Cylindrical battery

Abstract

The present invention relates to the technical field of cylindrical batteries, and discloses a cylindrical battery, including a cover plate assembly and a battery cell, wherein the cover plate assembly includes: a cover plate body is provided with a through hole, and the projection of the core winding hole on the cover plate body is staggered with the through hole; at least part of the pole is penetrated in the through hole, and the pole is fixedly connected to the cover plate body through the through hole; the current collector includes a pole welding part and a pole ear welding part, and the pole welding part is welded to the pole; a first step portion is provided between the pole ear welding part and the pole welding part, and in the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the pole welding part and the battery cell is less than the maximum distance between the pole ear welding part and the battery cell. Due to the provision of the first step portion, the cylindrical battery of the present invention can use a support or a fixture at the first step portion to resist the current collector when the current collector and the pole are welded, so as to facilitate the welding of the pole and the current collector.

Description

Technical Field

[0001] The present invention relates to the technical field of cylindrical batteries, and in particular to cylindrical batteries. Background Art

[0002] In some cylindrical batteries, the winding core hole of the cylindrical battery and the position of the pole are set correspondingly. During welding, the ejector pin is pushed up through the winding core hole to limit the protrusion and groove, which is convenient for welding the pole and the collector plate. However, in some cylindrical batteries, the positions of the winding core hole of the cylindrical battery and the groove of the pole are staggered, resulting in the collector plate and the pole being easily cold during welding, and the battery cell is easily damaged during the matching. Summary of the invention

[0003] In view of this, the present invention provides a cylindrical battery to solve the problem that a current collector and a pole are prone to cold welding during welding, and the pole or the current collector is prone to damage during fitting.

[0004] The present invention provides a cylindrical battery, comprising a cover plate assembly and a battery cell, wherein the battery cell comprises a winding hole; the cover plate assembly comprises:

[0005] The cover plate body is provided with a through hole, and the projection of the winding core hole on the cover plate body and the through hole are staggered with each other;

[0006] A pole, at least partly passed through the through hole, and the pole is fixedly connected to the cover plate body through the through hole;

[0007] A current collecting plate comprises a pole welding portion and a pole lug welding portion, wherein the pole welding portion is welded to the pole; a first step portion is provided between the pole lug welding portion and the pole welding portion, and in the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the pole welding portion and the battery cell is smaller than the maximum distance between the pole lug welding portion and the battery cell.

[0008] Beneficial effect: Since the through hole connecting the pole and the winding hole of the battery cell are staggered, the current collector and the pole cannot be positioned by the ejector pin passing through the winding hole when welding. Therefore, in the present embodiment, the first step portion is provided between the pole welding portion and the pole lug welding portion. When the current collector and the pole are welded, a support or a tooling fixture can be used at the first step portion to support the current collector to support the current collector when the current collector and the pole are welded, so that the pole welding portion is tightly connected to the pole, which is convenient for welding the pole and the current collector, avoiding the occurrence of cold welding when the current collector and the pole are welded, and avoiding damage to the battery cell during fitting. At the same time, due to the provision of the first step portion, the minimum distance between the pole welding portion and the battery cell is smaller than the maximum distance between the pole lug welding portion and the battery cell, and a height difference is formed between the pole welding portion and the pole lug welding portion, which can also improve the injection efficiency and the exhaust performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 A partial schematic diagram of a cover plate assembly of a cylindrical battery from one perspective according to an embodiment of the present invention;

[0011] Figure 2 A partial schematic diagram of a cover plate assembly of a cylindrical battery from another perspective according to an embodiment of the present invention;

[0012] Figure 3 A schematic diagram of a cover plate assembly of a cylindrical battery according to an embodiment of the present invention;

[0013] Figure 4 An exploded schematic diagram of a cover plate assembly of a cylindrical battery according to an embodiment of the present invention;

[0014] Figure 5 Another exploded schematic diagram of a cover plate assembly of a cylindrical battery according to an embodiment of the present invention;

[0015] Figure 6 This is another exploded schematic diagram of a cover plate assembly of a cylindrical battery according to an embodiment of the present invention;

[0016] Figure 7 A schematic diagram of a current collecting plate of a cylindrical battery from one perspective according to an embodiment of the present invention;

[0017] Figure 8 This is a schematic diagram of another perspective of a current collecting plate of a cylindrical battery according to an embodiment of the present invention.

[0018] Description of reference numerals:

[0019] 1. Cover plate body; 11. Through hole; 2. Pole; 21. Groove; 3. Collector; 31. Pole welding part; 311. Protrusion; 32. Ear welding part; 33. First step part; 34. Connecting part; 341. Positioning hole; 35. Second step part; 4. Injection molded part; 41. Avoidance hole; 42. Positioning column; 5. Lower insulating part; 6. First sealing part; 7. Second sealing part. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0021] Combine the following Figures 1 to 8 , describing an embodiment of the present invention.

[0022] According to an embodiment of the present invention, a cylindrical battery is provided, comprising a cover plate assembly and a battery cell, wherein the battery cell comprises a winding hole; the cover plate assembly comprises a cover plate body 1, a pole 2 and a current collecting plate 3; the cover plate body 1 is provided with a through hole 11, and the projection of the winding hole on the cover plate body 1 is staggered with the through hole 11; at least part of the pole 2 is passed through the through hole 11, and the pole 2 is fixedly connected to the cover plate body 1 through the through hole 11; the current collecting plate 3 comprises a pole welding portion 31 and a pole ear welding portion 32, and the pole welding portion 31 is welded to the pole 2; a first step portion 33 is provided between the pole ear welding portion 32 and the pole welding portion 31, and in the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the pole welding portion 31 and the battery cell is smaller than the maximum distance between the pole ear welding portion 32 and the battery cell.

[0023] Since the through hole 11 connecting the pole 2 and the winding hole of the battery cell are staggered, the current collecting plate 3 and the pole 2 cannot be positioned by the ejector pin passing through the winding hole when welding. Therefore, in the present embodiment, the first step portion 33 is provided between the pole welding portion 31 and the pole ear welding portion 32. When the current collecting plate 3 and the pole 2 are welded, a support or a tooling fixture can be used at the first step portion 33 to support the current collecting plate 3, so that the pole welding portion 31 is tightly connected to the pole 2, which is convenient for welding the pole 2 and the current collecting plate 3, avoiding the occurrence of cold welding when the current collecting plate 3 and the pole 2 are welded, and avoiding damage to the battery cell during fitting. At the same time, due to the provision of the first step portion 33, the minimum distance between the pole welding portion 31 and the battery cell is less than the maximum distance between the pole ear welding portion 32 and the battery cell, and a height difference is formed between the pole welding portion 31 and the pole ear welding portion 32, which can also improve the injection efficiency and the exhaust performance of the battery cell.

[0024] In one embodiment, a groove 21 is provided on the pole 2 ; a protrusion 311 is provided on the pole welding portion 31 ; at least a portion of the protrusion 311 is disposed in the groove 21 and welded to the pole 2 .

[0025] In one embodiment, in the arrangement direction of the cap plate assembly and the battery cells, the height difference h of the first step portion 33 satisfies the range of 0.1 mm≤h≤2 mm.

[0026] The height difference of the first step portion 33 is in the range of 0.1mm to 2mm, which is not only convenient for supporting when welding the collector plate 3 and the pole 2, but also avoids serious waste of internal space of the battery due to excessive height difference; and when this height difference is in the range of 0.1mm to 2mm, it is convenient for exhausting the battery during thermal runaway and for the infiltration of the electrolyte during liquid injection.

[0027] In a specific embodiment, in the arrangement direction of the cap plate assembly and the battery cells, the height difference h of the first step portion 33 is 0.1 mm.

[0028] In another specific embodiment, in the arrangement direction of the cap plate assembly and the battery cells, the height difference h of the first step portion 33 is 2 mm.

[0029] In yet another specific embodiment, in the arrangement direction of the cap plate assembly and the battery cells, the height difference h of the first step portion 33 is 1 mm.

[0030] In one embodiment, in the arrangement direction of the cap plate assembly and the battery cell, a ratio A of the height of the first step portion 33 to the height of the battery cell satisfies 0.01≤A≤0.03.

[0031] 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.

[0032] The ratio A of the height of the first step portion 33 to the height of the battery cell cannot be too high, otherwise it will affect the height of the battery cell of the cylindrical battery, and further affect the capacity of the cylindrical battery; the ratio A of the height of the first step portion 33 to the height of the battery cell cannot be too low, otherwise it will affect the injection efficiency of the cylindrical battery and the exhaust performance of the battery cell; therefore, when 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 of the battery cell of the cylindrical battery and the capacity of the cylindrical battery can be guaranteed, and the injection efficiency of the cylindrical battery and the exhaust performance of the battery cell will not be affected.

[0033] In a specific embodiment, in the arrangement direction of the cover plate assembly and the battery cell, a ratio A of the height of the first step portion 33 to the height of the battery cell may be 0.01, 0.03, or 0.02.

[0034] In a specific embodiment, the height of the battery cell may be 70 mm, 200 mm, or 135 mm.

[0035] In one embodiment, the cylindrical battery further includes a support member, which is disposed between the pole welding portion 31 and the battery cell and located at the first step portion 33 , and is made of an insulating material.

[0036] The support member is located at the first step portion 33 and is arranged between the pole welding portion 31 and the battery cell, which can improve the stability of the connection position when the current collecting plate 3 is connected to the pole ear, ensure the contact area between the battery cell and the current collecting plate 3 when the battery cell is placed on the current collecting plate 3, and prevent the battery cell from being crushed due to the small contact area when the battery cell is placed on the current collecting plate 3.

[0037] In one embodiment, two through holes 11 are provided on the cover body 1 at intervals, the pole 2 includes a first pole and a second pole, the first pole and the second pole are fixedly connected to the cover body 1 through the two through holes 11 respectively, and the polarities of the first pole and the second pole are opposite; the current collecting plate 3 includes a first current collecting plate and a second current collecting plate, the first current collecting plate and the second current collecting plate are arranged at intervals, the pole welding portion 31 of the first current collecting plate is connected to the first pole, and the pole welding portion 31 of the second current collecting plate is connected to the second pole; the height difference h of the first current collecting plate and the height difference h of the second current collecting plate both satisfy 0.5mm≤h≤2mm.

[0038] The cover body 1 is provided with two through holes 11, which can be connected to the first pole and the second pole respectively. The first current collecting disc and the second current collecting disc are spaced apart to avoid short circuit and stress pulling between the first current collecting disc and the second current collecting disc during welding, thereby avoiding damage and other problems.

[0039] In a specific embodiment, both the first current collecting disk and the second current collecting disk are provided with a pole welding portion 31 and a pole tab welding portion 32. The pole tab welding portion 32 of the first current collecting disk is connected to the positive pole tab of the battery cell, and the first pole is connected to the pole tab welding portion 31 of the first current collecting disk, thereby serving as the positive pole of the cylindrical battery; the pole tab welding portion 32 of the second current collecting disk is connected to the negative pole tab of the battery cell, and the second pole is connected to the pole tab welding portion 31 of the second current collecting disk, thereby serving as the negative pole of the cylindrical battery. Specifically, the height difference is the height difference h of the first step portion 33.

[0040] In a preferred embodiment, since two through holes 11 are provided on the cover body 1, respectively connecting the first pole and the second pole, the pole welding portion 31 of the first current collecting disk is connected to the first pole, and the pole welding portion 31 of the second current collecting disk is connected to the second pole. Therefore, the positive pole ear of the battery cell and the negative pole ear of the battery cell are arranged at one end of the battery cell, that is, at the end of the battery cell facing the cover body 1; and the positive pole ear of the battery cell and the negative pole ear of the battery cell are arranged at intervals, and are respectively welded to the pole ear welding portion 32 of the first current collecting disk and the pole ear welding portion 32 of the second current collecting disk.

[0041] In a specific embodiment, the height difference of the first step portion 33 of the first current collecting plate can be 0.5 mm, 2 mm, or 1.2 mm. The height difference of the first step portion 33 of the second current collecting plate can be 0.5 mm, 2 mm, or 1.2 mm.

[0042] In one embodiment, the projection of the winding core hole on the cover body 1 is located between the first pole and the second pole, and the height difference h of the first current collecting disk and the height difference h of the second current collecting disk both satisfy 0.5 mm ≤ h ≤ 1.8 mm.

[0043] In a specific embodiment, the projection of the winding core hole on the cover body 1 is located between the first pole and the second pole, and the height difference h of the first collecting disk and the height difference h of the second collecting disk can be 0.5 mm, or 1.8 mm, or 1.2 mm.

[0044] 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 current collecting plate and the height difference h of the second current collecting plate both satisfy 0.5 mm≤h≤1.5 mm.

[0045] In a specific embodiment, the first pole and the second pole are centrally symmetrically distributed on the cover body 1, and the height difference h of the first current collecting plate and the height difference h of the second current collecting plate can be 0.5 mm, or 1.5 mm, or 1 mm.

[0046] In one embodiment, the minimum distance D between the pole welding portion 31 of the first current collecting plate and the pole tab welding portion 32 of the second current collecting plate satisfies 0.7 mm≤D≤30 mm.

[0047] In a specific embodiment, the minimum distance D between the pole welding portion 31 of the first current collecting disk and the pole tab welding portion 32 of the second current collecting disk may be 0.7 mm, 30 mm, or 15 mm.

[0048] In one embodiment, the minimum distance E between the pole tab welding portion 32 of the first current collecting disk and the pole welding portion 31 of the second current collecting disk satisfies 0.7 mm≤E≤30 mm.

[0049] In a specific embodiment, the minimum distance E between the pole tab welding portion 32 of the first current collecting disk and the pole welding portion 31 of the second current collecting disk may be 0.7 mm, 30 mm, or 15 mm.

[0050] In one embodiment, a ratio B of the shortest distance between the tab welding portion 32 of the first current collecting disk and the tab welding portion 32 of the second current collecting disk to the radial width of the battery cell satisfies 1 / 30≤B≤1 / 2.

[0051] The larger the ratio B of the shortest distance between the lug welding portion 32 of the first current collector and the lug welding portion 32 of the second current collector to the radial width of the battery cell, the smaller the radial width of the battery cell is. When the radial width of the battery cell is too small, the insulation performance cannot be guaranteed. The smaller the ratio B of the shortest distance between the lug welding portion 32 of the first current collector and the lug welding portion 32 of the second current collector to the radial width of the battery cell is, the larger the radial width of the battery cell is. When the radial width of the battery cell is too large, the area of ​​the lug welding portion 32 of the current collector 3 will be reduced, and the welding area between the current collector 3 and the lug of the battery cell will be reduced, which will affect the flow area.

[0052] In a specific embodiment, a ratio B of the shortest distance between the tab welding portion 32 of the first current collecting disk and the tab welding portion 32 of the second current collecting disk to the radial width of the battery cell is 1 / 30.

[0053] In another specific embodiment, a ratio B of the shortest distance between the tab welding portion 32 of the first current collecting disk and the tab welding portion 32 of the second current collecting disk to the radial width of the battery cell is 1 / 2.

[0054] In a preferred embodiment, the shortest distance between the first current collecting plate's tab welding portion 32 and the second current collecting plate's tab welding portion 32 is in the range of 1 mm to 30 mm. The radial width of the cover plate is in the range of 30 mm to 60 mm.

[0055] In one embodiment, the pole 2 includes a first pole and a second pole, the first pole and the second pole are respectively located at the two ends of the battery cell, the two ends of the battery cell are provided with the cover body 1, the first pole and the second pole are respectively fixedly connected to the two cover bodies 1 through the two through holes 11, and the polarities of the first pole and the second pole are opposite. Alternatively, the cover body 1 is provided at one end of the battery cell, the first pole is fixedly connected to the cover body 1 through the through hole 11, a connection hole is provided on the battery shell at the other end of the battery cell, the projection of the winding hole on the battery shell is staggered with the connection hole, and the second pole is fixedly connected to the battery shell through the connection hole; the collector 3 includes a first collector and a second collector, the pole welding portion 31 of the first collector is connected to the first pole, and the pole welding portion 31 of the second collector is connected to the second pole; the height difference h of the first collector and the height difference h of the second collector both meet 0.1mm≤h≤1mm.

[0056] When the first pole and the second pole are respectively located at both ends of the battery cell, the height difference of the first step portion 33 of the first current collecting disk and the height difference of the first step portion 33 of the second current collecting disk do not need to be set large to avoid occupying too much space in the length direction of the battery cell.

[0057] In a specific embodiment, the first pole and the second pole are respectively located at two ends of the battery cell, and the height difference h of the first current collecting disk and the height difference h of the second current collecting disk can be 0.1 mm, or the height difference h can be 1 mm, or the height difference h can be 0.5 mm.

[0058] In one embodiment, in the arrangement direction of the cover plate assembly and the battery cell, a ratio A of the height of the first step portion 33 to the height of the battery cell satisfies 0.01≤A≤0.03; a height difference h of the first step portion 33 ranges from 0.1 mm to 2 mm, and a height range of the battery cell ranges from 70 mm to 200 mm.

[0059] 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 may be 0.01, 0.03, or 0.02; the height difference h of the first step portion 33 may be 0.1 mm, 2 mm, or 1 mm; the height of the battery cell may be 70 mm, 200 mm, or 135 mm.

[0060] In one embodiment, on each of the current collecting plates 3 , a ratio C of the area of ​​the pole tab welding portion 32 to the area of ​​the pole welding portion 31 satisfies 0.5≤C≤4.

[0061] On each current collecting disk 3, if the ratio C of the area of ​​the pole tab welding part 32 to the area of ​​the pole welding part 31 is too small, the area of ​​the pole welding part 31 of the current collecting disk 3 is too small relative to the area of ​​the pole tab welding part 32, and the current flow capacity of the pole welding part 31 and the current flow capacity of the pole tab welding part 32 are unbalanced; if the ratio C of the area of ​​the pole tab welding part 32 to the area of ​​the pole welding part 31 is too large, the area of ​​the pole welding part 31 is too small relative to the area of ​​the pole tab welding part 32, resulting in a reduction in the current flow capacity of the pole welding part 31, and the distance between the pole tab welding part 32 of the first current collecting disk and the pole tab welding part 32 of the second current collecting disk is too small, and the two are too close to each other, so that the insulation is affected.

[0062] In a specific embodiment, on each of the current collecting plates 3 , a ratio C of the area of ​​the pole tab welding portion 32 to the area of ​​the pole welding portion 31 is 0.5.

[0063] In another specific embodiment, on each of the current collecting plates 3 , a ratio C of the area of ​​the pole tab welding portion 32 to the area of ​​the pole welding portion 31 is 4.

[0064] In a preferred embodiment, on each current collecting plate 3, the ratio C of the area of ​​the pole tab welding portion 32 to the area of ​​the pole column welding portion 31 is 1, and the area of ​​the pole tab welding portion 32 of the first current collecting plate is 10 mm 2 The area of ​​the second collector plate's tab welding portion 32 is 8 mm 2 .

[0065] In one embodiment, an injection molded part 4 is further included, wherein the injection molded part 4 is connected to the cover body 1 , the collecting plate 3 is arranged between the injection molded part 4 and the cover body 1 , an avoidance hole 41 is provided on the injection molded part 4 , and the pole welding part 31 is arranged at the avoidance hole 41 .

[0066] The current collecting plate 3 is arranged between the injection molded part 4 and the cover plate body 1. The injection molded part 4 can not only enhance the connection stability between the current collecting plate 3 and the cover plate body 1, but also allow the pole welding part 31 to leak out through the avoidance hole 41, thereby ensuring the connection between the pole ear welding part 32 and the pole ear of the battery cell, and enhancing the connection convenience between the pole welding part 31 and the pole 2.

[0067] Preferably, the pole welding portion 31 and the pole tab welding portion 32 are arranged at the avoidance hole 41 .

[0068] In a specific embodiment, the cover body 1 is provided with two through holes 11 at intervals, the pole 2 includes a first pole and a second pole, the first pole and the second pole are respectively fixedly connected to the cover body 1 through the two through holes 11; the current collecting plate 3 includes a first current collecting plate and a second current collecting plate, the first current collecting plate and the second current collecting plate are arranged at intervals, the pole welding portion 31 of the first current collecting plate is connected to the first pole, the pole welding portion 31 of the second current collecting plate is connected to the second pole, and the injection molded part 4 is provided with two avoidance Hole 41, two avoidance holes 41 are arranged at intervals, the pole welding part 31 and the pole ear welding part 32 of the first current collecting disk leak out through one avoidance hole 41, and the pole welding part 31 and the pole ear welding part 32 of the second current collecting disk leak out through another avoidance hole 41; or the pole ear welding part 32 of the first current collecting disk leaks out through one avoidance hole 41, and the pole ear welding part 32 of the second current collecting disk leaks out through another avoidance hole 41; due to the insulation characteristics of the injection molded part 4 itself, the injection molded part 4 between the two avoidance holes 41 can play an insulating and separating role between the first current collecting disk and the second current collecting disk.

[0069] In one embodiment, a connecting portion 34 is further provided on the collecting plate 3, the pole welding portion 31 and the connecting portion 34 are respectively arranged at both ends of the pole lug welding portion 32, a second step portion 35 is provided between the connecting portion 34 and the pole lug welding portion 32, the minimum distance between the connecting portion 34 and the battery cell is smaller than the maximum distance between the pole lug welding portion 32 and the battery cell, and at least part of the connecting portion 34 is connected between the injection molded part 4 and the cover plate body 1.

[0070] The setting of the connecting portion 34 can enhance the stability of the collecting plate 3 through the injection molded part 4 and the cover body 1, and the setting of the second step portion 35 can not only make the pole ear welding portion 32 spaced apart from the cover body 1 have a relatively flat surface, enhance the welding effect between the pole ear welding portion 32 and the pole ear, but also ensure the contact area between the pole ear welding portion 32 and the battery cell.

[0071] In one embodiment, a positioning hole 341 is provided on the connecting portion 34 , and a positioning column 42 is provided on the injection molded part 4 . The positioning column 42 is positioned and inserted in the positioning hole 341 .

[0072] The positioning hole 341 and the positioning column 42 are positioned and plugged, so that the current collecting plate 3 can be positioned and fixed when the current collecting plate 3 is connected, thereby ensuring a good connection effect. The connection part 34 is provided with a positioning hole 341, and the injection molded part 4 is provided with a positioning column 42. The positioning hole 341 and the positioning column 42 can also be hidden to avoid taking up more space.

[0073] In one embodiment, there are at least two positioning holes 341 , and at least two positioning holes 341 are spaced apart from each other.

[0074] At least two positioning holes 341 are arranged at intervals, which can prevent the collecting plate 3 from rotating and ensure a better positioning effect.

[0075] In a specific embodiment, at least two positioning holes 341 are spaced apart and distributed along the radial direction of the current collecting plate 3 .

[0076] Preferably, there are two positioning holes 341 , both of which are circular holes and are spaced apart in the radial direction of the current collecting plate 3 , and the shape of the positioning column 42 matches the shape of the positioning hole 341 .

[0077] In a specific embodiment, the cover body 1 is provided with two through holes 11 at intervals, the pole 2 includes a first pole and a second pole, and the first pole and the second pole are fixedly connected to the cover body 1 through the two through holes 11 respectively; the current collecting plate 3 includes a first current collecting plate and a second current collecting plate, the first current collecting plate and the second current collecting plate are arranged at intervals, the pole welding portion 31 of the first current collecting plate is connected to the first pole, and the pole welding portion 31 of the second current collecting plate is connected to the second pole. The connection portion 34 of the first current collecting plate is opposite to and spaced from the pole welding portion 31 of the second current collecting plate; the connection portion 34 of the second current collecting plate is opposite to and spaced from the pole welding portion 31 of the first current collecting plate. The pole tab welding portion 32 is a fan ring, and the center of the pole tab welding portion 32 of the first current collecting plate coincides with the center of the pole tab welding portion 32 of the second current collecting plate.

[0078] In a specific embodiment, the cover assembly also includes a lower insulating member 5, which is arranged between the cover body 1 and the collecting plate 3. The lower insulating member 5 is provided with a through hole, which is coaxial with the through hole 11 and correspondingly arranged. The pole 2 is fixedly connected at the through hole and the through hole 11.

[0079] In a further embodiment, a first limiting flange and a second limiting flange are respectively provided at both ends of the pole 2, and the cover body 1 and the lower insulating member 5 are arranged between the first limiting flange and the second limiting flange. The lower insulating member 5 is plate-shaped, and the cover assembly further 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 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 2 and sandwiched between the cover body 1 and the second limiting flange.

[0080] In a preferred embodiment, a smooth transition is formed between the first step portion 33 and the pole welding portion 31 to avoid sharp edges and corners between the first step portion 33 and the pole welding portion 31, thereby avoiding damage to the cover body 1 and the lower insulating member 5 during the connection process.

[0081] In a preferred embodiment, a smooth transition is formed between the first step portion 33 and the tab welding portion 32 to avoid sharp edges and corners between the first step portion 33 and the tab welding portion 32, thereby avoiding damage to the battery cell caused by the sharp edges and corners during the connection process.

[0082] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present application.

Claims

1. A cylindrical battery, characterized in that: It includes a cover plate assembly and a battery cell, wherein the battery cell includes a winding hole; the cover plate assembly includes: The cover plate body (1) is provided with a through hole (11), and the projection of the winding core hole on the cover plate body (1) and the through hole (11) are arranged to be staggered with each other; A pole (2) at least partially penetrates the through hole (11), and the pole (2) is fixedly connected to the cover plate body (1) through the through hole (11); A current collecting plate (3), comprising a pole welding portion (31) and a pole lug welding portion (32), the pole welding portion (31) being welded to the pole (2); a first step portion (33) being provided between the pole lug welding portion (32) and the pole welding portion (31); in the arrangement direction of the cover plate assembly and the battery cell, the minimum distance between the pole welding portion (31) and the battery cell is smaller than the maximum distance between the pole lug welding portion (32) and the battery cell, and a ratio A of a height of the first step portion (33) to a height of the battery cell satisfies the following: 0.01≤A≤0.03; An injection molded part (4), the injection molded part (4) being connected to the cover plate body (1), the current collecting plate (3) being arranged between the injection molded part (4) and the cover plate body (1), a avoidance hole (41) being provided on the injection molded part (4), and the pole welding portion (31) being arranged at the avoidance hole (41).

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

3. The cylindrical battery according to claim 2, characterized in that: The cover plate body (1) is provided with two through holes (11) at intervals, the pole (2) comprises 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 respectively fixedly connected to the cover plate body (1) through the two through holes (11), and the polarities of the first pole and the second pole are opposite; the current collecting plate (3) comprises a first current collecting plate and a second current collecting plate, the first current collecting plate and the second current collecting plate are arranged at intervals, the pole welding portion (31) of the first current collecting plate is connected to the first pole, and the pole welding portion (31) of the second current collecting plate is connected to the second pole; the height difference h of the first current collecting plate and the height difference h of the second current collecting plate both satisfy 0.5 mm ≤ h ≤ 2 mm.

4. The cylindrical battery according to claim 2, characterized in that: The pole (2) comprises a first pole and a second pole, the first pole and the second pole are respectively located at two ends of the battery cell, the cover body (1) is provided at both ends of the battery cell, the first pole and the second pole are respectively fixedly connected to the two cover bodies (1) through the two through holes (11), and the polarities of the first pole and the second pole are opposite; or, the cover body (1) is provided at one end of the battery cell, the first pole is fixedly connected to the cover body (1) through the through hole (11), a connection hole is provided on the battery shell at the other end of the battery cell, the projection of the winding hole on the battery shell is staggered with the connection hole, and the second pole is fixedly connected to the battery shell through the connection hole; The current collecting plate (3) comprises a first current collecting plate and a second current collecting plate, the pole welding portion (31) of the first current collecting plate being connected to the first pole, and the pole welding portion (31) of the second current collecting plate being connected to the second pole; the height difference h of the first current collecting plate and the height difference h of the second current collecting plate both satisfy 0.1 mm ≤ h ≤ 1 mm.

5. The cylindrical battery according to claim 3, characterized in that: The projection of the winding core hole on the cover plate body (1) is located between the first pole and the second pole, and the height difference h of the first current collecting disc and the height difference h of the second current collecting disc both satisfy 0.5 mm ≤ h ≤ 1.8 mm.

6. The cylindrical battery according to claim 5, characterized in that: The first pole and the second pole are distributed on the cover plate body (1) in a centrally symmetrical manner, and the height difference h of the first current collecting plate and the height difference h of the second current collecting plate both satisfy 0.5 mm ≤ h ≤ 1.5 mm.

7. The cylindrical battery according to any one of claims 3, 5 or 6, characterized in that: The ratio B of the shortest distance between the pole lug welding portion (32) of the first current collecting disk and the pole lug welding portion (32) of the second current collecting disk 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, 5 or 6, characterized in that: On each of the current collecting plates (3), a ratio C of the area of ​​the pole tab welding portion (32) to the area of ​​the pole welding portion (31) satisfies 0.5≤C≤4.

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

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

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

12. The cylindrical battery according to any one of claims 1 to 6, characterized in that: It also comprises a support member, which is arranged between the pole welding portion (31) and the battery core and located at the first step portion (33), and is made of insulating material.

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