Cover plate assembly and battery

Abstract

The utility model relates to battery technical field discloses the cover plate subassembly and battery, include: cover plate body has first surface and second surface, cover plate body is provided with the pole hole, the pole structure is inserted in the pole, the connecting piece is opposite interval setting with second surface along the thickness direction, the one side of connecting piece to cover plate body forms recessed portion, and the second end portion stretches into to recessed portion, and the outer periphery of second end portion and groove side wall are connected with the setting of the seam weld weld mark, and the end surface of second end portion and groove bottom wall are connected with the setting of the penetration weld mark, the utility model connects through seam weld in the butt joint position of the outer periphery of second end portion and the groove side wall of recessed portion, connects through penetration weld in the contact position of the end surface of second end portion and the groove bottom wall of recessed portion, therefore, can make connecting piece connect with the pole structure through seam weld + penetration weld mode, reduce the risk of virtual welding of connecting piece and pole structure, improve the overcurrent capacity between connecting piece and pole structure.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cover plate assembly and a battery. Background Technology

[0002] A battery typically consists of a cover assembly, a casing, and battery cells. The battery cells store electrical energy, while the cover assembly directs the stored energy to the outside of the battery. Specifically, connecting tabs connect the terminals of the cover assembly to the tabs of the battery cells to facilitate current transfer. However, in existing technologies, through-welding is commonly used to weld the terminals and connecting tabs, which is prone to incomplete soldering and affects the current-carrying capacity between the terminals and connecting tabs. Utility Model Content

[0003] This invention provides a cover plate assembly and a battery to solve the problem that the welding of existing terminals and connecting pieces is prone to poor welding, which affects the current carrying capacity between the terminals and connecting pieces.

[0004] In a first aspect, this utility model provides a cover plate assembly, comprising: The cover plate body has a first surface and a second surface that are spaced apart from each other along the thickness direction, and the cover plate body has a through-hole along the thickness direction; A pole post structure is inserted into the pole post hole, and the first end and the second end of the pole post structure extend out of the first surface and the second surface, respectively. A connecting piece is spaced apart from the second surface along the thickness direction. A groove is formed on the side of the connecting piece facing the cover plate body. A groove sidewall is formed around the circumferential surface of the groove. A groove bottom wall is formed on the side of the connecting piece facing the pole structure along the thickness direction at the groove. The second end extends into the groove. The outer circumferential surface of the second end and the groove sidewall are connected by a seam weld. The end face of the second end and the groove bottom wall are connected by a through weld.

[0005] Beneficial effects: By providing a groove on the connecting piece and inserting the second end of the pole structure into the groove, the outer peripheral surface of the second end and the groove sidewall can be connected by seam welding at the butt joint, and the end face of the second end and the bottom wall of the groove can be connected by through welding at the contact joint. Therefore, the connecting piece can be connected to the pole structure by seam welding and through welding, reducing the risk of incomplete welding between the connecting piece and the pole structure, increasing the welding area between the connecting piece and the pole structure, and improving the current carrying capacity between the connecting piece and the pole structure.

[0006] In one optional embodiment, the connecting piece includes a piece body, a protrusion, and a connecting portion. The protrusion is disposed away from the cover plate body relative to the piece body. The connecting portion connects the piece body and the protrusion. The protrusion and the connecting portion enclose the groove portion to form the groove portion. The side of the connecting portion facing the groove portion forms the groove sidewall, and the side of the protrusion facing the groove portion forms the groove bottom wall.

[0007] In one optional embodiment, the pole structure includes a main body section and a welding section connected together, the main body section passing through the pole hole, the welding section forming the second end, and the outer peripheral surface of the welding section extending out of the outer peripheral surface of the main body section.

[0008] Beneficial effect: The welding section protrudes radially from the main body section, which facilitates seam welding at the joint between the outer circumference of the welding section and the groove sidewall of the groove.

[0009] In one optional embodiment, the pole structure further includes a riveting member that surrounds the outer periphery of the main body segment and is riveted to the main body segment. The riveting member is disposed opposite to the first surface along the thickness direction, and the cover plate body is sandwiched between the riveting member and the welding segment.

[0010] Beneficial effects: The welding section protrudes radially from the main body section, which can not only cooperate with the riveting parts to fasten the cover plate body, but also guide the flow and give full play to the function of the conductive parts.

[0011] In one optional embodiment, the thickness of the welded segment along the thickness direction is 'a', satisfying 0.5mm ≤ a ≤ 2mm; and / or, The minimum diameter of the main body segment is d1, which satisfies d1≥2mm.

[0012] Beneficial effects: By limiting the thickness of the welding section, while ensuring the structural strength of the pole structure and the welding strength with the connecting piece, the space occupied by the cover plate assembly along the thickness direction and the overall weight are reduced, thereby improving the volumetric energy density and gravimetric energy density of the battery. By limiting the diameter of the main body section, the structural strength of the pole structure is ensured, preventing problems such as breakage and ensuring the current carrying capacity of the pole structure.

[0013] In one optional embodiment, the diameter of the welded segment is d2, which satisfies d2≥d1+5.8, where the units of d1 and d2 are both mm.

[0014] Beneficial effects: By limiting the diameter of the welding section, it is ensured that the welding section protrudes radially from the main body section with sufficient dimensions, thereby improving the fastening effect on the cover plate body and ensuring the stability and reliability of the assembly of the pole structure and the cover plate body.

[0015] In one optional embodiment, the inner diameter of the groove is d3, which satisfies 0 < d3 - d2 ≤ 0.1 mm.

[0016] Beneficial effect: The inner diameter of the groove is slightly larger than the diameter of the welding section, which facilitates the insertion and mating of the welding section and the groove while ensuring the welding effect of the seam weld.

[0017] In one optional embodiment, the thickness of the connecting piece along the thickness direction is b, satisfying 0.5mm ≤ b ≤ 2mm; and / or, Both the seam weld and the through weld are arranged around the centerline of the pole structure. On the cross-section along the centerline, the distance between the seam weld and the through weld is L, which satisfies 1mm≤L≤2mm.

[0018] Beneficial effects: By limiting the thickness of the connecting piece, the structural strength of the connecting piece and the welding strength with the electrode structure are guaranteed, while reducing the space occupied by the cover plate assembly along the thickness direction and the overall weight, thereby improving the volumetric energy density and gravimetric energy density of the battery. By limiting the distance between the seam weld and the through weld, the overall welding quality is ensured while the space for the through weld is guaranteed to ensure the welding area of ​​the through weld, thereby improving the current flow capacity between the pole structure and the connecting piece.

[0019] Secondly, this utility model also provides a battery, comprising: The housing has an opening at at least one end; The aforementioned cover assembly is connected to the housing and seals the opening, and the housing and the cover assembly together form an accommodating space; The battery cell is disposed within the receiving space and electrically connected to the connecting piece.

[0020] Beneficial effects: It reduces the impedance of the cell's charge when it is transferred to the terminal structure via the connecting piece, improves the current transmission effect, and reduces battery heat generation; in addition, by setting a groove in the connecting piece to accommodate part of the terminal structure, the distance between the connecting piece and the cover plate body can be reduced, so that the connecting piece can fully occupy the thickness space of the cover plate body, save the space occupied by the cover plate assembly, provide more space for the cell, and improve the volumetric energy density of the battery.

[0021] In one optional embodiment, the cross-sectional area of ​​the electrode structure perpendicular to the thickness direction is S, the overcurrent coefficient of the electrode structure is k, and the capacity of the battery is C, satisfying S×k / C≥0.3, 3≤k≤12, where S is in mm. 2 The unit of k is Ah / mm 2 The unit of C is Ah.

[0022] Beneficial effects: By comprehensively limiting the cross-sectional area of ​​the electrode structure, the overcurrent coefficient of the electrode structure, and the capacity of the battery, the overcurrent capacity of the electrode structure is guaranteed. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model 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 this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure of a cover plate assembly according to an embodiment of the present utility model; Figure 2 for Figure 1 The bottom view of the cover plate assembly shown; Figure 3 for Figure 2 A cross-sectional view along the AA direction; Figure 4 for Figure 3 A magnified view of part B in the diagram; Figure 5 This is a schematic diagram of the structure of a connecting piece according to an embodiment of the present utility model.

[0025] Explanation of reference numerals in the attached figures: 1. Cover plate body; 11. First surface; 12. Second surface; 13. Pole post hole; 2. Pole post structure; 21. Main body section; 211. Basic column section; 212. Transition column section; 213. Deformed column section; 22. Welded section; 23. Riveted part; 3. Connecting piece; 31. Groove part; 32. Groove side wall; 33. Groove bottom wall; 34. Piece body; 35. Protrusion; 36. Connecting part; 4. Seam weld mark; 5. Penetrating weld mark; 6. Seam seal; 7. Upper insulating part; 8. Lower insulating part. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] The following is combined with Figures 1 to 5 The following describes embodiments of the present invention.

[0028] According to an embodiment of the present invention, a cover plate assembly is provided, comprising: a cover plate body 1 having a first surface 11 and a second surface 12 arranged at intervals along the thickness direction, and a pole post hole 13 extending through the cover plate body 1 along the thickness direction; a pole post structure 2 inserted into the pole post hole 13, with a first end and a second end of the pole post structure 2 extending out of the first surface 11 and the second surface 12 respectively; a connecting piece 3 arranged at intervals along the thickness direction from the second surface 12, a groove portion 31 formed on the side of the connecting piece 3 facing the cover plate body 1, a groove sidewall 32 formed around the periphery of the groove portion 31, a groove bottom wall 33 formed on the side of the connecting piece 3 facing the pole post structure 2 along the thickness direction at the groove portion 31, a second end extending into the groove portion 31, the outer periphery of the second end and the groove sidewall 32 being connected by a seam weld 4, and the end face of the second end and the groove bottom wall 33 being connected by a through weld 5.

[0029] By using the cover plate assembly of this embodiment, a groove 31 is provided on the connecting piece 3, and the second end of the pole post structure 2 is inserted into the groove 31. This allows the outer peripheral surface of the second end and the groove side wall 32 of the groove 31 to be connected by seam welding, and the end face of the second end and the bottom wall 33 of the groove 31 to be connected by through welding. Therefore, the connecting piece 3 can be connected to the pole post structure 2 by seam welding and through welding, reducing the risk of poor welding between the connecting piece 3 and the pole post structure 2, increasing the welding area between the connecting piece 3 and the pole post structure 2, and improving the current flow capacity between the connecting piece 3 and the pole post structure 2.

[0030] It is worth noting that in related technologies, the connecting piece 3 is typically a flat plate, meaning it lacks a groove 31. One surface of the connecting piece 3 along its thickness direction is attached to the end face of the pole post structure 2, and penetration welding is performed on the other side of the connecting piece 3 along its thickness direction to weld the connecting piece 3 and the pole post structure 2 together. However, penetration welding is prone to incomplete welds, and it requires high welding power and energy.

[0031] In this embodiment, firstly, the second end of the pole structure 2 is installed in the groove 31, and the connecting piece 3 is welded to the end face of the pole structure 2 at the second end using a through-welding method. Then, the connecting piece 3 and the pole structure 2 are welded at the mating position of the groove sidewall 32 and the outer peripheral surface of the second end using a seam welding method. This not only reduces the risk of incomplete welding, but also increases the welding area between the connecting piece 3 and the pole structure 2, thereby improving the connection effect between the connecting piece 3 and the pole structure 2, reducing the impedance between the connecting piece 3 and the pole structure 2, and improving the current carrying capacity between the connecting piece 3 and the pole structure 2.

[0032] It is worth noting that seam welding refers to a welding method in which two workpieces are assembled into a lap or butt joint and welded at the joint. Penetration welding refers to a welding method in which two workpieces are assembled in a stacked manner, allowing laser energy to penetrate one workpiece and fuse with the other.

[0033] Furthermore, in related technologies, one surface of the connecting piece 3 along the thickness direction is attached to the end face of the electrode structure 2, and penetration welding is performed on the other side of the connecting piece 3 along the thickness direction to weld the connecting piece 3 and the electrode structure 2 together. Therefore, in the thickness direction, the distance between the side of the connecting piece 3 facing the cover plate body 1 and the cover plate body 1 is relatively large, resulting in the cover plate assembly occupying a large space along the thickness direction, compressing the space for the battery cell and affecting the volumetric energy density of the battery.

[0034] In this embodiment, the pole structure 2 and the connecting piece 3 partially overlap in the thickness direction, which reduces the space occupied by the cover plate assembly in the thickness space, increases the space for the cell installation, and improves the volumetric energy density of the battery.

[0035] Specifically, in one embodiment, such as Figure 4 As shown, the connecting piece 3 includes a piece body 34, a protrusion 35, and a connecting part 36. The protrusion 35 is disposed away from the cover plate body 1 relative to the piece body 34. The connecting part 36 connects the piece body 34 and the protrusion 35. The protrusion 35 and the connecting part 36 enclose a groove 31. The side of the connecting part 36 facing the groove 31 forms a groove sidewall 32, and the side of the protrusion 35 facing the groove forms a groove bottom wall 33.

[0036] It is worth noting that the groove 31 is formed on the flat sheet by stamping, which is simple and convenient to achieve the forming of the connecting piece 3 in this embodiment.

[0037] In one embodiment, such as Figure 4As shown, the pole post structure 2 includes a main body section 21 and a welding section 22 connected together. The main body section 21 passes through the pole post hole 13, and the welding section 22 forms the second end. The outer peripheral surface of the welding section 22 extends beyond the outer peripheral surface of the main body section 21. This arrangement allows the welding section 22 to protrude radially from the main body section 21, facilitating seam welding at the mating position between the outer peripheral surface of the welding section 22 and the groove sidewall 32 of the groove portion 31.

[0038] It is worth noting that, such as Figure 4 As shown, the main body section 21 and the welding section 22 are connected along the thickness direction (that is, the axial direction of the pole structure 2), and the diameter of the welding section 22 is larger than the diameter of the main body section 21.

[0039] It is understandable that, such as Figure 4 As shown, the seam weld 4 connects the outer peripheral surface of the welding section 22 and the groove sidewall 32 of the groove portion 31, and the penetrating weld 5 connects the protrusion 35 and the side of the welding section 22 away from the main body section 21. That is, the protrusion 35 and the welding section 22 are penetrated welded on the side of the protrusion 35 away from the pole post structure 2.

[0040] In one embodiment, such as Figure 4 As shown, the pole structure 2 also includes a riveting member 23, which surrounds the outer periphery of the main body section 21 and is riveted to the main body section 21. The riveting member 23 is positioned opposite to the first surface 11 along the thickness direction, and the cover plate body 1 is sandwiched between the riveting member 23 and the welding section 22. This arrangement causes the welding section 22 to protrude radially from the main body section 21, which can both cooperate with the riveting member 23 to fasten the cover plate body 1 and to conduct current, thus fully utilizing the function of the conductive component.

[0041] Specifically, such as Figure 4 As shown, the main body segment 21 includes a base column segment 211, a transition column segment 212, and a deformable column segment 213 connected in sequence. The base column segment 211 is connected to the welded segment 22, and the deformable column segment 213 forms the aforementioned first end. The diameters of both the base column segment 211 and the deformable column segment 213 are larger than the diameter of the transition column segment 212, so as to clamp the portion of the riveted member 23 surrounding the outer periphery of the transition column segment 212 between the base column segment 211 and the deformable column segment 213.

[0042] Additionally, in one embodiment, such as Figure 4As shown, the cover plate assembly also includes a seal 6, which is disposed around the base column segment 211 and located on the welded segment 22, such that the seal 6 is compressed between the cover plate body 1 and the pole post structure 2. The cover plate assembly also includes an upper insulator 7, which is disposed between the cover plate body 1 and the base column segment 211, and between the cover plate body 1 and the riveting member 23. The cover plate assembly also includes a lower insulator 8, at least a portion of which is disposed between the cover plate body 1 and the welded segment 22, and between the cover plate body 1 and the sheet body 34.

[0043] It is worth noting that when assembling the cover plate assembly of this embodiment, firstly, the connecting piece 3 and the welding section 22 are connected by through welding and seam welding; then, the sealing member 6 is fitted into the base column section 211, and the lower insulating member 8 is fitted into the sealing member 6; then, the main body section 21 is inserted into the pole hole 13 from one side of the second surface 12, and the main body section 21 extends out of the first surface 11; finally, the upper insulating member 7 is installed on the first surface 11 and a part of the upper insulating member 7 extends into the pole hole 13, and then the riveting member 23 is fitted into the position of the transition column section 212, and the part of the main body section 21 of the transition column section 212 away from the base column section 211 is riveted to deform it into a deformed column section 213, thereby achieving the riveting fixation of the riveting member 23.

[0044] It should be further explained that the deformed column segment 213 is formed by riveting the main body segment 21 of the transition column segment 212 away from the foundation column segment 211 to allow the material to flow and be processed. Before riveting, the diameter of this main body segment 21 is the same as that of the transition column segment 212.

[0045] In one embodiment, such as Figure 4 As shown, the thickness of the welding section 22 along the thickness direction is 'a', satisfying 0.5mm ≤ a ≤ 2mm. By limiting the thickness of the welding section 22, while ensuring the structural strength of the electrode structure 2 and the welding strength with the connecting piece 3, the space occupied by the cover plate assembly along the thickness direction and the overall weight are reduced, thereby improving the volumetric energy density and gravimetric energy density of the battery.

[0046] It is worth noting that if the value of 'a' is too small, the welding segment 22 will be too thin, resulting in weak structural strength and a tendency to break. Furthermore, it will cause the weld penetration depth of the seam weld mark 4 and the penetration weld mark 5 to be small, affecting the welding strength of the welding segment 22 and the connecting piece 3. If the value of 'a' is too large, the welding segment 22 will be too thick, leading to an excessively large dimension of the electrode structure 2 along the thickness direction. This, in turn, will result in an excessively large space occupied by the cover assembly along the thickness direction, affecting the volumetric energy density of the battery. Additionally, it will cause the overall weight of the cover assembly to be excessive, affecting the gravimetric energy density of the battery.

[0047] Optionally, the value of 'a' can be any value among 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, and 2mm, or a value between any two of these values.

[0048] It should be noted that, along the thickness direction, the depth of the groove 31 is the same as or approximately the same as the thickness of the welded section 22.

[0049] In one embodiment, such as Figure 4 As shown, the minimum diameter of the main body segment 21 is d1, which satisfies d1≥2mm. By limiting the diameter of the main body segment 21, the structural strength of the pole structure 2 is ensured, preventing problems such as breakage, and ensuring the current carrying capacity of the pole structure 2.

[0050] It is worth noting that, in this embodiment, as Figure 4 As shown, the minimum diameter of the main body segment 21 is the diameter of the transition column segment 212.

[0051] In one embodiment, such as Figure 4 As shown, the diameter of the welding section 22 is d2, which satisfies d2≥d1+5.8, where the units of d1 and d2 are both mm. By limiting the diameter of the welding section 22, it is ensured that the welding section 22 protrudes radially from the main body section 21 with sufficient dimensions, thereby improving the fastening effect on the cover plate body 1 and ensuring the stability and reliability of the assembly of the pole post structure 2 and the cover plate body 1.

[0052] In one embodiment, such as Figure 4 As shown, the inner diameter of the groove 31 is d3, which satisfies 0 < d3 - d2 ≤ 0.1 mm. The inner diameter of the groove 31 is slightly larger than the diameter of the welding section 22, which facilitates the insertion and mating of the welding section 22 and the groove 31 while ensuring the welding effect of the seam weld mark 4.

[0053] It is worth noting that if the values ​​of d3-d2 are too small, the welding segment 22 will not be able to be inserted into the groove 31, affecting the assembly of the pole structure 2 and the connecting piece 3. If the values ​​of d3-d2 are too large, after the welding segment 22 is inserted into the groove 31, the gap between the outer circumferential surface of the welding segment 22 and the groove side wall 32 of the groove 31 will be too large, affecting the welding effect of the seam weld mark 4.

[0054] Optionally, d3-d2 can be any value from 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, or a value between any two values.

[0055] In one embodiment, such as Figure 4As shown, the thickness of the connecting piece 3 along the thickness direction is b, satisfying 0.5mm≤b≤2mm. By limiting the thickness of the connecting piece 3, while ensuring the structural strength of the connecting piece 3 and the welding strength with the electrode structure 2, the space occupied by the cover plate assembly along the thickness direction and the overall weight are reduced, thereby improving the volumetric energy density and gravimetric energy density of the battery.

[0056] It is worth noting that if the value of b is too small, the connecting piece 3 will be too thin, resulting in weak structural strength and making it prone to deformation or even breakage. Furthermore, it will cause the weld penetration depth of the seam weld mark 4 and the penetration weld mark 5 to be smaller, affecting the welding strength of the welded section 22 and the connecting piece 3. If the value of b is too large, the connecting piece 3 will be too thick, resulting in excessive space occupied by the cover plate assembly along the thickness direction, affecting the volumetric energy density of the battery. It will also cause the overall weight of the cover plate assembly to be too large, affecting the gravimetric energy density of the battery.

[0057] Optionally, the value of b can be any one of 0.5mm, 0.8mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, or a value between any two of these values.

[0058] In one embodiment, both the seam weld stamp 4 and the through weld stamp 5 are arranged around the centerline of the pole post structure 2, such as... Figure 4 As shown, on the cross-section along the axis, the distance between the seam weld mark 4 and the through weld mark 5 is L, satisfying 1mm≤L≤2mm. By limiting the distance between the seam weld mark 4 and the through weld mark 5, while ensuring the overall welding quality, the space for setting the through weld mark 5 is guaranteed to ensure the welding area of ​​the through weld mark 5, thereby improving the current flow capacity between the pole structure 2 and the connecting piece 3.

[0059] It is worth noting that if the value of L is too small, the seam weld mark 4 and the through weld mark 5 will be too close, which may cause them to overlap. Furthermore, the welding heat of the two weld marks will affect each other, thus affecting the welding quality. If the value of L is too large, the seam weld mark 4 and the through weld mark 5 will be too far apart, resulting in insufficient space for the through weld mark 5 in the connecting piece 3 and the welding section 22. This will affect the welding area of ​​the through weld mark 5 and reduce the current carrying capacity between the pole structure 2 and the connecting piece 3.

[0060] Optionally, L can be any value from 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or a value between any two of these values.

[0061] According to an embodiment of the present invention, another aspect provides a battery, comprising: a housing having an opening at at least one end; the aforementioned cover assembly connected to the housing and sealing the opening, the housing and the cover assembly forming an accommodating space; and a battery cell disposed within the accommodating space and electrically connected to a connecting piece 3.

[0062] The battery using this embodiment can reduce the impedance when the charge of the cell is transferred to the terminal structure 2 via the connecting piece 3, improve the current transmission effect, and reduce battery heat generation. Furthermore, by providing a groove in the connecting piece 3 to accommodate part of the terminal structure 2, the distance between the connecting piece 3 and the cover plate body 1 can be reduced, allowing the connecting piece 3 to fully occupy the thickness space of the cover plate body 1, saving space occupied by the cover plate assembly, providing more space for the cell, and improving the volumetric energy density of the battery.

[0063] Furthermore, in one embodiment, the cross-sectional area of ​​the electrode structure 2 perpendicular to the thickness direction is S, the overcurrent coefficient of the electrode structure 2 is k, and the battery capacity is C, satisfying S×k / C≥0.3, 3≤k≤12, where the unit of S is mm. 2 The unit of k is Ah / mm 2 The unit of C is Ah. The current-carrying capacity of the terminal structure 2 is ensured by comprehensively limiting the cross-sectional area of ​​the terminal structure 2, its overcurrent coefficient, and the battery capacity. That is, the overcurrent capacity of the terminal structure 2 is characterized by S×k / C. For example, when S×k / C=1, it means the overcurrent capacity of the terminal structure 2 is 1.

[0064] It is worth noting that, taking the cylindrical pole as an example (that is, the welded section 22, the basic column section 211, the transition column section 212 and the deformed column section 213 are all cylindrical columns), the cross-sectional area of ​​the pole structure 2 in the direction perpendicular to the thickness is S = π × (d / 2). 2 d is the diameter of the pole structure 2 at this cross-section. The current flow coefficient is related to the material of the pole structure 2. Generally, the pole structure 2 is made of copper or aluminum, so the value of the current flow coefficient k is usually 3 Ah / mm. 2 Up to 12 Ah / mm 2 Battery capacity is generally related to the overall size of the battery; that is, batteries of different sizes have different capacities.

[0065] For example, the battery capacity C = 324 Ah, and the overcurrent coefficient k of the terminal structure 2 (aluminum material) = 5 Ah / mm. 2 When S×k / C=1, we get S=C / k=324 / 5=64.8mm 2 Further calculations show that d = 9mm. It is understandable that for the pole post structure 2 in this embodiment, d1 ≥ d, that is, d1 ≥ 9mm; if the value of S is less than 64.8mm...2 If the current carrying capacity is less than 1, then the current carrying capacity is less than 1. If the value of S is greater than 64.8 mm... 2 If the current carrying capacity is greater than 1, then the current carrying capacity is greater than 1.

[0066] Although embodiments of the present 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 present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized by include: The cover plate body (1) has a first surface (11) and a second surface (12) that are spaced apart from each other along the thickness direction, and the cover plate body (1) has a through post hole (13) along the thickness direction. The pole post structure (2) is inserted into the pole post hole (13), and the first end and the second end of the pole post structure (2) extend out of the first surface (11) and the second surface (12) respectively; A connecting piece (3) is spaced apart from the second surface (12) along the thickness direction. A groove (31) is formed on the side of the connecting piece (3) facing the cover plate body (1). A groove sidewall (32) is formed around the circumferential surface of the groove (31). A groove bottom wall (33) is formed on the side of the connecting piece (31) facing the pole structure (2) along the thickness direction. The second end extends into the groove (31). The outer circumferential surface of the second end and the groove sidewall (32) are connected by a seam weld (4). The end face of the second end and the groove bottom wall (33) are connected by a through weld (5).

2. The cover plate assembly of claim 1, wherein, The connecting piece (3) includes a piece body (34), a protrusion (35) and a connecting part (36). The protrusion (35) is disposed away from the cover plate body (1) relative to the piece body (34). The connecting part (36) connects the piece body (34) and the protrusion (35). The protrusion (35) and the connecting part (36) enclose the groove (31). The side of the connecting part (36) facing the groove (31) forms the groove sidewall (32). The side of the protrusion (35) facing the groove forms the groove bottom wall (33).

3. The cover plate assembly of claim 1 or 2, wherein, The pole structure (2) includes a main body section (21) and a welding section (22) connected together. The main body section (21) passes through the pole hole (13), and the welding section (22) forms the second end. The outer peripheral surface of the welding section (22) extends out of the outer peripheral surface of the main body section (21).

4. The cover plate assembly of claim 3, wherein, The pole post structure (2) further includes a riveting member (23), which surrounds the outer periphery of the main body section (21) and is riveted to the main body section (21). The riveting member (23) is disposed opposite to the first surface (11) along the thickness direction. The cover plate body (1) is sandwiched between the riveting member (23) and the welding section (22).

5. The cover plate assembly of claim 3, wherein, Along the thickness direction, the thickness of the welded segment (22) is a, satisfying 0.5mm ≤ a ≤ 2mm; and / or, The minimum diameter of the main body segment (21) is d1, which satisfies d1≥2mm.

6. The cover plate assembly of claim 5, wherein, The diameter of the welded segment (22) is d2, which satisfies d2≥d1+5.8, where the units of d1 and d2 are both mm.

7. The cover plate assembly of claim 6, wherein, The inner diameter of the groove (31) is d3, which satisfies 0 < d3 - d2 ≤ 0.1 mm.

8. The cover plate assembly of claim 1 or 2, wherein, Along the thickness direction, the thickness of the connecting piece (3) is b, satisfying 0.5mm ≤ b ≤ 2mm; and / or, Both the seam weld stamp (4) and the through weld stamp (5) are arranged around the center line of the pole structure (2). On the cross section along the center line, the distance between the seam weld stamp (4) and the through weld stamp (5) is L, which satisfies 1mm≤L≤2mm.

9. A battery, characterized by include: The housing has an opening at at least one end; The cover plate assembly according to any one of claims 1 to 8 is connected to the housing and seals the opening, wherein the housing and the cover plate assembly enclose a receiving space; The battery cell is disposed within the receiving space and electrically connected to the connecting piece (3).

10. The battery of claim 9, wherein, The cross-sectional area of ​​the electrode structure (2) perpendicular to the thickness direction is S, the overcurrent coefficient of the electrode structure (2) is k, and the capacity of the battery is C, satisfying S×k / C≥0.3, 3≤k≤12, where the unit of S is mm. 2 The unit of k is Ah / mm 2 The unit of C is Ah.

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