Electrode tab welding apparatus, electrode tab welding method, and electrode assembly

Abstract

To provide an electrode tab welding device and an electrode tab welding method for preventing disconnection of an electrode tab.SOLUTION: The above and other aspects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: The electrode tab welding apparatus may include: a pair of tab guides for gathering the plurality of electrode tabs; a pair of alignment rollers for pressing the plurality of electrode tabs gathered by the pair of tab guides and rotating in a direction in which the outermost electrode tabs are pushed toward the electrode assembly; and a welding unit for welding the plurality of electrode tabs aligned by the pair of alignment rollers.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0186535 filed on December 23, 2021, and all contents disclosed in said Korean patent application are incorporated herein by reference as part of the present specification.

[0002] The present invention relates to an electrode tab welding apparatus and an electrode tab welding method for welding a plurality of electrode tabs, and an electrode assembly including a plurality of electrode tabs welded by said electrode tab welding apparatus or electrode tab welding method. [Background Art]

[0003] Generally, a secondary battery, unlike a non-rechargeable primary battery, refers to a battery capable of charging and discharging, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, and electric vehicles. In particular, lithium secondary batteries have a larger capacity and higher energy density than nickel-cadmium batteries or nickel-hydrogen batteries, so the degree of their utilization tends to increase rapidly.

[0004] Secondary batteries can be classified into cylindrical batteries and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet, depending on the shape of the battery case.

[0005] Figure 1 shows an example of a pouch-type secondary battery. The pouch-type secondary battery 1 includes an electrode assembly 10 formed by alternately stacking electrodes and separators, and a pouch 20 in which the electrode assembly 10 is housed. Electrode tabs 15 can be connected to the electrodes of the electrode assembly 10. The electrode tabs 15 can be welded to each other in a predetermined area and then connected to electrode leads 17. The pouch 20 includes a concave cup portion 21 to house the electrode assembly 10. One or two cup portions 21 can be formed in the pouch 20. Figure 1 illustrates a pouch 20 including a left cup portion and a right cup portion. Peripheral portions (terraces) 23 for sealing are formed around the periphery of the cup portion 21.

[0006] However, if deformation of the peripheral portion 23 of the pouch 20 applies a pulling force to the electrode tab 15, the electrode tab 15 may be gradually pulled and break. Alternatively, if expansion of the pouch 20 applies a pulling force to the electrode tab 15, the electrode tab 15 may be gradually pulled and break. Such breaks are considered a major cause of fire. In recent years, in the case of pouch-type secondary batteries, the length of the peripheral portion 23 has been reduced to increase energy density in response to the demand for higher capacity and performance. However, this leads to a reduction in the "length from the electrode assembly 10 to the welding point of the electrode tab 15," further increasing the risk of breakage. [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] One problem that the present invention aims to solve is to provide an electrode tab welding apparatus and an electrode tab welding method that prevent the electrode tab from breaking. Another problem that the present invention aims to solve is to provide an electrode assembly in which the disconnection of the electrode tabs is prevented. [Means for solving the problem]

[0008] An electrode tab welding apparatus according to an embodiment of the present invention can weld a plurality of electrode tabs of an electrode assembly. The electrode tab welding apparatus may include a pair of tab guides for gathering the plurality of electrode tabs, a pair of alignment rollers that pressurize the plurality of electrode tabs gathered by the pair of tab guides and rotate in a direction in which the outermost electrode tab is pushed toward the electrode assembly, and a welding section for welding the plurality of electrode tabs aligned by the pair of alignment rollers.

[0009] With respect to the electrode assembly, the point at which the pair of alignment rollers press on the plurality of electrode tabs may be farther away from the point at which the pair of tab guides press on the plurality of electrode tabs.

[0010] The pair of alignment rollers rotate while applying pressure to the plurality of electrode tabs when the pair of tab guides form a first interval, and can move away from the plurality of electrode tabs when the pair of tab guides form a second interval smaller than the first interval.

[0011] The welded portion can weld the plurality of electrode tabs when the pair of tab guides form the second interval. The pair of alignment rollers may include an elastomer material.

[0012] The pair of alignment rollers can be arranged so as to face each other with respect to the height of the electrode assembly, with the plurality of electrode tabs in between, and the distance between them can be adjusted.

[0013] An electrode tab welding method according to an embodiment of the present invention can weld a plurality of electrode tabs of an electrode assembly. The electrode tab welding method may include the steps of: a pair of tab guides approaching each other to gather the plurality of electrode tabs; a pair of alignment rollers rotating while pressurizing the plurality of electrode tabs gathered by the pair of tab guides, pushing the outermost electrode tab of the plurality of electrode tabs toward the electrode assembly; and a welding portion welding the plurality of electrode tabs aligned by the pair of alignment rollers toward each other.

[0014] When the pair of alignment rollers rotate, the pair of tab guides form a first spacing, and when the welding portion welds the plurality of electrode tabs, the pair of tab guides can form a second spacing that is narrower than the first spacing.

[0015] When the pair of alignment rollers rotate, a step can be created between the outer ends of the plurality of electrode tabs. When the welding portion welds the plurality of electrode tabs, the pair of alignment rollers can be separated from the plurality of electrode tabs.

[0016] An electrode assembly according to an embodiment of the present invention may include a plurality of electrodes stacked with separators in between, and a plurality of electrode tabs connected to the plurality of electrodes and welded to each other to form a welded portion. Both of the outermost electrode tabs of the plurality of electrode tabs may be bent outward in a convex shape. The outermost electrode tab may include a first section extending from the electrode and a second section extending from the first section and having a steeper slope than the first section. The first section may include a flat portion connected to the electrode and formed flat, and a curved portion connecting the flat portion and the second section and formed by bending.

[0017] Of the aforementioned multiple electrode tabs, the electrode tabs located on the outside can bend more significantly. The outermost end of the outermost electrode tab may have a step inward relative to the outer ends of the other electrode tabs. The outermost electrode tab may further include a third section that extends from the second section to the welded portion and has a gentler slope than the second section. [Effects of the Invention]

[0018] According to a preferred embodiment of the present invention, a welding part welds the plurality of electrode tabs while the plurality of electrode tabs are pressed toward the electrode assembly side by an alignment roller, so that for each electrode tab, particularly the outermost electrode tab, the length from the electrode to the welded portion can be increased. This can prevent breaking and disconnection of the electrode tabs, particularly the outermost electrode tab, caused by external force such as deformation such as bending of the electrode lead, and can improve the safety and reliability of the electrode assembly. In addition, effects that can be easily predicted by those skilled in the art from the configuration according to the preferred embodiment of the present invention can be included. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the invention described below, therefore, the present invention should not be construed as being limited only to the matters described in the drawings.

[0020] [Figure 1] It is a diagram showing an example of a pouch-type secondary battery. [Figure 2a] It is a diagram for explaining an example of a process applicable when welding an electrode tab of a pouch-type secondary battery. [Figure 2b] It is a diagram for explaining an example of a process applicable when welding an electrode tab of a pouch-type secondary battery. [Figure 2c] It is a diagram for explaining an example of a process applicable when welding an electrode tab of a pouch-type secondary battery. [Figure 2d] It is a diagram for explaining an example of a process applicable when welding an electrode tab of a pouch-type secondary battery. [Figure 3] It is a cross-sectional view showing a part of a battery module provided with a plurality of pouch-type batteries housed in a case. [Figure 4] It is a diagram for explaining the configuration and operation of an electrode tab welding apparatus according to an embodiment of the present invention. [Figure 5]It is a diagram for explaining the configuration and operation of an electrode tab welding apparatus according to an embodiment of the present invention. [Figure 6] It is a diagram for explaining the configuration and operation of an electrode tab welding apparatus according to an embodiment of the present invention. [Figure 7] It is a flowchart of an electrode tab welding method according to another embodiment of the present invention. [Figure 8] It is a diagram showing an electrode assembly according to still another embodiment of the present invention. MODE FOR CARRYING OUT THE INVENTION

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that a person having ordinary knowledge in the technical field to which the present invention pertains can easily carry out the present invention. However, the present invention may be embodied in various different forms, and is not restricted or limited by the following embodiments.

[0022] In order to clearly explain the present invention, detailed descriptions of related known technologies that are irrelevant to the description or may unnecessarily obscure the gist of the present invention are omitted. In the present specification, when reference numerals are assigned to constituent elements in each drawing, the same or similar reference numerals are assigned to the same or similar constituent elements throughout the specification.

[0023] In addition, terms and words used in the present specification and claims shall not be construed as being limited to ordinary or dictionary meanings. In accordance with the principle that inventors can properly define the concept of terms in order to describe their own invention in the best way, terms and words should be interpreted with meanings and concepts consistent with the technical idea of the present invention.

[0024] Figures 2a to 2d are diagrams for explaining an example of a process applicable when welding an electrode tab of a pouch-type secondary battery, and Figure 3 is a cross-sectional view showing a part of a battery module in which a plurality of pouch-type batteries are housed in a case.

[0025] First, as shown in Figure 2a, an electrode assembly 10 can be prepared in which multiple electrodes 11 and multiple separators 13 are stacked alternately. The multiple electrodes 11 may include positive and negative electrodes, and an electrode tab 15 may be connected to each electrode 11. For the sake of explanation, only a negative electrode tab connected to the negative electrode is shown in the drawing, but a person skilled in the art will easily understand that a positive electrode tab connected to the positive electrode can also be provided in the electrode assembly 10 and can be welded in the same manner as the negative electrode tab.

[0026] Next, as shown in Figure 2b, a pair of tab guides 30 can pressurize and gather multiple electrode tabs 15 together. The pair of tab guides 30 can face each other with multiple electrode tabs 15 in between in the height direction of the electrode assembly 10, and the distance between them can be adjusted.

[0027] Next, as shown in Figure 2c, multiple electrode tabs 15 can be welded through the weld joint 50. More specifically, the weld joint 50 can weld multiple electrode tabs 15 to form a welded portion 16. With respect to the electrode assembly 10, the welded portion 16 formed on the multiple electrode tabs 15 may be further away than the point where the multiple electrode tabs 15 are pressurized by a pair of tab guides 30.

[0028] Through this process, an electrode assembly 10 can be manufactured, which is equipped with multiple electrode tabs 15 welded to each other on a welded portion 16. After connecting electrode leads 17 (see Figure 1) to the multiple electrode tabs 15 welded to each other, the electrode assembly 10 can be placed in a pouch 20 (see Figure 1) to manufacture a pouch-type battery 1.

[0029] As shown in Figure 3, multiple pouch-type batteries 1 can be manufactured into a battery module by housing them in case C. However, the peripheral portion 23 of the pouch 20 may bend during the manufacturing of the battery module. This deformation of the peripheral portion 23 can induce bending of the electrode leads 17, which can create a pulling force on the electrode tabs 15 connected to the electrode leads 17. This force can cause the electrode tabs 15 to break due to the strong pulling, and this can be particularly pronounced in the outermost electrode tab 15a. The same problem of wire breakage can also occur when the pouch-type battery 1 expands.

[0030] The present invention, which will be explained in detail below, is intended to solve the above-mentioned problem of wire breakage. Figures 4 to 6 are diagrams illustrating the configuration and operation of an electrode tab welding apparatus according to one embodiment of the present invention.

[0031] An electrode tab welding apparatus according to one embodiment of the present invention can weld a plurality of electrode tabs 15 of an electrode assembly 10. More specifically, the electrode tab welding apparatus may include a pair of tab guides 30 for gathering a plurality of electrode tabs 15, a pair of alignment rollers 40 that pressurize the plurality of electrode tabs 15 gathered by the pair of tab guides 30 and rotate in a direction that pushes the electrode tabs 15 toward the electrode assembly 10, and a welding section 50 for welding the plurality of electrode tabs 15 aligned by the pair of alignment rollers 40.

[0032] A pair of tab guides 30 can face each other with multiple electrode tabs 15 in between in the height direction of the electrode assembly 10. The pair of tab guides 30 can be configured so that the distance between them can be adjusted. More specifically, at least one of the pair of tab guides 30 can be configured to move up and down in the height direction of the electrode assembly 10.

[0033] As shown in Figure 4, a pair of tab guides 30 can approach each other to collect multiple electrode tabs 15. In this process, the pair of tab guides 30 can come into contact with one pair of the outermost electrode tabs 15a of the multiple electrode tabs 15. The narrower the distance between a pair of tab guides 30, the stronger the pressure the pair of tab guides 30 can apply to multiple electrode tabs 15.

[0034] A pair of alignment rollers 40 can face each other with a plurality of electrode tabs 15 in between in the height direction of the electrode assembly 10. The pair of alignment rollers 40 can be configured so that the distance between them can be adjusted. More specifically, at least one of the pair of alignment rollers 40 can be configured to move up and down in the height direction of the electrode assembly 10.

[0035] As shown in Figure 4, a pair of alignment rollers 40 can rotate under pressure on a plurality of electrode tabs 15 gathered by a pair of tab guides 30. More specifically, the pair of alignment rollers 40 can contact a pair of outermost electrode tabs 15a and rotate in a direction that pushes the pair of outermost electrode tabs 15a toward the electrode assembly 10.

[0036] Multiple electrode tabs 15 can be pushed toward the electrode assembly 10 by mutual friction, and the electrode tabs 15 located further out can be pushed toward the electrode assembly 10 more. This can create a step difference s (see Figure 8) between the outer ends of the multiple electrode tabs 15. In other words, a pair of alignment rollers 40 can align the multiple electrode tabs 15 so that a step difference is created between the outer ends of the multiple electrode tabs 15.

[0037] The alignment roller 40 can have a high surface friction coefficient and be made of an elastic material. More specifically, the alignment roller 40 can include an elastomer material such as rubber. This maintains a high frictional force between the alignment roller 40 and the outermost electrode tab 15a, allowing the alignment roller 40 to rotate without slipping against the outermost electrode tab 15a. In addition, the alignment roller 40 can press against the outermost electrode tab 15a and be elastically deformed, thereby preventing damage to the outermost electrode tab 15a.

[0038] With respect to the electrode assembly 10, the pair of alignment rollers 40 can be located further away than the pair of tab guides 30. More specifically, with respect to the electrode assembly 10, the point at which the pair of alignment rollers 40 pressurize the multiple electrode tabs 15 may be further away than the point at which the pair of tab guides 30 pressurize the multiple electrode tabs 15.

[0039] As shown in Figure 5, after the multiple electrode tabs 15 are aligned, the pair of tab guides 30 can be used to further press and secure the multiple electrode tabs 15.

[0040] More specifically, a pair of alignment rollers 40 can rotate while applying pressure to the multiple electrode tabs 15 when a pair of tab guides 30 form a first interval g1, and can move away from the multiple electrode tabs 15 when a pair of tab guides 30 form a second interval g2 smaller than the first interval g1.

[0041] A pair of alignment rollers 40 can align multiple electrode tabs 15 when a pair of tab guides 30 form a first interval g1, and once the alignment of the multiple electrode tabs 15 is complete, the pair of tab guides 30 can move even closer to each other to form a second interval g2 that is smaller than the first interval g1.

[0042] When a pair of tab guides 30 form a first spacing g1, the multiple electrode tabs 15 are not completely fixed between the pair of tab guides 30 but are movable in the longitudinal direction. Therefore, when a pair of alignment rollers 40 rotate, the multiple electrode tabs 15 can be pushed inward between the pair of tab guides 30.

[0043] When a pair of tab guides 30 form a second interval g2, multiple electrode tabs 15 can be fixed between the pair of tab guides 30. This allows multiple electrode tabs 15 to be fixed between the pair of tab guides 30 in an aligned state.

[0044] Once multiple electrode tabs 15 are fixed between a pair of tab guides 30, a pair of alignment rollers 40 can move away from each other to separate them from the multiple electrode tabs 15.

[0045] As shown in Figure 6, the welded portion 50 can be formed by welding a plurality of electrode tabs 15 aligned by a pair of alignment rollers 40 to form the welded portion 16. The welded portion 16 may be the portion where the plurality of electrode tabs 15 are welded to each other.

[0046] The welded joint 50 can be welded with multiple electrode tabs 15 fixed by a pair of tab guides 30. More specifically, the welded joint 50 can weld multiple electrode tabs 15 when the pair of tab guides 30 form the second interval g2.

[0047] For example, the welding unit 50 can ultrasonically weld multiple electrode tabs 15. In this case, the welding unit 50 may include an anvil located on one side (e.g., the lower side) of the multiple electrode tabs 15 and a horn located on the other side (e.g., the upper side) of the multiple electrode tabs 15. The welding unit 50 can be configured so that the distance between the anvil and the horn can be adjusted. With the multiple electrode tabs 15 pressed between the anvil and the horn, the horn can vibrate at a high frequency, thereby welding the multiple electrode tabs 15 to each other.

[0048] With respect to the electrode assembly 10, the welded portion 50 may be located further away than the pair of tab guides 30. More specifically, with respect to the electrode assembly 10, the portion to be welded 16 may be located further away than the point where the pair of tab guides 30 pressurize the multiple electrode tabs 15.

[0049] The operation of the welding apparatus according to this embodiment will be described below. As shown in Figure 4, the pair of tab guides 30 can move closer to each other and press the outermost electrode tab 15a to gather multiple electrode tabs 15 together. At this time, the pair of tab guides 30 can apply relatively weak pressure so that the multiple electrode tabs 15 are not completely fixed in place.

[0050] Subsequently, the pair of alignment rollers 40 can move closer to each other and push the outermost electrode tab 15a, and can rotate so that the outermost electrode tab 15a is pushed toward the electrode assembly 10. This allows the multiple electrode tabs 15 to be pushed toward the electrode assembly 10 and aligned through the pair of tab guides 30. The further out the electrode tab 15 is located, the more it is pushed, so the multiple electrode tabs 15 can create a step between their outer ends.

[0051] Subsequently, as shown in Figure 5, the pair of tab guides 30 can move closer to each other to fully secure the multiple electrode tabs 15, and the pair of alignment rollers 40 can move away from each other, separating from the outermost electrode tabs 15a.

[0052] Subsequently, as shown in Figure 6, the welded portion 50 can be welded to form a welded portion 16 by welding multiple electrode tabs 15. Since the weld joint 50 welds the multiple electrode tabs 15 with the tab guide 30 fixed in place, the length L (see Figure 8) from the electrode assembly 10 to the welded part 16 can be increased relative to the electrode tabs 15, especially the outermost electrode tab 15a. In other words, the length of the electrode tabs 15, especially the outermost electrode tab 15a, can have a margin.

[0053] This prevents the electrode tabs 15, particularly the outermost electrode tab 15a, from breaking or disconnecting due to expansion of the electrode assembly 10 or external forces applied to the electrode tabs 15.

[0054] Figure 7 is a flowchart of an electrode tab welding method according to another embodiment of the present invention. The electrode tab welding method using the electrode tab welding apparatus described above will be described below as another embodiment of the present invention.

[0055] The electrode tab welding method according to this embodiment can weld multiple electrode tabs 15 of an electrode assembly 10. The electrode tab welding method may include the steps of: bringing a pair of tab guides 30 closer together to gather a plurality of electrode tabs 15 (S10); rotating a pair of alignment rollers 40 while pressurizing the plurality of electrode tabs 15 gathered by the pair of tab guides 30, pushing the outermost electrode tab 15a toward the electrode assembly 10 (S20); and welding a welding section 50 to weld the plurality of electrode tabs 15 aligned by the pair of alignment rollers 40 toward each other (S30).

[0056] During the step of collecting multiple electrode tabs 15 (S10), the pair of tab guides 30 move closer to each other and press the outermost electrode tab 15a to collect the multiple electrode tabs 15.

[0057] During step (S20) of pushing the outermost electrode tab 15a toward the electrode assembly 10, the pair of alignment rollers 40 can move closer to each other and push the outermost electrode tab 15a, and can rotate so that the outermost electrode tab 15a is pushed toward the electrode assembly 10.

[0058] As the pair of alignment rollers 40 rotate, the pair of tab guides 30 can form a first interval g1. The pair of tab guides 30 forming the first interval g1 can be pressed relatively weakly so that the multiple electrode tabs 15 are not completely fixed.

[0059] As a result, the multiple electrode tabs 15 can be pushed and aligned toward the electrode assembly 10 through a pair of tab guides 30 by frictional force between them. The further out the electrode tab 15 is located, the more it is pushed, so that the multiple electrode tabs 15 can create a step between them at their outer ends.

[0060] During the step (S30) of welding multiple electrode tabs 15 to each other, the welded portion 50 can form a welded portion 16 by welding the multiple electrode tabs 15 together. When the weld joint 50 welds multiple electrode tabs 15, a pair of tab guides 30 can form a second spacing g2 that is narrower than the first spacing g1. The pair of tab guides 30 forming the second spacing g2 can completely fix the multiple electrode tabs 15. As a result, the multiple electrode tabs 15 can be welded by the weld joint 50 while maintaining alignment.

[0061] Furthermore, when the welding section 50 welds multiple electrode tabs 15, the pair of alignment rollers 40 can be separated from the multiple electrode tabs 15. For example, the electrode assembly 10 can be moved from a first process position where the alignment rollers 40 are located to a second process position where the welding section 50 is located. This allows the welding section 15 to weld multiple electrode tabs 15 regardless of the position of the alignment rollers 40.

[0062] Figure 8 shows an electrode assembly according to yet another embodiment of the present invention. Hereinafter, an electrode assembly 10 including a plurality of electrode tabs 15 welded by the electrode tab welding apparatus or electrode tab welding method described above will be described as the present invention or another embodiment.

[0063] The electrode assembly 10 according to this embodiment may include a plurality of electrodes 11 stacked with a plurality of separators 13 in between, and a plurality of electrode tabs 15 connected to the plurality of electrodes 11 and welded to each other to form a welded portion 16. Of the plurality of electrode tabs 15, both outermost electrode tabs 15a can be bent outward in a convex shape.

[0064] At least some of the multiple electrode tabs 15 can be formed with an outward convex curve, and the further out the electrode tab 15 is located, the greater the curve it can take. Therefore, the outermost electrode tab 15a can take the greatest curve.

[0065] The length L from the electrode 11 to the welded portion 16 relative to the outermost electrode tab 15a can be longer than when the outermost electrode tab 15a is formed by being stretched rather than bent. This prevents the outermost electrode tab 15a from breaking or disconnecting due to expansion of the electrode assembly 10 or external forces applied to the electrode tab 15.

[0066] More specifically, the outermost electrode tab 15a may include a first section 151 extending from the electrode 11 and a second section 152 extending from the first section 151 and having a steeper slope than the first section 151. The outermost electrode tab 15a may further include a third section 153 extending from the second section 152 to the workpiece 16 and having a gentler slope than the second section 152. Such a configuration of the outermost electrode tab 15a is characterized by the fact that the outermost electrode tab 15a is pressed toward the electrode assembly 10 by the alignment roller 40 and welded in an aligned state.

[0067] The first section 151 may include a flat section 151a that is connected to the electrode 11 and is formed flat, and a curved section 151b that connects the flat section 151a to the second section 152 and is formed by bending. That is, the point at which the outermost electrode tab 15a begins to bend can be separated from the electrode 11 by a predetermined distance with the flat section 151a in between. This has the advantage of preventing excessive stress concentration from occurring on the outermost electrode tab 15a.

[0068] The outermost electrode tab 15a may have an inward step relative to the outermost electrode tabs 15. For example, the outermost electrode tab 15 and the outermost electrode tab may have a predetermined step S.

[0069] However, cutting or other processing may be performed to align the outer ends of multiple electrode tabs 15. In this case, a step does not need to be formed between the outer end of the outermost electrode tab 15a and the outer ends of the other electrode tabs 15a.

[0070] The above description is merely illustrative of the technical concept of the present invention, and a person with ordinary skill in the art to which the present invention belongs can make various modifications and variations without departing from the essential characteristics of the present invention.

[0071] Therefore, the embodiments disclosed in this invention are for illustrative purposes only and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0072] The scope of protection of this invention shall be interpreted in accordance with the claims described below, and all technical ideas within an equivalent scope shall be interpreted as being included within the scope of the rights of this invention. [Explanation of Symbols]

[0073] 10: Electrode assembly 11: Electrode 13: Separator 15: Electrode Tab 15a: Outermost electrode tab 151: Section 1 151a: Flat section 151b: Curve 152: Section 2 153: Section 3 16: Welded part 30: Tab Guide 40: Alignment Roller 50: Welded section

Claims

1. An electrode tab position adjustment device for adjusting the positions of multiple electrode tabs in an electrode assembly, A pair of tab guides for collecting the aforementioned multiple electrode tabs, A pair of alignment rollers pressurize the plurality of electrode tabs gathered by the pair of tab guides and rotate in a direction that pushes the outermost electrode tab toward the electrode assembly, An electrode tab positioning device, including one.

2. The electrode tab positioning device according to claim 1, wherein, with respect to the electrode assembly, the point at which the pair of alignment rollers press on the plurality of electrode tabs is farther away from the point at which the pair of tab guides press on the plurality of electrode tabs.

3. The aforementioned pair of alignment rollers When the pair of tab guides form a first interval, the plurality of electrode tabs are rotated while under pressure. The electrode tab positioning device according to claim 1, wherein the pair of tab guides separate from the plurality of electrode tabs when they form a second interval smaller than the first interval.

4. The electrode tab positioning device according to claim 1, wherein the pair of alignment rollers include an elastomer material.

5. The aforementioned pair of alignment rollers The electrode tab position adjustment device according to claim 1, wherein the plurality of electrode tabs are arranged to face each other with respect to the height direction of the electrode assembly, and the distance between them is adjusted.

6. An electrode tab position adjustment method for adjusting the positions of multiple electrode tabs in an electrode assembly, The steps include: bringing a pair of tab guides closer together to collect the plurality of electrode tabs; A pair of alignment rollers rotate while pressurizing the plurality of electrode tabs gathered by the pair of tab guides, pushing the outermost electrode tab of the plurality of electrode tabs toward the electrode assembly, A method for adjusting the position of electrode tabs, including the method described above.

7. When the pair of alignment rollers rotate, the pair of tab guides form a first interval. The electrode tab position adjustment method according to claim 6, wherein when welding the plurality of electrode tabs, the pair of tab guides have a second interval that is narrower than the first interval.

8. The electrode tab position adjustment method according to claim 6, wherein a step is generated between the outer ends of the plurality of electrode tabs when the pair of alignment rollers rotate.

9. The electrode tab position adjustment method according to claim 6, wherein when welding the plurality of electrode tabs, the pair of alignment rollers are separated from the plurality of electrode tabs.

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