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

Abstract

This disclosure 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 a portion of the plain area corresponding to the electrode tab is such that the polymer resin layer is removed and the first metal layer and the second metal layer face each other, 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. 10-2024-0053096 dated April 22, 2024, and all content disclosed in said Korean Patent Application is incorporated herein as part of this specification.

[0002] This disclosure 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 partial perspective view of a conventional secondary battery. As shown in Figure 1, the electrode assembly 1 has a structure in which numerous electrode tabs 2 extend outward, electrode leads 3 are interposed between these electrode 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 current collector with a three-layer structure, the resin layer interposed between the metal layers makes it difficult for current to flow between the current collector and the electrode lead, and it is also not easy to connect the electrode tab and the electrode lead. [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, this disclosure aims to provide an electrode current collector having a structure that facilitates current flow between the electrode tab and electrode lead 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.

[0012] Furthermore, this disclosure aims to provide an electrode current collector having a structure that can firmly fix the electrode tab and electrode lead 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. [Means for solving the problem]

[0013] As a technical means for achieving the aforementioned objectives, an electrode current collector according to one embodiment of the present disclosure 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 a portion of the plain area corresponding to the electrode tab is such that the polymer resin layer (20) is removed and the first metal layer (10) and the second metal layer (30) face each other.

[0014] Furthermore, in an electrode current collector according to one embodiment of the present disclosure, the region from which the polymer resin layer (20) has been removed is linear in shape having a predetermined width and length, and the linear shape is formed along the overall length direction or the overall width direction of the electrode current collector.

[0015] Furthermore, in an electrode current collector according to one embodiment of the present disclosure, the region from which the polymer resin layer (20) has been removed is characterized in that the linear shape having a predetermined width and length is zigzag, and the linear shape is formed along the overall length direction or the overall width direction of the electrode current collector.

[0016] Furthermore, in an electrode current collector according to one embodiment of the present disclosure, the region from which the polymer resin layer (20) has been removed is characterized in that linear shapes having a predetermined width and length intersect with each other.

[0017] Furthermore, in an electrode current collector according to one embodiment of the present disclosure, the region from which the polymer resin layer (20) has been removed is a discontinuous linear shape having a predetermined width and length, and the discontinuous linear shape is formed along the overall length direction or the overall width direction of the electrode current collector.

[0018] Furthermore, in an electrode current collector according to one embodiment of the present disclosure, the region from which the polymer resin layer (20) has been removed is characterized in that discontinuous linear shapes having a predetermined width and length intersect with each other.

[0019] Also, in the electrode current collector according to an embodiment of the present disclosure, the first metal layer (10) and the second metal layer (30) contain an aluminum or copper material,

[0020] The polymer resin layer (20) is characterized by containing at least one or more materials of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0021] Also, a method for manufacturing an electrode current collector for manufacturing the electrode current collector according to an embodiment of the present disclosure 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 partial region 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). A partial region of the blank portion corresponding to the electrode tab is characterized in that the polymer resin layer (20) is removed and the first metal layer (10) and the second metal layer (30) face each other.

[0022] Also, a method for manufacturing an electrode current collector according to an embodiment of the present disclosure is characterized in that, in the third step, a partial region of the polymer resin layer (20) is removed by an etching process.

[0023] Also, a method for manufacturing an electrode current collector according to an embodiment of the present disclosure 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) by a vapor deposition method.

[0024] Also, a method for manufacturing an electrode current collector according to an embodiment of the present disclosure is characterized in that, in the fourth step, the second metal layer (30) is formed on one surface of the polymer resin layer (20) by a vapor deposition method.

[0025] Furthermore, a method for manufacturing an electrode current collector according to one embodiment of the present disclosure 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 a portion of the blank area corresponding to the electrode tab is in a state where the polymer resin layer (20) has been removed and the first metal layer (10) and the second metal layer (30) are facing each other.

[0026] Furthermore, in a method for manufacturing an electrode current collector according to one embodiment of the present disclosure, the second step and the fourth step further include a lamination step in which heat and pressure are applied to bond the first metal layer (10) and the polymer resin layer (20) to each other.

[0027] Furthermore, a secondary battery electrode assembly including an electrode current collector according to one embodiment of the present disclosure is characterized by comprising: 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); one or more second electrodes (200) including a second electrode current collector (210) and 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).

[0028] Furthermore, in one embodiment of the secondary battery electrode assembly of this disclosure, 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. [Effects of the Invention]

[0029] As explained above, according to the electrode current collector, its manufacturing method, and secondary battery electrode assembly including the same, even if a resin layer is interposed between a pair of metal layers, a portion of the resin layer in the plain area of ​​the electrode current collector is removed, so that a portion of the first metal layer and a portion of the second metal layer face each other, making it easy for current to flow between the electrode current collector and the electrode lead.

[0030] Furthermore, according to the electrode current collector, its manufacturing method, and secondary battery electrode assembly including the same, even if a resin layer is interposed between a pair of metal layers, a portion of the resin layer in the plain area of ​​the electrode current collector is removed, so that a portion of the first metal layer and a portion of the second metal layer face each other. This structure allows the electrode current collector and the electrode lead to be easily fixed, as well as securely fixed. [Brief explanation of the drawing]

[0031] [Figure 1] This is a partial perspective view of a conventional secondary battery. [Figure 2] This is a perspective view of an electrode current collector according to the first embodiment of the present disclosure. [Figure 3] This is a cross-sectional view taken along the direction of line II in Figure 2. [Figure 4] This is a cross-sectional view taken along the line II-II in Figure 2. [Figure 5] This is a cross-sectional view of a first modified example of the first embodiment of the present disclosure, taken along the direction of line II in Figure 2. [Figure 6] This is a cross-sectional view of a first modified example of the first embodiment of the present disclosure, taken along the line II-II in Figure 2. [Figure 7] This is a plan view of a polymer resin layer according to a second modification of the first embodiment of the present disclosure. [Figure 8] This is a plan view of a polymer resin layer according to a third modification of the first embodiment of the present disclosure. [Figure 9] This is a cross-sectional view of an electrode current collector according to a second embodiment of the present disclosure, obtained by cutting along the direction of line II in Figure 2. [Figure 10] This is a cross-sectional view of an electrode current collector according to a second embodiment of the present disclosure, obtained by cutting along the direction of line II-II in Figure 2. [Figure 11] This is a flowchart illustrating the method for manufacturing an electrode current collector according to the first embodiment of this disclosure. [Figure 12] This is a conceptual diagram illustrating the method for manufacturing an electrode current collector according to the first embodiment of this disclosure. [Figure 13] This is a flowchart illustrating the method for manufacturing an electrode current collector according to the second embodiment of this disclosure. [Figure 14] This is a conceptual diagram illustrating the method for manufacturing an electrode current collector according to a second embodiment of the present disclosure. [Figure 15] This is an exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to a first embodiment of the present disclosure. [Figure 16] This is another exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to a first embodiment of the present disclosure. [Modes for carrying out the invention]

[0032] Hereinafter, embodiments that can be easily implemented by a person with ordinary skill in the art to which this disclosure pertains will be described in detail with reference to the attached drawings. However, in describing in detail the operating principles of preferred embodiments of this disclosure, if it is determined that a specific description of a related known function or configuration may unnecessarily obscure the gist of this disclosure, such detailed description will be omitted.

[0033] 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.

[0034] The following describes the electrode current collector according to this disclosure, its manufacturing method, and a secondary battery electrode assembly including the same.

[0035] Figure 2 is a perspective view of an electrode current collector according to the first embodiment of the present disclosure, Figure 3 is a cross-sectional view taken along the direction of line II in Figure 2, and Figure 4 is a cross-sectional view taken along the direction of line II-II in Figure 2.

[0036] Referring to Figures 2 to 4, the electrode current collector according to the first embodiment of this disclosure includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30.

[0037] First, when the electrode current collector of this disclosure 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 may be approximately 0.5 μm to 10 μm.

[0038] 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, and nonwoven fabrics.

[0039] Furthermore, the polymer resin layer 20 may be provided on one surface of the first metal layer 10. For example, with reference to Figure 3, one surface of the first metal layer 10 may be the surface facing the 12 o'clock direction.

[0040] 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.

[0041] The polymer resin layer 20 may be formed by removing a portion of the plain area B corresponding to the electrode tab. In other words, the polymer resin layer 20 may be formed by removing a portion of the area corresponding to the plain area B corresponding to the electrode tab.

[0042] The region removed from a portion of the plain area B of the polymer resin layer 20 may have a linear shape having a predetermined width and length. More specifically, the removed region of the polymer resin layer 20 may be formed along the overall length direction of the electrode current collector. Here, the removed region of the polymer resin layer 20 may have a linear shape with a length smaller than the overall length of the plain area B.

[0043] Here, the plain area B is the area where the first metal layer 10 and the second metal layer 30 of the electrode current collector according to this disclosure are not coated with an active material, and the opposite area with a surface A may be the area where the first metal layer 10 and the second metal layer 30 of the electrode current collector according to this disclosure are coated with an active material.

[0044] Furthermore, the polymer resin layer 20 may be provided in the area of ​​the textured portion 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.

[0045] 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.

[0046] 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.

[0047] The second metal layer 30 is provided on one surface of the polymer resin layer 20, and as described above, the polymer resin layer 20 is removed from the plain area B corresponding to the electrode tab, so that the first metal layer 10 and the second metal layer 30 can face each other.

[0048] Since a portion of the polymer resin layer 20 is removed, and there is no polymer resin layer 20 in a portion of the plain area B where the first metal layer 10 and the second metal layer 30 face each other, when a large number of electrode current collectors are stacked, the electrode current collectors can easily conduct electricity to each other.

[0049] On the other hand, the second metal layer 30 may have a thickness of approximately 0.5 μm to 10 μm, but is not limited to this.

[0050] For example, the first metal layer 10, the polymer resin layer 20, and the second metal layer 30 may be configured to have the same thickness as each other. Exemplarily, 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.

[0051] As another example, the first metal layer 10 and the second metal layer 30 may be configured to have the same thickness as each other, while the polymer resin layer 20 may be configured to have a different thickness from the first metal layer 10 and the second metal layer 30.

[0052] For 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.

[0053] Furthermore, the second metal layer 30 may be configured such that the thickness of the region containing the polymer resin layer 20 (i.e., the region in the textured area A and the plain area B where the polymer resin layer 20 was not removed) is the same as the thickness of the region without the polymer resin layer 20 (i.e., the region in the plain area B where the polymer resin layer 20 was removed).

[0054] However, the thickness of the second metal layer 30 is not limited to this, and it goes without saying that the second metal layer 30 may be configured such that the region of the first metal layer 10 where the polymer resin layer 20 is provided (i.e., the region in the textured area A and the plain area B where the polymer resin layer 20 has not been removed) has a thickness of approximately 0.5 μm to 10 μm, while the region of the first metal layer 10 where the polymer resin layer 20 is not provided (i.e., the region in the plain area B where the polymer resin layer 20 has been removed) has a thickness equal to the thickness of the polymer resin layer 20 plus the thickness of the polymer resin layer 20.

[0055] On the other hand, when the electrode current collector of this disclosure 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.

[0056] For example, the first metal layer 10 may be configured to include a copper (Cu) material. Here, the first metal layer 10 may have a thickness of approximately 0.5 μm to 10 μm.

[0057] 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).

[0058] Furthermore, the second metal layer 30 may be configured to have the same thickness as the first metal layer 10. The second metal layer 30 may have a thickness of approximately 0.5 μm to 10 μm.

[0059] Figure 5 is a cross-sectional view of the first modified example of the first embodiment of the present disclosure, cut along the direction of line II in Figure 2, and Figure 6 is a cross-sectional view of the first modified example of the first embodiment of the present disclosure, cut along the direction of line II-II in Figure 2.

[0060] In the first embodiment of the electrode current collector of this disclosure, an inclined surface may be formed on the side surface of the polymer resin layer 20.

[0061] More specifically, an inclined surface 21 may be formed on the side surface of the polymer resin layer 20 toward the region where the polymer resin layer 20 has been removed.

[0062] In other words, the polymer resin layer 20 may have a portion of the electrode tab region (the plain region B) removed, and an inclined surface 21 may be formed on the side surface facing the removed region.

[0063] Referring to Figure 5, the inclined surface 21 of the polymer resin layer 20 can be formed on one side (9 o'clock direction) toward the plain area B of the polymer resin layer 20. Also, referring to Figure 6, the inclined surface 21 of the polymer resin layer 20 can be formed on both sides (3 o'clock to 9 o'clock direction) toward the removed area of ​​the polymer resin layer 20.

[0064] With such an inclined surface 21, the polymer resin layer 20 can be configured so that the area of ​​the surface in contact with the first metal layer 10 (6 o'clock direction, with reference to Figure 6) is larger than the area of ​​the surface in contact with the second metal layer 30 (12 o'clock direction, with reference to Figure 6).

[0065] 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.

[0066] The remaining components are the same as those of the electrode current collector according to the first embodiment described above, so a redundant explanation will be omitted.

[0067] Figure 7 is a plan view of a polymer resin layer according to a second modification of the first embodiment of the present disclosure.

[0068] A second modification of the electrode current collector according to the first embodiment of this disclosure can be configured in a variety of linear forms in which the region from which the polymer resin layer 20 has been removed has a predetermined width and length.

[0069] First, referring to Figure 7(a), the linear region from which the polymer resin layer 20 has been removed can be formed along the entire width direction of the electrode current collector (from 3 o'clock to 9 o'clock, relative to Figure 7). Also, referring to Figure 7(b), the region from which the polymer resin layer 20 has been removed can be formed so that linear regions having predetermined widths and lengths intersect each other.

[0070] Furthermore, referring to Figures 7(c) to 7(e), the region from which the polymer resin layer 20 has been removed may be formed with a curved linear shape having a predetermined width and length. Such curved linear shapes of the polymer resin layer 20 may be formed along the entire length of the electrode current collector, along the entire width of the electrode current collector, or in a shape where the curved linear shapes intersect each other.

[0071] Furthermore, referring to Figures 7(f) to (h), the region from which the polymer resin layer 20 has been removed may have a zigzag linear structure having a predetermined width and length. Such zigzag linear structures of the polymer resin layer 20 may be formed along the entire length of the electrode current collector, along the entire width of the electrode current collector, or in a shape where the zigzag linear structures intersect each other.

[0072] Of course, the area from which the polymer resin layer 20 is removed may be the entire area of ​​plain area B. Here, the polymer resin layer 20 may be provided in the area of ​​textured area A, which is the remaining area after removing the electrode tab area (the area of ​​plain area B) formed on one side of the first metal layer 10 and the second metal layer 30.

[0073] The region from which the polymer resin layer 20 has been removed may be formed not only in a linear shape having the shape described above, but also in a variety of linear shapes having a predetermined width and length.

[0074] Figure 8 is a plan view of a polymer resin layer according to a third modification of the first embodiment of this disclosure.

[0075] A third modification of the electrode current collector according to the first embodiment of this disclosure is that the region from which the polymer resin layer 20 has been removed may be formed into a variety of discontinuous linear shapes having a predetermined width and length.

[0076] First, referring to Figure 8(a), the discontinuous linear shape formed in the dotted line form, which is the region where the polymer resin layer 20 has been removed, can be formed along the entire length direction of the electrode current collector (12 o'clock to 6 o'clock direction, with reference to Figure 8). Also, referring to Figure 8(b), the discontinuous linear shape formed in the dotted line form can be formed along the entire width direction of the electrode current collector (3 o'clock to 9 o'clock direction, with reference to Figure 8).

[0077] Furthermore, the region from which the polymer resin layer 20 has been removed may form discontinuous linear shapes with predetermined widths and lengths in the form of dashed lines.

[0078] Referring to Figures 8(c) and 8(d), the discontinuous linear shape formed in the form of a dashed line may be formed along the entire length of the electrode current collector or along its entire width.

[0079] Furthermore, the region from which the polymer resin layer 20 has been removed may be formed in the form of a dashed line with a discontinuous linear shape having a predetermined width and length.

[0080] Referring to Figures 8(e) and 8(f), the discontinuous linear shape formed in the dashed line form may be formed along the entire length of the electrode current collector or along its entire width.

[0081] Furthermore, as shown in Figure 8(g), the region from which the polymer resin layer 20 has been removed may be formed such that discontinuous linear shapes having a predetermined width and length intersect with each other. However, in Figure 8(g), the region from which the polymer resin layer 20 has been removed is formed in a shape where discontinuous linear shapes formed in a dashed line form intersect with each other, but it is not limited to this, and may be formed in a shape where discontinuous linear shapes formed in a dotted line form or a dashed-dotted line form intersect with each other.

[0082] Here, the shape where discontinuous linear shapes intersect means that discontinuous linear shapes formed along the entire length of the electrode current collector intersect with discontinuous linear shapes formed along the entire width of the electrode current collector.

[0083] The region from which the polymer resin layer 20 has been removed may not only be formed in a discontinuous linear shape having the shape described above, but may also be configured in a variety of discontinuous linear shapes having a predetermined width and length.

[0084] Figure 9 is a cross-sectional view of the electrode current collector according to the second embodiment of the present disclosure, cut along the direction of line II in Figure 2, and Figure 10 is a cross-sectional view of the electrode current collector according to the second embodiment of the present disclosure, cut along the direction of line II-II in Figure 2.

[0085] The electrode current collector according to the second embodiment of this disclosure includes a first metal layer 10, a polymer resin layer 20, and a second metal layer 30, similar to the first embodiment.

[0086] However, unlike the first embodiment, in the second embodiment, the first metal layer 10 may be thicker than the second metal layer 30. In other words, the thickness of the second metal layer 30 may be thinner than the thickness of the first metal layer 10.

[0087] 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.

[0088] When the first metal layer 10 is thicker than the second metal layer 30, the electrode current collector can be manufactured more easily. A detailed explanation of this will be given later.

[0089] Furthermore, the second metal layer 30 may be configured such that the thickness of the region where the polymer resin layer 20 is formed (i.e., the region in the textured area A and the plain area B where the polymer resin layer 20 was not removed) is the same as the thickness of the region where the polymer resin layer 20 is not formed (i.e., the region in the plain area B where the polymer resin layer 20 was removed).

[0090] However, the thickness of the second metal layer 30 is not limited to this, and it goes without saying that 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 (i.e., the region where the polymer resin layer 20 was not removed in the region of textured area A and the region of plain area B), 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 (i.e., the region where the polymer resin layer 20 was removed in the region of plain area B).

[0091] In the electrode current collector according to the second embodiment of the present disclosure, an inclined surface may be formed on the side surface of the polymer resin layer 20 toward the region of the polymer resin layer 20 that has been removed, as in the first modification of the electrode current collector according to the first embodiment.

[0092] Furthermore, the electrode current collector according to the second embodiment of this disclosure can be formed in a variety of linear forms in which the region from which the polymer resin layer 20 has been removed has a predetermined width and length, as in the second modified example of the electrode current collector according to the first embodiment.

[0093] Furthermore, the electrode current collector according to the second embodiment of this disclosure can be formed in a variety of discontinuous linear forms in which the region from which the polymer resin layer 20 has been removed has a predetermined width and length, as in the third modified example of the electrode current collector according to the first embodiment.

[0094] Figure 11 is a flowchart illustrating the method for manufacturing an electrode current collector according to the first embodiment of this disclosure, and Figure 12 is a conceptual diagram illustrating the method for manufacturing an electrode current collector according to the first embodiment of this disclosure.

[0095] Referring together to Figures 2 to 4, 11 and 12, the method for manufacturing an electrode current collector according to the first embodiment of the present disclosure includes a first step of preparing a polymer resin layer 20, a second step of forming a first metal layer 10 on the other side 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 side of the polymer resin layer 20.

[0096] First, regarding the method for manufacturing the positive electrode current collector, in the first step, the polymer resin layer 20 is prepared in sheet form using at least one of the following materials: polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

[0097] In the second stage, the first metal layer 10 is formed on the other side of the polymer resin layer 20 (at the 12 o'clock position, relative to Figure 12(b)). This can be done by vapor deposition.

[0098] Here, as the vapor deposition method, either a physical vapor deposition method, which vaporizes a solid metal target substance such as aluminum (Al) to form the first metal layer 10, or a chemical vapor deposition method, which decomposes an aluminum (Al) metal salt or a polymeric substance containing aluminum (Al) metal to form the first metal layer 10, can be used. Since such vapor deposition methods are known techniques, a detailed explanation of the principles will be omitted.

[0099] In the third stage, the polymer resin layer 20 can be partially removed by a etching process. The partially removed area by the etching process may be a part of the plain area B corresponding to the electrode tab.

[0100] For example, referring to Figure 12(c), in order to remove a portion of the polymer resin layer 20, the polymer resin layer 20 can be arranged such that the other side of the polymer resin layer 20 on which the first metal layer 10 is formed faces the 6 o'clock direction, and one side of the polymer resin layer 20 faces the 12 o'clock direction.

[0101] A portion of the polymer resin layer 20 can be removed in a linear shape having a predetermined width and length, and the linear shape can be formed along the entire length of the electrode current collector.

[0102] For example, the etching process to remove a portion of the polymer resin layer 20 can be carried out by a laser etching process using a laser unit 50. However, it is not limited to this, and the etching process to remove a portion of the polymer resin layer 20 can be carried out by various etching processes.

[0103] Furthermore, in the fourth stage, the second metal layer 30 can be formed by vapor deposition on one surface of the polymer resin layer 20, that is, on the surface facing the 12 o'clock direction with reference to (d) in Figure 12.

[0104] Here, the target material moves not only to one surface of the polymer resin layer 20, but also to a portion of the electrode tab region of the first metal layer 10 that is exposed by etching and does not overlap with the polymer resin layer 20.

[0105] Therefore, a portion of the plain area B corresponding to the electrode tab can be configured such that the first metal layer 10 and the second metal layer 30 face each other. That is, the second metal layer 30 can be in 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.

[0106] 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).

[0107] 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.

[0108] For 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 as each other. Exemplarily, 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.

[0109] As another example, the first metal layer 10 and the second metal layer 30 may be configured to have the same thickness as each other, while the polymer resin layer 20 may be configured to have a different thickness from the first metal layer 10 and the second metal layer 30.

[0110] 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.

[0111] In the second and fourth stages described above, the first metal layer 10 and the second metal layer 30 can be formed on one and the other surface of the polymer resin layer 20 by using the vapor deposition unit 40.

[0112] On the other hand, in the case of the first modified example of the electrode current collector according to the first embodiment of this disclosure, the only difference is that the side surface of the polymer resin layer toward the region from which the polymer resin layer has been removed is provided with an inclined surface, and the rest is the same as the manufacturing method of the electrode current collector described above.

[0113] In particular, when an inclined surface 21 is formed on the side surface of the polymer resin layer 20 toward the area where the polymer resin layer 20 has been removed (see Figures 5 and 6), the metal target material during the deposition process can reach the side surface of the polymer resin layer 20 more easily, thereby reliably preventing the formation of a space between the first metal layer 10 and the second metal layer 30.

[0114] Furthermore, in the case of the second and third modified examples of the electrode current collector according to the first embodiment of this disclosure, only the shape removed by etching differs, and the rest is the same as the manufacturing method of the electrode current collector described above.

[0115] 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 the same as the manufacturing method for the electrode current collector described above.

[0116] 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.

[0117] As described above, by removing a portion of the polymer resin layer located in the plain area corresponding to the electrode tab through an etching process, such that a portion of the first metal layer is exposed, an electrode current collector can be manufactured in which the plain area that functions as the electrode tab does not have a polymer resin layer.

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

[0119] Figure 13 is a flowchart illustrating the method for manufacturing an electrode current collector according to the second embodiment of this disclosure, and Figure 14 is a conceptual diagram illustrating the method for manufacturing an electrode current collector according to the second embodiment of this disclosure.

[0120] The method for manufacturing an electrode current collector according to the second embodiment of this disclosure differs from the method for manufacturing an electrode current collector according to the first embodiment in only a few steps; therefore, the same steps will be briefly described or omitted.

[0121] Referring together to Figures 9, 10, 13, and 14, the method for manufacturing an electrode current collector according to the second embodiment of the present disclosure 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.

[0122] First, in the case of a positive electrode current collector, the first metal layer 10 in the first stage may be configured to include an aluminum (Al) 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.

[0123] The second step is to form a sheet-like polymer resin layer 20 having a predetermined thickness on one surface of the first metal layer 10. For example, with reference to Figure 14(b), one surface of the first metal layer 10 may be the surface facing the 12 o'clock direction.

[0124] In the third stage, the polymer resin layer 20 can have a portion of its area, specifically a portion of the plain area B corresponding to the electrode tab, removed by the etching process. This has already been explained in detail, so it will be omitted here.

[0125] Furthermore, in the fourth stage, the second metal layer 30 can be formed on one surface of the polymer resin layer 20 by vapor deposition. For example, with reference to Figure 14(d), one surface of the polymer resin layer 20 may be the surface facing the 12 o'clock direction.

[0126] 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.

[0127] On the other hand, the method for manufacturing an electrode current collector according to the second embodiment of the present disclosure may include a lamination step between the second and fourth steps, in which heat and pressure are applied to bond the first metal layer 10 and the polymer resin layer 20 to each other as needed.

[0128] 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.

[0129] 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 method for manufacturing the electrode current collector according to the second embodiment described above.

[0130] For example, in the first and third stages, the first metal layer 10 and the second metal layer 30 may contain copper (Cu).

[0131] When the first metal layer 10 is thicker than the second metal layer 30, the electrode current collector can be manufactured more easily. Specifically, when manufacturing the electrode current collector according to the second embodiment of this disclosure, the first metal layer 10 is prepared in the form of a film or sheet, and then the polymer resin layer 20 and the second metal layer 30 are formed sequentially. Here, the thicker the first metal layer 10, the easier it is to prepare it in the form of a film or sheet.

[0132] Next, the secondary battery electrode assembly will be described. Figure 15 is an exploded perspective view of a secondary battery electrode assembly including an electrode current collector according to the first embodiment of this disclosure, and Figure 16 is another exploded perspective view of the secondary battery electrode assembly including an electrode current collector according to the first embodiment of this disclosure.

[0133] As shown in Figures 15 and 16, the secondary battery electrode assembly according to this disclosure has a structure in which one or more first electrodes 100 including an electrode current collector according to the first embodiment, one or more second electrodes 200, and one or more separator membranes 300 are stacked.

[0134] 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, but is not limited to, be located between the first electrode 100 and the second electrode 300, on the upper surface of the uppermost second electrode 300, and below the lowermost second electrode 300.

[0135] The first electrode 100 is composed of a first electrode current collector 110 and a first electrode tab 120 made 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 in a three-layer structure in which a polymer resin layer is interposed between a first metal layer containing aluminum (Al) material and a second metal layer.

[0136] A first electrode lead 400 is connected to the first electrode tab 120 of the first electrode 100, and a second electrode lead 500 is connected to the second electrode tab 220 of the second electrode 200.

[0137] Of course, the positive electrode active material is applied to the surface of one or both sides of the first electrode current collector 110.

[0138] 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; chemical formula Li 1+x Mn 2-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 LiNi 1-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 LiMn 2-x M xLithium 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 Mn 2-x You can use formulas like O4 (0.01 ≤ x ≤ 0.6).

[0139] On the other hand, conductive materials and binders can be mixed into the positive electrode active material, and fillers can be added as needed.

[0140] 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 fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0141] 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 at a concentration of 1 to 50% by weight based on the total weight of the mixture containing the positive electrode active material 120. 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.

[0142] Further, the second electrode 200 is 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 a single layer containing a copper (Cu) material, or may be configured in a three-layer structure in which a polymer resin layer is interposed between a pair of a first metal layer and a second metal layer.

[0143] Of course, the negative electrode active material is applied to the grounded portion on one or both surfaces of the second electrode current collector 210.

[0144] 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 Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8), etc. metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials that are Si, SiO, SiO2 alone or mixtures thereof, etc. can be used, but are not limited thereto.

[0145] 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.

[0146] Conductive materials are components used to further improve the conductivity of the negative electrode active material, and can be used in certain ratios, including carbon black such as 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.

[0147] 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).

[0148] 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 bilayer, polyethylene / polypropylene / polyethylene triple layer, polypropylene / polyethylene / polypropylene triple layer, and organic fiber filter paper, but is not limited to these.

[0149] Multiple first electrode tabs 120 can be electrically connected to each other via a single first electrode lead 400, and multiple second electrode tabs 220 can be electrically connected to each other via a single second electrode lead 500, as well as being firmly fixed to each other.

[0150] Here, the electrode tabs and electrode leads are not limited to welding methods such as ultrasonic welding (see, for example, Figure 15), but can also be riveted (see, for example, Figure 16) that penetrate both the electrode tabs and electrode leads simultaneously.

[0151] On the other hand, the second electrode 200, or in other words, 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 containing copper (Cu) material and a second metal layer.

[0152] Of course, in the case of the first electrode 100, the first electrode current collector 110 and the first electrode tab 120 may have a three-layer structure in which a polymer resin layer is interposed between a first metal layer containing aluminum (Al) material and a second metal layer, or they may be a single layer containing aluminum (Al) material.

[0153] On the other hand, Figures 15 and 16 illustrate a secondary battery electrode assembly including an electrode current collector according to the first embodiment, but it is clear that an electrode assembly similar to the structure described above can also be constructed in the case of an electrode current collector according to the second embodiment.

[0154] While specific parts of the content of this disclosure have been described in detail above, it will be obvious to those skilled in the art that such specific technologies are merely preferred modes of implementation and do not limit the scope of this disclosure, and that various modifications and alterations are possible within the scope of the disclosure and the technical concept, and it goes without saying that such variations and alterations also fall within the scope of the attached claims. [Explanation of symbols]

[0155] 10 1st metal layer 20 Polymer resin layer 21 Slope 30 Second metal layer 40 Evaporation Units 50 laser units 100 1st electrode 110 First electrode current collector 120 First electrode tab 200 2nd electrode 210 Second electrode current collector 220 Second electrode tab 300 Separation membrane 400 First electrode lead 500 Second electrode lead A Landed area 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 in which a portion of the plain area corresponding to the electrode tab has the polymer resin layer removed, so that the first metal layer and the second metal layer face each other.

2. The electrode current collector according to claim 1, wherein the region from which the polymer resin layer has been removed is linear having a predetermined width and length, and the linear is formed along the overall length direction or the overall width direction of the electrode current collector.

3. The electrode current collector according to claim 1, wherein the region from which the polymer resin layer has been removed has a linear shape with a predetermined width and length, and the linear shape is formed along the overall length direction or the overall width direction of the electrode current collector.

4. The electrode current collector according to claim 1, wherein the region from which the polymer resin layer has been removed is formed such that linear shapes having a predetermined width and length intersect with each other.

5. The electrode current collector according to claim 1, wherein the region from which the polymer resin layer has been removed is a discontinuous linear shape having a predetermined width and length, and the discontinuous linear shape is formed along the overall length direction or the overall width direction of the electrode current collector.

6. The electrode current collector according to claim 1, wherein the region from which the polymer resin layer has been removed is formed such that discontinuous linear shapes having a predetermined width and length intersect with each other.

7. The first metal layer and the second metal layer comprise aluminum or copper material. The method for manufacturing an electrode current collector according to claim 1, wherein the polymer resin layer comprises at least one material selected from polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), and nylon.

8. A manufacturing method for producing an electrode current collector according to any one of claims 1 to 7, The first step is to prepare the polymer resin layer, A second step involves forming a first metal layer on the other side of the polymer resin layer, A third step involves removing a portion of the polymer resin layer, The fourth step includes forming a second metal layer on one surface of the polymer resin layer, A method for manufacturing an electrode current collector, wherein a portion of the plain area corresponding to the electrode tab is in a state where the polymer resin layer is removed and the first metal layer and the second metal layer face each other.

9. The method for manufacturing an electrode current collector according to claim 8, wherein in the third step, a portion of the polymer resin layer is removed by a cutting process.

10. The method for manufacturing an electrode current collector according to claim 9, wherein in the second step, the first metal layer is formed on the other surface of the polymer resin layer by vapor deposition.

11. The method for manufacturing an electrode current collector according to claim 9, wherein in the fourth step, the second metal layer is formed on one surface of the polymer resin layer by vapor deposition.

12. A manufacturing method for producing an electrode current collector according to any one of claims 1 to 7, 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, A third step involves removing a portion of the polymer resin layer, The fourth step includes forming a second metal layer on one surface of the polymer resin layer, A method for manufacturing an electrode current collector, wherein a portion of the plain area corresponding to the electrode tab is in a state where the polymer resin layer is removed and the first metal layer and the second metal layer face each other.

13. The method for manufacturing an electrode current collector according to claim 12, further comprising a lamination step between the second and fourth steps, in which heat and pressure are applied to bond the first metal layer and the polymer resin layer to each other.

14. A secondary battery electrode assembly comprising an electrode current collector according to any one of claims 1 to 7, 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.

15. The secondary battery electrode assembly according to claim 14, wherein 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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