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, a boss and a connecting sheet; a first through hole penetrating through the top cover body is formed in the top cover body; the pole penetrates through the first through hole and is electrically connected with the tab of the battery cell through the connecting sheet; the boss is connected to one side of the top cover body and protrudes outwards in the height direction of the top cover body, and the boss is suitable for being connected with a box body of the battery pack in a supporting mode; the bosses and the first through holes are arranged at intervals in the length direction of the top cover body; the boss comprises a side wall and a cover body, the side wall is arranged on the side, away from the tab, of the top cover body in a surrounding mode, the cover body covers the opening end of the side wall to form an inner cavity, and the inner cavity is used for containing the tab and the connecting piece; the side wall and the cover body are both square. The side wall is perpendicular to the top cover body. According to the top cover assembly provided by the invention, the safety performance of the battery cell is improved, and the structural strength of the bosses and the tightness of arrangement along the top cover body are ensured.

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 multiple cells are electrically connected through a busbar. The housing provides physical support and protection for the battery modules. Each battery 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 provide bending space for the tabs, sufficient height needs to be reserved between the electrode assembly and the top cover body, which wastes the space inside the cell. Furthermore, the cell only contacts other structures in the cell module through the terminal post. When the upper surface of the cell is subjected to force, the terminal post is directly subjected to force, which increases the risk of short circuit and results in low structural strength. Summary of the Invention

[0004] This invention provides a top cover assembly, a battery cell, and a battery pack to solve the problems in the prior art where the top cover assembly only bears force through the poles, resulting in low strength of the battery cell, and the space reserved between the top cover assembly and the pole group for bending of the tabs, resulting in low battery cell capacity.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows: In a first aspect, the present invention provides a top cover assembly, comprising: The top cover body has a first through hole penetrating the top cover body; The electrode post passes through the first through hole and is electrically connected to the electrode tab of the battery cell through a connecting piece; A boss is connected to one side of the top cover body and protrudes outward along the height direction of the top cover body. The boss is adapted to be supported and connected to the battery pack housing. Along the length direction of the top cover body, the boss is spaced apart from the first through hole. The boss includes a side wall and a cover. The side wall surrounds the side of the top cover body away from the electrode tab. The cover covers the opening end of the side wall to form an inner cavity for accommodating the electrode tab and the connecting piece. Both the sidewall and the cover are square; the sidewall is perpendicular to the top cover body.

[0006] According to a top cover assembly provided by the present invention, the height of the side wall along the height direction of the top cover body is h, which satisfies: 2.0mm≤h≤6.5mm; The thickness of the sidewall is t, which satisfies: 1.2mm≤t≤2.0mm.

[0007] According to a top cover assembly provided by the present invention, the distance between the sidewall and the edge of the top cover body along the length direction of the top cover body is L2, satisfying: 3mm≤L2≤6mm; Along the width direction of the top cover body, the width of the top cover body is W, and the distance between the side wall and the edge of the top cover body is W1, satisfying: 1mm≤W1≤3mm, 2W1≥1 / 3W.

[0008] According to a top cover assembly provided by the present invention, the four corners of the sidewall are rounded, and the radius of the rounded arc is R, satisfying: 1.2≤R≤4.0; And / or, along the height direction of the top cover body, the projected area of ​​the cover body is S1, and the projected area of ​​the top cover body is S, satisfying: S1≤1 / 3S.

[0009] A top cover assembly according to the present invention further includes: a lower plastic layer; The lower plastic is located on the side of the top cover body facing the electrode ear. The lower plastic is attached to the side wall at the position corresponding to the inner cavity and is arranged circumferentially along the inner wall of the side wall, and is spaced apart from the cover body along the height direction of the top cover body.

[0010] According to a top cover assembly provided by the present invention, the inner side of the side wall is inclined along the height direction of the top cover body, and the cross-sectional area of ​​the side wall gradually increases from the end away from the cover body toward the end closer to the cover body.

[0011] A top cover assembly according to the present invention further includes: a connecting block; The connecting block is located on the side of the top cover body away from the electrode tab. The connecting block has a through hole, and the electrode post passes through the through hole and is connected to the connecting block.

[0012] According to a top cover assembly provided by the present invention, the distance between the connecting block and the side wall along the length direction of the top cover body is L1, which satisfies: 4.5mm≤L1≤8.5mm.

[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 in any of the preceding claims; 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 and connecting pieces.

[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.

[0015] The top cover assembly, battery cell, and battery pack provided by this invention, by providing protrusions on the sides of the terminals along the length of 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 heat-conducting 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 setting the protrusions in a hollow and separate manner, the inner cavity formed by the sidewalls and the cover body can not only accommodate the bent electrode tabs and connecting pieces, but also improve the production yield of the top cover assembly. The limitation on the shape of the cover body and the sidewalls further ensures the structural strength of the protrusions and the tightness of their arrangement along the top cover body. 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 provided by the present invention.

[0018] Figure 2 This is a top view of the top cover assembly provided by the present invention.

[0019] Figure 3 This invention provides Figure 2 AA sectional view.

[0020] Figure 4 This is a three-dimensional structural diagram of the cover provided by the present invention.

[0021] Figure 5 This is a three-dimensional structural diagram of the battery cell provided by the present invention.

[0022] Figure 6 This is a cross-sectional view of the battery cell provided by the present invention.

[0023] Figure label: 1. Top cover assembly; 11. Top cover body; 12. Pole post; 13. Boss; 14. Connecting piece; 15. Connecting block; 16. Lower plastic; 131. Side wall; 132. Cover body; 2. Electrode group; 21. Electrode ear; 3. Shell; 100. Battery cells. Detailed Implementation

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] The following is combined Figures 1 to 6 The top cover assembly, battery cell, and battery pack provided in this embodiment will be described in detail through specific implementation methods and application scenarios.

[0030] 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, a boss 13, and a connecting piece 14.

[0031] The top cover body 11 has a first through hole that penetrates the top cover body 11.

[0032] The electrode post 12 passes through the first through hole and is electrically connected to the electrode tab 21 of the battery cell 100 through the connecting piece 14.

[0033] 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 is adapted to be connected to the battery pack housing support. Along the length direction of the top cover body 11, the boss 13 is spaced apart from the first through hole. The boss 13 includes a side wall 131 and a cover 132. The side wall 131 surrounds the side of the top cover body 11 away from the tab 21. The cover 132 covers the opening end of the side wall 131 to form an inner cavity. The inner cavity is used to accommodate the tab 21 and the connecting piece 14.

[0034] In this embodiment, both the sidewall 131 and the cover 132 are square; the sidewall 131 is perpendicular to the top cover body 11.

[0035] It is understandable that the length, width, and height of the top cover body 11 are shown in the figure. Figure 1In this embodiment, a protrusion 13 is provided on the side of the terminal post 12, giving the space on the side of the terminal post 12 a raised structure. The protrusion 13 is used for supporting connection with the battery pack housing. Since the height of the protrusion 13 is higher than the height of the electrode group 2, when the surface of the cell 100 is subjected to external impact, the protrusion 13 can withstand the impact, ensuring that the terminal post 12 is not subjected to external impact. Furthermore, since the protrusion 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 cell pack.

[0036] 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.

[0037] The top cover assembly 1 in this embodiment also includes a connecting piece 14, which extends along the length of the top cover body 11. One end of the connecting piece 14 is connected to the pole post 12, and the other end of the connecting piece 14 is bent and extends into the inner cavity and is connected to the tab 21. The connecting piece 14 is arranged in a "Z" shape to ensure that the two ends connected to the pole post 12 and the tab 21 are parallel.

[0038] In this embodiment, the boss 13 is set as a hollow platform with the inner cavity facing the side of the tab 21. The tab 21 and the connecting piece 14 can be accommodated in the inner cavity after bending, thereby reducing the gap height between the pole group 2 and the top cover body 11, increasing the bending space of the tab 21, and thus increasing the capacity of the cell 100.

[0039] Furthermore, such as Figure 4 As shown, in this embodiment, the boss 13 is set separately, the side wall 131 surrounds one side of the top cover body 11, and the cover 132 is welded and fixed to the side wall 131. The side wall 131 and the cover 132 together form an inner cavity. Because the boss 13 is set separately, the size of the side wall 131 and the size of the cover 132 can be reasonably set, making the shape of the boss 13 easier to control, improving the production yield of the top cover assembly 1, and ensuring the structural strength of the top cover assembly 1.

[0040] It should be noted that the battery cell 100 has two terminals 12, namely a positive terminal and a negative terminal. In this embodiment, the top cover assembly 1 has one terminal 12, and the other terminal is located on the cover assembly on the other side of the battery cell 100.

[0041] Furthermore, since the strip-shaped hole is easier to process, the square sidewall 131 and the cover 132 have more regular shapes, and since the tab 21 is also a thin sheet structure, the square inner cavity formed by the square sidewall 131 and the cover 132 is convenient for accommodating the tab 21.

[0042] Furthermore, since the sidewall 131 is perpendicular to the top cover body 11, the vertical load from above the sidewall 131 can be directly and evenly transferred to the top cover body 11 through the sidewall 131, avoiding stress concentration and bending of the sidewall 131. In addition, the boss 13 is square, which can be closely arranged on the top cover body 11, reducing ineffective space and making it more conducive to the integrated design on the top cover body 11.

[0043] The top cover assembly 1 provided by the present invention has a protrusion 13 provided on the side of the pole 12 along the length direction of the top cover body 11. This not only enhances the structural strength of the top cover assembly 1 and thus improves the mechanical strength of the battery cell 100, but also 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 100, controlling the operating temperature of the battery cell 100, and improving the safety performance of the battery cell 100. Furthermore, by hollowing out the protrusion 13, the inner cavity formed by the side wall 131 and the cover body 132 can not only accommodate the bent pole tab 21 and the connecting piece 14, but also improve the production yield of the top cover assembly 1. The shape limitation of the cover body 132 and the side wall 131 further ensures the structural strength of the protrusion 13 and the tightness of its arrangement along the top cover body 11.

[0044] like Figure 2 and Figure 3 As shown, along the height direction of the top cover body 11, the height of the side wall 131 in this embodiment is h, which satisfies: 2.0mm≤h≤6.5mm.

[0045] The thickness of sidewall 131 is t, which satisfies: 1.2mm≤t≤2.0mm.

[0046] Understandably, since the tab 21 extends into the inner cavity and bends within it to connect with the connecting piece 14, the height h of the side wall 131 needs to meet a certain range to ensure sufficient bending space for the tab 21 and also to ensure the structural strength of the side wall 131. At the same time, to ensure the overall structural strength of the boss 13, the thickness t of the side wall 131 also needs to meet a certain range.

[0047] Specifically, the height h of the sidewall 131 can be 2.0 mm, 4.25 mm, or 6.5 mm. The thickness t of the sidewall 131 can be 1.2 mm, 1.6 mm, or 2.0 mm.

[0048] like Figure 2 As shown, in this embodiment, along the length of the top cover body 11, the distance between the side wall 131 and the edge of the top cover body 11 is L2, which satisfies: 3mm≤L2≤6mm.

[0049] Along the width direction of the top cover body 11, the width of the top cover body 11 is W, and the distance between the side wall 131 and the edge of the top cover body 11 is W1, satisfying: 1mm≤W1≤3mm, 2W1≥1 / 3W.

[0050] Understandably, in order to ensure the strength of the top cover body 11 and the reliability of the manufacturing process, the distance L2 from the side wall 131 to the edge of the top cover body 11 along the length direction of the top cover body 11 and the distance W1 along the width direction of the top cover body 11 need to meet certain ranges. Furthermore, the ratio of the distance W1 along the width direction of the top cover body 11 to the width W of the top cover body 11 also needs to meet certain ranges.

[0051] Specifically, L2 can be 3mm, 4.5mm, or 6mm. W1 can be 1mm, 2mm, or 3mm. 2W1 can be 1 / 3W, 1 / 2W, or 2 / 3W.

[0052] In this embodiment, the four corners of the sidewall 131 are rounded, with a radius of R, satisfying: 1.2≤R≤4.0.

[0053] Understandably, to avoid stress concentration at the four corners of the square hole, the four corners can be designed as rounded transition structures to improve the fatigue life and overall strength of the sidewall 131.

[0054] Specifically, the radius R of the arc can be 1.2, 2.6, or 4.0.

[0055] Along the height direction of the top cover body 11, the projected area of ​​the cover 132 in this embodiment is S1, and the projected area of ​​the top cover body 11 is S, satisfying: S1≤1 / 3S.

[0056] Understandably, in order to ensure the structural strength of the top cover body 11 and the reliability of the mounting pole 12, the ratio of the area of ​​the cover body 132 to the area of ​​the top cover body 11 in this embodiment needs to meet a certain range.

[0057] Specifically, S1 can be 1 / 3S, 1 / 4S, or 1 / 5S.

[0058] like Figure 3 As shown, the top cover assembly 1 in this embodiment also includes a lower plastic 16.

[0059] The lower plastic 16 is located on the side of the top cover body 11 facing the tab 21. The lower plastic 16 is attached to the side wall 131 at the position corresponding to the inner cavity and is arranged circumferentially along the inner wall of the side wall 131, and is spaced apart from the cover body 132 along the height direction of the top cover body 11.

[0060] Understandably, to avoid short circuits between the tab 21 and connecting piece 14 and the boss 13, this embodiment provides a lower plastic 16 on one side of the top cover body 11. The lower plastic 16 is attached to the inner wall of the side wall 131 at the location of the inner cavity and is arranged circumferentially around the side wall 131 to prevent short circuits caused by contact between the tab 21 and connecting piece 14 and the side wall 131. At the same time, to avoid interference between the lower plastic 16 in the inner cavity and the cover 132, affecting the assembly of the cover 132 and the side wall 131, the cover 132 and the lower plastic 16 are spaced a certain distance apart along the height direction of the top cover body 11.

[0061] like Figure 1 and Figure 3 As shown, along the height direction of the top cover body 11, the inner side of the side wall 131 in this embodiment is inclined, and the cross-sectional area of ​​the side wall 131 gradually increases from the end away from the cover body 132 toward the end closer to the cover body 132.

[0062] Understandably, to ensure easy assembly of the top of the side wall 131 with the cover 132, the inner side of the side wall 131 in this embodiment is inclined, presenting a flared structure. The larger end of the flared opening is located on one side of the cover 132. The assembly and disassembly of the cover 132 relative to the side wall 131 can be quickly performed.

[0063] like Figure 3 As shown, the top cover assembly 1 in this embodiment also includes a connecting block 15.

[0064] The connecting block 15 is located on the side of the top cover body 11 away from the electrode tab 21. The connecting block 15 has a through hole, and the electrode post 12 passes through the through hole and is connected to the connecting block 15.

[0065] It is understood that the connecting block 15 in this embodiment is a strip block, and the through hole is set at the center of symmetry of the strip block. The pole post 12 is connected to the center of symmetry of the strip block through the through hole, which improves the fixing stability of the pole post 12.

[0066] Specifically, the connecting block 15 can be a riveted aluminum block, and the top cover body 11 can be an aluminum plate.

[0067] like Figure 2 As shown, in this embodiment, the distance between the connecting block 15 and the side wall 131 along the length of the top cover body 11 is L1, which satisfies: 4.5mm≤L1≤8.5mm.

[0068] Understandably, in order to ensure the structural strength of the top cover body 11, the distance L1 between the connecting block 15 and the side wall 131 needs to meet a certain range. Furthermore, in order to ensure the performance of the pole group 2, such as the flatness and sealing performance of the pole post 12, the distance between the connecting block 15 and the side wall 131 also needs to meet a certain range.

[0069] Specifically, L1 can be 4.5mm, 6.5mm, or 8.5mm.

[0070] Secondly, such as Figure 5 and Figure 6 As shown, this embodiment provides a battery cell 100, including: an electrode group 2, a housing 3, and a top cover assembly 1 as described above.

[0071] The housing 3 has an opening, the top cover assembly 1 is disposed in the opening and surrounds the housing 3 to form a receiving cavity, the pole group 2 is disposed in the receiving cavity, and the pole group 2 is electrically connected to the top cover assembly 1 through the pole tab 21 and the connecting piece 14.

[0072] 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.

[0073] Understandably, the electrode assembly 2 is installed inside the housing 3, and the top cover assembly 1 is placed over the opening of the housing 3. The electrode assembly 2 is electrically connected to the electrode post 12 of the top cover assembly 1 through the electrode tab 21 to realize the transmission of current. The top cover assembly 1 and the housing 3 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.

[0074] In this embodiment, a boss 13 is provided on the top cover body 11. The boss 13 is suitable for connection with the battery pack housing support, which increases the force-bearing area of ​​the top cover body 11, avoids the pole post 12 being subjected to force alone, and improves the safety performance of the battery cell 100.

[0075] Thirdly, this embodiment provides a battery pack, including: a busbar, a housing, and the battery cell 100 as described above.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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 penetrating the top cover body; The electrode post passes through the first through hole and is electrically connected to the electrode tab of the battery cell through a connecting piece; A boss is connected to one side of the top cover body and protrudes outward along the height direction of the top cover body. The boss is adapted to be supported and connected to the battery pack housing. Along the length direction of the top cover body, the boss is spaced apart from the first through hole. The boss includes a side wall and a cover. The side wall surrounds the side of the top cover body away from the electrode tab. The cover covers the opening end of the side wall to form an inner cavity for accommodating the electrode tab and the connecting piece. Both the sidewalls and the cover are square. The sidewall is perpendicular to the top cover body.

2. The roof assembly of claim 1, wherein, Along the height direction of the top cover body, the height of the side wall is h, which satisfies: 2.0mm≤h≤6.5mm; The thickness of the sidewall is t, which satisfies: 1.2mm≤t≤2.0mm.

3. The roof assembly of claim 2, wherein, Along the length of the top cover body, the distance between the sidewall and the edge of the top cover body is L2, satisfying: 3mm≤L2≤6mm; Along the width direction of the top cover body, the width of the top cover body is W, and the distance between the side wall and the edge of the top cover body is W1, satisfying: 1mm≤W1≤3mm, 2W1≥1 / 3W.

4. The top cover assembly according to claim 2, characterized in that, The four corners of the sidewall are rounded, and the radius of the rounded arc is R, satisfying: 1.2≤R≤4.0; And / or, along the height direction of the top cover body, the projected area of ​​the cover body is S1, and the projected area of ​​the top cover body is S, satisfying: S1≤1 / 3S.

5. The top cover assembly according to claim 1, characterized in that, Also includes: Plastic bottom; The lower plastic is located on the side of the top cover body facing the electrode ear. The lower plastic is attached to the side wall at the position corresponding to the inner cavity and is arranged circumferentially along the inner wall of the side wall, and is spaced apart from the cover body along the height direction of the top cover body.

6. The top cover assembly according to claim 1, characterized in that, Along the height direction of the top cover body, the inner side of the side wall is inclined, and the cross-sectional area of ​​the side wall gradually increases from the end away from the cover body toward the end closer to the cover body.

7. The top cover assembly according to claim 1, characterized in that, Also includes: Connector block; The connecting block is located on the side of the top cover body away from the electrode tab. The connecting block has a through hole, and the electrode post passes through the through hole and is connected to the connecting block.

8. The top cover assembly according to claim 7, characterized in that, Along the length of the top cover body, the distance between the connecting block and the side wall is L1, which satisfies: 4.5mm≤L1≤8.5mm.

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 and connecting pieces.

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.

Images