Cylindrical battery

Abstract

A cylindrical battery, comprising a cover plate assembly and a battery cell. The cover plate assembly comprises a cover plate body (1) provided with through holes (11); the projection of a wound core hole on the cover plate body (1) is staggered from the through holes (11); at least part of each pole (2) passes through a through hole (11); the poles (2) are fixedly connected to the cover plate body (1) by means of the through holes (11); each current collector disc (3) comprises a pole welding portion (31) and a tab welding portion (32); the pole welding portion (31) is welded to a pole (2); a first step portion (33) is provided between the tab welding portion (32) and the pole welding portion (31); a support member or a tooling fixture can be used at the first step portion (33) to abut against the current collector disc (3), so as to facilitate welding between the pole (2) and the current collector disc (3).

Description

Cylindrical battery

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411442868.7, filed on October 16, 2024, entitled “Cylindrical Battery”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of cylindrical battery technology, specifically to cylindrical batteries. Background Technology

[0004] In some cylindrical batteries, the winding hole and the terminal post are positioned correspondingly. During welding, a push pin pushes through the winding hole to limit the protrusions and grooves, facilitating the welding of the terminal post and the current collector. However, in other cylindrical batteries, the winding hole and the groove of the terminal post are misaligned. This can lead to incomplete welds between the current collector and the terminal post during welding, and can also damage the cell during assembly. Summary of the Invention

[0005] In view of this, this application provides a cylindrical battery to solve the problems that the current collector and the terminal post are prone to poor soldering during welding, and that the terminal post or current collector is easily damaged during assembly.

[0006] This application provides a cylindrical battery, including a cover assembly and a battery cell, wherein the battery cell includes a winding hole; the cover assembly includes:

[0007] The cover plate body is provided with a through hole, and the projection of the core hole on the cover plate body is offset from the through hole;

[0008] The electrode post is at least partially inserted into the through hole, and the electrode post is fixedly connected to the cover plate body through the through hole;

[0009] The current collector includes a terminal welding part and a tab welding part, the terminal welding part being welded to the terminal; a first step is provided between the tab welding part and the terminal welding part, and in the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the terminal welding part and the battery cell is less than the maximum distance between the tab welding part and the battery cell.

[0010] Beneficial effects: Because the through holes connecting the terminals and the winding holes of the battery cell are staggered, it is impossible to position the current collector and terminals by using a pin passing through the winding hole when welding them. Therefore, in this embodiment, the first step between the terminal welding part and the electrode welding part allows the current collector to be supported by a support or tooling fixture at the first step when welding the current collector and the terminal, ensuring a tight connection between the terminal welding part and the terminal. This facilitates welding of the terminal and the current collector, avoids incomplete welding, and prevents damage to the battery cell during assembly. Furthermore, due to the first step, the minimum distance between the terminal welding part and the battery cell is less than the maximum distance between the electrode welding part and the battery cell, creating a height difference between them. This also improves the liquid injection efficiency and the battery cell's venting performance. Attached Figure Description

[0011] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0012] Figure 1 is a partial schematic diagram from one perspective of a cover plate assembly of a cylindrical battery according to an embodiment of this application;

[0013] Figure 2 is a partial schematic diagram from another perspective of a cover plate assembly of a cylindrical battery according to an embodiment of this application;

[0014] Figure 3 is a schematic diagram of a cover plate assembly for a cylindrical battery according to an embodiment of this application;

[0015] Figure 4 is an exploded view of a cover plate assembly of a cylindrical battery according to an embodiment of this application;

[0016] Figure 5 is another exploded view of a cover plate assembly of a cylindrical battery according to an embodiment of this application;

[0017] Figure 6 is another exploded view of a cover plate assembly of a cylindrical battery according to an embodiment of this application;

[0018] Figure 7 is a schematic diagram from one perspective of the current collector of a cylindrical battery according to an embodiment of this application;

[0019] Figure 8 is a schematic diagram of the current collector of a cylindrical battery according to an embodiment of this application from another perspective.

[0020] Explanation of reference numerals in the attached drawings: 1. Cover plate body; 11. Through hole; 2. Pole post; 21. Groove; 3. Collector plate; 31. Pole post welding part; 311. Protrusion; 32. Pole lug welding part; 33. First step part; 34. Connecting part; 341. Positioning hole; 35. Second step part; 4. Injection molded part; 41. Clearance hole; 42. Positioning post; 5. Lower insulating part; 6. First sealing part; 7. Second sealing part. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] The embodiments of this application are described below with reference to Figures 1 to 8.

[0023] According to an embodiment of this application, a cylindrical battery is provided, including a cover plate assembly and a battery cell. The battery cell includes a winding hole. The cover plate assembly includes a cover plate body 1, a terminal post 2, and a current collector 3. The cover plate body 1 has a through hole 11, and the projection of the winding hole on the cover plate body 1 is offset from the through hole 11. At least a portion of the terminal post 2 passes through the through hole 11, and the terminal post 2 is fixedly connected to the cover plate body 1 through the through hole 11. The current collector 3 includes a terminal post welding portion 31 and a tab welding portion 32, and the terminal post welding portion 31 is welded to the terminal post 2. A first step portion 33 is provided between the tab welding portion 32 and the terminal post welding portion 31. In the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the terminal post welding portion 31 and the battery cell is less than the maximum distance between the tab welding portion 32 and the battery cell.

[0024] Because the through hole 11 connecting the terminal post 2 and the core winding hole of the battery cell are staggered, the current collector 3 and the terminal post 2 cannot be positioned by the pin passing through the core winding hole when they are welded. Therefore, in this embodiment, the first step 33 between the terminal post welding part 31 and the electrode tab welding part 32 can be used to support the current collector 3 at the first step 33 when the current collector 3 and the terminal post 2 are welded, so that the terminal post welding part 31 and the terminal post 2 are tightly connected, which facilitates the welding of the terminal post 2 and the current collector 3, avoids the occurrence of incomplete welding when the current collector 3 and the terminal post 2 are welded, and avoids damage to the battery cell during the fit. At the same time, due to the setting of the first step 33, the minimum distance between the terminal post welding part 31 and the battery cell is less than the maximum distance between the electrode tab welding part 32 and the battery cell. The height difference between the terminal post welding part 31 and the electrode tab welding part 32 can also improve the liquid injection efficiency and the venting performance of the battery cell.

[0025] In one embodiment, the pole post 2 is provided with a groove 21; the pole post welding part 31 is provided with a protrusion 311; at least a portion of the protrusion 311 is disposed in the groove 21 and welded to the pole post 2.

[0026] In one embodiment, in the arrangement direction of the cover plate assembly and the battery cell, the height difference h of the first step portion 33 is within the range of 0.1mm≤h≤2mm.

[0027] The height difference of the first step 33 is in the range of 0.1mm to 2mm, which not only facilitates support when welding the current collector 3 and the terminal post 2, but also prevents serious waste of internal battery space due to excessive height difference; and when the height difference is in the range of 0.1mm to 2mm, it facilitates venting during battery thermal runaway and electrolyte wetting during electrolyte injection.

[0028] In one specific embodiment, the height difference h of the first step portion 33 is 0.1 mm in the arrangement direction of the cover plate assembly and the battery cell.

[0029] In another specific embodiment, the height difference h of the first step portion 33 is 2 mm in the arrangement direction of the cover plate assembly and the battery cell.

[0030] In yet another specific embodiment, the height difference h of the first step portion 33 is 1 mm in the arrangement direction of the cover plate assembly and the battery cell.

[0031] In one embodiment, in the arrangement direction of the cover plate assembly and the battery cell, the ratio A of the height of the first step portion 33 to the height of the battery cell satisfies 0.01≤A≤0.03.

[0032] In one embodiment, the height difference h of the first step portion 33 ranges from 0.1 mm to 2 mm, and the height of the battery cell ranges from 70 mm to 200 mm.

[0033] The ratio A between the height of the first step 33 and the height of the cell cannot be too high, otherwise it will affect the height of the cylindrical battery cell and thus the capacity of the cylindrical battery. The ratio A between the height of the first step 33 and the height of the cell cannot be too low, otherwise it will affect the electrolyte injection efficiency and the venting performance of the cylindrical battery cell. Therefore, when the ratio A between the height of the first step 33 and the height of the cell satisfies 0.01≤A≤0.03, the height of the cylindrical battery cell and the capacity of the cylindrical battery can be guaranteed, while the electrolyte injection efficiency and the venting performance of the cylindrical battery cell will not be affected.

[0034] In one specific embodiment, in the arrangement direction of the cover plate assembly and the battery cell, the ratio A of the height of the first step portion 33 to the height of the battery cell can be 0.01, 0.03, or 0.02.

[0035] In one specific embodiment, the height of the battery cell can be 70mm, 200mm, or 135mm.

[0036] In one embodiment, the cylindrical battery further includes a support member disposed between the terminal welding portion 31 and the cell, and located at the first stepped portion 33, the support member being made of an insulating material.

[0037] The support is located at the first step 33 and is disposed between the electrode welding part 31 and the battery cell. It can improve the stability of the connection position when the current collector 3 is connected to the electrode tab, ensure the contact area between the battery cell and the current collector 3 when the battery cell is placed on the current collector 3, and prevent the battery cell from being damaged due to the small contact area when the battery cell is placed on the current collector 3.

[0038] In one embodiment, the cover plate body 1 is provided with two through holes 11 spaced apart. The pole post 2 includes a first pole post and a second pole post. The first pole post and the second pole post are fixedly connected to the cover plate body 1 through the two through holes 11 respectively. The polarities of the first pole post and the second pole post are opposite. The collector plate 3 includes a first collector plate and a second collector plate. The first collector plate and the second collector plate are spaced apart. The pole post welding part 31 of the first collector plate is connected to the first pole post, and the pole post welding part 31 of the second collector plate is connected to the second pole post. The height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.5mm≤h≤2mm.

[0039] The cover plate body 1 is provided with two through holes 11, which can be connected to the first pole and the second pole respectively. The first collector and the second collector are spaced apart to avoid short circuits and to avoid damage caused by stress pulling during the welding process between the first collector and the second collector.

[0040] In a specific embodiment, both the first and second current collectors are provided with a terminal welding portion 31 and a tab welding portion 32. The tab welding portion 32 of the first current collector is connected to the positive tab of the battery cell, and the first terminal is connected to the terminal welding portion 31 of the first current collector, thus serving as the positive electrode of the cylindrical battery. The tab welding portion 32 of the second current collector is connected to the negative tab of the battery cell, and the second terminal is connected to the terminal welding portion 31 of the second current collector, thus serving as the negative electrode of the cylindrical battery. Specifically, the height difference is the height difference h of the first step portion 33.

[0041] In some embodiments, since the cover plate body 1 is provided with two through holes 11, which are respectively connected to the first pole and the second pole, the pole welding part 31 of the first current collector is connected to the first pole, and the pole welding part 31 of the second current collector is connected to the second pole, the positive and negative poles of the battery cell are provided at one end of the battery cell, that is, at the end of the battery cell facing the cover plate body 1; and the positive and negative poles of the battery cell are spaced apart and are welded to the pole welding parts 32 of the first current collector and the pole welding parts 32 of the second current collector respectively.

[0042] In a specific embodiment, the height difference of the first step portion 33 of the first collector plate can be 0.5mm, 2mm, or 1.2mm. The height difference of the first step portion 33 of the second collector plate can be 0.5mm, 2mm, or 1.2mm.

[0043] In one embodiment, the projection of the core hole on the cover plate body 1 is located between the first pole post and the second pole post, and the height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.5mm≤h≤1.8mm.

[0044] In a specific embodiment, the projection of the core hole on the cover plate body 1 is located between the first pole post and the second pole post. The height difference h of the first collector plate and the height difference h of the second collector plate can both be 0.5mm, 1.8mm, or 1.2mm.

[0045] In one embodiment, the first pole and the second pole are centrally symmetrically distributed on the cover plate body 1, and the height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.5mm≤h≤1.5mm.

[0046] In a specific embodiment, the first pole and the second pole are centrally symmetrically distributed on the cover plate body 1. The height difference h of the first collector plate and the height difference h of the second collector plate can both be 0.5mm, 1.5mm, or 1mm.

[0047] In one embodiment, the minimum distance D between the pole post welding portion 31 of the first collector plate and the pole lug welding portion 32 of the second collector plate satisfies 0.7mm≤D≤30mm.

[0048] In a specific embodiment, the minimum distance D between the pole post welding part 31 of the first collector disk and the pole lug welding part 32 of the second collector disk can be 0.7mm, 30mm, or 15mm.

[0049] In one embodiment, the minimum distance E between the tab welding portion 32 of the first collector plate and the pole welding portion 31 of the second collector plate satisfies 0.7mm≤E≤30mm.

[0050] In a specific embodiment, the minimum distance E between the tab welding portion 32 of the first collector plate and the pole welding portion 31 of the second collector plate can be 0.7mm, 30mm, or 15mm.

[0051] In one embodiment, the ratio B of the shortest distance between the tab welding portion 32 of the first current collector and the tab welding portion 32 of the second current collector to the radial width of the battery cell satisfies 1 / 30≤B≤1 / 2.

[0052] The larger the ratio B between the shortest distance 32 of the tabs of the first and second current collectors and the radial width of the battery cell, the smaller the radial width of the battery cell. When the radial width of the battery cell is too small, the insulation performance cannot be guaranteed. Conversely, the smaller the ratio B between the shortest distance 32 of the tabs of the first and second current collectors and the radial width of the battery cell, the larger the radial width of the battery cell. When the radial width of the battery cell is too large, the area of ​​the tabs of the current collectors 3 will be reduced, thus reducing the welding area between the current collectors 3 and the tabs of the battery cell, and affecting the current flow area.

[0053] In one specific embodiment, the ratio B of the shortest distance between the tab welding portion 32 of the first current collector and the tab welding portion 32 of the second current collector to the radial width of the battery cell is 1 / 30.

[0054] In another specific embodiment, the ratio B of the shortest distance between the tab welding portion 32 of the first current collector and the tab welding portion 32 of the second current collector to the radial width of the battery cell is 1 / 2.

[0055] In some embodiments, the shortest distance between the tab welding portion 32 of the first collector plate and the tab welding portion 32 of the second collector plate ranges from 1 mm to 30 mm. The radial width of the cover plate ranges from 30 mm to 60 mm.

[0056] In one embodiment, the electrode post 2 includes a first electrode post and a second electrode post, which are respectively located at both ends of the battery cell. Both ends of the battery cell are provided with a cover plate body 1. The first electrode post and the second electrode post are fixedly connected to the two cover plate bodies 1 through two through holes 11, and the polarities of the first electrode post and the second electrode post are opposite. Alternatively, one end of the battery cell is provided with a cover plate body 1, the first electrode post is fixedly connected to the cover plate body 1 through the through hole 11, and the other end of the battery cell has a connecting hole on the battery casing. The projection of the winding hole on the battery casing is offset from the connecting hole, and the second electrode post is fixedly connected to the battery casing through the connecting hole. The current collector 3 includes a first current collector plate and a second current collector plate. The electrode post welding part 31 of the first current collector plate is connected to the first electrode post, and the electrode post welding part 31 of the second current collector plate is connected to the second electrode post. The height difference h of the first current collector plate and the height difference h of the second current collector plate both satisfy 0.1mm ≤ h ≤ 1mm.

[0057] When the first terminal and the second terminal are located at the two ends of the battery cell, the height difference between the first step portion 33 of the first current collector and the first step portion 33 of the second current collector do not need to be set too large, so as to avoid occupying too much space in the length direction of the battery cell.

[0058] In a specific embodiment, the first terminal and the second terminal are located at the two ends of the battery cell, and the height difference h of the first current collector and the height difference h of the second current collector can both be 0.1mm, or the height difference h can also be 1mm, or the height difference h can also be 0.5mm.

[0059] In one embodiment, in the arrangement direction of the cover plate assembly and the battery cell, the ratio A of the height of the first step portion 33 to the height of the battery cell satisfies 0.01≤A≤0.03; the height difference h of the first step portion 33 ranges from 0.1mm to 2mm, and the height of the battery cell ranges from 70mm to 200mm.

[0060] In a specific embodiment, in the arrangement direction of the cover plate assembly and the battery cell, the ratio A of the height of the first step portion 33 to the height of the battery cell can be 0.01, 0.03, or 0.02; the height difference h of the first step portion 33 can be 0.1 mm, 2 mm, or 1 mm; and the height of the battery cell can be 70 mm, 200 mm, or 135 mm.

[0061] In one embodiment, the ratio C of the area of ​​the electrode tab welding portion 32 to the area of ​​the electrode post welding portion 31 on each of the current collectors 3 satisfies 0.5≤C≤4.

[0062] If the ratio C between the area of ​​the tab welding portion 32 and the area of ​​the pole welding portion 31 on each current collector 3 is too small, then the area of ​​the pole welding portion 31 on the current collector 3 is too small relative to the area of ​​the tab welding portion 32, resulting in an imbalance in the current carrying capacity of the pole welding portion 31 and the tab welding portion 32. If the ratio C between the area of ​​the tab welding portion 32 and the area of ​​the pole welding portion 31 is too large, then the area of ​​the pole welding portion 31 is too small relative to the area of ​​the tab welding portion 32, leading to a reduction in the current carrying capacity of the pole welding portion 31. Furthermore, it causes the distance between the tab welding portions 32 of the first current collector and the tab welding portions 32 of the second current collector to be too small, resulting in them being too close together and affecting the insulation.

[0063] In one specific embodiment, on each of the collector plates 3, the ratio C of the area of ​​the tab welding portion 32 to the area of ​​the pole welding portion 31 is 0.5.

[0064] In another specific embodiment, on each of the collector plates 3, the ratio C of the area of ​​the tab welding portion 32 to the area of ​​the pole welding portion 31 is 4.

[0065] In some embodiments, on each of the current collectors 3, the ratio C of the area of ​​the tab welding portion 32 to the area of ​​the pole welding portion 31 is 1, and the area of ​​the tab welding portion 32 of the first current collector is 10 mm². 2 The area of ​​the electrode tab welding part 32 of the second collector plate is 8mm². 2 .

[0066] In one embodiment, the system further includes an injection molded part 4, which is connected to the cover plate body 1. The manifold 3 is disposed between the injection molded part 4 and the cover plate body 1. The injection molded part 4 is provided with a clearance hole 41, and the pole welding part 31 is disposed at the clearance hole 41.

[0067] The current collector 3 is disposed between the injection molded part 4 and the cover plate body 1. The injection molded part 4 can enhance the connection stability between the current collector 3 and the cover plate body 1; and can also expose the electrode welding part 31 through the avoidance hole 41 to ensure the connection between the electrode welding part 32 and the electrode of the battery cell, and enhance the connection convenience between the electrode welding part 31 and the electrode 2.

[0068] Optionally, the pole post welding portion 31 and the pole lug welding portion 32 are disposed at the clearance hole 41.

[0069] In one specific embodiment, the cover plate body 1 is provided with two through holes 11 spaced apart. The pole post 2 includes a first pole post and a second pole post, which are respectively fixedly connected to the cover plate body 1 through the two through holes 11. The collector plate 3 includes a first collector plate and a second collector plate, which are spaced apart. The pole post welding part 31 of the first collector plate is connected to the first pole post, and the pole post welding part 31 of the second collector plate is connected to the second pole post. The injection molded part 4 is provided with two clearances. Two clearance holes 41 are provided at intervals. The electrode welding part 31 and the electrode welding part 32 of the first collector plate are exposed through one clearance hole 41, and the electrode welding part 31 and the electrode welding part 32 of the second collector plate are exposed through the other clearance hole 41; or the electrode welding part 32 of the first collector plate is exposed through one clearance hole 41, and the electrode welding part 32 of the second collector plate is exposed through the other clearance hole 41. Due to the insulation characteristics of the injection molded part 4 itself, the injection molded part 4 between the two clearance holes 41 can play an insulating separation role between the first collector plate and the second collector plate.

[0070] In one embodiment, the collector plate 3 is further provided with a connecting part 34, the electrode welding part 31 and the connecting part 34 are respectively provided at both ends of the electrode welding part 32, a second step part 35 is provided between the connecting part 34 and the electrode welding part 32, the minimum distance between the connecting part 34 and the battery cell is less than the maximum distance between the electrode welding part 32 and the battery cell, and at least part of the connecting part 34 is connected between the injection molded part 4 and the cover plate body 1.

[0071] In one embodiment, the collector plate 3 is further provided with a connecting part 34, the electrode welding part 31 and the connecting part 34 are respectively provided at both ends of the electrode welding part 32, a second step part 35 is provided between the connecting part 34 and the electrode welding part 32, the minimum distance between the connecting part 34 and the battery cell is greater than the maximum distance between the electrode welding part 32 and the battery cell, and at least part of the connecting part 34 is connected between the injection molded part 4 and the cover plate body 1.

[0072] The connection part 34 can enhance the stability of the current collector 3 through the injection molded part 4 and the cover plate body 1. Furthermore, the second step part 35 can ensure that the electrode welding part 32, which is spaced apart from the cover plate body 1, has a relatively flat surface, enhancing the welding effect between the electrode welding part 32 and the electrode, and also ensuring the contact area between the electrode welding part 32 and the battery cell.

[0073] In one embodiment, the connecting part 34 is provided with a positioning hole 341, and the injection molded part 4 is provided with a positioning post 42, which is positioned and inserted into the positioning hole 341.

[0074] The positioning hole 341 and the positioning post 42 are connected to position and fix the collector plate 3 during connection, ensuring a good connection effect. The positioning hole 341 is provided on the connecting part 34, and the positioning post 42 is provided on the injection molded part 4. The positioning hole 341 and the positioning post 42 can also be hidden, which also avoids occupying more space.

[0075] In one embodiment, the positioning hole 341 is at least two, and the at least two positioning holes 341 are spaced apart.

[0076] At least two positioning holes 341 are spaced apart to prevent the collector plate 3 from rotating and to ensure a better positioning effect.

[0077] In a specific embodiment, at least two positioning holes 341 are distributed at radial intervals along the collector plate 3.

[0078] Optionally, there are two positioning holes 341, both of which are round holes and are distributed at intervals along the radial direction of the collector plate 3. The shape of the positioning post 42 matches the shape of the positioning hole 341.

[0079] In one specific embodiment, the cover plate body 1 is provided with two through holes 11 spaced apart. The pole post 2 includes a first pole post and a second pole post, which are fixedly connected to the cover plate body 1 through the two through holes 11 respectively. The collector plate 3 includes a first collector plate and a second collector plate, which are spaced apart. The pole post welding part 31 of the first collector plate is connected to the first pole post, and the pole post welding part 31 of the second collector plate is connected to the second pole post. The connecting part 34 of the first collector plate is opposite to and spaced apart from the pole post welding part 31 of the second collector plate; the connecting part 34 of the second collector plate is opposite to and spaced apart from the pole post welding part 31 of the first collector plate. The tab welding part 32 is fan-shaped, and the center of the tab welding part 32 of the first collector plate coincides with the center of the tab welding part 32 of the second collector plate.

[0080] In a specific embodiment, the cover plate assembly further includes a lower insulating member 5, which is disposed between the cover plate body 1 and the collector plate 3. The lower insulating member 5 is provided with a through hole, which is coaxial with and corresponding to the through hole 11. The pole post 2 is fixedly connected to the through hole and the through hole 11.

[0081] In a further embodiment, the pole post 2 is provided with a first limiting flange and a second limiting flange at both ends, and the cover plate body 1 and the lower insulating member 5 are disposed between the first limiting flange and the second limiting flange. The lower insulating member 5 is plate-shaped, and the cover plate assembly also includes a first sealing member 6 and a second sealing member 7. The first sealing member 6 is sleeved on the outer periphery of the pole post 2 and sandwiched between the lower insulating member 5 and the first limiting flange; the second sealing member 7 is sleeved on the outer periphery of the pole post 2 and sandwiched between the cover plate body 1 and the second limiting flange.

[0082] In some embodiments, the first step portion 33 and the pole welding portion 31 are smoothly transitioned to avoid sharp edges between the first step portion 33 and the pole welding portion 31, and to prevent sharp edges from damaging the cover plate body 1 and the lower insulating member 5 during the connection process.

[0083] In some embodiments, the first step portion 33 and the electrode welding portion 32 are smoothly transitioned to avoid sharp edges between the first step portion 33 and the electrode welding portion 32, and to prevent sharp edges from damaging the battery cell during the connection process.

[0084] Although embodiments of this application 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 this application, and all such modifications and variations fall within the scope defined by this application.

Claims

1. A cylindrical battery, characterized by comprising: The battery includes a cover plate assembly and a battery cell, the battery cell including a winding core hole; the cover plate assembly includes: The cover plate body (1) is provided with a through hole (11), and the projection of the core hole on the cover plate body (1) is offset from the through hole (11); The pole post (2) is at least partially inserted into the through hole (11), and the pole post (2) is fixedly connected to the cover plate body (1) through the through hole (11); The collector plate (3) includes a pole welding part (31) and a tab welding part (32). The pole welding part (31) is welded to the pole (2). A first step part (33) is provided between the tab welding part (32) and the pole welding part (31). In the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the pole welding part (31) and the battery cell is less than the maximum distance between the tab welding part (32) and the battery cell. The ratio A of the height of the first step part (33) to the height of the battery cell satisfies 0.01≤A≤0.

03.

2. The cylindrical battery according to claim 1, characterized by, In the arrangement direction of the cover plate assembly and the battery cell, the height difference h of the first step portion (33) is within the range of 0.1mm≤h≤2mm.

3. The cylindrical battery according to claim 2, characterized by, The cover plate body (1) is provided with two through holes (11) spaced apart. The pole (2) includes a first pole and a second pole. The first pole and the second pole are located at one end of the battery cell. The first pole and the second pole are fixedly connected to the cover plate body (1) through the two through holes (11). The polarities of the first pole and the second pole are opposite. The current collector (3) includes a first current collector and a second current collector. The first current collector and the second current collector are spaced apart. The pole welding part (31) of the first current collector is connected to the first pole. The pole welding part (31) of the second current collector is connected to the second pole. The height difference h of the first current collector and the height difference h of the second current collector both satisfy 0.5mm≤h≤2mm.

4. The cylindrical battery according to claim 2, characterized by, The electrode post (2) includes a first electrode post and a second electrode post, which are located at both ends of the battery cell. Both ends of the battery cell are provided with the cover plate body (1). The first electrode post and the second electrode post are fixedly connected to the two cover plate bodies (1) through two through holes (11). The polarities of the first electrode post and the second electrode post are opposite. Alternatively, one end of the battery cell is provided with the cover plate body (1), and the first electrode post is fixedly connected to the cover plate body (1) through the through hole (11). The other end of the battery cell is provided with a connection hole on the battery casing. The projection of the core hole on the battery casing is offset from the connection hole. The second electrode post is fixedly connected to the battery casing through the connection hole. The collector plate (3) includes a first collector plate and a second collector plate. The pole welding part (31) of the first collector plate is connected to the first pole, and the pole welding part (31) of the second collector plate is connected to the second pole. The height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.1mm≤h≤1mm.

5. The cylindrical battery according to claim 3, characterized by The projection of the core hole on the cover plate body (1) is located between the first pole post and the second pole post. The height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.5mm≤h≤1.8mm.

6. The cylindrical battery according to claim 5, characterized by The first pole and the second pole are centrally symmetrically distributed on the cover plate body (1). The height difference h of the first collector plate and the height difference h of the second collector plate both satisfy 0.5mm≤h≤1.5mm.

7. The cylindrical battery according to any one of claims 3 or 5 or 6, characterized in that, The ratio B of the shortest distance between the electrode lug welding part (32) of the first collector plate and the electrode lug welding part (32) of the second collector plate to the radial width of the cover plate satisfies 1 / 30≤B≤1 / 2.

8. The cylindrical battery according to any one of claims 3 or 5 or 6, characterized in that, On each of the collector plates (3), the ratio C of the area of ​​the electrode lug welding part (32) to the area of ​​the electrode post welding part (31) satisfies 0.5≤C≤4.

9. The cylindrical battery according to any one of claims 3 or 5 or 6, characterized in that, The minimum distance D between the pole post welding part (31) of the first collector plate and the pole lug welding part (32) of the second collector plate satisfies 0.7mm≤D≤30mm.

10. The cylindrical battery according to any one of claims 3 or 5 or 6, characterized in that, The minimum distance E between the electrode lug welding part (32) of the first collector plate and the electrode post welding part (31) of the second collector plate satisfies 0.7mm≤E≤30mm.

11. The cylindrical battery according to any one of claims 1 to 6, characterized by, The pole post (2) is provided with a groove (21); the pole post welding part (31) is provided with a protrusion (311); at least part of the protrusion (311) is disposed in the groove (21) and welded to the pole post (2).

12. The cylindrical battery according to any one of claims 1 to 6, characterized by, It also includes a support member disposed between the electrode welding portion (31) and the battery cell, and located at the first step portion (33), the support member being made of insulating material.

13. The cylindrical battery according to any one of claims 1 to 12, wherein the height of the cell ranges from 70 mm to 200 mm.

14. The cylindrical battery according to any one of claims 1 to 13, wherein the radial width of the cover plate body (1) is in the range of 30mm-60mm.

15. The cylindrical battery according to any one of claims 1 to 14, further comprising an injection molded part (4), the injection molded part (4) being connected to the cover plate body (1), the current collector (3) being disposed between the injection molded part (4) and the cover plate body (1), the injection molded part (4) being provided with a clearance hole (41), and the electrode welding part (31) being disposed at the clearance hole (41).

16. The cylindrical battery according to claim 15, wherein the injection molded part (4) is provided with two clearance holes (41), the two clearance holes (41) are spaced apart, the electrode welding part (31) of the first current collector and the electrode welding part (32) are exposed through one of the clearance holes (41), and the electrode welding part (31) of the second current collector and the electrode welding part (32) are exposed through the other clearance hole (41); or the electrode welding part (32) of the first current collector is exposed through one of the clearance holes (41), and the electrode welding part (32) of the second current collector is exposed through the other clearance hole (41).

17. The cylindrical battery according to claim 15, wherein the current collector (3) is further provided with a connecting part (34), the electrode welding part (31) and the connecting part (34) are respectively provided at both ends of the electrode welding part (32), a second step part (35) is provided between the connecting part (34) and the electrode welding part (32), the minimum distance between the connecting part (34) and the cell is greater than the maximum distance between the electrode welding part (32) and the cell, and at least part of the connecting part (34) is connected between the injection molded part (4) and the cover plate body (1).

18. The cylindrical battery according to claim 17, wherein the connecting part (34) is provided with a positioning hole (341), and the injection molded part (4) is provided with a positioning post (42), wherein the positioning post (42) is positioned and inserted into the positioning hole (341).

19. The cylindrical battery according to claim 3, wherein the tab welding part 32 is fan-shaped, and the center of the tab welding part (32) of the first current collector coincides with the center of the tab welding part (32) of the second current collector.

20. The cylindrical battery according to any one of claims 1 to 13, wherein the first stepped portion (33) and the electrode welding portion (31) have a smooth transition.

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