Electrode assembly for secondary battery and battery cell comprising same

Abstract

The present invention relates to an electrode assembly for a secondary battery and a battery cell including same and, more specifically, to an electrode assembly for a secondary battery and a battery cell including same, the electrode assembly comprising at least one positive electrode including a positive electrode current collector and a positive electrode tab extending in one side direction of the positive electrode current collector; at least one negative electrode including a negative electrode current collector and a negative electrode tab extending in one side direction of the negative electrode current collector; a separator interposed between the positive electrode and the negative electrode; positive electrode leads electrically connected to the positive electrode tabs; and negative electrode leads electrically connected to the negative electrode tabs, wherein the positive electrode current collector has a first resin layer interposed between a pair of aluminum layers, and first metal foils are interposed between the positive electrode tabs and between the positive electrode tab located at the outermost portion and the positive electrode leads.

Description

Secondary battery electrode assembly and battery cell including the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 2023-0149455, filed November 1, 2023, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a secondary battery electrode assembly and a battery cell including the same, and more particularly, to a secondary battery electrode assembly having a structure in which electrode tabs and electrode leads having a structure in which a resin layer is interposed between a pair of metal layers can be firmly connected and fixed, and a battery cell including the same.

[0003]

[0004] As technological development and demand for mobile devices increase, rechargeable secondary batteries are increasingly being used as energy sources for a variety of mobile devices. Secondary batteries are also attracting attention as an energy source for electric and hybrid electric vehicles, offering an alternative to conventional gasoline and diesel vehicles that rely on fossil fuels.

[0005] Secondary batteries are classified into cylindrical and prismatic batteries, in which the electrode assembly is built into a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is built into a pouch-type case made of aluminum laminate sheet, depending on the shape of the battery case.

[0006] In particular, in the case of a pouch-type secondary battery, a plurality of positive and negative electrodes having a predetermined size are sequentially stacked with a separator interposed between them, and an electrode tab or a pair of electrode leads connected to the electrode tabs protrudes outside the case on one or both sides.

[0007] Meanwhile, the positive electrode current collector, onto which the positive active material is applied, typically uses an aluminum current collector. However, aluminum current collectors have been identified as a primary cause of fire for various reasons, and research is underway to replace them with current collectors with multilayer structures, such as those with a resin layer sandwiched between two metal layers.

[0008] When using a three-layer structure like this, it is expected that safety can be improved because the metal layer is thin, so the resistance is high in the event of a short circuit, and the current flow can be quickly blocked.

[0009] Fig. 1 is a partial schematic diagram of a secondary battery according to the prior art. As illustrated in Fig. 1, the electrode assembly (10) has a structure in which a plurality of tabs (20) extend outward, and electrode leads (30) are interposed between these tabs (20) and then fixed to each other through welding.

[0010] However, in the case of a three-layer structured current collector, a resin layer is provided in the middle, making it difficult to join the electrode tabs and electrode leads using a commonly used welding method.

[0011]

[0012] (Prior art literature)

[0013] (Patent Document 1) Korean Patent Publication No. 2022-0124358

[0014] (Patent Document 2) Korean Patent Publication No. 2023-0020177

[0015]

[0016] In order to solve the above problems, the present invention aims to provide a secondary battery electrode assembly having a structure in which electrode current collectors having a resin layer interposed between metal layers can be firmly connected to each other, and a battery cell including the same.

[0017] In addition, the present invention aims to provide a secondary battery electrode assembly having a structure in which an electrode current collector and an electrode lead, in which a resin layer is interposed between metal layers, can be firmly connected to each other, and a battery cell including the same.

[0018]

[0019] In order to solve the above problems, a secondary battery electrode assembly according to the present invention comprises: at least one positive electrode (100) including a positive electrode current collector (110) and a positive electrode tab (120) extending in one direction of the positive electrode current collector (110); at least one negative electrode (200) including a negative electrode current collector (210) and a negative electrode tab (220) extending in one direction of the negative electrode current collector (210); a separator (300) interposed between the positive electrode (100) and the negative electrode (200); a positive electrode lead (400) electrically connected to the positive electrode tabs (120); And a cathode lead (500) electrically connected to the cathode tabs (220); wherein the cathode current collector (110) is characterized in that a first resin layer (112) is interposed between a pair of aluminum layers (111), and a first metal foil (600) is interposed between the cathode tabs (120) and between the outermost cathode tab (120) and the cathode lead (400).

[0020] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) is characterized in that it is positioned along the longitudinal edge of the positive electrode tabs (120).

[0021] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) includes a first a metal foil (610) and a first b metal foil (620), and is characterized in that they are positioned along both longitudinal edges of the positive electrode tabs (120).

[0022] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) is characterized by having a wrinkled shape in which a band having a certain width and length is folded and has repeated hills and valleys.

[0023] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) is characterized in that it contains aluminum.

[0024] In addition, in the secondary battery electrode assembly according to the present invention, the positive electrode lead (400) is characterized in that it is fixed to the first metal foil (600) and the aluminum layer (111) by ultrasonic welding.

[0025] In addition, in the secondary battery electrode assembly according to the present invention, the first resin layer (112) is characterized in that it is made of PET (polyethylene terephthalate).

[0026] In addition, in the secondary battery electrode assembly according to the present invention, the negative electrode current collector (210) is characterized in that a second resin layer (212) is interposed between a pair of copper layers (211), and a second metal foil (700) is interposed between the negative electrode tabs (220) and between the negative electrode tab (220) located at the outermost end and the negative electrode lead (500).

[0027] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is characterized in that it is positioned along the longitudinal edge of the negative electrode tabs (220).

[0028] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) includes a second a metal foil (710) and a second b metal foil (720), and is characterized in that it is positioned along both longitudinal edges of the negative electrode tabs (220).

[0029] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is characterized by having a wrinkled shape in which a belt-shaped band having a certain width and length is folded and has repeated hills and valleys.

[0030] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is characterized in that it includes copper, nickel-coated copper, or a nickel-copper alloy.

[0031] In addition, in the secondary battery electrode assembly according to the present invention, the negative electrode lead (500) is characterized in that it is fixed to the second metal foil (700) and the copper layer (211) by ultrasonic welding.

[0032] In addition, in the secondary battery electrode assembly according to the present invention, the second resin layer (212) is characterized in that it is made of PET (polyethylene terephthalate) material.

[0033] In addition, the present invention is characterized by a battery cell including the secondary battery electrode assembly described above.

[0034]

[0035] According to the secondary battery electrode assembly and battery cell including the same according to the present invention, since a band-shaped band is bent along the longitudinal edge of the electrode tab, a wrinkled metal foil with repeated hills and valleys is interposed, and then ultrasonic welding is performed, there is an advantage in that the electrode tabs can be firmly fixed to each other.

[0036] In addition, according to the secondary battery electrode assembly and the battery cell including the same according to the present invention, there is an advantage in that the electrode tabs and the electrode leads can be securely fixed because ultrasonic welding is performed in a state in which a portion of the metal foil interposed between the electrode tabs overlaps between the electrode tabs and the electrode leads.

[0037]

[0038] Figure 1 is a partial schematic diagram of a secondary battery according to conventional technology.

[0039] Figure 2 is an exploded perspective view of a secondary battery electrode assembly according to the first embodiment of the present invention.

[0040] Figure 3 is a cross-sectional view of a positive electrode in a secondary battery electrode assembly according to the first embodiment of the present invention.

[0041] FIG. 4 is a drawing of a secondary battery electrode assembly according to a first embodiment of the present invention viewed from one direction.

[0042] FIG. 5 is a drawing of a secondary battery electrode assembly according to the first embodiment of the present invention viewed from another direction.

[0043] FIG. 6 is a flowchart illustrating a method of combining a positive electrode tab, a first metal member, and a positive electrode lead in a secondary battery electrode assembly according to a first embodiment of the present invention.

[0044] Figure 7 is an exploded perspective view of a secondary battery electrode assembly according to a second embodiment of the present invention.

[0045] Figure 8 is a cross-sectional view of a negative electrode in a secondary battery electrode assembly according to a second embodiment of the present invention.

[0046] FIG. 9 is a drawing of a secondary battery electrode assembly according to a second embodiment of the present invention viewed from one direction.

[0047] FIG. 10 is a drawing of a secondary battery electrode assembly according to a second embodiment of the present invention viewed from another direction.

[0048] FIG. 11 is a flowchart illustrating a method of combining a negative electrode tab, a second metal member, and a negative electrode lead in a secondary battery electrode assembly according to a second embodiment of the present invention.

[0049]

[0050] In this application, the terms “includes,” “has,” or “comprises” are intended to specify the presence of a feature, number, step, component, part, or combination thereof described in the specification, but should be understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0051] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0052]

[0053] Hereinafter, a secondary battery electrode assembly according to the present invention and a battery cell including the same will be described with reference to the attached drawings.

[0054] Fig. 2 is an exploded perspective view of a secondary battery electrode assembly according to a first embodiment of the present invention, and Fig. 3 is a cross-sectional view of a positive electrode in a secondary battery electrode assembly according to the first embodiment of the present invention. As illustrated in Figs. 2 and 3, the secondary battery electrode assembly according to the present invention has a structure in which at least one positive electrode (100), at least one negative electrode (200), and at least one separator (300) are laminated.

[0055] In detail, the separator (300) may be positioned between the anode (100) and the cathode (300), on the upper surface of the cathode (300) located at the top, and below the cathode (300) located at the bottom, but is not necessarily limited thereto.

[0056] In addition, the positive electrode (100) is electrically connected to the positive electrode lead (400), and the negative electrode (200) is electrically connected to the negative electrode lead (500). In particular, a first metal foil (600) is interposed between the positive electrodes (100) and between the positive electrode (100) and the positive electrode lead (400). A detailed description thereof will be provided later.

[0057] First, the positive electrode (100) can be composed of a positive electrode current collector (110) and a positive electrode tab (120). In a preferred first embodiment of the present invention, the positive electrode current collector (110) has a three-layer structure in which a first resin layer (112) is interposed between a pair of aluminum layers (111).

[0058] Here, the thickness of the aluminum layer is approximately 0.5 to 2 μm, and the first resin layer is made of polyethylene terephthalate (PET) material and has a thickness of approximately 5 to 10 μm, but is not necessarily limited thereto.

[0059] Alternatively, stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. may be used instead of aluminum, as long as it has high conductivity and does not cause chemical changes in the battery. Furthermore, to enhance the adhesive strength of the positive electrode active material, the surface may be finely textured, or may be formed into various shapes, such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics.

[0060] A positive electrode active material layer (113) is provided on each of the upper and lower surfaces exposed to the outside of a pair of aluminum layers (111).

[0061] The cathode active material is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with a higher transition metal; a lithium manganese oxide such as Li1+xMn2-xO4 (wherein, x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; a lithium copper oxide (Li2CuO2); a vanadium oxide such as LiV3O8, V2O5, Cu2V2O7; a Ni-site type lithium nickel oxide expressed by the chemical formula LiNi1-xMxO2 (wherein, M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); Lithium manganese composite oxides represented by the chemical formula LiMn2-xMxO2 (wherein, M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (wherein, M = Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which a portion of Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, LiNixMn2-xO4(0.01≤x≤0.6), etc. can be used.

[0062] Meanwhile, the positive electrode active material may be mixed with a conductive agent and a binder, and fillers may be added as needed.

[0063] The conductive agent is typically added in an amount of 1 to 50 wt% based on the total weight of the mixture including the positive electrode active material. The conductive agent is not particularly limited as long as it has conductivity and does not cause a chemical change in the battery. For example, graphite such as natural graphite or artificial graphite; carbon black such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black; conductive fibers such as carbon fiber or metal fiber; metal powders such as fluorocarbon, aluminum, and nickel powder; conductive whiskey such as zinc oxide or potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives can be used.

[0064] A binder is a component that assists in the bonding of the positive electrode active material and the conductive material and the bonding to the current collector, and is typically added in an amount of 1 to 50 wt% based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluororubber, and various copolymers.

[0065] Meanwhile, a non-conductive portion (not shown) on which a positive electrode active material layer is not formed in the positive electrode current collector (110) is punched into a certain shape to form a positive electrode tab (120).

[0066] The negative electrode (200) may be composed of a negative electrode current collector (210) and a negative electrode tab (220). The negative electrode current collector (210) is generally made to have a thickness of 3 to 500 μm, and is not particularly limited as long as it is conductive and does not cause chemical changes in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, charcoal, silver, etc., aluminum-cadmium alloy, etc. may be used.

[0067] In addition, the bonding strength of the negative electrode active material can be strengthened by forming fine irregularities on the surface, and it can be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics.

[0068] A negative electrode active material layer is provided on the upper and lower surfaces of the negative electrode current collector (210). As the negative electrode active material, for example, carbon such as non-graphitizable carbon and graphite carbon; LixFe2O3(0≤x≤1), LixWO2(0≤x≤1), SnxMe1-xMe'yOz(Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of group 1, group 2, and group 3 of the periodic table, halogen; 0 <x≤1; 1≤y≤3; 1≤z≤8) 등의 금속 복합 산화물; 리튬 금속; 리튬 합금; 규소계 합금; 주석계 합금; SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5 등의 금속 산화물; 폴리아세틸렌 등의 도전성 고분자; Li-Co-Ni계 재료; Si, SiO, SiO2 단독 또는 이들의 혼합물인 Si계 등을 사용할 수 있으나, 이들만으로 한정되는 것은 아니다.

[0069] Of course, a conductive material and a binder can be additionally mixed with the negative electrode active material to form a negative electrode active material layer.

[0070] Conductive agents are components for further improving the conductivity of the negative electrode active material, and may be used in a certain ratio, including carbon black such as acetylene black, Ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fibers or metal fibers; metal powders such as fluorinated carbon, aluminum, and nickel powders; conductive whiskies such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0071] The binder is a component that helps in the binding of the negative electrode active material and the conductive material and the binding to the current collector, and may include at least one selected from the group consisting of styrene butadiene rubber (SBR), acrylonitrile butadiene rubber, acrylic rubber, butyl rubber, fluoro rubber, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyethylene glycol (PEG), polyacrylonitrile (PAN), and polyacryl amide (PAM).

[0072] Meanwhile, a non-conductive portion (not shown) on which a negative electrode active material layer is not formed in the negative electrode current collector (210) is punched into a certain shape to form a negative electrode tab (220).

[0073] The separator (300) prevents a short between the aforementioned positive electrode (100) and negative electrode (200) and allows only the movement of lithium ions. The material of the separator is preferably one selected from among polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and an organic fiber filter paper, but is not limited thereto.

[0074] FIG. 4 is a drawing of a secondary battery electrode assembly according to a first embodiment of the present invention when viewed from one direction, FIG. 5 is a drawing of a secondary battery electrode assembly according to a first embodiment of the present invention when viewed from another direction, and FIG. 6 is a flowchart for explaining a method of combining a positive electrode tab, a first metal member, and a positive electrode lead in a secondary battery electrode assembly according to the first embodiment of the present invention.

[0075] Referring to FIGS. 2 to 6 together, the electrical connection structure of the positive tabs (120) and the positive lead (400) will be described.

[0076] Typically, a positive electrode tab is made entirely of metal and can be joined to a positive electrode lead through ultrasonic welding or the like. However, as previously described, the positive electrode collector and positive electrode tab according to the first embodiment of the present invention have a structure in which a first resin layer is interposed between a pair of aluminum layers. That is, due to the first resin layer constituting each positive electrode tab, it is difficult to firmly secure multiple positive electrode tabs, and also the positive electrode tabs and the positive electrode lead, by ultrasonic welding.

[0077] Therefore, in the first embodiment of the present invention, a first metal foil (600) is placed between the positive electrode tabs (120) and between the positive electrode tab (120) located at the outermost end and the positive electrode lead (400).

[0078] To explain in more detail, the first metal foil (600) has a wrinkled shape with repeated peaks and valleys formed by bending a band-shaped band having a certain width and length, and this first metal foil (600) is positioned at the longitudinal edge of the positive electrode tabs (120).

[0079] Here, it is possible for the first metal foil (600) to be formed as a single piece and provided on one longitudinal edge of the positive electrode tabs (120), but in order to more firmly fix the positive electrode tabs (120) and the positive electrode lead (400), it is more preferable for the first metal foil (600) to be formed of a first a metal foil (610) and a first b metal foil (620), and for each of these to be positioned along the longitudinal edges of both sides of the positive electrode tabs (120).

[0080] As a result, the first anode tab (610) and / or the first bnode metal foil (620) are positioned between the anode tab (120) located at the top and the anode lead (400), including between all the anode tabs (120), and then these are fixed together by ultrasonic welding, so that the anode tabs (120) and the anode lead (400) are electrically connected through the first anode foil (600).

[0081] Meanwhile, it is preferable that the first metal foil (600) includes the same aluminum material as the aluminum layer (111), but it can be changed as long as it can perform the same function.

[0082] The length of the first metal foil (600) is not particularly limited, but it is preferable that it not protrude outside the positive tab (120).

[0083] The positive lead (400) is preferably made of aluminum, but is not necessarily limited thereto.

[0084]

[0085] FIG. 7 is an exploded perspective view of a secondary battery electrode assembly according to a second embodiment of the present invention, and FIG. 8 is a cross-sectional view of a negative electrode in a secondary battery electrode assembly according to a second embodiment of the present invention.

[0086] A secondary battery electrode assembly according to a second embodiment of the present invention has a structure in which one or more positive electrodes (100), one or more negative electrodes (200), and one or more separators (300) are stacked, similar to the first embodiment.

[0087] However, unlike the first embodiment, in the second embodiment, the cathode (200) has a three-layer structure, and a second metal foil (700) is interposed between the cathode (200) and the cathode lead (500), so overlapping descriptions will be omitted and only the different configurations will be described.

[0088] The negative electrode (200) may be composed of a negative electrode current collector (210) and a negative electrode tab (220). In a preferred second embodiment of the present invention, the negative electrode current collector (210) has a three-layer structure in which a second resin layer (212) is interposed between a pair of copper layers (211).

[0089] Here, the thickness of the copper layer is approximately 0.5 to 2.0 μm, and the second resin layer is made of polyethylene terephthalate (PET) and has a thickness of approximately 3 to 10 μm, but is not necessarily limited thereto.

[0090] Of course, stainless steel, etc. mentioned above, can be used instead of copper if it has high conductivity without causing chemical changes in the battery.

[0091] A negative electrode active material layer (213) is provided on each of the upper and lower surfaces exposed to the outside of a pair of copper layers (211). Since these negative electrode active materials have been described above, their description will be omitted.

[0092] FIG. 9 is a drawing of a secondary battery electrode assembly according to a second embodiment of the present invention when viewed from one direction, FIG. 10 is a drawing of a secondary battery electrode assembly according to a second embodiment of the present invention when viewed from another direction, and FIG. 11 is a flowchart for explaining a method of combining a negative electrode tab, a second metal member, and a negative electrode lead in a secondary battery electrode assembly according to a second embodiment of the present invention.

[0093] Referring to FIGS. 7 to 11 together, the electrical connection structure of the negative tabs (220) and the negative lead (500) will be described.

[0094] Typically, the negative tab is made solely of metal and can be joined to the negative lead through ultrasonic welding, etc. However, as previously described, the negative current collector and negative tab according to the second embodiment of the present invention have a structure in which a second resin layer is interposed between a pair of copper layers. That is, due to the second resin layer constituting each negative tab, it is difficult to firmly secure multiple negative tabs, and also the negative tabs and the negative lead, by ultrasonic welding.

[0095] Therefore, in the second embodiment of the present invention, a second metal foil (700) is placed between the negative tabs (220) and between the negative tab (220) located at the outermost end and the negative lead (500).

[0096] To explain in more detail, the second metal foil (700) has a wrinkled shape with repeated peaks and valleys formed by bending a band-shaped band having a certain width and length, and this second metal foil (700) is positioned at the longitudinal edge of the negative tabs (220).

[0097] Here, it is possible for the second metal foil (700) to be formed as a single piece and provided on one edge of the length direction of the negative electrode tabs (220), but in order to more firmly fix the negative electrode tabs (220) and the negative electrode lead (500), it is more preferable for the second metal foil (700) to be formed of a seconda metal foil (710) and a secondb metal foil (720), and for each of these to be positioned along the length direction of both edges of the negative electrode tabs (220).

[0098] As a result, the second metal foil (710) and / or the second metal foil (720) are positioned between the uppermost negative tab (220) and the negative lead (500), including between all the negative tabs (220), and then these are fixed together by ultrasonic welding, so that the negative tabs (220) and the negative lead (500) are electrically connected through the second metal foil (700).

[0099] Meanwhile, the second metal foil (700) preferably includes the same copper as the copper layer (111), or nickel-coated copper or a nickel-copper alloy, but may be changed as long as it can perform the same function.

[0100] The length of the second metal foil (700) is not particularly limited, but it is preferable that it not protrude outside the negative tab (220).

[0101] Although not shown in the drawing, it may be a secondary battery electrode assembly combining the first embodiment and the second embodiment. For example, the positive electrode has a three-layer structure in which a first resin layer is interposed between a pair of aluminum layers, while the negative electrode has a three-layer structure in which a second resin layer is interposed between a pair of copper layers, and further, a first metal foil and a second metal foil are interposed between the positive electrode tab and the positive electrode lead, and between the negative electrode tab and the negative electrode lead, respectively.

[0102] The present invention may be a battery cell including the secondary battery electrode assembly described above, a battery module or battery pack including the battery cell, or a battery pack including the battery module.

[0103]

[0104] As described above, specific parts of the present invention have been described in detail. To those skilled in the art, such specific descriptions are merely preferred embodiments, and the scope of the present invention is not limited thereby. It is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present invention, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

[0105] (Explanation of symbols)

[0106] 100: Bipolar

[0107] 110: Positive current collector

[0108] 111: Aluminum layer 112: First resin layer

[0109] 113: Positive electrode active material layer

[0110] 120: Positive tab

[0111] 200: Cathode

[0112] 210: Negative current collector

[0113] 211: Copper layer 212: Second resin layer

[0114] 213: Negative active material layer

[0115] 220: Negative tab

[0116] 300: Membrane

[0117] 400: Positive lead

[0118] 500: Negative lead

[0119] 600: First metal foil

[0120] 610: 1a metal foil 620: 1b metal foil

[0121] 700: Second metal foil

[0122] 710: 2a metal foil 720: 2b metal foil

Claims

1. At least one anode including a positive electrode current collector and a positive electrode tab extending in one direction of the positive electrode current collector; At least one negative electrode comprising a negative current collector and a negative tab extending in one direction of the negative current collector; A separator interposed between the positive electrode and the negative electrode; a positive lead electrically connected to the positive tabs; and A negative lead electrically connected to the above negative tabs; The above positive electrode current collector has a first resin layer sandwiched between a pair of aluminum layers, A secondary battery electrode assembly characterized in that a first metal foil is interposed between the positive electrode tabs and between the positive electrode tab located at the outermost end and the positive electrode lead.

2. In paragraph 1, A secondary battery electrode assembly, characterized in that the first metal foil is positioned along the longitudinal edge of the positive electrode tabs.

3. In paragraph 2, A secondary battery electrode assembly, characterized in that the first metal foil includes a first a metal foil and a first b metal foil, and is positioned along both longitudinal edges of the positive electrode tabs.

4. In paragraph 3, A secondary battery electrode assembly characterized in that the first metal foil has a wrinkled shape with repeated hills and valleys formed by bending a band-shaped band having a certain width and length.

5. In paragraph 3, A secondary battery electrode assembly, characterized in that the first metal foil comprises aluminum.

6. In paragraph 5, A secondary battery electrode assembly characterized in that the positive electrode lead is fixed to the first metal foil and the aluminum layer by ultrasonic welding.

7. In paragraph 1, A secondary battery electrode assembly, characterized in that the first resin layer is made of PET (polyethylene terephthalate).

8. In paragraph 1, The above negative electrode current collector has a second resin layer interposed between a pair of copper layers, A secondary battery electrode assembly characterized in that a second metal foil is interposed between the negative tabs and between the negative tab located at the outermost end and the negative electrode lead.

9. In paragraph 8, A secondary battery electrode assembly, characterized in that the second metal foil is positioned along the longitudinal edge of the negative tabs.

10. In paragraph 9, A secondary battery electrode assembly, characterized in that the second metal foil includes a second a metal foil and a second b metal foil, and is positioned along both longitudinal edges of the negative tabs.

11. In paragraph 9, A secondary battery electrode assembly characterized in that the second metal foil has a wrinkled shape with repeated hills and valleys formed by bending a band-shaped band having a certain width and length.

12. In paragraph 11, A secondary battery electrode assembly, characterized in that the second metal foil comprises copper, nickel-coated copper, or a nickel-copper alloy.

13. In paragraph 12, A secondary battery electrode assembly characterized in that the negative lead is fixed to the second metal foil and copper layer by ultrasonic welding.

14. In paragraph 9, A secondary battery electrode assembly characterized in that the second resin layer is made of PET (polyethylene terephthalate) material.

15. A battery cell comprising a secondary battery electrode assembly according to any one of claims 1 to 14.

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