A top cover assembly, a secondary battery, and a battery module

Abstract

The application discloses a top cover assembly, a secondary battery and a battery module. The top cover assembly comprises a top cover, a lower plastic and a sealing nail. The top cover is provided with a first sub-liquid injection hole. The lower plastic is arranged on one side of the top cover. The lower plastic is provided with a second sub-liquid injection hole. The second sub-liquid injection hole is communicated with the first sub-liquid injection hole. The lower plastic is provided with a clamping piece on the side away from the top cover. The sealing nail comprises a sealing section and a clamping section which are connected in sequence. The sealing section is inserted into the first sub-liquid injection hole and the second sub-liquid injection hole to close the first sub-liquid injection hole and the second sub-liquid injection hole. The clamping section extends out of the second sub-liquid injection hole and is clamped with the clamping piece. The top cover assembly can effectively prevent the sealing nail from loosening and shifting, improve the sealing reliability of the sealing nail, reduce the risk of liquid leakage of the battery and improve the safety of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a top cover assembly, a secondary battery, and a battery module. Background Technology

[0002] In existing technology, a battery includes a casing, a top cover assembly, and bare cells. The bare cells are housed within the casing, and the top cover assembly is used to seal the opening of the casing. The top cover assembly mainly includes a top cover and a lower plastic layer. The top cover and lower plastic layer typically have injection holes for injecting electrolyte into the casing. After injection, the battery needs to undergo formation, and then the injection holes are sealed.

[0003] In related technologies, sealing the electrolyte filling hole typically involves first inserting a sealing pin into the filling hole on the top cover, then covering the sealing pin with an aluminum sheet, and finally welding the aluminum sheet to the top cover for sealing. However, when the battery is subjected to vibration or impact, the bare cell may shake and impact the sealing pin, causing the aluminum sheet to break or deform. This can easily lead to the sealing pin becoming loose or displaced, resulting in a risk of electrolyte leakage through the filling hole and reducing battery safety. Summary of the Invention

[0004] This application discloses a top cover assembly, a secondary battery, and a battery module, which can effectively prevent the sealing pins from loosening or shifting, improve the sealing reliability of the sealing pins, reduce the risk of battery leakage, and improve battery safety.

[0005] To achieve the above objectives, in a first aspect, this application discloses a top cover assembly, comprising:

[0006] Top cover, wherein a first sub-injection hole is provided on the top cover;

[0007] The lower plastic is disposed on one side of the top cover. The lower plastic is provided with a second sub-injection hole, which is connected to the first sub-injection hole. A snap-fit ​​component is provided on the side of the lower plastic away from the top cover.

[0008] The sealing pin includes a sealing section and a snap-fit ​​section connected in sequence. The sealing section is inserted into the first sub-injection hole and the second sub-injection hole to seal the first sub-injection hole and the second sub-injection hole. The snap-fit ​​section extends out of the second sub-injection hole and snaps into the snap-fit ​​member.

[0009] In this embodiment, the sealing pin includes a sealing section and a snap-fit ​​section connected in sequence. The sealing section is inserted into the first sub-injection hole and the second sub-injection hole to seal the first and second sub-injection holes. This allows the sealing pin to seal both the first and second sub-injection holes, preventing electrolyte leakage from the battery with the top cover assembly through the first and second sub-injection holes. Compared to the sealing section only being inserted into the first sub-injection hole, this method provides better sealing for both the first and second sub-injection holes.

[0010] The snap-fit ​​section of the sealing pin extends out of the second sub-injection hole and snaps into the snap-fit ​​component. This effectively prevents the sealing pin from sliding out of the second sub-injection hole when the battery with the top cover assembly is subjected to vibration, impact, or other factors that cause the bare cells inside the battery to shake and impact the sealing pin. This avoids the sealing pin from becoming loose or shifting due to the impact of the bare cells, improves the sealing reliability of the sealing pin, reduces the risk of battery leakage, and improves battery safety.

[0011] The snap-fit ​​component is located on the side of the lower plastic part away from the top cover. Compared to a snap-fit ​​component located on the top cover, the snap-fit ​​segment extends out of the second sub-injection hole and snaps into the snap-fit ​​component. When the bare battery cell impacts the sealing nail, the snap-fit ​​segment and the snap-fit ​​component are first subjected to the impact force of the bare battery cell, which can offset part of the impact force. This reduces the impact force transmitted to the aluminum sheet located outside the sealing nail and welded to the top cover. This makes the aluminum sheet less likely to break or deform due to the impact of the bare battery cell on the sealing nail, thus effectively preventing the sealing nail from loosening or shifting when impacted by the bare battery cell, and further improving the sealing reliability of the sealing nail.

[0012] In one possible implementation of the first aspect, a slot is provided on the outer peripheral wall of the snap-fit ​​segment, and the snap-fit ​​member snaps into the slot.

[0013] Therefore, during the process of inserting the sealing pin into the first and second sub-injection holes, the snap-fit ​​segment extends out of the second sub-injection hole and moves to the position of the snap-fit ​​component, thus snapping into the snap-fit ​​component, making the snap-fit ​​segment and the snap-fit ​​component simple and convenient.

[0014] In one possible implementation of the first aspect, the snap-fit ​​segment is a prismatic snap-fit ​​segment, the outer diameter of which is the same as the outer diameter of which is the sealing segment, and the prismatic snap-fit ​​segment includes a plurality of protruding ridges spaced circumferentially along the second sub-injection hole, and the snap-fit ​​groove is disposed on the protruding ridges.

[0015] Therefore, there can be multiple card slots, and the length of the card slots can be relatively short, which facilitates the connection between the card slots and the card connectors. At the same time, it also makes the manufacturing of the card slots simpler and easier to implement.

[0016] In one possible implementation of the first aspect, the snap-fit ​​member includes a snap ring having an insertion hole with a diameter smaller than the circumcircle diameter of the sealing section, the snap-fit ​​section passing through the insertion hole, and the snap ring engaging with the snap groove.

[0017] The diameter of the insertion hole on the retaining ring is smaller than the outer diameter of the sealing section. The retaining section is inserted into the insertion hole, and the retaining ring engages with the retaining groove. This effectively prevents the sealing section from sliding through the insertion hole onto the bare cell and avoids the sealing pin from slipping onto the bare cell. This prevents electrolyte from leaking out through the first and second sub-injection holes due to the sealing pin slipping onto the bare cell.

[0018] In one possible implementation of the first aspect, the snap-fit ​​component further includes a first connecting portion, one end of which is connected to the side of the lower plastic away from the top cover, and the other end is connected to the outer peripheral edge of the snap ring. The first connecting portion is provided with a first through hole, which is coaxially arranged with the second sub-injection hole, and the diameter of the first through hole is greater than or equal to the diameter of the second sub-injection hole.

[0019] One end of the first connecting part is connected to the side of the lower plastic away from the top cover, and the other end is connected to the outer peripheral edge of the retaining ring. When the bare battery cell hits the sealing nail, the first connecting part can also withstand part of the impact force and can offset part of the impact force through deformation, so that the retaining part can offset more impact force. This makes the impact force transmitted to the aluminum sheet located outside the sealing nail and welded to the top cover smaller, thereby preventing the sealing nail from loosening or shifting when hit by the bare battery cell, and further improving the sealing reliability of the sealing nail.

[0020] In one possible implementation of the first aspect, the snap-fit ​​component further includes a plurality of fan rings, which are spaced apart around the central axis of the second sub-injection hole and correspond one-to-one with the slots on the plurality of protrusions. The plurality of fan rings together form an insertion hole, the diameter of which is smaller than the outer diameter of the sealing section. The snap-fit ​​section passes through the insertion hole, and the fan rings snap into the slots.

[0021] Therefore, by having multiple fan rings spaced around the central axis of the second sub-injection hole, a first notch can be formed between two adjacent fan rings. Furthermore, the multiple fan rings are arranged one-to-one with multiple protrusions, so that the first notch between adjacent fan rings can correspond one-to-one with multiple protrusions. During the process of inserting the sealing pin into the first and second sub-injection holes, multiple slots can be inserted into multiple first notches. When the multiple slots move to the positions of the multiple first notches, the sealing pin can be rotated to make the fan rings lock into the slots, making the installation of the sealing pin simple and convenient.

[0022] In one possible implementation of the first aspect, the snap-fit ​​component further includes a plurality of second connecting portions, each of which is correspondingly provided with a plurality of fan rings. One end of each second connecting portion is connected to the side of the lower plastic away from the top cover, and the other end is connected to the outer edge of the corresponding fan ring. The plurality of second connecting portions together form a first through hole, which is coaxially provided with a second sub-injection hole, and the diameter of the first through hole is greater than or equal to the diameter of the second sub-injection hole.

[0023] Therefore, by setting multiple second connecting parts corresponding to multiple fan rings one by one, a second gap can be formed between two adjacent second connecting parts, and the second gap is connected to the first gap, so that the electrolyte can flow in multiple directions through multiple second gaps, so that multiple positions of the bare cell can be wetted at the same time, thereby improving the wetting efficiency of the electrolyte.

[0024] In one possible implementation of the first aspect, the sealing section is interference-fitted with the first sub-injection hole and the second sub-injection hole.

[0025] This results in greater frictional resistance between the sealing section and the wall of the first sub-injection hole, and between the sealing section and the wall of the second sub-injection hole. A larger force needs to be applied to the sealing section to make it move relative to the first and second sub-injection holes, thus improving the sealing performance between the sealing section and the first and second sub-injection holes and further enhancing the sealing reliability of the sealing pin.

[0026] In one possible implementation of the first aspect, a first guide surface is provided at the end of the snap-fit ​​segment away from the sealing segment, and a second guide surface is provided on the side of the snap-fit ​​member facing the second sub-injection hole, wherein the first guide surface abuts against the second guide surface.

[0027] Therefore, during the process of inserting the sealing pin into the first sub-injection hole and the second sub-injection hole, the sealing pin is subjected to a force moving towards the snap-fit ​​component through the contact between the first guide surface and the second guide surface, so that the snap-fit ​​segment can be snapped into the snap-fit ​​component more smoothly, which facilitates the installation of the sealing pin.

[0028] In one possible implementation of the first aspect, the first guide surface is circumferentially disposed on the outer peripheral wall of the snap-fit ​​section along the second sub-injection hole, and the second guide surface is circumferentially disposed on the side of the snap-fit ​​member facing the second sub-injection hole along the second sub-injection hole.

[0029] This allows the outer wall of the snap-fit ​​section to slide smoothly toward the snap-fit ​​component through the cooperation of the first guide surface and the second guide surface, and snap into the snap-fit ​​component, making the installation of the sealing nail smoother and more convenient.

[0030] In one possible implementation of the first aspect, the top cover assembly further includes a buffer disposed on the side of the snap-fit ​​member opposite to the lower plastic, the buffer being used to cushion the impact of the bare battery cell on the sealing pin.

[0031] By placing the buffer on the side of the snap-fit ​​component away from the lower plastic, the impact of the bare battery cell on the sealing pin is buffered. This allows the buffer to cooperate with the snap-fit ​​component to further reduce the impact force generated when the bare battery cell impacts the sealing pin, further preventing the sealing pin from loosening or shifting due to the impact of the bare battery cell, thus making the sealing reliability of the sealing pin higher.

[0032] In one possible implementation of the first aspect, the buffer includes a third connecting portion, which is an elastic connecting portion, and is disposed on the side of the snap-fit ​​member opposite to the lower plastic.

[0033] Therefore, by setting the third connection part as an elastic connection part, the third connection part can rebound to its original state after being impacted by the bare battery cell, so that the third connection part can withstand more impacts from the bare battery cell, making the buffering effect of the third connection part better and further improving the sealing reliability of the sealing nail.

[0034] In one possible implementation of the first aspect, the outer circle diameter of the third connecting portion is larger than the outer circle diameter of the snap-fit ​​member.

[0035] Therefore, when the bare battery cell impacts the sealing nail from the side, the third connection part can first contact the bare battery cell, effectively buffering the impact of the bare battery cell on the sealing nail from the side, further preventing the sealing nail from loosening or shifting due to the impact of the bare battery cell, thus making the sealing reliability of the sealing nail higher.

[0036] In one possible implementation of the first aspect, the buffer further includes a baffle disposed on the side of the third connection portion opposite to the snap-fit ​​member and along the axial direction of the second sub-injection hole, wherein the projection of the snap-fit ​​segment on the baffle is at least partially located on the baffle.

[0037] Therefore, when the bare battery cell hits the sealing nail, the bare battery cell can first come into contact with the baffle, preventing the bare battery cell from directly hitting the locking section of the sealing nail. The baffle can also first withstand the impact force applied by the bare battery cell and can offset part of the impact force through deformation, so that together with the third connection part, it can withstand a larger impact force, further improving the buffering effect of the buffer.

[0038] Secondly, this application discloses a secondary battery, comprising:

[0039] A housing having a receiving cavity and an opening that communicates with the receiving cavity;

[0040] A bare battery cell, wherein the bare battery cell is housed in the receiving cavity;

[0041] The top cover assembly according to any one of the first aspects is disposed at the opening to close the opening.

[0042] In this embodiment, the bare battery cell is housed in the receiving cavity of the casing, and the top cover assembly is disposed at the opening to close the opening, so that the bare battery cell can be located in the closed receiving cavity. The top cover assembly is any of the top cover assemblies in Embodiment 1 above. Therefore, when the secondary battery is subjected to vibration, impact, etc., causing the bare battery cell to shake in the receiving cavity and impact the sealing pin in the top cover assembly, the sealing pin can be limited by the snap-fit ​​of the snap-fit ​​member and the snap-fit ​​section, preventing the sealing pin from becoming loose or displaced, improving the sealing reliability of the sealing pin, thereby reducing the probability of battery leakage due to the bare battery cell impacting the sealing pin, and thus improving the safety of the battery.

[0043] Thirdly, this application also discloses a battery module, including the secondary battery described in the second aspect.

[0044] In this embodiment, the secondary battery in the battery module is any of the secondary batteries described in the second aspect above. Therefore, the secondary battery in this embodiment has the technical effects of the secondary battery described in the second aspect above. Furthermore, the top cover assembly in the secondary battery in the second aspect is any of the top cover assemblies described in the first aspect above. Therefore, the top cover assembly in this embodiment has the technical effects of the top cover assembly described in the first aspect above.

[0045] Compared with the prior art, the beneficial effects of this application are as follows:

[0046] In this application, the sealing pin includes a sealing section and a snap-fit ​​section connected in sequence. The sealing section is inserted into the first sub-injection hole and the second sub-injection hole to seal the first and second sub-injection holes, so that the sealing pin can seal both the first and second sub-injection holes to prevent the electrolyte in the battery with the top cover assembly from leaking through the first and second sub-injection holes. Compared with the sealing section being inserted only into the first sub-injection hole, the sealing pin can have better sealing performance for both the first and second sub-injection holes.

[0047] The snap-fit ​​section of the sealing pin extends out of the second sub-injection hole and snaps into the snap-fit ​​component. This effectively prevents the sealing pin from sliding out of the second sub-injection hole when the battery with the top cover assembly is subjected to vibration, impact, or other factors that cause the bare cells inside the battery to shake and impact the sealing pin. This avoids the sealing pin from becoming loose or shifting due to the impact of the bare cells, improves the sealing reliability of the sealing pin, reduces the risk of battery leakage, and improves battery safety.

[0048] The snap-fit ​​component is located on the side of the lower plastic part away from the top cover. Compared to a snap-fit ​​component located on the top cover, the snap-fit ​​segment extends out of the second sub-injection hole and snaps into the snap-fit ​​component. When the bare battery cell impacts the sealing nail, the snap-fit ​​segment and the snap-fit ​​component are first subjected to the impact force of the bare battery cell, which can offset part of the impact force. This reduces the impact force transmitted to the aluminum sheet located outside the sealing nail and welded to the top cover. This makes the aluminum sheet less likely to break or deform due to the impact of the bare battery cell on the sealing nail, thus effectively preventing the sealing nail from loosening or shifting when impacted by the bare battery cell, and further improving the sealing reliability of the sealing nail. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a perspective view of a top cover assembly provided in an embodiment of this application;

[0051] Figure 2 yes Figure 1 A three-dimensional view of the top cover assembly from another angle;

[0052] Figure 3 yes Figure 1 Enlarged view of position A in the middle;

[0053] Figure 4 This is a cross-sectional view of a top cover assembly provided in an embodiment of this application;

[0054] Figure 5 yes Figure 4 Enlarged view of position B in the image;

[0055] Figure 6 This is a perspective view of a sealing nail provided in an embodiment of this application;

[0056] Figure 7 This is a perspective view of a lower plastic body provided with a snap-fit ​​component according to an embodiment of this application;

[0057] Figure 8 yes Figure 7 Enlarged view of position C in the first type;

[0058] Figure 9 yes Figure 7 Enlarged view of the second type of position C;

[0059] Figure 10 yes Figure 7 Enlarged view of the third type of position C;

[0060] Figure 11 This is a cross-sectional view of a combination of a snap-fit ​​connector and a buffer provided in an embodiment of this application;

[0061] Figure 12 This is a perspective view of a secondary battery provided in an embodiment of this application;

[0062] Figure 13 This is a perspective view of a battery module provided in an embodiment of this application.

[0063] Explanation of reference numerals in the attached figures:

[0064] 1-Top cover; 11-First sub-injection hole; 2-Lower plastic; 21-Second sub-injection hole; 3a-Snap-fit ​​component; 31a-Snap ring; 31b-Fan ring; 311-Insert hole; 312-First notch; 313-Second guide surface; 32a-First connecting part; 32b-Second connecting part; 321-First through hole; 322-Second notch; 3b-Buffer component; 33-Third connecting part; 331-Second through hole; 34-Baffle; 4-Sealing pin; 41-Sealing section; 42-Snap-fit ​​section; 421-Protruding ridge; 4212-Slot; 422-First guide surface;

[0065] 10 - Top cover assembly; 20 - Bare battery cell; 30 - Housing;

[0066] 100 - Battery module; 110 - Secondary battery. Detailed Implementation

[0067] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0068] In this application, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; 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, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0069] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, elements, or components (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0070] This application discloses a top cover assembly, a secondary battery, and a battery module, which can effectively prevent the sealing pins from loosening or shifting, improve the sealing reliability of the sealing pins, reduce the risk of battery leakage, and improve battery safety.

[0071] The technical solution of this application will be further described below with reference to specific embodiments and accompanying drawings.

[0072] Example 1

[0073] Figure 1 The image shown is a perspective view of a top cover assembly provided in an embodiment of this application. Figure 2 for Figure 1 A three-dimensional view of the top cover assembly from another angle. Figure 3 for Figure 1 Enlarged view of position A in the middle. Figure 4 This is a cross-sectional view of a top cover assembly provided in an embodiment of this application. Figure 5 for Figure 4 Please refer to the enlarged image at position B in the image. Figures 1-5 As shown.

[0074] This embodiment provides a top cover assembly, including a top cover 1, a lower plastic part 2, and a sealing pin 4. The top cover 1 has a first sub-injection hole 11. The lower plastic part 2 is disposed on one side of the top cover 1 and has a second sub-injection hole 21, which communicates with the first sub-injection hole 11. A snap-fit ​​member 3a is provided on the side of the lower plastic part 2 facing away from the top cover 1. The sealing pin 4 includes a sealing section 41 and a snap-fit ​​section 42 connected in sequence. The sealing section 41 is inserted into the first sub-injection hole 11 and the second sub-injection hole 21 to seal them. The snap-fit ​​section 42 extends out of the second sub-injection hole 21 and snaps into the snap-fit ​​member 3a.

[0075] In this embodiment, a second sub-injection hole 21 is provided on the lower plastic 2. The second sub-injection hole 21 communicates with the first sub-injection hole 11, so that the first sub-injection hole 11 and the second sub-injection hole 21 together form an injection hole for electrolyte injection. The sealing pin 4 includes a sealing section 41 and a snap-fit ​​section 42 connected in sequence. The sealing section 41 is inserted into the first sub-injection hole 11 and the second sub-injection hole 21 to seal the first sub-injection hole 11 and the second sub-injection hole 21. This allows the sealing pin 4 to seal both the first sub-injection hole 11 and the second sub-injection hole 21, preventing electrolyte leakage from the battery with the top cover assembly 10 through the first sub-injection hole 11 and the second sub-injection hole 21. Compared to the sealing section 41 only being inserted into the first sub-injection hole 11, the sealing pin 4 provides better sealing performance for both the first sub-injection hole 11 and the second sub-injection hole 21.

[0076] When sealing the electrolyte injection holes, the sealing pin 4 is first inserted into the first sub-injection hole 11 and the second sub-injection hole 21. Then, an aluminum sheet is placed over the end of the sealing pin 4 near the top cover 1, and finally, the aluminum sheet is welded to the top cover 1 using laser welding. However, when the battery is subjected to vibration or impact, the bare cells inside the battery are prone to shaking and impacting the sealing pin 4, causing the aluminum sheet to break or deform, resulting in the sealing pin 4 becoming loose or displaced, which in turn leads to the risk of electrolyte leakage.

[0077] Based on this, the snap-fit ​​section 42 of the sealing pin 4 extends out of the second sub-injection hole 21 and snaps into the snap-fit ​​member 3a. When the battery with the top cover assembly 10 is subjected to vibration, impact, etc., causing the bare cells inside the battery to shake and impact the sealing pin 4, it can effectively prevent the sealing pin 4 from sliding out of the second sub-injection hole 21. This can avoid the sealing pin 4 from becoming loose or displaced due to the impact of the bare cells, improve the sealing reliability of the sealing pin 4, reduce the risk of battery leakage, and improve the safety of the battery.

[0078] The snap-fit ​​component 3a is located on the side of the lower plastic 2 away from the top cover 1. Compared to the snap-fit ​​component 3a being located on the top cover 1, the thickness of the top cover 1 can be thinner. Furthermore, the snap-fit ​​segment 42 extends out of the second sub-injection hole 21 and snaps into the snap-fit ​​component 3a. When the bare battery cell impacts the sealing nail 4, the snap-fit ​​segment 42 and the snap-fit ​​component 3a are first subjected to the impact force of the bare battery cell, which can offset part of the impact force. This reduces the impact force transmitted to the aluminum sheet located outside the sealing nail 4 and welded to the top cover 1. This makes it less likely for the aluminum sheet to break or deform due to the impact of the bare battery cell on the sealing nail 4. This effectively prevents the sealing nail 4 from loosening or shifting when impacted by the bare battery cell, further improving the sealing reliability of the sealing nail 4.

[0079] The lower plastic 2 is disposed on one side of the top cover 1. The lower plastic 2 can be disposed on the side of the top cover 1 facing the bare battery cell, which can effectively prevent the bare battery cell from directly contacting the top cover 1 and causing the top cover 1 to become charged, thus improving the safety of the battery.

[0080] The sealing section 41 is inserted into the first sub-injection hole 11 and the second sub-injection hole 21. The sealing section 41 and the first sub-injection hole 11 and the second sub-injection hole 21 can be an interference fit.

[0081] This results in greater frictional resistance between the sealing section 41 and the wall of the first sub-injection hole 11, and between the sealing section 41 and the wall of the second sub-injection hole 21. A greater force needs to be applied to the sealing section 41 to move it relative to the first sub-injection hole 11 and the second sub-injection hole 21, thus improving the sealing performance between the sealing section 41 and the first sub-injection hole 11, and between the sealing section 41 and the second sub-injection hole 21, further enhancing the sealing reliability of the sealing nail 4.

[0082] The sealing section 41 can have various shapes, such as cylindrical, prismatic, frustum, elliptical cylindrical, etc., and is not limited here. It can be set according to the shape of the first sub-injection hole 11 and the second sub-injection hole 21.

[0083] The aforementioned snap-fit ​​segment 42 and snap-fit ​​member 3a can be snapped together in various ways. In one possible implementation, a snap-fit ​​protrusion can be provided on the outer peripheral wall of the snap-fit ​​segment 42, and the snap-fit ​​member 3a can include a snap-fit ​​block connected to the lower plastic 2. The snap-fit ​​protrusion can snap onto the side of the snap-fit ​​block away from the lower plastic 2, so that when the sealing nail 4 is inserted into the first sub-injection hole 11 and the second sub-injection hole 21, and the snap-fit ​​segment 42 extends out of the second sub-injection hole 21, the snap-fit ​​protrusion can be located on the side of the snap-fit ​​block away from the lower plastic 2 and abut against the snap-fit ​​block to prevent the sealing nail 4 from moving in the direction of sliding out of the second sub-injection hole 21. The structure is simple and easy to implement.

[0084] Figure 6 The image shown is a perspective view of a sealing nail provided in an embodiment of this application. Please refer to... Figure 5 and Figure 6 As shown.

[0085] In another possible implementation, a slot 4212 is provided on the outer peripheral wall of the snap-fit ​​section 42, and the snap-fit ​​member 3a is snapped into the slot 4212.

[0086] Therefore, during the process of inserting the sealing nail 4 into the first sub-injection hole 11 and the second sub-injection hole 21, the snap-fit ​​section 42 extends out of the second sub-injection hole 21 and moves to the position of the snap-fit ​​member 3a, so that it can snap-fit ​​with the snap-fit ​​member 3a, making the snap-fit ​​between the snap-fit ​​section 42 and the snap-fit ​​member 3a simple and convenient.

[0087] The number of slots 4212 can be one, two, or more, and is not limited here. When there are two or more slots 4212, the engagement between the snap-fit ​​segment 42 and the snap-fit ​​member 3a can be more secure and stable.

[0088] In addition, the snap-fit ​​component 3a can be implemented in various ways. For example, the snap-fit ​​component 3a can be a snap-fit ​​protrusion that snaps into the snap-fit ​​groove 4212; or the snap-fit ​​component 3a can be a snap-fit ​​ring with the snap-fit ​​segment 42 inserted into it and the snap-fit ​​ring snapping into the snap-fit ​​groove 4212; or the snap-fit ​​component 3a can be a snap-fit ​​block that snaps into the snap-fit ​​groove 4212. There is no limitation on this.

[0089] Of course, the snap-fit ​​segment 42 and the snap-fit ​​component 3a can be implemented in other ways, which are not limited here. The following is a detailed explanation using the example of a snap-fit ​​segment 42 having a slot 4212 on its outer peripheral wall.

[0090] Optionally, such as Figure 6 As shown, the snap-fit ​​section 42 is a prismatic snap-fit ​​section. The outer diameter of the prismatic snap-fit ​​section is the same as the outer diameter of the sealing section 41. The prismatic snap-fit ​​section includes a plurality of protruding ridges 421 arranged circumferentially along the second sub-injection hole 21, and the snap-fit ​​groove 4212 is provided on the protruding ridges 421.

[0091] Therefore, the number of slots 4212 can be multiple, so that the snap-fit ​​segment 42 can snap into the snap-fit ​​member 3a through multiple slots 4212, making the snap-fit ​​between the snap-fit ​​segment 42 and the snap-fit ​​member 3a more stable. Furthermore, by setting the slots 4212 on the protrusion 421, the length of the slots 4212 can be shorter, facilitating the snap-fit ​​between the slots 4212 and the snap-fit ​​member 3a. At the same time, it also simplifies the manufacturing of the slots 4212 and makes them easier to implement.

[0092] The prism-shaped snap-fit ​​segment can be implemented in various ways. For example, the cross-sectional shape of the prism-shaped snap-fit ​​segment can be a triangle formed by three straight lines and three arcs connected at intervals, with the three arcs located at the three vertices of the triangle. In this case, the protruding ridge 421 can be formed by the arcs moving along the axial direction of the sealing segment 41. Alternatively, the cross-sectional shape of the prism-shaped snap-fit ​​segment can be a circle with multiple semicircles surrounding it. In this case, the protruding ridge 421 can be formed by the arcs of the semicircles moving along the axial direction of the sealing segment 41. Of course, the prism-shaped snap-fit ​​segment can also be implemented in other ways, which are not limited here.

[0093] Figure 7 The image shown is a perspective view of a lower plastic part provided with a snap-fit ​​component according to an embodiment of this application. Figure 8 The following is shown Figure 7 A magnified view of position C in the first type. Please refer to it. Figure 7and Figure 8 As shown.

[0094] Optionally, the snap-fit ​​component 3a includes a snap ring 31a, which has an insertion hole 311. The diameter of the insertion hole 311 is smaller than the outer diameter of the sealing section 41, and the snap-fit ​​section 42 passes through the insertion hole 311. The snap ring 31a snaps into the snap groove 4212.

[0095] It should be explained that the aforementioned snap ring 31a refers to the snap-fit ​​component 3a with a ring structure, which can be a circular ring, an elliptical ring, a square ring, etc., and is not limited here.

[0096] Therefore, since the diameter of the insertion hole 311 on the retaining ring 31a is smaller than the outer diameter of the sealing section 41, the retaining section 42 passes through the insertion hole 311, which can effectively prevent the sealing section 41 from sliding out through the insertion hole 311. Furthermore, the retaining ring 31a is engaged with the retaining groove 4212, which can further effectively prevent the sealing section 41 from sliding through the insertion hole 311 onto the bare battery cell, thus preventing the sealing nail 4 from sliding onto the bare battery cell. This can prevent the electrolyte from leaking out through the first sub-injection hole 11 and the second sub-injection hole 21 due to the sealing nail 4 sliding onto the bare battery cell, thereby further improving the sealing reliability of the sealing nail 4.

[0097] The shape of the insertion hole 311 can be various, such as any one of the following: circular, rhomboid, square, oval, etc., without limitation.

[0098] Optionally, such as Figure 7 and Figure 8 As shown, the snap-fit ​​component 3a also includes a first connecting part 32a. One end of the first connecting part 32a is connected to the side of the lower plastic 2 away from the top cover 1, and the other end is connected to the snap ring 31a. The end of the first connecting part 32a facing the lower plastic 2 is connected to the lower plastic 2. A first through hole 321 is provided on the first connecting part 32a. The first through hole 321 is coaxially arranged with the second sub-injection hole 21, and the diameter of the first through hole 321 is greater than or equal to the diameter of the second sub-injection hole 21.

[0099] Therefore, by connecting one end of the first connecting part 32a to the side of the lower plastic 2 away from the top cover 1 and the other end to the retaining ring 31a, when the bare battery cell strikes the sealing nail 4, the first connecting part 32a can also withstand part of the impact force, and can offset part of the impact force by deforming the first connecting part 32a, so that the retaining member 3a can offset more of the impact force, so that the impact force transmitted to the aluminum sheet located outside the sealing nail 4 and welded to the top cover 1 can be smaller, thereby better preventing the sealing nail 4 from loosening or shifting when struck by the bare battery cell, and further improving the sealing reliability of the sealing nail 4.

[0100] Furthermore, the diameter of the first through hole 321 is greater than or equal to the diameter of the second sub-injection hole 21, so that the sealing section 41 can also be located inside the first through hole 321, thereby enabling the sealing section 41 to fully seal the second sub-injection hole 21, further improving the sealing effect of the sealing section 41 on the second sub-injection hole 21.

[0101] The first connecting part 32a can be implemented in various ways. For example, the first connecting part 32a can be an annular column, which is simple and easy to implement; or the first connecting part 32a can be a connecting block, which is not limited here.

[0102] Figure 9 The following is shown Figure 7 A magnified view of the second type of location C. Please refer to this image. Figure 7 and Figure 9 As shown.

[0103] Optionally, the snap-fit ​​component 3a further includes a plurality of fan rings 31b, which are spaced apart around the central axis of the second sub-injection hole 21 and correspond one-to-one with the snap-fit ​​grooves 4212 on the plurality of protrusions 421. The plurality of fan rings 31b together form an insertion hole 311. The diameter of the insertion hole 311 is smaller than the outer diameter of the sealing section 41. The snap-fit ​​section 42 passes through the insertion hole 311, and the fan rings 31b snap-fit ​​with the snap-fit ​​grooves 4212.

[0104] It should be explained that the aforementioned fan ring 31b refers to a fan-shaped structure formed by two arc surfaces and two planes connecting the two ends of the two arc surfaces.

[0105] Multiple fan rings 31b are spaced around the central axis of the second sub-injection hole 21, so that a first notch 312 can be formed between two adjacent fan rings 31b. The multiple fan rings 31b are also arranged one-to-one with multiple protrusions 421, so that the first notch 312 between adjacent fan rings 31b can correspond one-to-one with multiple protrusions 421. During the process of inserting the sealing nail 4 into the first sub-injection hole 11 and the second sub-injection hole 21, multiple slots 4212 can be inserted into the multiple first notches 312. When the multiple slots 4212 move to the positions of the multiple first notches 312, the sealing nail 4 can be rotated to make the fan ring 31b lock in the slot 4212, so that the installation of the sealing nail 4 is simple and convenient.

[0106] The multiple fan rings 31b are evenly spaced around the central axis of the second sub-injection hole 21, so that the multiple first notches 312 formed are evenly arranged around the central axis of the second sub-injection hole 21. This allows the electrolyte to flow relatively evenly in all directions to the periphery of the second sub-injection hole 21 through the multiple first notches 312, enabling the electrolyte to simultaneously wet a large area of ​​the bare cell, further improving the electrolyte wetting efficiency.

[0107] Optionally, such as Figure 9 As shown, the snap-fit ​​component 3a also includes a plurality of second connecting parts 32b, which are respectively arranged in correspondence with a plurality of fan rings 31b. One end of the second connecting part 32b is connected to the side of the lower plastic 2 away from the top cover 1, and the other end is connected to the outer edge of the corresponding fan ring 31b. The plurality of second connecting parts 32b together form a first through hole 321. The first through hole 321 is coaxially arranged with the second sub-injection hole 21, and the diameter of the first through hole 321 is greater than or equal to the diameter of the second sub-injection hole 21.

[0108] Therefore, by setting multiple second connecting parts 32b corresponding one-to-one with multiple fan rings 31b, a second notch 322 can be formed between two adjacent second connecting parts 32b, and the second notch 322 is connected to the first notch 312. When electrolyte is injected into the injection hole, the electrolyte can flow through multiple second notches 322 to multiple directions of the second sub-injection hole 21, so as to simultaneously flow and wet multiple areas of the bare cell. This avoids the electrolyte being able to flow only through the first through hole 321 to the bare cell, resulting in a small wetted area of ​​the electrolyte, and further improves the wetted efficiency of the electrolyte.

[0109] The width of the first notch 312 and the width of the second notch 322 can be the same, so that the first notch 312 and the second notch 322 can be made at the same time, simplifying the manufacturing process of the first notch 312 and the second notch 322.

[0110] In some embodiments, such as Figure 5 and Figure 6 As shown, the end of the snap-fit ​​section 42 away from the sealing section 41 is provided with a first guide surface 422, and the snap-fit ​​member 3a is provided with a second guide surface 313 on the side facing the second sub-injection hole 21. The first guide surface 422 and the second guide surface 313 abut against each other.

[0111] Therefore, during the process of inserting the sealing nail 4 into the first sub-injection hole 11 and the second sub-injection hole 21, the sealing nail 4 is subjected to a force moving towards the snap-fit ​​member 3a through the contact between the first guide surface 422 and the second guide surface 313, so that the snap-fit ​​section 42 can be snapped into the snap-fit ​​member 3a more smoothly, which facilitates the installation of the sealing nail 4.

[0112] For example, when the snap fastener 3a includes a snap ring 31a and a first connecting portion 32a, the second guide surface 313 can be disposed at one end of the snap ring 31a facing the first connecting portion 32a. Specifically, the second guide surface 313 can be connected to the wall of the first through hole 321 on the snap fastener 3a and the side of the snap ring 31a facing the first connecting portion 32a. The second guide surface 313 is smoothly connected to the wall of the first through hole 321 and also smoothly connected to the side of the snap ring 31a facing the first connecting portion 32a. So that during the process of the sealing nail 4 being inserted into the first sub-injection hole 11 and the second sub-injection hole 21, the first guide surface 422 can move relatively smoothly along the first through hole 321 to the second guide surface 313 and abut against the second guide surface 313.

[0113] Optionally, the first guide surface 422 is circumferentially disposed on the outer peripheral wall of the snap-fit ​​section 42 along the second sub-injection hole 21, and the second guide surface 313 is circumferentially disposed on the side of the snap-fit ​​member 3a facing the second sub-injection hole 21 along the second sub-injection hole 21.

[0114] As a result, the outer wall of the snap-fit ​​section 42 can slide smoothly toward the snap-fit ​​member 3a through the cooperation of the first guide surface 422 and the second guide surface 313, and snap into the snap-fit ​​member 3a, making the installation of the sealing nail 4 smoother and more convenient.

[0115] Figure 10 The following is shown Figure 7 The magnified view of the third type of position C in the image. Figure 11 The image shown is a cross-sectional view of a snap-fit ​​and buffer assembly provided in an embodiment of this application. Please refer to... Figure 7 , Figure 10 and Figure 11 As shown.

[0116] In other embodiments, the top cover assembly 10 further includes a buffer 3b disposed on the side of the snap-fit ​​member 3a away from the lower plastic 2, and the buffer 3b is used to buffer the impact force of the bare battery cell on the sealing nail 4.

[0117] Therefore, by placing the buffer 3b on the side of the snap-fit ​​3a away from the lower plastic 2 to buffer the impact force of the bare cell on the sealing nail 4, the buffer 3b can cooperate with the snap-fit ​​3a to further reduce the impact force generated when the bare cell hits the sealing nail 4. This further prevents the sealing nail 4 from becoming loose or displaced due to the impact of the bare cell, making the sealing reliability of the sealing nail 4 higher. This reduces the risk of leakage due to the loosening or displacement of the sealing nail 4, thus making the battery safer.

[0118] For example, when the snap-fit ​​component 3a includes a first connecting portion 32a and a retaining ring 31a connected in sequence, and the first connecting portion 32a is connected between the lower plastic 2 and the retaining ring 31a, the buffer component 3b can be disposed on the side of the retaining ring 31a away from the lower plastic 2; alternatively, the buffer component 3b can be connected to the end of the first connecting portion 32a away from the lower plastic 2. In this case, the first connecting portion 32a can extend in the direction away from the retaining ring 31a to connect with the buffer component 3b, so that there can be a certain distance between the end of the buffer component 3b away from the lower plastic 2 and the snap-fit ​​segment 42, so that the buffer component 3b can have a better buffering effect.

[0119] Optionally, such as Figure 10 As shown, the buffer 3b includes a third connecting part 33, which is an elastic connecting part, and is disposed on the side of the snap-fit ​​member 3a away from the lower plastic 2.

[0120] Therefore, by setting the third connection part 33 as an elastic connection part, the third connection part 33 can rebound to its original state after being impacted by the bare battery cell, so that the third connection part 33 can withstand more impacts from the bare battery cell, making the buffering effect of the third connection part 33 better and further improving the sealing reliability of the sealing nail 4.

[0121] The third connecting part 33 can be a silicone third connecting part, a polyether ester third connecting part, a fluorosilicone rubber third connecting part, etc., and is not limited here.

[0122] The aforementioned third connecting part 33 can be implemented in various ways. In one possible implementation, the third connecting part 33 may include multiple buffer protrusions. The multiple buffer protrusions are arranged around the central axis of the second sub-injection hole 21 on the outer peripheral edge of the snap-fit ​​member 3a on the side opposite to the lower plastic 2. The multiple buffer protrusions extend along the axial direction of the second sub-injection hole 21. Along the axial direction of the second sub-injection hole 21, one end of the multiple buffer protrusions opposite to the lower plastic 2 protrudes out of the snap-fit ​​section 42, so that when the bare battery cell impacts and moves toward the sealing nail 4, the bare battery cell can abut against the multiple buffer protrusions first. The structure is simple and easy to implement.

[0123] In another possible implementation, the third connecting part 33 includes a tubular buffer tube. The buffer tube is disposed on the side of the snap-fit ​​member 3a away from the lower plastic 2. The cavity of the buffer tube is connected to and coaxial with the second sub-injection hole 21. Along the axial direction of the second sub-injection hole 21, the buffer tube protrudes from the snap-fit ​​section 42. The structure is simple and easy to implement. Moreover, the tubular third connecting part 33 can have high structural strength. When the bare battery cell impacts or moves against the sealing nail 4, the bare battery cell can first abut against the third connecting part 33. The third connecting part 33 can have high structural strength and can withstand a large impact force, so that when the bare battery cell shakes violently, the buffer member 3b can also have a good buffering effect.

[0124] When the snap-fit ​​component 3a includes a first connecting part 32a and a retaining ring 31a connected in sequence, and the first connecting part 32a is connected between the lower plastic 2 and the retaining ring 31a, the outer diameter of the third connecting part 33 can be greater than or equal to the outer diameter of the first connecting part 32a, so that the outer diameter of the third connecting part 33 can be greater than the outer diameter of the snap-fit ​​segment 42.

[0125] Optionally, such as Figure 10 and Figure 11 As shown, the outer diameter of the third connecting part 33 is larger than the outer diameter of the snap-fit ​​part 3a.

[0126] Therefore, when the bare battery cell impacts the sealing nail 4 from the side, the third connecting part 33 can first contact the bare battery cell, effectively buffering the impact of the bare battery cell on the sealing nail from the side, further preventing the sealing nail 4 from becoming loose or displaced due to the impact of the bare battery cell, thus making the sealing reliability of the sealing nail 4 higher.

[0127] In addition, such as Figure 10 and Figure 11 As shown, the third connecting part 33 is provided with a second through hole 331, which communicates with the second sub-injection hole 21 and is coaxial with the second sub-injection hole 21. The diameter of the second through hole 331 is larger than the outer circle diameter of the snap-fit ​​section 42.

[0128] Therefore, the second through hole 331 is connected to and coaxial with the second sub-injection hole 21, so that when the snap-fit ​​member 3a snaps into the snap-fit ​​section 42, the snap-fit ​​section 42 can be partially accommodated in the second through hole 331, avoiding interference between the snap-fit ​​section 42 and the third connecting part 33. Furthermore, the diameter of the second through hole 331 is larger than the outer diameter of the snap-fit ​​section 42, meaning there can be a gap between the wall of the second through hole 331 and the snap-fit ​​section 42, providing deformation space for the third connecting part 33 when it is subjected to impact deformation.

[0129] Furthermore, the third connection part 33 may also be provided with multiple third notches, which correspond one-to-one with multiple first notches 312, so that the electrolyte can also flow to the periphery of the second sub-injection hole 21 through the multiple third notches, so that more electrolyte can flow to a larger area of ​​the bare cell, resulting in a higher electrolyte wetting rate.

[0130] Optionally, such as Figure 10 and Figure 11 As shown, the buffer 3b also includes a baffle 34, which is disposed on the side of the third connecting part 33 away from the snap-fit ​​part 3a, and along the axial direction of the second sub-injection hole 21, the projection of the snap-fit ​​section 42 on the baffle 34 is at least partially located on the baffle 34.

[0131] Therefore, when the bare battery cell impacts the sealing nail 4, the bare battery cell can first contact the baffle 34, preventing the bare battery cell from directly impacting the locking section 42 of the sealing nail 4. The baffle 34 can also initially withstand the impact force applied by the bare battery cell and can offset part of the impact force through deformation, thus enabling it to withstand a larger impact force together with the third connecting part 33, further improving the buffering effect of the buffer member 3b. Furthermore, the baffle 34 is located on the side of the third connecting part 33 opposite to the locking member 3a, which allows the buffer member 3b to have better structural strength, enabling it to withstand greater forces and thus improving its buffering effect.

[0132] When the third connecting part 33 is provided with a second through hole 331 and the outer peripheral wall of the third connecting part 33 is provided with multiple third notches, the baffle 34 can be provided with multiple fourth notches. The multiple fourth notches are provided one-to-one with the multiple third notches, and the multiple fourth notches extend toward the geometric center of the baffle 34 and are interconnected, so that the electrolyte can also flow to the bare cell through the fourth notches, thereby allowing the electrolyte to also wet the part of the bare cell corresponding to the baffle 34, making the electrolyte wetting efficiency higher.

[0133] Example 2

[0134] Figure 12 The image shown is a perspective view of a secondary battery provided in an embodiment of this application. Please refer to... Figure 12 As shown.

[0135] This application also discloses a secondary battery 110, including: a housing 30, a bare cell 20, and a top cover assembly 10 of any one of the embodiments. The housing 30 has a receiving cavity and an opening is provided on the housing 30, which communicates with the receiving cavity. The bare cell 20 is housed in the receiving cavity. The top cover assembly 10 is disposed at the opening to close the opening.

[0136] In this embodiment, the bare cell 20 is housed in the receiving cavity of the housing 30, and the top cover assembly 10 is disposed at the opening to close the opening, so that the bare cell 20 can be located in the closed receiving cavity. The top cover assembly 10 is any of the top cover assembly 10 in the first embodiment described above. Thus, when the secondary battery 110 is subjected to vibration, impact, etc., causing the bare cell 20 to shake in the receiving cavity and impact the sealing nail 4 in the top cover assembly 10, the sealing nail 4 can be limited by the snap-fit ​​of the snap-fit ​​member 3a and the snap-fit ​​section 42, preventing the sealing nail 4 from becoming loose or displaced, improving the sealing reliability of the sealing nail 4, thereby reducing the probability of battery leakage due to the bare cell 20 impacting the sealing nail 4, and thus improving the safety of the battery.

[0137] Example 3

[0138] Figure 13The image shown is a perspective view of a battery module provided in an embodiment of this application. Please refer to... Figure 13 As shown.

[0139] This application also discloses a battery module, including the secondary battery 110 in Embodiment 2.

[0140] In this embodiment, the secondary battery 110 in the battery module 100 is any one of the secondary batteries 110 in Embodiment 2 above. Therefore, the secondary battery 110 in this embodiment has the technical effects of the secondary battery 110 in Embodiment 2 above. Since Embodiment 2 has fully explained the technical effects of the secondary battery 110, it will not be repeated here. Furthermore, the top cover assembly 10 in the secondary battery 110 of Embodiment 2 is any one of the top cover assemblies 10 in Embodiment 1 above. Therefore, the top cover assembly 10 in this embodiment has the technical effects of the top cover assembly 10 in Embodiment 1 above. Since Embodiment 1 has fully explained the technical effects of the top cover assembly 10, it will not be repeated here.

[0141] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A top cover assembly, characterized in that, include: Top cover (1), the top cover (1) is provided with a first sub-injection hole (11); The lower plastic (2) is disposed on one side of the top cover (1). The lower plastic (2) is provided with a second sub-injection hole (21), which is connected to the first sub-injection hole (11). A snap-fit ​​member (3a) is provided on the side of the lower plastic (2) away from the top cover (1). A sealing pin (4) includes a sealing section (41) and a snap-fit ​​section (42) connected in sequence. The sealing section (41) is inserted into the first sub-injection hole (11) and the second sub-injection hole (21) to seal the first sub-injection hole (11) and the second sub-injection hole (21). The snap-fit ​​section (42) extends out of the second sub-injection hole (21) and snaps into the snap-fit ​​member (3a). The outer peripheral wall of the snap-fit ​​section (42) is provided with a snap-fit ​​groove (4212), and the snap-fit ​​member (3a) snaps into the snap-fit ​​groove (4212); The snap-fit ​​section (42) is a prismatic snap-fit ​​section, which includes a plurality of protrusions (421) spaced circumferentially along the second sub-injection hole (21), and the snap-fit ​​groove (4212) is disposed on the protrusions (421). The snap-fit ​​component (3a) includes a plurality of fan rings (31b), which are spaced apart around the central axis of the second sub-injection hole (21) and are respectively corresponding to the slots (4212) on the plurality of protrusions (421).

2. The top cover assembly according to claim 1, characterized in that, The outer diameter of the prismatic snap-fit ​​section is the same as the outer diameter of the sealing section (41).

3. The top cover assembly according to claim 2, characterized in that, Multiple fan rings (31b) are arranged together to form an insertion hole (311). The diameter of the insertion hole (311) is smaller than the outer circle diameter of the sealing section (41). The snap-fit ​​section (42) passes through the insertion hole (311), and the fan ring (31b) snaps into the snap-fit ​​groove (4212).

4. The top cover assembly according to claim 3, characterized in that, The snap-fit ​​component (3a) further includes a plurality of second connecting parts (32b), which are respectively arranged in correspondence with a plurality of fan rings (31b). One end of the second connecting part (32b) is connected to the side of the lower plastic (2) away from the top cover (1), and the other end is connected to the outer edge of the corresponding fan ring (31b). The plurality of second connecting parts (32b) together form a first through hole (321). The first through hole (321) is coaxially arranged with the second sub-injection hole (21), and the diameter of the first through hole (321) is greater than or equal to the diameter of the second sub-injection hole (21).

5. The top cover assembly according to any one of claims 1-4, characterized in that, The sealing section (41) is press-fitted with the first sub-injection hole (11) and the second sub-injection hole (21).

6. The top cover assembly according to any one of claims 1-4, characterized in that, The snap-fit ​​section (42) is provided with a first guide surface (422) at one end away from the sealing section (41), and the snap-fit ​​member (3a) is provided with a second guide surface (313) on the side facing the second sub-injection hole (21). The first guide surface (422) abuts against the second guide surface (313).

7. The top cover assembly according to claim 6, characterized in that, The first guide surface (422) is circumferentially disposed on the outer peripheral wall of the snap-fit ​​section (42) along the second sub-injection hole (21), and the second guide surface (313) is circumferentially disposed on the side of the snap-fit ​​member (3a) facing the second sub-injection hole (21) along the second sub-injection hole (21).

8. The top cover assembly according to any one of claims 1-4, characterized in that, The top cover assembly (10) also includes a buffer (3b), which is disposed on the side of the snap-fit ​​member (3a) away from the lower plastic (2). The buffer (3b) is used to buffer the impact of the bare battery cell (20) on the sealing nail (4).

9. The top cover assembly according to claim 8, characterized in that, The buffer (3b) includes a third connecting part (33), which is an elastic connecting part, and the third connecting part (33) is disposed on the side of the snap-fit ​​member (3a) away from the lower plastic (2).

10. The top cover assembly according to claim 9, characterized in that, The outer diameter of the third connecting part (33) is larger than the outer diameter of the snap-fit ​​part (3a).

11. The top cover assembly according to claim 9, characterized in that, The buffer (3b) further includes a baffle (34), which is disposed on the side of the third connection (33) away from the snap-fit ​​(3a) and along the axial direction of the second sub-injection hole (21). The projection of the snap-fit ​​segment (42) on the baffle (34) is at least partially located on the baffle (34).

12. A secondary battery, characterized in that, include: The housing (30) has a receiving cavity and an opening that communicates with the receiving cavity; Bare battery cell (20), the bare battery cell (20) is housed in the receiving cavity; The top cover assembly (10) according to any one of claims 1-11, the top cover assembly (10) being disposed at the opening to close the opening.

13. A battery module, characterized in that, Includes the secondary battery (110) as described in claim 12.

Images