Secondary battery electrode tab processing apparatus and electrode tab processing method using the same

Abstract

The present invention relates to an electrode tab processing apparatus for a secondary battery and an electrode tab processing method using the same, and more particularly to an electrode tab processing apparatus for forming a connecting portion by cutting a predetermined region of an electrode tab extending toward one side of an electrode collector so that a metal foil can be connected to the electrode tab.

Description

[Technical Field]

[0001] This application claims priority under Korean Patent Application No. 10-2023-0141266 dated October 20, 2023, and all contents disclosed in said Korean Patent Application are incorporated herein by reference.

[0002] The present invention relates to a secondary battery electrode tab processing apparatus and an electrode tab processing method using the same, and more particularly to a secondary battery electrode tab processing apparatus capable of selectively cutting a certain region of an electrode tab and an electrode tab processing method using the same. [Background technology]

[0003] With increasing technological development and demand for mobile devices, rechargeable secondary batteries are being used as an energy source for a wide variety of mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being presented as alternatives to existing gasoline and diesel vehicles that use fossil fuels.

[0004] Rechargeable batteries are classified according to the shape of their battery case into cylindrical batteries and rectangular batteries, in which the electrode assembly is housed in a cylindrical or rectangular metal can, and pouch batteries, in which the electrode assembly is housed in a pouch-type case made of aluminum laminate sheet.

[0005] In particular, in the case of pouch-type secondary batteries, a number of positive and negative electrodes of a predetermined size are sequentially stacked with a separator membrane in between, and electrode tabs or a pair of electrode leads connected to electrode tabs protrude from one or both sides of the case.

[0006] On the other hand, aluminum current collectors are commonly used as positive electrode current collectors to which positive electrode active material is coated. However, since aluminum current collectors have been identified as the main cause of ignition for various reasons, research is being conducted to replace them with multilayer current collectors, such as current collectors with a resin layer interposed between two metal layers.

[0007] When using a current collector with such a three-layer structure, it is expected that safety can be improved because the thin metal layer provides high resistance during a short circuit, allowing for a rapid interruption of the current flow.

[0008] Figure 1 is a schematic diagram of a secondary battery according to conventional technology. As shown in Figure 1, the electrode assembly 10 has a structure in which numerous tabs 20 extend outward, electrode leads 30 are interposed between these tabs 20, and then fixed to each other by welding.

[0009] However, in the case of a three-layer current collector, a resin layer is provided in the middle, making it difficult to join the electrode tab and electrode lead using commonly used welding methods.

[0010] In connection with this, the applicant has previously filed an application for an invention relating to a secondary battery electrode assembly and a battery cell including the same, in which an electrode tab and electrode lead can be securely fixed by providing an incision line in the electrode tab, then passing a metal foil through it in a zigzag pattern, and then welding the electrode lead together with the metal foil and electrode tab.

[0011] However, a drawback is that a high level of skill is required of the operator in order to cut only a portion of the electrode tab and to pass the metal foil through the cut line. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Korean Patent Publication No. 10-2022-0124358 [Patent Document 2] Korean Patent Publication No. 10-2023-0020177 Specification [Patent Document 3] Korean Patent Publication No. 10-2023-0124641 [Overview of the project] [Problems that the invention aims to solve]

[0013] The present invention aims to solve the aforementioned problems by providing a secondary battery electrode tab processing apparatus and an electrode tab processing method using the same, which can process electrode tabs regardless of the operator's skill level when connecting an electrode tab having a resin layer interposed between metal layers and a metal foil. [Means for solving the problem]

[0014] The electrode tab processing apparatus according to the present invention, which solves the above-mentioned problems, is an electrode tab processing apparatus for forming a connecting portion by cutting a certain area of ​​an electrode tab so that a metal foil can be connected to an electrode tab extending in one direction to an electrode current collector, and includes a lower jig (800) disposed on one side of the electrode tab and an upper jig (900) disposed on the other side of the electrode tab, wherein a pair of first lower flat portions (811) are located separately along the longitudinal direction on the upper surface of the lower jig (800), and the pair of first lower flat portions (8 A lower raised portion (812) is provided between the 11), a pair of first upper flat portions (911) are spaced apart and positioned along the longitudinal direction on the lower surface of the upper jig (900), and an upper recessed portion (912) is provided between the pair of first upper flat portions (911) so as to interlock with the lower raised portion (812). When the electrode tab is pressed while positioned between the lower jig (800) and the upper jig (900), a connecting portion is formed through a pair of cut lines spaced at a certain interval, through which the metal foil can pass.

[0015] Furthermore, the electrode tab processing apparatus according to the present invention is characterized in that the upper surface of the lower jig (800) is further provided with a lower recessed portion (822) along the longitudinal direction, and the lower surface of the upper jig (900) is further provided with an upper raised portion (922) along the longitudinal direction so as to interlock with the lower recessed portion (822).

[0016] Also, in the electrode tab processing apparatus according to the present invention, the lower raised portion (812) is located at the center of the upper surface of the lower jig (800), the lower recessed portion (822) consists of a pair located on both sides of the lower raised portion (812), the upper recessed portion (912) is located at the center of the lower surface of the upper jig (900), and the upper raised portion (922) consists of a pair located on both sides of the upper recessed portion (912).

[0017] Also, in the electrode tab processing apparatus according to the present invention, the lower jig (800) includes a first lower body (810) provided with the lower raised portion (812) and a second lower body (820) where the lower recessed portion (822) is located, and the first lower body (810) and the second lower body (820) have a separable structure.

[0018] Also, in the electrode tab processing apparatus according to the present invention, the upper jig (900) includes a first upper body (910) provided with the upper recessed portion (912) and a second upper body (920) where the upper raised portion (922) is located, and the first upper body (910) and the second upper body (920) have a separable structure.

[0019] Also, in the electrode tab processing apparatus according to the present invention, the lower jig (800) further includes a first heating member (830).

[0020] Also, in the electrode tab processing apparatus according to the present invention, the upper jig (900) further includes a second heating member (930).

[0021] Also, in the electrode tab processing apparatus according to the present invention, the cross-section in the width direction of the lower raised portion (812) and the upper recessed portion (912) is semi-circular or semi-elliptical.

[0022] Also, in the electrode tab processing apparatus according to the present invention, the cross-section in the width direction of the lower recessed portion (822) and the upper raised portion (922) is semi-circular or semi-elliptical.

[0023] Furthermore, in the electrode tab processing apparatus according to the present invention, the electrode current collector is characterized by having a multilayer structure in which a resin layer is interposed between a pair of metal layers.

[0024] Furthermore, the method for processing an electrode tab using the electrode tab processing apparatus described above according to the present invention is characterized by comprising: a first step of positioning the electrode tab between the lower jig (800) and the upper jig (900); and a second step of moving one or more of the lower jig (800) and the upper jig (900) to press the electrode tab.

[0025] Furthermore, the electrode tab processing method according to the present invention is characterized in that one or more jigs, either the lower jig (800) or the upper jig (900), are heated before or during the second stage. [Effects of the Invention]

[0026] According to the secondary battery electrode tab processing apparatus and electrode tab processing method using the present invention, the apparatus includes a lower jig with a lower raised portion on its upper surface and an upper jig with an upper recessed portion on its lower surface that engages with the lower raised portion. After positioning the electrode tab between these lower and upper jigs, it is possible to form an incision line at a fixed position by pressing it.

[0027] Furthermore, according to the secondary battery electrode tab processing apparatus and electrode tab processing method using the present invention, the electrode tab is positioned between the lower jig and the upper jig before being pressed, so that the quality of the processed electrode tabs is the same regardless of the operator's skill level.

[0028] Furthermore, according to the secondary battery electrode tab processing apparatus and electrode tab processing method using the present invention, since the lower jig and upper jig have a structure in which a large number of unit members are connected, it is possible to replace only specific unit members, and thus the processing cost can be reduced. [Brief explanation of the drawing]

[0029] [Figure 1]This is a schematic diagram of a secondary battery using conventional technology. [Figure 2] This is an exploded perspective view of a secondary battery electrode assembly according to the first embodiment of the present invention. [Figure 3] This is a cross-sectional view of the positive electrode of a secondary battery electrode assembly according to the first embodiment of the present invention. [Figure 4] This is a top view of a secondary battery electrode assembly according to the first embodiment of the present invention. [Figure 5] This is a view from below of a secondary battery electrode assembly according to the first embodiment of the present invention. [Figure 6] Figure 4 is an enlarged exploded perspective view of part A of the electrode assembly shown in Figure 4. [Figure 7] This is an exploded perspective view of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 8] This is a cross-sectional view of the negative electrode of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 9] This is a top view of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 10] This is a view from below of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 11] Figure 9 is an enlarged, exploded perspective view of part B of the electrode assembly shown. [Figure 12] This is a perspective view of an electrode tab processing apparatus according to the first embodiment for processing electrode tabs of a secondary battery electrode assembly of the present invention. [Figure 13] Figure 12 is a cross-sectional view of the electrode tab processing apparatus in the AA direction. [Figure 14] Figure 12 is a perspective view from below of the upper jig of the electrode tab processing apparatus shown in Figure 12. [Figure 15] This is a perspective view of an electrode tab processing apparatus according to a second embodiment for processing electrode tabs of a secondary battery electrode assembly of the present invention. [Figure 16] This is a perspective view illustrating a method for processing electrode tabs of a secondary battery electrode assembly using the electrode tab processing apparatus according to the first embodiment. [Figure 17]This is an enlarged perspective view of the electrode tab of a secondary battery electrode assembly processed by the electrode tab processing apparatus according to the first embodiment. [Modes for carrying out the invention]

[0030] In this application, terms such as “includes,” “have,” or “equip” are intended to specify the presence of features, numbers, stages, operations, components, parts, or combinations thereof as described in the specification, and should be understood not to preemptively exclude the possibility of the presence or addition of one or more other features, numbers, stages, operations, components, parts, or combinations thereof.

[0031] Furthermore, the same reference numerals shall be used throughout the drawings for parts that have similar functions and operations. Throughout the specification, when it is said that one part is connected to another part, this includes not only direct connections but also indirect connections through other elements in between. Also, when it is said that a component is included, unless otherwise stated, it does not mean that other components are excluded, but rather that other components may be included.

[0032] The secondary battery electrode tab processing apparatus and electrode tab processing method using the same according to the present invention will be described below with reference to the attached drawings.

[0033] First, we will describe the secondary battery electrode assembly to which the electrode tab processing apparatus according to the present invention is intended to be used.

[0034] Figure 2 is an exploded perspective view of a secondary battery electrode assembly according to the first embodiment of the present invention, and Figure 3 is a cross-sectional view of the positive electrode of the secondary battery electrode assembly according to the first embodiment of the present invention.

[0035] As shown in Figures 2 and 3, the secondary battery electrode assembly according to the present invention has a structure in which one or more positive electrodes 100, one or more negative electrodes 200, and one or more separation membranes 300 are stacked.

[0036] In detail, the separation membrane 300 may be located between the positive electrode 100 and the negative electrode 200, on the upper surface of the uppermost negative electrode 200, and below the lowermost negative electrode 200, but is not necessarily limited to these positions.

[0037] Furthermore, the positive electrode 100 is electrically connected to the positive electrode lead 400, and the negative electrode 200 is electrically connected to the negative electrode lead 500. In particular, a first metal foil 600 is interposed between the positive electrode 100 and the positive electrode lead 400. A detailed explanation of this will be given later.

[0038] First, the positive electrode 100 may consist of a positive electrode current collector 110 and a positive electrode tab 120. In a preferred first embodiment of the present invention, the positive electrode current collector 110 has a three-layer structure in which a first resin layer 112 is interposed between a pair of aluminum layers 111.

[0039] Here, the thickness of the aluminum layer is approximately 0.5 to 2 μm, and the first resin layer is made of polyethylene terephthalate (PET) material with a thickness of approximately 5 to 10 μm, but is not necessarily limited to these dimensions.

[0040] Furthermore, if the material has high conductivity without causing chemical changes to the battery, stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. can be used instead of aluminum. In addition, fine irregularities can be formed on the surface to enhance the adhesion of the positive electrode active material, or various forms such as films, sheets, foils, nets, porous materials, foams, and nonwoven fabrics are possible.

[0041] A positive electrode active material layer 113 is provided on the upper and lower surfaces exposed to the outside from the pair of aluminum layers 111.

[0042] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2) or lithium nickel oxide (LiNiO2), or a compound substituted with a transition metal; chemical formula Li1+x Mn 2-x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, Cu2V2O7; chemical formula LiNi 1-x M x Ni-site type lithium nickel oxide represented as O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); chemical formula LiMn 2-x M x Lithium manganese complex oxides represented as O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiMn2O4, where part of the Li in the chemical formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, LiNi x Mn 2-x You can use formulas like O4 (0.01 ≤ x ≤ 0.6).

[0043] Furthermore, conductive materials and binders can be mixed into the positive electrode active material, and fillers can be added as needed. Since these conductive materials, binders, and fillers correspond to known substances, a detailed explanation will be omitted.

[0044] On the other hand, a blank area (not shown) in the positive electrode current collector 110 where the positive electrode active material layer is not formed is punched out into a predetermined shape to form a positive electrode tab 120.

[0045] The negative electrode 200 can be composed of a negative electrode current collector 210 and a negative electrode tab 220. The negative electrode current collector 210 is generally manufactured to have a thickness of 3 to 500 μm. Such a negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical changes to the battery. For example, copper, stainless steel, aluminum, nickel, titanium, fired carbon, or a surface-treated copper or stainless steel with carbon, nickel, titanium, silver, etc., or an aluminum cadmium alloy can be used.

[0046] Also, fine irregularities can be formed on the surface to strengthen the binding force of the negative electrode active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics can be used.

[0047] A negative electrode active material layer is provided on the upper and lower surfaces of the negative electrode current collector 210. As the negative electrode active material, for example, carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, 2, 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), etc. metal composite oxides; lithium metal; lithium alloys; silicon-based alloys; tin-based alloys; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials that are Si, SiO, SiO2 alone or a mixture of these can be used, but it is not limited to only these.

[0048] Of course, a conductive material and a binder can be additionally mixed into the negative electrode active material to form a negative electrode active material layer. Since these conductive materials and binders correspond to known substances, detailed descriptions are omitted.

[0049] On the other hand, a blank portion (not shown) of the negative electrode current collector 210, where the negative electrode active material layer is not formed, is punched out into a predetermined shape to form the negative electrode tab 220.

[0050] The separation membrane 300 prevents short circuits between the positive electrode 100 and the negative electrode 200, allowing only the movement of lithium ions. The material of such a separation membrane is preferably, but not limited to, one selected from polyethylene, polypropylene, polyethylene / polypropylene double layer, polyethylene / polypropylene / polyethylene triple layer, polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper.

[0051] Figure 4 is a top view of the secondary battery electrode assembly according to the first embodiment of the present invention, Figure 5 is a bottom view of the secondary battery electrode assembly according to the first embodiment of the present invention, and Figure 6 is an enlarged exploded perspective view of part A of the electrode assembly shown in Figure 4.

[0052] The electrical connection structure between the positive electrode tab 120 and the positive electrode lead 400 will be explained with reference to Figures 2 to 6.

[0053] Generally, since the positive electrode tab is made only of metal, it can be joined to the positive electrode lead by ultrasonic welding or the like. However, as mentioned above, the positive electrode current collector and positive electrode tab according to the first embodiment of the present invention have a structure in which a first resin layer is interposed between a pair of aluminum layers. That is, due to the first resin layer that constitutes each positive electrode tab, it is difficult to firmly fix a large number of positive electrode tabs, and the positive electrode tabs and positive electrode leads, using the ultrasonic welding method.

[0054] Therefore, in the first embodiment of the present invention, the first connecting portion 122 is formed together with the first cut line 121 along the entire length direction (x-axis direction) of the positive electrode tab 120, while the first metal foil 600 is positioned to penetrate the first cut line 121.

[0055] More specifically, two parallel first incision lines 121 are provided along the entire length (x-axis direction) of the positive electrode tab 120, spaced apart at a certain interval, and these first incision lines 121 form the first connecting portion 122.

[0056] Here, it is preferable that the first connecting portion 122 bulges upward so that the first metal foil 600 can easily penetrate the first cutting line 121. The apparatus and method for processing such a structure will be described later.

[0057] On the other hand, to prevent the first metal foil 600 passing through the first incision line 121 from detaching, it is preferable that both ends of the first incision line 121 be located inside the positive electrode tab 120.

[0058] After the first metal foil 600 passes through one of the two first incision lines 121, and then passes through the other first incision line 121, the first metal foil 600 is exposed on both sides of the positive electrode tab 120 in the width direction (z-axis direction), while the first connecting portion 122 is located in the center (see Figure 4).

[0059] On the other hand, on the back surface of the positive electrode tab 120, the first metal foil 600 is not exposed on both side edges in the width direction (z-axis direction), and the middle portion is exposed (see Figure 5).

[0060] As a result, since the first metal foil 600 is ribbon-shaped with two first incision lines 121 passing through it in a zigzag pattern, the numerous positive electrode tabs 120 are formed into a single tab bundle by the first metal foil 600.

[0061] Then, the positive electrode lead 400 is in close contact with a portion of the positive electrode tab 120 and a portion of the first metal foil 600, and is fixed to them by ultrasonic welding.

[0062] Here, it is preferable that the positive electrode lead 400 faces the side edges of the positive electrode tab 120 in the width direction (z-axis direction) where the first metal foil 600 is exposed. This is because the coupling and fixing of the side edges of the positive electrode tab 120 in the width direction (z-axis direction) with the positive electrode lead 400 is more effective in suppressing movement in the width direction (z-axis direction).

[0063] Of course, it goes without saying that the first metal foil 600 contributes to the electrical connection between the positive electrode tab 120 and the positive electrode lead 400.

[0064] On the other hand, while the first metal foil 600 is preferably made of the same aluminum material as the aluminum layer 111, it can be changed to any material that can perform the same function.

[0065] Furthermore, it is preferable that the length of the first metal foil 600 does not exceed the width of the positive electrode tab 120, and that the width of the first metal foil 600 is slightly shorter than the length of the first incision line 121.

[0066] The positive electrode lead 400 is preferably made of aluminum, but is not necessarily limited to this.

[0067] Figure 7 is an exploded perspective view of a secondary battery electrode assembly according to a second embodiment of the present invention, and Figure 8 is a cross-sectional view of the negative electrode of the secondary battery electrode assembly according to a second embodiment of the present invention.

[0068] The secondary battery electrode assembly according to the second embodiment of the present invention has a structure in which one or more positive electrodes 100, one or more negative electrodes 200, and one or more separation membranes 300 are stacked, similar to the first embodiment.

[0069] In the second embodiment, the negative electrode 200 has a three-layer structure, and a second metal foil 700 is interposed between the negative electrode 200 and the negative electrode lead 500, which is different from the first embodiment. Therefore, redundant explanations will be omitted, and only the differences in configuration will be described.

[0070] The negative electrode 200 may consist of a negative electrode current collector 210 and a negative electrode tab 220. The negative electrode current collector 210 according to a preferred second embodiment of the present invention has a three-layer structure in which a second resin layer 212 is interposed between a pair of copper layers 211.

[0071] Here, the thickness of the copper layer is approximately 0.5 to 2.0 μm, and the second resin layer is made of polyethylene terephthalate (PET), with a thickness of approximately 3 to 10 μm, but is not necessarily limited to these dimensions.

[0072] Of course, if a material has high conductivity without causing a chemical change in the battery, then stainless steel or other materials mentioned above can be used instead of copper.

[0073] In the pair of copper layers 211, a negative electrode active material layer 213 is provided on the upper and lower surfaces that are exposed to the outside. These negative electrode active materials have been described above and will be omitted here.

[0074] Figure 9 is a top view of the secondary battery electrode assembly according to the second embodiment of the present invention, Figure 10 is a bottom view of the secondary battery electrode assembly according to the second embodiment of the present invention, and Figure 11 is an enlarged exploded perspective view of part B of the electrode assembly shown in Figure 9.

[0075] The electrical connection structure between the negative electrode tab 220 and the negative electrode lead 500 will be explained with reference to Figures 7 to 11.

[0076] Generally, since the negative electrode tab is made only of metal, it can be bonded to the negative electrode lead by ultrasonic welding or the like. However, as mentioned above, the negative electrode current collector and negative electrode tab according to the second embodiment of the present invention have a structure in which a second resin layer is interposed between a pair of copper layers. That is, due to the second resin layer that constitutes each negative electrode tab, it is difficult to firmly fix a large number of negative electrode tabs to each other and to firmly fix the negative electrode tabs and negative electrode leads to each other using the ultrasonic welding method.

[0077] Therefore, in the second embodiment of the present invention, the second connecting portion 222 is formed together with the second incision line 221 along the entire length direction (x-axis direction) of the negative electrode tab 220, while the second metal foil 700 is positioned to penetrate the second incision line 221.

[0078] More specifically, two parallel second incision lines 221 are provided along the entire length of the negative electrode tab 220 (in the x-axis direction) at a certain distance apart, and these second incision lines 221 form the second connecting portion 222.

[0079] Here, it is preferable that the second connecting portion 222 bulges slightly upward so that the second metal foil 700 can easily penetrate the second cutting line 221. The apparatus and method for processing to create such a structure will be described later.

[0080] On the other hand, to prevent the second metal foil 700 passing through the second incision line 221 from detaching, it is preferable that both ends of the second incision line 221 be located inside the negative electrode tab 220.

[0081] After the second metal foil 700 passes through one of the two second incision lines 221, and then passes through the other second incision line 221, the second metal foil 700 is exposed on both sides of the negative electrode tab 220 in the width direction (z-axis direction), while the second connecting portion 222 is located in the center (see Figure 9).

[0082] On the other hand, on the back surface of the negative electrode tab 220, the second metal foil 700 is not exposed at both edges in the width direction (z-axis direction), while the middle portion is exposed (see Figure 10).

[0083] As a result, since the second metal foil 700 is ribbon-shaped with the two second incision lines 221 passing through it in a zigzag pattern, the negative electrode tab 220 is formed into a single tab bundle by the second metal foil 700.

[0084] Then, the negative electrode lead 500 is in close contact with a portion of the negative electrode tab 220 and a portion of the second metal foil 700, and is fixed to them by ultrasonic welding.

[0085] Here, it is preferable that the negative electrode lead 500 faces the side edges of the negative electrode tab 220 in the width direction (z-axis direction) where the second metal foil 700 is exposed. This is because the coupling and fixing of the side edges of the negative electrode tab 220 in the width direction (z-axis direction) with the negative electrode lead 500 is more effective in suppressing movement in the width direction (z-axis direction).

[0086] Of course, it goes without saying that the second metal foil 700 contributes to the electrical connection between the negative electrode tab 220 and the negative electrode lead 500.

[0087] On the other hand, the second metal foil 700 is preferably the same as or similar to the copper layer 211, copper coated with nickel, or a nickel-copper alloy, but it can be changed as long as it can perform the same function.

[0088] Furthermore, it is preferable that the length of the second metal foil 700 does not exceed the width of the negative electrode tab 220, and that the width of the second metal foil 700 is slightly shorter than the length of the second incision line 221.

[0089] The negative electrode lead 500 is made of nickel, but is not necessarily limited to this material.

[0090] Although not shown in the drawings, the secondary battery electrode assembly may be a combination of the first and second embodiments. For example, the positive electrode has a three-layer structure with a first resin layer interposed between a pair of aluminum layers, while the negative electrode has a three-layer structure with a second resin layer interposed between a pair of copper layers, and a first metal foil and a second metal foil are interposed between the positive electrode tab and the positive electrode lead, and between the negative electrode tab and the negative electrode lead, respectively.

[0091] Next, an electrode tab processing apparatus for processing positive and negative electrode tabs will be described, which provides the aforementioned tabs with cutting lines and connecting portions, in other words, a first cutting line and a first connecting portion for the positive electrode tab, and a second cutting line and a second connecting portion for the negative electrode tab.

[0092] Figure 12 is a perspective view of an electrode tab processing apparatus according to a first embodiment for processing electrode tabs of a secondary battery electrode assembly of the present invention, Figure 13 is a cross-sectional view of the electrode tab processing apparatus shown in Figure 12 in the AA direction, and Figure 14 is a perspective view of the upper jig of the electrode tab processing apparatus shown in Figure 12 viewed from below.

[0093] Referring to Figures 12 to 14, the electrode tab processing apparatus according to the present invention includes a rectangular hexahedron-shaped lower jig 800 and an upper jig 900.

[0094] The upper surface of the lower jig 800 is positioned on one side of the electrode tab to be machined, and the lower surface of the upper jig 900 is positioned on the other side of the electrode tab. However, it is also possible for the positions of the lower jig 800 and the upper jig 900 to be reversed.

[0095] First, to describe the lower jig 800 in detail, the lower jig 800 may include a first lower body 810, a second lower body 820, and a first heating member 830.

[0096] On the upper surface of the first lower body 810, a pair of first lower flat portions 811 are positioned spaced apart along the longitudinal direction (x-axis direction), and a lower raised portion 812 is provided between these pair of first lower flat portions 811. These first lower flat portions 811 and lower raised portion 812 are configured to form the cutting line and connecting portion of the electrode tab.

[0097] Here, it is preferable that the cross-section (xy plane) in the width direction of the lower raised portion 812 is semicircular or semielliptical.

[0098] The second lower fuselage 820 consists of a pair, one on each side of the first lower fuselage 810, with a pair of second lower flat portions 821 spaced apart on its upper surface along the longitudinal direction (x-axis direction), and a lower recessed portion 822 may be provided between these pairs of second lower flat portions 821.

[0099] Here, it is preferable that the cross-section (xy plane) in the width direction of the lower recessed portion 822 is semicircular or semielliptical.

[0100] The first and second lower fuselage sections 810 and 820 are preferably configured to be separable so that only specific lower fuselage sections can be replaced as needed. For example, these fuselage sections can be fixed together or replaced after separation using bolts and nuts (not shown) that pass through them, but are not limited to bolts and nuts as long as they can be fixed together and separated.

[0101] The first heating member 830 is positioned to penetrate the first lower body 810 and the second lower body 820, and is configured to heat the electrode tab to a constant temperature when forming the cut line and connecting portion of the electrode tab.

[0102] As mentioned above, it is advantageous for the connecting portion to protrude slightly upward to facilitate the fastening of the metal foil, and therefore it is preferable to process it while heating it to a constant temperature so that the electrode tab can be slightly stretched.

[0103] Although the drawings show the first heating member 830 positioned to penetrate the first lower fuselage 810 and the second lower fuselage 820, it is not necessary for the first heating member 830 to be positioned in a way that penetrates the fuselage, as long as it can heat the first lower fuselage 810 and the second lower fuselage 820.

[0104] Next, the upper jig 900 will be described in detail. The upper jig 900 may include a first upper body 910, a second upper body 920, and a second heating member 930.

[0105] On the lower surface of the first upper fuselage 910, a pair of first upper flat portions 911 are positioned spaced apart along the longitudinal direction (x-axis direction), and between these pair of first upper flat portions 911, an upper recessed portion 912 is provided so as to interlock with the lower raised portion 812 of the first lower fuselage 810 described above. Here, it is preferable that the cross-section (xy plane) of the upper recessed portion 912 in the width direction is the same semicircular or semielliptical shape as the lower raised portion 812.

[0106] The second upper fuselage 920 is composed of a pair of units, one on each side of the first upper fuselage 910. On its lower surface, a pair of second upper flat portions 921 are positioned spaced apart along the longitudinal direction (x-axis direction), and preferably, an upper raised portion 922 is provided between these pair of second upper flat portions 921 along the longitudinal direction (x-axis direction) so as to interlock with the lower recessed portion 822 of the second lower fuselage 820 described above.

[0107] Here, it is preferable that the cross-section (xy plane) in the width direction of the upper raised portion 922 is the same semicircular or semielliptical shape as the cross-section in the width direction of the lower recessed portion 822.

[0108] The first upper fuselage 910 and the second upper fuselage 920 are preferably configured to be separable so that only specific upper fuselages can be replaced as needed. For example, these fuselages can be fixed or separated and replaced using bolts and nuts (not shown) that pass through the first upper fuselage 910 and the second upper fuselage 920, but are not limited to bolts and nuts as long as they can be fixed and separated.

[0109] The second heating member 930 is positioned to penetrate the first upper body 910 and the second upper body 920, and is configured to heat the electrode tab to a certain temperature when forming the cut line and connecting portion of the electrode tab.

[0110] As mentioned above, it is advantageous for the connecting portion to protrude upward in a bulging manner to facilitate the fastening of the metal foil, and therefore it is preferable to process it while heating it to a constant temperature so that the electrode tab can be slightly stretched.

[0111] Although the drawing shows the second heating member 930 positioned to penetrate the first upper fuselage 910 and the second upper fuselage 920, it is not necessary for the second heating member 930 to be positioned in a way that penetrates the fuselage, as long as it can heat the first upper fuselage 910 and the second upper fuselage 920.

[0112] Figure 15 is a perspective view of an electrode tab processing apparatus according to a second embodiment for processing electrode tabs of a secondary battery electrode assembly of the present invention. The electrode tab processing apparatus according to the second embodiment is the same as the electrode tab processing apparatus according to the first embodiment described above, except for the configuration of the second lower body and the second upper body.

[0113] In the electrode tab processing apparatus according to the second embodiment, the upper surface of the second lower fuselage 820 is flat, and the corresponding lower surface of the second upper fuselage 920 is also flat.

[0114] Next, a method for processing electrode tabs using the electrode tab processing apparatus of the first embodiment will be described.

[0115] Figure 16 is a perspective view illustrating a method for processing electrode tabs of a secondary battery electrode assembly using the electrode tab processing apparatus according to the first embodiment, and Figure 17 is an enlarged perspective view of the electrode tabs of a secondary battery electrode assembly processed by the electrode tab processing apparatus according to the first embodiment.

[0116] Referring together to Figures 12, 16, and 17, the electrode tab processing method according to the present invention includes a first step of positioning the electrode tab between a lower jig 800 and an upper jig 900, and a second step of moving one or more of the lower jig 800 and the upper jig 900 to press the electrode tab.

[0117] The first step is to position the lower jig 800 on the lower surface of the positive electrode tab 120 and the upper jig 900 on the upper surface. Here, the first lower body 810 and the first upper body 910 must be positioned so as to overlap with the portion where the first incision line 121 and the first connecting portion 122 are to be formed.

[0118] The second stage involves moving the lower jig 800 upward, or moving the upper jig 900 downward, or moving both upward and downward simultaneously to press against the positive electrode tab 120.

[0119] When the lower jig 800 and the upper jig 900 engage, the first connecting portion 122 is processed to bulge slightly upward so that the first metal foil can easily penetrate the first cutting line 121.

[0120] In detail, both sides of the lower protrusion 812 of the first lower fuselage 810 and the inner surfaces of the upper protrusion 922 of the pair of second upper fuselage 920s act as block-shaped cutters, so that the first cutting line 121 is formed at the position where these intersect.

[0121] Furthermore, the first connecting portion 122, which overlaps with the lower protrusion 812 of the first lower fuselage 810, has a shape that bulges upward, similar to the outer shape of the lower protrusion 812. As a result, a gap is formed in the first connecting portion 122 around the first incision line 121, allowing the first metal foil to easily penetrate the first incision line 121.

[0122] On the other hand, it is more preferable to heat one or more of the lower jig 800 and the upper jig 900 before or during the second stage.

[0123] For example, the second stage can be performed after heating the electrode tab for a certain period of time, either with the upper surface of the lower jig 800 in close contact with the lower surface of the electrode tab, or with the upper surface of the lower jig 800 in close contact with the lower surface of the electrode tab and the lower surface of the upper jig 900 in close contact with the upper surface of the electrode tab.

[0124] This is advantageous because it provides conditions under which the electrode tab can be stretched, making it easier to process the first connecting portion 122 into a slightly bulging shape.

[0125] On the other hand, although only the method for processing positive electrode tabs using the electrode tab processing apparatus according to the first embodiment has been described, it is obvious that negative electrode tabs can be processed in the same process, and that both positive and negative electrode tabs can be processed using the electrode tab processing apparatus according to the second embodiment.

[0126] Although specific parts of the present invention have been described in detail above, it will be obvious to those skilled in the art that such specific techniques are merely preferred modes of implementation and do not limit the scope of the present invention. Various changes and modifications are possible within the scope of the present invention and the technical concept, and it goes without saying that such variations and modifications also fall within the scope of the appended claims. [Explanation of Symbols]

[0127] 100 positive electrode 110 Positive electrode current collector 111 Aluminum layer 112 1st resin layer 113 Cathode active material layer 120 Positive Tab 121 First incision line 122 1st connection part 200 negative electrode 210 Negative electrode current collector 211 Copper layer 212 2nd resin layer 213 Negative electrode active material layer 220 Negative Electrode Tabs 221 Second incision line 222 2nd connection part 300 Separation membrane 400 Positive Leads 500 Negative Leads 600 First Metal Foil 700 Second Metal Foil 800 Lower Jig 810 First Lower Fuselage 811 1st lower flat part 812 Lower ridge 820 Second Lower Fuselage 821 2nd lower flat part 822 Lower depression 830 First heating element 900 Top Jig 910 No. 1 Upper Fuselage 911 1st upper flat part 912 Upper depression 920 Second Upper Fuselage 921 2nd upper flat part 922 Upper ridge 930 Second heating element

Claims

1. An electrode tab processing apparatus for forming a connecting portion by cutting a certain area of ​​an electrode tab that extends in one direction toward one side of an electrode current collector, so that a metal foil can be connected to the electrode tab, The electrode tab includes a lower jig positioned on one side of the electrode tab and an upper jig positioned on the other side of the electrode tab. A pair of first lower flat portions are positioned along the longitudinal direction on the upper surface of the lower jig, spaced apart from each other, and a lower raised portion is provided between the pair of first lower flat portions. A pair of first upper flat portions are positioned along the longitudinal direction on the lower surface of the upper jig, spaced apart from each other, and an upper recessed portion is provided between the pair of first upper flat portions so as to interlock with the lower raised portion. An electrode tab processing apparatus, wherein when the electrode tab is pressed while positioned between the lower jig and the upper jig, a connecting portion is formed through a pair of cut lines spaced at a certain interval, through which the metal foil can pass.

2. The electrode tab processing apparatus according to claim 1, wherein the upper surface of the lower jig is further provided with a lower recessed portion along its longitudinal direction, and the lower surface of the upper jig is further provided with an upper raised portion along its longitudinal direction so as to interlock with the lower recessed portion.

3. The lower raised portion is located in the center of the upper surface of the lower jig, and the lower recessed portion consists of a pair located on both sides of the lower raised portion. The electrode tab processing apparatus according to claim 2, wherein the upper recessed portion is located in the center of the lower surface of the upper jig, and the upper raised portion consists of a pair located on both sides of the upper recessed portion.

4. The electrode tab processing apparatus according to claim 3, wherein the lower jig includes a first lower body having the lower protrusion and a second lower body in which the lower recess is located, and the first lower body and the second lower body are separable.

5. The electrode tab processing apparatus according to claim 3, wherein the upper jig includes a first upper body having the upper recessed portion and a second upper body on which the upper raised portion is located, and the first upper body and the second upper body are separable.

6. The electrode tab processing apparatus according to claim 3, wherein the lower jig further comprises a first heating member.

7. The electrode tab processing apparatus according to claim 3, wherein the upper jig further comprises a second heating member.

8. The electrode tab processing apparatus according to claim 3, wherein the cross-section in the width direction of the lower raised portion and the upper recessed portion is semicircular or semielliptical.

9. The electrode tab processing apparatus according to claim 3, wherein the cross-section in the width direction of the lower recessed portion and the upper raised portion is semicircular or semielliptical.

10. The electrode tab processing apparatus according to claim 1, wherein the electrode current collector has a multilayer structure in which a resin layer is interposed between a pair of metal layers.

11. An electrode tab processing method for processing electrode tabs using an electrode tab processing apparatus according to any one of claims 1 to 10, A first step involves positioning the electrode tab between the lower jig and the upper jig, A method for processing an electrode tab, comprising a second step of moving one or more jigs, either the lower jig or the upper jig, to press the electrode tab.

12. The electrode tab processing method according to claim 11, wherein one or more jigs, either the lower jig or the upper jig, are heated before or during the second stage.

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