Tab forming device

Abstract

The utility model discloses a tab forming device, include: first mould, including first template, the inside of first template is equipped with recess, and the lower extreme of first forming groove, first forming hole, U groove is equipped with indentation forming plate, and indentation forming plate and the groove wall cooperation of U groove form second forming groove, second mould, including second template, and the inside of second template is equipped with boss, and boss and recess cooperation form the coating area forming cavity of pole piece, the lower extreme of second template is equipped with first forming plate, tab cutting plate, second forming plate, and tab cutting plate and indentation forming plate cooperate on the one side of pole piece close to tab body and form indentation, bending roller is used for in first mould and second mould cooperation complete non -coating area punching -cutting after, and the folding part on pole piece is along indentation and is folded to the tab body place. The utility model can under the premise of not additional auxiliary material, fully promote material utilization, and effectively enhance the structural strength of tab.

Description

Technical Field

[0001] This utility model relates to an electrode forming device, belonging to the field of lithium-ion battery technology. Background Technology

[0002] In the field of stacked battery manufacturing, the electrodes of different types of batteries have clear structural commonalities: the electrodes adapted to VDA batteries or blade batteries have a rectangular symmetrical structure, while the electrodes adapted to prismatic batteries with stacked technology have a circular symmetrical structure, and both types of electrodes meet the characteristic of uniform mass distribution.

[0003] For the aforementioned electrodes with uniform quality and symmetrical structure, existing technologies propose using the centroid plumb line method (also known as the suspension method) to achieve electrode alignment. The specific operating principle is as follows (see...). Figure 1 As shown): Figure 1 Taking the rectangular electrode shown in (a) as an example, due to the symmetrical structure and uniform mass distribution of the electrode, its center of gravity B is located on the line connecting the midpoint of its length and the midpoint of its width. A circular positioning hole A is pre-drilled in the tab area along the extension of the line connecting the center of gravity and the midpoint of the width. In use, a metal slide rod C is passed through this circular positioning hole A, and the electrode slides naturally along the slide rod under its own gravity, ultimately achieving automatic alignment. Figure 1 (b).

[0004] However, in practical industrial applications, this center-of-gravity plumb line method has the following problems due to the extremely thin thickness of the electrode tabs: First, when the electrode tabs are matched and aligned with the metal slide rod, they inevitably bear contact forces and frictional forces. The insufficient thickness of the electrode tabs results in weak resistance to force, making them prone to tearing and ultimately causing the entire electrode sheet to be scrapped. Second, the weight of the electrode sheet itself acts directly on the electrode tabs, and the thinness limits the load-bearing capacity of the electrode tabs, making them very prone to breakage. In addition, if the surface smoothness of the metal slide rod does not meet the ideal standard, the thinness of the electrode tabs and the small contact area with the slide rod will further increase the friction between the two, making it difficult for the electrode sheet to slide down the slide rod and significantly reducing the electrode sheet alignment efficiency. Summary of the Invention

[0005] To address the problems existing in the prior art, this utility model provides an electrode tab forming device that can fully improve material utilization and effectively enhance the structural strength of the electrode tab without adding additional auxiliary materials.

[0006] To achieve the above objectives, this utility model employs an electrode tab forming device, comprising: The first mold includes a first template, the inner side of which is provided with a groove; the lower right side of the first template is provided with a first forming groove, the lower middle part of which is provided with a first forming hole, and the lower left side of which is provided with a U-shaped groove. The U-shaped groove is provided with an indentation forming plate, and the indentation forming plate and the groove wall of the U-shaped groove cooperate to form a second forming groove. The second mold, corresponding to the first mold, is used to form the tab. The second mold includes a second template, and a protruding plate is provided on the inner side of the second template. The protruding plate and the groove cooperate to form the coating area forming cavity of the electrode sheet. A first forming plate that cooperates with the first forming groove is installed on the lower right side of the second template, and a tab cutting plate is installed in the lower middle part. A second forming hole corresponding to the first forming hole is provided through the tab cutting plate, and the tab cutting plate and the indentation forming plate cooperate to form an indentation on the side of the electrode sheet near the tab body. A second forming plate that cooperates with the second forming groove is installed on the lower left side of the second template. A bending roller is set on one side of the first mold and the second mold. After the first mold and the second mold cooperate to complete the punching of the uncoated area, the folded part on the electrode sheet is folded along the indentation to the electrode tab body.

[0007] As an improvement, the end face of the electrode cutting plate facing the end face of the groove wall of the U-shaped groove where the indentation forming plate is connected is provided with an indentation groove, and the end face of the electrode cutting plate is provided with a straight protrusion that cooperates with the indentation groove; when the first mold and the second mold are closed, the protrusion is embedded in the indentation groove, and the two cooperate to form the indentation by pressing the uncoated area of ​​the electrode sheet near the electrode body.

[0008] As an improvement, both the first forming groove and the second forming groove are L-shaped; the first forming groove cooperates with the first forming plate to punch the waste material on the right side of the uncoated area of ​​the electrode sheet, and the second forming groove cooperates with the second forming plate to punch the waste material on the left side of the uncoated area of ​​the electrode sheet.

[0009] As an improvement, the first forming plate, the tab cutting plate, and the second forming plate are all movably mounted on the second template, and the heights of the first forming plate, the tab cutting plate, and the second forming plate are all the same as the convex plate.

[0010] As an improvement, the electrode has a symmetrical structure, which is rectangular or circular.

[0011] As an improvement, the electrode includes a coated area and an uncoated area. The folded portion and the electrode body are both located in the uncoated area, and the electrode body is connected to the edge of the coated area. The sidewall at the connection between the two adopts an arc transition, and the width of the folded portion is the same as the width of the electrode body.

[0012] As an improvement, the material of the uncoated area is metal foil.

[0013] As an improvement, the second forming hole on the tab cutting plate is coaxially arranged with the first forming hole on the first template.

[0014] Compared with the prior art, the beneficial effects of this utility model are: (1) Significantly improves the strength of the tab and reduces the risk of tearing. The device of this utility model uses a bending roller to precisely fold the folded part of the electrode along the indentation to form a double-layer metal foil reinforced structure, which increases the load-bearing capacity of the tab body by more than 1 times compared with the single-layer structure. This design can effectively avoid the problem of local stress concentration caused by the thinness of the single-layer foil when the metal slide rod passes through the positioning hole and the electrode slides down the slide rod under gravity during the stacking of the electrode by the center of gravity plumb line method, thereby reducing the scrap of the electrode caused by the tearing of the tab from the source.

[0015] (2) Accelerate electrode stacking efficiency. On the one hand, the device can simultaneously complete the punching and creasing of the non-coated waste area through the precise cooperation of the first and second forming grooves and the forming plate, simplifying the electrode tab pretreatment process; on the other hand, after the electrode tab strength is improved, the smoothness of the electrode sliding down the slide bar is improved, and there is no need to reduce the stacking speed due to the fear of tearing, which indirectly improves the operating efficiency of the electrode detachment device and the overall stacking rate.

[0016] (3) Ensure production quality and reduce defect rate. The device uses the cooperation of the convex plate and the groove to position the coating area to ensure the mold closing accuracy; at the same time, the double-layer structure reinforced the tabs can stably adapt to the alignment requirements of the center of gravity plumb line method, reduce the defective products caused by tab tearing and obstruction of sliding, and significantly improve the quality stability of stacking production. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the existing method for aligning electrode plates using the center of gravity plumb line method; in the diagram, A is the circular positioning hole, B is the center of gravity, and C is the metal sliding rod. Figure 2 This is a front view of the tab forming device of this utility model (bending roller not shown). Figure 3 This is a schematic diagram of the structure of the first mold of this utility model; Figure 4 This is a schematic diagram of the structure of the second mold of this utility model; Figure 5 This is an isometric view of the tab forming device of this utility model; Figure 6 This is a flowchart of the electrode tab forming process of this utility model; In the diagram: 1. First mold, 1-1. Groove, 1-2. First forming groove, 1-3. First forming hole, 1-4. Indentation forming plate, 1-5. Second forming groove, 1-6. Indentation groove; 2. Second mold, 2-1. Protruding plate; 3. First forming plate; 4. Tab cutting plate, 4-1. Second forming hole, 4-2. Protrusion; 5. Second forming plate; 6. Bending roller; 7. Coated area; 8. Uncoated area; 9. Punching area; 10. Indentation; 11. Folded part. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this application will be described in detail below through specific embodiments. It should be understood that the embodiments of this application and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. In the absence of conflict, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0020] In the description of this utility model, it should be understood that the terms "upper," "lower," "left," and "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0021] like Figures 2-6 As shown, an electrode forming device is used for electrode tab processing of lithium-ion battery sheets, including a first mold 1, a second mold 2 and a bending roller 6. The first mold 1 includes a rectangular first template. On the inner wall (mold-closing surface) of the first template facing the second mold 2, there is a groove 1-1 that matches the contour of the coating area 7 of the electrode sheet. The groove 1-1 is used to precisely define the position of the coating area 7 when the electrode sheet is placed, so as to avoid damage to the coating in subsequent processing steps. The lower right side of the first template is provided with a first forming groove 1-2, the middle of the lower end is provided with a first forming hole 1-3, and the lower left side is provided with a U-shaped groove. The U-shaped groove is fitted with an indentation forming plate 1-4. The outer peripheral wall of the indentation forming plate 1-4 is closely fitted with the groove wall of the U-shaped groove to form a second forming groove 1-5, which provides a fixed cutting edge for punching the waste material on the left side. The second mold 2 is correspondingly set to the first mold 1. Through the mold closing action, the tabs are punched and indented. The second mold 2 includes a second template parallel to the first template. A protruding plate 2-1 is integrally formed on the inner wall of the second template facing the first mold 1. The shape and size of the protruding plate 2-1 are perfectly matched with the groove 1-1 of the first template. When the mold is closed, the protruding plate 2-1 can be embedded in the groove 1-1, and the two enclose a closed electrode coating area forming cavity, completely enclosing and protecting the electrode coating area 7. A first forming plate 3 is movably installed on the lower right side of the second template. The first forming plate 3 is matched with the first forming groove 1-2 and is used to cooperate in punching the waste material on the right side of the non-coated area 8. A tab cutting plate 4 is movably installed in the middle of the lower end of the second template. A second forming hole 4-1 is provided through the tab cutting plate 4. The second forming hole 4-1 is correspondingly set to the first forming hole 1-3, and the tab cutting plate 4 can be used with the indentation forming plate 1-4. An indentation 10 is formed on the electrode sheet; a second forming plate 5 is movably installed on the lower left side of the convex plate 2-1, the second forming plate 5 is adapted to the second forming groove 1-5, and is used to punch the waste material on the left side of the uncoated area 8; The bending roller 6 is located on one side of the first mold 1 and the second mold 2 (near the side of the electrode folding part 11). The bending roller 6 is used to move along a preset trajectory to the folding part 11 of the electrode after the first mold 1 and the second mold 2 cooperate to punch the uncoated area 8, and to fold the folding part 11 of the electrode precisely along the indentation 10 to the electrode tab body to form a double-layer reinforced structure. After the folding is completed, the bending roller 6 can be reset along the original trajectory and wait for the next operation.

[0022] In some embodiments, such as Figure 3 As shown, a straight indentation groove 1-6 is formed at the connection between the indentation forming plate 1-4 and the first template (i.e., the wall of the U-shaped groove) and on the end face facing the tab cutting plate 4; correspondingly, a straight protrusion 4-2 that perfectly matches the shape and size of the indentation groove 1-6 is integrally formed on the end face of the tab cutting plate 4 facing the indentation forming plate 1-4. When the first mold 1 and the second mold 2 are closed, the straight protrusion 4-2 can be precisely embedded in the indentation groove 1-6. Through the squeezing action of the mold closing, a uniform depth and clear edge indentation 10 is formed on the surface of the uncoated area 8 of the electrode sheet near the tab body. This indentation 10 can provide a clear reference for the subsequent precise folding of the electrode sheet folding part 11 by the bending roller 6, avoiding folding misalignment.

[0023] In some embodiments, as shown in Figures 3 and 4, the first forming groove 1-2 and the second forming groove 1-5 have similar structures, both designed as L-shaped in the same direction. The first forming groove 1-2 forms a punching fit with the first forming plate 3 on the lower right side of the convex plate 2-1. This fit is specifically designed for precisely punching the waste material on the right side of the uncoated area 8 of the electrode sheet. The second forming groove 1-5 forms a punching fit with the second forming plate 5 on the lower left side of the convex plate 2-1. This fit is specifically designed for precisely punching the waste material on the left side of the uncoated area 8. Through corresponding punching on both sides, it can be ensured that the waste material on the left and right sides of the uncoated area 8 is completely separated from the electrode body, and the separation edge is flat and burr-free, avoiding waste residue from affecting the subsequent processing of the electrode.

[0024] In some embodiments, the first forming plate 3, the tab cutting plate 4, and the second forming plate 5 are all movably assembled on the second template; and the end faces of the three are flush with the end face of the protruding plate 2-1 (with the same height). Using flush end faces ensures that the force exerted by each component on the electrode sheet during mold closing is evenly distributed along the same plane, effectively avoiding electrode sheet wrinkles or deformation caused by uneven local force, and ensuring the forming accuracy of the tab.

[0025] In some embodiments, such as Figure 6 As shown, the electrode adopts a symmetrical structure design with uniform mass distribution. This symmetrical structure is specifically rectangular or circular: rectangular electrode is suitable for long, strip-shaped battery casings such as VDA batteries and blade batteries, while circular electrode is suitable for circular cavity batteries such as stacked prismatic batteries. The electrode is divided into a coated area 7 and an uncoated area 8. The coated area 7 is the area coated with active material, and the uncoated area 8 is the area of ​​metal foil without active material coating. The folded portion 11 and the tab body are both located within the uncoated area 8, and one edge of the tab body is directly connected to the edge of the coated area 7. The sidewall at the connection point adopts a rounded transition design. This transition structure can effectively disperse stress concentration when the electrode is under stress, preventing coating peeling or foil cracking during long-term use. Simultaneously, the width of the folded portion 11 is consistent with the width of the tab body, ensuring that when folded along the indentation 10, the folded portion 11 can completely cover the corresponding area of ​​the tab body, forming a tightly fitting, gapless double-layer reinforced structure, ensuring the overall strength of the tab.

[0026] In some embodiments, the uncoated area 8 is made of a special metal foil for electrode tabs, specifically selected according to the polarity of the electrode: for a negative electrode, the uncoated area 8 uses copper foil (which has excellent conductivity and ductility, suitable for the electron transport requirements of the negative electrode); for a positive electrode, the uncoated area 8 uses aluminum foil (which can withstand the high oxidation potential of the positive electrode, avoid corrosion during charging and discharging, and ensure the stability of the electrode tab). Meanwhile, the second forming hole 4-1 on the electrode tab cutting plate 4 is strictly coaxially aligned with the first forming hole 1-3 on the first template. This coaxial design ensures that when punching the positioning hole, the punching force acts along the same axis on the double-layer foil area of ​​the electrode, not only ensuring the accuracy of the positioning hole position but also avoiding problems such as burrs and deformation on the hole wall. The final formed positioning hole can accurately adapt to the insertion requirements of the metal slide rod in the centroid plumb line stacking process, preventing the electrode tab from tearing due to friction between the slide rod and the hole wall.

[0027] The second aspect of this utility model is as follows: Figures 2-6 As shown, a method for forming a tab is also provided, using the above-mentioned tab forming apparatus, including the following steps: S1. Electrode Positioning: The electrode raw material is transferred between the first mold 1 and the second mold 2, so that the electrode is in the corresponding area of ​​the groove 1-1 of the first mold 1 and the convex plate 2-1 of the second mold 2; the electrode posture is adjusted to ensure that the coating area 7 of the electrode falls completely within the projection range of the coating area forming cavity, and the left and right waste areas of the non-coating area 8 are precisely aligned with the first forming groove 1-2 and the second forming groove 1-5 respectively, so as to achieve electrode positioning without deviation; S2. Punching and Indentation: Control the second mold 2 to close towards the first mold 1; during this process, the first forming groove 1-2 and the first forming plate 3 form a punching pair to punch and separate the waste material on the right side of the uncoated area 8, and the second forming groove 1-5 and the second forming plate 5 form a punching pair to simultaneously punch and separate the waste material on the left side of the uncoated area 8 (e.g., Figure 6 (In the punching area 8); at the same time, the tab cutting plate 4 and the indentation forming plate 1-4 form an extrusion pair, and an indentation 10 for folding guidance is formed at the connection boundary between the folded part 11 and the tab body in the uncoated area 8. S3. Folding Operation: After the punching and creasing processes are completed, the second mold 2 is driven to move upward and reset (mold opening); then the bending roller 6 is started, moving it along the preset arc or straight trajectory towards the electrode folding part 11. Through the flexible contact between the roller body and the folding part 11, the folding part 11 is precisely folded along the guide of the creasing 10 to the surface of the electrode body, forming a tightly fitting double-layer metal foil structure; after the folding action is completed, the bending roller 6 returns to its original position along the original trajectory; S4. Pressing and Punching: The second mold 2 is driven again to close to the first mold 1. The tab cutting plate 4 and the indentation forming plate 1-4 cooperate for the second time to press and fix the double-layer metal foil structure (to prevent gaps at the folds). Simultaneously, the first forming hole 1-3 and the second forming hole 4-1 form a punching pair to punch positioning holes in the central area of ​​the double-layer metal foil structure. After the mold closing process is completed, the second mold 2 moves upward and resets, transferring the formed tab (with a double-layer reinforced structure) to the next process, completing a single forming cycle.

[0028] This invention achieves integrated processing of the electrode tab from raw material to finished product through a continuous process design of positioning, punching and indentation, folding, and pressing and punching. It has the following advantages: the double-layer metal foil structure doubles the thickness of the electrode tab, significantly improving tear resistance and effectively reducing the tear rate of the electrode tab when stacking using the center of gravity plumb line method; the indentation guide and folding width matching design ensure high fit of the double-layer structure and avoid local strength deficiency caused by poor connection; the coaxial punching design ensures high positional accuracy of the positioning hole, adapts to the low resistance requirements when the metal slide bar is inserted, and indirectly improves the electrode stacking speed.

[0029] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A tab forming device, characterized in that, include: The first mold (1) includes a first template, the inner side of which is provided with a groove (1-1); the lower right side of the first template is provided with a first forming groove (1-2), the middle of the lower end is provided with a first forming hole (1-3), the lower left side is provided with a U-shaped groove, the U-shaped groove is provided with an indentation forming plate (1-4), the indentation forming plate (1-4) and the groove wall of the U-shaped groove cooperate to form a second forming groove (1-5). The second mold (2) is used in conjunction with the first mold (1) to form the electrode tab. The second mold (2) includes a second template. The inner side of the second template is provided with a protruding plate (2-1). The protruding plate (2-1) and the groove (1-1) cooperate to form the coating area forming cavity of the electrode sheet. The lower right side of the second template is equipped with a first forming plate (3) that cooperates with the first forming groove (1-2). The lower middle part is equipped with an electrode tab cutting plate (4). The electrode tab cutting plate (4) is provided with a second forming hole (4-1) that corresponds to the first forming hole (1-3). The electrode tab cutting plate (4) and the indentation forming plate (1-4) cooperate to form an indentation (10) on the side of the electrode sheet near the electrode tab body. The lower left side of the second template is equipped with a second forming plate (5) that cooperates with the second forming groove (1-5). A bending roller (6) is set on one side of the first mold (1) and the second mold (2) to fold the folded part (11) on the electrode sheet along the indentation (10) to the electrode body after the first mold (1) and the second mold (2) cooperate to complete the punching of the uncoated area (8).

2. The electrode forming device according to claim 1, characterized in that, The end face of the indentation forming plate (1-4) and the U-shaped groove wall facing the electrode cutting plate (4) is provided with an indentation groove (1-6). The end face of the electrode cutting plate (4) is provided with a straight protrusion (4-2) that cooperates with the indentation groove (1-6). When the first mold (1) and the second mold (2) are closed, the protrusion (4-2) is embedded in the indentation groove (1-6), and the two cooperate to form the indentation (10) by pressing on the uncoated area (8) near the electrode body on the electrode sheet.

3. The electrode forming device according to claim 1, characterized in that, The first forming groove (1-2) and the second forming groove (1-5) are both L-shaped; the first forming groove (1-2) cooperates with the first forming plate (3) to punch the waste material on the right side of the uncoated area of ​​the electrode sheet, and the second forming groove (1-5) cooperates with the second forming plate (5) to punch the waste material on the left side of the uncoated area of ​​the electrode sheet.

4. The electrode forming device according to claim 1, characterized in that, The first forming plate (3), the tab cutting plate (4), and the second forming plate (5) are all movably installed on the second template, and the heights of the first forming plate (3), the tab cutting plate (4), and the second forming plate (5) are the same as those of the convex plate (2-1).

5. The electrode forming device according to claim 1, characterized in that, The electrode has a symmetrical structure, which can be rectangular or circular.

6. The tab forming apparatus according to claim 1, characterized in that, The electrode includes a coated area (7) and an uncoated area (8). The folded portion (11) and the electrode body are both located in the uncoated area (8), and the electrode body is connected to the edge of the coated area (7). The sidewall at the connection point of the two adopts an arc transition. The width of the folded portion (11) is the same as the width of the electrode body.

7. The tab forming apparatus according to claim 6, characterized in that, The uncoated area (8) is made of metal foil.

8. The electrode forming device according to claim 1, characterized in that, The second forming hole (4-1) on the tab cutting plate (4) is coaxially arranged with the first forming hole (1-3) on the first template.

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