Secondary battery electrode assembly and battery cell including the same

Abstract

The present invention relates to a secondary battery electrode assembly and a battery cell including the same. More particularly, the present invention relates to a secondary battery electrode assembly and a battery cell including the same, the secondary battery electrode assembly including: one or more positive electrodes including a positive electrode current collector and a positive electrode tab extending toward one side of the positive electrode current collector; one or more negative electrodes including a negative electrode current collector and a negative electrode tab extending toward one side of the negative electrode current collector; a separator interposed between the positive electrode and the negative electrode; a positive electrode lead electrically connected to the positive electrode tab; and a negative electrode lead electrically connected to the negative electrode tab, the positive electrode current collector having a first resin layer interposed between a pair of aluminum layers, and first metal foils interposed between the positive electrode tabs and between the outermost positive electrode tabs and the positive electrode lead.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0149455, 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 capable of firmly connecting and fixing an electrode tab and an electrode lead, the electrode tab having a structure in which a resin layer is interposed between a pair of metal layers, and a battery cell including the same. [Background technology]

[0003] As technological development and demand for mobile devices continues to grow, rechargeable secondary batteries are being used as energy sources for various mobile devices. Secondary batteries are also attracting attention as energy sources for electric vehicles and hybrid electric vehicles, which are being proposed as alternatives to existing gasoline-powered vehicles and diesel-powered vehicles that use fossil fuels.

[0004] Depending on the shape of the battery case, secondary batteries are classified into cylindrical batteries and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch batteries, in which the electrode assembly is housed in a pouch-shaped case made of an aluminum laminate sheet.

[0005] In particular, in the case of a pouch-type secondary battery, a number of positive and negative electrodes having a predetermined size are stacked in sequence with a separator interposed between them, and an electrode tab or a pair of electrode leads connected to the electrode tabs protrudes from one or both sides of the case to the outside.

[0006] Meanwhile, aluminum current collectors are commonly used as positive electrode current collectors on which the positive electrode active material is applied. However, as aluminum current collectors have been identified as a major cause of fires due to various reasons, research is being conducted to replace them with multi-layered current collectors, for example, current collectors with a structure in which a resin layer is sandwiched between two metal layers.

[0007] When using such a three-layered current collector, the metal layer is thin, so there is a large resistance in the event of a short circuit, allowing the flow of current to be quickly cut off, which is expected to improve safety.

[0008] Figure 1 is a partial schematic diagram of a secondary battery according to the prior art. As shown in Figure 1, the electrode assembly 10 has a structure in which a number of tabs 20 extend outward, electrode leads 30 are interposed between these tabs 20, and the tabs 20 are then fixed together by welding.

[0009] However, in the case of a three-layered current collector, since a resin layer is provided in the middle, it is difficult to join the electrode tab and the electrode lead using a commonly used welding method. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2022-0124358 [Patent Document 2] Korean Patent Publication No. 10-2023-0020177 Summary of the Invention [Problem to be solved by the invention]

[0011] In order to solve the above problems, an object of the present invention is to provide a secondary battery electrode assembly having a structure in which electrode current collectors, each having a resin layer interposed between metal layers, can be firmly connected to each other, and a battery cell including the same.

[0012] Another object of the present invention is to provide a secondary battery electrode assembly having a structure capable of firmly connecting an electrode current collector and an electrode lead, in which a resin layer is interposed between metal layers, and a battery cell including the same. [Means for solving the problem]

[0013] In order to solve the above problems, the secondary battery electrode assembly according to the present invention comprises one or more positive electrodes (100) including a positive electrode current collector (110) and a positive electrode tab (120) extending toward one side of the positive electrode current collector (110), one or more negative electrodes (200) including a negative electrode current collector (210) and a negative electrode tab (220) extending toward one side of the negative electrode current collector (210), a separator (300) interposed between the positive electrode (100) and the negative electrode (200), and a separator (300) for the positive electrode (100) and the negative electrode (200). The positive electrode current collector (110) includes a positive electrode lead (400) electrically connected to the positive electrode tab (120) and a negative electrode lead (500) electrically connected to the negative electrode tab (220). The positive electrode current collector (110) includes a pair of aluminum layers (111) with a first resin layer (112) interposed therebetween, and a first metal foil (600) is interposed between the positive electrode tabs (120) and between the outermost positive electrode tab (120) and the positive electrode lead (400).

[0014] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) is located along the edge of the positive electrode tab (120) in the longitudinal direction.

[0015] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) includes a 1a metal foil (610) and a 1b metal foil (620), and is located along both longitudinal edges of the positive electrode tab (120).

[0016] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) is a wave-shaped band having a certain width and length that is bent to form repeated peaks and valleys.

[0017] In addition, in the secondary battery electrode assembly according to the present invention, the first metal foil (600) contains aluminum.

[0018] In addition, in the secondary battery electrode assembly according to the present invention, the positive electrode lead (400) is fixed to the first metal foil (600) and the aluminum layer (111) by ultrasonic welding.

[0019] In addition, in the secondary battery electrode assembly according to the present invention, the first resin layer (112) is made of a PET (polyethylene terephthalate) material.

[0020] 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 outermost negative electrode tab (220) and the negative electrode lead (500).

[0021] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is located along the edge of the negative electrode tab (220) in the longitudinal direction.

[0022] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) includes a 2a metal foil (710) and a 2b metal foil (720), and is located along both longitudinal edges of the negative electrode tab (220).

[0023] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is a wave-shaped band having a certain width and length that is bent to form repeated peaks and valleys.

[0024] In addition, in the secondary battery electrode assembly according to the present invention, the second metal foil (700) is characterized by including copper, nickel-coated copper, or nickel-copper alloy.

[0025] In addition, in the secondary battery electrode assembly according to the present invention, the negative electrode lead (500) is fixed to the second metal foil (700) and the copper layer (211) by ultrasonic welding.

[0026] In addition, in the secondary battery electrode assembly according to the present invention, the second resin layer (212) is made of a PET (polyethylene terephthalate) material.

[0027] The present invention also features a battery cell including the above-described secondary battery electrode assembly. [Effects of the Invention]

[0028] In the secondary battery electrode assembly and battery cell including the same according to the present invention, a strip-shaped band is folded along the longitudinal edge of the electrode tab to interpose a corrugated metal foil having repeated peaks and valleys, and then ultrasonic welding is performed, which has the advantage of firmly fixing the electrode tabs to each other.

[0029] In addition, according to the secondary battery electrode assembly and the battery cell including the same according to the present invention, 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 lead, which has the advantage of enabling the electrode tabs and the electrode lead to be securely fixed together. [Brief explanation of the drawings]

[0030] [Figure 1] FIG. 1 is a partial schematic diagram of a secondary battery according to the prior art. [Figure 2] 1 is an exploded perspective view of a secondary battery electrode assembly according to a first embodiment of the present invention; [Figure 3] 1 is a cross-sectional view of a positive electrode of a secondary battery electrode assembly according to a first embodiment of the present invention. [Figure 4] 1 is a view showing a secondary battery electrode assembly according to a first embodiment of the present invention viewed from one direction; [Figure 5] 4 is a view showing the secondary battery electrode assembly according to the first embodiment of the present invention as viewed from another direction. FIG. [Figure 6] 4 is a flowchart illustrating a method for coupling a positive electrode tab, a first metal foil, and a positive electrode lead of a secondary battery electrode assembly according to a first embodiment of the present invention. [Figure 7]FIG. 10 is an exploded perspective view of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 8] FIG. 4 is a cross-sectional view of a negative electrode of a secondary battery electrode assembly according to a second embodiment of the present invention. [Figure 9] 10 is a view showing a secondary battery electrode assembly according to a second embodiment of the present invention viewed from one direction. [Figure 10] 10 is a view showing a secondary battery electrode assembly according to a second embodiment of the present invention as viewed from another direction. [Figure 11] 10 is a flowchart illustrating a method for coupling a negative electrode tab, a second metal foil, and a negative electrode lead of a secondary battery electrode assembly according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0031] In this application, the terms "comprises," "has," "has," and "comprises" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0032] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0033] Hereinafter, a secondary battery electrode assembly and a battery cell including the same according to the present invention will be described with reference to the accompanying drawings.

[0034] 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 of the secondary battery electrode assembly according to the first embodiment of the present invention. As shown in FIG. 2 and FIG. 3, the secondary battery electrode assembly according to the present invention has a stacked structure of one or more positive electrodes 100, one or more negative electrodes 200, and one or more separators 300.

[0035] In detail, the separator 300 may be located between the positive electrode 100 and the negative electrode 200, on the uppermost negative electrode 200, and below the lowermost negative electrode 200, but is not necessarily limited thereto.

[0036] In addition, a positive electrode lead 400 is electrically connected to the positive electrode 100, and a negative electrode lead 500 is electrically connected to the negative electrode 200. 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. This will be described in detail later.

[0037] First, the positive electrode 100 may be composed of a positive electrode current collector 110 and a positive electrode tab 120. The positive electrode current collector 110 according to the first preferred embodiment of the present invention has a three-layer structure in which a first resin layer 112 is interposed between a pair of aluminum layers 111.

[0038] 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 to this.

[0039] In addition, instead of aluminum, stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. can be used as long as it does not cause chemical changes in the battery and has high conductivity. In addition, to increase the adhesive strength of the positive electrode active material, the surface may be formed with fine irregularities, or various forms such as a film, sheet, foil, net, porous material, foam, or nonwoven fabric may be used.

[0040] A positive electrode active material layer 113 is provided on each of the upper and lower surfaces exposed to the outside of the pair of aluminum layers 111 .

[0041] Positive electrode active materials include layered compounds such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or compounds substituted with higher transition metals; 1+x Mn 2-x Lithium manganese oxides such as LiMnO4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x M x O2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); 2-x M x Lithium manganese composite oxides expressed as Li2Mn3MO8 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1); LiMn2O4, in which part of the Li in the chemical formula is replaced by an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, LiNi x Mn 2-x O4 (0.01≦x≦0.6) can be used.

[0042] On the other hand, a conductive material and a binder can be mixed into the positive electrode active material, and a filler can also be added as needed.

[0043] The conductive material 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. Such a conductive material is not particularly limited as long as it is conductive without causing chemical changes in the battery. Examples of such a conductive material include graphite such as natural graphite and artificial graphite; carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers such as carbon fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0044] The binder is a component that helps bind the positive electrode active material to the conductive material and 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.

[0045] Meanwhile, a blank portion (not shown) of the positive electrode current collector 110 where the positive electrode active material layer is not formed is punched out into a predetermined shape to form a positive electrode tab 120 .

[0046] 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 manufactured to have a thickness of 3 to 500 μm. The negative electrode current collector is not particularly limited as long as it is conductive and does not cause a chemical change in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, etc. may be used.

[0047] In addition, fine irregularities can be formed on the surface to strengthen the binding force of the negative electrode active material, and various forms such as films, sheets, foils, nets, porous bodies, foams, non-woven fabric bodies, etc. can be used.

[0048] 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 graphitizable carbon and graphite-based carbon; Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8) and other metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials that are Si, SiO, SiO2 alone or mixtures thereof, etc. can be used, but are not limited thereto.

[0049] Of course, a conductive material and a binder can be additionally mixed into the negative electrode active material to form a negative electrode active material layer.

[0050] The conductive material is a component for further improving the conductivity of the negative electrode active material, and carbon blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black; conductive fibers such as carbon fibers and metal fibers; metal powders such as carbon fluoride, aluminum, nickel powder; conductive whiskers such as zinc oxide, potassium titanate; conductive metal oxides such as titanium oxide; conductive materials such as polyphenylene derivatives, etc. can be used in a certain ratio.

[0051] The binder is a component that helps bind the negative electrode active material and the conductive material, etc., and 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).

[0052] Meanwhile, a blank portion (not shown) of the negative electrode current collector 210 where the negative electrode active material layer is not formed is punched out into a predetermined shape to form a negative electrode tab 220 .

[0053] The separator 300 prevents short circuits between the cathode 100 and anode 200 and allows only the movement of lithium ions. The material of the separator is preferably any one selected from the group consisting of polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited thereto.

[0054] FIG. 4 is a view of a secondary battery electrode assembly according to a first embodiment of the present invention viewed from one direction, FIG. 5 is a view of a secondary battery electrode assembly according to a first embodiment of the present invention viewed from another direction, and FIG. 6 is a flowchart illustrating a method of coupling a positive electrode tab, a first metal foil, and a positive electrode lead of a secondary battery electrode assembly according to a first embodiment of the present invention.

[0055] The electrical connection structure between the positive electrode tab 120 and the positive electrode lead 400 will be described with reference to FIGS.

[0056] Generally, positive electrode tabs are made of metal only and can be connected to positive electrode leads by ultrasonic welding, etc. However, as described above, the positive electrode current 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 that constitutes each positive electrode tab, it is difficult to firmly fasten multiple positive electrode tabs and the positive electrode leads to each other using ultrasonic welding.

[0057] Therefore, in the first embodiment of the present invention, the first metal foil 600 is disposed between the positive electrode tabs 120 and between the outermost positive electrode tab 120 and the positive electrode lead 400 .

[0058] More specifically, the first metal foil 600 is a corrugated shape in which a strip-shaped band having a certain width and length is folded to form repeated peaks and valleys, and this first metal foil 600 is located on the edge of the positive electrode tab 120 in the longitudinal direction.

[0059] Here, the first metal foil 600 may be formed as a single piece and provided on one longitudinal edge of the positive electrode tab 120. However, in order to more firmly fix the positive electrode tab 120 and the positive electrode lead 400, it is more preferable that the first metal foil 600 includes a 1a metal foil 610 and a 1b metal foil 620, each of which is located along both longitudinal edges of the positive electrode tab 120.

[0060] As a result, the 1a metal foil 610 and / or the 1b metal foil 620 are positioned between the uppermost positive electrode tab 120 and the positive electrode lead 400, including between all of the positive electrode tabs 120, and these are later fixed together by ultrasonic welding, thereby electrically connecting the positive electrode tab 120 and the positive electrode lead 400 via the 1a metal foil 600.

[0061] On the other hand, the first metal foil 600 preferably contains the same aluminum material as the aluminum layer 111, but may be modified as long as it can perform the same function.

[0062] The length of the first metal foil 600 is not particularly limited, but it is preferable that it does not protrude outside the positive electrode tab 120 .

[0063] The positive electrode lead 400 is preferably made of aluminum, but is not necessarily limited to this.

[0064] FIG. 7 is an exploded perspective view of an electrode assembly for a secondary battery according to a second embodiment of the present invention, and FIG. 8 is a cross-sectional view of a negative electrode of the electrode assembly for a secondary battery according to the second embodiment of the present invention.

[0065] The secondary battery electrode assembly according to the 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.

[0066] However, unlike the first embodiment, in the second embodiment, the negative electrode current collector 210 has a three-layer structure, and a second metal foil 700 is interposed between the negative electrode 200 and the negative electrode lead 500, so duplicated explanations will be omitted and only the different configurations will be described.

[0067] 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 according to the second preferred embodiment of the present invention has a three-layer structure in which a second resin layer 212 is interposed between a pair of copper layers 211.

[0068] Here, the copper layer has a thickness of approximately 0.5 to 2.0 μm, and the second resin layer is made of a polyethylene terephthalate (PET) material and has a thickness of approximately 3 to 10 μm, although this is not necessarily limited to this.

[0069] Of course, any material that has high conductivity and does not cause chemical changes in the battery, such as stainless steel, can be used instead of copper.

[0070] The negative electrode active material layers 213 are provided on the upper and lower surfaces exposed to the outside of the pair of copper layers 211. These negative electrode active materials have been described above, so a detailed description will be omitted.

[0071] FIG. 9 is a view of a secondary battery electrode assembly according to a second embodiment of the present invention viewed from one direction, FIG. 10 is a view of a secondary battery electrode assembly according to the second embodiment of the present invention viewed from another direction, and FIG. 11 is a flowchart illustrating a method of joining a negative electrode tab, a second metal foil, and a negative electrode lead of a secondary battery electrode assembly according to the second embodiment of the present invention.

[0072] 7 to 11, the electrical connection structure between the negative electrode tab 220 and the negative electrode lead 500 will be described.

[0073] Generally, negative electrode tabs are made of metal only and can be connected to negative electrode leads by ultrasonic welding, etc. However, as described above, the negative electrode current collector and negative electrode 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, the second resin layer constituting each negative electrode tab makes it difficult to firmly fasten multiple negative electrode tabs to each other using ultrasonic welding, and thus to firmly fasten the negative electrode tabs and negative electrode leads to each other.

[0074] Therefore, in the second embodiment of the present invention, the second metal foil 700 is disposed between the negative electrode tabs 220 and between the negative electrode tab 220 located at the outermost periphery and the negative electrode lead 500 .

[0075] More specifically, the second metal foil 700 is formed by folding a strip-shaped band having a certain width and length, forming a corrugated shape with repeated peaks and valleys, and this second metal foil 700 is located on the longitudinal edge of the negative electrode tab 220.

[0076] Here, the second metal foil 700 may be formed as a single piece and provided on one longitudinal edge of the negative electrode tab 220. However, in order to more firmly fix the negative electrode tab 220 and the negative electrode lead 500, it is more preferable that the second metal foil 700 includes a 2a metal foil 710 and a 2b metal foil 720, each of which is located along both longitudinal edges of the negative electrode tab 220.

[0077] As a result, the 2a metal foil 710 and / or the 2b metal foil 720 are positioned between the uppermost negative electrode tab 220 and the negative electrode lead 500, including between all of the negative electrode tabs 220, and these are later fixed together by ultrasonic welding, thereby electrically connecting the negative electrode tab 220 and the negative electrode lead 500 via the 2a metal foil 700.

[0078] On the other hand, the second metal foil 700 preferably contains the same copper as the copper layer 211, or nickel-coated copper or nickel-copper alloy, but may be modified as long as it can perform the same function.

[0079] The length of the second metal foil 700 is not particularly limited, but it is preferable that it does not protrude outside the negative electrode tab 220 .

[0080] Although not shown in the drawings, a secondary battery electrode assembly may also be possible that combines the first and second embodiments. For example, the positive electrode current collector has a three-layer structure in which a first resin layer is sandwiched between a pair of aluminum layers, while the negative electrode current collector has a three-layer structure in which a second resin layer is sandwiched between a pair of copper layers, and a first metal foil and a second metal foil are respectively sandwiched between the positive electrode tabs, between the positive electrode tab and the positive electrode lead, and between the negative electrode tabs, and between the negative electrode tab and the negative electrode lead.

[0081] The present invention may be a battery cell including the above-described secondary battery electrode assembly, a battery module or battery pack including the battery cell, or a battery pack including the battery module.

[0082] Although specific portions of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific techniques are merely preferred embodiments and do not limit the scope of the present invention. It is possible to make various changes and modifications within the scope and technical ideas of the present invention, and it goes without saying that such changes and modifications are also within the scope of the appended claims. [Explanation of symbols]

[0083] 100 positive electrode 110 Positive electrode current collector 111 Aluminum layer 112 1st resin layer 113 Cathode active material layer 120 Positive electrode tab 200 negative electrode 210 Negative electrode current collector 211 Copper layer 212 2nd resin layer 213 Negative electrode active material layer 220 Negative electrode tab 300 Separation membrane 400 Positive lead 500 Negative lead 600 First Metal Foil 610 No. 1a Metal Foil 620 No. 1b metal foil 700 Second metal foil 710 2a metal foil 720 No. 2b metal foil

Claims

1. one or more positive electrodes including a positive electrode current collector and a positive electrode tab extending toward one side of the positive electrode current collector; one or more negative electrodes including a negative electrode current collector and a negative electrode tab extending toward one side of the negative electrode current collector; a separator interposed between the positive electrode and the negative electrode; a positive electrode lead electrically connected to the positive electrode tab; a negative electrode lead electrically connected to the negative electrode tab, the positive electrode current collector has a pair of aluminum layers and a first resin layer interposed between them, a first metal foil is interposed between the positive electrode tabs and between the outermost positive electrode tab and the positive electrode lead;

2. The secondary battery electrode assembly according to claim 1 , wherein the first metal foil is located along an edge of the positive electrode tab in the longitudinal direction.

3. The secondary battery electrode assembly of claim 2 , wherein the first metal foil includes a metal foil 1a and a metal foil 1b, and is located along both longitudinal edges of the positive electrode tab.

4. 4. The electrode assembly of claim 3, wherein the first metal foil is a band having a predetermined width and length, folded to form a corrugated shape with repeated peaks and valleys.

5. The secondary battery electrode assembly according to claim 3 , wherein the first metal foil comprises aluminum.

6. The secondary battery electrode assembly according to claim 5 , wherein the positive electrode lead is fixed to the first metal foil and the aluminum layer by ultrasonic welding.

7. The secondary battery electrode assembly according to claim 1 , wherein the first resin layer is made of a PET material.

8. The negative electrode current collector has a pair of copper layers and a second resin layer interposed between them, The secondary battery electrode assembly of claim 1 , wherein a second metal foil is interposed between the negative electrode tabs and between the outermost negative electrode tab and the negative electrode lead.

9. The secondary battery electrode assembly according to claim 8 , wherein the second metal foil is located along an edge of the negative electrode tab in the longitudinal direction.

10. The secondary battery electrode assembly of claim 9 , wherein the second metal foils include a second metal foil 2a and a second metal foil 2b, and are located along both longitudinal edges of the negative electrode tab.

11. 10. The electrode assembly of claim 9, wherein the second metal foil is a corrugated band having a predetermined width and length, folded to form repeated peaks and valleys.

12. The secondary battery electrode assembly of claim 11 , wherein the second metal foil comprises copper, nickel-coated copper, or a nickel-copper alloy.

13. The secondary battery electrode assembly according to claim 12 , wherein the negative electrode lead is fixed to the second metal foil and the copper layer by ultrasonic welding.

14. The secondary battery electrode assembly according to claim 8 , wherein the second resin layer is made of a PET material.

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

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