Top cover structure and battery cell

Abstract

The utility model relates to the technical field of battery manufacturing provides a top cover structure and electric core, top cover structure includes top cover body, pole, sealing element and rigid support ring, and top cover body has the mounting hole, and top cover body is provided with plastic element, the pole is worn in the mounting hole, and the inner peripheral surface of mounting hole, the inner side wall surface of plastic element and the outer peripheral surface of pole jointly define annular sealing gap, and sealing element is located in sealing gap, rigid support ring is located in sealing gap and is located the top of sealing element, and the inner peripheral surface of rigid support ring is with sealing element interference fit, and the outer peripheral surface is with the inner peripheral surface of mounting hole abuts and / or with top cover body abuts, and the upper end surface of rigid support ring abuts with pole, and the lower end surface is with the upper end surface of sealing element interference fit, the utility model discloses through the setting of rigid support ring, so that can realize effective support through rigid support ring, to avoid pole subsidence, ensure the sealing effect of sealing element, improve the production quality of electric core.

Description

Technical Field

[0001] This utility model relates to the technical field of battery manufacturing, and in particular to a top cover structure and a battery cell. Background Technology

[0002] A typical battery cell structure includes a casing, with a top cover structure on top of the casing. The top cover structure is connected to the casing and forms a sealed housing space within the casing, where the electrode assembly is located. The electrode assembly and the cover plate assembly are welded together to form the entire battery circuit. For the cover plate assembly, insulation of the battery is usually achieved by attaching cover plate patches.

[0003] In related technologies, the top cover structure has a first plastic structure, which is connected to the top cover body. The electrode post is located inside the first plastic structure. During the assembly and flanging process, the electrode post applies pressure to the sealing ring to achieve sealing. However, due to the deformation of the thickness dimension during the connection of the first plastic structure, the electrode post sinks, which reduces the sealing effect of the sealing ring and affects the quality of the battery cell. Utility Model Content

[0004] This utility model provides a top cover structure and a battery cell to solve the defects in the prior art where the electrode post sinks and the sealing quality of the seals decreases.

[0005] This utility model provides a top cover structure, including: a top cover body, an electrode post, a sealing element, and a rigid support ring. The top cover body has a mounting hole, and plastic parts are fixedly disposed on two opposite surfaces in the thickness direction of the top cover body. The radially outer circumferential surface of the electrode post has an annular receiving groove and passes through the mounting hole. The radially inner circumferential surface of the mounting hole, the radially inner sidewall of the plastic part surrounding the edge of the mounting hole, and the receiving groove of the electrode post together define an annular sealing gap. The sealing element is sleeved on the outside of the electrode post and is located axially close to the top cover in the sealing gap. The first side of the main body; the rigid support ring is disposed within the sealing gap and axially close to the second side of the top cover body, the radial inner circumferential surface of the rigid support ring is interference-fitted with the radial outer circumferential surface of the sealing element; the radial outer circumferential surface of the rigid support ring abuts against the radial inner circumferential surface of the mounting hole, and / or the radial outer circumferential surface of the rigid support ring abuts against the surface of the top cover body near the axial outer end face of the pole post; the axial outer end face of the rigid support ring abuts against the axial outer end face of the receiving groove, and the axial inner end face of the rigid support ring is interference-fitted with the axial outer end face of the sealing element.

[0006] According to the top cover structure provided by this utility model, the rigid support ring has a straight cylindrical radial outer peripheral surface.

[0007] According to the top cover structure provided by this utility model, the rigid support ring has a stepped radial outer peripheral surface.

[0008] According to the top cover structure provided by this utility model, the sealing element includes a first annular sealing portion and a second annular sealing portion formed sequentially along its axial direction. The radial width of the first annular sealing portion is greater than the radial width of the second annular sealing portion, so that the sealing element forms a stepped structure.

[0009] According to the top cover structure provided by this utility model, the first annular sealing part is interference-fitted with the surface of the top cover body near the inner end face of the pole post; and the axial thickness of the first annular sealing part in its axial direction is H, and the axial compression of the contact portion between the axial outer end face of the first annular sealing part and the surface of the top cover body near the inner end face of the pole post is H1, and satisfies 20%≤H1 / H≤50%.

[0010] According to the top cover structure provided by this utility model, the radial overlap between the axial outer end face of the first annular sealing part and the surface of the top cover body near the inner end face of the pole post is 0.5mm≤L1≤1mm.

[0011] According to the top cover structure provided by this utility model, the axial thickness of the second annular sealing part is K, and the axial compression of the contact portion between the axial outer end face of the second annular sealing part and the axial inner end face of the rigid support ring is M, satisfying 15%≤M / K≤45%.

[0012] According to the top cover structure provided by this utility model, the radial overlap between the radial outer circumferential surface of the second annular sealing part and the radial inner circumferential wall surface of the rigid support ring is 0.2mm≤L2≤0.6mm.

[0013] According to the top cover structure provided by this utility model, the surface of the top cover body near the inner end face of the pole post is provided with a limiting protrusion, and a corresponding matching limiting part is provided on the plastic part, wherein the matching limiting part and the limiting protrusion cooperate to limit the movement.

[0014] The present invention also provides a battery cell, comprising: a housing and a top cover structure as described in any of the preceding claims; the housing having a receiving space for accommodating an electrode assembly; and the top cover structure being disposed on the top of the housing.

[0015] The top cover structure and battery cell provided by this utility model have a rigid support ring in the top cover structure, which enables effective support, thereby preventing the terminal post from sinking, ensuring the sealing effect of the seal, and improving the production quality of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the 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.

[0017] Figure 1 This is an exploded structural diagram of the top cover structure provided by this utility model.

[0018] Figure 2 This is a cross-sectional structural diagram of one embodiment of the top cover structure provided by this utility model.

[0019] Figure 3 This utility model provides Figure 2 Enlarged view of the local structure at point A in the middle.

[0020] Figure 4 This is one of the partial schematic diagrams of the rigid support ring connection structure in the top cover structure provided by this utility model.

[0021] Figure 5 This is a cross-sectional view of another embodiment of the top cover structure provided by this utility model.

[0022] Figure 6 This utility model provides Figure 5 Enlarged view of the local structure at point B.

[0023] Figure 7 This is a second partial schematic diagram of the rigid support ring connection structure in the top cover structure provided by this utility model.

[0024] Figure 8 This is a schematic diagram of the overall structure of the sealing element in the top cover structure provided by this utility model.

[0025] Figure label: 10. Top cover body; 11. Mounting hole; 20. Pole post; 21. Receiving groove; 30. Plastic part; 31. First plastic part; 32. Second plastic part; 40. Sealing element; 41. First annular sealing part; 42. Second annular sealing part; 50. Rigid support ring. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions 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 scope of protection of this utility model.

[0027] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of clarifying the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model according to the specific circumstances.

[0029] In this embodiment of the utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0031] In related technologies, during the molding process of the top cover structure, the plastic parts undergo deformation due to the temperature of the welding area. This results in a reduction in the axial thickness of the plastic parts, causing the entire pole to sink. Consequently, the effective extrusion deformation of the seal is reduced, leading to a decrease in the sealing effect. Furthermore, if the pressure applied to the pole during assembly is further increased, the first plastic part may experience excessive stress, causing it to crack.

[0032] It should be understood that in the following description of the defined orientation in the embodiments, the side of the top cover structure away from the internal structure of the battery cell in the thickness direction is axially outward, while the side closer to the internal structure of the battery cell is axially inward, the side closer to the center of the mounting hole is radially inward, and the side away from the center of the mounting hole is radially outward.

[0033] To address the issues in the relevant technologies, the following will be discussed in conjunction with... Figures 1-6This invention describes a top cover structure, comprising a top cover body 10, a pole post 20, a sealing element 40, and a rigid support ring 50. The top cover body 10 has a mounting hole 11, and plastic parts 30 are fixedly disposed on two opposing surfaces in the thickness direction of the top cover body 10. The radial outer circumferential surface of the pole post 20 has an annular receiving groove 21, which passes through the mounting hole 11. The radial inner circumferential surface of the mounting hole 11, the radial inner sidewall of the plastic part 30 surrounding the edge of the mounting hole 11, and the receiving groove 21 of the pole post 20 together define an annular sealing gap. The sealing element 40 is sleeved on the outside of the pole post 20 and located in the sealing gap. The rigid support ring 50 is located axially close to the first side of the top cover body 10; the rigid support ring 50 is located in the sealing gap and axially close to the second side of the top cover body 10. The radial inner circumferential surface of the rigid support ring 50 is interference-fitted with the radial outer circumferential surface of the seal 40. The radial outer circumferential surface of the rigid support ring 50 abuts against the radial inner circumferential surface of the mounting hole 11, and / or the radial outer circumferential surface of the rigid support ring 50 abuts against the surface of the top cover body 10 near the axial outer end face of the pole post 20. The axial outer end face of the rigid support ring 50 abuts against the axial outer end face of the receiving groove 21. The axial inner end face of the rigid support ring 50 is interference-fitted with the axial outer end face of the seal 40. The inner pole post 20 of the top cover structure is located inside the first plastic 31 and abuts against the first plastic 31 to support and install the pole post 20. In this embodiment, the pole post 20 can be effectively supported by the rigid support ring 50, thereby preventing the pole post 20 from sinking, ensuring the sealing effect of the seal 40, and improving the production quality of the battery cell.

[0034] Specifically, the rigid support ring 50 can be a metallic or non-metallic support ring, possessing high temperature resistance and good compressive strength. For example, the rigid support ring 50 can be a ceramic support ring, a steel support ring, etc. The rigid support ring 50 is positioned by defining its inner and outer circumferential surfaces, as well as its upper and lower end faces, ensuring the stability of its position.

[0035] Among them, such as 2, Figure 3As shown, the plastic part 30 located on the surface of the top cover body 10 near the axial outer end face of the pole post 20 (hereinafter referred to as the upper surface for ease of description) is the first plastic part 31, and the plastic part 30 located on the surface of the top cover body 10 near the axial inner end face of the pole post 20 (hereinafter referred to as the lower surface for ease of description) is the second plastic part 32. Both the first plastic part 31 and the second plastic part 32 are fixedly connected to the top cover body 10. In the initial state of pole post 20 installation, its axial top is a straight cylindrical structure. During the installation process, by turning the top of pole post 20 outward, the pole post 20 as a whole takes on an "I" shape after turning the flange. That is, after the top of pole post 20 is turned, an annular receiving groove 21 is formed on the outer peripheral surface of pole post 20. The portion of the first plastic part 31 near the edge of the mounting hole 11 and the portion of the second plastic part 32 near the edge of the mounting hole 11 are both located in the receiving groove 21. Furthermore, the sealing element 40 is a sealing ring, which is sleeved on the pole post 20 before sealing and located on the axial inner end face of the receiving groove 21, so as to cooperate with the lower surface of the top cover body 10 near the edge of the mounting hole 11 to achieve sealing.

[0036] In specific structures, such as Figure 2 , Figure 5 As shown, the terminal 20 includes a positive terminal 20 and a negative terminal 20. The positive terminal 20 is made entirely of aluminum, while the negative terminal 20 is divided into upper and lower parts. The upper part of the negative terminal 20 is made of aluminum, and the lower part is made of copper. By using an upper aluminum structure for the negative terminal 20, it can connect to the negative electrode material, acting as the battery casing, while maintaining a lightweight and corrosion-resistant profile. The copper part is mainly responsible for the conduction of current at the negative electrode; it has good conductivity and is relatively inexpensive.

[0037] It is understandable that the top cover structure is fixedly connected by welding during the manufacturing process. This welding process generates a large amount of heat, which can affect the thickness of the first plastic component 31 (30), causing the pole post 20 to sink and become difficult to support effectively, thus compromising sealing. In this embodiment, a rigid support ring 50 within the sealing gap provides effective support. The rigid support ring 50 is positioned by abutting against the sealing component 40, the pole post 20, and the top cover body 10. This further compresses the sealing ring, improving the sealing effect. Furthermore, because the rigid support ring 50 provides the necessary thickness support, it avoids excessive stress on the first plastic component 31, effectively preventing cracking due to excessive stress, and improving the yield and service life of the top cover structure.

[0038] In a specific configuration, one end of the second plastic 32 near the edge of the mounting hole 11 overlaps with the axial inner end face of the receiving groove 21 on the outer peripheral surface of the pole post 20, thereby enhancing the stability of the second plastic 32 and making the second plastic 32 more stable.

[0039] In this embodiment, different interference fit structures are achieved by employing different rigid support ring 50 structures to achieve the interference fit between the radial outer circumferential surface of the rigid support ring 50 and the mounting hole 11 and the top cover body 10. See the following embodiments for details.

[0040] In some embodiments, such as Figure 2 , Figure 3 As shown, the rigid support ring 50 has a cylindrical radial outer circumferential surface. By defining the rigid support ring 50, the radial outer circumferential surface of the rigid support ring 50 abuts against the radial inner circumferential surface of the mounting hole 11, which reduces the manufacturing cost and provides effective support and sealing.

[0041] Specifically, the rigid support ring 50 has a radial inner circumferential wall surface and a radial outer circumferential wall surface. A gap exists between the radial inner circumferential wall surface and the radial wall surface of the polar receiving groove 21, and it is interference-fitted with the radial outer circumferential surface of the sealing element 40. This causes the radial inner circumferential wall surface of the support ring to compress the sealing element, achieving a seal with the sealing element 40. The radial outer circumferential wall surface of the rigid support ring 50 abuts against the radial inner circumferential wall surface of the first plastic 31 located at the edge of the mounting hole 11 and the radial inner circumferential wall surface of the mounting hole 11 itself, thereby enabling radial positioning of the rigid support ring 50.

[0042] Furthermore, the axial inner end face of the rigid support ring 50 is interference-fitted with the upper end face of the seal 40, and the upper end face of the rigid support ring 50 abuts against the top surface of the receiving groove 21 of the pole post 20, thereby achieving axial positioning of the rigid support ring 50. That is, in the part of the seal 40 that is interference-fitted with the rigid support ring 50, there is a certain amount of compression in both the radial and axial directions, which can effectively limit the rigid support ring 50, thereby making the installation of the rigid support ring 50 more stable.

[0043] In a specific configuration, an arc-shaped transition surface is provided on the top edge of the inner peripheral wall of the rigid support ring 50. The arc-shaped transition surface facilitates the forming of the rigid support ring 50 and makes the overall compressive and tensile strength of the rigid support ring 50 higher.

[0044] In other embodiments, such as Figure 5 , Figure 6 As shown, the rigid support ring 50 has a cylindrical radial outer peripheral surface. The stepped outer peripheral surface can mate with the edge of the mounting hole 11, so that the radial outer peripheral surface of the rigid support ring 50 abuts against the radial inner peripheral surface of the mounting hole 11 and the upper surface of the top cover body 10 near the mounting hole 11, thereby making the connection of the rigid support ring 50 more stable.

[0045] Specifically, the stepped surface on the outer periphery of the rigid support ring 50 contacts the upper surface of the top cover body 10, and the axial outer end face of the rigid support ring 50 abuts against the axial outer end face of the pole post 20 receiving groove 21 to achieve axial positioning of the rigid support ring 50.

[0046] Furthermore, the radial outer peripheral wall of the rigid support ring 50 abuts against the radial inner peripheral wall of the first plastic 31 located at the edge of the mounting hole 11 and the radial inner peripheral wall of the mounting hole 11 itself, thereby achieving radial positioning of the rigid support ring 50. Moreover, since the sealing element 40 has a certain amount of compression in both the radial and axial directions at the interference fit portion with the rigid support ring 50, this effectively positions the rigid support ring 50, making the installation of the rigid support ring 50 more stable.

[0047] In some embodiments, such as Figure 4 , Figure 7 As shown, the seal 40 includes a first annular sealing portion 41 and a second annular sealing portion 42 formed sequentially along its axial direction. The radial width of the first annular sealing portion 41 is greater than the radial width of the second annular sealing portion 42, thus forming a stepped structure in the seal 40. The sealing performance can be further improved by providing two annular sealing portions.

[0048] Specifically, the seal 40 is a flexible sealing ring structure, and its radial outer circumferential surface is constructed in a stepped shape, thus forming a first annular sealing portion 41 and a second annular sealing portion 42. The first annular sealing portion 41 is used to cooperate with the lower surface of the top cover body 10 to achieve a seal, and the second annular sealing portion 42 is used to cooperate with the rigid support ring 50 to achieve a seal and to limit the movement of the rigid support ring 50. In other words, the seal 40 has two annular sealing areas, which improves the sealing performance.

[0049] It is understandable that the seal 40 is located in the sealing gap and is mainly used to achieve sealing and spacing between the pole post 20 and the top cover body 10. In this embodiment, by defining the radial outer peripheral surface of the seal 40 as a stepped structure, it can have a better sealing effect and also make the rigid support block have better stability.

[0050] In conjunction with the above embodiments, such as Figure 3 , Figure 5 , Figure 7 , Figure 8As shown, the first annular sealing part 41 is interference-fitted with the surface of the top cover body 10 near the inner end face of the pole post 20; and the axial thickness of the first annular sealing part 41 is H, and the axial compression of the contact portion between the outer end face of the first annular sealing part 41 and the surface of the top cover body 10 near the inner end face of the pole post 20 (hereinafter referred to as the lower surface for ease of description) is H1, satisfying 20%≤H1 / H≤50%. When the sealing element 40 achieves sealing, it is compressed to seal the gap between the connecting parts. In this embodiment, the interference fit between the first annular sealing part 41 and the lower surface of the top cover body 10 enables the sealing of the lower region of the sealing gap by the first annular sealing part 41, and by limiting the compression amount, the sealing element 40 can balance sealing performance and service life.

[0051] Specifically, the sealing element 40 is disposed in the receiving groove 21 of the pole post 20 and is located at the bottom of the receiving groove 21. The lower surface of the entire sealing element 40 is in contact with the bottom surface of the receiving groove 21, and the stepped surface of the sealing element 40 is in contact with the lower surface of the top cover body 10. The remaining part of the stepped surface is located in the installation gap, so that after the pole post 20 is flanged and formed, a part of the bottom edge of the mounting hole 11 is located below the stepped surface, thereby achieving an interference fit with the first annular sealing part 41.

[0052] If the value of H1 / H is too small, the sealing effect will be poor due to the small interference fit. If the interference fit exceeds the upper limit, the seal 40 will be over-compressed, its elastic deformation ability will be weakened, and its service life will be reduced. Of course, the value range of the axial thickness H of the first annular sealing part 41 in the thickness direction can be adjusted as needed. For example, the value range of H is 1mm-2.5mm.

[0053] In specific implementation methods, the value of H1 / H is 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0054] In conjunction with the above embodiments, such as Figure 3 , Figure 6 As shown, the radial overlap between the outer axial end face of the first annular sealing part 41 and the surface of the top cover body 10 near the inner end face of the pole post 20 (hereinafter referred to as the lower surface for ease of description) is 0.5mm≤L1≤1mm. By limiting the interference of the radial portion, it has a better sealing effect, while optimizing the overall structural layout and avoiding excessive redundancy.

[0055] Specifically, by limiting the radial overlap between the upper end face of the first annular sealing portion 41 and the lower surface of the top cover body 10 to greater than or equal to 0.5 mm, sufficient interference fit is provided to effectively prevent electrolyte leakage. However, excessive overlap can lead to assembly difficulties, excessive stress on the sealing ring, or permanent deformation failure. This embodiment, by limiting the overlap to between 0.5 mm and 1 mm, achieves an optimal balance between good sealing reliability and service life.

[0056] In specific embodiments, the radial overlap L1 is 0.5mm, 0.7mm, 0.9mm or 1mm.

[0057] In some embodiments, such as Figure 4 , Figure 7 As shown, the axial thickness of the second annular sealing portion 42 is K, and the axial compression of the contact portion between the axial outer end face of the second annular sealing portion 42 and the axial inner end face of the rigid support ring 50 is M, satisfying 15%≤M / K≤45%. When the sealing element 40 achieves sealing, it is compressed to seal the gap between the connecting components. The main body of the rigid support element is located above the second annular sealing portion 42, and it needs to be stably assembled through the second annular sealing portion 42. In this embodiment, the interference fit between the second annular sealing portion 42 and the rigid support ring 50 achieves both sealing performance between the rigid support ring 50 and the sealing element 40, as well as the stability of the connection between the rigid support ring 50 and itself. Furthermore, by limiting the compression amount, the sealing element 40 can balance sealing performance and service life.

[0058] Specifically, the seal 40 is disposed in the receiving groove 21 of the pole post 20 and is located on the axial inner side of the receiving groove 21. The axial inner end face of the seal 40 is in contact with the axial inner end face of the receiving groove 21, while the axial outer end face of the seal 40 is located in the sealing gap. The outer peripheral surface of the second annular sealing part 42 is in direct contact with the radial inner peripheral surface of the rigid support ring 50. After the pole post 20 is flanged and formed, the rigid support ring 50 applies a force to the seal 40 to achieve compression, thereby forming an interference fit.

[0059] If the value of M / K is too small, the sealing effect will be poor due to the small interference fit. If the interference fit exceeds the upper limit, the seal 40 will be over-compressed, its elastic deformation ability will be weakened, and its service life will be reduced. Of course, the value range of the axial thickness K of the first annular seal 41 in the thickness direction can be adjusted as needed. For example, the value range of K is 1.5mm-4mm.

[0060] In specific embodiments, the value of M / K is 15%, 20%, 35%, 30%, 35%, 40%, or 45%. It can be understood that the axial dimension of the second annular sealing part 42 is smaller than that of the first annular sealing part 41, which makes the value of M / K smaller than the value of H1 / H of the first annular sealing part 41.

[0061] In conjunction with the above embodiments, such as Figure 4 , Figure 7 As shown, the radial overlap between the radial outer circumferential surface of the second annular sealing part 42 and the radial inner circumferential wall surface of the rigid support ring 50 is 0.2mm ≤ L2 ≤ 0.6mm. By limiting the interference of the radial portion, it achieves a better sealing effect while optimizing the overall structural layout and avoiding excessive redundancy.

[0062] Specifically, by limiting the radial overlap between the axial outer end face of the second annular sealing portion 42 and the radial inner circumferential wall of the rigid support ring 50 to greater than or equal to 0.2 mm, sufficient interference fit is provided to effectively prevent electrolyte leakage. However, excessive interference fit can lead to assembly difficulties, excessive stress on the sealing ring, or permanent deformation failure. This embodiment, by limiting the overlap to between 0.2 mm and 0.6 mm, achieves an optimal balance between good sealing reliability and service life.

[0063] In specific embodiments, the radial overlap L2 is 0.2mm, 0.4mm, 0.5mm, or 0.6mm. It is understood that the radial dimension of the second annular sealing portion 42 is smaller than that of the first annular sealing portion 41, which makes the radial overlap L2 of the second annular sealing portion 42 less than the radial overlap L1 of the first annular sealing portion 41.

[0064] In some embodiments, a limiting protrusion is provided on the surface of the top cover body 10 near the inner end face of the pole post 20 (i.e., the lower surface of the top cover body 10), and a corresponding matching limiting part is provided on the plastic part 30. The matching limiting part and the limiting protrusion cooperate to limit the connection. During the assembly process, it is necessary to maintain the stability of the second plastic part 32 to improve the quality of the overall structural connection. In this embodiment, by limiting the limiting protrusion, it can be made more stable during connection, thereby improving the quality of the top cover structural connection.

[0065] Specifically, the top cover body 10 has an annular limiting protrusion on one side near the edge of the mounting hole 11, and a corresponding mating groove is provided on the second plastic 32. The limiting protrusion is located in the mating groove, thereby enabling the pre-positioning of the second plastic 32, which is conducive to the accurate mating of the second plastic 32 and improves the overall connection quality of the top cover structure.

[0066] This utility model also provides a battery cell, comprising: a housing and a top cover structure as provided in any of the above; the housing has a receiving space for accommodating an electrode assembly; the top cover structure is disposed on the top of the housing.

[0067] The battery cell provided in this example has the top cover structure of any of the aforementioned embodiments. Therefore, the battery cell in this example has the characteristic effects of each of the aforementioned top cover structures. To avoid redundancy in the effect description, it will not be repeated here.

[0068] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment, through the setting of the rigid support ring 50, enables effective support, thereby preventing the pole post 20 from sinking, ensuring the sealing effect of the seal 40, and improving the production quality of the battery cell. Furthermore, by limiting the interference fit between the seal 40 and the rigid support ring 50, the sealing performance of the seal 40 is improved while extending its service life.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A top cover structure, characterized in that, include: The top cover body has mounting holes, and plastic parts are fixedly installed on two opposite surfaces in the thickness direction of the top cover body; The electrode post has an annular receiving groove on its radially outer peripheral surface and passes through the mounting hole. The radially inner peripheral surface of the mounting hole, the radially inner sidewall of the plastic part surrounding the edge of the mounting hole, and the receiving groove of the electrode post together define an annular sealing gap. A sealing element, which is sleeved on the outside of the pole post and located on the first side of the sealing gap axially close to the top cover body; A rigid support ring is disposed within the sealing gap and axially close to the second side of the top cover body. The radial inner circumferential surface of the rigid support ring is interference-fitted with the radial outer circumferential surface of the seal. The radial outer circumferential surface of the rigid support ring abuts against the radial inner circumferential surface of the mounting hole, and / or the radial outer circumferential surface of the rigid support ring abuts against the surface of the top cover body near the axial outer end face of the pole post. The axial outer end face of the rigid support ring abuts against the axial outer end face of the receiving groove, and the axial inner end face of the rigid support ring is interference-fitted with the axial outer end face of the seal.

2. The top cover structure according to claim 1, characterized in that, The rigid support ring has a cylindrical radial outer circumferential surface.

3. The top cover structure according to claim 1, characterized in that, The rigid support ring has a stepped radial outer circumferential surface.

4. The top cover structure according to claim 1, characterized in that, The sealing element includes a first annular sealing portion and a second annular sealing portion formed sequentially along its axial direction. The radial width of the first annular sealing portion is greater than the radial width of the second annular sealing portion, so that the sealing element forms a stepped structure.

5. The top cover structure according to claim 4, characterized in that, The first annular sealing part is interference-fitted with the surface of the top cover body near the inner end face of the pole post; and the axial thickness of the first annular sealing part is H in its axial direction, and the axial compression of the contact portion between the outer end face of the first annular sealing part and the surface of the top cover body near the inner end face of the pole post is H1, satisfying 20%≤H1 / H≤50%.

6. The top cover structure according to claim 5, characterized in that, The radial overlap between the outer end face of the first annular seal and the surface of the top cover body near the inner end face of the pole post is 0.5mm≤L1≤1mm.

7. The top cover structure according to claim 4, characterized in that, The axial thickness of the second annular seal is K, and the axial compression of the contact portion between the axial outer end face of the second annular seal and the axial inner end face of the rigid support ring is M, satisfying 15%≤M / K≤45%.

8. The top cover structure according to claim 4, characterized in that, The radial overlap between the radial outer circumferential surface of the second annular sealing part and the radial inner circumferential wall surface of the rigid support ring is 0.2mm≤L2≤0.6mm.

9. The top cover structure according to claim 1, characterized in that, The top cover body has a limiting protrusion on the side near the inner end face of the pole post, and a corresponding matching limiting part is provided on the plastic part. The matching limiting part and the limiting protrusion cooperate to limit the movement.

10. A battery cell, characterized in that, include: case And the top cover structure according to any one of claims 1-9; the housing has a receiving space for accommodating the electrode assembly; The top cover structure is located on the top of the housing.

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