A tab shaping device and battery core-combining system for the core-combining process

Abstract

A tab shaping device and battery core-combining system for the core-combining process are disclosed, relating to the field of battery manufacturing technology. The tab shaping device includes an airbag rod, a positive electrode airbag, and a negative electrode airbag. The positive and negative electrode airbags are independently sleeved on the airbag rod, with a partition gap between them. An internal air channel is provided inside the airbag rod, extending to the rod section covered by the positive and negative electrode airbags and communicating with them respectively. This invention effectively avoids problems such as tab damage, stress concentration, and inconsistent bending that may occur with traditional mechanical rigid pressing.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to a tab shaping device for the core-gathering process. Background Technology

[0002] In battery manufacturing, the tabs, as key metal conductors connecting the internal electrodes of the cell to the external circuitry, directly affect the battery's final performance and safety through the precision and quality of their fabrication and subsequent processing. However, tabs are highly susceptible to deformation during production, a common and significant technical challenge. Tab deformation can lead to a series of negative consequences, including increased internal resistance, decreased charge / discharge performance, and shortened cycle life. More seriously, it can cause localized overheating, short circuits, and even thermal runaway due to poor contact, posing safety hazards.

[0003] In the prior art, for example, Chinese utility model patent with authorization announcement number CN223159854U discloses a battery tab shaping mechanism and device. The tab shaping mechanism of this utility model includes a first linear drive device and a shaping frame disposed at the output end of the first linear drive device. The shaping frame includes a connecting rod and multiple shaping rods disposed on the same side of the connecting rod. The end of the shaping rod facing away from the connecting rod has a guide structure that is narrow at the bottom and wide at the top, and narrow at the front and wide at the back, so as to shape the tab from the root to the top when it extends laterally to the side of the tab.

[0004] However, in the core-assembly process of aluminum-cased prismatic energy storage batteries, the traditional top-down, top-pressing shaping method has limitations due to the need to stack the wound cores. This method carries the risk of damaging the tabs. Furthermore, inconsistencies in the bending state of the tabs often occur during core assembly, and stress concentration due to ultrasonic welding can easily lead to the tabs being pulled apart during the assembly process. These problems can even cause the tabs to be inserted in reverse, resulting in a short circuit risk. Currently, tab shaping devices suitable for the core-assembly process are still insufficient, and a dedicated shaping solution that can adapt to the characteristics of this process and ensure consistent and reliable tab shape is needed. Utility Model Content

[0005] The technical problem to be solved by this utility model is the problem of short circuit caused by pulling the tabs during the core assembly process.

[0006] To achieve the above objectives, according to one aspect of the utility model, a tab shaping device for the core-combining process is provided, comprising an airbag rod, a positive electrode airbag, and a negative electrode airbag; the positive electrode airbag and the negative electrode airbag are independently sleeved on the airbag rod, and a partition gap is provided between the positive electrode airbag and the negative electrode airbag; the airbag rod has a central air channel inside, which extends to the rod segment covered by the positive electrode airbag and the negative electrode airbag, and communicates with the positive electrode airbag and the negative electrode airbag respectively.

[0007] As a preferred embodiment of the above technical solution, a rotating mechanism is also included, which is connected to the airbag rod and is used to drive the airbag rod to rotate clockwise or counterclockwise.

[0008] As a preferred embodiment of the above technical solution, the cross-sectional shape of the positive and negative airbags is an asymmetric composite curved surface, including an inner arc surface and an outer arc surface with different curvatures; the curvature center of the inner arc surface is located on the central axis of the airbag rod; the rotating mechanism is configured to drive the airbag rod, the positive airbag and the negative airbag to reciprocate around the central axis of the airbag rod with a limited angle.

[0009] As a preferred embodiment of the above technical solution, the projected area of ​​the outer arc surface is larger than the projected area of ​​the inner arc surface.

[0010] As a preferred embodiment of the above technical solution, the central air channel includes a central air supply channel extending along the axial direction of the airbag rod and a plurality of radial distribution channels communicating with the central air supply channel; the radial distribution channels are evenly distributed circumferentially within the wall of the airbag rod, and the outlet end of the radial distribution channels extends to the surface of the rod segment covered by the positive and negative airbags, forming a plurality of evenly distributed air holes.

[0011] As a preferred embodiment of the above technical solution, the two ends of the airbag rod are provided with rotary sealing joints for continuous air supply when the airbag rod rotates.

[0012] As a preferred embodiment of the above technical solution, the positive electrode airbag and the negative electrode airbag are inflatable airbag structures made of woven nylon.

[0013] A battery core assembly system includes a core folding mechanism, a cover plate, a pushing mechanism, and two sets of tab shaping devices as described in any of the above technical solutions. The two sets of tab shaping devices are suspended above the cover plate by the pushing mechanism and precisely aligned with the tab shaping station on the cover plate. The core folding mechanism is disposed on both sides of the cover plate to support two stacks of cores and perform a folding action to make the two stacks of cores overlap. The pushing mechanism is connected to the tab shaping device and is used to drive the entire device to move in a direction parallel to the plane of the cover plate.

[0014] In summary, this utility model has the following advantages: 1. This utility model achieves independent, flexible, and controllable inflation and shaping of the positive and negative electrode tabs by using independent positive and negative electrode airbags with a gap between them, in conjunction with the air channel inside the airbag rod. This effectively avoids problems such as electrode tab damage, stress concentration, and inconsistent bending that may be caused by traditional mechanical rigid pressing, and provides a reliable guarantee for the subsequent core bonding process. 2. Furthermore, the rotating mechanism drives the airbag rod to reciprocate around its central axis at a limited angle via a servo motor and reducer. This combination with the asymmetric composite curved surface design of the airbag allows the outer arc surface to generate a composite motion that combines rolling and crushing relative to the electrode surface, achieving extended crushing and flattening of the electrode from the center to both sides. 3. Furthermore, the air channel adopts a central air supply channel extending along the axial direction of the airbag rod, combined with radially distributed channels evenly arranged in the circumference, ultimately forming multiple sets of evenly distributed air holes on the surface of the rod section; in this way, it is ensured that the compressed gas can be evenly and synchronously filled into all parts of the positive and negative airbags, avoiding the problem of local deformation of the airbag or inconsistent force on the electrode tabs caused by uneven inflation pressure.

[0015] Further or other beneficial effects will be discussed in the embodiments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the electrode tab shaping device in the core-combining process of this utility model; Figure 2 This is a perspective view of the airbag rod and airbag assembly of this utility model; Figure 3 This is a schematic diagram of the cross-section of the airbag rod and the airbag of this utility model; Figure 4 This is a schematic diagram of the process of pressing the electrode sheet for the airbag of this utility model; Figure 5 This is a schematic diagram of the battery cell assembly system of this utility model; Among them, 100-airbag rod, 200-positive electrode airbag, 300-negative electrode airbag, 400-central air passage, 500-rotation mechanism, 231-inner arc surface, 232-outer arc surface, 401-central air supply passage, 402-radial distribution passage, 600-rotary sealing joint, 700-cover plate, 800-pushing mechanism, a-winding core, b-electrode tab. Detailed Implementation

[0017] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.

[0018] The present invention will be further explained below with reference to the embodiments: Example 1:

[0019] A tab shaping device for a core-combining process includes an airbag rod 100, a positive electrode airbag 200, and a negative electrode airbag 300. The positive electrode airbag 200 and the negative electrode airbag 300 are independently mounted on the airbag rod 100, with a pre-existing gap between them to ensure that the shaping operations of the positive and negative electrode tabs of the battery do not interfere with each other. An internal air channel 400 is provided inside the airbag rod 100, extending to the rod section covered by the positive electrode airbag 200 and the negative electrode airbag 300, and communicating with the positive electrode airbag 200 and the negative electrode airbag 300 respectively.

[0020] The central air channel 400 includes a central air supply channel 401 extending axially along the airbag rod 100 and a plurality of radial distribution channels 402 communicating with the central air supply channel 401; the radial distribution channels 402 are evenly distributed circumferentially within the wall of the airbag rod 100, and the outlet end of the radial distribution channels 402 extends to the surface of the rod segment covered by the positive electrode airbag 200 and the negative electrode airbag 300, forming a plurality of evenly distributed air holes.

[0021] To drive the airbag rod 100 and its positive and negative airbags 200 to move precisely, the device also includes a rotating mechanism 500. This rotating mechanism 500 typically includes a servo motor and a reducer. The servo motor is connected to the airbag rod 100 via the reducer and can drive the airbag rod 100 to reciprocate around its own central axis at a limited angle.

[0022] The airbag's cross-sectional shape is designed as an asymmetrical composite curved surface, comprising an inner arc surface 231 and an outer arc surface 232 with different curvatures. The center of curvature of the inner arc surface 231 is located on the central axis of the airbag rod 100, allowing it to conform well to the rod. Specifically, the inner arc surface 231 is a circular arc surface; the outer arc surface 232 consists of two symmetrically arranged arc surfaces with a smaller curvature than the inner arc surface 231 (i.e., a larger radius of curvature), and is smoothly tangent to the inner arc surface 231, giving the entire airbag cross-section an oval or teardrop shape. Thanks to the larger radius of curvature of the outer arc surface 232, its projected area is typically larger than that of the inner arc surface 231, thus providing a wider effective working area and improving the contact effect during shaping operations.

[0023] In the specific implementation process, the device is installed at the corresponding station in the core-combining process. First, the battery core to be shaped is precisely positioned so that its positive and negative tabs are aligned with the positive electrode airbag 200 and negative electrode airbag 300 on the airbag rod 100, respectively. Gas at a set pressure is independently injected into the two airbags through the air channel 400, causing them to expand and gently release and press the corresponding tabs. Then, the rotating mechanism 500 is activated to drive the airbag rod 100 to perform a controllable reciprocating rotational movement: for example, first rotating counterclockwise so that one side of the outer arc surface 232 is in contact with the electrode sheet and the area is shaped; then rotating clockwise to shape the adjacent area of ​​the electrode sheet using the other side of the arc surface (the operation sequence can also be reversed). The area processed by this device is the bending and deformation area of ​​the tabs during the core-combining of aluminum-cased square energy storage batteries. Fully flattening this area is crucial for subsequent core-combining processes. During this process, the unique asymmetric outer arc surface 232 of the airbag forms a composite motion combining rolling and pressing relative to the electrode surface, which can achieve a gentle and uniform extended flat processing of the electrode, effectively eliminating stress concentration caused by ultrasonic welding, making the bending shape of all electrodes highly consistent, and significantly reducing the risk of short circuits caused by poor electrode shape during the core assembly process.

[0024] To ensure that the airbag rod 100 can continuously receive gas supply when rotating, it is equipped with rotary sealing joints 600 (not shown in the figure) at both ends for connecting to an external gas source.

[0025] The positive electrode airbag 200 and the negative electrode airbag 300 are preferably inflatable airbag structures made of woven nylon, a material that combines flexibility, strength and durability. Example 2:

[0026] A battery core assembly system includes a core folding mechanism (not shown in the figure), a cover plate 700, a pushing mechanism 800, and two sets of tab shaping devices as described in Embodiment 1. The two sets of tab shaping devices are suspended above the cover plate 700 by the pushing mechanism 800 and precisely aligned with the tab b shaping station on the cover plate 700. The core a folding mechanism is disposed on both sides of the cover plate 700 to support two stacks of core a and perform a folding action to make the two stacks of core a overlap. The pushing mechanism 800 is connected to the tab shaping device and is used to drive the entire device to move horizontally in a direction parallel to the plane of the cover plate 700.

[0027] The specific core-combining process is as follows: The transport device transports the aluminum-cased square battery to be combined to the battery core-combining system. At this time, the two cores are located on the core-folding mechanism, and the tabs b and connecting pieces between the cores are located on the cover plate 700. The positive electrode connecting piece is made of aluminum, and the negative electrode connecting piece is made of copper. The core-folding mechanism starts to move, adjusting the angle between the core and the cover plate 700 to 135°~150°. The pushing mechanism 800 moves, pushing the two sets of tab-shaping devices horizontally to directly above the tabs b. The airbag inflates to press the tabs b tightly. Then, the airbag rotation step described in Example 1 is executed to complete the extended flattening process of the tabs. After the shaping is completed, the airbag is deflated and maintains a slight negative pressure state. The tab-shaping devices can be driven out of the working area by the pushing mechanism 800. Finally, the two cores are folded and contacted under the action of the core-folding mechanism, completing the core-combining process.

[0028] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0029] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A tab shaping device for the core-joining process, characterized in that, It includes an airbag rod (100), a positive electrode airbag (200), and a negative electrode airbag (300); the positive electrode airbag (200) and the negative electrode airbag (300) are independently sleeved on the airbag rod (100), and a partition gap is provided between the positive electrode airbag (200) and the negative electrode airbag (300); the airbag rod (100) has a central air channel (400) inside, which extends to the rod segment covered by the positive electrode airbag (200) and the negative electrode airbag (300), and communicates with the positive electrode airbag (200) and the negative electrode airbag (300) respectively.

2. The electrode tab shaping device for the core-combining process according to claim 1, characterized in that, It also includes a rotating mechanism (500) connected to the airbag rod (100) for driving the airbag rod (100) to rotate clockwise or counterclockwise.

3. The electrode tab shaping device for the core-combining process according to claim 2, characterized in that, The cross-sectional shape of the positive electrode airbag (200) and the negative electrode airbag (300) is an asymmetric composite curved surface, including an inner arc surface (231) and an outer arc surface (232) with different curvatures; the curvature center of the inner arc surface (231) is located on the central axis of the airbag rod (100); the rotating mechanism (500) is configured to drive the airbag rod (100), the positive electrode airbag (200) and the negative electrode airbag (300) to reciprocate around the central axis of the airbag rod (100) with a limited angle.

4. The electrode tab shaping device for the core-combining process according to claim 3, characterized in that, The projected area of ​​the outer arc surface (232) is greater than the projected area of ​​the inner arc surface (231).

5. The electrode tab shaping device for the core-combining process according to claim 1, characterized in that, The central air channel (400) includes a central air supply channel (401) extending axially along the airbag rod (100) and a plurality of radial distribution channels (402) communicating with the central air supply channel (401); the radial distribution channels (402) are evenly distributed circumferentially within the wall of the airbag rod (100), and the outlet end of the radial distribution channels (402) extends to the surface of the rod segment covered by the positive electrode airbag (200) and the negative electrode airbag (300), forming a plurality of evenly distributed air holes.

6. The electrode tab shaping device for the core-combining process according to claim 2, characterized in that, The airbag rod (100) is provided with rotary sealing joints (600) at both ends for continuous air supply when the airbag rod (100) rotates.

7. The electrode tab shaping device for the core-combining process according to claim 1, characterized in that, The positive electrode airbag (200) and the negative electrode airbag (300) are inflatable airbag structures made of woven nylon.

8. A battery cell assembly system, characterized in that, The device comprises a core folding mechanism, a cover plate (700), a pushing mechanism (800), and two sets of tab shaping devices as described in any one of claims 1-7; the two sets of tab shaping devices are suspended above the cover plate (700) via the pushing mechanism (800) and precisely aligned with the tab (b) shaping station on the cover plate (700); the core folding mechanism is disposed on both sides of the cover plate (700) for supporting two stacks of cores (a) and performing a folding action to make the two stacks of cores (a) overlap; the pushing mechanism (800) is connected to the tab shaping device and is used to drive its entirety to move in a direction parallel to the plane of the cover plate (700).

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