Battery cover plate and battery

Abstract

The invention belongs to the technical field of battery manufacturing, and provides a battery cover plate and a battery, the battery cover plate comprises a cover plate body, a sealing cover, a pole and a connecting sheet, and the cover plate body is provided with two welding through holes at intervals; the sealing cover is connected with the welding through hole to form a containing cavity, and the sealing cover protrudes from the cover plate body to the first side; the insulating inner cover is connected with the sealing cover through a clamping structure, and is positioned on the inner wall surface of one side, facing the accommodating cavity, of the sealing cover; the pole is arranged on the cover plate body and is provided with a first end part and a second end part, the first end part is positioned on the first side, and the second end part is positioned on the second side; one end of the connecting piece is connected with the second end part of the pole group, and the other end of the connecting piece is provided with a welding part which is positioned in the accommodating chamber. Through the arrangement of the welding through hole, the welding between the connecting sheet and the tab is realized, the problem of insufficient welding space in the related technology is solved, and the welding process is simplified.

Description

Technical Field

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

[0002] A power battery is a rechargeable battery used to power devices such as electric vehicles, primarily by storing and releasing electrical energy to drive an electric motor.

[0003] Typically, the connecting tabs and electrodes in a battery cover are connected by welding. In related technologies, due to the limited welding space, the connecting tabs and electrodes are often welded together first, and then the cover is assembled. This method makes the entire process relatively cumbersome (both the electrodes and connecting tabs need to be bent) and requires high welding precision. Summary of the Invention

[0004] This invention provides a battery cover and a battery to solve the defect of limited welding space between the connecting piece and the electrode tab in the prior art.

[0005] This invention provides a battery cover, comprising: a cover body, a sealing cover, an explosion-proof valve, a terminal post, and a connecting piece. Two welded through holes are provided through the cover body, spaced apart along the length of the cover body. The periphery of the sealing cover is sealed to the edge of the welded through holes to form a receiving chamber, and the main body of the sealing cover protrudes from the cover body towards a first side. The explosion-proof valve is disposed on the cover body between the two sealing covers. The terminal post is disposed on the cover body, and the post has a first end and a second end, the first end being located on a first side and protruding... The second end extends from the first side of the cover plate body to the second side of the cover plate body, away from the first side; one end of the connecting piece is connected to the second end, and the other end of the connecting piece has a welding part, which is located in the receiving cavity; wherein, in the thickness direction of the cover plate body, the height between the surface of the sealing cap facing the first side and the surface of the cover plate body facing the first side is H2, and the height between the end face of the pole facing the first side and the surface of the cover plate body facing the first side is H1, and satisfies 0.8mm≤H2-H1≤2.5mm.

[0006] According to the battery cover provided by the present invention, in the thickness direction of the cover body, the total projected area of ​​the two cover bodies facing the first side surface is S, and the projected area of ​​the sealing cover facing the first side surface is S1; and satisfies 0.4≤S1 / S≤0.75.

[0007] According to the battery cover provided by the present invention, the total projected area S1 of the two sealing covers facing the first side surface is greater than 1.2F / R, where F is the force acting on the sealing cover and R is the strength limit of the battery cell.

[0008] According to the battery cover provided by the present invention, in the thickness direction of the cover body, the thickness of the cover body is 1.5mm≤T≤3mm, and satisfies H2 / T≤3, wherein H2 is the height between the surface of the sealing cover facing the first side and the surface of the cover body facing the first side.

[0009] According to the battery cover plate provided by the present invention, along the length direction of the cover plate body, the distance between the welding through hole and the adjacent electrode post is 4mm≤G1≤10mm; along the length direction of the cover plate body, the distance between the welding through hole and the explosion-proof valve is 4mm≤G2≤10mm.

[0010] According to the battery cover provided by the present invention, the side of the sealing cover connected to the welding through hole has an edge portion, the width of which is 1.2mm≤D≤3.5mm.

[0011] According to the battery cover provided by the present invention, along the length direction of the cover body, the length of the cover body is 120mm≤L≤350mm, and the total length of the two sealing covers is L1, 0.35L≤2L1≤0.85L; along the width direction of the cover body, the width of the cover body is 22mm≤W≤85mm, and the total width of the two sealing covers is W1, 0.5W≤2W1≤0.9W.

[0012] According to the battery cover provided by the present invention, the cover body comprises a manganese-aluminum alloy body, and the yield strength α of the cover body is ≥110 MPa.

[0013] According to the battery cover provided by the present invention, the connecting piece is provided with a bending structure, and the welding part is formed by the bending structure extending into the receiving cavity.

[0014] The present invention also provides a battery, comprising: a housing and the battery cover plate provided above, wherein the housing has an assembly space for accommodating an electrode assembly; the battery cover plate is connected to the housing and seals the assembly space.

[0015] The battery cover and battery provided by the present invention have welding through holes on the cover body, and the welding part is located in the welding through holes. This facilitates the welding between the connecting piece and the tab, solves the problem of insufficient welding space in related technologies, simplifies the welding process, and reduces the difficulty of welding. Attached Figure Description

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

[0017] Figure 1 This is a schematic diagram of the overall exploded structure of the battery cover plate provided by the present invention.

[0018] Figure 2 This is a schematic diagram of the overall bottom view structure of the battery cover provided by the present invention.

[0019] Figure 3 This is a cross-sectional structural diagram of the battery cover plate provided by the present invention.

[0020] Figure 4 This is a top view of the battery cover provided by the present invention.

[0021] Figure 5 This is a schematic diagram of the overall structure of the sealing cover in the battery cover plate provided by the present invention.

[0022] Figure 6 This is one of the structural schematic diagrams of the battery cover plate connecting the electrode tabs provided by the present invention.

[0023] Figure 7 This is the second schematic diagram of the battery cover plate connecting the electrode tabs provided by the present invention.

[0024] Figure 8 This is a schematic diagram of the overall structure of the battery provided by the present invention.

[0025] Figure label: 10. Cover plate body; 11. Welded through hole; 20. Pole post; 201. First end; 202. Second end; 21. Positive pole post; 22. Negative pole post; 30. Connecting piece; 31. Positive connecting piece; 32. Negative connecting piece; 33. Bending structure; 40. Explosion-proof valve; 50. First plastic part; 60. Second plastic part; 70. Pole tab; 71. Positive pole tab; 72. Negative pole tab; 80. Sealing cover; 81. Snap-fit ​​groove; 81. Insulating inner cover; 90. Housing. Detailed Implementation

[0026] 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.

[0027] In the description of the embodiments of the present invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the purpose of clarifying the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0028] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0029] In embodiments of the present invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0031] In related technologies, battery covers are typically elongated plate-like structures with positive and negative terminals. These terminals are usually welded to tabs on the electrode assembly via their respective connecting tabs. Welding the tabs requires precise positioning. In these technologies, welding is performed before the cover is fully assembled with the casing. Specifically, the tabs and connecting tabs are welded using suitable welding equipment (during which both the connecting tabs and the tabs need to be bent for proper welding), and then the cover is assembled. This method results in a relatively complex process and requires high welding precision.

[0032] Regarding the problems in related technologies, such as Figures 1-7As shown, the present invention provides a battery cover plate, including a cover plate body 10, a sealing cover 80, an explosion-proof valve 40, a terminal post 20, and a connecting piece 30. Two welding through holes 11 are provided through the cover plate body 10, spaced apart along the length of the cover plate body 10. The periphery of the sealing cover 80 is sealed to the edge of the welding through holes 11 to form a receiving chamber, and the main body of the sealing cover 80 protrudes from the cover plate body 10 towards a first side. The explosion-proof valve 40 is disposed on the cover plate body 10 between the two sealing covers 80. The terminal post 20 is disposed on the cover plate body 10, and the post 20 has a first end 201 and a second end 202. The first end 201 is located on the first side and protrudes from the surface of the first side of the cover body 10, and the second end 202 is away from the first side and extends to the second side of the cover body 10; one end of the connecting piece 30 is connected to the second end 202, and the other end of the connecting piece 30 has a welding part located in the receiving cavity; wherein, in the thickness direction of the cover body 10, the height between the surface of the sealing cover 80 facing the first side and the surface of the cover body 10 facing the first side is H2, and the height between the end face of the pole post 20 facing the first side and the surface of the cover body 10 facing the first side is H1, and satisfies 0.8mm≤H2-H1≤2.5mm. The first ends 201 of the positive terminal 21 and negative terminal 22 on the cell cover are used to connect to an external circuit, thereby enabling the charging and discharging of the battery. In this embodiment, by providing a through-hole structure on the cover body 10, and placing the positive and negative welding parts in corresponding channels, it facilitates the welding between the connecting piece 30 and the tab 70, solving the problem of insufficient welding space in related technologies and reducing the difficulty of welding. Furthermore, by limiting the surface height of the sealing cover 80 to be higher than the end face of the terminal 20, the sealing cover 80 serves as the highest protruding position on the cover, thereby enabling the cover to bear pressure and improving the safety performance of the cell.

[0033] Specifically, the terminal post 20 includes a positive terminal post 21 and a negative terminal post 22. The positive terminal post 21 and the negative terminal post 22 are disposed on both sides of the welding through hole 11 in the length direction. The first ends of the positive terminal post 21 and the negative terminal post 22 are used to connect to the external circuit, thereby realizing the charging and discharging of the battery. The cover plate body 10 is used to connect with the housing 90 of the battery cell, thereby sealing the internal space formed inside the housing 90 for accommodating the electrode assembly. The electrode assembly is provided with a positive electrode tab 71 and a negative electrode tab 72. The positive electrode tab 71 is connected to the positive terminal post 21 through the positive electrode connecting piece 31, and the negative electrode tab 72 is connected to the negative terminal post 22 through the negative electrode connecting piece 32. Both the positive connecting piece 30 and the negative connecting piece 32 are provided with welding parts, which are used to weld to the tab 70. Furthermore, the height difference between the surface of the sealing cover 80 and the end face of the terminal post 20 should not be too large. An excessively large height difference will result in the main body of the sealing cover 80 being too tall, which will affect the overall layout of the battery cover and increase the overall weight of the battery cover. The height difference should also not be too low, as an excessively low height difference will result in the terminal post 20 being at risk of being subjected to pressure during external impacts, and will also lead to poor thermal separation.

[0034] In this embodiment, by limiting the height difference H2-H1 to between 0.8mm and 2.5mm, it is beneficial to the overall layout of the battery cover and can provide better thermal and electrical separation, thereby improving the safety performance of the battery.

[0035] In specific settings, the height difference H2-H1 between the surface of the sealing cover 80 and the surface of the pole post 20 can be 0.8mm, 0.9mm, 1.3mm, 1.5mm, 1.8mm, 2.0mm or 2.5mm.

[0036] In this process, laser welding equipment is used. The welding head of the laser welding equipment can extend into the corresponding welding position through the welding through hole 11, thereby achieving efficient welding. This method changes the traditional process that requires bending the tab 70 and connecting piece 30 before welding, reducing the requirements for welding precision and improving welding efficiency.

[0037] Furthermore, the sealing cap 80 is connected to the port position of the welding through hole 11 facing the first side, and the welding through hole 11 is sealed to prevent leakage of internal electrolyte and external impurities from entering the battery casing 90. The main body of the sealing cap 80 has a cover plate body 10 protruding towards the first side, forming a boss structure, and the surface position of the sealing cap 80 facing the first side is higher than the end face position of the pole post 20, so that it can withstand pressure through the boss when subjected to external impact force, thereby improving the safety performance of the battery cell.

[0038] Of course, the cover plate body 10 also has the necessary components of a conventional cover plate, such as... Figure 1 Figure 2As shown, a first plastic part 50 is provided on the first side surface of the cover plate body 10. The first plastic part 50 is connected to the cover plate body 10 and is sleeved on the outside of the positive electrode post 21 and the negative electrode post 22. The first plastic part 50 can prevent the positive electrode post 21 and the negative electrode post 22 from contacting the cover plate body 10, thereby improving the insulation performance.

[0039] A second plastic part 60 is provided on the second side surface of the cover plate body 10. The second plastic part 60 is connected to the cover plate body 10, and the shape of the second plastic part 60 is adapted to the shape of the cover plate body 10, so that the second plastic part 60 and the second side surface of the cover plate body 10 are in close contact. The second plastic part 60 has a receiving through hole communicating with the welding through hole 11. One end of the positive electrode connecting piece 31 is connected to the positive electrode post 21, and the positive electrode welding part of the other end extends to the opening position of the welding through hole 11 on the second side. Similarly, one end of the negative electrode connecting piece 32 is connected to the negative electrode post 22, and the negative electrode welding part of the other end extends to the opening position of the second welding through hole 11 on the second side. This allows the welding head to directly weld the electrode tab 70 and the connecting piece 30 through the welding through hole 11, so that the cover plate can be assembled first, and then welding can be performed after the assembly position is determined. This simplifies the overall assembly and improves the production efficiency of the product.

[0040] In some embodiments, such as Figure 3 As shown, an insulating inner cover 81 is provided on the inner wall of the sealing cover 80. The insulating inner cover 81 is provided on the inner wall of the sealing cover 80 by means of a connection structure or adhesive bonding, thereby realizing the insulation isolation between the welded part and the sealing cover 80 and improving the overall insulation performance of the cover plate.

[0041] Understandably, in related technologies, due to limited welding space, the tabs 70 need to be welded to the connecting piece before assembly. This method results in relatively cumbersome assembly procedures for the cover plate body 10 (both the tabs 70 and the connecting piece 30 need to be bent and contacted to achieve welding). In this embodiment, by setting the welding of the through hole 11 on the cover plate body 10, the welding area is limited to the area where the through hole is located, providing sufficient welding space, improving welding stability, simplifying the welding process, and achieving efficient welding of the product. Furthermore, the setting of the sealing cover 80 allows it to withstand pressure when subjected to external impacts through the raised sealing cover 80, improving the battery's safety performance.

[0042] In a specific configuration, the welding through hole 11 is an elongated through hole, and the connecting piece 30 includes a positive electrode connecting piece 31 and a negative electrode connecting piece 32. The part of the positive electrode connecting piece 31 used to connect with the positive electrode tab 71 is the positive electrode welding part, and the part of the negative electrode connecting piece 32 used to connect with the negative electrode tab 72 is the negative electrode welding part. The positive electrode welding part and the negative electrode welding part are located on both sides of the length direction of the through hole, that is, there is a certain distance between the positive electrode welding part and the negative electrode welding part, which can ensure an effective safe distance between them.

[0043] In specific welding processes, such as Figure 6 , Figure 7 As shown, in the width direction of the cover plate body 10, there are gaps between the two sides of the positive electrode connecting piece 31 and the extending direction of the inner walls on both sides of the welding through hole 11. By inserting the positive electrode tab 71 through the gap and folding it 90° to make it fit and contact the positive electrode welding part, and then inserting the welding head through the welding through hole 11, the two are welded together. Similarly, there are also gaps between the two sides of the negative electrode connecting piece 32. By inserting the negative electrode tab 72 through the gap and folding it 90° to make it fit and contact the negative electrode welding part, and then inserting the welding head through the welding through hole 11, the two are welded together.

[0044] It is understood that in this embodiment, when welding the connecting piece 30 to the electrode tab 70, it is only necessary to fold the electrode tab 70, and it is no longer necessary to fold the connecting piece 30. This reduces the difficulty of welding, and the welding is carried out through the welding through hole 11, which improves the welding quality between the connecting piece 30 and the electrode tab 70.

[0045] In some embodiments, such as Figure 3 As shown, in the thickness direction of the cover plate body 10, the projected area of ​​the cover plate body 10 facing the first side surface is S (e.g., ...). Figure 4 As shown in S=L*W), the total projected area of ​​the sealing cover 80 facing the first side surface is S1 (as shown in S=L*W). Figure 4 As shown, S1 = 2L1 * W1), and satisfies 0.4 ≤ S1 / S ≤ 0.75. The sealing cap 80 is used on the pressure-bearing end face, which can withstand external impacts. In this embodiment, by limiting the area ratio of the sealing cap 80 surface, the surface of the sealing cap 80 has a suitable area, thereby improving the pressure-bearing capacity and enhancing the safety performance of the battery.

[0046] Specifically, the area of ​​the sealing cover 80 directly affects the stress of its bearing capacity. If the area of ​​the sealing cover 80 is too small, its bearing capacity will be reduced due to excessive stress. If the surface area of ​​the sealing cover 80 is too large, it will affect the overall layout and the installation space of the terminal 20, which in turn will affect the current carrying capacity of the battery.

[0047] In this embodiment, by limiting the ratio of the projected area S1 of the sealing cover 80 facing the first side surface to the surface area S of the cover body 10, the sealing cover 80 can have a high pressure resistance, while not affecting the overall layout of the battery cover or the battery's overcurrent capability.

[0048] In a specific configuration, the ratio of the projected area S1 of the sealing cover 80 facing the first side surface to the surface area S of the cover plate body 10 is in the range of 0.4, 0.5, 0.55, 0.6, 0.65, 0.7 or 0.75.

[0049] In conjunction with the above embodiments, the projected area S1 of the sealing cover 80 facing the first side surface is greater than 1.2F / R, where F is the force acting on the sealing cover 80 and R is the strength limit of the battery cell. The surface of the sealing cover 80 facing the first side is used to withstand external forces. This embodiment improves the overall structural stability by limiting the projected area S1 of the sealing cover 80 facing the first side surface to be greater than the designed strength requirement.

[0050] Specifically, in S1>1.2F / R, 1.2 is a safety factor. This safety factor ensures that the system can operate safely under various uncertainties. By limiting its area, the stress 1.2F / S1 acting on the sealing cover 80 must be less than the cell strength limit R. Limiting its area ensures that the cell will not be damaged due to excessive stress when subjected to external impact, thus improving the safety of the cover.

[0051] In conjunction with the above embodiments, such as Figure 3 As shown, in the thickness direction of the cover body 10, the thickness of the cover body 10 is 1.5mm≤T≤3mm, and satisfies H2 / T≤3, where H2 is the height between the surface of the sealing cover 80 facing the first side and the surface of the cover body 10 facing the first side.

[0052] In conjunction with the above embodiments, the cover plate body 10 includes a manganese-aluminum alloy body, and the yield strength α of the cover plate body 10 is ≥110 MPa. By limiting the material and yield strength of the cover plate body 10, the structural strength of the cover plate body 10 can be improved, thereby enhancing its structural safety.

[0053] Specifically, yield strength is the critical stress value at which a material begins to undergo plastic deformation under external force. Limiting the yield strength of the cover plate body 10 to greater than or equal to 110 MPa ensures that the cover plate body 10 will not yield prematurely when facing external pressure, impact, or load, maintaining sufficient structural strength, avoiding failure or deformation, and thus improving the overall structural safety.

[0054] Furthermore, in high-intensity, frequently stressed applications such as battery packs, using materials with higher yield strength can ensure that the cover can withstand impact loads without deformation, ensuring the protection of the battery cells inside the battery pack, preventing safety hazards caused by cover deformation or damage, and improving service life.

[0055] In some embodiments, such as Figure 3 As shown, along the length of the cover body 10, the length of the cover body 10 is 120mm ≤ L ≤ 350mm, and the total length of the two sealing covers 80 is L1, where 0.35L ≤ 2L1 ≤ 0.85L; along the width of the cover body 10, the width of the cover body 10 is 22mm ≤ W ≤ 85mm, and the total width of the two sealing covers 80 is W1, where 0.5W ≤ W1 ≤ 0.9W. The length and width of the cover body 10 affect the magnitude of the external force it can withstand. In this embodiment, limiting the length and width ensures that the cover meets the requirements of strength, sealing, and function while having a reasonable production process and operational feasibility. Furthermore, limiting the length and width ratio of the sealing covers 80 facilitates the installation of the sealing covers 80 and improves the pressure-bearing capacity of the sealing covers 80.

[0056] Specifically, the cover body 10 has a long, strip-shaped plate structure, while the sealing cover 80 has a hollow cuboid structure. The length of the cover body 10 should not be too long, as this would affect the overall pressure-bearing capacity; nor should it be too short, as this would affect the coverage of the battery pack. This embodiment ensures sufficient support for the cover by limiting its length, while avoiding structural fragility or stress concentration caused by excessive length. Furthermore, the width of the cover body 10 also affects the overall strength and compressive strength. A cover body 10 that is too narrow may not be able to withstand significant impact forces, while one that is too wide may lead to material waste and increased weight. The aforementioned width range ensures that the cover has appropriate strength, preventing deformation or failure during battery pack operation.

[0057] Furthermore, the dimensions of the sealing cap 80 need to match the dimensions of the cover plate body 10 to provide good pressure resistance and facilitate the layout design of other structures on the cover plate. In this embodiment, by limiting the ratio of its length and width, the sealing cap 80 is made to have good pressure resistance while facilitating the layout design of other structures.

[0058] In specific settings, the total length L1 of the two sealing caps 80 can be 0.35L, 0.45L, 0.55L, 0.65L, 0.75L or 0.85L; the total width W1 of the two sealing caps 80 can be 0.5W, 0.6W, 0.7W, 0.8W or 0.9W.

[0059] In practical applications, the total length of the two sealing caps 80 is 42mm≤2L1≤297.5mm, and the total width of the two sealing caps 80 is 11mm≤2W1≤76.5mm. By stabilizing the total length and width of the sealing caps 80, the overall load-bearing capacity and sealing performance of the cover plate can be further ensured.

[0060] In some embodiments, the distance between the welded through-hole 11 and the adjacent pole post 20 is 4mm ≤ G1 ≤ 10mm; the distance between the welded through-hole 11 and the explosion-proof valve 40 is 4mm ≤ G2 ≤ ​​10mm. Multiple components and structures on the cover plate are connected by welding. This embodiment, by limiting the distance between the explosion-proof valve 40 and the welded through-hole 11, and between the pole post 20 and the welded through-hole 11, can effectively avoid the impact of heat generated during welding on the explosion-proof valve 40, thereby improving the safety performance of the cover plate.

[0061] Specifically, the distance G1 between the welded through hole 11 and the adjacent pole post 20 is equal to the distance G2 between the welded through hole 11 and the side adjacent to the explosion-proof valve 40. Specifically, as... Figure 4 As shown, the distance between the positive electrode post 21 and its adjacent welding through hole 11 is G1, and the distance between the negative electrode post 22 and its ringing welding through hole 11 is also G1. Since the electrode post 20 is a cylindrical structure, the shortest distance between the outer wall of the through hole used to install the electrode post 20 and the edge of the welding through hole 11 is G1. Similarly, G2 mentioned above is the shortest distance between the positive electrode post 21 and the negative electrode post 22 and the edge of the explosion-proof valve 40 on the adjacent side.

[0062] The connection can be made by limiting the spacing, which on the one hand can ensure that there is a certain effective distance between the various structures, which can facilitate the connection of the various structural components and avoid mutual interference during the connection of the structures. On the other hand, it can make the overall structure more compact and facilitate the layout design of the various structural components.

[0063] In specific settings, the distance G1 between the welding through hole 11 and the adjacent pole post 20 is equal to the distance G2 between the welding through hole 11 and the side adjacent to the explosion-proof valve 40, and the value is 4mm, 5mm, 6mm, 7mm, 8mm, 9mm or 10mm.

[0064] In some embodiments, such as Figure 5 As shown, the side of the sealing cap 80 connected to the welding through hole 11 has an edge portion. Extending from the inner wall to the outer wall of the sealing cap 80, the width of the edge portion is 1.2mm ≤ D ≤ 3.5mm. The edge portion of the sealing cap 80 is formed by a flange. In this embodiment, limiting the width of the flange, i.e., the width of the edge portion, ensures the yield of the finished sealing cap 80 and reduces the overall production cost.

[0065] Specifically, the sealing cap 80 is formed by stamping and flanging, and the width of the flanging directly affects the overall forming yield of the sealing cap 80.

[0066] In this embodiment, by limiting the width of the flange edge to between 1.2mm and 3.5mm, the yield can be effectively improved, and the edge can be connected to the welding through hole 11 port, thereby improving the stability of the sealing cover 80 connection.

[0067] In specific settings, the width D of the edge can be 1.2mm, 1.7mm, 2.2mm, 2.5mm, 2.8mm, 3.0mm or 3.5mm.

[0068] To verify the impact of various size limitations on battery performance, specific examples and proportions are provided below. R = 125 MPa. Table 1 lists variables; all dimensions are the same except for those indicated in the table.

[0069] Table 1: Based on the experiments shown in the table above, PACK simulation analysis of Examples 1 to 6 revealed that when the battery pack was subjected to a mechanical impact of magnitude F in the thickness direction, the stress values ​​of the materials on the upper surface of the sealing cover 80 and the upper surface of the aluminum sheet did not increase significantly. However, in Comparative Example 1, due to 1.2F / 2S1 > R, PACK simulation analysis showed that when the battery pack was subjected to a mechanical impact of magnitude F in the Z direction, the stress value of the materials on the upper surface of the sealing cover 80 increased by approximately 5.5%. In Comparative Example 2, due to 1.2F / 2S1 > R, PACK simulation analysis showed that when the battery pack was subjected to a mechanical impact of magnitude F in the Z direction, the stress value of the materials on the upper surface of the sealing cover 80 increased by approximately 4.5%. Comparative Examples 3 and 4, through structural verification, showed that while the material stress values ​​did not increase significantly, the sealing cover 80 had a higher area ratio, compressing the space of the terminal post 20, resulting in a reduced current carrying capacity and a serious design imbalance.

[0070] As can be seen from the above, when the sealing cover 80 structure is added to the cover plate body 10 and the design requirement of 1.2F / S1 < R (i.e., S1 > 1.2F / R) is met, the upper surface of the sealing cover 80 and the upper surface of the aluminum sheet do not undergo significant deformation when the battery pack is subjected to a Z-axis mechanical impact of magnitude F, and the strength of the sealing cover 80 and the cover plate structure meets the stress requirements. When the area of ​​the sealing cover 80 is insufficient, resulting in 1.2F / S1 > R, the stress value of the material on the upper surface of the sealing cover 80 increases when the battery pack is subjected to a Z-axis mechanical impact of magnitude F, indicating that the stress on the sealing cover 80 exceeds its yield strength and no longer meets the stress requirements. When 1.2F / S1 is much smaller than R, it indicates that the area occupied by the sealing cover 80 is too large, and the remaining space cannot meet the current requirements of the terminal post 20.

[0071] In some embodiments, the connecting piece 30 is provided with a bending structure 33, and the welded portion is formed by extending the bending structure 33 into the receiving cavity. The bending structure 33 allows the welded portion to be located within the receiving channel, and the structural strength of the connecting piece 30 is improved by bending the structure 33, thereby increasing the utilization rate of the internal space.

[0072] Specifically, such as Figure 2 As shown, the bending structure 33 makes the area of ​​the receiving channel facing the second side an unused space. This space is connected to the internal space of the battery casing 90, which effectively improves the expansion of the internal space and the utilization rate of the internal space.

[0073] It is understandable that by bending, the welded portion of the connecting piece 30 extends into the receiving channel, and the bending method can effectively improve the overall structural strength of the connecting piece 30 and enhance the structural stability of the welding with the tab 70.

[0074] The present invention also provides a battery, such as Figure 8 As shown, the device includes a housing 90 and a battery cover provided in the above embodiment. The housing 90 has an assembly space for accommodating the electrode assembly. The battery cover is connected to the housing 90 and seals the assembly space.

[0075] Specifically, the casing 90 has a flat, square main structure with an opening at the top. A battery cover is positioned at the opening and seals it, creating a closed assembly space inside. The welded through-hole 11 on the battery cover communicates with this assembly space. The welded through-hole 11 connects to the sealing cover 80 to form a receiving groove. This receiving groove expands the assembly space, allowing electrolyte to be injected through the injection hole, effectively increasing the amount of electrolyte injected into the receiving groove.

[0076] The battery provided in this example has the battery cover plate of the aforementioned embodiments. Therefore, the battery in this example has the characteristic effects of each of the aforementioned battery cover plate embodiments. To avoid redundancy in the effect description, it will not be repeated here.

[0077] 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 cover, characterized in that, include: The cover plate body has two welding through holes that penetrate the cover plate body and are spaced apart along the length of the cover plate body; A sealing cap, the periphery of which is sealed to the edge of the welded through hole to form a receiving chamber, and the main body of the sealing cap protrudes from the cover plate body toward the first side; An explosion-proof valve is disposed on the cover plate body between the two sealing covers; An electrode post is disposed on the cover plate body. The electrode post has a first end and a second end. The first end is located on a first side and protrudes from the surface of the first side of the cover plate body. The second end extends away from the first side to the second side of the cover plate body. A connecting piece, one end of which is connected to the second end, and the other end of which has a welding portion located within the receiving cavity; Wherein, in the thickness direction of the cover plate body, the height between the surface of the sealing cover facing the first side and the surface of the cover plate body facing the first side is H2, and the height between the end face of the pole facing the first side and the surface of the cover plate body facing the first side is H1, and satisfies 0.8mm≤H2-H1≤2.5mm.

2. The battery cover according to claim 1, characterized in that, In the thickness direction of the cover plate body, the projected area of ​​the cover plate body facing the first side surface is S, and the total projected area of ​​the two sealing covers facing the first side surface is S1; and satisfies 0.4≤S1 / S≤0.

75.

3. The battery cover according to claim 2, characterized in that, The total projected area S1 of the two sealing caps facing the first side surface is greater than 1.2F / R, where F is the force acting on the sealing caps and R is the strength limit of the battery cell.

4. The battery cover according to claim 1, characterized in that, In the thickness direction of the cover plate body, the thickness of the cover plate body is 1.5mm≤T≤3mm, and satisfies H2 / T≤3, where H2 is the height between the surface of the sealing cover facing the first side and the surface of the cover plate body facing the first side.

5. The battery cover according to claim 1, characterized in that, Along the length of the cover plate body, the distance between the welded through hole and the adjacent pole is 4mm≤G1≤10mm; along the length of the cover plate body, the distance between the welded through hole and the explosion-proof valve is 4mm≤G2≤10mm.

6. The battery cover according to claim 1, characterized in that, The sealing cap has an edge portion on the side connected to the welding through hole, and the width of the edge portion is 1.2mm≤D≤3.5mm.

7. The battery cover according to claim 1, characterized in that, Along the length of the cover plate body, the length of the cover plate body is 120mm≤L≤350mm, and the total length of the two sealing covers is L1, 0.35L≤2L1≤0.85L; Along the width direction of the cover plate body, the width of the cover plate body is 22mm≤W≤85mm, and the total width of the two sealing covers is W1, 0.5W≤2W1≤0.9W.

8. The battery cover according to claim 1, characterized in that, The cover plate body comprises a manganese-aluminum alloy body, and the yield strength α of the cover plate body is ≥110 MPa.

9. The battery cover according to claim 1, characterized in that, The connecting piece is provided with a bending structure, and the welding part is formed by the bending structure extending into the receiving cavity.

10. A battery, characterized in that, include: A housing having an assembly space for accommodating the electrode assembly; The battery cover according to any one of claims 1-9, wherein the battery cover is connected to the housing and seals the assembly space.

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