Sheet winding device for secondary battery manufacturing

Abstract

According to one embodiment of the present invention, there is provided a sheet winding device for manufacturing a secondary battery, which includes at least two bobbins including a running bobbin on which a winding process is performed and a standby bobbin that waits during the winding process, and a sensor disposed at a predetermined distance from the standby bobbin, the sensor detecting a mark for identifying a position where the sheet wound on the running bobbin is automatically attached to the standby bobbin. When the winding process on the running bobbin is completed, the sheet wound on the running bobbin is attached to the outer peripheral surface of the standby bobbin, and then the winding process is performed.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0142920, dated October 31, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an apparatus used in a winding process of a sheet for manufacturing a secondary battery, and more particularly to a sheet winding apparatus for manufacturing a secondary battery that automatically recognizes a position where an electrode sheet or a separator sheet is connected to a bobbin, thereby improving winding performance for the electrode sheet or the separator sheet. [Background technology]

[0003] Recently, with the depletion of fossil fuels causing rising energy prices and increasing concerns about environmental pollution, the demand for environmentally friendly alternative energy sources has become an essential factor for future life. As a result, research into various power generation technologies, such as nuclear, solar, wind, and tidal power, is ongoing, and there is also great interest in power storage devices to use the energy produced in this way more efficiently.

[0004] In particular, with the increasing technological development and demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing, and accordingly, much research is being conducted on secondary batteries that can meet various demands.

[0005] Demand for lithium secondary batteries, such as lithium ion batteries and lithium ion polymer batteries, which have advantages such as high energy density, discharge voltage, and output stability, is high.

[0006] The secondary battery may include a positive electrode and a negative electrode. The positive electrode comprises a positive electrode coated portion where a positive electrode active material is coated on a positive electrode current collector and a positive electrode uncoated portion where no positive electrode active material is coated. Similarly, the negative electrode comprises a negative electrode coated portion where a negative electrode active material is coated on a negative electrode current collector and a negative electrode uncoated portion where no negative electrode active material is coated. Electrode tabs are provided on the positive electrode uncoated portion and the negative electrode uncoated portion, respectively.

[0007] A porous separator is interposed between the positive and negative electrodes, which insulates the positive and negative electrodes from each other and allows active material ions to be exchanged between the electrodes, thereby causing an electrochemical reaction.

[0008] These secondary batteries can also be classified according to the structure of the electrode assembly, which includes a stack of positive and negative electrodes and a separator interposed between the positive and negative electrodes. Representative examples include a jelly-roll (wound) electrode assembly, in which long sheet-shaped positive and negative electrodes are wound up with a separator interposed between them, and a stacked (laminate) electrode assembly, in which multiple positive and negative electrodes cut into predetermined sizes are stacked in order with a separator interposed between them. Recently, to address the issues associated with the jelly-roll and stacked electrode assemblies, a stack / folding electrode assembly has been developed, which is a hybrid of the jelly-roll and stacked types, in which unit cells, each consisting of a predetermined number of positive and negative electrodes stacked with a separator interposed between them, are placed on a separator film and wound in order.

[0009] Meanwhile, each electrode constituting the electrode assembly is manufactured in a sheet form and provided to the secondary battery manufacturing process. Typically, the electrode sheet that has undergone the electrode manufacturing process is wound into a roll on a predetermined bobbin. The electrode sheet is wound around the bobbin while being supported by a final bobbin located at the front end of the bobbin.

[0010] Referring to FIG. 1 , in a conventional sheet winding device 1 for manufacturing secondary batteries, double-sided tape 30 is attached to a linear mark 20 on a bobbin 10 where the starting portion of an electrode sheet is to be attached. Furthermore, to ensure that the starting portion of the electrode sheet is accurately attached to the mark 20 on the bobbin 10, at least one of two mounting portions 40 on both sides of the bobbin 10 is provided with a convex dog 50 that guides the starting portion of the electrode sheet, and the dog 50 is positioned on an extension of the mark 20. An operator attaches the bobbin 10 to the sheet winding device 1 for manufacturing secondary batteries and rotates the dog 50 so that the mark 20 on the bobbin 10 is positioned in front of the operator. Furthermore, after aligning the starting portion of the electrode sheet with the mark 20, the operator manually attaches the electrode sheet to the double-sided tape 30 on the surface of the bobbin 10. The electrode sheet winding process then begins.

[0011] There is a demand for converting such a conventional manual sheet winding device 1 for manufacturing secondary batteries into an automated process to increase convenience and efficiency of the process. Summary of the Invention [Problem to be solved by the invention]

[0012] An object of the present invention is to provide a sheet winding device for secondary battery manufacturing that has a structure that can automatically recognize the attachment position of a sheet (electrode sheet or separator sheet) for secondary battery manufacturing on a bobbin used in the winding process of the sheet, automatically attach the sheet to the bobbin, and wind up the sheet.

[0013] Another object of the present invention is to use such a sheet winding device for manufacturing a secondary battery to increase the convenience and efficiency of the process while also reducing the defect rate of electrode winding rolls by attaching electrode rolls to accurate positions.

[0014] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0015] According to one embodiment of the present invention, a sheet winding device for manufacturing a secondary battery includes at least two bobbins including a running bobbin on which a winding process is performed and a standby bobbin that waits during the winding process, and a sensor disposed at a predetermined distance from the standby bobbin, the sensor detecting a mark for identifying a position where the sheet wound on the running bobbin is automatically attached to the standby bobbin. When the winding process on the running bobbin is completed, the sheet wound on the running bobbin may be attached to an outer peripheral surface of the standby bobbin, and then the winding process may be performed.

[0016] The position of the standby bobbin to which the sheet is attached may be directed toward the sheet side by detecting the mark by the sensor.

[0017] An adhesive portion to which a starting end of the sheet is attached may be provided on an outer peripheral surface of the standby bobbin, and the sheet may be attached onto the adhesive portion of the standby bobbin when the sensor detects the mark.

[0018] The winding machine may further include a turret that supports the running bobbin and the standby bobbin and rotates the running bobbin and the standby bobbin, and when the winding process on the running bobbin is completed by the rotation of the turret, the winding process on the standby bobbin may be subsequently performed.

[0019] The sheet moves between the standby bobbin and the pressure applying section and is wound onto the running bobbin. When the winding process on the running bobbin is completed, the sheet may be attached to the outer peripheral surface of the standby bobbin by the pressure applying section, cut by a cutting section, and then the winding process on the standby bobbin may be carried out.

[0020] When winding of the sheet onto the running bobbin is completed, the sensor may detect the mark on the standby bobbin.

[0021] The sensor may detect the mark on the standby bobbin in advance during the winding process on the running bobbin.

[0022] The winding device may further include a pressure unit that attaches the sheet to the outer peripheral surface of the standby bobbin when the winding process on the traveling bobbin is completed.

[0023] The mark may have a color that is distinguishable from the outer peripheral surface of the standby bobbin, and the sensor may be a laser light sensor or a color sensor.

[0024] The adhesive portion may have a band shape and be positioned along the length of the bobbin, and the adhesive portion may be positioned in contact with the mark or spaced a predetermined distance from the mark.

[0025] The outer peripheral surface of the standby bobbin may be surrounded by a film portion, and the adhesive portion may be attached onto the film portion.

[0026] The film portion may be made of PET (polyethylene terephthalate), PP (polypropylene), or HDPE (high density polyethylene).

[0027] The mark may be a finishing tape that finishes and fixes the end of the film portion.

[0028] The pressure unit may be a nip roller that is reciprocally movable toward the standby bobbin.

[0029] The sheet conveying device may further include a guide portion for changing or guiding the moving direction of the sheet.

[0030] The guide portion may further include a first guide portion positioned on a movement path of the sheet between the running bobbin and the standby bobbin, and the first guide portion may maintain tension of the sheet between the running bobbin and the first guide portion, and maintain tension between the first guide portion and the standby bobbin.

[0031] The first guide portion may be a guide roller.

[0032] The guide portion may further include a dancer roller.

[0033] The mark may be a line that is displayed along the entire length of the bobbin, or a set of lines or dots that are displayed only partially along the length of the bobbin.

[0034] The sheet may be any one of a positive electrode sheet, a negative electrode sheet, and a separator sheet of a secondary battery. [Effects of the Invention]

[0035] The present invention automatically recognizes the attachment position of a sheet (electrode sheet or separator sheet) on a bobbin used in the winding process of the secondary battery manufacturing sheet, and automatically attaches the sheet to the bobbin, thereby increasing the convenience and efficiency of the process. At the same time, even in such an automated process, the electrode roll can be attached to a precise position, which has the advantage of significantly reducing the defect rate of the electrode winding roll. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a diagram schematically illustrating a sheet winding device for manufacturing a secondary battery according to a conventional technique. [Figure 2] 1 is a diagram schematically illustrating a sheet winding device for manufacturing a secondary battery according to an embodiment of the present invention. [Figure 3] 3 is a front view of the sheet winding device for manufacturing secondary batteries shown in FIG. 2. FIG. [Figure 4] 3 is a side view of the sheet winding device for manufacturing a secondary battery shown in FIG. 2. FIG. [Figure 5] 3 is a front view of a bobbin attached to the sheet winding device for manufacturing a secondary battery shown in FIG. 2. FIG. [Figure 6] FIG. 2 is a perspective view of a bobbin according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0037] DETAILED DESCRIPTION OF THE INVENTION The present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

[0038] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown. Thicknesses are exaggerated in the drawings to clearly show various layers and regions. In the drawings, the thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0039] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "on" or "above" in the direction opposite to gravity.

[0040] Furthermore, throughout the specification, when a part is said to "comprise" a certain element, this does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0041] Furthermore, throughout the specification, the term "on a plane" means the part in question viewed from above, and the term "on a cross section" means the part in question cut vertically and viewed from the side.

[0042] Furthermore, since the upper / lower surfaces or top / bottom of a particular part may be determined differently depending on the reference direction, throughout this specification, "upper surface" and "lower surface" refer to two surfaces that face each other on the z-axis in that part, and "upper surface" and "lower surface" are defined as surfaces that are located in opposite directions on the z-axis in that part.

[0043] Fig. 2 is a schematic diagram showing a sheet winding device 100 for manufacturing secondary batteries according to one embodiment of the present invention. Fig. 3 is a front view of the sheet winding device 100 for manufacturing secondary batteries shown in Fig. 2. Fig. 4 is a side view of the sheet winding device 100 for manufacturing secondary batteries shown in Fig. 2. Fig. 5 is a front view of a bobbin 110 attached to the sheet winding device 100 for manufacturing secondary batteries shown in Fig. 2.

[0044] The sheet winding device 100 for manufacturing a secondary battery according to one embodiment of the present invention can be used to rewind an electrode sheet (positive electrode sheet or negative electrode sheet) that has undergone a series of processes, such as coating and drying, in a secondary battery electrode manufacturing process. Alternatively, it can be used to rewind a separator sheet. However, the present invention is not limited thereto and can be applied to various environments, such as to rewind other films or sheets used in the electrode manufacturing process. For convenience of explanation, the following description will be given of the case where an electrode sheet is wound. The following description can be similarly applied to the case where other sheets, such as a separator sheet, are wound.

[0045] 2 to 5, a sheet winding device 100 for manufacturing a secondary battery according to one embodiment of the present invention includes at least two bobbins 110 onto which an electrode sheet is wound. In this embodiment, the device includes two bobbins 110.

[0046] Of the two bobbins 110, the running bobbin is the running bobbin 110a, and the standby bobbin is the standby bobbin 110b. The running bobbin 110a is the bobbin on which the electrode sheet is wound. The standby bobbin 110b is a bobbin that is on standby, and when winding on the running bobbin 110a is complete, it replaces the running bobbin 110a and is again used to wind the electrode sheet in the same manner.

[0047] On the other hand, the present invention is not limited to the above, and the winding process may be performed simultaneously by providing multiple running bobbins 110a, or by providing multiple standby bobbins 110b and having an operator attach multiple standby bobbins 110b to the secondary battery manufacturing sheet winding device 100 at once, and once winding onto one bobbin 110 is completed, winding onto the next bobbin 110, thereby performing the winding process sequentially.

[0048] A film portion 120 is surrounded on the outer circumferential surface of the bobbin 110 along the periphery of the bobbin 110. The film portion 120 is, for example, vinyl, and may also be, for example, PET (polyethylene terephthalate), PP (polypropylene), or HDPE (high-density polyethylene). The film portion 120 may be wound multiple times around the outer circumferential surface of the bobbin 110. An adhesive portion 140 is adhered to the outer circumferential surface of the film portion 120 surrounding the bobbin 110, and an electrode sheet is again adhered onto the adhesive portion 140. The adhesive portion 140 may be, for example, double-sided tape. That is, after the film portion 120 (vinyl) is surrounded on the outer circumferential surface of the bobbin 110, the adhesive portion 140 (double-sided tape) is attached thereon, and the electrode sheet is wound on top of that. That is, the adhesive portion 140 may be provided on the outer circumferential surface of the bobbin 110 with the film portion 120 interposed therebetween.

[0049] This prevents the surface of the bobbin 110 from being contaminated by the adhesive portion 140, and allows the bobbin 110 to be reused repeatedly.

[0050] Meanwhile, a mark 130 is provided on the outer circumferential surface of the bobbin 110 or on the outer circumferential surface of the film unit 120 surrounding the bobbin 110. The position where the starting portion (starting end) of the electrode sheet is attached, i.e., the position of the adhesive unit 140 described below, is determined based on the mark 130. The sensor 150 is, for example, a laser light sensor or a color sensor, and the mark 130 has a color different from the color of the outer circumferential surface of the bobbin 110 or the film unit 120 so that the sensor 150 can detect color. In the case of a laser light sensor, it is a laser-type photoelectric sensor that recognizes the presence or absence of the mark 130 based on the intensity of light reflected by the white film unit 120 and the colored mark 130 and then returned. As a result, the position of the mark 130 can be detected, thereby identifying the position of the adhesive unit 140. The sensor 150 is disposed near the bobbin 110 at a predetermined distance from the bobbin 110.

[0051] When the film portion 120 surrounds the bobbin 110, the mark 130 may be located at the end of the film portion 120 along the length of the bobbin 110. Alternatively, the mark 130 may be located on the outer circumferential surface of the bobbin 110 along the length of the bobbin 110, and the film portion 120 may be made of a transparent material.

[0052] Furthermore, there are no limitations on the shape or form of the mark 130, as long as it indicates the start of the electrode sheet and the color can be detected by the sensor 150. The mark 130 may be a solid or dotted line, a line that is displayed along the entire length of the bobbin 110, or a set of lines or dots that are displayed only partially along the length of the bobbin 110. For example, the mark 130 may be a solid line that extends along the entire length of the bobbin 110, or a set of dots that are displayed at various points along the length of the bobbin 110. Various modifications and variations are possible.

[0053] 7 is a perspective view of the bobbin according to the embodiment of the present invention of Fig. 6. In this embodiment, the mark 130 is a finishing sticker for fixing the film portion 120.

[0054] On the other hand, the adhesive portion 140 may be attached to the entire outer circumferential surface of the bobbin 110. In this case, when the electrode sheet is wound along the adhesive portion 140 that is surrounded by the entire bobbin 110, if the electrode sheet is mistakenly attached to part or all of the adhesive portion 140 and is attached in a manner that causes bending or unevenness in the electrode sheet, the electrode roll R that is subsequently wound onto the bobbin 110 may not be smooth.

[0055] 2 to 5 again, the adhesive portion 140 has a band shape with a certain width and is more preferably attached along the portion of the outer circumferential surface of the bobbin 110 where the mark 130 is located, or at a predetermined distance from the mark 130. In the latter case, as will be described later, after the electrode sheet is fixed to the adhesive portion 140 located at the mark 130, the bobbin 110 can be rotated while maintaining a certain tension on the electrode sheet, allowing the electrode sheet to be smoothly wound around the bobbin 110.

[0056] FIG. 5 shows a case where the adhesive portion 140 is attached to a part of the outer circumferential surface of the bobbin 110 at a predetermined distance (for example, 10 mm) from the mark 130.

[0057] 5, the adhesive part 140 is attached using the mark 130 as a reference. An operator may surround the film part 120 around the bobbin 110 in advance, attach the adhesive part 140 thereon, and then attach the bobbin 110 to the sheet winding device 100 for manufacturing a secondary battery. Alternatively, after the bobbin 110 is attached to the sheet winding device 100 for manufacturing a secondary battery, the film part 120 may be surrounded by a nip roller or the like provided in the sheet winding device 100 for manufacturing a secondary battery, and the adhesive part 140 may be attached. Various modifications and variations are possible.

[0058] 2, a method in which an electrode sheet is wound onto the traveling bobbin 110a and then wound onto the standby bobbin 110b in the same manner will be described. When the winding of the electrode sheet onto the traveling bobbin 110a is completed, the following operation is performed to attach the electrode sheet to the standby bobbin 110b.

[0059] First, the standby bobbin 110b rotates slowly, and the sensor 150 detects the mark 130 on the standby bobbin 110b, and the mark 130 is positioned at a predetermined position where it can come into contact with the pressure unit 160. The pressure unit 160 is, for example, a nip roller.

[0060] The sensor 150 may sense the color of the mark 130 and position the mark 130 to face the pressure unit 160. Alternatively, the sensor 150 may sense the color of the mark 130, and the standby bobbin 110b may rotate a further amount of time or a predetermined angle, and then the mark 130 may be positioned to face the pressure unit 160. This can be modified and changed in various ways depending on the various environments in which the present invention is embodied, i.e., the spacing between the standby bobbin 110b, the sensor 150, and the pressure unit 160. The important point is that the sensor 150 detects the mark 130 and, as will be described later, can accurately attach the electrode sheet to the electrode attachment position (i.e., the adhesive portion 140) of the standby bobbin 110b.

[0061] In addition, when the winding of the electrode sheet onto the running bobbin 110a is completed, the sensor 150 may detect the mark 130 on the standby bobbin 110b, but even while the running bobbin 110a is winding the electrode sheet, the sensor 150 may detect the mark 130 on the standby bobbin 110b in advance, and the electrode attachment position (i.e., the adhesive portion 140) of the standby bobbin 110b may be made to wait in advance in the direction of the electrode sheet.

[0062] The electrode sheet passes between the pressure unit 160 and the standby bobbin 110b. The pressure unit 160 moves to the standby bobbin 110b side, attaches the electrode sheet to the adhesive portion 140 of the standby bobbin 110b, and then moves away from the standby bobbin 110b. At this time, the cutting unit 170 cuts the electrode sheet along the dotted line shown in FIG. 2.

[0063] Meanwhile, the turret 180 rotates 180 degrees around its central axis, and the standby bobbin 110b, to which the electrode sheet is attached, moves toward the existing traveling bobbin 110a and begins winding the electrode sheet. For ease of explanation, the names traveling bobbin 110a and standby bobbin 110b have been used, but when the standby bobbin 110b moves toward the traveling bobbin 110a to wind the electrode sheet, the standby bobbin 110b in the previous winding step becomes the traveling bobbin 110a in this winding step, the electrode roll that was wound onto the traveling bobbin 110a in the previous winding step is detached and transported to the next process, and when a new bobbin 110 is attached, it becomes the standby bobbin 110b for this winding step.

[0064] The rotation angle of the turret 180 is not limited to the above and can be modified or changed depending on various environments in which the present invention is embodied. For example, various modifications and changes can be made by changing the number of bobbins 110, the position at which the traveling bobbin 110a that winds the electrode sheet is attached, and the position at which the standby bobbin 110b to which the electrode sheet is attached in the pressure unit 160 is attached.

[0065] The sheet winding device 100 for manufacturing a secondary battery further includes a guide unit 190 that changes or guides the moving direction of the electrode sheet. The number, type, and position of the guide unit 190 are not particularly limited and can be variously modified and changed depending on the environment in which the present invention is embodied. The guide unit 190 may be in the form of a roller, for example. The guide roller 190a located in the path between the running bobbin 110a and the standby bobbin 110b facilitates winding onto the running bobbin 110a and also facilitates attachment of the electrode sheet to the standby bobbin 110b by the pressure unit 160. The guide roller 190a also supports the electrode sheet and maintains tension on the electrode sheet, thereby preventing the running bobbin 110a and the standby bobbin 110b from unintentionally affecting each other due to their respective operations. The sheet winding device 100 for manufacturing a secondary battery may further include a dancer roller 190c in the path of the electrode sheet.

[0066] The sheet winding device 100 for manufacturing secondary batteries also includes a frame (not shown) that supports the bobbin 110 and the turret 180, and driving means (not shown) that drives each of the components such as the bobbin 110, the turret 180, and the pressure unit 160.

[0067] In the same manner as described above, the traveling bobbin 110a and the standby bobbin 110b rotate and sequentially wind up the electrode sheet.

[0068] According to the present invention, after the winding process on one bobbin is completed, the sheet can be automatically attached to another bobbin immediately and the winding process can be resumed, thereby reducing the time required to change bobbins and increasing the production efficiency of the process.

[0069] Those skilled in the art will appreciate that various applications and modifications can be made within the scope of the present invention based on the above content.

[0070] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the appended claims also fall within the scope of the present invention. [Explanation of symbols]

[0071] 100: Sheet winding device for secondary battery manufacturing 110: Bobbin 110a: Traveling bobbin 110b: Standby bobbin 120: Film section 130: Mark 140: Adhesive part 150: Sensor 160: Pressure section 170: Cutting section 180: Turret 190: Guide section

Claims

1. An apparatus for winding up a sheet for manufacturing a secondary battery, At least two bobbins including a running bobbin on which a winding process is performed and a standby bobbin on which the winding process is performed; a sensor disposed at a predetermined distance from the standby bobbin, the sensor detecting a mark for identifying a position where the sheet wound on the running bobbin is automatically attached to the standby bobbin; When the winding process on the running bobbin is completed, the sheet wound on the running bobbin is attached to the outer peripheral surface of the standby bobbin, and then the winding process is carried out.

2. The sheet winding device for manufacturing a secondary battery according to claim 1, wherein the sheet is one of a positive electrode sheet, a negative electrode sheet, and a separator sheet of a secondary battery.

3. The sheet winding device for manufacturing a secondary battery according to claim 1 , wherein when the sensor detects the mark, the position of the standby bobbin to which the sheet is attached is turned toward the sheet side.

4. An adhesive portion is provided on the outer peripheral surface of the standby bobbin to which the starting end of the sheet is attached, The sheet winding device for manufacturing a secondary battery according to claim 1 , wherein the sheet is attached onto the adhesive portion when the mark is detected by the sensor.

5. a turret that supports the running bobbin and the standby bobbin and rotates the running bobbin and the standby bobbin; The sheet winding device for manufacturing a secondary battery according to claim 1 , wherein when the winding process on the traveling bobbin is completed by the rotation of the turret, the winding process on the standby bobbin is subsequently performed.

6. The sheet passes between the standby bobbin and the pressure unit, moves, and is wound around the traveling bobbin.

2. The sheet winding device for manufacturing a secondary battery according to claim 1, wherein, when the winding process on the running bobbin is completed, the sheet is attached to the outer peripheral surface of the standby bobbin by the pressing unit, and then cut by the cutting unit, after which the winding process on the standby bobbin is carried out.

7. The sheet winding device for manufacturing a secondary battery according to claim 1 , wherein the sensor detects the mark on the standby bobbin when winding of the sheet on the traveling bobbin is completed.

8. The sheet winding device for manufacturing a secondary battery according to claim 1 , wherein the sensor detects the mark on the standby bobbin in advance during a winding process on the traveling bobbin.

9. The sheet winding device for manufacturing a secondary battery according to claim 1 , further comprising a pressure unit that attaches the sheet to an outer peripheral surface of the standby bobbin when the winding process on the traveling bobbin is completed.

10. the mark has a color that is distinguishable from the outer peripheral surface of the standby bobbin, The sheet winding device for producing a secondary battery according to claim 1 , wherein the sensor is a laser light sensor or a color sensor.

11. the adhesive portion has a band shape and is located along the length of the bobbin; The sheet winding device for manufacturing a secondary battery according to claim 4 , wherein the adhesive portion is located in contact with the mark or spaced a predetermined distance from the mark.

12. The sheet winding device for manufacturing a secondary battery according to claim 4 , wherein an outer peripheral surface of the standby bobbin is surrounded by a film portion, and the adhesive portion is attached onto the film portion.

13. The sheet winding device for manufacturing a secondary battery according to claim 12, wherein the film portion is made of PET (polyethylene terephthalate), PP (polypropylene), or HDPE (high density polyethylene).

14. The sheet winding device for manufacturing a secondary battery according to claim 12 , wherein the mark is a finishing tape that finishes and fixes an end of the film portion.

15. The sheet winding device for manufacturing a secondary battery according to claim 9 , wherein the pressure unit is a nip roller that is reciprocally movable toward the standby bobbin.

16. The sheet winding device for manufacturing a secondary battery according to claim 1 , further comprising a guide unit for changing or guiding a moving direction of the sheet.

17. The guide unit further includes a first guide unit located on a path of movement of the sheet between the running bobbin and the standby bobbin, 17. The sheet winding device for manufacturing a secondary battery according to claim 16, wherein the first guide portion maintains tension of the sheet between the running bobbin and the first guide portion, and maintains tension between the first guide portion and the standby bobbin.

18. The sheet winding device for manufacturing a secondary battery according to claim 17 , wherein the first guide portion is a guide roller.

19. The sheet winding device for manufacturing a secondary battery according to claim 16 , wherein the guide portion further includes a dancer roller.

20. 2. The sheet winding device for manufacturing a secondary battery according to claim 1, wherein the mark is a line displayed along the entire length of the bobbin, or a plurality of lines or dots displayed only partially along the length of the bobbin.

Images