Top cover assembly, battery cell and battery pack

Abstract

The application 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, an explosion-proof valve and a boss. The top cover body is formed with a first through hole and a second through hole penetrating through the top cover body. The first through hole and the second through hole are arranged at intervals along the length direction of the top cover body. The pole is arranged in the first through hole and is electrically connected with the tab of the battery cell. The explosion-proof valve is arranged in the second through hole. The boss is arranged between the pole and the explosion-proof valve along the length direction of the top cover body. The outer surface of the boss is provided with a rib. The top cover assembly provided by the application can not only enhance the structural strength of the top cover assembly, thereby improving the mechanical strength of the battery cell, but also realize the thermal-electric separation of the pole and the explosion-proof valve, increase the heat dissipation area of the top cover body and the pasting area with the heat conduction layer, improve the heat dissipation efficiency of the battery cell, control the use temperature of the battery cell, and improve the safety performance 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] With the rapid development of new energy vehicles and energy storage equipment, the requirements for battery structural safety and energy density are increasing. The battery cell is the smallest unit in the battery cell module. In the existing technology, the battery cell consists of a top cover assembly, an electrode assembly, and a housing. The top cover assembly and the housing are fixedly connected by welding to form a closed space to accommodate the electrode assembly. The electrode post passes through the top cover assembly and is electrically connected to the electrode tab of the electrode assembly.

[0003] Currently, the battery cell only contacts other structures within the battery cell module through the terminals. When the upper surface of the battery cell is subjected to force, the terminals bear the force directly, which increases the risk of short circuits and results in low structural strength. Furthermore, when the battery cell dissipates heat, heat is only conducted through the terminals and the heat-conducting layer, leading to poor heat dissipation. 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 top cover assembly only relies on the terminals for stress and heat conduction, resulting in low strength and poor heat dissipation of the battery cell.

[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] The top cover body has a first through hole and a second through hole that penetrate the top cover body, and the first through hole and the second through hole are spaced apart along the length direction of the top cover body;

[0008] The electrode post is inserted through the first through hole and electrically connected to the electrode tab of the battery cell;

[0009] An explosion-proof valve is installed in the second through hole;

[0010] A boss is provided along the length of the top cover body between the pole and the explosion-proof valve, and the outer surface of the boss is provided with ribs.

[0011] According to a top cover assembly provided by the present invention, a plurality of ribs are provided, and the plurality of ribs are arranged at intervals along the length direction or width direction of the top cover body.

[0012] According to a top cover assembly provided by the present invention, a plurality of ribs are evenly spaced, and the spacing between adjacent ribs is b, wherein b satisfies: 3mm≤b≤6mm.

[0013] According to a top cover assembly provided by the present invention, when the ribs are spaced apart along the length direction of the top cover body, the number of ribs is n, the width of the ribs is a, the width of the outer surface of the boss along the width direction of the top cover body is c, and the ratio of the total width na of the plurality of ribs to c satisfies the following range: 10%≤na / c≤30%;

[0014] Alternatively, when the ribs are spaced apart along the width direction of the top cover body, the number of ribs is n, the width of the ribs is a, the length of the outer surface of the boss along the length direction of the top cover body is d, and the ratio of the total width na of the plurality of ribs to d satisfies the following range: 10%≤na / d≤30%.

[0015] According to a top cover assembly provided by the present invention, the height of the rib along the height direction of the top cover body is h, where h satisfies: 0.5mm≤h≤1mm;

[0016] The width of the rib is a, where a satisfies: 1mm≤a≤2mm;

[0017] And / or, the length of the rib is the same as the length or width of the boss;

[0018] The area of ​​the side of the rib parallel to the surface of the boss is S0, and the outer surface area of ​​the boss is S, satisfying: 8%≤S0 / S≤25%.

[0019] According to a top cover assembly provided by the present invention, the boss is hollow, and a receiving cavity is formed on the side of the boss facing the electrode assembly along the height direction of the top cover body, the receiving cavity being used to receive the electrode tab.

[0020] According to a top cover assembly provided by the present invention, the boss is a truncated cone.

[0021] The taper of the truncated cone is β, and β satisfies: 15°≤β≤25°;

[0022] And / or, the boss and the top cover body are integrally formed.

[0023] According to a top cover assembly provided by the present invention, along the height direction of the top cover body, the height of the pole above the top cover body is H1, and the height of the boss is H2, wherein H1 and H2 satisfy: 1.5mm≤H2-H1≤3.0mm;

[0024] And / or, the length of the top cover body is L, where L satisfies: 150mm≤L≤300mm;

[0025] The width of the top cover body is W, and W satisfies: 25mm≤W≤75mm;

[0026] The boss has a length of L1 and a width of W1, satisfying the following conditions: 0.3≤2L1 / L≤0.45, 0.65≤W1 / W≤0.80.

[0027] 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;

[0028] 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.

[0029] Thirdly, the present invention provides a battery pack, comprising: a busbar, a housing, and battery cells as described above;

[0030] 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.

[0031] The top cover assembly, battery cell, and battery pack provided by this invention, by setting a boss between the terminal post and the explosion-proof valve along the length direction of the top cover body, and setting ribs on the outer surface of the boss, not only enhances the structural strength of the top cover assembly through the boss, thereby improving the mechanical strength of the battery cell, but also achieves thermoelectric separation of the terminal post and the explosion-proof valve. Furthermore, by increasing the surface area of ​​the top cover body through the boss and ribs, the heat dissipation area of ​​the top cover body and the bonding area with the heat-conducting layer are increased, thereby 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. Attached Figure Description

[0032] 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.

[0033] Figure 1 This is a three-dimensional structural diagram of the top cover assembly in the prior art.

[0034] Figure 2 This is a three-dimensional structural diagram of a battery pack in the prior art.

[0035] Figure 3 This is a front view of a battery cell in the prior art.

[0036] Figure 4 It is in the existing technology Figure 3 A magnified view of the X-section.

[0037] Figure 5This is a three-dimensional structural diagram of the first type of top cover assembly provided by the present invention.

[0038] Figure 6 This is a top view of the first type of top cover assembly provided by the present invention.

[0039] Figure 7 This is a three-dimensional structural diagram of the first type of battery cell provided by the present invention.

[0040] Figure 8 This is a front view of the first type of battery cell provided by the present invention.

[0041] Figure 9 This invention provides Figure 8 A magnified view of the Y-section.

[0042] Figure 10 This is a three-dimensional structural diagram of the second type of top cover assembly provided by the present invention.

[0043] Figure 11 This is a top view of the second type of top cover assembly provided by the present invention.

[0044] Figure 12 This is a three-dimensional structural diagram of the second type of battery cell provided by the present invention.

[0045] Figure 13 This is a front view of the second type of battery cell provided by the present invention.

[0046] Figure 14 This invention provides Figure 13 A magnified view of the Z-section.

[0047] Figure 15 This is a left view of the second type of battery cell provided by the present invention.

[0048] Figure label:

[0049] 1. Top cover assembly;

[0050] 11. Top cover body; 12. Pole post; 13. Explosion-proof valve; 14. Boss; 15. Liquid injection hole; 16. Insulating component; 141. Rib;

[0051] 2. Electrode group; 21. Electrode ear;

[0052] 3. Housing; 100. Busbar. Detailed Implementation

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] The following is combined with Figures 1 to 15 The top cover assembly, battery cell, and battery pack provided in the embodiments of the present invention will be described in detail through specific implementation methods and application scenarios.

[0059] Firstly, such as Figure 5 and Figure 10 As shown, this embodiment provides a top cover assembly 1, including: a top cover body 11, a pole post 12, an explosion-proof valve 13, and a boss 14.

[0060] The top cover body 11 has a first through hole and a second through hole that penetrate the top cover body 11. The first through hole and the second through hole are arranged at intervals along the length direction of the top cover body 11.

[0061] The electrode post 12 passes through the first through hole and is electrically connected to the electrode tab 21 of the battery cell.

[0062] The explosion-proof valve 13 is installed in the second through hole.

[0063] Along the length of the top cover body 11, the boss 14 is located between the pole post 12 and the explosion-proof valve 13, and the outer surface of the boss 14 is provided with ribs 141.

[0064] Understandably, such as Figures 1 to 4 As shown, in the prior art, the electrode group 2 of the battery cell 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 3. The terminal post 12 protrudes from both sides of the top cover body 11 through the first through hole. One end of the terminal post 12 is welded to the electrode tab 21 of the battery cell, and the other end is used to connect to the tab on the busbar 100. When the battery cells are 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 only contacts other components of the battery pack through the terminal post 12.

[0065] In this embodiment, a boss 14 is provided between the pole post 12 and the explosion-proof valve 13, so that the space between the pole post 12 and the explosion-proof valve 13 has a raised structure. When the surface of the battery cell is subjected to external force, the boss 14 can share the external force on the pole post 12. Furthermore, since the boss 14 has a certain structural strength, it can support the top cover body 11, avoid short circuits in the battery cell, and improve the mechanical strength of the entire battery cell package.

[0066] Meanwhile, when the battery cells are stacked to form a battery cell module, the upper surface of the battery cell 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 14. 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 14 in this embodiment is better, which is more conducive to the heat dissipation of the battery cell, more conducive to controlling the operating temperature of the battery cell, and extending the service life of the battery cell.

[0067] Furthermore, since the boss 14 is located between the pole post 12 and the explosion-proof valve 13, it can also isolate the pole post 12 and the explosion-proof valve 13, achieving thermoelectric separation and improving the safety performance of the battery cell.

[0068] Specifically, the boss 14 can be a frustum of a cylinder, a frustum of a cone, or a curved surface. The boss 14 can be a hollow platform or a solid platform, without any specific limitation.

[0069] Furthermore, to increase the outer surface area of ​​the boss 14, this embodiment provides ribs 141 on the outer surface of the boss 14. The ribs 141 can improve the structural strength of the boss 14, ensuring that the structure of the boss 14 is more stable when subjected to external impact. In addition, the ribs 141 can increase the outer surface area of ​​the boss 14, thereby increasing the heat dissipation area of ​​the boss 14 and the bonding area with the thermally conductive layer, further improving the safety performance of the battery cell.

[0070] Specifically, the reinforcing bar 141 can extend along a straight line, a broken line, or an arc. There can be one or more reinforcing bars 141.

[0071] Optionally, the cross-section of the stiffener 141 can be triangular, trapezoidal, or arc-shaped to achieve optimal mechanical support.

[0072] The top cover assembly 1 provided by the present invention has a boss 14 provided between the pole post 12 and the explosion-proof valve 13 along the length direction of the top cover body 11, and a rib 141 provided on the outer surface of the boss 14. This not only enhances the structural strength of the top cover assembly 1 through the boss 14, thereby improving the mechanical strength of the battery cell and realizing the thermoelectric separation of the pole post 12 and the explosion-proof valve 13, but also increases the surface area of ​​the top cover body 11 through the boss 14 and the rib 141, 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, controlling the operating temperature of the battery cell, and improving the safety performance of the battery cell.

[0073] like Figure 5 and Figure 10 As shown, this embodiment has multiple ribs 141, which are arranged at intervals along the length or width of the top cover body 11.

[0074] Understandably, in order to improve the structural strength of the boss 14 and prevent stress concentration or deformation when the boss 14 is under load, multiple ribs 141 are provided at intervals on the outer surface of the boss 14. The multiple ribs 141 are arranged along the length or width direction of the top cover body 11, which allows the ribs 141 to cover the entire length or width of the boss 14, improve the overall longitudinal or transverse rigidity and bending resistance of the boss 14, prevent the boss 14 from bending or sagging along the length or width direction, improve load distribution, and facilitate processing and manufacturing.

[0075] like Figure 10 As shown, in one example, multiple reinforcing bars 141 are arranged in parallel at intervals along the length direction.

[0076] like Figure 5 As shown, in one example, multiple reinforcing bars 141 are arranged in parallel at intervals along the width direction.

[0077] like Figure 6 and Figure 11 As shown, in this embodiment, multiple reinforcing bars 141 are evenly spaced, and the spacing between adjacent reinforcing bars 141 is b, where b satisfies: 3mm≤b≤6mm.

[0078] It is understood that in this embodiment, multiple ribs 141 are evenly spaced along the length or width of the top cover body 11 to improve the uniformity of the strength of the outer surface of the boss 14.

[0079] Specifically, the spacing b between adjacent reinforcing bars 141 can be 3mm, 4.5mm, or 6mm.

[0080] like Figure 6 and Figure 11As shown, in the case where the ribs 141 are spaced apart along the length direction of the top cover body 11, the number of ribs 141 in this embodiment is n, the width of the ribs 141 is a, the width of the outer surface of the boss 14 along the width direction of the top cover body 11 is c, and the range of the ratio of the total width na of the multiple ribs 141 to c is: 10%≤na / c≤30%.

[0081] Understandably, in this embodiment, the ribs 141 extend along the length of the top cover body 11. The ribs 141 are not only distributed on the top surface of the boss 14, but also on its sides. Ribs 141 connect the two sides of the boss 14 to its top surface on its outer surface. Along the width direction of the top cover body 11, the width c of the outer surface of the boss 14 refers to the sum of the width of the boss 14 and the widths of its two sides. The total width of the multiple ribs 141 is na, and na / c refers to the ratio of the total width of the ribs 141 to the width of the outer surface of the boss 14. When the ratio of the total width of the ribs 141 to the width of the outer surface of the boss 14 is within a selected range, the outer surface temperature during the cell cycling process can be reasonably controlled, extending the lifespan of the cell.

[0082] Specifically, the na / c ratio can be 10%, 20%, or 30%.

[0083] like Figure 6 and Figure 11 As shown, in the case where the ribs 141 are spaced apart along the width direction of the top cover body 11, the number of ribs 141 in this embodiment is n, the width of the ribs 141 is a, the length of the outer surface of the boss 14 along the length direction of the top cover body 11 is d, and the range of the ratio of the total width na of the multiple ribs 141 to d is: 10%≤na / d≤30%.

[0084] Understandably, in this embodiment, the ribs 141 extend along the width direction of the top cover body 11. The ribs 141 are not only distributed on the top surface of the boss 14, but also on its sides. Ribs 141 connect the two sides and the top surface of the boss 14 on its outer surface. Along the length direction of the top cover body 11, the length d of the outer surface of the boss 14 refers to the sum of the length of the boss 14 and the lengths of its two sides. The total width of the multiple ribs 141 is na, and na / d refers to the ratio of the total width of the ribs 141 to the length of the outer surface of the boss 14. When the ratio of the total width of the ribs 141 to the length of the outer surface of the boss 14 is within a selected range, the outer surface temperature during the cell cycling process can be reasonably controlled, extending the cell's service life.

[0085] Specifically, na / d can be 10%, 20%, or 30%.

[0086] like Figure 8 , Figure 9 , Figure 13 , Figure 14 and Figure 15 As shown, along the height direction of the top cover body 11, the height of the rib 141 in this embodiment is h, and h satisfies: 0.5mm≤h≤1mm.

[0087] The width of rib 141 is a, and a satisfies: 1mm≤a≤2mm.

[0088] Understandably, the height of rib 141 is the height of the projection of rib 141 toward the height direction of the top cover body 11, that is, the distance between the top surface of the boss 14 and the highest point of rib 141. The width of rib 141 is the projection width of rib 141 toward the top surface of the boss 14.

[0089] Specifically, the height of the reinforcing rib 141 can be 0.5mm, 0.75mm, or 1mm. The width 'a' of the reinforcing rib 141 can be 1mm, 1.5mm, or 2mm.

[0090] like Figure 5 and Figure 10 As shown, in this embodiment, the length of the rib 141 is the same as the length or width of the boss 14.

[0091] Understandably, when the rib 141 extends along the length of the top cover body 11, the length of the rib 141 is the same as the length of the boss 14, ensuring that the rib 141 can be fully laid along the length of the boss 14, which helps to improve the uniformity of the strength of the boss 14 in the length direction. When the rib 141 extends along the width of the top cover body 11, the length of the rib 141 is the same as the width of the boss 14, ensuring that the rib 141 can be fully laid along the width of the boss 14, which helps to improve the uniformity of the strength of the boss 14 in the width direction.

[0092] like Figure 6 and Figure 11 As shown, in this embodiment, the area of ​​the side of the rib 141 parallel to the surface of the boss 14 is S0, and the outer surface area of ​​the boss 14 is S, satisfying: 8%≤S0 / S≤25%.

[0093] Understandably, since the side of the rib 141 parallel to the surface of the boss 14 can be bonded with structural adhesive for heat dissipation, and the ratio of the area of ​​the side of the rib 141 parallel to the surface of the boss 14 to the outer surface area of ​​the boss 14 is within a selected range, the outer surface temperature of the cell during the cycle process can be reasonably controlled, thus extending the service life of the cell.

[0094] Specifically, S0 / S can be 8%, 16.5%, or 25%.

[0095] like Figure 5 and Figure 10 As shown, the boss 14 in this embodiment is hollow. Along the height direction of the top cover body 11, a receiving cavity is formed on the side of the boss 14 facing the pole group 2. The receiving cavity is used to receive the pole tab 21.

[0096] Understandably, in existing technologies, sufficient height needs to be reserved between the electrode group 2 and the top cover body 11 in order to provide bending space for the tab 21 within the battery cell. For example... Figure 3 and Figure 4 As shown, the height H of the insulating member 16 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.

[0097] In this embodiment, the boss 14 is designed as a hollow platform, with the receiving cavity facing the side of the tab 21. The tab 21 can be accommodated within the receiving cavity, thereby reducing the distance between the electrode group 2 and the top cover body 11, thus increasing the capacity of the battery cell. Furthermore, the protrusion height of the boss 14 faces outward from the top cover body 11, also filling the space between the pole post 12 and the explosion-proof valve 13, thereby increasing the energy density of the battery cell.

[0098] like Figure 12 As shown, the boss 14 in this embodiment is also provided with a liquid injection hole 15, which is connected to the receiving cavity of the boss 14.

[0099] Understandably, the injection hole 15 is used to inject electrolyte during the cell manufacturing process. The injection hole 15 is located on the top surface of the boss 14 and is a circular through hole. A removable sealing plug is installed inside the hole, and the sealing plug is used to seal the injection hole 15 after the electrolyte injection is completed.

[0100] The height of the boss 14 ensures that the injection hole 15 is higher than the surface of the top cover body 11, facilitating the connection of the injection pipeline, reducing the risk of electrolyte spillage, and improving injection efficiency. The injection hole 15 is designed to avoid sharing space with the electrode post 12 and the explosion-proof valve 13, and the sealing plug can be replaced separately, reducing the risk of overall seal failure due to injection. The injection hole 15 is integrated into the boss 14, eliminating the need to occupy other areas of the top cover body 11, making the top cover assembly 1 more compact and reserving more space for the electrode group 2 and other components.

[0101] like Figure 8 , Figure 9 , Figure 13 and Figure 14 As shown, the boss 14 in this embodiment is a cone-shaped platform; the taper of the cone-shaped platform is β, and β satisfies: 15°≤β≤25°.

[0102] Understandably, the conical platform helps to disperse concentrated loads, reduce stress concentration at the mating joint, improve the load-bearing capacity and stability of the boss 14, avoid local damage, and is easy to process due to its regular shape.

[0103] Specifically, the taper β of the truncated cone can be 15°, 20°, or 25°.

[0104] like Figure 5 and Figure 10 As shown, in this embodiment, the boss 14 and the top cover body 11 are integrally formed.

[0105] Understandably, the boss 14 and the top cover body 11 are made of the same material. The one-piece molding structure simplifies the production process and ensures the reliability of the connection between the boss 14 and the top cover body 11.

[0106] Alternatively, the one-piece molding structure can be achieved by stamping, stretching, or embossing.

[0107] In one example, the boss 14 can be a stamped cone-shaped platform, which is easy to stamp, has a high production yield, and is easy to process and manufacture.

[0108] like Figure 8 , Figure 9 , Figure 13 and Figure 14 As shown, along the height direction of the top cover body 11, the height of the pole post 12 above the top cover body 11 in this embodiment is H1, and the height of the boss 14 is H2. H1 and H2 satisfy: 1.5mm≤H2-H1≤3.0mm.

[0109] Understandably, in order to avoid stress on the terminal post 12 when the battery cells are assembled into a battery pack, in this embodiment, the height of the boss 14 on the side of the top cover body 11 away from the tab 21 is slightly higher than the total height after the terminal post 12 is welded with the tab. The force on the battery pack is transmitted to the top cover body 11 through the boss 14, which improves the strength of the battery cells.

[0110] Specifically, H2-H1 can be 1.5mm, 2.25mm, or 3.0mm.

[0111] like Figure 6 and Figure 11 As shown, the length of the top cover body 11 in this embodiment is L, and L satisfies: 150mm≤L≤300mm.

[0112] The width of the top cover body 11 is W, and W satisfies: 25mm≤W≤75mm;

[0113] The boss 14 has a length of L1 and a width of W1, satisfying the following conditions: 0.3≤2L1 / L≤0.45, 0.65≤W1 / W≤0.80.

[0114] It is understood that the length and width of the top cover body 11 in this embodiment are limited, and the ratio of the length of the boss 14 to the length of the top cover body 11 and the ratio of the width of the boss 14 to the width of the top cover body 11 are also limited. When the boss 14 is provided on the top cover body 11, a certain distance needs to be reserved around the boss 14 to facilitate the processing of the boss 14 and to ensure the structural strength of the top cover body 11.

[0115] 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. 2L1 / L ​​can be 0.3, 0.375, or 0.45. W1 / W can be 0.65, 0.725, or 0.80.

[0116] like Figure 6 and Figure 11 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.

[0117] Two bosses 14 are provided, and the two bosses 14 are arranged sequentially between the pole post 12 and the explosion-proof valve 13.

[0118] Understandably, in this embodiment, two terminals 12 are installed on the top cover body 11, one is a positive terminal 12 and the other is a negative terminal 12. Along the length of the top cover body 11, the negative terminal 12 and the positive terminal 12 are respectively located at both ends of the top cover body 11, and the negative terminal 12 and the positive terminal 12 are respectively connected to the electrode group 2 of the battery cell.

[0119] An explosion-proof valve 13 is provided between the positive terminal 12 and the negative terminal 12. A boss 14 is provided between the positive terminal 12 and the explosion-proof valve 13, as well as between the negative terminal 12 and the explosion-proof valve 13, thereby ensuring that the positive terminal 12 and the negative terminal 12 have corresponding bosses 14 to disperse the pressure, improving the structural strength of the top cover assembly 1 and ensuring the safety of the battery cell.

[0120] Secondly, such as Figure 7 and Figure 12 As shown, this embodiment provides a battery cell, including: an electrode group 2, a housing 3, and a top cover assembly 1 as described above.

[0121] The electrode assembly 2 is located inside the housing 3, and the top cover assembly 1 is fixed to the opening end of the housing 3. The electrode assembly 2 is electrically connected to the top cover assembly 1 through the electrode tab 21.

[0122] Specifically, since the battery cell 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 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.

[0123] Understandably, the electrode assembly 2 is installed inside the housing 3, and the top cover assembly 1 is placed over the open end 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 current transmission. Since the top cover assembly 1 has a boss 14 between the electrode post 12 and the explosion-proof valve 13 on the top cover body 11, and has ribs 141 on the boss 14, the contact heat dissipation area of ​​the upper surface of the top cover body 11 is increased, which is beneficial to control the working temperature of the battery cell, extend the service life of the battery cell, 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.

[0124] In this embodiment, the production line tests various parameters of the boss 14 to verify the technical effects of different data. With the ribs 141 spaced apart along the width direction of the top cover body 11, the height of the ribs 141, the width of the ribs 141, the spacing between adjacent ribs 141, the ratio of the total width n of multiple ribs 141 to the length of the outer surface of the boss 14, and the ratio of the area of ​​the side of the ribs 141 parallel to the surface of the boss 14 to the outer surface area of ​​the boss 14 are changed sequentially. During the battery cell's cycling process, the temperature rise of the outer surface of the battery cell is measured.

[0125] As can be seen in Table 1, when the structural design of the rib 141 meets the above requirements, the outer surface temperature of the cell during cycling can be controlled below 43℃, which is 2-12℃ lower than that of the prior art. When the height, quantity, or width of the rib 141 is insufficient, resulting in an insufficient proportion of the rib 141's width or area, the temperature rise will be relatively higher.

[0126] Table 1: Examples

[0127]

[0128] With the ribs 141 spaced apart along the length of the top cover body 11, the height of the ribs 141, the width of the ribs 141, the spacing between adjacent ribs 141, the ratio of the total width n of the multiple ribs 141 to the width of the outer surface of the boss 14, and the ratio of the area of ​​the side of the ribs 141 parallel to the surface of the boss 14 to the outer surface area of ​​the boss 14 are changed sequentially. During the cycle of the battery cell, the temperature rise of the outer surface of the battery cell is measured.

[0129] It is evident that when the rib 141 structural design meets the above requirements, the outer surface temperature of the cell during cycling can be controlled below 40℃, which is 5-15℃ lower than that of existing technologies. When the height, quantity, or width of the rib 141 is insufficient, resulting in an insufficient proportion of the rib 141's width or area, the temperature rise will be relatively higher.

[0130] Table 2: Examples

[0131]

[0132] Thirdly, this embodiment provides a battery pack, including: a busbar 100, a housing, and the aforementioned battery cells.

[0133] The housing forms a cavity, and multiple battery cells are stacked in the cavity; the busbar 100 is connected to the terminals 12 of the multiple battery cells.

[0134] Specifically, since the battery pack includes battery cells, and the specific structure of the battery cells refers to 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 obtained by all the technical solutions of the above embodiments, which will not be described in detail here.

[0135] Understandably, after the battery cells are grouped together within the housing cavity, the terminal 12 of each battery cell is welded to the tap on the busbar 100. The busbar 100 connects the stacked battery cells into groups, and the tap is fixedly connected to the housing through a heat-conducting layer. Because this embodiment provides a boss 14 between the terminal 12 and the explosion-proof valve 13, the overall capacity of the battery pack is increased, thereby improving the performance of the battery pack.

[0136] 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, and the first through hole and the second through hole are spaced apart along the length direction of the top cover body; 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 in the second through hole; A boss is provided along the length of the top cover body between the pole and the explosion-proof valve, and the outer surface of the boss is provided with ribs; The ribs are provided in multiple ways, and the multiple ribs are arranged at intervals along the length or width of the top cover body; Along the height direction of the top cover body, the height of the rib is h, where h satisfies: 0.5mm≤h≤1mm; The width of the rib is a, where a satisfies: 1mm≤a≤2mm; The length of the rib is the same as the length or width of the boss; The area of ​​the side of the rib parallel to the surface of the boss is S0, and the outer surface area of ​​the boss is S, satisfying: 8%≤S0 / S≤25%; When the ribs are spaced apart along the length of the top cover body, the number of ribs is n, the width of the ribs is a, the width of the outer surface of the boss along the width direction of the top cover body is c, and the ratio of the total width na of the plurality of ribs to c satisfies the following range: 10%≤na / c≤30%; Alternatively, when the ribs are spaced apart along the width direction of the top cover body, the number of ribs is n, the width of the ribs is a, the length of the outer surface of the boss along the length direction of the top cover body is d, and the ratio of the total width na of the plurality of ribs to d satisfies the following range: 10%≤na / d≤30%.

2. The top cover assembly according to claim 1, characterized in that, The ribs are evenly spaced apart, and the distance between adjacent ribs is b, where b satisfies: 3mm≤b≤6mm.

3. The top cover assembly according to claim 1, characterized in that, The protrusion is hollow, and along the height direction of the top cover body, a receiving cavity is formed on the side of the protrusion facing the electrode assembly, which is used to accommodate the electrode tab.

4. The top cover assembly according to claim 3, characterized in that, The boss is a cone-shaped platform; The taper of the truncated cone is β, and β satisfies: 15°≤β≤25°; And / or, the boss and the top cover body are integrally formed.

5. The top cover assembly according to claim 1, characterized in that, Along the height direction of the top cover body, the pole is higher than the top cover body by a height of H1, and the boss is higher by a height of H2. H1 and H2 satisfy: 1.5mm≤H2-H1≤3.0mm; 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; The boss has a length of L1 and a width of W1, satisfying the following conditions: 0.3≤2L1 / L≤0.45, 0.65≤W1 / W≤0.

80.

6. 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 5; 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.

7. A battery pack, characterized in that, include: Busbar, housing, and battery cell as described in claim 6; 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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