Tab guide and electrode tab welding device including the same

Abstract

Tab guides according to embodiments of the present invention can urge multiple electrode tabs together. The tab guide may include a contact portion that contacts the electrode tab, and a mounting portion to which the contact portion is detachably mounted and having a higher rigidity than the contact portion.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0010291 filed on January 24, 2022 and Korean Patent Application No. 10-2023-0005565 filed on January 13, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a tab guide that presses a plurality of electrode tabs together, and an electrode tab welding device including the same. [Background technology]

[0003] In general, secondary batteries are batteries that can be charged and discharged, unlike primary batteries that cannot be recharged, and are widely used in electronic devices such as mobile phones, laptops, and camcorders, as well as electric vehicles, etc. In particular, lithium secondary batteries have a larger capacity and higher energy density than nickel-cadmium batteries or nickel-metal hydride batteries, and therefore their use is rapidly increasing.

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

[0005] FIG. 1 is a diagram showing an example of a pouch-type secondary battery.

[0006] 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.

[0007] The pouch 20 includes a concave cup portion 21 for accommodating the electrode assembly 10. The pouch 20 may be formed with one or two cup portions 21. FIG. 1 shows a pouch 20 including a pair of cup portions 21. A peripheral portion 23 is formed around the edge of the cup portion 21 by sealing. The peripheral portion 23 can be said to be a terrace.

[0008] A plurality of electrode tabs 15 may be connected to the plurality of electrodes of the electrode assembly 10. The plurality of electrode tabs 15 may be welded to each other in predetermined areas and then connected to an electrode lead 17.

[0009] During the welding process of the plurality of electrode tabs 15, the plurality of electrode tabs 15 can be welded together while being gathered together by a tab guide. The tab guide gradually wears out as the welding process is repeated, and therefore, replacement work is required at regular intervals for maintenance.

[0010] Conventionally, such replacement work has been cumbersome and time-consuming, and there have been problems with the high cost of wearing out the tab guides. Furthermore, when replacing the tab guides, the alignment of the tab guides, such as their horizontality and parallelism, can be misaligned, which can lead to a deterioration in the welding quality of the multiple electrode tabs. Summary of the Invention [Problem to be solved by the invention]

[0011] SUMMARY OF THE INVENTION An object of the present invention is to provide a tab guide that can be quickly replaced and has low wear costs, and an electrode tab welding device including the same.

[0012] Another object of the present invention is to provide a tab guide capable of maintaining high welding quality of a plurality of electrode tabs and an electrode tab welding device including the same. [Means for solving the problem]

[0013] A tab guide according to an embodiment of the present invention may press a plurality of electrode tabs together. The tab guide may include a contact portion that contacts the electrode tabs, and a mounting portion to which the contact portion is detachably mounted, the mounting portion having higher rigidity than the contact portion.

[0014] The contact portion may have a surface friction coefficient lower than that of the mounting portion.

[0015] The contact portion may have a surface friction coefficient of 0.1 or less.

[0016] The mounting portion may be made of a metallic material, and the contact portion may be made of a non-metallic material.

[0017] The contact portion may be made of polyetheretherketone, polyamide, or alumina.

[0018] The contact portion may have a lower wear resistance than the mounting portion.

[0019] The material forming the contact portion is made of the above material, and a ball made of alumina is pressed against a disk rotating at 100 RPM with a force of 15 kgf( Converting it into When a wear test is carried out in which a load of 147 N is applied for 2 hours, the wear amount of the disk is 0.15 g or less.

[0020] The contact portion may include a body detachably attached to the attachment portion, and a protrusion connected to the body, protruding toward the electrode tab, and having a thickness thinner than that of the body.

[0021] A fastening protrusion may be formed on one of the mounting portion and the contact portion, and a fastening groove for restraining the fastening protrusion may be formed on the other of the mounting portion and the contact portion.

[0022] The fastening protrusion and the fastening groove may extend parallel to a width direction of the electrode tab.

[0023] The mounting portion may be larger in size than the contact portion.

[0024] The mounting portion may have a fastening hole formed therein to be fastened to an elevator that raises and lowers the tab guide.

[0025] An electrode tab welding apparatus according to an embodiment of the present invention may weld a plurality of electrode tabs together. The electrode tab welding apparatus may include a tab guide that presses the plurality of electrode tabs together and a welding unit that welds the plurality of electrode tabs gathered by the tab guide. The tab guide may include a contact portion that contacts the electrode tabs and a mounting portion to which the contact portion is detachably mounted, the mounting portion having higher rigidity than the contact portion. [Effects of the Invention]

[0026] According to a preferred embodiment of the present invention, the contact portion can be detachably attached to the attachment portion, so that when wear or the like occurs in the contact portion, it is not necessary to replace the entire tab guide, and maintenance can be performed by simply replacing the contact portion, which has the advantages of reducing the cost of consumables for the tab guide and simplifying tab guide maintenance.

[0027] Furthermore, the high rigidity of the mounting portion minimizes the risk of misalignment of the tab guide, and when replacing the contact portion with respect to the mounting portion, the alignment of the contact portion can be reliably maintained, thereby providing the advantage of maintaining high welding quality for multiple electrode tabs.

[0028] Other effects include those that can be easily predicted by those skilled in the art from the configurations according to the preferred embodiments of the present invention. [Brief explanation of the drawings]

[0029] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention to be given later, serve to further understand the technical concept of the present invention, and therefore the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] FIG. 1 is a diagram showing an example of a pouch-type secondary battery. [Figure 2] 1 is a schematic diagram for explaining the configuration and operation of an electrode tab welding device according to an embodiment of the present invention; [Figure 3] 1 is a schematic diagram for explaining the configuration and operation of an electrode tab welding device according to an embodiment of the present invention; [Figure 4] 1 is a schematic diagram for explaining the configuration and operation of an electrode tab welding device according to an embodiment of the present invention; [Figure 5] FIG. 10 is a front view of a tab guide according to another embodiment of the present invention. [Figure 6] FIG. 10 is a front view of a tab guide according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily understand the preferred embodiments of the present invention. However, the present invention can be realized in various different forms and is not limited to the following embodiments.

[0031] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or related known technologies that may obscure the gist of the present invention will be omitted, and when assigning reference symbols to components in each drawing in this specification, the same or similar reference symbols will be assigned to the same or similar components throughout the specification.

[0032] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to explain his or her invention in the best possible way.

[0033] 2 to 4 are schematic diagrams illustrating the configuration and operation of an electrode tab welding device according to one embodiment of the present invention. More specifically, Fig. 2 is a schematic diagram showing a state before a plurality of electrode tabs 15 are gathered by a tab guide 100, Fig. 3 is a schematic diagram showing a state in which a plurality of electrode tabs 15 are gathered by the tab guide 100, and Fig. 4 is a schematic diagram showing a state in which a plurality of electrode tabs 15 are welded by a welding portion 50.

[0034] An electrode tab welding apparatus according to an embodiment of the present invention can weld together a plurality of electrode tabs 15 provided in an electrode assembly 10. As shown in FIG. 2, the electrode assembly 10 may be formed by alternately stacking a plurality of electrodes 11 and a plurality of separators 13. The plurality of electrodes 11 may include positive and negative electrodes, and an electrode tab 15 may be connected to each electrode 11. For convenience of explanation, only a negative electrode tab connected to a negative electrode is shown in the drawings, but those skilled in the art will readily understand that a positive electrode tab connected to a positive electrode can also be provided in the electrode assembly 10 and welded in the same manner as the negative electrode tab.

[0035] More specifically, the electrode tab welding device may include a tab guide 100 that presses the plurality of electrode tabs 15 together, and a welding section 50 that welds the plurality of electrode tabs 15 gathered by the tab guide 100.

[0036] The tab guide 100 may be positioned on at least one side of the plurality of electrode tabs 15 .

[0037] For example, a pair of tab guides 100 may be provided facing each other across the multiple electrode tabs 15 in the height direction of the electrode assembly 10 (e.g., a direction parallel to the Z axis in FIG. 2). In this case, the tab guides 100 can press the multiple electrode tabs 15 from both sides. For example, the pair of tab guides 100 may include a lower tab guide 100A located below the multiple electrode tabs 15 and an upper tab guide 100B located above the multiple electrode tabs 15.

[0038] The distance between the pair of tab guides 100 may be adjustable. To this end, at least one of the pair of tab guides 100 may be provided to be movable up and down. As shown in Fig. 3, the pair of tab guides 100 can gather the electrode tabs 15 by bringing them close to each other and applying pressure to the electrode tabs 15.

[0039] The closer the gap between the pair of tab guides 100 is, the stronger the pressure that the pair of tab guides 100 can apply to the plurality of electrode tabs 15 .

[0040] However, it is not limited thereto, and it goes without saying that the tab guide 100 may be located on one side of the plurality of electrode tabs 15 and a general support portion (not shown) may be located on the other side.

[0041] 4, the welding portion 50 can weld the plurality of electrode tabs 15 gathered by the tab guide 100. That is, the welding portion 50 can form the welded portion 16 by welding the plurality of electrode tabs 15 together.

[0042] For example, the welding unit 50 may ultrasonically weld the electrode tabs 15 together. In this case, the welding unit 50 may include an anvil located on one side (e.g., below) of the electrode tabs 15 and a horn located on the other side (e.g., above) of the electrode tabs 15. The welding unit 50 may be configured so that the distance between the anvil and the horn is adjustable. With the electrode tabs 15 pressed between the anvil and the horn, the horn may vibrate at a high frequency, thereby welding the electrode tabs 15 together.

[0043] With respect to the electrode assembly 10, the welding portion 50 may be located farther from the pair of tab guides 100. More specifically, with respect to the electrode assembly 10, the welded portion 16 may be located farther from the point where the pair of tab guides 30 press the multiple electrode tabs 15.

[0044] Through this process, an electrode assembly 10 can be manufactured, which includes a plurality of electrode tabs 15 welded to each other at welded portions 16. Electrode leads are connected to the plurality of welded electrode tabs 15, and then the electrode assembly 10 is housed in a pouch, thereby manufacturing a pouch-type battery.

[0045] Meanwhile, the tab guide 100 according to one embodiment of the present invention may include a contact portion 110 that contacts the electrode tab 15, and a mounting portion 120 to which the contact portion 110 is detachably mounted and which has higher rigidity than the contact portion 110.

[0046] Because the contact portion 110 is detachably attached to the attachment portion 120, when wear or the like occurs in the contact portion 110, it is not necessary to replace the entire tab guide 100, and maintenance can be performed by simply replacing the contact portion 110. This reduces the cost of consumables for the tab guide 100 and simplifies maintenance of the tab guide 100.

[0047] The material of the mounting portion 120 may have higher rigidity than the material of the contact portion 110. More specifically, the mounting portion 120 may be made of a metal material, and the contact portion 110 may be made of a non-metal material. Even more specifically, the mounting portion 120 may be made of a steel material. The contact portion 110 may be made of a polyetheretherketone (PEEK) material. However, the material is not limited thereto, and the contact portion 110 may include other materials such as polyamide or alumina. Therefore, the high rigidity of the mounting portion 120 can minimize the risk of misalignment of the tab guide 100, and when the contact portion 110 is replaced with respect to the mounting portion 120, the alignment of the contact portion 110 can be maintained with high reliability.

[0048] The surface friction coefficient of the contact portion 110 may be lower than the surface friction coefficient of the mounting portion 120. This prevents the electrode tab 15 from being damaged by friction with the contact portion 110. The surface friction coefficient of the contact portion 110 is preferably 0.1 or less. Such a surface friction coefficient can be measured using the well-known test DIN 53375. Alternatively, the surface friction coefficient of the contact portion 110 may be 0.03 or more, but is not limited to this.

[0049] The wear resistance of the contact portion 110 may be lower than that of the mounting portion 120. This is because, as described above, the rigidity of the mounting portion 120 is higher than that of the contact portion 110. However, if the wear resistance of the contact portion 110 is too low, there is a problem that the replacement cycle of the contact portion 110 becomes shorter and the wear cost becomes higher. Therefore, it is preferable that the material forming the contact portion 110 has a predetermined wear resistance.

[0050] In a known ball-on-disk wear test, the amount of wear of the material forming the contact portion 110 is preferably 0.15 g or less. More specifically, a ball made of alumina is applied with a force of 15 kgf ( Converting it intoThe disk may also satisfy the condition that the amount of wear of the disk is 0.15 g or less when pressed for two hours under a load of 147 N. If a disk material with an amount of wear of 0.15 g or more is used as the material for contact portion 110, the wear resistance of contact portion 110 will be too low, making it inappropriate.

[0051] As an experimental example, in the ball-on-disk test, when the disk material was polyamide, the wear amount was measured to be 0.103 g, when the disk material was polyetheretherketone (PEEK), the wear amount was measured to be 0.001 g, and when the disk material was alumina, the wear amount was measured to be 0.013 g. In other words, polyetheretherketone, polyamide, or alumina can be selected as the material of the contact portion 110. In contrast, when the disk material was zirconia, the wear amount was measured to be 0.892 g. In other words, zirconia is not suitable as a material for the contact portion 110.

[0052] The contact portion 110 may include a main body 111 detachably attached to the mounting portion 120, and a protrusion 112 connected to the main body 111 and protruding toward the electrode tab 15. The main body 111 and the protrusion 112 may be integrally formed.

[0053] The main body 111 and the protrusion 112 may have a predetermined thickness in the length direction of the electrode tab 15 (e.g., a direction parallel to the X-axis in FIG. 2). The protrusion 112 may have a thickness thinner than the main body 111. More specifically, the main body 111 may have a first thickness t1, and the protrusion 112 may have a second thickness t2 thinner than the first thickness t1.

[0054] The body 111 is formed relatively thick so that it can be firmly attached to the mounting part 120. The protrusions 112 are formed relatively thin so that the electrode tabs 15 can be precisely pressed and gathered.

[0055] As described above, the contact portion 110 may be detachably fastened to the mounting portion 120. More specifically, a fastening protrusion 115 may be formed on one of the contact portion 110 and the mounting portion 120, and a fastening groove 125 for restraining the fastening protrusion 115 may be formed on the other of the contact portion 110 and the mounting portion 120. Hereinafter, a case where the fastening protrusion 115 is formed on the contact portion 110 and the fastening groove 125 is formed on the mounting portion 120 will be described as an example.

[0056] The tab guide 100 may extend parallel to the width direction of the electrode tab 15. The fastening protrusion 115 and the fastening groove 125 may extend parallel to the width direction of the electrode tab 15. Therefore, the contact portion 110 can move in the width direction of the electrode tab 15 relative to the mounting portion 120 to be fastened and separated. In addition, the contact portion 110 can be constrained by the mounting portion 120 in the width direction and height direction of the tab guide 100.

[0057] More specifically, the fastening protrusion 115 may include a protrusion 116 protruding from the contact portion 110 toward the mounting portion 120 and locking portions 117 protruding on both sides in the thickness direction from the end of the protrusion 116. The fastening groove 125 may include a narrow groove 126 into which the protrusion 116 is inserted and a wide groove 127 into which the locking portion 117 is inserted. Therefore, the locking portion 117 of the fastening protrusion 115 cannot pass through the narrow groove 126 of the fastening groove 125 and may be restricted in the height direction of the electrode assembly 10.

[0058] 5 and 6 are front views of tab guides according to other embodiments of the present invention. More specifically, Fig. 5 is a front view of a lower tab guide 100A of the pair of tab guides 100, and Fig. 6 is a front view of an upper tab guide 100B of the pair of tab guides 100.

[0059] Below, any content that overlaps with the above will be omitted.

[0060] In each tab guide 100, the height h2 of the mounting portion 120 may be greater than the height h1 of the contact portion 110. Furthermore, the width of the mounting portion 120 and the width of the contact portion 110 may be the same or similar to each other. That is, the size of the mounting portion 120 may be greater than the size of the contact portion 110. This reduces the wear cost of the contact portion 110, and the mounting portion 120 can maintain the alignment of the contact portion 110 with higher reliability.

[0061] The mounting portion 120 may have a fastening hole 129 formed therein to be fastened to an elevator (not shown) that raises and lowers the tab guide 100. Because the mounting portion 120 has high rigidity, the fastening hole 129 can be firmly fastened to the elevator using a fastening member such as a screw, thereby maintaining the alignment of the tab guide 100 with even greater reliability.

[0062] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0063] Therefore, the embodiments disclosed in the present invention are for illustrative purposes only and are not intended to limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0064] The scope of protection of the present invention should be interpreted by the appended claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0065] 10 Electrode assembly 11 electrodes 13 Separation membrane 15 Electrode tab 16 Welded part 50 Welded Section 100 Tab Guide 100A Lower Tab Guide 100B Upper Tab Guide 110 Contact part 111 Main Unit 112 Protrusion 115 Fastening protrusion 120 Mounting part 125 Fastening groove 129 Fastening hole

Claims

1. In a tab guide that presses a plurality of electrode tabs together, a contact portion that contacts the electrode tab; a mounting portion to which the contact portion is detachably attached, the mounting portion having higher rigidity than the contact portion.

2. The tab guide according to claim 1 , wherein the contact portion has a surface friction coefficient lower than a surface friction coefficient of the mounting portion.

3. The tab guide according to claim 1 , wherein the contact portion has a surface friction coefficient of 0.1 or less.

4. The tab guide of claim 1 , wherein the mounting portion is made of a metallic material and the contact portion is made of a non-metallic material.

5. The tab guide according to claim 1 , wherein the contact portion is made of polyetheretherketone, polyamide, or alumina.

6. The tab guide of claim 1 , wherein the contact portion has a lower wear resistance than the mounting portion.

7. The material forming the contact portion is 2. The tab guide according to claim 1, wherein when a wear test is conducted in which a ball made of an alumina material is pressed against a disk made of the material and rotating at 100 RPM with a load of 15 kgf (equivalent to 147 N) for two hours, the amount of wear of the disk is 0.15 g or less.

8. The contact portion is a main body detachably attached to the attachment portion; The tab guide of claim 1 , further comprising: a protrusion coupled to the body, protruding toward the electrode tab, the protrusion having a thickness less than that of the body.

9. a fastening protrusion is formed on one of the mounting portion and the contact portion; The tab guide according to any one of claims 1 to 8, wherein the other of the mounting portion and the contact portion is formed with a fastening groove for restraining the fastening protrusion.

10. The tab guide according to claim 9 , wherein the fastening protrusion and the fastening groove extend parallel to a width direction of the electrode tab.

11. The tab guide of claim 1 , wherein the mounting portion is larger in size than the contact portion.

12. The tab guide according to claim 1 or 11, wherein the mounting portion is formed with a fastening hole to be fastened to an elevator device that raises and lowers the tab guide.

13. An electrode tab welding device for welding a plurality of electrode tabs together, a tab guide that presses the plurality of electrode tabs together; a welding portion that welds the plurality of electrode tabs gathered by the tab guide, The tab guide is a contact portion that contacts the electrode tab; and a mounting portion to which the contact portion is detachably mounted, the mounting portion having higher rigidity than the contact portion.

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