Tab welding structure and battery

Abstract

The utility model provides a tab welding structure and a battery, relates to the technical field of batteries, and aims to solve the technical problems that full tab welding affects the overcurrent performance of a pole piece and increases current loss. The tab welding structure comprises a winding body which comprises a pole piece and a full tab, the full tab is electrically connected with the pole piece, and the full tab is located at one end of the winding body; the current collecting piece is welded with the full tab to form a plurality of welding spot groups, the plurality of welding spot groups are radially distributed around the center of the winding body, and a plurality of welding spots in each welding spot group are arranged in a wave shape along the radial direction of the winding body. The current guiding uniformity of the winding body can be improved, and the current loss amount can be reduced.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular, to an ear welding structure and a battery. Background Art

[0002] In a cylindrical battery, an ear is welded to a current collector disk to form a plurality of solder joints, and current is conducted to the electrode plate through the solder joints. In the related art, the welding of the ear and the current collector disk is usually performed by full-ear laser welding. Although this welding method is simple to process, the current flow path after ear welding has no regular pattern, the current flow is relatively chaotic, and some parts of the electrode plate will have repeated overcurrent, increasing the current loss and affecting the overcurrent performance of the electrode plate. Summary of the Utility Model

[0003] Embodiments of this application provide an ear welding structure and a battery to improve the technical problems that full-ear welding affects the overcurrent performance of the electrode plate and increases current loss.

[0004] In a first aspect, embodiments of this application provide an ear welding structure, including:

[0005] A wound body;

[0006] A full ear, formed at an end of the wound body and electrically connected to the wound body;

[0007] A current collector member, welded to the full ear to form a plurality of solder joint groups, the plurality of solder joint groups being radially distributed around the center of the wound body, and a plurality of solder joints in each solder joint group being arranged in a wavy shape along the radial direction of the wound body.

[0008] In some embodiments of this application, along the circumferential direction of the wound body, among the plurality of solder joint groups, the angular distance error range between two adjacent solder joint groups is between 0° and 5°.

[0009] In some embodiments of this application, along the circumferential direction of the wound body, the plurality of solder joint groups are equiangularly spaced.

[0010] In some embodiments of this application, each solder joint group includes a plurality of solder joint subgroups, and a plurality of solder joints in each solder joint subgroup are arranged in an arc shape along the radial direction of the wound body.

[0011] In some embodiments of this application, the full ear is wound around the wound body for multiple turns, a plurality of solder joints on the full ear are sequentially spaced along the winding direction of the wound body, the number of solder joints formed on each turn of the full ear is equal, and along the winding direction, a plurality of the solder joints are equidistantly spaced on the same turn of the full ear.

[0012] In some embodiments of the present application, two adjacent sub - groups of welding points along the circumferential direction of the winding body form a pair of sub - groups of welding points. The distance between the two sub - groups of welding points in each pair of sub - groups of welding points is positively correlated with the distance of the pair of sub - groups of welding points from the center of the winding body along the radial direction.

[0013] In some embodiments of the present application, the arc distance between the two sub - groups of welding points in each pair of sub - groups of welding points is: D = n×s;

[0014] Wherein, D represents the arc distance between two adjacent sub - groups of welding points in a pair of sub - groups of welding points, n represents the number of sub - groups of welding points arranged successively outward along the radial direction of the winding body, and s represents the arc distance between two adjacent welding points in the first winding of the winding body.

[0015] In some embodiments of the present application, the welding points are dot - shaped, and the diameter range of the welding points is 0.5 to 3 mm.

[0016] In some embodiments of the present application, the winding body includes a positive extreme and a negative extreme, and the full tab is connected to the positive extreme or the negative extreme.

[0017] In a second aspect, an embodiment of the present application provides a battery, including the tab welding structure as described in the first aspect.

[0018] Advantages of the embodiments of the present application:

[0019] In the embodiments of the present application, mainly by forming a plurality of radially - arranged welding - point groups on the full tab, the welding points in the welding - point groups can be restricted within a certain area and have a certain arrangement rule. Compared with the random arrangement of welding points in the related art, it is more regular, improving the current - carrying capacity of the electrode sheet and reducing the current loss caused by the random arrangement of welding points. Specifically, first, forming a full tab on the winding body is simpler in process compared with forming a plurality of tabs; then, welding the full tab to the current collector to form a plurality of welding - point groups, and the plurality of welding - point groups are radially distributed around the center of the winding body. The plurality of welding points in each welding - point group are arranged in a wavy shape along the radial direction of the winding body, which is beneficial to limiting the plurality of welding points in the welding - point group to a specific area, and the plurality of welding - point groups are radially arranged with a certain regularity. When the tab receives the current from the current collector and conducts the current into the winding body through the welding - point group, compared with the random arrangement of welding points, it can effectively improve the regularity of current conduction, reduce the loss of current during the flowing process, and improve the current - carrying capacity of the electrode sheet. The wavy arrangement can also effectively distinguish from the "V" - shaped or "cross - shaped" welding - point structure distributions used in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0021] Figure 1 is a three-dimensional schematic diagram of an ear welding structure provided by an embodiment of the present application;

[0022] Figure 2 is a plan view of an ear welding structure provided by an embodiment of the present application;

[0023] Figure 3 is a trajectory simulation schematic diagram of the solder joints other than the solder joint group not being cancelled in the embodiment of the present application.

[0024] Explanation of reference numerals:

[0025] 100, winding body; 110, full ear; 200, solder joint group; 210, sub-solder joint group; 211, solder joint; 300, current collector; Q, winding direction. Specific embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. 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 orientation terms such as "upper" and "lower" usually refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the accompanying drawings; and "inner" and "outer" refer to the outline of the device.

[0027] Please refer to Figure 1 and Figure 2 , the embodiments of the present application provide an ear welding structure, including:

[0028] Winding body 100;

[0029] Full ear, formed at the end of the winding body 100 and electrically connected to the winding body 100;

[0030] The current collector 300 is welded to the full tab 110 to form a plurality of solder joint groups 200. The plurality of solder joint groups 200 are radially distributed around the center of the wound body 100, and the plurality of solder joints 211 in each solder joint group 200 are arranged in a wavy shape along the radial direction of the wound body 100.

[0031] The technical solution provided by the present application mainly forms a plurality of radially arranged solder joint groups 200 on the full tab 110, so that the solder joints 211 in the solder joint groups 200 can be restricted within a certain area and have a certain arrangement rule. Compared with the random arrangement of the solder joints 211 in the related art, it is more regular, improves the current-carrying capacity of the electrode sheet and reduces the current loss caused by the random arrangement of the solder joints 211. Specifically, first, a full tab 110 is formed on the wound body 100. Compared with forming a plurality of tabs, forming the full tab 110 is simpler in process; then, the full tab 110 is welded to the current collector 300 to form a plurality of solder joint groups 200, and the plurality of solder joint groups 200 are radially distributed around the center of the wound body 100. The plurality of solder joints 211 in each solder joint group 200 are arranged in a wavy shape along the radial direction of the wound body 100, which is beneficial to limit the plurality of solder joints 211 in the solder joint group 200 to a specific area, and the plurality of solder joint groups 200 are radially arranged and have a certain regularity. When the tab receives the current from the current collector 300 and conducts the current into the wound body 100 through the solder joint group 200, compared with the random arrangement of the solder joints 211, it can effectively improve the regularity of current conduction, reduce the loss of current during the flowing process, and improve the current-carrying capacity of the electrode sheet. The wavy setting can also effectively distinguish from the "V"-shaped or "cross-shaped" solder joint 211 structure distribution adopted in the related art.

[0032] It should be noted that the solder joint group 200 refers to defining a plurality of solder joints 211 as a group, that is, the solder joint group 200. The plurality of solder joint groups 200 are radially distributed around the center of the wound body 100, which means that the plurality of solder joint groups 200 are circumferentially spaced around the center of the wound body 100, and each solder joint group 200 has a certain length in the radial direction of the wound body 100.

[0033] In some embodiments, the current collector 300 is a current collecting plate, and the full tab 110 is welded to the current collecting plate to form a plurality of solder joint groups. The current collecting plate, as the welding object of the full tab 110, is mainly used for current collection to form a larger current output or input. Of course, for the current collector 300, in other embodiments, it can also be of other shapes, such as columnar, square sheet-like, etc., without limitation.

[0034] In some embodiments, the winding body 100 includes wound electrode tabs and a separator attached to the electrode tabs. The electrode tabs are integrally formed and connected with the full tab 110, and the full tab 110 is flattened and covers one end of the winding body 100 in the axial direction. One of the differences between the electrode tabs and the full tab 110 is that the electrode tabs are coated with active paste, while the full tab 110 is not coated with active paste. The tabs are wound as the electrode tabs are wound. After the electrode tabs form the winding body 100, a flattening process is performed on the tabs so that the tabs cover one side of the winding body 100 in the axial direction.

[0035] In some embodiments, along the circumferential direction of the winding body 100, among the plurality of solder joint groups 200, the angular distance error range between two adjacent solder joint groups 200 is between 0° and 5°, so that the angles and arc distances between two adjacent solder joint groups 200 in the circumferential direction tend to be equal, that is, the plurality of solder joint groups 200 tend to be arranged at equal arc distances in the circumferential direction, effectively improving the problem that more current is lost during the flow process due to the irregular distribution of the solder joints 211, which is beneficial to improving the uniformity of current introduction into the electrode tabs and reducing current loss. It should be noted that the angular distance is the included angle between the connection line between the first solder joint 211 and the last solder joint 211 along the radial direction of the winding body 100 in the previous solder joint group 200 and the connection line between the first solder joint 211 and the last solder joint 211 along the radial direction of the winding body 100 in the subsequent solder joint group 200 among two adjacent solder joint groups 200.

[0036] It should also be noted that the angular distance error range is from 0° to 5°, including the two end values of 0° and 5°. Within this angular range, the influence on the position of the solder joints 211 and the uniformity of current inflow is relatively small, which is beneficial to taking into account both the uniformity of current inflow and reducing the precision of the arrangement of the solder joint groups 200. Preferably, the angular error range between the plurality of first included angles is 0°, that is, along the circumferential direction of the winding body 100, the plurality of solder joint groups 200 are arranged at equal angular distances. Because although the angular error range is limited to a relatively small range in this embodiment, with the increase in the number of winding turns, the position error of the distribution of the solder joint groups 200 will be gradually amplified. Therefore, on the premise of having conditions, it is still preferred that the angular distance error range is 0°.

[0037] In some embodiments, each solder joint group 200 includes a plurality of solder joint sub - groups 210, and the plurality of solder joint sub - groups 210 are linearly arranged in the radial direction, so that the plurality of solder joint sub - groups 210 can tend to be neatly arranged, avoiding the situation where the plurality of solder joint sub - groups 210 are arranged in a disorderly manner in the radial direction. Moreover, by linearly arranging the plurality of solder joint sub - groups 210 in the radial direction, it is also beneficial to confirm the position of the solder joints 211 before welding and make the welding control and the confirmation of the position of the solder joints 211 simpler during welding.

[0038] Further, the multiple solder joints 211 in each solder joint sub-group 210 are arranged in an arc shape along the radial direction of the winding body 100, so that the multiple solder joints 211 in each solder joint sub-group 210 have a certain arrangement rule. The specific arrangement rule is to be arranged in an arc shape along the radial direction, mainly for the convenience of determining the positions of the solder joints 211. Specifically, before determining the solder joints 211, the pole piece has been wound along the winding direction Q to form the winding body 100. Of course, the winding body 100 formed by winding here also includes the separator. Since the separator is wound together with the pole piece and the present application does not involve the structure and positional relationship of the separator, for the subsequent description of the winding of the winding body 100, for the sake of simplicity, the description of the pole piece winding to form the winding body 100 is adopted. Based on the shape of the winding body 100, the positions and quantities of the solder joints 211 will be simulated according to the actual situation. The simulation method of the solder joints 211 is realized by determining the arc distance between adjacent solder joints 211 along the winding direction Q. Then, according to the structure and position of the solder joint sub-group 210, the simulated solder joints 211 that do not belong to the solder joint sub-group 210 are cancelled, and the equal arc distance setting between the multiple solder joints 211 on each circle can be obtained. The determination of the positions of the solder joints 211 is relatively simple and accurate.

[0039] In this embodiment, please refer to Figure 3 , take the inner diameter of the winding as 2.5 mm, the outer diameter as 40 mm, and the number of winding turns as 90 turns; take the arc distance between adjacent solder joints 211 as 4 mm; take the angle between two adjacent solder joint groups 200 as 45°, and the angular distance error as 0°, that is, there is no angular error. First, according to the preset parameters, using simulation software such as AutoCAD, simulate the shape of the winding body 100 with the solder joint groups 200 and the trajectories of the solder joints 211. Here, the trajectories of the solder joints 211 need to be divided into two steps. The first step is to form multiple solder joints 211 along the winding direction Q according to the arc distance between adjacent solder joints 211. The second step is to cancel the solder joints 211 that do not belong to the solder joint groups 200 or the solder joint sub-groups 210 according to the positions of the multiple solder joint groups 200 or the solder joint sub-groups 210. Thus, the final trajectories of the solder joints 211 for welding are obtained. At this time, the trajectories of the solder joints 211 of the solder joint sub-group 210 are in an arc shape, and multiple wave-shaped solder joint groups 200 arranged along the radial direction will be formed on each solder joint sub-group 210. According to the angle of 45° and the arc distance of 4 mm, it can be inferred that the first circle of solder joint sub-groups 210 arranged along the circumferential direction is obtained by canceling a group of solder joints 211 between adjacent solder joint sub-groups 210, and the second circle of solder joint sub-groups 210 is obtained by canceling three groups of solder joints 211 between adjacent solder joint sub-groups 210, and so on. Please refer to Figure 3, the arc distance between adjacent solder point sub - groups 210 in the first circle is 8 mm, the arc distance between adjacent solder point sub - groups 210 in the second circle is 16 mm, the arc distance between adjacent solder point sub - groups 210 in the third circle is 24 mm, and the arc distance between adjacent solder point sub - groups 210 in the fourth circle is 32 mm. Since the trajectory of the solder points 211 is formed according to an equal arc distance of 4 mm, it can ensure that the arc distances between multiple solder points 211 on each winding of the winding body 100 are equal, thereby improving the uniformity of current introduction between the full - pole ear 110 and the pole piece. As the number of winding turns increases and the number of solder points 211 increases, a wavy solder point group 200 can be formed.

[0040] Further, the full - pole ear 110 winds around the winding body 100 for multiple turns. The multiple solder points 211 on the full - pole ear 110 are arranged at intervals in sequence along the winding direction Q of the winding body 100. The number of solder points 211 formed on each winding of the full - pole ear 110 is equal, and on the same winding of the full - pole ear 110, along the winding direction Q, the multiple solder points 211 are arranged at equal arc distances. By defining that the multiple solder points 211 on each winding are arranged at equal arc distances and the number of solder points 211 on each winding is equal, as the winding increases, the arc distance between adjacent solder points 211 in each winding will gradually increase, so that the multiple solder points 211 are arranged in an arc shape in the radial direction, forming the solder point group 200. It should be noted that each winding here refers to taking one side of the pole piece as the starting point of winding until the winding first passes through the starting point as one winding, and subsequently, the position passing through the starting point is used as the end point of this winding and the starting point of the next winding.

[0041] In some embodiments, two adjacent solder point sub - groups 210 along the circumferential direction of the winding body 100 form a solder point sub - group pair. The distance between the two solder point sub - groups 210 in each solder point sub - group pair is positively correlated with the distance of the solder point sub - group pair from the center of the winding body 100 in the radial direction, that is, the farther away from the center of the winding body 100, the greater the distance between two adjacent solder point sub - groups 210 in the circumferential direction, and the distance increases linearly. It should be noted that the distance between two solder point sub - groups 210 refers to the distance between the centers of the patterns formed by the two solder point sub - groups 210.

[0042] Further, the arc distance between the two solder point sub - groups 210 in each solder point sub - group pair is: D = n×s;

[0043] Wherein, D represents the arc distance between two adjacent ones of the solder dot sub - groups 210 in one solder dot sub - group pair, n represents the number of the solder dot sub - groups 210 arranged successively radially outward along the winding body 100, and s represents the arc distance between two adjacent solder dots 211 in the first winding of the winding body 100. It can also be seen from the calculation formula of the arc distance between two adjacent solder dot sub - groups 210 that the arc distance is proportional to the number of the solder dot sub - groups 210 arranged successively in the radial direction of the winding body 100 and away from the center of the winding body 100, and is also proportional to the arc distance between two adjacent solder dots 211 in the first winding of the winding body 100.

[0044] It should be noted that the solder dots 211 described in any of the above - mentioned embodiments are all formed by spot - welding. By using the spot - welding method, the distances of the solder dots 211 on the full - pole ear 110 along the winding direction Q are uniform, which is beneficial for the pole ear to uniformly introduce current into the electrode plate. Moreover, by forming the solder dots 211 by spot - welding, the size of the solder dots 211 can be changed according to the actual situation, so as to meet the requirements for the pulling force between the pole ear and the current collector plate in different situations. For the shape of the solder dots 211, according to the actual situation, such as the distance between adjacent winding turns, the distance between adjacent solder dots 211 in the winding direction Q, etc., the solder dots 211 can be set as square - shaped, round - dot - shaped, etc. In this embodiment, round - dot - shaped is preferably used for convenient spot - welding operation. For the diameter range of the solder dots 211, it can be taken as 0.5 to 3 mm.

[0045] It should also be noted that, in order to clearly show the positions of the solder dots 211 in the drawings, the solder dots 211 in all the drawings are represented in the form of hollow dots. The hollow dots are not the actual shapes of the solder dots 211 and should not limit the structural shapes of the solder dots 211.

[0046] In some embodiments, the winding body 100 includes a positive extreme and a negative extreme. The full - pole ear 110 is connected to the positive extreme or the negative extreme, without specific limitation, and can be selected according to the actual situation.

[0047] The embodiments of the present application provide a battery, including the pole - ear welding structure described in any of the above - mentioned embodiments. It should be noted that, because this battery includes the pole - ear welding structure described in any of the above - mentioned embodiments, this battery has beneficial effects similar to or the same as those of the pole - ear welding structure. For the specific derivation process of the beneficial effects, please refer to the embodiments of the pole - ear welding structure part and will not be elaborated here.

[0048] The above has introduced the embodiments of the present application in detail. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A tab welding structure, characterized in that: include: winding body; A full-pole lug is formed at an end of the winding body and is electrically connected to the winding body; The current collector is welded with the full tab to form a plurality of welding point groups, wherein the plurality of welding point groups are radially distributed around the center of the winding body, and the plurality of welding points in each welding point group are arranged in a wave shape along the radial direction of the winding body.

2. The electrode tab welding structure according to claim 1, characterized in that: Along the circumference of the winding body, among the plurality of welding point groups, an angular distance error range between two adjacent welding point groups is between 0° and 5°.

3. The electrode tab welding structure according to claim 2, characterized in that: Along the circumference of the winding body, the plurality of welding point groups are arranged at equal angular distances.

4. The electrode tab welding structure according to claim 1, characterized in that: Each of the welding point groups includes a plurality of welding point subgroups, and a plurality of welding points in each of the welding point subgroups are arranged in an arc shape along the radial direction of the winding body.

5. The electrode tab welding structure according to claim 4, characterized in that: The full pole tab is wound multiple times with the winding body, and the multiple welding points on the full pole tab are arranged in sequence at intervals along the winding direction of the winding body. The number of welding points formed on each circle of the full pole tab is equal, and on the same circle of the full pole tab, along the winding direction, the multiple welding points are arranged at equal arc distances.

6. The electrode tab welding structure according to claim 4, characterized in that: Two adjacent welding point subgroups along the circumferential direction of the winding body form a welding point subgroup pair, and the distance between the two welding point subgroups in each welding point subgroup pair is positively correlated with the distance of the welding point subgroup pair from the center of the winding body along the radial direction.

7. The electrode tab welding structure according to claim 6, characterized in that: The arc distance between the two welding point subgroups in each welding point subgroup pair is: D=n×s; Wherein, D represents the arc distance between two adjacent weld point subgroups in a weld point subgroup pair, n represents the number of weld point subgroups arranged sequentially radially outwardly along the winding body, and s represents the arc distance between two adjacent weld points in the first turn of the winding body.

8. The electrode tab welding structure according to any one of claims 1 to 7, characterized in that: The welding spot is in the shape of a round spot, and the diameter of the welding spot ranges from 0.5 to 3 mm.

9. The electrode tab welding structure according to any one of claims 1 to 7, characterized in that: The winding body includes a positive terminal and a negative terminal, and the full tab is connected to the positive terminal or the negative terminal.

10. A battery, characterized in that: It comprises the electrode tab welding structure as claimed in any one of claims 1 to 9.

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