Cover plate structure and battery cell

Abstract

The invention relates to the technical field of batteries, and discloses a cover plate structure and a battery cell. The cover plate structure comprises a cover plate body, the cover plate body is provided with a plurality of installation through holes arranged at intervals in the X direction, the cover plate body is provided with two first side edges oppositely arranged in the X direction, and the two first side edges are oppositely arranged in the X direction; body areas are respectively formed in areas between two adjacent mounting through holes and between the first side edge and one mounting through hole adjacent to the first side edge on the cover plate body; the plurality of reinforcing ribs are arranged in the body area, the total projection area of orthographic projections of the reinforcing ribs on the cover plate body in the Z direction is S0, the contour area of the cover plate body is S, and S0 / S is larger than or equal to 0.025 and smaller than or equal to 0.06. Therefore, stress concentration can be avoided, the product forming yield can be improved, the structural strength of the cover plate body can be effectively improved, and the risk of abnormal deformation or cracking of the cover plate body and the mounting through holes is reduced.

Description

Technical Field

[0001] This invention relates to the field of battery technology, specifically to cover plate structures and battery cells. Background Technology

[0002] Batteries are currently widely used in various fields such as transportation power supplies, power storage, and new energy storage power supplies. A battery cell generally includes a cover assembly, a casing, electrode assembly, electrolyte, and internal and external insulating materials. The cover assembly consists of a cover body and a casing, which are welded together to form a sealed space with sufficient strength to protect the electrode assembly. The cover body typically integrates structures such as terminals, explosion-proof valves, and electrolyte injection holes. To improve the utilization rate of cell space and increase battery pack capacity, the thickness of individual cells is gradually being reduced. However, this results in a very narrow cover body, while simultaneously requiring the integration of functional areas such as terminals, explosion-proof valves, and electrolyte injection holes, leading to weaker structural strength and poorer stability of the cover body. Summary of the Invention

[0003] In view of this, the present invention provides a cover plate structure and a battery cell to solve the problems of weak structural strength and poor stability of the cover plate body.

[0004] In a first aspect, the present invention provides a cover plate structure, comprising: a cover plate body having a plurality of mounting through holes spaced apart along the X direction, the cover plate body having two first side edges arranged opposite each other along the X direction, and along the X direction, the areas on the cover plate body located between two adjacent mounting through holes and between the first side edges and one adjacent mounting through hole each forming a body area; and a plurality of reinforcing ribs disposed in the body areas, the total projected area of ​​the orthographic projection of the reinforcing ribs along the Z direction on the cover plate body being S0, and the outline area of ​​the cover plate body being S, wherein 0.025≤S0 / S≤0.06.

[0005] Beneficial effects: By setting reinforcing ribs in the body area of ​​the cover plate body, the structural strength of the area between two adjacent mounting through holes and between the mounting through holes at both ends and the first side can be strengthened by the reinforcing ribs. Furthermore, by limiting the ratio S0 / S between the total projected area S0 of the reinforcing ribs along the Z direction on the cover plate body 1 and the outline area S of the cover plate body to be between 0.025 and 0.06, it is possible to avoid excessive reinforcing ribs, prevent the material flow area from overlapping during the stamping of the cover plate structure, thereby avoiding stress concentration, reducing cracking, and improving the product molding yield. At the same time, it can ensure that there are sufficient reinforcing ribs on the cover plate body, thereby effectively improving the structural strength of the cover plate body and reducing the risk of abnormal deformation or cracking of the body area and mounting through holes of the cover plate body under external extrusion and impact, thereby improving the safety and reliability of the battery cell.

[0006] In one alternative implementation, one or more of the reinforcing ribs are provided in one of the body regions.

[0007] Beneficial effects: Based on the size of the body area, an appropriate number of reinforcing ribs can be selected and set to ensure that the reinforcing ribs in the body area can provide sufficient reinforcement while avoiding excessive density of reinforcing ribs in the same body area, which would affect the product molding yield.

[0008] In one optional embodiment, at least one of the body regions is provided with a plurality of the reinforcing ribs, and among the plurality of reinforcing ribs located in the same body region, at least two first reinforcing ribs are arranged in parallel with each other, and the distance between two adjacent first reinforcing ribs is c, wherein 5mm≤c≤10mm.

[0009] Beneficial effects: It can ensure the smooth molding of the cover plate body and reinforcing ribs, avoid cracking, improve the molding yield, and ensure that the reinforcing ribs effectively enhance the structural strength of the cover plate body.

[0010] In one alternative embodiment, among the multiple reinforcing ribs located in the same body region, a second reinforcing rib is further included, which is disposed intersecting with the first reinforcing rib.

[0011] Beneficial effects: By setting first and second reinforcing ribs that intersect in the same body area, the stress situation of the body area can be improved in different directions. All the reinforcing ribs in the body area are connected into a whole, which has better integrity and stability, further strengthening the structural strength of the body area, thereby further strengthening the structural strength of the cover plate body.

[0012] In one optional embodiment, the reinforcing rib includes a transverse rib extending in the Y direction and / or a longitudinal rib extending in the X direction; the first reinforcing rib is a transverse rib and the second reinforcing rib is a longitudinal rib; or, the first reinforcing rib is a longitudinal rib and the second reinforcing rib is a transverse rib.

[0013] Beneficial effects: By setting the reinforcing ribs as transverse ribs extending along the Y direction, making the reinforcing ribs parallel to the first side edge of the cover plate body, the reinforcing ribs strengthen the cover plate body along the Y direction. The transverse ribs can more effectively improve the structural strength of the cover plate body in the width direction of the battery cell, thereby improving the safety and reliability of the battery cell. It also facilitates the arrangement and processing of the reinforcing ribs, resulting in a simple reinforcing rib structure and a high product yield. Alternatively, by setting the reinforcing ribs as longitudinal ribs extending along the X direction, making the reinforcing ribs consistent with the length direction of the cover plate body, the reinforcing ribs strengthen the cover plate body along the X direction, improving the structural strength and stability of the cover plate body in the length direction of the battery cell. The ribs also facilitate the layout and stamping of reinforcing ribs, improving product yield. Alternatively, by setting reinforcing ribs that include both transverse and longitudinal ribs, intersecting transverse and longitudinal ribs can be present in the same body area, reinforcing the cover plate body simultaneously along the X and Y directions. The interlaced layout of the reinforcing ribs connects the transverse and longitudinal ribs into a whole, enhancing the integrity and stability of the reinforcing ribs. This more effectively improves the structural strength and stability of the cover plate body, allowing it to better disperse and resist external forces when subjected to them, reducing the risk of deformation and cracking, and further improving the safety and reliability of the cover plate structure.

[0014] In one optional embodiment, the area between the first side and the adjacent mounting through hole forms a first body area, and the cover plate body is further provided with an identification part, which is located in the first body area;

[0015] At least one horizontal rib is provided between the marking part and the adjacent mounting through hole, or at least one vertical rib is provided on each side of the marking part along the Y direction.

[0016] Beneficial effects: By setting the marking section, the positive / negative pole positions on the cover plate assembly can be quickly and accurately identified, thus facilitating the accurate correspondence between the cover plate structure and the positive / negative pole tabs of the pole group, thereby improving the assembly efficiency of the battery cell. Furthermore, by setting a horizontal rib between the marking section and the mounting through hole, the structural strength of the area between the marking section and the mounting through hole can be strengthened, thereby further improving the structural strength of the cover plate body and the deformation resistance of the mounting through hole. Alternatively, by setting at least one longitudinal rib on each side of the marking section along the Y direction, the structural strength of the area where the marking section is located can be strengthened along the X direction, further improving the structural strength of the cover plate body. At the same time, since the marking section is usually located near the edge of the battery cell, the longitudinal ribs can also strengthen the structural strength at the edge of the battery cell, thereby improving the overall reliability of the battery cell.

[0017] In one optional embodiment, along the X direction, the distance from the reinforcing rib adjacent to the first side to the first side is a1, where 3mm≤a1≤5mm; the cover plate body also has two second side edges arranged opposite each other along the Y direction, and the shortest distance along the Y direction between the reinforcing rib and the second side edge is a2, where 3mm≤a2≤5mm;

[0018] And / or, in the direction perpendicular to the extension of the reinforcing rib, the width of the reinforcing rib is b, wherein 0.7mm ≤ b ≤ 1.2mm.

[0019] Beneficial effects: By limiting the values ​​of a1 and a2 to the range of 3mm to 5mm, it can be ensured that the reinforcing ribs can effectively enhance the edge structural strength of the cover plate body and guarantee the welding quality, while avoiding cracking during processing caused by the reinforcing ribs being too close to the edge.

[0020] And / or, by limiting the width b of the reinforcing rib to between 0.7 mm and 1.2 mm, it is possible to ensure that the reinforcing rib can be formed smoothly and has sufficient structural strength to achieve a good reinforcing effect, while avoiding stress concentration caused by excessive width of the reinforcing rib, thereby improving the reliability of the cover plate structure.

[0021] In one alternative embodiment, the cover plate body forms a first surface on one side along the Z direction;

[0022] The reinforcing rib is constructed as a convex rib on the first surface; or, the reinforcing rib is constructed as a concave rib on the first surface; or, the reinforcing rib includes convex ribs and concave ribs constructed on the first surface, with the convex ribs and concave ribs being distributed alternately.

[0023] Beneficial effects: The raised ribs protrude along the Z-direction from the first surface, increasing the local structural strength of the cover plate body on the first surface and effectively enhancing its structural strength. The raised ribs are also simple in structure and easy to mold. The recessed ribs are formed by recessing a portion of the first surface along the Z-direction, creating grooves that improve the stress distribution on the first surface. The recessed ribs can constrain and suppress deformation of the cover plate body, further enhancing its local structural strength and reducing bending deformation under external forces. They also prevent protrusions from forming on the first surface, facilitating subsequent application of cover plate patches and ensuring the insulation of the first surface, thus improving the safety of the battery cell. The alternating distribution of raised and recessed ribs on the first surface further increases the surface complexity of the cover plate body, fully utilizing the advantages of both to further enhance its structural strength and stability.

[0024] In one optional embodiment, along the Z direction, the size of the reinforcing rib is h, and the thickness of the cover plate body is t, wherein 0.10≤h / t≤0.15, 1.5≤t≤2.5mm, and 0.2mm≤h≤0.3mm;

[0025] And / or, the dimension of the cover plate body along the X direction is A, 90mm≤A≤180mm; the dimension of the cover plate body along the Y direction is B, 15mm≤B≤70mm.

[0026] Beneficial effects: By limiting the ratio of the dimension h of the reinforcing rib along the Z direction to the thickness t of the cover plate body 1 to between 0.10 and 0.15, and limiting t to between 1.5 mm and 2.5 mm, and h to between 0.2 mm and 0.3 mm, it can ensure that the reinforcing rib has sufficient structural strength and achieves a good reinforcing effect, while avoiding the problem of stress concentration caused by the excessive dimension of the reinforcing rib along the Z direction, and avoiding excessive weight and volume of the cover plate body 1, thereby improving the energy density of the battery cell;

[0027] And / or, by limiting A to a value within the range of 90mm to 180mm and B to a value within the range of 15mm to 70mm, it is possible to ensure that the cover plate body has sufficient structural strength and assembly space, while avoiding excessive weight and volume due to excessive size, thereby improving the overall performance and reliability of the battery cell.

[0028] Secondly, the present invention also provides a battery cell, comprising: a housing having an open end; an electrode assembly disposed within the inner cavity of the housing; and a cover plate assembly covering the open end of the housing, the cover plate assembly comprising the cover plate structure described above. Since the battery cell includes a cover plate structure and has the same effects as the cover plate structure, it will not be described further here. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is an exploded view of a battery cell before its improvement.

[0031] Figure 2 for Figure 1 A partially enlarged schematic diagram of the battery cell shown;

[0032] Figure 3 This is a schematic diagram of the first type of cover plate structure when the reinforcing rib is a convex rib according to an embodiment of the present invention;

[0033] Figure 4 for Figure 3 A magnified view of part A in the diagram;

[0034] Figure 5 for Figure 3 A schematic diagram showing the division of the body area and the opening area on the cover plate structure;

[0035] Figure 6 This is a schematic diagram of the second cover plate structure when the reinforcing rib is a convex rib according to an embodiment of the present invention;

[0036] Figure 7 This is a schematic diagram of the third type of cover plate structure when the reinforcing rib is a raised rib according to an embodiment of the present invention;

[0037] Figure 8 This is a schematic diagram of the first type of cover plate structure when the reinforcing rib is a concave rib according to an embodiment of the present invention;

[0038] Figure 9 for Figure 8 A magnified view of part B in the diagram;

[0039] Figure 10 This is a schematic diagram of the second cover plate structure when the reinforcing rib is a concave rib according to an embodiment of the present invention;

[0040] Figure 11 This is a schematic diagram of the third type of cover plate structure when the reinforcing rib is a concave rib according to an embodiment of the present invention;

[0041] Figure 12 This is a schematic diagram of the first type of cover plate structure in an embodiment of the present invention, where the reinforcing ribs are alternately distributed with convex and concave ribs.

[0042] Figure 13 This is a schematic diagram of the second cover plate structure in an embodiment of the present invention, where the reinforcing ribs are alternately distributed with convex and concave ribs.

[0043] Figure 14 for Figure 13 A magnified view of part C in the diagram.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Cover plate body; 100. First surface; 101. First side; 102. Second side; 103. Marking part; 111. First body area; 112. Second body area; 113. Opening area; 201. Horizontal rib; 202. Longitudinal rib; 3. Shell; 4. Electrode group; 5. Electrode post; 6. Explosion-proof valve. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] Lithium-ion batteries are a common type of battery, widely used in various fields such as transportation power supplies, power storage, new energy storage power supplies, and aerospace due to their advantages such as large capacity, high operating voltage, strong charge retention, and long cycle life. Figures 1 to 2 As shown, a battery cell generally includes a cover assembly, a housing 3, an electrode assembly 4, electrolyte, and inner and outer insulating materials. The cover assembly includes a cover body 1, which is welded to the housing 3 to form a sealed space with a certain strength to protect the electrode assembly. The cover body 1 has mounting holes such as electrode post holes and explosion-proof valve holes for installing electrode posts and explosion-proof valves. To improve the utilization rate of battery cell space and increase battery pack capacity, the thickness of a single battery cell is gradually being reduced. However, this results in a very narrow cover body, while the cover body needs to integrate functional areas such as electrode posts, explosion-proof valves, and electrolyte injection holes, making the structural strength of the cover body weak and its stability poor. To improve the safety of the battery cell, the strength of the cover body needs to be strengthened.

[0048] The following is combined with Figures 3 to 14 The following describes embodiments of the present invention.

[0049] According to an embodiment of the present invention, a cover plate structure is provided, comprising: a cover plate body 1 and a plurality of reinforcing ribs. The cover plate body 1 has a plurality of mounting through holes spaced apart along the X direction. The cover plate body 1 has two first side edges 101 arranged opposite each other along the X direction. Along the X direction, the areas on the cover plate body 1 located between two adjacent mounting through holes and between the first side edge 101 and its adjacent mounting through hole each form a body area. The plurality of reinforcing ribs are disposed in the body areas. The total projected area of ​​the orthographic projection of the reinforcing ribs along the Z direction on the cover plate body 1 is S0, and the outline area of ​​the cover plate body 1 is S, wherein 0.025≤S0 / S≤0.06. It should be noted that the cover plate structure has X, Y, and Z directions that intersect each other; preferably, the X, Y, and Z directions are perpendicular to each other. The X direction refers to... Figures 3 to 4 The middle arrow points to the direction of "X"; the Y direction refers to... Figures 3 to 4 The middle arrow points to the direction of "Y"; the Z direction refers to... Figures 3 to 4 The direction of the "Z" indicated by the middle arrow.

[0050] It should be noted that the orthographic projection of the reinforcing rib along the Z direction onto the cover plate body 1 refers to the orthographic projection of the reinforcing rib along the Z direction onto the plane containing the first surface 100 of the cover plate body 1. Since each reinforcing rib is elongated, the area of ​​the orthographic projection of each reinforcing rib along the Z direction onto the cover plate body 1 is equal to the product of its dimension along the X direction and its dimension along the Y direction. S0 is the sum of the projected areas of all reinforcing ribs on the surface of the cover plate body 1; S is equal to the product of the dimension of the cover plate body 1 along the X direction and its dimension along the Y direction. If S0 / S is less than 0.025, then... If the total projected area of ​​the reinforcing ribs is too small compared to the outline area of ​​the cover plate body 1, the reinforcing area of ​​the reinforcing ribs is insufficient, the reinforcing effect provided is insufficient, and the structural strength of the cover plate body 1 cannot be effectively improved. If S0 / S is greater than 0.06, the total projected area of ​​the reinforcing ribs is too large compared to the outline area of ​​the cover plate body 1, there are too many reinforcing ribs, the density of the reinforcing ribs is too high, and the distance between the reinforcing ribs and their adjacent mounting holes or the edge of the cover plate body 1 is too close. Since the cover plate structure is formed by stamping, the material flow area is highly overlapping during stamping, stress is concentrated, cracking is easy, and the forming yield is low.

[0051] By applying the cover plate structure of this embodiment, reinforcing ribs are provided in the body area of ​​the cover plate body 1, so that the structural strength of the area between two adjacent mounting through holes on the cover plate body 1 and between the mounting through holes at both ends and the first side 101 can be strengthened by the reinforcing ribs. Furthermore, by limiting the ratio S0 / S between the total projected area S0 of the reinforcing ribs along the Z direction on the cover plate body 1 and the outline area S of the cover plate body 1 to be between 0.025 and 0.06, it is possible to avoid excessive reinforcing ribs, prevent the material flow area from overlapping during the stamping of the cover plate structure, thereby avoiding stress concentration, reducing cracking, and improving the product molding yield. At the same time, it is possible to ensure that there are sufficient reinforcing ribs on the cover plate body 1, thereby effectively improving the structural strength of the cover plate body 1 and reducing the risk of abnormal deformation or cracking of the body area and mounting through holes of the cover plate body 1 under external extrusion and impact, thereby improving the safety and reliability of the battery cell.

[0052] Optionally, the value of S0 / S is any one of 0.025, 0.03, 0.035, 0.04, 0.045, 0.05, 0.055, 0.06 or a value between any two values.

[0053] It should be noted that the mounting through-hole penetrates the cover plate body 1 along the Z direction. The mounting through-hole includes a pole post hole and an explosion-proof valve hole. The pole post hole is suitable for installing the pole post 5, and the explosion-proof valve hole is suitable for installing the explosion-proof valve 6. In this embodiment, the cover plate structure provides reinforcing ribs in the body area on both sides of the pole post hole and the explosion-proof valve hole along the X direction. This not only improves the structural strength of the cover plate body 1, but also reduces the risk of abnormal deformation and cracking of the explosion-proof valve 6 due to external pressure and impact. It also reduces the deformation of the cover plate body 1 during the riveting process of the cover plate assembly, thereby improving the cover plate production yield.

[0054] Of course, the mounting through holes may also include electrolyte injection holes (not shown in the figure). The electrolyte injection holes are used to inject electrolyte into the cell. The reinforcing ribs set on both sides of the electrolyte injection holes along the X direction can reduce the deformation of the electrolyte injection holes under external force and reduce the risk of electrolyte leakage from the cell.

[0055] Further integration Figure 5 As shown, along the X direction, the cover plate body 1 includes two first body areas 111 located at both ends, at least one second body area 112 located between the two first body areas 111, and at least two opening areas 113. The opening area 113 refers to the area on the cover plate body 1 with mounting through holes, and the second body area 112 is the area between the two connected opening areas 113. The dimensions of the first body area 111, the second body area 112, and the opening area 113 along the Y direction are all equal to the dimensions of the cover plate body 1 along the Y direction. No reinforcing ribs are provided in the opening area 113, and the reinforcing ribs are provided in the first body area 111 and the second body area 112 to facilitate the layout and stamping of the reinforcing ribs.

[0056] In one embodiment, the cover plate body 1 has two mounting through holes, namely a pole hole and an explosion-proof valve hole. Correspondingly, there are two opening areas 113 and one second body area 112. The cover plate body 1 includes a first body area 111, an opening area 113, a second body area 112, and a first body area 111 connected in sequence.

[0057] In one embodiment, one or more reinforcing ribs are provided in a body area. Here, a body area refers to a first body area 111 or a second body area 112. Since the dimensions of each body area are different along the X direction, an appropriate number of reinforcing ribs can be selected according to the size of the body area to ensure that the reinforcing ribs in the body area can provide sufficient reinforcement while avoiding excessive density of reinforcing ribs in the same body area, which would affect the product molding yield.

[0058] In one embodiment, a first surface 100 is formed on one side of the cover plate body 1 along the Z direction, and a second surface is formed on the other side. When the cover plate structure is assembled with components such as the housing 3 to form a battery cell, the first surface 100 faces the outside of the housing 3, and the second surface faces the inside of the housing 3; further combined with Figures 3 to 7 As shown, the reinforcing rib is constructed as a raised rib on the first surface 100. The raised rib protrudes from the first surface 100 along the Z direction. The arrangement of the raised rib can increase the local structural strength of the cover plate body 1 on the first surface 100, thereby effectively strengthening the structural strength of the cover plate body 1. Moreover, the raised rib has a simple structure and is easy to form. It should be noted that a groove corresponding to the raised rib is constructed on the second surface to facilitate the stamping and forming of the reinforcing rib.

[0059] In addition, in other embodiments, further combined Figures 8 to 11 As shown, the reinforcing rib is constructed as a concave rib on the first surface 100. The concave rib is formed by a portion of the first surface 100 recessed along the Z-direction, creating a groove on the first surface 100. This improves the stress distribution on the first surface and helps to constrain and suppress deformation of the cover plate body 1. The concave rib also enhances the local structural strength of the cover plate body 1 on the first surface 100, reducing bending deformation under external forces. Furthermore, the concave rib prevents the formation of protrusions on the first surface 100, facilitating the subsequent attachment of cover plate patches to the first surface 100, thus ensuring the insulation of the first surface and improving the safety of the battery cell. It should be noted that a corresponding protrusion is constructed on the second surface to facilitate the stamping of the concave rib and ensure that the reinforcing rib effectively strengthens the structural strength of the cover plate body 1.

[0060] In addition, in other embodiments, further combined Figures 12 to 14 As shown, the reinforcing ribs include raised and recessed ribs constructed on the first surface 100, with the raised and recessed ribs alternating. This alternating distribution of raised and recessed ribs on the first surface 100 further increases the surface complexity of the cover plate body 1, fully utilizing the advantages of both to further enhance the structural strength and stability of the cover plate body 1. Specifically, the raised ribs protrude from the first surface 100 along the Z-direction, providing additional support and effectively resisting external compression and impact; the recessed ribs form grooves on the first surface 100, constraining and suppressing the deformation of the cover plate body 1, especially significantly reducing the risk of bending deformation under complex external forces. It should be noted that the second surface of the cover plate body 1 also has an alternating distribution of raised and recessed ribs, with the raised ribs on the second surface facing the recessed ribs on the first surface, and vice versa, to facilitate the stamping and forming of the reinforcing ribs.

[0061] In one embodiment, at least one body area is provided with multiple reinforcing ribs. Among the multiple reinforcing ribs located in the same body area, at least two first reinforcing ribs are arranged parallel to each other. The distance between two adjacent first reinforcing ribs is c, where 5mm ≤ c ≤ 10mm. It should be noted that the reinforcing ribs are elongated. The distance between two adjacent first reinforcing ribs refers to the distance between two adjacent first reinforcing ribs in the direction perpendicular to the extension of the first reinforcing rib, that is, the dimension of the solid portion between two adjacent first reinforcing ribs along the direction perpendicular to the extension of the first reinforcing rib. If c is less than 5mm, the distance between two adjacent reinforcing ribs is too close. During the stamping process of the cover plate structure, the material flow areas of the two parallel and adjacent reinforcing ribs overlap, resulting in serious stress concentration problems, easy cracking, and greater processing difficulty. If c is greater than 10mm, the distance between two parallel adjacent reinforcing ribs is too far, and the reinforcing effect of the reinforcing ribs on the cover plate body 1 is insufficient. Therefore, by limiting the spacing c between two adjacent first reinforcing ribs to between 5mm and 10mm, it is possible to ensure the smooth forming of the cover plate body 1 and the reinforcing ribs, avoid cracking, improve the forming yield, and ensure that the reinforcing ribs effectively strengthen the structural strength of the cover plate body 1.

[0062] Optionally, the value of c is any one of 5mm, 6mm, 7mm, 8mm, 9mm, 10mm or a value between any two of them.

[0063] In one embodiment, among the multiple reinforcing ribs located in the same body area, a second reinforcing rib is also included, which intersects with the first reinforcing rib. By providing both the first and second reinforcing ribs intersecting in the same body area, the stress distribution of the body area can be improved in different directions. All the reinforcing ribs in the body area are connected into a whole, resulting in better integrity and stability, further strengthening the structural strength of the body area, and thus further strengthening the structural strength of the cover plate body 1.

[0064] Preferably, the second reinforcing rib is perpendicular to the first reinforcing rib, which facilitates processing and provides a good reinforcing effect.

[0065] In one embodiment, such as Figures 3 to 5 , Figures 8 to 9 , Figures 12 to 14As shown, the reinforcing ribs are transverse ribs 201 extending along the Y direction. The first reinforcing rib is a transverse rib 201, and several transverse ribs 201 are distributed at intervals along the X direction. Each body area has one or more transverse ribs 201. By setting the reinforcing ribs as transverse ribs 201 extending along the Y direction, the reinforcing ribs are parallel to the first side edge 101 of the cover plate body 1. The reinforcing ribs reinforce the cover plate body 1 along the Y direction. Since the battery cell is subjected to relatively large external forces of compression and impact in the width direction during use, the setting of transverse ribs 201 can more effectively improve the structural strength of the cover plate body 1 in the width direction of the battery cell, thereby improving the safety and reliability of the battery cell. It also facilitates the arrangement and processing of the reinforcing ribs, and the reinforcing rib structure is simple, resulting in a high product yield.

[0066] Additionally, in other embodiments, such as Figure 6 , Figure 10 As shown, the reinforcing rib is a longitudinal rib 202 extending along the X direction. The first reinforcing rib is a longitudinal rib 202. There are at least two longitudinal ribs 202 spaced apart along the Y direction in the same body area, preferably two. By setting the reinforcing rib as a longitudinal rib 202 extending along the X direction, the reinforcing rib is aligned with the length direction of the cover plate body 1. The reinforcing rib strengthens the cover plate body 1 along the X direction, improving the structural strength and stability of the cover plate body 1 in the length direction of the battery cell. The setting of the longitudinal rib 202 also facilitates the layout of the reinforcing rib and stamping, improving the product production yield.

[0067] In other embodiments... Figure 11 As shown, the reinforcing ribs include transverse ribs 201 extending along the Y direction and longitudinal ribs 202 extending along the X direction. The first reinforcing rib is a transverse rib 201, and the second reinforcing rib is a longitudinal rib 202. By setting the reinforcing ribs to include both transverse ribs 201 and longitudinal ribs 202, intersecting transverse ribs 201 and longitudinal ribs 202 can be simultaneously present in the same body area. This allows for simultaneous reinforcement of the cover plate body 1 along both the X and Y directions. Furthermore, the interlaced layout of the reinforcing ribs connects the transverse ribs 201 and longitudinal ribs 202 into a whole, enhancing the integrity and stability of the reinforcing ribs. This more effectively improves the structural strength and stability of the cover plate body 1, enabling the cover plate body 1 to better disperse and resist external forces when subjected to them, reducing the risk of deformation and cracking, and further improving the safety and reliability of the cover plate structure. It is understood that, as an alternative implementation, such as... Figure 7 As shown, the first reinforcing rib can also be set as a longitudinal rib 202 and the second reinforcing rib as a transverse rib 201. This can also achieve the same body area with intersecting longitudinal and transverse reinforcing ribs, thereby further increasing the structural strength and improving the reliability of the cover plate body.

[0068] In one embodiment, the area between the first side 101 and the adjacent mounting through hole forms a first body area 111. The cover plate body 1 is further provided with an identification portion 103, which is located within the first body area 111, and further combined with… Figure 3 , Figure 8 , Figures 11 to 13 As shown, at least one horizontal rib 201 is provided between the marking part 103 and the adjacent mounting through hole. It should be noted that the marking part 103 is used to mark the positive and negative terminals. The marking part 103 is a "+" or "-" shaped engraving located on the first surface 100 of the cover plate body 1. By providing the marking part 103, the positive / negative terminal positions on the cover plate assembly can be quickly and accurately identified, thereby facilitating the accurate correspondence between the cover plate structure and the positive / negative terminal tabs of the electrode group, thus improving the assembly efficiency of the battery cell. Furthermore, by providing the horizontal rib 201 between the marking part 103 and the mounting through hole, the structural strength of the area between the marking part 103 and the mounting through hole can be strengthened, thereby further improving the structural strength of the cover plate body 1 and the deformation resistance of the mounting through hole.

[0069] It should be noted that for a battery cell with tabs at both ends, two cover plate assemblies are usually provided. Each cover plate assembly has a terminal (positive or negative terminal) on its cover plate body 1. The number of marking parts 103 on the cover plate body 1 is one, and the marking part 103 is a symbol corresponding to the polarity of the terminal. For a battery cell with tabs at one end, one cover plate assembly is usually provided. The cover plate body 1 has both a positive terminal and a negative terminal. The number of marking parts 103 on the cover plate body 1 is two (not shown in the figure), including a "+" near the positive terminal and a "-" near the negative terminal.

[0070] In addition, in other embodiments, further combined Figure 6 , Figure 7 and Figure 10 As shown, at least one longitudinal rib 202 is provided on each side of the marking portion 103 along the Y direction. By providing at least one longitudinal rib 202 on each side of the marking portion 103 along the Y direction, the structural strength of the area where the marking portion 103 is located can be strengthened along the X direction, further improving the structural strength of the cover plate body 1. At the same time, since the marking portion 103 is usually located near the edge of the battery cell, the longitudinal ribs 202 can also strengthen the structural strength at the edge of the battery cell, thereby improving the overall reliability of the battery cell. Preferably, one longitudinal rib 202 is provided on each side of the marking portion 103 along the Y direction, which ensures the strengthening effect while facilitating processing and forming. Of course, two or more longitudinal ribs 202 can also be provided on each side of the marking portion 103 along the Y direction to further improve the strengthening effect.

[0071] In one embodiment, along the X direction, the distance from the reinforcing rib adjacent to the first side 101 to the first side 101 is a1, where 3mm≤a1≤5mm; the cover plate body 1 also has two second side 102 arranged opposite each other along the Y direction, and the shortest distance between the reinforcing rib and the second side 102 along the Y direction is a2, where 3mm≤a2≤5mm. It should be noted that after the cover plate structure is assembled with the shell 3, the edge of the cover plate body 1 is welded to the opening end of the shell 3. Therefore, a certain welding position needs to be left at the edge of the cover plate body 1. a1 and a2 are the distances from the reinforcing rib to the edge of the cover plate body 1. If a1 or a2 is less than 3mm, the reinforcing rib is too close to the edge of the cover plate body 1, and the reserved welding size on the cover plate body 1 is insufficient. When the cover plate body 1 is welded to the shell 3, the welding laser can easily reach the reinforcing rib, thus affecting the structural strength of the reinforcing rib. The weld strength after welding is insufficient, the weld quality is poor, and during the stamping process of the cover plate structure, the material flow at the edge is restricted, which can easily cause stress concentration and cracking. If a1 or a2 is greater than 5mm, the reinforcing rib is too far from the edge of the cover plate body 1, and the reinforcement effect at the edge is weakened. Therefore, by limiting the values ​​of a1 and a2 to the range of 3mm to 5mm, it can be ensured that the reinforcing rib can effectively enhance the edge structural strength of the cover plate body 1 and guarantee the welding quality, while avoiding the problem of cracking during processing caused by the reinforcing rib being too close to the edge.

[0072] In one embodiment, the width of the reinforcing rib is b in the direction perpendicular to its extension, where 0.7mm ≤ b ≤ 1.2mm. It should be noted that when the reinforcing rib is a transverse rib 201, its extension direction is the Y direction, and b is the dimension of the transverse rib 201 along the X direction; when the reinforcing rib is a longitudinal rib 202, its extension direction is the X direction, and b is the dimension of the longitudinal rib 202 along the Y direction; that is, b refers to the width of the reinforcing rib. If b is less than 0.7mm, the width of the reinforcing rib is too small, making molding difficult, resulting in insufficient structural strength and an insignificant reinforcing effect. If b is greater than 1.2mm, the width of the reinforcing rib is too large, leading to severe stress concentration at the connection between the reinforcing rib and the cover plate body 1, increasing the risk of cracking. Therefore, by limiting the width b of the reinforcing rib to between 0.7mm and 1.2mm, it is possible to ensure smooth molding of the reinforcing rib, guarantee sufficient structural strength for a good reinforcing effect, and avoid stress concentration caused by excessively large reinforcing rib width, thereby improving the reliability of the cover plate structure.

[0073] Optionally, the value of b is any one of 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm or a value between any two of these values.

[0074] In one embodiment, the size of the reinforcing rib along the Z-direction is h, and the thickness of the cover plate body 1 is t, where 0.10 ≤ h / t ≤ 0.15, 1.5 ≤ t ≤ 2.5 mm, and 0.2 mm ≤ h ≤ 0.3 mm. It should be noted that when the reinforcing rib is a raised rib, h refers to the size by which the reinforcing rib protrudes from the first surface 100 of the cover plate body 1 along the Z-direction; when the reinforcing rib is a recessed rib, h refers to the size by which the reinforcing rib is recessed into the first surface 100 of the cover plate body 1 along the Z-direction. If the ratio of h / t is less than 0.10, the size of the reinforcing rib along the Z-direction relative to the thickness of the cover plate body 1 is too low, resulting in insufficient structural strength and insignificant reinforcement. If the ratio of h / t is greater than 0.15, the size of the reinforcing rib along the Z-direction relative to the thickness of the cover plate body 1 is too large, leading to significant deformation during stamping and resulting in severe stress concentration at the connection between the reinforcing rib and the cover plate body 1, increasing the risk of cracking. Meanwhile, if the thickness t of the cover plate body 1 is less than 1.5mm, the cover plate body 1 is too thin overall and the structural strength is insufficient, making it prone to deformation or cracking during processing and use; if the thickness t of the cover plate body 1 is greater than 2.5mm, the cover plate body 1 is too thick overall, which will not only increase the overall weight and volume of the battery cell, but also lead to a decrease in the energy density of the battery cell.

[0075] Therefore, by limiting the ratio of the dimension h of the reinforcing rib along the Z direction to the thickness t of the cover plate body 1 to between 0.10 and 0.15, while limiting t to between 1.5 mm and 2.5 mm, and h to between 0.2 mm and 0.3 mm, it is possible to ensure that the reinforcing rib has sufficient structural strength and achieves a good reinforcing effect, while avoiding the problem of stress concentration caused by the excessive dimension of the reinforcing rib along the Z direction, and avoiding excessive weight and volume of the cover plate body 1, thereby improving the energy density of the battery cell.

[0076] In one embodiment, the dimension of the cover plate body 1 along the X direction is A, where 90mm ≤ A ≤ 180mm; the dimension of the cover plate body 1 along the Y direction is B, where 15mm ≤ B ≤ 70mm. If A is less than 90mm or B is less than 15mm, the size of the cover plate body 1 is too small, failing to meet the assembly and usage requirements of the battery cell, and its structural strength is insufficient. If A is greater than 180mm or B is greater than 70mm, the size of the cover plate body 1 is too large, which not only increases the overall weight and volume of the battery cell but may also cause inconvenience during assembly and use. Therefore, by limiting A to a value within the range of 90mm to 180mm and B to a value within the range of 15mm to 70mm, it is possible to ensure that the cover plate body 1 has sufficient structural strength and assembly space while avoiding excessive weight and volume due to excessive size, thereby improving the overall performance and reliability of the battery cell.

[0077] It should be noted that in this embodiment, the cover plate structure, along with the pole post 5, the explosion-proof valve 6, the upper plastic part, the lower plastic part, etc., are assembled together to form a cover plate assembly, which is used to assemble with the housing 3.

[0078] The following examples illustrate the impact of different parameter values ​​on the performance of the cover plate structure. The test results of the embodiments and comparative examples are shown in Tables 1 to 3.

[0079] Experiment 1: When the reinforcing rib is a raised rib, the cover plate structure is produced using the parameters of Examples 1 to 10 and Comparative Examples 1 to 3. The flatness data of the cover plate body 1 after riveting and assembly is tracked (the data of one shift is tracked for each example and comparative example scheme, the total production capacity of the cover plate is about 1.5W EA (pieces), and the flatness design requirement value of the cover plate body 1 is ≤0.3mm). The verification results are shown in Table 1.

[0080] Table 1

[0081]

[0082]

[0083] Where n is the number of reinforcing ribs, S0 = (Ba × 2) × b × n, S = A × B, and the same applies to Tables 2 and 3, which will not be repeated hereafter.

[0084] As can be seen from Table 1, for the cover plate structures of Examples 1 to 10, all parameters are within the range defined in this application, and the pass rate of the flatness of the cover plate body is 99.79% or higher, which is a high pass rate. However, for the cover plate structure of Comparative Example 1, b = 0, that is, no reinforcing ribs are provided on the cover plate body 1, S0 / S is 0, and the pass rate of the flatness of the cover plate body is 95.9%. For the cover plate structure of Comparative Example 2, S0 / S is 2.18%, which is less than 0.025 and is not within the range defined in this application, and the pass rate of the flatness of the cover plate body is 96.2%. For the cover plate structure of Comparative Example 3, S0 / S is 6.67%, which is greater than 0.06 and is not within the range defined in this application, and the pass rate of the flatness of the cover plate body is 96.7%. That is, the pass rates of the cover plate structures of Comparative Examples 1 to 3 are all low.

[0085] As can be seen, when the ribs adopt the parameter range defined in this embodiment, after the cover plate assembly is riveted, the proportion of poor flatness of the cover plate body 1 is greatly reduced, and the overall structural strength of the cover plate structure is improved.

[0086] Experiment 2: Using the schemes of the embodiments and comparative examples in Experiment 1, cover plate structures were produced and assembled into cover plate assemblies. After the cover plate assemblies were assembled with the housing 3, extrusion tests were conducted on the explosion-proof valve positions on the cover plate assemblies. For each embodiment and comparative example, 10 EA (units) of cover plate assemblies were subjected to extrusion tests to verify the rupture of the explosion-proof valve. The verification results are shown in Table 2. Extrusion method: The extrusion head was a hemisphere with a radius of 25 mm; the extrusion speed was 0.01 mm / s; and the extrusion displacement was 2 mm.

[0087] Table 2

[0088]

[0089]

[0090] As shown in Table 2, for the cover plate structures of Examples 1 to 10, all parameters are within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valves did not rupture after compression. However, for the cover plate structure of Comparative Example 1, b = 0, that is, no reinforcing ribs are provided on the cover plate body 1, and S0 / S is 0. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 2 EA after compression. For the cover plate structure of Comparative Example 2, S0 / S is 2.18%, which is less than 0.025 and is not within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 1 EA after compression. For the cover plate structure of Comparative Example 3, S0 / S is 6.67%, which is greater than 0.06 and is not within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 1 EA after compression.

[0091] As can be seen, when the ribs adopt the parameter range defined in this embodiment, the overall structural strength of the cover plate assembly is improved, and the risk of the explosion-proof valve cracking under external pressure is greatly reduced.

[0092] Experiment 3: When the reinforcing rib is concave, the cover plate structure was produced using the parameters of Examples 11 to 20 and Comparative Examples 4 to 6, and assembled into a cover plate assembly. After the cover plate assembly was assembled with the shell 3, a compression test was conducted at the explosion-proof valve position of the cover plate assembly to verify the rupture of the explosion-proof valve. The verification results are shown in Table 3. The compression method was as follows: the compression head was a hemisphere with a radius of 25 mm; the compression speed was 0.01 mm / s; and the compression displacement was 2 mm.

[0093] Table 3

[0094]

[0095]

[0096] As shown in Table 3, for the cover plate structures of Examples 11 to 20, all parameters are within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valves did not rupture after compression. However, for the cover plate structure of Comparative Example 4, b = 0, that is, no reinforcing ribs are provided on the cover plate body 1, and S0 / S is 0. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 2 EA after compression. For the cover plate structure of Comparative Example 5, S0 / S is 1.56%, which is less than 0.025 and is not within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 2 EA after compression. For the cover plate structure of Comparative Example 6, S0 / S is 6.34%, which is greater than 0.06 and is not within the range defined in this application. A total of 10 EA cover plate assemblies were subjected to compression tests, and the explosion-proof valve ruptured for 1 EA after compression.

[0097] As can be seen, when the concave ribs adopt the parameter range defined in this embodiment, the overall structural strength of the cover plate assembly is improved, and the risk of the explosion-proof valve cracking under external pressure is greatly reduced.

[0098] The cover plate structure of this embodiment can improve the structural strength of the cover plate body 1 by adding a convex rib structure, a concave rib structure, or an alternating concave and convex rib structure to the cover plate body 1. At the same time, it can reduce the risk of abnormal deformation and cracking of the explosion-proof valve on the cover plate assembly due to external pressure and impact, improve the safety performance of the battery cell, and reduce the deformation of the cover plate body 1 during the riveting process of the cover plate assembly, thereby improving the yield of cover plate production.

[0099] According to an embodiment of the present invention, in another aspect, a battery cell is also provided, comprising: a housing, an electrode assembly, and a cover plate assembly. The housing has an open end; the electrode assembly is disposed within the inner cavity of the housing; the cover plate assembly covers the open end of the housing, and the cover plate assembly includes the cover plate structure described above. The battery cell including the cover plate structure has the same effects as the cover plate structure, and will not be described again here.

[0100] In one embodiment, the cover plate assembly further includes: a pole post 5, which is installed in a pole post hole on the cover plate body 1; an explosion-proof valve 6, which is installed in an explosion-proof valve hole on the cover plate body 1; a riveting block, which is disposed on the side of the cover plate body 1 away from the housing 3 and sleeved on the outer periphery of the pole post 5; an upper plastic part, which is disposed between the cover plate body 1 and the riveting block to ensure the insulation between the cover plate body 1 and the riveting block; and a lower plastic part, which is disposed on the side of the cover plate body 1 facing the inner cavity of the housing 3.

[0101] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate structure, characterized in that, include: The cover plate body has a plurality of mounting through holes spaced apart along the X direction. The cover plate body has two first side edges arranged opposite each other along the X direction. Along the X direction, the area on the cover plate body between two adjacent mounting through holes and between the first side edge and one of the adjacent mounting through holes each form a body area. A number of reinforcing ribs are disposed in the body area. The total projected area of ​​the reinforcing ribs along the Z direction on the cover body is S0, and the outline area of ​​the cover body is S, wherein 0.025≤S0 / S≤0.

06.

2. The cover plate structure according to claim 1, characterized in that, One or more of the reinforcing ribs are provided in one of the body regions.

3. The cover plate structure according to claim 2, characterized in that, At least one of the body regions is provided with multiple reinforcing ribs. Among the multiple reinforcing ribs located in the same body region, at least two first reinforcing ribs are arranged in parallel with each other. The distance between two adjacent first reinforcing ribs is c, where 5mm≤c≤10mm.

4. The cover plate structure according to claim 3, characterized in that, Among the multiple reinforcing ribs located in the same body area, a second reinforcing rib is also included, which is intersecting with the first reinforcing rib.

5. The cover plate structure according to claim 4, characterized in that, The reinforcing ribs include transverse ribs extending in the Y direction and / or longitudinal ribs extending in the X direction. The first reinforcing rib is a transverse rib, and the second reinforcing rib is a longitudinal rib; or, the first reinforcing rib is a longitudinal rib, and the second reinforcing rib is a transverse rib.

6. The cover plate structure according to claim 5, characterized in that, The area between the first side and the adjacent mounting through hole forms a first body area, and the cover plate body is also provided with an identification part, which is located in the first body area; At least one horizontal rib is provided between the marking part and the adjacent mounting through hole, or at least one vertical rib is provided on each side of the marking part along the Y direction.

7. The cover plate structure according to claim 1, characterized in that, Along the X direction, the distance from the reinforcing rib adjacent to the first side to the first side is a1, where 3mm≤a1≤5mm; the cover plate body also has two second side edges arranged opposite each other along the Y direction, and the shortest distance along the Y direction between the reinforcing rib and the second side edge is a2, where 3mm≤a2≤5mm; And / or, in the direction perpendicular to the extension of the reinforcing rib, the width of the reinforcing rib is b, wherein 0.7mm ≤ b ≤ 1.2mm.

8. The cover plate structure according to any one of claims 1 to 7, characterized in that, The cover plate body forms a first surface on one side along the Z direction; The reinforcing rib is constructed as a convex rib on the first surface; or, the reinforcing rib is constructed as a concave rib on the first surface; or, the reinforcing rib includes convex ribs and concave ribs constructed on the first surface, with the convex ribs and concave ribs being distributed alternately.

9. The cover plate structure according to any one of claims 1 to 7, characterized in that, Along the Z direction, the size of the reinforcing rib is h, and the thickness of the cover plate body is t, wherein 0.10≤h / t≤0.15, 1.5≤t≤2.5mm, and 0.2mm≤h≤0.3mm; And / or, the dimension of the cover plate body along the X direction is A, 90mm≤A≤180mm; the dimension of the cover plate body along the Y direction is B, 15mm≤B≤70mm.

10. A battery cell, characterized in that, include: The shell has an open end; The electrode assembly is disposed within the inner cavity of the housing; A cover assembly, disposed over the opening end of the housing, the cover assembly comprising the cover structure of any one of claims 1 to 9.

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