Top cover assembly, battery cell and battery pack

Abstract

This invention relates to the field of battery technology, providing a top cover assembly, a battery cell, and a battery pack. The top cover assembly includes: a top cover body, terminals, and a boss; the terminals pass through the top cover body and are electrically connected to the tabs of the battery cell; at least one boss is provided, connected to one side of the top cover body and protruding outward; the boss and the top cover body are integrally formed, and the boss includes a side wall and a top wall, with both ends of the side wall connected to the top cover body and the top wall, respectively; wherein, the thickness of the top cover body is t1, and the height of the boss from the side of the top cover body away from the tabs is h; along the length direction of the top cover body, the projected length of the side wall towards the top cover body along the height direction of the top cover body is L, satisfying: when h ≤ 1.5t1, 1.5t1 ≤ L ≤ 10 mm; when h > 1.5t1, 2h ≤ L ≤ 10 mm. This invention can ensure the support strength and molding yield of the boss, thereby ensuring the safety of the battery cell.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a top cover assembly, a battery cell, and a battery pack. Background Technology

[0002] The battery pack includes a housing and battery modules assembled inside the housing. Each battery module consists of multiple cells, and the terminals of the cells are electrically connected through a busbar. The housing provides physical support and protection for the battery modules. Each cell includes a housing, a top cover assembly, and an electrode assembly. The electrode assembly is located within a cavity formed by the housing and the top cover assembly, and the terminals pass through the top cover assembly and are electrically connected to the tabs of the electrode assembly.

[0003] Currently, in order to increase the capacity and support strength of the top cover assembly, bosses are set on the top cover assembly. The rationality of the structural dimensions of the bosses will affect their forming and strength. Summary of the Invention

[0004] This invention provides a top cover assembly, a battery cell, and a battery pack to solve the problem in the prior art where the dimensions of the boss structure in the top cover assembly are not set reasonably, affecting the forming and strength of the boss.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, the present invention provides a top cover assembly, comprising:

[0007] Top cover body;

[0008] The electrode post is inserted through the top cover body along the height direction of the top cover body and is electrically connected to the electrode tab of the battery cell;

[0009] The top cover body has at least one boss, which is connected to one side of the top cover body and protrudes outward along the height direction of the top cover body. The boss and the top cover body are integrally formed. The boss includes a side wall and a top wall, and the two ends of the side wall are respectively connected to the top cover body and the top wall.

[0010] Wherein, along the height direction of the top cover body, the thickness of the top cover body is t1, and the height of the boss from the side of the top cover body away from the tab is h; along the length direction of the top cover body, the projected length of the sidewall toward the top cover body along the height direction of the top cover body is L, satisfying:

[0011] When h ≤ 1.5t1, 1.5t1 ≤ L ≤ 10mm;

[0012] When h > 1.5t1, 2h ≤ L ≤ 10mm.

[0013] According to a top cover assembly provided by the present invention, a boss is provided, the boss extends along the length direction of the top cover body and is spaced apart from the pole post.

[0014] According to a top cover assembly provided by the present invention, the side wall and the top wall are connected by an arc transition, and the thickness of the thinnest part of the side wall is t2, which satisfies: 0.5t1≤t2.

[0015] According to a top cover assembly provided by the present invention, the distance between the connection point of the side wall and the top cover body and the edge of the top cover body along the length or width direction of the top cover body is L1, satisfying: t1≤L1.

[0016] According to a top cover assembly provided by the present invention, the thickness t1 of the top cover body along the height direction satisfies: 0.8mm≤t1≤3mm;

[0017] And / or, along the height direction of the top cover body, the height h of the highest boss from the side of the top cover body opposite to the tab satisfies: 0.2mm≤h≤5mm.

[0018] According to a top cover assembly provided by the present invention, two pole posts are provided, and the two pole posts are respectively disposed on both sides of the boss along the length direction of the top cover body.

[0019] According to a top cover assembly provided by the present invention, the boss has an inner cavity formed on the side facing the electrode assembly, the inner cavity being used to accommodate the electrode tab;

[0020] The boss has a liquid injection hole at its center, and the liquid injection hole is connected to the inner cavity of the boss.

[0021] According to a top cover assembly provided by the present invention, the top wall protrudes from one side of the inner cavity, the injection hole is a stepped hole, the injection hole includes a first hole segment and a second hole segment, the first hole segment is located on the side of the top wall away from the tab, the second hole segment is connected to the first hole segment, and the inner diameter of the first hole segment is larger than the inner diameter of the second hole segment.

[0022] 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;

[0023] The housing has an opening, the top cover assembly is disposed in the opening and surrounds the housing to form a receiving cavity, the electrode assembly is disposed in the receiving cavity, and the electrode assembly is electrically connected to the top cover assembly through electrode tabs.

[0024] Thirdly, the present invention provides a battery pack, comprising: a busbar, a housing, and battery cells as described above;

[0025] 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.

[0026] The top cover assembly, battery cell, and battery pack provided by this invention, by providing at least one protrusion on the top cover body, not only enhance the structural strength of the top cover assembly and thus improve the mechanical strength of the battery cell, but also increase 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, controlling the operating temperature of the battery cell, and improving the safety performance of the battery cell. Furthermore, by integrally molding the protrusion with the top cover body, forming the protrusion by stamping, and limiting the relative relationship between the projection length of the sidewall of the protrusion on the top cover body, the thickness of the top cover body, and the protrusion height of the protrusion, it is ensured that the protrusion does not occupy too much surface area of ​​the top cover body, while also ensuring the support strength and molding yield of the protrusion, thereby ensuring the safety of the battery cell. Attached Figure Description

[0027] 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.

[0028] Figure 1 This is a three-dimensional structural diagram of the first type of top cover assembly provided by the present invention.

[0029] Figure 2 This is a cross-sectional view of the first type of top cover assembly provided by the present invention.

[0030] Figure 3 This is a three-dimensional structural diagram of the second type of top cover assembly provided by the present invention.

[0031] Figure 4 This is a top view of the second type of top cover assembly provided by the present invention.

[0032] Figure 5 This invention provides Figure 4 AA sectional view.

[0033] Figure 6 This invention provides Figure 5 A magnified view of part K.

[0034] Figure 7 This invention provides Figure 4 BB cross-sectional view.

[0035] Figure 8 This is a three-dimensional structural diagram of the battery cell provided by the present invention.

[0036] Figure label:

[0037] 1. Top cover assembly;

[0038] 11. Top cover body; 12. Pole post; 13. Boss; 14. Injection hole; 131. Side wall; 132. Top wall; 141. First hole section; 142. Second hole section;

[0039] 2. Casing; 100. Battery cell. Detailed Implementation

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] The following is combined with Figures 1 to 8 The top cover assembly, battery cell, and battery pack provided in this invention will be described in detail through specific embodiments and application scenarios.

[0046] Firstly, such as Figure 1 and Figure 3 As shown, this embodiment provides a top cover assembly 1, including: a top cover body 11, a pole post 12, and a boss 13.

[0047] The pole post 12 is inserted through the top cover body 11 along the height direction of the top cover body 11 and is electrically connected to the electrode tab of the battery cell 100.

[0048] At least one boss 13 is provided. The boss 13 is connected to one side of the top cover body 11 and protrudes outward along the height direction of the top cover body 11. The boss 13 and the top cover body 11 are integrally formed. The boss 13 includes a side wall 131 and a top wall 132. The two ends of the side wall 131 are respectively connected to the top cover body 11 and the top wall 132.

[0049] Wherein, along the height direction of the top cover body 11, the thickness of the top cover body 11 is t1, and the height of the boss 13 from the side of the top cover body 11 away from the pole ear is h; along the length direction of the top cover body 11, the projected length of the side wall 131 towards the top cover body 11 along the height direction of the top cover body 11 is L, satisfying:

[0050] When h ≤ 1.5t1, 1.5t1 ≤ L ≤ 10mm.

[0051] When h > 1.5t1, 2h ≤ L ≤ 10mm.

[0052] It is understandable that the length, width, and height of the top cover body 11 are shown in the figure. Figure 1 In this embodiment, a boss 13 is provided on the top cover body 11, giving the outward-facing space of the top cover body 11 a raised structure. The boss 13 is used for supporting and connecting with the battery pack housing. Since the height of the boss 13 is higher than the height of the electrode assembly, the boss 13 can withstand the impact of external forces when the surface of the cell 100 is subjected to such forces, ensuring that the terminal post 12 is not impacted. Furthermore, since the boss 13 has a certain structural strength, it can support the top cover body 11, preventing short circuits in the cell 100 and improving the mechanical strength of the entire battery pack.

[0053] Meanwhile, when the cells 100 are stacked to form a cell module, the upper surface of the cell 100 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 13. 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 13 in this embodiment is better, which is more conducive to the heat dissipation of the cell 100, more conducive to controlling the operating temperature of the cell 100, and extending the service life of the cell 100.

[0054] Since the boss 13 in this embodiment is a one-piece molded structure, the one-piece molded structure can be achieved by stamping. The boss 13 and the top cover body 11 are made of the same piece of material. The one-piece molded structure formed by stamping simplifies the production process and ensures the reliability of the connection between the boss 13 and the top cover body 11.

[0055] Furthermore, the stamped boss 13 is a hollow platform with its inner cavity facing the side of the electrode tab. After the electrode tab is bent, it can be accommodated in the inner cavity, thereby reducing the distance between the electrode group and the top cover body 11, increasing the bending space of the electrode tab, and thus increasing the capacity of the battery cell 100.

[0056] Furthermore, in this embodiment, the boss 13 includes a top wall 132 and a side wall 131. The side wall 131 surrounds one side of the top cover body 11, and the side wall 131 and the top wall 132 together form an inner cavity.

[0057] Since at least one boss 13 is provided in this embodiment, there can be only one boss 13 or multiple bosses 13, which can be spaced apart along the length of the top cover body 11. The heights of the multiple bosses 13 can be the same or different. The top wall 132 of the tallest boss 13 is connected to the battery pack housing support.

[0058] Similarly, as Figure 2 and Figure 4 As shown, the pole post 12 can be set either on the side of the boss 13 or inside the boss 13. The pole post 12 only needs to be exposed on the top wall 132 of the boss 13.

[0059] Specifically, the top cover body 11 can be made of aluminum, stainless steel, or titanium alloy.

[0060] Meanwhile, to meet the forming and strength requirements of the boss 13, this embodiment limits the parameters of the boss 13. Since the boss 13 is formed by stamping the top cover body 11, and the side wall 131 connects the top cover body 11 and the top wall 132, the projected length L of the side wall 131 towards the top cover body 11 needs to meet a certain range. If the projected length L of the side wall 131 is too small, the side wall 131 lacks strength and cannot provide sufficient support for the top wall 132. If the projected length L of the side wall 131 is too large, the projected area of ​​the side wall 131 towards the top cover body 11 is too large, and the boss 13 occupies too much area of ​​the top cover body 11, affecting the placement of other structures in locations on the top cover body 11 where the boss 13 is not present.

[0061] Since the thickness of the top cover body 11 is t1 and the protrusion height of the highest boss 13 is h, when h ≤ 1.5t1, the minimum value of the length L is limited by 1.5t1. Furthermore, the maximum length L cannot exceed 10mm. When h > 1.5t1, the minimum value of the length L is limited by 2h, and the maximum length L cannot exceed 10mm. By limiting the ratio of the projected length L of the side wall 131 to the thickness of the top cover body 11 or the protrusion height h of the highest boss 13, the structural strength of the side wall 131 is ensured, thereby providing stable support for the top wall 132. For the stamping process, limiting the length L also ensures the forming yield of the boss 13 and prevents cracks from appearing in the boss 13 during stamping.

[0062] The top cover assembly 1 provided by the present invention, by providing at least one boss 13 on the top cover body 11, not only enhances the structural strength of the top cover assembly 1 through the boss 13, thereby improving the mechanical strength of the battery cell 100, but also increases the surface area of ​​the top cover body 11 through the boss 13, 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 100, controlling the operating temperature of the battery cell 100, and improving the safety performance of the battery cell 100. Furthermore, by integrally forming the boss 13 with the top cover body 11, forming the boss 13 by stamping, and limiting the relative relationship between the projection length of the side wall 131 of the boss 13 on the top cover body 11, the thickness of the top cover body 11, and the protrusion height of the boss 13, it is ensured that the boss 13 does not occupy too much surface area of ​​the top cover body 11, and that the support strength and forming yield of the boss 13 are also ensured, thereby ensuring the safety of the battery cell 100.

[0063] like Figure 3 As shown, this embodiment has a boss 13, which extends along the length of the top cover body 11 and is spaced apart from the pole post 12.

[0064] Understandably, in order to reduce processing steps and achieve regularity on the top cover body 11, only one boss 13 is provided in this embodiment. The boss 13 is spaced apart from the terminal post 12, and the boss 13 can abut against the battery pack housing to support the top cover body 11.

[0065] like Figure 4 , Figure 5 and Figure 6 As shown, in this embodiment, the sidewall 131 and the top wall 132 are connected by a circular arc transition. The thickness of the thinnest part of the sidewall 131 is t2, which satisfies: 0.5t1≤t2.

[0066] Understandably, to avoid stress concentration at the connection of the stamped boss 13, the sidewall 131 and top wall 132 of this embodiment are connected by an arc transition to improve the fatigue life and overall strength of the sidewall 131. Furthermore, since the sidewall 131 is formed by thinning the top cover body 11, the thickness of the thinnest part of the sidewall 131 is limited to prevent insufficient strength due to excessively small thickness t2, which could lead to cracking of the sidewall 131.

[0067] Specifically, t2 / t1 can be 0.5, 0.6, or 0.7.

[0068] like Figure 4 , Figure 5 , Figure 6 and Figure 7As shown, along the length or width direction of the top cover body 11, the distance between the connection point of the side wall 131 and the top cover body 11 and the edge of the top cover body 11 in this embodiment is L1, which satisfies: t1≤L1.

[0069] Understandably, the distance between the connection point of the sidewall 131 and the top cover body 11 and the edge of the top cover body 11 needs to meet a certain range. The edge of the top cover body 11 can be the edge along the length direction of the top cover body 11 or the edge along the width direction of the top cover body 11. The ratio of the distance L1 to the thickness t1 of the top cover body 11 should not be too small to avoid the appearance of collapsed edges and burrs on the edge of the top cover body 11.

[0070] Specifically, L1 / t1 can be 1, 1.5, or 2.

[0071] like Figure 4 , Figure 5 and Figure 6 As shown, along the height direction of the top cover body 11, the thickness t1 of the top cover body 11 in this embodiment satisfies: 0.8mm≤t1≤3mm.

[0072] It is understandable that the thickness of the top cover body 11 in this embodiment needs to meet a certain range, and it cannot be too large or too small. If the thickness of the top cover body 11 is too small, it will be difficult to weld the top cover body 11 and will affect the structural strength of the top cover body 11. If the thickness of the top cover body 11 is too large, the weight will be too large, occupying the internal space of the battery cell 100 and increasing the cost.

[0073] Specifically, the thickness t1 of the top cover body 11 can be 0.8mm, 1.9mm, or 3mm.

[0074] like Figure 4 , Figure 5 and Figure 6 As shown, along the height direction of the top cover body 11, the height h of the highest boss 13 in this embodiment from the side of the top cover body 11 away from the tab satisfies: 0.2mm≤h≤5mm.

[0075] Understandably, when there are multiple protrusions 13, and the heights of these protrusions 13 are not equal, the highest protrusion 13 abuts against the battery pack housing for support. Due to the limitations of the internal space of the battery cell 100, the height of the highest protrusion 13 cannot be too high, lest the protrusion 13 extend into the battery cell 100 and the flatness angle of the top wall 132 be poor. The height of the highest protrusion 13 also cannot be too small, lest it fail to support the housing.

[0076] Specifically, the height h can be 0.2mm, 1.25mm, or 5mm.

[0077] As shown in Table 1, the production line of this embodiment tests various indicators of the battery cell 100 to verify the technical effects of different data. The battery cell 100 is analyzed by successively changing the height h of the highest boss 13 from the side of the top cover body 11 away from the tab, the thickness t1 of the top cover body 11, the projection length L of the side wall 131 along the height direction of the top cover body 11 towards the top cover body 11, and the thickness t2 of the thinnest part of the side wall 131.

[0078] It can be seen that for Examples 1-6, when h≤1.5t1, 1.5t1≤L≤10mm, 0.5t1≤t2; for Examples 7-8, when h>1.5t1, 2h≤L≤10mm, 0.5t1≤t2, the parameters of the top cover assembly 1 in this embodiment are satisfied, the flatness of the boss 13 meets the requirements, the top cover assembly 1 has no abnormalities, and the yield requirement is met. For Comparative Examples 1-2, when h≤1.5t1, 1.5t1≤L≤10mm, 0.5t1≤t2 are not satisfied; for Comparative Example 3, when h>1.5t1, 2h≤L≤10mm, 0.5t1≤t2 are also not satisfied, the flatness of the boss 13 does not meet the requirements, and stamping cracks appear on the side of the boss 13, indicating that the processing of the top cover assembly 1 is unqualified.

[0079] Table 1: Examples and Comparative Examples

[0080]

[0081] like Figure 3 As shown, this embodiment has two pole posts 12, which are located on both sides of the boss 13 along the length of the top cover body 11.

[0082] Understandably, the two terminals 12 are the positive terminal and the negative terminal, respectively. The positive terminal and the negative terminal are located on opposite sides of the protrusion 13.

[0083] like Figure 4 and Figure 5 As shown, the boss 13 in this embodiment has an inner cavity on the side facing the electrode assembly, which is used to accommodate the electrode tab.

[0084] The boss 13 has a liquid injection hole 14 at its center, and the liquid injection hole 14 is connected to the inner cavity of the boss 13.

[0085] Understandably, the injection hole 14 is used to inject electrolyte during battery manufacturing. The injection hole 14 penetrates the top wall 132 of the boss 13 and communicates with the inner cavity of the boss 13. The electrolyte can be injected into the inner cavity through the injection hole 14 and smoothly enter the interior of the cell 100. Since the injection hole 14 is located at the center of the boss 13, the electrolyte can fill the entire inner cavity to the maximum extent, which is beneficial for electrolyte wetting.

[0086] like Figure 4 and Figure 7 As shown, in this embodiment, the top wall 132 protrudes towards the inner cavity, and the injection hole 14 is a stepped hole. The injection hole 14 includes a first hole section 141 and a second hole section 142. The first hole section 141 is located on the side of the top wall 132 away from the tab, and the second hole section 142 is connected to the first hole section 141. The inner diameter of the first hole section 141 is larger than the inner diameter of the second hole section 142.

[0087] Understandably, to facilitate the smooth flow of electrolyte from the injection hole 14, the top wall 132 has a protruding feature to accommodate the second hole segment 142. Since the diameter of the first hole segment 141 is larger than that of the second hole segment 142, after the electrolyte is injected into the second hole segment 142, it is drawn into the second hole segment 142. Due to the reduction in the flow area, the flow rate of the electrolyte is accelerated, which is beneficial to the injection speed of the electrolyte.

[0088] Secondly, such as Figure 8 As shown, this embodiment provides a battery cell 100, including: an electrode group, a housing 2, and a top cover assembly 1 as described above.

[0089] The housing 2 has an opening, the top cover assembly 1 is disposed in the opening and surrounds the housing 2 to form a receiving cavity, the electrode assembly is disposed in the receiving cavity, and the electrode assembly is electrically connected to the top cover assembly 1 through electrode tabs.

[0090] Specifically, since the battery cell 100 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 100 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.

[0091] Understandably, the electrode assembly is inserted into the housing 2, and the top cover assembly 1 is placed over the opening of the housing 2. The electrode assembly is electrically connected to the pole post 12 of the top cover assembly 1 through the electrode tabs to realize the transmission of current. The top cover assembly 1 and the housing 2 constitute the outer shell of the battery cell 100, forming protection for the internal components of the battery cell 100 and being able to withstand a certain amount of external impact.

[0092] In this embodiment, a protrusion 13 is provided on the top cover body 11. The protrusion 13 is suitable for connection with the battery pack housing support, which increases the stress-bearing area of ​​the top cover body 11, avoids the terminal post 12 being subjected to stress alone, and improves the safety performance of the battery cell 100. Furthermore, the projected length of the side wall 131 of the protrusion 13 on the top cover body 11 is limited, which ensures that the protrusion 13 does not occupy too much surface area of ​​the top cover body 11, and also ensures the support strength and molding yield of the protrusion 13, thereby ensuring the safety of the battery cell 100.

[0093] Thirdly, this embodiment provides a battery pack, including: a busbar, a housing, and the battery cell 100 as described above.

[0094] The housing forms a receiving cavity, and multiple battery cells 100 are provided, with multiple battery cells 100 stacked in the receiving cavity; the busbar is connected to the terminals 12 of the multiple battery cells 100.

[0095] Specifically, since the battery pack includes a cell 100, and the specific structure of the cell 100 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.

[0096] Understandably, after the battery cells 100 are grouped together within the receiving cavity, the terminal post 12 of each battery cell 100 is welded to the tap on the busbar. The busbar connects the stacked battery cells 100 into groups, and the tap is fixedly connected to the housing through a heat-conducting layer. Because this embodiment provides a protrusion 13 on the side of the terminal post 12, the overall capacity of the battery pack is increased, thereby improving the performance of the battery pack.

[0097] In traditional battery pack structures, the battery pack relies solely on the casing to withstand external impacts. The casing plate opposite the terminal post 12 has a large area, and if its rigidity is insufficient, it is prone to deformation. To prevent casing deformation from causing compression damage to the busbar and terminal post 12, a large space needs to be reserved between the busbar and the casing in the structural design, and supporting foam needs to be installed between them. Some designs also incorporate concave and convex structures on the casing plate to enhance its rigidity and prevent deformation. However, these measures result in a large gap between the cell 100 and the casing, wasting space. Increasing the casing thickness to increase rigidity would increase the weight of the battery pack, hindering lightweight design.

[0098] To address this, this embodiment provides a boss 13 on the outer surface of the top cover body 11. The boss 13 is used to support and connect with the casing, so that the outer shell of the battery cell 100 itself also serves as a supporting load-bearing component. Under the support of the outer shell, large deformation of the casing can be avoided, thereby reducing the thickness of the casing and the weight of the battery pack. Furthermore, while ensuring that the casing does not cause crush damage to the busbars and terminals 12, the distance between the busbars and the casing can be reduced, thereby increasing the volume of the battery cell 100. This fully utilizes the internal space of the casing, increasing the capacity of the battery cell 100 and the energy density of the entire battery pack.

[0099] 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: Top cover body; The electrode post is inserted through the top cover body along the height direction of the top cover body and is electrically connected to the electrode tab of the battery cell; The top cover body has at least one boss, which is connected to one side of the top cover body and protrudes outward along the height direction of the top cover body. The boss and the top cover body are integrally formed. The boss includes a side wall and a top wall, and the two ends of the side wall are respectively connected to the top cover body and the top wall. Wherein, along the height direction of the top cover body, the thickness of the top cover body is t1, and the height of the boss from the side of the top cover body away from the tab is h; along the length direction of the top cover body, the projected length of the sidewall toward the top cover body along the height direction of the top cover body is L, satisfying: When h ≤ 1.5t1, 1.5t1 ≤ L ≤ 10mm; When h > 1.5t1, 2h ≤ L ≤ 10mm.

2. The top cover assembly according to claim 1, characterized in that, The boss is provided, and the boss extends along the length direction of the top cover body and is spaced apart from the pole post.

3. The top cover assembly according to claim 1 or 2, characterized in that, The sidewall and the top wall are connected by a circular arc transition. The thickness of the thinnest part of the sidewall is t2, which satisfies: 0.5t1≤t2.

4. The top cover assembly according to claim 1 or 2, characterized in that, Along the length or width direction of the top cover body, the distance between the connection point of the side wall and the top cover body and the edge of the top cover body is L1, satisfying: t1≤L1.

5. The top cover assembly according to claim 1, characterized in that, Along the height direction of the top cover body, the thickness t1 of the top cover body satisfies: 0.8mm≤t1≤3mm; And / or, along the height direction of the top cover body, the height h of the highest boss from the side of the top cover body opposite to the tab satisfies: 0.2mm≤h≤5mm.

6. The top cover assembly according to claim 2, characterized in that, The pole is provided in two positions, which are located on both sides of the boss along the length of the top cover body.

7. The top cover assembly according to claim 6, characterized in that, The protrusion has an inner cavity on the side facing the electrode assembly, and the inner cavity is used to accommodate the electrode tab. The boss has a liquid injection hole at its center, and the liquid injection hole is connected to the inner cavity of the boss.

8. The top cover assembly according to claim 7, characterized in that, The top wall protrudes towards the inner cavity, and the injection hole is a stepped hole. The injection hole includes a first hole section and a second hole section. The first hole section is located on the side of the top wall away from the tab, and the second hole section is connected to the first hole section. The inner diameter of the first hole section is larger than the inner diameter of the second hole section.

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 housing has an opening, the top cover assembly is disposed in the opening and surrounds the housing to form a receiving cavity, the electrode assembly is disposed in the receiving cavity, 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.

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