Sheet cutting and fusing device

Abstract

A sheet cutting and fusing device includes: an upper cutter arranged at the uppermost surfaces of at least two sheets overlapping each other; a lower cutter arranged at the lowermost surface of the sheet, wherein the upper cutter includes: a first cutting surface that contacts the lower cutter without any step when the upper cutter moves vertically; a first fusing portion consisting of a surface parallel to the first cutting surface in a state where a first step is formed to extend from the first cutting surface; a lower surface facing the sheet; a first connecting portion consisting of a curved surface connecting the lower surface and the first fusing portion to each other, and the lower cutter includes: a second cutting surface that contacts the upper cutter without any step when the lower cutter moves vertically; a second fusing portion consisting of a surface parallel to the second cutting surface in a state where a second step is formed to extend from the second cutting surface; an upper surface facing the sheet; and a second connecting portion consisting of a curved angle connecting the upper surface and the second fusing portion to each other.

Description

Technical Field

[0001] This application claims priority from Korean Patent Application No. 2021-0016767, filed on February 5, 2021, which is hereby incorporated by reference in its entirety.

[0002] The present invention relates to a sheet material cutting and fusing device, and more particularly, to a sheet material cutting and fusing device including a structure forming steps at an upper cutter and a lower cutter, so that two or more sheets can be cut and fused simultaneously. Background Art

[0003] A lithium secondary battery may be manufactured using a method of housing an electrode assembly configured to have a structure in which a positive electrode, a sheet, and a negative electrode are sequentially stacked in a battery case and hermetically sealing the battery case.

[0004] The sheet cutting and fusing device according to the present invention can be applied to any sheet material, as long as the sheet material is thin, such as a separator used in a battery, and is configured so that a portion of one sheet material and a portion of another sheet material can be melted and coupled to each other. Throughout this specification, when a sheet material is described as being applied to a battery, the sheet material refers to a commonly used separator material.

[0005] The electrode assembly includes a monopolar battery configured to have a structure in which a first electrode and a sheet are stacked, a single cell configured to have a structure in which a first electrode, a sheet, and a second electrode are stacked, or a bicell configured to have a structure in which a first electrode, a sheet, a second electrode, a sheet, and a third electrode are stacked. In addition, a sheet may be further added to the outer surface of the first electrode or the second electrode of the monocell, or a sheet may be further added to the outer surface of the first electrode or the third electrode of the bicell.

[0006] Each electrode constituting the electrode assembly is manufactured by applying the electrode mixture to one surface or opposite surfaces of a thin current collector made of copper, aluminum, or nickel, drying and pressing it, and cutting it into unit electrodes.

[0007] The unit electrodes thus manufactured are stacked and laminated in a state where the sheets are interposed between the positive electrode and the negative electrode, thereby manufacturing a unit cell.

[0008] In the single cell, the sheet is placed between the first electrode and the second electrode, and another sheet is located at a surface opposite to the surface of the first electrode or the second electrode that faces the sheet.

[0009] In order to manufacture a unit cell configured to stack two electrodes and two sheets or a unit cell configured to stack two electrodes and two or three sheets, as described above, a first sheet having a first electrode provided thereon and a second sheet having a second electrode provided thereon are arranged and laminated so that the first electrode and the second electrode overlap each other, and then the first sheet and the second sheet are cut.

[0010] After the first and second sheets are cut, they are moved to the next step of the process. When the first and second sheets are folded or deviated from their original positions, the electrodes may be exposed, which may cause serious safety-related problems such as short circuits in the battery cells and fires during use of the battery cells.

[0011] Related to this, Figure 1 is a schematic diagram of a conventional sheet cutting device. Figure 2 is a cross-sectional view showing a sheet cutting sequence performed by a conventional sheet cutting device, Figure 3 is a schematic diagram showing the configuration of an upper cutter and a lower cutter when a conventional sheet material cutting device is applied to two sheets.

[0012] Reference Figures 1 to 3 , the first electrode 10 is provided on an upper sheet, which is one of two sheets 30 overlapping each other, and the second electrode 20 is provided on a lower sheet.

[0013] An upper cutter 40 and a lower cutter 50 configured to cut the sheet are provided at the uppermost surface and the lowermost surface of the sheet 30 , respectively.

[0014] The upper cutter 40 includes a first cutting surface 43 configured to cut the sheet 30 while overlapping with the lower cutter 50, a lower surface 44 arranged parallel to and facing the sheet 30, and an inclined portion 45, which is a surface inclined relative to the sheet. The lower cutter 50 includes a second cutting surface 53 configured to cut the sheet 30 while overlapping with the upper cutter 40, and an upper surface 54 arranged parallel to and facing the sheet 30.

[0015] The upper cutter 40 is configured so that the lower surface 44 and the first cutting surface 43 are perpendicularly joined to each other, and the lower cutter 50 is configured so that the upper surface 54 and the second cutting surface 53 are perpendicularly joined to each other. Therefore, when the first cutting surface 43 and the second cutting surface 53 intersect each other, the sheet 30 is cut.

[0016] Therefore, when using Figures 1 to 3In the case of the sheet cutting device shown, the sheet can be cut; however, the sheet may be transferred to a subsequent process while the remaining portion of the sheet extending further than the outer periphery of the electrode is not fixed. In this case, the remaining portion of the sheet may be folded or the sheets may be separated from each other.

[0017] In this regard, Patent Document 1 discloses a pair of blades configured to rotate in opposite directions to cut a separator (sheet) on which electrodes are sequentially arranged at intervals. In Patent Document 1, the blades are configured to cut two sheets to manufacture a single cell or bicell including the two sheets; however, the blades only function to cut the sheets.

[0018] Patent Document 2 discloses a membrane (sheet) cutting device including a cutter member configured to cut a sheet and a heat transfer unit having a heating member configured to heat the cutter member, wherein the sheet is heated to its melting temperature or higher to cut the sheet.

[0019] Patent Document 2 melts the sheet material so that when the melted sheet material hardens, a smooth reinforcement portion is formed on the cut portion of the sheet material. However, Patent Document 2 discloses cutting of only a single sheet material. Therefore, there is no disclosure of a technique for preventing two or more sheets from being folded during transfer.

[0020] Patent Document 3 discloses a cutting machine configured to cut a membrane (sheet), wherein a first slitter and a second slitter configured to cut the sheet each include a heating portion so as to shrink a cut portion of the sheet.

[0021] In Patent Document 3, a heating unit is provided to shrink the cut portion of the sheet; however, a first slitting knife and a second slitting knife are used in the slitting process. That is, Patent Document 3 does not disclose a technique for preventing misalignment of two or more stacked sheets.

[0022] Therefore, there is a need for a technology that can prevent electrodes stacked on a sheet from being exposed due to folding of the sheet or change in the position of the sheet when the sheet is moved to a subsequent electrode manufacturing process in a cut state without changing the electrode manufacturing process.

[0023] (Prior art literature)

[0024] Korean Patent Publication No. 2169008 (October 16, 2020) (“Patent Document 1”)

[0025] Korean Patent Publication No. 2003471 (July 18, 2019) (“Patent Document 2”)

[0026] Korean Patent Publication No. 1608634 (March 29, 2016) (“Patent Document 3”) Summary of the Invention

[0027] Technical issues

[0028] The present invention has been made in view of the above problems, and an object of the present invention is to provide a sheet cutting and fusing device including a structure forming steps at an upper cutter and a lower cutter so that two or more sheets can be cut and fused simultaneously.

[0029] Another object of the present invention is to provide a sheet cutting and fusing device capable of simultaneously cutting and fusing sheets of unit cells so that when the sheets are transferred to a subsequent process in a cut state without increasing the number of electrode manufacturing steps, the sheets are kept stably fixed.

[0030] Technical Solution

[0031] The sheet cutting and fusing apparatus according to the present invention is applicable to any sheet as long as the sheet is thin, such as a separator used in a battery, and is configured so that a portion of one sheet and a portion of another sheet can be melted and coupled to each other.

[0032] To achieve the above-mentioned object, the present invention provides a sheet cutting and fusing device comprising: an upper cutter provided at the uppermost surfaces of at least two sheets overlapping each other; and a lower cutter provided at the lowermost surfaces of the sheets, wherein the upper cutter includes a first cutting surface configured to contact the lower cutter without any step when the upper cutter moves vertically; a first fusing portion constituted by a surface parallel to the first cutting surface in a state in which a first step is formed to extend from the first cutting surface; a lower surface configured to face the sheets; and a first connecting portion constituted by a curved surface connecting the lower surface and the first fusing portion to each other, and

[0033] The lower cutter includes a second cutting surface configured to contact the upper cutter without any step when the lower cutter moves vertically; a second fusion portion composed of a surface parallel to the second cutting surface in a state in which a second step is formed to extend from the second cutting surface; an upper surface configured to face the sheet; and a second connecting portion composed of a curved surface connecting the upper surface and the second fusion portion to each other.

[0034] Each of the upper cutter and the lower cutter may include a structure capable of being heated.

[0035] The upper cutter and / or the lower cutter may move so that the first cutting surface and the second cutting surface contact each other without any step, and may cut the sheet due to compression, shear force, or melting caused by the intersection between the first cutting surface and the second cutting surface.

[0036] Alternatively, the upper cutter and / or the lower cutter may move so that the first cutting surface and the second cutting surface overlap each other, and the sheet may be cut due to compression, shear force, or melting of the first and second fused portions.

[0037] Alternatively, the upper cutter and / or the lower cutter may move so that the first cutting surface and the second cutting surface overlap each other, and the sheet may be cut due to compression, shear force, or melting of the first step and the second step.

[0038] When the sheet is disposed at any one of between the first cut surface and the second cut surface, between the first fusion portion and the second fusion portion, and between the first step and the second step, the sheet may be fused.

[0039] The first cut surface, the first fusion portion, the second cut surface, and the second fusion portion may have the same temperature, and the temperature thereof may be lower than that of the first step and the second step.

[0040] The upper cutter may be disposed at an uppermost surface of the sheet, the lower cutter may be disposed at a lowermost surface of the sheet, and a lower surface of the upper cutter and an upper surface of the lower cutter may be disposed parallel to the sheet.

[0041] Alternatively, the upper cutter may be provided at the uppermost surface of the sheet, the lower cutter may be provided at the lowermost surface of the sheet, and the lower surface of the upper cutter and the upper surface of the lower cutter may be provided obliquely with respect to the sheet.

[0042] The sheet may include a first sheet and a second sheet stacked with an electrode placed between the first sheet and the second sheet, and the stacked electrodes and other stacked electrodes may be arranged at a predetermined distance from each other, and the predetermined distance may be greater than the sum of the length from the first connecting portion to the first cutting surface and the length from the second connecting portion to the second cutting surface.

[0043] The height of each of the first step and the second step may be equal to or smaller than the thickness of at least two sheets overlapping each other.

[0044] In addition, the present invention provides a unit cell manufactured by cutting a sheet using a sheet cutting and fusing device, wherein the unit cell is a single cell or a bicell, the single cell is configured so that a sheet, a first electrode, a sheet, and a second electrode are stacked, the bicell is configured so that a first electrode, a sheet, a second electrode, a sheet, and a third electrode are stacked, and the sheets whose unidirectional outer peripheries are parallel to each other in each of the single cell and the bicell are thermally fused.

[0045] In addition, the present invention can provide various combinations of the above-mentioned solutions.

[0046] Beneficial effects

[0047] As apparent from the above description, the sheet cutting and fusing apparatus according to the present invention can cut at least two sheets overlapping each other and fuse the peripheries of the sheets, thereby preventing the sheets from being folded or wrinkled during transfer.

[0048] Furthermore, in order to simultaneously cut and fuse the sheet, the structure of each of the upper cutter and the lower cutter configured to cut the sheet may be changed, so that the sheet can be simultaneously cut and fused by signal processing.

[0049] Therefore, no separate device or space is required for sheet fusing.

[0050] In addition, when the stepped surfaces of the upper and lower cutters abut each other, the sheet can be melted and cut. In this case, the need to manage the parallelism tolerance of the upper and lower cutters can be reduced, and the replacement cycle of the upper and lower cutters due to wear of the upper and lower cutters can be extended, thereby making it easier to manage the manufacturing process.

[0051] Furthermore, since the number of stops in the manufacturing process can be reduced, production yields can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 is a schematic diagram of a conventional sheet cutting device.

[0053] Figure 2 are cross-sectional views illustrating a sheet cutting sequence performed by a conventional sheet cutting device.

[0054] Figure 3 is a schematic diagram showing the structures of an upper cutter and a lower cutter when a conventional sheet material cutting device is applied to two sheets.

[0055] Figure 4 1 is a diagram showing a sheet cutting and fusing apparatus according to a first embodiment of the present invention.

[0056] Figure 52 is a view showing a sheet cutting and fusing apparatus according to a second embodiment of the present invention.

[0057] Figure 6 1 and 2 are views illustrating a process of cutting and fusing a sheet using the sheet cutting and fusing apparatus according to the second embodiment of the present invention.

[0058] Figure 7 1 and 2 are views illustrating a process of cutting and fusing a sheet using the sheet cutting and fusing apparatus according to the third embodiment of the present invention.

[0059] Figure 8 is a view showing a unit cell manufactured using the sheet cutting and fusing apparatus according to the present invention. DETAILED DESCRIPTION

[0060] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, when describing the operating principles of the preferred embodiments of the present invention in detail, detailed descriptions of known functions and configurations contained herein will be omitted when they may obscure the subject matter of the present invention.

[0061] In addition, the same reference numerals are used throughout the drawings to represent components that perform similar functions or operations. When a component is said to be connected to another component throughout the specification, not only can the component be directly connected to the other component, but the component can also be indirectly connected to the other component via the other component. In addition, the inclusion of a certain element does not mean the exclusion of other elements, but rather means that these elements may be further included unless otherwise specified.

[0062] In addition, unless otherwise limited, the description embodying elements by limitation or addition can be applied to all inventions and does not limit a specific invention.

[0063] Furthermore, in the present disclosure and claims, the singular form is intended to include the plural form unless otherwise stated.

[0064] In addition, in the invention content and claims of this application, unless otherwise stated, "or" includes "and". Therefore, "including A or B" refers to three cases, namely, the case including A, the case including B, and the case including A and B.

[0065] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0066] Figures 4 to 8 An embodiment of the sheet cutting and fusing apparatus according to the present invention is shown. Figures 4 to 8In the invention, a sheet material for a battery, namely a separator, is described by way of example. However, the sheet material cutting and fusing apparatus according to the present invention is applicable to any sheet material as long as the sheet material is thin and configured so that a portion of one sheet material and a portion of another sheet material can be melted and coupled to each other.

[0067] Reference Figure 4 The first electrodes 10 are arranged at a predetermined distance W from each other on the upper surface of the upper sheet 30, which is one of the sheets overlapping each other, and the second electrodes 20 are arranged at a predetermined distance W from each other on the upper surface of the lower sheet 30, which is another of the sheets overlapping each other.

[0068] The first electrode 10 and the second electrode 20 pass through a sheet cutting and fusing device composed of an upper cutter 100 and a lower cutter 200 arranged in a state of completely overlapping each other in the Y-axis direction (i.e., the stacking direction), whereby the two sheets 30 overlapping each other can be cut while the outer peripheries of the sheets 30 are adhered to each other by heat fusion.

[0069] Specifically, the sheet cutting and fusing device according to the first embodiment includes an upper cutter 100 and a lower cutter 200, the upper cutter 100 is arranged at the uppermost surface of at least two sheets 30 overlapping each other, and the lower cutter 200 is arranged at the lowermost surface of the sheet 30, wherein the upper cutter 100 includes: a first cutting surface 130, which is configured to contact the lower cutter 200 without any step when the upper cutter moves vertically; a first fusion portion 120, which is composed of a surface parallel to the first cutting surface 130 in a state where a first step 110 is formed to extend from the first cutting surface 130; a lower surface 140, which is configured to face the sheet 30; and a first connecting portion 150, which is a curved surface connecting the lower surface 140 and the first fusion portion 120 to each other.

[0070] The lower cutter 200 includes: a second cutting surface 230, which is configured to contact the upper cutter 100 without any step when the lower cutter moves vertically; a second fusion portion 220, which is composed of a surface parallel to the second cutting surface 230 in a state where a second step 210 is formed to extend from the second cutting surface 230; an upper surface 240, which is configured to face the sheet 30; and a second connecting portion 250, which is a curved surface connecting the upper surface 240 and the second fusion portion 220 to each other.

[0071] The sheet cutting and fusing apparatus according to the present invention simultaneously performs the process of cutting the sheet and the process of heat-fusing the outer periphery of the sheet. Specifically, each of the first connecting portion 150 connecting the first fusion portion 120 and the lower surface 140 of the first cutting surface 130 and the second connecting portion 250 connecting the second fusion portion 220 and the upper surface 240 of the second cutting surface 230 is formed into a curved shape.

[0072] In addition, a step is formed between the first cut surface 130 and the first fusion portion 120 , a step is formed between the second cut surface 230 and the second fusion portion 220 , and the first cut surface 130 and the second cut surface 230 are moved so as not to overlap each other.

[0073] Therefore, even if the lowermost end of the upper cutter and the uppermost end of the lower cutter intersect to be adjacent to each other, the sheet is not cut because an empty space is formed therebetween.

[0074] Additionally, each of the upper cutter and the lower cutter includes a structure capable of being heated.

[0075] That is, each of the upper cutter and the lower cutter may be configured so that the temperature thereof may be raised to a temperature at which the sheet is melted.

[0076] When the sheet is cut using the upper and lower cutters, the temperature of each cutter has risen to the sheet melting temperature, and sheet bonding portions where the melted sheets are attached to each other are formed on opposite sides of the cut line.

[0077] The upper cutter 100 and / or the lower cutter 200 may move so that the first cutting surface 130 and the second cutting surface 230 contact each other without any step, and the sheet 30 may be cut due to compression, shear force or melting of the intersection therebetween.

[0078] Figure 4 The sheet cutting and fusing device shown is configured so that when the upper cutter 100 is set at the upper surface of one of the sheets 30 and the lower cutter 200 is set at the lower surface of another one of the sheets 30, the lower surface 140 of the upper cutter 100 and the upper surface 240 of the lower cutter 200 are set parallel to the sheet 30.

[0079] Therefore, the electrode and the sheet 30 moving between the upper cutter 100 and the lower cutter 200 can be supported thereunder.

[0080] Figure 5 2 is a view showing a sheet cutting and fusing apparatus according to a second embodiment of the present invention.

[0081] Reference Figure 5, the first electrodes 10 are arranged at a predetermined distance W from each other on the upper surface of the upper sheet 30, which is one of the sheets overlapping each other, and the second electrodes 20 are arranged at a predetermined distance W from each other on the upper surface of the lower sheet 30, which is another of the sheets overlapping each other.

[0082] The first electrode 10 and the second electrode 20 pass through a sheet cutting and fusing device composed of an upper cutter 300 and a lower cutter 400 arranged to completely overlap each other in the Y-axis direction (i.e., the stacking direction), whereby the two sheets 30 overlapping each other can be cut while the outer peripheries of the sheets 30 are adhered to each other by heat fusion.

[0083] Specifically, the sheet cutting and fusing device according to the second embodiment includes an upper cutter 300 and a lower cutter 400, the upper cutter 300 is arranged at the uppermost surface of at least two sheets 30 overlapping each other, and the lower cutter 400 is arranged at the lowermost surface of the sheet 30, wherein the upper cutter 300 includes: a first cutting surface 330, which is configured to contact the lower cutter 400 without any step when the upper cutter moves vertically; a first fusion portion 320, which is composed of a surface parallel to the first cutting surface 330 in a state where the first step 310 is formed to extend from the first cutting surface 330; and a first connecting portion 350, which is a curved surface connecting the lower surface 340 and the first fusion portion 320 to each other.

[0084] The lower cutter 400 includes: a second cutting surface 430, which is configured to contact the upper cutter 300 without any step when the lower cutter moves vertically; a second fusion portion 420, which is composed of a surface parallel to the second cutting surface 430 in a state where the second step 410 is formed to extend from the second cutting surface 430; an upper surface 440, which is configured to face the sheet 30; and a second connecting portion 450, which is a curved surface connecting the upper surface 440 and the second fusion portion 420 to each other.

[0085] The sheet cutting and fusing apparatus according to the present invention simultaneously performs the process of cutting the sheet and the process of heat-fusing the outer periphery of the sheet. Specifically, each of the first connection portion 350 connecting the first fusion portion 320 and the lower surface 340 of the first cutting surface 330 and the second connection portion 450 connecting the second fusion portion 420 and the upper surface 440 of the second cutting surface 430 is formed into a curved shape.

[0086] In addition, a step is formed between the first cut surface 330 and the first fusion portion 320 , a step is formed between the second cut surface 430 and the second fusion portion 420 , and the first cut surface 330 and the second cut surface 430 are moved so as not to overlap each other.

[0087] Therefore, even if the lowermost end of the upper cutter and the uppermost end of the lower cutter intersect to be adjacent to each other, the sheet is not cut because an empty space is formed therebetween.

[0088] Additionally, each of the upper cutter and the lower cutter includes a structure capable of being heated.

[0089] That is, each of the upper cutter and the lower cutter may be configured so that the temperature thereof may be raised to a temperature at which the sheet is melted.

[0090] When the sheet is cut using the upper and lower cutters, the temperature of each cutter has risen to the sheet melting temperature, and sheet bonding portions where the melted sheets are attached to each other are formed on opposite sides of the cut line.

[0091] Figure 5 The sheet cutting and fusing device shown is configured so that when the upper cutter 300 is set at the upper surface of one of the sheets 30 and the lower cutter 400 is set at the lower surface of another one of the sheets 30, the lower surface 340 of the upper cutter 300 and the upper surface 440 of the lower cutter 400 are set at an inclination relative to the sheet 30.

[0092] Figure 6 1 and 2 are views illustrating a process of cutting and fusing a sheet using the sheet cutting and fusing apparatus according to the second embodiment of the present invention.

[0093] Reference Figure 6 When the sheet 30 is placed in an overlapping state between the first cutting surface 330 and the second fusion portion 420 and between the second cutting surface 430 and the first fusion portion 320 , the heated upper cutter 300 and the lower cutter 400 melt the sheet, thereby forming the heat fusion portion 370 .

[0094] The upper cutter 300 moves downward so that the first cutting surface 330 and the second cutting surface 430 face each other in close contact, and the sheets are melted and adhered to each other before the first cutting surface 330 and the second cutting surface 430 intersect. When the first cutting surface 330 and the second cutting surface 430 intersect each other, particularly when the first corner 360 and the second corner 460 abut each other, the sheet 30 is cut.

[0095] Therefore, the two sheets are cut in a state where the outer peripheries of the sheets are coupled to each other by heat fusion while the sheets are overlapped with each other.

[0096] Taking into account the fact that the two sheets are attached to each other in a state of close contact between the first cutting surface of the upper cutter and the second fusion portion of the lower cutter, and between the first fusion portion of the upper cutter and the second cutting surface of the lower cutter, the height H of each of the first step 310 and the second step 410 can be equal to or less than the thickness of at least two sheets overlapping each other.

[0097] Also refer to Figure 5 and Figure 6 The sheet material includes a first sheet and a second sheet stacked with an electrode interposed therebetween, the electrodes being spaced apart by a predetermined distance W, and the distance W being greater than the sum of the length from the first connection portion 350 to the first cutting surface 330 and the length from the second connection portion 450 to the second cutting surface 430. When the distance W between the electrodes is set, as described above, when the upper cutter and the lower cutter intersect each other, the electrodes are not pressed, thereby preventing damage to the electrodes. In addition, the electrodes do not need to be disposed at the first connection portion and the second connection portion, thereby preventing the electrodes from being separated from the sheet material.

[0098] Figure 7 1 and 2 are views illustrating a process of cutting and fusing a sheet using the sheet cutting and fusing apparatus according to the third embodiment of the present invention.

[0099] Reference Figure 7 , the upper cutter 500 moves downward so that the first cutting surface 530 of the upper cutter 500 and the second cutting surface 630 of the lower cutter 600 overlap with each other, the first cutting surface 530 of the upper cutter 500 and the second cutting surface 630 of the lower cutter 600 do not intersect with each other, and the upper cutter moves downward until the first step 510 is in close contact with the second step 610 with the sheet located therebetween.

[0100] The two sheets 30 are attached in close contact with each other between the first cutting surface 530 of the upper cutter and the second fusion bond 620 of the lower cutter and between the first fusion bond 520 of the upper cutter and the second cutting surface 630 of the lower cutter, thereby forming the heat fusion bond 370 .

[0101] When the upper cutter 500 moves further downward and thus at least a portion of the first step 510 and at least a portion of the second step 610 face each other to be in close contact with each other, the sheet 30 is cut.

[0102] In the case of Figure 7In the sheet cutting and fusing apparatus of the structure shown, the sheet 30 can be cut due to compression, shearing force, or melting of the first step 510 and the second step 610. Therefore, even if a sharp structure such as a cutter is not provided at each of the first step 510 and the second step 610, a smooth cut portion can be formed after the cut portion of the sheet is cooled.

[0103] The first cutting surface 530, the first fusion portion 520, the second cutting surface 630, and the second fusion portion 620 may have the same temperature, and the temperatures of the first cutting surface 530, the first fusion portion 520, the second cutting surface 630, and the second fusion portion 620 may be lower than the temperatures of the first step 510 and the second step 610, so that the sheets are melted and separated from each other at the first step 510 and the second step 610, and as described above, the materials that are in close contact with each other between the first cutting surface 530 and the second fusion portion 620 and between the second cutting surface 630 and the first fusion portion 520 are melted and adhered to each other.

[0104] For example, the sheet material according to the present invention may be a sheet material comprising a polyolefin-based material. As another example, the sheet material may include a substrate made of a polyolefin-based material (including polyethylene and polypropylene), and an inorganic coating layer formed on one surface or opposite surfaces of the substrate. The inorganic coating layer may be composed of a mixture of an inorganic material capable of improving heat resistance and a binder configured to bind particles of the inorganic material.

[0105] For example, the temperatures of the first cutting surface 530 , the first fusion bond 520 , the second cutting surface 630 , and the second fusion bond 620 may be set to a range of 80° C. to 150° C., and the temperatures of the first step 510 and the second step 610 may be set to a range of 160° C. to 200° C.

[0106] The upper cutter 500 and / or the lower cutter 600 may move so that the first cutting surface 530 and the second cutting surface 630 overlap each other, and the sheet may be fused or cut due to compression, shear force, or melting of the first and second fusion bonds 520 and 620 .

[0107] In use Figures 4 to 7 With any one of the sheet cutting and fusing apparatuses shown in , the sheet can be fused when the sheet is disposed at any one of between the first cutting surface and the second cutting surface, between the first fusion portion and the second fusion portion, and between the first step and the second step.

[0108] When the upper cutter 100, 300, or 500 and the lower cutter 200, 400, or 600 of the sheet cutting and fusing apparatus according to the present invention are continuously used, the edges of the first step 110, 310, or 510, the first cutting surface 130, 330, or 530, the second step 210, 410, or 610, and the second cutting surface 230, 430, or 630 may become dull. In the case where the edges are slightly worn, only the first step 110, 310, or 510, the first cutting surface 130, 330, or 530, the second step 210, 410, or 610, and the second cutting surface 230, 430, or 630 may be reworked. When the sizes of the first step 110, 310 or 510 and the second step 210, 410 or 610 are reduced, thereby not simultaneously performing the cutting and fusing according to the present invention, the lower surface 140 or 340, the first connecting portion 150, 350 or 550, the upper surface 240 or 440 and the second connecting portion 250, 450 or 650 are also processed.

[0109] Figure 8 is a view showing a unit cell manufactured using the sheet cutting and fusing apparatus according to the present invention.

[0110] Reference Figure 8 The unit cell is a bicell configured such that the first electrode 10, the sheet 30, the second electrode 20, the sheet 30, and the first electrode 10 are stacked. The sheets of the bicell parallel to each other are heat-fused in one direction, thereby forming a heat-fused portion 370.

[0111] Therefore, when the bicell is transferred to a subsequent electrode manufacturing process, a state in which the sheets are stably attached to each other can be maintained, whereby a short circuit or the outbreak of fire due to exposure of the electrodes can be prevented.

[0112] Those skilled in the art to which the present invention pertains will appreciate that, based on the above description, various applications and modifications are possible within the scope of the present invention.

[0113] (Description of Reference Symbols)

[0114] 10: First electrode

[0115] 20: Second electrode

[0116] 30: Sheet

[0117] 40, 100, 300, 500: Upper cutter

[0118] 110, 310, 510: First step

[0119] 120, 320, 520: first fusion part

[0120] 43, 130, 330, 530: First cutting surface

[0121] 44, 140, 340: lower surface

[0122] 50, 350, 550: first connection part

[0123] 360: First Angle

[0124] 45: inclined portion

[0125] 50, 200, 400, 600: lower cutter

[0126] 210, 410, 610: Second step

[0127] 220, 420, 620: Second fusion zone

[0128] 53, 230, 430, 630: Second cutting surface

[0129] 54, 240, 440: upper surface

[0130] 250, 450, 650: Second connection part

[0131] 460: Second Corner

[0132] 370: Thermal fusion section

[0133] W: distance

Claims

1. A sheet cutting and fusing device comprising: an upper cutter disposed at the uppermost surfaces of at least two sheets overlapping each other; as well as A lower cutter, provided at the lowermost surface of the sheet, Wherein the upper cutter comprises: a first cutting surface configured to contact the lower cutter without any step when the upper cutter moves vertically; a first fusion portion formed of a surface extending from the first cutting surface to form a first step and parallel to the first cutting surface; a lower surface configured to face the sheet; and a first connecting portion composed of a curved surface connecting the lower surface and the first fusion portion to each other, Wherein the lower cutter comprises: a second cutting surface configured to contact the upper cutter without any step when the lower cutter moves vertically; a second fusion portion consisting of a surface extending from the second cut surface to form a second step and parallel to the second cut surface; an upper surface configured to face the sheet; and The second connecting portion is composed of a curved surface connecting the upper surface and the second fusion portion to each other. 2 . The sheet cutting and fusing apparatus according to claim 1 , wherein each of the upper cutter and the lower cutter comprises a structure capable of being heated.

3. The sheet cutting and fusing apparatus according to claim 1, wherein The upper cutter and / or the lower cutter moves so that the first cutting surface and the second cutting surface contact each other without any step, and The sheet is cut due to compression, shear force, or melting caused by the intersection between the first cutting surface and the second cutting surface.

4. The sheet cutting and fusing apparatus according to claim 1, wherein The upper cutter and / or the lower cutter moves so that the first cutting surface and the second cutting surface overlap each other, and The sheet is cut due to compression, shear force, or melting of the first and second fused portions.

5. The sheet cutting and fusing apparatus according to claim 1, wherein The upper cutter and / or the lower cutter moves so that the first cutting surface and the second cutting surface overlap each other, and The sheet is cut due to compression, shear force, or melting of the first and second steps. 6 . The sheet cutting and fusing device according to claim 1 , wherein the sheet is fused when the sheet is disposed at any one of between the first cutting surface and the second cutting surface, between the first fused portion and the second fused portion, and between the first step and the second step.

7. The sheet cutting and fusing apparatus according to claim 5, wherein The first cutting surface, the first fusion portion, the second cutting surface and the second fusion portion have the same temperature, and The same temperature is lower than the temperatures of the first step and the second step.

8. The sheet cutting and fusing apparatus according to claim 1, wherein The upper cutter is provided at the uppermost surface of the sheet, The lower cutter is provided at the lowermost surface of the sheet, and A lower surface of the upper cutter and an upper surface of the lower cutter are disposed parallel to the sheet.

9. The sheet cutting and fusing apparatus according to claim 1, wherein The upper cutter is provided at the uppermost surface of the sheet, The lower cutter is provided at the lowermost surface of the sheet, and A lower surface of the upper cutter and an upper surface of the lower cutter are disposed obliquely with respect to the sheet.

10. The sheet cutting and fusing apparatus according to claim 1, wherein The sheet includes a first sheet and a second sheet, the first sheet and the second sheet are stacked with an electrode interposed therebetween, The stacked electrodes and other stacked electrodes are spaced apart from each other by a predetermined distance, and The predetermined distance is greater than a sum of a length from the first connection portion to the first cutting surface and a length from the second connection portion to the second cutting surface. 11 . The sheet cutting and fusing apparatus according to claim 1 , wherein a height of each of the first step and the second step is equal to or smaller than a thickness of at least two sheets overlapped with each other.

12. A unit battery manufactured by cutting a sheet using the sheet cutting and fusing apparatus according to any one of claims 1 to 11, wherein The unit cell is a single cell configured such that a sheet, a first electrode, a sheet, and a second electrode are stacked, or a bicell configured such that a first electrode, a sheet, a second electrode, a sheet, and a third electrode are stacked, and The sheets of one-way outer periphery of each of the single cell and the bi-cell, which are parallel to each other, are heat-fused.

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