Foil tab forming apparatus and foil tab forming method

Abstract

Provided are a foil tab forming apparatus and a foil tab forming method. The foil tab forming apparatus forms at least one of an anode foil tab and a cathode foil tab disposed at an upper portion and a lower portion of an electrode assembly, respectively, and includes a pre-forming jig that moves from a peripheral portion of the electrode assembly toward a winding center portion of the electrode assembly to pressurize the foil tab to bend it, and a forming jig that moves in a direction parallel to a winding axis of the electrode assembly to pressurize the foil tab that has been bent once by the pre-forming jig.

Description

Technical Field

[0001] This invention relates to a foil tab forming apparatus and a foil tab forming method. Background Technology

[0002] Conventional cylindrical secondary batteries employ a structure in which tabs connecting the electrode assembly and external terminals are welded to the uncoated portion of the electrode assembly. In such a structure, the current path is limited and the resistance of the electrode assembly itself is high.

[0003] To address this issue, attempts have been made to increase the number of tabs connected to the electrode assembly, but the applicability of this approach is limited. To further resolve this problem, it is possible to use the uncoated anode and cathode portions, located respectively at the upper and lower parts of the electrode assembly, as tabs themselves. That is, a scheme could be considered that utilizes anode foil tabs and cathode foil tabs extending upwards and downwards, respectively, parallel to the extending direction of the winding center axis of the electrode assembly, to embody the electrical connection.

[0004] Thus, when the uncoated anode portion and the uncoated cathode portion, which have the shape of extending to the upper and lower parts of the electrode assembly respectively, are used as electrode tabs, in order to increase the bonding area with the current collector, it is advisable to bend the uncoated anode portion and the uncoated cathode portion.

[0005] Therefore, there is a need to develop a molding apparatus that can smoothly perform the bending process of the uncoated anode and uncoated cathode portions of the electrode assembly, as well as a molding method using such a molding apparatus. Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] The present invention was developed in view of the above-mentioned problems. The purpose of the present invention is to enable the smooth execution of the process of forming the anode foil tabs and / or cathode foil tabs of the electrode assembly.

[0008] In addition, the object of the present invention is to uniformly form the anode foil tabs and / or cathode foil tabs of the electrode assembly over the entire area from the outer periphery of the electrode assembly to the winding center of the electrode assembly.

[0009] However, the problems to be solved by the present invention are not limited to those described above. Those skilled in the art can clearly understand other problems not mentioned in this specification from the following description of the invention.

[0010] Methods for solving problems

[0011] A foil tab forming apparatus according to an embodiment of the present invention for solving the above-mentioned problems forms a foil tab of an electrode assembly having an outer periphery and a winding center portion defining a winding axis. The foil tab forming apparatus is characterized in that it includes a forming jig that moves in a direction parallel to the winding axis of the electrode assembly to apply pressure to the foil tab.

[0012] The aforementioned foil tab forming apparatus further includes: a pre-forming fixture that moves from the outer periphery of the electrode assembly toward the winding center of the electrode assembly to apply pressure to the foil tab to bend it.

[0013] The aforementioned forming fixture applies pressure to the foil tabs that have undergone one bending process by the aforementioned preforming fixture.

[0014] The aforementioned preforming fixture includes a plurality of opening and closing blocks arranged around the outer periphery of the electrode assembly and moving in a direction toward the winding center of the electrode assembly to bend the foil tabs.

[0015] The opening and closing block has a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

[0016] The forming fixture described above has a width that is the same as or greater than the diameter of the electrode assembly described above.

[0017] The forming fixture rotates with the same axis as the winding axis of the electrode assembly as reference.

[0018] The aforementioned forming fixture rotates clockwise or counterclockwise.

[0019] The forming fixture described above performs both the pressing and rotating actions of the foil tabs.

[0020] The forming jig described above has a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

[0021] The forming fixture includes: a first pressure block located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; and a second pressure block located at a position corresponding to a second region in the foil tab that is adjacent to the winding center of the electrode assembly.

[0022] The pressure surfaces of the first pressure block and the second pressure block have the same inclination, and the surface of the forming fixture opposite to the foil tab is defined.

[0023] The first pressure block and the second pressure block can move independently along a direction parallel to the winding axis of the electrode assembly.

[0024] The forming fixture is configured as follows: with the pressing surfaces of the first pressing block and the second pressing block forming the same plane, they move together toward the foil tab and apply pressure once; then, with the first pressing block remaining in its original position, the second pressing block moves further toward the foil tab to apply pressure a second time.

[0025] The forming fixture is configured such that after the first and second pressurizations are completed, the lowest end of the second pressurizing block is positioned at the same height as or higher than the lowest end of the first pressurizing block.

[0026] The first pressure block and the second pressure block mentioned above rotate together or independently with reference to the same axis as the winding shaft mentioned above.

[0027] The forming fixture includes: a first pressure block located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; a third pressure block located at a position corresponding to a third region in the foil tab that is adjacent to the winding center of the electrode assembly; and a second pressure block located at a position corresponding to a second region in the foil tab that is located between the first region and the third region.

[0028] The forming fixtures are a pair of forming fixtures arranged along the winding axis of the electrode assembly at two ends on opposite sides of the electrode assembly.

[0029] The pair of forming jigs rotate in opposite directions relative to each other, with the same axis as the winding axis of the electrode assembly.

[0030] The aforementioned preforming fixtures are a pair of preforming fixtures arranged along the winding axis of the electrode assembly at two ends on opposite sides of the electrode assembly.

[0031] In addition, a foil tab forming method according to an embodiment of the present invention for solving the above-mentioned problems is used to form a foil tab of an electrode assembly having an outer peripheral portion and a winding center portion defining a winding axis. The foil tab forming method includes the following steps: (S1) pressing the foil tab along a direction parallel to the winding axis of the electrode assembly using a forming jig to bend the foil tab.

[0032] The above-mentioned foil tab forming method further includes the following steps: (S0) Before the above-mentioned (S1) step, the foil tab is bent by applying pressure from the outer periphery of the electrode assembly toward the winding center of the electrode assembly using a pre-forming jig.

[0033] In step (S1) above, pressure is applied to the foil tab that has been preformed through step (S0) above to further bend the foil tab.

[0034] The above (S0) step is performed using the preforming fixture described above. The preforming fixture has a plurality of opening and closing blocks arranged around the outer periphery of the electrode assembly and moving in a direction toward the winding center of the electrode assembly to bend the foil tab.

[0035] The above (S0) step is performed using a preforming fixture, which has a plurality of opening and closing blocks. The plurality of opening and closing blocks have a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

[0036] The above (S1) step is performed using a forming fixture, which has a width that is the same as or greater than the diameter of the electrode assembly.

[0037] The above (S1) step is performed using a forming fixture configured to rotate with reference to the same axis as the winding axis of the electrode assembly.

[0038] The above (S1) step is performed using a forming fixture, which is configured to simultaneously perform the pressing and rotating actions of the foil tabs.

[0039] In step (S1) above, the forming jig rotates clockwise to orient the foil tabs clockwise.

[0040] In step (S1) above, the forming jig rotates counterclockwise to orient the foil tabs counterclockwise.

[0041] The above (S1) step is performed by a forming fixture, which has a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

[0042] The above (S1) step is performed by a forming fixture, which includes: a first pressure block located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; and a second pressure block located at a position corresponding to a second region in the foil tab that is adjacent to the winding center of the electrode assembly.

[0043] The above (S1) step is performed by a forming fixture, wherein the pressing surface of the first pressing block and the pressing surface of the second pressing block in the forming fixture have the same inclination.

[0044] The above (S1) step is performed by a forming fixture, wherein the first pressure block and the second pressure block in the forming fixture can move independently along a direction parallel to the winding axis of the electrode assembly.

[0045] The above-mentioned (S1) step includes the following steps: (S11) moving together toward the foil tab to perform a first pressurization while the pressurizing surfaces of the first pressurizing block and the second pressurizing block form the same plane; and (S12) after performing the above-mentioned (S11) step, moving the second pressurizing block further toward the foil tab while the first pressurizing block remains in its original position to perform a second pressurization.

[0046] After performing steps (S11) and (S12) above, the lowest end of the second pressure block is located at the same height as or higher than the lowest end of the first pressure block.

[0047] The first and second pressure blocks are rotated together or independently with the same axis as the winding shaft as the reference to perform the above (S1) step.

[0048] The above-described (S1) step is performed by a forming fixture, which includes: a first pressure block located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; a third pressure block located at a position corresponding to a third region in the foil tab that is adjacent to the winding center of the electrode assembly; and a second pressure block located at a region corresponding to a second region in the foil tab that is located between the first region and the third region.

[0049] The above (S1) step is performed by a forming fixture, wherein the pressing surfaces of the first pressing block, the second pressing block, and the third pressing block of the forming fixture have the same inclination.

[0050] The above-mentioned (S1) step includes the following steps: (S11) moving together toward the foil tab to perform one pressurization while the pressurizing surfaces of the first pressurizing block, the second pressurizing block, and the third pressurizing block are in the same plane; (S12) after performing the above-mentioned (S11) step, while the first pressurizing block is in its original position, moving toward the foil tab with the pressurizing surfaces of the second pressurizing block and the third pressurizing block in the same plane to perform a second pressurization; and (S13) after performing the above-mentioned (S12) step, while the first pressurizing block and the second pressurizing block are in their original positions, moving toward the foil tab with the third pressurizing block to perform a third pressurization.

[0051] The above (S1) step is performed using a pair of the above-mentioned forming jigs, which are arranged at both ends of the electrode assembly on opposite sides of the electrode assembly along the winding axis of the electrode assembly.

[0052] The above (S1) step is performed by rotating the pair of forming jigs in opposite directions relative to each other with the same axis as the winding axis of the electrode assembly as reference.

[0053] The above (S0) step is performed using a pair of the above preforming fixtures, which are arranged at both ends of the electrode assembly on opposite sides of the electrode assembly along the winding axis of the electrode assembly.

[0054] Invention Effects

[0055] According to the present invention, the process of forming anode foil tabs and / or cathode foil tabs of electrode assemblies can be performed smoothly.

[0056] Furthermore, according to the present invention, the anode foil tabs and / or cathode foil tabs of the electrode assembly are uniformly formed over the entire area from the outer periphery of the electrode assembly to the winding center of the electrode assembly.

[0057] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems. Those skilled in the art can clearly understand other problems not mentioned herein from the following description of the invention. Attached Figure Description

[0058] The accompanying drawings illustrate preferred embodiments of the invention and, together with the detailed description of the invention described below, further explain the technical concept of the invention. Therefore, the scope of the invention is not limited to these drawings.

[0059] Figure 1 and Figure 2 This is a diagram showing an electrode assembly and a current collector plate attached to the foil tab, formed by a foil tab forming apparatus according to an embodiment of the present invention.

[0060] Figure 3 This is a diagram illustrating the operation of the preforming fixture of a foil tab forming apparatus constituting an embodiment of the present invention.

[0061] Figure 4 This is a diagram showing a forming fixture that constitutes a foil tab forming apparatus according to an embodiment of the present invention.

[0062] Figure 5 It is set at Figure 4 The diagram illustrates the operation of the second pressure block of the forming fixture.

[0063] Figure 6 It is through Figure 4The diagram illustrates a single pressurization process performed by the forming fixture shown.

[0064] Figure 7 It is through Figure 4 The diagram illustrates the secondary pressurization performed by the forming fixture shown.

[0065] Figure 8 This figure illustrates the forming process performed by a forming jig constituting another embodiment of the foil tab forming apparatus of the present invention.

[0066] Figure 9 and Figure 10 This is a diagram illustrating an exemplary configuration of the molding fixture of the present invention.

[0067] Figure 11 This is a diagram showing the orientation of a foil tab formed by a forming jig that rotates counterclockwise according to the present invention.

[0068] Symbol Explanation

[0069] C: Electrode assembly

[0070] T: Foil electrode

[0071] P: Current collector

[0072] 10: Pre-forming fixture

[0073] 11: Open / Closed Blocks

[0074] 12: Opening and closing frame

[0075] 14: Elongated hole

[0076] 16: Guiding Components

[0077] 20, 30: Forming fixtures

[0078] 21, 31: First pressure block

[0079] 22, 32: Second pressure block

[0080] 33: Third pressure block Detailed Implementation

[0081] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Before proceeding, the terms and words used in this specification and claims should not be limited to their ordinary or dictionary meanings. Given the principle that inventors may appropriately define terms and concepts in order to best illustrate their invention, they should be interpreted as conforming to the meaning and concept of the technical idea of ​​the present invention. Therefore, the embodiments described in this specification and the structures illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. At the time of this application, various equivalents and modifications that can replace them may exist.

[0082] The foil tab forming apparatus of the present invention is an apparatus capable of smoothly forming at least one of the anode foil tabs and cathode foil tabs respectively disposed on the upper and lower parts of a gel roll type electrode assembly.

[0083] Figure 1 and Figure 2 The diagram illustrates the structure of a foil tab T formed by the foil tab forming apparatus of the present invention. The aforementioned foil tab T refers to a tab extending upwards (parallel to) the winding axis of the electrode assembly C. Figure 1 The first electrode, uncoated portion, extends in a direction parallel to the Z-axis and / or downwards (within the direction of the Z-axis). Figure 1 The electrode assembly C has a second electrode uncoated portion extending in a direction parallel to the Z-axis. The electrode assembly C has a structure for winding a laminate including a first electrode, a second electrode, and a separation membrane between the first and second electrodes with a winding axis as a reference. In this specification, the case where the first electrode is the anode and the second electrode is the cathode will be described as an example. The anode has an uncoated portion formed on one end of its width direction based on the state of the laminate before winding, and the cathode has an uncoated portion formed on the other end of its width direction based on the state of the laminate before winding. When the electrode assembly C is formed by winding a laminate including such an anode and cathode, the upper end of the electrode assembly C has an uncoated area of ​​the anode active material, i.e., an uncoated anode portion, and the lower end has an uncoated area of ​​the cathode active material, i.e., an uncoated cathode portion.

[0084] Aluminum foil can be used as the electrode plate constituting the anode, and copper foil can be used as the electrode plate constituting the cathode. Therefore, in this specification, the uncoated portions of the anode and cathode are referred to as foil tabs T. The anode foil tab and the cathode foil tab are respectively shaped to extend above and below the electrode assembly C, that is, to extend in opposite directions.

[0085] A current collector (P) is bonded to the aforementioned foil tab T. To improve the bonding force between the current collector (P) and the foil tab T and reduce the resistance at the bonding area, a flat bonding interface needs to be formed, thus maximizing the bonding area between the foil tab T and the current collector (P). For this purpose, the end of the foil tab T extends in a direction parallel to the current collector (P), causing the foil tab T to bend. For smooth bending, a foil tab is formed continuously from the center of the electrode assembly C to its outermost edge, for example... Figure 2 The diagram illustrates the process of notching to create multiple segments, which are then bent.

[0086] The foil tab forming apparatus of the present invention makes the foil tabs bend smoothly and uniformly throughout the entire area around the outer periphery of the electrode assembly C, and throughout the entire area from the outer periphery of the electrode assembly C to the winding center.

[0087] Reference Figure 3 and Figure 4 The aforementioned foil tab forming apparatus is an apparatus for forming at least one of the anode foil tabs and cathode foil tabs respectively disposed on the upper and lower parts of the electrode assembly C. The foil tab forming apparatus includes a forming jig 20 for forming the foil tab T, and a pre-forming jig 10 for pre-forming the foil tab T before it is formed by the forming jig 20. This specification is based on the premise that the foil tab forming apparatus of the present invention includes the pre-forming jig 10 and the forming jig 20; however, it is possible that the foil tab forming apparatus of the present invention may not include the pre-forming jig 10. In this case, as described later, the forming jig 20 of the present invention performs concentrated forming according to the time difference between different areas of the foil tab T, thereby achieving uniform and accurate forming over the entire area of ​​the foil tab T.

[0088] Reference Figure 3 The preforming jig 10 moves from the outer periphery of the electrode assembly C toward the winding center of the electrode assembly C to apply pressure and bend the foil tab T. The preforming jig 10 is a pair of jigs 10 respectively disposed at both ends of opposite sides of the electrode assembly C along the winding axis of the electrode assembly C. The preforming jig 10 includes a plurality of opening and closing blocks 11. The plurality of opening and closing blocks 11 are disposed around the outer periphery of the electrode assembly C and move toward the winding center of the electrode assembly C to bend the foil tab T. The opening and closing blocks 11 have a surface that slopes upward from the outer periphery of the electrode assembly C toward the winding center of the electrode assembly C. That is, each opening and closing block 11 has a surface that slopes upward in such a way that the thickness of the opening and closing block 11 decreases from the outside to the inside.

[0089] Reference Figure 3 , Figure 4 and Figure 5 The forming jig 20 moves in a direction parallel to the winding axis of the electrode assembly C to apply pressure to the foil tab T, which has been pre-formed by the pre-forming jig 10. The forming jig 20 has, for example, a generally cylindrical shape. The forming jig 20 is a pair of forming jigs arranged at both ends of the electrode assembly C on opposite sides along the winding axis of the electrode assembly C.

[0090] The forming jig 20 has a width that is the same as or larger than the diameter of the electrode assembly C. This is to form the entire area of ​​the foil tab T when pressure is applied using the forming jig 20. The forming jig 20 rotates about an axis that is the same as the winding axis of the electrode assembly C. When the forming jig 20 is formed as a pair and is respectively provided at both ends in the height direction (parallel to the Z-axis) of the electrode assembly C, the rotation directions of the pair of forming jigs 20 are opposite to each other. The forming jigs 20 together perform the pressing and rotating actions of the foil tab T. When pressing and rotating are performed together, a smoother and more natural bending can be performed. When the rotation direction of the forming jig 20 is clockwise, the foil tab T is oriented in a clockwise direction (see reference). Figure 2 Conversely, when the rotation direction of the forming fixture 20 is counterclockwise, the foil tab T is oriented counterclockwise (see reference). Figure 11 ).

[0091] The forming jig 20 described above has a surface that slopes upward from the outer periphery of the electrode assembly C toward the winding center, opposite to the foil tab T. That is, the forming jig 20 has a surface that slopes upward in such a way that the thickness of the forming jig 20 decreases from the outside toward the center. This structure of the forming jig 20 prevents damage to the electrode assembly C caused by applying excessive force to the foil tab T when pressure is applied, and allows for natural bending.

[0092] The forming jig 20 includes a first pressure block 21 and a second pressure block 22. The first pressure block 21 is located in a first region adjacent to the outer periphery of the electrode assembly C in the foil tab T. The second pressure block 22 is located in a second region adjacent to the winding center of the electrode assembly C in the foil tab T. For example, when the forming jig 20 has a generally cylindrical shape, the second pressure block 22 has a hollow cylindrical shape, and the first pressure block 21 is disposed in the hollow portion of the second pressure block 22.

[0093] The pressure surfaces of the first pressure block 21 and the second pressure block 22 have approximately the same inclination. In this case, the pressure surfaces of the first pressure block 21 and the second pressure block 22 form approximately the same plane. That is, the pressure surfaces of the first pressure block 21 and the second pressure block 22 are connected to each other to define the surface of the forming jig 20 opposite to the foil tab T.

[0094] The first pressure block 21 and the second pressure block 22 described above can move independently along a direction parallel to the winding axis of the electrode assembly C (a direction parallel to the Z-axis). For example, as Figure 5 As shown, the second pressure block 22 moves further toward the foil tab T while the first pressure block 21 is stopped.

[0095] Reference Figure 6 and Figure 7 The forming jig 20 moves together toward the foil tab T with the pressing surfaces of the first pressing block 21 and the second pressing block 22 forming the same plane to perform a first pressing. After performing the first pressing, the forming jig 20 moves the second pressing block 22 further toward the foil tab T while keeping the first pressing block 21 in its original position to perform a second pressing. Thus, the forming jig 20 includes multiple pressing blocks 21 and 22, and by using the pressing block 22, which is located more centrally, to perform further pressing, a more refined forming process is achieved. Due to the inclination direction of the pressing surfaces of the forming jig 20, the bending position of the foil tab T moves from the outer periphery of the electrode assembly C toward the winding center towards the end of the foil tab T during pressing. Therefore, when performing further pressing using the second pressing block 22, such deviations in the bending position can be reduced.

[0096] On the other hand, after the first and second pressurizations are completed, the forming jig 20 positions the lowermost end 22a of the second pressurizing block 22 at the same height or higher than the lowermost end 21a of the first pressurizing block 21. This is because if the pressure is applied too deeply through the second pressurizing block 22, the bending position deviation at the boundary between the first pressurizing block 21 and the second pressurizing block 22 may be too large.

[0097] The first pressure block 21 and the second pressure block 22 described above rotate together or independently with reference to the same axis as the winding axis of the electrode assembly C. That is, the first pressure block 21 and the second pressure block 22 can be connected to a drive unit and rotate together, or they can be connected to separate drive units and rotate independently.

[0098] The first pressure block 21 and the second pressure block 22 are moved toward the foil tab T with their respective pressure surfaces forming approximately the same plane. The foil tab T is bent by pressure and rotation (one-time forming). Then, while maintaining the rotation of the first pressure block 21, an additional bend is performed by applying additional pressure and rotation using the second pressure block 22 (secondary forming). The first region of the foil tab T is formed in a concentrated manner through this one-time forming. Of course, the second region is also formed during the concentrated forming of the first region. Furthermore, the second region of the foil tab T is formed in a concentrated manner through this two-time forming. The second region continues to be formed during the concentrated forming of the second region.

[0099] The decision on whether to continue molding the remaining areas during the period of concentrated molding of either the first or second region is determined based on the position of the molding fixture 20 in the vertical direction (parallel to the Z-axis).

[0100] On the other hand, refer to Figure 8 ,and Figure 4 and even Figure 7 The molding jig 20 shown in the figure is different from the one shown in the figure, which has three pressure blocks 31, 32, and 33. However, the number of pressure blocks 21, 22, 31, 32, and 33 included in the molding jigs 20 and 30 is not limited to two or three. More pressure blocks can be included for more precise molding.

[0101] The first pressure block 31 is located in a position corresponding to a first region in the foil tab T that is adjacent to the outer periphery of the electrode assembly C. The third pressure block 33 is located in the foil tab T in a position corresponding to a third region in the foil tab T that is adjacent to the core side of the electrode assembly C, i.e., the winding center. The second pressure block 32 is located in the foil tab T in a second region located between the first and third regions. The pressure surfaces of the first pressure block 31, the second pressure block 32, and the third pressure block 33 each have approximately the same inclination. Thus, the inclination surfaces of the first pressure block 31, the second pressure block 32, and the third pressure block 33 can define the surface of the forming jig 30 opposite to the foil tab T.

[0102] like Figure 8As illustrated, when the forming fixture 30 includes a first pressure block 31, a second pressure block 32, and a third pressure block 33, the three pressure blocks 31, 32, and 33 move and rotate toward the foil tab T with their pressure surfaces forming approximately the same plane, thereby forming the foil tab T (one-time forming). Through this one-time forming, the first region of the foil tab T is formed in a concentrated manner. Of course, during the concentrated forming of the first region, the second and third regions are also formed simultaneously. Thus, after the one-time forming is completed, the second pressure block 32 and the third pressure block 33 move further while maintaining their pressure surfaces forming approximately the same plane, thereby similarly performing pressure and rotation to form the foil tab T (secondary forming). Through this secondary forming, the second region of the foil tab T can be formed in a concentrated manner. At this time, the rotation of the first pressure block 31 can be maintained, thereby allowing the forming of the first and third regions to continue while the second region is being formed in a concentrated manner. The third pressure block 33, after being further pressurized by the second pressure block 32, moves further to perform pressurization and rotation to form the foil tab T (three-stage forming). Through this three-stage forming, the third region of the foil tab T is formed in a concentrated manner. At this time, the rotational state of the first pressure block 31 and the second pressure block 33 can be maintained, so that the forming of the first and second regions can continue while the forming of the third region is concentrated.

[0103] The decision on whether to continue molding the remaining areas during the period of concentrated molding of any one of the first, second, and third areas is determined based on the position of the molding fixture 20 in the vertical direction (parallel to the Z-axis).

[0104] Reference Figure 3 , Figure 9 and Figure 10The diagram illustrates an exemplary configuration of the preforming fixture 10 described above. The preforming fixture 10 includes, for example, an opening / closing frame 12 having a plurality of elongated holes 14. Each opening / closing block 11 is supported within its corresponding elongated hole 14 by a guide member 16 extending through the elongated hole 14. As the opening / closing frame 12 rotates about an axis parallel to the winding axis of the electrode assembly C, the guide member 16 moves within the elongated hole 14. The elongated hole 14 has a curved shape, allowing the opening / closing block 11 to move easily toward and away from the winding axis of the electrode assembly C. The overall movement of the opening / closing block 11 is similar to, for example, the opening and closing of an aperture. That is, the opening / closing block 11, in conjunction with the opening / closing frame 12, performs a closing action by moving toward the electrode assembly C disposed within the hollow space formed in the opening / closing frame 12, and an opening action by moving away from the electrode assembly C. On the other hand, the opening and closing block 11 is opened and closed by rotating the opening and closing frame 12, and the guide member 16 is moved along the extension direction of the elongated hole 14 to open and close.

[0105] Next, the foil tab forming method of the present invention will be described. The foil tab forming method of the present invention is a method of forming the foil tab T of the electrode assembly C by means of the foil tab forming apparatus of the present invention as described above.

[0106] Referring to the above Figures 3 to 8 The foil tab forming method of the present invention is a method for forming at least one foil tab T of the anode foil tab and the cathode foil tab located at the upper and lower parts of the electrode assembly C, respectively.

[0107] The above-described foil tab forming method, as a method for forming a foil tab T of an electrode assembly C having an outer periphery and a winding center portion defining a winding axis, includes: (S1) a step of bending the foil tab T by applying pressure to it in a direction parallel to the winding axis of the electrode assembly C using a forming jig 20. The above-described foil tab forming method further includes: (S0) a step of bending the foil tab T by applying pressure to it from the outer periphery of the electrode assembly C toward the winding center portion of the electrode assembly C using a pre-forming jig 10 before step (S1). In this case, step (S1) is a step of further bending the pre-formed foil tab T by applying pressure according to step (S0).

[0108] The above-described (S0) step is performed using a preforming fixture 10, which includes a plurality of opening and closing blocks 11 arranged around the outer periphery of the electrode assembly C and moving in a direction toward the winding center of the electrode assembly C to bend the foil tab T. The above-described (S0) step is performed using the preforming fixture 10 with the plurality of opening and closing blocks 11, which have surfaces opposite to the foil tab T that are inclined upwards in a direction from the outer periphery of the electrode assembly C toward the winding center. The above-described (S0) step can be performed using a pair of the above-described preforming fixtures 10, which are arranged along the winding axis of the electrode assembly C at opposite ends of the electrode assembly C. That is, the above-described (S0) step is a preforming step of the first foil tab (first polarity) and the second foil tab (second polarity) respectively located at the two ends of the electrode assembly C in the height direction (parallel to the Z-axis). The preforming of the first foil tab and the preforming of the second foil tab can be performed simultaneously or with a time difference.

[0109] The above-described step (S1) can be performed using a forming jig 20, which has a width equal to or greater than the diameter of the electrode assembly C. The forming jig 20 rotates about an axis identical to the winding axis of the electrode assembly C. The forming jig 20 performs both pressing and rotating actions on the foil tab T simultaneously. In step (S1), the forming jig 20 rotates clockwise to orient the foil tab T clockwise. Alternatively, in step (S1), the forming jig 20 can also rotate counterclockwise to orient the foil tab T counterclockwise.

[0110] The above-described (S1) step is performed using a forming jig 20, which has a surface opposite to the foil tab T that slopes upward from the outer periphery of the electrode assembly C toward the winding center. The forming jig 20 includes: a first pressure block 21 located at a position corresponding to a first region in the foil tab T adjacent to the outer periphery of the electrode assembly C; and a second pressure block 22 located at a position corresponding to a second region in the foil tab T adjacent to the winding center of the electrode assembly C.

[0111] The above-described (S1) step is performed by a forming fixture 20, which provides the same inclination for the pressing surfaces of the first pressing block 21 and the second pressing block 22. The forming fixture 20 also allows the first pressing block 21 and the second pressing block 22 to move independently along a direction parallel to the winding axis of the electrode assembly C.

[0112] The above-mentioned step (S1) includes the following steps: (S11) moving the first pressing block 21 and the second pressing block 22 together to perform a first pressing while the pressing surfaces of the first pressing block 21 and the second pressing block 22 are in the same plane; and (S12) after performing the above-mentioned step (S21), moving the second pressing block 22 further toward the foil tab T to perform a second pressing while keeping the first pressing block 21 in its original position. At this time, after performing the above-mentioned steps (S11) and (S12), the lowermost end 22a of the second pressing block is located at the same height as or higher than the lowermost end 21a of the first pressing block 21. The first pressing block 21 and the second pressing block 22 rotate together or independently with the same axis as the winding shaft as a reference to perform the above-mentioned step (S1).

[0113] On the other hand, the above-described (S1) step is performed by a forming jig 30, which includes: a first pressure block 31 located at a position corresponding to a first region in the foil tab T that is adjacent to the outer periphery of the electrode assembly C; a third pressure block 33 located at a position corresponding to a third region in the foil tab T that is adjacent to the winding center of the electrode assembly C; and a second pressure block 32 located at a region in the foil tab T that is located between the first region and the third region. The above-described (S1) step is performed by a forming jig 20 in which the pressure surfaces of the first pressure block 31, the second pressure block 32, and the third pressure block 33 have substantially the same inclination. In this case, step (S1) includes the following steps: (S11) moving together towards the foil tab T with the pressing surfaces of the first pressing block 31, the second pressing block 32, and the third pressing block 33 forming the same plane to perform a first pressing; (S12) after performing step (S11), moving towards the foil tab T with the pressing surfaces of the second pressing block 32 and the third pressing block 33 forming the same plane while keeping the first pressing block 31 in its original position to perform a second pressing; and (S13) after performing step (S12), moving towards the foil tab T with the third pressing block 33 in its original position while keeping the first pressing block 31 and the second pressing block 32 in their original positions to perform a third pressing. Step (S1) is performed using a pair of forming jigs 20, which are located at two opposite ends of the electrode assembly C along the winding axis of the electrode assembly C. That is, step (S1) above refers to the process of forming the first foil tab (first polarity) and the second foil tab (second polarity) located at both ends of the electrode assembly C in the height direction (parallel to the Z-axis). In this case, step (S1) is performed by rotating the pair of forming jigs 20 in opposite directions relative to each other, with the same axis as the winding axis of the electrode assembly C as the reference. The forming of the first foil tab and the forming of the second foil tab can be performed simultaneously or with a time difference.

[0114] As described above, according to the foil tab forming apparatus and / or the foil tab forming method of the present invention, the foil tab T of the electrode assembly C is divided into multiple regions along the approximate radial direction of the electrode assembly C, and each region is individually and centrally formed, thereby achieving effective and accurate forming. Furthermore, according to the foil tab forming apparatus and / or the foil tab forming method of the present invention, simultaneous rotation and pressure can be applied, thereby enabling smoother forming.

[0115] The present invention has been described above with reference to specific embodiments and accompanying drawings. However, the present invention is not limited thereto. Those skilled in the art can make various modifications and variations within the equivalent scope of the technical concept of the present invention and the claims set forth below.

Claims

1. A foil tab forming apparatus for forming foil tabs of an electrode assembly, the electrode assembly having an outer peripheral portion and a winding center portion defining a winding shaft. The foil tab forming device is characterized by including: A forming jig, which moves in a direction parallel to the winding axis of the electrode assembly, applies pressure to the foil tabs. The aforementioned forming fixture has a cylindrical shape. The forming jig has a surface that slopes upward from the outer periphery of the electrode assembly toward the winding center portion, opposite to the foil tab. The aforementioned forming fixture includes: The first pressure block is located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; and The second pressure block is located at a position corresponding to the second region adjacent to the winding center of the electrode assembly in the aforementioned foil tab, and The first pressure block has a cylindrical shape with a hollow central portion, and the second pressure block is disposed in the hollow central portion of the first pressure block. The aforementioned foil tab forming apparatus also includes: A pre-forming fixture moves from the outer periphery of the electrode assembly toward the winding center of the electrode assembly to apply pressure to the foil tabs and bend them. The aforementioned forming fixture applies pressure to the foil tabs that have undergone one bending process by the aforementioned pre-forming fixture.

2. The foil tab forming apparatus according to claim 1, characterized in that, The aforementioned preforming fixture includes: Multiple opening and closing blocks are arranged around the outer periphery of the electrode assembly and move in a direction toward the winding center of the electrode assembly to bend the foil tabs.

3. The foil tab forming apparatus according to claim 2, characterized in that, The opening and closing block has a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

4. The foil tab forming apparatus according to claim 1, characterized in that, The forming fixture described above has a width that is the same as or greater than the diameter of the electrode assembly described above.

5. The foil tab forming apparatus according to claim 1, characterized in that, The forming fixture described above rotates with reference to the same axis as the winding axis of the electrode assembly described above.

6. The foil tab forming apparatus according to claim 5, characterized in that, The aforementioned forming fixture rotates clockwise or counterclockwise.

7. The foil tab forming apparatus according to claim 5, characterized in that, The forming fixture described above performs both the pressing and rotation of the foil tabs.

8. The foil tab forming apparatus according to claim 1, characterized in that, The pressure surfaces of the first pressure block and the second pressure block have the same inclination, and the surface of the forming fixture opposite to the foil tab is defined.

9. The foil tab forming apparatus according to claim 1, characterized in that, The first pressure block and the second pressure block can move independently along a direction parallel to the winding axis of the electrode assembly.

10. The foil tab forming apparatus according to claim 8, characterized in that, The forming fixture is configured as follows: with the pressing surfaces of the first pressing block and the second pressing block forming the same plane, they move together toward the foil tab to perform a first pressing; then, with the first pressing block remaining in its original position, the second pressing block moves further toward the foil tab to perform a second pressing.

11. The foil tab forming apparatus according to claim 10, characterized in that, The forming fixture is configured such that after the first and second pressurizations are completed, the lowest end of the second pressurizing block is positioned at the same height as or higher than the lowest end of the first pressurizing block.

12. The foil tab forming apparatus according to claim 1, characterized in that, The first pressure block and the second pressure block mentioned above rotate together or independently with reference to the same axis as the winding shaft mentioned above.

13. The foil tab forming apparatus according to claim 1, characterized in that, The above-mentioned forming fixture includes: The first pressure block is located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly. The third pressure block is located at a position corresponding to the third region adjacent to the winding center of the electrode assembly in the aforementioned foil tab; and The second pressure block is located at a position corresponding to the second region in the foil tab located between the first region and the third region.

14. The foil tab forming apparatus according to claim 1, characterized in that, The forming fixtures are a pair of forming fixtures arranged along the winding axis of the electrode assembly at two ends on opposite sides of the electrode assembly.

15. The foil tab forming apparatus according to claim 14, characterized in that, The pair of forming jigs rotate in opposite directions relative to each other, with the same axis as the winding axis of the electrode assembly.

16. The foil tab forming apparatus according to claim 1, characterized in that, The aforementioned preforming fixtures are a pair of preforming fixtures arranged along the winding axis of the electrode assembly at two ends on opposite sides of the electrode assembly.

17. A method for forming foil tabs, comprising forming foil tabs of an electrode assembly having an outer peripheral portion and a winding center portion defining a winding shaft. The foil tab forming method includes the following steps: (S1) The foil tab is bent by applying pressure to it in a direction parallel to the winding axis of the electrode assembly using a forming jig. Its features are, The above-described (S1) step is performed using the forming fixture described above. The forming fixture has a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center. The above-described (S1) step is performed using a forming fixture, which includes: a first pressure block located at a position corresponding to a first region in the foil tab adjacent to the outer periphery of the electrode assembly; and a second pressure block located at a position corresponding to a second region in the foil tab adjacent to the winding center of the electrode assembly. The forming fixture has a cylindrical shape, the first pressure block has a cylindrical shape with a hollow central portion, and the second pressure block is disposed in the hollow central portion of the first pressure block. The above-mentioned foil tab forming method also includes the following steps: (S0) Prior to step (S1) above, the foil tab is bent by applying pressure from the outer periphery of the electrode assembly toward the winding center of the electrode assembly using a pre-forming jig. In step (S1) above, pressure is applied to the foil tab that has been preformed through step (S0) above, causing the foil tab to bend further.

18. The foil tab forming method according to claim 17, characterized in that, The above (S0) step is performed using the preforming fixture described above. The preforming fixture has a plurality of opening and closing blocks arranged around the outer periphery of the electrode assembly and moving in a direction toward the winding center of the electrode assembly to bend the foil tab.

19. The foil tab forming method according to claim 18, characterized in that, The above (S0) step is performed using a pre-forming fixture, which has a plurality of opening and closing blocks. The plurality of opening and closing blocks have a shape in which the surface opposite to the foil tab is inclined upward from the outer periphery of the electrode assembly in the direction toward the winding center.

20. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed using a forming fixture, which has a width that is the same as or greater than the diameter of the electrode assembly.

21. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed using a forming fixture configured to rotate with reference to the same axis as the winding axis of the electrode assembly.

22. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed using a forming fixture, which is configured to simultaneously perform the pressing and rotating actions on the foil tabs.

23. The foil tab forming method according to claim 22, characterized in that, In the above (S1) step, the forming jig rotates clockwise to orient the foil tabs clockwise.

24. The foil tab forming method according to claim 22, characterized in that, In the above (S1) step, the forming jig is rotated counterclockwise to orient the foil tabs counterclockwise.

25. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed by a forming fixture, wherein the pressing surface of the first pressing block and the pressing surface of the second pressing block in the forming fixture have the same inclination.

26. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed by a forming fixture, wherein the first pressure block and the second pressure block in the forming fixture can move independently along a direction parallel to the winding axis of the electrode assembly.

27. The foil tab forming method according to claim 25, characterized in that, The above (S1) step includes the following steps: (S11) With the pressing surfaces of the first pressing block and the second pressing block forming the same plane, they move together toward the foil tab to perform one pressing operation; and (S12) After performing the above (S11) step, while keeping the first pressure block in its original position, the second pressure block is moved further toward the foil tab to perform secondary pressure.

28. The foil tab forming method according to claim 27, characterized in that, After performing steps (S11) and (S12) above, the lowest end of the second pressure block is located at the same height as or higher than the lowest end of the first pressure block.

29. The foil tab forming method according to claim 17, characterized in that, The first and second pressure blocks are rotated together or independently with the same axis as the winding shaft as the reference to perform the above (S1) step.

30. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed using a forming fixture, which includes: A first pressure block is located at a position corresponding to a first region in the foil tab that is adjacent to the outer periphery of the electrode assembly; a third pressure block is located at a position corresponding to a third region in the foil tab that is adjacent to the winding center of the electrode assembly; and a second pressure block is located at a region corresponding to a second region in the foil tab that is located between the first region and the third region.

31. The foil tab forming method according to claim 30, characterized in that, The above (S1) step is performed by a forming fixture, wherein the pressing surfaces of the first pressing block, the second pressing block, and the third pressing block of the forming fixture have the same inclination.

32. The foil tab forming method according to claim 31, characterized in that, The above (S1) step includes the following steps: (S11) When the pressing surfaces of the first pressing block, the second pressing block, and the third pressing block form the same plane, they move together toward the foil tab to perform one pressurization. (S12) After performing step (S11), with the first pressure block remaining in its original position, and the pressure surfaces of the second and third pressure blocks forming the same plane, they move toward the foil tab to perform secondary pressure application; and (S13) After performing the above (S12) step, while the first pressure block and the second pressure block remain in their original positions, the third pressure block moves toward the foil tab and performs three pressure applications.

33. The foil tab forming method according to claim 17, characterized in that, The above (S1) step is performed using a pair of the above forming jigs, which are arranged at both ends of the electrode assembly on opposite sides of the electrode assembly along the winding axis of the electrode assembly.

34. The foil tab forming method according to claim 33, characterized in that, The above (S1) step is performed by rotating a pair of forming jigs in opposite directions relative to each other, with the same axis as the winding axis of the electrode assembly.

35. The foil tab forming method according to claim 17, characterized in that, The above (S0) step is performed using a pair of the above preforming fixtures, which are arranged at both ends of the electrode assembly on opposite sides of the electrode assembly along the winding axis of the electrode assembly.

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