Dry electrode manufacturing equipment

Abstract

The present invention discloses dry electrode manufacturing equipment. According to the present invention, a powder sheet forming device for processing a dry material containing an electrode active material into a sheet shape, a calendering device including at least one calendering unit each having a pair of rolling rolls for rolling an electrode sheet supplied from the powder sheet forming device, and one laminating roll for forming an electrode by bonding the electrode sheet rolled to a target thickness via the calendering device to a current collector are included, and an electrode manufacturing equipment can be provided in which the laminating roll is arranged to face one of the pair of rolling rolls of the calendering unit that finally rolls the electrode sheet.

Description

Technical Field

[0001] The present invention relates to dry electrode manufacturing equipment, and more specifically, to dry electrode manufacturing equipment that can stably manufacture an electrode sheet by measuring and adjusting the tension of the electrode sheet during a calendering process, and can minimize the possibility of wire breakage occurring in the electrode sheet after the calendering process.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0137646 filed on October 24, 2022, and all of the contents disclosed in the specification and drawings of the application are incorporated into this application.

Background Art

[0003] An electrode used in a lithium secondary battery is usually formed by laminating an electrode active material layer formed by binding an electrode active material and a conductive material used as needed with a binder on a current collector. Generally, an electrode has been manufactured using a wet manufacturing method such as applying a slurry for a coated electrode containing an electrode active material, a binder, a conductive material, etc. on a current collector and heat-treating to remove the solvent. However, in these methods, further energy and processes are required to dry the polymer film and effectively remove the solvent from the slurry for the coated electrode, so there is a problem in that the efficiency and economy of the process are inferior.

[0004] Therefore, many dry manufacturing methods for manufacturing an electrode without using a slurry for a coated electrode have been proposed. There are techniques such as mixing an electrode active material, a binder, and a conductive material without a liquid medium such as a solvent or a dispersion medium, and then passing the powder mixture through a rolling roll to manufacture an electrode sheet.

[0005] However, during a calendering process in which an electrode sheet is passed through a plurality of rolling rolls to manufacture an electrode having a target thickness, a slight difference occurs in the supply and conveyance speed of the electrode sheet, the rotational speed between the rolling rolls, etc., causing the electrode sheet to be partially stagnated and jammed frequently.

[0006] In addition, the calendaring process can be repeated from once to three times according to the active material material, process conditions, etc. For example, in order to manufacture an electrode having a target thickness, as shown in FIG. 1, the calendaring process may be performed in the first, second, and third times in sequence. However, when the calendaring process is performed in this way, there is a problem that the thickness of the electrode sheet becomes thinner and thinner, the breaking strength decreases, and the possibility of disconnection gradually increases. In particular, as in the portion indicated by "E1" in FIG. 1, in the process of the electrode sheet moving to the lamination device after the last calendaring process, the electrode sheet moves while floating in the air, and at this time, the possibility of disconnection is the highest. Summary of the Invention Problems to be Solved by the Invention

[0007] The present invention has been devised in view of the above circumstances, and its object is to provide an electrode manufacturing facility capable of suppressing as much as possible the possibility of disconnection of the finally rolled electrode sheet after the calendaring process.

[0008] Another object of the present invention is to provide an electrode manufacturing facility capable of preventing the electrode sheets from being entangled with each other due to the stagnation and congestion phenomena of the electrode sheets during the calendaring process.

[0009] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems at all, 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

[0010] To solve the above problems, the electrode manufacturing equipment according to the present invention includes a powder sheet forming device that processes a dry material containing an electrode active material into a sheet shape, at least one calendering device including a pair of rolling rolls respectively, for rolling the electrode sheet supplied from the powder sheet forming device, and one laminating roll that combines the electrode sheet rolled to a target thickness via the calendering device with a current collector to form an electrode. The laminating roll can be arranged to face either one of the pair of rolling rolls of the rolling unit that finally rolls the electrode sheet.

[0011] The rolling unit includes an upper rolling roll and a lower rolling roll located below the upper rolling roll, and the thickness of the electrode sheet can be adjusted according to the interval between the upper rolling roll and the lower rolling roll.

[0012] The laminating roll is arranged to face the lower rolling roll, and can be provided such that the electrode sheet and the current collector are pressure-bonded while passing through between the laminating roll and the lower rolling roll at the same time.

[0013] The electrode manufacturing equipment further includes a slitting unit that cuts the periphery of the electrode sheet, and the slitting unit can be arranged to face the lower rolling roll that faces the laminating roll.

[0014] The slitting unit can be provided to cut both end portions in the width direction of the electrode sheet that has passed between the upper rolling roll and the lower rolling roll.

[0015] The at least one rolling unit is a plurality of rolling units arranged apart from each other, and the calendering device may further include a tension adjustment mechanism that measures the tension applied to the electrode sheet conveyed between the plurality of rolling units and controls the rotation speed of the rolling roll.

[0016] The tension adjustment mechanism may be configured to control the rotational speed of the rolling rolls of the rolling unit disposed in front of or behind or both in front of and behind the electrode sheet.

[0017] When the tension of the electrode sheet becomes strong, the tension adjustment mechanism decelerates the rotational speed of the rolling roll disposed behind the tension adjustment mechanism (or accelerates the rotational speed of the rolling roll disposed in front), and when the tension of the electrode sheet becomes weak, the tension adjustment mechanism accelerates the rotational speed of the rolling roll disposed behind the tension adjustment mechanism (or decelerates the rotational speed of the rolling roll disposed in front). The tension adjustment mechanism may be configured as such.

[0018] The tension adjustment mechanism includes a tension holding roll that rotates and is positioned above the electrode sheet, and a displacement detector that measures the displacement of the tension holding roll, and may be configured to control the rotational speed of the rolling roll based on the displacement amount derived by the displacement detector.

[0019] The tension adjustment mechanism may further include a guide member including guide slits coupled to the rotating shafts on both sides of the tension holding roll to guide the up-and-down movement of the tension holding roll, and a load member connected to the tension holding roll to apply a constant load to the tension holding roll.

[0020] When the tension holding roll is displaced upward, based on the displacement amount, the tension adjustment mechanism decelerates the rotational speed of the rolling roll located behind the tension holding roll (or accelerates the rotational speed of the rolling roll disposed in front), and when the tension holding roll is displaced downward, based on the displacement amount, the tension adjustment mechanism accelerates the rotational speed of the rolling roll located behind the tension holding roll (or decelerates the rotational speed of the rolling roll disposed in front). The tension adjustment mechanism may be configured as such.

[0021] According to another example, the tension adjustment mechanism includes a tension sensing roll that is located on and rotates on the electrode sheet, and a sensor that measures a change in the load of the tension sensing roll, and may be configured to control the rotation speed of the rolling roll according to the change in the load measured by the sensor.

[0022] When the load of the tension sensing roll increases, the tension adjustment mechanism is configured to decelerate the rotation speed of the rolling roll located behind the tension sensing roll (or accelerate the rotation speed of the rolling roll arranged in the front) based on the amount of change in the load, and when the load of the tension sensing roll decreases, accelerate the rotation speed of the rolling roll located behind the tension sensing roll (or decelerate the rotation speed of the rolling roll arranged in the front) based on the amount of change in the load.

[0023] The electrode manufacturing equipment may further include a pre-tension adjustment mechanism that measures the tension applied to the electrode sheet conveyed between the powder sheet forming device and the rolling unit and controls the rotation speed of the supply roll or the rolling roll. The powder sheet forming device includes a pair of supply rolls that roll the dry material into a sheet shape.

[0024] The at least one rolling unit may be one rolling unit.

[0025] The electrode manufacturing equipment may further include a winding roll for winding the electrode.

Advantages of the Invention

[0026] According to the present invention, it is possible to provide electrode manufacturing equipment that can stably manufacture dry electrodes by minimizing the possibility of disconnection of the finally rolled electrode sheet after the calendaring process.

[0027] In addition, when manufacturing a dry electrode, the present invention has the effect of improving the efficiency and economy of the process by eliminating the stagnation and congestion phenomena of the electrode sheet.

[0028] In addition to these, the present invention can have various other effects, and regarding this, it will be described in the column of each implementation configuration, or for effects that can be easily analogized by those skilled in the art, such descriptions will be omitted.

Brief Description of the Drawings

[0029]

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Modes for Carrying Out the Invention

[0030] 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. Thus, there may be various equivalents and modified embodiments that can replace them at the time of this application.

[0031] Figure 2 is a schematic configuration diagram of an electrode manufacturing facility according to a first embodiment of the present invention.

[0032] As shown in Figure 2, the electrode manufacturing facility according to the present invention includes a powder sheeting processing device 100, a calendering processing device 200, and one lamination roll 300.

[0033] In the powder sheeting processing device 100, the dry material 1 is rolled to manufacture the electrode sheet 10 so that the electrode sheet 10 reaches the target porosity.

[0034] The powder sheeting processing device 100 includes a hopper 110 that contains the dry material 1 including the electrode active material, and a pair of supply rolls 120 that are arranged to face each other and rotate at the lower part of the hopper 110. The dry material 1 is input into and rolled by the pair of supply rolls 120 to primarily obtain a film-shaped electrode sheet 10. At this time, as the dry material 1, in addition to the electrode active material, various additives can be used. For example, a conductive material and a binder can be further added.

[0035] As the electrode active material, any components that are usually used for the positive and negative electrodes of a lithium secondary battery can be used.

[0036] The conductive material is used for the purpose of improving the electrical conductivity of the electrode, and generally, any conductive material that is used in the technical field of lithium secondary batteries can be used.

[0037] The binder is a component that helps bind the electrode active material and the conductive material, etc., and adhere to the current collector 20. Similarly to the above-mentioned conductive material, generally, any binder that is used in the technical field of lithium secondary batteries can be used.

[0038] The dry material 1 is put into a pair of supply rolls 120 arranged side by side horizontally or vertically in a mixed state (in the present invention, for the sake of better understanding, the description is limited to the horizontal direction) and rolled. Since the process is primarily for the purpose of processing the dry material 1, which is initially mixed in powder form, into a sheet form, the interval between the pair of supply rolls 120 included in the powder sheeting device 100 may be relatively larger than the interval between the pair of rolling rolls 211 and 212 included in the calendar processing device 200. Also, by making the rotational speeds of the pair of supply rolls 120 different from each other, a shearing force can be applied to sheet the dry material (sheeting). The larger the speed ratio of the pair of supply rolls 120, the thinner the thickness of the sheet and the lower the density. Therefore, an appropriate speed ratio and the interval between the supply rolls are set to process the dry material 1 into a sheet having a desired thickness and density.

[0039] The electrode sheet 10 rolled by the pair of supply rolls 120 and discharged downward is supported by a plurality of guide rolls 30 and the direction is switched horizontally. The guide rolls 30 are not operated by a separate drive motor, but are fixed and rotated at a certain position so that the movement of the film supported by minimal friction is performed smoothly.

[0040] The electrode sheet 10 rolled through the supply roll 120 is usually very rough at the peripheral edge and in an irregularly uneven state. Therefore, the slitting unit 40 cuts the peripheral edges on both sides in the width direction of the electrode sheet 10 so that the lengths in the width direction of the electrode sheets are aligned. Here, the slitting unit 40 is a means for cutting the peripheral edges on both sides in the width direction of the electrode sheet 10, and can be composed of, for example, a predetermined cutting blade and a drive source such as a motor for driving the cutting blade.

[0041] As shown in FIG. 2, the slitting unit 40 can be arranged between the supply roll 120 and the calendar processing device 200 in order to cut the peripheral edges on both sides of the electrode sheet before performing the calendar processing step. Further, the slitting unit 40 can be arranged so as to face the lower rolling roll 212 of the third rolling unit 210C described later in order to cut the peripheral edges on both sides of the electrode sheet once again after the calendar processing step and immediately before the lamination step.

[0042] The calendar processing device 200 is a device for stepwise rolling the electrode sheet 10 supplied from the powder sheet forming device 100 to process it to a target thickness before bonding it to the current collector 20.

[0043] Hereinafter, with reference to FIGS. 2 to 5, the calendar processing device 200 according to the first embodiment of the present invention will be described.

[0044] The calendar processing device 200 includes a pair of rolling rolls arranged to face each other and rotate, and a plurality of rolling units 210 arranged to be separated from each other, and a tension adjustment mechanism 220. For example, as shown in FIG. 2, the rolling unit 210 includes a first rolling unit 210A, a second rolling unit 210B, and a third rolling unit 210C, each of which includes a pair of rolling rolls 211 and 212, and can be arranged to be separated from each other by a predetermined interval in the lateral direction.

[0045] In this way, the rolling unit 210 includes a pair of rolling rolls 211 and 212 that rotate at a certain interval. While passing the electrode sheet 10 between the pair of rolling rolls 211 and 212, the thickness of the electrode sheet 10 can be adjusted according to the separation distance between the rolling rolls. Specifically, the pair of rolling rolls 211 and 212 are arranged side by side in the vertical or horizontal direction (in the present invention, for better understanding, the description is based on the rolling rolls arranged in the vertical direction). By rotating in different directions from each other, the electrode sheet 10 passing between them is pressed to reduce the thickness of the electrode sheet 10 and the electrode sheet 10 is stretched in the longitudinal direction. By performing the pressing, the particles contained in the electrode sheet 10 are stretched and the inside of the electrode sheet 10 becomes denser.

[0046] More specifically, the rolling unit 210 includes an upper rolling roll 211 and a lower rolling roll 212 located below the upper rolling roll 211 and arranged to face the upper rolling roll 211. One of the upper rolling roll 211 and the lower rolling roll 212 is movable in the direction of the opposing rolling roll. That is, the interval between the rolling rolls can be adjusted by the movement of the rolling rolls. At this time, the thickness of the electrode sheet 10 passing through the rolling unit 210 is adjusted according to the interval between the upper rolling roll 211 and the lower rolling roll 212. When the conveyance of the electrode sheet 10 is limited to the right side direction, the upper rolling roll 211 rotates counterclockwise and the lower rolling roll 212 rotates clockwise. For example, in the case of the first rolling unit 210A to the second rolling unit 210B, the upper rolling roll 211 rotates counterclockwise and the lower rolling roll 212 rotates clockwise so that the electrode sheet 10 is conveyed in the right side direction. In the case of the third rolling unit 210C, the upper rolling roll 211 rotates clockwise and the lower rolling roll 212 rotates counterclockwise so that the electrode sheet 10 can be conveyed in the left side direction.

[0047] The rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 in the present invention can be adjusted to be the same as each other or different from each other. For example, the higher the density of the electrode sheet 10 is adjusted such that the rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 are the same as each other, and the thinner the thickness of the electrode sheet is adjusted such that the rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 are different from each other.

[0048] The plurality of rolling units 210 can be configured such that the distance between the pair of rolling rolls becomes narrower as they proceed in the conveyance direction of the electrode sheet 10. That is, the distance between the upper rolling roll 211 and the lower rolling roll 212 of the third rolling unit 210C that presses the electrode sheet 10 last is provided to be narrower than the distance between the upper rolling roll 211 and the lower rolling roll 212 of the first rolling unit 210A that first presses the electrode sheet 10. This is because when the electrode sheet 10 in the state first introduced into the calendering process is pressed all at once to be processed to a desired thickness, there is a possibility that the electrode sheet 10 may break or be crushed during the process. Instead, when the electrode sheet 10 is pressed step by step, the burden on the electrode sheet 10 is reduced, so that the electrode sheet 10 can be stably processed to a desired thickness.

[0049] Returning to FIG. 2, it can be seen that the calendering apparatus 200 of the present invention includes a tension adjustment mechanism 220 that measures the tension applied to the electrode sheet 10 conveyed between the plurality of rolling units 210 and controls the rotational speed of the rolling roll.

[0050] The tension adjustment mechanism 220 can be configured to control the rotational speed of each rolling roll included in the rolling unit 210 disposed in front of or behind or in front and behind the electrode sheet 10.

[0051] For example, when the tension of the electrode sheet 10 increases, the tension adjustment mechanism 220 decelerates the rotational speed of the rolling roll disposed behind the electrode sheet 10 (or accelerates the rotational speed of the rolling roll disposed in front), and when the tension of the electrode sheet 10 decreases, the rotational speed of the rolling roll disposed behind the electrode sheet 10 is accelerated. At this time, the rotational speed ratio of the paired rolling rolls can be maintained.

[0052] Specifically, the tension adjustment mechanism 220 included in the calendering apparatus 200 according to the first embodiment of the present invention includes a tension holding roll 221 that rotates positioned above the electrode sheet 10 and a displacement detector 225 that measures the displacement of the tension holding roll 221, and controls the rotational speed of the rolling roll based on the displacement amount of the tension holding roll 221 derived by the displacement detector 225. Here, the tension holding roll 221 may mean a dancer roll.

[0053] With reference to FIGS. 3 to 5, the configuration, operation method, and control system of the tension adjustment mechanism 220 that controls the rotational speed of the rolling roll will be described in more detail.

[0054] Referring to FIG. 3, it can be seen that the tension holding roll 221 is positioned above the electrode sheet 10 and transmits a certain load to the electrode sheet 10.

[0055] In addition, the tension adjustment mechanism 220 further includes a guide member 222 including guide slits 223 coupled to the rotating shafts on both sides of the tension holding roll 221 to guide the tension holding roll 221 to move up and down, and a load member 224 connected to the rotating shaft of the tension holding roll 221 to apply a certain load (force F) to the tension holding roll 221.

[0056] The tension holding roll 221 can be rotatably coupled to a rotating shaft. For example, the tension holding roll 221 and the rotating shaft can be connected via a member (not shown) such as a bearing. The rotating shafts protruding through both side surfaces of the tension holding roll 221 can be respectively coupled to guide members 222. Specifically, the rotating shafts can be inserted into and supported by guide slits 223 formed along the height direction of the guide members 222. The guide members 222 are fixed to the bottom surface or the like, and the rotating shafts support the tension holding roll 221 while moving up and down along the guide slits 223.

[0057] The tension holding roll 221 can be held in a state of receiving a constant load (force F) in the direction of gravity, and the electrode sheet 10 will be transmitted a constant force F through the tension holding roll 221 by the load. The load can be directly transmitted to the rotating shaft connected to the tension holding roll 221. Specifically, the load can be generated by a load member 224 connected to the rotating shaft. The load member 224 can be composed of, for example, a spring, a pneumatic pressure (not shown), a weight (not shown), etc., and a load of a certain magnitude can be applied to the tension holding roll 221 by the load member 224. Taking the spring as an example, one end of the spring can be coupled to the rotating shaft and the other end can be fixed to the bottom surface. The load can be limited by the return force and length of the spring fixed to the bottom surface.

[0058] As a result, the tension holding roll 221 will continuously apply a constant load corresponding to the return force of the spring to the electrode sheet 10.

[0059] The displacement detector 225 is a device that measures the change in the position of the tension holding roll 221. The displacement detector 225 may be an ordinary detector that measures the displacement of a dancer roll, and the measurement method thereof is not necessarily particularly limited in the present invention.

[0060] Next, referring to FIG. 4, rolling units 210 including an upper rolling roll 211 and a lower rolling roll 212 are respectively arranged in front of and behind a tension holding roll 221. It can be seen that the electrode sheet 10 that has passed through the rolling unit 210 located in the front passes through the tension holding roll 221 and then passes through the rolling unit 210 located in the rear. Between the two rolling units 210, a pair of support rolls R1 for supporting the electrode sheet 10 and switching the conveyance direction may be further provided. Specifically, the electrode sheet 10 conveyed from the rolling unit 210 located in front of the tension holding roll 221 is guided downward by the support roll R1 and passes through the lower part of the tension holding roll 221. After that, the electrode sheet 10 that has passed through the tension holding roll 221 moves upward and is then guided forward by the other support roll R2 and conveyed to the rolling unit 210 located behind the tension holding roll 221. At this time, the electrode sheet 10 passing through the lower part of the tension holding roll 221 receives a certain load from the tension holding roll 221.

[0061] That is, the tension holding roll 221 is transmitted a certain force F through a spring with a part fixed to the bottom surface, and the tension holding roll 221 applies the same force F to the electrode sheet 10 passing through the lower part. For example, when the electrode sheet 10 is loose, the support condition for supporting the tension holding roll 221 becomes weak, and the tension holding roll 221 will be displaced downward. Conversely, when the electrode sheet 10 is taut, the support condition for supporting the tension holding roll 221 becomes strong, and the tension holding roll 221 will be displaced upward.

[0062] Next, referring to FIG. 5, the tension adjusting mechanism 220 of the present invention may further include a control unit 229 for controlling the rotation speeds of a pair of rolling rolls 211 and 212 provided in the rolling unit 210.

[0063] The control unit 229 may sense the displacement of the tension holding roll 221 via the displacement detector 225 and control the respective rotation speeds of the rolling rolls.

[0064] For example, when the tension holding roll 221 is displaced upward, the tension adjusting mechanism 220 decelerates the rotational speed of a pair of rolling rolls located behind the tension holding roll 221 or accelerates the rotational speed of a pair of rolling rolls located in front of it based on the amount of displacement, so that the tension applied to the electrode sheet 10 can be kept constant.

[0065] For example, due to the difference in the rotational speeds of the respective rolling rolls included in the rolling unit 210, the tension may change, causing the electrode sheet to become slack or taut compared to the normal state. As a result, although the tension holding roll is movable up and down, the control unit 229 can sense this via the displacement detector 225 and control the rotational speeds of the respective rolling rolls.

[0066] That is, in the calendering process, there may be a slight difference in the supply and conveyance speed of the electrode sheet, the rotational speed between the rolling rolls, etc., which may cause the electrode sheet to become slack or overly taut. As a result, when the tension holding roll 221 moves up and down, the position of the tension holding roll 221 may be displaced. At this time, the displacement of the tension holding roll 221 is detected by the displacement detector 225, and the detected displacement data of the tension holding roll 221 is passed to the control unit 229. Based on the amount of displacement of the tension holding roll 221, the control unit 229 will adjust the rotational speed of the rolling rolls included in either one of the rolling units 210 located in front of and behind the tension holding roll 221. At this time, the adjustment of the rotational speed of the rolling rolls is achieved by controlling the rotational speeds of the drive motors M1, M2, M1', M2' connected to the respective rolling rolls.

[0067] For example, if the tension holding roll 221 is displaced downward between the first rolling unit 210A and the second rolling unit 210B, the control unit 229 decelerates the rotational speed of a pair of rolling rolls included in the first rolling unit 210A or accelerates the rotational speed of a pair of rolling rolls included in the second rolling unit 210B. Then, the electrode sheet 10 can be conveyed at an appropriate speed without slackening under a constant tension applied by the tension holding roll.

[0068] For example, if the tension holding roll 221 is displaced downward between the first rolling unit 210A and the second rolling unit 210B, the control unit 229 decelerates the rotational speed of a pair of rolling rolls included in the first rolling unit 210A or accelerates the rotational speed of a pair of rolling rolls included in the second rolling unit 210B. Then, the electrode sheet 10 can be conveyed at an appropriate speed without slackening while maintaining an appropriate tension by the tension holding roll 221.

[0069] For another example, if the tension holding roll 221 is displaced upward, the control unit 229 accelerates the rotational speed of a pair of rolling rolls included in the first rolling unit 210A or decelerates the rotational speed of a pair of rolling rolls included in the second rolling unit. Then, the electrode sheet 10 can be conveyed without being overly taut while maintaining an appropriate tension by the tension holding roll 221.

[0070] As described above, by moving up and down, the tension holding roll 221, together with the control unit 229, detects changes in the tension of the electrode sheet 10 and controls the rotational speed of the rolling rolls included in the rolling unit 210 located in front of or behind the electrode sheet 10, thereby playing a role in ensuring that the electrode sheet 10 maintains a constant tension.

[0071] Next, referring to FIG. 6, the electrode manufacturing equipment according to the present invention includes a lamination roll 300 that forms an electrode by attaching an electrode sheet 10 rolled to a target thickness via the calendar processing device to a current collector 20. The one lamination roll 300 is arranged to face one of a pair of rolling rolls of a third rolling unit 210C that finally rolls the electrode sheet 10.

[0072] For example, as in the embodiment configuration of FIG. 6, by arranging the lamination roll to face the lower rolling roll 212 of the third rolling unit 210C directly, the electrode sheet 10 with the thinnest thickness after the calendar processing step by the third rolling unit 210C, that is, the last calendar processing step, can be prevented from being conveyed while floating in the air until it is attached to the current collector 20 (as in FIG. 1 of the prior art). That is, according to the above configuration of the present invention, since the electrode sheet 10 is not conveyed while floating in the air from the time the last calendar processing step is performed until it is attached to the current collector 20, almost no tension is applied to the electrode sheet 10. As a result, there is an effect that the possibility of wire breakage is suppressed as much as possible. Thereby, the lamination process can be stably performed, and the yield of electrode production is improved.

[0073] More specifically, the calendar processing step by the third rolling unit 210C, that is, the last calendar processing step and the lamination step are configured to be continuously performed by three rollers arranged in the vertical direction. Here, the three rollers mean the upper rolling roll 211, the lower rolling roll 212 of the third rolling unit 210C, and the lamination roll 300. And the upper rolling roll 211 of the third rolling unit 210C may be configured to rotate in the clockwise direction, the lower rolling roll 212 may be configured to rotate in the counterclockwise direction, and the lamination roll 300 may be configured to rotate in the clockwise direction.

[0074] According to the above configuration, while the electrode sheet 10 is wound in the clockwise direction along the upper rolling roll 211, it passes between the upper rolling roll 211 and the lower rolling roll 212, and after being finally rolled to the target thickness, the conveying direction can be switched and it can be conveyed in the counterclockwise direction along the lower rolling roll 212.

[0075] In this way, in the process of the electrode sheet 10 being wound and conveyed in the counterclockwise direction along the lower rolling roll 212, the slitting process can be performed again. This is to align the length in the width direction of the electrode sheet 10 by cutting the portions where the electrode sheet 10 is rolled by the last calendar process and the peripheral edges on both sides in the width direction have an irregular bumpy shape. For this reason, the slitting unit 40 can be arranged to face the lower rolling roll 212 at a position further forward than the lamination roll 300 and configured to cut both end portions in the width direction of the electrode sheet 10. Such a slitting unit 40 can be realized by a rotatable disk-shaped cutting blade.

[0076] As described above, the electrode sheet 10 passes between the lower rolling roll 212 and the lamination roll 300 while being wound in the counterclockwise direction along the lower rolling roll 212 in a state where both end portions in the width direction have been cut through the slitting process. At this time, the electrode sheet 10 can be bonded to each other by heat and pressure while passing together between the lower rolling roll 212 and the lamination roll 300 with the current collector 20 supplied from the current collector supply roll 120. The current collector 20 is located below the electrode sheet 10 to which the current collector supply roll 50 is conveyed and is bonded to the lower surface of the electrode sheet 10.

[0077] Here, the current collector 20 can be made of materials such as stainless steel, aluminum, nickel, titanium, fired carbon, copper, and stainless steel or aluminum alloy surface-treated with copper / carbon / nickel / titanium / silver, etc. In addition to these, generally, any current collector 20 used in the technical field of lithium secondary batteries may be used.

[0078] Generally, after coating the current collector 20 with an electrode slurry manufactured in a slurry form by dispersing an electrode material in a solvent, the electrode is manufactured through a drying step. However, in the case of the present invention, since the electrode sheet 10 manufactured by rolling the dry material 1 is directly attached to the current collector 20 without using a solvent, a separate drying process becomes unnecessary.

[0079] As described above, the electrode sheet 10 having achieved the target thickness, tissue density, porosity, etc. through the calendar processing step and the slit processing step is manufactured. After passing through the lamination step of attaching the electrode sheet 10 and the current collector 20, a dry electrode film can be completed. The dry electrode film can be wound around a winding roll 60 for storage or transportation.

[0080] On the other hand, a double-sided laminated electrode can be manufactured by laminating (laminating) an electrode sheet on the back surface of the single-sided laminated electrode film manufactured by the above-described method. (In this case, the current collector of the current collector supply roll 50 in FIG. 6 can replace the single-sided laminated electrode film.) Alternatively, for example, other calendar processing devices and slit processing facilities arranged to face the above-described calendar processing device and slit processing facilities may be constructed to manufacture a double-sided laminated electrode.

[0081] Next, with reference to the drawings, the electrode manufacturing equipment according to the second embodiment of the present invention will be described.

[0082] The same member numbers as those in the foregoing embodiment indicate the same members, and duplicate descriptions of the same members are omitted. The description will focus on the differences from the foregoing embodiment.

[0083] That is, as shown in FIG. 7, the electrode manufacturing equipment according to the second embodiment of the present invention has differences in the tension adjustment mechanism 230 of the calendar processing device 200 compared with the aforementioned first embodiment, and the remaining configurations are substantially the same. Therefore, the configuration of the tension adjustment mechanism 230 according to the second embodiment will be described in detail.

[0084] The tension adjustment mechanism 230 included in the calendar processing device 200 according to the second embodiment of the present invention includes a tension sensing roll 231 that rotates in contact with one side of the electrode sheet 10 and a sensor 233 that measures a change in the load of the tension sensing roll 231, and controls the rotation speed of the rolling roll according to the change in the load measured by the sensor 233.

[0085] FIG. 8 is a schematic perspective view of the tension adjustment mechanism 230 of the present invention.

[0086] Referring to FIG. 8, the tension adjustment mechanism 230 of the present invention may include a support block 234 that supports the tension sensing roll 231 on both sides of the tension sensing roll 231 and measures a change in the load of the tension sensing roll 231. Specifically, it can be seen that the tension sensing roll 231 is arranged to rotate while being in contact with one side of the electrode sheet 10 and supporting the electrode sheet 10, and the rotating shaft 232 passes through the tension sensing roll 231. The tension sensing roll 231 can be supported and rotated by the rotating shaft 232. The rotating shafts 232 protruding through both side surfaces of the tension sensing roll 231 can be respectively coupled to the support blocks 234. Specifically, the rotating shaft 232 can be fitted into and supported by a groove (not shown) formed on the side surface of the support block 234. A sensor 233 capable of sensing a change in the weight of the rotating shaft 232 may be further included at a portion of the groove in contact with the rotating shaft 232. (For reference, the sensor 233 may be arranged under the support block 234 and configured to measure a change in weight.)

[0087] The sensor 233 provided in the groove will sense a change in the weight of the rotating shaft 232 that supports the tension sensing roll 231, and this principle is substantially the same as that of a normal electronic scale for measuring weight.

[0088] The tension sensing roll 231 is located below the electrode sheet 10 and receives a certain tension from the electrode sheet 10. At this time, if the tension of the electrode sheet 10 is strong, the force F pressing the tension sensing roll 231 located below becomes strong, and the load of the tension sensing roll 231 recorded by the sensor 233 increases. Conversely, when the tension of the electrode sheet 10 becomes weak, the force F pressing the tension sensing roll 231 located below becomes weak, and the load of the tension sensing roll 231 recorded by the sensor 233 decreases.

[0089] The sensor 233 is to measure the change in the load of the tension sensing roll 231 transmitted through the rotating shaft 232. Such a sensor 233 can be replaced with a normal load cell for measuring changes such as the force F and pressure applied to the roll.

[0090] Similar to the first embodiment, the tension adjustment mechanism 230 according to the second embodiment may include a control unit 229 that controls the rotation speed ratio of a pair of rolling rolls.

[0091] The control unit 229 controls the rotation speed of the rolling roll to be accelerated or decelerated according to the amount of change in the load of the tension sensing roll 231 measured by the sensor 233.

[0092] Referring to FIGS. 8 and 9, the load on the tension sensing roll 231 that receives a load in the gravitational direction due to the tension of the electrode sheet 10 will change in proportion to the amount of change in the tension of the electrode sheet 10. Then, the change in the load on the tension sensing roll 231 is sensed by the sensor 233, and the amount of change in the load on the tension sensing roll 231 is transmitted to the control unit 229. Based on the amount of change in the load on the tension sensing roll 231, the control unit 229 adjusts, for example, the rotational speed of the rolling roll included in either the first rolling unit 210A or the second rolling unit 210B located in front of and behind the tension sensing roll 231. At this time, the adjustment of the rotational speed of the rolling roll is achieved by controlling the rotational speeds of the drive motors M1, M2, M1', and M2' connected to the respective rolling rolls 211 and 212.

[0093] For example, when the tension of the electrode sheet 10 weakens and the load on the tension sensing roll 231 decreases, the control unit 229 accelerates the rotational speed of a pair of rolling rolls included in the second rolling unit 210B, for example. At this time, if the process continues without detecting the state where the tension of the electrode sheet 10 has weakened, there is a risk that the electrode sheet 10 may become slack and cannot be transported normally, or a phenomenon may occur where the electrode sheet 10 is wound around the rolling roll and becomes jammed or crushed.

[0094] For another example, when the tension of the electrode sheet 10 strengthens and the load on the tension sensing roll 231 increases, the control unit 229 decelerates the rotational speed of a pair of rolling rolls included in the second rolling unit 210B, for example. At this time, if the process continues without detecting the state where the tension of the electrode sheet 10 has strengthened, there is a risk that the electrode sheet 10 may break during the process due to being taut.

[0095] As described above, the tension adjustment mechanism 230 detects a change in the tension of the electrode sheet 10 by using a change in the load on the tension sensing roll 231, and controls the rotational speed of the rolling rolls included in the rolling unit located in front of or behind the electrode sheet 10, thereby being able to play a role in adjusting the tension of the electrode sheet 10.

[0096] FIG. 10 is a schematic configuration diagram of an electrode manufacturing facility according to a third embodiment of the present invention.

[0097] Next, an electrode manufacturing facility according to a third embodiment of the present invention will be described.

[0098] The same member numbers as those in the foregoing embodiments indicate the same members, and duplicate descriptions of the same members are omitted. The description will focus on the differences from the foregoing embodiments.

[0099] The electrode manufacturing facility according to the third embodiment of the present invention is characterized in that the rolling unit 210 included in the calendering device is single, as compared with the foregoing first and second embodiments. That is, according to the electrode manufacturing facility according to the third embodiment, an electrode sheet 10 having a target thickness is manufactured by a single calendering process, and as shown in FIG. 10, the slitting unit and the lamination roll 300 are arranged so as to face the lower rolling roll 212, respectively, so that the slitting process and the lamination process can be performed while the electrode sheet 10 rotates along the circumference of the lower rolling roll 212.

[0100] Such an electrode manufacturing facility according to the third embodiment, as compared with the electrode manufacturing facilities according to the first and second embodiments, has a single rolling unit, and can omit other accompanying devices such as the tension adjustment mechanisms 220 and 230, making it easy to construct and operate the facility, and moreover, significantly reducing the facility construction cost.

[0101] FIG. 11 is a schematic configuration diagram of an electrode manufacturing facility according to a fourth embodiment of the present invention.

[0102] As shown in FIG. 11, the electrode manufacturing equipment according to the fourth embodiment of the present invention may include a powder sheet forming device 100, a calendering device 200, and a laminating roll 300. In particular, the rolling rolls constituting the calendering device 200 according to the present embodiment may be configured such that a number of rolling rolls are continuously arranged horizontally (laterally) at a predetermined interval from each other. In this case, compared with the electrode manufacturing equipment according to the first and second embodiments, other accompanying devices such as the tension adjusting mechanisms 220 and 230 can be omitted. And compared with the third embodiment, further rolling of the electrode film is possible.

[0103] FIG. 12 is a schematic configuration diagram of the electrode manufacturing equipment according to the fifth embodiment of the present invention.

[0104] The same member numbers as those in the foregoing embodiments indicate the same members, and overlapping descriptions of the same members are omitted, and the description will focus on the differences from the foregoing embodiments.

[0105] The electrode manufacturing equipment according to the present invention may further include a pre-tension adjusting mechanism 400 between the powder sheet forming device 100 and the rolling unit 210 of the calendering device 200. The pre-tension adjusting mechanism 400 may be configured to substantially have the same configuration and function as the foregoing tension adjusting mechanism 220. The pre-tension adjusting mechanism 400 may be arranged at the position of the guide roll 30 located between the powder sheet forming device 100 and the rolling unit 210 of the calendering device 200 shown in FIGS. 2, 7, 10, and 11, respectively. In this case, the guide roll 30 may be omitted.

[0106] Specifically, as shown in FIG. 12, the pre-tension adjusting mechanism 400 may be arranged between the powder sheet forming device 100 and the rolling unit 210 of the calendering device 200 in the electrode manufacturing equipment according to the fifth embodiment of the present invention.

[0107] The pre-tension adjustment mechanism 400 may be configured to control the rotational speed of a pair of supply rolls 120 disposed in front of the electrode sheet 10 or a pair of rolling rolls 211 and 212 disposed behind the electrode sheet 10, or to control the rotational speed ratio of the pair of supply rolls 120 and / or the pair of rolling rolls 211 and 212.

[0108] Further, the pre-tension adjustment mechanism 400 includes a tension holding roll 410 that rotates and is positioned above the electrode sheet 10 and a displacement detector (not shown) that measures the displacement of the tension holding roll 410, and is configured to control the rotational speed of the supply roll 120 or the rolling rolls 211 and 212 based on the displacement amount of the tension holding roll 221 derived by the displacement detector.

[0109] For example, when the tension of the electrode sheet 10 increases, the pre-tension adjustment mechanism 400 decelerates the rotational speed of a pair of rolling rolls 211 and 212 disposed behind the electrode sheet 10 (or accelerates the rotational speed of a pair of supply rolls 120 disposed in front), and conversely, when the tension of the electrode sheet 10 decreases, accelerates the rotational speed of a pair of rolling rolls 211 and 212 disposed behind the electrode sheet 10. At this time, the rotational speed ratio of the paired rolling rolls 211 and 212 that rotate together may be kept. Other components related to the pre-tension adjustment mechanism 400 shall be replaced with the description of the aforementioned tension adjustment mechanism 220.

[0110] According to the pre-tension adjustment mechanism 400 according to the fifth embodiment of the present invention as described above, the electrode sheet 10 rolled by the pair of supply rolls 120 and discharged downward can be supported by the tension holding roll 410 of the pre-tension adjustment mechanism 400 and guided upward. In addition, the phenomenon of stagnation and clogging of the electrode sheet 10 between the powder sheet forming device 100 and the calendar processing device 200 can be eliminated, and the manufacturing process of the electrode can be made smoother.

[0111] As described above, the present invention has been explained with reference to limited embodiments and drawings. However, 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 and implement them.

[0112] On the other hand, in this specification, terms indicating directions such as up, down, left, right, front, and rear are used, but these terms are merely used for ease of explanation, and it is obvious to those skilled in the art of the present invention that they may vary depending on the position of the object in question and the position of the observer, etc.

Claims

1. Equipment for manufacturing a dry electrode, comprising: A powder sheet forming device for processing a dry material containing an electrode active material into a sheet; A calendar processing device including at least one rolling unit each having a pair of rolling rolls for rolling an electrode sheet supplied from the powder sheet forming device; One lamination roll for forming an electrode by laminating the electrode sheet rolled to a target thickness via the calendar processing device onto a current collector; and The lamination roll is arranged to face one of the pair of rolling rolls of the rolling unit that finally rolls the electrode sheet. An electrode manufacturing equipment.

2. The rolling unit includes an upper rolling roll and a lower rolling roll located below the upper rolling roll, The electrode manufacturing equipment according to claim 1, wherein the thickness of the electrode sheet is adjusted according to the interval between the upper rolling roll and the lower rolling roll.

3. The lamination roll is arranged to face the lower rolling roll, The electrode manufacturing equipment according to claim 2, wherein the electrode sheet and the current collector are simultaneously passed through and crimped between the lamination roll and the lower rolling roll.

4. The electrode manufacturing equipment further includes a slitting unit for cutting the periphery of the electrode sheet, The electrode manufacturing equipment according to claim 2, wherein the slitting unit is arranged to face the lower rolling roll facing the lamination roll.

5. The electrode manufacturing equipment according to claim 4, wherein the slitting unit is provided to cut both end portions in the width direction of the electrode sheet passing between the upper rolling roll and the lower rolling roll.

6. The at least one rolling unit is a plurality of rolling units arranged apart from each other, The electrode manufacturing equipment according to claim 1, wherein the calendar processing device further includes a tension adjustment mechanism for measuring the tension applied to the electrode sheet conveyed between the plurality of rolling units and controlling the rotation speed of the rolling roll.

7. The electrode manufacturing equipment according to claim 6, wherein the tension adjustment mechanism controls the rotation speed of each rolling roll of the rolling unit arranged in front of or behind or in front and behind the electrode sheet, or the rotation speed ratio of the pair of rolling rolls provided in the rolling unit.

8. The tension adjustment mechanism is When the tension of the electrode sheet increases, the rotational speed of the rolling roll disposed behind the tension adjustment mechanism is decelerated, or the rotational speed of the rolling roll disposed in front is accelerated. When the tension of the electrode sheet decreases, the rotational speed of the rolling roll disposed behind the tension adjustment mechanism is accelerated, or the rotational speed of the rolling roll disposed in front is decelerated. The electrode manufacturing equipment according to claim 6.

9. The tension adjustment mechanism includes a tension holding roll that rotates and is positioned above the electrode sheet, and a displacement detector that measures the displacement of the tension holding roll. The electrode manufacturing equipment according to claim 6, wherein the tension of the electrode sheet is measured according to the displacement derived by the displacement detector, and the rotational speed of the rolling roll is controlled based on the tension.

10. The tension adjustment mechanism includes a guide member including guide slits coupled to the rotating shafts on both sides of the tension holding roll to guide the tension holding roll to move vertically, and a load member connected to the tension holding roll to apply a constant load to the tension holding roll. The electrode manufacturing equipment according to claim 9.

11. The tension adjustment mechanism decelerates the rotational speed of the rolling roll located behind the tension holding roll or accelerates the rotational speed of the rolling roll disposed in front based on the displacement amount when the tension holding roll is displaced upward, and accelerates the rotational speed of the rolling roll located behind the tension holding roll or decelerates the rotational speed of the rolling roll disposed in front based on the displacement amount when the tension holding roll is displaced downward. The electrode manufacturing equipment according to claim 9.

12. The tension adjustment mechanism includes a tension sensing roll that rotates and is positioned on the electrode sheet, and a sensor that measures the change in the load of the tension sensing roll. The electrode manufacturing equipment according to claim 6, wherein the rotational speed of the rolling roll is controlled according to the change in the load measured by the sensor.

13. The tension adjustment mechanism when the load of the tension sensing roll increases, based on the change amount of the load, decelerates the rotational speed of the rolling roll disposed behind the tension sensing roll or accelerates the rotational speed of the rolling roll disposed in front, When the load on the tension sensing roll decreases, based on the amount of change in the load, the rotational speed of the rolling roll located behind the tension sensing roll is accelerated, or the rotational speed of the rolling roll arranged in front is decelerated. The electrode manufacturing equipment according to claim 12.

14. The powder sheet forming device includes a pair of supply rolls for rolling the dry material into a sheet shape. The electrode manufacturing equipment further includes a pre-tension adjustment mechanism that measures the tension applied to the electrode sheet conveyed between the powder sheet forming device and the rolling unit and controls the rotational speed of the supply roll or the rolling roll. The electrode manufacturing equipment according to claim 6.

15. The at least one rolling unit is one rolling unit. The electrode manufacturing equipment according to claim 1.

16. The electrode manufacturing equipment further includes a winding roll for winding the electrode. The electrode manufacturing equipment according to claim 1.

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