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

Abstract

The utility model relates to battery technology field, concretely relates to electric core cover plate subassembly, electric core and battery package. Electric core cover plate subassembly includes cover plate body, pole, first sealing washer and second sealing washer. Pole includes pole column body and pole bottom plate, along the length direction of cover plate body, pole column body is eccentric arrangement on pole bottom plate, pole column body is insulated with cover plate body, the surface of pole bottom plate is equipped with the annular sealing groove around pole column body to cover plate body, first sealing washer is set up on pole column body, second sealing washer is located in sealing groove and is sealed between cover plate body and pole bottom plate by compression, and the compression rate of second sealing washer satisfies preset condition. The utility model discloses through sealing groove and double sealing washer design, effectively solved the problem of poor sealing of eccentric pole because of the bottom plate warping, avoids the electrochemical corrosion or insulation aging between pole and cover plate body, reduces the short circuit risk.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cell cover assembly, a cell, and a battery pack. Background Technology

[0002] Lithium-ion batteries have become the mainstream power source for new energy vehicles, energy storage systems, and other fields due to their high energy density and long cycle life. With the continuous expansion of application scenarios, the requirements for battery safety and reliability are increasing, especially the sealing performance of the internal structure of the cell, which directly affects the battery's insulation performance and long-term stability. However, under the trend of higher energy density and more compact battery designs, the structural optimization of key components such as the cover plate and terminals faces even greater challenges.

[0003] As a core sealing component of a battery, the cell cover typically consists of the cover body, terminals, sealing rings, and insulating materials. The connection between the terminals and the cover must ensure a tight seal to prevent electrolyte leakage or external environmental intrusion. Traditionally, terminals are often centrally symmetrically arranged. However, to adapt to the spatial layout or electrical performance requirements of battery modules, eccentric terminal structures have gradually been adopted. The inconsistent lengths on both sides of the terminal base plate lead to uneven mechanical distribution, placing higher demands on the sealing process.

[0004] In eccentric electrode structures, due to the significant difference in length between the two sides of the base plate, the longer side is prone to localized warping during assembly due to uneven stress. This leads to insufficient compression of the sealing ring between the electrode and the cover plate, creating micro-gaps. Electrolyte may seep into the cover plate through these gaps, causing insulation failure or even a short circuit risk. Furthermore, the thermal stress during long-term charging and discharging can exacerbate the warping problem, further deteriorating the sealing performance. Utility Model Content

[0005] In view of this, the present invention provides a cell cover assembly, a cell, and a battery pack to solve the problem of poor sealing caused by the warping of the eccentric terminal post in the cell cover.

[0006] In a first aspect, this utility model provides a battery cell cover assembly, including a cover body, a terminal post, a first sealing ring, a first insulating element, and a second sealing ring. The cover body has a first terminal post mounting hole; the terminal post includes a terminal post body and a terminal post base plate; along the length direction of the cover body, the terminal post body is eccentrically arranged on the terminal post base plate; along the thickness direction of the cover body, the terminal post base plate is located at one end face of the first terminal post mounting hole, and the terminal post body passes through the first terminal post mounting hole and is insulatedly connected to the cover body; the surface of the terminal post base plate facing the cover body has an annular sealing groove surrounding the terminal post body; the first sealing ring is sleeved on the terminal post body, and at least a portion of the first sealing ring is located at the first terminal post mounting hole. Between the inner wall of the hole and the pole post body, at least another part of the first sealing ring is located between the cover plate body and the pole post base plate; the first insulating element is disposed between the cover plate body and the pole post base plate, insulatingly connecting the cover plate body and the pole post base plate; the second sealing ring is disposed in the sealing groove and is compressed and sealed between the first insulating element and the pole post base plate, the height of the second sealing ring before compression is H, in mm, the depth of the sealing groove is h, in mm, and the compression rate of the second sealing ring satisfies: 28% ≤ (Hh) / H×100% ≤ 45%.

[0007] Beneficial effects: The battery cell cover assembly provided by this utility model effectively solves the problem of poor sealing caused by the warping of the base plate of the eccentric electrode by adding an annular sealing groove to the electrode base plate and introducing a second sealing ring, combined with the double sealing structure of the first sealing ring. Specifically, the first sealing ring between the electrode body and the first electrode mounting hole and the second sealing ring between the electrode base plate and the cover plate form a synergistic sealing effect. Even if the electrode base plate warps locally due to the eccentric structure of the electrode, the second sealing ring can still fill the gap through compression deformation and block the electrolyte penetration path.

[0008] This invention controls the compression rate of the second sealing ring within the range of 28% to 45%, which ensures sufficient elastic deformation to compensate for the warping of the base plate and avoids leakage caused by insufficient compression, while also avoiding permanent deformation or rupture of the sealing ring due to excessive compression, thus ensuring the long-term sealing stability of the battery cell cover assembly.

[0009] This invention fundamentally solves the sealing problem of eccentric electrode structures through the design of sealing grooves and double sealing rings, blocking electrolyte penetration, avoiding electrochemical corrosion or insulation aging between the electrode and the cover plate, reducing the risk of short circuits, and taking into account the space constraints and long-term sealing requirements of high-energy-density batteries, thus significantly improving the safety and service life of the battery.

[0010] In one optional embodiment, the width of the sealing groove is K, in mm, which satisfies: 0.5mm≤K≤2.0mm.

[0011] In one optional embodiment, the distance from the first side of the pole base plate to the outer ring of the sealing groove along the length direction of the cover plate body is a, in mm, and the distance from the second side of the pole base plate to the outer ring of the sealing groove along the length direction of the cover plate body is b, in mm. The first side and the second side of the pole base plate are arranged opposite to each other, satisfying: 0.65mm≤a≤2.5mm, 0.8mm≤b≤2.8mm.

[0012] In one optional embodiment, along the width direction of the cover plate body, the distance from both sides of the pole post base plate to the outer ring of the sealing groove is c, in mm, satisfying: 0.65mm≤c≤2.0mm.

[0013] In one optional embodiment, the pole base plate is provided with at least one chamfer, and the vertical distance from the outer ring of the sealing groove to the chamfer is d, in mm, which satisfies: 0.65mm≤d≤2.5mm.

[0014] In one optional embodiment, the pole post includes a first column segment directly connected to the pole post base plate, and a first sealing ring is sleeved on the first column segment; along the width direction of the cover plate body, the distance from the inner ring of the sealing groove to the first column segment is A, in mm, and along the length direction of the cover plate body, the distance from the inner ring of the sealing groove to the first column segment is B, in mm, satisfying: 0.8mm≤A≤2.5mm, 1.0mm≤B≤5.5mm.

[0015] In one optional embodiment, the distance from the inner ring of the first side of the sealing groove to the axis of the pole post along the length direction of the cover plate body is L1, in mm; the distance from the inner ring of the second side of the sealing groove to the axis of the pole post along the length direction of the cover plate body is L2, in mm. The inner rings of the first side and the second side of the sealing groove are arranged opposite to each other along the length direction of the cover plate body, satisfying: L1 < L2, 4.5mm ≤ L1 ≤ 15mm, 8.5mm ≤ L2 ≤ 50mm.

[0016] In one optional implementation, the thickness of the pole base plate is T, in mm, which satisfies: 1.0 mm ≤ T ≤ 3.5 mm.

[0017] Secondly, this utility model also provides a battery cell, including a housing, an electrode assembly, and a battery cell cover assembly according to any one of the above technical solutions. The housing has a receiving cavity and an open end communicating with the receiving cavity; the electrode assembly is disposed in the receiving cavity of the housing; the battery cell cover assembly is disposed at the open end of the housing, sealing the electrode assembly in the receiving cavity.

[0018] Beneficial effects: Since the battery cell includes the battery cell cover assembly, it has all the technical effects of the battery cell cover assembly, which will not be elaborated here.

[0019] Thirdly, this utility model also provides a battery pack, including the battery cells described in the above technical solutions.

[0020] 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

[0021] To more clearly illustrate the specific embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is an exploded view of the structure of a battery cell cover assembly according to an embodiment of the present utility model;

[0023] Figure 2 for Figure 1 The cell cover assembly shown is a top view after assembly.

[0024] Figure 3 For along Figure 2 Sectional view at point AA;

[0025] Figure 4 for Figure 3 A magnified view of a portion of the pole;

[0026] Figure 5 For along Figure 2 Sectional view at point BB;

[0027] Figure 6 for Figure 1 The diagram shows the structural schematic of the electrode post in the battery cell cover assembly.

[0028] Figure 7 for Figure 6 A top view of the pole shown;

[0029] Figure 8 For along Figure 7 Sectional view at CC;

[0030] Figure 9 For along Figure 7 Sectional view at point DD;

[0031] Figure 10 This is a schematic diagram of the structure of the first sealing ring.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Cover plate body; 101. First pole mounting hole; 102. Explosion-proof valve mounting hole; 2. Pole; 201. Pole body; 2011. First column section; 202. Pole base plate; 203. Sealing groove; 3. First sealing ring; 301. First sealing section; 302. Second sealing section; 4. Second sealing ring; 5. Riveting block; 501. Second pole mounting hole; 6. First insulating component; 601. Third pole mounting hole; 7. Second insulating component; 701. Fourth pole mounting hole; 8. Explosion-proof valve; 9. Explosion-proof valve protective patch. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] The design of the eccentric terminal block structure stems primarily from the dual constraints of the battery cover's spatial arrangement and the requirements for tab welding. In the compact design of lithium-ion batteries, the internal space of the cover is often limited by module layout or electrical performance requirements, preventing the terminal block from being centrally positioned. Simultaneously, the terminal block base plate needs to provide sufficient solder area for tab welding to ensure welding strength and conductivity reliability. Therefore, along the length of the cover, the terminal block base plate must be designed with an asymmetrical structure to meet the minimum length requirement for the solder area, while the terminal block itself is offset to one side due to space constraints, thus forming the eccentric terminal block structure.

[0036] In an eccentric pole structure, the center lines of the pole rod and the pole base plate do not coincide, resulting in a significant eccentric arrangement along the length of the cover plate. This causes the pole base plate to have inconsistent lengths on both sides of the pole rod axis. The longer side of the pole base plate provides sufficient welding area for the electrode lugs, ensuring welding quality.

[0037] While the eccentric pole design solved the space and welding requirements, it also introduced sealing challenges. Due to the difference in length on both sides of the pole base plate, the forces during assembly are unbalanced, and the longer side is prone to local deformation (such as warping) due to stress concentration, affecting the sealing performance.

[0038] To solve this technical problem, this utility model provides a cell cover assembly, a cell, and a battery pack.

[0039] The following is combined with Figures 1 to 10 The following describes embodiments of the present invention.

[0040] 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 terminal post 2, a first sealing ring 3, a first insulating member 6, and a second sealing ring 4. The cover body 1 is provided with a first terminal post mounting hole 101; the terminal post 2 includes a terminal post body 201 and a terminal post base plate 202; along the length direction of the cover body 1 (referring to...) Figure 2 In the X direction), the pole post 201 is eccentrically arranged on the pole post base plate 202; along the thickness direction of the cover plate body 1, the pole post base plate 202 is located at one end face of the first pole post mounting hole 101, and the pole post 201 passes through the first pole post mounting hole 101 and is insulatedly connected to the cover plate body 1; the surface of the pole post base plate 202 facing the cover plate body 1 is provided with an annular sealing groove 203 surrounding the pole post 201; the first sealing ring 3 is sleeved on the pole post 201, and at least a portion of the first sealing ring 3 is located on the inner wall of the first pole post mounting hole 101 and the pole post 201. Between the cover plate body 1 and the pole post base plate 202, at least another part of the first sealing ring 3 is located between the cover plate body 1 and the pole post base plate 202; the first insulating member 6 is disposed between the cover plate body 1 and the pole post base plate 202, insulatingly connecting the cover plate body 1 and the pole post base plate 202; the second sealing ring 4 is disposed in the sealing groove 203 and is compressed and sealed between the cover plate body 1 and the pole post base plate 202, the height of the second sealing ring 4 before compression is H, in mm, the depth of the sealing groove 203 is h, in mm, and the compression rate of the second sealing ring 4 satisfies: 28% ≤ (Hh) / H×100% ≤ 45%.

[0041] The battery cell cover assembly provided by this utility model effectively solves the problem of poor sealing caused by the warping of the base plate of the eccentric electrode by adding an annular sealing groove 203 on the electrode base plate 202 and introducing a second sealing ring 4, combined with the double sealing structure of the first sealing ring 3. Specifically, the first sealing ring 3 between the electrode body 201 and the first electrode mounting hole 101 and the second sealing ring 4 between the electrode base plate 202 and the cover plate form a synergistic sealing effect. Even if the electrode base plate 202 is partially warped due to the eccentric structure of the electrode 2, the second sealing ring 4 can still fill the gap by compression deformation and block the electrolyte penetration path.

[0042] This invention controls the compression rate of the second sealing ring 4 within the range of 28% to 45%, which can ensure sufficient elastic deformation to compensate for the warping of the base plate and avoid leakage caused by insufficient compression, while also avoiding permanent deformation or rupture of the sealing ring due to excessive compression, thus ensuring the long-term sealing stability of the battery cell cover assembly.

[0043] By setting a sealing groove 203 on the pole base plate 202, the second sealing ring 4 is located in the sealing groove 203. The sealing groove 203 can radially position the second sealing ring 4, so that it can evenly fill the sealing contact surface when under pressure, evenly disperse the assembly stress, and reduce the stress concentration on one side caused by eccentricity.

[0044] During battery charging and discharging, the second sealing ring 4 can be finely adjusted to change shape due to thermal expansion and contraction or mechanical vibration, continuously compensating for the gaps caused by slight deformation of the terminal base plate 202, and maintaining the sealing of the contact interface.

[0045] This invention fundamentally solves the sealing problem of the eccentric electrode structure through the sealing groove 203 and the double sealing ring design, blocking electrolyte penetration, avoiding electrochemical corrosion or insulation aging between the electrode 2 and the cover plate body 1, reducing the risk of short circuit, and taking into account the space constraints and long-term sealing requirements of high energy density batteries, thus significantly improving the safety and service life of the battery.

[0046] Furthermore, since the pole base plate 202 has an approximately rectangular structure, the sealing groove 203 also has an approximately rectangular structure. The four corners of the sealing groove 203 are chamfered or rounded. If the four corners of the sealing groove 203 are right angles, the second sealing ring 4 is easily cut or deformed by sharp edges during compression, leading to local stress concentration and accelerating the aging or damage of the sealing ring. The rounded or chamfered design can smoothly transition the stress distribution, avoid mechanical damage to the sealing ring, and extend its service life and sealing effect.

[0047] Furthermore, the first sealing ring 3 includes a first sealing section 301 extending axially and a second sealing section 302 extending radially. The first sealing section 301 is located between the inner wall of the first pole mounting hole 101 and the pole body 201, and the second sealing section 302 is located between the cover plate body 1 and the pole base plate 202. The first sealing ring 3 can form a double seal between the pole 2 and the cover plate body 1 in both the axial and radial directions.

[0048] In some embodiments, the width of the sealing groove 203 is K, in mm, which satisfies: 0.5mm≤K≤2.0mm.

[0049] Specifically, the sealing groove 203 has a structure of equal width.

[0050] In the eccentric pole structure of the cell cover plate assembly, by controlling the width K of the sealing groove 203 within the range of 0.5mm to 2.0mm, the effective compression and filling of the sealing ring can be ensured, and the second sealing ring 4 can compensate for the sealing defects caused by the local warping of the pole base plate 202.

[0051] If the sealing groove 203 is too narrow, i.e. K<0.5mm, the second sealing ring 4 will be difficult to fully embed in the sealing groove 203. The material cannot expand freely during compression, resulting in excessive local stress, which may cause the second sealing ring 4 to tear or be permanently deformed. In addition, the narrow space may restrict the deformation path of the second sealing ring 4, reducing the sealing compensation ability of the second sealing ring 4 for poor sealing caused by the local warping of the pole post base plate 202.

[0052] If the sealing groove 203 is too wide, i.e. K>2.0mm, it may cause excessive radial flow after the sealing ring is compressed, which may result in insufficient contact pressure on the sealing surface, weakening the sealing interface fit. In addition, the excess space may cause the sealing ring to shift during vibration or thermal cycling, forming a leakage channel.

[0053] In addition, this width range is suitable for common sealing materials such as silicone and fluororubber, which can accommodate their compression deformation while maintaining sufficient resilience.

[0054] With a compression ratio requirement of 28% to 45%, the width of the sealing groove 203, ranging from 0.5mm to 2.0mm, can precisely control the filling rate of the sealing ring after compression, ensuring that the sealing surface is subjected to uniform force.

[0055] In some embodiments, along the length direction of the cover plate body 1, the distance from the first side of the pole base plate 202 to the outer ring of the sealing groove 203 is a, in mm; along the length direction of the cover plate body 1, the distance from the second side of the pole base plate 202 to the outer ring of the sealing groove 203 is b, in mm; the first side and the second side of the pole base plate 202 are arranged opposite to each other, satisfying: 0.65mm≤a≤2.5mm, 0.8mm≤b≤2.8mm.

[0056] In this embodiment, the sealing groove 203 on the pole base plate 202 adopts an asymmetrical layout.

[0057] On the short side of the pole base plate 202, the distance 'a' from the first side of the pole base plate 202 to the outer ring of the sealing groove 203 is controlled within the range of 0.65mm to 2.5mm. This can provide a more uniform compression space for the sealing ring, prevent excessive hardening due to material accumulation on the short side, or avoid the risk of the sealing ring being extruded due to insufficient space on the short side.

[0058] Since the long side of the pole base plate 202 is more prone to warping and deformation, which can cause sealing problems, the distance b from the second side of the pole base plate 202 to the outer ring of the sealing groove 203 is controlled within the range of 0.8mm to 2.8mm on the long side. This can enhance the inhibitory effect of the second sealing ring 4 on the warping of the pole base plate 202 on the long side and improve the sealing effect.

[0059] By limiting the ranges of a and b, the sealing pressure on both sides of the electrode base plate 202 can be balanced, thereby improving the overall sealing effect of the cell cover assembly.

[0060] In some embodiments, along the width direction of the cover body 1 (refer to...) Figure 2 In the Y direction), the distance between the two sides of the pole base plate 202 and the outer ring of the sealing groove 203 is c, in mm, and satisfies: 0.65mm≤c≤2.0mm.

[0061] The cover plate body 1 has a rectangular structure, and the length direction of the pole post base plate 202 is consistent with the length direction of the cover plate body 1. Along the width direction of the cover plate body 1, the pole post base plate 202 is less likely to warp and deform. Therefore, along the width direction of the cover plate body 1, the distances from the two sides of the pole post base plate 202 to the outer ring of the sealing groove 203 are equal, and no differentiation is required.

[0062] In this embodiment, the distance c between the two sides of the pole base plate 202 and the outer ring of the sealing groove 203 is limited to the range of 0.65mm to 2.0mm.

[0063] If the distance is too small, c<0.65mm, the edge of the sealing groove 203 is too close to the side of the pole base plate 202, which may cause the material of the second sealing ring 4 to not expand sufficiently when it is compressed, resulting in excessive local stress and increasing the risk of the sealing ring tearing or permanent deformation.

[0064] If the distance is too large, c>2.0mm, the sealing groove 203 is too close to the center of the pole base plate 202, which may cause the second sealing ring 4 to fail to effectively cover the edge of the pole base plate 202 after compression. Under extreme working conditions (such as vibration or thermal cycling), micro-leakage may occur in the edge area of ​​the pole base plate 202.

[0065] In some embodiments, the pole base plate 202 is provided with at least one chamfer, and the vertical distance from the outer ring of the sealing groove 203 to the chamfer is d, in mm, which satisfies: 0.65mm≤d≤2.5mm.

[0066] In this embodiment, the vertical distance from the outer ring of the sealing groove 203 to the chamfer is d≥0.65mm to ensure that the sealing ring will not contact the chamfer edge when compressed, thus avoiding the material being sheared or cut; and the vertical distance from the outer ring of the sealing groove 203 to the chamfer is d≤2.5mm to ensure that the sealing ring can still cover the chamfer transition area after compression, thus preventing the formation of a leakage channel.

[0067] In some embodiments, the pole post 201 includes a first post segment 2011 directly connected to the pole post base plate 202, and a first sealing ring 3 is sleeved on the first post segment 2011; along the width direction of the cover plate body 1, the distance from the inner ring of the sealing groove 203 to the first post segment 2011 is A, in mm, and along the length direction of the cover plate body 1, the distance from the inner ring of the sealing groove 203 to the first post segment 2011 is B, in mm, satisfying: 0.8mm≤A≤2.5mm, 1.0mm≤B≤5.5mm.

[0068] In this embodiment, along the width direction of the cover plate body 1, the distance A from the inner ring of the sealing groove 203 to the first column segment 2011 is at least 0.8 mm, ensuring that the first sealing ring 3 and the second sealing ring 4 form an effective sealing gradient in the width direction. This enhances the synergistic effect of the two sealing rings and increases the interface sealing pressure.

[0069] Along the length of the cover plate body 1, the distance B from the inner ring of the sealing groove 203 to the first column section 2011 is at most 5.5mm. That is, on the long side of the pole post base plate 202, the distance from the inner ring of the sealing groove 203 to the first column section 2011 allows the second sealing ring 4 to fully compensate for the asymmetric deformation of the pole post base plate 202.

[0070] In some embodiments, along the length direction of the cover plate body 1, the distance from the inner ring of the first side of the sealing groove 203 to the axis of the pole post 201 is L1, in mm; along the length direction of the cover plate body 1, the distance from the inner ring of the second side of the sealing groove 203 to the axis of the pole post 201 is L2, in mm. The inner rings of the first side and the second side of the sealing groove 203 are arranged opposite to each other along the length direction of the cover plate body 1, satisfying: L1 < L2, 4.5mm ≤ L1 ≤ 15mm, 8.5mm ≤ L2 ≤ 50mm.

[0071] The battery cell cover assembly provided by this utility model, for the double sealing ring design of the eccentric pole structure, controls the distance L1 from the inner ring of the sealing groove 203 on the short side of the pole base plate 202 to the axis of the pole body 201 within the range of 4.5mm to 15mm, and controls the distance L2 from the inner ring of the sealing groove 203 on the long side of the pole base plate 202 to the axis of the pole body 201 within the range of 8.5mm to 50mm, to ensure the sealing performance on both sides of the eccentric pole.

[0072] In some embodiments, the thickness of the pole base plate 202 is T, in mm, and satisfies: 1.0 mm ≤ T ≤ 3.5 mm.

[0073] The main function of the electrode base plate 202 is to be welded to the electrode tabs or connecting pieces. In this embodiment, the thickness of the electrode base plate 202 is controlled within the range of 1.0mm to 3.5mm. If the electrode base plate 202 is too thin, i.e., T < 1.0mm, the structural strength of the electrode base plate 202 itself is insufficient, and it is prone to deformation. It will also affect the performance of the second sealing ring 4 due to the heat of welding. If the electrode base plate 202 is too thick, i.e., T > 3.5mm, the structural strength of the electrode base plate 202 itself will be improved, but it will also occupy too much bending space for the electrode tabs, affecting the cell capacity. At the same time, the increased weight will cause material waste.

[0074] In some embodiments, the device further includes a riveting block 5; the riveting block 5 is provided with a second pole mounting hole 501; the first insulating member 6 is provided with a third pole mounting hole 601; the pole base plate 202 and the riveting block 5 are respectively provided on two opposite surfaces of the cover plate body 1, and the pole body 201 passes through the third pole mounting hole 601, the first pole mounting hole 101 and the second pole mounting hole 501 in sequence and is riveted to the riveting block 5.

[0075] The battery cell cover assembly provided in this embodiment of the utility model, by opening a sealing groove 203 on the electrode base plate 202 and adding a second sealing ring 4, embeds the second sealing ring 4 into the sealing groove 203 of the electrode base plate 202, and then through the assembly between the first insulating member 6 and the electrode base plate 202, the first insulating member 6 and the electrode base plate 202 are tightly attached and compressed to form a sealing part, which achieves the effect of secondary sealing and solves the problem of poor sealing caused by the warping of the eccentric electrode base plate 202.

[0076] In some embodiments, the cell cover assembly further includes a second insulating member 7, which has a receiving groove, and the riveting block 5 is disposed in the receiving groove. The second insulating member 7 has a fourth terminal mounting hole 701. The terminal post 201 passes sequentially through the third terminal mounting hole 601 of the first insulating member 6, the first terminal mounting hole 101 of the cover body 1, the fourth terminal mounting hole 701 of the second insulating member 7, and the second terminal mounting hole 501 of the riveting block 5, and is then riveted to the riveting block 5.

[0077] Furthermore, the first sealing section 301 of the first sealing ring 3 extends axially to the second insulating member 7, and the second sealing section 302 of the first sealing ring 3 extends radially to the first insulating member 6, so as to improve the sealing performance of the cell cover assembly.

[0078] In some embodiments, both the first insulating member 6 and the second insulating member 7 are plastic parts.

[0079] In some embodiments, the cell cover assembly further includes an explosion-proof valve 8 and an explosion-proof valve protection patch 9. The cover body 1 is also provided with an explosion-proof valve mounting hole 102, the explosion-proof valve 8 is disposed within the explosion-proof valve mounting hole 102, and the explosion-proof valve protection patch 9 is disposed on the cover body 1. The explosion-proof valve 8 is used for directional pressure relief when overpressure occurs inside the cell. The explosion-proof valve protection patch 9 provides protection for the explosion-proof valve 8.

[0080] 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 any of the above embodiments. The housing has a receiving cavity and an open end communicating with the receiving cavity; the electrode assembly is disposed within the receiving cavity of the housing; the battery cell cover assembly is disposed at the open end of the housing, sealing the electrode assembly within the receiving cavity.

[0081] The cell cover assembly is one of the core structural components of a battery cell. Its function extends beyond simple encapsulation, encompassing multiple critical aspects such as safety, electrical performance, thermal management, and production efficiency. The cell cover assembly forms a sealed space with the cell housing through laser welding or adhesive sealing, preventing electrolyte leakage and the intrusion of external moisture / oxygen. The terminals (positive and negative) of the cell cover assembly are welded to the cell tabs via internal connecting tabs and externally connected to the battery system busbar. The cell cover assembly must withstand the expansion stress of the electrode sheets during battery charging and discharging to prevent deformation that could lead to seal failure.

[0082] 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.

[0083] According to an embodiment of the present invention, in a third aspect, a battery pack is also provided, including the battery cells described in the above embodiments.

[0084] Since the battery pack includes the battery cells and has all the technical benefits of the battery cells, it will not be elaborated here.

[0085] Although embodiments of the present 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 present 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 a first pole post mounting hole; The electrode post includes an electrode post body and an electrode post base plate; along the length direction of the cover plate body, the electrode post body is eccentrically arranged on the electrode post base plate; along the thickness direction of the cover plate body, the electrode post base plate is located at one end face of the first electrode post mounting hole, the electrode post body passes through the first electrode post mounting hole and is insulatedly connected to the cover plate body; the surface of the electrode post base plate facing the cover plate body is provided with an annular sealing groove surrounding the electrode post body. A first sealing ring is sleeved on the pole post body. At least a portion of the first sealing ring is located between the inner wall of the first pole post mounting hole and the pole post body, and at least another portion of the first sealing ring is located between the cover plate body and the pole post bottom plate. A first insulating element is disposed between the cover plate body and the pole base plate, thereby insulatingly connecting the cover plate body and the pole base plate. The second sealing ring is disposed within the sealing groove and is compressed and sealed between the first insulating element and the pole base plate. The height of the second sealing ring before compression is H (in mm), and the depth of the sealing groove is h (in mm). The compression ratio of the second sealing ring satisfies: 28%≤(Hh) / H×100%≤45%.

2. The cell cover assembly according to claim 1, characterized in that, The width of the sealing groove is K, in mm, and satisfies: 0.5mm≤K≤2.0mm.

3. The cell cover assembly according to claim 1 or 2, characterized in that, Along the length of the cover plate body, the distance from the first side edge of the pole post base plate to the outer ring of the sealing groove is 'a', in mm. Along the length of the cover plate body, the distance from the second side of the pole post base plate to the outer ring of the sealing groove is b, in mm. The first side and the second side of the pole post base plate are arranged opposite to each other, satisfying the following: 0.65mm≤a≤2.5mm, 0.8mm≤b≤2.8mm.

4. The cell cover assembly according to claim 1 or 2, characterized in that, Along the width direction of the cover plate body, the distance from both sides of the pole post base plate to the outer ring of the sealing groove is c, in mm. satisfy: 0.65mm≤c≤2.0mm.

5. The cell cover assembly according to claim 1 or 2, characterized in that, The base plate of the pole post is provided with at least one chamfer, and the vertical distance from the outer ring of the sealing groove to the chamfer is d, in mm, satisfying: 0.65mm≤d≤2.5mm.

6. The cell cover assembly according to claim 1 or 2, characterized in that, The pole post body includes a first column segment that is directly connected to the pole post base plate, and the first sealing ring is sleeved on the first column segment; Along the width direction of the cover plate body, the distance from the inner ring of the sealing groove to the first column segment is A, in mm. Along the length of the cover plate body, the distance from the inner ring of the sealing groove to the first column segment is B, in mm. satisfy: 0.8mm≤A≤2.5mm 1.0mm≤B≤5.5mm.

7. The cell cover assembly according to claim 1 or 2, characterized in that, Along the length of the cover plate body, the distance from the inner ring of the first side of the sealing groove to the axis of the pole post is L1, in mm. Along the length of the cover plate body, the distance from the inner ring of the second side of the sealing groove to the axis of the pole post is L2, in mm. The inner rings on the first and second sides of the sealing groove are arranged opposite to each other along the length of the cover plate body, satisfying the following: L1 < L2, 4.5mm≤L1≤15mm 8.5mm≤L2≤50mm.

8. The cell cover assembly according to claim 1 or 2, characterized in that, The thickness of the pole base plate is T, in mm, and satisfies: 1.0mm≤T≤3.5mm.

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

10. A battery pack, characterized in that, Includes the battery cell described in claim 9.

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