Secondary battery

Abstract

Provided is a secondary battery comprising: a stack-type electrode assembly having a plurality of unit batteries stacked in a first direction and having respective electrode tabs of the plurality of unit batteries at opposite ends of the stack-type electrode assembly in a second direction perpendicular to the first direction; a multi-functional terminal block (MTB) provided at the opposite ends of the stack-type electrode assembly; and a laminate sheet surrounding the side surface of the stack-type electrode assembly, wherein the MTB comprises: a bus bar structure electrically connected to the electrode tabs; and an MTB housing accommodating the bus bar structure, and the bus bar structure comprises: a first bus bar plate into which the plurality of electrode tabs are inserted together; and a second bus bar plate in surface contact with the first bus bar plate.

Description

secondary batteries

[0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery having a busbar structure capable of connecting a plurality of electrode tabs simply and with high reliability.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0170392, filed November 30, 2023, the entire disclosure of which is incorporated herein by reference.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged multiple times. They are widely used as a power source for various wireless devices, including handsets, laptops, and cordless vacuum cleaners. Recently, improved energy density and economies of scale have dramatically reduced the per-unit manufacturing cost of secondary batteries. Furthermore, as the range of battery electric vehicles (BEVs) has increased to match that of fuel-powered vehicles, the primary use of secondary batteries is shifting from mobile devices to mobility.

[0004] Meanwhile, demand for large-capacity battery packs for electric vehicles and other applications is increasing. Large-capacity battery packs installed in automobiles are expected to increase capacity and enhance safety.

[0005] The technical problem to be achieved by the present invention is to provide a secondary battery having a busbar structure capable of connecting a plurality of electrode tabs simply and with high reliability.

[0006] In order to achieve the above technical problem, the present invention provides a secondary battery including a stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and each of the plurality of unit cells has electrode tabs at both ends in a second direction perpendicular to the first direction; a multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and a laminate sheet covering a side surface of the stacked electrode assembly, wherein the MTB includes a busbar structure electrically connected to the electrode tabs and an MTB housing that accommodates the busbar structure, and the busbar structure includes a first busbar plate into which a plurality of electrode tabs are inserted together and a second busbar plate in surface contact with the first busbar plate.

[0007] In some embodiments, the first busbar plate includes two or more slits, each slit into which a plurality of electrode tabs can be inserted.

[0008] In some embodiments, the stacked electrode assembly includes two or more electrode groups, and electrode tabs included in one electrode group can be inserted into one slit.

[0009] In some embodiments, the second busbar plate may be in surface contact with the first busbar plate with the ends of the plurality of electrode tabs interposed therebetween.

[0010] In some embodiments, the second busbar plate may include a first portion in surface contact with the first busbar plate and a second portion extending from the first portion and bent.

[0011] In some embodiments, the second portion may be electrically connected to an electrode terminal portion of the MTB.

[0012] In some embodiments, the second portion may extend and be bent 180 degrees from the first portion.

[0013] In some embodiments, the first busbar plate and the second busbar plate can be area welded.

[0014] In some embodiments, the first busbar plate and the second busbar plate may be joined by an electromagnetic pulse technique (EMPT).

[0015] Another aspect of the present invention provides a secondary battery comprising: a stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and have electrode tabs of each of the plurality of unit cells at opposite ends in a second direction perpendicular to the first direction; a multifunctional terminal block (MTB) provided at the opposite ends of the stacked electrode assembly; and a laminate sheet wrapping a side surface of the stacked electrode assembly, wherein the MTB includes a busbar structure electrically connecting the electrode tabs and an MTB housing accommodating the busbar structure, wherein the busbar structure includes a first busbar plate and a second busbar plate in surface contact with each other, and the second busbar plate includes a first portion in surface contact with the first busbar plate and a second portion extended from the first portion and bent.

[0016] In some embodiments, the first portion includes a plurality of slits into which electrode tabs can be inserted, and a plurality of electrode tabs can be inserted into each of the plurality of slits.

[0017] In some embodiments, the plurality of electrode tabs may extend between the first busbar plate and the second busbar plate.

[0018] In some embodiments, the plurality of electrode tabs may be integrated between the first busbar plate and the second busbar plate such that an interface with at least one of the first busbar plate and the second busbar plate is not identified.

[0019] In some embodiments, the second portion may extend and be bent 180 degrees from the first portion.

[0020] In some embodiments, the first portion of the first busbar plate and the second busbar plate may be joined by an electromagnetic pulse technique (EMPT).

[0021] The secondary battery of the present invention has the effect of connecting a plurality of electrode tabs to a busbar structure in a simple yet highly reliable manner.

[0022] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0023] Figure 1 is a perspective view showing the main parts of a secondary battery according to one embodiment of the present invention.

[0024] Fig. 2 is a partial perspective view showing an enlarged portion of a part of the secondary battery of Fig. 1.

[0025] Figure 3 is a schematic perspective view showing the appearance of the laminate sheet removed from the secondary battery of Figure 1.

[0026] Figure 4 is an exploded perspective view showing an end portion of a secondary battery according to one embodiment of the present invention.

[0027] Figure 5 is a schematic diagram showing a cross-section of the secondary battery shown in Figure 4, cut through the electrode terminal portion.

[0028] Figure 6 is a conceptual diagram illustrating a method of joining multiple electrode tabs to a first busbar plate and a second busbar plate.

[0029] Figures 7 to 9 are conceptual diagrams showing aspects in which a plurality of electrode tabs are integrated when the first busbar plate and the second busbar plate are joined.

[0030] Figure 10 is a schematic side view showing the main part of a secondary battery end according to one embodiment of the present invention.

[0031] Fig. 11 is a partially exploded perspective view showing a method of bonding laminate sheets of a secondary battery according to one embodiment of the present invention.

[0032] Fig. 12 is a partial cross-sectional view of a laminate sheet according to one embodiment of the present invention.

[0033] FIG. 13 is a schematic perspective view of a battery pack according to one embodiment of the present invention.

[0034] Fig. 14 is an exploded perspective view schematically illustrating the configuration of the battery pack of Fig. 13.

[0035] Figure 15 is a perspective view showing the battery cells of Figure 14 mounted in a pack housing.

[0036] Figure 16 is an exploded perspective view showing an end portion of a secondary battery according to another embodiment of the present invention.

[0037] Figure 17 is a schematic diagram showing a cross-section of the secondary battery illustrated in Figure 16, cut through the electrode terminal portion.

[0038] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments of the present invention may be modified in various different forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. It is preferable to interpret that the embodiments of the present invention are provided to more completely explain the present invention to those of ordinary skill in the art. Like numbers refer to like elements throughout. Furthermore, various elements and areas in the drawings are schematically drawn. Therefore, the present invention is not limited by the relative sizes or spacings depicted in the accompanying drawings.

[0039] While terms like "first" and "second" may be used to describe various components, these components are not limited by these terms. These terms are used solely to distinguish one component from another. For example, a first component could be referred to as a "second component," and vice versa, without departing from the scope of the present invention.

[0040] The terminology used in this application is only used to describe specific embodiments and is not intended to limit the inventive concept. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, it should be understood that the expressions "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, operations, components, parts, or combinations thereof.

[0041] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by those of ordinary skill in the art to which the present invention pertains. Furthermore, it is to be understood that commonly used terms, such as those defined in dictionaries, should be interpreted to have a meaning consistent with their meaning within the relevant technical context, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0042] In some embodiments, where implementations are otherwise feasible, specific process sequences may be performed in a different order than described. For example, two processes described in succession may be performed substantially simultaneously, or in a reverse order from the described order.

[0043] In the accompanying drawings, variations in the shapes depicted may be expected, for example, depending on manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to the specific shapes of the regions depicted herein, but should include, for example, changes in shapes resulting from the manufacturing process. All terms "and / or" used herein include each and every combination of one or more of the mentioned components. In addition, the term "substrate" used herein may mean the substrate itself, or a laminated structure including the substrate and a predetermined layer or film formed on the surface thereof. In addition, the "surface of the substrate" in this specification may mean the exposed surface of the substrate itself, or the outer surface of a predetermined layer or film formed on the substrate.

[0044]

[0045] (Example 1)

[0046] Fig. 1 is a perspective view showing the main part of a secondary battery (100) according to one embodiment of the present invention. Fig. 2 is a partial perspective view showing an enlarged portion of a part of the secondary battery (100) of Fig. 1. Fig. 3 is a schematic perspective view showing the secondary battery (100) of Fig. 1 with the laminate sheet (130) removed.

[0047] In the drawings below, the secondary battery (100) is illustrated as being defined in a vertical coordinate system defined by a first direction along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis, which are perpendicular to each other, but the first direction, the second direction, and the third direction are not particularly limited as long as they are relatively perpendicular to each other.

[0048] Referring to FIGS. 1 to 3, the secondary battery (100) includes a stacked electrode assembly (110), a multifunctional terminal block (MTB) (120a, 120b), and a laminate sheet (130).

[0049] The stacked electrode assembly (110) may include a plurality of unit cells (111) stacked in a first direction (e.g., X-axis direction). Each of the unit cells (111) may have an electrode material applied on a metal foil that acts as a current collector.

[0050] Each of the unit cells (111) may have a thin plate-shaped body extending in a second direction (e.g., the Y-axis direction). Each of the unit cells (111) may be a positive electrode unit cell or a negative electrode unit cell. In some embodiments, the plurality of unit cells (111) may be formed by alternately stacking positive electrode unit cells and negative electrode unit cells one by one. The positive electrode unit cell and the negative electrode unit cell may be separated from each other by a separator.

[0051] In some other embodiments, the plurality of unit batteries (111) may be formed by alternately stacking a plurality of positive unit batteries and a plurality of negative unit batteries. The plurality of positive unit batteries and the plurality of negative unit batteries may be separated from each other by a separator.

[0052] The stacked electrode assembly (110) may have electrode tabs (116) at both ends in the second direction (e.g., Y-axis direction). The electrode tabs (116) may be extensions of the non-conductive portions of the current collectors of the plurality of unit cells (111).

[0053] The stacked electrode assembly (110) may include a first electrode group (110a) and a second electrode group (110b) stacked in a first direction (e.g., in the X-axis direction). The unit cells (111) of the first electrode group (110a) are stacked in the first direction (e.g., in the X-axis direction), and the electrode tabs (116) of the unit cells (111) may be joined to each other on both sides. In addition, the unit cells (111) of the second electrode group (110b) are stacked in the first direction (e.g., in the X-axis direction), and the electrode tabs (116) of the unit cells (111) may be joined to each other on both sides.

[0054] In some embodiments, the first electrode group (110a) may have first electrode tabs (116a) laminated with a predetermined polarity on one side and second electrode tabs (116b) laminated with a different polarity on the other side. In addition, the second electrode group (110b) may have third electrode tabs (116c) laminated with a predetermined polarity on one side and fourth electrode tabs (116d) laminated with a different polarity on the other side.

[0055] A first MTB (120a) may be provided at one end of the stacked electrode assembly (110) in the second direction (e.g., Y-axis direction), and a second MTB (120b) may be provided at the other end. One of the first MTB (120a) and the second MTB (120b) may be electrically connected to the positive electrode side of the stacked electrode assembly (110), and the other may be electrically connected to the negative electrode side of the stacked electrode assembly (110). The second MTB (120b) may have substantially the same configuration as the first MTB (120a) except for the polarity. Hereinafter, the first MTB (120a) will be described, but a person skilled in the art will be able to understand the configuration of the second MTB (120b) therefrom.

[0056] In some embodiments, the first MTB (120a) may include an MTB housing (122), an electrode terminal portion (124) accommodated within the MTB housing (122), and a busbar structure (125) (see FIG. 4) electrically connecting the electrode terminal portion (124) and the joined electrode tabs (116).

[0057] The MTB housing (122) may include a material having relatively high rigidity, such as metal, and defines the exterior of the first MTB (120a). In some embodiments, the MTB housing (122) may be made of aluminum (Al), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), manganese (Mn), or an alloy containing one or more of these.

[0058] The MTB housing (122) may include a through hole (122h) exposing the electrode terminal portion (124) described below. The through hole (122h) may be provided in the MTB housing (122) so that the electrode terminal portion (124) is exposed toward the second direction (e.g., Y-axis direction). Therefore, the through hole (122h) may be provided on a plane perpendicular to the second direction (e.g., Y-axis direction) of the MTB housing (122). In addition, the through hole (122h) may have an opening that is open in the longitudinal direction of the electrode assembly (110). The shape of the through hole (122h) may be configured to match the outer shape of the portion where the electrode terminal portion (124) is exposed to the outside.

[0059] In some embodiments, the electrode terminal portion (124) may have an exposed surface facing outward from the MTB housing (122) that is flat. In some embodiments, the exposed surface may have a flat surface extending perpendicular to the second direction (e.g., the Y-axis direction). In some embodiments, the electrode terminal portion (124) may have a free surface in the shape of a disk and may be exposed to the outside.

[0060] In some embodiments, an electrically insulating insulating gasket (129) may be provided between the electrode terminal portion (124) and the MTB housing (122) so that the electrode terminal portion (124) is electrically insulated from the MTB housing (122).

[0061] In some embodiments, the first MTB (120a) may include a venting disk configured to rupture when the internal pressure of the secondary battery (100) excessively increases, thereby releasing gas that causes the excessively increased internal pressure. The venting disk is not restored to its original state when it ruptures due to a thermal event occurring within the secondary battery (100). The venting disk may be any venting disk known in the art and is not particularly limited.

[0062] In some embodiments, the MTB housing (122) may further include a fusion resin layer (122p) on the side.

[0063] The above-mentioned fusion resin layer (122p) is a layer of thermoplastic resin, and may contain, for example, one or more of polyolefin resin, polyester resin, polyamide resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyacrylonitrile, polyurethane, polycarbonate, polyacetal, polyacrylate, and modified polyvinyl alcohol resin.

[0064] The above polyolefin resin includes, for example, polyethylene, polypropylene, poly(1-butene), poly(4-methyl-1-pentene), an ethylene-propylene copolymer, a copolymer of ethylene and an α-olefin having 4 or more carbon atoms, a copolymer of polyolefin and maleic anhydride, an ethylene-vinyl ester copolymer, an ethylene-acrylic acid ester copolymer, or a modified polyolefin obtained by graft-modifying these with an unsaturated carboxylic acid or a derivative thereof, but the present invention is not limited thereto.

[0065] The above polyester resin includes polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate, but the present invention is not limited thereto.

[0066] The above polyamide resin includes nylon 6, nylon 6·6, nylon 6 / 66 copolymer, nylon 11, nylon 12, or poly(m-xylene adipamide), but the present invention is not limited thereto.

[0067] The above-mentioned fusion resin layer (122p) may be cast, or may be stretched or rolled in one or two axes.

[0068] In some embodiments, the fusion resin layer (122p) may at least partially cover a side surface of the MTB housing (122). In some embodiments, the fusion resin layer (122p) may extend from an inner end (122ie) of the side surface of the MTB housing (122) toward an outer end (122oe) of the side surface of the MTB housing (122). Here, the inner end (122ie) refers to an end adjacent to the electrode tabs (116). In some embodiments, the fusion resin layer (122p) may surround a side surface of the MTB housing (122) with a predetermined width between the inner end (122ie) and the outer end (122oe). In some embodiments, the fusion resin layer (122p) may extend along the side of the MTB housing (122) with a predetermined width between the inner end (122ie) and the outer end (122oe).

[0069] In some embodiments, the fusion resin layer (122p) may surround a side surface of the MTB housing (122) while having a constant width between the inner end (122ie) and the outer end (122oe). In some embodiments, the fusion resin layer (122p) may extend in a first direction (e.g., X-axis direction) and / or a third direction (e.g., Z-axis direction) while having a constant width between the inner end (122ie) and the outer end (122oe).

[0070] In some embodiments, the fusion resin layer (122p) may extend along the side of the MTB housing (122) with a constant width between the inner end (122ie) and the outer end (122oe).

[0071] In some embodiments, the fusion resin layer (122p) may cover the entire side surface of the MTB housing (122).

[0072] The above-mentioned fusion resin layer (122p) may have a thickness of, for example, about 20 μm to about 400 μm. In some embodiments, the fusion resin layer (122p) may have a thickness of from about 20 μm to about 400 μm, from about 30 μm to about 380 μm, from about 40 μm to about 360 μm, from about 50 μm to about 340 μm, from about 60 μm to about 320 μm, from about 70 μm to about 300 μm, from about 80 μm to about 280 μm, from about 90 μm to about 260 μm, from about 100 μm to about 240 μm, from about 110 μm to about 220 μm, from about 120 μm to about 200 μm, from about 130 μm to about 180 μm, from about 140 μm to about 160 μm, or a range between any two of these values.

[0073] If the thickness of the above-mentioned fusion resin layer (122p) is too thin, the mechanical strength may be insufficient. If the thickness of the above-mentioned fusion resin layer (122p) is too thick, it may be economically disadvantageous.

[0074] The above-mentioned fusion resin layer (122p) may be fused with the laminate sheet (130). In some embodiments, the above-mentioned fusion resin layer (122p) may extend from an end portion (130e) of the laminate sheet (130). In some embodiments, the above-mentioned fusion resin layer (122p) may be exposed from an edge portion (130e) of the laminate sheet (130) and then extend toward the outer end portion (122oe).

[0075] In some embodiments, the first MTB (120a) may further include a check valve (128). The check valve (128) may be configured to open to discharge internal gas when the internal pressure of the secondary battery (100) becomes higher than a predetermined pressure, and to close again when the internal pressure is relieved by the discharge of the gas. The check valve (128) does not have a part that is ruptured by the discharge of the gas, and can be restored to its original state after the discharge of the internal gas.

[0076] The secondary battery (100) further includes an electrolyte. The electrolyte may be an electrolyte used for a typical lithium secondary battery and is not particularly limited. In some embodiments, the electrolyte may be injected immediately before sealing the laminate sheet (130). In some embodiments, the electrolyte may be injected through an electrolyte injection port provided in the first MTB (120a) after sealing the laminate sheet (130).

[0077]

[0078] Figure 4 is an exploded perspective view showing an end portion of a secondary battery (100) according to one embodiment of the present invention.

[0079] Referring to FIG. 4, the first MTB (120a) includes an MTB housing (122), a bus bar structure (125) housed inside the MTB housing (122), and an electrode terminal portion (124) electrically connected to the bus bar structure (125).

[0080] The above busbar structure (125) can be electrically connected to the electrode tabs (116a, 116c) of the stacked electrode assembly (110). The above busbar structure (125) can electrically connect the electrode tabs (116a, 116c) and the electrode terminal portion (124).

[0081] The above busbar structure (125) may include a first busbar plate (1251) and a second busbar plate (1252). The first busbar plate (1251) and the second busbar plate (1252) are electrically connected to each other. In some embodiments, the first busbar plate (1251) and the second busbar plate (1252) may be area-welded to each other.

[0082] In some embodiments, the first busbar plate (1251) and the second busbar plate (1252) may each be independently made of copper (Cu), nickel (Ni), aluminum (Al), iron (Fe), cobalt (Co), platinum (Pt), molybdenum (Mo), tin (Sn), palladium (Pd), or an alloy including one or more of these.

[0083] In some embodiments, the first busbar plate (1251) may be a generally flat plate. The first busbar plate (1251) may include slits (1251s) through which the electrode tabs (116a, 116c) may pass. The first electrode tabs (116a) may have a corresponding slit (1251s). In addition, the third electrode tabs (116c) may have a corresponding slit (1251s). Those skilled in the art will appreciate that the second electrode tabs (116b) and the fourth electrode tabs (116d) may also have corresponding slits within the first busbar plate accommodated within the second MTB (120b).

[0084] Specifically, the first electrode tabs (116a) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a first electrode group (110a), and are inserted into one slit (1251s). In addition, the third electrode tabs (116c) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a second electrode group (110b), and are inserted into another slit (1251s). That is, electrode tabs (116a, 116c) included in one electrode group (110a, 110b) can be inserted into one slit (1251s).

[0085] The second busbar plate (1252) may include a first portion (1252a) configured to be in surface contact with the first busbar plate (1251). In addition, the second busbar plate (1252) may include a second portion (1252b) that is electrically connected to the first portion (1252a) and extends by bending from the first portion (1252a). In some embodiments, the second portion (1252b) may extend by bending 180 degrees from the first portion (1252a). The second portion (1252b) may be electrically connected to the electrode terminal portion (124).

[0086] In some embodiments, the first portion (1252a) of the second busbar plate (1252) may extend substantially parallel to the second portion (1252b). The first portion (1252a) and the second portion (1252b) may be two portions positioned on opposite sides of a single folded flat plate.

[0087] The busbar structure (125) may be housed within the MTB housing (122). The busbar structure (125) may be electrically connected to an electrode terminal portion (124) extending through a through-hole (122h) of the MTB housing (122). In some embodiments, the busbar structure (125) may be configured to be in direct contact with the electrode terminal portion (124). In some embodiments, the electrode terminal portion (124) may be configured to be in direct contact with a second busbar plate (1252) of the busbar structure (125). In some embodiments, the electrode terminal portion (124) may be configured to be in direct contact with a second portion (1252b) of the second busbar plate (1252).

[0088] Although the first MTB (120a) has been described above, a person skilled in the art will understand from the above description that the second MTB (120b) located on the opposite side of the first MTB (120a) can also be configured in the same manner.

[0089]

[0090] Figure 5 is a schematic diagram showing a cross-section of the secondary battery (100) shown in Figure 4, cut through the electrode terminal portion (124).

[0091] Referring to FIG. 5, a plurality of electrode tabs (116a, 116c) may extend between a first busbar plate (1251) and a second busbar plate (1252). In some embodiments, the plurality of electrode tabs (116a, 116c) may extend along an interface between the first busbar plate (1251) and the second busbar plate (1252) after penetrating through a slit (1251s) of the first busbar plate (1251). In some embodiments, the plurality of electrode tabs (116a, 116c) may extend in a first direction (e.g., an X-axis direction) between the first busbar plate (1251) and the second busbar plate (1252).

[0092] As illustrated in FIG. 5, the ends of the plurality of electrode tabs (116a, 116c) have two sides extending in parallel. In some embodiments, one side of the ends of the plurality of electrode tabs (116a, 116c) may be in contact with a first bus bar plate (1251) and may extend in a first direction (e.g., in the X-axis direction). In some embodiments, the other side of the ends of the plurality of electrode tabs (116a, 116c) may be in contact with a second bus bar plate (1252) and may extend in the first direction (e.g., in the X-axis direction).

[0093] In some embodiments, the plurality of electrode tabs (116a, 116c) may include a shock absorbing portion that is bent in a predetermined direction in a portion that is not inserted into the slit (1251s).

[0094]

[0095] FIG. 6 is a conceptual diagram illustrating a method of combining the plurality of electrode tabs (116a) with the first bus bar plate (1251) and the second bus bar plate (1252).

[0096] Referring to Fig. 6, the plurality of electrode tabs (116a) can be passed through a slit (1251s) formed in the first bus bar plate (1251). Thereafter, the ends of the plurality of electrode tabs (116a) can be bent in one direction. At this time, the ends of the plurality of electrode tabs (116a) may not be in close contact with the first bus bar plate (1251).

[0097] Then, the second busbar plate (1252) can be brought into contact with the first busbar plate (1251) and then area-welded. In other words, the first busbar plate (1251) and the second busbar plate (1252) can be area-welded while the ends of the plurality of electrode tabs (116a) are interposed between the first busbar plate (1251) and the second busbar plate (1252). In some embodiments, the welding of the first busbar plate (1251) and the second busbar plate (1252) can be cold welding.

[0098] Methods for area welding include, for example, explosion welding, compression welding, and electromagnetic pulse technique (EMPT). In some embodiments, the second busbar plate (1252) can be joined to the first busbar plate (1251) by EMPT. When EMPT is used to join the first busbar plate (1251) and the second busbar plate (1252), a strong electrical repulsive force (see arrow direction) can be applied to the second busbar plate (1252) while the first busbar plate (1251) is fixed.

[0099] Area welding can have a stronger bonding strength than bonding methods that bond only along a specific line or only at a specific point because the second busbar plate (1252) is bonded to the first busbar plate (1251) over a specific area. In particular, the EMPT method can bond the first busbar plate (1251) and the second busbar plate (1252) with high reliability and at a high speed.

[0100] By joining the first busbar plate (1251) and the second busbar plate (1252), the ends of the plurality of electrode tabs (116a) come into close contact with the first busbar plate (1251) and / or the second busbar plate (1252). In some embodiments, the ends of the plurality of electrode tabs (116a) may be integrated with the first busbar plate (1251). In some embodiments, the ends of the plurality of electrode tabs (116a) may be integrated with the second busbar plate (1252).

[0101] Conventionally, in order to electrically connect multiple electrode tabs to a busbar, the multiple electrode tabs had to be first welded together and then welded to electrode leads. However, in embodiments of the present invention, not only is the electrode lead omitted, but multiple electrode tabs belonging to each electrode group are inserted into a busbar structure and then all electrode tabs are welded at once, so the manufacturing process can be significantly simplified. Furthermore, since the electrode tabs are cold-welded in an area-wise manner, they can be joined to the busbar structure with high reliability and joint strength, and defects due to welding burn can be prevented.

[0102]

[0103] Figures 7 to 9 are conceptual diagrams showing aspects in which a plurality of electrode tabs (116) are integrated when the first bus bar plate (1251) and the second bus bar plate (1252) are joined.

[0104] Referring to FIG. 7, the first busbar plate (1251) and the second busbar plate (1252) can be brought into close contact with each other by being joined. The plurality of electrode tabs (116) can extend between the busbar plate (1251) and the second busbar plate (1252) after passing through the slit of the first busbar plate (1251). By joining the first busbar plate (1251) and the second busbar plate (1252), the plurality of electrode tabs (116) can be integrated with the second busbar plate (1252). In some embodiments, the plurality of electrode tabs (116) can be integrated with the second busbar plate (1252) such that the interface is not confirmed. In FIG. 7, the dotted line between the plurality of electrode tabs (116) and the second bus bar plate (1252) conceptually represents the interface before complete bonding.

[0105] In some embodiments, an interface may be identified between the plurality of electrode tabs (116) and the first busbar plate (1251). However, even if the interface is identified, sufficient bonding strength and electrical conductivity may be compensated because the plurality of electrode tabs (116) and the first busbar plate (1251) are in extremely close contact.

[0106] Although FIG. 7 shows that an interface exists between the first busbar plate (1251) and the second busbar plate (1252), a person skilled in the art will understand that the interface may not be identified between the first busbar plate (1251) and the second busbar plate (1252) depending on the method and conditions of area welding.

[0107] Referring to FIG. 8, the first busbar plate (1251) and the second busbar plate (1252) are joined, so that the plurality of electrode tabs (116) can be integrated with the first busbar plate (1251). In some embodiments, the plurality of electrode tabs (116) can be integrated with the first busbar plate (1251) so that the interface is not identified. In FIG. 8, the dotted line between the plurality of electrode tabs (116) and the first busbar plate (1252) conceptually represents the interface before being completely joined.

[0108] In some embodiments, an interface may be identified between the plurality of electrode tabs (116) and the second busbar plate (1252). However, even if the interface is identified, sufficient bonding strength and electrical conductivity may be compensated because the plurality of electrode tabs (116) and the second busbar plate (1252) are in extremely close contact.

[0109] Although FIG. 8 shows that an interface exists between the first busbar plate (1251) and the second busbar plate (1252), a person skilled in the art will understand that the interface may not be identified between the first busbar plate (1251) and the second busbar plate (1252) depending on the method and conditions of area welding.

[0110]

[0111] Referring to FIG. 9, the first busbar plate (1251) and the second busbar plate (1252) are joined together, so that the plurality of electrode tabs (116) can be integrated with the first busbar plate (1251) and the second busbar plate (1252). In some embodiments, the plurality of electrode tabs (116) can be integrated with the first busbar plate (1251) and the second busbar plate (1252) so that the interface is not confirmed.

[0112] Although FIG. 9 shows that an interface exists between the first busbar plate (1251) and the second busbar plate (1252), a person skilled in the art will understand that the interface may not be identified between the first busbar plate (1251) and the second busbar plate (1252) depending on the method and conditions of area welding.

[0113]

[0114] Figure 10 is a schematic side view showing the main part of a secondary battery (100) according to one embodiment of the present invention.

[0115] Referring to FIG. 10, a busbar structure (125) is accommodated within an MTB housing (122), and the busbar structure (125) can be electrically connected to an electrode terminal portion (124). A plurality of overlapping electrode tabs (116) can extend in a first direction (e.g., X-axis direction) between the first busbar plate (1251) and the second busbar plate (1252) after passing through a slit of the first busbar plate (1251).

[0116] A first portion (1252a) of a second busbar plate (1252) may be in surface contact with the first busbar plate (1251). A second portion (1252b) of the second busbar plate (1252) may extend from the first portion (1252a) of the second busbar plate (1252) and be bent 180 degrees. The second portion (1252b) may be electrically connected to the electrode terminal portion (124). In some embodiments, the second portion (1252b) may be in direct contact with the electrode terminal portion (124). In some embodiments, the second portion (1252b) may be electrically connected to the electrode terminal portion (124) via another conductor.

[0117] In some embodiments, the first busbar plate (1251) and the second busbar plate (1252) may be electrically insulated from the MTB housing (122).

[0118] Although FIG. 10 illustrates an example in which the second bus bar plate (1252) is bent 180 degrees about the X-axis, a person skilled in the art will understand that the second bus bar plate (1252) may also be bent 180 degrees about the Z-axis.

[0119]

[0120] Fig. 11 is a partially exploded perspective view showing a method of joining a laminate sheet (130) of a secondary battery (100) according to one embodiment of the present invention. Fig. 12 is a partial cross-sectional view of a laminate sheet (130) according to one embodiment of the present invention.

[0121] Referring to FIGS. 11 and 12, the laminate sheet (130) may be configured to wrap around a side surface of the stacked electrode assembly (110). In some embodiments, the laminate sheet (130) may be attached to a side surface of the MTB (120a, 120b) so as to at least partially cover the side surface of the MTB (120a, 120b). In some embodiments, a pair of parallel edge portions (130e) of the laminate sheet (130) may cover the entire side surfaces of the MTB (120a, 120b) that are parallel to the second direction (e.g., the Y-axis direction). In some other embodiments, the pair of parallel edge portions (130e) of the laminate sheet (130) may cover only a portion of the side surfaces of the MTB (120a, 120b) that are parallel to the second direction (e.g., Y-axis direction).

[0122] The above laminate sheet (130) may include a flexible metal layer (134), an inner resin layer (132) provided on one side of the metal layer (134), and an outer resin layer (136) provided on the other side of the metal layer (134).

[0123] The metal layer (134) can maintain an appropriate thickness and prevent water vapor, oxygen, and other gases from penetrating from the outside to the inside, and can prevent electrolyte leakage. In some embodiments, the metal layer (134) may include at least one selected from iron (Fe), carbon (C), chromium (Cr), manganese (Mn), nickel (Ni), aluminum (Al), and alloys thereof, but is not limited thereto. When the metal layer (134) is made of a material containing iron, the mechanical strength is strengthened, and when it is made of an aluminum material, the flexibility is improved, and thus, aluminum metal foil is mainly used.

[0124] The above metal layer (134) can be relatively easily deformed by a force applied from the outside, and can be configured to have an appropriate thickness and mechanical strength so that cracks or holes do not occur even when repeatedly deformed.

[0125] In some embodiments, the metal layer (134) can have a thickness of about 20 micrometers (μm) to about 100 μm. In some embodiments, the thickness of the metal layer (134) can have a range of about 20 μm to about 100 μm, about 25 μm to about 95 μm, about 30 μm to about 90 μm, about 35 μm to about 85 μm, about 40 μm to about 80 μm, about 45 μm to about 75 μm, about 50 μm to about 70 μm, about 55 μm to about 60 μm, or any two of these values.

[0126] The internal resin layer (132) provided on one side of the metal layer (134) may include a heat-sealing layer. In some embodiments, the internal resin layer (132) may include a polyolefin-based material capable of performing a sealing function through fusion. In some embodiments, the internal resin layer (132) may include a modified propylene such as cast polypropylene (CPP), or a polypropylene-butylene-ethylene terpolymer.

[0127] The above inner resin layer (132) can be formed by coating or laminating one side of the above metal layer (134).

[0128] The external resin layer (136) provided on the other side of the metal layer (134) can act as a base substrate and a protective layer for forming the laminate sheet (130). The external resin layer (136) can include an insulating material such as polyethylene terephthalate (PET) or nylon.

[0129] In some embodiments, the inner resin layer (132) and the outer resin layer (136) may each have a thickness of about 10 micrometers (μm) to about 50 μm. In some embodiments, the thickness of each of the inner resin layer (132) and the outer resin layer (136) may have a thickness of about 10 μm to about 50 μm, about 12 μm to about 48 μm, about 15 μm to about 45 μm, about 17 μm to about 43 μm, about 20 μm to about 40 μm, about 22 μm to about 38 μm, about 25 μm to about 35 μm, about 27 μm to about 33 μm, or a range between any two of these values.

[0130] In some embodiments, an adhesive resin layer may be further provided between the inner resin layer (132) and the metal layer (134) and / or between the outer resin layer (136) and the metal layer (134). The adhesive resin layer may be provided for smooth adhesion between different materials. The adhesive resin layer may be formed as a single layer or multiple layers. In some embodiments, the adhesive resin layer may include a polyolefin-based resin, a polyurethane-based resin, an epoxy-based resin, or a mixture thereof.

[0131] In some embodiments, the inner resin layer (132) may be fused to a fusion resin layer (122p) provided on the side surfaces of the MTBs (120a, 120b) at both ends in the second direction (e.g., Y-axis direction). As the inner resin layer (132) surrounds the side surfaces of the MTBs (120a, 120b) and is fused to the fusion resin layer (122p), the stacked electrode assembly (110) may be sealed within the laminate sheet (130).

[0132] The inner resin layer (132) facing the first MTB (120a) can be melted by heating while in contact with the fusion resin layer (122p) on the side of the first MTB (120a) and then cooled to be fused on the side, thereby forming a first sealing portion (130m1). The inner resin layer (132) facing the second MTB (120b) can be melted by heating while in contact with the fusion resin layer (122p) on the side of the second MTB (120b) and then cooled to be fused on the side, thereby forming a second sealing portion (130m2).

[0133] The ends (130t) of the laminate sheet (130) surround the sides of the MTBs (120a, 120b) and the stacked electrode assembly (110) and are then fused to each other to form a joint (130m) (see FIG. 1). Specifically, the laminate sheet (130) can be pressed against each other in the joint (130m) so that the inner resin layers (132) face each other, and then the facing inner resin layers (132) can be fused to each other.

[0134] The above-mentioned joining part (130m) may be positioned on any one side of the stacked electrode assembly (110). In some embodiments, the joining part (130m) may surround the stacked electrode assembly (110) and be positioned in a third direction (e.g., the Z-axis direction) of the stacked electrode assembly (110).

[0135]

[0136] (Example 2)

[0137] FIG. 13 is a schematic perspective view of a battery pack (1) according to one embodiment of the present invention, FIG. 14 is an exploded perspective view schematically showing the configuration of the battery pack (1) of FIG. 13, and FIG. 15 is a perspective view showing the battery cells (100) of FIG. 14 mounted in a pack housing.

[0138] Referring to FIGS. 13 to 15, a battery pack (1) according to one embodiment of the present invention includes a plurality of battery cells (100), an electrical component assembly (500), a pack housing (300), and a pack cover (600).

[0139] The battery cells (100) are stacked in a first direction (e.g., X-axis direction), and a cooling pad (200) may be interposed between the battery cells. In some embodiments, the stack of the battery cells (100) and the cooling pad (200) may be stored directly within the pack housing (300) without being stored within another frame. However, a person skilled in the art will understand that various modifications are possible with respect to the method of storing the battery cells (100).

[0140] For example, a stack of the battery cells (100) and the cooling pads (200) may be housed in a module frame to form a battery module, and the battery modules may be housed in the pack housing (300). The module frame may be configured in the shape of a rectangular parallelepiped box that surrounds the outer surface of the stack of the battery cells (100) and the cooling pads (200) so that the stack of the battery cells (100) and the cooling pads (200) may be held inside. The module frame may be made of a metal material having high mechanical rigidity so as to sufficiently protect the battery cells (100) from swelling and external impact.

[0141] The electrical component assembly (500) may include a relay device, a current sensor, a fuse, a BMS (Battery Management System), an MSD (Manual Service Disconnector), etc. The relay device is a switching component that selectively opens and closes a charging / discharging path through which current flows, and can block the flow of charging / discharging current when an abnormality occurs in the battery pack (1). The BMS refers to a battery management device that overall controls the charging / discharging operation of battery cells (100), and can be said to be a component typically included in the battery pack (1). In addition, the MSD is a system for selectively cutting off the power of a high-voltage battery by a physical method, and cuts off the power by disconnecting the service plug when necessary.

[0142] This battery assembly (500) can be packaged together with battery cells (100) by a pack housing (300) and a pack cover (600) so as not to be exposed to the outside.

[0143] The pack housing (300) can be said to be a structure that provides a space for storing battery cells (100) and an electrical component assembly (200) inside and is provided with a bracket (332) or a mounting structure (343, 353) so that it can be coupled to the body of a vehicle.

[0144] The pack housing (300) provides mechanical support to the battery modules (100) and the electrical component assembly (500) and protects them from external impacts, etc., and therefore can be manufactured from a metal material with high rigidity.

[0145] The pack housing (300) according to the present embodiment may include a lower frame (310) provided in the form of a wide plate on which battery cells (100) can be mounted, a front frame (320), a rear frame (330), a right side frame (340), and a left side frame (350) that are vertically coupled along the edge of the lower frame (310) to form a wall. In addition, the pack housing (300) may further include a center beam (370) and cross beams (360) to define a space on which the battery cells (100) can be mounted. One end of the center beam (370) may be coupled to the front frame (320) and the other end may be coupled to the rear frame (330). In some embodiments, one end of the cross beam (360) may be coupled to the center beam (370) and the other end may be coupled to the right side frame (340) or the left side frame (350). In some embodiments, the crossbeam (360) may extend across the center beam (370) and have one end coupled to the right side frame (340) and the other end coupled to the left side frame (350).

[0146] In some embodiments, the lower frame (310), the front frame (320), the rear frame (330), the right side frame (340), the left side frame (350), and the cross beam (360) may each be an aluminum extrusion structure, and the pack housing (300) may be formed by welding and / or bolting the frames.

[0147] For example, by manufacturing the frames by extruding aluminum with a mixture of empty spaces and ribs inside and welding them to form the pack housing (300), the weight of the pack housing (300) can be reduced and the mechanical rigidity can have reliability exceeding the required level.

[0148] In some embodiments, a heat sink may be further provided within the pack housing (300). The heat sink may be provided in the form of a plate having a flow path therein to absorb and discharge heat from another object through thermal contact. In some embodiments, the lower frame (310) may include an inlet port (410a) through which cooling water may be introduced, an outlet port (410b) through which cooling water may be discharged, and a cooling water channel through which cooling water may flow.

[0149] The battery cells (100) may be electrically connected by inter-bus bars (510, 520, 530). The inter-bus bars may include a first inter-bus bar (510) that electrically connects the battery modules (100) arranged 2x2 along a first direction (e.g., X-axis direction) and a second direction (e.g., Y-axis direction). In some embodiments, the first inter-bus bar (510) may be provided at a position where the center beam (370) and the cross beam (360) intersect.

[0150] Additionally, the inter-busbars may include a second inter-busbar (520) that electrically connects the electrically connected battery cells (100) to an external load or charging system. The second inter-busbar (520) need not be directly connected to the external load or charging system, and may be connected to the external load or charging system through the electrical equipment assembly (500).

[0151] The above battery modules (100) may include a first group of battery cells (100A) positioned on one side of the center beam (370) and a second group of battery cells (100B) positioned on the other side. The inter-bus bars may include a third inter-bus bar (530) electrically connecting the first group of battery cells (100A) and the second group of battery cells (100B).

[0152]

[0153] (Example 3)

[0154] Fig. 16 is an exploded perspective view showing an end portion of a secondary battery (100) according to another embodiment of the present invention. The secondary battery (100) illustrated in Fig. 16 differs from the embodiment described with reference to Fig. 4 only in that the number of electrode groups has increased. Therefore, the following description will focus on these differences, and description of overlapping details will be omitted.

[0155] Referring to FIG. 16, the busbar structure (125) can be electrically connected to the electrode tabs (116a, 116c, 116e, 116f) of the stacked electrode assembly (110). The busbar structure (125) can electrically connect the electrode tabs (116a, 116c, 116e, 116f) and the electrode terminal portion (124).

[0156] In some embodiments, the first busbar plate (1251) may be a generally flat plate. The first busbar plate (1251) may include slits (1251s) through which the electrode tabs (116a, 116c, 116e, 116f) may pass. The first electrode tabs (116a) may have one slit (1251s) corresponding thereto. The third electrode tabs (116c) may have one slit (1251s) corresponding thereto.

[0157] An additional third electrode group (110c) may have fifth electrode tabs (116e). An additional fourth electrode group (110d) may have sixth electrode tabs (116f). The fifth electrode tabs (116e) may have a corresponding slit (1251s). The sixth electrode tabs (116f) may have a corresponding slit (1251s).

[0158] A person skilled in the art will appreciate that electrode tabs positioned opposite to the electrode tabs (116a, 116c, 116e, 116f) may also have corresponding slits within the first busbar plate accommodated within the second MTB (120b).

[0159] The first electrode tabs (116a) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a first electrode group (110a), and are inserted into one slit (1251s). The third electrode tabs (116c) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a second electrode group (110b), and are inserted into another slit (1251s). The fifth electrode tabs (116e) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a third electrode group (110c), and are inserted into one slit (1251s). The sixth electrode tabs (116f) are a plurality of electrode tabs provided on one side of a plurality of unit cells belonging to a fourth electrode group (110d), and are inserted into another slit (1251s).

[0160] That is, electrode tabs (116a, 116c, 116e, 116f) included in one electrode group (110a, 110b, 110c, 110d) can be inserted into one slit (1251s).

[0161] Although the first MTB (120a) has been described above, a person skilled in the art will understand from the above description that the second MTB (120b) located on the opposite side of the first MTB (120a) can also be configured in the same manner.

[0162]

[0163] Figure 17 is a schematic diagram showing a cross-section of the secondary battery (100) shown in Figure 16, cut through the electrode terminal portion (124).

[0164] Referring to FIG. 17, a plurality of electrode tabs (116a, 116c, 116e, 116f) may extend between a first busbar plate (1251) and a second busbar plate (1252). In some embodiments, the plurality of electrode tabs (116a, 116c, 116e, 116f) may extend along an interface between the first busbar plate (1251) and the second busbar plate (1252) after penetrating through a slit (1251s) of the first busbar plate (1251). In some embodiments, the plurality of electrode tabs (116a, 116c, 116e, 116f) may extend in a first direction (e.g., an X-axis direction) between the first busbar plate (1251) and the second busbar plate (1252).

[0165] As illustrated in FIG. 5, the ends of the plurality of electrode tabs (116a, 116c, 116e, 116f) have two sides extending in parallel. In some embodiments, one side of the ends of the plurality of electrode tabs (116a, 116c, 116e, 116f) may contact a first bus bar plate (1251) and extend in a first direction (e.g., in the X-axis direction). In some embodiments, the other side of the ends of the plurality of electrode tabs (116a, 116c, 116e, 116f) may contact a second bus bar plate (1252) and extend in the first direction (e.g., in the X-axis direction).

[0166] In some embodiments, the plurality of electrode tabs (116a, 116c, 116e, 116f) may include a shock absorbing portion that is bent in a predetermined direction at a portion that is not inserted into the slit (1251s).

[0167] While the embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, modifications to future embodiments of the present invention will not depart from the scope of the invention.

[0168] [Explanation of symbols]

[0169] 1: Battery pack

[0170] 100: Secondary battery

[0171] 110: Stacked electrode assembly

[0172] 111: Unit battery

[0173] 116, 116a, 116b, 116c, 116d, 116e, 116f: Electrode tabs

[0174] 120a: 1st MTB

[0175] 120b: 2nd MTB

[0176] 122: MTB Housing

[0177] 122h: Penetration hole

[0178] 122p: Fusion resin layer

[0179] 124: Electrode terminal section

[0180] 125: Busbar structure

[0181] 128: Check valve

[0182] 129: Insulating gasket

[0183] 130: Laminate sheet

[0184] 200: Cooling pad

[0185] 300: Pack Housing

[0186] 500: Full-scale assembly

[0187] 600: Pack Cover

[0188] 1251: First busbar plate

[0189] 1251s: Slit

[0190] 1252: Second busbar plate

[0191] 1252a: Part 1

[0192] 1252b: Part 2

Claims

1. A stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and each of the plurality of unit cells has electrode tabs at both ends in a second direction perpendicular to the first direction; A multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and A laminate sheet covering the side surface of the stacked electrode assembly; Including, The above MTB includes a busbar structure electrically connected to the electrode tabs and an MTB housing accommodating the busbar structure, A secondary battery, wherein the busbar structure includes a first busbar plate into which a plurality of electrode tabs are inserted together and a second busbar plate in surface contact with the first busbar plate.

2. In paragraph 1, The above first busbar plate includes two or more slits, A secondary battery characterized in that a plurality of electrode tabs are inserted into each slit.

3. In paragraph 2, The above stacked electrode assembly comprises two or more electrode groups, A secondary battery characterized in that electrode tabs included in one electrode group are inserted into one slit.

4. In paragraph 1, A secondary battery, characterized in that the second busbar plate is in surface contact with the first busbar plate with the ends of the plurality of electrode tabs interposed therebetween.

5. In paragraph 1, A secondary battery, characterized in that the second busbar plate includes a first portion that makes surface contact with the first busbar plate and a second portion that extends from the first portion and is bent.

6. In paragraph 5, A secondary battery, characterized in that the second part is electrically connected to the electrode terminal of the MTB.

7. In paragraph 5, A secondary battery, characterized in that the second part is extended by being bent 180 degrees from the first part.

8. In paragraph 1, A secondary battery, characterized in that the first busbar plate and the second busbar plate are area welded.

9. In paragraph 8, A secondary battery, characterized in that the first busbar plate and the second busbar plate are joined by an electromagnetic pulse technique (EMPT).

10. A stacked electrode assembly in which a plurality of unit cells are stacked in a first direction and each of the plurality of unit cells has electrode tabs at both ends in a second direction perpendicular to the first direction; A multifunctional terminal block (MTB) provided at both ends of the stacked electrode assembly; and A laminate sheet covering the side surface of the stacked electrode assembly; Including, The above MTB includes a busbar structure electrically connecting the electrode tabs and an MTB housing accommodating the busbar structure, A secondary battery, wherein the busbar structure includes a first busbar plate and a second busbar plate which are in surface contact with each other, and the second busbar plate includes a first portion which is in surface contact with the first busbar plate and a second portion which is extended from the first portion and bent.

11. In Article 10, The first portion includes a plurality of slits into which electrode tabs can be inserted; A secondary battery characterized in that a plurality of electrode tabs are inserted into each of the plurality of slits.

12. In paragraph 11, A secondary battery, characterized in that the plurality of electrode tabs extend between the first bus bar plate and the second bus bar plate.

13. In paragraph 12, A secondary battery, characterized in that the plurality of electrode tabs are integrated so that an interface with at least one of the first bus bar plate and the second bus bar plate is not confirmed between the first bus bar plate and the second bus bar plate.

14. In paragraph 10, A secondary battery, characterized in that the second part is extended by being bent 180 degrees from the first part.

15. In paragraph 10, A secondary battery, characterized in that the first portion of the first busbar plate and the second busbar plate are joined by an electromagnetic pulse technique (EMPT).

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