Method for producing electrode assembly

Abstract

The present invention relates to a method for manufacturing an electrode assembly, and more particularly, to a method for manufacturing an electrode assembly, which can ensure the degree of freedom of cell design (such as the degree of freedom of tab position design), solve the problem of separator folding, and at the same time, improve the degree of freedom of cell design (such as the degree of freedom of tab position design) by improving the limitation of a conventional lamination technique. And the problem that the diaphragm is not cut due to process tolerance is prevented.

Description

Technical Field

[0001] Cross-reference to related applications

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0101553, filed on August 3, 2023, and Korean Patent Application No. 10-2024-0098745, filed on July 25, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to a method for manufacturing an electrode assembly, and more specifically, to a method for manufacturing an electrode assembly that overcomes the limitations of conventional lamination techniques to ensure freedom of cell design (such as freedom of connector location design), solves the folding problem of the separator, and prevents the problem of uncut separator due to process tolerances. Background Technology

[0004] In recent years, energy prices have increased due to the depletion of fossil fuels, environmental pollution has become a major concern, and the demand for environmentally friendly alternative energy sources is becoming an indispensable factor in future life. Therefore, research on various power generation technologies such as solar, wind, and tidal power is ongoing, and energy storage devices such as batteries for more efficient use of generated electricity are also attracting significant attention.

[0005] Furthermore, with the increasing technological development and demand for electronic mobile devices and battery-powered electric vehicles, the demand for batteries as an energy source is rapidly increasing. Therefore, much research has been conducted on batteries capable of meeting various needs.

[0006] Rechargeable batteries are gaining attention as an energy source for various products such as mobile devices and electric vehicles. They are considered an excellent renewable energy source that can replace existing products that use fossil fuels, and are also valued as an environmentally friendly energy source because they do not produce byproducts from energy use.

[0007] The secondary battery includes an electrode assembly formed by alternating layers of electrodes and a separator, and a battery casing housing the electrode assembly. Furthermore, various methods for manufacturing electrode assemblies exist in the related art. For example, lamination, folding, stack-folding, roll-up, and laminated lamination methods are well known in industry. Among these, the Z-folding method (or zigzag folding method), obtained by sequentially and alternately arranging at least one negative electrode and at least one positive electrode on one or both surfaces of a rectangular separator and folding the resulting structure in a zigzag direction, is a representative manufacturing method that improves the efficiency of electrode assembly production.

[0008] Figure 1 This is a conceptual perspective view illustrating a method for manufacturing electrode assemblies in a Z-fold manner according to related technologies.

[0009] Reference Figure 1 The rectangular diaphragm 30 can be folded in a zigzag shape using a Z-folding method. The positive electrode 12 and negative electrode 11 can then be inserted between the zigzag-shaped diaphragm 30 to manufacture the electrode assembly 90. Specifically, the diaphragm 30 can be folded once, the positive electrode 12 can be placed on the folded diaphragm 30, the diaphragm 30 can be folded again on the placed positive electrode 12, and the negative electrode 11 can be placed on the folded diaphragm 30. These processes can be repeated to manufacture the electrode assembly 90. The positive electrode connector 12-1 and the negative electrode connector 11-1 can be attached to the positive electrode 12 and the negative electrode respectively to protrude. Therefore, even when the diaphragm 30 is folded, the positive electrode connector 12-1 and the negative electrode connector 11-1 may not be completely covered by the diaphragm 30, but rather stacked such that at least a portion of each of the positive electrode connector 12-1 and the negative electrode connector 11-1 protrudes beyond the diaphragm 30. When the zigzag folding is completed in this manner, the finished electrode assembly 90 can be manufactured. Figure 1 The finished electrode assembly 90 is shown at the bottom. The electrode assembly 90 has a shape in which the positive terminal 12-1 and the negative terminal 11-1 are completely covered by the diaphragm 30, and at least a portion of each of the positive terminal 12-1 and the negative terminal 11-1 protrudes to the outside of the diaphragm laminate and is thus connected to an external terminal or electrode lead.

[0010] However, conventional Z-folding methods can be problematic when neither of electrodes 11 nor 12 has a simple rectangular shape. For example, if the electrode includes a recessed portion and the electrode connector is disposed within the recessed portion, problems arise when applying conventional Z-folding methods as is. This is because when the diaphragm 30 covers the electrode during the zigzag folding process, the recessed portion of the electrode and the electrode connector disposed within the recessed portion may be completely covered by the diaphragm 30, thus making it unusable for the electrode connector subsequently. Furthermore, if an attempt is made to simply cut the recessed portion of the diaphragm 30 to solve this problem, the electrode connector may be cut off or damaged during the cutting process of the diaphragm 30, thus the problem remains unresolved. Summary of the Invention

[0011] Technical issues

[0012] The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to provide a method for manufacturing electrode assemblies that can improve the limitations of stacking technology to ensure the degree of freedom in cell design (such as the degree of freedom in connector position design).

[0013] Furthermore, the object of the present invention is to provide a method for manufacturing an electrode assembly that solves the problem of folded diaphragms and prevents uncut diaphragms due to process tolerances when stacking electrode diaphragms to manufacture an electrode assembly.

[0014] Technical solution

[0015] According to the present invention, a method for manufacturing an electrode assembly includes the following steps: a pre-cut portion forming process, which prepares a diaphragm and pre-cuts a portion of the diaphragm for each unit length of the diaphragm to form a pre-cut portion; an electrode laminate forming process, which folds the diaphragm that has undergone the pre-cut portion forming process and inserts electrodes provided with electrode connectors between the folded diaphragms to form an electrode laminate, wherein the electrode connectors are connected to the electrode connectors; a main cutting process, which forms a cutting line connected to the pre-cut portion such that the diaphragm disposed in the electrode laminate at a position corresponding to the electrode connector, thereby cutting the diaphragm; and a diaphragm scrap removal process, which removes the diaphragm scrap cut in the main cutting process.

[0016] The electrode connector connection portion of the electrode can have a recessed shape and include a bottom side protruding from the electrode connector and a side extending from the bottom side. In the pre-cutting process, the diaphragm can be pre-cut so that the pre-cut portion has a line shape spaced at a predetermined distance from the bottom side in the state of the electrode stack.

[0017] The predetermined distance can be less than the protruding length of the electrode connector from the bottom side.

[0018] In the electrode laminate forming process, the folding process of the diaphragm may include folding the diaphragm into a zigzag shape, and in the process of folding the diaphragm into a zigzag shape, the diaphragm may be folded in a zigzag pattern for each unit length.

[0019] The main cutting process may include a first cutting process, which cuts the diaphragm to form a cutting line parallel to the side at a predetermined distance from the side.

[0020] The main cutting process may include a second cutting process, which cuts the diaphragm to form a cutting line that connects the cutting line formed in the first cutting process to the cutting line formed in the pre-cutting process.

[0021] In the second cutting process, the diaphragm can be cut so that the cutting line formed in the second cutting process has a curved shape.

[0022] In the second cutting process, the diaphragm can be cut such that the cutting line formed in the second cutting process is further recessed toward the bottom side than the cutting line formed by the pre-cut section.

[0023] The first cutting process and the second cutting process can be executed sequentially.

[0024] The first cutting process and the second cutting process can be performed simultaneously.

[0025] In the main cutting process, a multi-layered membrane stack can be cut in one step while the electrode stack is in its state.

[0026] The pre-cut section forming process can be performed using laser cutting or mold cutting methods.

[0027] The main cutting process can be performed using laser cutting or mold cutting methods.

[0028] The method may also include a diaphragm waste removal process, which removes the diaphragm waste cut in the main cutting process, after the main cutting process.

[0029] Beneficial effects

[0030] The method for manufacturing the electrode assembly according to the invention can overcome the limitations of conventional electrode diaphragm stacking techniques to ensure freedom in cell design (freedom in connector location).

[0031] Furthermore, the method for manufacturing electrode assemblies according to the present invention can solve the problem of membrane folding and prevent the problem of uncut membranes due to process tolerances when stacking electrode membranes to manufacture electrode assemblies. Attached Figure Description

[0032] Figure 1 This is a conceptual perspective view illustrating a method for manufacturing electrode assemblies in a Z-fold manner according to related technologies.

[0033] Figure 2 This is a flowchart schematically illustrating a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0034] Figure 3 This is a perspective view used to explain the pre-cut portion formation process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0035] Figure 4 This is a plan view showing an electrode inserted into a diaphragm in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0036] Figure 5 This is a perspective view used to explain the electrode stack formation process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0037] Figure 6This is a perspective view used to explain the main cutting process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0038] Figure 7 yes Figure 6 An enlarged plan view of the diaphragm cutting line section shown.

[0039] Figure 8 This is a perspective view used to explain the electrode waste removal process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0040] Figure 9 This is a plan view showing an electrode assembly manufactured in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0041] Figure 10 It is shown Figure 9 Enlarged view of part E within the dashed box.

[0042] Figure 11 It is along Figure 10 A cross-sectional view taken from line A-A'.

[0043] Figure 12 It is along Figure 10 The cross-sectional view taken by line B-B'. Detailed Implementation

[0044] Preferred embodiments of the invention will be described in detail below with reference to the accompanying drawings, enabling those skilled in the art to readily practice the invention. However, the invention may be implemented in several different forms and is not limited to or construed as follows.

[0045] To clearly explain the invention, detailed descriptions of parts unrelated to the essential points of the invention or to relevant known technologies have been omitted, and reference numerals have been added to the parts in each drawing. In this case, the same or similar reference numerals are assigned to the same or similar elements throughout the specification.

[0046] Furthermore, the terms or words used in this specification and claims should not be construed as having a general meaning or a dictionary-based meaning, but should be interpreted as meaning and concept based on the principle that the inventor may appropriately define the concepts of the terms in order to best describe and explain his or her invention, in accordance with the scope of the invention.

[0047] Method for manufacturing electrode assemblies

[0048] Figure 1 This is a conceptual perspective view illustrating a method for manufacturing electrode assemblies in a Z-fold manner according to related technologies. Figure 2This is a flowchart schematically illustrating a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 3 This is a perspective view used to explain the pre-cut portion formation process in a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 4 This is a plan view showing an electrode inserted into a diaphragm in a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 5 This is a perspective view used to explain the electrode stack formation process in a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 6 This is a perspective view used to explain the main cutting process in a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 7 yes Figure 6 An enlarged plan view of the diaphragm cutting line section shown. Figure 8 This is a perspective view used to explain the electrode waste removal process in a method for manufacturing an electrode assembly according to an embodiment of the present invention.

[0049] Reference Figure 2 According to an embodiment of the present invention, a method for manufacturing an electrode assembly 100 may be a method for manufacturing an electrode assembly formed by stacking electrodes 110, wherein the electrodes 110 include an electrode connector connection portion 113 and a diaphragm 130. Here, the electrode connector connection portion 113 may have an inwardly recessed shape. For this purpose, the method for manufacturing an electrode assembly 100 according to an embodiment of the present invention includes a pre-cut portion forming process P1, an electrode stack forming process P2, a main cutting process P3, and a diaphragm waste removal process P4.

[0050] Reference Figure 3 The pre-cut portion forming process P1 can be a process for preparing the diaphragm 130 to form the pre-cut portion 131, wherein a portion of the diaphragm 130 is pre-cut for each unit length of the diaphragm 130. For example... Figure 3 As shown, the pre-cut portion forming process P1 can be a process of preparing a rectangular diaphragm 130 to form a pre-cut portion 131, wherein a portion of the diaphragm 130 is pre-cut. The pre-cut portion forming process P1 can be performed by forming the pre-cut portions 131 at regular intervals while the long diaphragm 130 is unfolded into a flat surface, and it can also be performed by bending or folding the diaphragm 130 into the desired shape. Alternatively, it can be performed by extruding the diaphragm 130 using rollers, and various other methods are feasible.

[0051] The pre-cut portion forming process P1 can be performed by laser cutting or die cutting. In addition, the pre-cut portion 131 can be formed for each unit length of the diaphragm, and the unit length can be the same as the interval at which the diaphragm 130 is folded when the diaphragm 130 is later folded to manufacture the electrode laminate 99.

[0052] Reference Figure 4 and Figure 5 The electrode stack forming process P2 can be a process of forming an electrode stack 99 by zig-folding a diaphragm 130 that has undergone a pre-cutting forming process P1 and inserting an electrode 110 having an electrode connector connection portion 113, wherein the electrode connector is connected between the zig-folded diaphragms 130.

[0053] Figure 4 An electrode 110 is shown inserted between diaphragms 130. The electrode 110 may include a positive electrode 110-2 and a negative electrode 110-1. The electrode 110 may have an inwardly recessed shape and may be provided with an electrode connector connection portion 113 to which an electrode connector is connected; in particular, it may be provided with an electrode connector connection portion 113 that is recessed in a quadrilateral shape. The electrode connector connection portion 113 may include a bottom side 114 and a side 115.

[0054] Electrode 110 may be provided with an electrode connector provided on electrode connector connection portion 113. In electrode connector connection portion 113, bottom side 114 may be a side from which electrode connector 111 protrudes. Furthermore, side 115 may be a side extending from bottom side 114. Side 115 and bottom side 114 may intersect each other at a predetermined angle. In this embodiment, bottom side 114 and side 115 may be in a perpendicular relationship. Positive electrode 110-2 may be provided with positive electrode connector 111-2, and negative electrode 110-1 may be provided with negative electrode connector 111-1.

[0055] Reference Figure 5 In the electrode laminate formation process P2, the long rectangular diaphragm 130, on which the pre-cut portion 131 has already been formed, can be zigzag-folded, and Figure 4 The positive electrode 110-2 and negative electrode 110-1 shown can be inserted between the zigzag-folded diaphragms 130 to create an electrode stack 99. Here, the zigzag folding process of the diaphragms 130 can be a process of zigzag folding for each unit length of the diaphragms 130 to be folded as described above. This ensures that each pre-cut portion 131 matches each electrode 110.

[0056] In particular, the electrode laminate formation process P2 can be a process of folding the separator 130 once, placing the positive electrode 110-2 on the folded separator 130, folding the separator 130 again on the placed positive electrode 110-2, and placing the negative electrode 110-1 on the folded separator 130. Furthermore, these processes can be repeated to manufacture the electrode laminate 99. The positive electrode connector 111-2 and the negative electrode connector 111-1 are attached to the positive electrode 110-2 and the negative electrode 110-1, respectively, and when folding is performed using the separator 130, the positive electrode connector 111-2 and the negative electrode connector 111-1 are first covered by the separator 130 and laminated. When the zigzag folding is completed in this manner, it can provide... Figure 5 The bottommost part of the finished electrode stack 99 is shown.

[0057] In the electrode laminate 99 manufactured as described above, the pre-cut portion 131 may be in the form of a line spaced apart from the bottom side edge 114 by a predetermined distance D (see [reference]). Figure 7 Here, the predetermined distance D can be less than the protruding length L of the electrode connector 111 protruding from the bottom side 114. For this purpose, in the previously performed pre-cut portion forming process P1, in the state of the electrode stack 99, the diaphragm 130 can be pre-cut such that the pre-cut portion 131 has the form of a line spaced apart from the bottom side 114 by a predetermined distance D.

[0058] More specifically, for example, the negative electrode 110-1 may be larger than the positive electrode 110-2, and the pre-cut portion 131 may be in the form of a line spaced apart from the bottom side 114 of the electrode connector connection portion 113 formed on the negative electrode 110-1 by a predetermined distance D.

[0059] Reference Figure 6 The main cutting process P3 can be a process of cutting the diaphragm 130 along the cutting line CL connected to the pre-cutting section 131, so that the diaphragm 130 provided in the electrode stack 99 at the position corresponding to the electrode connector connection section 113 is cut off.

[0060] Additionally, refer to Figure 8 The diaphragm waste removal process P4 can be a process that removes the diaphragm waste 150 cut in the main cutting process P3 after the main cutting process P3. After completing the diaphragm waste removal process P4, the electrode assembly 100 can be manufactured.

[0061] When the electrode assembly 100 is manufactured using the method described above for manufacturing the electrode assembly 100 according to an embodiment of the present invention, the limitations of conventional stacking technology can be improved to ensure the freedom of cell design (such as the freedom of connector location design).

[0062] In particular, conventional cell designs have no problem when the electrode connector 111 is positioned away from the separator 130. However, since the electrode connector 111 is located in the electrode connector connection portion 113, which has a shape recessed into the electrode 110, it is difficult to cut the separator 130 when the electrode connector 111 is covered by the separator 130 in the state of the electrode stack 99, thus exposing the electrode connector 111. The electrode connector may be damaged during the cutting process, or it may require a very complex and difficult operation to cut the electrode connector without damaging it. This becomes a constraint on the design of the position of the electrode connector 111.

[0063] In other words, in conventional technology, if one attempts to cut the diaphragm 130 corresponding to the electrode connector connection 113 of the electrode 110 while keeping the electrode connector 111 as is, there is a high risk that the cutting line and the electrode connector will overlap, damaging or cutting the electrode connector 111. Therefore, it is difficult to cut the diaphragm 130 as is.

[0064] Alternatively, to address this problem, one could consider a scenario where the portion of the diaphragm 130 corresponding to the shape of the electrode connector connection 113 is pre-cut completely for folding. However, in the completely cut portion, the tension of the diaphragm 130 may be lost, and therefore, folding defects may occur during lamination due to surrounding airflow or static electricity. In particular, a defect may occur where the portion of the diaphragm 130 corresponding to the corner K of the electrode 110 (from which the electrode connector connection 113 begins) is prone to folding (see...). Figure 8 This is problematic because it hinders mass production and product safety. Therefore, it can be seen that the method for manufacturing the electrode assembly 100 according to an embodiment of the present invention solves the problem of folding of the diaphragm 130.

[0065] Reference Figure 7 In the method for manufacturing an electrode assembly 100 according to an embodiment of the present invention, the main cutting process P3 may include a first cutting process and a second cutting process.

[0066] The first cutting process can be a process of cutting the diaphragm 130 such that the cutting line is formed parallel to the side 115 at a predetermined distance G from the side 115. When naming the cutting line for convenience, the pre-cut portion 131 formed by the pre-cut portion forming process can be referred to as the first cutting line 131. When the pre-cut portion 131 is considered the first cutting line 131, the cutting line formed in the first cutting process can be referred to as... Figure 7 The second cutting line 132 is shown.

[0067] The second cutting process can be a process of cutting the diaphragm 130 to form a cutting line that connects the cutting line 132 formed by the first cutting process to the cutting line 131 formed by the pre-cutting part forming process P1. That is, based on Figure 7 The second cutting process can be to cut the diaphragm 130 to form a third cutting line 133 that connects the first cutting line 131 (which serves as the pre-cut portion 131) to the second cutting line 132. The first and second cutting processes can be performed sequentially or simultaneously. The diaphragm 130 can be cut so that the diaphragm waste 150 is completely separated from the electrode laminate 99.

[0068] In the pre-cutting process P1, if the diaphragm 130 is cut individually, the main cutting process P3 (i.e., the first and second cutting processes) can be performed by cutting the diaphragm 130 stacked with multiple layers in a single operation while the electrode stack 99 is in place. In other words, the diaphragm stack can be cut in one operation while maintaining the multiple diaphragms 130 stacked in the stacking direction. The specific method for cutting the diaphragm 130 as described above can be a laser cutting method or a die cutting method.

[0069] Reference Figure 7 In the main cutting process P3 according to an embodiment of the present invention, the diaphragm 130 can be cut such that the cutting line formed by the second cutting process (i.e., the third cutting line 133) has a shape that is more recessed toward the bottom side 114 than the cutting line of the pre-cut portion (i.e., the first cutting line 131).

[0070] based on Figure 7 The second cutting process forming the third cutting line 133 can be a process of cutting a diaphragm, wherein the end of the second cutting line 132 descends further than the pre-cut portion 131 toward the bottom side 114, and then rises again to intersect with the pre-cut portion 131. If the third cutting line 133 is cut into a shape that is more concave than the pre-cut portion 131 toward the bottom side 114, the pre-cut portion 131 and the third cutting line 133 can have a stepped shape.

[0071] like Figure 7 As shown, due to tolerances during the formation process of the pre-cut portions 131, the pre-cut portions 131 may not be perfectly aligned. That is, due to tolerances, multiple pre-cut portions 131 formed at corresponding positions on the diaphragm 130 may not align into a single line after folding. Figure 7As shown, it may appear to be aligned with multiple slightly misaligned lines. In this case, in order for the third cutting line 133 to intersect all the lines of the pre-cut section 131, it may be necessary to cut during the ascent to pass through all the lines of the pre-cut section 131. In this case, the third cutting line 133 has a shape that is recessed towards the bottom side 114.

[0072] If this method is not followed, and the third cutting line 133 is provided to intersect the pre-cut portion 131 in the horizontal direction (i.e., in the direction in which the pre-cut portion 131 extends), there may be layers of the diaphragm 130 where the third cutting line 133 does not intersect the pre-cut portion 131. Therefore, performing the cutting such that the third cutting line 133 intersects the pre-cut portion 131 in a way that descends and then rises to have a shape that is more recessed toward the bottom side 114 than the pre-cut portion 131 can be a more efficient way to manufacture an electrode assembly 100 with excellent quality and no cutting defects. As a result, problems such as uncut diaphragm 130 due to process tolerances can be prevented.

[0073] Alternatively, when the second cutting line 132 is formed in the first cutting process, there may be a method to perform cutting so that the second cutting line 132 passes through all the lines of the pre-cut portion 131 in one go without performing a separate second cutting process. However, in this case, cutting must be performed so that the second cutting line 132 is relatively further away from the side 115. In this case, the second cutting line 132 is formed further away from the side. That is, the length of the diaphragm 130 protruding from the side 115 becomes longer. In this case, unnecessary space waste may occur in the electrode assembly 100 as the final product.

[0074] Therefore, in the present invention, in the first cutting process, cutting can be performed by cutting the second cutting line 132 from the side 115 at an optimal distance (or minimum distance), and in the second cutting process, the third cutting line 133 can descend and then rise to have a shape that is more concave than the pre-cut portion 131 toward the bottom side 114, thereby preventing space waste and achieving optimal space efficiency.

[0075] In order to perform a smooth and fast operation, the diaphragm 130 can be cut in the second cutting process, so that the cutting line 133 formed by the second cutting process has a curved shape.

[0076] In this embodiment, the case where the electrode connector connection portion 113 has an inwardly recessed shape has been described, but this does not mean that the shape of the electrode connector connection portion 113 is limited to this, and other shapes can also be included within the scope of the present invention. That is, if the freedom of cell design (freedom of connector position design, etc.) is ensured, and production efficiency is achieved by performing the pre-cutting part forming process P1, the present invention can be applied even if the shape of the electrode connector connection portion 113 is not an inwardly recessed shape.

[0077] Electrode assembly

[0078] Figure 9 This is a plan view showing an electrode assembly manufactured in a method for manufacturing an electrode assembly according to an embodiment of the present invention. Figure 10 It is shown Figure 9 Enlarged view of part E within the dashed box. Figure 11 It is along Figure 10 A cross-sectional view taken from line A-A'. Figure 12 It is along Figure 10 The cross-sectional view taken by line B-B'.

[0079] The electrode assembly according to another embodiment of the present invention differs from the foregoing embodiments in that it relates to an electrode assembly manufactured by the method for manufacturing an electrode assembly described in the foregoing embodiments.

[0080] As many details as possible that are repeated in the method for manufacturing the electrode assembly will be omitted, and the differences will be described below. That is, it is obvious that if anything not described in this embodiment is needed, it can be supplemented by the content described in the method for manufacturing the electrode assembly according to the foregoing embodiment.

[0081] Reference Figure 9 and Figure 10According to another embodiment of the present invention, the electrode assembly 100 may include a diaphragm 130 and an electrode 110, and may be in the form of a laminate of the electrode 110 and the diaphragm 130. Here, the diaphragm 130 has a zigzag folded laminated form, and the electrode 110 may be configured to be inserted between the diaphragms 130. Furthermore, the electrode 110 may have an electrode connector connection portion 113 to which an electrode connector is connected. Furthermore, the electrode 110 may be a positive electrode 110-2 or a negative electrode 110-1. The electrode 110 may be provided with an electrode connector 111. Here, the electrode connector 111 includes a positive electrode connector 111-2 and a negative electrode connector 111-1. The positive electrode 110-2 may be provided with a positive electrode connector 111-2. The negative electrode 110-1 may be provided with a negative electrode connector 111-1. Furthermore, the electrode connector 111 may be provided on the electrode connector connection portion 113. That is, the electrode 110 may be provided with an electrode connector 111 provided on the electrode connector connection portion 113. Additionally, the diaphragm 130 can be cut into a shape corresponding to the electrode connector connection portion 113 at a position corresponding to the electrode connector connection portion 113. The electrode assembly 100 according to an embodiment of the present invention can have the above-described structure to improve the limitations of conventional stacking technology and ensure the freedom of cell design (such as the freedom of connector position design).

[0082] In the electrode assembly 100 according to an embodiment of the present invention, the electrode 110 may be provided with an electrode connector connection portion 113. Here, the electrode 110 may be, for example, a negative electrode 110-1.

[0083] Furthermore, the electrode connector connection portion 113 may have a recessed shape. Specifically, the electrode connector connection portion 113 may include a bottom side 114 protruding from the electrode connector 111 and a side 115 extending from the bottom side 114. Furthermore, the protruding length L of the electrode connector 111 protruding from the bottom side 114 may be less than the recess depth H of the electrode connector connection portion 113, which is measured based on the bottom side 114 (see [link to relevant documentation]). Figure 10 ).

[0084] Additionally, similarly, refer to Figure 9 and Figure 10 The diaphragm 130, which has a zigzag stacked shape, may include a first cutting line 131, a second cutting line 132, and a third cutting line 133.

[0085] The first cutting line 131 may have a line shape that is spaced apart from the bottom side 114 by a predetermined distance D. In the method for manufacturing an electrode assembly 100 according to an embodiment of the present invention, a pre-cut portion 131 may be formed in a diaphragm 130 by performing a pre-cut portion forming process P1, and the first cutting line 131 may be a cutting line formed by the pre-cut portion forming process P1.

[0086] Reference Figure 10 The predetermined distance D between the first cutting line 131 and the bottom side 114 can be less than the protruding length L of the electrode connector 111 protruding from the bottom side 114. This can be the result of manufacturing the electrode assembly 100 in such a way that the pre-cut portion 131 is formed in the pre-cut portion forming process P1 as a line shape spaced apart from the bottom side 114 by a predetermined distance D, but the predetermined distance is less than the protruding length of the electrode connector 111 protruding from the bottom side 114.

[0087] The second cutting line 132 may be a cutting line that extends parallel to the side 115 at a predetermined distance G from it. The second cutting line 132 may be a cutting line formed by the main cutting process P3 performed in the method for manufacturing the electrode assembly 100 according to an embodiment of the present invention. More specifically, the second cutting line 132 may be a cutting line formed by the first cutting process during the main cutting process P3.

[0088] The third cutting line 133 may be a cutting line connecting the second cutting line 132 to the first cutting line 131. The third cutting line 133 may be formed with a shape that is more concave towards the bottom side 114 than the first cutting line 131. Due to this shape, the first cutting line 131 and the third cutting line 133 may have a stepped shape. As described above, the electrode assembly 100 with this shape can prevent problems such as uncut diaphragm 130 due to process tolerances, and since the second cutting line 132 is formed at an optimal (or minimum) distance from the side 115, space is not wasted, and optimal space efficiency can be achieved.

[0089] In order to perform a smooth and fast operation, the diaphragm 130 can be cut in the second cutting process of the main cutting process P3, such that the cutting line formed by the second cutting process has a curved shape, and therefore, the third cutting line 133 can be formed into a shape having a curved shape or a part of a circular shape.

[0090] Reference Figure 11 In the electrode assembly 100 according to an embodiment of the present invention, based on a cross-sectional view of the laminate cut along the lamination direction of the diaphragm 130, the diaphragm 130 can have a relatively more uniform electrode 110-diaphragm 130 overhang value X1 along the lamination direction at the location of the first cut line 131. Additionally, referring to... Figure 12 The diaphragm 130 may have a relatively non-uniform electrode 110-diaphragm 130 overhang value X2 along the stacking direction at the location of the second cutting line 132. Here, the electrode 110-diaphragm 130 overhang value (X) refers to the distance value from the end of the electrode 110 to the end of the diaphragm 130.

[0091] in particular, Figure 11 It is along Figure 10 The cross-sectional view is taken by line A-A', and the cross-section of the diaphragm 130 in the stacking direction at the first cutting line 131 is shown. Figure 12 It is along Figure 10 The cross-sectional view of line B-B' is shown, and the cross-section of the diaphragm 130 in the stacking direction at the second cutting line 132 is also shown.

[0092] exist Figure 11 In the variation of the length of each diaphragm 130, it can be seen that the diaphragm 130 has a relatively uniform length. That is to say, referring to... Figure 11 It can be seen that the electrode 110-diaphragm 130 overhang value X1 at the position of the first cutting line 131 does not vary significantly among the multiple diaphragms 130 arranged along the stacking direction, and is relatively uniform. Here, the electrode 110-diaphragm 130 overhang value can specifically be the negative electrode-diaphragm overhang value. That is, the electrode 110-diaphragm 130 overhang value can represent the distance between the end of the negative electrode 110-1 and the end of the diaphragm 130.

[0093] When considering the electrode 110-diaphragm 130 overhang value at the position of the first cutting line 131, the end of the diaphragm 130 can be formed by the first cutting line 131 in the pre-cutting section forming process P1. In the pre-cutting section forming process P1, the diaphragms 130 are cut one by one at a set position, so the position of the end of the diaphragm 130 can be determined consistently. Therefore, the end of the diaphragm 130 can be formed at a substantially uniform position except for minor tolerances. Therefore, a uniform electrode 110-diaphragm 130 overhang value X1 can be provided at the position of the first cutting line 131.

[0094] On the other hand, refer to Figure 12 It can be seen that the electrode 110-diaphragm 130 overhang value X2 varies at the position of the second cutting line 132, and is relatively more uneven among the multiple diaphragms 130 placed along the stacking direction. Here, the electrode 110-diaphragm 130 overhang value can specifically be the negative electrode-diaphragm overhang value. That is, the electrode 110-diaphragm 130 overhang value can represent the distance between the end of the negative electrode 110-1 and the end of the diaphragm 130.

[0095] When considering the electrode 110-diaphragm 130 overhang value at the location of the second cutting line 132, the end of the diaphragm 130 can be formed by the second cutting line 132 in the main cutting process P3. In the main cutting process P3, the laminate of the diaphragm 130, in which multiple layers are laminated in the state of the electrode laminate 99, can be cut in one go. If the laminate of the diaphragm 130 is cut in one go while being held in this way, the cutting length between the laminated diaphragms 130 in the thickness direction may vary due to friction between the cutting tool and the diaphragm 130, differences in the contact area between the diaphragms, and sliding phenomena between the diaphragms 130. Therefore, the end of the diaphragm 130 can be formed at a substantially non-uniform location. Therefore, a relatively more non-uniform electrode 110-diaphragm 130 overhang value X1 can be provided at the location of the second cutting line 132.

[0096] In particular, refer to Figure 12 Based on a cross-sectional view of the diaphragm stack cut along the stacking direction, the diaphragm 130 at the position of the second cutting line 132 can have an electrode 110-diaphragm 130 overhang value that gradually decreases and then gradually increases along the stacking direction. This can be a shape formed by cutting the diaphragm stack by holding the stack in one step and cutting the stack in the vertical direction, wherein multiple layers are stacked in the state of the electrode stack 99. Furthermore, when vertically cut by a vertically symmetrical cutting mechanism, the stacked diaphragm 130 can be vertically symmetrical based on the electrode 110-diaphragm 130 overhang value at the position of the second cutting line 132, based on the diaphragm 135 stacked at an intermediate height.

[0097] As described above, in the electrode assembly 100 implemented by the embodiments of the present invention, the limitations of conventional stacking technology can be improved, ensuring the freedom of cell design (such as the freedom of connector position design), solving the folding problem of the separator, and preventing the problem of uncut separator due to process tolerances.

[0098] Secondary batteries

[0099] A secondary battery according to another embodiment of the present invention can be provided. The secondary battery according to an embodiment of the present invention may include the electrode assembly 100 described above and a battery casing (not shown) capable of accommodating the electrode assembly 100.

[0100] Secondary batteries can overcome the limitations of traditional stacking technology, ensuring freedom in cell design (such as freedom in connector placement), solving the folding problem of the separator, and preventing the problem of uncut separators due to process tolerances.

[0101] Although embodiments of the invention have been described with reference to specific examples, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.

[0102] [Description of the symbol]

[0103] 99: Electrode laminate

[0104] 90, 100: Electrode assemblies

[0105] 110: Electrode

[0106] 11. 110-1: Negative electrode

[0107] 12, 110-2: Positive electrode

[0108] 111: Electrode connector

[0109] 111-1: Negative terminal connector

[0110] 111-2: Positive terminal connector

[0111] 113: Electrode connector connection part

[0112] 114: Bottom side

[0113] 115: Side

[0114] 30, 130: Diaphragm

[0115] 131: Pre-cutting section, first cutting line

[0116] 132: Second cutting line

[0117] 133: Third cutting line

[0118] 135: A diaphragm stacked at an intermediate height.

[0119] 150: Diaphragm waste

[0120] P1: Pre-cut section forming process

[0121] P2: Electrode laminate formation process

[0122] P3: Main Cutting Process

[0123] P4: Diaphragm Waste Removal Process

Claims

1. A method for manufacturing an electrode assembly, the method comprising the following steps: A pre-cut portion forming process, wherein a diaphragm is prepared and a portion of the diaphragm is pre-cut for each unit length of the diaphragm to form a pre-cut portion; An electrode laminate forming process is described in which the diaphragm that has undergone the pre-cutting part forming process is folded, and electrodes with electrode connectors are inserted between the folded diaphragms to form an electrode laminate, wherein the electrode connectors are connected to the electrode connectors. The main cutting process forms a cutting line connected to the pre-cut portion, thereby cutting the diaphragm located in the electrode stack at a position corresponding to the electrode connector connection portion; and A diaphragm waste removal process removes the diaphragm waste cut in the main cutting process.

2. The method according to claim 1, wherein, The electrode connector of the electrode has a recessed shape and includes a bottom side protruding from it and a side extending from the bottom side. In the pre-cutting process, the diaphragm is pre-cut so that the pre-cut portion has a linear shape that is spaced a predetermined distance from the bottom side in the state of the electrode stack.

3. The method according to claim 2, wherein, The predetermined distance is less than the protruding length of the electrode connector from the bottom side.

4. The method according to claim 1, wherein, In the electrode laminate formation process, the process of folding the diaphragm includes folding the diaphragm into a zigzag shape, and In the process of folding the diaphragm into the zigzag shape, the diaphragm is folded in a zigzag pattern for each unit length.

5. The method according to claim 2, wherein, The main cutting process includes a first cutting process, which cuts the diaphragm to form a cutting line parallel to the side at a predetermined distance from the side.

6. The method according to claim 5, wherein, The main cutting process includes a second cutting process, which cuts the diaphragm to form a cutting line that connects the cutting line formed in the first cutting process to the cutting line formed in the pre-cutting process.

7. The method according to claim 6, wherein, In the second cutting process, the diaphragm is cut such that the cutting line formed in the second cutting process has a curved shape.

8. The method according to claim 6, wherein, In the second cutting process, the diaphragm is cut such that the cutting line formed in the second cutting process is further recessed toward the bottom side than the cutting line formed by the pre-cut portion.

9. The method according to claim 6, wherein, The first cutting process and the second cutting process are executed sequentially.

10. The method according to claim 6, wherein, The first cutting process and the second cutting process are performed simultaneously.

11. The method according to claim 1, wherein, In the main cutting process, the diaphragm stack with multiple layers is cut in one step while the electrode stack is in its state.

12. The method according to claim 1, wherein, The pre-cut section forming process is performed by laser cutting or mold cutting.

13. The method according to claim 1, wherein, The main cutting process is performed by laser cutting or mold cutting.

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