Secondary battery and method for manufacturing secondary battery

Abstract

A secondary battery according to one aspect of the present invention comprises: a current-collecting assembly including a current-collecting plate holder, which is made of an insulating material, a first current-collecting plate, which is coupled to an upper portion of one side of the current-collecting plate holder and in which a plurality of first slits and a first connection terminal are formed, and a second current-collecting plate, which is coupled to an upper portion of the other side of the current-collecting plate holder and in which a plurality of second slits and a second connection terminal are formed; a plurality of first electrode tabs including a first foil tab group and a second foil tab group; and a cap assembly in which are positioned a first electrode terminal and a second electrode terminal electrically connected to the first current-collecting plate and the second current-collecting plate, respectively, wherein the first foil tab group and the second foil tab group are respectively inserted into the plurality of first slits and coupled to the inner surfaces of the first slits.

Description

Secondary battery and method for manufacturing a secondary battery

[0001] This application claims priority to Korean Patent Application No. 10-2025-0010078 filed on January 23, 2025, the entire disclosure of said application is incorporated herein by reference.

[0002] The present invention relates to a secondary battery and a method for manufacturing a secondary battery.

[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] Among them, lithium secondary batteries primarily use lithium-based oxides and carbon materials as positive and negative active materials, respectively. In addition, lithium secondary batteries are equipped with 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.

[0005] Meanwhile, lithium secondary batteries can be classified according to the shape of the battery case into can-type secondary batteries, in which the electrode assembly is embedded in a metal can, and pouch-type secondary batteries, in which the electrode assembly is embedded in a pouch of aluminum laminate sheets. Furthermore, can-type secondary batteries can be further classified into cylindrical batteries and prismatic batteries depending on the shape of the metal can.

[0006] In the manufacturing of secondary batteries, a process is carried out in which multiple electrode tabs connected to electrode plates are welded to a current collector plate. The current collector plate with the welded electrode tabs is connected to the terminals of the cap assembly.

[0007] Multiple electrode tabs are attached to the lower or upper surface of a current collector plate to be coupled thereto. However, if the electrode tabs are attached to the lower surface of the current collector plate, the distance between the electrode assembly and the current collector plate increases, which reduces the energy density of the secondary battery; conversely, if the electrode tabs are attached to the upper surface of the current collector plate, the length of the electrode tabs increases, which causes a problem of increased resistance.

[0008] Furthermore, although the positive and negative current collector plates, to which the electrode tabs are attached, are individually coupled to the cap assembly, connection to the terminals is difficult if either of the plates is not aligned with the coupling position of the cap assembly. In this case, since the plates are already welded to the electrode tabs, it is difficult to adjust their position, resulting in poor assemblability with the cap assembly.

[0009] The objective of the present invention is to provide a secondary battery and a method for manufacturing the same, wherein the current collector plate is integrated to improve assemblability with a cap assembly.

[0010] Another objective of the present invention is to provide a secondary battery capable of reducing resistance to current by reducing the length of the electrode tab, and a method for manufacturing the same.

[0011] A secondary battery according to one aspect of the present invention comprises: a plurality of first electrode tabs each coupled to a plurality of first electrodes and including a first foil tab group and a second foil tab group; a plurality of second electrode tabs each coupled to a plurality of second electrodes and including a third foil tab group and a fourth foil tab group; a current collector holder formed of an insulating material having a first hole formed on one side and a second hole formed on the other side; a first current collector plate coupled to the upper side of the current collector holder and having a plurality of first slits formed vertically connected to the first hole and a first connection terminal formed therein; a second current collector plate coupled to the upper side of the other side of the current collector holder and having a plurality of second slits formed vertically connected to the second hole and a second connection terminal formed therein; a current collector assembly comprising a first electrode terminal and a second electrode terminal positioned to be electrically connected to the first current collector plate and the second current collector plate, respectively, wherein the first foil tab group and the second foil tab group are each inserted into the plurality of first slits and the It is coupled to the inner surface of the first slit.

[0012] The above plurality of first slits may be spaced apart from each other in the width direction.

[0013] The plurality of first slits may be spaced apart by the same distance from the center in the width direction of the first collector plate.

[0014] The above first hole may be formed in multiple numbers.

[0015] The lower surface of the above-mentioned collector plate holder may be inclined toward the plurality of first holes.

[0016] The corner where the lower surface of the above-mentioned collector plate holder meets the inner surface of the plurality of first holes can be rounded.

[0017] Each of the plurality of first slits may include a slit inclined section connected to the first hole and formed at an angle with respect to the lower surface of the first collector plate, and a slit vertical section connected to the slit inclined section and formed perpendicularly to the lower surface of the first collector plate.

[0018] The vertical section of the slit above may be offset from the first hole above and below.

[0019] The above plurality of first slits can be formed in different rows.

[0020] A first cut may be formed on one side in the width direction of the first collector plate.

[0021] The first incision above can be connected to the plurality of first slits in the longitudinal direction.

[0022] The first foil tab group and the second foil tab group, each inserted into the plurality of first slits, may be oriented in a direction perpendicular to the upper surface of the first collector plate.

[0023] The first foil tab group and the second foil tab group may be placed in different columns.

[0024] The above cap assembly may further include a cap plate having a first terminal hole into which the first connection terminal is inserted and a second terminal hole into which the second connection terminal is inserted.

[0025] The distance between the first connection terminal and the second connection terminal may be the same as the distance between the first terminal hole and the second terminal hole.

[0026] A method for manufacturing a secondary battery according to one aspect of the present invention comprises: an insertion step of inserting the first foil tab group and the second foil tab group into the plurality of first slits, respectively; a cutting step of cutting the first foil tab group and the second foil tab group protruding above the first current collector plate; a welding step of welding the first foil tab group and the second foil tab group to the inner surface of the first slit; and an assembly step of inserting the first connecting terminal into the first terminal hole to combine the current collector assembly and the cap assembly.

[0027] In the above welding step, a welding line can be formed across the first slit in the width direction.

[0028] According to one aspect of the present invention, the current collector plate is integrated to improve assemblability with the cap assembly.

[0029] According to one aspect of the present invention, the resistance to current can be reduced by reducing the length of the electrode tab.

[0030] FIG. 1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention.

[0031] FIG. 2 is a perspective view showing a disassembled state of a part of the secondary battery of FIG. 1.

[0032] FIG. 3 is a perspective view illustrating the state in which the electrode tabs are connected.

[0033] FIG. 4 is a perspective view showing the configuration of a current collection assembly in a disassembled state.

[0034] Figure 5 is a top view of the first collector plate as seen from above.

[0035] Figure 6 is a cross-sectional view illustrating the state before the electrode tab is inserted.

[0036] Figure 7 is a cross-sectional view of a current collection assembly.

[0037] FIG. 8 is a cross-sectional view illustrating the state in which the electrode tab is inserted.

[0038] Figure 9 is a cross-sectional view illustrating the state in which the electrode tab is cut.

[0039] FIGS. 10a and FIGS. 10b are cross-sectional views illustrating the state in which an electrode tab of a secondary battery is inserted according to a second embodiment of the present invention.

[0040] FIG. 11 is a modified example of the current collection assembly of FIG. 10.

[0041] FIG. 12 is a cross-sectional view illustrating a current collection assembly of a secondary battery according to a third embodiment of the present invention.

[0042] FIG. 13 is a cross-sectional view illustrating the state in which the electrode tab is welded.

[0043] FIG. 14 is a perspective view showing the disassembled configuration of a current collection assembly of a secondary battery according to the fourth embodiment of the present invention.

[0044] FIG. 15 is a perspective view illustrating a current collection assembly of a secondary battery according to the fifth embodiment of the present invention.

[0045] FIGS. 16a to 16c are top views of electrode tabs being inserted into a current collection assembly.

[0046] FIG. 17 is a block diagram showing a method for manufacturing a secondary battery according to a first embodiment of the present invention.

[0047] Figures 18a and 18b are drawings illustrating the insertion step of Figure 17.

[0048] Figures 19a and 19b are drawings showing the cutting steps of Figure 17.

[0049] Figure 20 is a drawing showing the welding steps of Figure 17.

[0050] FIG. 21 is a perspective view illustrating a battery module including the secondary battery of FIG. 1.

[0051] FIG. 22 is a perspective view illustrating a battery pack including the battery module of FIG. 21.

[0052] 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.

[0053] 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.

[0054] In this specification, "length direction" means the ±x direction of FIG. 2, "width direction" means the ±y direction of FIG. 2, and "height direction" means the ±z direction of FIG. 2.

[0055] 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.

[0056] Hereinafter, a secondary battery according to the first embodiment of the present invention will be described.

[0057] FIG. 1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention, FIG. 2 is a perspective view illustrating a partially disassembled configuration of the secondary battery of FIG. 1, and FIG. 3 is a perspective view illustrating a state in which an electrode tab is coupled.

[0058] Referring to FIGS. 1 to 3, a secondary battery (10) according to a first embodiment of the present invention comprises an electrode assembly (300) in which a separator (350) is interposed between a first electrode (310) and a second electrode (330), a current collection assembly (500) electrically connected to the electrode assembly (300), a case (100) in which the electrode assembly (300) is accommodated, and a cap assembly (700) that seals the case (100).

[0059] The electrode assembly (300) can be formed by interposing a separator (350) between the first electrode (310) and the second electrode (330) that are alternately arranged. That is, the separator (350) is positioned between the first electrode (310) and the second electrode (330), and the electrode assembly (300) can be formed by alternately stacking the first electrode (310), the separator (350), the second electrode (330), and the separator (350). Here, the first electrode (310) and the second electrode (330) may be positive and negative electrodes, respectively, and conversely, the first electrode (310) and the second electrode (330) may be electrodes of different polarities, such as negative and positive electrodes, respectively.

[0060] The first electrode (310) and the second electrode (330) may include an electrode active portion (311, 331), which is an area where an active material is applied to a thin plate formed of a metal foil, and an electrode tab (313, 333), which is an area where an active material is not applied.

[0061] The first electrode active part (311) may have an active material such as a transition metal oxide coated on a metal foil such as aluminum, and the second electrode active part (331) may have an active material such as graphite or carbon coated on a metal foil such as copper or nickel.

[0062] The first electrode tab (313) may protrude to one side of the first electrode active portion (311), and the second electrode tab (333) may protrude to one side of the second electrode active portion (331). At this time, the first electrode tab (313) and the second electrode tab (333) may protrude in parallel toward the cap assembly (700). Alternatively, the first electrode tab (313) and the second electrode tab (333) may protrude in different directions.

[0063] The first electrode tab (313) and the second electrode tab (333) are formed by cutting so as to protrude from the metal foil, so they can be formed integrally with the metal foil of the first electrode active part (311) and the second electrode active part (331), respectively.

[0064] The first electrode tab (313) and the second electrode tab (333) can be spaced apart with different polarities.

[0065] Each of the first electrode tab (313) and the second electrode tab (333) is formed by overlapping a plurality of thin films, and can be connected so that the thin films come into contact with each other using ultrasonic welding, laser welding, etc., to facilitate the movement of current.

[0066] The separator (350) is positioned between the first electrode (310) and the second electrode (330), more specifically between the first electrode active portion (311) and the second electrode active portion (331), to prevent short circuits between them and to enable the movement of ions. For example, the separator (350) may be made of various materials such as polyethylene, polypropylene, or a composite film thereof.

[0067] Meanwhile, the electrode assembly (300) can be wrapped with an insulating film or insulating tape to be insulated from the case (100). The insulating film or insulating tape may be made of a material that has excellent insulating performance even at high temperatures, such as polypropylene or polyimide.

[0068] In this embodiment, the electrode assembly (300) may be formed by winding the first electrode (310) and the second electrode (330) (wound type), or by overlapping the first electrode (310) and the second electrode (330) parallel to each other (stack type).

[0069] In addition, in this embodiment, one electrode assembly (300) can be accommodated in one case (100). That is, each electrode assembly (300) can be accommodated in each case (100). By doing so, each electrode assembly (300) is individually protected, thereby reducing the risk of short circuits with other electrode assemblies (300) and heat accumulation, which can prevent the risk of thermal runaway. However, it is not necessarily limited to this, and multiple electrode assemblies (300) can be accommodated in one case (100).

[0070] The current collection assembly (500) includes a current collection plate holder (550) formed of an insulating material, a first current collection plate (510) coupled to the upper side of one side of the current collection plate holder (550), and a second current collection plate (530) coupled to the upper side of the other side of the current collection plate holder (550). The current collection assembly (500) is formed by connecting the respective separated current collection plates (510, 530) through the current collection plate holder (550) to form an integrated structure, and is used as a single current collection component.

[0071] An insulating current collector plate holder (550) can connect current collector plates (510, 530) of different polarities so that they are maintained at a set interval, and at the same time prevent short circuits between different electrodes (310, 330) in an integrated current collector assembly (500).

[0072] A first current collector plate (510) is attached to the upper side of one end in the longitudinal direction (x direction) of the current collector plate holder (550), and a second current collector plate (530) is attached to the upper side of the other end. Each current collector plate (510, 530) may be attached to the current collector plate holder (550) using an adhesive, adhesive tape, etc. Alternatively, each current collector plate (510, 530) may be formed integrally with the current collector plate holder (550) using an insert injection method.

[0073] The first collector plate (510) and the second collector plate (530) may be spaced apart from each other in the longitudinal direction (x direction) at the top of the collector plate holder (550). The first collector plate (510) and the second collector plate (530) may be formed in the shape of a rectangle with a width (y direction) equal to or smaller than that of the collector plate holder (550).

[0074] Unlike the collector plate holder (550) coupled to the bottom, the first collector plate (510) and the second collector plate (530) can be manufactured from a conductive material. Accordingly, the first collector plate (510) can electrically connect the first electrode terminal (710) exposed to the outside of the cap assembly (700) and the first electrode tab (313) to each other, and the second collector plate (530) can electrically connect the second electrode terminal (730) exposed to the outside of the cap assembly (700) and the second electrode tab (333) to each other.

[0075] A first slit (511) and a second slit (531) are formed in the first collector plate (510) and the second collector plate (530), respectively, and each slit (511, 531) is connected vertically to a first hole (551, see FIG. 4) and a second hole (553, see FIG. 4) formed in the collector plate holder (550).

[0076] The first electrode tab (313) is inserted into the first hole (551, see FIG. 4) and the first slit (511), and the second electrode tab (333) is inserted into the second hole (553, see FIG. 4) and the second slit (531).

[0077] The first electrode tab (313) inserted into the first slit (511) is coupled to the inner surface in the width direction (y direction) of the first slit (511). The first electrode tab (313) is provided in plurality, and some of the plurality of first electrode tabs (313) may be coupled to the inner surface in the width direction (y direction) of the first slit (511).

[0078] The second electrode tab (333) inserted into the second slit (531) is also coupled to the inner surface in the width direction (y direction) of the second slit (531). The second electrode tab (333) is also provided in multiple numbers, and some of the multiple second electrode tabs (333) may be coupled to the inner surface in the width direction (y direction) of the second slit (531).

[0079] The electrode tabs (313, 333) can be joined to the current collector plates (510, 530) by welding, and the welding can be laser welding, ultrasonic welding, etc.

[0080] The electrode tabs (313, 333) can be directly welded with their upper portions exposed to the slits (511, 531), but alternatively, welding can be performed by placing a metal plate over the slits (511, 531).

[0081] In some cases, insulating tape or insulating film, etc., may cover the welded area. As a result, the electrode tab (313, 333) welded to the inner surface of the slit (511, 531) can be insulated from the cap assembly (700). That is, as described below, the electrode tab (313, 333) is electrically connected to the electrode terminal (710, 730) through the current collector plate (510, 530), and direct contact with the cap assembly (700) can be blocked. At this time, the insulating tape or insulating film may be made of a material that has excellent insulating performance even at high temperatures, such as polypropylene or polyimide.

[0082] When the electrode tabs (313, 333) are coupled to the current collector plates (510, 530), each electrode (310, 330) can be electrically connected to the current collector plates (510, 530).

[0083] The first current collector plate (510) and the second current collector plate (530) can be electrically connected to the first electrode terminal (710) and the second electrode terminal (730), respectively. When the current collector plates (510, 530) are connected to the electrode terminals (710, 730), respectively, the respective electrodes (310, 330) can be electrically connected to the respective electrode terminals (710, 730).

[0084] Meanwhile, the current collector plate (510, 530) can be connected to each electrode terminal (710, 730) through the connection terminal (513, 533).

[0085] The first connection terminal (513) can be coupled to the upper surface of the first collector plate (510). The first connection terminal (513) may be located approximately in the center of the first collector plate (510), but is not limited thereto and may be located off-center on one side in the width direction (y-direction) of the first collector plate (510). The first connection terminal (513) may be formed integrally with the first collector plate (510) in a column shape. The first connection terminal (513) can be inserted into the first terminal hole (711) to electrically connect the first collector plate (510) and the first electrode terminal (710). When the first collector plate (510) and the first electrode terminal (710) are electrically connected, the first electrode (310) and the first electrode terminal (710) can be electrically connected.

[0086] The second connection terminal (533) can be coupled to the upper surface of the second collector plate (530). The second connection terminal (533) may be located approximately in the center of the second collector plate (530), but is not limited thereto and may be located off-center on one side in the width direction (y-direction) of the second collector plate (530). The second connection terminal (533) may be formed integrally with the second collector plate (530) in a column shape. The second connection terminal (533) can be inserted into the second terminal hole (731) to electrically connect the second collector plate (530) and the second electrode terminal (730). When the second collector plate (530) and the second electrode terminal (730) are electrically connected, the second electrode (330) can be electrically connected to the second electrode terminal (730).

[0087] The distance (D1) between the first connection terminal (513) and the second connection terminal (533) may be the same as the distance (D2) between the first terminal hole (711) and the second terminal hole (731). Since each connection terminal (513, 533) is integrated into the current collection assembly (500) and its position is constrained, when the first connection terminal (513) is aligned with the position of the first terminal hole (711), the second connection terminal (533) can also be aligned with the position of the second terminal hole (731).

[0088] Accordingly, since the current collector plate (510, 530) and the cap assembly (700) can be connected by aligning only one of the connection terminals (513, 533) to the corresponding terminal hole without individually adjusting the position of each connection terminal (513, 533), each connection terminal (513, 533) can be simultaneously aligned to the corresponding terminal hole (711, 731). As a result, the assembly efficiency of the current collector plate (510, 530) and the cap assembly (700) can be improved.

[0089] The specific structure of the other current collection assembly (500) will be described later.

[0090] The cap assembly (700) seals the opening of the case (100) in which the electrode assembly (300) is accommodated inside, and may include a cap plate (750), a first electrode terminal (710), and a second electrode terminal (730).

[0091] The cap plate (750) may be in the shape of a plate covering the opening of the case (100). The cap plate (750) may have a shape corresponding to the shape of the opening of the case (100). The cap plate (750) may be formed of the same material as the case (100), and the cap plate (750) may be fixed to the case (100) by laser welding.

[0092] The cap plate (750) may be formed with an electrolyte injection port (770) for injecting an electrolyte, a first terminal hole (711) into which a first connection terminal (513) is inserted, a second terminal hole (731) into which a second connection terminal (533) is inserted, and a vent hole (740) that opens when the pressure inside the case (100) exceeds a predetermined pressure value. However, the location of the vent hole (740) is not necessarily limited thereto and may be formed on one side of the case (100), for example, on the side or bottom surface of the case (100).

[0093] The first electrode terminal (710) and the second electrode terminal (730) may be formed protruding from the cap plate (750). The first electrode terminal (710) may be electrically connected to the first electrode (310) through the first current collector plate (510), and the second electrode terminal (730) may be electrically connected to the second electrode (330) through the second current collector plate (530).

[0094] The first electrode terminal (710) and the second electrode terminal (730) may be formed in the shape of a circular or square plate. These first electrode terminal (710) and the second electrode terminal (730) may be connected to a busbar, etc.

[0095] A first insulating member (not shown) is disposed between the first electrode terminal (710) and the cap plate (750) so that the first electrode terminal (710) and the cap plate (750) can be insulated from each other. Additionally, a second insulating member (not shown) is disposed between the second electrode terminal (730) and the cap plate (750) so that the second electrode terminal (730) and the cap plate (750) can be insulated from each other.

[0096] The case (100) forms the exterior of the secondary battery (10), and a space is formed inside to accommodate an electrode assembly (300), and an opening may be formed on one side. The case (100) may have a rectangular shape and may be made of a rigid material capable of protecting the electrode assembly (300) accommodated inside. For example, the case (100) may be made of a metal such as aluminum or stainless steel.

[0097] An electrolyte may be accommodated together with an electrode assembly (300) inside the case (100). The electrolyte may consist of a lithium salt such as LiPF6, LiBF4 in an organic solvent such as EC, PC, DEC, EMC, or DMC. The electrolyte may be in a liquid, solid, or gel form.

[0098] Meanwhile, a battery module (M) can be configured by including a plurality of secondary batteries (10) according to the present embodiment (see FIG. 21). A plurality of secondary batteries (10) can be connected to each other by a busbar (B), etc. to form a battery module (M). Additionally, a battery pack (P) can be configured by including a plurality of battery modules (M) (see FIG. 22). A battery pack (P) can be configured by arranging a plurality of battery modules (M) within an upper pack housing (VC) and a lower pack housing (LC) that constitute a pack housing (C). Furthermore, the battery pack (P) can be provided to a means of transport that moves cargo, people, etc., or performs work while moving. Such means of transport may include bicycles, heavy equipment, agricultural and fishing equipment, automobiles, buses, airplanes, etc. Here, the automobile may be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The automobile may include a four-wheeled or two-wheeled vehicle. The means of transport may operate by receiving power from the battery pack (P).

[0099] FIG. 4 is a perspective view showing the configuration of a current collection assembly in a disassembled state, FIG. 5 is a top view of the first current collection plate viewed from above, and FIG. 6 is a cross-sectional view showing the state before the electrode tab is inserted. FIG. 7 is a cross-sectional view of the current collection assembly, FIG. 8 is a cross-sectional view showing the state with the electrode tab inserted, and FIG. 9 is a cross-sectional view showing the state with the electrode tab cut.

[0100] As illustrated in FIGS. 4 and 5, the current collection assembly (500) includes a current collection plate holder (550) formed of an insulating material, a first current collection plate (510) coupled to one side of the current collection plate holder (550), and a second current collection plate (530) coupled to the other side of the current collection plate holder (550).

[0101] The current collector holder (550) may be formed by extending in the length direction (x direction). The current collector holder (550) may be manufactured in the shape of a rectangle in which the length (x direction) is longer than the width (y direction). The width (y direction) of the current collector holder (550) may be equal to or smaller than the width (y direction) of the electrode assembly (300). The length (x direction) of the current collector holder (550) may also be equal to or smaller than the length (x direction) of the electrode assembly (300).

[0102] The current collector holder (550) is formed from an insulating material, such as plastic or silicone rubber. The current collector holder (550) can be formed by processing the insulating material or by injection molding.

[0103] A first hole (551) configured to allow the insertion of a first electrode tab (313) is formed on one side in the longitudinal direction (x direction) of the current collector plate holder (550), and a second hole (553) configured to allow the insertion of a second electrode tab (333) is formed on the other side in the longitudinal direction (x direction). The length (L2) of the first hole (551) and the second hole (553) may be equal to or slightly larger than the length (L) of the first electrode tab (313) and the second electrode tab (333), respectively.

[0104] A first current collector plate (510) is attached to the upper side of one end in the longitudinal direction (x direction) of the current collector plate holder (550), and a second current collector plate (530) is attached to the upper side of the other end.

[0105] As described above, a first slit (511x, 511y) is formed in the first collector plate (510), and a second slit (531x, 531y) is formed in the second collector plate (530).

[0106] The first slits (511x, 511y) and the second slits (531x, 531y) are each formed in multiple numbers. The multiple first slits (511x, 511y) are connected vertically to the first hole (551). The multiple first electrode tabs (313) are inserted into the first hole (551) and the multiple first slits (511x, 511y). The multiple second slits (531x, 531y) are also connected vertically to the second hole (553), and the multiple second electrode tabs (333) are inserted into the second hole (553) and the multiple second slits (531x, 531y). To this end, the length (L1) of the first slit (511x, 511y) and the second slit (531x, 531y) may be equal to or slightly larger than the length (L2) of the first hole (551) and the second hole (553), respectively.

[0107] A plurality of first slits (511x, 511y) may be spaced apart from each other in the width direction (y direction). Specifically, a plurality of first slits (511x, 511y) may be spaced apart by the same distance from the width direction center (X) of the first collector plate (510).

[0108] A plurality of second slits (531x, 531y) can also be spaced apart from each other in the width direction (y direction) and can be spaced apart by the same distance from the center in the width direction of the second collector plate (530).

[0109] Accordingly, a plurality of first slits (511x, 511y) can be formed at equal distances from both ends in the width direction (y direction) of the first collector plate (510), and a plurality of second slits (531x, 531y) can also be formed at equal distances from both ends in the width direction (y direction) of the second collector plate (530). As a result, each electrode tab (313, 333) can be inserted into each slit (511x, 511y, 531x, 531y) without being biased to one side in the width direction (y direction).

[0110] In this embodiment, the structure of the first electrode tab (313) and the first current collector plate (510) can be applied in the same way to the second electrode tab (333) and the second current collector plate (530). Below, the structure of the first electrode tab (313), the current collector plate holder (550), and the first current collector plate (510) is described as an example, and redundant descriptions of the second electrode tab (333) and the second current collector plate (530) are omitted.

[0111] Referring to FIG. 6, the first electrode tabs (313) may be provided in plurality. The plurality of first electrode tabs (313) may be gathered at the center in the width direction (y direction) and inserted sequentially into the first hole (551) and the first slit (511x, 511y).

[0112] More specifically, a plurality of first electrode tabs (313) may include a first foil tab group (313a) and a second foil tab group (313b). The first foil tab group (313a) is inserted into a first slit (511x, 511y) of one of (e.g., 511x), and the second foil tab group (313b) is inserted into a first slit (511x, 511y) of the other of (e.g., 511y).

[0113] As illustrated in FIG. 7, the inner surface (511xa, 511ya) of the first slit (511x, 511y) may have a cross-section perpendicular to the lower surface of the first collector plate (510). Additionally, the facing inner surface (551a) of the first hole (551) may also have a cross-section perpendicular to the upper surface of the collector plate holder (550).

[0114] The inner surface (511xa, 511ya) of the first slit (511x, 511y) and the inner surface (551a) of the first hole (551) can be connected continuously. For example, the inner surface (511xa, 511ya) of the first slit (511x, 511y) and the inner surface (551a) of the first hole (551) can be connected in a straight line without forming a step.

[0115] According to this, since the first foil tab group (313a, see FIG. 6) and the second foil tab group (313b, see FIG. 6) inserted into the first hole (551) can both pass through the first slit (511x, 511y), the process of inserting the first foil tab group (313a, see FIG. 6) and the second foil tab group (313b, see FIG. 6) into the plurality of first slits (511x, 511y) can be made easier.

[0116] Referring to FIGS. 8 and 9, the inserted first foil tab group (313a) and second foil tab group (313b) may have an upper portion (E) protruding above the first collector plate (510). The protruding upper portion (E) may be cut at a height similar to the upper surface of the first collector plate (510). As a result, the first foil tab group (313a) and the second foil tab group (313b) may have a height similar to the upper surface of the first collector plate (510). That is, after cutting, the height of the first foil tab group (313a) and the second foil tab group (313b) may be the same as the height of the upper surface of the first collector plate (510), or may be slightly higher or slightly lower than the upper surface of the first collector plate (510).

[0117] The cut first foil tab group (313a) and the second foil tab group (313b) may have ends perpendicular to the upper surface of the first collector plate (510). That is, the first foil tab group (313a) inserted into the first slit (511x, see FIG. 7) may face a direction perpendicular to the upper surface of the first collector plate (510), and the second foil tab group (313b) inserted into the second slit (511y, see FIG. 7) may face a direction perpendicular to the upper surface of the first collector plate (510).

[0118] In this state, the first foil tab group (313a) is joined to the inner surface (511xa) of the first slit, and the second foil tab group (313b) is joined to the inner surface (511ya) of the first slit. The first foil tab group (313a) and the second foil tab group (313b) can be welded to the inner surfaces (511xa, 511ya) of the first slit.

[0119] To explain in more detail with respect to the first foil tab group (313a), a portion of the first foil tab group (313a) adjacent to the inner surface (511xa) of the first slit may be welded to the inner surface (511xa) of the first slit. The remaining portion of the first foil tab group (313a) may be welded to the portion of the first foil tab group (313a) that is welded to the inner surface (511xa).

[0120] The second foil tab group (313b) can also be welded to the inner surface (511ya) of the first slit in the same way. As a result, the first foil tab group (313a) and the second foil tab group (313b) are each joined to the inner surfaces (511xa, 511ya) of the first slit and can be electrically connected to the first current collector plate (510).

[0121] At this time, welding energy can be irradiated from the upper part of the first collector plate (510) toward the first collector plate (510) (see FIG. 13). The welding energy can cross the first slit (511x, 511y) in the width direction (y direction) to form a welding line in the width direction (y direction) (see FIG. 20).

[0122] The welding line may be parallel to the width direction (y direction), but is not necessarily limited thereto, and may be formed in a pattern that crosses the width (y direction) of the first slit (511x, 511y) at various angles, such as a diagonal shape or a V shape.

[0123] In the case of this embodiment, the first electrode tab (313) penetrates the current collection assembly (500) vertically. Accordingly, the length (H, see FIG. 4) of the first electrode tab (313) can be made short, thereby reducing resistance and heat generation due to current, and effectively improving the heat generation problem.

[0124]

[0125] Hereinafter, a secondary battery according to the second embodiment of the present invention will be described.

[0126] FIGS. 10a and FIGS. 10b are cross-sectional views illustrating the state in which an electrode tab of a secondary battery is inserted according to a second embodiment of the present invention.

[0127] Since the secondary battery according to the second embodiment of the present invention has the same structure as the first embodiment described above, except for the current collector holder (550), a redundant description of the repeated configuration is omitted.

[0128] Referring to FIG. 10a, a plurality of first holes (551x, 551y) may be formed in the collector plate holder (550). Accordingly, a plurality of first slits (511x, 511y) may each be connected vertically to a plurality of first holes (551x, 551y).

[0129] Specifically, a plurality of first holes (551x, 551y) may be formed spaced apart from each other in the width direction (y direction), and the spacing between the plurality of first holes (551x, 551y) may be the same as the spacing between the plurality of first slits (511x, 511y). Accordingly, a first slit (511x, 511y) of one (e.g., 511x) may be located above a first hole (551x, 551y) of one (e.g., 511x), and a first slit (511x, 511y) of another (e.g., 511y) may be located above a first hole (551x, 551y) of the other (e.g., 551y).

[0130] The lower surface of the collector plate holder (550) can be formed to be inclined toward a plurality of first holes (551x, 551y).

[0131] Specifically, the lower surface of the collector plate holder (550) can be tilted toward adjacent first holes (551x, 551y) at each end in the width direction (y direction). Accordingly, the thickness of the collector plate holder (550) can gradually decrease as it approaches the adjacent first holes (551x, 551y) at each end in the width direction (y direction).

[0132] Between the multiple first holes (551x, 551y), the lower surface of the collector plate holder (550) can be symmetrically inclined toward the first holes (551x) and the first holes (551y). That is, in this area, the lower surface of the collector plate holder (550) can be inclined in an approximately 'V' shape.

[0133] The inclined lower surface of the collector plate holder (550) can guide the first electrode tab (313) toward a plurality of first holes (551x, 551y).

[0134] Specifically, as illustrated in FIG. 10a, when the current collection assembly (500) is lowered toward the first electrode tab (313), it can sequentially come into contact with the lower surface of the current collection plate holder (550), starting from the first electrode tab (313) located at the end in the width direction (y direction). As illustrated in FIG. 10b, when the current collection assembly (500) is lowered further, the first electrode tab (313) can be guided into a plurality of first holes (551x, 551y) by the inclined lower surface of the current collection plate holder (550). Subsequently, other first electrode tabs (313) adjacent to the inner side in the width direction (y direction) can sequentially come into contact with the lower surface of the current collection plate holder (550) and be sequentially guided into a plurality of first holes (551x, 551y). In the same manner as above, the first foil tab group (313a) can be guided by the inclined lower surface of the collector plate holder (550) and inserted into the first hole (551x) and the first slit (511x), and the second foil tab group (313b) can be guided by the inclined lower surface of the collector plate holder (550) and inserted into the first hole (551y) and the first slit (511y).

[0135] Therefore, in the case of the present embodiment, a separate process of gathering a plurality of first electrode tabs (313) toward the first hole (551x, 551y) is not required, so the manufacturing process of the secondary battery (10) can be simplified.

[0136] FIG. 11 is a modified example of the current collection assembly of FIG. 10a and FIG. 10b.

[0137] As shown in FIG. 11, the corner where the lower surface of the collector plate holder (550) meets the inner surface (551xa, 551ya) of the plurality of first holes (551x, 551y) can be rounded. Accordingly, the lower surface of the collector plate holder (550) and the inner surface (551xa, 551ya) of the plurality of first holes (551x, 551y) can be connected to a curved surface. Specifically, the lower surface of the collector plate holder (550) and the inner surface (551xa, 551ya) of the plurality of first holes (551x, 551y) can be connected to a curved surface that is convex downward.

[0138] The area between the plurality of first holes (551x, 551y) may be formed as a curved surface on the lower surface of the collector plate holder (550). Specifically, the lower surface of the collector plate holder (550) between the plurality of first holes (551x, 551y) may be formed as a downwardly convex curved surface, and may be connected downwardly convexly to the inner surface (551xa, 551ya) of the plurality of first holes (551x, 551y) as described above.

[0139] According to the present variation, the first foil tab group (313a, see FIG. 10b) and the second foil tab group (313b, see FIG. 10b) come into contact with a curved surface, thereby reducing the risk of disconnection, so the electrical stability of the secondary battery (10) can be improved.

[0140]

[0141] A secondary battery according to the third embodiment of the present invention will be described below.

[0142] FIG. 12 is a cross-sectional view illustrating a current collection assembly of a secondary battery according to a third embodiment of the present invention, and FIG. 13 is a cross-sectional view illustrating the state in which an electrode tab is welded.

[0143] The secondary battery according to the third embodiment of the present invention has the same structure as the first embodiment and variations described above, except for the shape of the first slit (511x, 511y), so a redundant description of the same configuration is omitted.

[0144] As shown in FIGS. 12 and 13, the first slit (511x, 511y) may be formed at an angle in some sections.

[0145] Specifically, the first slit (511x) is vertically connected to the first hole (551) and penetrates the first collector plate (510) vertically, and may include a slit inclined section (511x1) and a slit vertical section (511x2).

[0146] The slit inclined section (511x1) can be formed at an angle to the lower surface of the first collector plate (510), and the slit vertical section (511x2) can be formed vertically to the lower surface of the first collector plate (510).

[0147] The slit slope section (511x1) can be connected to the first hole (551) at the bottom and to the slit vertical section (511x2) at the top. That is, the slit slope section (511x1) can be formed at an angle between the first hole (551), which is formed in the vertical direction (z direction), and the slit vertical section (511x2).

[0148] The first slit (511y) may likewise include a slit slope section (511y1) and a slit vertical section (511y2). However, the slit slope section (511y1) of the first slit (511y) may be formed to be sloped in the opposite direction to the slit slope section (511x1) of the first slit (511x).

[0149] The first electrode tab (313) can be inserted sequentially into the first hole (551) and the first slit (511x, 511y) and welded to the inner surface of the slit vertical section (511x2, 511y2).

[0150] Although not illustrated, the corner where the slit slope section (511x1, 511y1) and the slit vertical section (511x2, 511y2) or the first hole (551) meet can be rounded. As a result, the risk of disconnection of the first electrode tab (313) inserted into the first slit (511x, 511y) is reduced, and the electrical stability of the secondary battery (10) can be improved.

[0151] The first hole (551) is formed at the center of the width direction (y direction) of the collector plate holder (550), but the slit vertical section (511x2, 511y2) may be formed offset to one side of the width direction (y direction) of the first collector plate (510).

[0152] For example, the slit vertical section (511x2) may be formed offset in the +y direction from the center of the first collector plate (510), and the slit vertical section (511y2) may be formed offset in the -y direction from the center of the first collector plate (510).

[0153] At this time, the slit vertical section (511x2, 511y2) may be offset vertically from the first hole (551). That is, the slit vertical section (511x2, 511y2) and the first hole (551) may not overlap vertically. When the first collector plate (510) is viewed from above, the slit vertical section (511x2, 511y2) may not overlap with the first hole (551).

[0154] As a result, as shown in FIG. 13, even if welding energy is irradiated vertically on the upper surface of the first current collector plate (510), it does not reach the electrode assembly (300, see FIG. 10b), so damage to the electrode assembly (300, see FIG. 10b) can be prevented during the welding process, and the electrical stability of the secondary battery (10) can be improved.

[0155] Meanwhile, although not illustrated, a plurality of first slits (511x, 511y) may consist only of slit slope sections (511x1, 511y1). In this case, the slit slope sections (511x1, 511y1) may obliquely penetrate the upper and lower surfaces of the first collector plate (510) in opposite directions. A plurality of first electrode tabs (313: 313a, 313b) may be welded to the inner surface of the slit slope sections (511x1, 511y1) while facing in an inclined direction relative to the upper surface of the first collector plate (510).

[0156] However, even in this case, the portion where the multiple first electrode tabs (313: 313a, 313b) are welded may not overlap vertically with the first hole (551). That is, even in this case, the multiple first electrode tabs (313: 313a, 313b) may be welded at positions vertically offset from the first hole (551). As a result, welding energy does not reach the electrode assembly (see FIG. 8), thereby preventing damage to the electrode assembly (300, see FIG. 8) and improving the electrical stability of the secondary battery (10).

[0157] Hereinafter, a secondary battery according to the fourth embodiment of the present invention will be described.

[0158] FIG. 14 is a perspective view illustrating a current collection assembly of a secondary battery according to a fourth embodiment of the present invention.

[0159] The secondary battery according to the fourth embodiment of the present invention is made of the same structure as the first embodiment and variations described above, except for the arrangement structure of the first foil tab group (313a) and the second foil tab group (313b) and the arrangement structure of the plurality of first slits (511x, 511y), so a redundant description of the same configuration is omitted.

[0160] In addition, in this embodiment, the arrangement structure of the third foil tab group (333a) and the fourth foil tab group (333b) and the arrangement structure of the plurality of second slits (531x, 531y) are identical to the arrangement structure of the first foil tab group (313a) and the second foil tab group (313b) and the arrangement structure of the plurality of first slits (511x, 511y), so a redundant description thereof is omitted.

[0161] Referring to FIG. 14, the first foil tab group (313a) and the second foil tab group (313b) may be arranged in different columns. For example, the first foil tab group (313a) and the second foil tab group (313b) may form two different columns.

[0162] Specifically, the first foil tab group (313a) may be arranged in a line along the width direction (y direction), and the second foil tab group (313b) may also be arranged in a line along the width direction (y direction). However, the first foil tab group (313a) and the second foil tab group (313b) may be arranged at different length direction (x direction) positions.

[0163] Accordingly, a plurality of first slits (511x, 511y) may also be formed in different rows. For example, one first slit (511x) may be formed on the upper part of the first foil tab group (313a), and another first slit (511y) may be formed on the upper part of the second foil tab group (313b).

[0164] Accordingly, the first foil tab group (313a) and the second foil tab group (313b) arranged in different columns can be inserted into the first slit (511x) and the first slit (511y), respectively.

[0165] The first foil tab group (313a) can be inserted into the first slit (511x), cut, and then welded to the inner side of the first slit (511x) in the width direction (y direction). The second foil tab group (313b) can also be inserted into the first slit (511y), cut, and then welded to the inner side of the first slit (511y) in the width direction (y direction).

[0166] In the present embodiment, since a plurality of first slits (511x, 511y) are formed in different rows and do not overlap in the width direction (y direction), the width (y direction) of the first slits (511x, 511y) can be designed to be larger. As a result, the first foil tab group (313a) and the second foil tab group (313b) can be easily inserted into the first slits (511x, 511y), thereby improving the efficiency of the insertion process.

[0167]

[0168] Hereinafter, a secondary battery according to the fifth embodiment of the present invention will be described.

[0169] FIG. 15 is a perspective view illustrating a current collection assembly of a secondary battery according to a fifth embodiment of the present invention, and FIG. 16a to 16c are top views taken from above showing an electrode tab being inserted into the current collection assembly.

[0170] The secondary battery according to the fifth embodiment of the present invention has the same structure as the first embodiment and variations described above, except for the method of inserting the electrode tabs (313, 333), so a redundant description of the same configuration is omitted.

[0171] As illustrated in FIG. 15, a portion of the side of the first current collector plate (510) is cut to form a first cut portion (512), and a plurality of first electrode tabs (313) can be inserted into the first cut portion (512) from the side of the first current collector plate (510).

[0172] More specifically, the first collector plate (510) may have one side in the width direction (y direction) cut to form a first cut portion (512). By the first cut portion (512), one side of the first collector plate (510) in the width direction (y direction) may be opened. The first cut portion (512) may be connected to a plurality of first slits (511x, 511y) in the length direction (x direction).

[0173] Referring to FIGS. 16a to 16c for further details, a plurality of first electrode tabs (313) can be inserted into a first cut portion (512) through an open side of the first current collector plate (510). At this time, the first electrode tabs (313) may be inserted into the first cut portion (512) without being gathered together, or they may be inserted into the first cut portion (512) while gathered together.

[0174] A plurality of first electrode tabs (313) inserted into the first incision (512) can be inserted into a plurality of first slits (511x, 511y) by sliding in the longitudinal direction (x direction). Although not illustrated, the first electrode tabs (313) can be easily inserted into the first slits (511x, 511y) by appropriately rotating the current collection assembly (500) clockwise or counterclockwise during this process.

[0175] The first current collector plate (510) may further include a plurality of first slit guides (514x, 514y) that guide a plurality of first electrode tabs (313) inserted into the first incision (512) to a plurality of first slits (511x, 511y), respectively.

[0176] A plurality of first slit guides (514x, 514y) may be located between the plurality of first slits (511x, 511y) and at one end of the first collector plate (510) that is open in the width direction (y direction) of the first collector plate (510).

[0177] Alternatively, although not illustrated, a plurality of first slit guides (514x, 514y) may be formed between the plurality of first slits (511x, 511y) and at both ends in the width direction (y direction) of the first collector plate (510).

[0178] A plurality of first slit guides (514x, 514y) may be formed at an angle toward each first slit (511x, 511y) from the first cut portion (512) or may be rounded.

[0179] A plurality of first electrode tabs (313) inserted into a first cut portion (512) on the side of the first current collector plate (510) can be slid toward a plurality of first slits (511x, 511y) as the current collector assembly (500) moves in the -x direction or the electrode assembly (300) moves in the +x direction. At this time, the sliding plurality of first electrode tabs (313) can be guided by a plurality of first slit guides (514x, 514y) and inserted into each of the plurality of first slits (511x, 511y).

[0180] Specifically, the first electrode tabs (313) of the first foil tab group (313a) can slide along the first slit guide (514x) and be gathered into one to be inserted into the first slit (511x). The first electrode tabs (313) of the second foil tab group (313b) can slide along a plurality of first slit guides (514x, 514y) and be gathered into one to be inserted into the first slit (511y).

[0181] According to the above structure, the combined length (L1) of the first incision (512) and the first slit (511x) can satisfy the relationship L1 > 2L when compared to the length (L) of the first electrode tab (313). That is, the combined length (L1) of the first incision (512) and the first slit (511x) can be greater than twice the length (L) of the first electrode tab (313).

[0182] In the case of the second collector plate (530), the second slit (531x, 531y), the second cut portion (532), and the second slit guide (534x, 534y) may be formed in the same way as the first collector plate (510).

[0183] The first electrode tab (313) and the second electrode tab (333) can be inserted into the first incision (512) and the second incision (532), respectively, at once by moving the current collection assembly (500) in the -y direction or by moving the electrode assembly (300) in the +y direction. Subsequently, the current collection assembly (500) can be inserted into the plurality of first slits (511x, 511y) and the plurality of second slits (531x, 531y), respectively, at once by moving the current collection assembly (500) in the -x direction or by moving the electrode assembly (300) in the +x direction.

[0184] The collector plate holder (550) can be formed to correspond to the structure of the first collector plate (510) and the second collector plate (530). That is, the collector plate holder (550) can have a first hole (551, see FIG. 4), an incision, and a guide formed in a shape corresponding to a plurality of first slits (511x, 511y), a first incision (512), and a plurality of first slit guides (514x, 514y).

[0185] In the case of the present embodiment, since the electrode tabs (313, 333) are inserted through the side of the current collection assembly (500), the process of inserting the electrode tabs (313, 333) into each slit (511, 531) can be facilitated. Accordingly, the manufacturing process of the secondary battery (10) can be simplified.

[0186]

[0187] Hereinafter, a method for manufacturing a secondary battery according to the first embodiment of the present invention will be described.

[0188] FIG. 17 is a block diagram showing a method for manufacturing a secondary battery according to a first embodiment of the present invention, and FIG. 18a and FIG. 18b are diagrams showing the insertion step of FIG. 17. FIG. 19a and FIG. 19b are diagrams showing the cutting step of FIG. 17, and FIG. 20 is a diagram showing the welding step of FIG. 17.

[0189] As illustrated in FIG. 17, a method for manufacturing a secondary battery according to a first embodiment of the present invention comprises an insertion step (S300) of inserting a first foil tab group (313a) and a second foil tab group (313b) into a plurality of first slits (511x, 511y), a cutting step (S500) of cutting the first foil tab group (313a) and the second foil tab group (313b), a welding step (S700) of welding the first foil tab group (313a) and the second foil tab group (313b) to the inner surface of a plurality of first slits (511x, 511y), and an assembly step (S900) of inserting a first connection terminal (513) into a first terminal hole (711) to combine a current collection assembly (500) and a cap assembly (700).

[0190] Referring to FIG. 18a, prior to the insertion step (S300), a receiving step (S100) in which the electrode assembly (300) is received in the case (100) may be performed. Subsequently, the first electrode tab (313) may be gathered towards the center in the width direction (y-direction). However, the receiving step (S100) is not necessarily performed prior to the insertion step (S300). The receiving step (S100) may be performed between the welding step (S700) and the assembly step (S900), which will be described later, or it may be performed after the assembly step (S900).

[0191] As illustrated in FIG. 18b, in the insertion step (S300), the current collection assembly (500) is lowered or the electrode assembly (300) is raised so that the first foil tab group (313a) is inserted sequentially into the first hole (551) and the first slit (511x), and the second foil tab group (313b) is inserted sequentially into the first hole (551) and the first slit (511y). In this case, the current collection assembly (500) is spaced apart from the electrode assembly (300) by a predetermined distance vertically and is positioned on the upper part of the electrode assembly (300).

[0192] However, the first foil tab group (313a) and the second foil tab group (313b) are not necessarily inserted in a manner where the current collection assembly (500) descends, and the first foil tab group (313a) and the second foil tab group (313b) may be inserted to the side of the current collection assembly (500) as in the aforementioned fifth embodiment (see FIG. 15 and FIG. 16a to 16c).

[0193] Referring to FIGS. 19a and 19b, in the cutting step (S500), the upper portion (E) of the first foil tab group (313a) and the second foil tab group (313b) protruding above the first collector plate (510) can be cut. Specifically, the upper portion (E) of the first foil tab group (313a) and the second foil tab group (313b) can be cut at a height similar to the upper surface of the first collector plate (510). As a result, the first foil tab group (313a) and the second foil tab group (313b) can be formed at a height similar to the upper surface of the first collector plate (510). That is, after cutting, the height of the first foil tab group (313a) and the second foil tab group (313b) may be the same as the height of the upper surface of the first collector plate (510), or may be slightly higher or slightly lower than the upper surface of the first collector plate (510).

[0194] Referring to FIG. 20, in the welding step (S700), the first foil tab group (313a) and the second foil tab group (313b) can be welded to the inner surface (511xa) of the first slit (511x) and the inner surface (511ya) of the first slit (511y), respectively.

[0195] The first foil tab group (313a) and the second foil tab group (313b) can be directly welded with their upper portions exposed to the first slit (511x, 511y), but alternatively, welding can be performed by placing a metal plate over the first slit (511x, 511y).

[0196] Welding may be applied using laser welding or ultrasonic welding, and welding energy may be directed from the upper part of the first collector plate (510) toward the first collector plate (510).

[0197] Specifically, welding energy can be irradiated across the first slit (511x, 511y) in the width direction (y direction). Accordingly, multiple welding lines can be formed across the first foil tab group (313a) and the second foil tab group (313b) in the width direction (y direction).

[0198] The welding line may be parallel to the width direction (y direction), but is not necessarily limited thereto, and may be formed in a pattern that crosses the width (y direction) of the first slit (511x, 511y) at various angles, such as a diagonal shape or a V shape.

[0199] Once welding is complete, the assembly step (S900) can proceed.

[0200] Referring again to FIG. 3, in the assembly step (S900), a cap assembly (700) may be placed on top of a current collection assembly (500). For the combination of the current collection assembly (500) and the cap assembly (700), a first terminal hole (711) may be aligned at the position of a first connection terminal (513).

[0201] At this time, the distance (D1) between the first connection terminal (513) and the second connection terminal (533) may be the same as the distance (D2) between the first terminal hole (711) and the second terminal hole (731). Since each connection terminal (513, 533) is integrated into the current collection assembly (500) and its position is constrained, when the first connection terminal (513) is aligned to the position of the first terminal hole (711), the second connection terminal (533) can also be automatically aligned to the position of the second terminal hole (731).

[0202] In this state, the first connection terminal (513) is inserted into the first terminal hole (711), and the second connection terminal (533) is inserted into the second terminal hole (731) so that the current collection assembly (500) and the cap assembly (700) can be combined.

[0203] That is, the current collection assembly (500) according to the present invention, the secondary battery (10) including the same, and the method of manufacturing the same allow one connection terminal to be aligned with a corresponding terminal hole and the other connection terminal to be aligned with a corresponding terminal hole without individually adjusting the position of each connection terminal (513, 533), so that each connection terminal (513, 533) can be simultaneously aligned with a corresponding terminal hole (711, 731). As a result, the assembly efficiency of the current collection plate (510, 530) and the cap assembly (700) can be improved.

[0204] In addition, the current collection assembly (500) according to the present invention, the secondary battery (10) including the same, and the method of manufacturing the same are such that the electrode tabs (313, 333) penetrate the current collection assembly (500) vertically and are connected to the current collection plates (510, 530). Accordingly, the length (H, see FIG. 4) of the first electrode tab (313) can be made short, thereby reducing resistance and heat generation according to the current, so the heat generation problem can be effectively improved.

[0205] 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 first electrode tabs, each coupled to a plurality of first electrodes and comprising a first foil tab group and a second foil tab group; A plurality of second electrode tabs, each coupled to a plurality of second electrodes and including a third foil tab group and a fourth foil tab group; A current collection assembly comprising: a current collection plate holder formed of an insulating material having a first hole formed on one side and a second hole formed on the other side; a first current collection plate coupled to the upper side of the current collection plate holder and having a plurality of first slits formed vertically connected to the first hole and a first connection terminal formed thereon; and a second current collection plate coupled to the upper side of the other side of the current collection plate holder and having a plurality of second slits formed vertically connected to the second hole and a second connection terminal formed thereon; and It includes a cap assembly having a first electrode terminal and a second electrode terminal located thereon, which are electrically connected to the first current collector plate and the second current collector plate, respectively. A secondary battery in which the first foil tab group and the second foil tab group are each inserted into the plurality of first slits and coupled to the inner surface of the first slits.

2. In Paragraph 1, The above plurality of first slits are spaced apart from each other in the width direction, a secondary battery.

3. In Paragraph 2, The plurality of first slits above are spaced apart by the same distance from the center in the width direction of the first current collector plate, in a secondary battery.

4. In Paragraph 1, A secondary battery in which the first hole is formed in plurality.

5. In Paragraph 4, A secondary battery in which the lower surface of the above-mentioned current collector holder is inclined toward the plurality of first holes.

6. In Paragraph 4, A secondary battery in which the corner where the lower surface of the above-mentioned collector plate holder meets the inner surface of the plurality of first holes is rounded.

7. In Paragraph 1, Each of the above plurality of first slits is, A slit slope section connected to the first hole and formed at an angle with respect to the lower surface of the first collector plate; and A secondary battery comprising a slit vertical section connected to the above-mentioned slit inclined section and formed vertically on the lower surface of the first current collector plate.

8. In Paragraph 7, The above-mentioned vertical slit section is a secondary battery that is vertically offset from the above-mentioned first hole.

9. In Paragraph 1, A secondary battery in which the plurality of first slits are formed in different rows.

10. In Paragraph 1, A secondary battery having a first cut formed on one side in the width direction of the first current collector plate.

11. In Paragraph 10, A secondary battery in which the first cut portion is connected to the plurality of first slits in the longitudinal direction.

12. In Paragraph 1, A secondary battery in which the first foil tab group and the second foil tab group, each inserted into the plurality of first slits, face in a direction perpendicular to the upper surface of the first current collector plate.

13. In Paragraph 1, A secondary battery in which the first foil tab group and the second foil tab group are arranged in different columns.

14. In Paragraph 1, The above cap assembly is, A secondary battery further comprising a cap plate having a first terminal hole into which the first connection terminal is inserted and a second terminal hole into which the second connection terminal is inserted.

15. In Paragraph 14, The distance between the first connection terminal and the second connection terminal is, A secondary battery having the same distance between the first terminal hole and the second terminal hole.

16. A method for manufacturing a secondary battery according to claim 15, An insertion step of inserting the first foil tab group and the second foil tab group into the plurality of first slits, respectively; A cutting step for cutting the first foil tab group and the second foil tab group protruding above the first collector plate; A welding step of welding the first foil tab group and the second foil tab group to the inner surface of the first slit; and A method for manufacturing a secondary battery, comprising an assembly step of inserting the first connection terminal into the first terminal hole to combine the current collection assembly and the cap assembly.

17. In Paragraph 16, In the above welding step, A method for manufacturing a secondary battery in which a welding line is formed across the first slit in the width direction.

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