Cylindrical battery

Abstract

Cylindrical battery comprising a cover plate assembly and a battery cell, wherein the battery cell includes a winding core hole, and wherein the cover plate assembly comprises: a cover plate body (1) provided with a through hole (11), wherein a projection of the winding core hole onto the cover plate body (1) is offset from the through hole (11); a connection (2) which passes at least partially through the through hole (11), wherein the connection (2) is firmly connected to the cover plate body (1) via the through hole (11); a current collector plate (3) comprising a terminal weld section (31) and a tab weld section (32), wherein the terminal weld section (31) is welded to the terminal (2); wherein a first stepped section (33) is provided between the tab welding section (32) and the connection welding section (31) and a minimum distance between the connection welding section (31) and the battery cell in an arrangement direction of the cover plate arrangement and the battery cell is less than a maximum distance between the tab welding section (32) and the battery cell.

Description

TECHNICAL AREA

[0001] The present application relates to the field of technology of cylindrical batteries or accumulators and specifically to a cylindrical battery or a cylindrical accumulator. BACKGROUND

[0002] In some cylindrical batteries, the winding core hole and terminal are aligned. During welding, an alignment pin passes through the winding core hole to define a projection and groove, facilitating the welding of the terminal and current collector plate. However, in some cylindrical batteries, the winding core hole and terminal groove are offset, creating a risk of misalignment during welding of the current collector plate and terminal, and a risk of damage to the battery cell during installation. SUMMARY

[0003] In view of this, the present application provides a cylindrical battery to solve the problems that during welding there is a risk of the power collector plate and the connection being welded incorrectly, and that the connection or the power collector plate is at risk of being damaged during installation.

[0004] The present application provides a cylindrical battery comprising a cover plate arrangement and a battery cell, wherein the battery cell contains a winding core hole; the cover plate arrangement comprises the following: a cover plate body provided with a through hole, wherein a projection of the winding core hole onto the cover plate body is offset from the through hole; a connection that passes at least partially through the through-hole, wherein the connection is firmly connected to the cover plate body via the through-hole; a current collector plate comprising a terminal weld section and a tab weld section, wherein the terminal weld section is welded to the terminal; wherein a first stepped section is provided between the tab weld section and the terminal weld section, and a minimum distance between the terminal weld section and the battery cell is less than a maximum distance between the tab weld section and the battery cell in one arrangement direction of the cover plate arrangement and the battery cell.

[0005] ADVANTAGES: Because the through-hole connecting the terminal is offset from the winding core hole of the battery cell, positioning cannot be achieved by an alignment pin passing through the winding core hole when the current collector plate and the terminal are welded together.Therefore, according to this embodiment, the provision of the first stepped section between the terminal welding section and the tab welding section allows the use of a support or bracket on the first stepped section to rest against the current collector plate when the current collector plate and the terminal are welded, so that the terminal welding section and the terminal are firmly connected, which facilitates the welding of the terminal and the current collector plate, avoids the occurrence of faulty welds when the current collector plate is welded to the terminal, and avoids damage to the battery cell during installation.Meanwhile, due to the provision of the first stepped section, the minimum distance between the terminal welding section and the battery cell is smaller than the maximum distance between the tab welding section and the battery cell, with the terminal welding section and the tab welding section consequently forming a height difference between them, which can also improve the liquid injection efficiency and the gas venting performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] To more clearly illustrate the technical solutions according to the specific embodiments of the present application or in the prior art, the drawings necessary for use in describing the specific embodiments or the prior art are briefly presented below. Obviously, the drawings in the following description are some embodiments of the present application, and a person skilled in the art in the field can derive other drawings from these without creative effort. Fig. Figure 1 is a partially schematic view, viewed from one perspective, of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 2 is a partially schematic view, viewed from a different perspective, of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 3 is a schematic view of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 4 is a schematic exploded view of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 5 is a further schematic exploded view of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 6 is a further schematic exploded view of a cover plate arrangement of a cylindrical battery according to an embodiment of the present application; Fig. Figure 7 is a schematic view, from one perspective, of a current collector plate of a cylindrical battery according to an embodiment of the present application; and Fig. Figure 8 is a schematic view, viewed from a different perspective, of a current collector plate of a cylindrical battery according to an embodiment of the present application. REFERENCE MARK:

[0007] 1, Cover plate body; 11, Through hole; 2, Connection; 21, Groove; 3, Current collector plate; 31, Connection weld section; 311, Projection; 32, Tab weld section; 33, First stepped section; 34, Connecting section; 341, Positioning hole; 35, Second stepped section; 4, Injection molded part; 41, Relief hole; 42, Positioning pin; 5, Lower insulating element; 6, First sealing element; 7, Second sealing element. DETAILED DESCRIPTION

[0008] To clarify the objectives, technical solutions, and advantages of the embodiments of the present application, the technical solutions according to the embodiments of the present application are described below in detail with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are a subset of the embodiments of the present application and not all embodiments. All other embodiments that a person skilled in the art could obtain based on the embodiments of the present application without inventive effort are intended to fall within the scope of protection of the present application.

[0009] The embodiments of the present application are described below with regard to the Fig. 1 to 8 described.

[0010] According to one embodiment of the present application, a cylindrical battery is provided comprising a cover plate assembly and a battery cell. The battery cell includes a winding core hole; the cover plate assembly comprises a cover plate body 1, a terminal 2, and a current collector plate 3; the cover plate body 1 is provided with a through-hole 11, wherein a projection of the winding core hole onto the cover plate body 1 is offset from the through-hole 11; at least a portion of the terminal 2 passes through the through-hole 11, and the terminal 2 is firmly connected to the cover plate body 1 via the through-hole 11; the current collector plate 3 comprises a terminal weld section 31 and a tab weld section 32, wherein the terminal weld section 31 is welded to the terminal 2;A first stepped section 33 is provided between the tab welding section 32 and the connection welding section 31, and a minimum distance between the connection welding section 31 and the battery cell is less than a maximum distance between the tab welding section 32 and the battery cell in one arrangement direction of the cover plate arrangement and the battery cell.

[0011] Because the through-hole 11 connected to terminal 2 is offset from the winding core hole of the battery cell, no positioning can be achieved by an alignment pin passing through the winding core hole when the current collector plate 3 and terminal 2 are welded together.Therefore, according to this embodiment, the provision of the first stepped section 33 between the terminal welding section 31 and the tab welding section 32 enables the use of a support or bracket on the first stepped section 33 to rest against the current collector plate 3 when the current collector plate 3 and the terminal 2 are welded, so that the terminal welding section 31 and the terminal 2 are firmly connected, which facilitates the welding of the terminal 2 and the current collector plate 3, avoids the occurrence of a faulty weld when the current collector plate 3 is welded to the terminal 2, and avoids damage to the battery cell during installation.Meanwhile, due to the provision of the first stepped section 33, the minimum distance between the terminal weld section 31 and the battery cell is smaller than the maximum distance between the tab weld section 32 and the battery cell, with the terminal weld section 31 and the tab weld section 32 forming a height difference between them, which can also improve the liquid injection efficiency and the gas venting performance of the battery cell.

[0012] According to one embodiment, the connection 2 has a groove 21 therein; a projection 311 is provided on the connection weld section 31; at least one section of the projection 311 is arranged in the groove 21 and welded to the connection 2.

[0013] According to one embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, a height difference h of the first stepped section 33 fulfills the following: 0.1 mm ≤ h ≤ 2 mm.

[0014] A height difference of the first stepped section 33 in a range of 0.1 mm to 2 mm not only facilitates carrying when the current collector plate 3 is welded to the terminal 2, but also does not cause any serious waste of the battery's interior space due to an excessive height difference; where, if the height difference is in the range of 0.1 mm to 2 mm, it can facilitate gas venting during the thermal runaway of the battery and electrolyte infiltration during liquid injection.

[0015] According to a specific embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, the height difference h of the first stepped section 33 is 0.1 mm.

[0016] According to another specific embodiment, the height difference h of the first stepped section is 33 2 mm in the arrangement direction of the cover plate arrangement and the battery cell.

[0017] According to a further specific embodiment, the height difference h of the first stepped section is 33 1 mm in the arrangement direction of the cover plate arrangement and the battery cell.

[0018] According to one embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, a ratio A of a height of the first stepped section 33 to a height of the battery cell satisfies the following: 0.01 ≤ A ≤ 0.03.

[0019] According to one embodiment, the range of the height difference h of the first stepped section 33 is 0.1 mm-2 mm, while the range of the height of the battery cell is 70 mm-200 mm.

[0020] The ratio A of the height of the first stepped section 33 to the height of the battery cell cannot be too high; if it is too high, it would affect the height of the cylindrical battery cell and consequently the battery's capacity. The ratio A of the height of the first stepped section 33 to the height of the battery cell cannot be too low; if it is too low, it would affect the liquid injection efficiency and the gas venting performance of the cylindrical battery. Therefore, if the ratio A of the height of the first stepped section 33 to the height of the battery cell is 0.01 ≤ A ≤ 0.03, it not only ensures the battery cell height and capacity of the cylindrical battery but also does not affect the liquid injection efficiency or the gas venting performance of the battery cell.

[0021] According to a specific embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, the ratio A of the height of the first stepped section 33 to the height of the battery cell can be 0.01, 0.03 or 0.02.

[0022] According to a specific embodiment, the height of the battery cell can be 70 mm, 200 mm, or 135 mm.

[0023] According to one embodiment, the cylindrical battery further comprises a support element, wherein the support element is arranged between the connection weld section 31 and the battery cell and is located on the first stepped section 33, wherein the support element consists of an insulating material.

[0024] The support element is located at the first stepped section 33 and is positioned between the connection welding section 31 and the battery cell, which can improve stability at a connection where the current collector plate 3 is connected to an electrode tab, ensure a contact area between the battery cell and the current collector plate 3 when the battery cell is positioned on the current collector plate 3, and prevent crushing of the battery cell caused by a small contact area when the battery cell is positioned on the current collector plate 3.

[0025] According to one embodiment, two through-holes 11 in the cover plate body 1 are spaced apart from each other, the terminal 2 comprises a first terminal and a second terminal, wherein the first terminal and the second terminal are each firmly connected to the cover plate body 1 via the two through-holes 11, and the first terminal and the second terminal have opposite polarities. The current collector 3 comprises a first current collector and a second current collector, wherein the first current collector and the second current collector are spaced apart from each other, the terminal weld section 31 of the first current collector is connected to the first terminal, the terminal weld section 31 of the second current collector is connected to the second terminal; and the height difference h of the first current collector and the height difference h of the second current collector both satisfy the following: 0.5 mm ≤ h ≤ 2 mm.

[0026] Two through-holes 11 are provided on the cover plate body 1, which can each be connected to the first terminal and the second terminal, wherein the first current collector plate and the second current collector plate are spaced apart from each other to avoid the occurrence of a short circuit and also to avoid problems such as damage caused by voltage pulling between the first current collector plate and the second current collector plate during a welding process.

[0027] According to a specific embodiment, both the first current collector plate and the second current collector plate are provided with the terminal weld section 31 and the tab weld section 32, wherein the tab weld section 32 of the first current collector plate is connected to a positive electrode tab of the battery cell, and the first terminal is connected to the terminal weld section 31 of the first current collector plate, thereby serving as a positive electrode of the cylindrical battery; wherein the tab weld section 32 of the second current collector plate is connected to a negative electrode tab of the battery cell, and the second terminal is connected to the terminal weld section 31 of the second current collector plate, thereby serving as a negative electrode of the cylindrical battery. Specifically, the height difference is the height difference h of the first stepped section 33.

[0028] According to a preferred embodiment, two through-holes 11 are provided in the cover plate body 1 and each is connected to the first terminal and the second terminal, wherein the terminal weld section 31 of the first current collector plate is connected to the first terminal and the terminal weld section 31 of the second current collector plate is connected to the second terminal. Therefore, a positive electrode tab of the battery cell and a negative electrode tab of the battery cell are arranged at one end of the battery cell, i.e., at an end of the battery cell facing the cover plate body 1; wherein the positive electrode tab of the battery cell and the negative electrode tab of the battery cell are spaced apart from each other and are each welded to the tab weld section 32 of the first current collector plate and the tab weld section 32 of the second current collector plate.

[0029] According to a specific embodiment, the height difference of the first stepped section 33 of the first current collector plate can be 0.5 mm, 2 mm, or 1.2 mm. The height difference of the first stepped section 33 of the second current collector plate can be 0.5 mm, 2 mm, or 1.2 mm.

[0030] According to one embodiment, the projection of the winding core hole onto the cover plate body 1 is located between the first terminal and the second terminal, wherein the height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy the following: 0.5 mm ≤ h ≤ 1.8 mm.

[0031] According to a specific embodiment, the projection of the winding core hole onto the cover plate body 1 is located between the first terminal and the second terminal, wherein the height difference h of the first current collector plate and the height difference h of the second current collector plate can both be 0.5 mm or can also be 1.8 mm or can also be 1.2 mm.

[0032] According to one embodiment, the first terminal and the second terminal are distributed in central symmetry on the cover plate body 1, wherein the height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy the following: 0.5 mm ≤ h ≤ 1.5 mm.

[0033] According to a specific embodiment, the first terminal and the second terminal are distributed in central symmetry on the cover plate body 1, wherein the height difference h of the first current collector plate and the height difference h of the second current collector plate can both be 0.5 mm or can also be 1.5 mm or can also be 1 mm.

[0034] According to one embodiment, a minimum distance D between the connection weld section 31 of the first current collector plate and the tab weld section 32 of the second current collector plate satisfies the following: 0.7 mm ≤ D ≤ 30 mm.

[0035] According to a specific embodiment, the minimum distance D between the connection weld section 31 of the first current collector plate and the tab weld section 32 of the second current collector plate can be 0.7 mm, 30 mm, or 15 mm.

[0036] According to one embodiment, a minimum distance E between the tab welding section 32 of the first current collector plate and the connection welding section 31 of the second current collector plate satisfies the following: 0.7 mm ≤ E ≤ 30 mm.

[0037] According to a specific embodiment, the minimum distance E between the tab welding section 32 of the first current collector plate and the connection welding section 31 of the second current collector plate can be 0.7 mm, 30 mm, or 15 mm.

[0038] According to one embodiment, a ratio B of a minimum distance between the tab welding section 32 of the first current collector plate and the tab welding section 32 of the second current collector plate to a radial width of the battery cell satisfies the following: 1 / 30 ≤ B ≤ 1 / 2.

[0039] The larger the ratio B of the minimum distance between the tab weld section 32 of the first current collector plate and the tab weld section 32 of the second current collector plate to the radial width of the battery cell, the smaller the radial width of the battery cell. If the radial width of the battery cell is too small, the insulation performance cannot be guaranteed. Conversely, the smaller the ratio B of the minimum distance between the tab weld section 32 of the first current collector plate and the tab weld section 32 of the second current collector plate to the radial width of the battery cell, the larger the radial width of the battery cell. If the radial width of the battery cell is too large, this would reduce the area of ​​the tab weld section 32 of the current collector plate 3, decrease the weld area between the current collector plate 3 and the electrode tab of the battery cell, and affect the current-carrying area.

[0040] According to a specific embodiment, the ratio B of the minimum distance between the tab welding section 32 of the first current collector plate and the tab welding section 32 of the second current collector plate to the radial width of the battery cell is 1 / 30.

[0041] According to another specific embodiment, the ratio B of the minimum distance between the tab welding section 32 of the first current collector plate and the tab welding section 32 of the second current collector plate to the radial width of the battery cell is 1 / 2.

[0042] According to a preferred embodiment, the minimum distance between the tab weld section 32 of the first current collector plate and the tab weld section 32 of the second current collector plate ranges from 1 mm to 30 mm. The radial width of the cover plate ranges from 30 mm to 60 mm.

[0043] According to one embodiment, the terminal 2 comprises a first terminal and a second terminal, wherein the first terminal and the second terminal are each located at opposite ends of the battery cell, and the cover plate bodies 1 are provided at both ends of the battery cell. The first terminal and the second terminal are each rigidly connected to two cover plate bodies 1 via two through-holes 11, the first terminal and the second terminal having opposite polarities. Alternatively, the cover plate body 1 is provided at one end of the battery cell, the first terminal is rigidly connected to the cover plate body 1 via the through-hole 11, a connection hole is provided in a battery housing at the other end of the battery cell, a projection of the winding core hole onto the battery housing is offset from the connection hole, and the second terminal is rigidly connected to the battery housing via the connection hole.The current collector plate 3 comprises a first current collector plate and a second current collector plate, the terminal weld section 31 of the first current collector plate is connected to the first terminal, the terminal weld section 31 of the second current collector plate is connected to the second terminal, and the height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy the following: 0.1 mm ≤ h ≤ 1 mm.

[0044] If the first terminal and the second terminal are located at opposite ends of the battery cell, the height difference of the first stepped section 33 of the first current collection plate and the height difference of the first stepped section 33 of the second current collection plate must both not be set too large in order to avoid taking up too much space in one longitudinal direction of the battery cell.

[0045] According to a specific embodiment, the first terminal and the second terminal are located at opposite ends of the battery cell, wherein the height difference h of the first current collector plate and the height difference h of the second current collector plate can both be 0.1 mm, or the height difference h can also be 1 mm, or the height difference h can also be 0.5 mm.

[0046] According to one embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, a ratio A of the height of the first stepped section 33 to the height of the battery cell is as follows: 0.01 ≤ A ≤ 0.03; the height difference of the first stepped section 33 ranges from 0.1 mm to 2 mm and the height of the battery cell ranges from 70 mm to 200 mm.

[0047] According to a specific embodiment, in the arrangement direction of the cover plate arrangement and the battery cell, the ratio A of the height of the first stepped section 33 to the height of the battery cell can be 0.01, 0.03, or 0.02; the height difference h of the first stepped section 33 can be 0.1 mm, 2 mm, or 1 mm; the height of the battery cell can be 70 mm, 200 mm, or 135 mm.

[0048] According to one embodiment, on each of the current collector plates 3, the ratio C of an area of ​​the tab welding section 32 to an area of ​​the connection welding section 31 is as follows: 0.5 ≤ C ≤ 4.

[0049] If the ratio C of the area of ​​the tab welding section 32 to the area of ​​the connecting welding section 31 is too small, the area of ​​the connecting welding section 31 is too large relative to the area of ​​the tab welding section 32 on each current collector plate 3, with the current carrying capacity of the connecting welding section 31 and the current carrying capacity of the tab welding section 32 being unbalanced. If the ratio C of the area of ​​the tab welding section 32 to the area of ​​the connection welding section 31 is too large, the area of ​​the connection welding section 31 is too small relative to the area of ​​the tab welding section 32, which leads to a reduced current-carrying capacity of the connection welding section 31 and makes the distance between the tab welding section 32 of the first current collector plate and the tab welding section 32 of the second current collector plate too small, with the two being too close together, so that the insulation is affected.

[0050] According to a specific embodiment, on each of the current collector plates 3 the ratio C of the area of ​​the tab welding section 32 to the area of ​​the connection welding section 31 is 0.5.

[0051] According to another specific embodiment, on each of the current collector plates 3 the ratio C of the area of ​​the tab welding section 32 to the area of ​​the connection welding section 31 is 4.

[0052] According to a preferred embodiment, on each of the current collector plates 3 the ratio C of the area of ​​the tab weld section 32 to the area of ​​the connection weld section 31 is 1, the area of ​​the tab weld section 32 of the first current collector plate is 10 mm² 2 and the area of ​​the tab welding section 32 of the second current collector plate is 8 mm 2 .

[0053] According to one embodiment, the cylindrical battery further comprises an injection-molded part 4, wherein the injection-molded part 4 is connected to the cover plate body 1, the current collector plate 3 is arranged between the injection-molded part 4 and the cover plate body 1, the injection-molded part 4 is provided with a relief hole 41 and the connection weld section 31 is arranged at the relief hole 41.

[0054] The current collector plate 3 is arranged between the injection-molded part 4 and the cover plate body 1, wherein the injection-molded part 4 can not only improve the connection stability between the current collector plate 3 and the cover plate body 1, but can also expose the connection welding section 31 through the relief hole 41, which ensures the connection between the tab welding section 32 and the electrode tab of the battery cell and improves the suitability of the connection between the connection welding section 31 and the connection 2.

[0055] Preferably, the connecting weld section 31 and the tab weld section 32 are arranged at the relief hole 41.

[0056] According to a specific embodiment, the cover plate body 1 has two through holes 11 spaced apart from each other, and the connection 2 comprises a first connection and a second connection, wherein the first connection and the second connection are each firmly connected to the cover plate body 1 via the two through holes 11. The current collector plate 3 comprises a first current collector plate and a second current collector plate, wherein the first current collector plate and the second current collector plate are spaced apart from each other, the connection weld section 31 of the first current collector plate is connected to the first connection, and the connection weld section 31 of the second current collector plate is connected to the second connection.Two relief holes 41 are provided on the injection-molded part 4, with the two relief holes 41 being spaced apart. The terminal weld section 31 and the tab weld section 32 of the first current collector plate are exposed through one relief hole 41, and the terminal weld section 31 and the tab weld section 32 of the second current collector plate are exposed through another relief hole 41. Alternatively, the tab weld section 32 of the first current collector plate is exposed through one relief hole 41, while the tab weld section 32 of the second current collector plate is exposed through another relief hole 41. Due to the insulating properties of the injection-molded part 4 itself, the area between the two relief holes 41 can serve to provide an insulating separation between the first and second current collector plates.

[0057] According to one embodiment, the current collector plate 3 is further provided with a connecting section 34, wherein the connection welding section 31 and the connecting section 34 are each arranged at two ends of the tab welding section 32, a second stepped section 35 is provided between the connecting section 34 and the tab welding section 32, a minimum distance between the connecting section 34 and the battery cell is less than a maximum distance between the tab welding section 32 and the battery cell, and at least one section of the connecting section 34 is connected between the injection-molded part 4 and the cover plate body 1.

[0058] The provision of the connecting section 34 can improve the stability of the current collector plate 3 through the injection-molded part 4 and the cover plate body 1. The provision of the second stepped section 35 not only allows the tab welding section 32, spaced apart from the cover plate body 1, to have a relatively flat surface, which improves the welding effect between the tab welding section 32 and the electrode tab, but also ensures the contact area between the tab welding section 32 and the battery cell.

[0059] According to one embodiment, the connecting section 34 is provided with a positioning hole 341, the injection molded part 4 is provided with a positioning pin 42, and the positioning pin 42 is positioned and inserted into the positioning hole 341.

[0060] The positioning of the positioning hole 341 and the positioning pin 42 allows the power busbar 3 to be positioned and fixed when the power busbar 3 is connected, ensuring a secure connection. The connection section 34 is provided with the positioning hole 341, and the injection-molded part 4 is provided with the positioning pin 42, which also conceals the positioning hole 341 and the positioning pin 42 and avoids taking up additional space.

[0061] According to one embodiment, there are at least two positioning holes 341, wherein the at least two positioning holes 341 are spaced apart from each other.

[0062] The at least two spaced-apart positioning holes 341 can prevent the current collector plate 3 from rotating, and consequently ensure a good positioning effect.

[0063] According to a specific embodiment, the at least two positioning holes 341 are spaced apart from each other along a radial direction of the current collector plate 3.

[0064] Preferably there are two positioning holes 341, wherein the two positioning holes 341 are both circular holes and are spaced apart from each other along a radial direction of the current collector plate 3, wherein one shape of the positioning pin 42 corresponds to one shape of the positioning hole 341.

[0065] According to a specific embodiment, two through-holes 11 in the cover plate body 1 are spaced apart from each other, and the connection 2 comprises a first connection and a second connection, wherein the first connection and the second connection are each rigidly connected to the cover plate body 1 via the two through-holes 11. The current collector 3 comprises a first current collector and a second current collector, wherein the first current collector and the second current collector are spaced apart from each other, the connection weld section 31 of the first current collector is connected to the first connection, and the connection weld section 31 of the second current collector is connected to the second connection.The connecting section 34 of the first current collector plate is opposite and spaced apart from the connecting weld section 31 of the second current collector plate; the connecting section 34 of the second current collector plate is opposite and spaced apart from the connecting weld section 31 of the first current collector plate. The tab weld section 32 has a sector ring shape, with a center point of the tab weld section 32 of the first current collector plate and a center point of the tab weld section 32 of the second current collector plate coinciding.

[0066] According to a specific embodiment, the cover plate arrangement further comprises a lower insulating element 5, which is arranged between the cover plate body 1 and the current collector plate 3, wherein the lower insulating element 5 is provided with a through-hole, the through-hole and the through-hole 11 are arranged coaxially and accordingly, and the connection 2 is firmly connected to the through-hole and the through-hole 11.

[0067] According to a further embodiment, two ends of the connection 2 are each provided with a first limiting flange and a second limiting flange, wherein the cover plate body 1 and the lower insulating element 5 are arranged between the first limiting flange and the second limiting flange. The lower insulating element 5 has a plate shape. The cover plate arrangement further comprises a first sealing element 6 and a second sealing element 7, wherein the first sealing element 6 is arranged on an outer circumference of the connection 2 and is clamped between the lower insulating element 5 and the first limiting flange; wherein the second sealing element 7 is arranged on an outer circumference of the connection 2 and is clamped between the cover plate body 1 and the second limiting flange.

[0068] According to a preferred embodiment, there is a smooth transition between the first stepped section 33 and the connecting weld section 31 to avoid sharp corners between the first stepped section 33 and the connecting weld section 31 and to prevent damage to the cover plate body 1 and the lower insulating element 5 by the sharp corners during assembly.

[0069] According to a preferred embodiment, there is a smooth transition between the first stepped section 33 and the tab-welded section 32 to avoid sharp edges between the first stepped section 33 and the tab-welded section 32 and to prevent damage to the battery cell from the sharp edges during assembly.

[0070] Although the embodiments of the present application have been described with respect to the drawings, a person skilled in the art may make various modifications and variations without deviating from the inventive concept and scope of protection of the present application, such modifications and variations falling within the scope of protection defined by the present application.

Claims

[1] Cylindrical battery comprising a cover plate assembly and a battery cell, wherein the battery cell includes a winding core hole, and wherein the cover plate assembly comprises: a cover plate body (1) provided with a through hole (11), wherein a projection of the winding core hole onto the cover plate body (1) is offset from the through hole (11); a connection (2) which passes at least partially through the through hole (11), wherein the connection (2) is firmly connected to the cover plate body (1) via the through hole (11); a current collector plate (3) comprising a terminal weld section (31) and a tab weld section (32), wherein the terminal weld section (31) is welded to the terminal (2); wherein a first stepped section (33) is provided between the tab welding section (32) and the connection welding section (31) and a minimum distance between the connection welding section (31) and the battery cell in an arrangement direction of the cover plate arrangement and the battery cell is less than a maximum distance between the tab welding section (32) and the battery cell. [2] Cylindrical battery according to claim 1, wherein in the arrangement direction of the cover plate arrangement and the battery cell a height difference h of the first stepped section (33) fulfills the following: 0.1 mm≤h≤2 mm. [3] Cylindrical battery according to claim 2, wherein two through-holes (11) on the cover plate body (1) are spaced apart from each other, the terminal (2) comprises a first terminal and a second terminal, wherein the first terminal and the second terminal are located at one end of the battery cell, the first terminal and the second terminal are each firmly connected to the cover plate body (1) via the two through-holes (11), the first terminal and the second terminal have opposite polarities; the current collector plate (3) comprises a first current collector plate and a second current collector plate, wherein the first current collector plate and the second current collector plate are spaced apart from each other, the terminal weld section (31) of the first current collector plate is connected to the first terminal, the terminal weld section (31) of the second current collector plate is connected to the second terminal;A height difference h of the first current collector plate and a height difference h of the second current collector plate both satisfy the following: ; 0.5 mm≤h≤2 mm. [4] Cylindrical battery according to claim 2 or 3, wherein the terminal (2) comprises a first terminal and a second terminal, the first terminal and the second terminal are each located at opposite ends of the battery cell, two cover plate bodies (1) are provided at both ends of the battery cell, the first terminal and the second terminal are each firmly connected to the two cover plate bodies (1) via two through holes (11), and the first terminal and the second terminal have opposite polarities; or the cover plate body (1) is provided at one end of the battery cell, the first terminal is firmly connected to the cover plate body (1) via the through hole (11), a connection hole is provided in a battery housing at the other end of the battery cell, the projection of the winding core hole onto the battery housing is offset from the connection hole, and the second terminal is firmly connected to the battery housing via the connection hole; and the current collector plate (3) comprises a first current collector plate and a second current collector plate, the terminal weld section (31) of the first current collector plate is connected to the first terminal, the terminal weld section (31) of the second current collector plate is connected to the second terminal; and a height difference h of the first current collector plate and a height difference h of the second current collector plate both satisfy the following: 0.1 mm≤h≤1 mm. [5] Cylindrical battery according to claim 3 or 4, wherein the projection of the winding core hole onto the cover plate body (1) is located between the first terminal and the second terminal and the height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy the following: 0.5 mm≤h≤1.8 mm. [6] Cylindrical battery according to claim 5, wherein the first terminal and the second terminal are distributed in central symmetry on the cover plate body (1) and the height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy the following: 0.5 mm≤h≤1.5 mm. [7] Cylindrical battery according to any one of claims 1 to 6, wherein in the arrangement direction of the cover plate arrangement and the battery cell a ratio A of a height of the first stepped section (33) to a height of the battery cell satisfies the following: 0.01≤A≤0.

03. [8] Cylindrical battery according to any one of claims 3 to 7, wherein a ratio B of a minimum distance between the tab weld section (32) of the first current collector plate and the tab weld section (32) of the second current collector plate to a radial width of the cover plate satisfies the following: 1 / 30≤B≤1 / 2. [9] Cylindrical battery according to any one of claims 3 to 8, wherein on each current collector plate (3) a ratio C of an area of ​​the tab welding section (32) to an area of ​​the terminal welding section (31) satisfies the following: 0.5≤C≤4. [10] Cylindrical battery according to any one of claims 3 to 9, wherein a minimum distance D between the terminal weld section (31) of the first current collector plate and the tab weld section (32) of the second current collector plate fulfills the following: 0.7 mm≤D≤30 mm. [11] Cylindrical battery according to any one of claims 3 to 10, wherein a minimum distance E between the tab weld section (32) of the first current collector plate and the terminal weld section (31) of the second current collector plate fulfills the following: 0.7 mm≤E≤30 mm. [12] Cylindrical battery according to any one of claims 1 to 11, wherein the terminal (2) has a groove (21) therein; a projection (311) is provided on the terminal weld section (31); and at least one section of the projection (311) is arranged in the groove (21) and welded to the terminal (2). [13] Cylindrical battery according to any one of claims 1 to 12, which further comprises a support element, wherein the support element is arranged between the connection weld section (31) and the battery cell and is located on the first stepped section (33), wherein the support element consists of an insulating material.

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