Electrode cutter for preventing electrode delamination

Abstract

The present invention provides an electrode cutter for preventing or reducing long and thin delaminated materials, such as swarf, generated during an electrode cutting process, or reducing the length thereof. The electrode cutter includes an upper cutter and a lower cutter, and has a zigzag cutting part provided on one surface of the upper cutter and / or one surface of the lower cutter in the lengthwise direction of a blade. Through the zigzag shape, delaminated materials can be prevented or the length thereof can be remarkably reduced.

Description

Electrode cutter to prevent electrode detachment

[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 method, and an electrode assembly including the electrode. 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 method, and an electrode assembly including the electrode.

[0002] A lithium secondary battery includes an electrode assembly including a positive electrode coated with a positive electrode active material, a negative electrode coated with a negative electrode active material, a separator positioned between the positive electrode and the negative electrode to prevent short circuiting and enable movement of lithium ions (Li-ions), a battery case that accommodates the electrode assembly, and an electrolyte that is injected into the inside of the battery case to enable movement of lithium ions.

[0003] The above positive and negative electrodes can be manufactured in the form of unit electrodes by coating a positive active material and a negative active material on a positive current collector and a negative current collector in the form of long sheets, respectively, drying and rolling them, and then cutting them to have a certain size.

[0004] A conventional electrode cutting device for manufacturing such a unit electrode comprises a transport unit for transporting a long sheet-shaped electrode coated, dried, and rolled with an electrode active material, and a cutter installed on one side of the transport unit. The cutter is divided into an upper cutter and a lower cutter. Specifically, the upper cutter is fixed to the upper side and the lower cutter is installed to the lower side with respect to the long sheet-shaped electrode. When the long sheet-shaped electrode is transported to the electrode cutting device, the cutter blades of the upper cutter and the lower cutter are brought into contact to cut the long sheet-shaped electrode.

[0005] If the above-mentioned cutting process of the upper and lower layers is repeated, the cutter blades may wear out or bend, causing the cut portion of the long sheet-shaped electrode to be cut unevenly or burrs or loose powder to be generated. In addition to continuous use, defects may also occur due to installation errors, such as a widening of the clearance between the upper and lower layers or a mismatch in the installation surfaces of the upper and lower layers.

[0006] Problems that occur during the cutting process of the above-mentioned long sheet-shaped electrode occur in the current collector, positive electrode active material, or negative electrode active material, which is a metal thin film. Since the gap between the upper and lower coatings is narrow, the friction between the cutter blades and the electrode active material is strong. Due to the friction, defects may occur in the electrode active material even when the cutter is in a normal state. When the adhesive force inside the electrode active material is weak or the adhesive force between the electrode active material and the current collector is weak, the electrode active material itself may fall off from the cut surface of the long sheet-shaped electrode, or the electrode active material and the current collector may fall off, generating detachment or detachment powder (hereinafter referred to as "detachment material").

[0007] In particular, the above-mentioned detached material generated from the negative electrode is often in the form of a small, long string. This causes a short-circuit defect where the negative electrode and the positive electrode contact each other or a bridge defect where the negative electrode and the positive electrode are connected. The above-mentioned detached material referred to here is not simply a powder, but is attached to the negative electrode or the cut portion of the positive electrode in a thin, long form like a string or thread. Fig. 1 shows a cross-section of the negative electrode to which such detached material is attached. In Fig. 1, the part arranged long to the left and right of the center is the negative electrode, and the part protruding up and down from here like a thread is the detached material. In Fig. 1, the bright or white color above and below the negative electrode represents a separator.

[0008] By increasing the binder content within the electrode active material, the adhesive strength of the electrode active material can be enhanced, thereby reducing or preventing the formation of detached materials. However, this approach poses a problem: the increased binder content within the electrode leads to increased resistance, which in turn degrades the performance of the battery itself.

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

[0010] Referring to FIG. 2, the central electrode (10) and the upper and lower electrodes (20) are cut by the first cutter (40) and the second cutter (50), respectively, and after passing through the laminated portion (60), are manufactured into unit electrodes of a certain size by the third cutter (70). The electrode cutter according to the present invention relates to the first cutter (40) and the second cutter (50) that cut the electrodes (10, 20) in the form of long sheets. However, even if the shape of the electrode is not a long sheet shape but an already cut shape, the same problem occurs during the process of cutting it again, and thus, it is not necessarily limited to the long sheet shape.

[0011] Fig. 3 is a side view of an electrode cutting device according to the prior art, showing a portion of the electrode cutting device having a link-type assembly structure in which individual parts of the upper and lower units are directly and stepwise fastened to the main frame. In Fig. 3, an upper section (42) and a lower section (46) are arranged. The electrode is cut at the cross-section where the upper section (42) and the lower section (46) touch.

[0012] Fig. 4 is a perspective view of the upper part (42) and the lower part (46) of a cutter according to the prior art. Referring to Fig. 4, the upper part (42) according to the prior art is in the shape of a rectangular parallelepiped that is long and thin overall, and includes an upper part body (44) that is symmetrically inclined upward (z-axis) toward the inside of the rectangular parallelepiped about the center of the blade length direction, an upper part first blade (45A) and an upper part second blade (45B) that are symmetrically arranged about the center of the upper part blade (43) that is the center of the lower part of the upper part body (44) in the blade length direction and have blades that are inclined upward only on the front surface (-y direction) of the upper part body (44). The lower part (46) includes a lower part body (48) that is in the shape of a rectangular parallelepiped that is long and thin overall. In the upper part (42), there may be no upward (z-axis) inclined shape inward of the rectangular solid, and there may be no upper part first edge (45A) and upper part second edge (45B), and it is not necessarily limited to the shape of the above-mentioned FIG. 4.

[0013] When cutting an electrode using the same upper and lower layers as in Fig. 4, a detached material as in Fig. 1 is generated. Fig. 5 is a schematic diagram of an electrode assembly in which electrodes including a detached material (12) according to the prior art are laminated. Referring to Fig. 5, an electrode assembly (100A) according to the prior art is one example of three positive electrodes (20A), two negative electrodes (10A), and five separators (30), and the shape of the electrode assembly is not limited thereto. A short circuit defect in which the negative electrode and the positive electrode contact each other or a bridge defect in which the negative electrode and the positive electrode are connected occurs due to a detached material (12) in a thin and long shape like a thread attached to or connected from the negative electrode (10A), which is indicated darker. The detached material (12) may be a negative electrode active material or a current collector of the negative electrode, but in many cases is a negative electrode active material.

[0014] Patent Document 1 relates to an electrode plate cutting device, which reduces the generation of burrs and removes foreign substances generated during electrode plate cutting. Patent Document 1 includes a gap adjustment means that automatically adjusts the gap between the upper and lower coatings.

[0015] Patent Document 2 provides a means for removing foreign substances generated during cutting.

[0016] Patent Document 3 provides a cartridge-shaped blade to maintain a constant gap between the upper and lower coatings. The cartridge-shaped blade allows for easy adjustment of the gap and balance between the upper and lower coatings.

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

[0018] Patent Document 5 discloses an electrode assembly including a cutting feature capable of notching the outer peripheral end into a sawtooth shape. Patent Document 5 specifically relates to a technology for a small cylindrical battery, wherein the outer peripheral portion of the entire circular electrode assembly is manufactured in a sawtooth shape to maintain the outer shape itself as a cylindrical shape.

[0019] In this way, the prior art improves the gap or parallelism between the top and bottom coatings in order to remove burrs on the metal thin film, which is the current collector, generated during cutting. The detached material according to the present invention may also be caused by the adhesive strength of the electrode active material itself, and may occur in the top and bottom coatings under normal conditions. Therefore, the problem of the gap or alignment between the top and bottom coatings according to the prior art cannot be solved only. Even when a cutter with a unique shape is used, not only does the area of ​​the blade similar to the top and bottom coatings of the prior art exist, but the blade seems to limit the shape of the electrode assembly itself. Furthermore, the prior art does not recognize the problem of detached material that the present invention is trying to solve, and it seems that it is unable to solve it.

[0020] Republic of Korea Patent Publication No. 2006-0027258 (Patent Document 1)

[0021] Republic of Korea Patent Publication No. 2017-0097515 (Patent Document 2)

[0022] Republic of Korea Patent Publication No. 2022-0013246 (Patent Document 2)

[0023] Republic of Korea Patent Publication No. 2023-0042561 (Patent Document 4)

[0024] Republic of Korea Patent Publication No. 2064926 ('Patent Document 5')

[0025] The present invention is intended to solve the above problems, and provides an electrode cutter for preventing, reducing, or shortening the length of detached materials generated during the process of cutting an electrode, an electrode cutting method using the same, an electrode manufactured by the method, and an electrode assembly including the electrode.

[0026] In order to achieve the above purpose, the present invention provides an electrode cutter including an upper and lower coating for electrode cutting, wherein the upper and lower coatings contact each other to cut the electrode, and at least one of one side of the upper coating and one side of the lower coating includes a cutting portion in a zigzag shape along the blade length direction.

[0027] These electrode cutters are typically used in an electrode assembly manufacturing device that includes one or more transport rollers for moving electrode sheets, a laminating unit for laminating the electrode sheets by applying heat and pressure, and a notching cutter for notching the electrode sheets to form electrodes.

[0028] The above electrode can be either a positive electrode or a negative electrode, and can be a positive electrode, a negative electrode, an anode, or an anode and a cathode depending on the type of active material and binder used in the positive electrode and the negative electrode.

[0029] The back surface of the upper coating and the back surface of the lower coating, specifically the lower back surface of the upper coating and the upper back surface of the lower coating, are in contact with each other to cut the electrode. The cutting portion may be provided on at least one of the back surface of the upper coating and the back surface of the lower coating, specifically the lower back surface of the upper coating and the upper back surface of the lower coating. In addition, the cutting portion may be provided on both the back surface of the upper coating and the back surface of the lower coating, specifically the lower back surface of the upper coating and the upper back surface of the lower coating. In this case, the cutting portion is provided on the surface where the upper coating and the lower coating are in contact with each other.

[0030] The above-mentioned cutting portion may be provided only in a portion of the upper and / or lower coating. Specifically, the cutting portion may be provided only in a portion along the longitudinal direction of the upper and / or lower coating. In another example, the cutting portion may be provided only in a portion along a direction perpendicular to the longitudinal direction of the upper and / or lower coating. In another example, the cutting portion may be provided only in a portion along the longitudinal direction of the upper and / or lower coating and in a portion along a direction perpendicular to the longitudinal direction of the upper and / or lower coating.

[0031] The above-mentioned cut portion may be arranged over the entire upper and lower sections. In this case, the entire upper and lower sections may have a zigzag shape.

[0032] The above zigzag shape may be at least one of a triangular waveform shape, a polygonal waveform shape having a shape of four or more angles, and a curved waveform shape.

[0033] The above zigzag shape may be repeated with the same shape or with different shapes.

[0034] The length of one line segment of the above zigzag shape is 3mm or less, preferably 2mm or less. The line segment referred to here refers to a line segment when the zigzag shape is a polygon, and when the zigzag shape is a curve, it refers to the length between the parts where the curve shape is sharply bent.

[0035] The above-mentioned upper surface may be in the shape of a rectangular parallelepiped that is long and thin overall, and the lower surface may also be in the shape of a rectangular parallelepiped that is long and thin overall. In this case, the cut portion may be provided on the rear surface of the upper surface and / or the lower surface.

[0036] Another form of the above-mentioned upper blade includes a body of a lower blade having a shape of a rectangular parallelepiped that is long and thin overall, and a shape in which the lower part is inclined upward toward the inside of the rectangular parallelepiped symmetrically about the center of the blade length direction, a first upper blade and a second upper blade that are symmetrically arranged in the center of the lower blade length direction center of the upper blade of the upper blade body and have blades that are 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 upper blade and the second upper blade.

[0037] Another form of the above-mentioned figure may be one in which only an upwardly inclined shape is added to the inside of the above-mentioned rectangular solid, in which case the cut portion may be provided on the rear side of the above-mentioned figure or the above-mentioned figure body.

[0038] Another form of the above-mentioned upper blade may be a form in which only the first upper blade and the second upper blade are added, and in this case, the cutting part may be provided on the back of the first upper blade and the second upper blade.

[0039] The above-mentioned lower blade includes a lower blade body having a rectangular shape with an overall length and a thin thickness, a lower blade having an upwardly inclined blade provided only on the front surface of the lower blade body, and the cutting portion may be provided on the rear surface of the lower blade.

[0040] In another form of the above-mentioned lower body, there may be no lower body. In this case, the cutting part may be provided on the rear side of the lower body.

[0041] The present invention also provides an electrode cutter further equipped with a delamination material removal unit for removing delamination material and / or burrs generated during the electrode cutting.

[0042] The present invention can also provide 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.

[0043] The present invention provides an electrode assembly formed by laminating electrodes and separators, wherein at least one of the electrodes has a zigzag shape on at least one side other than the electrode tab protrusion.

[0044] The length of one line segment of the above zigzag shape is 3mm or less, preferably 2mm or less. The line segment referred to here refers to a line segment when the zigzag shape is a polygon, and when the zigzag shape is a curve, it refers to the length between the parts where the curve shape is sharply bent.

[0045] The present invention can also provide a problem solving means by arbitrarily combining the above problem solving means.

[0046] The present invention can provide an electrode cutter for preventing, reducing, or shortening the length of thin and long detached materials such as threads that are generated during the process of cutting an electrode, an electrode cutting method using the same, an electrode manufactured by the method, and an electrode assembly including the electrode.

[0047] The electrode cutter according to the present invention has a zigzag-shaped cutting section, so that even if a thin and long detached substance like a thread is generated, the length of the blade according to each zigzag shape is short, so that the length of the detached substance is shortened, thereby preventing or reducing a short circuit defect where the cathode and anode come into contact or a bridge defect where the cathode and anode are connected.

[0048] Figure 1 is a photograph of a cross-section of a cathode in which a detached substance has been generated according to a conventional technique.

[0049] Figure 2 is a schematic diagram of a conventional electrode lamination device.

[0050] Fig. 3 is a side view of an electrode cutting device according to the prior art.

[0051] Figure 4 is a perspective view of the upper and lower parts of a cutter according to the prior art.

[0052] Figure 5 is a schematic diagram of an electrode assembly in which electrodes containing a desorption material according to a conventional technology are laminated.

[0053] Figure 6 is a perspective view of the upper and lower parts of a cutter according to the first embodiment of the present invention.

[0054] Figure 7 is a perspective view of the front and back of the upper and lower parts according to the first embodiment of the present invention.

[0055] Figure 8 is a front view, a side view, a bottom view, and an enlarged view of a cut portion of the rear surface of a painting according to the first embodiment of the present invention.

[0056] Figure 9 is a schematic diagram of a cutter according to a second embodiment of the present invention.

[0057] Figure 10 is a schematic diagram of a cathode when using a cutter according to the present invention.

[0058] Figure 11 is a schematic diagram of an electrode assembly in which electrodes are laminated according to the present invention.

[0059] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those with ordinary skill in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0060] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0061] Additionally, the description that concretizes or adds components may be applied to all inventions unless there are special limitations, and is not limited to the description of a specific invention.

[0062] Additionally, throughout the description and claims of the invention herein, the singular includes the plural unless otherwise stated.

[0063] Additionally, throughout the description and claims of the present invention, the term "or" includes "and" unless otherwise stated. Therefore, "comprising A or B" means all three cases of including A, including B, or including A and B.

[0064] Additionally, all numerical ranges include the extreme values ​​and all intermediate values ​​between them, unless explicitly stated otherwise.

[0065] The present invention is described in detail with examples according to the drawings.

[0066] Fig. 6 is a perspective view of the upper and lower parts of a cutter according to the first embodiment of the present invention, and Fig. 7 is a perspective view of the front and rear parts of the upper and lower parts according to the first embodiment of the present invention.

[0067] In Fig. 7, (a) and (b) are the front and back of the upper part, respectively, and (c) and (d) are the front and back of the lower part. In the upper part (142) and the lower part (146) for electrode cutting, the back of the upper part (142) and the back of the lower part (146) contact each other to cut the electrode. Fig. 6 shows the arrangement of the upper part (142) and the lower part (146) for actually cutting the electrode. Zigzag cutting portions (149A, 149B) are provided on the back of the upper part (142) and the back of the lower part (146), respectively, in the direction of the blade length. In all drawings, x, y, z representing coordinates are set based on Fig. 4 or Fig. 6.

[0068] The upper part (142) is a rectangular parallelepiped shape that is long in the x direction and thin in the y direction, and has a main body (144) that is symmetrically inclined in the z direction inside the rectangular parallelepiped with the center of the x direction, which is the blade length direction, in the lower part, and a first upper part blade (145A) and a second upper part blade (145B) that are symmetrically arranged around the center of the upper part blade (143), which is the center of the lower part blade length direction of the upper part body (144), and have blades that are inclined in the z direction, which is upward, only on the -y direction surface, which is the front surface of the upper part body (144), and a cutting portion (149A) is provided on the y direction surface, which is the rear surface of the first upper part blade (145A) and the second upper part blade (145B). The cutting portion (149A) is provided on the surface where the upper part (142) and the lower part (146) contact each other.

[0069] The lower blade (146) includes a lower blade body (148) in the shape of a rectangular parallelepiped that is long and thin overall, a lower blade (147) having a blade that is inclined only on the y-direction surface, which is the front surface of the lower blade body (148), and a cutting portion (149B) is provided only on the y-direction surface, which is the rear surface of the lower blade (147). The width of the lower blade (147) in the -z direction, which is perpendicular to the blade length direction, may be smaller than the width of the upper blade first blade (145A) or the upper blade second blade (145B) in the z direction, which is perpendicular to the blade length direction.

[0070] Although not shown in the drawing, unlike the cut portions (149A, 149B) according to FIGS. 6 and 7, the cut portion may be provided only on a portion of the upper coating (142) and / or the lower coating (146). Specifically, the cut portion may be provided only on a portion of the rear surface of the upper coating first blade (145A) and the upper coating second blade (145B), and the rear surface of the lower coating blade (147). In a first example, the cut portion may be provided only on a portion along the blade length direction among the rear surfaces of the upper coating first blade (145A) and the upper coating second blade (145B). In a second example, the cut portion may be provided only on a portion along the direction perpendicular to the blade length direction among the rear surfaces of the upper coating first blade (145A) and the upper coating second blade (145B). In the third example, the first upper blade (145A) and the second upper blade (145B) may be provided only in a part along the rear blade length direction and in a part along the direction perpendicular to the blade length direction of the first upper blade (145A) and the second upper blade (145B). Since the lower blade (146) must be engaged with the upper blade (142), in all three cases above, the cut portion is provided only in a part of the three cases so that the lower blade (146) fits thereto.

[0071] The cut portions (149A, 149B) according to FIGS. 6 and 7 are specifically provided along the entire length direction of the upper first blade (145A), the upper second blade (145B), and the rear blade (148) and along the direction perpendicular to the length direction of the upper first blade (145A), the upper second blade (145B), and the lower blade (148). That is, in the case of FIGS. 6 and 7, the upper first blade (145A) and the upper second blade (145B) are formed, and the cut portions (149A, 149B) are provided in all of the corresponding portions.

[0072] The back surface of the upper and lower surfaces contact each other to cut the electrode, so the first upper blade, the second upper blade, and the lower blade may not be essential components. In addition, the shape of the upper blade body slanting upward in the z direction inside the rectangular parallelepiped may not be an essential component. However, considering the actual gap between the upper and lower blades, the stress applied to the cut portion, the discharge of the cut portion, etc., if the first upper blade, the second upper blade, and the lower blade are provided with an inclined shape and an inclined surface, the cutting may be more efficient.

[0073] That is, unlike FIGS. 6 and 7, the first upper and second upper blades may be provided in a form in which there is no inclined portion along the x-axis direction, no inclined portion along the z-axis direction, or no inclined portion along the x-axis direction and no inclined portion along the z-axis direction (not shown in the drawing). The lower blade may also have no inclined portion. If the 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 back surfaces of the upper and lower blades are in contact, the cutting portions should be arranged closer by the size of the intersection. If the cutting portions are provided only on the upper or lower blades, they are arranged in the same way as the conventional case in which the back surfaces of the upper and lower blades are in contact.

[0074] FIG. 8 is a front view (a), a side view (b), a bottom view (c) of the rear surface of the upper part (142) according to the first embodiment of the present invention, and an enlarged view of the cut portion (149A). As a specific example, the length in the x direction, which is the blade length direction of the upper part (142), may be 400 mm, and the length in the z direction, which is the height, may be 100 mm. The cut portion (149A) of the upper part and the cut portion (149B) of the lower part are interlocked with each other, and the interval and angle of the zigzag are the same, and when the upper part (142) and the lower part (146) come into contact, they should be interlocked with each other. As an example of the cut portion (149A), the interval (P) of the zigzag is 5.5 mm, and the angle (θ) is 90 degrees.

[0075] Although the embodiments according to the present invention only show the same zigzag shape, it is not limited thereto. In addition, although Fig. 1 shows a prior art for a negative electrode, the electrode cutter according to the present invention can be applied to all of a negative electrode, a positive electrode, and a current collector. The negative electrode and positive electrode referred to here specifically refer to a negative electrode active material and a positive electrode active material. Even if a desorbed substance is generated, since the size of the separator is larger than the electrode active material layer, desorbed substances below a certain size do not affect a short circuit defect or bridge generation. The present invention takes this into consideration and configures the cutting part in a zigzag shape to limit the size of the desorbed substance that may be generated.

[0076] The size of the detached material generated during actual cutting, or more precisely, the length of the detached material, is determined by the length of a line segment in the zigzag shape of the cut section. The line segment referred to here refers to a line segment when the zigzag shape is a polygon, and when the zigzag shape is a curve, it refers to the length between the parts where the curve shape sharply bends.

[0077] To prevent short circuits, etc., the length of one line segment of the zigzag shape of the cut section is 3 mm or less, preferably 2 mm or less. However, in order to form a zigzag shape, the angle (θ) must be less than 180 degrees. As the angle (θ) approaches 0, the width of the entire zigzag shape increases, so more active material is discarded by the cut section. Considering only this point, it is desirable to make the angle (θ) large, but a problem may occur in which the detached material is not cut but connected due to the viscosity of the active material, the gap between the upper and lower layers, etc. Therefore, in actual application, it is necessary to configure it to be less than 180 degrees.

[0078] Considering these points, it can be seen that the zigzag shape does not require the lengths and angles of the line segments to be the same, and that the purpose of the present invention can be achieved simply by forming the zigzag shape. Referring to the zigzag shape presented as an example in the present invention and the above description, a person skilled in the art can easily understand that not only the zigzag in the form of a kind of triangular wave as exemplified in the drawing, but also the zigzag in the form of other polygonal wave shapes, and even the zigzag in the form of a curved wave shape, are possible.

[0079] Fig. 9 is a schematic diagram of a top view (242) of a cutter according to a second embodiment of the present invention. The top view (242) according to Fig. 9 has a form in which a cutting portion (249A) is provided on the entire top view body without distinction between the front and back. In the case of such a top view (242), the bottom view must also have a corresponding form, so it has a form similar to the top view (242). Although the zigzag form of Fig. 9 is depicted larger than that of Fig. 8, this is only an example, and the zigzag form is preferably the same size as described in Fig. 8, and the form can also be modified as described in Fig. 8.

[0080] Since the electrode is cut in a zigzag shape at the cutting portion, it is desirable to limit the length of one end of the zigzag shape so that the maximum size of the detached material does not exceed the thickness of the electrode. However, since the cutting shape is a zigzag shape, even if the length of one end of the zigzag shape is greater than the electrode thickness, the detached material does not grow in a straight line due to the zigzag shape, or the detached material is easily broken again after cutting due to the zigzag shape, so the length becomes shorter. Therefore, the length of one end of the zigzag shape is not necessarily limited only by the thickness of the electrode.

[0081] Fig. 10 is a schematic diagram of a negative electrode (110A) when using a cutter according to the present invention. Fig. 10 (a) shows that the left and right sides of the surface from which the negative electrode tab protrudes are cut in a zigzag shape, and (b) is a drawing for comparison when a positive electrode (120A) is laminated on the negative electrode (110A). The zigzag shape is schematically shown to be somewhat exaggerated compared to the actual proportions. When the negative electrode is larger than the positive electrode, when cutting both sides of the negative electrode in a zigzag shape, it is preferable that the minimum width of the zigzag-cut portion be larger than that of the positive electrode. This is to reduce the probability of the negative electrode and the positive electrode coming into contact even if a detached substance is generated.

[0082] As described in Fig. 8, the length of one line segment of the zigzag shape of the cut section of the negative electrode according to Fig. 10 is 3 mm or less, preferably 2 mm or less. Fig. 10 shows that the angle formed by the zigzag shape is 90 degrees as in Fig. 8, but is not limited thereto. However, in order to form a zigzag shape, the angle must be less than 180 degrees. As the angle approaches 0, the width of the entire zigzag shape increases, so that more active material is discarded by the cut section. Considering only this point, it is preferable to make the angle (θ) large. However, a problem may occur in which the desorbed material is not cut but connected due to the viscosity of the active material, the gap between the upper and lower layers, etc., and therefore, in actual application, it is necessary to configure it to be less than 180 degrees. Fig. 11 is a schematic diagram of an electrode assembly (100B) in which electrodes are laminated according to the present invention. Referring to Fig. 11, the electrode assembly (100B) is one example of three positive electrodes (20A), two negative electrodes (110A), and five separators (30), and the shape of the electrode assembly is not limited thereto. The length of the thin and long detached material (12A) attached to the negative electrode (110A) like a thread is significantly reduced compared to the detached material (12) of the electrode assembly according to the prior art (see Fig. 5). As a result, a short circuit defect where the negative electrode and the positive electrode come into contact or a bridge defect where the negative electrode and the positive electrode are connected, which may occur in the conventional electrode assembly (100A), can be prevented or reduced.

[0083] Anyone with ordinary knowledge in the field to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

[0084] (Explanation of symbols)

[0085] 100: Electrode lamination device

[0086] 100A, 100B: Electrode assembly

[0087] 10: Central electrode

[0088] 10A, 110A: Negative

[0089] 12, 12A: Desorbed substances

[0090] 20: Upper and lower electrodes

[0091] 20A, 120A: Positive

[0092] 30: Membrane

[0093] 40: First cutter

[0094] 50: Second cutter

[0095] 60: Laminated section

[0096] 70: Third cutter

[0097] 42, 142, 242: Sangdo

[0098] 43, 143: Central part of Sangdo-nal

[0099] 44, 144: Main body of the Sangdo

[0100] 45A, 145A: First day of the Sangdo

[0101] 45B, 145B: Second day of the Sangdo

[0102] 46, 146: Hado

[0103] 147: Hadonal

[0104] 48, 148: Body of the lower body

[0105] 149A, 149B, 249A: Cut-off

[0106] P: Zigzag spacing

[0107] θ: angle

Claims

1. In an electrode cutter including an upper and lower cut for electrode cutting, An electrode cutter comprising a zigzag-shaped cutting portion along the blade length direction on at least one of the upper surface and the lower surface, which cut the electrode by contacting each other with the upper surface and the lower surface.

2. In paragraph 1, The back surface of the upper surface and the back surface of the lower surface contact each other to cut the electrode, The above-mentioned cutting part is an electrode cutter provided on at least one of the rear surface of the upper surface and the rear surface of the lower surface.

3. In paragraph 2, An electrode cutter having a cutting portion provided on the rear surface of the upper surface and the rear surface of the lower surface.

4. In paragraph 2, An electrode cutter in which the cutting portion is provided only in a portion along the blade length direction of the upper and / or lower surfaces.

5. In paragraph 2, An electrode cutter in which the cutting portion is provided only in a portion along a direction perpendicular to the blade length direction of the upper and / or lower blades.

6. In paragraph 1 An electrode cutter in which the cutting portion is provided on the upper and lower surfaces, and the cutting portion is arranged on the entire upper and lower surfaces.

7. In paragraph 1 The above zigzag shape is an electrode cutter having at least one of a triangular waveform shape, a polygonal waveform shape having a square or larger shape, and a curved waveform shape.

8. In paragraph 1 The above zigzag shape is an electrode cutter in which the same shape is repeated or in which different shapes are continued.

9. In paragraph 1 An electrode cutter in which the length of one line segment of the zigzag shape is 3 mm or less.

10. In paragraph 1, The above diagram is, The main body of the upper body is a rectangular prism with a long overall length and thin thickness; Including, The above cutting part is an electrode cutter provided on the rear side of the above body.

11. In paragraph 1, The above diagram is, The upper body is in the shape of a rectangular solid with a long length and thin thickness, and the lower part is symmetrically inclined upward toward the inside of the rectangular solid in the direction of the blade length; The first and second blades of the upper blade are arranged symmetrically in the center of the lower blade length of the upper blade body, and the blades are provided with an upwardly inclined shape only on the front surface of the upper blade body; Including, The above-mentioned cutting part is an electrode cutter provided on the rear surface of the first upper surface blade and the second upper surface blade.

12. In paragraph 1, The above is, The lower body is a rectangular body with a long length and thin thickness; Including, The above cutting part is an electrode cutter provided on the rear side of the lower body.

13. In paragraph 1, The above is, The lower body is a rectangular body with a long length and thin thickness; A lower blade having an upwardly inclined blade provided only on the front of the upper body; Including, The above cutting part is an electrode cutter provided on the rear side of the above-mentioned lower blade.

14. In paragraph 1, An electrode cutter further comprising a delamination removal unit for removing delamination and / or burrs generated during the above electrode cutting.

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

16. An electrode manufactured by the method according to Article 15.

17. An electrode assembly comprising an electrode according to Article 16.

18. In an electrode assembly formed by laminating electrodes and separators, An electrode assembly in which at least one of the above electrodes has a zigzag shape on at least one side other than the electrode tab protrusion.

19. In paragraph 18, An electrode assembly in which the length of one line segment of the zigzag shape is 3 mm or less.

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