Current collector and battery cell

Abstract

The utility model provides a current collector and a battery cell, and relates to the technical field of batteries. The current collector comprises a first conductive part, the first conductive part extends along a first direction, the first conductive part is provided with a first surface deviating from the core package, the first surface is provided with a groove, and the groove extends along the first direction; wherein the groove divides the first conductive part into a vertical part and a welding part. According to the application, the groove is formed between the vertical part and the welding part, so that the material of the connecting part between the vertical part and the welding part can be reduced, the internal stress of the welding part in the bending process towards the vertical part can be reduced, and the obstruction of the connecting part on the approaching of the welding part towards the vertical part can be reduced; and the gap between the welding part and the vertical part is reduced.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a current collector and a battery cell. Background Art

[0002] In power batteries, there are many ways to set the pole ears of square batteries. One of them is that the positive pole ears and the negative pole ears are respectively set at the two ends of the length direction of the core package, and the current collector is used as a transition piece between the pole ears and the pole column. The core package is formed by stacking the positive electrode sheet, the negative electrode sheet and the diaphragm in sequence, and it has two end faces and a wide face and a narrow face connected to the two end faces. The current collector includes a horizontal part, a vertical part and a welding part. Among them, the horizontal part is parallel to the end face of the core package and is connected to the pole column; the vertical part is parallel to the narrow face of the core package, one end of which is connected to the horizontal part and one side is connected to the welding part. In order to facilitate the welding of the pole ears to the current collector, the welding part is parallel to the pole ears during welding. After the welding is completed, in order to facilitate the core package into the shell, the welding part needs to be bent at the connection between the welding part and the vertical part so that the welding part is close to the vertical part, thereby reducing the distance between the welding part and the core package.

[0003] After this current collector is bent, there is a large gap at the connection between the welding part and the vertical part, which causes the current collector to be larger in the length direction of the core package, which in turn causes the current collector to occupy more space inside the battery cell, which has an adverse effect on the energy density of the battery cell.

[0004] In addition, after the current collector is bent, the gap will cause the distance between one side of the connection between the welding part and the vertical part and the vertical part to be larger, while the distance between the other side of the welding part and the vertical part to be smaller, resulting in poor parallelism of the welding part relative to the vertical part, which will cause the edge of the welding part away from the bending part to bulge toward the insulating part of the battery cell and pierce the insulating part. As a result, there is a risk of short circuit inside the battery. Utility Model Content

[0005] The embodiments of the present application provide a current collector and a battery cell, which can improve the problem of a large gap between the welding portion and the vertical portion after the welding portion is bent toward the vertical portion.

[0006] In a first aspect, an embodiment of the present application provides a current collecting part, which includes a first conductive part, the first conductive part is extended along a first direction, the first conductive part has a first surface facing away from the core package, the first surface is provided with a groove, and the groove is extended along the first direction; wherein the groove divides the first conductive part into a vertical part and a welding part.

[0007] In one embodiment, the width of the groove opening is d1, and the width of the groove bottom is d2, satisfying: d1>d2.

[0008] In one embodiment, the width of the notch of the groove is d1, and the thickness of the first conductive portion is d0, which satisfies: 0.3d0≤d1≤4.3d0.

[0009] In one embodiment, the width of the groove bottom of the groove is d2, satisfying: d2>0.

[0010] In one embodiment, the first conductive portion has a second surface away from the first surface, the thickness of the first conductive portion is d0, and the minimum distance between the second surface and the bottom of the groove is d3, satisfying: 0.3d0≤d3≤0.97d0.

[0011] In one embodiment, there are two grooves, and the two grooves are arranged in parallel between the vertical portion and the welding portion.

[0012] In one embodiment, a middle groove is provided on the first surface, the middle groove is extended along the axis of the groove, the middle groove is located between the two grooves, and both sides of the middle groove in the width direction are respectively connected with the two grooves.

[0013] In one embodiment, the thickness of the first conductive portion is d0, and the distance between the first surface and the bottom of the middle groove is d4, satisfying: 0<d4≤2 / 3d0.

[0014] In one embodiment, the two grooves have a first groove wall close to the middle groove, the first groove walls of the two grooves are intersectingly arranged, and the middle groove is arranged at the intersection between the first groove walls; or, the two grooves are spaced apart, along the width direction of the middle groove, the middle part of the middle groove is arranged in the gap between the two grooves, and the two sides of the middle groove are respectively connected with the two grooves.

[0015] In one embodiment, a pole mating hole is provided on the horizontal portion.

[0016] In one embodiment, along the axis of the groove, the horizontal portion has a third surface away from the vertical portion, the third surface is provided with a first sink, the first sink is arranged along the circumference of the pole matching hole, and the first sink is connected to the pole matching hole.

[0017] In one embodiment, along the axis of the groove, the horizontal portion has a fourth surface close to the vertical portion, the fourth surface is provided with a second sink, the second sink is arranged along the circumference of the pole matching hole, and the second sink is connected to the pole matching hole.

[0018] In the second aspect, an embodiment of the present application provides a battery cell, which includes a shell, a core pack, a pole and the aforementioned current collector; the shell has a accommodating cavity; the core pack is arranged in the accommodating cavity; the pole is passed through one end of the shell; and the current collector connects the pole with the pole ear of the core pack.

[0019] In a third aspect, an embodiment of the present application provides a battery pack, which includes a battery box and the aforementioned battery cell, wherein there are multiple battery cells, and the multiple battery cells are arranged in the battery box.

[0020] Beneficial effects of the embodiments of the present application:

[0021] In an embodiment of the present application, a groove is provided between the vertical portion and the welding portion, so that the material of the connection portion between the vertical portion and the welding portion can be reduced, thereby reducing the internal stress of the welding portion during the bending process toward the vertical portion, and further reducing the obstruction of the connection portion to the welding portion approaching the vertical portion, so that the gap between the welding portion and the vertical portion is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 is a schematic structural diagram of a current collecting member provided in an embodiment of the present application;

[0024] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0025] Figure 3 It is a schematic diagram of the first bending of the welding portion provided in the embodiment of the present application and the matching of the pole ear;

[0026] Figure 4 It is a schematic diagram of the welding portion provided in the embodiment of the present application being matched with the tab after being bent for the second time;

[0027] Figure 5 is a schematic diagram of the structure of the groove after the welding portion is bent for the second time provided in an embodiment of the present application;

[0028] Figure 6 It is a structural schematic diagram of another groove after the welding portion is bent for the second time according to an embodiment of the present application;

[0029] Figure 7 is a schematic diagram of the structure of the groove provided in the embodiment of the present application;

[0030] Figure 8 is a structural schematic diagram of another current collecting member provided in an embodiment of the present application;

[0031] Fig. 9 yes Figure 8 The enlarged view of point B in the middle;

[0032] Fig.10 It is a structural schematic diagram of another groove after the welding portion is bent for the second time according to an embodiment of the present application;

[0033] Fig.11 is a schematic diagram of the structure of another groove provided in an embodiment of the present application;

[0034] Fig.12 is a partial structural schematic diagram of a longitudinal section of a pole matching hole provided in an embodiment of the present application;

[0035] Fig.13 is a schematic diagram of the cooperation between the horizontal portion and the pole provided in the embodiment of the present application;

[0036] Fig.14 is a schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0037] Fig.15 yes Fig.14 Enlarged view of point C in the middle.

[0038] Description of reference numerals:

[0039] 001-current collecting parts;

[0040] 011-horizontal part; 111-pole matching hole; 112-third surface; 113-first sinking platform; 114-fourth surface; 115-second sinking platform;

[0041] 012-vertical part;

[0042] 013-first conductive portion; 131-groove; 1311-first groove wall; 132-first surface; 133-second surface; 134-middle groove;

[0043] 014-Welding department;

[0044] 002-battery cell; 021-shell; 211-accommodation cavity; 022-cover; 023-core package; 024-pole; 025-pole ear. DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0046] In addition, it should be understood that the specific embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0047] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0048] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] To facilitate understanding of the scheme of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0050] See also Figure 1 and Figure 1 , Figure 1 is a schematic structural diagram of a current collecting member 001 provided in an embodiment of the present application, Figure 2 yes Figure 1 Enlarged view of point A in the middle. An embodiment of the present application provides a current collector 001, which includes a first conductive portion 013. The first conductive portion 013 is extended along a first direction. The first conductive portion 013 has a first surface 132 facing away from the core package. The first surface 132 is provided with a groove 131. The groove 131 is extended along the first direction. Among them, the groove 131 divides the first conductive portion 013 into a vertical portion 012 and a welding portion 014.

[0051] The first direction is the axial direction of the battery cell.

[0052] It can be understood that the current collector 001 is mainly formed by stamping a plate. After stamping, the vertical portion 012 and the welding portion 014 are located in the same horizontal plane. In order to adapt to the connection between the electrode tab and the current collector 001, the welding portion 014 is bent for the first time at the connection between the welding portion 014 and the vertical portion 012, so that the welding portion 014 is perpendicular to the vertical portion 012. When the welding portion 014 is perpendicular to the vertical portion 012, the electrode tab is welded to the welding portion 014, as shown in FIG. Figure 3 As shown, Figure 3 014 is a schematic diagram of the first bending of the welding portion 014 provided in the embodiment of the present application and the matching of the pole lug. After the pole lug is welded to the welding portion 014, the welding portion 014 is bent for the second time at the connection between the welding portion 014 and the vertical portion 012 so that the welding portion 014 is close to the vertical portion 012. Figure 4 As shown, Figure 4 Schematic diagram of the welding portion 014 provided in the embodiment of the present application after the second bending and matching with the tab. After the first conductive portion 013 is provided with a groove 131, the welding portion 014 is bent toward the vertical portion 012 with the groove 131 as the axis, so that the welding portion 014 is parallel to the vertical portion 012 and close to the vertical portion 012.

[0053] Specifically, when there is only one groove 131, it can be disposed adjacent to the welding portion 014, such as Figure 5 As shown, Figure 5 014 is a schematic diagram of the structure of the groove 131 after the second bending of the welding portion 014 provided in the embodiment of the present application; it can also be arranged adjacent to the vertical portion 012, such as Figure 6 As shown, Figure 6 It is a structural schematic diagram of another groove 131 after the welding portion 014 is bent for the second time provided in an embodiment of the present application. Figure 5 and Figure 6 The diagram shown is a cross-sectional view of the current collector 001 perpendicular to the extending direction of the groove 131 after the welding portion 014 is bent for the second time. Figure 5 and Figure 6 In the embodiment, the angle between the center line of the groove wall on both sides of the groove 131 and the surface of the welding part 014 facing the vertical part 012 is α, which satisfies: 90°<α<180°. Based on the arrangement of the groove 131, the gap size a between the welding part 014 and the vertical part 012 is small. For example, when the thickness d0 of the current collector 001 is 2 mm, a≤3 mm. When the thickness d0 of the current collector 001 is 0.5 mm, the opposing surfaces of the welding part 014 and the vertical part 012 are in contact, that is, a=0.

[0054] The parallelism of the welding portion 014 with respect to the vertical portion 012 is n, satisfying: n≤1.

[0055] In addition, the current collecting member 001 is a conductive material, which may be, but is not limited to: a nickel sheet, a nickel-plated metal sheet, an aluminum sheet, or a copper sheet.

[0056] Exemplarily, the groove 131 may be, but is not limited to, a V-shaped groove, a rectangular groove, a semicircular groove, or a trapezoidal groove.

[0057] In this embodiment, by providing a groove 131 between the vertical portion 012 and the welding portion 014, the material of the connection portion between the vertical portion 012 and the welding portion 014 can be reduced, thereby reducing the internal stress of the welding portion 014 during the bending process toward the vertical portion 012, and further reducing the resistance of the connection portion to the welding portion 014 approaching the vertical portion 012, so that the gap between the welding portion 014 and the vertical portion 012 is reduced.

[0058] Thus, on the one hand, the space occupied by the current collector 001 inside the battery cell 002 can be reduced, and on the other hand, the spacing between the two sides of the welding portion 014 and the vertical portion 012 can be made consistent, thereby improving the parallelism between the welding portion 014 and the vertical portion 012, so as to avoid the edge of the welding portion 014 on the side away from the bending portion from protruding toward the insulating part of the battery cell 002, thereby ultimately improving the reliability of the battery.

[0059] In addition, by providing the groove 131 , the groove 131 can guide the bending of the welding portion 014 , thereby ensuring that the welding portion 014 can be bent along the groove 131 , thereby improving the bending accuracy and bending consistency of the current collecting member 001 .

[0060] In addition, the current collecting part 001 is a metal part with elasticity. By setting the groove 131, the rebound amplitude of the welding part 014 after bending can be controlled and reduced, thereby improving the bending accuracy of the welding part 014, which is beneficial to improving the position accuracy of the welding part 014, and further facilitates the welding of the pole ear and the welding part 014 and the shelling of the core package 023.

[0061] See also Figure 7 , Figure 7 1 is a schematic diagram of the structure of the groove 131 provided in an embodiment of the present application. In one embodiment, the width of the groove opening of the groove 131 is d1, and the width of the groove bottom of the groove 131 is d2, which satisfies: d1>d2.

[0062] It can be understood that when the width of the groove 131 is not greater than the width of the bottom of the groove 131, when the welding portion 014 is bent toward the vertical portion 012, the groove walls on both sides of the groove 131 will collide and squeeze each other, thereby causing the internal stress to be relatively large during the bending process, hindering the welding portion 014 from approaching the vertical portion 012, and not conducive to reducing the gap between the welding portion 014 and the vertical portion 012.

[0063] Based on this, in this embodiment, by setting the width of the notch of the groove 131 to be greater than the width of the groove bottom of the groove 131, it is possible to avoid the groove walls on both sides of the groove 131 from abutting against and squeezing each other during the bending process of the welding portion 014, thereby reducing the internal stress of the welding portion 014 during the bending process toward the vertical portion 012, thereby reducing the obstruction of the connection between the welding portion 014 and the vertical portion 012 to the welding portion 014 approaching the vertical portion 012. In this way, the gap between the welding portion 014 and the vertical portion 012 can be reduced.

[0064] See also Figure 7 In one embodiment, the width of the notch of the groove 131 is d1, and the thickness of the first conductive portion 013 is d0, which satisfies: 0.3d0≤d1≤4.3d0.

[0065] It can be understood that d1 can be but is not limited to 0.3d0, 0.9d0, 1.3d0, 1.5d0, 2d0, 2.3d0, 0.3d0, 0.3d0, 0.3d0, 0.3d0, 0.3d0, 0.3d0, 4.3d0.

[0066] In this embodiment, by limiting the width of the notch of the groove 131, on the one hand, it can avoid that the width of the notch is too small and the internal stress in the bending process is not significantly eliminated, and on the other hand, it can avoid that the width of the notch is too large and the strength of the current collecting member 001 is reduced.

[0067] See also Figure 7 In one embodiment, the width of the bottom of the groove 131 is d2, satisfying: d2>0.

[0068] Exemplarily, d2 ≥ 0.2d0. For example, when d0 is 4 mm, d2 ≥ 0.8 mm.

[0069] In this embodiment, by limiting the width of the groove 131, the groove walls on both sides of the groove 131 have a large spacing, so that when the welding portion 014 is bent, the groove walls on both sides of the groove 131 can be prevented from abutting or squeezing each other, thereby reducing the internal stress of the welding portion 014 during the bending process toward the vertical portion 012, thereby reducing the obstruction of the connection between the welding portion 014 and the vertical portion 012 to the welding portion 014 approaching the vertical portion 012. In this way, the gap between the welding portion 014 and the vertical portion 012 can be reduced.

[0070] See also Figure 7 In one embodiment, the first conductive portion 013 has a second surface 133 away from the first surface 132, the thickness of the first conductive portion 013 is d0, and the minimum distance between the second surface 133 and the bottom of the groove 131 is d3, satisfying: 0.3d0≤d3≤0.97d0.

[0071] It can be understood that d3 can be but is not limited to 0.3d0, 0.36d0, 0.4d0, 0.45d0, 0.5d0, 0.53d0, 0.58d0, 0.6d0, 0.7d0, 0.8d0, 0.93d0, and 0.97d0.

[0072] In addition, the thickness d0 of the first conductive portion 013 refers to the distance between the first surface 132 and the second surface 133 when the first conductive portion 013 is not provided with the groove 131 .

[0073] In this embodiment, by limiting the minimum spacing between the second surface 133 and the bottom of the groove, on the one hand, the strength of the current collector 001 at the groove 131 can be ensured based on the minimum value of the specified spacing, thereby avoiding cracks in the current collector 001 at the groove 131; on the other hand, the minimum depth of the groove 131 can be ensured based on the maximum value of the specified spacing, thereby reducing the internal stress of the welding portion 014 during the bending process of the vertical portion 012. As a result, the connection between the vertical portion 012 and the welding portion 014 can reduce the resistance of the welding portion 014 to the approach of the vertical portion 012, thereby reducing the gap between the welding portion 014 and the vertical portion 012, and can also help improve the bending consistency of the welding portion 014 along the length direction of the groove 131, thereby reducing the impact of inconsistent bending on the battery energy density.

[0074] See also Figure 8 and Fig. 9 , Figure 8 is a structural schematic diagram of another current collecting member 001 provided in an embodiment of the present application, Fig. 9 yes Figure 8 In one embodiment, there are two grooves 131. The two grooves 131 are arranged side by side between the vertical portion 012 and the welding portion 014.

[0075] Specifically, when there are two grooves 131, after the welding portion 014 is bent twice, the structure of the groove 131 is as follows: Fig.10 As shown, Fig.10 FIG. 1 is a schematic diagram of the structure of another groove 131 after the welding portion 014 is bent for the second time according to an embodiment of the present application. Fig.10 In the figure, the groove 131 close to the welding portion 014 is the first groove 131, and the angle between the center line of the groove walls on both sides of the first groove 131 and the surface of the welding portion 014 facing the vertical portion 012 is α, which satisfies: 90°<α<180°, and the second groove 131 close to the vertical portion 012, the angle between the center line of the groove walls on both sides of the second groove 131 and the surface of the welding portion 014 facing the vertical portion 012 is β, which satisfies: 90°<β<180°.

[0076] After the welding portion 014 is bent for the second time, the surface of the connection portion between the welding portion 014 and the vertical portion 012 away from the groove 131 may be composed of two arc segments, one of which connects the surface of the vertical portion 012 and the other arc segment, and the other arc segment connects the surface of the welding portion 014 and the previous arc segment. The surface of the connection portion away from the groove 131 may also be composed of two arc segments and a plane segment located between the two arc segments, such as Fig.10 In the thickness direction of the welding portion 014, the width of the plane segment is h, which satisfies: 1 / 3d0<h<3d0.

[0077] It can be understood that the two grooves 131 can be arranged at intervals, or the adjacent sides of the two grooves 131 can be connected to each other, that is, the adjacent groove walls of the two grooves 131 are arranged to intersect with each other.

[0078] In addition, since the current collecting member 001 has a certain thickness, when the welding portion 014 is bent to be close to the vertical portion 012, two corners are formed between the vertical portion 012 and the welding portion 014. The stress at the corners is relatively large, which greatly hinders the bending of the welding portion 014.

[0079] When bending, the welding portion 014 is bent toward the vertical portion 012 with the central symmetry line between the two grooves 131 as the axis, so that the welding portion 014 is parallel to the vertical portion 012 and moves closer to the vertical portion 012 .

[0080] Based on this, in the present embodiment, by providing two grooves 131, on the one hand, stress can be reduced by reducing the material at the two corners, so as to reduce the obstruction of the connection between the welding portion 014 and the vertical portion 012 to the welding portion 014 approaching the vertical portion 012, thereby reducing the gap between the welding portion 014 and the vertical portion 012; on the other hand, based on the grooves 131 provided at the two corners, the bending can be concentrated in the two grooves 131, thereby providing a more accurate bending guide for the bending of the welding portion 014, thereby improving the bending accuracy of the welding portion 014.

[0081] In addition, through the above-mentioned arrangement, the springback amplitude of the welding portion 014 after bending can be further controlled and reduced, thereby improving the bending accuracy of the welding portion 014, which is beneficial to improving the position accuracy of the welding portion 014, and further beneficial to the welding of the tab and the welding portion 014 and the insertion of the core package 023 into the shell.

[0082] See also Fig.11 , Fig.111 is a schematic diagram of the structure of another groove 131 provided in an embodiment of the present application. In one embodiment, an intermediate groove 134 is provided on the first surface 132. The intermediate groove 134 is extended along the axis of the groove 131. The intermediate groove 134 is located between the two grooves 131. Both sides of the intermediate groove 134 in the width direction are respectively connected with the two grooves 131, that is, the groove bottom of the intermediate groove 134 is respectively intersected with the groove walls of the two grooves 131 adjacent thereto.

[0083] It can be understood that when bending, the welding portion 014 is bent toward the vertical portion 012 with the middle groove 134 as the axis, so that the welding portion 014 is parallel to the vertical portion 012 and moves closer to the vertical portion 012 .

[0084] In this embodiment, by providing the middle groove 134, the material between the two grooves 131 can be reduced, thereby further reducing the internal stress of the welding portion 014 during the bending process toward the vertical portion 012, and further reducing the obstruction of the connection between the welding portion 014 and the vertical portion 012 to the welding portion 014 approaching the vertical portion 012, so that the gap between the welding portion 014 and the vertical portion 012 is further reduced.

[0085] See also Fig.11 In one embodiment, the thickness of the first conductive portion 013 is d0, and the distance between the first surface 132 and the bottom of the middle groove 134 is d4, satisfying: 0<d4≤2 / 3d0.

[0086] It can be understood that d4 can be but is not limited to 0.1d0, 0.22d0, 0.28d0, 0.3d0, 0.4d0, 0.51d0, 0.6d0, 2 / 3d0.

[0087] In this embodiment, through the above-mentioned definition, on the one hand, an intermediate groove 134 can be provided between the two groove bottoms to reduce the material between the two grooves 131, thereby further reducing the internal stress of the welding portion 014 during the bending process toward the vertical portion 012, so as to improve the bending consistency of the welding portion 014 on the groove 131; on the other hand, the strength of the current collecting part 001 at the groove 131 is ensured based on the maximum depth of the intermediate groove 134 defined, thereby avoiding cracks in the current collecting part 001 at the intermediate groove 134.

[0088] In one embodiment, the two grooves 131 have a first groove wall 1311 close to the middle groove 134, the first groove walls 1311 of the two grooves 131 are intersectingly arranged, and the middle groove 134 is arranged at the intersection between the first groove walls 1311; or, the two grooves 131 are spaced apart, and along the width direction of the middle groove 134, the middle part of the middle groove 134 is arranged in the interval between the two grooves 131, and the two sides of the middle groove 134 are respectively connected with the two grooves 131.

[0089] It is understood that the two grooves 131 can be arranged at intervals or partially intersecting. For example, when the thickness of the current collecting member 001 is relatively small, the two grooves 131 can be arranged to partially intersect, and when the thickness of the current collecting member 001 is relatively large, the two grooves 131 can be arranged at intervals.

[0090] See also Figure 1 In one embodiment, the current collecting member 001 further includes a horizontal portion 011. The horizontal portion 011 is arranged along the second extension. The second direction intersects the first direction. Specifically, the second direction is perpendicular to the vertical portion.

[0091] It can be understood that after the current collector 001 is stamped from a plate, the horizontal portion 011, the vertical portion 012 and the welding portion 014 are located in the same horizontal plane. In order to adapt to the connection between the pole and the pole ear, the horizontal portion 011 is bent at the connection between the horizontal portion 011 and the vertical portion 012 so that the horizontal portion 011 is perpendicular to the vertical portion 012. When the current collector is applied to a battery cell, the horizontal portion 011 is parallel to the top cover of the battery cell.

[0092] Specifically, a pole mating hole 111 is provided on the horizontal portion 011 .

[0093] It can be understood that the end of the pole close to the horizontal portion 011 is plugged into the pole matching hole 111. After plugging, the pole and the horizontal portion 011 are fixed by welding.

[0094] The matching clearance between the pole and the pole matching hole 111 is t, which satisfies: 0.025mm≤t≤1mm. The matching clearance t can be, but is not limited to, 0.025mm, 0.075mm, 0.128mm, 0.3mm, 0.6mm, 0.7mm, 0.85mm, 0.92mm, and 1mm.

[0095] In this embodiment, by providing the pole matching hole 111 on the horizontal portion 011 , the pole can be plugged into the horizontal portion 011 based on the hole, thereby improving the positioning accuracy between the pole and the horizontal portion 011 .

[0096] See also Fig.12 , Fig.12 1 is a partial structural schematic diagram of a longitudinal section of a pole mating hole 111 provided in an embodiment of the present application. In one embodiment, along the axis of the groove 131, the horizontal portion 011 has a third surface 112 that is away from the vertical portion 012. The third surface 112 is provided with a first sink 113. The first sink 113 is provided along the circumference of the pole mating hole 111. The first sink 113 is connected to the pole mating hole 111.

[0097] It can be understood that a ring body is provided on the outer peripheral surface of the pole to cooperate with the first sinking platform 113. The end of the pole close to the horizontal portion 011 is inserted into the pole matching hole 111, and the ring body is located in the first sinking platform 113 and cooperates with the first sinking platform 113 to stop. Fig.13 As shown, Fig.13 It is a schematic diagram of the cooperation between the horizontal portion 011 and the pole provided in the embodiment of the present application.

[0098] In this embodiment, through the above arrangement, the matching surface between the horizontal portion 011 and the pole can be increased, thereby improving the positioning accuracy between the horizontal portion 011 and the pole.

[0099] See also Fig.12 In one embodiment, along the axis of the groove 131, the horizontal portion 011 has a fourth surface 114 away from the vertical portion 012, and the fourth surface 114 is provided with a second sink 115, which is arranged along the circumference of the pole matching hole 111. The second sink 115 is connected to the pole matching hole 111.

[0100] It can be understood that the pole is welded to the horizontal portion 011, for example, by laser welding.

[0101] Based on this, in this embodiment, by providing the second sinking platform 115, the operability of welding between the pole and the horizontal portion 011 is improved, thereby facilitating the improvement of the welding quality between the pole and the horizontal portion.

[0102] See also Fig.14 , Fig.14 002 is a schematic diagram of the structure of the battery cell 002 provided in the embodiment of the present application. Accordingly, the embodiment of the present application also provides a battery cell 002, which includes a shell, a core package 023, a pole 024 and the aforementioned current collector 001. The shell has a receiving cavity 211. The core package 023 is arranged in the receiving cavity 211. The pole 024 is inserted into one end of the shell; the current collector 001 connects the pole 024 with the pole ear 025 of the core package 023.

[0103] It can be understood that when the core package 023 is located in the accommodating cavity 211, one side of the core package is disposed opposite to the welding portion 014. Fig.15 As shown, Fig.15 yes Fig.14 Enlarged view of point C in the middle.

[0104] The housing includes a cover 022 and a shell 021 , wherein the cover 022 covers one end of the shell 021 . The pole 024 is disposed on the cover 022 .

[0105] In addition, the battery cell 002 can be applied to a battery. The battery includes a battery box and the aforementioned battery cell 002. There are multiple battery cells 002. Multiple battery cells 002 are arranged in the battery box. Multiple battery cells 002 are connected in parallel or in series. The battery is applied to electrical equipment, such as electric vehicles.

[0106] In this embodiment, by using the aforementioned current collector 001, the gap between the welding portion 014 and the vertical portion 012 can be reduced. In this way, on the one hand, the space occupied by the current collector 001 inside the battery cell 002 can be reduced, so that the energy density of the battery cell 002 is improved; on the other hand, the parallelism between the welding portion 014 and the vertical portion 012 can be improved to prevent the edge of the welding portion 014 away from the connection portion with the vertical portion 012 from protruding toward the insulating member of the battery cell 002, thereby improving the reliability of the battery cell 002.

[0107] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A current collecting member, characterized in that: It includes a first conductive part, which is extended along a first direction. The first conductive part has a first surface facing away from the core package, and the first surface is provided with a groove, which is extended along the first direction; wherein the groove divides the first conductive part into a vertical part and a welding part.

2. The current collecting member according to claim 1, characterized in that: The width of the groove opening is d1, and the width of the groove bottom is d2, which satisfies: d1>d2.

3. The current collecting member according to claim 1, characterized in that: The width of the notch of the groove is d1, and the thickness of the first conductive portion is d0, which satisfies: 0.3d0≤d1≤4.3d0.

4. The current collecting member according to claim 1, characterized in that: The width of the groove bottom is d2, which satisfies: d2>0.

5. The current collecting member according to claim 1, characterized in that: The first conductive portion has a second surface away from the first surface, the thickness of the first conductive portion is d0, and the minimum distance between the second surface and the bottom of the groove is d3, which satisfies: 0.3d0≤d3≤0.97d0.

6. The current collecting member according to any one of claims 1 to 5, characterized in that: There are two grooves, and the two grooves are arranged in parallel between the vertical portion and the welding portion.

7. The current collecting member according to claim 6, characterized in that: The first surface is provided with a middle groove, the middle groove is extended along the axis of the groove, the middle groove is located between the two grooves, and both sides of the middle groove in the width direction are respectively connected with the two grooves.

8. The current collecting member according to claim 7, characterized in that: The thickness of the first conductive portion is d0, and the distance between the first surface and the bottom of the middle groove is d4, which satisfies: 0<d4≤2 / 3d0.

9. The current collecting member according to claim 7 or 8, characterized in that: The two grooves have a first groove wall close to the middle groove, the first groove walls of the two grooves are arranged to intersect, and the middle groove is arranged at the intersection between the first groove walls; Alternatively, the two grooves are arranged at intervals, the middle groove is arranged between the two grooves, and two sides of the middle groove are respectively connected with the two grooves.

10. A battery cell, characterized in that: include: A housing having a receiving cavity; A core package, disposed in the accommodating cavity; A pole, passing through one end of the shell; The current collector according to any one of claims 1 to 9, wherein the current collector connects the pole to the pole ear of the core package.

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