Electrode assembly, secondary battery comprising same, and method for manufacturing electrode assembly

Abstract

An electrode assembly according to an aspect of the present invention comprises: a plurality of positive electrode plates and a plurality of negative electrode plates which are alternately arranged; and separators interposed between the positive electrode plates and the negative electrode plates, wherein the separators include inner portions in contact with the positive electrode plates or the negative electrode plates and connection portions which connect the inner portions and protrude from side ends of the positive electrode plates, and at least one of the connection portions may be disposed to surround other connection portions.

Description

Electrode assembly, secondary battery including the same, and method for manufacturing the electrode assembly

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0014676 dated February 5, 2025 and Korean Patent Application No. 10-2025-0208453 dated December 23, 2026, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0002] The present invention relates to an electrode assembly applicable to a rechargeable and dischargeable secondary battery, a secondary battery, and a method for manufacturing an electrode assembly.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages over nickel-based batteries, such as the ability to freely charge and discharge due to almost no memory effect, a very low self-discharge rate, and high energy density.

[0005] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. Additionally, the lithium secondary battery comprises a positive plate and a negative plate coated with these positive and negative active materials, respectively; an electrode assembly in which the positive and negative plates are arranged with a separator in between; and an outer casing that seals and encloses the electrode assembly together with an electrolyte.

[0006] These secondary batteries stack multiple electrodes by repeating the process of placing an electrode plate on a separator, covering the electrode with the separator again, and placing an electrode with a different polarity on top.

[0007] In addition, to improve the stacking speed of electrode plates, a process is being applied in which electrode plates are placed between separators while folding them in a zigzag pattern. However, the electrode plate stacking process has the problem of requiring a significant amount of time.

[0008] The present invention provides an electrode assembly, a secondary battery, and a method for manufacturing an electrode assembly that can improve productivity.

[0009] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0010] An electrode assembly according to one aspect of the present invention comprises a plurality of alternately arranged positive plates, a plurality of negative plates, and a separator interposed between the positive plates and the negative plates, wherein the separator comprises a plurality of inner portions in contact with the positive plates or the negative plates and a plurality of connecting portions that connect the inner portions and protrude further than the side edge of the positive plate, and at least one of the connecting portions may be arranged to surround another connecting portion.

[0011] According to one aspect of the present invention, the connecting portion may include a plurality of first connecting portions protruding from one side end of the inner portion and a plurality of second connecting portions protruding from the other side end of the inner portion.

[0012] According to one aspect of the present invention, the second connecting portions may be stacked in a direction intersecting the stacking direction of the electrode assembly.

[0013] According to one aspect of the present invention, the first connecting portion may be spaced apart with the positive plate or the negative plate in between.

[0014] According to one aspect of the present invention, the second connecting part disposed on the outermost side among the second connecting parts can connect the inner parts disposed on the outermost side of the electrode assembly.

[0015] According to one aspect of the present invention, the width of any one of the second connecting portions may be formed to be larger than the width of another second connecting portion positioned closer to the side end of the positive plate.

[0016] According to one aspect of the present invention, a plurality of the first connecting portions may have the same width.

[0017] According to one aspect of the present invention, the width of the second connecting portions may gradually increase as it moves away from the side end of the positive plate.

[0018] According to one aspect of the present invention, the gap between the inner parts connected by any one of the second connecting parts may be formed to be larger than the gap between the inner parts connected by the second connecting part positioned closer to the side end of the anode plate.

[0019] According to one aspect of the present invention, the separator comprises a first separator end and a second separator end located at a longitudinal end, wherein the first separator end is located at the end of a portion in contact with the innermost cathode plate, and the second separator end may be located at the end of a portion surrounding the outermost anode plate or the cathode plate.

[0020] According to one aspect of the present invention, the anode plate includes a protruding first tab, the first tabs are stacked to form a first tab bundle, and the electrode assembly may include two first tab bundles.

[0021] A secondary battery according to another aspect of the present invention comprises an electrode assembly including a plurality of positive plates and a plurality of negative plates arranged alternately, and a separator interposed between the positive plates and the negative plates, a case in which the electrode assembly is received, and a terminal exposed to the outside of the case, wherein the separator comprises a plurality of inner portions in contact with the positive plates or the negative plates and a plurality of connecting portions that connect the inner portions and protrude further than the side edge of the positive plates, and at least one of the connecting portions may be arranged to surround another connecting portion.

[0022] According to another aspect of the present invention, the connecting portion may include a plurality of first connecting portions protruding from one side end of the inner portion and a plurality of second connecting portions protruding from the other side end of the inner portion.

[0023] According to another aspect of the present invention, the second connecting portions may be stacked in a direction intersecting the stacking direction of the electrode assembly.

[0024] According to another aspect of the present invention, the first connecting part may be spaced apart with the positive plate or the negative plate in between.

[0025] A method for manufacturing an electrode assembly according to another aspect of the present invention may include an electrode stacking step of forming a laminate by folding a separator in a zigzag shape and arranging a plurality of positive plates and a plurality of negative plates between the separators, wherein a plurality of positive plates are arranged in one layer of the laminate and a plurality of negative plates are arranged in an upper or lower layer of the layer in which the positive plates are arranged; a pressing step of pressing the laminate; and a folding step of folding the laminate to form an electrode assembly.

[0026] According to another aspect of the present invention, the laminate may include a first stack in which the positive plate and the negative plate are alternately stacked, and a second stack disposed next to the first stack in which the positive plate and the negative plate are alternately stacked.

[0027] According to another aspect of the present invention, the electrode stacking step may form the stack on a first support and a second support, wherein the first stack is stacked on the first support and the second stack is stacked on the second support.

[0028] According to another aspect of the present invention, the positive plate has a first tab and the negative plate has a second tab, and in the electrode stacking step, the first tab of the positive plate placed in the first stack is spaced apart at a predetermined interval from one side end of the positive plate, and the first tab of the positive plate placed in the second stack may be spaced apart at the opposite side end of the positive plate by the same interval.

[0029] According to another aspect of the present invention, the positive plate has a first tab and the negative plate has a second tab, and in the electrode stacking step, the first tab protruding from the positive plate placed in the first stack is spaced apart by a first distance from one side end of the positive plate, and the first tab protruding from the positive plate placed in the second stack may be spaced apart by a second distance longer than the first distance from the side end opposite the one side end of the positive plate.

[0030] According to another aspect of the present invention, the first stack may be formed higher than the second stack.

[0031] According to another aspect of the present invention, the first stack may include a greater number of layers than the second stack.

[0032] According to another aspect of the present invention, the electrode stacking step may place only one positive plate or negative plate on the uppermost part of the stack.

[0033] According to another aspect of the present invention, the electrode stacking step may include a first alignment step of arranging two positive plates side by side on the separator, a first cover step of folding the separator to cover the positive plates, a second alignment step of arranging two negative plates side by side on the separator covering the positive plates, and a second cover step of folding the separator to cover the negative plates.

[0034] According to another aspect of the present invention, the electrode stacking step may stack the electrode plates such that the gap between the electrode plates located at the bottom and parallel thereto is larger than the gap between the electrode plates located at the top.

[0035] In the folding step according to another aspect of the present invention, the gap between the separators connected to each other at one end of the electrode assembly is uniform, and the gap between the separators connected to each other at the other end of the electrode assembly may be formed such that the outer portion in the thickness direction of the electrode assembly is larger than the inner portion in the thickness direction of the electrode assembly.

[0036] In the folding step according to another aspect of the present invention, the first connecting portions connecting the separator at one end of the electrode assembly are spaced apart in the thickness direction of the electrode assembly without overlapping, and the second connecting portion connecting the separator at the other end of the electrode assembly may overlap.

[0037] In the folding step according to another aspect of the present invention, the first length of the first connecting portion connecting the separators at one end of the electrode assembly is formed uniformly, and the second length of the second connecting portion connecting the separators at the other end of the electrode assembly may be formed such that the outer portion in the thickness direction of the electrode assembly is longer than the inner portion in the thickness direction of the electrode assembly.

[0038] According to another aspect of the present invention, the stacking step may fold the separator while supporting it by placing a support roller on the separator on which the positive plate or negative plate is placed.

[0039] According to another aspect of the present invention, the folding step involves folding a laminate using a folding device having a first folding plate and a second folding plate, wherein the first folding plate and the second folding plate can be rotated so as to be upright while the laminate is positioned on the first folding plate and the second folding plate.

[0040] According to an electrode assembly and a method for manufacturing an electrode assembly according to one embodiment of the present invention, a plurality of electrode plates are arranged in one layer and a laminate is folded to form an electrode assembly, thereby improving the productivity of the electrode assembly and preventing misalignment.

[0041] FIG. 1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention.

[0042] Figure 2 is a cross-sectional view taken along line II-II in Figure 1.

[0043] FIG. 3 is a perspective view illustrating an electrode assembly according to a first embodiment of the present invention.

[0044] FIG. 4 is a flowchart illustrating a method for manufacturing an electrode assembly according to a first embodiment of the present invention.

[0045] FIG. 5 is a flowchart illustrating the electrode stacking step according to the first embodiment of the present invention.

[0046] FIG. 6 is a diagram showing the process of stacking electrode plates according to the first embodiment of the present invention.

[0047] FIG. 7 is a diagram showing the process of applying pressure to a laminate according to the first embodiment of the present invention.

[0048] FIG. 8 is a diagram showing the process of folding a laminate according to the first embodiment of the present invention.

[0049] FIG. 9 is a drawing showing an electrode assembly according to a first embodiment of the present invention.

[0050] FIG. 10 is a flowchart illustrating a method for manufacturing an electrode assembly according to a second embodiment of the present invention.

[0051] FIG. 11 is a drawing showing a laminated body stacked according to a second embodiment of the present invention.

[0052] FIG. 12 is a drawing showing an electrode assembly according to a second embodiment of the present invention.

[0053] FIG. 13 is a flowchart for explaining a method for manufacturing an electrode assembly according to a third embodiment of the present invention.

[0054] FIG. 14 is a diagram showing the process of stacking electrode plates according to a third embodiment of the present invention.

[0055] FIG. 15 is a drawing showing a folded electrode assembly according to a third embodiment.

[0056] FIG. 16 is a flowchart illustrating a method for manufacturing an electrode assembly according to a fourth embodiment of the present invention.

[0057] FIG. 17 is a diagram showing the process of stacking electrode plates according to the fourth embodiment of the present invention.

[0058] FIG. 18 is a flowchart illustrating a method for manufacturing an electrode assembly according to a fifth embodiment of the present invention.

[0059] FIG. 19 is a drawing showing the process of folding a laminate according to the fifth embodiment of the present invention.

[0060] FIG. 20 is a drawing showing a folded electrode assembly according to the fifth embodiment of the present invention.

[0061] FIG. 21 is a flowchart for explaining a method for manufacturing an electrode assembly according to a sixth embodiment of the present invention.

[0062] FIG. 22 is a diagram showing the process of stacking electrode plates according to the 6th embodiment of the present invention.

[0063] FIG. 23 is a plan view showing a folded electrode assembly according to the 6th embodiment.

[0064] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0065] The terms used in this invention are used merely to describe specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this invention, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0066] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that in the accompanying drawings, identical components are indicated by the same reference numerals whenever possible. Furthermore, detailed descriptions of known functions and configurations that may obscure the essence of the present invention will be omitted. For the same reason, some components in the accompanying drawings may be exaggerated, omitted, or schematically depicted.

[0067] Hereinafter, a secondary battery according to the first embodiment of the present invention will be described.

[0068] FIG. 1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a perspective view illustrating an electrode assembly according to a first embodiment of the present invention.

[0069] Referring to FIGS. 1 to 3, the secondary battery (100) according to the present embodiment may include an electrode assembly (10) comprising a positive electrode plate (11) and a negative electrode plate (12), a case (30) housing the electrode assembly (10), and a cap assembly (20) coupled to the case (30). The cap assembly (20) may include a cap plate (21) coupled to an opening of the case (30), terminals (23, 24) installed on the cap plate (21), and current collectors (41, 42) electrically connecting the terminals (23, 24) to the electrode assembly (10).

[0070] The electrode assembly (10) includes an anode plate (11) and a cathode plate (12), and a separator (13, see FIG. 3) interposed between the anode plate (11) and the cathode plate (12). The structure may be formed such that the anode plate (11) and the cathode plate (12) are alternately inserted between the separator (13) which is folded in a zigzag shape. The separator (13) prevents short circuits and enables the movement of ions, and there are no restrictions on the material of the separator (13).

[0071] The positive plate (11) may include a coating portion, which is an area where a positive active material is applied to a metal foil made of aluminum or the like, and a first tab (11a) where no active material is applied.

[0072] The negative plate (12) may include a coating portion, which is an area where a positive active material is applied to a metal foil made of copper or the like, and a second tab (12a) where no active material is applied.

[0073] The separator (13) may include an inner portion (134) that contacts the positive plate (11) or negative plate (12) and a plurality of connecting portions (CN1) that protrude from the side end of the inner portion (134).

[0074] The connecting portion (CN1) may protrude further than the side edges of the positive plate (11) and the negative plate (12). The inner portion (134) may be inserted between the positive plate (11) and the negative plate (12) to come into contact with the positive plate (11) and the negative plate (12). Additionally, the inner portion (134) positioned at the outermost side may be positioned to surround the positive plate (11) or the negative plate (12) to come into contact with either the positive plate (11) or the negative plate (12).

[0075] The connecting portion (CN1) may include a first connecting portion (131) protruding from one side end of the inner portion (134) and a second connecting portion (132) protruding from the other side end of the inner portion (134).

[0076] The first connecting part (131) may protrude further than one side end of the positive plate (11), and the second connecting part (132) may protrude further than the other side end of the positive plate (11). The second connecting part (132) may protrude from the side end opposite to the side end where the first connecting part (131) protrudes.

[0077] The first connecting portion (131) may be formed to surround the side end of a positive plate (11) or a negative plate (12). Additionally, the side end of the positive plate (11) or the negative plate (12) that is not surrounded by the separator (13) may be located between the first connecting portions (131).

[0078] Accordingly, the first connecting portion (131) is spaced apart in the thickness direction (x-axis direction) of the electrode assembly (10) with the positive plate (11) or negative plate (12) in between, and the width (W11) of the first connecting portions (131) can be formed uniformly.

[0079] A plurality of second connecting portions (132) may be formed to surround at least two positive plates (11) or negative plates (12). However, the second connecting portion (132) located at the innermost side of the electrode assembly (10) may be formed to surround one negative plate (12).

[0080] The second connecting portions (132) are arranged to surround other second connecting portions (132), and the second connecting portions (132) can be stacked in a direction (y-axis direction) that intersects the stacking direction (x-axis direction) of the electrode assembly (10).

[0081] As in the present embodiment, if the first connecting portions (131) protruding from one side end of the electrode assembly (10) are spaced apart from each other, the electrolyte can rapidly penetrate between the first connecting portions (131). Additionally, if the second connecting portions (132) protruding from the opposite side end are stacked and wrapped around each other, damage to the side end of the positive plate (11) or negative plate (12) due to external impact can be prevented.

[0082] The inner portion (134) in contact with the electrode plate positioned at the very bottom of the electrode assembly (10) and the inner portion (134) in contact with the electrode plate positioned at the very top of the electrode assembly (10) can be connected by a second connecting portion (132) on one side of the electrode assembly (10).

[0083] Two inner portions, each positioned on the outermost side of the electrode assembly (10), can be connected by a second connecting portion (132). Additionally, the second connecting portions (132) can be stacked in a direction away from the side ends of the positive plate (11) and the negative plate (12) (in the y-axis direction).

[0084] The width (W12) of the second connecting part (132) may be formed such that the part further from the side edge of the positive plate (11) or negative plate (12) is larger than the part closer to it. For example, among the second connecting parts (132), the width (W12) of the second connecting part (132) located on the inner side closer to the side edge of the positive plate (11) may be formed to be smaller than the width (W12) of the second connecting part (132) located further outward.

[0085] Additionally, the width (W12) of the stacked second connecting portions (132) can gradually increase as it moves away from the side of the positive plate (11) or negative plate (12).

[0086] The gap (G12, illustrated in FIG. 9) between the inner parts (134) connected by the second connecting parts (132) may gradually increase as it moves away from the side edge of the positive plate (11). The second connecting part (132) located closest to the side edge of the positive plate (11) may connect inner parts (134) that have a small gap, spaced apart with one electrode plate in between, and the second connecting part (132) surrounding it from the outside may connect inner parts (134) that have a relatively large gap, spaced apart with three electrode plates in between. Meanwhile, the gap (G11, illustrated in FIG. 9) between the inner parts (134) connected by the first connecting parts (131) may be uniform.

[0087] The separator (13) includes a first separator end (135) and a second separator end (136) located at the longitudinal end, and the first separator end (135) and the second separator end (136) may be located at the same side of the electrode assembly (10).

[0088] The first separator end (135) is located between the positive plate (11) or the negative plate (12), and is located at the end of the separator (13) that is in contact with the negative plate (12) located at the innermost side of the electrode assembly (10), and the second separator end (136) may be located at the end of the portion surrounding the positive plate (11) or the negative plate (12) located at the outermost side of the electrode assembly (10).

[0089] As in the first embodiment, if the first separator end (135) and the second separator end (136) are located on the same side of the electrode assembly, and the first separator end (135) is located on the outermost side and the second separator end (136) is located on the inner side, the electrode assembly (10) can be easily manufactured by folding the laminate.

[0090] The first tab (11a) may protrude from the side end of the positive plate (11), and the second tab (12a) may protrude from the side end of the negative plate (12). The first tab (11a) and the second tab (12a) may protrude in the same direction, but may protrude in the direction toward the cap plate (21) (z-axis direction). In this embodiment, the first tab (11a) and the second tab (12a) are described as protruding in the same direction, but are not necessarily limited thereto, and the first tab (11a) and the second tab (12a) may protrude in different directions.

[0091] The first tab (11a) and the second tab (12a) may be spaced apart in the width direction (y-axis direction) of the case (30). Additionally, the first tabs (11a) and the second tabs (12a) may be stacked in the thickness direction (x-axis direction) of the case (30).

[0092] Additionally, the first tap (11a) can be connected to the first terminal (23) via the first current collector (41), and the second tap (12a) can be connected to the second terminal (22) via the second current collector (42).

[0093] The case (30) may be formed in the shape of a box having an internal space for accommodating the electrode assembly (10). The case (30) may be formed in various shapes, such as prismatic, cylindrical, or pouch-shaped. A single electrode assembly (10) or multiple electrode assemblies (10) may be inserted into the case (30).

[0094] The electrode assembly (10) and the electrolyte may be accommodated together inside the case (30). The electrolyte may be in the form of a liquid, solid, or gel.

[0095] The cap plate (21) is made of a plate material that covers the opening of the case (30) and may have a shape corresponding to the shape of the opening of the case (30). The cap plate (21) may be fixed to the case (30) by welding.

[0096] In the cap plate (21), an electrolyte injection port (H1) for injecting the electrolyte and a vent hole (H2) in which a vent member (27) is installed may be formed. A sealing plug (28) that blocks the electrolyte injection port (H1) may be installed in the electrolyte injection port (H1), and a vent member (25) that opens at a preset pressure may be formed in the vent hole (H2).

[0097] The terminals (23, 24) are coupled to the cap plate (21) and exposed to the outside of the case (30), and one or two terminals (23, 24) may be installed on the cap plate (21). When two terminals (23, 24) are installed on the cap plate (21), the first terminal (23) may be a positive terminal and the second terminal (24) may be a negative terminal. When one terminal is installed on the cap plate (21), the case (30) may be charged as a negative terminal.

[0098] The first terminal (23) and the second terminal (24) may be formed in a plate shape. An insulating gasket (25) may be installed between the first terminal (23) and the cap plate (21), and an insulating gasket (26) may also be installed between the second terminal (24) and the cap plate (21). Additionally, the gaskets (25, 26) may extend downward and be located between the current collector (41, 42) and the cap plate (21). The gaskets (25, 26) may be formed as a single component or divided into multiple components.

[0099] The first terminal (23) is electrically connected to the first tap (11a) via the first current collector (41), and the second terminal (24) can be electrically connected to the second tap (12a) via the second current collector (42).

[0100] The first terminal (23) and the second terminal (24) are formed in a plate shape, and a hole may be formed in the center of the first terminal (23) and the second terminal (24) into which a connecting column of the first current collecting member (41) or the second current collecting member (42) is inserted.

[0101] The first current collector (41) may include a column inserted into the first terminal (23) and a current collector plate supported at the bottom of the column to which the first tab (11a) is joined. Accordingly, the first current collector (41) can electrically connect the first tab (11a) and the first terminal (23).

[0102] The second current collector (42) may include a column inserted into the first terminal (24) and a current collector plate supported at the bottom of the column to which the second tab (12a) is joined. Accordingly, the second current collector (42) can electrically connect the second tab (12a) and the second terminal (24).

[0103] The upper insulating member (50) is installed between the cap plate (21) and the electrode assembly (10) to insulate the cap plate (21) and the electrode assembly (10). The upper insulating member (50) may be formed in a shape corresponding to the cap plate (21) and may be formed in the shape of a long rectangular plate. The upper insulating member (50) may be positioned to face the cap plate (21) but may be positioned parallel to the cap plate (21).

[0104] Hereinafter, a method for manufacturing an electrode assembly according to the first embodiment of the present invention will be described.

[0105] FIG. 4 is a flowchart for explaining a method for manufacturing an electrode assembly according to a first embodiment of the present invention, FIG. 5 is a flowchart for explaining an electrode stacking step according to a first embodiment of the present invention, FIG. 6 is a diagram showing the process of stacking electrode plates according to a first embodiment of the present invention, FIG. 7 is a diagram showing the process of pressing a stack according to a first embodiment of the present invention, FIG. 8 is a diagram showing the process of folding a stack according to a first embodiment of the present invention, and FIG. 9 is a diagram showing an electrode assembly according to a first embodiment of the present invention.

[0106] Referring to FIGS. 4 to 9, the method for manufacturing an electrode assembly according to the present embodiment may include an electrode stacking step (S110), a pressurizing step (S120), and a folding step (S130).

[0107] The electrode stacking step (S110) forms a stack by arranging a plurality of positive plates (11) and a plurality of negative plates (12) between the separator (13). The electrode stacking step (S110) places the separator (13) on the first support (210) and the second support (220) located in the center. Additionally, the positive plates (11) and negative plates (12) are alternately supplied onto the separator (13) while folding the separator (13) in a zigzag shape. Accordingly, a stack (140) can be formed in which the positive plates (11) and negative plates (12) are alternately stacked between the separator (13) folded in a zigzag shape.

[0108] The positive plates (11) may be located on the first table (230) and the negative plates (12) may be located on the second table (240), and the first table (230) and the second table (240) may be spaced apart with the first support (210) and the second support (220) in between.

[0109] The laminate (140) may be formed on the first support (210) and the second support (220), and the laminate (140) may include a first stack (141) in which active plates are stacked and a second stack (142) disposed next to the first stack (141).

[0110] The electrode stacking step (S110) may stack a first stack (141) on a first support (210) and stack a second stack (142) on a second support (220). The first stack (141) and the second stack (142) may be connected by a separator.

[0111] The electrode stacking step (S110) may include a first alignment step (S111), a first cover step (S112), a second alignment step (S113), and a second cover step (S114).

[0112] The first alignment step (S111) supplies two positive plates (11) loaded on the first table (230) onto the separator (13), and the two positive plates (11) can be arranged side by side on the separator (13). The separator (13) and the two positive plates (11) can form a single layer. The two positive plates (11) can be arranged parallel to each other and spaced apart in the longitudinal direction (y-axis direction) of the separator (13) on the same plane.

[0113] Additionally, the positive plates (11) arranged in one layer may be arranged so that the first tab (11a) protrudes in the same direction. Here, one positive plate (11) may be placed on the separator (13) of the first support (210) to form a first stack (141), and another positive plate (11) may be placed on the separator (13) of the second support (220) to form a second stack (142).

[0114] The first tab (11a) placed in the first stack (141) is positioned adjacent to one side end of the positive plate (11), and the first tab (11a) placed in the second stack (142) can be positioned adjacent to the opposite side end of one side end of the positive plate (11).

[0115] To explain in more detail, the first tab (11a) placed on the first support (210) is spaced apart from one end of the positive plate (11) at a predetermined interval, and the first tab (11a) placed on the second support (220) is spaced apart from the other end of the positive plate (11) at a predetermined interval, provided that the spacing at which the first tab (11a) is spaced from one end or the other end may be the same.

[0116] Accordingly, when the laminate (140) is folded, the first tabs (11a) can be stacked at corresponding positions to form a bundle of first tabs.

[0117] The first cover step (S112) involves folding the separator (13) to cover the upper surface of the two positive plates (11). The first cover step (S112) can fold the separator (13) supplied from the upper direction into a zigzag shape using a folding device (not shown). The folding device consists of a roller and a member that moves the roller, and the separator (13) can be folded into a zigzag shape as the roller moves left and right.

[0118] The second alignment step (S113) involves placing a plurality of negative plates (12) on the separator (13), and two negative plates (12) may be placed side by side on the separator (13). Accordingly, two negative plates (12) are placed on a layer placed above or below the layer where the positive plates (11) are placed, and the two negative plates (12) may be placed parallel to each other and spaced apart in the longitudinal direction (y-axis direction) of the separator (13) on the same plane.

[0119] Here, one cathode plate (12) may be placed on a first support (210) to form a first stack (141), and another cathode plate (12) may be placed on a second support (220) to form a second stack (142). Additionally, the cathode plates (12) may be arranged so that the second tab (12a) protrudes in the same direction, and the second tab (12a) and the first tab (11a) may protrude in the same direction. However, the present invention is not limited thereto, and the first tab (11a) and the second tab (12a) may be arranged so that they protrude in opposite directions.

[0120] The second tab (12a) placed in the first stack (141) may be placed adjacent to one side end of the cathode plate (12), and the second tab (12a) placed in the second stack (142) may be placed adjacent to the opposite side end of one side end of the cathode plate (12). Accordingly, when the stack (140) is folded, the second tabs (12a) may be stacked at corresponding positions to form a bundle of second tabs.

[0121] The second cover step (S114) folds the separator (13) to simultaneously cover the upper surfaces of the two cathode plates (12). The second cover step (S114) can fold the separator in a zigzag shape using a folding device (not shown).

[0122] The first alignment step (S111), the first cover step (S112), the second alignment step (S113), and the second cover step (S114) may be repeated sequentially multiple times. Additionally, the electrode stacking step (S110) according to the present embodiment may further include a third alignment step in which only one anode plate (11) is placed on a separator covering the cathode plates (12) after the first alignment step (S111), the first cover step (S112), the second alignment step (S113), and the second cover step (S114) are completed.

[0123] In the electrode stacking step (S110), only one positive plate (11) or negative plate (12) is positioned at the very top. Accordingly, the electrode plates can be prevented from coming into contact with each other during folding.

[0124] As illustrated in FIG. 7, the first stack (141) may include one more layer than the second stack (142), and accordingly, the first stack (141) may be formed higher than the second stack (142).

[0125] In the pressurization step (S120), after cutting the separator (13), the laminate (140) is placed on the press device (260), and the laminate (140) can be pressed with the press device (260). In the pressurization step (S120), the first stack (141) and the second stack (142) are placed together on the press device (260), and the first stack (141) and the second stack (142) can be pressed simultaneously. Accordingly, the positive plate (11), the separator, and the negative plate (12) can be in close contact with each other. At this time, the pressurization step (S120) may also pressurize the laminate (140) while heating it to a preset temperature.

[0126] Referring to FIG. 8, the folding step (S130) forms an electrode assembly (10) by folding the pressurized laminate (140) in a folding device (270) so that the second stack (142) is positioned on top of the first stack (141).

[0127] The folding step (S130) can form an electrode assembly (10) by folding the separator at the spaced portion between the first stack (141) and the second stack (142). The folding device (270) includes a first folding plate (271) and a second folding plate (272), and the folding step (S130) can place the first stack (141) on the first folding plate (271) and place the second stack (142) together on the second folding plate (272).

[0128] A spaced-apart region is formed between the first stack (141) and the second stack (142), and the electrode assembly (10) can be formed in a folded structure in the region between the first stack (141) and the second stack (142).

[0129] The second folding plate (272) is installed so as to be rotatable with respect to the first folding plate (271), and when the second folding plate (272) rotates, the second stack (142) can be positioned on the first stack (141).

[0130] Referring to FIG. 9, an electrode assembly (10) can be formed in a Z-stack and folding manner by a folding step (S130). In the folding step (S130), the gap (G11) between the separators (13) connected to each other at one end of the electrode assembly (10) can be made uniform.

[0131] Meanwhile, in the folding step (S130), the gap (G12) between the separators (13) connected to each other at the other end of the electrode assembly (10) may be formed such that the outer portion in the thickness direction of the electrode assembly (10) is larger than the inner portion in the thickness direction of the electrode assembly (10). Additionally, the gap (G12) between the separators connected to each other at the other end of the electrode assembly (10) may gradually increase from the inner portion in the thickness direction of the electrode assembly (10) to the outer portion.

[0132] In the folding step (S130), a plurality of first connecting parts (131) and a plurality of second connecting parts (132) may be formed on the side of the electrode assembly (10). The width (W11) of the first connecting parts (131) may be formed uniformly.

[0133] Additionally, the separator (13) in contact with the electrode plate positioned at the very bottom of the electrode assembly (10) and the separator (13) in contact with the electrode plate positioned at the very top of the electrode assembly (10) can be connected to each other on one side of the electrode assembly (10).

[0134] In the folding step (S130), the first connecting part (131) connecting the separator (13) at one end of the electrode assembly (10) may be spaced apart in the thickness direction of the electrode assembly (10) without overlapping. Meanwhile, in the folding step (S130), the second connecting part (132) connecting the separator (13) at the other end of the electrode assembly (10) may be formed in a stacked structure with overlap.

[0135] The width (W12) of the stacked second connecting portions (132) may gradually increase as they move away from the side of the positive plate (11) or negative plate (12) of the electrode assembly (10). For example, the second connecting portion (132) located at the outermost side may be positioned to surround the electrode plates placed at the outermost side of the electrode assembly (10) and may have the longest width (W12). The second connecting portion (132) located at the innermost side may be positioned with one negative plate (12) in between and may have the shortest width (W12).

[0136] In the folding step (S130), the first connecting portion (131) may be formed to wrap around the side end of one positive plate (11) or negative plate (12). Additionally, the side end of the positive plate (11) or negative plate (12) that is not wrapped by the separator (13) may be located between the first connecting portions (131).

[0137] In the folding step (S130), some of the second connecting portions (132) may be formed to surround at least two positive plates (11) or negative plates (12). However, the second connecting portion (132) located at the innermost side of the electrode assembly (10) may be formed to surround one negative plate (12).

[0138] In the folding step (S130), the folded electrode assembly (10) includes a first separator end (135) and a second separator end (136) located at the longitudinal end of the separator (13). The first separator end (135) is located between the positive plate (11) or the negative plate (12) and is located at the end of the separator that is in contact with the negative plate (12) located at the innermost side of the electrode assembly (10), and the second separator end may be located at the end of the portion that surrounds the positive plate (11) or the negative plate (12) located at the outermost side of the electrode assembly (10).

[0139] Additionally, separators (13) located on different layers of the electrode assembly (10) can be symmetrically connected to each other with respect to the center of the thickness direction of the electrode assembly (10) by means of a second connecting part (132). Additionally, the electrode assembly (10) can be sealed after being inserted into a metal case or pouch case to form a secondary battery (100).

[0140] As described above, according to the present embodiment, a plurality of electrode plates (11, 12) are stacked simultaneously and folded to form an electrode assembly (10), thereby significantly improving productivity and ensuring precise alignment.

[0141] Hereinafter, a method for manufacturing an electrode assembly according to a second embodiment of the present invention will be described.

[0142] FIG. 10 is a flowchart for explaining a method for manufacturing an electrode assembly according to a second embodiment of the present invention, FIG. 11 is a drawing showing a laminated structure according to a second embodiment of the present invention, and FIG. 12 is a drawing showing an electrode assembly according to a second embodiment of the present invention.

[0143] Referring to FIGS. 10 to 12, the method for manufacturing an electrode assembly according to the present embodiment may include an electrode stacking step (S210), a pressurizing step (S220), and a folding step (S230).

[0144] The electrode stacking step (S210) involves folding the separator (13) in a zigzag shape and alternately supplying positive plates (11) and negative plates (12) onto the separator (13) to arrange a plurality of positive plates (11) and a plurality of negative plates (12) between the separator (13). Accordingly, a stack (140) can be formed in which positive plates (11) and negative plates (12) are alternately stacked between the separator (13) folded in a zigzag shape.

[0145] Referring to FIG. 11, the electrode stacking step (S210) can form a stack (140) by stacking two positive plates (11) in parallel on one layer and stacking two negative plates (12) in parallel on the upper or lower side of the positive plates (11).

[0146] The electrode stacking step (S210) can stack the electrode plates (11, 12) such that the gap (G2) between the electrode plates (11, 12) located at the bottom is larger than the gap (G2) between the electrode plates (11, 12) located at the top. Additionally, the electrode stacking step (S210) can stack the electrode plates (11, 12) located on the same layer such that the gap between them gradually decreases as it goes from the bottom to the top.

[0147] Accordingly, when folding the laminate (140) to form the electrode assembly (10), it can be easily folded.

[0148] The pressurization step (S220) can press the laminate (140) with a press device after cutting the separator (13).

[0149] Meanwhile, referring to FIG. 12, the folding step (S230) folds the pressurized laminate (140) using a folding device. In the folding step (S230), the width of the first connecting part (131) connecting the separator (13) at one end of the electrode assembly (10) folded can be made uniform.

[0150] On the other hand, in the folding step (S230), the width of the second connecting part (132) connecting the separator (13) at the other end of the electrode assembly (10) can be formed such that the part further from the end of the electrode plate is longer than the part closer.

[0151] Additionally, the width of the second connecting part (132) at the other end of the electrode assembly (10) may gradually increase as it moves away from the side end of the electrode plate.

[0152] Hereinafter, a method for manufacturing an electrode assembly according to a third embodiment of the present invention will be described.

[0153] FIG. 13 is a flowchart for explaining a method for manufacturing an electrode assembly according to a third embodiment of the present invention, FIG. 14 is a diagram showing the process of stacking electrode plates according to a third embodiment of the present invention, and FIG. 15 is a diagram showing a folded electrode assembly according to a third embodiment.

[0154] Referring to FIGS. 13 to 15, the method for manufacturing an electrode assembly according to the present embodiment may include an electrode stacking step (S310), a pressurizing step (S320), and a folding step (S330). Since the pressurizing step (S320) and the folding step (S330) according to the present embodiment are performed as the same or similar processes as the pressurizing step and the folding step according to the first embodiment described above, a redundant description of the same or similar configuration is omitted.

[0155] The electrode stacking step (S310) involves folding the separator (13) in a zigzag shape and alternately supplying positive plates (11) and negative plates (12) onto the separator (13) to arrange a plurality of positive plates (11) and a plurality of negative plates (12) between the separator (13). Accordingly, positive plates (11) and negative plates (12) are alternately stacked between the separator (13) folded in a zigzag shape to form a stack (140).

[0156] The electrode stacking step (S310) can form a stack (140) by stacking two positive plates (11) in parallel on one layer and stacking two negative plates (12) in parallel on the upper or lower side of the positive plates (11).

[0157] The positive plates (11) arranged in one layer can be arranged so that the first tabs (15, 16) protrude in the same direction. Here, one positive plate (11) can be placed on the first support (210) to form the first stack (141), and the other positive plate (11) can be placed on the second support (220) to form the second stack (142).

[0158] In the electrode stacking step (S310), the first tab (15) protruding from the anode plate (11) placed in the first stack (141) and the first tab (16) of the anode plate (11) placed in the second stack (142) can be stacked such that they are placed at different distances from the side ends of the anode plate (11).

[0159] For example, in the electrode stacking step (S310), the first tab (15) protruding from the positive plate (11) placed in the first stack (141) may be spaced apart by a first distance (L21) from one side end of the positive plate (11), and the first tab (16) protruding from the positive plate (11) placed in the second stack (142) may be spaced apart by a second distance (L22) that is longer than the first distance (L21) from the opposite side end of the positive plate (11).

[0160] The first tabs (15) of the positive plate (11) placed in the second stack (141) and the first tabs (16) of the positive plate (11) placed in the second stack (142) can form two first tab bundles spaced apart in the width direction of the electrode assembly (10) when folded. However, the first tabs (15, 16) may be placed offset to one side with respect to the center in the width direction of the electrode assembly (10).

[0161] Additionally, the cathode plates (12) may be arranged so that the second tabs (17, 18) protrude in the same direction. Here, one cathode plate (12) may be placed on the first support (210) to form the first stack (141), and the other cathode plate (12) may be placed on the second support (220) to form the second stack (142).

[0162] The second tab (17) protruding from the cathode plate (12) placed in the first stack (141) and the second tab (18) of the cathode plate (12) placed in the second stack (142) can be placed at different distances from the side ends of the cathode plate (12).

[0163] For example, a second tab (17) protruding from a cathode plate (12) placed in a first stack (141) may be spaced apart by a third distance (L31) from one side end of the cathode plate (12), and a second tab (18) protruding from a cathode plate (12) placed in a second stack (142) may be spaced apart by a fourth distance (L32) that is longer than the third distance (L31) from the opposite side end of the cathode plate (12).

[0164] The second tabs (17) of the cathode plate (12) placed in the first stack (141) and the second tabs (18) of the cathode plate (12) placed in the second stack (142) can form two second tab bundles spaced apart in the width direction of the electrode assembly (10) when folded. However, the second tabs (17, 18) may be placed offset to the other side with respect to the center in the width direction of the electrode assembly (10).

[0165] Accordingly, the electrode assembly (10) includes two first tab bundles and two second tab bundles, the first tab bundles are positioned off to one side with respect to a virtual reference line (XL1) passing through the widthwise center of the electrode assembly (10), and the second tab bundles can be positioned off to the other side with respect to the virtual reference line (XL1) of the electrode assembly (10).

[0166] Hereinafter, a method for manufacturing an electrode assembly according to the fourth embodiment of the present invention will be described.

[0167] FIG. 16 is a flowchart for explaining a method for manufacturing an electrode assembly according to a fourth embodiment of the present invention, and FIG. 17 is a diagram showing the process of stacking electrode plates according to a fourth embodiment of the present invention.

[0168] Referring to FIGS. 16 and 17, the method for manufacturing an electrode assembly according to the present embodiment may include an electrode stacking step (S410), a pressurizing step (S420), and a folding step (S430).

[0169] The electrode stacking step (S410) alternately supplies positive plates (11) and negative plates (12) onto the separator (13) while folding the separator (13) in a zigzag shape, thereby arranging a plurality of positive plates (11) and a plurality of negative plates (12) between the separator (13). Accordingly, positive plates (11) and negative plates (12) can be alternately stacked between the separator (13) folded in a zigzag shape.

[0170] The electrode stacking step (S410) can form a stack (140) by stacking two positive plates (11) in parallel on one layer and stacking two negative plates (12) in parallel on the upper or lower part of the positive plates (11).

[0171] The electrode stacking step (S410) involves placing two positive plates (11) on the separator (13), supporting the separator (13) using a support roller (350), and then folding the separator (13). Additionally, the electrode stacking step (S410) may involve placing two negative plates (12) on the separator (13), and then positioning the support roller (350) so that the separator is supported by the support roller (350) and folded.

[0172] In the pressurization step (S420), after removing the support roller (350) from the separator (13) and cutting the separator (13), the laminate (140) can be pressed with a press device. Meanwhile, in the folding step (S430), the pressed laminate (140) is folded to form an electrode assembly (10).

[0173] Hereinafter, a method for manufacturing an electrode assembly according to the fifth embodiment of the present invention will be described.

[0174] FIG. 18 is a flowchart for explaining a method for manufacturing an electrode assembly according to a fifth embodiment of the present invention, FIG. 19 is a diagram showing a process of folding a laminate according to a fifth embodiment of the present invention, and FIG. 20 is a diagram showing an electrode assembly folded according to a fifth embodiment of the present invention.

[0175] Referring to FIGS. 18 to 20, the method for manufacturing an electrode assembly according to the fifth embodiment may include an electrode stacking step (S510), a pressurizing step (S520), and a folding step (S530).

[0176] The electrode stacking step (S510) and the pressurizing step (S520) according to the present embodiment are performed in the same process as the electrode stacking step and the pressurizing step according to the first embodiment described above, so a redundant description of the same configuration is omitted.

[0177] The folding step (S530) forms an electrode assembly (10) by rotating the first stack (141) and the second stack (142) while the pressurized laminate (140) is positioned in the folding device (400).

[0178] The folding step (S530) places the first stack (141) and the second stack (142) together on the folding device (400), and the folding device (400) may include a first folding plate (410) and a second folding plate (420). The first folding plate (410) and the second folding plate (420) may be rotatably formed. The folding step (S530) places the first stack (141) on the first folding plate (410) and places the second stack (142) on the second folding plate (420).

[0179] In the folding step (S530), a folding roller (360) is installed between the first stack (141) and the second stack (142), and the separator (13) is slightly pressed downward using the folding roller (360). In the folding step (S530), the first folding plate (410) and the second folding plate (420) are rotated in this state so that they are upright, and accordingly, the first stack (141) and the second stack (142) can come into contact and be stacked.

[0180] Hereinafter, a method for manufacturing an electrode assembly according to the 6th embodiment of the present invention will be described.

[0181] FIG. 21 is a flowchart for explaining a method for manufacturing an electrode assembly according to a sixth embodiment of the present invention, FIG. 22 is a diagram showing the process of stacking electrode plates according to a sixth embodiment of the present invention, and FIG. 23 is a plan view showing a folded electrode assembly according to a sixth embodiment.

[0182] Referring to FIGS. 21 to 23, the method for manufacturing an electrode assembly according to the present embodiment may include an electrode stacking step (S610), a pressurizing step (S620), and a folding step (S630). Since the pressurizing step (S620) and the folding step (S630) according to the present embodiment are performed as the same or similar processes as the pressurizing step and the folding step according to the first embodiment described above, a redundant description of the same or similar configuration is omitted.

[0183] The electrode stacking step (S610) involves folding the separator (13) in a zigzag shape and alternately supplying positive plates (11) and negative plates (12) onto the separator (13) to arrange a plurality of positive plates (11) and a plurality of negative plates (12) between the separator (13). Accordingly, positive plates (11) and negative plates (12) are alternately stacked between the separator (13) folded in a zigzag shape to form a stack (140).

[0184] The electrode stacking step (S610) can form a stack (140) by stacking two positive plates (11) in parallel on one layer and stacking two negative plates (12) in parallel on the upper or lower part of the positive plates (11).

[0185] The positive plates (11) arranged in one layer can be arranged so that the first tabs (15, 16) protrude in the same direction. Here, one positive plate (11) can be placed on the first support (210) to form the first stack (141), and the other positive plate (11) can be placed on the second support (220) to form the second stack (142).

[0186] In the electrode stacking step (S610), the first tab (15) protruding from the anode plate (11) placed in the first stack (141) and the first tab (16) of the anode plate (11) placed in the second stack (142) can be stacked such that they are placed at the same distance from one side end of the anode plate (11).

[0187] However, the first tabs (15) of the positive plate (11) placed in the first stack (141) and the first tabs (16) of the positive plate (11) placed in the second stack (142) can form two first tab bundles (61, 62) spaced apart in the width direction of the electrode assembly (10) when folded. Here, the first tabs (15, 16) can be placed in different areas based on the center in the width direction of the electrode assembly (10).

[0188] Additionally, the cathode plates (12) may be arranged so that the second tabs (17, 18) protrude in the same direction. However, the second tabs (17, 18) may protrude in the opposite direction to the direction in which the first tabs (15, 16) protrude.

[0189] Here, one cathode plate (12) may be placed on a first support (210) to form a first stack (141), and another cathode plate (12) may be placed on a second support (220) to form a second stack (142).

[0190] The second tab (17) protruding from the cathode plate (12) placed in the first stack (141) and the second tab (18) of the cathode plate (12) placed in the second stack (142) can be placed at the same distance from one side end of the cathode plate (12).

[0191] However, the second tabs (17) of the cathode plate (12) placed in the first stack (141) and the second tabs (18) of the cathode plate (12) placed in the second stack (142) can form two second tab bundles (63, 64) spaced apart in the width direction of the electrode assembly (10) when folded. Here, the second tabs (17, 18) can be placed in different areas based on the center in the width direction of the electrode assembly (10).

[0192] Accordingly, the electrode assembly (10) includes two first tab bundles (61, 62) and two second tab bundles (63, 64), and the first tab bundles (61, 62) and the second tab bundles (63, 64) may protrude in opposite directions. In this case, the positive terminal and the negative terminal of the secondary battery may protrude in opposite directions.

[0193] Accordingly, according to the present embodiment, an electrode assembly having a plurality of first tab bundles (61, 62) and second tab bundles (63, 64) can be easily manufactured.

[0194] Although an embodiment of the present invention has been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes are also to be included within the scope of the rights of the present invention.

Claims

1. A plurality of alternately arranged positive plates, a plurality of negative plates, and a separator interposed between the positive plates and the negative plates, comprising The separator comprises a plurality of inner portions in contact with the anode plate or the cathode plate, and a plurality of connecting portions that connect the inner portions and protrude further than the side edge of the anode plate. An electrode assembly having at least one of the above-mentioned connections arranged to surround another connection.

2. In Paragraph 1, The above-mentioned connecting portion comprises a plurality of first connecting portions protruding from one side end of the inner portion and a plurality of second connecting portions protruding from the other side end of the inner portion, forming an electrode assembly.

3. In Paragraph 2, The above second connecting portions are arranged in a stacked manner intersecting the stacking direction of the electrode assembly, forming an electrode assembly.

4. In Paragraph 3, The first connecting part is an electrode assembly spaced apart with the positive plate or the negative plate in between.

5. In Paragraph 2, The second connecting portion positioned at the outermost of the second connecting portions above connects the inner portions each positioned at the outermost of the electrode assembly.

6. In Paragraph 2, An electrode assembly in which the width of one of the above-mentioned second connecting portions is formed to be larger than the width of another second connecting portion positioned closer to the side end of the anode plate.

7. In Paragraph 6, A plurality of the above-mentioned first connecting portions have the same width, forming an electrode assembly 8. In Paragraph 6, An electrode assembly, wherein the width of the second connecting portions gradually increases as it moves away from the side edge of the positive plate, 9. In Paragraph 2, An electrode assembly in which the gap between the inner portions connected by any one of the second connecting portions is greater than the gap between the inner portions connected by the second connecting portion positioned closer to the side end of the anode plate.

10. In Paragraph 1, The above separator includes a first separator end and a second separator end located at the longitudinal end, and An electrode assembly in which the first separator end is located at the end of the portion in contact with the innermost cathode plate, and the second separator end is located at the end of the portion surrounding the outermost anode plate or the cathode plate.

11. In Paragraph 1, The above-mentioned positive plate includes a protruding first tab, the first tabs are stacked to form a first tab bundle, and the electrode assembly includes two first tab bundles, an electrode assembly.

12. An electrode assembly comprising a plurality of alternately arranged positive plates and a plurality of negative plates, and a separator interposed between the positive plates and the negative plates; A case in which the above electrode assembly is accommodated; and It includes a terminal exposed to the outside of the above case, The separator comprises a plurality of inner portions in contact with the anode plate or the cathode plate, and a plurality of connecting portions that connect the inner portions and protrude further than the side edge of the anode plate. A secondary battery in which at least one of the above-mentioned connections is arranged to surround another connection.

13. In Paragraph 12, A secondary battery comprising a plurality of first connecting portions protruding from one end of the inner portion and a plurality of second connecting portions protruding from the other end of the inner portion.

14. In Paragraph 13, A secondary battery in which the second connecting portions are stacked in a direction intersecting the stacking direction of the electrode assembly.

15. In Paragraph 14, The above first connecting portion is a secondary battery spaced apart with the positive plate or the negative plate in between.

16. In a method for manufacturing an electrode assembly, An electrode stacking step comprising folding a separator in a zigzag shape and arranging a plurality of positive plates and a plurality of negative plates between the separators to form a laminate, wherein a plurality of positive plates are arranged in one layer of the laminate, and a plurality of negative plates are arranged in a layer above or below the layer where the positive plates are arranged; A pressing step for pressing the above laminate; and A method for manufacturing an electrode assembly, comprising a folding step of folding the above-mentioned laminate to form an electrode assembly.

17. In Paragraph 16, A method for manufacturing an electrode assembly, wherein the above-described laminate comprises a first stack in which the positive plate and the negative plate are alternately stacked, and a second stack disposed next to the first stack in which the positive plate and the negative plate are alternately stacked.

18. In Paragraph 17, A method for manufacturing an electrode assembly, wherein the electrode stacking step comprises forming the stack on a first support and a second support, wherein the first stack is stacked on the first support and the second stack is stacked on the second support.

19. In Paragraph 17, The above positive plate has a first tab, and the above negative plate has a second tab, and A method for manufacturing an electrode assembly, wherein in the electrode stacking step, a first tab protruding from an anode plate placed in the first stack is spaced apart at a predetermined interval from one side end of the anode plate, and a first tab protruding from an anode plate placed in the second stack is spaced apart at the opposite side end of the anode plate by the same interval.

20. In Paragraph 17, The above positive plate has a first tab, and the above negative plate has a second tab, and A method for manufacturing an electrode assembly, wherein in the electrode stacking step, a first tab protruding from an anode plate placed in the first stack is spaced apart by a first distance from one side end of the anode plate, and a first tab protruding from an anode plate placed in the second stack is spaced apart by a second distance longer than the first distance from the side end opposite one side end of the anode plate.

21. In Paragraph 17, A method for manufacturing an electrode assembly in which the first stack is formed higher than the second stack.

22. In Paragraph 17, A method for manufacturing an electrode assembly, wherein the first stack comprises a greater number of layers than the second stack.

23. In Paragraph 16, A method for manufacturing an electrode assembly in which the electrode stacking step comprises placing only one positive plate or a negative plate on the top of the stack.

24. In Paragraph 16, A method for manufacturing an electrode assembly, wherein the electrode stacking step comprises a first alignment step of arranging two positive plates side by side on the separator, a first cover step of folding the separator to cover the positive plates, a second alignment step of arranging two negative plates side by side on the separator covering the positive plates, and a second cover step of folding the separator to cover the negative plates.

25. In Paragraph 16, A method for manufacturing an electrode assembly, wherein the electrode stacking step is located at the bottom and the electrode plates are stacked such that the gap between the parallel electrode plates is formed to be larger than the gap between the electrode plates located at the top.

26. In Paragraph 16, A method for manufacturing an electrode assembly, wherein in the folding step, the gap between the separators connected to each other at one end of the electrode assembly is uniform, and the gap between the separators connected to each other at the other end of the electrode assembly is formed larger in the outer portion in the thickness direction of the electrode assembly than in the inner portion in the thickness direction of the electrode assembly.

27. In Paragraph 16, A method for manufacturing an electrode assembly, wherein in the folding step, first connecting portions connecting a separator at one end of the electrode assembly are spaced apart in the thickness direction of the electrode assembly without overlapping, and second connecting portions connecting a separator at the other end of the electrode assembly are overlapped.

28. In Paragraph 16, In the above folding step, the first length of the first connecting portion connecting the separators at one side end of the electrode assembly is uniformly formed, and A method for manufacturing an electrode assembly, wherein the second length of a second connecting portion connecting a separator at the other end of the electrode assembly is formed such that the outer portion in the thickness direction of the electrode assembly is longer than the inner portion in the thickness direction of the electrode assembly.

29. In Paragraph 16, The above stacking step is a method for manufacturing an electrode assembly in which a support roller is placed on a separator on which an anode plate or a cathode plate is placed to support the separator and then the separator is folded.

30. In Paragraph 16, A method for manufacturing an electrode assembly, wherein the above folding step involves folding a laminate using a folding device having a first folding plate and a second folding plate, and rotating the first folding plate and the second folding plate so that they are erected while the laminate is positioned on the first folding plate and the second folding plate.

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