Secondary battery and method for manufacturing secondary battery
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LG ENERGY SOLUTION LTD
- Filing Date
- 2026-01-20
- Publication Date
- 2026-07-30
Smart Images
Figure KR2026001137_30072026_PF_FP_ABST
Abstract
Description
Secondary battery and method for manufacturing a secondary battery
[0001] This application claims priority to Korean Patent Application No. 10-2025-0010080 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 and a first connection terminal formed that are aligned with the upper side of the first hole; and a second current collector plate coupled to the upper side of the current collector holder and having a plurality of second slits formed and a second connection terminal formed that are aligned with the upper side of the second hole; a current collector assembly comprising a first electrode terminal and a second electrode terminal positioned thereon, which are 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 upper surface of the first collector plate.
[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 upper surface of the first collector plate may be formed to be inclined toward the plurality of first slits at both ends.
[0015] The above first hole may be formed in multiple numbers.
[0016] The lower surface of the above-mentioned collector plate holder may be inclined toward the plurality of first holes.
[0017] 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.
[0018] On the upper surface of the above-mentioned collector plate holder, a first fixing part may be formed protrudingly, which is inserted into each of the plurality of first slits and fixes the first collector plate to the upper part of the collector plate holder.
[0019] The first fixing part can wrap around the inner surface of the first slit.
[0020] The above plurality of first slits can be formed in different rows.
[0021] The first foil tab group and the second foil tab group can be folded and coupled to the upper surface of the first current collector plate.
[0022] The first foil tab group and the second foil tab group can be folded in opposite directions.
[0023] The first foil tab group and the second foil tab group can be folded in the same direction.
[0024] The first foil tab group above may have at least a portion bent in one direction and the remaining portion bent in the opposite direction to the one direction.
[0025] The first foil tab group and the second foil tab group may be placed in different columns.
[0026] 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.
[0027] 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.
[0028] 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 bending step of bending the first foil tab group and the second foil tab group; a welding step of welding the first foil tab group and the second foil tab group to the upper surface of the first current collector plate; 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.
[0029] According to one aspect of the present invention, the current collector plate is integrated to improve assemblability with the cap assembly.
[0030] According to one aspect of the present invention, the resistance to current can be reduced by reducing the length of the electrode tab.
[0031] FIG. 1 is a perspective view illustrating a secondary battery according to a first embodiment of the present invention.
[0032] FIG. 2 is a perspective view showing a disassembled state of a part of the secondary battery of FIG. 1.
[0033] FIG. 3 is a perspective view illustrating the state in which the electrode tabs are connected.
[0034] FIG. 4 is a perspective view showing the configuration of a current collection assembly in a disassembled state.
[0035] Figure 5 is a top view of the first collector plate as seen from above.
[0036] FIGS. 6a to 6d are cross-sectional views illustrating the state in which the electrode tab is bent and coupled to the current collector plate.
[0037] Figure 7a is a cross-sectional view of a current collection assembly.
[0038] FIGS. 7b, FIGS. 8a, and FIGS. 8b are various variations of a current collection assembly.
[0039] FIGS. 9a and 9b 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. 10 is a modified example of the current collection assembly of FIG. 9.
[0041] FIG. 11 is a perspective view showing the disassembled configuration of a current collection assembly of a secondary battery according to a third embodiment of the present invention.
[0042] FIG. 12 is a cross-sectional view of the current collection assembly of FIG. 11.
[0043] FIG. 13 is a modified example of the current collection assembly of FIG. 12.
[0044] FIG. 14 is a perspective view illustrating a current collection assembly of a secondary battery according to a fourth embodiment of the present invention.
[0045] FIG. 15 is a top view of the electrode tabs combined.
[0046] FIG. 16 is a perspective view illustrating a current collection assembly of a secondary battery according to the fifth embodiment of the present invention.
[0047] FIGS. 17a to 17c are top views of electrode tabs being inserted into a current collection assembly.
[0048] FIG. 18 is a block diagram showing a method for manufacturing a secondary battery according to a first embodiment of the present invention.
[0049] Figures 19a and 19b are drawings illustrating the insertion step of Figure 18.
[0050] Figures 20a and 20b are drawings showing the bending steps of Figure 18.
[0051] Figure 21 is a drawing showing the welding steps of Figure 18.
[0052] FIG. 22 is a perspective view illustrating a battery module including the secondary battery of FIG. 1.
[0053] FIG. 23 is a perspective view illustrating a battery pack including the battery module of FIG. 22.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] Hereinafter, a secondary battery according to the first embodiment of the present invention will be described.
[0059] 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.
[0060] 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).
[0061] 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.
[0062] 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.
[0063] 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.
[0064] 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.
[0065] 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.
[0066] The first electrode tab (313) and the second electrode tab (333) can be spaced apart with different polarities.
[0067] 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.
[0068] 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.
[0069] 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.
[0070] 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).
[0071] 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).
[0072] 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.
[0073] 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).
[0074] 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.
[0075] 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).
[0076] 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.
[0077] 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 aligned with the upper portion of the first hole (551, see FIG. 4) and the second hole (553, see FIG. 4) formed in the collector plate holder (550).
[0078] 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).
[0079] Each inserted electrode tab (313, 333) can be bent and joined to the upper surface of the current collector plate (510, 530). The electrode tabs (313, 333) can be joined to the current collector plate (510, 530) by welding, and the welding can be laser welding, ultrasonic welding, etc.
[0080] The electrode tabs (313, 333) can be welded directly while in contact with the upper surface of the current collector plate (510, 530), but alternatively, welding can be performed by placing a metal plate over the electrode tabs (313, 333).
[0081] In some cases, insulating tape or insulating film, etc., may cover the welded area. As a result, the electrode tabs (313, 333) welded to the current collector plates (510, 530) can be insulated from the cap assembly (700). That is, as described below, the electrode tabs (313, 333) are electrically connected to the electrode terminals (710, 730) through the current collector plates (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) may be formed on 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 or may be coupled to the first collector plate (510). The first connection terminal (513) may 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) may be electrically connected.
[0086] The second connection terminal (533) may be formed on the upper surface of the second current collector plate (530). The second connection terminal (533) may be located approximately in the center of the second current 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 current collector plate (530). The second connection terminal (533) may be formed integrally with the second current collector plate (530) in a column shape or may be coupled to the second current collector plate (530). The second connection terminal (533) may be inserted into the second terminal hole (731) to electrically connect the second current collector plate (530) and the second electrode terminal (730). When the second current collector plate (530) and the second electrode terminal (730) are electrically connected, the second electrode (330) and the second electrode terminal (730) may be electrically connected.
[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 easily 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. 22). 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. 23). 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. 6a to 6d are cross-sectional views showing the electrode tab bent and coupled to the current collection plate.
[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 slit (511x, 511y) and the second slit (531x, 531y) are each formed in multiple numbers. The multiple first slits (511x, 511y) and the multiple second slits (531x, 531y) are each aligned above the first hole (551) and the second hole (553), respectively, so that the first electrode tab (313) and the second electrode tab (333) can be inserted therein. 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 FIGS. 6a to 6d, 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 slits (511x, 511y).
[0112] A plurality of first electrode tabs (313) may include a first foil tab group (313a) inserted into a first slit (511x, 511y) of one (e.g., 511x) and a second foil tab group (313b) inserted into a first slit (511x, 511y) of the other (e.g., 511y).
[0113] The first foil tab group (313a) and the second foil tab group (313b) can each be folded and coupled to the upper surface of the first collector plate (510).
[0114] Specifically, the first foil tab group (313a) and the second foil tab group (313b) can be folded in opposite directions and coupled to the upper surface of the first collector plate (510). For example, as shown in FIG. 6a, the first foil tab group (313a) and the second foil tab group (313b) can be folded in directions away from each other, or as shown in FIG. 6b, they can be folded in directions facing each other and coupled to the upper surface of the first collector plate (510). When folded to face each other, the first foil tab group (313a) and the second foil tab group (313b) can be overlapped and coupled to the upper surface of the first collector plate (510), but alternatively, they can be coupled to the upper surface of the first collector plate (510) without overlapping.
[0115] Alternatively, as shown in FIG. 6c, the first foil tab group (313a) and the second foil tab group (313b) may be folded in the same direction. Accordingly, both the first foil tab group (313a) and the second foil tab group (313b) may be folded in one direction and coupled to the upper surface of the first collector plate (510).
[0116] Alternatively, the first foil tab group (313a) and the second foil tab group (313b) may each be divided and folded in at least a portion. For example, as shown in FIG. 6d, at least a portion (313a1) of the first foil tab group (313a) may be folded in one direction, and the remaining portion (313a2) may be folded in the opposite direction. Likewise, at least a portion (313b1) of the second foil tab group (313b) may be folded in one direction, and the remaining portion (313b2) may be folded in the opposite direction.
[0117] Accordingly, a portion (313a2) of the first foil tab group and a portion (313b1) of the second foil tab group may be bent in a direction facing each other. The facing portions (313a2) of the first foil tab group and the portion (313b1) of the second foil tab group may overlap each other and be coupled to the upper surface of the first current collector plate (510), but alternatively, they may be coupled to the upper surface of the first current collector plate (510) without overlapping.
[0118] As described above, when the first foil tab group (313a) and the second foil tab group (313b) are inserted into a plurality of first slits (511x, 511y), folded, and then coupled to the upper surface of the first current collector plate (510), the first electrode tab (313) penetrates the current collector 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 thus effectively improving the heat generation problem.
[0119] FIG. 7a is a cross-sectional view of a current collection assembly, and FIG. 7b, FIG. 8a, and FIG. 8b are various variations of the current collection assembly.
[0120] As illustrated in FIG. 7a, the upper surface of the first collector plate (510) has a flat cross-section, and 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 inner surface (551a) facing the first hole (551) may also have a cross-section perpendicular to the upper surface of the collector plate holder (550).
[0121] 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.
[0122] According to this, since the first foil tab group (313a, see FIGS. 6a to 6d) and the second foil tab group (313b, see FIGS. 6a to 6d) 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 FIGS. 6a to 6d) and the second foil tab group (313b, see FIGS. 6a to 6d) into the plurality of first slits (511x, 511y) can be made easier.
[0123] Referring to FIG. 7b, the corner where the upper surface of the first current collector plate (510) meets the inner surface (511xa, 511ya) of the first slit (511x, 511y) can be rounded. The first foil tab group (313a) and the second foil tab group (313b) can be smoothly bent at the first slit (511x, 511y) and joined to the upper surface of the first current collector plate (510). As a result, the risk of disconnection of the first electrode tab (313) is reduced, which has the advantage of improving the electrical stability of the secondary battery (10).
[0124] Referring to FIG. 8a, the upper surface of the first collector plate (510) may be formed to be inclined toward a plurality of first slits (511x, 511y). Specifically, the upper surface of the first collector plate (510) may be inclined toward adjacent first slits (511x, 511y) at each end of the width direction (y-direction). Accordingly, the thickness of the first collector plate (510) may decrease as it moves toward adjacent first slits (511x, 511y) at each end of the width direction (y-direction). However, the thickness may remain constant between the plurality of first slits (511x, 511y).
[0125] As the upper surface of the first current collector plate (510) is formed to be inclined toward the first slit (511x, 511y), the first foil tab group (313a) and the second foil tab group (313b) may not be excessively bent when coupled to the upper surface of the first current collector plate (510). As a result, the risk of disconnection of the first electrode tab (313) is reduced, and the electrical stability of the secondary battery (10) is improved.
[0126] In addition, in this case, since the area where the first foil tab group (313a) and the second foil tab group (313b) are welded to the upper surface of the first current collector plate (510) increases, the first electrode tab (313) can be stably connected to the first current collector plate (510).
[0127] Referring to FIG. 8b, the corner where the inclined upper surface of the first collector plate (510) meets the inner surface (511xa, 511ya) of the first slit (511x, 511y) can be rounded. Accordingly, the inclined upper surface of the first collector plate (510) and the inner surface (511xa, 511ya) of the first slit (511x, 511y) can be connected to a curved surface. Specifically, the inclined upper surface of the first collector plate (510) and the inner surface (511xa, 511ya) of the first slit (511x, 511y) can be connected to an upwardly convex curved surface.
[0128] In the area between the plurality of first slits (511x, 511y), the upper surface of the first collector plate (510) may be formed as a curved surface. For example, in the area, the upper surface of the first collector plate (510) may be formed as an upwardly convex curved surface.
[0129] According to the structure of the present variation, the first foil tab group (313a, see FIGS. 6a to 6d) and the second foil tab group (313b, see FIGS. 6a to 6d) come into contact with the curved surface, thereby reducing the risk of disconnection, so the electrical stability of the secondary battery (10) can be improved.
[0130]
[0131] Hereinafter, a secondary battery according to the second embodiment of the present invention will be described.
[0132] FIGS. 9a and 9b 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.
[0133] 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.
[0134] Referring to FIG. 9a, 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 aligned above a plurality of first holes (551x, 551y).
[0135] 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 aligned above a first hole (551x, 551y) of one (e.g., 511x), and a first slit (511x, 511y) of another (e.g., 511y) may be aligned above a first hole (551x, 551y) of the other (e.g., 551y).
[0136] The lower surface of the collector plate holder (550) can be formed to be inclined toward a plurality of first holes (551x, 551y).
[0137] 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).
[0138] 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.
[0139] 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).
[0140] Specifically, as illustrated in FIG. 9a, 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. 9b, 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).
[0141] Therefore, in the case of the present embodiment, a separate process of gathering the first electrode tab (313) toward the first hole (551x, 551y) is not required, so the manufacturing process of the secondary battery (10) can be simplified.
[0142] FIG. 10 is a modified example of the current collection assembly of FIG. 9a and FIG. 9b.
[0143] As shown in FIG. 10, 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.
[0144] 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.
[0145] According to the present variation, the first foil tab group (313a, see FIG. 9b) and the second foil tab group (313b, see FIG. 9b) come into contact with the curved surface, thereby reducing the risk of disconnection, so the electrical stability of the secondary battery (10) can be improved.
[0146]
[0147] A secondary battery according to the third embodiment of the present invention will be described below.
[0148] FIG. 11 is a perspective view showing the configuration of a current collection assembly of a secondary battery according to a third embodiment of the present invention in an exploded state, FIG. 12 is a cross-sectional view of the current collection assembly of FIG. 11, and FIG. 13 is a modified example of the current collection assembly of FIG. 12.
[0149] The secondary battery according to the third embodiment of the present invention is formed with the same structure as the first embodiment and variations described above, except for the first fixing part (555) and the second fixing part (557), so a redundant description of the same configuration is omitted. In addition, in this embodiment, the second fixing part (557) has the same structure as the first fixing part (555), so the first fixing part (555) is described as an example below, and a description of the redundant second fixing part (557) is omitted.
[0150] Referring to FIGS. 11 and 12, a first fixing part (555) and a second fixing part (557) may be formed protrudingly on the upper surface of the collector plate holder (550).
[0151] The first fixing part (555) may be formed as a pair facing each other in the width direction (y direction). The pair of first fixing parts (555) may be formed protruding from the upper surface of the collector plate holder (550) and inserted into each of the plurality of first slits (511x, 511y). The pair of first fixing parts (555) inserted into the plurality of first slits (511x, 511y) may wrap around the inner surface (511xa, 511ya) of the first slits (511x, 511y).
[0152] The first collector plate (510) can be fixed to the upper part of the collector plate holder (550) by fitting the inner surface (511xa, 511ya) of the first slit (511x, 511y) to the outer side of a pair of first fixing parts (555).
[0153] According to the present embodiment, the first current collector plate (510) can be fixed to the current collector plate holder (550) in a simple manner, so that the first current collector plate (510) and the current collector plate holder (550) can be integrated without a separate bonding process, thereby improving the manufacturing efficiency of the current collector assembly (500).
[0154] Meanwhile, the facing inner surfaces of a pair of first fixed parts (555) may have a cross-section perpendicular to the upper surface of the collector plate holder (550).
[0155] Alternatively, as shown in FIG. 13, the facing inner surfaces of a pair of first fixed parts (555) may be formed as curved surfaces.
[0156] Specifically, the inner surface of the first fixing part (555) can be formed as a convex curved surface inward in the width direction (y direction). Accordingly, the first foil tab group (313a) and the second foil tab group (313b) inserted into the first hole (551) and the plurality of first slits (511x, 511y) are bent smoothly in contact with the curved surface, thereby reducing the risk of disconnection and improving the electrical stability of the secondary battery (10).
[0157] However, it is not limited to the above examples, and the inner surface of a pair of facing first fixed parts (555) may have a slanted cross-section such that the width increases from the top to the bottom.
[0158] Additionally, although not illustrated in this embodiment, the first fixing part (555) is not necessarily limited to a pair of structures and may be formed as a rectangular structure inserted into each of the first slits (511x, 511y).
[0159]
[0160] Hereinafter, a secondary battery according to the fourth embodiment of the present invention will be described.
[0161] FIG. 14 is a perspective view illustrating a current collection assembly of a secondary battery according to a fourth embodiment of the present invention, and FIG. 15 is a top view looking from above showing the electrode tabs combined.
[0162] 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.
[0163] 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.
[0164] Referring to FIGS. 14 and 15, 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.
[0165] 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.
[0166] 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).
[0167] 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, and folded.
[0168] For example, a first foil tab group (313a) inserted into a first slit (511x) may have a portion (313a1) bent toward one side in the width direction (y direction) and the remaining portion (313a2) bent toward the other side in the width direction (y direction).
[0169] Likewise, the second foil tab group (313b) inserted into the first slit (511y) may have a portion (313b1) bent toward one side in the width direction (y direction) and the remaining portion (313b2) bent toward the other side in the width direction (y direction).
[0170] The first foil tab group (313a) and the second foil tab group (313b), each bent as described above, can be joined to the upper surface of the first collector plate (510) by welding.
[0171] In the present embodiment, the first foil tab group (313a) and the second foil tab group (313b) are not gathered into a single row but are divided into different rows and inserted into a plurality of first slits (511). As a result, the first foil tab group (313a) and the second foil tab group (313b) do not overlap, and the weldable area on the upper surface of the first current collector plate (510) is increased, thereby improving the convenience of welding.
[0172]
[0173] Hereinafter, a secondary battery according to the fifth embodiment of the present invention will be described.
[0174] FIG. 16 is a perspective view illustrating a current collection assembly of a secondary battery according to a fifth embodiment of the present invention, and FIG. 17a to 17c are top views taken from above showing an electrode tab inserted into the current collection assembly.
[0175] 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.
[0176] As shown in FIG. 16, 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).
[0177] 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).
[0178] With reference to FIGS. 17a to 17c 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 into one, or they may be inserted into the first cut portion (512) with gathered into one.
[0179] 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.
[0180] 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.
[0181] 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).
[0182] 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).
[0183] 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.
[0184] 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).
[0185] Specifically, the first foil tab group (313a) of the first electrode tabs (313) can slide along the first slit guide (514x) and be gathered into one to be inserted into the first slit (511x). The second foil tab group (313b) of the first electrode tabs (313) can slide along a plurality of first slit guides (514x, 514y) and be gathered into one to be inserted into the first slit (511y).
[0186] 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).
[0187] 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).
[0188] 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.
[0189] 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).
[0190] 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.
[0191]
[0192] Hereinafter, a method for manufacturing a secondary battery according to the first embodiment of the present invention will be described.
[0193] FIG. 18 is a block diagram showing a method for manufacturing a secondary battery according to a first embodiment of the present invention, and FIG. 19a and FIG. 19b are diagrams showing the insertion step of FIG. 18. FIG. 20a and FIG. 20b are diagrams showing the bending step of FIG. 18, and FIG. 21 is a diagram showing the welding step of FIG. 18.
[0194] As illustrated in FIG. 18, a method for manufacturing a secondary battery according to a first embodiment of the present invention includes 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 bending step (S500) of bending 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 upper surface of a first current collector plate (510), and an assembly step (S900) of inserting a first connection terminal (513) into a first terminal hole (711) to combine a current collector assembly (500) and a cap assembly (700).
[0195] Referring to FIG. 19a, 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) described later, or it may be performed after the assembly step (S900).
[0196] As illustrated in FIG. 19b, 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 vertically apart from the electrode assembly (300) by a predetermined distance and is positioned on the upper part of the electrode assembly (300).
[0197] However, the first foil tap group (313a) and the second foil tap group (313b) are not necessarily inserted in a manner where the current collection assembly (500) descends, and the first foil tap group (313a) and the second foil tap group (313b) may be inserted to the side of the current collection assembly (500) as in the aforementioned fifth embodiment (see FIG. 16 and FIG. 17a to 17c).
[0198] Referring to FIG. 20a, in the bending step (S500), the jig (J) descends toward the inserted first foil tab group (313a) and second foil tab group (313b). The jig (J) has a protruding lower portion to be inserted into each of the plurality of first slits (511x, 511y), and wings may be formed on both sides. At this time, the two wings of the jig (J) may be formed as curved or inclined surfaces. The two wings of the jig (J) may be curved plates or inclined plates, but are not limited thereto and may be ring-shaped, consisting only of edges. The two wings of the jig (J) may have a width smaller than that of the first electrode tabs (313a, 313b) in the longitudinal direction (x-direction) (see FIG. 21).
[0199] As illustrated in FIG. 20b, the jig (J) descends and bends the first foil tab group (313a) and the second foil tab group (313b). For example, the jig (J) may bend the first foil tab group (313a) to one side in the width direction (y direction) and bend the second foil tab group (313b) to the other side in the width direction (y direction). Alternatively, depending on the position of the protruding lower part of the jig (J), the first foil tab group (313a) and the second foil tab group (313b) may both be bent in the same direction, bent in directions facing each other, or bent as in FIG. 6d.
[0200] Meanwhile, the jig (J) can descend to a certain height and then have its wings catch on the upper surface of the first collector plate (510). Accordingly, the jig (J) can bend the first foil tab group (313a) and the second foil tab group (313b) and then temporarily fix the positions of the first foil tab group (313a) and the second foil tab group (313b) with its wings.
[0201] Referring to FIG. 21, in the welding step (S700), the first foil tab group (313a) and the second foil tab group (313b) can be welded to the upper surface of the first collector plate (510). Specifically, the welding of the first foil tab group (313a) and the second foil tab group (313b) can be carried out in an area (W) that does not overlap with the jig (J) among the areas where the upper surface of the first collector plate (510) contacts.
[0202] The first foil tap group (313a) and the second foil tap group (313b) can be welded directly in the W area while in contact with the upper surface of the first collector plate (510), but alternatively, the jig (J) can be removed and a metal plate can be placed over the first foil tap group (313a) and the second foil tap group (313b) to perform the welding.
[0203] Welding can be performed using laser welding or ultrasonic welding, and can be performed in patterns such as x-direction, y-direction, diagonal direction, and zigzag direction. Once welding is completed, the jig (J) is removed and the assembly step (S900) can proceed.
[0204] 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).
[0205] 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).
[0206] 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.
[0207] That is, according to the present invention, the current collection assembly (500), the secondary battery (10) including the same, and the manufacturing method thereof 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.
[0208] 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) each pass through a plurality of slits (511, 531) and are coupled to the upper surface of the current collection plate (510, 530), thereby allowing the electrode tabs (313, 333) to penetrate the current collection assembly (500) vertically and be connected to the current collection plate (510, 530). Accordingly, the length (H, see FIG. 4) of the electrode tabs (313, 333) can be manufactured to be short, thereby reducing resistance and heat generation according to the current, and thus the heat generation problem can be effectively improved.
[0209] 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 and a first connection terminal formed that are aligned with the upper side of the first hole; and a second current collection plate coupled to the upper side of the current collection plate holder and having a plurality of second slits formed and a second connection terminal formed that are aligned with the upper side of the second hole; 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 a plurality of first slits and coupled to the upper surface of the first current collector plate.
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 upper surface of the first current collector plate is formed to be inclined toward the plurality of first slits at both ends.
5. In Paragraph 1, A secondary battery in which the first hole is formed in plurality.
6. In Paragraph 5, A secondary battery in which the lower surface of the above-mentioned current collector holder is inclined toward the plurality of first holes.
7. In Paragraph 5, 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.
8. In Paragraph 1, On the upper surface of the above current collector holder, A secondary battery having a first fixing part protrudingly formed to be inserted into each of the plurality of first slits and to fix the first collector plate to the upper part of the collector plate holder.
9. In Paragraph 8, The above-mentioned first fixing part surrounds the inner surface of the first slit, a secondary battery.
10. In Paragraph 1, A secondary battery in which the plurality of first slits are formed in different rows.
11. In Paragraph 1, A secondary battery in which the first foil tab group and the second foil tab group are folded and coupled to the upper surface of the first current collector plate.
12. In Paragraph 11, A secondary battery in which the first foil tab group and the second foil tab group are folded in opposite directions.
13. In Paragraph 11, A secondary battery in which the first foil tab group and the second foil tab group are folded in the same direction.
14. In Paragraph 11, The above-mentioned first foil tab group is, A secondary battery in which at least a portion is bent in one direction and the remaining portion is bent in the opposite direction to the said one direction.
15. In Paragraph 1, A secondary battery in which the first foil tab group and the second foil tab group are arranged in different columns.
16. 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.
17. In Paragraph 16, 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.
18. A method for manufacturing a secondary battery according to claim 17, An insertion step of inserting the first foil tab group and the second foil tab group into the plurality of first slits, respectively; A folding step for folding the first foil tab group and the second foil tab group; A welding step of welding the first foil tab group and the second foil tab group to the upper surface of the first collector plate; 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.