Electrode current collector, method for manufacturing the same, and secondary battery electrode assembly including the same

Abstract

The present invention relates to an electrode current collector comprising a first metal layer, a polymer resin layer provided on one surface of the first metal layer, and a second metal layer provided on one surface of the polymer resin layer, wherein the area of ​​the polymer resin layer is smaller than the area of ​​the first metal layer and the second metal layer, a method for manufacturing the same, and a secondary battery electrode assembly including the same.

Description

[Technical Field]

[0001] This application claims priority under Korean Patent Application No. 10-2024-0034130 dated March 11, 2024, and all contents disclosed in said Korean Patent Application are included as part of this specification.

[0002] The present invention relates to an electrode current collector, a method for manufacturing the same, and a secondary battery electrode assembly including the same, and more particularly to an electrode current collector having a structure in which a resin layer is interposed between a pair of metal layers, a method for manufacturing the same, and a secondary battery electrode assembly including the same. [Background technology]

[0003] As technological development and demand for mobile devices increase, rechargeable secondary batteries are being used as an energy source for a variety of mobile devices. Secondary batteries are also attracting attention as an energy source for electric vehicles and hybrid electric vehicles, which are being presented as alternatives to existing gasoline and diesel vehicles that use fossil fuels.

[0004] Rechargeable batteries are classified into cylindrical and rectangular batteries, in which the electrode assembly is housed in a cylindrical or rectangular metal can, and pouch-type batteries, in which the electrode assembly is housed in a pouch-type case made of aluminum laminate sheet, depending on the shape of the battery case.

[0005] In particular, in the case of pouch-type secondary batteries, a number of positive and negative electrodes of a predetermined size are sequentially stacked with a separator membrane in between, and electrode tabs or a pair of electrode leads connected to electrode tabs protrude from one or both sides to the outside of the case.

[0006] Figure 1 is a schematic diagram of a secondary battery according to conventional technology. As shown in Figure 1, the electrode assembly 1 has a structure in which numerous tabs 2 extend outward, electrode leads 3 are interposed between these tabs 2, and then fixed to each other by welding.

[0007] On the other hand, the positive electrode to which the positive electrode active material is coated generally uses an aluminum current collector. However, since aluminum current collectors have been identified as the main cause of ignition for various reasons, research is being conducted to replace them with composite current collectors, such as current collectors with a structure in which a resin layer is interposed between two metal layers.

[0008] When using a current collector with such a three-layer structure, it is expected that the thin metal layer will create a large resistance in the event of a short circuit, allowing for a rapid interruption of the current flow and thus improving safety.

[0009] However, in the case of a three-layer current collector, a resin layer is interposed in the middle up to the tab portion, making it difficult to join the electrode tab and electrode lead using commonly used welding methods. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Korean Patent Publication No. 10-2022-0124358 [Overview of the project] [Problems that the invention aims to solve]

[0011] To solve the aforementioned problems, the present invention aims to provide an electrode current collector having a structure that allows the electrode tab and electrode lead to be easily fixed even when a resin layer is interposed between two metal layers, and a method for manufacturing the same.

[0012] Furthermore, the present invention aims to provide a secondary battery electrode assembly having a structure that facilitates current flow between numerous electrode tabs and electrode leads. [Means for solving the problem]

[0013] As a technical means for achieving the above-mentioned objectives, an electrode current collector according to one embodiment of the present invention includes a first metal layer (10), a polymer resin layer (20) provided on one surface of the first metal layer (10), and a second metal layer (30) provided on one surface of the polymer resin layer (20), wherein the area of ​​the polymer resin layer (20) is smaller than the area of ​​the first metal layer (10) and the second metal layer (30).

[0014] Furthermore, in an electrode current collector according to one embodiment of the present invention, the polymer resin layer (20) is provided in the remaining region excluding the electrode tab region formed on one side of the first metal layer (10) and the second metal layer (30).

[0015] Furthermore, in an electrode current collector according to one embodiment of the present invention, the polymer resin layer (20) is characterized in that an inclined surface (21) is formed toward the side where the electrode tab region is formed.

[0016] Furthermore, in an electrode current collector according to one embodiment of the present invention, the thickness of the first metal layer (10) is configured to be greater than the thickness of the second metal layer (30).

[0017] Furthermore, an electrode current collector manufacturing method according to one embodiment of the present invention includes a first step of preparing a first metal layer (10), a second step of forming a polymer resin layer (20) on one surface of the first metal layer (10), and a third step of forming a second metal layer (30) on one surface of the polymer resin layer (20) by vapor deposition, wherein the area of ​​the polymer resin layer (20) is smaller than the area of ​​the first metal layer (10) and the second metal layer (30).

[0018] Furthermore, in a method for manufacturing an electrode current collector according to one embodiment of the present invention, the method further includes a laminating step between the second and third steps, in which heat and pressure are applied to bond the first metal layer (10) and the polymer resin layer (20) to each other.

[0019] Also, in the method for manufacturing an electrode current collector according to an embodiment of the present invention, in the second step, the polymer resin layer (20) is formed in a remaining region excluding an electrode tab region formed on one side of the first metal layer (10).

[0020] Also, in the method for manufacturing an electrode current collector according to an embodiment of the present invention, in the third step, the vapor deposition method is a physical vapor deposition method or a chemical vapor deposition method.

[0021] Also, in the method for manufacturing an electrode current collector according to an embodiment of the present invention, in the third step, by vapor depositing up to the electrode tab region of the first metal layer (10), the second metal layer (30) contacts one surface of the first metal layer (10) and one surface of the polymer resin layer (20).

[0022] Also, in the method for manufacturing an electrode current collector according to an embodiment of the present invention, the first metal layer and the second metal layer include an aluminum or copper material. The method for manufacturing an electrode current collector according to claim 9.

[0023] Also, in the method for manufacturing an electrode current collector according to an embodiment of the present invention, the polymer resin layer (20) includes at least one or more materials of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0024] Furthermore, a secondary battery electrode assembly including an electrode current collector according to one embodiment of the present invention is characterized by comprising: a first electrode current collector (110) and one or more first electrodes (100) including a first electrode current collector (110) and a first electrode tab (120) extending in one direction from the first electrode current collector (110); a second electrode current collector (210) and one or more second electrodes (200) including a second electrode tab (220) extending in one direction from the second electrode current collector (210); a separation membrane (300) interposed between the first electrode (100) and the second electrode; a first electrode lead (400) electrically connected to the first electrode tab (120); and a second electrode lead (500) electrically connected to the second electrode tab (220).

[0025] Furthermore, in a secondary battery electrode assembly according to one embodiment of the present invention, the first electrode tab (120) and the first electrode lead (400) are fixed to each other by welding.

[0026] Furthermore, in a secondary battery electrode assembly according to one embodiment of the present invention, the second electrode tab (220) and the second electrode lead (500) are fixed to each other by welding. [Effects of the Invention]

[0027] As described above, the electrode current collector, the method for manufacturing the same, and the secondary battery electrode assembly including the same according to the present invention have the advantage that, after forming a polymer resin layer on one surface of the first metal layer such that a portion of the first metal layer is exposed, a second metal layer is formed by vapor deposition, thereby allowing the electrode tab and electrode lead to be firmly fixed by ultrasonic welding or the like.

[0028] Furthermore, the secondary battery electrode assembly according to the present invention has the advantage that, since the electrode tabs do not have a polymer resin layer, the electrode tabs and electrode leads have a structure that facilitates current flow. [Brief explanation of the drawing]

[0029] [Figure 1] This is a schematic diagram of a secondary battery using conventional technology.

[0030] [Figure 2] This is a cross-sectional view of an electrode current collector according to the first embodiment of the present invention.

[0031] [Figure 3] This is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention.

[0032] [Figure 4] This is a cross-sectional view of an electrode current collector according to a third embodiment of the present invention.

[0033] [Figure 5] This is a cross-sectional view of an electrode current collector according to a fourth embodiment of the present invention.

[0034] [Figure 6] This is a flowchart illustrating a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0035] [Figure 7] This is a conceptual diagram illustrating the method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0036] [Figure 8] This is an exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to the first embodiment of the present invention. [Modes for carrying out the invention]

[0037] Hereinafter, with reference to the attached drawings, embodiments that allow a person with ordinary skill in the art to carry out the present invention will be described in detail. However, in describing in detail the operating principles of preferred embodiments of the present invention, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0038] Furthermore, the same reference numerals shall be used throughout the drawings for parts that have similar functions and operations. Throughout the specification, when it is said that one part is connected to another part, this includes not only direct connections but also indirect connections through other elements in between. Also, when it is said that a component is included, unless otherwise stated, it does not mean that other components are excluded, but rather that other components may be included.

[0039] The following describes the electrode current collector according to the present invention, its manufacturing method, and a secondary battery electrode assembly including the same.

[0040] Figure 2 is a cross-sectional view of an electrode current collector according to a first embodiment of the present invention.

[0041] Referring to Figure 2, the electrode current collector according to the first embodiment of the present invention includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30.

[0042] First, when the electrode current collector of the present invention is provided as a positive electrode current collector, the first metal layer 10 may be configured to include an aluminum (Al) material. Here, the thickness of the first metal layer 10 is approximately 0.5 μm to 10 μm, in the form of a thin sheet.

[0043] Of course, the first metal layer 10 can be made of stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel with a surface treatment of carbon, nickel, titanium, silver, etc., instead of aluminum, as long as it has high conductivity without causing chemical changes to the battery. Furthermore, fine irregularities can be formed on the surface to enhance the adhesion of the electrode active material, or it can take various forms such as films, sheets, foils, nets, porous materials, foams, or nonwoven fabrics.

[0044] Furthermore, the polymer resin layer 20 may be provided on one surface of the first metal layer 10. For example, with reference to Figure 2, one surface of the first metal layer 10 may be the surface facing the 12 o'clock direction.

[0045] Such a polymer resin layer 20 may be composed of at least one material from among polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon. For example, the polymer resin layer 20 can be made of polyethylene terephthalate (PET) material and may have a thickness of approximately 1 μm to 15 μm, but is not limited to this.

[0046] The area of ​​the polymer resin layer 20 may be smaller than the area of ​​the first metal layer 10 and the second metal layer 30. For example, the area of ​​the polymer resin layer 20 may correspond to the area of ​​the remaining region excluding the electrode tab region formed at the 9 o'clock position when using Figure 2 as a reference.

[0047] Here, the electrode tab region may be the region corresponding to the plain portion B of the electrode current collector according to the present invention, where an active material is applied to a portion of the first metal layer 10 and the second metal layer 30, and the plain portion B is not applied to a portion of the first metal layer 10 and the second metal layer 30.

[0048] Therefore, the polymer resin layer 20 may be provided in the textured area A, which is the remaining area after removing the electrode tab region formed on one side of the first metal layer 10 and the second metal layer 30.

[0049] Furthermore, the second metal layer 30 may be provided on one surface of the polymer resin layer 20. Here, the second metal layer 30 may be made of the same material as the first metal layer 10; for example, if the first metal layer 10 contains aluminum (Al) material, the second metal layer 30 may also contain aluminum (Al) material.

[0050] Of course, as mentioned above, the metal forming the second metal layer 30 can be any metal that has high conductivity without causing chemical changes to the battery. Instead of aluminum, stainless steel, nickel, titanium, plastic carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., can be used. Furthermore, various forms are possible, such as those with fine irregularities on the surface to enhance the adhesion of the electrode active material, or films, sheets, foils, nets, porous materials, foams, and nonwoven fabrics.

[0051] The second metal layer 30 can be formed to a thickness of approximately 0.5 μm to 10 μm, but is not limited to this.

[0052] For example, if the first metal layer 10 is 1.0 μm thick and the polymer resin layer 20 is 6.0 μm thick, the thickness of the second metal layer 30 may be 1.0 μm.

[0053] As another example, if the first metal layer 10 is 5.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 may be 5.0 μm.

[0054] As another example, the first metal layer 10 may be thicker than the second metal layer 30. In other words, the second metal layer 30 may be thinner than the first metal layer 10.

[0055] For example, if the first metal layer 10 is 9.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 may be 1.0 μm.

[0056] As mentioned above, if the first metal layer 10 is thicker than the second metal layer 30, the electrode current collector can be manufactured more easily. The electrode current collector according to the present invention is made by preparing a film-like or sheet-like first metal layer 10, and then sequentially forming a polymer resin layer 20 and a second metal layer 30. This is because the thicker the first metal layer 10, the easier it is to manufacture the film-like or sheet-like first metal layer 10.

[0057] On the other hand, when the electrode current collector of the present invention is provided as a negative electrode current collector, only the materials of the first metal layer 10 and the second metal layer 30 are different, and the rest is substantially the same as the positive electrode current collector described above.

[0058] For example, the first metal layer 10 may be configured to include copper (Cu) material. Here, the thickness of the first metal layer 10 is approximately 0.5 μm to 10 μm, in the form of a thin sheet.

[0059] Furthermore, the second metal layer 30 may be composed of the same material as the first metal layer 10. For example, if the first metal layer 10 contains copper (Cu), the second metal layer 30 may also be configured to contain copper (Cu).

[0060] Figure 3 is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention.

[0061] The electrode current collector according to the second embodiment of the present invention includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30, similar to the first embodiment.

[0062] However, unlike the first embodiment, in the second embodiment, the second metal layer 30 may be formed to a thickness of approximately 0.5 μm to 10 μm in the region where the polymer resin layer 20 is formed on the first metal layer 10 (region A with a texture), and to a thickness equal to the thickness of the polymer resin layer 20 added to the second metal layer 30 in the region where the polymer resin layer 20 is not formed on the first metal layer 10 (region B without a texture).

[0063] In other words, in the second embodiment, the thickness of the electrode current collector can be such that the thickness of the region where the polymer resin layer 20 is formed (region A with a texture) is the same as the thickness of the region where the polymer resin layer 20 is not formed (region B without a texture), by forming the second metal layer 30 with a thickness equal to the thickness of the polymer resin layer 20 added to the region where the polymer resin layer 20 is not formed (region B without a texture).

[0064] For example, if the first metal layer 10 is 1.0 μm thick and the polymer resin layer 20 is 6.0 μm thick, the thickness of the second metal layer 30 in the region where the polymer resin layer 20 is formed (region A with a textured surface) is 1.0 μm, while the thickness of the region where the polymer resin layer 20 is not formed (region B without a textured surface) may be 7 μm.

[0065] As another example, if the first metal layer 10 is 5.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 in the region where the polymer resin layer 20 is formed (region A with a texture) may be 5.0 μm, while the thickness of the region where the polymer resin layer 20 is not formed (region B without a texture) may be 10 μm.

[0066] As another example, the first metal layer 10 may be thicker than the second metal layer 30. In other words, the second metal layer 30 may be thinner than the first metal layer 10.

[0067] For example, if the first metal layer 10 is 9.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 in the region where the polymer resin layer 20 is formed (region A with a textured surface) is 1.0 μm, while the thickness of the region where the polymer resin layer 20 is not formed (region B without a textured surface) may be 6 μm.

[0068] On the other hand, when the electrode current collector of the present invention is provided as a negative electrode current collector, only the materials of the first metal layer 10 and the second metal layer 30 are different, and the rest is substantially the same as the positive electrode current collector described above.

[0069] Figure 4 is a cross-sectional view of an electrode current collector according to a third embodiment of the present invention.

[0070] The electrode current collector according to the third embodiment of the present invention includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30, similar to the first and second embodiments.

[0071] However, unlike the first and second embodiments, in the third embodiment, an inclined surface 21 is formed on one side of the polymer resin layer 20.

[0072] Referring to Figure 4, the polymer resin layer 20 may include an inclined surface 21 formed toward the side where the electrode tab region (plain area B) is formed (9 o'clock direction, with reference to Figure 4).

[0073] The inclined surface 21 may be one side surface extending from the surface in contact with the first metal layer 10 to the surface on which the second metal layer 30 is formed. Such an inclined surface 21 may be formed by the area of ​​the surface in contact with the first metal layer 10 (6 o'clock direction, with reference to Figure 4) being larger than the area of ​​the surface in contact with the second metal layer 30 (12 o'clock direction, with reference to Figure 4).

[0074] Furthermore, for example, the inclined surface 21 may be configured to have an inclination angle greater than 0° and less than 90° when one surface of the first metal layer 10 is used as a reference.

[0075] On the other hand, in the electrode current collector according to the third embodiment, similar to the electrode current collector according to the first embodiment, the thickness of the second metal layer 30 may be configured such that the thickness of the region where the polymer resin layer 20 is formed (region A with a texture) and the thickness of the region where the polymer resin layer 20 is not formed (region B without a texture) are the same.

[0076] Figure 5 is a cross-sectional view of an electrode current collector according to a fourth embodiment of the present invention.

[0077] The electrode current collector according to the fourth embodiment of the present invention includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30, similar to the third embodiment, and an inclined surface 21 is formed on one side of the polymer resin layer 20.

[0078] However, unlike the third embodiment, in the fourth embodiment, the second metal layer 30 may be formed to a thickness of approximately 0.5 μm to 10 μm in the region where the polymer resin layer 20 is formed on the first metal layer 10 (region A with a texture), and to a thickness equal to the thickness of the polymer resin layer 20 added to the second metal layer 30 in the region where the polymer resin layer 20 is not formed on the first metal layer 10 (region B without a texture).

[0079] In other words, in the fourth embodiment, the thickness of the electrode current collector can be such that the thickness of the region where the polymer resin layer 20 is formed (region A with a texture) is the same as the thickness of the region where the polymer resin layer 20 is not formed (region B without a texture), by forming the second metal layer 30 to the thickness of the polymer resin layer 20 plus the thickness of the polymer resin layer 20 in the region where the polymer resin layer 20 is not formed (region B without a texture).

[0080] Figure 6 is a flowchart illustrating the electrode current collector manufacturing method according to the first embodiment of the present invention, and Figure 7 is a conceptual diagram illustrating the electrode current collector manufacturing method according to the first embodiment of the present invention.

[0081] Referring together to Figures 2, 6, and 7, the method for manufacturing an electrode current collector according to the first embodiment of the present invention includes a first step of preparing a first metal layer 10, a second step of forming a polymer resin layer 20 on one surface of the first metal layer 10, and a third step of forming a second metal layer 30 on one surface of the polymer resin layer 20 by vapor deposition.

[0082] First, regarding the method for manufacturing the positive electrode current collector, in the first step, the first metal layer 10 may be configured to include an aluminum (Al) material. Here, the thickness of the first metal layer 10 is approximately 0.5 μm to 10 μm, in the form of a thin sheet.

[0083] The second step is to form a sheet-like polymer resin layer 20 having a certain thickness on one surface of the first metal layer 10. For example, with reference to Figure 7(b), one surface of the first metal layer 10 may be the surface facing the 12 o'clock direction.

[0084] Here, the method for forming the polymer resin layer 20 is not particularly limited, but as an example, the polymer resin layer 20 can be formed by applying a polymer resin in slurry form or by layering a polymer resin in sheet form.

[0085] The polymer resin layer 20 may be composed of at least one material selected from polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0086] Furthermore, the polymer resin layer 20 may be configured to have a smaller area than the area of ​​the first metal layer 10. For example, the area of ​​the polymer resin layer 20 may be configured to correspond to the area of ​​the remaining region of the first metal layer 10, i.e., the region formed at the 10 o'clock position when using Figure 7(b) as a reference.

[0087] In other words, in the second stage, the polymer resin layer 20 can be formed on one surface of the first metal layer 10 in the region corresponding to the textured area A.

[0088] The third step is to form a second metal layer 30 on one surface of the polymer resin layer 20 by vapor deposition.

[0089] Here, as the vapor deposition method, either a physical vapor deposition method, which vaporizes the target substance, a solid metal, to form the second metal layer 30, or a chemical vapor deposition method, which decomposes a metal salt or a polymer substance containing metal to form the second metal layer 30, can be used. Since such vapor deposition methods are known techniques, a detailed explanation of the principles will be omitted.

[0090] In this third stage, the target substance moves not only to one surface of the polymer resin layer 20, but also to the electrode tab region (plain region B) of the first metal layer 10, which is exposed without overlapping with the polymer resin layer 20. Therefore, the second metal layer 30 can come into contact with a portion of one surface of the first metal layer 10 and the entire surface of one surface of the polymer resin layer 20.

[0091] Here, the target material for forming the second metal layer 30 is the same material as the first metal layer 10. For example, if the first metal layer 10 is aluminum (Al), then the target material is also aluminum (Al).

[0092] Furthermore, the second metal layer 30 may be formed to have a thickness of approximately 0.5 μm to 10 μm, but is not limited to this.

[0093] For example, if the first metal layer 10 is 1.0 μm thick and the polymer resin layer 20 is 6.0 μm thick, the thickness of the second metal layer 30 may be 1.0 μm.

[0094] As another example, if the first metal layer 10 is 5.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 may be 5.0 μm.

[0095] As another example, the second metal layer 30 may be thinner than the first metal layer 10. In other words, the thickness of the first metal layer 10 may be thicker than the thickness of the second metal layer 30.

[0096] For example, if the first metal layer 10 is 9.0 μm thick and the polymer resin layer 20 is 5.0 μm thick, the thickness of the second metal layer 30 may be 1.0 μm.

[0097] In this third step, the second metal layer 30 can be formed using the deposition unit 40 so as to be in contact with one surface of the polymer resin layer 20 and the electrode tab region of the first metal layer 10.

[0098] Furthermore, the electrode current collector manufacturing method according to the present invention may include a laminating step between the second and third steps in which a certain range of heat and pressure is applied to the first metal layer 10 and the polymer resin layer 20, if necessary.

[0099] Through this lamination step, the first metal layer 10 and the polymer resin layer 20 can be bonded to each other. Of course, if the polymer resin layer 20 is formed by applying a slurry of polymer resin, the lamination step involving heat and pressure can be omitted.

[0100] On the other hand, by applying a positive electrode active material to a predetermined area on one or both sides of the electrode current collector manufactured by the process described above, an electrode, or more specifically a positive electrode, can be obtained.

[0101] More specifically, the active material can be applied to the other surface of the first metal layer 10 (at the 6 o'clock position, relative to Figure 2) and / or to one surface of the second metal layer 30 (at the 12 o'clock position, relative to Figure 2).

[0102] Here, the active material is the positive electrode active material, and is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with a transition metal; chemical formula Li1+ x Mn2- x Lithium manganese oxides such as O4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, V2O5, Cu2V2O7; chemical formula LiNi1- x Ni-site type lithium nickel oxide represented as MxO2 (where M = Co, Mn, Al, Cu, Fe, Mg, B, or Ga, and x = 0.01 to 0.3); chemical formula LiMn2- x M x Lithium manganese complex oxides represented as O2 (where M = Co, Ni, Fe, Cr, Zn, or Ta, and x = 0.01 to 0.1) or Li2Mn3MO8 (where M = Fe, Co, Ni, Cu, or Zn); LiMn2O4, where part of the Li in the chemical formula is substituted with an alkaline earth metal ion; disulfide compounds; Fe2(MoO4)3, LiNi x Mn2- x You can use formulas such as O4 (0.01 ≤ x ≤ 0.6).

[0103] On the other hand, conductive materials and binders can be mixed into the positive electrode active material, and fillers can be added as needed.

[0104] The conductive material is usually added in an amount of 1 to 50% by weight, based on the total weight of the mixture containing the positive electrode active material. Such conductive materials are not particularly limited as long as they are conductive without causing a chemical change to the battery, and examples of such materials that can be used include graphite such as natural graphite or 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 fibers and metal fibers; 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.

[0105] The binder is a component that helps to bond the positive electrode active material to the conductive material and to the current collector, and is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture containing the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-dientelpolymer (EPDM), sulfonated EPDM, styrene-butylene rubber, fluororubber, and various copolymers.

[0106] Furthermore, in the electrode current collector, the plain area B, where the positive electrode active material is not coated, can be notched into a certain shape to form an electrode tab. However, if necessary, the entire plain area B can also be used as an electrode tab without the notching process.

[0107] On the other hand, when manufacturing the negative electrode current collector, only the materials of the first metal layer 10 and the second metal layer 30 are different; the rest is substantially the same as the positive electrode current collector manufacturing method described above.

[0108] For example, in the first stage, the first metal layer 10 can be configured to include a copper (Cu) material. Here, the first metal layer 10 is in the form of a thin sheet with a thickness of approximately 0.5 μm to 10 μm.

[0109] Also, in the third stage, the target material for forming the second metal layer 30 is the same material as the first metal layer 10. For example, when the first metal layer 10 is copper (Cu), the target material is also copper (Cu).

[0110] Moreover, the second metal layer 30 can be formed to have a thickness of approximately 0.5 μm to 10 μm, but is not limited thereto. For example, the second metal layer 30 is formed on one surface of the polymer resin layer 20 to a thickness of approximately 0.5 μm to 2 μm, and can be formed to a thickness that is the sum of the thickness of the polymer resin layer 20 in the region (plain area B region) where the polymer resin layer 20 is not formed on the first metal layer 10.

[0111] As an example, when the first metal layer 10 is 1.0 μm and the polymer resin layer 20 is 6.0 μm, the thickness of the second metal layer 30 in the region (patterned area A region) where the polymer resin layer 20 is formed is 1.0 μm, while the region (plain area B region) where the polymer resin layer 20 is not formed can be 7 μm.

[0112] On the other hand, by applying a negative electrode active material to a predetermined region on one or both surfaces of an electrode current collector having a structure in which the first metal layer 10 and the second metal layer 30 of a copper (Cu) material are located on both surfaces of the polymer resin layer 20, an electrode, more specifically a negative electrode, is obtained.

[0113] For example, the negative electrode active material includes carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3 (0 ≦ x ≦ 1), Li x WO2 (0 ≦ x ≦ 1), Sn x Me1- x Me’ y O zMetal composite oxides such as (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); 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 only.

[0114] 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.

[0115] 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, 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.

[0116] The binder is a component that helps to bond the negative electrode active material to conductive materials 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, fluororubber, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinyl alcohol (PVA), polyacrylic acid (PAA), polyethylene glycol (PEG), polyacrylonitrile (PAN), and polyacrylamide (PAM).

[0117] As described above, by forming a polymer resin layer on one surface of the first metal layer such that a portion of the first metal layer is exposed, and then forming a second metal layer by vapor deposition, it is possible to manufacture an electrode current collector in which the plain portion that functions as the electrode tab does not have a polymer resin layer.

[0118] Furthermore, since the second metal layer is formed by physical or chemical vapor deposition, a separate process for fixing the first metal layer and the second metal layer, or the polymer resin layer and the second metal layer, can be omitted.

[0119] Furthermore, the first metal layer can also be formed in sheet form by vapor deposition.

[0120] The electrode current collector manufacturing method according to the second embodiment of the present invention can be manufactured in the same manner as the first embodiment, with the only difference being the thickness of the second metal layer in the plain region where the polymer resin layer is not formed.

[0121] Furthermore, when the electrode current collector of the present invention is provided as a negative electrode current collector, only the materials of the first metal layer and the second metal layer are different, and the rest can be manufactured in the same manner as the positive electrode current collector manufacturing method according to the first embodiment described above.

[0122] Furthermore, the electrode current collector manufacturing method according to the third embodiment of the present invention can be manufactured in the same manner as the positive electrode current collector manufacturing method according to the first embodiment described above, except that the polymer resin layer is provided with an inclined surface.

[0123] In particular, when an inclined surface 21 is formed on one side of the polymer resin layer 20 (see Figure 4), the metal target material can reach the side surface of the polymer resin layer 20 more easily during the vapor deposition process, thereby reliably preventing the formation of a space between the first metal layer 10 and the second metal layer 30.

[0124] Furthermore, the electrode current collector manufacturing method according to the fourth embodiment of the present invention can be manufactured in the same manner as the first embodiment, except that an inclined surface is formed on one side of the polymer resin layer, and the only difference is the thickness of the second metal layer in the plain area where the polymer resin layer is not formed.

[0125] The following describes a secondary battery electrode assembly including an electrode current collector manufactured by the electrode current collector manufacturing method according to the present invention.

[0126] Figure 8 is an exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to a first embodiment of the present invention.

[0127] As shown in Figure 8, the secondary battery electrode assembly according to the present invention has a structure in which one or more first electrodes 100, one or more second electrodes 200, and one or more separation membranes 300 are stacked.

[0128] Here, the first electrode 100 may be the positive electrode, and the second electrode 200 may be the negative electrode. The separation membrane 300 may be located between the first electrode 100 and the second electrode 200, on the upper surface of the uppermost second electrode 200, and below the lowermost second electrode 200, but is not limited to these positions.

[0129] Furthermore, the first electrode 100 can be electrically connected to the first electrode lead 400, and the second electrode 200 can be electrically connected to the second electrode lead 500.

[0130] Referring together to Figures 2 through 8, the first electrode 100 may consist of a first electrode current collector 110 and a first electrode tab 120.

[0131] Here, the first electrode current collector 110 has a three-layer structure in which a polymer resin layer 20 is interposed between a first metal layer 10 containing aluminum (Al) material and a second metal layer 30, and the first electrode tab 120 may consist only of the first metal layer 10 and the second metal layer 30.

[0132] The second electrode 200 may consist of a second electrode current collector 210 and a second electrode tab 220 made of copper (Cu) material.

[0133] The separation membrane 300 is interposed between the first electrode 100 and the second electrode 200 to prevent short circuits and allow only the movement of lithium ions. The material of such a separation membrane is preferably one selected from polyethylene, polypropylene, polyethylene / polypropylene double layer, polyethylene / polypropylene / polyethylene triple layer, polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited to these.

[0134] On the other hand, multiple first electrodes 100 can be electrically connected to one another via a single first electrode lead 400.

[0135] Generally, in electrode current collectors where a resin layer is interposed between a pair of aluminum layers, when the thickness direction (y-axis direction) is taken as the reference, the resin layer located in the center of the electrode tab makes it difficult to firmly fix a large number of electrode tabs and electrode leads using ultrasonic welding, and also makes it difficult to electrically connect each electrode tab and electrode lead.

[0136] However, in the case of the first electrode current collector 110 manufactured by the electrode current collector manufacturing method according to the present invention, since the first electrode tab 120 consists of a first metal layer 10 and a second metal layer 30, not only can a large number of first electrode tabs 120 and first electrode leads 400 be firmly fixed by welding, but each first electrode tab 120 and first electrode lead 400 is electrically connected.

[0137] Here, welding may be ultrasonic welding, but is not necessarily limited to this.

[0138] Similarly, multiple second electrodes 200 can be electrically connected via a single second electrode lead 500.

[0139] For example, the first electrode 100 includes a first electrode current collector 110 with a three-layer structure in which a polymer resin layer 20 is interposed between a first metal layer 10 and a second metal layer 30 made of aluminum (Al), while the second electrode 200 was described as a second electrode current collector 210 consisting of a single layer of copper (Cu). However, even in the case of the second electrode 200, the second electrode current collector 210 may have a three-layer structure in which a polymer resin layer 20 is interposed between a first metal layer 10 and a second metal layer 30 made of copper (Cu).

[0140] Furthermore, although a secondary battery electrode assembly including an electrode current collector according to the first embodiment has been described, it is obvious that the same electrode assembly structure as described above can also be constructed in the case of an electrode current collector according to the second embodiment, which has a different thickness of the second metal layer, and in the case of electrode current collectors according to the third and fourth embodiments, which include a polymer resin layer with an inclined surface.

[0141] Although specific parts of the present invention have been described in detail above, such specific techniques are merely preferred modes of implementation and do not limit the scope of the present invention. It will be obvious to those skilled in the art that various changes and modifications are possible within the scope of the present invention and its technical concept, and it goes without saying that such variations and modifications also fall within the scope of the appended claims. [Explanation of symbols]

[0142] 10 1st metal layer

[0143] 20 Polymer resin layer 21 Slope

[0144] 30 Second metal layer

[0145] 40 Evaporation Units

[0146] 100 1st electrode

[0147] 110 First electrode current collector

[0148] 120 First electrode tab

[0149] 200 2nd electrode

[0150] 210 Second electrode current collector

[0151] 220 Second electrode tab

[0152] 300 Separation membrane

[0153] 400 First electrode lead

[0154] 500 Second electrode lead

[0155] A Landed area

[0156] B Plain area

Claims

1. The first metal layer and A polymer resin layer provided on one surface of the first metal layer, The polymer resin layer includes a second metal layer provided on one surface of the polymer resin layer, An electrode current collector wherein the area of ​​the polymer resin layer is smaller than the area of ​​the first metal layer and the second metal layer.

2. The electrode current collector according to claim 1, wherein the polymer resin layer is provided in the remaining region excluding the electrode tab region formed on one side of the first metal layer and the second metal layer.

3. The electrode current collector according to claim 2, wherein the polymer resin layer has an inclined surface formed toward the side where the electrode tab region is formed.

4. The electrode current collector according to claim 2, wherein the thickness of the first metal layer is greater than the thickness of the second metal layer.

5. A manufacturing method for producing an electrode current collector according to any one of claims 1 to 4, The first step is to prepare the first metal layer, A second step involves forming a polymer resin layer on one surface of the first metal layer, The third step includes forming a second metal layer on one surface of the polymer resin layer by vapor deposition, A method for manufacturing an electrode current collector, wherein the area of ​​the polymer resin layer is smaller than the area of ​​the first metal layer and the second metal layer.

6. The method for manufacturing an electrode current collector according to claim 5, further comprising a laminating step between the second and third steps, in which heat and pressure are applied to bond the first metal layer and the polymer resin layer to each other.

7. The method for manufacturing an electrode current collector according to claim 5, wherein in the second step, the polymer resin layer is formed in the remaining region excluding the electrode tab region formed on one side of the first metal layer.

8. The method for manufacturing an electrode current collector according to claim 7, wherein in the third step, the vapor deposition method is a physical vapor deposition method or a chemical vapor deposition method.

9. The method for manufacturing an electrode current collector according to claim 8, wherein in the third step, the first metal layer is deposited up to the electrode tab region, and the second metal layer is in contact with one surface of the first metal layer and one surface of the polymer resin layer.

10. The method for manufacturing an electrode current collector according to claim 9, wherein the first metal layer and the second metal layer include aluminum or copper material.

11. The method for manufacturing an electrode current collector according to claim 7, wherein the polymer resin layer comprises at least one material selected from polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

12. A secondary battery electrode assembly comprising an electrode current collector according to any one of claims 1 to 4, A first electrode comprising a first electrode current collector and one or more first electrodes including a first electrode tab extending in one direction from the first electrode current collector, A second electrode comprising a second electrode current collector and one or more second electrodes including a second electrode tab extending in one direction from the second electrode current collector, A separation membrane interposed between the first electrode and the second electrode, The first electrode tab is electrically connected to the first electrode lead, A secondary battery electrode assembly comprising a second electrode tab and a second electrode lead electrically connected thereto.

13. The secondary battery electrode assembly according to claim 12, wherein the first electrode tab and the first electrode lead are fixed to each other by welding.

14. The secondary battery electrode assembly according to claim 12, wherein the second electrode tab and the second electrode lead are fixed to each other by welding.

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