Battery cell cover plate and battery cell

Abstract

The present invention relates to the technical field of batteries, and provides a battery cell cover plate and a battery cell, the battery cell cover plate comprises: a cover plate body, the cover plate body comprises a substrate portion and a bending portion, and has a first side and a second side opposite to each other in the thickness direction of the cover plate body, the bending portion is connected with the substrate portion at both ends in the length direction of the cover plate body, and the first side and the second side are opposite to each other. The bending part is bent relative to the substrate part and forms a boss on the first side; a reinforcing rib is arranged at the joint of the base plate part and the bending part; and the pole penetrates through the substrate part along the thickness direction and is convexly arranged on the first side. The battery cell cover plate can be connected with a box body of a battery pack in a supporting manner through the bosses, so that the volume of the battery cell is increased under the condition that the box body does not cause extrusion damage to a busbar and a pole, and the utilization rate of the internal space of the battery pack is improved.

Description

Technical Field

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

[0004] This invention provides a cell cover and a cell to solve the problem of low internal space utilization in battery packs in the prior art.

[0005] This invention provides a battery cell cover plate, comprising: The cover plate body includes a base plate portion and a bent portion, and has a first side and a second side opposite to each other in its thickness direction. The bent portion is connected to the base plate portion at both ends in the length direction of the cover plate body. The bent portion is bent relative to the base plate portion and forms a boss on the first side. A reinforcing rib is provided at the connection between the base plate portion and the bent portion. The pole post is inserted through the substrate portion along the thickness direction and protrudes from the first side.

[0006] According to a battery cell cover plate provided by the present invention, the boss includes a top wall and two side walls, the two ends of the top wall in the length direction are respectively connected to the base plate portion through one of the side walls, and the reinforcing rib extends from the side wall to the base plate portion.

[0007] According to a battery cell cover provided by the present invention, each of the sidewalls is provided with a plurality of reinforcing ribs spaced apart along the width direction of the cover body.

[0008] According to the present invention, in the thickness direction of the cover plate body, the height of the boss relative to the substrate portion is H1, and the height of the reinforcing rib relative to the substrate portion is H2; in the width direction of the cover plate body, the width of the cover plate body is W1, and the width of the reinforcing rib is W2; the thickness of the substrate portion is T1, the wall thickness of the sidewall is T2, and the wall thickness of the top wall is T3. Wherein, the reinforcing ribs are located on the first side, and the number of reinforcing ribs corresponding to each sidewall is two, 0.5≤H2 / H1≤0.7, 0.15≤2W2 / W1≤0.2; and / or, T1≥2mm, 1.0≤T2 / T1≤1.2, 1.0≤T3 / T1≤1.2.

[0009] A cell cover plate provided by the present invention further includes: An explosion-proof valve is provided with a vent hole on the cover plate body. The explosion-proof valve is installed on the cover plate body and is opposite to the vent hole. The pole, the boss and the explosion-proof valve are spaced apart in the length direction. The boss is located between the explosion-proof valve and the pole.

[0010] According to a battery cell cover plate provided by the present invention, the number of the bending portions is two, a base plate portion is connected between the two bending portions, and the explosion-proof valve is disposed on the base plate portion between the two bending portions; And / or, the base plate is provided with a mounting groove, the explosion-proof valve is disposed in the mounting groove, and the distance between the reinforcing rib and the mounting groove is B; B≥6mm.

[0011] A cell cover plate provided by the present invention further includes: The upper plastic is located on the first side, and the substrate is provided with a positioning groove. The upper plastic is disposed in the positioning groove, and the pole is inserted through the upper plastic. In the length direction, the distance between the reinforcing rib and the positioning groove is A, where A≥3mm.

[0012] A cell cover plate provided by the present invention further includes: An insulating component includes a fixed plate and a folding plate. The fixed plate is located on the second side of the cover plate body and has a support portion protruding in a direction away from the cover plate body. The pole is inserted through the fixed plate. The folding plate is folded and connected to the support portion, so that the folding plate can be fastened or opened relative to the fixed plate. When the folding plate is fastened to the fixing plate, the folding plate covers the pole post, and both the support and the folding plate are adapted to abut against the pole group of the battery cell.

[0013] A cell cover plate provided by the present invention further includes: A connecting piece is located between the fixing plate and the folding plate. The connecting piece includes a base portion and an extension portion. The base portion is connected to the pole post. The fixing plate forms a groove on the side away from the cover plate body, corresponding to the position of the boss. The extension portion is located in the groove and is used for welding to the pole lug of the pole assembly.

[0014] 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.

[0015] The present invention provides a cell cover and a cell. By constructing a bent portion on the cover body, the bent portion protrudes to one side of the cover body to form a boss. After the cell is assembled into the housing, it can be supported and connected to the plate of the housing using the boss. That is, the outer shell of the cell itself acts as a supporting load-bearing component, so as to prevent the plate of the housing from deforming under impact. This allows for an increase in the volume of the cell while ensuring that the housing does not cause crush damage to the busbars and terminals, so as to make full use of the space inside the housing and increase the capacity of a single cell and the entire battery pack. It also reduces the thickness of the plate of the housing, which is beneficial to the lightweight design of the battery pack. The heat of the cell can be transferred to the housing through the boss, improving the heat dissipation efficiency of the battery pack. At the same time, reinforcing ribs are provided at the connection between the bent portion and the base plate of the cover body, increasing the structural strength of the boss and improving the impact resistance of the cover body. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is one of the three-dimensional 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 three-dimensional structural schematic diagram of the battery cell cover plate provided by the present invention.

[0021] Figure 5 yes Figure 4 A schematic diagram showing the folding plate of the battery cell cover in the open state.

[0022] Figure 6 This is a schematic diagram of the battery cell provided by the present invention.

[0023] Figure 7 This is a schematic diagram of the assembly structure of the cell cover plate and electrode assembly provided by the present invention.

[0024] Figure label: 1. Cover plate body; 11. Base plate; 111. Positioning groove; 112. Mounting groove; 12. Boss; 121. Top wall; 122. Side wall; 13. Reinforcing rib; 21. Pole post; 22. Connecting piece; 221. Base; 222. Extension; 3. Explosion-proof valve; 4. Insulating component; 41. Fixing plate; 410. Groove; 411. Fitting part; 4111. Exhaust structure; 412. Support part; 42. Folding plate; 5. Top plastic; 6. Pole group; 61. Pole tab; 7. Cell housing. Detailed Implementation

[0025] 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.

[0026] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "first" and "second" are numbered for the purpose of clearly identifying product components and do not represent any substantial difference. The directions of "upper," "lower," "left," and "right" are all based on the directions shown in the accompanying drawings. 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.

[0027] The following is combined with Figures 1-7 The present invention describes the cell cover plate and the cell.

[0028] like Figure 1As shown, the battery cell cover plate provided in this embodiment of the invention includes a cover plate body 1 and an electrode post 21. The cover plate body 1 includes a base plate portion 11 and a bent portion, and has a first side and a second side opposite to each other in its thickness direction. The bent portion is connected to the base plate portion 11 at both ends in the length direction of the cover plate body 1, and the bent portion is bent relative to the base plate portion 11 and forms a boss 12 on the first side. A reinforcing rib 13 is provided at the connection between the base plate portion 11 and the bent portion. The electrode post 21 passes through the base plate portion 11 along the thickness direction of the cover plate body 1 and protrudes from the first side of the cover plate body 1.

[0029] The cell cover is applied to the cell, which includes a cell housing 7, electrode assembly 6, and the cell cover. The cell housing 7 has an opening, and the cell cover is positioned at the opening and surrounds the cell housing 7 to form a receiving cavity. The electrode assembly 6 is disposed within the receiving cavity. The cell housing 7 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 61 of the terminal post 21. The battery module is assembled into a housing to form a battery pack.

[0030] For the length and width directions of the cover plate body 1, please refer to [reference needed]. Figure 1 The thickness direction of the cover plate body 1 is perpendicular to the length and width directions. Specifically, the cover plate body 1 can be integrally stamped from a single sheet to form a base plate portion 11 and a bent portion. The bent portion protrudes towards the first side of the cover plate body 1 to form a boss 12, and the pole post 21 protrudes from the first side to form a pole post terminal. The second side of the cover plate body 1 faces the pole group 6 inside the receiving cavity.

[0031] The second side of the cover plate body 1 forms a recess corresponding to the position of the boss 12. This recess can be used to accommodate the tab 61, which helps to increase the space utilization rate within the cell housing 7 and increase the capacity of the cell. The boss 12 is also suitable for supporting and connecting with the battery pack casing to bear the impact force transmitted from the casing. The part of the casing that supports and connects with the boss 12 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 cell, and the boss 12 supporting and connecting with the cold plate.

[0032] Optionally, in the thickness direction of the cover plate body 1, the protrusion height of the boss 12 relative to the base plate portion 11 is greater than the protrusion height of the pole post 21 relative to the base plate portion 11, so that a certain space is reserved between the pole post 21 and the housing for the installation of the busbar.

[0033] A reinforcing rib 13 is provided at the connection between the bent portion and the base plate portion 11. It is understood that a portion of the reinforcing rib 13 is connected to the bent portion, and another portion is connected to the base plate portion 11, to locally strengthen the connection between the bent portion and the base plate portion 11 and improve the overall impact resistance of the boss 12. The principal stress direction of the boss 12 is consistent with the thickness direction of the cover plate body 1. The reinforcing rib 13 extends along the length direction of the cover plate body 1, which helps to increase the structural strength of the boss 12 and helps to disperse the stress of the boss 12.

[0034] Optionally, the sidewall 122 of the bent portion is inclined relative to the base plate portion 11. That is, the boss 12 has a trapezoidal structure, 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 is limited, the space for accommodating the tab 61 can be increased.

[0035] 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.

[0036] The battery cell cover provided in this embodiment of the invention features a bent portion on the cover body 1, with the bent portion protruding to one side of the cover body 1 to form a boss 12. After the battery cell is assembled into the housing, the boss 12 can be used to support and connect with the housing plate, meaning the battery cell's outer shell acts as a supporting component to prevent deformation of the housing plate under impact. This allows for an increase in the battery cell's volume while ensuring the housing does not cause compression damage to the busbars and terminals 21, thus fully utilizing the space within the housing and increasing the capacity of a single battery cell and the entire battery pack. It also reduces the thickness of the housing plate, which is beneficial for lightweight battery pack design. The heat from the battery cell can be transferred to the housing through the boss 12, improving the battery pack's heat dissipation efficiency. Furthermore, reinforcing ribs 13 are provided at the connection between the bent portion of the cover body 1 and the base plate 11, increasing the structural strength of the boss 12 and improving the impact resistance of the cover body 1.

[0037] like Figure 1 and Figure 2As shown in the embodiment of the present invention, the boss 12 includes a top wall 121 and two side walls 122. The top wall 121 is connected to the base plate portion 11 at both ends in the length direction of the cover plate body 1 through a side wall 122, and the reinforcing rib 13 extends from the side wall 122 to the base plate portion 11.

[0038] The top wall 121 is connected to the base plate portion 11 at both ends via a side wall 122, forming a U-shaped structure at the bend. The top wall 121 is used for support connection with the housing. A reinforcing rib 13 connects the side wall 122 and the base plate portion 11 to strengthen the structural strength of the connection point between the side wall 122 and the base plate portion 11, i.e., the root of the boss 12, preventing deformation under impact. By providing the reinforcing rib 13, the rigidity and strength of the boss 12 can be increased without significantly increasing the wall thickness of the boss 12.

[0039] Furthermore, each sidewall 122 is provided with a plurality of reinforcing ribs 13 spaced apart along the width direction of the cover plate body 1. It can be understood that a plurality of reinforcing ribs 13 are provided at both ends of the bent portion where they connect to the base plate portion 11 in the length direction of the cover plate body 1, and the plurality of reinforcing ribs 13 at each end are spaced apart along the width direction of the cover plate body 1.

[0040] In this embodiment of the invention, the cross-sectional shape of the reinforcing rib 13 on the orthogonal plane along the length and thickness directions of the cover plate body 1 is triangular, which can effectively improve the impact resistance of the boss 12.

[0041] like Figure 2 and Figure 3 As shown, in the thickness direction of the cover plate body 1, the height of the boss 12 relative to the base plate portion 11 is H1, and the height of the reinforcing rib 13 relative to the base plate portion 11 is H2; in the width direction of the cover plate body 1, the width of the cover plate body 1 is W1, the width of the reinforcing rib 13 is W2, the thickness of the base plate portion 11 is T1, the wall thickness of the side wall 122 is T2, and the wall thickness of the top wall 121 is T3.

[0042] Among them, the reinforcing rib 13 is located on the first side of the cover plate body 1, and the number of reinforcing ribs 13 corresponding to each side wall 122 is two, 0.5≤H2 / H1≤0.7, 0.15≤2W2 / W1≤0.2; and / or, T1≥2mm, 1.0≤T2 / T1≤1.2, 1.0≤T3 / T1≤1.2.

[0043] If the H2 / H1 value is too small, it indicates that the height of the reinforcing rib 13 is too low, resulting in poor reinforcement of the root of the boss 12 and a risk of buckling and cracking under impact. If the H2 / H1 value is too large, it indicates that the height of the reinforcing rib 13 is too high, making the boss 12 prone to brittle fracture near the top wall 121 of the reinforcing rib 13. This results in poor impact energy absorption and does not meet the requirements of the stamping process.

[0044] If the 2W2 / W1 value is too small, the reinforcing effect of the stiffener 13 on the boss 12 is not good, and the impact resistance of the boss 12 is insufficient. If the 2W2 / W1 value is too large, the contribution of the stiffener 13 to the stiffness increases or decreases, and it does not meet the requirements of the stamping process, and increases the weight and cost of the cover plate body 1.

[0045] If T1 ≥ 2 mm, and T2 / T1 and T3 / T1 are too small, it indicates that the thickness of the top wall 121 and the side wall 122 is too thin. The top wall 121 is prone to denting or tearing under pressure, and the side wall 122 is prone to buckling or bending. If T2 / T1 and T3 / T1 are too large, it indicates that the thickness of the top wall 121 and the side wall 122 is too thick, which wastes materials and increases the weight and cost of the cover plate body 1.

[0046] Furthermore, such as Figure 3 As shown, the dimension of the reinforcing rib 13 along the length of the cover plate body 1 is L2, which is 70mm long, provided that 0.5≤H2 / H1≤0.7 and 0.15≤2W2 / W1≤0.2 are satisfied. 3 ≤H2×W2×L2≤100mm 3 If the value of H2×W2×L2 is too small, it indicates that the length L2 of the reinforcing rib 13 is too small, and the reinforcing effect of the reinforcing rib 13 on the boss 12 is not good; if the value of H2×W2×L2 is too large, it indicates that the length of the reinforcing rib 13 extending to the substrate portion 11 is too long, exceeding the requirement, causing ineffective waste and occupying a large space of the substrate portion 11.

[0047] like Figure 1 As shown, some embodiments of the present invention provide a cell cover plate that also includes an explosion-proof valve 3. The cover plate body 1 is provided with a vent hole, and the explosion-proof valve 3 is installed on the cover plate body 1 and opposite to the vent hole. The pole post 21, the boss 12 and the explosion-proof valve 3 are spaced apart along the length of the cover plate body 1, and the boss 12 is located between the explosion-proof valve 3 and the pole post 21.

[0048] It is understandable that an explosion-proof valve 3 is provided on a base plate 11 connected to one end of the bending portion, and an electrode post 21 is provided on a base plate 11 connected to the other end of the bending portion. The explosion-proof valve 3 and the electrode post 21 are separated by the boss 12.

[0049] When the internal pressure of the battery cell exceeds the safety threshold of the explosion-proof valve 3, the explosion-proof valve 3 opens, allowing the high-temperature, high-pressure gas in the containment chamber to be discharged through the explosion-proof valve 3, reducing the internal pressure of the battery cell and preventing it from exploding. In this embodiment, by providing a boss 12 between the explosion-proof valve 3 and the terminal post 21, the boss 12 can block the high-temperature gas or liquid discharged from the explosion-proof valve 3 from reaching the terminal post 21 and the busbar, achieving thermoelectric isolation and improving the safety performance of the battery pack.

[0050] It should be noted that the battery cell has two terminals 21, namely a positive terminal 21 and a negative terminal 21. In the embodiments of the present invention, the number of terminals 21 on the battery cell cover plate can be one or two, and a boss 12 is provided between each terminal 21 and the explosion-proof valve 3.

[0051] Optionally, such as Figure 2 As shown, there are two bends, and a base plate 11 is connected between the two bends. The explosion-proof valve 3 is disposed on the base plate 11 between the two bends.

[0052] It is understood that there are three base plate portions 11, and the three base plate portions 11 and two bending portions are arranged alternately along the length of the cover plate body 1. One base plate portion 11 is located between two bending portions, and the other two base plate portions 11 are located on the side of the two bending portions that are far apart from each other. The two bending portions form two bosses 12, and the explosion-proof valve 3 is located between the two bosses 12, which can effectively prevent the high-temperature gas or liquid discharged from the explosion-proof valve 3 from spreading and splashing to both sides. When the bosses 12 are connected to the battery pack housing support, a space is formed between the base plate portion 11 and the housing for the gas to be discharged by the explosion-proof valve 3.

[0053] Optionally, two base plate portions 11 are symmetrically distributed on both sides of the explosion-proof valve 3, and two bent portions are also symmetrically distributed on both sides of the explosion-proof valve 3.

[0054] When there is one pole post 21, the pole post 21 and the explosion-proof valve 3 are located on opposite sides of a bend. When there are two pole posts 21, the two pole posts 21 are located on opposite sides of the explosion-proof valve 3 and are separated from the explosion-proof valve 3 by a boss 12.

[0055] Furthermore, such as Figure 2 As shown, the base plate 11 has a mounting groove 112, and the explosion-proof valve 3 is disposed within the mounting groove 112. An exhaust port is located at the bottom of the mounting groove 112. The distance between the reinforcing rib 13 and the mounting groove 112 is B, where B ≥ 6 mm. This improves the stamping yield of the mounting groove 112 and the reinforcing rib 13 area, ensures structural reliability, prevents deformation of the mounting groove 112, and improves the assembly yield of the explosion-proof valve 3 and the cover plate body 1.

[0056] like Figure 1As shown, the battery cell cover provided in this embodiment of the invention also includes an upper plastic 5, which is located on the first side of the cover body 1. The base plate portion 11 is provided with a positioning groove 111, and the upper plastic 5 is disposed in the positioning groove 111. The electrode post 21 passes through the upper plastic 5. In the length direction of the cover body 1, the distance between the reinforcing rib 13 and the positioning groove 111 is A, where A ≥ 3 mm. This can improve the stamping yield of the positioning groove 111 and the reinforcing rib 13 area, ensure structural reliability, avoid deformation of the positioning groove 111, and improve the assembly yield of the upper plastic 5 and the cover body 1. At the same time, during the assembly process of the electrode post 21 and the cover body 1, the reinforcing rib 13 will not interfere with the operating equipment.

[0057] Specifically, the pole post 21 includes a connecting post and a rivet block. The connecting post passes through the cover plate body 1 and the upper plastic 5. The rivet block is located on the side of the upper plastic 5 away from the cover plate body 1. The connecting post and the rivet block are riveted together to fix the pole post 21, the upper plastic 5, and the cover plate body 1. The upper plastic 5 is positioned in the positioning groove 111, serving as an insulating seal between the rivet block and the cover plate body 1. An insulating sealing ring is provided between the connecting post and the cover plate body 1, serving as an insulating isolation between the connecting post and the cover plate body 1.

[0058] like Figure 3 and Figure 4 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 12, and the electrode post 21 passes through the insulating member 4. The insulating member 4 is provided with a venting structure opposite to the vent hole so that the gas inside the battery cell can be discharged from the explosion-proof valve 3.

[0059] When the cell cover is installed on the cell housing, the insulating member 4 is located between the cover body 1 and the electrode group 6, serving as insulation between the cover body 1 and the electrode group 6. The pole post 21 passes through both the cover body 1 and the insulating member 4, with one end of the pole post 21 located on the side of the insulating member 4 away from the cover body 1, for connection with the pole tab 61 of the electrode group 6.

[0060] In traditional cell cover structures, the insulating component 4 only abuts against the end face of the electrode group 6 through two support parts 412 at both ends. However, the contact area between the insulating component 4 and the electrode group 6 is small, resulting in poor fixation of the electrode group 6. When the cell is subjected to external impact, the electrode group 6 is prone to shifting, which can cause the base of the pole post 21 to damage the electrode group 6.

[0061] 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 second side of the cover plate body 1 and has a support portion 412 protruding away from the cover plate body 1, through which the electrode post 21 passes. The folding plate 42 is folded and connected to the support portion 412, so that the folding plate 42 can be folded or opened relative to the fixing plate 41. Wherein, when the folding plate 42 is folded to the fixing plate 41, the folding plate 42 covers the electrode post 21, and both the support portion 412 and the folding plate 42 are adapted to abut against the electrode group 6 of the battery cell.

[0062] 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 12.

[0063] It is understandable that there is a height difference between the fitting part 411 and the support part 412 in the thickness direction of the cover plate body 1. When the folding plate 42 is folded over 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 support part 412, so that the support part 412 and the folding plate 42 can simultaneously abut against the electrode group 6. In this way, the support part 412 and the folding plate 42 can simultaneously abut against the electrode group 6, thereby increasing the contact area between the insulating member 4 and the electrode group 6, improving the fixing effect of the insulating member 4 on the electrode group 6, thereby preventing the electrode group 6 from shifting, preventing the base of the pole post 21 from damaging the electrode group 6 and the pole tab 61 from being pulled, and improving the safety performance of the battery cell.

[0064] The fixing plate 41 and the cover plate body 1 are in a concave-convex fit. Specifically, a recess is formed on the second side of the cover plate body 1 corresponding to the position of the boss 12, 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, and this groove 410 can be used to accommodate the tabs 61 of the electrode assembly 6.

[0065] like Figure 4As shown, the fixing plate 41, corresponding to the area of ​​the explosion-proof valve 3, is provided with an exhaust structure 4111 communicating with the exhaust port. The exhaust structure 4111 includes a plurality of through holes spaced apart from each other. It can be understood that the exhaust structure 4111 and the exhaust port are opposite each other in the thickness direction of the cover plate body 1, and the area enclosed by the outer periphery of the exhaust structure 4111 covers the area of ​​the exhaust port, so as to facilitate the exhaust of the explosion-proof valve 3. While ensuring the exhaust of the explosion-proof valve 3, the fixing plate 41, corresponding to the area of ​​the explosion-proof valve 3, also has sufficient structural strength to prevent breakage during installation.

[0066] Optionally, such as Figure 5 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 arranged in a one-to-one correspondence. The exhaust structure 4111 is located between the two folding plates 42.

[0067] Specifically, two support portions 412 are respectively located 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 exhaust structure 4111 to avoid obstructing the exhaust structure 4111.

[0068] In some embodiments, the folding plate 42 is a flat plate, and the folding plate 42 may be adjacent to or spaced apart from the groove 410. When the folding plate 42 is folded onto the fixing plate 41, the side of the folding plate 42 away from the fixing plate 41 is flush with the support portion 412.

[0069] In other embodiments, the folding plate 42 is a bent plate conformally to the fixing plate 41, extending from the support portion 412 into the groove 410, with a portion covering the base plate portion 11 where the pole post 21 is located, and another portion bending and extending into the adjacent groove 410.

[0070] like Figure 5 As shown, some embodiments of the present invention provide a cell cover plate that further includes a connecting piece 22. The connecting piece 22 is located between the fixing plate 41 and the folding plate 42. The connecting piece 22 includes a base portion 221 and an extension portion 222, the base portion 221 being connected to the electrode post 21. 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 boss 12, and the extension portion 222 is located in the groove 410 for welding to the electrode tab 61 of the electrode assembly 6.

[0071] It is understandable that when the folding plate 42 is folded over the fixing plate 41, the folding part, the base part 221 and the part of the fixing plate 41 corresponding to the base plate part 11 are stacked in sequence in the thickness direction of the cover plate body 1, and the extension part 222 extends from the base part 221 along the fixing plate 41 into the groove 410.

[0072] After the cell cover is assembled with the electrode assembly 6, the insulating component 4 is located between the cover body 1 and the electrode assembly 6. The support portion 412 and the folding plate 42 abut against the end face of the electrode assembly 6. The groove 410 of the fixing plate 41 defines an accommodating space between itself and the end face of the electrode assembly 6. The electrode tabs 61 of the electrode assembly 6 can be folded into this accommodating space and welded to the extension portion 222. In this way, the internal space of the boss 12 is fully utilized, allowing for a larger space inside the cell to accommodate the body of the electrode assembly 6. This is beneficial for increasing the space utilization rate inside the cell casing 7, thereby further increasing the capacity of the cell.

[0073] like Figure 6 As shown, this embodiment of the invention also provides a battery cell, which includes a battery cell housing 7, an electrode group 6, and a battery cell cover plate as described in any of the above embodiments. The battery cell housing 7 has an opening, and the battery cell cover plate is disposed at the opening and surrounds the battery cell housing 7 to form a receiving cavity. The electrode group 6 is disposed within the receiving cavity, and the electrode tabs 61 of the electrode group 6 are connected to the electrode posts 21.

[0074] When assembling the battery cell, the electrode group 6 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 6. Then, the electrode group 6 is installed into the battery cell housing 7, and the cover body 1 is welded to the battery cell housing 7. Before being installed into the housing, the outside of the electrode group 6 is usually wrapped with an insulating film to provide insulation between the electrode group 6 and the battery cell housing 7.

[0075] Furthermore, such as Figure 7 As shown, the folding plate 42 and the support portion 412 of the cell cover abut against the end face of the electrode group 6. The electrode tab 61 is folded into the space defined by the groove 410 of the insulating member 4 and the electrode group 6.

[0076] The length dimension L of the cover plate body is defined, and the width dimension W is defined. Based on the parameter value ranges specified in this embodiment, a Design of Experiments (DOE) is conducted using cover plate bodies with diameters of 150mm ≤ L ≤ 300mm and 25mm ≤ W ≤ 75mm as the test subjects. Stamping tests are performed on the cover plate body for each case, and the stamping yield is statistically analyzed. For each case, several battery cells are randomly selected, and a Z-axis (thickness direction of the cover plate body) stamping test is conducted on the boss to detect the structural stress at the boss location. The structural strength of the boss is determined based on the stress increase. The experimental results are shown in Table 1, where W1, W2, H1, H2, and L2 are in mm.

[0077] Table 1: Experimental Data 1

[0078] 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 includes a base plate portion and a bent portion, and has a first side and a second side opposite to each other in its thickness direction. The bent portion is connected to the base plate portion at both ends in the length direction of the cover plate body. The bent portion is bent relative to the base plate portion and forms a boss on the first side. A reinforcing rib is provided at the connection between the base plate portion and the bent portion. The pole post is inserted through the substrate portion along the thickness direction and protrudes from the first side.

2. The cell cover plate according to claim 1, characterized in that, The boss includes a top wall and two side walls. The top wall is connected to the base plate portion at both ends in the length direction through one of the side walls. The reinforcing rib extends from the side wall to the base plate portion.

3. The cell cover plate according to claim 2, characterized in that, Each of the sidewalls has a plurality of reinforcing ribs spaced apart along the width direction of the cover plate body.

4. The cell cover plate according to claim 2, characterized in that, In the thickness direction of the cover plate body, the height of the boss relative to the base plate portion is H1, and the height of the reinforcing rib relative to the base plate portion is H2; in the width direction of the cover plate body, the width of the cover plate body is W1, and the width of the reinforcing rib is W2; the thickness of the base plate portion is T1, the wall thickness of the side wall is T2, and the wall thickness of the top wall is T3. Wherein, the reinforcing ribs are located on the first side, and the number of reinforcing ribs corresponding to each sidewall is two, 0.5≤H2 / H1≤0.7, 0.15≤2W2 / W1≤0.2; and / or, T1≥2mm, 1.0≤T2 / T1≤1.2, 1.0≤T3 / T1≤1.

2.

5. The cell cover plate according to claim 1, characterized in that, Also includes: An explosion-proof valve is provided with a vent hole on the cover plate body. The explosion-proof valve is installed on the cover plate body and is opposite to the vent hole. The pole, the boss and the explosion-proof valve are spaced apart in the length direction. The boss is located between the explosion-proof valve and the pole.

6. The cell cover plate according to claim 5, characterized in that, The number of the bending portions is two, and a base plate portion is connected between the two bending portions. The explosion-proof valve is disposed on the base plate portion between the two bending portions. And / or, the base plate is provided with a mounting groove, the explosion-proof valve is disposed in the mounting groove, and the distance between the reinforcing rib and the mounting groove is B; B≥6mm.

7. The cell cover plate according to claim 1, characterized in that, Also includes: The upper plastic is located on the first side, and the substrate is provided with a positioning groove. The upper plastic is disposed in the positioning groove, and the pole is inserted through the upper plastic. In the length direction, the distance between the reinforcing rib and the positioning groove is A, where A≥3mm.

8. The cell cover plate according to claim 1, characterized in that, Also includes: An insulating component includes a fixed plate and a folding plate. The fixed plate is located on the second side of the cover plate body and has a support portion protruding in a direction away from the cover plate body. The pole is inserted through the fixed plate. The folding plate is folded and connected to the support portion, so that the folding plate can be fastened or opened relative to the fixed plate. When the folding plate is fastened to the fixing plate, the folding plate covers the pole post, and both the support and the folding plate are adapted to abut against the pole group of the battery cell.

9. The cell cover plate according to claim 8, characterized in that, Also includes: A connecting piece is located between the fixing plate and the folding plate. The connecting piece includes a base portion and an extension portion. The base portion is connected to the pole post. The fixing plate forms a groove on the side away from the cover plate body, corresponding to the position of the boss. The extension portion is located in the groove and is used for welding to the pole lug of the pole assembly.

10. 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 9, 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.

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