Secondary battery manufacturing apparatus and secondary battery manufacturing method

Abstract

An apparatus for manufacturing a secondary battery includes: a plurality of electrodes and separators alternately stacked; electrode tabs provided at end portions of the plurality of electrodes; and an electrode lead combined with the electrode tab, the manufacturing apparatus includes: an upper fixing mold and a lower fixing mold that fix the electrode lead with the electrode lead interposed therebetween; and a lower molding die disposed to be spaced apart from the lower fixed die toward an outer end of the electrode lead and a plurality of upper molding dies disposed to be spaced apart from the upper fixed die toward an end of the electrode lead, where the plurality of upper molding dies includes a first upper molding die disposed to be spaced apart from the lower fixed die toward an outer end of the electrode lead and a second upper molding die disposed to be spaced apart from the upper fixed die toward an end of the electrode lead. The first upper forming die is used for fixing an electrode lead; and a second upper molding die for forming a first bent portion and a second bent portion, and the first upper molding die and the second upper molding die are separated from each other and are sequentially disposed in a direction from the electrode assembly toward an end portion of the electrode lead.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0088171 filed in the Korean Intellectual Property Office on July 18, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a manufacturing apparatus and a manufacturing method of a secondary battery, and in particular, to a manufacturing apparatus and a manufacturing method of a secondary battery capable of preventing disconnection by reducing tensile stress applied to a joint between an electrode lead and an electrode tab. Background Art

[0004] Due to the rapid growth in the use of fossil fuels, the demand for the use of alternative energy and clean energy is also growing, and as a part of this, the most active research field is power generation and storage using electrochemistry.

[0005] Currently, a secondary battery may be a representative example of an electrochemical device using such an electrochemical energy source, and the scope of use thereof is gradually expanding.

[0006] Recently, with the development of technology and the growing demand for portable devices such as portable computers, mobile phones and cameras, the demand for secondary batteries as energy sources is also growing rapidly. Among them, many studies have been conducted on lithium secondary batteries that exhibit high energy density and working potential, long cycle life and low self-discharge rate, and lithium secondary batteries have been commercialized and widely used.

[0007] In addition, as the concern for environmental issues grows, research on electric vehicles and hybrid vehicles that can replace vehicles using fossil fuels (e.g., gasoline vehicles and diesel vehicles), which are one of the main causes of air pollution, has been conducted. Nickel metal hydride secondary batteries are mainly used as energy sources for electric vehicles and hybrid vehicles, but research on the use of lithium secondary batteries with high energy density and discharge voltage has been actively conducted, and a part of lithium secondary batteries has been commercialized.

[0008] The positive electrode and the negative electrode are manufactured by coating the positive electrode active material or the negative electrode active material, the binder and the conductive material in the form of slurry on the current collector and drying them to form an electrode mixture layer, a separator is interposed between the positive electrode and the negative electrode, and the electrode assembly obtained by laminating the positive electrode, the negative electrode and the separator is built into the battery case together with the electrolyte to manufacture such a lithium secondary battery. The electrode tabs extending from the individual battery cells in the electrode assembly built into the battery case are welded together and welded to be connected to the electrode lead. The lithium secondary battery can be electrically connected to an external device through the electrode lead.

[0009] Figure 1 and Figure 2 is a diagram showing, by way of example, a manufacturing apparatus of a secondary battery according to the related art.

[0010] Figure 1 is a diagram showing a state before an electrode lead is bent in a manufacturing apparatus of a secondary battery according to the related art, and Figure 2 is a diagram showing a state after an electrode lead is bent in a manufacturing apparatus of a secondary battery according to the related art.

[0011] Reference Figure 1 and Figure 2 , the electrode assembly 1 is formed by stacking a plurality of positive electrodes and negative electrodes with a separator interposed therebetween, and the electrode assembly 1 may be housed in a battery case 2 to manufacture a secondary battery. The electrode tabs 3 connected to the respective electrodes included in the electrode assembly 1 may be collected and welded to be connected to the electrode lead 4 as shown. The electrode lead film 5 surrounding the electrode lead 4 may be located on the electrode lead 4 to increase the sealing force with the battery case 2.

[0012] The electrode lead 4 can be electrically connected to an external device and can be appropriately molded into various shapes according to the environment of the connection state. In order to form the electrode lead 4, a process of bending the electrode lead 4 into an appropriate shape is required. For such bending, Figure 1 and Figure 2 As shown, an upper mold 30 and a lower mold 40 having the shape of the electrode lead 4 to be obtained are prepared, the joint portion of the battery case 2 and the electrode lead 4 is fixed by the upper fixed mold 10 and the lower fixed mold 20, and in this state, the upper mold 30 is combined with the lower mold 40 to press the electrode lead 4. At this time, in particular, a strong tensile force is applied to the joint portion A between the electrode lead 4 and the electrode tab 3 by the force of pressing the electrode lead 4, so the joint portion A of the electrode tab 3 and the electrode lead 4 may be disconnected. Summary of the invention

[0013] Technical issues

[0014] The problem to be solved by the present disclosure is a manufacturing apparatus and a manufacturing method of a secondary battery capable of preventing disconnection from occurring in a joint portion between an electrode tab and an electrode lead due to a tensile force occurring in a molding process of the electrode lead.

[0015] However, the problems solved by the exemplary embodiments of the present disclosure are not limited to the above-mentioned problems, and can be variously extended within the scope of the technical concept included in the present disclosure.

[0016] Technical Solution

[0017] According to an exemplary embodiment of the present disclosure, a manufacturing device for a secondary battery includes: a plurality of electrodes and separators alternately stacked; an electrode terminal tab, which is arranged at the ends of the plurality of electrodes; and an electrode lead, which is combined with the electrode terminal tab, the manufacturing device includes: an upper fixed mold and a lower fixed mold, the upper fixed mold and the lower fixed mold fix the electrode lead with the electrode lead interposed therebetween; and a lower molding mold and a plurality of upper molding molds, the lower molding mold is arranged to be spaced apart from the outer end of the lower fixed mold toward the electrode lead, and the plurality of upper molding molds are arranged to be spaced apart from the end of the upper fixed mold toward the electrode lead, wherein the plurality of upper molding molds include a first upper molding mold, the first upper molding mold is used to fix the electrode lead; and a second upper molding mold, the second upper molding mold is used to form a first bent portion and a second bent portion, and the first upper molding mold and the second upper molding mold are separated from each other and are arranged sequentially in a direction from the electrode assembly to the end of the electrode lead.

[0018] The first upper molding die and the second upper molding die may be moved independently of each other.

[0019] The manufacturing apparatus may further include: a third upper molding die disposed adjacent to the second upper molding die in a direction from the electrode assembly toward the end of the electrode lead and forming a third bent portion.

[0020] The third upper molding mold may be separated from the first upper molding mold and the second upper molding mold, and may be independently movable.

[0021] Only the electrode lead may be disposed between the first upper molding die and the lower molding die.

[0022] According to another exemplary embodiment of the present disclosure, a method for manufacturing a secondary battery, the secondary battery comprising: a plurality of electrodes and separators alternately stacked; an electrode terminal tab, the electrode terminal tab being arranged at the ends of the plurality of electrodes; and an electrode lead, the electrode lead being combined with the electrode terminal tab, the manufacturing method comprising: fixing the electrode lead for the first time at a first fixing portion between an upper fixing mold and a lower fixing mold; fixing the electrode lead for the second time at a second fixing portion spaced apart from the first fixing portion toward an outer end of the electrode lead by lowering the first upper molding mold toward the lower molding mold, and forming a first bent portion and a second bent portion in the electrode lead by lowering a second upper molding mold adjacent to the first upper molding mold on the outer end side of the electrode lead toward the lower molding mold.

[0023] The manufacturing method may further include: forming a third bent portion in the electrode lead by lowering a third upper molding die located closer to the outer end of the electrode lead than the second upper molding die toward the lower molding die while the second upper molding die is lowered.

[0024] In the second fixing portion, only the electrode lead may be disposed between the first upper molding die and the lower molding die.

[0025] In the first fixing part, an electrode lead, a lead film surrounding the electrode lead, and a battery case of the secondary battery may be arranged between the upper fixing mold and the lower fixing mold.

[0026] In the first fixing part and the second fixing part, the same amount of force may be applied to the upper fixing mold and the first upper molding mold to press the electrode lead.

[0027] A force pressing the electrode lead by the first upper molding die in the second fixing portion may be greater than a force pressing the electrode lead by the upper fixing die in the first fixing portion.

[0028] Beneficial Effects

[0029] According to an exemplary embodiment of the present disclosure, disconnection in a bonding portion between an electrode tab and an electrode lead may be prevented by minimizing the occurrence of a tensile force in a molding process of the electrode lead.

[0030] The effects of the present disclosure are not limited to the above-mentioned effects, and other unmentioned effects will be clearly understood by those skilled in the art from the description of the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a diagram showing a state before an electrode lead is bent in a manufacturing apparatus of a secondary battery according to the related art.

[0032] Figure 2 is a diagram showing a state after an electrode lead is bent in a manufacturing apparatus of a secondary battery according to the related art.

[0033] Figure 3 is a diagram illustrating a state before an electrode lead is bent in a manufacturing apparatus of a secondary battery according to an exemplary embodiment of the present disclosure.

[0034] Figure 4 It is shown Figure 3 FIG. 1 is a diagram showing a state in which an electrode lead is bent in a secondary battery manufacturing apparatus.

[0035] Figures 5 to 7 is a diagram illustrating a method of manufacturing a secondary battery according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings to allow those skilled in the art to implement the present disclosure. The present disclosure can be implemented in various forms and is not limited to the examples described herein.

[0037] In order to clearly explain the present disclosure, parts not related to the explanation are omitted. Throughout the entire specification, the same or similar components are marked with the same reference numerals.

[0038] The size and thickness of each component shown in the drawings may be arbitrarily shown for the convenience of explanation, and therefore, the present disclosure is not necessarily limited to the exemplary embodiments shown in the drawings. In the drawings, the thickness of layers, films, planes, regions, etc. are exaggerated for the sake of clarity. In addition, in the drawings, the thickness of some layers and regions may be exaggerated for the convenience of explanation.

[0039] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or there can be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements. In addition, when an element is "above" or "on" a reference portion, this means that the element is above or below the reference portion, and this does not necessarily mean that the element is "above" or "on" in the opposite direction of gravity.

[0040] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “include” or “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0041] Throughout the specification, when it is referred to as “in a plan view”, it means that a target element is viewed from above, and when it is referred to as “in a cross-sectional view”, it means that a vertically-cut target element is viewed from the side.

[0042] In the following, reference will be made to Figure 3 and Figure 4 A manufacturing apparatus of a secondary battery according to an exemplary embodiment of the present disclosure is described.

[0043] The secondary battery includes an electrode assembly 1 housed in a battery case 2 and an electrode lead 4 drawn out from the battery case 2 for electrical connection to the outside. The electrode assembly 1 is a power generation device capable of charge and discharge, and has a structure in which negative electrodes and positive electrodes are alternately stacked with a separator interposed therebetween. Electrode tabs 3 are formed by extending from the ends of the electrodes included in the electrode assembly 1, respectively. The electrode tabs 3 may be collected to be welded together at one point, and the collected electrode tabs 3 and the electrode lead 4 may be joined by a method such as welding.

[0044] One end of the electrode lead 4 may be electrically connected to the electrode terminal tab 3, extending through the sealing portion of the battery case 2, and the opposite end protruding outward from the battery case 2. The lead film 5 may be provided to surround the electrode lead 4 at least at one of the upper and lower portions of the electrode lead 4. The lead film 5 may improve the sealing performance between the sealing portion of the battery case 2 and the electrode lead 4, while preventing a short circuit from occurring in the electrode lead 4 during heat fusion.

[0045] Reference Figure 3 and Figure 4 , a manufacturing device for a secondary battery according to an exemplary embodiment of the present disclosure is a device for molding the portion of the above-mentioned electrode lead 4 protruding to the outside of the battery case 2, and includes an upper fixed mold 100 and a lower fixed mold 200 for fixing the electrode lead 4 and a plurality of upper molding molds 300 and a lower molding mold 400 that are in direct contact with the electrode lead 4 for molding the shape of the electrode lead 4.

[0046] The upper fixing mold 100 and the lower fixing mold 200 are used to fix the electrode lead 4 during the molding process, and in particular, to support the electrode lead 4 to be fixed to a portion of the battery case 2 to fix the electrode lead 4. To this end, as shown in FIG. Figure 3 and Figure 4 As shown, the upper fixed mold 100 and the lower fixed mold 200 are formed to vertically contact and press the portion where the battery case 2 and the electrode lead 4 overlap each other, that is, the first fixed portion P1. In the first fixed portion P1, the lead film 5 covering the electrode lead and the battery case 2 thermally fused to the lead film 5 may also be interposed and fixed between the upper fixed mold 100 and the lower fixed mold 200 together with the electrode lead 4.

[0047] The lower molding die 400 is spaced apart toward the outer end of the electrode lead 4 and is disposed adjacent to the lower fixing die 200. The lower molding die 400 is in direct contact with the electrode lead 4 and is combined with the upper molding die 300 with the electrode lead 4 interposed therebetween, and a molding surface in contact with the electrode lead 4 has a shape corresponding to the electrode lead 4 to be molded. In the present exemplary embodiment, a case having three curved surfaces is taken as an example, but is not limited thereto, and various modifications may be made depending on the final shape of the electrode lead 4 to be obtained.

[0048] The upper molding die 300 is spaced apart from the upper fixed die 100 toward the outer end of the electrode lead 4. A plurality of upper molding dies 300 may be provided, and in the present exemplary embodiment, an example including three upper molding dies 300 is described, but the present disclosure is not limited thereto, and the number and position of the upper molding dies 300 may be variously adjusted.

[0049] Reference Figure 3 and Figure 4In the present exemplary embodiment, the upper molding die 300 includes a first upper molding die 310, a second upper molding die 320, and a third upper molding die 330. The first upper molding die 310, the second upper molding die 320, and the third upper molding die 330 are sequentially arranged in a direction from the upper fixed mold 100 to the outer end of the electrode lead 4. The molding surface facing the lower molding die 400 in a state where the three upper molding dies 300 are combined has a shape corresponding to the shape of the electrode lead 4 to be molded. In addition, the first upper molding die 310, the second upper molding die 320, and the third upper molding die 330 are formed separately from each other, and therefore, can be independently controlled during the process. For example, the first upper molding die 310, the second upper molding die 320, and the third upper molding die 330 can be sequentially lowered one by one, and controlled to press the electrode lead 4 to be combined with the lower molding die 400.

[0050] At this time, the first upper molding die 310 can press the electrode lead 4 in the second fixing portion P2 in a state where the electrode lead 4 is interposed between the first upper molding die 310 and the lower molding die 400. The second fixing portion P2 is spaced apart from the first fixing portion P1 in the direction toward the outer end of the electrode lead 4. In the portion where the second fixing portion P2 is located, only the electrode lead 4 extends, and the lead film 5 and the battery case 2 are not provided. Therefore, in the second fixing portion P2, fixation can be performed in a state where only the electrode lead 4 is provided between the lower molding die 400 and the first upper molding die 310, and fixation can be performed by pressing the electrode lead 4 more reliably than in the first fixing portion P1. In addition, in some cases, the length of the electrode lead 4 fixed at the second fixing portion P2 can be increased by increasing the width of the second fixing portion P2 within a range where no interference occurs between the molds, and therefore, the electrode lead 4 can be fixed with a stronger force.

[0051] The second upper molding die 320 is spaced apart from the first upper molding die 310 in the direction toward the outer end of the electrode lead 4. The molding surface of the second upper molding die 320 has a shape continuous with the first upper molding die 310 and has a shape corresponding to the first curved portion 41 and the second curved portion 42 ( Figure 6 ), but not limited thereto, the molding surface of the second upper molding mold 320 may have various shapes according to the shape of the electrode lead 4.

[0052] The third upper molding die 330 is separated from the second upper molding die 320 in the direction toward the outer end of the electrode lead 4. The molding surface of the third upper molding die 330 may have a shape continuous with the second upper molding die 320 and may have a shape similar to the third curved portion 43 ( Figure 6 ), but not limited thereto, the molding surface of the third upper molding mold 330 may have various shapes according to the shape of the electrode lead 4.

[0053] The first upper molding die 310, the second upper molding die 320, and the third upper molding die 330 may be separated from each other and sequentially descended to be combined with the lower molding die 400, thereby molding the electrode lead 4. According to this configuration, since additional fixing is performed in the second fixing portion P2 by the first upper molding die 310, the magnitude of the tensile force applied to the electrode lead 4 during the molding of the electrode lead 4 can be reduced. That is, the tensile force applied to the electrode lead 4, especially the joint A between the electrode lead 4 and the electrode terminal tab 3, is generated as much as the direction in which the electrode lead 4 is pulled out during molding, but can be reduced by the friction force generated by fixing in the first fixing portion P1 and the second fixing portion P2. In the related art, fixing is performed only in the first fixing portion P1, and since the electrode lead 4 is fixed in the corresponding portion via the lead film 5 and the battery case 2, the friction force generated by the fixing is not enough to reduce the magnitude of the tensile force generated during molding and transmitted to the joint A between the electrode lead 4 and the electrode terminal tab 3, thereby causing problems such as disconnection. However, in this exemplary embodiment, since additional fixation is performed in the second fixing portion P2 and only the electrode lead 4 is directly fixed in the corresponding portion, the magnitude of the friction force can be further increased, and therefore, the magnitude of the tensile force generated during molding can be sufficiently reduced, and therefore, disconnection can be prevented from occurring in the joint A between the electrode lead 4 and the electrode tab 3.

[0054] In addition, compared with the case where the molding die presses the electrode lead 4 at one time, the molding die is separated and sequentially lowered to press the electrode lead 4, and therefore, the magnitude of the tensile force generated at one time is reduced, thereby effectively preventing the disconnection of the electrode lead 4. As described above, according to the manufacturing apparatus of the secondary battery of the exemplary embodiment of the present disclosure, the disconnection can be prevented by minimizing the tensile force applied to the electrode lead 4 and the electrode tab 3 during the bending of the electrode lead 4.

[0055] Hereinafter, as a manufacturing method using the manufacturing apparatus of the above-mentioned secondary battery, a manufacturing method of a secondary battery according to one exemplary embodiment and another exemplary embodiment of the present disclosure will be described.

[0056] Figures 5 to 7 is a diagram illustrating a method of manufacturing a secondary battery according to an exemplary embodiment of the present disclosure.

[0057] Reference Figure 5In the manufacturing method of a secondary battery according to an exemplary embodiment of the present disclosure, first, the electrode lead 4 is fixed between the upper fixed mold 100 and the lower fixed mold 200 (first fixed portion P1). After that, the first upper molding mold 310 descends toward the lower molding mold 400. At this time, the electrode lead 4 can be additionally fixed in the second fixed portion P2, or the upper molding mold 300 can be sequentially descended to be applied without additional fixation. In the case of additional fixation, not only the electrode lead 4 can be fixed to a portion of the battery case 2, but also the lead film 5 can be fixed to a portion of the battery case 2, and only the electrode lead 4 can be fixed to the second fixed portion P2.

[0058] In addition, pressure may be applied to the first fixing part P1 and the second fixing part P2 by the upper fixing mold 100 or the first upper molding mold 310 for additional fixing. Thus, the electrode lead 4 can be fixed more reliably. At this time, the force applied in the first fixing part P1 and the second fixing part P2 may be the same, or a greater force may be applied in the second fixing part P2. In the second fixing part P2, only the electrode lead 4 is fixed, and since the strength of the electrode lead 4 is greater than that of the battery case 2 etc. fixed in the first fixing part P1, the possibility of bending and damage due to resisting greater pressure can be reduced. Therefore, when it is necessary to increase the fixing strength, it is preferred to increase the fixing strength by increasing the pressure in the second fixing part P2.

[0059] Next, refer to Figure 6 , the second upper molding die 320 disposed adjacent to the first upper molding die 310 descends toward the lower molding die 400 to form the first curved portion 41 and the second curved portion 42. That is, the first curved portion 41 may be formed in a portion where the first upper molding die 310 and the second upper molding die 320 are continuous, and may be bent as the second upper molding die 320 descends pressing the electrode lead 4. The second curved portion 42 may be formed to be bent along the shape of the molding surface of the second upper molding die 320.

[0060] Finally, refer to Figure 7 , the molding of the electrode lead 4 can be completed by lowering the third upper molding die 330 to form the third bent portion 43 .

[0061] As described above, in the manufacturing method of molding the electrode lead 4 using the manufacturing apparatus of the secondary battery according to the exemplary embodiment of the present disclosure, since the electrode lead 4 is fixed by the first fixing part and the second fixing part P when the electrode lead 4 is pressed and the tensile force is applied, the tensile force applied to the electrode lead 4 can be reduced. In addition, since the tensile force is applied sequentially in the order of approaching the electrode assembly, rather than the tensile force being applied at once by the molding die across the entire area of ​​the electrode lead 4, the tensile force applied to the electrode lead 4 can be dispersed over time, thereby preventing disconnection that may occur when excessive tensile force is applied to the electrode lead 4. In addition, in the present exemplary embodiment, molding is performed by dividing the upper molding die 300 into three sections, but the upper molding die 300 may be divided in various ways according to the shape of the electrode lead 4 and the process conditions to perform molding.

[0062] Hereinafter, tensile forces generated in a method of manufacturing a secondary battery according to an exemplary embodiment of the present disclosure and a method of manufacturing a secondary battery according to a comparative example will be measured, and the results thereof will be described.

[0063] In Example 1, press Figures 5 to 7 In the manufacturing method, the first upper molding mold 310, the second upper molding mold 320 and the third upper molding mold 330 are moved in sequence by about 12 mm. At this time, in the first fixing part P1, a pressure of 45 kgf is applied, and in the second fixing part P2, only the first upper molding mold 310, the second upper molding mold 320 and the third upper molding mold 330 perform molding in sequence without being fixed.

[0064] In Example 2, molding was performed in the same manner as in Example 1, but fixing was additionally performed in the second fixing portion P2 by applying a pressure of a force of 45 kgf.

[0065] In Example 3, molding was performed in the same manner as in Example 2, but the widths of the first upper molding die 310 and the lower molding die 400 were increased by 2.5 mm toward the fixing dies 100 and 200, and in the second fixing portion P2, fixing was performed in a state where the length of the electrode lead 4 and the die in contact with each other was increased. Therefore, the contact area between the electrode lead 4 and the die in the second fixing portion P2 was increased to 3 times compared to Example 2, and therefore, fixing was performed in the second fixing portion P2 by applying a pressure of 135 kgf increased to three times.

[0066] Meanwhile, in the comparative example, by using Figure 1 and Figure 2 mold, in the same manner as in Example 1, moving the upper mold 30 approximately 12 mm to mold the electrode lead 4.

[0067] During molding in Examples 1 to 3 and the Comparative Example, the maximum value of the tensile force applied to the joint portion A between the electrode tab 3 and the electrode lead 4 may be measured. The results are shown in Table 1 below.

[0068] [Table 1]

[0069] Maximum tensile force (N) Compared with the comparative example, the change rate of the maximum tensile force (%) Comparison Examples 665.4 - Example 1 439.9 —33.9 Example 2 332.0 -50.1 Example 3 172.5 —74.1

[0070] As shown in Table 1, in the case of the example of the present disclosure, it is confirmed that the maximum tensile force value is significantly lower than that of the comparative example. Therefore, it can be seen that according to the exemplary embodiment of the present disclosure, the disconnection of the electrode tab 3 and the electrode lead 4 can be prevented during the molding process of the electrode lead 4.

[0071] The exemplary embodiments of the present disclosure have been described in detail, but the scope of the present disclosure is not limited thereto, and various variations and modifications made by those skilled in the art using the basic concepts of the present disclosure defined in the claims also belong to the scope of the present disclosure.

[0072] <Description of Reference Numerals>

[0073] 3: Electrode terminal block

[0074] 4: Electrode leads

[0075] 100: Upper fixed mold

[0076] 200: Lower fixed mold

[0077] 300: Upper forming die

[0078] 310: First upper molding die

[0079] 320: Second upper molding die

[0080] 330: The third upper molding die

[0081] 400: Lower forming die

Claims

1. A secondary battery manufacturing device, comprising: A plurality of electrodes and separators are alternately stacked; An electrode terminal tab, the electrode terminal tab being disposed at the end of the plurality of electrodes; and an electrode lead, wherein the electrode lead is combined with the electrode terminal tab, and the manufacturing device comprises: an upper fixed mold and a lower fixed mold for fixing the electrode lead with the electrode lead interposed therebetween; and a lower molding die and a plurality of upper molding dies, wherein the lower molding die is arranged to be spaced apart from the outer end of the lower fixed die toward the electrode lead, and the plurality of upper molding dies are arranged to be spaced apart from the end of the upper fixed die toward the electrode lead, The plurality of upper molding dies include a first upper molding die, the first upper molding die is used to fix the electrode lead; and a second upper molding die, the second upper molding die is used to form a first curved portion and a second curved portion, and The first upper molding die and the second upper molding die are separated from each other and are sequentially disposed in a direction from the electrode assembly toward an end portion of the electrode lead.

2. The manufacturing device according to claim 1, wherein: The first upper molding die and the second upper molding die are movable independently of each other.

3. The manufacturing device according to claim 1, further comprising: A third upper molding die is disposed adjacent to the second upper molding die in a direction from the electrode assembly toward the end of the electrode lead and forms a third bent portion.

4. The manufacturing device according to claim 3, wherein: The third upper molding die is separated from the first upper molding die and the second upper molding die, and is independently movable.

5. The manufacturing device according to claim 1, wherein: Only the electrode lead is disposed between the first upper molding die and the lower molding die.

6. A method for manufacturing a secondary battery, the secondary battery comprising: A plurality of electrodes and separators are alternately stacked; An electrode terminal tab, the electrode terminal tab being disposed at the end of the plurality of electrodes; and an electrode lead, wherein the electrode lead is combined with the electrode terminal tab, and the manufacturing method comprises: Fixing the electrode lead to a first fixing portion between an upper fixing mold and a lower fixing mold for the first time; By lowering the first upper molding die toward the lower molding die, the electrode lead is secondarily fixed to a second fixing portion spaced apart from the first fixing portion toward the outer end of the electrode lead, and A first bent portion and a second bent portion are formed in the electrode lead by lowering the second upper molding die adjacent to the first upper molding die on the outer end side of the electrode lead toward the lower molding die.

7. The manufacturing method according to claim 6, further comprising: In a state where the second upper molding die is lowered, a third upper molding die located closer to the outer end of the electrode lead than the second upper molding die is lowered toward the lower molding die to form a third bent portion in the electrode lead.

8. The manufacturing method according to claim 6, wherein: In the second fixing portion, only the electrode lead is disposed between the first upper molding die and the lower molding die.

9. The manufacturing method according to claim 8, wherein: In the first fixing part, the electrode lead, a lead film surrounding the electrode lead, and a battery case of the secondary battery are arranged between the upper fixing mold and the lower fixing mold.

10. The manufacturing method according to claim 6, wherein: In the first fixing part and the second fixing part, the same amount of force is applied to the upper fixing mold and the first upper molding mold to press the electrode lead.

11. The manufacturing method according to claim 6, wherein: A force pressing the electrode lead by the first upper molding die in the second fixing portion is greater than a force pressing the electrode lead by the upper fixing die in the first fixing portion.

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