Battery confluence plate, battery and welding method of battery confluence plate and roll core

Abstract

The invention discloses a battery confluence plate, a battery and a welding method of the battery confluence plate and a roll core. The battery confluence plate comprises a confluence plate main body, a roll core connecting part, a positive pole connecting part and a center hole, a positive pole connecting part is arranged at the central position of the convergence plate main body; a central hole is formed in the central position of the positive pole connecting part; a positive pole output cover plate of the battery is arranged right above the positive pole connecting part; the top surface of the positive pole connecting part is fixedly connected with the bottom surface of the positive pole output cover plate; a plurality of radially distributed convergence disc hollow grooves are formed in the convergence disc main body; a roll core connecting part is arranged between any two adjacent hollow grooves of the convergence disc; and the roll core connecting part is used for being connected with a positive tab at the top of a roll core of the battery in a welding manner in a laser lap welding manner. According to the battery confluence plate, the battery and the welding method of the battery confluence plate and the roll core disclosed by the invention, the confluence plate can be reliably connected with the positive tab at the top of the battery roll core, and the connection reliability is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery busbar, a method for welding a battery busbar and a winding core, and a battery. Background Art

[0002] At present, large cylindrical full-tab batteries (large cylindrical batteries, i.e. large-size cylindrical batteries, such as 4680, 4695 and other large cylindrical batteries) have excellent engineering and technical properties and a high safety factor due to their unique structural design. The failure degradation capability of the battery system is significantly lower than that of other types of cells (such as soft-pack and square).

[0003] However, due to its relatively complex structure, the assembly process covers many welding processes, especially the welding connection between the busbar and the positive ear on the top of the battery core. The current connection method between the busbar and the positive ear on the top of the battery core is generally: laser penetration welding. However, the laser penetration welding method has a low penetration depth CPK (CPK is the process capability index), insufficient process stability, and cannot guarantee the welding quality, and thus cannot guarantee the connection reliability between the busbar and the positive ear on the top of the battery core, which easily leads to poor welding.

[0004] In addition, based on existing detection technology, poor laser penetration welding problems cannot be visually detected, and thus the reliability of battery assembly cannot be guaranteed.

[0005] Therefore, there is an urgent need to develop a technology that can solve the above problems. Summary of the invention

[0006] The purpose of the present invention is to provide a battery busbar, a method for welding a battery busbar and a winding core, and a battery in view of the technical defects in the prior art.

[0007] To this end, the present invention provides a battery busbar, which includes: a busbar body, a winding core connection portion, a positive pole connection portion and a center hole;

[0008] Wherein, a positive pole connection portion is provided at the center of the busbar body;

[0009] A center hole is provided at the center of the positive electrode column connection portion;

[0010] Directly above the positive electrode column connection portion, a positive electrode output cover plate of the battery is used to be arranged;

[0011] The top surface of the positive electrode column connection portion is fixedly connected to the bottom surface of the positive electrode output cover plate of the battery;

[0012] Wherein, a plurality of radially distributed first busbar hollow grooves are arranged on the busbar body;

[0013] A winding core connecting portion is respectively provided between any two adjacent hollow grooves of the first busbar;

[0014] The multiple winding core connection parts are centrally symmetrically distributed with the central hole as the center;

[0015] The core connection part is used to be welded and connected to the positive electrode ear at the top of the battery core by laser lap welding.

[0016] In addition, the present invention also provides a battery, which includes the battery busbar as described above.

[0017] In addition, the present invention also provides a method for welding a battery busbar and a winding core as described above, comprising the following steps:

[0018] Step S1, first prepare the positive electrode sheet and the negative electrode sheet, then perform the winding operation of the positive electrode sheet, the negative electrode sheet and the separator, and after the winding is completed, perform the tab flattening operation on the positive electrode sheet and the negative electrode sheet to complete the preparation of the winding core with full tabs;

[0019] Step S2, moving the winding core obtained in step S1 to the busbar welding station, performing the loading of the battery busbar as described above, and completing the centering operation between the battery busbar and the winding core with all the tabs;

[0020] Step S3, taking a photo of the connection between the battery busbar and the winding core, and locating a weldable position adjacent to the connection of the winding core;

[0021] Step S4, using laser welding equipment to overlap weld the weldable position of the winding core connection part and the positive electrode ear of the winding core, so as to complete the welding electrical connection between the busbar and the positive electrode ear of the winding core;

[0022] Step S5, judging the welding quality between the battery busbar and the positive electrode ear at the top of the winding core by performing visual inspection.

[0023] It can be seen from the technical solution provided by the present invention that, compared with the prior art, the present invention provides a battery busbar, a method for welding a battery busbar and a core, and a battery. The present invention is scientifically designed and designed for the busbar structure. It can reliably connect the busbar with the positive pole ear at the top of the battery core, ensure the connection reliability between the busbar and the positive pole ear at the top of the battery core, and has great practical significance.

[0024] In addition, the present invention eliminates the traditional electrical connection form of the busbar by laser penetrating the pole ear welding, and changes it to the form of lap welding for electrical connection between the busbar and the pole ear, and performs corresponding supporting structural design. The CPK (CPK is the process capability index) of the lap welding is higher, and in terms of strength, the laser lap welding is stronger, which is conducive to ensuring the welding quality, and then ensuring the connection reliability between the busbar and the pole ear.

[0025] In addition, the application of the present invention can solve the problem that it is difficult to detect the welding effect of the busbar and the tab when assembling the existing battery, and realize the visual detection of the busbar and the tab welding. Since the present invention adopts the form of lap welding of the busbar and the tab for electrical connection, its welding effect can be visually detected by the existing visual detection technology, which is conducive to improving the reliability of battery assembly, thereby increasing the battery assembly efficiency and yield rate.

[0026] After testing, it is found that the battery busbar and battery provided by the present invention have high reliability and are easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a battery busbar provided by the present invention;

[0028] Figure 2 It is a schematic diagram of the overall welding effect of a battery busbar and a battery winding core (specifically, the positive electrode ear at the top of the winding core) provided by the present invention;

[0029] Figure 3 It is a partial welding schematic diagram of the battery busbar provided by the present invention and the battery winding core (specifically the positive electrode ear at the top of the winding core), that is, Figure 2 An enlarged schematic diagram of part A shown in FIG.

[0030] Figure 4 is a cross-sectional view of a battery provided by the present invention;

[0031] In the figure, 1-battery busbar; 2-battery shell; 3-battery cover; 4-winding core; 5-positive electrode output cover. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0035] In addition, 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] See also Figures 1 to 4 The present invention provides a battery busbar, which is applied to a battery, and includes: a busbar body 101, a winding core connection portion (i.e., a battery cell electrode group connection portion) 102, a positive electrode column connection portion 103, and a center hole 104;

[0037] Among them, a positive pole connection portion 103 is provided at the center of the busbar body 101;

[0038] A center hole 104 is provided at the center of the positive electrode column connecting portion 103;

[0039] Directly above the positive electrode column connection portion 103, a positive electrode output cover plate 5 of the battery is provided;

[0040] The top surface of the positive electrode column connecting portion 103 is fixedly connected to the bottom surface of the positive electrode output cover plate 5 of the battery;

[0041] The main body 101 of the busbar is provided with a plurality of (for example, six) radially distributed first busbar hollow grooves 1021;

[0042] A winding core connection portion (i.e., a cell electrode group connection portion) 102 is respectively provided between any two adjacent first busbar hollow grooves 1021;

[0043] The plurality of winding core connection parts 102 are centrally symmetrically distributed with the central hole 104 as the center;

[0044] It should be noted that the winding core connection parts 102 include a plurality of them, which can be symmetrically arranged about the central hole 104 .

[0045] The winding core connection portion 102 is used to be welded and connected to the positive electrode ear 401 at the top of the winding core (ie, the battery cell electrode group) 4 of the battery by laser lap welding, so as to ensure the electrical connection effect.

[0046] In the present invention, the distance between any two adjacent first bus plate hollow grooves 1021 is equal.

[0047] In the present invention, the included angles of the central axes of any two adjacent first bus plate hollow grooves 1021 are equal, for example, both are 60°.

[0048] In specific implementation, the busbar body 101 is provided with six radially distributed first busbar hollow grooves 1021;

[0049] The included angle between the central axes of any two adjacent first bus plate hollow grooves 1021 is 60°.

[0050] In the present invention, a plurality of second busbar hollow grooves 1022 are evenly distributed along the circumferential direction on the busbar body 101;

[0051] A plurality of second bus plate hollow grooves 1022 are alternately distributed in sequence at one end (ie, the outer end) of the plurality of first bus plate hollow grooves 1021 away from the central hole 104;

[0052] In a specific implementation, the middle section of each second bus plate hollow groove 1022 is directly connected to one end of a first bus plate hollow groove 1021 away from the central hole 104 .

[0053] In a specific implementation, the total number of the second busbar hollow slots 1022 is equal to half of the total number of the first busbar hollow slots 1021;

[0054] The total number of the first bus plate hollow slots 1021 is an even number.

[0055] In a specific implementation, the shapes of the edges of the inner and outer sides (ie, the side close to the center hole 104 and the side away from the center hole 104 ) of the second bus plate hollow groove 1022 are both arc-shaped.

[0056] Furthermore, the length of the outer edge of the second bus plate hollow groove 1022 is greater than the length of the inner edge thereof.

[0057] In the present invention, the battery comprises a hollow battery shell 2;

[0058] A winding core (i.e., a battery cell electrode group) 4 is arranged in the battery shell 2;

[0059] The top of the battery shell 2 is sealed with a positive electrode output cover plate 5;

[0060] The bottom of the battery shell 2 is sealed with a battery cover 3 serving as a negative electrode output terminal;

[0061] The top of the battery cover 3 is connected to the negative electrode ear at the bottom of the winding core (i.e., the battery cell electrode group) 4;

[0062] The edges of the battery cover 3 are sealed and connected to the inner wall of the lower part of the battery shell 2 (specifically, they are fixed by welding).

[0063] It should be noted that the battery shell 2 and the positive electrode output cover plate 5 are separated and insulated from each other (for example, separated from each other by an insulating ring).

[0064] In a specific implementation, the battery cover 3 and the negative electrode ear at the bottom of the winding core (ie, the battery cell electrode group) 4 are connected by laser welding, and specifically, laser penetration welding can be adopted.

[0065] In a specific implementation, the negative electrode ear at the bottom of the winding core (ie, the battery cell electrode group) 4 and the positive electrode ear 401 at the top of the winding core (ie, the battery cell electrode group) 4 are both full-electrode ears.

[0066] In the present invention, in a specific implementation, the overall shape of the busbar body 101 is circular;

[0067] The thickness of the busbar body 101 ranges from 0.01 mm to 0.6 mm.

[0068] In the present invention, the top surface of the positive electrode column connecting portion 103 is fixedly connected to the bottom surface of the positive electrode output cover plate 5 by welding, so as to maintain electrical connection.

[0069] In specific implementation, Figure 1 , Figure 4 As shown, the positive pole connection portion 103 is located in the inner center area of ​​the busbar body 101 and is used for laser welding and electrical connection with the positive output cover plate 5;

[0070] In a specific implementation, the positive electrode column connection portion 103 and the positive electrode output cover plate 5 are connected by laser penetration welding to maintain electrical connection.

[0071] In a specific implementation, the positive pole connecting portion 103 is vertically protruded and disposed on the top of the busbar body 101 .

[0072] In a specific implementation, the cross-sectional shape of the positive electrode column connecting portion 103 is a circular ring.

[0073] In the present invention, it should be noted that, in the present invention, the center hole 104 is arranged in the central area of ​​the positive electrode column connecting portion 103, which is used for positioning during the welding process of the busbar body 101 and the winding core (i.e., the battery cell pole group) 4, and for assisting the electrolyte to penetrate into the winding core (i.e., the battery cell pole group) 4.

[0074] In the present invention, in a specific implementation, the busbar is a battery positive electrode busbar.

[0075] In the present invention, in a specific implementation, a rivet 501 is vertically penetrated through the center of the positive output cover plate 5;

[0076] The bottom of the rivet 501 is welded to the top of the positive electrode column connecting portion 103 to maintain the electrical connection effect.

[0077] In the present invention, in a specific implementation, the winding core connection portion 102 is located in the inner area of ​​the busbar body 101 .

[0078] In the present invention, see Figure 2 , Figure 3 As shown, the specific welding track distribution position (i.e., the distribution position of the welding track B, which is also the specific welding area) of the core connection portion 102 and the positive electrode ear 401 at the top of the core (i.e., the battery cell electrode group) 4 of the battery includes: the edge of the first busbar hollow groove 1021 adjacent to the core connection portion 102, and / or the edge of the second busbar hollow groove 1022 adjacent to the core connection portion 102;

[0079] The positive electrode ear 401 of the winding core 4 is located directly below the first busbar hollow groove 1021 and the second busbar hollow groove 1022;

[0080] In a specific implementation, the top surface of the positive electrode tab 401 serves as the bottom of the first bus plate hollow groove 1021 and the bottom of the second bus plate hollow groove 1022 , and contacts the bottom surface of the winding core connecting portion 102 .

[0081] In specific implementation, the specific welding trajectory distribution position (i.e., the distribution position of the welding trajectory B) of the core connection part 102 and the positive electrode ear at the top of the battery core (i.e., the battery cell electrode group) 4 preferably includes: the radially distributed side edges of the first bus plate hollow groove 1021 adjacent to the core connection part 102, and / or the inner and outer side edges of the edges of the second bus plate hollow groove 1022 along the circumferential distribution.

[0082] It should be noted that, for the present invention, Figures 1 to 3As shown, the core connection portion 102 is in the inner area of ​​the busbar body 101, and the edges of the slots adjacent to the core connection portion 102 (i.e., the edges of the first busbar hollow groove 1021 and the second busbar hollow groove 1022) are used as weldable areas, and are electrically connected to the positive electrode ear 401 at the top of the core 4 by laser lap welding;

[0083] It should be noted that, for the present invention, in order to ensure the welding effect and realize visual detection, the core connection part 102 and the positive pole ear at the top of the battery core 4 are electrically connected by lap welding; the core connection part 102 is arranged on the inner side of the busbar body 101, and is located in the weldable range of the positive pole ear 401 of the core 4.

[0084] It should be noted that the core connection portion 102 is arranged in the internal range of the busbar body 101, and the internal range of the busbar body 101 is the weldable range of the 4 pole ears of the core, for example, generally φ5.0mm-φ42.0mm (that is, the distribution area of ​​the core connection portion 102 is the area between 5mm and 42mm away from the center point of the center hole 104).

[0085] It should be noted that the specific position for welding (lap welding) between the positive ear 401 at the top of the core 4 and the core connection part 102 is the seam position between the edge of the positive ear 401 and the core connection part 102 (that is, the edge of the adjacent slot), and the welding operation is performed on the seam position.

[0086] In specific implementation, the core connection part 102 and the positive ear 401 on the top of the core 4 are electrically connected by lap welding. Specifically, a ring spot laser can be selected, the laser welding power is 200w-450w, the welding trajectory is a straight line or a spiral line, the effective welding depth is 0.05mm-0.25mm, and the effective weld width is 0.05mm-0.5mm.

[0087] It should be noted that the current electrical connection between the busbar and the tab of a full-tab battery is made by traditional laser penetration welding, which cannot achieve online non-destructive testing of the electrical connection between the busbar and the tab during the assembly process. Laser penetration welding generally uses a destructive method to test the welding effect of the core. However, due to the outward connection position of the busbar laser lap welding, industrial visual inspection technology can be used to perform non-contact image acquisition, processing and analysis of the busbar welding position, thereby achieving full inspection of the battery cell busbar welding process.

[0088] For the present invention, considering the technical characteristics of the stacked full-tab battery, there are annular weldable areas and vulnerable areas of the welding diaphragm. To ensure welding reliability, the winding core connection part of the busbar is provided with an annular weldable area (i.e., the second busbar hollow groove 1022 distributed in an annular manner). To ensure the electrical connection effect of the full-tab battery, the hollow grooves inside the winding core connection part are provided with radial and circumferential directions (i.e., the first busbar hollow groove 1021 and the second busbar hollow groove 1022) to ensure the current capacity of the battery cell.

[0089] It should be noted that, for the present invention, since the connection position between the busbar and the core ear produced by laser lap welding is facing the outside of the core, based on existing visual inspection technologies, such as 2D and 3D visual inspection, welding defects such as lap welding deviation, cold welding, and blowout spots can be identified in time.

[0090] In a specific implementation, the first busbar hollow groove 1021 and the second busbar hollow groove 1022 are vertical through holes formed by stamping on the busbar body 101 .

[0091] In specific implementation, the shape of the first bus plate hollow slot 1021 is rectangular;

[0092] The second bus plate hollow groove 1022 is in the shape of a sector ring (i.e., a section of a circular ring);

[0093] In a specific implementation, the overall through hole shape formed by the first bus plate hollow groove 1021 and the second bus plate hollow groove 1022 is a “T-shape”.

[0094] It should be noted that, according to the needs of the user, the specific shapes of the first bus plate hollow groove 1021 and the second bus plate hollow groove 1022, as well as the combined shape of the two, can also be adjusted.

[0095] In a specific implementation, the first bus plate hollow groove 1021 extends in a radial direction on the bus plate body 101 , and the second bus plate hollow groove 1022 extends in a circumferential direction on the bus plate body 101 .

[0096] In a specific implementation, the radial inner end of the first bus plate hollow groove 1021 is not connected to the positive electrode column connecting portion 103 .

[0097] It should be noted that the present invention is specially designed for the busbar structure, and the welding process between the busbar structure and the winding core is changed from traditional penetration welding to lap welding, so that the welding effect can be visually detected, thereby improving the reliability of battery assembly.

[0098] Based on the busbar provided by the present invention, the present invention further provides a battery, which includes the battery busbar 1 described above;

[0099] The battery busbar 1 is connected to the positive electrode ear at the top of the battery winding core.

[0100] The present invention also provides a method for welding a battery busbar and a winding core, specifically a method for welding a battery busbar and a positive electrode ear at the top of a battery winding core, which specifically includes the following steps:

[0101] Step S1, first use laser cutting equipment (existing equipment) to prepare positive and negative electrode sheets with tabs cut, then perform winding operations on the positive and negative electrode sheets and the separator, and after the winding is completed, perform tab flattening operations on the positive and negative electrode sheets (which is an existing conventional full-tab processing operation, performed using existing tab flattening equipment), and complete the preparation of the winding core with full tabs;

[0102] It should be noted that the full-pole ear technology is proposed in contrast to the traditional single-pole ear or multi-pole ear. The current full-pole ear technology for lithium-ion batteries mainly includes two types, namely, flattened pole ear forming and cut and stacked pole ear forming. The cut and stacked pole ear forming technology is widely used because of its low self-discharge rate and less metal foreign matter. In order to ensure the flattening effect of the cut pole ear, the pole ears on the edges of the positive and negative electrode sheets need to be cut with laser die-cutting equipment. The pole ears after cutting are cut pole ears.

[0103] It should be noted that the preparation technology of the positive and negative electrode sheets with cut tabs is the existing well-known preparation technology of full-tab batteries, which will not be described in detail here.

[0104] In step S1 , the separator is located between the positive electrode sheet and the negative electrode sheet to separate the two and avoid short circuit.

[0105] It should be noted that the method for preparing the positive electrode sheet and the negative electrode sheet in step S1 is a conventional method.

[0106] Step S2, moving the winding core obtained in step S1 to the busbar welding station (a station in the existing production process), performing the battery busbar loading as described above, and completing the centering operation between the battery busbar and the winding core with full tabs;

[0107] Step S3, using an industrial visual camera (i.e., existing equipment) to take a picture of the connection between the battery busbar and the winding core, and locate the weldable position adjacent to the winding core connection (i.e., the weldable area, i.e., the edge of the adjacent slot, specifically, the edge of the first busbar hollow groove 1021 and the second busbar hollow groove 1022);

[0108] Step S4, using laser welding equipment (i.e., existing equipment) to overlap-weld the weldable position (i.e., weldable area) of the core connection portion and the positive electrode ear of the core, thereby completing the welding electrical connection between the busbar and the positive electrode ear of the core;

[0109] In step S4, a ring spot laser can be selected, the laser welding power is 200w-450w, the welding trajectory is a straight line or a spiral line, the effective welding penetration is 0.10mm-0.25mm, and the effective weld width is 0.1mm-0.5mm;

[0110] Step S5, through visual inspection, judge the welding quality between the battery busbar and the positive pole ear on the top of the winding core; specifically: use a post-welding visual camera to take a picture of the welding area, upload it to the defect analysis system (an existing system), and then use the existing visual inspection technology to judge the welding effect of the lap welding between the busbar and the pole ear.

[0111] It should be noted that the defect analysis system, post-weld visual camera and industrial visual camera are all mature supporting equipment used in the existing visual inspection technology, which are existing well-known technologies and will not be described in detail here. Visual inspection technology is an existing mature technology that has been promoted and applied in the field of battery production and will not be described in detail here.

[0112] It should be noted that the present invention cancels the traditional form of electrical connection of the busbar by laser penetrating the pole ear welding, and changes it to the form of lap welding for electrical connection between the busbar and the pole ear, and carries out corresponding supporting structural design (such as the design of the first busbar hollow groove 1021 and the second busbar hollow groove 1022 adjacent to the winding core connection part, and the corresponding position design of the winding core connection part and the positive pole ear). The CPK (CPK is the process capability index) of the lap welding is higher, and in terms of strength, the laser lap welding is stronger, which is conducive to ensuring the welding quality, and then ensuring the connection reliability between the busbar and the pole ear.

[0113] The application of the present invention can solve the problem that it is difficult to detect the welding effect of the busbar and the tab when assembling the existing battery, and realize the visual detection of the busbar and the tab welding. Since the present invention adopts the form of lap welding of the busbar and the tab for electrical connection, its welding effect (i.e. welding quality) can be visually detected by the existing visual detection technology, which is conducive to improving the reliability of battery assembly, thereby increasing the battery assembly efficiency and yield rate.

[0114] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A battery busbar, characterized in that: include: A busbar body (101), a winding core connection portion (102), a positive pole connection portion (103) and a center hole (104); Wherein, a positive pole connecting portion (103) is provided at the center of the busbar body (101); A center hole (104) is provided at the center of the positive electrode column connecting portion (103); A positive electrode output cover plate (5) of the battery is arranged directly above the positive electrode column connection portion (103); The top surface of the positive electrode column connection portion (103) is fixedly connected to the bottom surface of the positive electrode output cover plate (5) of the battery; Wherein, the main body (101) of the busbar is provided with a plurality of radially distributed first busbar hollow grooves (1021); A winding core connection portion (102) is respectively provided between any two adjacent first busbar hollow grooves (1021); The plurality of winding core connection portions (102) are distributed in a centrally symmetrical manner with the central hole (104) as the center; The winding core connection portion (102) is used to be welded and connected to the positive electrode ear (401) at the top of the winding core (4) of the battery by laser lap welding.

2. The battery busbar according to claim 1, characterized in that: The spacing between any two adjacent first bus plate hollow grooves (1021) is equal; and / or, The included angles of the central axes of any two adjacent first busbar hollow grooves (1021) are equal; and / or, The main body (101) of the busbar is provided with six radially distributed first busbar hollow grooves (1021); The included angle between the central axes of any two adjacent first busbar hollow grooves (1021) is 60°.

3. The battery busbar according to claim 1, wherein: A plurality of second busbar hollow grooves (1022) are evenly distributed along the circumference of the busbar main body (101); The plurality of second bus plate hollow grooves (1022) are alternately distributed in sequence at one end of the plurality of first bus plate hollow grooves (1021) away from the central hole (104).

4. The battery busbar according to claim 3, characterized in that: The middle section of each second bus plate hollow groove (1022) is directly connected to one end of a first bus plate hollow groove (1021) away from the central hole (104); and / or, The total number of the second busbar hollow slots (1022) is equal to half the total number of the first busbar hollow slots (1021); and / or, The total number of the hollow slots (1021) of the first busbar is an even number; and / or, The shapes of the inner and outer edges of the second busbar hollow groove (1022) are both arc-shaped; and / or, The length of the outer edge of the second busbar hollow groove (1022) is greater than the length of the inner edge thereof; and / or, The positive electrode ear (401) of the winding core (4) is located directly below the first busbar hollow groove (1021) and the second busbar hollow groove (1022); The top surface of the positive electrode ear (401) serves as the bottom of the first busbar hollow groove (1021) and the bottom of the second busbar hollow groove (1022), and is in contact with the bottom surface of the winding core connecting portion (102); and / or, The first busbar hollow groove (1021) and the second busbar hollow groove (1022) are vertical through holes formed by stamping on the busbar body (101).

5. The battery busbar according to any one of claims 1 to 4, characterized in that: The battery comprises a hollow battery shell (2); A winding core (4) is arranged inside the battery shell (2); A positive electrode output cover plate (5) is sealed and arranged on the top of the battery shell (2); A battery cover (3) serving as a negative electrode output terminal is sealed at the bottom of the battery shell (2); The top of the battery cover (3) is connected to the negative electrode ear at the bottom of the winding core (4); The edges around the battery cover (3) are sealed and connected to the inner wall of the lower part of the battery shell (2).

6. The battery busbar according to any one of claims 1 to 4, characterized in that: A positive pole connecting portion (103) is vertically protruded and arranged on the top of the busbar body (101); and / or, The cross-sectional shape of the positive electrode column connecting portion (103) is annular; and / or, A rivet (501) is vertically penetrated at the center of the positive electrode output cover plate (5); The bottom of the rivet (501) is welded to the top of the positive electrode column connecting portion (103).

7. The battery busbar according to claim 3 or 4, characterized in that: The specific welding track distribution position of the core connection part (102) and the positive electrode ear (401) at the top of the battery core (4) includes: the edge of the first bus plate hollow groove (1021) adjacent to the core connection part (102), and / or the edge of the second bus plate hollow groove (1022) adjacent to the core connection part (102).

8. The battery busbar according to claim 7, characterized in that: The specific welding track distribution position of the core connection part (102) and the positive ear (401) at the top of the battery core (4) includes: the radially distributed side edges of the first bus plate hollow groove (1021) adjacent to the core connection part (102), and / or the inner and outer side edges of the second bus plate hollow groove (1022) along the circumferential distribution.

9. A battery, characterized in that: The invention comprises a battery busbar as claimed in any one of claims 1 to 8.

10. A method for welding a battery busbar and a winding core according to any one of claims 1 to 8, characterized in that: The following steps are involved: Step S1, first prepare the positive electrode sheet and the negative electrode sheet, then perform the winding operation of the positive electrode sheet, the negative electrode sheet and the separator, and after the winding is completed, perform the tab flattening operation on the positive electrode sheet and the negative electrode sheet to complete the preparation of the winding core with full tabs; Step S2, moving the winding core obtained in step S1 to a busbar welding station, performing loading of the battery busbar as described in any one of claims 1 to 8, and completing the centering operation between the battery busbar and the winding core with full tabs; Step S3, taking a photo of the connection between the battery busbar and the winding core, and locating a weldable position adjacent to the connection of the winding core; Step S4, using laser welding equipment to overlap weld the weldable position of the winding core connection part and the positive electrode ear of the winding core, so as to complete the welding electrical connection between the busbar and the positive electrode ear of the winding core; Step S5, judging the welding quality between the battery busbar and the positive electrode ear at the top of the winding core by performing visual inspection.

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