Battery cell cover plate, battery cell and battery pack

Abstract

The present invention relates to the technical field of batteries, and provides a battery cell cover plate, a battery cell and a battery pack, the battery cell cover plate comprises: a cover plate body, the cover plate body is provided with a boss, the boss comprises a plurality of convex parts laminated along the thickness direction of the cover plate body, and the topmost convex part is provided with an exhaust hole penetrating through the cover plate body; the pole column is arranged on the cover plate body in a penetrating manner along the thickness direction, and the pole column and the boss are arranged at an interval in the length direction of the cover plate body; and the anti-explosion valve is arranged on the convex part at the topmost part and is opposite to the exhaust hole. The battery cell cover plate is favorable for fully utilizing the internal space of the box body, the capacity of the battery cell and the energy density of the whole battery pack are improved, and the heat of the battery cell can be transferred to the box body through the at least one convex part, so that the heat dissipation efficiency of the battery cell is improved.

Description

Technical Field

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

[0002] The battery pack includes a casing and battery modules assembled inside the casing. Each battery module consists of multiple cells, with the terminals of these cells electrically connected via busbars. The casing provides physical support for the battery modules, protecting them from external impacts and pressure, while also preventing the intrusion of moisture, dust, and other impurities. As users' demands for longer battery life continue to increase, current battery technology faces a contradiction: battery capacity development lags behind market demand, leading to user range anxiety.

[0003] In traditional battery pack structures, to prevent the busbars and terminals from being squeezed when the casing deforms under external impact, a large space is left between the busbars and the battery pack casing. However, this results in low utilization of the internal space of the battery pack, which is not conducive to improving the energy density of the battery pack. In addition, the busbars and terminals have low heat dissipation efficiency, which can easily cause heat accumulation and affect the performance of the battery pack. Summary of the Invention

[0004] This invention provides a cell cover, a cell, and a battery pack to solve the problems of low internal space utilization and low heat dissipation efficiency in the prior art.

[0005] This invention provides a battery cell cover plate, comprising: The cover plate body is provided with a boss, the boss includes a plurality of protrusions stacked along the thickness direction of the cover plate body, and the topmost protrusion is provided with an exhaust hole penetrating the cover plate body; The pole is inserted through the cover plate body along the thickness direction and is spaced apart from the boss in the length direction of the cover plate body; An explosion-proof valve is installed on the topmost protrusion and opposite the vent hole.

[0006] A cell cover plate provided by the present invention further includes: An insulating component is disposed on the side of the cover plate body away from the boss. The insulating component has an exhaust structure opposite to the exhaust hole, and the pole passes through the insulating component.

[0007] According to the present invention, a cell cover plate and a connecting piece are provided. The insulating member has a groove formed on the side away from the cover plate body corresponding to the boss. The groove is adapted to accommodate the electrode tab of the electrode assembly. The connecting piece is connected to the electrode post and extends from the electrode post into the groove. The connecting piece located in the groove is used to connect the electrode tab.

[0008] According to a battery cell cover plate provided by the present invention, the protrusion is provided with reinforcing ribs, and the reinforcing ribs extend from one of the protrusions to the other protrusion.

[0009] According to a battery cell cover plate provided by the present invention, the plurality of protrusions include a first protrusion and a second protrusion, the second protrusion being provided on the upper surface of the first protrusion, and the vent hole being provided on the second protrusion; the reinforcing rib connecting the first protrusion and the second protrusion extends from the upper surface of the second protrusion along the length direction to the upper surface of the first protrusion.

[0010] According to a battery cell cover plate provided by the present invention, the second protrusion has a top wall and a first side wall and a second side wall disposed opposite to each other in the length direction, the first side wall and the second side wall are both connected to the top wall and the first protrusion; the protrusion is provided with a plurality of first reinforcing ribs and a plurality of second reinforcing ribs, the first reinforcing ribs extend along the length direction and sequentially connect the top wall, the first side wall and the first protrusion, and the second reinforcing ribs extend along the length direction and sequentially connect the top wall, the second side wall and the first protrusion; Multiple first reinforcing ribs are spaced apart in the width direction of the cover plate body, multiple second reinforcing ribs are spaced apart in the width direction, and multiple first reinforcing ribs and multiple second reinforcing ribs are arranged opposite each other in the length direction.

[0011] According to the present invention, a battery cell cover plate is provided, wherein a plurality of first reinforcing ribs and a plurality of second reinforcing ribs are symmetrically arranged in the length direction, the second protrusion has a dimension of W1 in the width direction of the cover plate body, each of the first reinforcing ribs has a dimension of w in the width direction, and the number of the first reinforcing ribs is n, wherein 0.1≤nw / W1≤0.2.

[0012] According to the present invention, a battery cell cover plate is provided, wherein the vent hole is disposed on the top wall of the second protrusion, the thickness of the top wall is T1, the height of the reinforcing rib is T2, and the length of the reinforcing rib extending to the upper surface of the first protrusion is A, 0.6≤T2 / T1≤0.9, A≥2.5mm; And / or, the projected area of ​​the second protrusion in the thickness direction is S1, and the sum of the projected areas of all the reinforcing ribs located on the second protrusion in the thickness direction is S2, 0.08≤S2 / S1≤0.12.

[0013] The present invention also provides a battery cell, comprising: The battery cell casing has an opening; In any of the above-mentioned cell cover plates, the cell cover plate is disposed in the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

[0014] The present invention also provides a battery pack, comprising: The housing is provided with clearance holes; In any of the above-mentioned battery cells, multiple battery cells are disposed in the housing, the topmost protrusion of the boss passes through the clearance hole, and at least one of the other protrusions is supported and connected to the housing.

[0015] The present invention provides a cell cover, a cell, and a battery pack. By providing a boss on the cover body, the boss is configured as a stepped boss comprising multiple stacked protrusions. An explosion-proof valve is located on the topmost protrusion, which can pass through a clearance hole on the battery pack housing, placing the explosion-proof valve outside the housing space of the battery pack used to house the cell. At least one other protrusion is adapted to support and connect with the housing, allowing the cell's outer shell to also serve as a supporting load-bearing component. Under the support of the outer shell, significant deformation of the housing can be avoided, thereby reducing the housing thickness and the weight of the battery pack. Furthermore, while ensuring that the housing does not cause compression damage to the busbars and terminals, the distance between the busbars and the housing can be reduced, thereby increasing the cell volume to fully utilize the internal space of the housing, increasing the cell capacity and the overall energy density of the battery pack. The heat from the cell can be transferred to the housing through at least one protrusion, improving the cell's heat dissipation efficiency. 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 one of the overall structural schematic diagrams of the battery cell cover plate provided by the present invention.

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

[0019] Figure 3 This is a side view of the battery cell cover plate provided by the present invention.

[0020] Figure 4 This is the second schematic diagram of the overall structure of the battery cell cover plate provided by the present invention.

[0021] Figure 5 yes Figure 4 A schematic diagram of the battery cell cover from another perspective.

[0022] Figure 6 yes Figure 5 A schematic diagram showing the folding plate of the battery cell cover in the open state.

[0023] Figure 7 This is the third schematic diagram of the overall structure of the battery cell cover plate provided by the present invention.

[0024] Figure 8 yes Figure 7 A schematic diagram showing the folding plate of the battery cell cover in the open state.

[0025] Figure 9 This is a schematic diagram of the electrode assembly of the battery cell provided by the present invention.

[0026] Figure 10 yes Figure 9 A schematic diagram of the pole group from another perspective.

[0027] Figure 11 This is a schematic diagram of the assembly structure of the cell cover plate and electrode assembly provided by the present invention.

[0028] Figure label: 1. Cover plate body; 11. Boss; 111. First protrusion; 112. Second protrusion; 113. Reinforcing rib; 113a. First reinforcing rib; 113b. Second reinforcing rib; 12. Base plate; 121. Reference surface; 21. Pole post; 22. Connecting piece; 221. Base; 222. Extension; 3. Explosion-proof valve; 4. Insulating component; 40. Recess; 401. First groove; 402. Second groove; 41. Fixing plate; 410. Groove; 411. Fitting part; 4111. First fitting plate; 4112. Second fitting plate; 4113. Third fitting plate 41131, First exhaust structure; 4114, First connecting plate; 4115, Second connecting plate; 412, Support part; 4121, Slot; 42, Folding plate; 421, First plate body; 422, Second plate body; 423, Third plate body; 4231, Second exhaust structure; 424, Third connecting plate; 425, Limiting plate; 426, Fourth connecting plate; 43, Notch; 5, Electrode assembly; 50, Connecting end face; 51, Electrode lug; 52, Protrusion; 521, First groove; 522, Second groove; 5201, Top surface; 5202, Side surface. Detailed Implementation

[0029] 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.

[0030] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first"..."fourth" are numbering for the purpose of clearly identifying product components and do not represent any substantial difference. The terms "installed," "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 direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. 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. Furthermore, "multiple" means two or more. In the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0031] The following is combined with Figures 1-11 The present invention describes a cell cover, a cell, and a battery pack.

[0032] like Figure 1 As shown, the battery cell cover provided in this embodiment of the invention includes a cover body 1, a terminal post 21, and an explosion-proof valve 3. The cover body 1 has a boss 11, which includes multiple protrusions stacked along the thickness direction of the cover body 1. The topmost protrusion has a vent hole penetrating the cover body 1. The terminal post 21 passes through the cover body 1 along the thickness direction and is spaced apart from the boss 11 along the length direction of the cover body 1. The explosion-proof valve 3 is installed on the topmost protrusion and faces the vent hole.

[0033] The cell cover is applied to the cell, which includes a cell housing, electrode assembly 5, and the cell cover. The cell housing has an opening, and the cell cover is positioned at the opening and surrounds the cell housing to form a receiving cavity. The electrode assembly 5 is disposed within the receiving cavity. The cell housing and the cover body 1 are welded together to form the outer shell of the cell, providing protection for the internal components and withstanding certain external impacts. A terminal post 21 protrudes from the outer surface of the cover body 1 to form a terminal terminal, used for connection to a busbar, allowing multiple cells to be connected via the busbar to form a battery module. The other end of the terminal post 21 is located within the receiving cavity and connected to the tab 51 of the terminal post 21. The battery module is assembled into a housing to form a battery pack.

[0034] For the length and width directions of the cover plate body 1, see [reference]. Figure 1The thickness direction of the cover plate body 1 is perpendicular to the length and width directions. Specifically, the cover plate body 1 has a first side and a second side opposite to each other in its thickness direction. The first side faces the outside of the cell and has a boss 11 formed thereon. The electrode post 21 protrudes from the first side to form an electrode post terminal. The second side faces the electrode group 5 inside the receiving cavity. Optionally, a recess is formed on the side of the cover plate body 1 away from the boss 11, corresponding to the position of the boss 11. This recess can be used to accommodate the electrode tab 51 and / or the electrode group 5, which helps to increase the space utilization rate inside the cell housing and increase the capacity of the cell.

[0035] The boss 11 is formed by stamping a sheet metal. For example, the boss 11 can be formed by stamping a separate sheet metal and then welded to the substrate. Alternatively, the boss 11 can be formed by stamping the cover plate body 1 as a single piece, which not only allows the cover plate body 1 to form a recess to accommodate the tab 51, but also simplifies the manufacturing process of the cover plate body 1.

[0036] The boss 11 includes multiple protrusions stacked along the thickness direction of the cover plate body 1. It can be understood that the cross-sectional area of ​​the multiple protrusions decreases sequentially along the protruding direction of the boss 11, forming a stepped boss 11. The topmost protrusion is provided with an exhaust port for installing the explosion-proof valve 3. When the boss 11 is formed by a stamping process, it can be formed through multiple stamping processes, reducing the height of a single stamping, avoiding plate breakage, and ensuring the structural strength of the boss 11.

[0037] It should be noted that the battery pack casing forms an accommodating space and is provided with a clearance hole connecting the inside and outside of the accommodating space. The topmost protrusion of the boss 11 passes through this clearance hole. When the internal pressure of the battery cell exceeds the safety threshold of the explosion-proof valve 3, the explosion-proof valve 3 opens, and the high-temperature and high-pressure gas inside the battery cell is discharged out of the accommodating space through the explosion-proof valve 3. Any one or more protrusions of the boss 11, except for the topmost protrusion, can be supported and connected to the battery pack casing to bear the impact force transmitted from the casing. The part of the casing that is supported and connected to the boss 11 can be the casing shell; or, the casing includes a shell and a cold plate, with the cold plate located between the shell and the battery cell, and the boss 11 supported and connected to the cold plate.

[0038] like Figure 1 As shown, taking a boss 11 with two protrusions as an example, the two protrusions are a first protrusion 111 and a second protrusion 112. The second protrusion 112 protrudes from the upper surface of the first protrusion 111. The upper surface of the first protrusion 111 is suitable for connection with the battery pack housing support. The vent is provided on the second protrusion 112. The second protrusion 112 is located at the middle of the first protrusion 111 in the length direction of the cover plate body 1, which facilitates stamping and forming. The first protrusion 111 can be connected to the battery pack housing support through the portions located on both sides of the second protrusion 112 to provide more stable support.

[0039] In traditional battery pack structures, the battery pack relies solely on the casing to withstand external impacts. However, the casing plate opposite the terminal post 21 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 21, 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 and the casing, wasting space. Increasing the casing thickness to increase rigidity would increase the weight of the battery pack, hindering lightweight design. Furthermore, the heat from the cell cover is dissipated only through conduction between the terminal post 21 and the busbar, and through its own thermal radiation, resulting in low heat dissipation efficiency and easy heat accumulation. When the electrode post 21 and the explosion-proof valve 3 are located at the same end of the battery cell, when the battery cell experiences thermal runaway, the substances discharged from the explosion-proof valve 3 can easily reach the electrode post 21, affecting the thermoelectric isolation effect.

[0040] The battery cell cover provided in this embodiment of the invention features a boss 11 on the cover body 1. The boss 11 is a stepped boss comprising multiple stacked protrusions. An explosion-proof valve 3 is located on the topmost protrusion, which can pass through a clearance hole in the battery pack housing, placing the explosion-proof valve 3 outside the housing space of the battery pack used to house the battery cell. At least one other protrusion is adapted to support and connect with the housing, allowing the battery cell's outer shell to also serve as a supporting component. Under the support of the outer shell, significant deformation of the housing can be avoided, thereby reducing the thickness of the housing and the weight of the battery pack. Furthermore, while ensuring that the housing does not cause compression damage to the busbars and terminals 21, the distance between the busbars and the housing can be reduced, thereby increasing the volume of the battery cell. This fully utilizes the internal space of the housing, increasing the capacity of the battery cell and the energy density of the entire battery pack. Simultaneously, the heat from the battery cell can be transferred to the housing through at least one protrusion, improving the heat dissipation efficiency of the battery cell. The explosion-proof valve 3 can be located outside the enclosure space of the enclosure. By utilizing the enclosure isolation pole 21 and the explosion-proof valve 3, the thermoelectric isolation effect is improved.

[0041] It should be noted that the battery cell has two terminals 21, namely a positive terminal and a negative terminal. In this embodiment of the invention, the number of terminals 21 on the battery cell cover can be one or two. Figure 1 As shown, the cell cover plate is provided with two pole posts 21. In the length direction of the cell cover plate, the boss 11 is located between the two pole posts 21 to form better support and protection for the pole posts 21 on both sides.

[0042] Optionally, the boss 11 is integrally bent from the cover plate body 1 along its length direction, that is, the recess formed on the second side of the cover plate body 1 extends through the opposite sides of the cover plate body 1 along its width direction. This boss 11 can be manufactured by a stamping process, and the bent shape of the boss 11 helps improve its processing stability. Specifically, the cover plate body 1 includes a base plate portion 12 and a bent portion. The bent portion is connected to the base plate portion 12 at both ends along the length direction of the cover plate body 1. The bent portion is bent relative to the base plate portion 12 to form the boss 11, and two pole posts 21 are correspondingly inserted into the two base plate portions 12.

[0043] like Figure 1 and Figure 3 As shown, the battery cell cover provided in this embodiment of the invention also includes an insulating member 4. The insulating member 4 is disposed on the side of the cover body 1 away from the boss 11, and the insulating member 4 is provided with an exhaust structure opposite to the exhaust hole, and the electrode post 21 passes through the insulating member 4.

[0044] When the cell cover is installed on the cell housing, the insulating component 4 is located between the cover body 1 and the electrode group 5, providing insulation between them. The electrode post 21 passes through both the cover body 1 and the insulating component 4, with one end of the electrode post 21 located on the side of the insulating component 4 away from the cover body 1, for connection to the electrode tab 51 of the electrode group 5. The vent hole and venting structure are connected to allow internal gas to be discharged from the explosion-proof valve 3.

[0045] Furthermore, such as Figure 3 and Figure 4 As shown, the cell cover also includes a connecting piece 22. A groove 410 is formed on the side of the insulating member 4 away from the cover body 1, corresponding to the position of the boss 11. The groove 410 is adapted to accommodate the tabs 51 of the electrode assembly 5. The connecting piece 22 is connected to the pole post 21 and extends from the pole post 21 into the groove 410. The connecting piece 22 located in the groove 410 is used to connect the tabs 51.

[0046] Specifically, a recess is formed on the side of the cover plate body 1 near the insulating member 4, corresponding to the position of the boss 11, and the insulating member 4 mates with the recess. A protrusion is formed on the side of the insulating member 4 near the cover plate body 1, and the protrusion is located within the recess of the cover plate body 1. A groove 410 is formed on the side of the insulating member 4 away from the cover plate body 1, corresponding to the position of the protrusion. The groove 410 is a stepped groove adapted to the stepped boss 11. The tabs 51 of the electrode assembly 5 can be retracted into the groove 410, making full use of the space inside the boss 11, allowing more space inside the cell to accommodate the body of the electrode assembly 5, improving the space utilization rate inside the cell, and increasing the cell capacity. Optionally, the shape of the protrusion of the insulating member 4 is adapted to the shape of the recess of the cover plate body 1 to maximize the use of the internal space of the boss 11.

[0047] Optionally, both the first protrusion 111 and the second protrusion 112 include a top wall and a side wall connected to the top wall and inclined relative to the top wall. That is, both the first protrusion 111 and the second protrusion 112 are trapezoidal bosses 11, which is beneficial to improving the production yield of the stamping process. At the same time, when the space of the cover plate body 1 along its length direction is limited, the length of the groove 410 can be increased.

[0048] In traditional cell cover structures, the insulating component 4 only abuts against the end face of the electrode group 5 through two support parts 412 at both ends. However, the contact area between the insulating component 4 and the electrode group 5 is small, resulting in poor fixation of the electrode group 5. When the cell is subjected to external force, the electrode group 5 is prone to shifting, which can cause the base of the pole post 21 to damage the electrode group 5.

[0049] In this regard, such as Figures 5-8 As shown, in some embodiments of the present invention, the insulating member 4 includes a fixing plate 41 and a folding plate 42. The fixing plate 41 is located on the side of the cover plate body 1 away from the boss 11 and has a support portion 412 protruding away from the cover plate body 1. The folding plate 42 is folded and connected to the support portion 412, so that the folding plate 42 can be fastened or opened relative to the fixing plate 41. The pole post 21 passes through the cover plate body 1 and the fixing plate 41 along the thickness direction of the cover plate body 1. Wherein, when the folding plate 42 is fastened to the fixing plate 41, the folding plate 42 covers the pole post 21, and both the support portion 412 and the folding plate 42 are adapted to abut against the electrode group 5 of the battery cell.

[0050] Specifically, the fixing plate 41 has a fitting portion 411 and a support portion 412 protruding from the fitting portion 411. The fitting portion 411 is fitted to the cover plate body 1, and the support portion 412 protrudes from the fitting portion 411 on the side away from the cover plate body 1, that is, the support portion 412 is a locally thickened portion on the fixing plate 41. The folding plate 42 and the support portion 412 are arranged along the length direction of the cover plate body 1, and one end of the folding plate 42 in the length direction is folded and connected to the support portion 412. Optionally, in the length direction of the cover plate body 1, the pole post 21 is located between the support portion 412 and the boss 11.

[0051] It is understandable that there is a height difference between the fitting part 411 and the supporting part 412 in the thickness direction of the cover plate body 1. When the folding plate 42 is fastened to the fixing plate 41, at least a portion of the side of the folding plate 42 away from the fixing plate 41 is flush with the supporting part 412, so that the supporting part 412 and the folding plate 42 can simultaneously abut against the electrode group 5. In this way, the supporting part 412 and the folding plate 42 can simultaneously abut against the electrode group 5, thereby increasing the contact area between the insulating member 4 and the electrode group 5, improving the fixing effect of the insulating member 4 on the electrode group 5, thereby preventing the electrode group 5 from shifting, preventing the base of the pole post 21 from damaging the electrode group 5 and the pole tab 51 from being pulled, and improving the safety performance of the battery cell.

[0052] Among them, such as Figure 6and Figure 8 As shown, the fixing plate 41 is provided with a first exhaust structure 41131, and the exhaust hole is connected to the first exhaust structure 41131. In the thickness direction of the cover plate body 1, the projection of the exhaust hole is located within the projection distribution range of the first exhaust structure 41131. It can be understood that the first exhaust structure 41131 and the exhaust hole are opposite to each other in the thickness direction of the cover plate body 1, and the area enclosed by the outer periphery of the first exhaust structure 41131 covers the area of ​​the exhaust hole, so as to facilitate the exhaust of the explosion-proof valve 3.

[0053] In some alternative embodiments, such as Figure 5 and Figure 6 As shown, there are two of each of the support part 412, the folding plate 42, and the pole post 21, with each of the two support parts 412, the two folding plates 42, and the two pole posts 21 corresponding to one another. The boss 11 is located between the two pole posts 21, and the vent is located between the two folding plates 42.

[0054] Specifically, two support portions 412 are respectively disposed at both ends of the fixing plate 41 along the length of the cover plate body 1, and two pole posts 21 are respectively located on the side of the two support portions 412 that are close to each other. Two folding plates 42 are also located on the side of the two support portions 412 that are close to each other, and the two folding plates 42 are respectively used to cover the two pole posts 21. The two folding plates 42 are located on both sides of the first exhaust structure 41131 to avoid obstructing the first exhaust structure 41131.

[0055] In other alternative embodiments, such as Figure 7 and Figure 8 As shown, the fixing plate 41 has two support portions 412 spaced apart along the length of the cover plate body 1. One end of the folding plate 42 is folded and connected to one support portion 412, so that the folding plate 42 can be fastened or opened relative to the fixing plate 41. When the folding plate 42 is fastened to the fixing plate 41, the other end of the folding plate 42 is connected to the other support portion 412.

[0056] It is understood that, unlike the above embodiment which has two folding plates 42, this embodiment only has one folding plate 42. When it is fastened to the fixing plate 41, the folding plate 42 is connected between the two support parts 412, which simplifies the assembly steps of the cell cover and the electrode group 5.

[0057] The folding plate 42 has a folded connecting end and a free end opposite to each other along the length of the cover body 1. The folded connecting end is folded and connected to one support part 412, and the free end overlaps with another support part 412. Specifically, the other support part 412 is provided with a slot 4121. When the folding plate 42 is fastened to the fixing plate 41, the free end is located within the slot 4121. Optionally, the support part 412 and the free end are engaged in a limit fit along the width of the cover body 1 to ensure accurate positioning of the fastening position of the folding plate 42.

[0058] like Figure 8 As shown, when the insulating member 4 has only one folding plate 42, the folding plate 42 is provided with a second exhaust structure 4231. When the folding plate 42 is fastened to the fixing plate 41, the exhaust hole, the first exhaust structure 41131, and the second exhaust structure 4231 are connected. In the thickness direction of the cover plate body 1, the projection of the exhaust hole is located within the projection distribution range of the first exhaust structure 41131, and the projection of the first exhaust structure 41131 is located within the projection distribution range of the second exhaust structure 4231. In this way, the portion of the fixing plate 41 outside the first exhaust structure 41131 can be avoided from blocking the exhaust hole, and the portion of the folding plate 42 outside the second exhaust structure 4231 can be avoided from blocking the first exhaust structure 41131, which is conducive to the smooth exhaust of the explosion-proof valve 3.

[0059] Optionally, multiple longitudinally and transversely arranged ribs can be provided inside the vent hole. These ribs can support the explosion-proof valve 3 and prevent deformation of the explosion-proof valve 3 during welding.

[0060] In this embodiment of the invention, both the first exhaust structure 41131 and the second exhaust structure 4231 can be a single through hole with a relatively large opening. Alternatively, both the first exhaust structure 41131 and the second exhaust structure 4231 can include multiple through holes with smaller openings, which can ensure the structural strength of the fixing plate 41 and the folding plate 42.

[0061] Specifically, the first exhaust structure 41131 includes a plurality of first through holes spaced apart from each other, and the second exhaust structure 4231 includes a plurality of second through holes spaced apart from each other. The area of ​​each exhaust hole is S1, and the overlap area of ​​the exhaust holes, the plurality of first through holes, and the plurality of second through holes in the thickness direction of the cover plate body 1 is S4. Optionally, S4 / S1 ≥ 0.8. This overlap area is the actual ventilation area; by setting S4 / S1 ≥ 0.8, it can be ensured that the explosion-proof valve 3 can exhaust smoothly.

[0062] like Figure 6 and Figure 8 As shown, in this embodiment of the invention, the fixing plate 41 is recessed into the cover plate body 1. A groove 410 is formed on the side of the fixing plate 41 away from the cover plate body 1 corresponding to the recessed position. Figure 5 and Figure 6 As shown, when the folding plate 42 is fastened to the fixing plate 41, the side of the insulating member 4 away from the cover plate body 1 forms a groove 40 corresponding to the position of the groove 410.

[0063] Specifically, a recess is formed on the side of the cover plate body 1 near the insulating member 4, corresponding to the position of the boss 11, and a protrusion is formed on the side of the fixing plate 41 near the cover plate body 1, with the protrusion located within the recess. A groove 410 is formed on the side of the fixing plate 41 away from the cover plate body 1, corresponding to the position of the protrusion. After the folding plate 42 is fastened to the fixing plate 41, a recess 40 is formed on the side of the insulating member 4 away from the cover plate body 1, corresponding to the position of the groove 410.

[0064] In embodiments where the cell cover has two folding plates 42, the folding plates 42 can be adjacent to or spaced apart from the groove 410, or they can extend from the support portion 412 into the groove 410, as long as the two folding plates 42 do not obstruct the first exhaust structure 41131. When the folding plates 42 extend into the groove 410, the folding plates 42 can be configured as bent plates conformally to the fixing plate 41. Optionally, the folding plates 42 extend into the area within the groove 410 corresponding to the first protrusion 111, avoiding obstruction of the exhaust holes on the second protrusion 112.

[0065] In an embodiment where a folding plate 42 is provided on the cell cover, the folding plate 42 can be configured as a bent plate conformally to the fixing plate 41, so that when the folding plate 42 is fastened to the fixing plate 41, a groove 40 is formed on the side of the insulating member 4 away from the cover body 1.

[0066] In some embodiments of the present invention, the pole post 21 passes through the cover plate body 1 and the fixing plate 41, and the connecting piece 22 is located between the fixing plate 41 and the folding plate 42. For example... Figure 6 As shown, the connecting piece 22 includes a base portion 221 and an extension portion 222. The base portion 221 is connected to the pole post 21, and the extension portion 222 is located in the groove 410 for welding to the pole lug 51 of the pole assembly 5. When the folding plate 42 is fastened to the fixing plate 41, the folding plate 42 covers the base portion 221 and the extension portion 222.

[0067] Specifically, the connecting piece 22 extends from the pole post 21 into the groove 410 according to the shape of the fixing plate 41. The base portion 221 is located outside the groove 410, and the extension portion 222 is located inside the groove 410. The base portion 221 and the extension portion 222 are connected by an inclined portion.

[0068] When assembling the cell cover and the electrode assembly 5, first open the folding plate 42 and weld the electrode tab 51 of the electrode assembly 5 to the extension 222 located in the groove 410; then fasten the folding plate 42 to cover the entire connecting piece 22, and also cover the welded part of the electrode tab 51; finally, abut the end face of the electrode assembly 5 against the support part 412 of the cell cover and the folding plate 42. The folding plate 42 covers the welded part of the electrode tab 51, and plays a role in closing and fixing the electrode tab 51.

[0069] like Figure 6 and Figure 8 As shown, the folding plate 42 has a first plate 421 and a second plate 422. The first plate 421 is folded and connected to the support portion 412. When the folding plate 42 is fastened to the fixing plate 41, the first plate 421 covers the base portion 221, and the second plate 422 is located in the groove 410 and covers the extension portion 222.

[0070] It is understandable that when the folding plate 42 is fastened to the fixing plate 41, the side of the first plate 421 away from the fixing plate 41 is flush with the support part 412, so that after the cell cover is assembled with the electrode group 5, the support part 412 and the first plate 421 simultaneously abut against the end face of the electrode group 5.

[0071] Specifically, such as Figure 6 As shown, the fixing plate 41 has a first bonding plate 4111, a first connecting plate 4114, a second bonding plate 4112, a second connecting plate 4115, and a third bonding plate 4113 connected in sequence to form a stepped plate. A support portion 412 protrudes from the first bonding plate 4111, and a connecting piece 22 extends from the first bonding plate 4111 to the second bonding plate 4112. The first bonding plate 4111 is bonded to the substrate portion 12, the second bonding plate 4112 is bonded to the top wall of the first protrusion 111, the third bonding plate 4113 is bonded to the top wall of the second protrusion 112, the first connecting plate 4114 is opposite to the side wall of the first protrusion 111, and the second connecting plate 4115 is opposite to the side wall of the second protrusion 112. The two ends of the third bonding plate 4113 are symmetrical to each other and are connected in sequence to the second connecting plate 4115, the second bonding plate 4112, the first connecting plate 4114 and the first bonding plate 4111.

[0072] In an embodiment where the cell cover has two folding plates 42, each folding plate 42 includes a first plate body 421 and a second plate body 422, and the two folding plates 42 can be symmetrically arranged about the boss 11.

[0073] Specifically, such as Figure 6As shown, the folding plate 42 has a first plate 421, a third connecting plate 424, and a second plate 422 connected in sequence to form a stepped plate. The first plate 421 is opposite to the first bonding plate 4111, the third connecting plate 424 is opposite to the first connecting plate 4114, and the second plate 422 is opposite to the second bonding plate 4112. Optionally, the folding plate 42 also has a limiting plate 425, which is connected to the end of the second plate 422 away from the first plate 421, and is opposite to the second connecting plate 4115. The limiting plate 425 can be engaged with the second connecting plate 4115 to pre-position the folding plate 42.

[0074] In an embodiment where a folding plate 42 is provided on the cell cover, such as Figure 8 As shown, the folding plate 42 has a first plate 421, a third connecting plate 424, a second plate 422, a fourth connecting plate 426, and a third plate 423 connected in sequence to form a stepped plate. The first plate 421 is opposite to the first bonding plate 4111, the third connecting plate 424 is opposite to the first connecting plate 4114, the second plate 422 is opposite to the second bonding plate 4112, the fourth connecting plate 426 is opposite to the second bonding plate 4112, and the third plate 423 is opposite to the third bonding plate 4113. The two ends of the third plate 423 are symmetrically connected to each other and are sequentially joined by the fourth connecting plate 426, the second plate 422, the third connecting plate 424, and the first plate 421. One of the first plates 421 is folded and connected to a support portion 412, and the other first plate 421 overlaps with another support portion 412. The third plate 423 is provided with a second exhaust structure 4231 that communicates with the first exhaust structure 41131.

[0075] Optionally, the first connecting plate 4114 is inclined relative to the second bonding plate 4112, and the second connecting plate 4115 is inclined relative to the third bonding plate 4113. Correspondingly, the third connecting plate 424 is inclined relative to the second plate body 422, the limiting plate 425 is inclined relative to the second plate body 422, and the fourth connecting plate 426 is inclined relative to the third plate body 423.

[0076] like Figure 5 and Figure 7 As shown, in some embodiments of the present invention, the width of the second plate 422 is smaller than the width of the first plate 421 in the width direction of the cover plate body 1. Since the welding part of the electrode lug 51 is pressed between the second plate 422 and the extension 222, the electrode lug 51 needs to be bent and folded within the groove 40. By setting the width of the second plate 422 to be smaller than the width of the first plate 421, space is provided to allow for the bending of the electrode lug 51, thus preventing the electrode lug 51 from being bent and damaged.

[0077] like Figure 6 and Figure 8As shown, in some embodiments of the present invention, the folding plate 42 and the fixing plate 41 are integrally formed, and a notch 43 extending along the folding line is formed between the side of the folding plate 42 near the fixing plate 41 and the support portion 412. Specifically, the notch 43 is formed between the first plate 421 of the folding plate 42 near the fixing plate 41 and the support portion 412.

[0078] Optionally, the folding plate 42 and the fixing plate 41 are integrally molded plastic parts. The notch 43 is formed between the folding connection end of the folding plate 42 and the support part 412, that is, the thickness of the folding plate 42 is reduced at the position corresponding to the notch 43, so as to facilitate the folding of the folding plate 42 and enable it to be well fastened to the fixing plate 41.

[0079] like Figure 1 As shown, in some embodiments of the present invention, the boss 11 is provided with reinforcing ribs 113, which extend from one protrusion to another. It is understood that a portion of the reinforcing rib 113 is connected to one protrusion and another portion is connected to another protrusion. The reinforcing rib 113 connects at least two adjacent protrusions to locally reinforce multiple protrusions and improve the overall impact resistance of the boss 11.

[0080] Optionally, the reinforcing rib 113 extends along the length of the cover plate body 1. The principal stress direction of the protrusion is consistent with the stacking direction of the multiple protrusions. The reinforcing rib 113 extends from one protrusion to another and along the length of the cover plate body 1, which helps to increase the structural strength of the protrusion and helps to disperse the stress of the protrusion.

[0081] The reinforcing rib 113 can protrude from the first side of the cover plate body 1, that is, on the same side of the cover plate body 1 as the boss 11, or it can protrude from the second side of the cover plate body 1. When the reinforcing rib 113 protrudes from the first side of the cover plate body 1, the reinforcing rib 113 and the boss 11 can be stamped together, simplifying the process.

[0082] like Figure 3 As shown, in one specific embodiment, the plurality of protrusions include a first protrusion 111 and a second protrusion 112. The second protrusion 112 protrudes from the upper surface of the first protrusion 111, and the upper surface of the first protrusion 111 is adapted to be connected to the housing support of the battery pack. A vent is provided on the second protrusion 112. A reinforcing rib 113 connecting the first protrusion 111 and the second protrusion 112 extends from the upper surface of the second protrusion 112 along the length direction to the upper surface of the first protrusion 111.

[0083] It is understood that the reinforcing rib 113 protrudes in the same direction as the boss 11, and the reinforcing rib 113 extends along the length of the cover plate body 1. The second protrusion 112 protrudes from the upper surface of the first protrusion 111, and a part of the reinforcing rib 113 is connected to the upper surface of the first protrusion 111, and another part is connected to the upper surface of the second protrusion 112.

[0084] Since the boss 11 is a structure that bends along the length of the cover plate body 1, it is prone to bending deformation when subjected to impact. The extension direction of the reinforcing rib 113 is consistent with the bending direction of the boss 11, which can improve the bending stiffness of the boss 11, thereby improving the overall structural strength of the boss 11.

[0085] In this embodiment of the invention, the cover plate body 1 has a reference surface 121, which is a plane on the side of the cover plate body 1 where the boss 11 is provided, for example, the reference surface 121 is formed on the base plate portion 12. The boss 11 and the pole post 21 both protrude from the reference surface 121. In the thickness direction of the cover plate body 1, the protrusion height of the pole post 21 relative to the reference surface 121 is less than the protrusion height of the first protrusion 111 relative to the reference surface 121, so that a certain space is reserved between the pole post 21 and the housing for the installation of the busbar.

[0086] Furthermore, in the structure of the battery module, the height of the busbar relative to the reference surface 121 is less than the protrusion height of the first protrusion 111 relative to the reference surface 121, so that there is a certain gap between the busbar and the housing. This gap can be used to maintain a safe distance between the busbar and the housing, and can also be used to install adhesive with thermal conductivity.

[0087] In some embodiments of the present invention, such as Figure 2 As shown, the second protrusion 112 has a top wall and a first side wall and a second side wall disposed opposite to each other along the length of the cover body 1. Both the first and second side walls connect the top wall and the first protrusion 111. The boss 11 is provided with a plurality of first reinforcing ribs 113a and a plurality of second reinforcing ribs 113b. The first reinforcing ribs 113a extend along the length of the cover body 1 and sequentially connect the top wall, the first side wall, and the first protrusion. The second reinforcing ribs 113b extend along the length and sequentially connect the top wall, the second side wall, and the first protrusion. The plurality of first reinforcing ribs 113a are spaced apart along the width of the cover body 1, and the plurality of second reinforcing ribs 113b are spaced apart along the width of the cover body 1. The plurality of first reinforcing ribs 113a and the plurality of second reinforcing ribs 113b are disposed opposite each other along the length of the cover body 1.

[0088] Understandably, the upper surface of the second protrusion 112 is formed in the top wall, and the vent hole penetrates the top wall. Multiple first reinforcing ribs 113a and multiple second reinforcing ribs 113b are spaced apart along the length, and the vent hole is located between the multiple first reinforcing ribs 113a and multiple second reinforcing ribs 113b. The first and second sides of the second protrusion 112 are its main stress areas. The first side is structurally reinforced by the multiple first reinforcing ribs 113a, and the second side is structurally reinforced by the multiple second reinforcing ribs 113b, to prevent deformation and increased structural stress in the second protrusion 112 when the boss 11 is impacted, thus avoiding abnormal cracking of the explosion-proof valve 3.

[0089] The multiple first reinforcing ribs 113a and multiple second reinforcing ribs 113b are arranged opposite each other in the length direction of the cover plate body 1, which can form an exhaust channel extending along the length direction of the cover plate body 1 on the upper surface of the second protrusion 112. The gas discharged by the explosion-proof valve 3 can flow along the exhaust channel, which is beneficial to improving the exhaust efficiency.

[0090] like Figure 2 As shown in the figure, as a specific example, there are three of each of the first reinforcing rib 113a and the second reinforcing rib 113b, so that two exhaust channels extending along the length direction of the cover plate body 1 are formed on the second protrusion 112. When multiple battery cells are arranged along the width direction of the cover plate body 1, exhaust channels are also formed between the first reinforcing rib 113a and the second reinforcing rib 113b of two adjacent battery cells.

[0091] It should be noted that the multiple first reinforcing ribs 113a may be of unequal length, and the multiple second reinforcing ribs 113b may also be of unequal length. The multiple first reinforcing ribs 113a and multiple second reinforcing ribs 113b may be arranged according to the shape of the exhaust hole. For example, the distance between each first reinforcing rib 113a and each second reinforcing rib 113b and the edge of the exhaust hole may be equal, so that the first reinforcing ribs 113a and the second reinforcing ribs 113b have a relatively long length, thereby forming an effective exhaust channel.

[0092] Optionally, a plurality of first reinforcing ribs 113a and a plurality of second reinforcing ribs 113b are spaced apart along the length of the cover plate body 1.

[0093] It is understood that, along the length of the cover plate body 1, there is a certain distance between the integral structure of the multiple first reinforcing ribs 113a and the integral structure of the multiple second reinforcing ribs 113b, and the vent is located between the two. When multiple battery cells are arranged along the width of the cover plate body 1, the vent channels on the second protrusions 112 of two adjacent battery cells can be interconnected in the width direction, which is beneficial to improving venting efficiency.

[0094] like Figure 2As shown, in some embodiments of the present invention, a plurality of first reinforcing ribs 113a and a plurality of second reinforcing ribs 113b are symmetrically arranged in the length direction of the cover plate body 1. The second protrusion 112 has a dimension W1 in the width direction of the cover plate body 1, and each first reinforcing rib 113a has a dimension w in the width direction of the cover plate body 1. The number of first reinforcing ribs 113a is n, wherein 0.1≤nw / W1≤0.2.

[0095] It is understandable that the first reinforcing rib 113a and the second reinforcing rib 113b, which are opposite each other in the length direction of the cover plate body 1, have the same structural dimensions. That is, the dimension of each second reinforcing rib 113b in the width direction of the cover plate body 1 is also w, and the number of second reinforcing ribs 113b is also n. By setting 0.1≤nw / W1≤0.2, the second protrusion 112 has sufficient strength while avoiding the reinforcing ribs 113 from affecting the exhaust effect of the explosion-proof valve 3.

[0096] like Figure 3 As shown, in some embodiments of the present invention, the exhaust hole is disposed on the top wall of the second protrusion 112, the thickness of the top wall is T1, the height of the reinforcing rib 113 is T2, and the length of the reinforcing rib 113 extending to the upper surface of the first protrusion 111 is A, where 0.6≤T2 / T1≤0.9 and A≥2.5mm. The reinforcing rib 113 can be the first reinforcing rib 113a and the second reinforcing rib 113b in the above embodiments.

[0097] With the extension direction of the reinforcing rib 113 aligned with the bending direction of the boss 11, the bending stiffness of the area corresponding to the reinforcing rib 113 on the boss 11 can be effectively improved by setting the height of the reinforcing rib 113 to satisfy 0.6≤T2 / T1≤0.9. By setting the length of the reinforcing rib 113 on the first protrusion 111 to satisfy A≥2.5mm, the structural strength at the connection between the first protrusion 111 and the second protrusion 112 can be guaranteed, reducing the impact on the second protrusion 112 when the first protrusion 111 is subjected to compression.

[0098] In some embodiments of the present invention, the projected area of ​​the second protrusion 112 in the thickness direction of the cover plate body 1 is S1, and the sum of the projected areas of all the reinforcing ribs 113 on the second protrusion 112 in the thickness direction of the cover plate body 1 is S2, where 0.08 ≤ S2 / S1 ≤ 0.12. S2 / S1 is the area ratio of all the reinforcing ribs 113 on the second protrusion 112. If the area ratio of the reinforcing ribs 113 is too small, the structural strength of the protrusion 11 will be insufficient, and the supporting effect will be poor. If the area ratio of the reinforcing ribs 113 is too large, it will affect the exhaust effect of the explosion-proof valve 3.

[0099] This invention also provides a battery cell, which includes a battery cell housing, an electrode assembly 5, and a battery cell cover plate as provided in any of the above embodiments. The battery cell housing has an opening, and the battery cell cover plate is disposed at the opening and surrounds the battery cell housing to form a receiving cavity. The electrode assembly 5 is disposed within the receiving cavity, and the electrode tabs 51 of the electrode assembly 5 are connected to the electrode posts 21.

[0100] When assembling the battery cell, the electrode group 5 and the terminal post 21 of the battery cell cover are first welded together, and the battery cell cover is assembled to one end of the electrode group 5. Then, the electrode group 5 is installed into the battery cell housing, and the cover body 1 is welded to the battery cell housing. Before being installed into the housing, the outside of the electrode group 5 is usually wrapped with an insulating film to provide insulation between the electrode group 5 and the battery cell housing.

[0101] like Figure 9 As shown, in some embodiments of the present invention, the pole group 5 has two pole lugs 51 at the position corresponding to the second plate 422 of the folding plate 42. The two pole lugs 51 are arranged in the width direction of the cover plate body 1 and symmetrically distributed on both sides of the second plate 422. The dimension of the second plate 422 in the width direction of the cover plate body 1 is smaller than the distance between the two pole lugs 51 at their folded positions.

[0102] Specifically, the end of the extension 222 away from the base 221 is provided with two welding parts spaced apart along the width direction of the cover plate body 1. The two welding parts are welded to the two electrode tabs 51 of the electrode assembly 5 to reduce the impact of welding heat on the electrode tabs 51. The two electrode tabs 51 are respectively gathered from both sides of the folding plate 42 between the folding plate 42 and the extension 222, and are welded to the two welding parts of the extension 222 one by one. In order to avoid the folding plate 42 being too wide and interfering with the gathering of the electrode tabs 51, both sides of the folding plate 42 in the length direction are recessed by a certain width relative to the gathering position of the electrode tabs 51.

[0103] like Figure 9 As shown, the electrode assembly 5 includes a first component and a second component that are independent of each other, each having an electrode tab 51. One end of the connecting piece 22 is connected to the electrode post 21, and the other end has two welding portions spaced apart in the width direction of the cover plate body 1. The electrode tab 51 of the first component is welded to one of the welding portions, and the electrode tab 51 of the second component is welded to the other welding portion. In this way, the welding heat of one electrode tab 51 and the welding portion can be avoided from affecting the welding of the other electrode tab 51, thus improving the welding yield of the electrode tab 51.

[0104] like Figure 10As shown, during welding, the first and second components can be placed on opposite sides of the cover plate body 1 along its length, with the tabs 51 of the first and second components facing each other. After welding the tabs 51 of both components to the pole post 21, the first and second components are flipped to their combined state, so that the ends of both components with tabs 51 are facing the cover plate body 1, thus completing the assembly of the pole group 5 and the cover plate body 1. See [link to documentation]. Figure 11 .

[0105] like Figure 9 As shown, in some embodiments of the present invention, the electrode assembly 5 has a connecting end face 50, on which a protrusion 52 is provided. An electrode tab 51 is connected to the connecting end face 50 and located beside the protrusion 52, which is housed within a groove 410 of the insulating member 4. In this way, the space within the housing can be fully utilized, increasing the volume of the electrode assembly 5 and thus increasing the capacity of the battery cell. The boss 11 formed by the bend in the cover plate body 1 can increase the internal space of the boss 11, increasing the volume of the protrusion 52, i.e., increasing the capacity of the battery cell.

[0106] It is understood that the electrode group 5 is formed by stacking multiple electrode sheets in the width direction of the cover plate body 1. Each electrode sheet has a protrusion at one end corresponding to the electrode tab 51, and the protrusions of multiple electrode sheets are stacked to form a protrusion 52.

[0107] Optionally, as shown in Figure 9, the surface of the convex shroud 52 is provided with a groove structure, which forms an exhaust channel inside the battery cell. The side of the convex shroud 52 furthest from the connecting end face 50 is the upper surface of the convex shroud 52, which is positioned opposite to the exhaust holes on the cover plate body 1 and the exhaust structure on the insulating component 4, allowing the groove structure on it to communicate with the exhaust holes and exhaust structure. When thermal runaway occurs in the battery cell, the gas inside the battery cell can flow along the exhaust channel to the explosion-proof valve 3, improving the exhaust effect.

[0108] In some embodiments, the trench structure includes at least one first trench 521, which extends along the length of the connecting end face 50 and penetrates both sides of the protrusion 52. This facilitates the entry of gas from the inside of the battery cell, corresponding to the two sides in the width direction of the cover plate body 1, into the first trench 521.

[0109] In some embodiments, the trench structure includes at least one second trench 522, which extends along the width direction of the connecting end face 50 and penetrates the opposite sides of the protrusion 52. This facilitates the entry of gas inside the battery cell corresponding to the two sides of the cover plate body 1 along the length direction into the second trench 522.

[0110] In some embodiments, the trench structure includes at least one first trench 521 and at least one second trench 522. The first trench 521 extends along the length direction of the connecting end face 50 and penetrates the opposite sides of the protrusion 52, and the second trench 522 extends along the width direction of the connecting end face 50 and penetrates the opposite sides of the protrusion 52. This facilitates the entry of gas from the periphery of the battery cell into the trench structure, improving exhaust efficiency.

[0111] like Figure 9 As shown, in some embodiments of the present invention, the convex bulge 52 has a top surface 5201 and a side surface 5202. The two ends of the top surface 5201 in the length direction of the cover plate body 1 are respectively connected to the connecting end surface 50 through a side surface 5202 to form a trapezoidal convex bulge 52. The first groove 521 extends from one end of the side surface 5202 away from the top surface 5201 to the other end of the side surface 5202 away from the top surface 5201.

[0112] It is understood that the side surface 5202 is inclined relative to the connecting end face 50, and the side surface 5202 and the connecting end face 50 are set at an obtuse angle. The first groove 521 extends from one end of the side surface 5202 connected to the connecting end face 50 to the other end of the side surface 5202 connected to the connecting end face 50, so that the airflow flowing along the connecting end face 50 can smoothly enter the first groove 521.

[0113] like Figure 5 and Figure 7 As shown, in some embodiments of the present invention, the sink 40 includes a first sink 401 and a second sink 402. The first sink 401 is formed on the side of the insulating member 4 facing the electrode assembly 5, corresponding to the position of the first protrusion 111. The second sink 402 is recessed in the first sink 401 and is disposed opposite to the second protrusion 112. The protrusion 52 extends into the second sink 402 and is positioned and engaged with the second sink 402 in the longitudinal direction of the cover plate body 1.

[0114] It is understood that the groove 40 is a stepped groove composed of a first groove 401 and a second groove 402. The deeper second groove 402 is used to limit the engagement with the protrusion 52 of the electrode assembly 5, which can play an assembly and positioning role during the assembly of the cell cover and the electrode assembly 5. It can also prevent the electrode assembly 5 from shifting and damaging the electrode tab 51 along the length direction of the cover body 1 when the cell is subjected to external force impact. The space formed between the connecting end face 50 of the electrode assembly 5 and the first groove 401 can be used to accommodate the electrode tab 51.

[0115] The length dimension L of the cover plate body is defined, and the width dimension W is defined. Based on the parameter ranges specified in this embodiment, a Design of Experiments (DOE) is conducted using cover plates with diameters of 150mm ≤ L ≤ 300mm and 25mm ≤ W ≤ 75mm. For each case, five battery cells are randomly selected, and a stamping test is performed on the boss along the thickness direction of the cover plate body. The deformation of the boss, the venting of the explosion-proof valve, and whether the explosion-proof valve experiences abnormal cracking are observed. The experimental results are shown in Table 1. In the table, W1, T1, and T2 are in mm, and S1 and S2 are in mm. 2 .

[0116] Table 1: Experimental Data 1

[0117] Table 1 shows the experimental results. When the cover plate body meets the design requirements of the above embodiments, as shown in Cases 1-9 in Table 1, the structural strength of the cover plate body is sufficient when the battery cell withstands external impact through the protrusions of the cover plate body, and there is no obvious deformation in any part. Conversely, as shown in Cases 10-13 in Table 1, the second protrusion of the cover plate body still has the problem of deformation, and the terminal post is still at risk of being crushed, leading to a short circuit in the battery cell.

[0118] This invention also provides a battery pack, which includes a housing and battery cells. The housing has clearance holes. Multiple battery cells are disposed within the housing, and the topmost protrusion of the boss 11 passes through the clearance holes, while at least one of the other protrusions is supported and connected to the housing.

[0119] The battery pack includes at least a plurality of battery cells arranged along the width direction of the cover body 1. The battery pack also includes a busbar, through which the terminals of two adjacent battery cells are connected. In the thickness direction of the cover body 1, the busbar is located between the terminal 21 and the housing.

[0120] Optionally, as shown in the figure, in the thickness direction of the cover body 1, the height of the busbar relative to the reference surface 121 of the cover body 1 is less than the height of the second protrusion 112 relative to the reference surface 121. When the side of the housing facing the terminal is flat, a gap still exists between the busbar and the housing while ensuring the support connection between the protrusion 11 and the housing. This ensures that the protrusion 11 serves as the main load-bearing part of the cell, protecting the busbar and the terminal 21, and improving the safety of the battery pack.

[0121] In some embodiments of the present invention, the housing includes a first plate and a second plate disposed opposite to each other. A clearance hole is provided in the first plate, and the protrusion of the boss 11 is supported and connected to the first plate; the two can be directly contacted or bonded together with insulating and thermally conductive adhesive. The end of the battery cell furthest from the battery cell cover is supported and connected to the second plate.

[0122] In some embodiments, the first plate and the second plate can be the shell structure of a housing. For example, the first plate is the top cover of the housing, and the second plate is the bottom shell of the housing. The housing shell is typically made of thermally conductive steel or aluminum. The heat from the battery cell is transferred to the housing through the protrusions 11 of the battery cell and the battery cell shell, and then convects with the outside air through the housing.

[0123] In other embodiments, the first plate portion includes a first housing and a first cold plate, the first cold plate being located between the first housing and the battery cell, the protrusion of the boss 11 being abutted against the first cold plate, and a clearance hole penetrating at least through the first cold plate. The second plate portion includes a second housing and a second cold plate, the second cold plate being located between the second housing and the battery cell, with one end of the battery cell away from the battery cell cover abutted against the second cold plate. The first cold plate and the second cold plate can be any of a liquid cooling plate, a direct cooling plate, or a phase change material cold plate. The heat from the battery cell can be transferred to the first and second cold plates through the boss 11 and the housing, improving the cooling effect on the battery pack.

[0124] 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 battery cell cover plate, characterized in that, include: The cover plate body is provided with a boss, the boss includes a plurality of protrusions stacked along the thickness direction of the cover plate body, and the topmost protrusion is provided with an exhaust hole penetrating the cover plate body; The pole is inserted through the cover plate body along the thickness direction and is spaced apart from the boss in the length direction of the cover plate body; An explosion-proof valve is installed on the topmost protrusion and opposite the vent hole.

2. The cell cover plate according to claim 1, characterized in that, Also includes: An insulating component is disposed on the side of the cover plate body away from the boss. The insulating component has an exhaust structure opposite to the exhaust hole, and the pole passes through the insulating component.

3. The cell cover plate according to claim 2, characterized in that, Also includes: A connecting piece is provided, wherein a groove is formed on the side of the insulating member away from the cover plate body corresponding to the protrusion, the groove being adapted to accommodate the tab of the electrode assembly, the connecting piece being connected to the pole post and extending from the pole post into the groove, and the connecting piece located in the groove being used to connect the tab.

4. The cell cover plate according to claim 1, characterized in that, The boss is provided with reinforcing ribs that extend from one of the bosses to the other.

5. The cell cover plate according to claim 4, characterized in that, The plurality of protrusions include a first protrusion and a second protrusion, the second protrusion being provided on the upper surface of the first protrusion, and the vent hole being provided on the second protrusion; the reinforcing rib connecting the first protrusion and the second protrusion extends from the upper surface of the second protrusion along the length direction to the upper surface of the first protrusion.

6. The cell cover plate according to claim 5, characterized in that, The second protrusion has a top wall and a first side wall and a second side wall disposed opposite to each other in the length direction. The first side wall and the second side wall are both connected to the top wall and the first protrusion. The boss is provided with a plurality of first reinforcing ribs and a plurality of second reinforcing ribs. The first reinforcing ribs extend along the length direction and connect the top wall, the first side wall and the first protrusion in sequence. The second reinforcing ribs extend along the length direction and connect the top wall, the second side wall and the first protrusion in sequence. Multiple first reinforcing ribs are spaced apart in the width direction of the cover plate body, multiple second reinforcing ribs are spaced apart in the width direction, and multiple first reinforcing ribs and multiple second reinforcing ribs are arranged opposite each other in the length direction.

7. The cell cover plate according to claim 6, characterized in that, The plurality of first reinforcing ribs and the plurality of second reinforcing ribs are symmetrically arranged in the length direction. The second protrusion has a dimension of W1 in the width direction of the cover plate body. Each of the first reinforcing ribs has a dimension of w in the width direction. The number of the first reinforcing ribs is n, where 0.1≤nw / W1≤0.

2.

8. The cell cover plate according to claim 5, characterized in that, The exhaust hole is disposed on the top wall of the second protrusion, the thickness of the top wall is T1, the height of the reinforcing rib is T2, the length of the reinforcing rib extending to the upper surface of the first protrusion is A, 0.6≤T2 / T1≤0.9, A≥2.5mm; And / or, the projected area of ​​the second protrusion in the thickness direction is S1, and the sum of the projected areas of all the reinforcing ribs located on the second protrusion in the thickness direction is S2, 0.08≤S2 / S1≤0.

12.

9. A battery cell, characterized in that, include: The battery cell casing has an opening; The cell cover plate as described in any one of claims 1 to 8, wherein the cell cover plate is disposed at the opening and surrounds the cell housing to form a receiving cavity; An electrode assembly is disposed within the receiving cavity, and the electrode tabs of the electrode assembly are connected to the electrode post.

10. A battery pack, characterized in that, include: The housing is provided with clearance holes; As described in claim 9, a plurality of the battery cells are disposed in the housing, the topmost protrusion of the boss passes through the clearance hole, and at least one of the other protrusions is supported and connected to the housing.

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