Top cover assembly, battery cell and battery pack

Abstract

The invention relates to the technical field of batteries, and provides a top cover assembly, a battery cell and a battery pack, the top cover assembly comprises a top cover body, a pole and an explosion-proof valve; a first through hole and a second through hole which penetrate through the top cover body are formed in the top cover body, and the first through hole and the second through hole are arranged at an interval in the length direction of the top cover body; in the area where the second through hole is located, the top cover body is bent to form a boss protruding towards one side. The second through hole is a countersink hole and comprises a countersink part and a through hole part which are coaxially arranged, and the countersink part is communicated with the outer side of the boss; the pole penetrates through the first through hole and is electrically connected with the tab of the battery cell; the anti-explosion valve is installed on the inner wall of the through hole part. According to the invention, the mechanical strength of the battery cell can be improved, the heat dissipation efficiency of the battery cell is improved, the use temperature of the battery cell is controlled, and the anti-explosion valve is mounted on the inner wall of the through hole part in a settling manner, so that the pole and the anti-explosion valve are effectively protected, and the safety performance of the battery cell is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a top cover assembly, a battery cell and a battery pack. BACKGROUND

[0002] With the rapid development of new energy vehicles and energy storage devices, the requirements for structural safety and energy density of batteries are increasing. The battery cell is the smallest unit in the battery cell module. In the prior art, the battery cell is composed of a top cover assembly, a pole group and a shell. The top cover assembly and the shell are fixedly connected by welding to form a closed space for accommodating the pole group. The pole is arranged in the top cover assembly and electrically connected with the pole lug of the pole group.

[0003] Currently, the battery cell only contacts other structures in the battery pack through the pole. When the upper surface of the battery cell is stressed, the pole is directly stressed. The risk of short circuit of the battery cell is high, and the structural strength is low. In addition, when the battery cell is cooled, heat is only conducted through the pole and the heat conduction layer, and the cooling effect is poor. SUMMARY

[0004] The present application provides a top cover assembly, a battery cell and a battery pack to solve the problem of low strength and poor heat dissipation of the battery cell caused by the top cover assembly only being stressed and conducting heat through the pole in the prior art.

[0005] To solve the above technical problems, the present application is implemented as follows: In a first aspect, the present application provides a top cover assembly, comprising: a top cover body, a first through hole and a second through hole penetrating the top cover body are formed, the first through hole and the second through hole are arranged at intervals along the length direction of the top cover body; in the area where the second through hole is located, the top cover body is bent to form a boss protruding towards one side; the second through hole is a counterbore, which comprises a counterbore part and a through hole part arranged coaxially, and the counterbore part is arranged in communication with the outside of the boss; a pole arranged in the first through hole and electrically connected with the pole lug of the battery cell; an explosion-proof valve mounted on the inner wall of the through hole part.

[0006] According to the top cover assembly provided by the present application, the inner wall of the counterbore part is provided with a reinforcing rib; The two ends of the reinforcing rib are respectively arranged in abutment with the side surfaces of the counterbore part along the height direction and the width direction of the top cover body.

[0007] According to the top cover assembly provided by the present application, a plurality of reinforcing ribs are arranged at intervals along the circumferential side of the counterbore part; The projected width of the reinforcing rib on the side of the top cover body opposite to the tab is b, the number of the reinforcing ribs is n, and the perimeter of the countersunk hole is C, satisfying: 0.1≤nb / C≤0.25.

[0008] According to a top cover assembly provided by the present invention, along the height direction of the top cover body, the projection height of the reinforcing rib on the inner wall of the countersunk hole is the same as the height of the countersunk hole. And / or, the cross-section of the reinforcing rib is a triangular structure, the triangular structure having a connected first side and a second side, the first side being in contact with the side of the countersunk portion along the height direction of the top cover body, and the second side being in contact with the side of the countersunk portion along the width direction of the top cover body.

[0009] According to a top cover assembly provided by the present invention, along the height direction of the top cover body, the depth of the countersunk hole is H2, and the thickness of the top wall of the boss is T2, satisfying: 1.5mm≤H2≤3mm, H2 / T2≤2; And / or, the inner wall of the through hole has an annular step, the explosion-proof valve is installed on the side of the annular step facing the countersunk hole, and the height of the annular step is H3, H3 satisfies: H3≥1.2mm.

[0010] According to a top cover assembly provided by the present invention, the boss is a truncated cone. The taper of the truncated cone is β, and β satisfies: 20°≤β≤25°.

[0011] According to a top cover assembly provided by the present invention, two pole posts are provided, and the two pole posts are respectively disposed at both ends of the top cover body along the length direction of the top cover body; The boss is located between the two pole posts, and the second through hole is located in the middle of the boss.

[0012] According to a top cover assembly provided by the present invention, along the height direction of the top cover body, the height of the boss is H1, the thickness of the top cover body is T1, and the thickness of the top wall of the boss is T2, satisfying: T1≥2mm, 0.75≤T2 / T1≤1.1, 2≤H1 / T1≤2.75; And / or, along the length of the top cover body, the distance between the bend of the boss and the pole post is a, where a satisfies: a≥2.5mm; And / or, the length of the top cover body is L, where L satisfies: 150mm≤L≤300mm; The width of the top cover body is W, and W satisfies: 25mm≤W≤75mm.

[0013] In a second aspect, the present invention provides a battery cell comprising: an electrode assembly, a housing, and a top cover assembly as described above; The electrode assembly is located inside the housing, the top cover assembly is fixed to the opening end of the housing, and the electrode assembly is electrically connected to the top cover assembly through electrode tabs.

[0014] Thirdly, the present invention provides a battery pack, comprising: a busbar, a housing, and battery cells as described above; The housing forms a receiving cavity, and multiple battery cells are provided, with the multiple battery cells stacked in the receiving cavity; the busbar is connected to the terminals of the multiple battery cells; The upper surface of the boss is bonded to the box body through an adhesive layer.

[0015] The top cover assembly, battery cell, and battery pack provided by this invention form a boss by bending the top cover body in the area where the explosion-proof valve is located. This not only enhances the structural strength of the top cover assembly and thus improves the mechanical strength of the battery cell, achieving thermoelectric separation of the terminal and the explosion-proof valve, but also increases the surface area of ​​the top cover body, thereby increasing the heat dissipation area of ​​the top cover body and the bonding area with the thermally conductive layer, improving the heat dissipation efficiency of the battery cell and controlling the operating temperature of the battery cell. Furthermore, the second through hole for installing the explosion-proof valve is set as a countersunk hole, which includes a countersunk portion and a through portion. The explosion-proof valve is installed in a recessed manner on the inner wall of the through portion, effectively protecting the terminal and the explosion-proof valve and improving the safety performance of the battery cell. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention 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 invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of the top cover assembly in the prior art.

[0018] Figure 2 This is a three-dimensional structural diagram of a battery pack in the prior art.

[0019] Figure 3 This is a front view of a battery cell in the prior art.

[0020] Figure 4 It is in the existing technology Figure 3 A magnified view of the X-section.

[0021] Figure 5 This is one of the three-dimensional structural schematic diagrams of the top cover assembly provided by the present invention.

[0022] Figure 6 This is a front view of the top cover assembly provided by the present invention.

[0023] Figure 7 This is a top view of the top cover assembly provided by the present invention.

[0024] Figure 8 This invention provides Figure 7 UU sectional view.

[0025] Figure 9 This invention provides Figure 8 A magnified view of part K.

[0026] Figure 10 This is the second three-dimensional structural schematic diagram of the top cover assembly provided by the present invention.

[0027] Figure 11 This is a bottom view of the top cover assembly provided by the present invention.

[0028] Figure 12 This is one of the schematic diagrams of the top cover assembly and pole assembly provided by the present invention.

[0029] Figure 13 This is the second schematic diagram of the top cover assembly and pole assembly provided by the present invention.

[0030] Figure 14 This is a partial view of the assembly diagram of the reinforcing rib and the countersunk hole provided by the present invention.

[0031] Figure 15 This is a schematic diagram of the assembly of the reinforcing rib and the second through hole provided by the present invention.

[0032] Figure 16 This is a three-dimensional structural diagram of the battery cell provided by the present invention.

[0033] Figure 17 This is a front view of the battery cell provided by the present invention.

[0034] Figure label: 1. Top cover assembly; 11. Top cover body; 12. Pole post; 13. Explosion-proof valve; 14. First insulating component; 15. Reinforcing rib; 16. Limiting plate; 111. First through hole; 112. Second through hole; 113. Boss; 141. Vent hole; 151. First side; 152. Second side; 161. Inclined section; 162. Horizontal section; 1111. Countersunk hole; 1112. Through hole; 11121. Annular step; 2. Electrode assembly; 21. Electrode tab; 22. Protrusion; 221. Exhaust groove; 100, busbar; 200, battery cell. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0036] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of clarifying the embodiments of the present invention 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 the present invention. 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.

[0037] In the description of the embodiments of the present invention, 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 the present invention according to the specific circumstances.

[0038] In embodiments of the present invention, 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," "over," and "on top" of 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.

[0039] 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.

[0040] The following is combined with Figures 1 to 17 The top cover assembly, battery cell, and battery pack provided in this invention will be described in detail through specific embodiments and application scenarios.

[0041] Firstly, such as Figure 5 , Figure 7 , Figure 8 and Figure 9 As shown, this embodiment provides a top cover assembly 1, including: a top cover body 11, a pole post 12, and an explosion-proof valve 13.

[0042] The top cover body 11 has a first through hole 111 and a second through hole 112 penetrating the top cover body 11. The first through hole 111 and the second through hole 112 are spaced apart along the length of the top cover body 11. In the area where the second through hole 112 is located, the top cover body 11 is bent to form a boss 113 protruding to one side. The second through hole 112 is a countersunk hole, which includes a countersunk portion 1111 and a through portion 1112 arranged coaxially. The countersunk portion 1111 is connected to the outer side of the boss 113.

[0043] The electrode post 12 passes through the first through hole 111 and is electrically connected to the electrode tab 21 of the battery cell 200.

[0044] The explosion-proof valve 13 is installed on the inner wall of the through hole 1112.

[0045] Understandably, such as Figures 1 to 4 As shown, in the prior art, the electrode group 2 of the battery cell 200 is electrically connected to the terminal post 12 on the top cover assembly 1 via the electrode tab 21. The top cover assembly 1 is installed at the open end of the housing. The terminal post 12 protrudes from both sides of the top cover body 11 through the first through hole 111. One end of the terminal post 12 is welded to the electrode tab 21 of the battery cell 200, and the other end is used to connect to the tab on the busbar 100. When the battery cell 200 is assembled into a battery pack, since all other structures on the top cover body 11 except for the terminal post 12 are flush with the top cover body 11, the battery cell 200 only contacts other components of the battery pack through the terminal post 12.

[0046] In this embodiment, a boss 113 is provided in the area where the explosion-proof valve 13 is located, giving the space where the explosion-proof valve 13 is located a raised structure. When the surface of the battery cell 200 is subjected to external impact, the boss 113 can share the external force on the terminal post 12. Furthermore, since the boss 113 has a certain structural strength, it can support the top cover body 11, preventing short circuits in the battery cell 200 and improving the mechanical strength of the entire battery cell package.

[0047] Meanwhile, when the cells 200 are stacked to form a cell module, the upper surface of the cell 200 can conduct heat dissipation through contact with the heat-conducting layer via the electrode post 12, and also through contact with the heat-conducting layer via the boss 113. Compared with the prior art, where most of the top cover body 11 can only dissipate heat through thermal radiation, the contact heat conduction effect of the boss 113 in this embodiment is better, which is more conducive to the heat dissipation of the cell 200, more conducive to controlling the operating temperature of the cell 200, and extending the service life of the cell 200.

[0048] Furthermore, since the explosion-proof valve 13 is located on the boss 113, the explosion-proof valve 13 and the pole post 12 are at different spatial heights, which can also isolate the pole post 12 and the explosion-proof valve 13, achieve thermoelectric separation, and improve the safety performance of the battery cell 200.

[0049] In the prior art, in the battery cell 200, sufficient height needs to be reserved between the electrode group 2 and the top cover body 11 to provide bending space for the tab 21. For example... Figure 3 and Figure 4 As shown, the height H of the insulating component of the top cover body 11 is usually in the range of 6≤H≤9, and the gap H0 between the pole group 2 and the top cover body 11 is usually in the range of 4≤H0≤6.

[0050] In this embodiment, the top cover body 11 is bent to form a protrusion 113. The protrusion 113 is a hollow platform with a accommodating space facing the side of the electrode 21. The electrode 21 can be accommodated within the accommodating space, thereby reducing the height gap between the electrode group 2 and the top cover body 11 and increasing the capacity of the battery cell 200. Furthermore, the protrusion height of the protrusion 113 faces outward from the top cover body 11, also filling the space between the electrode post 12 and the explosion-proof valve 13, thus increasing the energy density of the battery cell 200.

[0051] like Figure 15As shown, further, to reduce the height of the explosion-proof valve 13 relative to the top surface of the boss 113, the second through hole 112 in this embodiment is configured as a countersunk hole. Along the height direction of the top cover body 11, the countersunk hole 1111 and the through hole 1112 are sequentially connected, with the diameter of the countersunk hole 1111 being larger than the diameter of the through hole 1112. The explosion-proof valve 13 is installed on the inner wall of the through hole 1112 and extends towards the tab 21. The height of the countersunk hole 1111 is the height by which the explosion-proof valve 13 is reduced relative to the top surface of the boss 113. By installing the explosion-proof valve 13 in a countersunk manner, the explosion-proof valve 13 and the top surface of the boss 113 are not located on the same plane. When the top surface of the boss 113 is deformed under pressure, the impact on the explosion-proof valve 13 is reduced.

[0052] The top cover assembly 1 provided by the present invention forms a boss 113 by bending the top cover body 11 in the area where the explosion-proof valve 13 is located. This not only enhances the structural strength of the top cover assembly 1 through the boss 113, thereby improving the mechanical strength of the battery cell 200, but also achieves thermoelectric separation of the electrode post 12 and the explosion-proof valve 13. Furthermore, the boss 113 increases the surface area of ​​the top cover body 11, thereby increasing the heat dissipation area of ​​the top cover body 11 and the bonding area with the heat-conducting layer, improving the heat dissipation efficiency of the battery cell 200, and controlling the operating temperature of the battery cell 200. In addition, the second through hole 112 for installing the explosion-proof valve 13 is set as a countersunk hole, which includes a countersunk portion 1111 and a through portion 1112. The explosion-proof valve 13 is installed in a recessed manner on the inner wall of the through portion 1112, effectively protecting the electrode post 12 and the explosion-proof valve 13, and improving the safety performance of the battery cell 200.

[0053] like Figure 5 and Figure 14 As shown, the inner wall of the countersunk hole portion 1111 in this embodiment is provided with reinforcing ribs 15.

[0054] The two ends of the reinforcing rib 15 abut against the sides of the countersunk hole portion 1111 along the height and width directions of the top cover body 11, respectively.

[0055] Understandably, in order to further improve the structural strength of the second through hole 112, this embodiment provides a reinforcing rib 15 on the inner wall of the countersunk hole portion 1111. When the boss 113 is subjected to external impact, the reinforcing rib 15 can ensure that the structure of the boss 113 is more stable.

[0056] The two ends of the reinforcing rib 15 abut against the sides of the countersunk hole 1111, thereby improving the structural strength of the two adjacent sidewalls of the countersunk hole 1111. Specifically, the reinforcing rib 15 can extend toward the center of the explosion-proof valve 13 or be inclined relative to the center of the explosion-proof valve 13; there can be one or more reinforcing ribs 15.

[0057] Optionally, the cross-section of the stiffener 15 can be square, trapezoidal or arc-shaped to achieve the optimal mechanical support effect.

[0058] like Figure 5 and Figure 7 As shown, this embodiment has multiple reinforcing ribs 15, which are spaced apart along the periphery of the countersunk hole portion 1111.

[0059] The projected width of the reinforcing rib 15 on the side of the top cover body 11 away from the tab 21 is b, the number of reinforcing ribs 15 is n, and the perimeter of the countersunk hole 1111 is C, satisfying: 0.1≤nb / C≤0.25.

[0060] Understandably, in order to improve the structural strength of the boss 113 and prevent stress concentration or deformation of the boss 113 under load, multiple reinforcing ribs 15 are provided at intervals around the periphery of the countersunk hole portion 1111. The multiple reinforcing ribs 15 cover the circumference of the countersunk hole portion 1111, improve the overall rigidity and bending resistance of the second through hole 112, prevent the countersunk hole from bending or sagging along the circumference, improve load distribution, and facilitate processing and manufacturing.

[0061] In order to reasonably arrange the reinforcing ribs 15, the ratio of the sum of the widths of multiple reinforcing ribs 15 to the perimeter of the countersunk hole 1111 needs to meet a certain range, so that the structural strength of the countersunk hole 1111 can be strengthened without causing structural redundancy.

[0062] Specifically, nb / C can be 0.1, 0.175, or 0.25.

[0063] like Figure 5 and Figure 14 As shown, along the height direction of the top cover body 11, the projection height of the reinforcing rib 15 on the inner wall of the countersunk hole portion 1111 in this embodiment is the same as the height of the countersunk hole portion 1111.

[0064] Understandably, in order to make the height of the top surface of the boss 113 consistent, the height of the reinforcing rib 15 in this embodiment is the same as the height of the countersunk hole 1111, so that the depth direction of the countersunk hole 1111 is reinforced along the height direction of the top cover body 11, and the reinforcing rib 15 does not extend out of the countersunk hole 1111 and affect the height of the boss 113.

[0065] like Figure 5 and Figure 14 As shown, the cross-section of the reinforcing rib 15 in this embodiment is a triangular structure. The triangular structure has a connected first side 151 and a second side 152. The first side 151 is attached to the side of the countersunk portion 1111 along the height direction of the top cover body 11, and the second side 152 is attached to the side of the countersunk portion 1111 along the width direction of the top cover body 11.

[0066] Understandably, based on the stability of the triangular structure, the triangular structure can enhance stiffness and resistance to deformation, effectively dispersing and transmitting external forces acting on the countersunk hole 1111 through the triangular truss structure. Furthermore, the first side 151 and the second side 152 of the triangular structure act as ribs, providing additional support to the sides of the countersunk hole 1111, thereby improving strength and load-bearing capacity.

[0067] like Figure 7 , Figure 8 and Figure 9 As shown, along the height direction of the top cover body 11, the depth of the countersunk hole 1111 in this embodiment is H2, and the thickness of the top wall of the boss 113 is T2, satisfying: 1.5mm≤H2≤3mm, H2 / T2≤2.

[0068] Understandably, the countersunk hole 1111 can be machined using a stamping structure. Due to the limitations of the stamping process, the depth of the countersunk hole 1111 needs to meet certain limits to facilitate machining. Furthermore, since the countersunk hole 1111 is formed on the top surface of the boss 113, the ratio of the height of the countersunk hole 1111 to the thickness of the top wall of the boss 113 needs to meet certain limits.

[0069] Specifically, H2 can be 1.5mm, 2.25mm, or 3mm. H2 / T2 can be 2, 1.5, or 1.

[0070] like Figure 7 , Figure 8 , Figure 9 and Figure 15 As shown, the inner wall of the through hole 1112 in this embodiment has an annular step 11121. The explosion-proof valve 13 is installed on the side of the annular step 11121 facing the countersunk hole 1111. The height of the annular step 11121 is H3, and H3 satisfies: H3≥1.2mm.

[0071] Understandably, to facilitate the installation of the explosion-proof valve 13 in the recessed hole, this embodiment provides an annular step 11121 in the through hole portion 1112. The explosion-proof valve 13 can be circumferentially welded to the step surface of the annular step 11121, thereby improving the connection strength between the explosion-proof valve 13 and the through hole portion 1112. Furthermore, since the annular step 11121 forms a circumferentially reinforced structure, it improves the structural strength of the through hole portion 1112 and avoids deformation and bending of the through hole portion 1112.

[0072] Specifically, H3 can be 1.2mm, 1.3mm, or 1.4mm.

[0073] like Figure 17As shown, the boss 113 in this embodiment is a cone-shaped platform; the taper of the cone-shaped platform is β, and β satisfies: 20°≤β≤25°.

[0074] Understandably, the conical pedestal helps to disperse concentrated loads, reduce stress concentration at the mating joint, improve the load-bearing capacity and stability of the boss 113, avoid local damage, and is easy to process due to its regular shape.

[0075] Specifically, the taper β of the truncated cone can be 20°, 22.5°, or 25°.

[0076] like Figure 17 As shown, in this embodiment, the boss 113 and the top cover body 11 are integrally formed.

[0077] Understandably, the boss 113 and the top cover body 11 are made of the same piece of material. The one-piece molding structure simplifies the production process and ensures the reliability of the connection between the boss 113 and the top cover body 11.

[0078] Alternatively, the one-piece molding structure can be achieved by stamping, stretching, or embossing.

[0079] In one example, the boss 113 can be a conical platform formed by stamping. The stamping of conical platforms is easy to achieve, has a high production yield, and is easy to process and manufacture.

[0080] like Figure 5 As shown, this embodiment has two pole posts 12, which are located at both ends of the top cover body 11 along the length of the top cover body 11.

[0081] The boss 113 is located between the two pole posts 12, and the second through hole 112 is located in the middle of the boss 113.

[0082] Understandably, in this embodiment, two terminals 12 are installed on the top cover body 11, one is a positive terminal and the other is a negative terminal. Along the length of the top cover body 11, the negative terminal and the positive terminal are respectively located at both ends of the top cover body 11, and the negative terminal and the positive terminal are respectively connected to the electrode group 2 of the battery cell 200.

[0083] An explosion-proof valve 13 is provided between the positive and negative terminals, and a boss 113 is formed between the positive and negative terminals, thereby ensuring that the boss 113 disperses the pressure between the positive and negative terminals, improving the structural strength of the top cover assembly 1, and ensuring the safety of the battery cell 200.

[0084] Furthermore, the explosion-proof valve 13 is installed in the middle of the boss 113, and the distance from the positive terminal and the negative terminal is equal, which makes the structure of the top cover body 11 more regular, easier to process and manufacture, and can effectively isolate the explosion-proof valve 13 from the positive terminal and the negative terminal.

[0085] like Figure 7 , Figure 8 and Figure 9 As shown, in this embodiment, along the height direction of the top cover body 11, the height of the boss 113 is H1, the thickness of the top cover body 11 is T1, and the thickness of the top wall of the boss 113 is T2, satisfying: T1≥2mm, 0.75≤T2 / T1≤1.1, 2≤H1 / T1≤2.75.

[0086] Understandably, in order to ensure the structural strength of the boss 113, the ratio of the thickness of the top cover body 11, the thickness of the top wall of the boss 113 to the thickness of the top cover body 11, and the ratio of the height of the boss 113 to the thickness of the top cover body 11 need to meet certain ranges to ensure the support strength and structural strength of the boss 113.

[0087] Specifically, T1 can be 2mm, 2.5mm, or 3mm; T2 / T1 can be 0.75, 0.925, or 1.1; H1 / T1 can be 2, 2.375, or 2.75.

[0088] like Figure 7 As shown, along the length of the top cover body 11, the distance between the bend of the boss 113 and the pole post 12 in this embodiment is a, where a satisfies: a≥2.5mm.

[0089] Understandably, the bend of the boss 113 needs to be spaced a certain distance from the pole post 12 to prevent the boss 113 from colliding with the pole post 12 when under force, thus damaging the pole post 12.

[0090] Specifically, 'a' can be 2.5mm, 3mm, or 3.5mm.

[0091] like Figure 5 As shown, the length of the top cover body 11 in this embodiment is L, and L satisfies: 150mm≤L≤300mm.

[0092] The width of the top cover body 11 is W, and W satisfies: 25mm≤W≤75mm.

[0093] It is understood that the length and width of the top cover body 11 in this embodiment are limited to accommodate the assembly requirements of different battery cell capacities 200, while avoiding excessive length that could lead to material redundancy or structural deformation.

[0094] Specifically, the length L of the top cover body 11 can be 150mm, 225mm, or 300mm. The width W of the top cover body 11 can be 25mm, 50mm, or 75mm.

[0095] like Figure 10 As shown, the top cover assembly 1 in this embodiment also includes a first insulating member 14.

[0096] The first insulating member 14 is provided on the side of the top cover body 11 facing the tab 21. The first insulating member 14 extends along the length of the top cover body 11. The area of ​​the first insulating member 14 corresponding to the explosion-proof valve 13 has an exhaust hole 141.

[0097] To isolate the top cover body 11 from the pole post 12 and to provide insulation protection for the pole post 12 and the explosion-proof valve 13, this embodiment provides a first insulating member 14 on the side of the top cover body 11 facing the pole lug 21. The first insulating member 14 is provided along its entire length and has a through hole for the pole post 12 to pass through, as well as an exhaust hole 141 for facilitating the exhaust of the explosion-proof valve 13.

[0098] In this embodiment, there are multiple exhaust holes 141, which are evenly spaced and form an exhaust channel with the explosion-proof valve 13. When the battery cell 200 fails due to high temperature, the high temperature gas can be quickly discharged to the outside of the battery cell 200 to ensure the safety of the battery cell 200.

[0099] Furthermore, a limiting plate 16 is provided in the area of ​​the first insulating member 14 corresponding to the explosion-proof valve 13. There are two limiting plates 16, which are spaced apart. One end of the two limiting plates 16 is connected to the first insulating member 14, and the other end abuts against the pole group 2. The limiting space formed between the two limiting plates 16 is used to accommodate the protrusion 22 of the pole group 2.

[0100] Understandably, in order to limit the displacement of the electrode assembly 2 along the length direction of the top cover body 11, the first insulating member 14 in this embodiment is equipped with limiting plates 16. Two limiting plates 16 are spaced apart on the side of the first insulating member 14 facing the electrode assembly 2, and located in the area corresponding to the explosion-proof valve 13. Simultaneously, a protrusion 22 is provided on the portion of the electrode assembly 2 located between the two limiting plates 16, the length of the protrusion 22 being less than the distance between the two limiting plates 16. When the electrode assembly 2 is assembled with the top cover assembly 1, the protrusion 22 of the electrode assembly 2 engages within the limiting space formed by the two limiting plates 16, and the limiting plates 16 stop the protrusion 22 from both sides, thereby limiting the displacement of the electrode assembly 2 along the length direction of the top cover body 11 and fixing the electrode assembly 2. When the cell 200 is subjected to impact, the electrode group 2 is prevented from moving along the length of the top cover body 11 and damaging the tab 21. In addition, the limiting plate 16 can also isolate the tab 21 and the electrode group 2 to prevent the electrode group 2 from being cut, thus improving the safety performance of the cell 200.

[0101] Specifically, the limiting plate 16 and the top cover body 11 can be installed vertically or at an angle. The limiting plate 16 can be a strip plate, an arc plate, or a zigzag plate.

[0102] It should be noted that, along the length of the top cover body 11, the space between the pole post 12 and the explosion-proof valve 13, where the boss 113 is located, is used to accommodate the pole lug 21. The limiting plate 16 is located beside the pole lug 21 and does not interfere with the pole lug 21.

[0103] like Figure 6 As shown, the limiting plate 16 in this embodiment includes an inclined section 161.

[0104] One end of the inclined section 161 is connected to the first insulating member 14, and the other end of the inclined section 161 abuts against the pole group 2.

[0105] Along the height direction of the top cover body 11, the two inclined sections 161 are symmetrically arranged with respect to the center of the second through hole 112, and are arranged in a divergent manner from the connection with the first insulating member 14, and the distance between the two inclined sections 161 gradually increases.

[0106] Understandably, as the distance between the two inclined sections 161 gradually increases, the assembly cross section between the pole group 2 and the protrusion 22 also gradually increases. This makes it easier to assemble the pole group 2 with the first insulating member 14 when the protrusion 22 of the pole group 2 is installed toward the limiting space, as it first passes through a larger cross section and then is gradually pushed toward a smaller cross section.

[0107] like Figure 6 As shown, the limiting plate 16 in this embodiment also includes a horizontal segment 162.

[0108] The horizontal section 162 is connected to the other end of the inclined section 161, and is parallel to and abuts against the pole group 2. The horizontal section 162 and the inclined section 161 are arranged at an angle.

[0109] Understandably, the horizontal section 162 can be installed in close contact with the pole group 2, increasing the contact area between the inclined section 161 and the pole group 2, making the contact between the limiting plate 16 and the pole group 2 more stable. Furthermore, the contact between the limiting plate 16 and the pole group 2 is changed from line contact to surface contact, making the support structure between the pole group 2 and the top cover body 11 stronger.

[0110] like Figure 6 As shown, the thickness of the limiting plate 16 in this embodiment is t, and t satisfies: t≥0.8mm.

[0111] Understandably, in order to ensure the structural strength of the limiting plate 16, the thickness of the limiting plate 16 needs to meet a certain range.

[0112] Specifically, the thickness t of the limiting plate 16 can be 0.8mm, 0.9mm, or 1.0mm.

[0113] like Figure 17As shown, along the height direction of the top cover body 11, the assembly gap between the protrusion 22 and the first insulating member 14 in this embodiment is h, which satisfies: 0.2mm≤h≤0.5mm.

[0114] Understandably, when assembling the electrode assembly 2 with the top cover assembly 1, in order to ensure the unobstructed exhaust passage between the electrode assembly 2 and the top cover assembly 1, an assembly gap needs to be reserved between the electrode assembly 2 and the first insulating component 14 so that when the battery experiences thermal runaway, the generated high-temperature gas can be discharged to the explosion-proof valve 13 through the exhaust port 141 of the first insulating component 14.

[0115] Specifically, h can be 0.2mm, 0.35mm, or 0.5mm.

[0116] Secondly, such as Figure 16 As shown, this embodiment provides a battery cell 200, including: an electrode group 2, a housing, and a top cover assembly 1 as described above.

[0117] The electrode assembly 2 is located inside the housing, and the top cover assembly 1 is fixed to the opening end of the housing. The electrode assembly 2 is electrically connected to the top cover assembly 1 through the electrode tab 21.

[0118] Specifically, since the battery cell 200 includes a top cover assembly 1, and the specific structure of the top cover assembly 1 is as described in the above embodiments, the battery cell 200 shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects obtained by all the technical solutions of the above embodiments, which will not be described in detail here.

[0119] Understandably, the electrode assembly 2 is installed inside the housing, and the top cover assembly 1 is placed over the opening of the housing. The electrode assembly 2 is electrically connected to the electrode post 12 of the top cover assembly 1 through the electrode tab 21 to achieve current transmission. Since the top cover assembly 1 bends to form a protrusion 113 in the area where the explosion-proof valve 13 is located on the top cover body 11, the contact heat dissipation area on the upper surface of the top cover body 11 is increased, which is beneficial to control the operation of the battery cell 200, extend the service life of the battery cell 200, and increase the stress area of ​​the top cover body 11, avoiding the electrode post 12 from being subjected to stress alone, thus improving the safety performance of the battery cell 200. Furthermore, the second through hole 112 for installing the explosion-proof valve 13 is set as a countersunk hole, which includes a countersunk portion 1111 and a through portion 1112. The explosion-proof valve 13 is installed in a recessed manner at the connection between the countersunk portion 1111 and the through portion 1112, effectively protecting the electrode post 12 and the explosion-proof valve 13, thus improving the safety performance of the battery cell 200.

[0120] like Figure 12 and Figure 13As shown, taking the top cover assembly 1 with two pole posts 12 as an example, the assembly process of pole group 2 and top cover assembly 1 is explained. First, the pole group 2 and the pole tabs 21 are in a flat state. The two pole groups 2 are placed on both sides of the top cover body 11 along the width direction of the top cover body 11. The two pole tabs 21 are aligned with the two pole posts 12 respectively, and the pole tabs 21 are welded to the pole posts 12. Then, the two pole groups 2 are rotated 90° away from the top cover assembly 1, so that the top cover assembly 1 is located on the side of the pole group 2. Finally, the pole group 2 is installed into the housing, and the top cover assembly 1 is located at the opening end of the housing.

[0121] like Figure 12 As shown, in this embodiment, the protrusion 22 of the pole group 2 is provided with an exhaust groove 221 on the side facing the top cover assembly 1; the exhaust groove 221 extends along the length direction of the top cover body 11.

[0122] Understandably, to ensure the smooth flow of the exhaust channel of the explosion-proof valve 13, the protrusion 22 of the electrode assembly 2 in this embodiment is provided with an exhaust groove 221. The exhaust groove 221 is connected to the exhaust hole 141 of the first insulating member 14, so that the high-temperature gas has enough space to flow until it reaches the explosion-proof valve 13. Furthermore, since the exhaust groove 221 is arranged along the length of the top cover body 11, the high-temperature gas from other parts of the electrode assembly 2 can also enter the exhaust groove 221 from both sides of the protrusion 22, which is beneficial to the flow of high-temperature gas.

[0123] like Figure 17 As shown, the taper of the protrusion 22 of the pole group 2 in this embodiment is θ, and θ satisfies: 20°≤θ≤25°.

[0124] The tilt angle of the limiting plate 16 is γ, and γ satisfies: γ=θ.

[0125] Understandably, in order to ensure the assembly effect of the electrode group 2 and the top cover assembly 1, the taper of the protrusion 22 of the electrode group 2 is set to be consistent with the tilt angle of the limiting plate 16. When the electrode group 2 moves due to the external force on the cell 200, the protrusion 22 can fit completely with the limiting plate 16, which can better stop the electrode group 2 and enhance the limiting effect of the electrode group 2.

[0126] Specifically, the taper θ of the protrusion 22 can be 20°, 22.5°, or 25°. The tilt angle γ of the limiting plate 16 can be 20°, 22.5°, or 25°.

[0127] like Figure 17 As shown, in this embodiment, the distance between the outer wall of the protrusion 22 of the pole group 2 and the side of the limiting plate 16 facing the protrusion 22 is A, which satisfies: 0.7mm≤A≤1.5mm.

[0128] Understandably, the distance between the protrusion 22 of the pole group 2 and the limiting plate 16 needs to meet a certain range to avoid the limiting effect of the pole group 2 being too obvious if the distance is too large, or the limiting plate 16 interfering with the pole group 2 if the distance is too small.

[0129] Specifically, A can be 0.7mm, 1.1mm, or 1.5mm.

[0130] like Figure 11 and Figure 16 As shown, in this embodiment, along the width direction of the top cover body 11, the width of the pole group 2 is W1, and the width of the limiting plate 16 is W2, satisfying: 3mm≤W1-W2≤10mm.

[0131] Understandably, in order to ensure the aesthetics of the pole group 2 and the top cover assembly 1 after installation, the width of the limiting plate 16 should be smaller than the width of the pole group 2, and the width of the limiting plate 16 should be as close as possible to the width of the pole group 2, so as to facilitate the limiting effect of the limiting plate 16 on the pole group 2.

[0132] Specifically, W1-W2 can be 3mm, 6.5mm, or 10mm.

[0133] like Figure 13 and Figure 17 As shown, along the length of the top cover body 11, the distance between the tab 21 and the limiting plate 16 in this embodiment is W3, which satisfies: W3≥2mm.

[0134] Understandably, after the electrode tab 21 and the electrode post 12 are welded together, the distance between the electrode tab 21 and the limiting plate 16 needs to meet a certain range in order to prevent the limiting plate 16 from interfering with the electrode tab 21 and affecting the normal operation of the battery cell 200.

[0135] Specifically, W3 can be 2mm, 2.5mm, or 3mm.

[0136] In this embodiment, the production line tests various indicators of the top cover assembly 1 to verify the technical effects of different data. The thickness T1 of the top cover body 11, the thickness T2 of the top wall of the boss 113, the height H1 of the boss 113, the depth H2 of the countersunk hole 1111, the number n of the reinforcing ribs 15, the projected width b on the top cover body 11, the perimeter C of the countersunk hole 1111, the ratio T2 / T1 of the thickness of the top wall of the boss 113 to the thickness of the top cover body 11, the ratio H1 / T1 of the height of the boss 113 to the thickness of the top cover body 11, the ratio H2 / T2 of the depth of the countersunk hole 1111 to the thickness of the top wall of the boss 113, and the ratio nb / C of the sum of the widths of the multiple reinforcing ribs 15 to the perimeter of the countersunk hole 1111 are used to perform simulation analysis on the battery cell 200.

[0137] It is evident that when the structural design of the top cover assembly 1 meets the above requirements, the strength of each part of the top cover assembly 1 meets the overall package design requirements; conversely, weak parts are prone to deformation, affecting the structural strength.

[0138] Table 1

[0139] Table 2

[0140] Thirdly, this embodiment provides a battery pack, including: a busbar 100, a housing, and the aforementioned battery cells 200.

[0141] The housing forms a receiving cavity, and multiple battery cells 200 are provided, with multiple battery cells 200 stacked in the receiving cavity; the busbar 100 is connected to the terminal post 12 of the multiple battery cells 200, and the upper surface of the boss 113 is bonded to the housing through an adhesive layer.

[0142] Specifically, since the battery pack includes a cell 200, and the specific structure of the cell 200 is as described in the above embodiments, the battery pack shown in this embodiment includes all the technical solutions of the above embodiments. Therefore, it has at least all the beneficial effects achieved by all the technical solutions of the above embodiments, which will not be described in detail here.

[0143] Understandably, after the battery cells 200 are grouped together in the receiving cavity, the terminal 12 of each battery cell 200 is welded to the tap on the busbar 100. The busbar 100 connects the stacked battery cells 200 into groups, and the tap is fixedly connected to the housing through a heat-conducting layer. In this embodiment, a boss 113 is provided in the area where the explosion-proof valve 13 is located on the top cover body 11, and an adhesive layer is provided on the top surface of the boss 113. The boss 113 is then glued and fixed to the housing after contact, allowing the boss 113 to transfer heat through direct contact with the housing. Since the explosion-proof valve 13 is installed in a recessed manner on the boss 113, it effectively protects the terminal 12 and the explosion-proof valve 13, thereby improving the performance of the battery pack.

[0144] 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 of the technical features; and these 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 the present invention.

Claims

1. A top cover assembly, applied to a battery cell, characterized in that, include: The top cover body has a first through hole and a second through hole that penetrate the top cover body. The first through hole and the second through hole are spaced apart along the length direction of the top cover body. In the area where the second through hole is located, the top cover body is bent to form a boss that protrudes to one side. The second through hole is a countersunk hole, which includes a countersunk portion and a through portion that are coaxially arranged. The countersunk portion is connected to the outside of the boss. The electrode post is inserted through the first through hole and electrically connected to the electrode tab of the battery cell; An explosion-proof valve is installed on the inner wall of the through hole.

2. The top cover assembly according to claim 1, characterized in that, The inner wall of the countersunk hole is provided with reinforcing ribs; The two ends of the reinforcing rib abut against the sides of the countersunk hole along the height and width directions of the top cover body, respectively.

3. The top cover assembly according to claim 2, characterized in that, The reinforcing ribs are provided in multiple ways, and the multiple reinforcing ribs are spaced apart along the periphery of the countersunk hole portion; The projected width of the reinforcing rib on the side of the top cover body opposite to the tab is b, the number of the reinforcing ribs is n, and the perimeter of the countersunk hole is C, satisfying: 0.1≤nb / C≤0.

25.

4. The top cover assembly according to claim 2, characterized in that, Along the height direction of the top cover body, the projection height of the reinforcing rib on the inner wall of the countersunk hole is the same as the height of the countersunk hole. And / or, the cross-section of the reinforcing rib is a triangular structure, the triangular structure having a connected first side and a second side, the first side being in contact with the side of the countersunk portion along the height direction of the top cover body, and the second side being in contact with the side of the countersunk portion along the width direction of the top cover body.

5. The top cover assembly according to claim 1, characterized in that, Along the height direction of the top cover body, the depth of the countersunk hole is H2, and the thickness of the top wall of the boss is T2, satisfying: 1.5mm≤H2≤3mm, H2 / T2≤2; And / or, the inner wall of the through hole has an annular step, the explosion-proof valve is installed on the side of the annular step facing the countersunk hole, and the height of the annular step is H3, H3 satisfies: H3≥1.2mm.

6. The top cover assembly according to claim 1, characterized in that, The boss is a cone-shaped platform; The taper of the truncated cone is β, and β satisfies: 20°≤β≤25°.

7. The top cover assembly according to claim 1, characterized in that, The pole is provided in two positions, which are located at both ends of the top cover body along the length of the top cover body. The boss is located between the two pole posts, and the second through hole is located in the middle of the boss.

8. The top cover assembly according to claim 1, characterized in that, Along the height direction of the top cover body, the height of the boss is H1, the thickness of the top cover body is T1, and the thickness of the top wall of the boss is T2, satisfying: T1≥2mm, 0.75≤T2 / T1≤1.1, 2≤H1 / T1≤2.75; And / or, along the length of the top cover body, the distance between the bend of the boss and the pole post is a, where a satisfies: a≥2.5mm; And / or, the length of the top cover body is L, where L satisfies: 150mm≤L≤300mm; The width of the top cover body is W, and W satisfies: 25mm≤W≤75mm.

9. A battery cell, characterized in that, include: The electrode assembly, the housing, and the top cover assembly as described in any one of claims 1 to 8; The electrode assembly is located inside the housing, the top cover assembly is fixed to the opening end of the housing, and the electrode assembly is electrically connected to the top cover assembly through electrode tabs.

10. A battery pack, characterized in that, include: Busbar, housing, and battery cell as described in claim 9; The housing forms a receiving cavity, and multiple battery cells are provided, with the multiple battery cells stacked in the receiving cavity; the busbar is connected to the terminals of the multiple battery cells; The upper surface of the boss is bonded to the box body through an adhesive layer.

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