Tab guide and electrode tab welding device including 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, a secondary battery means a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in electronic devices such as mobile phones, notebook computers, and camcorders, as well as electric vehicles, etc. In particular, lithium secondary batteries have a larger capacity than nickel-cadmium batteries or nickel-metal hydride batteries and a higher energy density, and therefore their use is showing a rapid increase.

[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-type 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 have one or two cup portions 21. FIG. 1 shows the 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 called 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 one another 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 to each other while being gathered together by a tab guide. The tab guide gradually wears out as the welding process is repeated, and therefore requires replacement at regular intervals for maintenance.

[0010] Conventionally, such replacement work was troublesome and time-consuming, and there were problems with the high wear cost of the tab guide. In addition, when replacing the tab guide, the alignment of the tab guide, such as its horizontality and parallelism, may be shifted, which may result in a deterioration in the welding quality of the multiple electrode tabs. Summary of the Invention [Problem to be solved by the invention]

[0011] 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] According to an embodiment of the present invention, a tab guide 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 and having higher rigidity than the contact portion.

[0014] The contact portion may have a surface friction coefficient lower than a surface friction coefficient 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 may be made of the above material and may satisfy the condition that when a wear test is conducted in which a ball made of an alumina material is pressed against a disk rotating at 100 RPM with a load of 15 kgf for two hours, the wear amount of the disk is 0.15 g or less.

[0020] The contact portion may include a body detachably mounted to the mounting 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 device according to an embodiment of the present invention can weld a plurality of electrode tabs together. The electrode tab welding device may include a tab guide that presses the plurality of electrode tabs together, and a welding portion that welds the plurality of electrode tabs gathered by the tab guide. 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 higher rigidity than the contact portion. Effect 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, there is no need to replace the entire tab guide, and maintenance can be performed by simply replacing the contact portion, which has the advantages of reducing consumable costs for the tab guide and simplifying maintenance of the tab guide.

[0027] Additionally, the high rigidity of the mounting portion minimizes the risk of the tab guide becoming misaligned, and when the contact portion is replaced relative to the mounting portion, the alignment of the contact portion can be reliably maintained, thereby providing the advantage of maintaining high welding quality of the 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 description 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 described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters depicted in such drawings. [Figure 1] FIG. 1 is a diagram showing an example of a pouch-type secondary battery. [Diagram 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; [Diagram 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; [Diagram 5] FIG. 13 is a front view of a tab guide according to another embodiment of the present invention. [Figure 6] FIG. 13 is a front view of a tab guide according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] The present invention will be described in detail below with reference to the accompanying drawings, in order to enable a person skilled in the art to easily carry out the present invention. However, the present invention may be embodied 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 referring to components in each drawing in this specification, the same or similar reference symbols will be used for the same or similar components throughout the specification.

[0032] Furthermore, the terms and words used in this specification and the claims should not be interpreted in a limited manner to their ordinary or dictionary meanings, but should be interpreted in a manner consistent with the technical ideas 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 manner.

[0033] Fig. 2 to Fig. 4 are schematic diagrams for explaining 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] The electrode tab welding device 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 a positive electrode and a negative electrode, 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 a person skilled in the art will easily 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 multiple electrode tabs 15 together, and a welding portion 50 that welds the multiple electrode tabs 15 gathered by the tab guide 100.

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

[0037] For example, a pair of tab guides 100 may be provided to face each other across the multiple electrode tabs 15 in the height direction of the electrode assembly 10 (for example, a direction parallel to the Z axis in FIG. 2). In this case, the tab guide 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 so as to be movable up and down. As shown in Fig. 3, the pair of tab guides 100 can gather the multiple electrode tabs 15 by pressing the multiple electrode tabs 15 close to each other.

[0039] The closer the distance between the pair of tab guides 100 is, the stronger the pressure the pair of tab guides 100 can apply to the multiple 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 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 such 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 than the pair of tab guides 100. More specifically, with respect to the electrode assembly 10, the welded portion 16 may be located farther than a point where the pair of tab guides 30 press the multiple electrode tabs 15.

[0044] Through such a process, it is possible to manufacture an electrode assembly 10 having a plurality of electrode tabs 15 welded to each other at welded portions 16. It is possible to manufacture a pouch-type battery by connecting electrode leads to the plurality of electrode tabs 15 welded to each other and then housing the electrode assembly 10 in a pouch.

[0045] Meanwhile, the tab guide 100 according to an 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 has higher rigidity than the contact portion 110.

[0046] Because contact portion 110 is detachably attached to attachment portion 120, when wear or the like occurs in contact portion 110, it is not necessary to replace the entire tab guide 100, and maintenance can be performed by simply replacing contact portion 110. This reduces the cost of consumables for tab guide 100 and simplifies maintenance of 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. 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. Thus, due to the high rigidity of the mounting portion 120, the possibility of misalignment of the tab guide 100 can be minimized, 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 part 110 may be lower than the surface friction coefficient of the mounting part 120. This can prevent the electrode tab 15 from being damaged by friction caused by the contact part 110. The surface friction coefficient of the contact part 110 is preferably 0.1 or less. Such a surface friction coefficient can be measured by the well-known test DIN53375. Alternatively, the surface friction coefficient of the contact part 110 may be 0.03 or more, but is not limited thereto.

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

[0050] In a known ball-on-disk wear test, the wear amount of the material constituting the contact portion 110 is preferably 0.15 g or less. More specifically, when 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 for 2 hours, the wear amount of the disk may satisfy the condition of 0.15 g or less. If a disk material with a wear amount of 0.15 g or more is used as the material of the contact portion 110, the wear resistance of the contact portion 110 is too low, and this is inappropriate.

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

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

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

[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. Thus, 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 portion 116 protruding from the contact portion 110 toward the mounting portion 120, and locking portions 117 protruding from ends of the protrusion portion 116 on both sides in the thickness direction. The fastening groove 125 may include a narrow groove portion 126 into which the protrusion portion 116 is inserted, and a wide groove portion 127 into which the locking portion 117 is inserted. Thus, the locking portion 117 of the fastening protrusion 115 cannot pass through the narrow groove portion 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 a 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. Also, 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 can reduce 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. Since the mounting portion 120 has high rigidity, the fastening hole 129 can be firmly fastened to the elevator by a fastening member such as a screw, thereby making it possible to maintain the alignment of the tab guide 100 with even higher reliability.

[0062] The above description is merely an illustrative example of 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 not intended to limit the technical idea of ​​the present invention, but are intended to explain the same, and such embodiments do not limit the scope of the technical idea of ​​the present invention.

[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 parts 50 Welding 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 a higher rigidity than the contact portion.

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

3. The tab guide of 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 of claim 1 , wherein the contact portion is made of a material selected from the group consisting of polyetheretherketone, polyamide, and 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 of 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 for two hours, the wear amount of the disk is 0.15 g or less.

8. The contact portion is A main body that is detachably attached to the attachment portion; 2. 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 claim 1 , wherein the other one of the mounting portion and the contact portion is formed with a fastening groove for restraining the fastening protrusion.

10. The tab guide of 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 that raises and lowers the tab guide.

13. An electrode tab welding apparatus for welding a plurality of electrode tabs together, a tab guide that presses the 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 a higher rigidity than the contact portion.

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