A current collector welding tool

Abstract

The present disclosure relates to the technical field of battery manufacturing, and particularly relates to a current collector welding tool, which comprises a welding table and a shaping body. The current collector has a folding area close to the direction of the core package and a welding area away from the direction of the core package, and is laid on the welding table. The shaping body has a shaping part which is attached to the current collector to shape the current collector, so that the current collector can be bent to form a redundant area between the folding area and the welding area. The current collector welding tool has a simple overall structure. By arranging the shaping body on the welding table, the current collector is attached to the shaping body to form a bent redundant area, so that the current collector in the bottom area can have a certain length allowance. In the subsequent lug rotating and lifting process, the current collector in the bottom area will not be pulled and broken due to the too short length, so as to improve the preparation yield of the battery cell and improve the product quality.

Description

Technical Field

[0001] This disclosure relates to the field of battery manufacturing technology, and in particular to a tooling for welding current collectors. Background Technology

[0002] With the rapid development of the battery industry, batteries are widely used in automobiles, energy storage, and other fields. A battery mainly consists of a cell pack and its tabs. The cell pack is mainly composed of cell materials and electrolyte. In the tab welding process, an eccentric welding method is often used, that is... Figures 1-4 As shown, the current collector 10 at one end of the core package 20 needs to be gathered towards the thickness side of the core package 20 and laid on the welding platform 1, followed by welding to the tab 30 and rotation lifting. During the rotation lifting process of the tab 30, Figure 4 The current collector 10 in region A needs to be bent upwards. Due to its short length, it is subject to a large pulling force. During the rotation and lifting process of the tab 30, the current collector 10 in this region is very prone to breakage, which leads to high voltage and low capacity, which is not conducive to improving the yield of the battery. Utility Model Content

[0003] To address the aforementioned technical problems, this disclosure provides a tooling for welding current collectors.

[0004] This disclosure provides a welding fixture for a current collector, wherein the current collector is constricted towards one side of the core packing thickness direction, the current collector has a constricted area close to the core packing direction and a welding area away from the core packing direction, wherein the welding fixture for the current collector includes a welding table and a shaping body disposed on the welding table, the current collector is laid on the welding table, the shaping body has a shaping part, the shaping part is fitted with the current collector to shape the current collector, so that the current collector can be bent between the constricted area and the welding area to form a redundant area.

[0005] Optionally, the shaping part has an arcuate area so that the redundant area is curved.

[0006] Optionally, the shaping part has at least two connected mating surfaces.

[0007] Optionally, the shaping part has three sequentially connected mating surfaces.

[0008] Optionally, of the three sequentially connected bonding surfaces, two of the bonding surfaces are arranged in parallel, and the other bonding surface intersects perpendicularly with the two parallel bonding surfaces.

[0009] Optionally, a transition fillet is provided between two adjacent mating surfaces.

[0010] Optionally, the welding fixture for the current collector further includes a pressing body, which is used to move and press down the current collector in the direction of the shaping part to form the redundant area on the current collector.

[0011] Optionally, the pressure body is made of an elastic material.

[0012] Optionally, the pressing body has a mating portion on the side facing the shaping body, and the mating portion is adapted to the shape of the shaping body.

[0013] Optionally, two shaping bodies are provided at intervals, with the two shaping bodies respectively disposed at both ends of the welding table.

[0014] The technical solution provided in this disclosure has the following advantages compared with the prior art: The welding fixture for current collectors in this embodiment has a simple overall structure. By setting a shaping body on the welding table, the current collector and the shaping body are attached to form a bent redundant area, which allows the current collector in the bottom area to have a certain length margin. This prevents the current collector in the bottom area from being pulled and broken due to being too short during the subsequent rotation and lifting of the electrode tab, thereby improving the cell manufacturing yield and product quality. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0016] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the existing current collector welding process Figure 1 ; Figure 2 A schematic diagram of the existing current collector welding process Figure 2 ; Figure 3 A schematic diagram of the existing current collector welding process Figure 3 ; Figure 4 A schematic diagram of the existing current collector welding process Figure 4 ; Figure 5 This is a schematic diagram of the welding process after using the current collector welding fixture described in the embodiments of this disclosure. Figure 1 ; Figure 6This is a schematic diagram of the welding process after using the current collector welding fixture described in the embodiments of this disclosure. Figure 2 ; Figure 7 This is a schematic diagram of the welding process after using the current collector welding fixture described in the embodiments of this disclosure. Figure 3 ; Figure 8 This is a schematic diagram of the welding process after using the current collector welding fixture described in the embodiments of this disclosure. Figure 4 ; Figure 9 This is a schematic diagram of the structure of the shaping body and the pressing body described in the embodiments of this disclosure. Figure 1 ; Figure 10 This is a schematic diagram of the structure of the shaping body and the pressing body described in the embodiments of this disclosure. Figure 2 ; Figure 11 This is a top view of the welding table and the shaping body described in the embodiments of this disclosure; Figure 12 This is a side view of the welding table and the shaping body described in the embodiments of this disclosure.

[0018] in, 1. Welding work surface; 2. Shaping body; 21. Shaping section; 211. Arc area; 212. Fitting surface; 2121. Transition fillet; 3. Pressing body; 31. Fitting part; 10. Current collector; 101. Gathering area; 102. Welding area; 103. Redundancy area; 20. Core packaging; 30. Polar ear; 40. Welding head. Detailed Implementation

[0019] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0020] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0021] like Figures 1-4 As shown, existing soft-pack lithium batteries mostly use eccentric welding for their current collectors. During the pre-welding process, such as... Figure 1As shown, the current collector 10 at one end of the core package 20 is first gathered towards the thickness side of the core package 20 and laid on the welding table 1 (the attached diagram of this embodiment shows a downward gathering as an example), and the current collector 10 located on the welding table 1 is pre-welded. Then, as... Figure 2 As shown, the pre-welded current collector 10 is cut to a suitable length, and the tab 30 is welded to the cut current collector 10. Then, as... Figure 3 and Figure 4 As shown, bend the tab 30 to 90° and then rotate and lift it. Figure 4 As shown, the current collector 10 in region A at the bottom is relatively short. During the rotation and lifting process of the tab 30, the current collector 10 in region A needs to bend upward. Due to its short length, it is subject to a large pulling force and is very prone to breakage, which in turn leads to high voltage and low capacitance.

[0022] To address the aforementioned problems, this embodiment provides a tooling for welding current collectors, such as... Figure 5 As shown, it specifically includes a welding table 1 and a shaping body 2 disposed on the welding table 1.

[0023] Exemplarily, in some embodiments, the shaping body 2 protrudes from the welding platform 1, and the shaping body 2 is generally a boss structure, extending onto the welding platform 1. The current collector 10 is constricted towards the side of the core package 20 in the thickness direction (see attached figure for this embodiment). Figure 5 Taking a downward convergence as an example, the current collector 10 has a convergence area 101 near the core package 20 and a welding area 102 away from the core package 20. The welding area 102 is the area where the current collector 10 will be pre-welded later. Further, the shaping body 2 has a shaping part 21. In this embodiment, the shaping part 21 is located at the top of the shaping body 2. When the current collector 10 is laid on the welding table 1, the shaping part 21 at the top of the shaping body 2 can fit against the current collector 10 to shape it, so that the current collector 10 can be bent between the convergence area 101 and the welding area 102 to form a redundant area 103. This allows the current collector 10 located at the bottom region to have a certain length allowance, so that during the subsequent rotation and lifting of the electrode tab 30, such as... Figure 8 As shown, the current collector 10 located in the bottom region will not break due to excessive length, thereby improving the cell manufacturing yield and product quality.

[0024] Exemplarily, in some embodiments, to allow the current collector 10 to adhere to the shaping part 21 to form a redundant area 103, after the current collector 10 is laid on the welding table surface 1, the current collector 10 can be manually pressed by a worker to allow it to adhere to the shaping part 21 and form the redundant area 103. Furthermore, as... Figure 5As shown, a movable pressing body 3 can also be provided above the shaping body 2. The pressing body 3 can move towards the shaping part 21 to press down the current collector 10, so as to form a redundant area 103 on the current collector 10. In this embodiment, it is preferable to form the redundant area 103 by cooperating with the shaping body 2 to improve the degree of automation and work efficiency. Preferably, the width of the pressing body 3 is greater than or equal to the width of the shaping body 2, so that the pressing body 3 can cooperate effectively with the shaping body 2.

[0025] In some embodiments, such as Figure 9 As shown, the shaping part 21 of the shaping body 2 has an arc-shaped area 211, which allows the current collector 10 to fit against the arc-shaped area 211 to form an arc-shaped bending redundant area 103. This is suitable for current collectors 10 with thin foil and few layers, that is, it is more suitable for negative electrode copper foil current collectors with a single layer <6μm, which is beneficial for its forming and avoids cracking. It can be understood that because the current collector 10 is thin and has few layers, it is easier to form. The arc-shaped area 211 fits against the current collector 10, which can effectively avoid local stress concentration in the current collector 10, thereby avoiding cracking.

[0026] In some embodiments, the shape of the shaping part 21 includes, but is not limited to, the arc shape described above. For example, the shaping part 21 may also have two connected mating surfaces 212, which are arranged at an angle and mated to the current collector 10 to form a V-shaped redundant area 103. Furthermore, the shaping part 21 may also have three or more mating surfaces 212 to make the cross-section of the shaping body 2 rectangular or trapezoidal.

[0027] For example, in this embodiment, such as Figure 10As shown, when the shaping part 21 has three bonding surfaces 212, two of the three bonding surfaces 212 are arranged in parallel, and the other bonding surface 212 intersects the two parallel bonding surfaces 212 perpendicularly, so that the cross-section of the shaped body 2 is rectangular. This is suitable for current collectors 10 with thicker foil and more layers, that is, it is more suitable for positive aluminum foil current collectors. Each bonding surface 212 can be bonded to the current collector 10, so that the current collector 10 is subjected to uniform force, which is beneficial for the formation of the redundant area 103, and at the same time, it is not easy for local breakage to occur. Understandably, since the current collector 10 has a relatively thick foil and many layers, using an arc-shaped shaping part 21 would make it difficult to form a distinct shape and redundant areas 103 (the arc-shaped shaping part 21 only has one bending segment, while the three connected bonding surfaces 212 have at least two bending segments, resulting in a more obvious shape). Furthermore, a thicker and more layered current collector 10 requires greater pressure for molding. When using an arc-shaped shaping part 21, the current collector 10 at the highest point of the arc is prone to tensile breakage under high pressure. In contrast, the rectangular shaping body 2 has a flat top structure, making it less susceptible to tensile breakage. Therefore, when the current collector 10 has many layers and the foil is thick and difficult to mold, a rectangular shaping body 2 is preferred; when the current collector 10 has fewer layers and the foil is thinner and easier to mold, an arc-shaped shaping body 2 is preferred.

[0028] In addition to the above-described form, the shaping part 21 may also have four, five or more mating surfaces 212 connected end to end, so that the redundant area 103 forms a polygonal structure, including but not limited to the shape shown in the attached drawings of this embodiment, and the design may be selected according to the actual situation.

[0029] Furthermore, such as Figure 10 As shown, a transition fillet 2121 is provided between two adjacent mating surfaces 212 in this embodiment to eliminate stress concentration at the corner, prevent the current collector 10 from cracking, and also prevent the current collector 10 from being scratched.

[0030] In some embodiments, the pressure body 3 may be made of an elastic material so that the pressure body 3 can make soft contact with the current collector 10, further preventing the current collector 10 from undergoing hard contact fracturing.

[0031] In some embodiments, such as Figure 9 and Figure 10 As shown, the pressing body 3 has a mating part 31 on the side facing the shaping body 2. In this embodiment, the mating part 31 has an inwardly recessed groove structure, and the shape of the mating part 31 matches the shape of the shaping part 21. That is, as shown... Figure 9 As shown, when the shaping part 21 has an arc-shaped area 211 and the cross-section of the shaping body 2 has an arc-shaped structure, the mating part 31 corresponds to an arc-shaped groove; when the shaping part 21 has three connected mating surfaces 212, as... Figure 10As shown, the mating part 31 is a rectangular groove to fit the shaping part 21, which facilitates the forming of the redundant area 103.

[0032] Optionally, such as Figure 11 As shown, two shaping bodies 2 can be provided at intervals, located at both ends of the welding table 1 respectively. When one shaping body 2 is worn, the other shaping body 2 can be used as a spare part so as not to delay the production schedule.

[0033] Optionally, such as Figure 11 and Figure 12 As shown, the width dimension L of the shaping body 2 in this embodiment is designed and adjusted according to the production process, and the protrusion height dimension H of the shaping body 2 is determined according to the foil thickness and number of layers of the current collector 10. For example, the height dimension H = single layer foil thickness * total number of layers * 30%.

[0034] Optionally, in this embodiment, the pressing body 3 can be directly fixedly mounted on the welding head 40, such as... Figure 5 As shown, the pressing body 3 moves synchronously with the welding head 40 to complete the molding and pre-welding of the current collector 10. In addition, the pressing body 3 can also be designed independently of the welding head 40. After the pressing body 3 and the shaping body 2 are pressed together, the welding head 40 is then started to perform pre-welding. The method can be selected according to the actual situation, including but not limited to the method shown in this embodiment. In this embodiment, it is preferred that the pressing body 3 is directly fixed on the welding head 40.

[0035] It is worth noting that in some embodiments, the shaping part 21 of the shaping body 2 can also be a groove structure, and the mating part 31 of the pressing body 3 can be a protrusion structure. Their combined use can also cause the current collector 10 to bend between the gathering area 101 and the welding area 102 to form a redundant area 103, which can also achieve the above purpose. In this embodiment, the shaping part 21 of the shaping body 2 is a protrusion structure and the mating part 31 of the pressing body 3 is a groove structure as an example, including but not limited to the forms shown in the attached drawings of this embodiment.

[0036] In summary, the specific usage process of the welding fixture for current collectors in this embodiment can be referred to as follows: First, such as Figure 5 As shown, the current collector 10 at one end of the core package 20 is first gathered to one side and laid on the welding table 1 (the attached figure of this embodiment takes the gathering downward as an example), and the current collector 10 is laid flat on the shaping body 2. Then the pre-welding begins. The welding head 40 and the pressing body 3 move down synchronously. The pressing body 3 moves down and cooperates with the shaping body 2 to squeeze the current collector 10, so as to form a redundant area 103 on the current collector 10. The welding head 40 moves down to pre-weld the welding area 102 of the current collector 10 (in some embodiments, if the pressing body 3 is not set, after the current collector 10 is laid flat on the shaping body 2, the worker can manually press the current collector 10 on the shaping body 2 to form the redundant area 103, and then perform pre-welding). Subsequently, as Figure 6 As shown, the pre-welded current collector 10 is cut to a suitable length, that is, the welding area 102 of the current collector 10 is cut and shaped, and the electrode tab 30 is welded and fixed to the welding area 102 of the current collector 10 by the main welding. Finally, as Figure 7 and Figure 8 As shown, after bending and rotating the tab 30, since the current collector 10 has a redundant area 103 formed on it, that is, a certain length margin is left, the current collector 10 in the bottom area is not prone to being pulled and broken when the tab 30 is bent and lifted, which can effectively improve the yield of the battery cell.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A welding fixture for a current collector, wherein the current collector (10) is constricted towards one side of a core package (20) in the thickness direction, the current collector (10) having a constriction area (101) in the direction close to the core package (20) and a welding area (102) in the direction away from the core package (20), characterized in that, The welding fixture for the current collector includes a welding table (1) and a shaping body (2) disposed on the welding table (1). The current collector (10) is laid on the welding table (1). The shaping body (2) has a shaping part (21). The shaping part (21) fits against the current collector (10) to shape the current collector (10) so that the current collector (10) can be bent between the gathering area (101) and the welding area (102) to form a redundant area (103).

2. The tooling for welding current collectors according to claim 1, characterized in that, The shaping part (21) has an arc surface area (211) so that the redundant area (103) is curved.

3. The tooling for welding current collectors according to claim 1, characterized in that, The shaping part (21) has at least two connected mating surfaces (212).

4. The tooling for welding current collectors according to claim 3, characterized in that, The shaping part (21) has three sequentially connected mating surfaces (212).

5. The tooling for welding current collectors according to claim 4, characterized in that, Of the three sequentially connected bonding surfaces (212), two of the bonding surfaces (212) are arranged in parallel, and the other bonding surface (212) intersects perpendicularly with the two parallel bonding surfaces (212).

6. The tooling for welding current collectors according to claim 3, characterized in that, A transition fillet (2121) is provided between two adjacent mating surfaces (212).

7. The tooling for welding current collectors according to any one of claims 1-6, characterized in that, The welding fixture for the current collector also includes a pressing body (3), which is used to move and press down the current collector (10) in the direction of the shaping part (21) to form the redundant area (103) on the current collector (10).

8. The tooling for welding current collectors according to claim 7, characterized in that, The pressure body (3) is made of an elastic material.

9. The tooling for welding current collectors according to claim 7, characterized in that, The pressing body (3) has a fitting part (31) on the side facing the shaping body (2), and the fitting part (31) is adapted to the shape of the shaping part (21).

10. The tooling for welding current collectors according to any one of claims 1-6, characterized in that, Two shaping bodies (2) are spaced apart, and the two shaping bodies (2) are respectively located at both ends of the welding table (1).

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