Secondary battery, battery module, and battery pack

Abstract

A secondary battery according to one aspect of the present invention comprises: a current collector assembly including a first electrode tab, a second electrode tab, a current collector plate holder made of an insulating material, a first current collector plate, which is coupled to the upper portion of one side of the current collector plate holder and includes a first connection terminal, and a second current collector plate, which is coupled to the upper portion of the other side of the current collector plate holder and includes a second connection terminal; and a cap assembly in which a first electrode terminal and a second electrode terminal electrically connected to the first current collector plate and the second current collector plate, respectively, are positioned, wherein the first electrode tab is coupled to a side surface of the first current collector plate, and the second electrode tab is coupled to a side surface of the second current collector plate.

Description

Secondary batteries, battery modules, and battery packs

[0001] The present application claims priority to Korean Patent Application No. 10-2025-0010081 filed on January 23, 2025 and Korean Patent Application No. 10-2026-0006517 filed on January 13, 2026, the disclosure of said applications in its entirety is incorporated herein by reference.

[0002] The present invention relates to a secondary battery, a battery module, and a battery pack.

[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] The positive and negative current collector plates, each equipped with an electrode tab, are individually attached to the cap assembly; however, if either of the plates is not aligned with the connection position on the cap assembly, connection to the terminal is difficult. 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.

[0008] In addition, depending on the position where multiple electrode tabs are coupled to the current collector plate, there is a problem in that the distance between the electrode assembly and the current collector plate increases, reducing the energy density of the secondary battery, and the length of the electrode tabs increases, leading to increased resistance.

[0009] The objective of the present invention is to provide a secondary battery, a battery module, and a battery pack in which a 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, a battery module, and a battery pack capable of reducing resistance to current by reducing the length of the electrode tab.

[0011] A secondary battery according to one aspect of the present invention comprises: a case; an electrode assembly housed in the case and comprising a first electrode and a second electrode; a first electrode tab coupled to the first electrode; a second electrode tab coupled to the second electrode; a current collector holder formed of an insulating material; a first current collector plate coupled to the upper side of one side of the current collector holder and having a first connection terminal formed thereon; and a current collector assembly comprising a second current collector plate coupled to the upper side of the other side of the current collector holder and having a second connection terminal formed thereon; and a cap assembly that seals the case and has 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, wherein the first electrode tab is coupled to the side of the first current collector plate and the second electrode tab is coupled to the side of the second current collector plate.

[0012] The above first electrode tab may be provided in multiple numbers.

[0013] The plurality of first electrode tabs can be coupled to both sides in the width direction of the first current collector plate.

[0014] The above plurality of first electrode tabs can be arranged in the same row.

[0015] At least one of the plurality of first electrode tabs may have an end perpendicular to the upper surface of the first current collector plate.

[0016] The plurality of first electrode tabs mentioned above can be arranged in different columns.

[0017] The side of the above-mentioned collector plate holder may have an inclined cross-section.

[0018] The side and bottom surfaces of the above-mentioned collector plate holder can form a single curved surface.

[0019] The above-mentioned first collector plate may have one side in the width direction cut to form a first cut portion.

[0020] The first incisions are formed in plurality, and the plurality of first incisions may be located on both sides in the width direction of the first collector plate.

[0021] The plurality of first incisions may be formed at positions that overlap when the first collector plate is viewed in the width direction.

[0022] The plurality of first cuts mentioned above may be formed at positions staggered from each other when the first collector plate is viewed in the width direction.

[0023] The first collector plate above can have its side end bent to wrap around the side of the collector plate holder.

[0024] The width of the first current collector plate may be smaller than the width of the electrode assembly.

[0025] 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.

[0026] 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.

[0027] A battery module according to one aspect of the present invention includes a secondary battery.

[0028] A battery pack according to one aspect of the present invention includes a battery module.

[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. 4a is a top view of the electrode assembly.

[0035] FIG. 4b is a top view of the electrode assembly and the current collection assembly.

[0036] Figure 5 is a cross-sectional view illustrating the state in which the electrode tabs are connected.

[0037] Figure 6a is a modified example of the electrode tab of Figure 4a.

[0038] FIG. 6b is a top view of the electrode tab of FIG. 6a connected to the current collection assembly.

[0039] FIG. 7 is a cross-sectional view illustrating a current collection assembly of a secondary battery according to a second embodiment of the present invention.

[0040] Fig. 8 is a modified example of the current collection assembly of Fig. 7.

[0041] FIG. 9 is a top view of a current collection assembly of a secondary battery according to a third embodiment of the present invention.

[0042] FIG. 10 is a top view showing the state in which an electrode tab is coupled to the current collection assembly of FIG. 9.

[0043] FIG. 11 is a modified example of the electrode tab and current collection assembly of FIG. 10.

[0044] FIG. 12 is a cross-sectional view of a secondary battery according to the fourth embodiment of the present invention.

[0045] FIG. 13 is a perspective view illustrating a battery module including the secondary battery of FIG. 1.

[0046] FIG. 14 is a perspective view illustrating a battery pack including the battery module of FIG. 13.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Hereinafter, a secondary battery according to the first embodiment of the present invention will be described.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] The first electrode tab (313) and the second electrode tab (333) can be spaced apart with different polarities.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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).

[0065] 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.

[0066] 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 length (x direction) of the current collector holder (550) may be equal to or smaller than the length (x direction) of the electrode assembly (300).

[0067] 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.

[0068] 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).

[0069] 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 in the longitudinal direction (x direction). 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.

[0070] 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 greater than that of the collector plate holder (550).

[0071] 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.

[0072] A first electrode tab (313) is attached to the side (511) of the first collector plate (510), and a second electrode tab (333) is attached to the side (531) of the second collector plate (530). The electrode tabs (313, 333) can be attached to the collector plates (510, 530) by welding, and the welding can be laser welding, ultrasonic welding, etc.

[0073] In some cases, insulating tape or insulating film, etc., may cover the welded area. As a result, the first electrode tab (313) welded to the side (511) of the first current collector plate (510) and the second electrode tab (333) welded to the side (531) of the second current collector plate (530) can be insulated from the cap assembly (700). That is, as described below, the first electrode tab (313) and the second electrode tab (333) are electrically connected to the first electrode terminal (710) and the second electrode terminal (730), respectively, through the first current collector plate (510) and the second current collector plate (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.

[0074] 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).

[0075] 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).

[0076] Meanwhile, the current collector plate (510, 530) can be connected to each electrode terminal (710, 730) through the connection terminal (513, 533).

[0077] 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.

[0078] 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.

[0079] 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).

[0080] Accordingly, the first current collector plate (510) and the second current collector plate (530) can be connected to the cap assembly (700) by aligning only one of the first current collector terminal (513) and the second current collector terminal (533) to the corresponding terminal hole without individually adjusting the positions of the first current collector terminal (513) and the second current collector terminal (533). That is, the first current collector terminal (513) and the second current collector terminal (533) can be simultaneously aligned to the corresponding first and second terminal holes (711, 731). As a result, the assembly efficiency of the first current collector plate (510), the second current collector plate (530), and the cap assembly (700) can be improved.

[0081] The specific structure of the other current collection assembly (500) will be described later.

[0082] 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).

[0083] 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.

[0084] 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).

[0085] 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).

[0086] 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.

[0087] A first terminal 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 terminal 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.

[0088] Meanwhile, the cap assembly (700) may further include a top insulator (790) positioned between the current collection assembly (500) and the cap plate (750). The top insulator (790) may be coupled to the lower surface of the cap plate (750) as a separate component from the current collection assembly (500).

[0089] Based on the top insulator (790), a current collection assembly (500) may be located at the bottom and a cap plate (750) at the top. Specifically, the top insulator (790) may be located between the current collection plates (510, 530) and the cap plate (750). Based on the current collection plates (510, 530), a current collection plate holder (550) may be located at the bottom of the current collection plates (510, 530), and the top insulator (790) may be located at the top of the current collection plates (510, 530). This top insulator (790) can insulate the cap plate (750) from the current collection plates (510, 530).

[0090] The top insulator (790) may have a shape that covers the entire lower surface of the cap plate (750), but is not necessarily limited thereto and may be formed in two separate parts, each having a shape corresponding to the first current collector plate (510) and the second current collector plate (530).

[0091] 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.

[0092] 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.

[0093] Meanwhile, a battery module (M) can be configured by including a plurality of secondary batteries (10) according to the present embodiment (see FIG. 13). 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. 14). 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).

[0094] FIG. 4a is a top view of the electrode assembly, FIG. 4b is a top view of the electrode assembly and the current collector assembly, and FIG. 5 is a cross-sectional view showing the state in which the electrode tab is combined.

[0095] 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.

[0096] As illustrated in FIG. 4a, a plurality of first electrode tabs (313) can be arranged in a row. A plurality of first electrode tabs (313) can all be arranged in the same row. That is, when viewed in the width direction (y direction), the positions of the plurality of first electrode tabs (313) in the length direction (x direction) may overlap.

[0097] Referring to FIG. 4b, the current collection assembly (500) can be placed on the upper part of the electrode assembly (300). At this time, a plurality of first electrode tabs (313a, 313b) are coupled to the side (511) of the first current collection plate (510).

[0098] More specifically, a plurality of first electrode tabs (313a, 313b) may be coupled to both sides (511) in the width direction (y direction) of the first current collector plate (510). For example, some (313a) of the plurality of first electrode tabs (313a, 313b) may be coupled to the side (511) in the +y direction of the first current collector plate (510), and the remaining portion (313b) may be coupled to the side (511) in the -y direction of the first current collector plate (510).

[0099] A plurality of first electrode tabs (313a, 313b) can be symmetrically coupled to both sides (511) of the first current collector plate (510). That is, the plurality of first electrode tabs (313a, 313b) coupled to both sides (511) may have their positions in the length direction (x direction) overlap when viewed in the width direction (y direction).

[0100] Referring to FIG. 5, a plurality of first electrode tabs (313) can be pressed and bent by a current collection assembly (500) positioned above. The bent plurality of first electrode tabs (313) can bypass the current collection assembly (500) in the width direction (y direction) so that their ends face the +z direction.

[0101] Although not illustrated, the corner where the side (551) of the current collector holder (550) and the bottom surface of the current collector holder (550) meet can be rounded. A plurality of first electrode tabs (313) can be smoothly bent along the corner of the current collector holder (550). As a result, the risk of disconnection of the first electrode tabs (313) is reduced, and the electrical stability of the secondary battery (10) can be improved.

[0102] The ends of the plurality of first electrode tabs (313) can be formed at approximately the same height. For example, although not illustrated, the portions of the plurality of first electrode tabs (313) that protrude above the first current collector plate (510) when the current collector assembly (500) is positioned can be cut. That is, the plurality of first electrode tabs (313) can be cut at a height similar to the upper surface of the first current collector plate (510) by bypassing the first current collector plate (510). As a result, the ends of the plurality of first electrode tabs (313) can be located at the same height as the upper surface of the first current collector plate (510).

[0103] In this state, a plurality of first electrode tabs (313) can be welded to both sides (511) in the width direction (y direction) of the first current collector plate (510). Some (313a) of the plurality of first electrode tabs (313) can be welded to the side (511) in the +y direction of the first current collector plate (510), and the remaining portion (313b) can be welded to the side (511) in the -y direction of the first current collector plate (510).

[0104] Meanwhile, the side surface (511) in the width direction (y direction) of the first collector plate (510) may have a cross-section perpendicular to the upper surface of the first collector plate (510). Accordingly, a plurality of first electrode tabs (313a, 313b) coupled to the side surface (511) may have ends perpendicular to the upper surface of the first collector plate (510). However, depending on the case, only some of the first electrode tabs (313) adjacent to the side surface (511) may have ends perpendicular to the upper surface of the first collector plate (510), while the other first electrode tabs (313) may have ends facing in a direction inclined with respect to the upper surface of the first collector plate (510).

[0105] The width (W) of the first collector plate (510) may be the same as the width of the collector plate holder (550). At this time, the side (551) of the collector plate holder (550) may also have a cross-section perpendicular to the upper surface of the collector plate holder (550). That is, the side (511) of the first collector plate (510) and the side (551) of the collector plate holder (550) may be connected in a straight line.

[0106] However, the width (W) of the first current collector plate (510) may be smaller than the width (W1) of the electrode assembly (300). For example, the width (W) of the first current collector plate (510) may be 50% or more and 90% or less of the width (W1) of the electrode assembly (300). In this case, both the current collector assembly (500) and the electrode assembly (300) can be compactly accommodated within a case (100, see FIG. 3), thereby improving the energy density of the secondary battery (10).

[0107] FIG. 6a is a modified example of the electrode tab of FIG. 4a, and FIG. 6b is a top view of the electrode tab of FIG. 6a connected to a current collection assembly.

[0108] Referring to FIGS. 6a and 6b, a plurality of first electrode tabs (313a, 313b) may be arranged in different columns.

[0109] Specifically, some (313a) of the plurality of first electrode tabs (313a, 313b) are arranged in a line, and other parts (313b) are also arranged in a line, but some of the first electrode tabs (313a) and other parts of the first electrode tabs (313b) may be arranged in different rows. That is, some of the first electrode tabs (313a) and other parts of the first electrode tabs (313b) may be arranged staggered with respect to each other when viewed in the width direction (y direction).

[0110] Accordingly, a plurality of first electrode tabs (313a, 313b) may be coupled to each other on both sides (511) of the first current collector plate (510) in an alternating manner. That is, the plurality of first electrode tabs (313a, 313b) coupled to the first current collector plate (510) may not overlap each other when viewed in the width direction (y direction). Some of the first electrode tabs (313a) and other parts of the first electrode tabs (313b) may be coupled asymmetrically to both sides (511) of the first current collector plate (510).

[0111] If the first electrode tab (313) is bent and coupled to the upper surface of the first current collector plate (510), there is a problem in that the length of the first electrode tab (313) increases, thereby increasing the resistance to current.

[0112] Conversely, if the first electrode tab (313) is bent and coupled to the lower surface of the first current collector plate (510) (assuming there is no current collector plate holder (500)), the distance between the first current collector plate (510) and the electrode assembly (300) increases by the bent length, causing a problem where the energy density of the secondary battery (10) decreases.

[0113] According to the structure of the present embodiment and variations, a plurality of first electrode tabs (313a, 313b) are coupled to the side (511) of the first current collector plate (510) at the same height as the first current collector plate (510). As a result, the length of the electrode tabs is short, so the resistance is reduced, and the distance between the first current collector plate (510) and the electrode assembly (300) is relatively close, so the energy density of the secondary battery (10) can be improved.

[0114]

[0115] Hereinafter, a secondary battery according to the second embodiment of the present invention will be described.

[0116] FIG. 7 is a cross-sectional view illustrating a current collection assembly of a secondary battery according to a second embodiment of the present invention, and FIG. 8 is a modified example of the current collection assembly of FIG. 7.

[0117] Since the secondary battery (10) according to the second embodiment of the present invention has the same structure as the first embodiment and modified example described above, except for the shape of the current collector holder (550), a redundant description of the repeated configuration is omitted.

[0118] As illustrated in FIG. 7, the side (551) of the collector plate holder (550) may have an inclined cross-section. For example, the side (551) of the collector plate holder (550) may be inclined so that its width increases from the bottom to the top of the collector plate holder (550).

[0119] At this time, the side (511) of the first collector plate (510) may be continuously connected to the side (551) of the collector plate holder (550). That is, the first collector plate (510) may not protrude or sink beyond the collector plate holder (550) in the width direction (y direction). That is, the width (W) of the first collector plate (510) may be equal to the maximum value of the width of the collector plate holder (550).

[0120] Although not illustrated, the corner where the inclined side (551) of the collector plate holder (550) and the lower surface of the collector plate holder (550) meet can be rounded. Accordingly, the lower surface and the side (551) of the collector plate holder (550) can be smoothly connected.

[0121] Referring to FIG. 8, the side (551) and the bottom surface of the collector plate holder (550) may form a single curved surface. For example, the side (551) and the bottom surface of the collector plate holder (550) may form a curved surface that is convex downward.

[0122] In the case of the present embodiment and variations, the side (551) of the current collector holder (550) can be formed at an angle, rounded, or formed as a single curved surface together with the bottom surface, thereby allowing the plurality of first electrode tabs (313, see FIG. 5) to be smoothly bent. As a result, the risk of disconnection of the first electrode tabs (313) is reduced, and the electrical stability of the secondary battery (10) can be improved.

[0123]

[0124] A secondary battery according to the third embodiment of the present invention will be described below.

[0125] FIG. 9 is a top view of a current collection assembly of a secondary battery according to a third embodiment of the present invention, FIG. 10 is a top view showing an electrode tab coupled to the current collection assembly of FIG. 9, and FIG. 11 is a modified example of the electrode tab and current collection assembly of FIG. 10.

[0126] The secondary battery (10) according to the third embodiment of the present invention is made of the same structure as the first embodiment and modified example described above, except for the structure of the first cut portion (512a, 512b) and the second cut portion (532a, 532b), so a redundant description of the repeated configuration is omitted.

[0127] In addition, since the second incision (532a, 532b) in this embodiment is formed with the same shape as the first incision (512a, 512b), the first incision (512a, 512b) is described as an example and a redundant description of the second incision (532a, 532b) is omitted.

[0128] As shown in FIG. 9, a first cut (512a, 512b) may be formed on the width direction (y direction) side of the first collector plate (510).

[0129] The first cut may be formed as a single one-sided portion in the width direction (y direction) of the first collector plate (510), but alternatively, the first cut portions (512a, 512b) may be formed as multiple portions on both sides in the width direction (y direction) of the first collector plate (510).

[0130] For example, one first incision (512a) may be formed by partially cutting the side of the first collector plate (510) in the +y direction. Another first incision (512b) may be formed by partially cutting the side of the first collector plate (510) in the -y direction.

[0131] At this time, the first cut portion (512a) and the first cut portion (512b) may be formed in the same row. That is, a plurality of first cut portions (512a, 512b) may be formed at overlapping positions when the first collector plate (510) is viewed in the width direction (y direction). A plurality of first cut portions (512a, 512b) may be formed symmetrically on both sides of the first collector plate (510) in the width direction (y direction).

[0132] As shown in FIG. 10, when a plurality of first electrode tabs (313a, 313b) are formed in the same row, the plurality of first electrode tabs (313a, 313b) can be inserted into corresponding first cut portions (512a, 512b).

[0133] A portion of the first electrode tab (313a) can be inserted into the first cut (512a) and coupled to the +y direction side (511) of the first current collector plate (510). Another portion of the first electrode tab (313b) can be inserted into the first cut (512b) on the opposite side and coupled to the -y direction side (511) of the first current collector plate (510).

[0134] That is, a plurality of first electrode tabs (313a, 313b) can each be inserted into a first cut portion (512a, 512b) and symmetrically coupled to both sides (511) of the first current collector plate (510). The plurality of first electrode tabs (313a, 313b) coupled to both sides (511) can be coupled at an overlapping position when viewed in the width direction (y direction).

[0135] Alternatively, as shown in FIG. 11, when multiple first electrode tabs (313a, 313b) are formed in different rows, a current collection assembly (500) in which first cut portions (512a, 512b) are formed in different rows may be used.

[0136] Referring to FIG. 11, a plurality of first cuts (512a, 512b) are formed on both sides in the width direction (y direction) of the first collector plate (510), and the first cuts (512a) and the first cuts (512b) may be formed in different rows.

[0137] That is, a plurality of first cut sections (512a, 512b) may be formed at positions that are staggered from each other when the first collector plate (510) is viewed in the width direction (y direction). When the first collector plate (510) is viewed in the width direction (y direction), a plurality of first cut sections (512a, 512b) may be formed at positions that do not overlap each other. A plurality of first cut sections (512a, 512b) may be formed asymmetrically on both sides of the first collector plate (510) in the width direction (y direction).

[0138] A plurality of first electrode tabs (313a, 313b) formed in different rows can be inserted into corresponding first cuts (512a, 512b). A plurality of first electrode tabs (313a, 313b) inserted into each first cut (512a, 512b) can be coupled to the +y direction side (511) and the -y direction side (511) of the first current collector plate (510).

[0139] In the case of the present embodiment and variations, first cut portions (512a, 512b) are formed on both sides in the width direction (y direction) of the first current collector plate (510), and a plurality of first electrode tabs (313a, 313b) can be inserted into the corresponding first cut portions (512a, 512b) and each can be coupled to the side (511) of the first current collector plate (510).

[0140] Therefore, the first electrode tabs (313a, 313b) are not excessively bent to be coupled to both sides (511) of the first current collector plate (510), thereby reducing the risk of disconnection and improving the electrical stability of the secondary battery (10).

[0141]

[0142] Hereinafter, a secondary battery according to the fourth embodiment of the present invention will be described.

[0143] FIG. 12 is a cross-sectional view of a secondary battery according to the fourth embodiment of the present invention.

[0144] Since the secondary battery (10) according to the fourth embodiment of the present invention has the same structure as the first embodiment and modified example described above, except for the structure of the first current collector plate (510), a redundant description of the repeated configuration is omitted.

[0145] As shown in FIG. 12, the width (W) of the first collector plate (510) may be larger than the width (W2) of the collector plate holder (550). Accordingly, both ends of the first collector plate (510) in the width direction (y direction) may protrude in the width direction (y direction) relative to the side (551) of the collector plate holder (550).

[0146] At this time, the side end in the width direction (y direction) of the first collector plate (510) can be bent.

[0147] Specifically, the side end in the width direction (y direction) of the first collector plate (510) can be bent in the -z direction. The bent side end of the first collector plate (510) can wrap around the side (551) of the collector plate holder (550).

[0148] The first collector plate (510) may have both ends in the width direction (y direction) bent, and in this case, the bent ends of the first collector plate (510) may wrap around both sides (551) in the width direction (y direction) of the collector plate holder (550).

[0149] The bent ends of the first collector plate (510) can have cross-sections of both sides (511) perpendicular to the upper surface of the first collector plate (510).

[0150] As described above, a plurality of first electrode tabs (313a, 313b) can each be connected to both sides (511) of the first current collector plate (510).

[0151] In this case, since the width direction (y-direction) side of the current collection assembly (500) corresponds to the side (511) of the first current collection plate (510), the area where multiple first electrode tabs (313a, 313b) are joined can be increased. Accordingly, welding of the first current collection plate (510) and multiple first electrode tabs (313a, 313b) can be made easier.

[0152] Meanwhile, although not illustrated, the two sides (511) of the first collector plate (510) may have an inclined cross-section as in FIG. 7 or a curved cross-section as in FIG. 8.

[0153] In this case, since the area of ​​the side (511) of the first current collector plate (510) to which the plurality of first electrode tabs (313a, 313b) are joined is further increased, welding of the first current collector plate (510) and the plurality of first electrode tabs (313a, 313b) can be made easier.

[0154]

[0155] Referring again to FIG. 3, the secondary battery (10) according to the present invention can align one of the connection terminals (513, 533) to a corresponding terminal hole and align the other connection terminal to 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 to a 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.

[0156] In addition, in the secondary battery (10) according to the present invention, electrode tabs (313, 333) are each coupled to the side (511, 531) of the current collector (510, 530) at the same height as the current collector (510, 530). Accordingly, the length of the electrode tabs (313, 333) can be manufactured to be short, thereby reducing resistance, and the overall height of the secondary battery (10) can be lowered, thereby improving energy density.

[0157] 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. Case; An electrode assembly that is housed in the above case and includes a first electrode and a second electrode; A first electrode tab coupled to the first electrode; A second electrode tab coupled to the second electrode; A current collection assembly comprising a current collection plate holder formed of an insulating material, a first current collection plate coupled to the upper side of one side of the current collection plate holder and having 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 second connection terminal formed thereon; and It includes a cap assembly that seals the above case and has 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 electrode tab is coupled to the side of the first current collector plate and the second electrode tab is coupled to the side of the second current collector plate.

2. In Paragraph 1, A secondary battery in which the first electrode tabs are provided in plurality.

3. In Paragraph 2, A secondary battery in which the plurality of first electrode tabs are coupled to both sides in the width direction of the first current collector plate.

4. In Paragraph 2, A secondary battery in which the plurality of first electrode tabs are arranged in the same row.

5. In Paragraph 2, A secondary battery in which at least one of the plurality of first electrode tabs has an end perpendicular to the upper surface of the first current collector plate.

6. In Paragraph 2, A secondary battery in which the plurality of first electrode tabs are arranged in different rows.

7. In Paragraph 1, A secondary battery having a side of the above-mentioned current collector holder having an inclined cross-section.

8. In Paragraph 1, A secondary battery in which the side and bottom surfaces of the above-mentioned current collector holder form a single curved surface.

9. In Paragraph 1, The above-mentioned first current collector plate is a secondary battery in which one side in the width direction is cut to form a first cut portion.

10. In Paragraph 9, The above first incision is formed in multiple numbers, and A secondary battery in which the plurality of first cuts are located on both sides in the width direction of the first current collector plate.

11. In Paragraph 10, The above plurality of first incisions are, A secondary battery formed at an overlapping position when the first current collector plate is viewed in the width direction.

12. In Paragraph 10, The above plurality of first incisions are, A secondary battery formed at staggered positions when the first current collector plate is viewed in the width direction.

13. In Paragraph 1, The above-mentioned first collector plate is, A secondary battery having a side end that is bent to wrap around the side of the current collector holder.

14. In Paragraph 1, A secondary battery in which the width of the first current collector plate is smaller than the width of the electrode assembly.

15. 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.

16. In Paragraph 15, 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.

17. A battery module comprising a secondary battery according to any one of claims 1 to 16.

18. A battery pack comprising a battery module according to claim 17.

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