Electrode current collector, manufacturing method therefor, and secondary battery electrode assembly comprising same

Abstract

The present invention relates to an electrode current collector, a manufacturing method therefor, and a secondary battery electrode assembly comprising same, the 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 in some region of an uncoated part corresponding to an electrode tab, the polymer resin layer is removed so that the first metal layer and the second metal layer face each other.

Description

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

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0053096, filed April 22, 2024, the entire contents of which are incorporated herein by reference.

[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.

[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] Fig. 1 is a partial perspective view of a secondary battery according to the prior art. As illustrated in Fig. 1, the electrode assembly (1) has a structure in which a plurality of electrode tabs (2) extend outward, and electrode leads (3) are interposed between these electrode tabs (2) and then fixed to each other through welding.

[0008] Meanwhile, the cathode, where the positive electrode 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 composite current collectors, such as those with a structure that includes a resin layer sandwiched between two metal layers.

[0009] 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.

[0010] However, in the case of a current collector having a three-layer structure, not only is it difficult to conduct current between the current collectors and electrode leads due to the resin layer interposed between the metal layers, but it is also not easy to connect the electrode tabs and the electrode leads.

[0011]

[0012] (Prior art literature)

[0013] (Patent Document 1) Korean Patent Publication No. 10-2022-0124358

[0014]

[0015] In order to solve the above problems, the present invention aims to provide an electrode current collector having a structure in which electrode tabs and electrode leads are easily conductive even when a resin layer is interposed between two metal layers, a method for manufacturing the same, and a secondary battery electrode assembly including the same.

[0016] In addition, the present invention aims to provide an electrode current collector having a structure capable of firmly fixing electrode tabs and electrode leads even when a resin layer is interposed between two metal layers, a method for manufacturing the same, and a secondary battery electrode assembly including the same.

[0017]

[0018] As a technical means for achieving the above purpose, an electrode current collector according to one embodiment of the present invention comprises: 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 polymer resin layer (20) is removed in a portion of a non-coated portion corresponding to an electrode tab, so that the first metal layer (10) and the second metal layer (30) face each other.

[0019] In addition, in the electrode current collector according to one embodiment of the present invention, the removed area of ​​the polymer resin layer (20) is a linear shape having a certain width and length, and the linear shape is formed along the electric field direction or the full width direction of the electrode current collector.

[0020] In addition, in the electrode current collector according to one embodiment of the present invention, the removed area of ​​the polymer resin layer (20) is characterized in that a line having a certain width and length is in a zigzag shape, and the line is formed along the electric field direction or the full width direction of the electrode current collector.

[0021] In addition, in the electrode current collector according to one embodiment of the present invention, the removed area of ​​the polymer resin layer (20) is characterized in that lines having a certain width and length are formed to intersect each other.

[0022] In addition, in the electrode current collector according to one embodiment of the present invention, the removed area of ​​the polymer resin layer (20) is a discontinuous line having a certain width and length, and the discontinuous line is characterized in that it is formed along the electric field direction or the full width direction of the electrode current collector.

[0023] In addition, in the electrode current collector according to one embodiment of the present invention, the removed area of ​​the polymer resin layer (20) is characterized in that discontinuous lines having a certain width and length are formed to intersect each other.

[0024] In addition, in the electrode current collector according to one embodiment of the present invention, the first metal layer (10) and the second metal layer (30) include aluminum or copper material,

[0025] The above polymer resin layer (20) is characterized by including at least one material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0026] In addition, a method for manufacturing an electrode current collector according to one embodiment of the present invention includes a first step of preparing the polymer resin layer (20); a second step of forming a first metal layer (10) on the other surface of the polymer resin layer (20); a third step of removing a portion of the polymer resin layer (20); and a fourth step of forming a second metal layer (30) on one surface of the polymer resin layer (20); wherein the polymer resin layer (20) is removed from a portion of the non-coated portion corresponding to the electrode tab, so that the first metal layer (10) and the second metal layer (30) face each other.

[0027] In addition, the electrode current collector manufacturing method according to one embodiment of the present invention is characterized in that, in the third step, a portion of the polymer resin layer (20) is removed by an etching process.

[0028] In addition, the electrode current collector manufacturing method according to one embodiment of the present invention is characterized in that, in the second step, the first metal layer (10) is formed on the other surface of the polymer resin layer (20) through a deposition method.

[0029] In addition, the electrode current collector manufacturing method according to one embodiment of the present invention is characterized in that, in the fourth step, the second metal layer (30) is formed on one surface of the polymer resin layer (20) through a deposition method.

[0030] In addition, a method for manufacturing an electrode current collector 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); a third step of removing a portion of the polymer resin layer (20); and a fourth step of forming a second metal layer (30) on one surface of the polymer resin layer (20); wherein the polymer resin layer (20) is removed from a portion of a non-coated portion corresponding to an electrode tab, so that the first metal layer (10) and the second metal layer (30) face each other.

[0031] In addition, in the electrode current collector manufacturing method according to one embodiment of the present invention, it is characterized in that a lamination step of applying heat and pressure to the first metal layer (10) and the polymer resin layer (20) to adhere to each other is further included between the second step and the fourth step.

[0032] In addition, a secondary battery electrode assembly including an electrode current collector according to one embodiment of the present invention is characterized by including at least one first electrode (100) including a first electrode current collector (110) and a first electrode tab (120) extending in one direction of the first electrode current collector (110); at least one second electrode (200) including a second electrode current collector (210) and a second electrode tab (220) extending in one direction of the second electrode current collector (210); a separator (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).

[0033] In addition, the secondary battery electrode assembly according to one embodiment of the present invention is characterized in that the first electrode tab (120) and the first electrode lead (400), or the second electrode tab (220) and the second electrode lead (500) are fixed to each other by welding.

[0034]

[0035] As described above, according to the electrode current collector, the manufacturing method thereof, and the secondary battery electrode assembly including the same according to the present invention, even if a resin layer is interposed between a pair of metal layers, a part of the resin layer in the non-conductive region of the electrode current collector is removed, so that a part of the first metal layer and a part of the second metal layer face each other, making it easy for the electrode current collectors and the electrode lead to conduct current.

[0036] In addition, according to the electrode current collector, the manufacturing method thereof, and the secondary battery electrode assembly including the same according to the present invention, even if a resin layer is interposed between a pair of metal layers, a part of the resin layer in the non-conductive region of the electrode current collector is removed, so that a part of the first metal layer and a part of the second metal layer face each other, so that not only is it easy to fix the electrode current collectors and the electrode lead, but they can also be fixed firmly.

[0037]

[0038] Figure 1 is a partial perspective view of a secondary battery according to the prior art.

[0039] Figure 2 is a perspective view of an electrode current collector according to a first embodiment of the present invention.

[0040] Figure 3 is a cross-sectional view taken along the Ⅰ-Ⅰ direction of Figure 2.

[0041] Figure 4 is a cross-sectional view taken along the II-II direction of Figure 2.

[0042] FIG. 5 is a cross-sectional view taken along the direction Ⅰ-Ⅰ of FIG. 2 as a first modified example according to the first embodiment of the present invention.

[0043] FIG. 6 is a cross-sectional view taken along the direction II-II of FIG. 2 as a first modified example according to the first embodiment of the present invention.

[0044] Fig. 7 is a plan view of a polymer resin layer as a second modified example according to the first embodiment of the present invention.

[0045] Fig. 8 is a plan view of a polymer resin layer as a third modified example according to the first embodiment of the present invention.

[0046] FIG. 9 is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention, taken along the direction I-I of FIG. 2.

[0047] FIG. 10 is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention, taken along the direction II-II of FIG. 2.

[0048] Figure 11 is a flowchart for explaining a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0049] Figure 12 is a conceptual diagram for explaining a method for manufacturing an electrode current collector according to the first embodiment of the present invention.

[0050] Figure 13 is a flowchart for explaining a method for manufacturing an electrode collector according to a second embodiment of the present invention.

[0051] Figure 14 is a conceptual diagram for explaining a method for manufacturing an electrode collector according to a second embodiment of the present invention.

[0052] Figure 15 is an exploded perspective view of a secondary battery electrode assembly including an electrode collector according to the first embodiment of the present invention.

[0053] FIG. 16 is another exploded perspective view of a secondary battery electrode assembly including an electrode collector according to the first embodiment of the present invention.

[0054]

[0055] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0056] 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.

[0057]

[0058] Hereinafter, an electrode current collector according to the present invention, a method for manufacturing the same, and a secondary battery electrode assembly including the same will be described.

[0059] FIG. 2 is a perspective view of an electrode current collector according to a first embodiment of the present invention, FIG. 3 is a cross-sectional view taken along the direction I-I of FIG. 2, and FIG. 4 is a cross-sectional view taken along the direction II-II of FIG. 2.

[0060] Referring to FIGS. 2 to 4, 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).

[0061] 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 provided to include an aluminum (Al) material, and at this time, the thickness of the first metal layer (10) may be provided to be approximately 0.5 to 10 μm.

[0062] Of course, the first metal layer (10) may be made of stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. instead of aluminum, as long as it has high conductivity and does not cause chemical changes in the battery. In addition, in order to increase the adhesive strength of the electrode active material, various shapes such as fine unevenness on the surface, film, sheet, foil, net, porous body, foam, non-woven fabric, etc. are possible.

[0063] Additionally, the polymer resin layer (20) may be provided on one side of the first metal layer (10). For example, with reference to FIG. 3, one side of the first metal layer (10) may be a side facing the 12 o'clock direction.

[0064] This polymer resin layer (20) may be provided to include at least one material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon. For example, the polymer resin layer (20) may be formed of polyethylene terephthalate (PET), and may have a thickness of approximately 1 to 15 μm, but is not limited thereto.

[0065] The polymer resin layer (20) may be provided by removing a portion of the non-coated portion (B) corresponding to the electrode tab. In other words, the polymer resin layer (20) may be provided by removing a portion of the area corresponding to the non-coated portion (B) corresponding to the electrode tab.

[0066] The area removed from a portion of the non-coated portion (B) of the polymer resin layer (20) may be a linear shape having a certain width and length. More specifically, the removed area of ​​the polymer resin layer (20) may be formed along the electric field direction of the electrode current collector. In this case, the removed area of ​​the polymer resin layer (20) may be a linear shape having a length smaller than the electric field direction length of the non-coated portion (B) region.

[0067] Here, the non-conductive region (B) may be a region where the active material is not applied to the first metal layer (10) and the second metal layer (30) of the electrode current collector according to the present invention, and the opposite region, the maintenance region (A), may be a region where the active material is applied to the first metal layer (10) and the second metal layer (30) of the electrode current collector according to the present invention.

[0068] In addition, the polymer resin layer (20) can be provided for all areas of the maintenance portion (A), excluding the electrode tab area formed on one side of the first metal layer (10) and the second metal layer (30).

[0069] The second metal layer (30) may be provided on one side of the polymer resin layer (20). Here, the second metal layer (30) may be provided to include the same material as the first metal layer (10), for example, when the first metal layer (10) includes an aluminum (Al) material, the second metal layer (30) may also include an aluminum (Al) material.

[0070] Of course, as previously explained, the metal forming the second metal layer (30) may be stainless steel, nickel, titanium, calcined carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, etc. instead of aluminum, as long as it has high conductivity without causing chemical changes in the battery. In addition, in order to increase the adhesive strength of the electrode active material, various shapes such as fine unevenness may be formed on the surface, or a film, sheet, foil, net, porous body, foam, or non-woven fabric may be used.

[0071] The second metal layer (30) is provided on one side of the polymer resin layer (20), but as described above, the polymer resin layer (20) is removed from the non-coated area (B) corresponding to the electrode tab, so that the first metal layer (10) and the second metal layer (30) can face each other.

[0072] Since a portion of the polymer resin layer (20) is removed and there is no polymer resin layer (20) in a portion of the non-coated portion (B) where the first metal layer (10) and the second metal layer (30) face each other, when a plurality of electrode current collectors are stacked, it is easy for the electrode current collectors to conduct current to each other.

[0073] Meanwhile, the second metal layer (30) may be provided with a thickness of approximately 0.5 to 10 μm, but is not limited thereto.

[0074] For example, the first metal layer (10), the polymer resin layer (20), and the second metal layer (30) may be provided to have the same thickness. For example, when the first metal layer (10) is 5.0 μm and the polymer resin layer (20) is 5.0 μm, the thickness of the second metal layer (30) may be 5.0 μm.

[0075] As another example, the first metal layer (10) and the second metal layer (30) may be provided to have the same thickness, but the polymer resin layer (20) may be provided to have a thickness different from the thicknesses of the first metal layer (10) and the second metal layer (30).

[0076] For 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) may be 1.0 μm.

[0077] In addition, the second metal layer (30) may be provided with the same thickness in the area where the polymer resin layer (20) is provided (i.e., the area where the polymer resin layer (20) is not removed in the maintenance area (A) area and the non-conductive area (B) area) and in the area where the polymer resin layer (20) is not provided (i.e., the area where the polymer resin layer (20) is removed in the non-conductive area (B) area).

[0078] However, the thickness of the second metal layer (30) is not limited thereto, and the second metal layer (30) may be provided with a thickness of approximately 0.5 to 10 μm in an area where the polymer resin layer (20) is provided on the first metal layer (10) (i.e., an area where the polymer resin layer (20) is not removed in the maintenance area (A) area and the non-coated area (B) area), but may be provided with a thickness that is the sum of the thickness of the polymer resin layer (20) in an area where the polymer resin layer (20) is not provided on the first metal layer (10) (i.e., an area where the polymer resin layer (20) is removed in the non-coated area (B) area).

[0079] Meanwhile, when the electrode current collector of the present invention is provided as a negative 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 current collector described above.

[0080] For example, the first metal layer (10) may be provided to include a copper (Cu) material, and at this time, the first metal layer (10) may be provided to have a thickness of approximately 0.5 to 10 μm.

[0081] Additionally, the second metal layer (30) may be formed of the same material as the first metal layer (10), for example, when the first metal layer (10) includes a copper (Cu) material, the second metal layer (30) may also include a copper (Cu) material.

[0082] Additionally, the second metal layer (30) may be provided to have the same thickness as the first metal layer (10). The second metal layer (30) may be provided to have a thickness of approximately 0.5 to 10 μm.

[0083]

[0084] FIG. 5 is a cross-sectional view taken along the direction Ⅰ-Ⅰ of FIG. 2 as a first modified example according to the first embodiment of the present invention, and FIG. 6 is a cross-sectional view taken along the direction Ⅱ-Ⅱ of FIG. 2 as a first modified example according to the first embodiment of the present invention.

[0085] In a first modified example of the electrode current collector according to the first embodiment of the present invention, an inclined surface may be formed on the side surface of the polymer resin layer (20).

[0086] To explain in more detail, an inclined surface (21) may be formed on the side of the polymer resin layer (20) facing the area from which the polymer resin layer (20) has been removed.

[0087] In other words, the polymer resin layer (20) may have a portion of the electrode tab area (the non-conductive area (B) area) removed, and an inclined surface (21) may be formed on the side facing the removed area.

[0088] Referring to Fig. 5, the inclined surface (21) of the polymer resin layer (20) can be formed on one side (9 o'clock direction) facing the non-coated area (B) of the polymer resin layer (20). Also, referring to Fig. 6, the inclined surface (21) of the polymer resin layer (20) can be formed on both sides (3 o'clock-9 o'clock direction) facing the removed area of ​​the polymer resin layer (20).

[0089] By means of this inclined surface (21), the polymer resin layer (20) can be provided with an area of ​​the surface (6 o'clock direction in Fig. 6) that comes into contact with the first metal layer (10) larger than the area of ​​the surface (12 o'clock direction in Fig. 6) that comes into contact with the second metal layer (30).

[0090] For example, the inclined surface (21) may be provided to have an inclination angle greater than 0° and less than 90° with respect to one surface of the first metal layer (10).

[0091] The remaining configurations are the same as the electrode current collector according to the first embodiment described above, so redundant descriptions will be omitted.

[0092]

[0093] Fig. 7 is a plan view of a polymer resin layer as a second modified example according to the first embodiment of the present invention.

[0094] A second modified example of the electrode current collector according to the first embodiment of the present invention may be provided in a linear form of various shapes with a removed area of ​​the polymer resin layer (20) having a certain width and length.

[0095] First, referring to (a) of Fig. 7, the linear region, which is the removed region of the polymer resin layer (20), can be formed along the full width direction of the electrode current collector (3 o'clock to 9 o'clock direction based on Fig. 7). In addition, referring to (b) of Fig. 7, the removed region of the polymer resin layer (20) can be formed such that linear regions having a certain width and length intersect each other.

[0096] In addition, referring to (c) to (e) of FIG. 7, the removed area of ​​the polymer resin layer (20) may be formed into a curved line having a certain width and length. The curved line of the polymer resin layer (20) may be formed in the direction of the electric field of the electrode current collector, in the direction of the full width of the electrode current collector, or in a shape in which the curved lines intersect each other.

[0097] Also, referring to (h) of (f) of FIG. 7, the removed area of ​​the polymer resin layer (20) may be formed with lines having a zigzag shape having a certain width and length. The lines having the zigzag shape of the polymer resin layer (20) may be formed in the direction of the electric field of the electrode current collector, the direction of the full width of the electrode current collector, or in a shape in which the zigzag-shaped lines intersect each other.

[0098] Of course, the removed area of ​​the polymer resin layer (20) may be the entire area of ​​the non-conductive portion (B). In this case, the polymer resin layer (20) may be provided for the area of ​​the maintenance portion (A), which is the remaining area excluding the electrode tab area (non-conductive portion (B) area) formed on one side of the first metal layer (10) and the second metal layer (30).

[0099] The removed area of ​​the polymer resin layer (20) may be formed in a linear shape as described above, as well as in various linear shapes having a certain width and length.

[0100]

[0101] Fig. 8 is a plan view of a polymer resin layer as a third modified example according to the first embodiment of the present invention.

[0102] A third modified example of the electrode current collector according to the first embodiment of the present invention may be provided in a form of various discontinuous lines having a certain width and length in which the removed area of ​​the polymer resin layer (20) is formed.

[0103] First, referring to (a) of Fig. 8, the discontinuous line formed by the dotted line, which is the removed area of ​​the polymer resin layer (20), can be formed along the electric field direction of the electrode current collector (12 o'clock to 6 o'clock direction based on Fig. 8). In addition, referring to (b) of Fig. 8, the discontinuous line formed by the dotted line can be formed along the full width direction of the electrode current collector (3 o'clock to 9 o'clock direction based on Fig. 8).

[0104] Additionally, the removed area of ​​the polymer resin layer (20) can be formed as a discontinuous linear line with a certain width and length in the form of a single-dot chain line.

[0105] Referring to (c) and (d) of FIG. 8, the discontinuous line formed by the dashed-dotted line can be formed along the electric field direction of the electrode current collector or along the full width direction.

[0106] And, the removed area of ​​the polymer resin layer (20) can be formed as a discontinuous linear line with a certain width and length in the form of a broken line.

[0107] Referring to (e) and (f) of FIG. 8, the discontinuous lines formed by the broken lines can be formed along the electric field direction of the electrode current collector or along the full width direction.

[0108] Also, as shown in (g) of Fig. 8, the removed area of ​​the polymer resin layer (20) may be formed so that discontinuous lines having a certain width and length intersect each other. However, in Fig. 8 (g), the removed area of ​​the polymer resin layer (20) is formed in a shape where discontinuous lines formed as broken lines intersect each other, but is not limited thereto, and discontinuous lines formed as dotted lines or single-dot chain lines may be formed in a shape where discontinuous lines formed as dotted lines or single-dot chain lines intersect each other.

[0109] Here, the shape in which discontinuous lines intersect each other means that the discontinuous lines formed along the electric field direction of the electrode current collector and the discontinuous lines formed along the full width direction of the electrode current collector intersect each other.

[0110] The area from which the polymer resin layer (20) has been removed may be formed not only as a discontinuous linear shape as described above, but may also be provided as a discontinuous linear shape of various shapes having a certain width and length.

[0111]

[0112] FIG. 9 is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention, taken along the direction I-I of FIG. 2, and FIG. 10 is a cross-sectional view of an electrode current collector according to a second embodiment of the present invention, taken along the direction II-II of FIG. 2.

[0113] 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.

[0114] However, unlike the first embodiment, in the second embodiment, the first metal layer (10) may be formed thicker than the second metal layer (30). In other words, the thickness of the second metal layer (30) may be formed thinner than the thickness of the first metal layer (10).

[0115] For example, if the first metal layer (10) is 9.0 μm and the polymer resin layer (20) is 5.0 μm, the thickness of the second metal layer (30) may be 1.0 μm.

[0116] When the first metal layer (10) is thicker than the second metal layer (30), the manufacture of the electrode current collector can be made much easier, and a detailed description of this will be provided later.

[0117] In addition, the second metal layer (30) may have the same thickness in the area where the polymer resin layer (20) is formed (i.e., the area where the polymer resin layer (20) is not removed in the maintenance area (A) area and the non-conductive area (B) area) and in the area where the polymer resin layer (20) is not formed (i.e., the area where the polymer resin layer (20) is removed in the non-conductive area (B) area).

[0118] However, the thickness of the second metal layer (30) is not limited thereto, and the second metal layer (30) may be formed with a thickness of approximately 0.5 to 10 μm in an area where the polymer resin layer (20) is formed on the first metal layer (10) (i.e., an area where the polymer resin layer (20) is not removed in the maintenance area (A) area and the non-coated area (B) area), but may be formed with a thickness that is the sum of the thickness of the polymer resin layer (20) in an area where the polymer resin layer (20) is not formed on the first metal layer (10) (i.e., an area where the polymer resin layer (20) is removed in the non-coated area (B) area).

[0119] The electrode current collector according to the second embodiment of the present invention may have an inclined surface formed on the side of the polymer resin layer (20) facing the removed area of ​​the polymer resin layer (20), like the first modified example of the electrode current collector according to the first embodiment.

[0120] In addition, the electrode current collector according to the second embodiment of the present invention can be formed in various linear shapes with a removed area of ​​the polymer resin layer (20) having a certain width and length, like the second modified example of the electrode current collector according to the first embodiment.

[0121] In addition, the electrode current collector according to the second embodiment of the present invention can be formed in various discontinuous linear shapes with a certain width and length, such as the third modified example of the electrode current collector according to the first embodiment, in which the removed area of ​​the polymer resin layer (20) has a certain width and length.

[0122]

[0123] FIG. 11 is a flowchart for explaining a method for manufacturing an electrode current collector according to a first embodiment of the present invention, and FIG. 12 is a conceptual diagram for explaining a method for manufacturing an electrode current collector according to a first embodiment of the present invention.

[0124] Referring to FIGS. 2 to 4, 11 and 12 together, a method for manufacturing an electrode current collector according to a first embodiment of the present invention includes a first step of preparing a polymer resin layer (20), a second step of forming a first metal layer (10) on the other surface of the polymer resin layer (20), a third step of removing a portion of the polymer resin layer (20), and a fourth step of forming a second metal layer on one surface of the polymer resin layer (20).

[0125] First, regarding the method of manufacturing the positive electrode collector, in the first step, the polymer resin layer (20) is prepared in a sheet shape using at least one material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0126] In the second step, a first metal layer (10) is formed on the polymer resin layer (20) surface (12 o'clock direction based on Fig. 12(b)), and can be formed through a deposition method.

[0127] Here, the deposition method may be a physical vapor deposition method that forms a first metal layer (10) by making a solid metal, for example, aluminum (Al), which is a target material, into vapor, or a chemical vapor deposition method that forms a first metal layer (10) by decomposing an aluminum (Al) metal salt or a polymer material containing aluminum (Al) metal. Since these deposition methods correspond to known technologies, a detailed description of the principles and the like will be omitted.

[0128] In the third step, a portion of the polymer resin layer (20) may be removed by an etching process. The portion of the area removed by the etching process may be a portion of the non-coated area (B) corresponding to the electrode tab.

[0129] For example, referring to (c) of FIG. 12, in order to remove a portion of the polymer resin layer (20), the other side of the polymer resin layer (20) on which the first metal layer (10) is formed may be arranged so that it faces the 6 o'clock direction and one side of the polymer resin layer (20) faces the 12 o'clock direction.

[0130] A portion of the polymer resin layer (20) can be removed in a linear manner having a certain width and length, and the linear manner can be formed along the electric field direction of the electrode current collector.

[0131] For example, the etching process for removing a portion of the polymer resin layer (20) may be performed as a laser etching process using a laser unit (50). However, the present invention is not limited thereto, and the etching process for removing a portion of the polymer resin layer (20) may be performed through various etching processes.

[0132] Also, in the fourth step, the second metal layer (30) can be formed through a deposition method on one side of the polymer resin layer (20), that is, the side facing the 12 o'clock direction as shown in (d) of FIG. 12.

[0133] At this time, the target material moves not only to one side of the polymer resin layer (20), but also to a part of the electrode tab area of ​​the first metal layer (10) that is exposed by etching and is not overlapped with the polymer resin layer (20).

[0134] Accordingly, in some areas of the non-conductive portion (B) corresponding to the electrode tab, the first metal layer (10) and the second metal layer (30) may be provided in a state where they face each other. That is, the second metal layer (30) may be in contact with some areas of one surface of the first metal layer (10) and all areas of one surface of the polymer resin layer (20).

[0135] Here, the target material for forming the second metal layer (30) is the same material as the first metal layer (10), for example, aluminum (Al).

[0136] Additionally, the second metal layer (30) can be formed to a thickness of approximately 0.5 to 10 μm, but is not limited thereto.

[0137] As an example, the first metal layer (10), the polymer resin layer (20), and the second metal layer (30) may be formed to have the same thickness. For example, when the first metal layer (10) is 5.0 μm and the polymer resin layer (20) is 5.0 μm, the thickness of the second metal layer (30) may be 5.0 μm.

[0138] Additionally, as another example, the first metal layer (10) and the second metal layer (30) may be provided to have the same thickness, but the polymer resin layer (20) may be provided to have a thickness different from the thicknesses of the first metal layer (10) and the second metal layer (30).

[0139] For example, if 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) may be 1.0 μm.

[0140] The second and fourth steps described above can form a first metal layer (10) and a second metal layer (30) on one side and the other side of the polymer resin layer (20) by using a deposition unit (40).

[0141] Meanwhile, in the case of the first modified example of the electrode current collector according to the first embodiment of the present invention, the remainder is the same as the electrode current collector manufacturing method described above, except that an inclined surface is provided on the side of the polymer resin layer facing the removed area of ​​the polymer resin layer.

[0142] In particular, when an inclined surface (21) is formed on the side of the polymer resin layer (20) toward the removed area of ​​the polymer resin layer (20) (see FIGS. 5 and 6), the metal target material during the deposition process can more easily reach the side of the polymer resin layer (20), and thus the formation of an empty space between the first metal layer (10) and the second metal layer (30) can be reliably prevented.

[0143] In addition, in the case of the second modified example of the electrode current collector according to the first embodiment of the present invention and the third modified example of the electrode current collector according to the first embodiment of the present invention, only the shape removed by etching is different, and the rest is the same as the electrode current collector manufacturing method described above.

[0144]

[0145] When manufacturing a negative electrode collector, only the materials of the first metal layer (10) and the second metal layer (30) are different, and the rest is the same as the electrode collector manufacturing method described above.

[0146] For example, in the second and fourth steps, the target material for forming the first metal layer (10) and the second metal layer (30) may include a copper (Cu) material.

[0147] As described above, by removing a portion of the polymer resin layer located in the non-conductive region corresponding to the electrode tab through an etching process so that a portion of the first metal layer is exposed, it is possible to manufacture an electrode current collector having a structure in which the non-conductive region that functions as the electrode tab portion does not have a polymer resin layer.

[0148] In addition, since the first metal layer and the second metal layer are formed by a physical vapor deposition method or a chemical vapor deposition method, it is possible to omit a separate process for fixing the first metal layer and the polymer resin layer, the first metal layer and the second metal layer, or the polymer resin layer and the second metal layer.

[0149]

[0150] FIG. 13 is a flowchart for explaining a method for manufacturing an electrode current collector according to a second embodiment of the present invention, and FIG. 14 is a conceptual diagram for explaining a method for manufacturing an electrode current collector according to a second embodiment of the present invention.

[0151] The method for manufacturing an electrode collector according to the second embodiment of the present invention differs from the method for manufacturing an electrode collector according to the first embodiment in only some steps, and therefore the same steps will be briefly described or omitted.

[0152] Referring to FIGS. 9, 10, 13, and 14 together, a method for manufacturing an electrode current collector according to a second 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), a third step of removing a portion of the polymer resin layer (20), and a fourth step of forming a second metal layer (30) on one surface of the polymer resin layer (20).

[0153] First, in the case of the positive electrode collector, the first metal layer (10) in the first step may be provided to include an aluminum (Al) material, and at this time, the first metal layer (10) is in the shape of a thin sheet having a thickness of approximately 0.5 to 10 μm.

[0154] The second step is a step of forming a sheet-shaped polymer resin layer (20) having a certain thickness on one side of the first metal layer (10). For example, based on (b) of Fig. 14, one side of the first metal layer (10) may be a side facing the 12 o'clock direction.

[0155] In the third step, the polymer resin layer (20) may have some areas removed by an etching process, i.e., some areas of the non-coated area (B) corresponding to the electrode tabs. Since this has already been described in detail, it will be omitted.

[0156] Also, in the fourth step, the second metal layer (30) can be formed on one side of the polymer resin layer (20) through a deposition method. For example, based on (d) of FIG. 14, one side of the polymer resin layer (20) can be a side facing the 12 o'clock direction.

[0157] Here, the target material for forming the second metal layer (30) is aluminum (Al), which is the same material as the first metal layer (10).

[0158] Meanwhile, in the electrode current collector manufacturing method according to the second embodiment of the present invention, a lamination step of applying heat and pressure to the first metal layer (10) and the polymer resin layer (20) to adhere to each other may be included between the second and fourth steps, if necessary.

[0159] Through this lamination step, the first metal layer (10) and the polymer resin layer (20) can be adhered to each other. Of course, if the polymer resin layer (20) is formed by applying a polymer resin in a slurry state, the lamination step of applying heat and pressure can be omitted.

[0160] When manufacturing the negative electrode 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 electrode collector manufacturing method according to the second embodiment described above.

[0161] For example, in the first and third steps, the first metal layer (10) and the second metal layer (30) may include copper (Cu).

[0162] When the first metal layer (10) is thicker than the second metal layer (30), the manufacture of the electrode current collector can be made much easier. Specifically, when manufacturing the electrode current collector according to the second embodiment of the present invention, a first metal layer (10) in a film shape or sheet shape is prepared, and then a polymer resin layer (20) and a second metal layer (30) are sequentially formed. The thicker the first metal layer (10), the easier it is to prepare it in a film shape or sheet shape.

[0163]

[0164] Continuing, a secondary battery electrode assembly will be described. FIG. 15 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, and FIG. 16 is another exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to a first embodiment of the present invention.

[0165] As illustrated in FIGS. 15 and 16, 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 separators (300) including the electrode current collector according to the first embodiment are laminated.

[0166] Here, the first electrode (100) may be an anode, and the second electrode (200) may be a cathode. The separator (300) may be positioned between the first electrode (100) and the second electrode (300), on the upper surface of the second electrode (300) located at the top, and below the second electrode (300) located at the bottom, but is not limited thereto.

[0167] The first electrode (100) may be composed of a first electrode current collector (110) and a first electrode tab (120) formed of an electrode current collector according to the third embodiment, and the first electrode current collector (110) and the first electrode tab (120) may be formed of a three-layer structure in which a polymer resin layer is interposed between a first metal layer and a second metal layer including an aluminum (Al) material.

[0168] The first electrode tab (120) of the first electrode (100) is connected to the first electrode lead (400), and the second electrode tab (220) of the second electrode (200) is connected to the second electrode lead (500).

[0169] Of course, a positive electrode active material is applied to one or both sides of the first electrode current collector (110).

[0170] Here, the positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with a transition metal of a higher order; 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.

[0171] Meanwhile, the positive electrode active material may be mixed with a conductive agent and a binder, and fillers may be added as needed.

[0172] 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.

[0173] 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.

[0174] In addition, the second electrode (200) may be composed of a second electrode current collector (210) and a second electrode tab (220), and the second electrode current collector (210) and the second electrode tab (220) may be formed of a single layer including a copper (Cu) material, or a three-layer structure in which a polymer resin layer is interposed between a pair of first metal layers and a second metal layer.

[0175] Of course, a negative electrode active material is applied to one or both sides of the second electrode current collector (210).

[0176] For example, the negative active material is carbon such as non-graphitizable carbon, graphitic carbon, etc.; 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, 2, 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.

[0177] 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.

[0178] 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.

[0179] 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).

[0180] The separator (300) is interposed between the first electrode (100) and the second electrode (200) to prevent a short and only allow 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.

[0181] A plurality of first electrode tabs (120) can be electrically connected to each other through one first electrode lead (400), and a plurality of second electrode tabs (220) can be firmly fixed to each other through one second electrode lead (500).

[0182] Here, the electrode tabs and electrode leads are not limited to welding methods such as ultrasonic welding (e.g., Fig. 15), and it is also possible to use a rivet structure (e.g., Fig. 16) that penetrates the electrode tabs and electrode leads simultaneously.

[0183] Meanwhile, the second electrode (200), that is, the second electrode current collector (210) and the second electrode tab (220), may have a three-layer structure in which a polymer resin layer is interposed between a first metal layer and a second metal layer containing a copper (Cu) material.

[0184] Of course, in the case of the first electrode (100), the first electrode current collector (110) and the first electrode tab (120) may be formed as a three-layer structure in which a polymer resin layer is interposed between a first metal layer and a second metal layer containing aluminum (Al) material, or may be a single layer containing aluminum (Al) material.

[0185] Meanwhile, FIGS. 15 and 16 describe a secondary battery electrode assembly including an electrode current collector according to the first embodiment, but it is obvious that an electrode assembly having the same structure as described above can also be configured in the case of an electrode current collector according to the second embodiment.

[0186]

[0187] 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.

[0188] (Explanation of symbols)

[0189] 10: First metal layer

[0190] 20: Polymer resin layer 21: Inclined surface

[0191] 30: Second metal layer

[0192] 40: Deposition unit

[0193] 50: Laser Unit

[0194] 100: First electrode

[0195] 110: First electrode current collector

[0196] 120: First electrode tab

[0197] 200: Second electrode

[0198] 210: Second electrode current collector

[0199] 220: Second electrode tab

[0200] 300: Membrane

[0201] 400: First electrode lead

[0202] 500: Second electrode lead

[0203] A: Maintenance Department

[0204] B: No one

Claims

1. First metal layer; A polymer resin layer provided on one surface of the first metal layer; and Including a second metal layer provided on one side of the polymer resin layer, An electrode current collector characterized in that the polymer resin layer is removed from a portion of the non-conductive portion corresponding to the electrode tab, so that the first metal layer and the second metal layer face each other.

2. In paragraph 1, An electrode current collector, characterized in that the removed area of ​​the polymer resin layer is a linear shape having a certain width and length, and the linear shape is formed along the electric field direction or the full width direction of the electrode current collector.

3. In paragraph 1, An electrode current collector characterized in that the removed area of ​​the polymer resin layer has a zigzag shape with a certain width and length, and the line is formed along the electric field direction or the full width direction of the electrode current collector.

4. In paragraph 1, An electrode current collector characterized in that the removed area of ​​the polymer resin layer is formed so that lines having a certain width and length intersect each other.

5. In paragraph 1, An electrode current collector, characterized in that the removed area of ​​the polymer resin layer is a discontinuous line having a certain width and length, and the discontinuous line is formed along the electric field direction or the full width direction of the electrode current collector.

6. In paragraph 1, An electrode current collector characterized in that the removed area of ​​the polymer resin layer is formed such that discontinuous lines having a certain width and length intersect each other.

7. In paragraph 1, The first metal layer and the second metal layer include aluminum or copper material, A method for manufacturing an electrode current collector, characterized in that the polymer resin layer comprises at least one material selected from the group consisting of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

8. In a manufacturing method for manufacturing an electrode current collector according to any one of claims 1 to 7, Step 1: preparing the polymer resin layer; A second step of forming a first metal layer on the other surface of the polymer resin layer; A third step of removing a portion of the polymer resin layer; and A fourth step of forming a second metal layer on one surface of the polymer resin layer; including: A method for manufacturing an electrode current collector, characterized in that the polymer resin layer is removed from a portion of the non-conductive portion corresponding to the electrode tab, so that the first metal layer and the second metal layer face each other.

9. In paragraph 8, A method for manufacturing an electrode current collector, characterized in that, in the third step, a portion of the polymer resin layer is removed by an etching process.

10. In paragraph 9, A method for manufacturing an electrode current collector, characterized in that in the second step, the first metal layer is formed on the other surface of the polymer resin layer through a deposition method.

11. In paragraph 9, A method for manufacturing an electrode current collector, characterized in that in the fourth step, the second metal layer is formed on one surface of the polymer resin layer through a deposition method.

12. In a manufacturing method for manufacturing an electrode current collector according to any one of claims 1 to 7, Step 1: Preparing the first metal layer; A second step of forming a polymer resin layer on one surface of the first metal layer; A third step of removing a portion of the polymer resin layer; and A fourth step of forming a second metal layer on one surface of the polymer resin layer; including: A method for manufacturing an electrode current collector, characterized in that the polymer resin layer is removed from a portion of the non-conductive portion corresponding to the electrode tab, so that the first metal layer and the second metal layer face each other.

13. In paragraph 12, A method for manufacturing an electrode current collector, characterized in that between the second step and the fourth step, a lamination step is further included for applying heat and pressure to the first metal layer and the polymer resin layer to adhere to each other.

14. In a secondary battery electrode assembly including an electrode collector according to any one of claims 1 to 7, At least one first electrode comprising a first electrode current collector and a first electrode tab extending in one direction of the first electrode current collector; At least one second electrode comprising a second electrode current collector and a second electrode tab extending in one direction of the second electrode current collector; A separator interposed between the first electrode and the second electrode; a first electrode lead electrically connected to the first electrode tab; and A secondary battery electrode assembly characterized by including a second electrode lead electrically connected to the second electrode tab.

15. In paragraph 14, A secondary battery electrode assembly, characterized in that the first electrode tab and the first electrode lead, or the second electrode tab and the second electrode lead, are fixed to each other by welding.

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