Electrode sheet notching system

Abstract

The present invention provides a notching system for an electrode sheet having a slurry applied to a surface of a current collector, comprising: an electrode unwinder for unwinding an electrode sheet; a film unwinder for unwinding a protective film to be laminated on the electrode sheet; a notching device for notching an uncoated portion of the electrode sheet, which is a portion of the electrode sheet that is not coated with a slurry, when the electrode sheet is provided with a protective film laminated thereon; and a rewinder for winding up the notched electrode sheet. In the present invention having the above-mentioned configuration, the notching process is performed in a state where the electrode sheet and the protective film are laminated, so that it is possible to solve the problems of the electrode sheet being cut or torn, and the problem of the graphite powder being separated from the surface of the electrode sheet, which induces scratches.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0139571, filed on October 19, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a notching system for an electrode sheet in which a slurry is applied to the surface of a thin metal current collector, and more specifically to an electrode sheet notching system that can prevent the electrode sheet from being cut or the surface from being scratched by foreign matter (graphite powder) during notching processing. [Background technology]

[0003] 2. Description of the Related Art Lithium secondary batteries, which are rechargeable and lightweight yet have high energy density and power density, are widely used as energy sources for various devices.

[0004] In addition, hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and electric vehicles (EVs) have been proposed as alternatives to solving the air pollution and greenhouse gas problems of conventional internal combustion engine vehicles that use fossil fuels such as gasoline and diesel, and lithium secondary batteries are attracting attention as a power source for these alternative internal combustion engine vehicles.

[0005] Such secondary batteries generally have a structure including an electrode assembly having a structure in which electrodes (negative and positive electrodes) and separators are alternately stacked, an electrolyte (electrolytic solution) that transfers ions to the electrodes, and a case that houses the electrode assembly and the electrolyte.

[0006] In addition, the manufacturing process of the secondary battery is broadly divided into an electrode plate process in which positive and negative electrodes are manufactured, respectively; an assembly process in which the positive and negative electrodes are manufactured as an electrode assembly and then the electrode assembly is inserted into a case together with an electrolyte; and a chemical formation process in which the movement of ions in the electrode assembly is activated. Each of the electrode plate process, assembly process, and chemical formation process is divided into individual detailed processes.

[0007] Here, the electrode plate process includes a mixing process in which an active material, a conductive material, and a binder are added and mixed to prepare a slurry, a coating process in which the mixed slurry is applied to a current collector, a pressing process in which the slurry is pressed onto the surface of the current collector, and a notching process in which the electrode sheet prepared by adhering the slurry to the surface of the current collector is cut to size (or simultaneously with cutting) and sheared to form electrode tabs (notching process).

[0008] Here, the current collector has a landed portion where the slurry is applied (coated) and an uncoated portion where the slurry is not applied. That is, the electrode sheet has a structure in which the slurry is applied to a width narrower than that of the current collector, but the middle portion is not coated with the slurry along the longitudinal direction, resulting in landed portions on both sides and an uncoated portion between them (see FIG. 3).

[0009] Furthermore, notching is performed by punching with a notching device 7 so that electrode tabs T (see FIG. 3) remain and the other portions are cut off. The notching device 7 includes a lower die placed below the electrode sheet 1 and an upper die placed above the electrode sheet 1, and the upper die descends to strike the uncoated portions of the electrode sheet 1, thereby processing the electrode tabs T in the uncoated portions.

[0010] 1, which shows a simplified conventional notching system, a conventional electrode sheet notching system includes an electrode unwinder 5 from which the electrode sheet 1 is unwound and continuously supplied, a notching device 7 that is disposed in the path along which the electrode sheet 1 is transported and notches the electrode tabs in the uncoated portions, and a rewinder 8 on which the "notched electrode sheet" 1a is wound up. A roller 6 for changing the transport path of the electrode substrate 1 may also be included.

[0011] On the other hand, when the electrode sheet 1 is a negative electrode, the current collector is made of copper and has a structure in which a negative electrode slurry is applied, and when the electrode sheet 1 is a positive electrode, the current collector is made of aluminum and has a structure in which a positive electrode slurry is applied.

[0012] In the case of positive electrodes, the current collector material made of aluminum has insufficient elasticity during notching, resulting in tearing, cutting (disconnection), or breakage. Such tearing, cutting, or breakage increases the processing time for the continuous notching process and increases waste.

[0013] In the case of the negative electrode, the negative electrode slurry contains powdered graphite. However, there is a problem in that the graphite separates from the surface of the electrode sheet 1 and adheres to the rollers 6. The graphite that adheres and accumulates on the surface of the rollers 6 causes scratches on the surface of the electrode sheet 1 while the electrode sheet 1 is being transported. Summary of the Invention [Problem to be solved by the invention]

[0014] Therefore, the main object of the present invention is to provide an electrode sheet notching system that can prevent the problem of tearing, cutting, or damage to the electrode sheet and eliminate the problem of graphite adhering to the surface of the electrode sheet and causing scratches. [Means for solving the problem]

[0015] In order to achieve the above object, the present invention provides a notching system for an electrode sheet having a current collector surface coated with a slurry, comprising: an electrode unwinder that unwinds the electrode sheet; a film unwinder that unwinds a protective film to be laminated on the electrode sheet; a notching device that notches a plain portion of the electrode sheet, which is a portion of the electrode sheet that is not coated with a slurry, when the electrode sheet is provided with the protective film laminated thereon; and a rewinder that winds up the notched electrode sheet.

[0016] The electrode sheet and the protective film may further include a tension roller that is disposed in a path along which the electrode sheet and the protective film are transported in a stacked state, and slides in a predetermined direction to apply pressure to the electrode sheet and the protective film, thereby maintaining tension within a predetermined range.

[0017] The protective film has a width greater than that of the electrode sheet such that a portion of the protective film protrudes from each side of the electrode sheet when laminated with the electrode sheet.

[0018] The electrode sheet is a positive electrode sheet in which positive electrode slurry is applied to the surface of a positive electrode current collector, and the protective film is laminated so as to be located on the bottom surface of the positive electrode sheet when the positive electrode sheet enters the notching device.

[0019] The electrode sheet is a negative electrode sheet in which negative electrode slurry is applied to the surface of a negative electrode current collector, and the film unwinder includes a first film unwinder that unwinds the protective film to be laminated on the bottom surface of the electrode sheet and a second film unwinder that unwinds the protective film to be laminated on the top surface of the electrode sheet so that the protective film is positioned and laminated on each of the top and bottom surfaces of the negative electrode sheet when the negative electrode sheet enters the notching device.

[0020] The protective film has a width wider than the electrode sheet so that a portion of the protective film protrudes from each of both sides of the electrode sheet when laminated on the electrode sheet, and the protective film laminated on the bottom surface of the electrode sheet and the protective film laminated on the top surface of the electrode sheet are aligned so that both ends of the protective film are aligned in the width direction across the electrode sheet.

[0021] The uncoated portion is formed to be located at the center along the longitudinal direction of the electrode sheet, and the electrode sheet and the protective film are notched by the notching device so that the uncoated portion is cut, thereby separating the electrode sheet and the protective film into a first processed body and a second processed body, and the rewinder includes a first rewinder on which the first processed body is wound, and a second rewinder on which the second processed body is wound.

[0022] One of the first rewinder and the second rewinder is positioned at a height lower than the notching device, and the other is positioned at a height higher than the notching device.

[0023] The notching device includes a lower mold disposed below the electrode sheet and an upper mold disposed above the electrode sheet, and when the electrode sheet is positioned between the lower mold and the upper mold, the upper mold or the lower mold strikes the uncoated portion of the electrode sheet to process it into a predetermined shape.

[0024] The device further includes a film recovery device that separates and recovers the protective film from the notched electrode sheet. [Effects of the Invention]

[0025] In the present invention having the above configuration, notching is performed in a state where the electrode sheet and the protective film are stacked, so that problems such as cutting or tearing of the electrode sheet and problems such as separation of graphite powder from the surface of the electrode sheet causing scratches can be prevented or minimized.

[0026] In other words, the protective sheet disperses the tension applied to the electrode sheet, thereby suppressing breakage, and since the surface of the electrode sheet is covered with the protective film, separation of the graphite powder can be fundamentally prevented.

[0027] Furthermore, since the tension roller is further included, the tension applied to the transported electrode sheet can be easily adjusted.

[0028] The protective film is configured to have a width wider than the electrode sheet so that a portion thereof protrudes from each side of the electrode sheet when laminated on the electrode sheet. This reduces the possibility of the electrode sheet being separated from the protective film even if the electrode sheet is separated from its designated position during attachment of the electrode sheet and the protective film.

[0029] The electrode sheet is notched and divided into a first processed body and a second processed body, which are collected by a first rewinder and a second rewinder, respectively, so that the processed products can be collected separately.

[0030] Since the device further includes a film recovery device that separates and recovers the protective film from the notched electrode sheet, the electrode sheet can be provided with the protective film removed. [Brief explanation of the drawings]

[0031] [Figure 1] FIG. 1 is a simplified diagram of a conventional notching system. [Figure 2] 1 is a simplified diagram of a notching system according to a first embodiment of the present invention; FIG. [Figure 3] 1A and 1B are diagrams showing how notching is performed by a notching device and an enlarged view of the notched portion. [Figure 4] FIG. 4 shows a simplified diagram of a notching system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0032] The present invention will now be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in various different forms and is not limited to the embodiments set forth below.

[0033] In order to clearly explain the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used to refer to the same or similar components throughout the specification.

[0034] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is superimposed on the technical idea of ​​the present invention, based on the principle that an inventor can appropriately define the concept of a term in order to explain his or her invention in the best possible way.

[0035] The present invention relates to an electrode sheet notching system that can prevent or minimize the occurrence of cuts and scratches on an electrode sheet. Hereinafter, an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0036] First embodiment In the present invention, a notching system is provided as a first embodiment in which notching is performed in a state in which a protective film 2 is laminated on one surface of an electrode sheet 1, thereby preventing the electrode sheet 1 from being cut during the process.

[0037] Referring to FIG. 2, which shows a simplified diagram of a notching system according to a first embodiment of the present invention, the notching system provided in this embodiment comprises an electrode unwinder 10, a film unwinder 20, a notching device 40 and a rewinder 50.

[0038] The electrode unwinder 10 rotates in an unwinding direction while the electrode sheet 1, in which the slurry is applied to the surface of the current collector, is wound up, and continuously unwinds the electrode sheet 1.

[0039] Although a negative electrode sheet can also be used as the electrode sheet 1 provided in this embodiment, it is preferable to use a positive electrode sheet because this is provided for the purposes of relatively simplifying the process, reducing production costs, and preventing cutting or damage to the electrode sheet 1. That is, the electrode sheet 1 provided in this embodiment is provided by applying positive electrode slurry to the surface of an aluminum positive electrode current collector.

[0040] The film unwinder 20 has a protective film 2 wound thereon. The protective film 2 is wound to have a length longer than the electrode sheet 1, and is unwound continuously while the electrode sheet 1 continues to be unwound.

[0041] In addition, the protective film 2 and the electrode sheet 1 are unwound from the film unwinder 20 and the electrode unwinder 10, respectively, and are then joined on the transport path to be stacked (overlapped or overlapped), and are transported in a stacked state.

[0042] That is, as shown in Figure 2, stacking is performed before passing through the first roller of the multiple rollers 61 arranged in the transport path, and the protective film 2 and the electrode sheet 1 are closely adhered to each other while moving through each roller 61 in the stacked state.

[0043] Here, as shown in FIG. 3, which shows the notching process being performed by the notching device 40 and an enlarged view of the notched portion, the protective film 2 has a width slightly wider than that of the electrode sheet 1 so that a portion of the protective film 2 protrudes from each side of the electrode sheet 1 when laminated with the electrode sheet 1.

[0044] That is, referring to Figure 3, when the electrode sheet 1 provided in the present invention is viewed from above, a coated portion 1'' coated with a slurry and an uncoated portion 1' not coated with a slurry are formed on the surface of the current collector. As shown in the figure, an uncoated portion 1' is formed along the longitudinal direction between the coated portions 1'' on both sides coated with the slurry.

[0045] Therefore, the protective film 2 further protrudes by a predetermined length in the width direction (vertical direction in FIG. 3) from each end of the land portion 1'' on both sides of the current collector.

[0046] As shown in FIG. 3, the protective film 2 is transported via a plurality of rollers 61 while being laminated with the electrode sheet 1, and at least one of the plurality of rollers 61 is composed of a tension roller 60 that can rotate and slide.

[0047] That is, the tension roller 60 is arranged in the path along which the electrode sheet 1 and the protective film 2 are transported in a stacked state, and is configured to apply pressure to the electrode sheet 1 and the protective film 2 by sliding back and forth in a predetermined direction (for example, the up-down direction or the left-right direction in Figure 2) to maintain the tension within a predetermined range.

[0048] While being transported through multiple rollers 61, the electrode sheet 1 and the protective film 2 move in different directions but remain horizontal as they enter the notching device 40. At this time, the protective film 2 enters the notching device 40 while positioned on the bottom surface of the electrode sheet 1. That is, with reference to FIG. 2, the protective film 2 is placed on the bottom and the electrode sheet 1 is placed on top as they enter the notching device 40.

[0049] Therefore, when the electrode sheet 1 and the protective film 2 are provided in a laminated state, the notching device 40 notches the uncoated portion 1' of the electrode sheet 1 where no slurry is applied.

[0050] The notching device 40 includes a lower die 42 disposed below the electrode sheet 1 and an upper die 41 disposed above the electrode sheet 1. When the electrode sheet 1 is positioned between the lower die 42 and the upper die 41, as shown in Fig. 3, the upper die 41 and the lower die 42 (or only one of the upper die and the lower die) slide up and down to strike (punch), thereby notching the plain portion 1' of the electrode sheet 1 so that electrode tabs T of a predetermined shape are formed.

[0051] On the other hand, in the case where the lower die 42 is fixed and only the upper die 41 descends, the upper die 41 strikes the electrode sheet 1 first, thereby preventing or minimizing the deterioration of processability due to the adhesion of the protective film 2.

[0052] By striking the upper die 41 and the lower die 42, the electrode tabs T remain in the uncoated portion 1' and the other portions are removed. As a result, as shown in Fig. 3, the electrode tabs T are formed on both sides of the uncoated portion 1', and the electrode sheet 1 and the protective film 2 are divided into two in the longitudinal direction by the notching device 40, into a first workpiece 1a' and a second workpiece 1a''.

[0053] The rewinder 50 also individually winds up the first and second workpieces 1a' and 1a'' of the notched electrode sheet 1.

[0054] That is, the rewinder 50 includes a first rewinder 50a around which the first workpiece 1a' is wound, and a second rewinder 50b around which the second workpiece 1a'' is wound.

[0055] One of the first rewinder 50a and the second rewinder 50b is located at a height lower than the notching device 40, and the other is located at a height higher than the notching device 40, and they independently wind up the first workpiece 1a' and the second workpiece 1a''. A tension roller 60 and a roller for changing the travel path may be selectively disposed on the path along which the first workpiece 1a' and the second workpiece 1a'' move to the first rewinder 50a and the second rewinder 50b, respectively.

[0056] Meanwhile, the first workpiece 1a' and the second workpiece 1a'' are wound up with the protective film 2 laminated on the electrode sheet 1. Therefore, a film recovery device (not shown) may be added to separate and recover the protective film 2 from the electrode sheet 1 before the first workpiece 1a' and the second workpiece 1a'' are fed to the next process.

[0057] The film collecting device may be provided in a form in which, when separating the first processed body 1a' wound around the first rewinder 50a from the second processed body 1a'' wound around the second rewinder 50b, only the protective film 2 is wound and separated. The film collecting device may have a structure in which the first processed body 1a' and the second processed body 1a'' are rotated and wound simultaneously with the first rewinder 50a and the second rewinder 50b while the ends of the protective film 2 are fixed in the first processed body 1a' and the second processed body 1a'', thereby separating only the protective film 2, or may be provided to have the structure of another known separating device.

[0058] Alternatively, the film recovery device may be configured to be positioned before the first rewinder 50a and the second rewinder 50b, remove the protective film 2 from the notched first workpiece 1a' and the second workpiece 1a'', and wind only the electrode sheet 1 onto the first rewinder 50a and the second rewinder 50b.

[0059] Second embodiment In the present invention, a notching system is provided as a second embodiment, in which notching is performed in a state in which protective films 2 and 3 are laminated on both sides of an electrode sheet 1, thereby preventing scratches caused by the graphite powder.

[0060] As shown in FIG. 4, which shows a simplified notching system according to a second embodiment of the present invention, the notching system provided in this embodiment also includes an electrode unwinder 10, a film unwinder 20, a notching device 40, and a rewinder 50.

[0061] Although a positive electrode sheet can be used as the electrode sheet 1 provided in this embodiment, if the only purpose is to prevent cutting and nicking, providing a protective film 2 on only one side is sufficient, and therefore the notching system according to the first embodiment is more preferable in terms of production costs. Therefore, since the purpose of providing this embodiment is to prevent scratches caused by scattering or adhesion of graphite powder on the electrode sheet 1, it is preferable to use a negative electrode sheet. That is, the electrode sheet 1 provided in this embodiment is provided by coating a negative electrode slurry on the surface of a copper negative electrode current collector.

[0062] The film unwinder 20 includes a first film unwinder 20a that unwinds the protective film 2 to be laminated on the bottom surface of the electrode sheet 1, and a second film unwinder 20b that unwinds the protective film 3 to be laminated on the top surface of the electrode sheet 1 (here, the top and bottom surfaces are based on the up and down direction when entering the notching device).

[0063] Meanwhile, the protective films 2 and 3 wound on the first film unwinder 20a and the second film unwinder 20b may be provided to have basically the same material and the same thickness, but the protective films 2 and 3 that are fed into the notching device and subjected to impact when notching is performed may be formed to be thinner or made of a different material so as not to affect processability or to minimize the effect.

[0064] The protective films 2 and 3 provided from the first film unwinder 20a and the second film unwinder 20b, respectively, are wound up to have a length longer than the electrode sheet 1, and are unwound continuously while the electrode sheet 1 continues to be unwound.

[0065] In addition, the protective films 2, 3 and the electrode sheet 1 are unwound from the first film unwinder 20a, the second film unwinder 20b and the electrode unwinder 10, respectively, and are joined on the transport path where they are stacked and transported in a stacked state.

[0066] That is, as shown in Figure 4, stacking is performed before passing through the first roller of the multiple rollers 61 arranged in the transport path, and while the electrode sheet 1 moves through each roller 61 in a stacked state, protective films 2 and 3 are adhered to each of the two surfaces of the electrode sheet 1.

[0067] As in the first embodiment, the protective films 2 and 3 have a width wider than that of the electrode sheet 1 so that when laminated on the electrode sheet 1, a portion of each of the protective films 2 and 3 protrudes from both sides of the electrode sheet 1. Here, the protective films 2 and 3 laminated on one side and the other side of the electrode sheet 1 are provided to have the same width. In addition, the protective film 2 laminated on the bottom surface of the electrode sheet 1 and the protective film 3 laminated on the top surface of the electrode sheet 1 are aligned such that both ends of the protective films 2 and 3 meet in the width direction across the electrode sheet 1.

[0068] On the other hand, to prevent movement of the electrode sheet 1 during notching, at least one of the protective films 2 and 3 may protrude widthwise from the electrode sheet 1, with additional adhesive applied to the portion where the protective films 2 and 3 face each other, and the protective films may be bonded in an aligned state with the other protective film. This allows the electrode sheet 1 to be notched with movement prevented between the protective films 2 and 3, thereby reducing the defect rate and enabling more precise notching.

[0069] In this embodiment, the uncoated portion 1' is also formed to be located at the center along the longitudinal direction of the electrode sheet 1, and the electrode sheet 1 and the protective films 2 and 3 are notched by a notching device 40 so that the uncoated portion 1' is cut off, thereby separating the electrode sheet 1 and the protective films 2 and 3 into a first workpiece 1a' and a second workpiece 1a''. The rewinder 50 is also composed of a first rewinder 50a that winds the first workpiece 1a' and a second rewinder 50b that winds the second workpiece 1a'', and is configured to wind up the first workpiece 1a' and the second workpiece 1a'' respectively.

[0070] As described above, the notching device 40 provided in this embodiment also has a structure including a lower die 42 disposed below the electrode sheet 1 and an upper die 41 disposed above the electrode sheet 1, and strikes the uncoated portion 1' to form the electrode tab T. The notching device 40 may further include a film recovery device (not shown) that separates and recovers the protective films 2 and 3 from the notched electrode sheet 1. Here, the film recovery device may be structured to be coupled to the upper die 41 or the lower die 42, and configured so that the protective films 2 and 3 are peeled off as they pass through the notching device 40.

[0071] In the present invention having the above-described configuration, notching is performed in a state in which the electrode sheet 1 and the protective film are laminated, thereby eliminating the problems of the electrode sheet 1 being cut or torn, and the problem of graphite powder being separated from the surface of the electrode sheet 1 and causing scratches.

[0072] In other words, the protective sheet disperses the tension applied to the electrode sheet, thereby suppressing breakage, and since the surface of the electrode sheet is covered with the protective film, separation of the graphite powder can be fundamentally prevented.

[0073] Furthermore, since the tension roller is further included, the tension applied to the transported electrode sheet can be easily adjusted.

[0074] The protective film is configured to have a width wider than the electrode sheet so that a portion thereof protrudes from each side of the electrode sheet when laminated on the electrode sheet. This reduces the possibility of the electrode sheet being separated from the protective film even if the electrode sheet is separated from its designated position during attachment of the electrode sheet and the protective film.

[0075] The electrode sheet 1 is notched and divided into a first processed body 1a' and a second processed body 1a'', which are collected by a first rewinder and a second rewinder, respectively, so that the processed products can be collected separately.

[0076] Since the device further includes a film recovery device that separates and recovers the protective film from the notched electrode sheet, the electrode sheet can be provided with the protective film removed.

[0077] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited thereto, and various implementations within the technical spirit of the present invention and the scope of equivalents of the appended claims can be made by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0078] 1 Electrode sheet 2, 3 Protective film 5 Electrode Unwinder 6. Laura 7 Notching device 8 Rewinder 10 Electrode Unwinder 20 Film Unwinder 20a No. 1 film unwinder 20b Second film unwinder 40 Notching device 41 Upper mold 42 Lower mold 50 Rewinder 60 Tension roller 61 Laura

Claims

1. A notching system for an electrode sheet in which a slurry is applied to a surface of a current collector, an electrode unwinder from which the electrode sheet is unwound; a film unwinder for unwinding a protective film to be laminated on the electrode sheet; a notching device that notches a plain portion of the electrode sheet, which is a portion of the electrode sheet on which the protective film is laminated, when the electrode sheet is provided; and a rewinder on which the notched electrode sheet is wound; The protective film has a width greater than that of the electrode sheet so that a portion of the protective film protrudes from each of both sides of the electrode sheet when laminated with the electrode sheet.

2. A notching system for an electrode sheet in which a slurry is applied to the surface of a current collector, comprising: an electrode unwinder from which the electrode sheet is unwound; a film unwinder for unwinding a protective film to be laminated on the electrode sheet; a notching device that notches a plain portion of the electrode sheet, which is a portion of the electrode sheet on which the protective film is laminated, when the electrode sheet is provided; and a rewinder on which the notched electrode sheet is wound; The electrode sheet notching system further includes a tension roller that is disposed in a path along which the electrode sheet and the protective film are transported in a stacked state, and slides in a predetermined direction to apply pressure to the electrode sheet and the protective film, thereby maintaining tension within a predetermined range.

3. the electrode sheet is a positive electrode sheet in which a positive electrode slurry is applied to the surface of a positive electrode current collector, The electrode sheet notching system according to claim 1 , wherein the protective film is laminated so as to be located on the bottom surface of the positive electrode sheet when the positive electrode sheet enters the notching device.

4. the electrode sheet is a negative electrode sheet in which a negative electrode slurry is applied to the surface of a negative electrode current collector, 2. The electrode sheet notching system according to claim 1, wherein the film unwinders include: a first film unwinder that unwinds the protective film to be laminated on the bottom surface of the electrode sheet; and a second film unwinder that unwinds the protective film to be laminated on the top surface of the electrode sheet, so that the protective film is located on each of the top and bottom surfaces of the negative electrode sheet when the negative electrode sheet enters the notching device.

5. the protective film has a width greater than that of the electrode sheet such that a portion of the protective film protrudes from each of both sides of the electrode sheet when laminated with the electrode sheet; 5. The electrode sheet notching system according to claim 4, wherein the protective film laminated on the bottom surface of the electrode sheet and the protective film laminated on the top surface of the electrode sheet are aligned so that both ends of the protective film are aligned in the width direction across the electrode sheet.

6. The uncoated portion is formed to be located at the center along the longitudinal direction of the electrode sheet, The electrode sheet and the protection film are divided into a first workpiece and a second workpiece by performing a notching process using the notching device so that the uncoated portion is cut off, The rewinder 2. The electrode sheet notching system of claim 1, comprising: a first rewinder around which the first workpiece is wound; and a second rewinder around which the second workpiece is wound.

7. 7. The electrode sheet notching system of claim 6, wherein one of the first rewinder and the second rewinder is positioned at a height lower than the notching device, and the other is positioned at a height higher than the notching device.

8. The notching device is a lower mold disposed below the electrode sheet; and an upper mold disposed above the electrode sheet; 2. The electrode sheet notching system according to claim 1, wherein when the electrode sheet is positioned between the lower mold and the upper mold, the upper mold or the lower mold strikes the uncoated portion of the electrode sheet to process it so that it is formed into a predetermined shape.

9. The electrode sheet notching system according to any one of claims 1 to 8, further comprising a film recovery device that separates and recovers the protective film from the notched electrode sheet.

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