Unwinding device for manufacturing secondary batteries and secondary battery manufacturing system including the same

Abstract

The unwinding device for manufacturing a secondary battery according to the present invention may include an unwinding machine that rotates and unwinds a coated base material wound in a roll shape about a rotating shaft, a conveying unit including a first conveying roll arranged so as to be closest to the unwinding machine, and a correction unit provided on the rotating shaft for correcting the position of the rotating shaft with respect to the first conveying roll.

Description

Technical Field

[0001] The present invention relates to an unwinding device for manufacturing secondary batteries and an energy storage system including the same, and more specifically, to an unwinding device for manufacturing secondary batteries in which distortion of a coating substrate is suppressed as much as possible during the unwinding process in a roll-to-roll process for manufacturing secondary batteries, and an energy storage system including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0182923 filed on December 23, 2022, and all of the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] Generally, a secondary battery refers to a battery that can be repeatedly charged and discharged, such as a lithium-ion battery, a lithium polymer battery, a nickel cadmium battery, a nickel metal hydride battery, or a nickel zinc battery. Such a secondary battery can be manufactured by accommodating an electrode assembly including a positive electrode and a negative electrode laminated with each other with an insulating separator in a case of various shapes and sealing the case.

[0004] In addition, the electrodes and separators of secondary batteries can be manufactured using a roll-to-roll process. That is, while unwinding and transporting a strip-shaped substrate wound in a roll, coating processes, drying processes, roll press processes, slit processes, notching processes, etc. can be continuously performed in an in-line manner. In such a roll-to-roll method, the processes of winding and unwinding can be performed for each process.

[0005] In particular, a process of unwinding an electrode reel on which a base material processed after a slitting process is wound is required for performing a notching process. In this process, as time passes, the amount of winding of the electrode (or the base material, semi-processed coated base material, hereinafter collectively referred to as the coated base material) wound on the electrode reel inevitably decreases, and the moving angle of the coated base material moving from the electrode reel to the conveying roller (or the approaching angle of the base material toward the conveying roller) has to be changed. When the moving angle of the coated base material unwound in this way changes, the degree of bending (folding) of the coated base material engaged with the conveying unit becomes different, and as a result, there is a problem that distortion of the coated base material is caused. That is, based on any one of the conveying rollers, the degree of bending formed by the base material being fed out and the base material moving from the electrode reel to the conveying roller may increase. In particular, such a phenomenon tends to be severe in the first conveying roller. Such a bending phenomenon increases the possibility of wrinkles occurring in the non-electrode portion, and the wrinkles prevent the position of the tab from being uniformly formed in the non-electrode portion of the electrode, which may cause folding, damage, and defects of the tab in the subsequent notching process.

Summary of the Invention

Problems to be Solved by the Invention

[0006] The present invention was conceived in view of the above circumstances, and the problem to be solved by the present invention is to provide an unwinding device for manufacturing a secondary battery that reduces the change in the moving angle of the coated base material moving from the unwinder to the first conveying roll and suppresses the distortion of the coated base material as much as possible, and a secondary battery manufacturing system including the same.

[0007] The technical problem to be solved by the present invention is not limited to the above-mentioned problems, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0008] The unwinding device for manufacturing a secondary battery according to the present invention for solving the above problems includes an unwinding machine that rotates and unwinds a coated substrate wound in a roll shape around a rotating shaft, a conveying unit including a first conveying roll arranged so as to be closest to the unwinding machine, and a correction unit provided on the rotating shaft for correcting the position of the rotating shaft with respect to the first conveying roll.

[0009] The correction unit can move the position of the rotating shaft in a first direction so that the entry angle of the coated substrate formed from the first conveying roll to the outer peripheral surface of the coated substrate wound by the unwinding machine falls within a preset range.

[0010] The unwinding device for manufacturing a secondary battery may further include a sensor unit that senses the distance to the outer peripheral surface of an electrode reel, which is the wound coated substrate.

[0011] The sensor unit can sense the distance of the outer peripheral surface of the electrode reel that changes while the coated substrate is being unwound and sense the thickness of the wound coated substrate.

[0012] The correction unit may further include a lifting frame and an up / down drive unit connected to the lifting frame for driving the rotating shaft up / down in the first direction.

[0013] A hub bearing to which the rotating shaft is rotatably coupled may be provided on the lifting frame.

[0014] The unwinding machine further includes a support frame, and a long hole may be formed in the support frame so that the rotating shaft moves up / down.

[0015] The sensor unit may be provided on the support frame.

[0016] The sensor unit can measure the flight time of light irradiated on and reflected from the outer peripheral surface of the electrode reel.

[0017] The up / down drive unit can be a pneumatic or hydraulic cylinder.

[0018] According to another embodiment, the unwinding device for manufacturing the secondary battery may further include a conveyance roll correction unit that corrects the position of the conveyance unit in a second direction.

[0019] Here, the conveyance roll correction unit may include a correction rod rotatably connected to the first conveyance roll, and a rod drive unit that drives the correction rod to move forward or backward in the second direction.

[0020] Further, according to the present invention, a secondary battery manufacturing system including the above-described unwinding device for manufacturing a secondary battery can be provided.

Effects of the Invention

[0021] According to one aspect of the present invention, even if the winding amount of the coated substrate wound on the unwinder decreases, the rotation axis of the unwinder with respect to the conveyance unit is corrected, so that the change in the movement angle of the coated substrate moving from the unwinder to the first conveyance roll is reduced, and the distortion of the coated substrate is suppressed as much as possible.

[0022] Also, according to one aspect of the present invention, while the wound coated substrate is being unwound, the sensor unit moves the rotation axis so as to correspond to the winding amount of the coated substrate, and with respect to the first conveyance roll, it is possible to suppress as much as possible the degree of bending formed by the substrate being fed out and the substrate moving from the electrode reel to the conveyance roller. As a result, it is possible to reduce folding, damage, and defects of the tabs during the notching process.

[0023] The effects of the present invention are not limited to the above-described effects at all, and other effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from this specification and the accompanying drawings.

[0024] The drawings attached to this specification illustrate desirable embodiments of the present invention and are for the purpose of further understanding the technical idea of the present invention together with the content of the invention. Therefore, the present invention is not to be construed as being limited only to the matters described in the drawings.

Brief Description of the Drawings

[0025]

Figure 1

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Figure 3

Figure 4

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Figure 7

Figure 8

Figure 9

Modes for Carrying Out the Invention

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings. Prior to this, the terms and words used in this specification and the claims are not to be construed as being limited to their ordinary or dictionary meanings. The inventor interprets them in accordance with the meaning and concept corresponding to the technical idea of the present invention in accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain the invention in the best way. Therefore, it should be understood that the embodiments described in this specification and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. At the time of this application, there may be various equivalents and modified embodiments that can replace them.

[0027] FIG. 1 is a diagram schematically showing a side portion of a winding device for manufacturing a secondary battery according to an embodiment of the present invention, FIG. 2 is a diagram schematically showing a front portion of a winding device for manufacturing a secondary battery according to an embodiment of the present invention, and FIG. 3 is a partially enlarged view of FIG. 2.

[0028] Referring to FIGS. 1 to 3, a winding device 10 for manufacturing a secondary battery according to an embodiment of the present invention may include a winder 100, a conveying unit 200 including a first conveying roll 210, a sensor unit 300, and a correction unit 400.

[0029] The winder 100 may be a component for unwinding the coated substrate M. The coated substrate M may be a metal foil corresponding to a current collector of an electrode, or a porous polymer substrate corresponding to an insulator of a separator. Alternatively, the coated substrate M may be an electrode or an electrode sheet on which an electrode active material is coated and dried on the above-described substrate. In the present embodiment, it may be a slit electrode sheet for a notching process.

[0030] The winder 100 may unwind the coated substrate M wound in a roll shape by rotating it around a rotation shaft 120. Specifically, the winder 100 may include a support frame 110 and a rotation shaft 120 rotatably coupled to the support frame 110.

[0031] The pair of support frames 110 can be arranged such that they are separated by a distance corresponding to a predetermined width formed by the wound coating substrate M. A rotary shaft 120 can be rotatably coupled between the pair of support frames 110. Such support frames 110 may be formed with elongated holes 111 so that the rotary shaft 120 moves up / down. Through the elongated holes 111, the rotary shaft 120 is movable in a first direction. For example, the first direction can be the vertical direction or the perpendicular direction. In contrast, due to the elongated holes 111, the movement of the rotary shaft 120 can be restricted in other directions (for example, the Y-axis direction, etc.).

[0032] A sensor unit 300 can be arranged on such support frames 110. The sensor unit 300 can be arranged at the center of a pair of support frames 110 separated by a distance corresponding to a predetermined width.

[0033] The rotary shaft 120 can be arranged on the elongated holes 111, and a coating substrate M generated by winding a strip-shaped secondary battery substrate may be wound around the rotary shaft 120. Here, the portion around which the coating substrate M is wound is referred to as an electrode reel MR, and the electrode reel MR can be coupled onto the rotary shaft 120. The coating substrate M unwound from the electrode reel MR can be conveyed in the longitudinal direction (MD: Machine Direction) by a first conveying roll 210. For example, an electrode reel MR (reel) around which a coating substrate M that has undergone a slitting process is wound can be unwound through the unwinder 100, conveyed in the longitudinal direction (MD), and fed into a notching process or notching equipment.

[0034] The conveying unit 200 may be a part that conveys the unwound coated substrate M. For this purpose, the conveying unit 200 may include a plurality of conveying rolls. And the conveying unit 200 includes a plurality of conveying rolls, and the plurality of conveying rolls are arranged sequentially and continuously, and can continuously unwind the unwound coated substrate M and supply it to subsequent equipment. Only the first conveying roll 210 is shown in the figure, and other conveying rolls are omitted.

[0035] The conveying unit 200 may include a first conveying roll 210 arranged to be closest to the unwinder 100. The first conveying roll 210 may be the first to come into contact with the coated substrate M unwound from the electrode reel MR. Such a first conveying roll 210 has a different moving path for the coating sheet unwound from the electrode reel MR according to the relative position with the rotating shaft 120 of the unwinder 100, and the entering angle of the coated substrate M with respect to the first conveying roll 210 may change.

[0036] The sensor unit 300 may be a part that senses the distance to the outer peripheral surface of the coated substrate M. The sensor unit 300 may sense the distance of the outer peripheral surface of the coated substrate M that is changed while the coated substrate M is being unwound, and sense the thickness of the wound coated substrate M. That is, the sensor unit 300 may measure the distance to the outer peripheral surface of the wound coated substrate M, that is, the outermost outer peripheral surface of the electrode reel MR, and sense the thickness of the wound coated substrate M.

[0037] The correction unit 400 may be provided on the rotating shaft 120 and may be a part that corrects the position of the rotating shaft 120 with respect to the first conveying roll 210. The correction unit 400 may move the position of the rotating shaft 120 in the first direction (Z-axis direction) so that the entering angle of the coated substrate M formed from the first conveying roll 210 to the outer peripheral surface of the coated substrate M wound by the unwinder 100 falls within a preset range.

[0038] That is, in the unwinding process, the thickness of the electrode reel MR decreases, whereby the moving path of the coating sheet unwound from the electrode reel MR becomes different, and the entry angle of the coating substrate M with respect to the first conveying roll 210 can change. The correction unit 400 can move the rotating shaft 120 engaged with the electrode reel MR downward in a first direction so that the entry angle of the coating substrate M falls within a preset range.

[0039] Through such a configuration, the change in the moving angle of the coating substrate M moving from the unwinder 100 to the first conveying roll 210 is reduced, and the distortion of the coating substrate M is suppressed as much as possible.

[0040] Hereinafter, the sensor unit 300 and the correction unit 400 will be described in detail.

[0041] FIG. 4 is a diagram showing an unwinding device for manufacturing a secondary battery according to an embodiment of the present invention.

[0042] It is necessary to detect whether the winding amount of the coating substrate M wound on the unwinder 100 decreases or the thickness of the electrode reel MR decreases. For this reason, a sensor unit 300 may be provided in the unwinding device 10 for manufacturing a secondary battery in this embodiment.

[0043] Returning to FIGS. 3, 1, and 2, the sensor unit 300 may be provided on the support frame 110. Such a sensor unit 300 may be a distance sensor. The sensor unit 300 can measure the time of flight (TOF) of the light irradiated on and reflected from the outer peripheral surface of the wound coating substrate M, that is, the electrode reel MR. It may be configured to sense the distance from a predetermined position to the outer peripheral surface of the electrode reel MR while the electrode reel MR is unwound from the unwinder 100.

[0044] On the other hand, the moving angle of the coating substrate M moving between such an electrode reel MR and the conveying unit 200, particularly the first conveying roll 210, changes as the radius of the electrode reel MR decreases over time. Therefore, it is necessary to correct the rotation axis 120 of the unwinder 100 with respect to the conveying unit 200.

[0045] The correction unit 400 may be configured to correct the position of the rotation axis 120 that rotates while supporting the electrode reel MR according to the distance sensed by the sensor unit 300.

[0046] Specifically, the correction unit 400 may include a lifting frame 410 and an up / down drive unit 420 connected to the lifting frame 410 to drive the rotation axis 120 in the first direction up / down.

[0047] The lifting frame 410 may be configured to support the rotation axis 120 of the unwinder 100. A hub bearing to which the rotation axis 120 is rotatably coupled may be provided on the lifting frame 410. Thereby, the lifting frame 410 can support the rotation axis 120 rotatably.

[0048] Such a lifting frame 410 can move up / down in the first direction (Z-axis direction).

[0049] The up / down drive unit 420 may be a part that drives the lifting frame 410 up / down in the first direction. The up / down drive unit 420 may be configured to correct the position of the rotation axis 120 that supports the electrode reel MR by changing the position of the lifting frame 410 corresponding to the amount of change in the distance sensed by the sensor unit 300. The up / down drive unit 420 in the present embodiment may be a pneumatic or hydraulic cylinder.

[0050] According to the present embodiment, even if the winding amount of the coating base material M of the electrode reel MR decreases on the unwinder 100, the rotation axis 120 of the unwinder 100 with respect to the conveying unit 200 is corrected, so that the coating base material M moves from the unwinder 100 to the first conveying roll 210. The change in the movement angle of the coating base material M is reduced, and the distortion of the coating base material M is suppressed as much as possible.

[0051] Further, while the wound coating base material M is being unwound, the sensor unit 300 moves the rotation axis 120 so as to correspond to the winding amount of the coating base material M. Based on the first conveying roll 210, the degree of bending formed by the coating base material M traveling from the feeding base material and the electrode reel MR to the first conveying roll 210 can be suppressed as much as possible. As a result, folding, damage, and defects of the tab can be reduced during the notching process.

[0052] Hereinafter, the correction operation of the correction unit 400 will be described in more detail.

[0053] FIG. 5 is a diagram showing a correction operation of an unwinding device for manufacturing a secondary battery according to an embodiment of the present invention.

[0054] Referring back to FIG. 4, the electrode reel MR is engaged with the rotation axis 120, and the unwinder 100 can rotate and unwind the electrode reel MR around the rotation axis 120. When the electrode reel MR rotates and is unwound around the rotation axis 120, the unwound coating base material M can be conveyed in the longitudinal direction (MD: Machine Direction) by the first conveying roll 210.

[0055] While the electrode reel MR is being unwound, the sensor unit 300 can sense the distance from a predetermined position to the outer peripheral surface of the electrode reel MR. For example, the sensor unit 300 is arranged so as to be aligned with the rotation axis 120 of the unwinder 100 in the Z-axis direction and can sense the distance to the outer peripheral surface of the electrode reel MR.

[0056] Referring to FIG. 5, as time passes, the radius of the electrode reel MR decreases, and the distance sensed by the sensor unit 300 increases. The flight time (TOF) of the light irradiated and reflected on the outer peripheral surface of the wound coating substrate M is measured.

[0057] The correction unit 400 can correct the position of the rotating shaft 120 that rotates while supporting the electrode reel MR according to the distance sensed by the sensor unit 300. That is, the up / down drive unit 420 of the correction unit 400 changes the position of the lifting frame 410 corresponding to the amount of change in the distance sensed by the sensor unit 300. By driving in the first direction and slightly moving the lifting frame 410 downward, the position of the rotating shaft 120 can be corrected. For example, in the figure, the correction unit 400 can move the rotating shaft 120 in the -Z-axis direction so that the outer peripheral surface of the electrode reel MR is located within a predetermined range with reference to the Z direction.

[0058] According to the present embodiment, even if the winding amount of the coating substrate M of the electrode reel MR onto the unwinder 100 decreases, the rotating shaft 120 of the unwinder 100 with respect to the conveying unit 200 is corrected, so that the change in the moving angle of the coating substrate M moving from the unwinder 100 to the first conveying roll 210 is reduced, and the distortion of the coating substrate M is suppressed as much as possible.

[0059] Also, while the wound coating substrate M is being unwound, the sensor unit 300 moves the rotating shaft 120 so as to correspond to the winding amount of the coating substrate M, and with reference to the first conveying roll 210, the degree of bending formed by the coating substrate M going from the fed substrate and the electrode reel MR to the first conveying roll 210 can be suppressed as much as possible. Thereby, folding, damage, and defects of the tab can be reduced during the notching process.

[0060] FIG. 6 is a diagram showing the state of the electrode unwound and moved by an existing unwinder, and FIG. 7 is a diagram showing the state of the electrode unwound and moved according to the present invention.

[0061] As shown in FIG. 6(a), in the case of an electrode that is unwound and conveyed from an electrode reel MR in which strip-shaped electrodes are wound in a roll shape at the initial stage of the roll-to-roll process, since the degree of bending in the first conveying roll 210 is not large, wrinkles do not occur in the non-patterned portion of the electrode.

[0062] On the other hand, as shown in FIG. 6(b), in the case of an electrode that is unwound and conveyed from an electrode reel MR with a reduced radius as the roll-to-roll process is performed, since the degree of bending in the conveying roller becomes large, wrinkles occur in the non-patterned portion of the electrode due to the bending. As a result, it can be confirmed that folding or damage of the tabs provided in the non-patterned portion of the electrode occurs, and there is a risk of causing a decrease in the yield and quality of the electrode.

[0063] In the case of an electrode that is unwound and conveyed from an electrode roll at the initial stage of the roll-to-roll process, since the degree of bending in the first conveying roll 210 is not large, as shown in FIG. 7(a), wrinkles do not occur in the non-patterned portion of the electrode.

[0064] Also, as the roll-to-roll process is performed, even when the radius of the electrode roll is reduced, the correction unit 400 takes into account the reduced thickness of the electrode reel MR and moves the height of the rotation axis 120 in the -Z axis direction to correct the position of the electrode reel MR. As a result, in order to maintain the degree of bending of the coating substrate M in the first conveying roll 210 as in the initial stage, as shown in FIG. 7(b), wrinkles do not occur in the non-patterned portion of the electrode. Thereby, folding, damage, and defects of the tabs can be reduced during the notching process.

[0065] Next, with reference to FIGS. 8 and 9, another embodiment of the unwinding device for manufacturing a secondary battery according to the present invention will be briefly described.

[0066] FIG. 8 is a diagram schematically showing a first conveying roll and a conveying roll correction unit in an unwinding device for manufacturing a secondary battery according to another embodiment of the present invention, and FIG. 9 is a diagram showing a correction operation of the conveying roll correction unit in the unwinding device for manufacturing a secondary battery according to another embodiment of the present invention.

[0067] The same member numbers as in the previous drawings indicate the same members, and duplicate descriptions of the same members are omitted. The description will focus on the differences from the above-described embodiments.

[0068] Referring to FIGS. 8 and 9, in an unwinding device for manufacturing a secondary battery according to another embodiment of the present invention, a conveying roll correction unit 220 may be provided in the conveying unit 200.

[0069] The conveying roll correction unit 220 can correct the position of the conveying unit 200 in the second direction. Specifically, the conveying roll correction unit 220 may include a correction rod 221 rotatably connected to the first conveying roll 210, and a rod driving unit 222 that drives the correction rod 221 to move forward or backward in the second direction.

[0070] The correction rod 221 can position the first conveying roll 210 in the second direction according to the degree of expansion and contraction. And the correction rod 221 can be driven by the rod driving unit 222. In the drawing, the correction rod 221 expands and contracts, and the first conveying roll 210 can move upward to the right. At this time, the rotation axis 120 does not move.

[0071] In this way, by correcting the position of the first conveying roll 210, the change in the moving angle of the coating substrate M moving from the unwinder 100 to the first conveying roll 210 is reduced, and the distortion of the coating substrate M is suppressed as much as possible.

[0072] For example, the correction unit 400 moves the rotating shaft 120 with which the electrode reel MR is engaged in the first direction. However, if excessive displacement of the rotating shaft 120 has to be corrected, the correction unit 400 will be burdened. Also, since the weight of the electrode reel MR itself may be quite high, there may be a limit to the correction work by the correction unit 400.

[0073] On the other hand, if the position of the first conveying roll 210 according to the present embodiment can be adjusted in the second direction, without moving the position of the rotating shaft 120, the change in the moving angle of the coating substrate M moving to the first conveying roll 210 can be reduced, and the distortion of the coating substrate M can be suppressed as much as possible. Alternatively, although not shown, a case where a smaller displacement movement of the correction unit 400 is combined with the operation of the conveying roll correction unit 220 may also be considered. Therefore, the degree of bending formed by the coating substrate M going from the electrode reel MR to the first conveying roll 210 can be suppressed as much as possible, and ultimately, folding, damage, and defects of the tab can be reduced during the notching process.

[0074] On the other hand, a secondary battery manufacturing system according to an embodiment of the present invention includes the unwinding device 10 for manufacturing a secondary battery described above.

[0075] Depending on the embodiment, the secondary battery manufacturing system may further include any one or two or more of a coating material manufacturing device, a coating device, a drying device, a rolling device, a slitting device, and a notching device.

[0076] The coating material manufacturing device may be configured to manufacture by blending a coating material for forming an electrode active layer where an actual electrochemical reaction occurs in the electrode.

[0077] For example, when the electrode to be manufactured is a wet electrode, the coating material manufacturing apparatus may be configured to mix, as the coating material, an electrode active material, which is an essential element of the electrode, a conductive material, a filler, a binder for binding between powders and adhesion to a current collector, and a solvent for imparting viscosity and dispersing powders, to produce a slurry-like electrode mixture having fluidity.

[0078] On the other hand, when the electrode to be manufactured is a dry electrode, the coating material mixing apparatus may be configured to mix, as the coating material, a conductive material, a filler, a binder, etc. together with the electrode active material to produce a powder-like electrode mixture. In this case, the secondary battery manufacturing system may not include the drying apparatus.

[0079] The coating apparatus may be configured to apply the coating material to an electrode foil corresponding to a current collector. When the electrode to be manufactured is a dry electrode, the coating apparatus may include a calendar roll for calendaring the powder-like coating material to generate a free-standing electrode film, and a laminating roll for pressing and laminating the electrode film onto the surface of the electrode foil.

[0080] The drying apparatus may be applied when the electrode to be manufactured is a wet electrode, and may be configured to dry the coating material applied to the electrode foil. When the electrode to be manufactured is a dry electrode, the drying apparatus may be omitted.

[0081] The rolling apparatus may be configured to perform a roll pressing process on the electrode with the coating layer formed thereon to adjust the thickness of the coating layer.

[0082] The slitting apparatus may be configured to slit the coated electrode.

[0083] The notching apparatus may be configured to form notches in the plain part of the slit electrode.

[0084] As described above, according to the present invention, while the wound base material is unwound, the distance sensor senses the distance from a predetermined position to the outer peripheral surface of the wound base material, and the correction unit 400 corrects the position of the rotating shaft 120 according to the distance sensed by the distance sensor. Thus, even when the radius of the base material wound in a roll shape in the roll-to-roll process for manufacturing a secondary battery is reduced due to the unwinding of the base material, the moving angle of the unwound and moving portion of the base material can be maintained within a certain range, and it is possible to provide a unwinding device 10 for manufacturing a secondary battery that can prevent distortion of the base material accompanying a change in the moving angle, and a secondary battery manufacturing system including the same.

[0085] In this specification, directional terms such as up, down, left, right, front, and back are used, but these terms are merely used for ease of explanation and may vary depending on the position of the object and the position of the observer, etc., which is self-evident to those skilled in the art of the present invention.

[0086] As described above, the present invention has been described with reference to limited embodiments and drawings, but the present invention is not limited thereby, and it goes without saying that those having ordinary knowledge in the technical field to which the present invention pertains can make various modifications and variations within the equivalent scope of the technical idea of the present invention and the appended claims.

[0087] The drawings and the like attached for the purpose of explaining the present invention and illustrating its embodiments may be shown in an exaggerated form in order to emphasize or highlight the technical content according to the present invention. However, it should be understood that various modified application forms can be adopted at the level of an ordinary technician in this technical field in consideration of the content described above and the illustrated matters.

Claims

1. An unwinding device that rotates and unwinds a coated base material wound in a roll shape around a rotating shaft, a conveying unit including a first conveying roll arranged so as to be closest to the unwinding device, a correction unit provided on the rotating shaft for correcting the position of the rotating shaft with respect to the first conveying roll, and an unwinding device for manufacturing a secondary battery, including the above.

2. The correction unit moves the position of the rotating shaft in a first direction so that the entry angle of the coated base material formed from the first conveying roll to the outer peripheral surface of the coated base material wound by the unwinding device falls within a preset range. The unwinding device for manufacturing a secondary battery according to Claim 1.

3. The unwinding device for manufacturing a secondary battery according to Claim 2, further including a sensor unit for sensing the distance to the outer peripheral surface of the electrode reel, which is the wound coated base material.

4. The sensor unit senses the distance of the outer peripheral surface of the electrode reel that changes while the coated base material is being unwound and senses the thickness of the wound coated base material. The unwinding device for manufacturing a secondary battery according to Claim 3.

5. The correction unit further includes: a lifting frame, and a lifting drive unit connected to the lifting frame for driving the rotating shaft to move up / down in the first direction. The unwinding device for manufacturing a secondary battery according to Claim 3, further including the above.

6. A hub bearing to which the rotating shaft is rotatably coupled is provided on the lifting frame. The unwinding device for manufacturing a secondary battery according to Claim 5.

7. The unwinding device further includes a support frame, and a long hole is formed in the support frame so that the rotating shaft moves up / down. The unwinding device for manufacturing a secondary battery according to Claim 3.

8. The sensor unit is provided on the support frame. The unwinding device for manufacturing a secondary battery according to Claim 7.

9. The sensor unit measures the flight time of light irradiated on and reflected from the outer peripheral surface of the electrode reel. The unwinding device for manufacturing a secondary battery according to Claim 3.

10. The lifting drive unit is a pneumatic or hydraulic cylinder. The unwinding device for manufacturing a secondary battery according to Claim 5.

11. The unwinding device for manufacturing a secondary battery according to Claim 1, further including a conveying roll correction unit for correcting the position of the conveying unit in a second direction.

12. The conveyance roll correction unit is a correction rod rotatably connected to the first conveyance roll, a rod drive unit that drives the correction rod to move forward or backward in the second direction, and the unwinding device for manufacturing a secondary battery according to claim 11.

13. A secondary battery manufacturing system including the unwinding device for manufacturing a secondary battery according to any one of claims 1 to 12.

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