Electrode manufacturing apparatus

Abstract

An electrode manufacturing apparatus according to one embodiment of the present invention includes a support roll that supports an electrode sheet including a coated portion and an uncoated portion and transports the electrode sheet in a first direction, at least one pressure roll that contacts the electrode sheet with the support roll and pressurizes the uncoated portion at a position corresponding to the uncoated portion between the support roll and the pressure roll, a level sensor that detects a level of the uncoated portion, and a control unit that controls the pressure roll in response to the level detected by the level sensor, and the at least one pressure roll is movable in a second direction intersecting the first direction.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2022 - 0049065 filed on April 20, 2022 and Korean Patent Application No. 10 - 2023 - 0034088 filed on March 15, 2023, and all the contents disclosed in the documents of the said patent applications are included as part of this specification.

[0002] The present invention relates to an electrode manufacturing apparatus, and specifically to an electrode manufacturing apparatus including a system capable of preventing wrinkles from occurring in an electrode sheet.

Background Art

[0003] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries as an energy source has been rapidly increasing. In particular, secondary batteries are attracting attention not only as an energy source for mobile devices such as mobile phones, digital cameras, notebook computers, and wearable devices, but also as an energy source for power devices such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] A secondary battery can be formed by inserting an electrode assembly composed of a positive electrode, a negative electrode, and a separator into a case and then sealing it. Here, electrodes for secondary batteries such as positive electrodes and negative electrodes include a coated portion and an uncoated portion on a current collector. The coated portion has an active material layer coated with an active material slurry, and the uncoated portion corresponds to a plain portion not coated with the active material slurry. In particular, in the case of the uncoated portion, since its thickness is very thin, folds or wrinkles may occur during the electrode manufacturing process, and thus a device capable of controlling this is required.

[0005] FIG. 1 is a drawing showing an electrode support roll in a conventional electrode manufacturing apparatus and an electrode sheet passing through it.

[0006] Referring to Figure 1, the electrode sheet 1 is formed with a structure that includes a coated portion 7 on which the electrode mixture 5 is applied to a metal foil 3, and an uncoated portion 9 on which the electrode mixture 5 is not applied. Such an electrode sheet 1 can sequentially undergo processes such as being transported to one side via at least one roller 10, or being rolled between two rollers 10.

[0007] During this process, as the electrode sheet 1 is supported by the roll 10 and moves, wrinkles, creases, and curls may occur in the uncoated portion 9 due to the difference in thickness between the coated portion 7 and the uncoated portion 9. Furthermore, if the coated portion 7 is coated in a stripe pattern and comes into contact with the roll 10 during processes such as drying or tensioning, creases and wrinkles may occur in the uncoated portion 9. In particular, the uncoated portion 9 is a part where only a thin metal foil 3 exists, making it vulnerable at creases, and at the same time, depending on its position during the process, the occurrence of such wrinkles and creases may increase further in environments with high temperatures. Such creases and wrinkles can cause wire breakage and defects, leading to increased losses and a decrease in equipment efficiency and productivity. [Overview of the project] [Problems that the invention aims to solve]

[0008] The problem that this invention aims to solve is to provide an electrode manufacturing apparatus that can prevent wrinkles from forming in the uncoated portion of the electrode sheet during the electrode manufacturing process.

[0009] The problems that this invention aims to solve are not limited to those described above, and any problems not mentioned will be clearly understood by a person with ordinary skill in the art to which this invention pertains, based on this specification and the accompanying drawings. [Means for solving the problem]

[0010] An electrode manufacturing apparatus according to one embodiment of the present invention includes a support roll for supporting an electrode sheet including a coated portion and an uncoated portion and for transporting the electrode sheet in a first direction, at least one pressure roll that contacts the support roll with the electrode sheet between the support roll and the pressure roll and pressurizes the uncoated portion at a position corresponding to the uncoated portion, a level sensor for sensing the level of the uncoated portion, and a control unit for controlling the pressure roll in accordance with the level sensed by the level sensor, wherein the at least one pressure roll is movable in a second direction intersecting the first direction.

[0011] The pressure roll moves to the area where there is a change in the level of the uncoated portion detected by the level sensor, and can apply pressure to the uncoated portion.

[0012] The pressure roll can move along the support portion extending in the second direction.

[0013] The support portion is movable along the first direction.

[0014] The control unit can control the height of the pressure roll in accordance with the level of the uncoated portion detected by the level sensor.

[0015] The width of the pressure roll can be the same as or greater than the width of the uncoated portion.

[0016] The system may further include a suction roll that supports the electrode sheet downstream of the support roll along the first direction.

[0017] The suction roll may include a plurality of suction holes.

[0018] The plurality of suction holes can be arranged in a symmetrical, screw-like shape with respect to the longitudinal center of the suction roll.

[0019] The control unit can control the pressure sucked by the suction connected to the suction roll by reflecting the level of the uncoated portion sensed by the level sensor.

Advantages of the Invention

[0020] According to the embodiment, in the electrode manufacturing process, even if wrinkles occur in the uncoated portion of the electrode sheet, they can be quickly removed and the state where the wrinkles are removed can be maintained, thereby preventing defects from occurring due to the wrinkles and folds in the uncoated portion.

[0021] The effects of the present invention are not limited to the effects described above, and the effects not mentioned are clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from this specification and the attached drawings.

Brief Description of the Drawings

[0022] [Figure 1] It is a drawing showing a roll for supporting an electrode and an electrode sheet passing through the same in a conventional electrode manufacturing apparatus. [Figure 2] It is a drawing schematically showing an electrode manufacturing apparatus according to an embodiment of the present invention. [Figure 3] It is a drawing showing a part of the electrode manufacturing apparatus of FIG. 2. [Figure 4] It is a cross-sectional view showing an enlarged view for explaining a portion for pressing an uncoated portion in the electrode manufacturing apparatus of FIG. 2. [Figure 5] It is a drawing showing a suction roll in the electrode manufacturing apparatus of FIG. 2.

Modes for Carrying Out the Invention

[0023] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them.

[0024] The present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0025] To clearly explain the present invention, unnecessary explanatory parts have been omitted, and identical or similar components throughout the specification are given the same reference numerals.

[0026] Furthermore, the dimensions and thicknesses of each component shown in the drawings are arbitrary for the sake of explanation, and therefore the present invention is not necessarily limited to those shown.

[0027] In the drawings, the thicknesses were enlarged to clearly represent multiple layers and regions. Furthermore, for ease of explanation, the thicknesses of some layers and regions were exaggerated in the drawings.

[0028] Furthermore, when a specification states that a certain part "includes" a certain component, unless otherwise specified, this means that it may include other components rather than excluding them.

[0029] Furthermore, throughout the specification, "on a plane" means when the subject is viewed from above, and "on a cross-section" means when the subject is viewed from the side of a cross-section obtained by cutting the subject perpendicularly.

[0030] The following describes an electrode manufacturing apparatus according to an embodiment of the present invention. However, although only a portion of the process section of the electrode manufacturing apparatus to which the present invention is applied is described as an example, the invention is not necessarily limited to this, and the technical ideas of the present invention can be applied to any process in which the technical problems recognized in the present invention occur during electrode sheet manufacturing. Furthermore, in the description, the electrode is described with reference to the upper surface of the current collector, but the invention is not necessarily limited to this, and the lower surface can be described in the same or similar manner.

[0031] Figure 2 is a schematic diagram of an electrode manufacturing apparatus according to one embodiment of the present invention, Figure 3 is a diagram showing a part of the electrode manufacturing apparatus of Figure 2, and Figure 4 is an enlarged cross-sectional view of the electrode manufacturing apparatus of Figure 2 to illustrate the part that pressurizes the uncoated portion.

[0032] Referring to Figures 2 to 4, an electrode manufacturing apparatus 100 according to one embodiment of the present invention includes a support roll 200 that supports the electrode sheet 1 and transports the electrode sheet 1 in a first direction (A1), a pressure roll 300 that contacts the support roll 200 with the electrode sheet 1 between the support roll 200 and the pressure roll 300, a level sensor 500 that senses the level of the uncoated portion 9 of the electrode sheet 1, and a control unit 600 that controls the pressure roll 300 in accordance with the level sensed by the level sensor 500.

[0033] The support roll 200 plays the role of supporting and transporting the electrode sheet 1, which has the electrode mixture 5 applied to the metal foil 3. Such a support roll 200 can be applied to transport rolls, rolling rolls, slitters, etc. in the electrode manufacturing process, and is applicable without limitation as long as it is a roll that supports the electrode sheet 1.

[0034] Referring to Figure 4, the electrode sheet 1 can be formed with a structure that includes a coated portion 7 on which the electrode mixture 5 is applied to the metal foil 3, and an uncoated portion 9 on which the electrode mixture 5 is not applied. In particular, the coated portion 7 can be formed in a stripe pattern, and multiple uncoated portions 9 can be formed between these coated portions 7. The uncoated portion 9 is a part where the electrode mixture 5 is not formed, and only the metal foil 3 is located. Therefore, it is fragile to folds, and if exposed to environments such as high heat depending on its position during the process, the occurrence of wrinkles, folds, and waviness (curling) may increase further. Therefore, it is necessary to prevent the occurrence of such wrinkles, folds, or waviness.

[0035] Therefore, the electrode manufacturing apparatus 100 of this embodiment includes a pressure roll 300 and a level sensor 500. The pressure roll 300 is positioned between the support roll 200 and the electrode sheet 1, in contact with the support roll 200, and is configured to apply pressure to the uncoated portion 9 in particular, corresponding to the uncoated portion 9. Its width is formed to be smaller than the width of the support roll 200, and preferably it can be formed to correspond to the width of the uncoated portion 9, but it is not limited to this, and it can also be formed to be slightly larger than the width of the uncoated portion 9.

[0036] The pressure roll 300 is supported by a rod-shaped support portion 310 that extends in a second direction (A2) intersecting the first direction (A1), which is the direction in which the electrode sheet 1 travels. The pressure roll 300 can be formed to be movable along the support portion 310 in the second direction (A2), that is, across the width direction of the electrode sheet 1. With this configuration, the pressure roll 300 moves to a position corresponding to an uncoated area 9 where wrinkles, folds, or undulations have occurred, and applies pressure to the uncoated area 9 so that the wrinkles, folds, or undulations spread out. Referring to Figure 4, in the case of an uncoated area 9 located between coated areas 7, only a thin film of metal foil 5 is present, so folds are likely to occur as shown in Figure 4. By applying pressure only to that area with the pressure roll 300, the folds can be spread out without damaging the coated areas 7, thereby preventing defects. Furthermore, in this embodiment, since the pressure roll 300 is configured to be movable in the second direction (A2), even if there are multiple positions for the uncoated portion 9, or if the position of the uncoated portion 9 changes due to a change in the width of the coated portion 7, it is possible to move to the area where a crease has occurred and spread the crease regardless.

[0037] On the other hand, the support portion 310 itself is movable along the first direction (A1). In other words, it senses the area where wrinkles or folds occur, and the pressure roll 300 moves along the support portion 310 in the second direction (A2) or the support portion 310 moves in the first direction (A1) so that the pressure roll 300 is accurately positioned to correspond to that location. Furthermore, although this embodiment has been described as an example in which the pressure roll 300 is supported by a rod-shaped support portion 310, it is not limited to this, and the pressure roll 300 itself can be connected to a robot arm or the like and configured to move to the area where wrinkles or folds occur.

[0038] The level sensor 500, configured to sense the level of the uncoated portion 9, can be positioned downstream of the electrode sheet 1 in the direction of travel, as shown in Figure 2, but is not limited to this, and may also be positioned upstream of the pressure roll 300. The level sensor 500 can sense the level of the uncoated portion 9 by, for example, irradiating it with a laser, but is not limited to this, and various sensors capable of level sensing can be applied. When the level of the uncoated portion 9 is measured by the level sensor 500, if it is determined to be higher than a predetermined value that has been input in advance (for example, the level (height) when the metal foil 3 is in close contact with the support roll 200), it is determined that a crease, wrinkle, or undulation has occurred in that portion. Subsequently, the pressure roll 300 is moved to the position corresponding to the uncoated portion 9 where the wrinkle, crease, or undulation has occurred, and pressure is applied to the uncoated portion 9 so that the wrinkle, crease, or undulation spreads.

[0039] At this time, the height of the pressure roll 300 can be adjusted according to the degree of the level measured by the level sensor 500. In other words, if the level increase is large, the height of the pressure roll 300 can be further lowered to increase the pressure applied when the pressure roll 300 is in contact with the uncoated portion 9, and if the level increase is small, the height of the pressure roll 300 can be relatively increased to decrease the pressure applied when the pressure roll 30 and the uncoated portion 9 are in contact. Alternatively, an elastic member (not shown) can be provided between the pressure roll 300 and the support portion 310, and the elasticity of the elastic member can be used to control the application of appropriate pressure.

[0040] Thus, the pressure roll 300 can further include a suction roll 400 that supports the electrode sheet 1 downstream of the support roll 200 along the first direction (A1) so that tension can be applied to the electrode sheet 1, which may have wrinkles, folds, or undulations, and maintain a taut state. Figure 5 is a diagram showing the suction roll in the electrode manufacturing apparatus of Figure 2. Referring to Figure 5, a plurality of suction holes 410 are formed on the surface of the suction roll 400, and the inside of the suction roll 400 is connected to a suction device (not shown) and is configured to suck the electrode sheet 1 in contact with the surface through the suction holes 410.

[0041] As shown in Figure 5, the multiple suction holes 410 can be formed on the surface of the cylindrical suction roll 400 in a screw-like manner, and in particular, they can be formed symmetrically with respect to the longitudinal center (C) of the suction roll 400. With this configuration, the force applied by the suction holes 410 is applied symmetrically so as to face outwards from the electrode sheet 1, thereby applying tension to the electrode sheet 1 and maintaining a taut state. Therefore, even if wrinkles, folds, or undulations in the uncoated area are spread by the pressure roll 300, it is possible to prevent further wrinkles, folds, or undulations from occurring. In addition, it is possible to prevent the electrode sheet 1 from meandering and becoming biased to one side.

[0042] The suction pressure of the suction roll 400 can be adjusted according to the number of level fluctuations detected by the level sensor 500. That is, if wrinkles, creases, or undulations occur in multiple parts of the uncoated area 9, stronger suction pressure can be applied to prevent wrinkles, creases, or undulations, and if the number of areas with wrinkles, creases, or undulations is small, the suction pressure can be controlled to decrease.

[0043] Thus, according to the embodiment of the present invention, even in an electrode sheet 1 where both a coated portion 7 and an uncoated portion 9 are present, wrinkles, creases, or undulations in the uncoated portion 9 can be prevented, and defects and wire breakage caused by wrinkles, creases, or undulations can be prevented. The configuration of the pressure roll 300, suction roll 400, and level sensor 500 included in the electrode manufacturing apparatus of this embodiment can be applied to various processes throughout the entire electrode manufacturing process. In particular, since wrinkles, creases, or undulations in the uncoated portion 9 are more likely to occur in high-temperature environments, the apparatus of this embodiment can be applied more effectively when applied to the outlet of an oven that has undergone a high-temperature drying process, etc.

[0044] Although 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 by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0045] 1 Electrode Sheet 3 Metal foil 5. Electrode mixture 7. Coating section 9 Uncoated area 100 Electrode manufacturing equipment 200 support rolls 300 Pressure Rolls 310 Support part 400 suction rolls 410 suction holes 500 level sensor 600 Control Unit

Claims

1. A support roll that supports an electrode sheet including a coated portion and an uncoated portion, and transports the electrode sheet in a first direction. At least one pressure roll that places the electrode sheet between the support roll and the pressure roll, in contact with the support roll, and applies pressure to the uncoated portion at a position corresponding to the uncoated portion, A level sensor for sensing the level of the uncoated portion, and Includes a control unit that controls the pressure roll in accordance with the level sensed by the level sensor, The pressure roll moves in a second direction intersecting the first direction. The system further includes a suction roll that supports the electrode sheet downstream of the support roll along the first direction, The suction roll includes a plurality of suction holes, An electrode manufacturing apparatus in which the plurality of suction holes are arranged in a symmetrical screw shape with respect to the longitudinal center of the suction roll.

2. The electrode manufacturing apparatus according to claim 1, wherein the pressure roll moves to a portion where there is a change in the level of the uncoated portion detected by the level sensor, and pressurizes the uncoated portion.

3. The electrode manufacturing apparatus according to claim 1 or 2, wherein the pressure roll moves along a support portion extending in the second direction.

4. The electrode manufacturing apparatus according to claim 3, wherein the support portion moves along the first direction.

5. The electrode manufacturing apparatus according to claim 1 or 2, wherein the control unit controls the height of the pressure roll in accordance with the level of the uncoated portion sensed by the level sensor.

6. The electrode manufacturing apparatus according to claim 1 or 2, wherein the width of the pressure roll is the same as or greater than the width of the uncoated portion.

7. The electrode manufacturing apparatus according to claim 1 or 2, wherein the control unit controls the pressure applied by the suction connected to the suction roll in accordance with the level of the uncoated portion sensed by the level sensor.

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