shape of the pole rod, the contact area between the mold and the workpiece is large and the frictional resistance is high after pressing, which leads to a sharp increase in demolding force and easily causes mold jamming.

[0005] Low production efficiency: The problem of mold jamming not only requires frequent machine downtime for mold maintenance, but may also lead to workpiece ejection failure or mold damage, which seriously restricts the production cycle and yield rate.

[0006] Surface quality defects: High demolding force can easily cause scratches, deformation or even dimensional deviations on the electrode surface, affecting the sealing performance of subsequent welding and the stability of current conduction. Summary of the Invention

[0007] In view of this, the present invention provides a terminal post, a battery cell, and a battery pack to solve the problem of difficult terminal post demolding.

[0008] In a first aspect, the present invention provides an electrode post, comprising an electrode post base plate and an electrode post body. The electrode post body includes a first post segment and a second post segment; the first end of the first post segment is connected to the electrode post base plate, and a first stepped surface is formed between the first post segment and the electrode post base plate; the first end of the second post segment is connected to the second end of the first post segment, and in the XY plane, the outer circle dimension of the first post segment is larger than the outer circle dimension of the second post segment, and a second stepped surface is formed between the second post segment and the first post segment; the electrode post is a product produced by an upsetting process, the demolding direction is the opposite direction of Z, the parting surface is the first stepped surface, and the sidewalls of both the first post segment and the second post segment are designed as inclined walls that facilitate demolding; the included angle between the sidewall of the first post segment and the electrode post base plate is a first demolding angle, which is 90°-θ1, satisfying: 0.1°≤θ1≤2°; the included angle between the sidewall of the second post segment and the electrode post base plate is a second demolding angle, which is 90°-θ2, satisfying: 0.1°≤θ2≤2°.

[0009] Beneficial effects: By optimizing the structural design of the pole body, the present invention sets demolding angles on the side walls of both the first and second pole sections, so that the pole can be more smoothly ejected from the mold after pressing, thereby significantly improving production efficiency, improving product dimensional consistency, and enhancing the overall performance of the pole.

[0010] Specifically, traditional pole pieces typically employ a symmetrical racetrack-shaped or cylindrical structure with identical dimensions at both ends, resulting in high demolding resistance after pressing and a tendency for jamming. This invention, however, reduces the contact area between the pole piece and the mold during demolding by setting a small demolding angle (0.1°≤θ≤2°) in the first and second pole sections, significantly lowering frictional resistance and effectively preventing jamming. This smooth demolding reduces downtime for maintenance, improves equipment stability, and significantly enhances production efficiency.

[0011] In addition, the pole is less prone to deformation or scratches during demolding, which reduces the scrap rate and increases the yield rate.

[0012] Furthermore, traditional terminals, due to the large demolding force during pressing and demolding, are prone to surface deformation or dimensional deviations, affecting subsequent assembly (such as welding and sealing). This invention optimizes the demolding angle, enabling the terminals to maintain higher dimensional accuracy after molding. The demolding angle design reduces stress concentration during ejection, preventing bending or localized deformation of the terminal body during demolding. Improved dimensional consistency of the terminals ensures precise fit with components such as the cover plate and casing, enhancing battery sealing and electrical connection reliability.

[0013] In one alternative implementation, the height of the first column segment is h1 in mm, which satisfies the condition: 2.5 mm ≤ h1 ≤ 6 mm.

[0014] In one alternative implementation, the height of the second column segment is h2 in mm, which satisfies the condition: 2.5 mm ≤ h2 ≤ 6 mm.

[0015] In one optional embodiment, the projections of the first column segment and the second column segment along the Z direction are both racetrack-shaped, including two circular arc edges arranged opposite each other along the X direction and two straight edges arranged opposite each other along the Y direction; the distance between the center points of the two circular arc edges at the first end of the first column segment is D, in mm, satisfying: 4mm≤D≤30mm; the distance between the center points of the two circular arc edges at the first end of the second column segment is d, in mm, satisfying: 3.2mm≤d≤30mm.

[0016] In one optional embodiment, the radius of the arc edge at the first end of the first column segment is R1, in mm, satisfying: 2mm≤R1≤20mm; the radius of the arc edge at the first end of the second column segment is r1, in mm, satisfying: 1.5mm≤r1≤19.6mm.

[0017] In one optional implementation, the projections of the first column segment and the second column segment along the Z direction are both circular; the radius of the first end of the first column segment is R2, in mm, which satisfies: 2mm≤R2≤20mm.

[0018] In one alternative implementation, the radius of the first end of the second column segment is r2, in mm, which satisfies: 1.5mm≤r2≤19.6mm.

[0019] In one alternative implementation, the terminal post includes a positive terminal post and / or a negative terminal post.

[0020] In a second aspect, the present invention also provides a battery cell, including a housing, an electrode assembly, and a cover plate assembly. 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 cover plate assembly is disposed in the opening of the housing and encapsulates the electrode assembly inside the housing; the cover plate assembly includes a cover plate body, a riveting block, a first insulating element, a second insulating element, a sealing ring, and the electrode post as described in the above technical solution; the cover plate body is provided with a first electrode post mounting hole, the riveting block is provided with a second electrode post mounting hole, the electrode post base plate and the riveting block are respectively disposed on two opposite surfaces of the cover plate body, the electrode post body passes through the first electrode post mounting hole and the second electrode post mounting hole in sequence and is riveted to the riveting block; the first insulating element is disposed between the electrode post base plate and the cover plate body, insulatingly connecting the electrode post base plate and the cover plate body; the second insulating element is disposed between the riveting block and the cover plate body, insulatingly connecting the riveting block and the cover plate body; the sealing ring is sleeved on the first segment of the electrode post, at least a part of the sealing ring is disposed between the first segment and the first electrode post mounting hole of the cover plate body, and at least another part of the sealing ring is disposed between the electrode post base plate and the cover plate body, sealingly connecting the electrode post and the cover plate body.

[0021] Beneficial effects: The cover plate assembly is used to seal the openings of the battery 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 terminals of the cover plate assembly provide a path for current inflow and outflow, ensuring current conduction during the charging and discharging process of the battery cell. Using the terminals in the above technical solution can significantly improve the production efficiency of the battery cell, improve product dimensional consistency, and enhance the overall performance of the battery cell.

[0022] Since the battery cell includes the terminals and has all the technical effects of the terminals, it will not be elaborated here.

[0023] Thirdly, the present invention also provides a battery pack comprising multiple battery cells from more than one technical solution, wherein the battery cells are electrically connected to each other.

[0024] 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

[0025] 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.

[0026] Figure 1 This is a schematic diagram of the structure of a pole post before riveting according to an embodiment of the present invention;

[0027] Figure 2 for Figure 1 A top view of the pole shown;

[0028] Figure 3 for Figure 1 The front view of the pole column is shown;

[0029] Figure 4 for Figure 1 The diagram shows the structure of the pole after riveting.

[0030] Figure 5 This is a schematic diagram of the structure of a riveting block in a battery cell according to an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of a cover plate assembly in a battery cell according to an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of another pole post before riveting according to an embodiment of the present invention;

[0033] Figure 8 for Figure 7A top view of the pole shown;

[0034] Figure 9 for Figure 7 The front view of the pole shown.

[0035] Explanation of reference numerals in the attached figures:

[0036] 1. Pole post; 101. Pole post base plate; 102. Pole post body; 1021. First post segment; 1022. Second post segment; 10221. First assembly segment; 10222. Second assembly segment; 10223. Riveting hole; 103. First step surface; 104. Second step surface; 2. Cover plate body; 201. First pole post mounting hole; 202. Explosion-proof valve mounting hole; 3. Riveting block; 301. Second pole post mounting hole; 3011. First hole segment; 3012. Second hole segment; 4. First insulating component; 5. Second insulating component; 6. Sealing ring; 7. Explosion-proof valve; 8. Explosion-proof valve protective patch. Detailed Implementation

[0037] 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.

[0038] The following is combined Figures 1 to 9 The following describes embodiments of the present invention.

[0039] According to an embodiment of the present invention, in a first aspect, a pole post 1 is provided, comprising a pole post base plate 101 and a pole post body 102. The pole post body 102 includes a first column segment 1021 and a second column segment 1022; a first end of the first column segment 1021 is connected to the pole post base plate 101, and a first step surface 103 is formed between the first column segment 1021 and the pole post base plate 101; a first end of the second column segment 1022 is connected to the second end of the first column segment 1021, and in the XY plane, the outer circumference of the first column segment 1021 is larger than the outer circumference of the second column segment 1022, and a second step surface 104 is formed between the second column segment 1022 and the first column segment 1021; the pole post 1 is a press-fitted pole post. For the manufactured product, the demolding direction is the opposite of Z, the parting surface is the first step surface 103, and the side walls of the first column segment 1021 and the second column segment 1022 are both designed as inclined walls for easy demolding; the angle between the side wall of the first column segment 1021 and the pole base plate 101 is the first demolding angle, which is 90° - θ1, satisfying: 0.1° ≤ θ1 ≤ 2°; the angle between the side wall of the second column segment 1022 and the pole base plate 101 is the second demolding angle, which is 90° - θ2, satisfying: 0.1° ≤ θ2 ≤ 2°.

[0040] Upsetting is a metal plastic forming process that uses high pressure applied to a metal material at room temperature to cause plastic deformation within a mold cavity, thereby manufacturing parts of a specific shape. Specifically, in some embodiments, the pole post 1 is formed using a cold heading process. When using the cold heading process, the demolding direction of the pole post 1 is the opposite direction of Z, that is, in... Figure 3 In the middle, the direction is perpendicular to the bottom plate 101 of the pole column and pointing upwards.

[0041] Reference Figure 2 The X direction is the length direction of the pole base plate 101, and the Y direction is the width direction of the pole base plate 101. After the pole 1 is assembled to the cover plate body 2, the X direction is the length direction of the cover plate body 2, and the Y direction is the width direction of the cover plate body 2.

[0042] This invention optimizes the structural design of the pole post 102 by setting demolding angles on the side walls of the first column segment 1021 and the second column segment 1022, so that the pole post 1 can be more smoothly ejected from the mold after pressing, thereby significantly improving production efficiency, improving product size consistency, and improving the overall performance of the pole post 1.

[0043] Specifically, traditional pole pieces typically employ a symmetrical racetrack-shaped or cylindrical structure with identical dimensions at both ends, resulting in high demolding resistance after pressing and a tendency for jamming. This invention addresses this by setting a small demolding angle (0.1°≤θ≤2°) in the first and second pole sections 1021 and 1022. This reduces the contact area between the pole piece 1 and the mold during demolding, significantly lowering frictional resistance and effectively preventing jamming. Smooth demolding reduces downtime for maintenance, improves equipment stability, and significantly enhances production efficiency.

[0044] In addition, the pole 1 is less prone to deformation or scratches during demolding, which reduces the scrap rate and increases the yield rate.

[0045] Furthermore, traditional terminals, due to the large demolding force during pressing and demolding, are prone to surface deformation or dimensional deviations, affecting subsequent assembly (such as welding and sealing). This invention optimizes the demolding angle, enabling the terminal 1 to maintain higher dimensional accuracy after molding. The demolding angle design reduces stress concentration during ejection, preventing bending or localized deformation of the terminal 102 during demolding. The improved dimensional consistency of the terminal 1 ensures better fit with components such as the cover and casing, enhancing battery sealing and electrical connection reliability.

[0046] The demolding angle of the first column segment 1021 is 90° - θ1, and the demolding angle of the second column segment 1022 is 90° - θ2. θ1 and θ2 are both within the range of 0.1° to 2°. θ1 and θ2 can be equal or unequal.

[0047] θ1 and θ2 affect the demolding of the electrode post and the surface roughness after demolding. When θ1 < 0.1° and θ2 < 0.1°, the demolding force of the electrode post is large, making demolding difficult, and the surface roughness is large, which does not meet the usage requirements.

[0048] θ1 also affects the push-pull force performance of the pole post. When θ1 > 2°, the material expansion at the head of the pole post is insufficient, and the push-pull force does not meet the requirements.

[0049] θ2 also affects the temperature rise of the electrode. When θ2 > 2°, the diameter of the electrode decreases significantly, failing to meet the overcurrent requirements, resulting in a larger temperature rise of the electrode.

[0050] Therefore, controlling θ1 and θ2 within the range of 0.1° to 2° can reduce the demolding resistance of the pole, making the pole easier to demold, while also ensuring the surface quality of the pole, and ensuring that the pole has sufficient push-pull force performance and qualified temperature rise.

[0051] In some embodiments, the height of the first column segment 1021 is h1 in mm, which satisfies the following condition: 2.5 mm ≤ h1 ≤ 6 mm.

[0052] In this embodiment, the height h1 of the first column segment 1021 is limited to the range of 2.5mm to 6mm to ensure that the flow of metal material is more uniform during the pressing process, and to avoid material accumulation or local stress concentration caused by excessive height, thereby improving the forming quality.

[0053] If h1 is too small, less than 2.5mm, the supporting effect of the first column segment 1021 will be weak, which may cause the pole 1 to bend and deform during the pressing or subsequent assembly process; if h1 is too large, greater than 6mm, since the first column segment 1021 will cooperate with the cover body 2 in the cell cover assembly, the thickness of the cover body 2 will increase accordingly, resulting in an increase in the overall thickness of the cell cover assembly and affecting the cell capacity.

[0054] With the combined effect of the height h1 of the first column segment 1021 and the demolding angle 90°-θ1, the demolding force of the pressing mold can be further reduced, thereby reducing mold wear and the risk of mold jamming.

[0055] In some embodiments, the height of the second column segment 1022 is h2 in mm, which satisfies the following condition: 2.5 mm ≤ h2 ≤ 6 mm.

[0056] In this embodiment, the height h2 of the second column segment 1022 is limited to the range of 2.5mm to 6mm to ensure that the flow of metal material is more uniform during the pressing process, and to avoid material accumulation or local stress concentration caused by excessive height, thereby improving the forming quality.

[0057] If h2 is too small, less than 2.5mm, the supporting effect of the second column segment 1022 will be weak, which may cause the pole 1 to bend and deform during pressing or subsequent assembly. If h2 is too large, greater than 6mm, since the second column segment 1022 will cooperate with the riveting block 3 in the cell cover assembly, the second column segment 1022 being too high will cause a height difference between the pole 1 and the riveting block 3 after riveting, resulting in poor welding appearance between the pole 1 and the riveting block 3.

[0058] With the combined effect of the height h2 of the second column segment 1022 and the demolding angle 90°-θ2, the demolding force of the pressing mold can be further reduced, thereby reducing mold wear and the risk of mold jamming.

[0059] In some embodiments, the projections of the first column segment 1021 and the second column segment 1022 along the Z direction are both racetrack-shaped, including two arc edges arranged opposite each other along the X direction and two straight edges arranged opposite each other along the Y direction; the distance between the center points of the two arc edges at the first end of the first column segment 1021 is D, in mm, satisfying: 4mm≤D≤30mm; the distance between the center points of the two arc edges at the first end of the second column segment 1022 is d, in mm, satisfying: 3.2mm≤d≤30mm.

[0060] Specifically, the first end of the first column segment 1021 is at Figure 3 This is represented by the lower end of the first column segment 1021. The first end of the second column segment 1022 is... Figure 3 This is represented by the lower end of the second column segment 1022.

[0061] In this embodiment, pole post 1 is a racetrack-shaped structure, as shown in the reference. Figure 2 S1 refers to the straight edge, and S2 refers to the rounded edge. The straight edge is set along the length direction of pole post 1.

[0062] Reference Figure 2 and Figure 3 In this embodiment, the distance D between the center points of the two arc edges at the first end of the first column segment 1021 and the distance d between the center points of the two arc edges at the first end of the second column segment 1022 are limited. D is controlled within the range of 4mm to 30mm, and d is controlled within the range of 3.2mm to 30mm. This ensures that the first column segment 1021 and the second column segment 1022 have sufficient cross-sectional area to withstand the mechanical load and vibration during battery operation, while avoiding the increase in weight and stress concentration caused by excessive size, making the overall force on the pole post 1 more balanced.

[0063] Reference Figure 2 and Figure 3 The second end of the first column segment 1021 is connected to the second column segment 1022, and the second end of the first column segment 1021 is also... Figure 3 The distance between the center points of the two arc edges at the upper end of the first column segment 1021 and the second end of the first column segment 1021 is D', where the value of D' is determined by D, h1, and θ1. The second end of the second column segment 1022 is the end furthest from the first column segment 1021, that is... Figure 3 The distance between the center points of the two arc edges at the upper end of the second column segment 1022 is d', and the value of d' is determined based on d, h2 and θ2.

[0064] In some embodiments, the radius of the arc edge at the first end of the first column segment 1021 is R1, in mm, satisfying: 2mm≤R1≤20mm; the radius of the arc edge at the first end of the second column segment 1022 is r1, in mm, satisfying: 1.5mm≤r1≤19.6mm.

[0065] Specifically, both the first column segment 1021 and the second column segment 1022 are racetrack-shaped columns, with their straight edges tangent to the circular arc edges at both ends. Therefore, along the Y direction, the distance between the two straight edges is the diameter of the circular arc edge. That is, along the Y direction, the distance between the two straight edges in the lower end face of the first column segment 1021 is 2×R1, and the distance between the two straight edges in the lower end face of the second column segment 1022 is 2×r1.

[0066] By limiting the radius of the arc edges of the first column segment 1021 and the second column segment 1022, that is, limiting the dimensions of the two column segments along the Y direction, R1≥2mm and r1≥1.5mm can ensure that the pole post 1 has sufficient conductive contact area, which is beneficial to reducing internal resistance; R1≤20mm and r1≤19.6mm can prevent the pole post 1 from being too large, which would affect the riveting effect and welding quality of the pole post 1 and the riveting block 3.

[0067] Reference Figure 2 and Figure 3 The radius of the arc at the second end of the first column segment 1021 is R1', and the value of R1' is determined based on R1, h1, and θ1. The radius of the arc at the second end of the second column segment 1022 is r1', and the value of r1' is determined based on r1, h2, and θ2.

[0068] In some embodiments, the projections of the first column segment 1021 and the second column segment 1022 along the Z direction are both circular; the radius of the first end of the first column segment 1021 is R2 in mm, which satisfies: 2mm≤R2≤20mm.

[0069] The electrode post 1 provided by this invention is also applicable to circular electrode posts, that is, the projections of the first column segment 1021 and the second column segment 1022 along the Z direction are both circular. For circular electrode posts, in this embodiment, the radius R2 of the lower end face of the first column segment 1021 is limited to the range mentioned above. R1≥2mm ensures that the electrode post 1 has sufficient conductive contact area, which is beneficial to reducing internal resistance; R1≤20mm avoids the electrode post 1 being too large, which would affect the riveting effect and welding quality of the electrode post 1 and the riveting block 3.

[0070] Reference Figure 8 and Figure 9 The second end of the first column segment 1021, that is Figure 9 The upper end of the first column segment 1021, and the radius of the second end of the first column segment 1021 is R2', the value of R2' is determined according to R2, h1 and θ1.

[0071] In some embodiments, the radius of the first end of the second column segment 1022 is r2, in mm, which satisfies: 1.5mm≤r2≤19.6mm.

[0072] For circular poles, in this embodiment, the radius r2 of the lower end face of the second pole segment 1022 is limited to the range mentioned above. r1≥1.5mm ensures that the pole 1 has sufficient conductive contact area, which is beneficial to reducing internal resistance; r1≤19.6mm avoids the pole 1 being too large, which would affect the riveting effect and welding quality of the pole 1 and the riveting block 3.

[0073] Reference Figure 8 and Figure 9The second end of the second column segment 1022 is the end furthest from the first column segment 1021, that is... Figure 9 The upper end of the second column segment 1022, the radius of the second end of the second column segment 1022 is r2', the value of r2' is determined according to r2, h2 and θ2.

[0074] In some embodiments, the electrode post 1 includes a positive electrode post and / or a negative electrode post.

[0075] The electrode post 1 provided by this invention is applicable to both positive and negative electrodes. Specifically, the positive electrode post is usually made of aluminum; the negative electrode post is usually made of copper or a copper-aluminum composite material.

[0076] In some embodiments, the projections of the first column segment 1021 and the second column segment 1022 along the Z direction are both racetrack-shaped, including two arc edges arranged opposite each other along the X direction and two straight edges arranged opposite each other along the Y direction; or, the projections of the first column segment 1021 and the second column segment 1022 along the Z direction are both circles.

[0077] The pole post 1 provided by the present invention has a difference in size at both ends of the first column segment 1021 and the second column segment 1022, which makes the side wall of the first column segment 1021 and the normal of the pole post base plate 101 form an angle θ1, and the side wall of the second column segment 1022 and the normal of the pole post base plate 101 form an angle θ2. This makes the pole post 1 easier to demold and the product size consistency higher. Compared with the traditional racetrack-shaped pole post or circular pole post, the pole post 1 of the present invention has higher production efficiency and higher performance.

[0078] 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 cover plate assembly. 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 cover plate assembly is disposed in the opening of the housing and encapsulates the electrode assembly within the housing; the cover plate assembly includes a cover plate body 2, a riveting block 3, a first insulating member 4, a second insulating member 5, a sealing ring 6, and the electrode post 1 in the above embodiments; the cover plate body 2 is provided with a first electrode post mounting hole 201, the riveting block 3 is provided with a second electrode post mounting hole 301, the electrode post base plate 101 and the riveting block 3 are respectively disposed on two opposite surfaces of the cover plate body 2, and the electrode post body 102 passes sequentially through the first electrode post mounting hole 201 and the second electrode post mounting hole. 301 and riveted to the riveting block 3; the first insulating member 4 is disposed between the pole post base plate 101 and the cover plate body 2, insulatingly connecting the pole post base plate 101 and the cover plate body 2; the second insulating member 5 is disposed between the riveting block 3 and the cover plate body 2, insulatingly connecting the riveting block 3 and the cover plate body 2; the sealing ring 6 is sleeved on the first column section 1021 of the pole post 1, at least a part of the sealing ring 6 is disposed between the first column section 1021 and the first pole post mounting hole 201 of the cover plate body 2, and at least another part of the sealing ring 6 is disposed between the pole post base plate 101 and the cover plate body 2, sealingly connecting the pole post 1 and the cover plate body 2.

[0079] The cover assembly is used to seal the opening of the battery 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 1 of the cover assembly provides a path for current inflow and outflow, ensuring current conduction during the charging and discharging process of the battery cell. For the battery cell, using the terminal post 1 of the cover assembly as described in the above embodiment can significantly improve the cell's production efficiency, improve product dimensional consistency, and enhance the overall performance of the battery cell.

[0080] Specifically, in some embodiments, the second pole post mounting hole 301 of the riveting block 3 is a stepped hole, including a first hole segment 3011 and a second hole segment 3012 whose dimensions increase sequentially in the direction away from the cover plate body 2. The first column segment 1021 of the pole post 102 mates with the first pole post mounting hole 201 of the cover plate body 2, and the second column segment 1022 of the pole post 102 mates with the second pole post mounting hole 301 of the riveting block 3 and is riveted. During the riveting process, the second column segment 1022 expands and deforms toward the second hole segment 3012 of the riveting block 3, eventually forming a riveting bracket to achieve riveting with the riveting block 3. After riveting deformation, the second column segment 1022 includes a first assembly segment 10221 that mates with the first hole segment 3011 of the riveting block 3 and a second assembly segment 10222 that mates with the second hole segment 3012 of the riveting block 3. The second column segment 1022 of the pole post 1 forms a riveting hole 10223 under the action of the riveting punch. The riveting hole 10223 is a blind hole.

[0081] Since the pole post 1 provided by this invention is applicable to both racetrack-shaped pole posts and circular pole posts, when the pole post 1 is a racetrack-shaped pole post, the first pole post mounting hole 201 of the cover plate body 2 and the second pole post mounting hole 301 of the riveting block 3 are both racetrack-shaped holes adapted to the pole post 1. Correspondingly, when the pole post 1 is a circular pole post, the first pole post mounting hole 201 of the cover plate body 2 and the second pole post mounting hole 301 of the riveting block 3 are both circular holes adapted to the pole post 1.

[0082] The first insulating component 4 and the second insulating component 5 are used to ensure insulation between the cover plate body 2 and the riveting block 3, as well as between the cover plate body 2 and the pole post 1, thereby preventing short circuits or leakage in the battery cell and improving the safety and reliability of the battery cell.

[0083] Furthermore, in some embodiments, both the first insulating element 4 and the second insulating element 5 are plastic parts.

[0084] The sealing ring 6 can form a double seal along the axial and radial direction of the pole post 1 between the pole post 1 and the cover plate body 2, thereby improving the sealing performance, reliability and safety of the battery cell.

[0085] In some embodiments, the cover assembly of the battery cell further includes an explosion-proof valve 7 and an explosion-proof valve protective patch 8. The cover body 2 has an explosion-proof valve mounting hole 202, within which the explosion-proof valve 7 is disposed. The explosion-proof valve protective patch 8 is affixed to the upper surface of the explosion-proof valve mounting hole 202, providing protection for the explosion-proof valve 7. The explosion-proof valve 7 is used to rapidly open and release pressure in the event of thermal runaway of the battery cell, ensuring the safety performance of the battery.

[0086] Since the battery cell includes terminal 1 and has all the technical effects of terminal 1, it will not be elaborated here.

[0087] In some embodiments, the battery cell also includes a bare battery cell insulating sheet. Specifically, the bare battery cell insulating sheet is wrapped around the outside of the electrode assembly, serving to provide electrical insulation and protect the electrode assembly from damage by the housing welds.

[0088] According to an embodiment of the present invention, a third aspect also provides a battery pack including a plurality of cells as described in the above embodiments, wherein the cells are electrically connected to each other.

[0089] In some embodiments, the riveting blocks 3 of each battery cell are welded together via busbars to achieve conductive connection.

[0090] To verify the technical effects of the present invention, three specific experimental cases are provided below.

[0091] Experimental objective: To verify the effects of θ1 and θ2 on the demolding force, surface roughness, push-pull force performance, and temperature rise of the pole post.

[0092] Experimental plan: Prepare samples of different pole columns and the cell cover plate assemblies after assembly. Among them, except for the different values of θ1 and θ2, other parameters remain the same, such as the pole column material, the height of the first column section, and the height of the second column section, etc.

[0093] Testing items:

[0094] 1. Push-pull force performance test; Measured by a push-pull force machine, apply a pushing force to the pole column until the cell cover plate assembly fails (such as deformation of the cell cover plate assembly or detachment of the pole column, etc.). The testing machine records the loaded force value in real time. The pushing force before the failure of the cell cover plate assembly is the maximum pushing force value that the cell cover plate assembly can withstand. Record the maximum pushing force value, denoted as F1, with the unit of N. F1≥800N is qualified.

[0095] 2. Demolding force test; Use a force sensor to monitor the force value during the demolding process in real time. Denote it as F2, with the unit of N. F2≤80N is qualified.

[0096] 3. Surface quality inspection of the pole column after demolding; Measured by a profilometer (stylus roughness meter). The surface roughness Ra≤1.0 is qualified.

[0097] 4. Pole column temperature rise. Use a temperature sensor to test the temperature of the pole column rod part, denoted as ΔT. ΔT≤55°C is qualified. [[ID=I7]]

[0098] All of the above four tests can be carried out by methods well-known to those skilled in the art.

[0099] The following are the experimental data of the first group. The measured results are shown in Table 1.

[0100] Table 1

[0101]

[0102] The following are the experimental data of the second group. The measured results are shown in Table 2.

[0103] Table 2

[0104]

[0105] The following are the experimental data of the third group. The measured results are shown in Table 3.

[0106] Table 3

[0107]

[0108] It can be seen from the comparison of each case in Tables 1 to 3 that:

[0109] θ1 and θ2 affect the demolding of the electrode post and the surface roughness after demolding. When θ1 < 0.1° and θ2 < 0.1°, the demolding force of the electrode post is large, making demolding difficult, and the surface roughness is large, which does not meet the usage requirements.

[0110] θ1 also affects the push-pull force performance of the pole post. When θ1 > 2°, the material expansion at the head of the pole post is insufficient, and the push-pull force does not meet the requirements.

[0111] θ2 also affects the temperature rise of the electrode. When θ2 > 2°, the diameter of the electrode decreases significantly, failing to meet the overcurrent requirements, resulting in a larger temperature rise of the electrode.

[0112] Therefore, controlling θ1 and θ2 within the range of 0.1° to 2° can reduce the demolding resistance of the pole, making the pole easier to demold, while also ensuring the surface quality of the pole, and ensuring that the pole has sufficient push-pull force performance and qualified temperature rise.

[0113] Since the battery pack includes the battery cells and has all the technical benefits of the battery cells, it will not be elaborated here.

[0114] 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 pole, characterized in that The pole post comprises: a pole post bottom plate; a pole post column body comprising a first column segment and a second column segment; a first end of the first column segment is connected with the pole post bottom plate, and a first stepped surface is formed between the first column segment and the pole post bottom plate; a first end of the second column segment is connected with a second end of the first column segment, and an outer dimension of the first column segment is greater than an outer dimension of the second column segment in an X-Y plane, and a second stepped surface is formed between the second column segment and the first column segment; the pole post is a product of a piling process, a demolding direction is a reverse direction of Z, a parting surface is the first stepped surface, and a side wall of the first column segment and a side wall of the second column segment are both provided as inclined walls that are easy to demold; an included angle between the side wall of the first column segment and the pole post bottom plate is a first demolding angle, the first demolding angle is 90°-θ1, and 0.1°≤θ1≤2° is satisfied; an included angle between the side wall of the second column segment and the pole post bottom plate is a second demolding angle, the second demolding angle is 90°-θ2, and 0.1°≤θ2≤2° is satisfied; a height of the first column segment is h1, and 2.5mm≤h1≤6mm is satisfied; a height of the second column segment is h2, and 2.5mm≤h2≤6mm is satisfied.

2. The pole according to claim 1, characterized in that projections of the first column segment and the second column segment along the Z direction are both in the shape of a racetrack, comprising two circular arc edges arranged oppositely along the X direction and two straight edges arranged oppositely along the Y direction; a center point distance of the two circular arc edges of the first end of the first column segment is D, and 4mm≤D≤30mm is satisfied; a center point distance of the two circular arc edges of the first end of the second column segment is d, and 3.2mm≤d≤30mm is satisfied.

3. The pole post according to claim 2, wherein: a radius of the circular arc edge of the first end of the first column segment is R1, and 2mm≤R1≤20mm is satisfied; a radius of the circular arc edge of the first end of the second column segment is r1, and 1.5mm≤r1≤19.6mm is satisfied.

4. The pole according to claim 1, wherein the projections of the first column segment and the second column segment along the Z direction are both in the shape of a circle; a radius of the first end of the first column segment is R2, and 2mm≤R2≤20mm is satisfied.

5. The pole according to claim 4, characterized in that a radius of the first end of the second column segment is r2, and 1.5mm≤r2≤19.6mm is satisfied.

6. The pole as claimed in claim 1, characterized in that the pole post comprises a positive pole post and / or a negative pole post.

7. An electric cell characterized by The shell has a receiving cavity and an opening communicating with the receiving cavity; the electrode assembly is arranged in the receiving cavity of the shell; the cover plate assembly is arranged in the opening of the shell, and the electrode assembly is packaged in the shell; the cover plate assembly comprises a cover plate body, a riveting block, a first insulating piece, a second insulating piece, a sealing ring, and the pole post according to any one of claims 1 to 6. ​ The cover plate body is provided with a first pole post installation hole, the riveting block is provided with a second pole post installation hole, the pole post bottom plate and the riveting block are respectively arranged on two opposite surfaces of the cover plate body, the pole post column body passes through the first pole post installation hole and the second pole post installation hole in sequence and is riveted with the riveting block; The first insulating piece is arranged between the pole post bottom plate and the cover plate body, and insulatingly connects the pole post bottom plate and the cover plate body; The second insulating piece is arranged between the riveting block and the cover plate body, and insulatingly connects the riveting block and the cover plate body; The sealing ring is sleeved on the first column segment of the pole post, at least a part of the sealing ring is arranged between the first column segment and the first pole post installation hole of the cover plate body, and at least another part of the sealing ring is arranged between the pole post bottom plate and the cover plate body, so as to sealingly connect the pole post and the cover plate body.

8. A battery pack, characterized by, A plurality of the battery cell according to claim 7 are electrically connected between each other.

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