Electrode cutter to prevent electrode detachment

Abstract

The present invention provides an electrode cutter for preventing or reducing the length of detached material in the form of long, thin threads generated during the process of cutting an electrode. The electrode cutter includes an upper blade and a lower blade, and at least one of the upper blade and the lower blade has a zigzag cutting portion along the length of the blade. This zigzag cutting portion can prevent or significantly reduce the length of detached material.

Description

[Technical Field]

[0001] The present invention relates to an electrode cutter for preventing electrode detachment, an electrode cutting method using the same, an electrode manufactured by the same method, and an electrode assembly including the same. More specifically, the present invention relates to an electrode cutter for preventing or reducing burrs or detached powder generated during the process of cutting an electrode, an electrode cutting method using the same, an electrode manufactured by the same method, and an electrode assembly including the electrode. [Background technology]

[0002] A lithium secondary battery includes an electrode assembly including a positive electrode coated with a positive active material, a negative electrode coated with a negative active material, and a separator positioned between the positive electrode and the negative electrode to prevent short circuits and to allow lithium ions (Li-ions) to move; a battery case that houses the electrode assembly; and an electrolyte that is injected into the battery case to allow lithium ions to move.

[0003] The positive electrode and the negative electrode may be fabricated in the form of a unit electrode by coating a positive electrode active material and a negative electrode active material on a long sheet-shaped positive electrode current collector and a long sheet-shaped negative electrode current collector, drying and rolling the coated material, and then cutting the coated material into a predetermined size.

[0004] A conventional electrode cutting device for manufacturing such unit electrodes comprises a transfer unit that seats and transfers a long sheet-like electrode that has been coated with an electrode active material, dried, and rolled, and a cutter installed on one side of the transfer unit. The cutter is divided into an upper cutter and a lower cutter. Specifically, the upper cutter is fixed on the upper side and the lower cutter is installed on the lower side, with the long sheet-like electrode at the center. When the long sheet-like electrode is transferred to the electrode cutting device, the cutter blade of the upper cutter comes into contact with the cutter blade of the lower cutter, cutting the long sheet-like electrode.

[0005] As the cutting process of the upper and lower blades is repeatedly performed, the cutter blades may wear or bend, causing rough cutting of the long sheet electrode or generating burrs or detached powder. In addition to continuous use, defects may also occur due to installation errors such as an increase in clearance between the upper and lower blades or mismatch in the installation surfaces of the upper and lower blades.

[0006] Problems that occur during the cutting process of the long sheet-like electrode occur in the current collector, which is a thin metal film, and the positive and negative electrode active materials. Because the gap between the upper and lower blades is narrow, friction between the cutter blade and the electrode active material is large. This friction can cause defects in the electrode active material, even when the cutter is in a normal state. If the adhesive strength within the electrode active material or the adhesive strength between the electrode active material and the current collector is weak, the electrode active material itself may come off from the cut surface of the long sheet-like electrode, or the electrode active material and the current collector may come off, resulting in detachment, or detached powder (hereinafter referred to as "detached material").

[0007] In particular, the detached material generated at the negative electrode is often in the form of a long, narrow string. This can lead to short circuits where the negative electrode and positive electrode come into contact, or bridge defects connecting the negative electrode and positive electrode. The detached material referred to here is not simply powder, but has a long, thin string-like shape and is attached to the cut portion of the negative electrode or positive electrode. Figure 1 shows a cross section of a negative electrode with such detached material attached. In Figure 1, the long parts arranged on the left and right of the center are the negative electrode, and the thread-like parts protruding above and below it are the detached material. In Figure 1, the bright or white colors above and below the negative electrode represent the separator.

[0008] Increasing the binder content in the electrode active material can increase the adhesive strength of the electrode active material, thereby reducing or preventing the release of materials. However, in this case, there is a problem that the increased binder content in the electrode increases the resistance, resulting in a decrease in the performance of the battery itself.

[0009] Figure 2 is a schematic diagram of a conventional electrode lamination apparatus 100. The electrode lamination apparatus 100 shown in Figure 2 is an apparatus for manufacturing an electrode in which a total of five layers are laminated from the top (z-axis direction): upper and lower electrodes 20, a separator 30, a central electrode 10, a separator 30, and upper and lower electrodes 20, and is presented as an example. In Figure 2, the tab portions of the electrodes are omitted.

[0010] 2, the central electrode 10 and the upper and lower electrodes 20 are cut by a first cutter 40 and a second cutter 50, respectively, and then passed through a stacking unit 60, after which they are manufactured into unit electrodes of a certain size by a third cutter 70. The electrode cutter according to the present invention relates to the first cutter 40 and the second cutter 50 that cut long sheet-like electrodes 10 and 20. However, even if the electrodes are not in the form of long sheets but are in the form of pre-cut electrodes, the same problem occurs during the cutting process, so the application is not necessarily limited to long sheet-like electrodes.

[0011] Figure 3 is a side view of a conventional electrode cutting device, showing part of a link-type assembly structure in which the individual components of the upper and lower units are directly fastened to the main frame in stages. An upper blade 42 and a lower blade 46 are arranged in Figure 3. The electrode is cut at the end surface where the upper blade 42 and the lower blade 46 come into contact.

[0012] FIG. 4 is a perspective view of an upper blade 42 and a lower blade 46 of a conventional cutter. Referring to FIG. 4, the conventional upper blade 42 has an overall long, thin rectangular parallelepiped shape. It includes an upper blade body 44, the lower portion of which is tilted inward (along the z-axis) with the center of the blade's length as the symmetry point. It also includes a first upper blade 45A and a second upper blade 45B, which are symmetrically arranged at the lower portion of the upper blade body 44 at a central portion 43 of the upper blade, the center of the blade's length, and which have blades tilted upward only on the front surface (-y direction) of the upper blade body 44. The lower blade 46 includes a lower blade body 48, the overall long, thin rectangular parallelepiped shape. The upper blade 42 does not necessarily have to have an upward (along the z-axis) tilt on the inner side of the rectangular parallelepiped, and the first upper blade 45A and the second upper blade 45B may not be present. Therefore, the configuration of FIG. 4 is not necessarily limited to that shown.

[0013] When cutting an electrode using the upper and lower blades shown in FIG. 4, detached material as shown in FIG. 1 is generated. FIG. 5 is a schematic diagram of an electrode assembly in which electrodes including detached material 12 according to the prior art are stacked. Referring to FIG. 5, the prior art electrode assembly 100A is an example having three positive electrodes 20A, two negative electrodes 10A, and five separators 30, but the shape of the electrode assembly is not limited thereto. The detached material 12, which is long and thin like a thread attached to or connected to the negative electrode 10A (shown relatively dark), can cause a short circuit in which the negative electrode and positive electrode come into contact with each other or a bridge in which the negative electrode and positive electrode are connected. The detached material 12 can be a negative electrode active material or a negative electrode current collector, but in most cases it is a negative electrode active material.

[0014] Patent Document 1 relates to an electrode plate cutting device that reduces the generation of burrs and removes foreign matter that occurs when cutting electrode plates. Patent Document 1 is equipped with a gap adjustment means that automatically adjusts the gap between the upper blade and the lower blade.

[0015] Patent Document 2 is provided with a means for removing foreign matter generated during cutting.

[0016] Patent Document 3 provides a cartridge-type blade to maintain a constant gap between the upper and lower blades, which makes it easy to adjust the gap and balance between the upper and lower blades.

[0017] Patent document 4 discloses a unit cell manufacturing device including an L-shaped cutter corresponding to the shape of the electrode to be cut, and a unit cell manufacturing method using the same, but the "L" shape also includes a long blade like the conventional upper and lower blades.

[0018] Patent Document 5 discloses an electrode assembly including cutting that can notch the outer peripheral edge into a sawtooth shape. Patent Document 5 specifically relates to technology related to small cylindrical batteries, in which the entire outer periphery of a circular electrode assembly is manufactured into a sawtooth shape to maintain the outer shape itself.

[0019] As described above, the prior art has improved the gap and parallelism between the upper and lower blades to remove burrs from the metal thin film, which serves as the current collector, during cutting. The detached material in the present invention can also be generated by the adhesive force of the electrode active material itself, and therefore can occur in the upper and lower blades in a steady state. Therefore, the problems of the prior art cannot be solved solely by improving the gap or alignment between the upper and lower blades. Even when a uniquely shaped cutter is used, not only is there a long blade region similar to that of the conventional upper and lower blades, but the blade appears to limit the shape of the electrode assembly itself. Furthermore, the prior art not only fails to recognize the problem of detached material that the present invention aims to solve, but also appears unable to resolve it. [Prior art documents] [Patent documents]

[0020] [Patent Document 1] Korean Patent Publication No. 10-2006-0027258 [Patent Document 2] Korean Patent Publication No. 10-2017-0097515 [Patent Document 3] Korean Patent Publication No. 10-2022-0013246 [Patent Document 4] Korean Patent Publication No. 10-2023-0042561 [Patent Document 5] Korean Patent No. 10-2064926 Summary of the Invention [Problem to be solved by the invention]

[0021] The present invention has been made to solve the above problems, and aims to provide an electrode cutter for preventing or reducing the amount of detached material generated during the process of cutting an electrode, or for shortening the length of the detached material, an electrode cutting method using the same, an electrode manufactured by the method, and an electrode assembly including the electrode. [Means for solving the problem]

[0022] To achieve the above object, the present invention provides an electrode cutter including an upper blade and a lower blade for cutting an electrode, wherein at least one of a surface of the upper blade and a surface of the lower blade, which contact each other to cut the electrode, includes a zigzag-shaped cutting portion along the length of the blade.

[0023] Such an electrode cutter is typically used in an electrode assembly manufacturing apparatus that includes one or more transfer rollers for moving an electrode sheet, a lamination unit for laminating the electrode sheet by applying heat and pressure, and a notching cutter for notching the electrode sheet to form an electrode.

[0024] The electrode may be either a positive electrode or a negative electrode, and may be a positive electrode, a negative electrode, or a positive and a negative electrode depending on the types of active materials and binders used in the positive and negative electrodes.

[0025] The rear surfaces of the upper blade and the lower blade, specifically, the rear surface of the lower blade's lower part and the rear surface of the upper blade's upper part, contact each other to cut the electrode. The cutting portion may be provided on at least one of the rear surfaces of the upper blade and the lower blade, specifically, the rear surface of the lower blade's lower part and the rear surface of the upper blade's upper part. Alternatively, the cutting portion may be provided on both the rear surfaces of the upper blade and the lower blade, specifically, the rear surface of the lower blade's lower part and the rear surface of the upper blade's upper part. In this case, the cutting portion is provided on the surface where the upper blade and the lower blade contact each other.

[0026] The cutting portion may be provided only on a portion of the upper blade and / or the lower blade. Specifically, it may be provided only on a portion of the upper blade and / or the lower blade along the length of the blade. As another example, it may be provided only on a portion of the upper blade and / or the lower blade along a direction perpendicular to the length of the blade. As yet another example, it may be provided only on a portion of the upper blade and / or the lower blade along the length of the blade and only on a portion of the upper blade and / or the lower blade along a direction perpendicular to the length of the blade.

[0027] The cutting portion may be disposed on the entire upper blade and the entire lower blade, in which case the entire upper blade and the entire lower blade may have a zigzag shape.

[0028] The zigzag shape may be one or more of a triangular waveform, a polygonal waveform with four or more sides, and a curved waveform.

[0029] The zigzag pattern may be a repeat of identical shapes or a connection of non-identical shapes.

[0030] The length of one line segment of the zigzag pattern is 3 mm or less, preferably 2 mm or less. The line segment referred to here refers to a line segment when the zigzag pattern is polygonal, and when the zigzag pattern is curved, refers to the length between sharp bends in the curved pattern.

[0031] The upper blade may have a generally long and thin rectangular parallelepiped shape, and the lower blade may also have a generally long and thin rectangular parallelepiped shape. In this case, the cutting portion may be provided on a rear surface of the upper blade and / or the lower blade.

[0032] Another form of the upper blade may include an upper blade body having an overall long and thin rectangular parallelepiped shape, the lower part of which is inclined inward of the rectangular parallelepiped relative to the upper part of the upper blade, with the center of the blade's length as the symmetry point, and first and second upper blades arranged symmetrically at the center of the upper blade, which is the center of the lower blade's length, of the upper blade body, and having blades inclined upward only on the front surface of the upper blade body, and the cutting portion may be provided on the rear surface of the first and second upper blades.

[0033] Another form of the upper blade may further include a form inclined upwardly on the inside of the rectangular parallelepiped, in which case the cutting portion may be provided on the rear surface of the upper blade or the upper blade body.

[0034] Another embodiment of the upper blade is a form including only the first and second upper blades, in which case the cutting portion may be provided on the rear surfaces of the first and second upper blades.

[0035] The lower knife may include a lower knife body having a rectangular parallelepiped shape that is long and thin overall, and a lower knife blade having a blade that is inclined upward only on the front surface of the lower knife body, and the cutting portion may be provided on the rear surface of the lower knife blade.

[0036] In another embodiment of the lower knife, the lower knife may not have a lower knife blade. In this case, the cutting portion may be provided on the rear surface of the lower knife body.

[0037] The present invention also provides an electrode cutter that further includes a detached material remover that removes detached material and / or burrs generated during the electrode cutting.

[0038] The present invention also provides a method for cutting an electrode using the electrode cutter, an electrode manufactured by the electrode cutter, an electrode assembly including the electrode, a battery module or battery pack including the electrode assembly, and a product including the electrode assembly.

[0039] The present invention also provides an electrode assembly formed by stacking electrodes and separators, wherein at least one of the electrodes does not have an electrode tab protrusion, and at least one surface of the electrode does not have a zigzag shape.

[0040] The length of one line segment of the zigzag pattern is 3 mm or less, preferably 2 mm or less. The line segment referred to here refers to a line segment when the zigzag pattern is polygonal, and when the zigzag pattern is curved, refers to the length between sharp bends in the curved pattern.

[0041] Furthermore, it is possible to provide a solution to the problem by arbitrarily combining the above-mentioned solutions. [Effects of the Invention]

[0042] The present invention provides an electrode cutter for preventing or reducing long, thin, thread-like detached material generated during the process of cutting an electrode, or for shortening the length of the detached material, an electrode cutting method using the electrode cutter, an electrode manufactured by the method, and an electrode assembly including the electrode.

[0043] The electrode cutter according to the present invention has a zigzag cutting portion. Therefore, even if detached material in a long, thin, thread-like shape is generated, the length of the detached material is shortened due to the short length of the blades of each zigzag shape, thereby preventing or reducing short circuit defects in which the negative and positive electrodes come into contact with each other and bridge defects in which the negative and positive electrodes are connected. [Brief explanation of the drawings]

[0044] [Figure 1] 1 is a photograph showing a cut surface of a negative electrode in which desorbed substances have been generated according to the prior art. [Figure 2] FIG. 1 is a schematic diagram of a general electrode lamination device. [Figure 3] FIG. 1 is a side view of an electrode cutting device according to the prior art. [Figure 4] FIG. 1 is a perspective view of an upper blade and a lower blade of a conventional cutter. [Figure 5] 1 is a schematic diagram of an electrode assembly in which electrodes containing a release material according to the prior art are stacked; [Figure 6] 1 is a perspective view of an upper blade and a lower blade of a cutter according to a first embodiment of the present invention. FIG. [Figure 7] 1A and 1B are perspective views of the front and rear of an upper blade and a lower blade according to a first embodiment of the present invention. [Figure 8] 1A to 1C are a front view, a side view, and a bottom view of the rear surface of an upper knife according to a first embodiment of the present invention, and an enlarged view of a cutting portion. [Figure 9] FIG. 10 is a schematic view of an upper blade of a cutter according to a second embodiment of the present invention. [Figure 10] FIG. 1 is a schematic diagram of a negative electrode when a cutter according to the present invention is used. [Figure 11] 1 is a schematic diagram of an electrode assembly in which electrodes are stacked according to the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0045] Hereinafter, with reference to the accompanying drawings, a detailed description will be given of an embodiment of the present invention that will enable a person skilled in the art to easily carry out the present invention. Hereinafter, in describing the operation principle of the preferred embodiment of the present invention in detail, detailed description of related well-known functions or configurations will be omitted if it is determined that such detailed description may unnecessarily obscure the gist of the present invention.

[0046] Furthermore, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection via another element therebetween. Furthermore, unless otherwise specified, "including a certain element" does not mean that other elements are excluded, but that other elements may also be included.

[0047] Furthermore, descriptions that limit or add specific elements are applicable to all inventions and are not limited to a particular invention unless otherwise specified.

[0048] Furthermore, throughout the description of the present invention and the claims, the singular includes the plural unless otherwise stated.

[0049] Furthermore, throughout the description of the present invention and the claims, unless otherwise specified, "or" includes "and." Therefore, "including A or B" means three cases: including A, including B, or including both A and B.

[0050] Furthermore, all numerical ranges include both endpoints and all intermediate values ​​therebetween unless expressly stated to the contrary.

[0051] The present invention will now be described in detail with reference to the accompanying drawings, in which: FIG.

[0052] FIG. 6 is a perspective view of the upper blade and the lower blade of the cutter according to the first embodiment of the present invention, and FIG. 7 is a perspective view of the front and rear of the upper blade and the lower blade according to the first embodiment of the present invention.

[0053] In Figure 7, (a) and (b) show the front and rear surfaces of the upper blade, respectively, and (c) and (d) show the front and rear surfaces of the lower blade. In the upper blade 142 and the lower blade 146 used for electrode cutting, the rear surface of the upper blade 142 and the rear surface of the lower blade 146 come into contact with each other to cut the electrode. Figure 6 shows the arrangement of the upper blade 142 and the lower blade 146 for essentially cutting the electrode. The rear surfaces of the upper blade 142 and the lower blade 146 each have zigzag cutting portions 149A and 149B along the blade length. In all drawings, the coordinates x, y, and z are set based on Figure 4 or Figure 6.

[0054] The upper blade 142 has a rectangular parallelepiped shape that is long in the x direction and thin in the y direction. The upper blade body 144 has an upper blade portion that is symmetrically arranged at its lower end inclined inward in the z direction with the center of the blade in the x direction (the length direction) as the symmetry point. The upper blade body 144 also includes a first upper blade 145A and a second upper blade 145B, which are symmetrically arranged at a center portion 143 of the upper blade, which is the center of the length direction of the lower blade of the upper blade body 144, and which have blades that are symmetrically arranged at a center portion 143 of the upper blade, which is the length direction of the lower blade of the upper blade body 144, and which are slanted upward in the z direction only on the -y direction surface (the front surface) of the upper blade body 144. The cutting portion 149A is provided on the y direction surface (the rear surface) of the first upper blade 145A and the second upper blade 145B. The cutting portion 149A is provided on the surface where the upper blade 142 and the lower blade 146 come into contact with each other.

[0055] The lower knife 146 generally includes a lower knife body 148 in the form of a long, thin rectangular parallelepiped, and a lower knife blade 147 with a blade that is inclined only on the y-direction surface, which is the front surface of the lower knife body 148, and the cutting portion 149B is provided only on the y-direction surface, which is the rear surface of the lower knife blade 147. The width of the lower knife blade 147 in the -z direction, which is perpendicular to the length direction of the blade, may be smaller than the width of the first upper knife blade 145A or the second upper knife blade 145B in the z direction, which is perpendicular to the length direction of the blade.

[0056] Although not shown in the drawings, unlike the cutting portions 149A and 149B shown in FIGS. 6 and 7, cutting portions may be provided only on a portion of the upper blade 142 and / or the lower blade 146. Specifically, they may be provided only on a portion of the rear surface of the first upper blade 145A and the second upper blade 145B and on a portion of the rear surface of the lower blade 147. As a first example, they may be provided only on a portion of the rear surface of the first upper blade 145A and the second upper blade 145B along the blade length. As a second example, they may be provided only on a portion of the rear surface of the first upper blade 145A and the second upper blade 145B along the blade length. As a third example, they may be provided only on a portion of the rear surface of the first upper blade 145A and the second upper blade 145B along the blade length and on a portion of the rear surface of the first upper blade 145A and the second upper blade 145B along the blade length. Since the lower blade 146 must be engaged with the upper blade 142, in the three examples, only some of the three types of lower blades 146 are provided with cutting portions.

[0057] 6 and 7, the cutting portions 149A, 149B are provided along the entire length of the rear surfaces of the first upper blade 145A, the second upper blade 145B, and the lower blade 147, and .... That is, in the case of FIGS. 6 and 7, the first upper blade 145A and the second upper blade 145B are formed, and the cutting portions 149A, 149B are provided on the entire surfaces of the first upper blade 145A, the second upper blade 145B, and the lower blade 147.

[0058] Because the rear surfaces of the upper blade and the lower blade come into contact with each other to cut the electrode, the first upper blade, the second upper blade, and the lower blade are not required. Also, the upper blade body may not be required to be inclined inward in the z-direction. However, considering the gap between the upper blade and the lower blade, the stress acting on the cut portion, and the removal of the cut portion, it may be more efficient to have the first upper blade, the second upper blade, and the lower blade with an inclined shape and an inclined surface.

[0059] That is, unlike FIGS. 6 and 7, the first and second upper blades may have a configuration in which there is no inclined portion along the x-axis direction, no inclined portion along the z-axis direction, or neither inclined portion along the x-axis direction nor inclined portion along the z-axis direction (not shown). The lower blade may also have no inclined portion. If cutting portions are provided on both the upper and lower blades, the cutting portions may be arranged to interlock with each other. In this case, unlike the conventional case in which the rear surfaces of the upper and lower blades contact each other, the cutting portions must be arranged closer to each other by the size of the intersection. If cutting portions are provided only on the upper or lower blades, they are arranged in the same manner as the conventional case in which the rear surfaces of the upper and lower blades contact each other.

[0060] 8A, 8B, and 8C are front, side, and bottom views of the rear of the upper blade 142 according to the first embodiment of the present invention, respectively, and an enlarged view of the cutting portion 149A. As a specific example, the length of the upper blade 142 in the x-direction, which is the blade length direction, may be 400 mm, and the length in the z-direction, which is the height, may be 100 mm. The cutting portion 149A of the upper blade and the cutting portion 149B of the lower blade are configured to interlock with each other, so the zigzag spacing and angle are the same, and when the upper blade 142 and the lower blade 146 come into contact, they must interlock with each other. In one example of the cutting portion 149A, the zigzag spacing P is 5.5 mm, and the angle θ is 90 degrees.

[0061] Although the present invention illustrates an embodiment in which the zigzag pattern is uniform, the present invention is not limited thereto. Furthermore, while FIG. 1 illustrates a conventional technique for anodes, the electrode cutter of the present invention can be applied to anodes, cathodes, and current collectors. The anode and cathode herein specifically refer to the anode active material and cathode active material. Even if detached material is generated, because the separator is larger than the electrode active material layer, detached material below a certain size does not affect short circuit failure or bridging. Taking this into consideration, the present invention limits the size of detached material that may be generated by configuring the cutting portion in a zigzag pattern.

[0062] The size of the released material generated during actual cutting, or more precisely, the length of the released material, is determined by the length of one line segment of the zigzag shape of the cut. The line segment here refers to a line segment when the zigzag shape is polygonal, and when the zigzag shape is curved, it refers to the length between the sharp bends in the curve.

[0063] To prevent short circuits, the length of each line segment of the zigzag cut is 3 mm or less, preferably 2 mm or less. However, to form the zigzag shape, the angle θ must be less than 180 degrees. The closer the angle θ is to 0, the greater the overall width of the zigzag cut, resulting in more active material being discarded at the cut. Considering this alone, a larger angle θ is preferable. However, in practical applications, the angle θ should be less than 180 degrees because problems may arise in which the released material is not cut but is instead joined due to the viscosity of the active material or the gap between the upper and lower blades.

[0064] In consideration of this, it can be seen that the zigzag shape does not need to have the same length or angle of the line segments, and the object of the present invention can be achieved simply by forming the zigzag shape. Referring to the zigzag shapes presented as examples in the present invention and the above description, those skilled in the art can easily understand that the zigzag shapes can be modified not only to the zigzag shape of a triangular waveform exemplified in the drawings, but also to zigzags of other polygonal waveforms and even curved waveforms.

[0065] Figure 9 is a schematic diagram of an upper blade 242 of a cutter according to a second embodiment of the present invention. The upper blade 242 shown in Figure 9 has a cutting portion 249A formed over the entire upper blade body, without distinction between the front and rear surfaces. In the case of such an upper blade 242, the lower blade must also have a corresponding shape, resulting in a shape similar to that of the upper blade 242. Although the zigzag shape in Figure 9 is depicted larger than in Figure 8, this is merely an example, and the zigzag shape is preferably the same size as that described in Figure 8, and the shape can also be modified as described in Figure 8.

[0066] Because the electrode is cut in a zigzag pattern at the cutting portion, it is preferable to limit the length of one end of the zigzag pattern so that the maximum size of the released material does not exceed the thickness of the electrode. However, because the cutting is zigzag, even if the length of one end of the zigzag pattern is greater than the thickness of the electrode, the zigzag pattern prevents the released material from extending in a straight line, or the zigzag pattern makes the released material easily break again after cutting, shortening the length. Therefore, the length of one end of the zigzag pattern is not necessarily limited solely by the thickness of the electrode.

[0067] FIG. 10 is a schematic diagram of an anode 110A when a cutter according to the present invention is used. (a) of FIG. 10 shows the left and right sides of the surface from which the anode tab protrudes cut in a zigzag pattern, and (b) is a diagram for comparison when a cathode 120A is stacked on an anode 110A. The zigzag pattern is exaggerated slightly from its actual size. When the anode is larger than the cathode and both sides of the anode are cut in a zigzag pattern, it is preferable that the minimum width of the zigzag cut be larger than that of the cathode. This is to reduce the possibility of contact between the anode and cathode even if detached materials are generated.

[0068] As described with reference to FIG. 8, the length of each line segment of the zigzag cut in the negative electrode of FIG. 10 is 3 mm or less, preferably 2 mm or less. While the zigzag cut in FIG. 10 is 90 degrees, the angle is not limited to this. However, the angle must be less than 180 degrees to form a zigzag cut. The closer the angle is to 0, the wider the overall zigzag cut, resulting in more active material being wasted at the cut. Considering this point alone, a larger angle θ is preferable. However, in practical applications, the angle θ should be less than 180 degrees because problems may occur in which the released material is not cut but is instead joined due to the viscosity of the active material or the gap between the upper and lower blades. FIG. 11 is a schematic diagram of an electrode assembly 100B in which electrodes are stacked according to the present invention. Referring to FIG. 11, the electrode assembly 100B is an example including three positive electrodes 20A, two negative electrodes 110A, and five separators 30, but the shape of the electrode assembly is not limited thereto. The length of the thread-like, long, thin detached material 12A attached to the negative electrode 110A is significantly reduced compared to the detached material 12 of the conventional electrode assembly (see FIG. 5). As a result, it is possible to prevent or reduce short circuits where the negative electrode and the positive electrode come into contact and bridges where the negative electrode and the positive electrode are connected, which can occur in the conventional electrode assembly 100A.

[0069] Those skilled in the art will be able to make various applications and modifications within the scope of the present invention based on the above content. [Explanation of symbols]

[0070] 100 Electrode lamination device 100A, 100B electrode assembly 10 center electrode 10A, 110A negative pole 12, 12A Desorbed Materials 20 Upper and lower electrodes 20A, 120A positive electrode 30 Separation membrane 40 First Cutter 50 Second Cutter 60 Laminated section 70 No. 3 カッター 42, 142, 242 (Use the knife) 43, 143, the central part of the upper blade 44, 144 Upper knife body 45A, 145A First Upper Cutting Edge 45B, 145B, second upper cutting edge 46, 146 cuts 147 Lower blade 48, 148 lower knife body Cut-off sections 149A, 149B, and 249A P ジグザグinterval θ angle

Claims

1. An electrode cutter including an upper blade and a lower blade for cutting an electrode, At least one of the upper blade surface and the lower blade surface, which come into contact with each other to cut the electrode, includes a zigzag cutting portion along the length of the blade.

2. The rear surface of the upper blade and the rear surface of the lower blade come into contact with each other to cut the electrode; The electrode cutter according to claim 1 , wherein the cutting portion is provided on at least one of a rear surface of the upper blade and a rear surface of the lower blade.

3. The electrode cutter according to claim 2 , wherein the cutting portion is provided on a rear surface of the upper blade and a rear surface of the lower blade.

4. The electrode cutter according to claim 2 , wherein the cutting portion is provided only partially along the length of the blade of the upper blade and / or the lower blade.

5. The electrode cutter according to claim 2 , wherein the cutting portion is provided only partially along a direction perpendicular to a length direction of the blade of the upper blade and / or the lower blade.

6. The electrode cutter according to claim 1 , wherein the cutting portion is provided on the upper blade and the lower blade, and the cutting portion is disposed over the entire upper blade and the lower blade.

7. The electrode cutter according to claim 1 , wherein the zigzag shape is at least one of a triangular waveform, a polygonal waveform having four or more sides, and a curved waveform.

8. The electrode cutter according to claim 1 , wherein the zigzag pattern is formed by repeating identical shapes or connecting non-identical shapes.

9. The electrode cutter according to claim 1 , wherein the length of each line segment of the zigzag pattern is 3 mm or less.

10. The upper blade includes an upper blade body having a generally long and thin rectangular parallelepiped shape, The electrode cutter according to claim 1 , wherein the cutting portion is provided on a rear surface of the upper blade body.

11. The upper blade is an upper blade body having a rectangular parallelepiped shape with a long and thin overall length, the lower part of which is symmetrical about the center of the blade length and tilted upward toward the inside of the rectangular parallelepiped; a first upper blade and a second upper blade, which are symmetrically arranged at a center portion of the upper blade, which is the center of the length direction of the lower blade of the upper blade body, and which have a blade inclined upward only on the front surface of the upper blade body; Including, The electrode cutter according to claim 1 , wherein the cutting portion is provided on a rear surface of the first upper blade and the second upper blade.

12. The lower blade includes a lower blade body having an overall long and thin rectangular parallelepiped shape, The electrode cutter according to claim 1 , wherein the cutting portion is provided on a rear surface of the lower blade body.

13. The lower blade is A blade body having a rectangular parallelepiped shape that is long and thin overall; a lower blade having an upwardly inclined blade provided only on the front surface of the lower blade body; Including, The electrode cutter according to claim 1 , wherein the cutting portion is provided on a rear surface of the lower blade.

14. The electrode cutter according to claim 1 , further comprising a detached material removal unit that removes detached material and / or burrs generated during the electrode cutting.

15. A method for cutting an electrode using the electrode cutter according to any one of claims 1 to 14.

16. 16. An electrode manufactured by the method of claim 15.

17. An electrode assembly comprising the electrode of claim 16.

18. An electrode assembly formed by stacking an electrode and a separator, At least one of the electrodes does not have an electrode tab protrusion, and at least one surface of the electrode assembly has a zigzag shape.

19. The electrode assembly of claim 18, wherein the length of each line segment of the zigzag pattern is 3 mm or less.

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