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. More specifically, by measuring and adjusting the tension of an electrode sheet during a calendar processing step, the electrode sheet can be stably manufactured, and the present invention relates to dry electrode manufacturing equipment capable of minimizing the possibility of wire breakage occurring in the electrode sheet after performing the calendar processing step.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0137646 filed on October 24, 2022, and all 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 necessary 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 calendar processing step of passing an electrode sheet through a plurality of rolling rolls to manufacture an electrode having a desired 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] Furthermore, the calendering process can be repeated one to three times, depending on the active material and process conditions. For example, to manufacture an electrode with a desired thickness, calendering may be performed in the order of first, second, and third times, as shown in Figure 1. However, performing calendering in this manner has the problem that the thickness of the electrode sheet becomes thinner and thinner, reducing the breaking strength and gradually increasing the possibility of wire breakage. In particular, as shown in the part indicated as "E1" in Figure 1, the electrode sheet floats in mid-air during the process of moving to the lamination device after the final calendering, and this is when the possibility of wire breakage is highest. [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention was devised in view of the above circumstances, and its purpose is to provide electrode manufacturing equipment that can minimize the possibility of wire breakage occurring in the electrode sheet that is finally rolled after the calendering process.

[0008] Another object of the present invention is to provide electrode manufacturing equipment that can prevent electrode sheets from becoming entangled with each other due to stagnation and congestion during the calendering process.

[0009] However, the technical problems that this invention aims to solve are not limited in any way to those described above, and other problems not mentioned should be clearly understood by those skilled in the art from the description of the invention below. [Means for solving the problem]

[0010] To solve the above problems, the electrode manufacturing equipment according to the present invention includes a powder sheet processing apparatus for processing a dry material containing an electrode active material into a sheet; a calendering apparatus including at least one rolling unit, each equipped with a pair of rolling rolls, for rolling the electrode sheet supplied from the powder sheet processing apparatus; and a lamination roll for bonding the electrode sheet, which has been rolled to a desired thickness via the calendering apparatus, with a current collector to form an electrode, wherein the lamination roll may be positioned to face each other with either of the pair of rolling rolls of the rolling unit that ultimately 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 to match the distance between the upper rolling roll and the lower rolling roll.

[0012] The lamination roll may be arranged to face the lower rolling roll and be configured such that the electrode sheet and the current collector are pressed together while simultaneously passing between the lamination roll and the lower rolling roll.

[0013] The electrode manufacturing equipment further includes a slitting unit for cutting the periphery of the electrode sheet, and the slitting unit may be positioned to face the lower rolling roll which faces the lamination roll.

[0014] The slitting unit may be provided to cut both ends in the width direction of the electrode sheet as it passes 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 apparatus may further include a tension adjustment mechanism that measures the tension applied to the electrode sheet being transported between the plurality of rolling units and controls the rotational speed of the rolling rolls.

[0016] The tension adjustment mechanism may be configured to control the rotational speed of the rolling rolls of a rolling unit positioned in front of, behind, or between the electrode sheet.

[0017] The tension adjustment mechanism may be configured such that when the tension of the electrode sheet increases, it reduces the rotational speed of the rolling rolls located behind the tension adjustment mechanism (or accelerates the rotational speed of the rolling rolls located in front of it), and when the tension of the electrode sheet decreases, it accelerates the rotational speed of the rolling rolls located behind the tension adjustment mechanism (or reduces the rotational speed of the rolling rolls located in front of it).

[0018] The tension adjustment mechanism may include a tension-holding roll positioned above the electrode sheet and rotating, and a displacement detector for measuring the displacement of the tension-holding roll, and may be configured to control the rotational speed of the rolling roll based on the amount of displacement derived by the displacement detector.

[0019] The tension adjustment mechanism may further include a guide member including guide slits that are coupled to the rotation axes on both sides of the tension-holding roll to guide the tension-holding roll so that it can move up and down, and a load member that is connected to the tension-holding roll to apply a constant load to the tension-holding roll.

[0020] The tension adjustment mechanism may be configured to decelerate the rotational speed of the rolling roll located behind the tension-holding roll (or accelerate the rotational speed of the rolling roll located in front of it) based on the amount of displacement when the tension-holding roll is displaced upward, and to accelerate the rotational speed of the rolling roll located behind the tension-holding roll (or decelerate the rotational speed of the rolling roll located in front of it) based on the amount of displacement when the tension-holding roll is displaced downward.

[0021] According to another example, the tension adjustment mechanism includes a tension sensing roll that rotates and is located 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 decelerates the rotation speed of the rolling roll located behind the tension sensing roll (or accelerates 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, it accelerates the rotation speed of the rolling roll located behind the tension sensing roll (or decelerates the rotation speed of the rolling roll arranged in the front) based on the amount of change in the load, and may be configured to do so.

[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 processing device and the rolling unit, where the powder sheet forming processing device includes a pair of supply rolls for rolling the dry material into a sheet shape, and controls the rotation speed of the supply roll or the rolling roll.

[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 suppressing as much as possible the possibility of disconnection of the finally rolled electrode sheet after the calendering process.

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

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

Brief Description of the Drawings

[0029] [Figure 1] It is a schematic configuration diagram of an electrode manufacturing facility according to the prior art. [Figure 2] It is a schematic configuration diagram of an electrode manufacturing facility according to the first embodiment of the present invention. [Figure 3] It is a perspective view of the tension adjustment mechanism in FIG. 2. [Figure 4] It is a diagram showing a driving example of the tension adjustment mechanism according to the first embodiment of the present invention. [Figure 5] It is a control system diagram of the tension adjustment mechanism in FIG. 4. [Figure 6] It is a diagram showing an enlarged view of the portion of the third rolling unit in FIG. 2. [Figure 7] It is a schematic configuration diagram of an electrode manufacturing facility according to the second embodiment of the present invention. [Figure 8] It is a perspective view of the tension adjustment mechanism in FIG. 7. [Figure 9] It is a control system diagram of the tension adjustment mechanism in FIG. 8. [Figure 10] It is a schematic configuration diagram of an electrode manufacturing facility according to the third embodiment of the present invention. [Figure 11] It is a schematic configuration diagram of an electrode manufacturing facility according to the fourth embodiment of the present invention. [Figure 12] It is a schematic configuration diagram of an electrode manufacturing facility according to the fifth embodiment of the present invention.

Modes for Carrying Out the Invention

[0030] Preferred embodiments of the present invention will now be described in detail based on the accompanying drawings. Prior to this, terms and words used in this specification and in the claims are not to be interpreted in their ordinary or dictionary sense, but rather in accordance with the principle that the inventor may appropriately define the concepts of terms in order to best describe the invention, and are to be interpreted in the sense and concepts corresponding to the technical idea of ​​the present invention. Therefore, the embodiments described herein and the configurations shown in the drawings are merely preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention; it should be understood that there may be a variety of equivalent and modified embodiments that can be substituted for these at the time of this application.

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

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

[0033] In the powder sheet processing apparatus 100, the electrode sheet 10 is manufactured by rolling the dry material 1 so that the electrode sheet 10 reaches the desired porosity.

[0034] The powder sheet processing apparatus 100 includes a hopper 110 containing a dry material 1 containing an electrode active material, and a pair of rotating feed rolls 120 positioned opposite each other at the bottom of the hopper 110. The dry material 1 is fed into the pair of feed rolls 120 and rolled to temporarily obtain a film-like electrode sheet 10. In this case, in addition to the electrode active material, a wide variety of additives can be used as the dry material 1, but for example, conductive materials and binders may be added.

[0035] As the electrode active material, any component commonly used for the positive and negative electrodes of lithium secondary batteries can be used.

[0036] The aforementioned conductive material is used to improve the electrical conductivity of the electrode, and any conductive material commonly used in the field of lithium secondary batteries can be used.

[0037] The binder is a component that assists in the bonding of the electrode active material with the conductive material and its adhesion to the current collector 20. Similar to the conductive material, any binder commonly used in the field of lithium secondary batteries can be used.

[0038] The dry material 1 is fed into a pair of supply rolls 120 arranged horizontally or vertically (in this invention, for the sake of understanding, it is described only horizontally) in a mixed state and rolled. Since the above process is performed for the purpose of processing the dry material 1, which has been initially mixed in powder form, into a sheet, the distance between the pair of supply rolls 120 included in the powder sheeting apparatus 100 may be relatively larger than the distance between the pair of rolling rolls 211 and 212 included in the calendering apparatus 200. Furthermore, by making the rotation speeds of the pair of supply rolls 120 different from each other, shear force can be applied to sheet the dry material. The larger the speed ratio of the pair of supply rolls 120, the thinner the sheet becomes and the lower the density becomes. For this reason, the dry material 1 is processed into a sheet with the desired thickness and density by setting an appropriate speed ratio and distance between the supply rolls.

[0039] The electrode sheet 10, which is rolled by the pair of supply rolls 120 and discharged downward, is supported by a plurality of guide rolls 30 and its direction is switched horizontally. The guide rolls 30 are not driven by a separate drive motor, but are fixed in a fixed position and rotate to ensure smooth movement of the supported film with minimal friction.

[0040] The electrode sheet 10 rolled via the supply roll 120 usually has very rough and irregularly uneven edges. Therefore, the slitting unit 40 cuts the edges on both sides in the width direction of the electrode sheet 10 so that the length of the electrode sheet in the width direction is uniform. The slitting unit 40 is a means for cutting the edges on both sides in the width direction of the electrode sheet 10 and may consist, for example, of a predetermined cutting blade and a drive source such as a motor that drives the cutting blade.

[0041] As shown in Figure 2, the slitting unit 40 may be positioned between the supply roll 120 and the calendering device 200 to cut the peripheral edges on both sides of the electrode sheet before the calendering process. Alternatively, the slitting unit 40 may be positioned opposite the lower rolling roll 212 of the third rolling unit 210C, which will be described later, to cut the peripheral edges on both sides of the electrode sheet once more after the calendering process and immediately before the lamination process.

[0042] The calendering apparatus 200 is a device for rolling the electrode sheet 10 supplied from the powder sheet processing apparatus 100 in stages to the desired thickness before bonding it with the current collector 20.

[0043] In the following, a calendering apparatus 200 according to the first embodiment of the present invention will be described with reference to Figures 2 to 5.

[0044] The calendering apparatus 200 includes a plurality of rolling units 210, each having a pair of rolling rolls that are arranged opposite each other and rotate, and arranged apart from each other, and a tension adjustment mechanism 220. For example, as shown in Figure 2, the rolling units 210 may include a first rolling unit 210A, a second rolling unit 210B, and a third rolling unit 210C, each having a pair of rolling rolls 211, 212, and arranged apart from each other by a predetermined distance in the lateral direction.

[0045] Thus, the rolling unit 210 includes a pair of rolling rolls 211 and 212 that rotate at a fixed distance apart, but the thickness of the electrode sheet 10 can be adjusted by an amount corresponding to the distance between the rolling rolls as the electrode sheet 10 passes between the pair of rolling rolls 211 and 212. Specifically, the pair of rolling rolls 211 and 212 are arranged to be aligned in the vertical or horizontal direction (in this invention, for the sake of understanding, the explanation is based on rolling rolls arranged in the vertical direction), and by rotating in different directions from each other, they press the electrode sheet 10 passing between them, reducing the thickness of the electrode sheet 10 and stretching the electrode sheet 10 in the longitudinal direction. By performing this pressing, the particles contained in the electrode sheet 10 are stretched, and the inside of the electrode sheet 10 becomes even 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 positioned opposite the upper rolling roll 211. Either the upper rolling roll 211 or the lower rolling roll 212 is movable in the direction of the opposing rolling roll. That is, the distance between the rolling rolls can be adjusted by moving the rolling roll. In this case, the thickness of the electrode sheet 10 passing through the rolling unit 210 is adjusted by an amount corresponding to the distance between the upper rolling roll 211 and the lower rolling roll 212. If the transport of the electrode sheet 10 is limited to the rightward 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 to the right, and 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 is conveyed to the left.

[0047] In the present invention, the rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 can be adjusted to be the same or different from each other. For example, the more the rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 are adjusted to be the same, the higher the density of the electrode sheet 10 becomes, and the more the rotational speeds of the upper rolling roll 211 and the lower rolling roll 212 are adjusted to be different, the thinner the electrode sheet becomes.

[0048] The plurality of rolling units 210 may be configured such that the distance between a pair of rolling rolls narrows as they move in the direction of transport 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, which presses the electrode sheet 10 last, may be even narrower than the distance between the upper rolling roll 211 and the lower rolling roll 212 of the first rolling unit 210A, which presses the electrode sheet 10 first. This is because if the electrode sheet 10 is pressed all at once in the state in which it was first fed into the calendering process to process it to the desired thickness, there is a possibility that the electrode sheet 10 may be broken or crushed during the process. Instead, by pressing the electrode sheet 10 in stages, the load on the electrode sheet 10 is reduced, making it possible to process the electrode sheet 10 stably to the desired thickness.

[0049] Returning to Figure 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 being conveyed between a plurality of rolling units 210 and controls the rotational speed of the rolling rolls.

[0050] The tension adjustment mechanism 220 may be configured to control the rotational speed of each rolling roll included in the rolling unit 210, which is positioned in front of, behind, or between the electrode sheet 10.

[0051] For example, when the tension of the electrode sheet 10 increases, the tension adjustment mechanism 220 will reduce the rotational speed of the rolling rolls positioned behind the electrode sheet 10 (or accelerate the rotational speed of the rolling rolls positioned in front of it), and when the tension of the electrode sheet 10 decreases, it will accelerate the rotational speed of the rolling rolls positioned behind the electrode sheet 10. 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 above the electrode sheet 10 and a displacement detector 225 that measures the displacement of the tension-holding roll 221, and controls the rotation speed of the rolling roll based on the amount of displacement of the tension-holding roll 221 derived by the displacement detector 225. Here, the tension-holding roll 221 may refer to a dancer roll.

[0053] Referring to Figures 3 to 5, the configuration, operation method, and control system of the tension adjustment mechanism 220, which controls the rotational speed of the rolling mill rolls, will be explained in more detail.

[0054] Referring to Figure 3, it can be seen that the tension-holding roll 221 is located above the electrode sheet 10 and transmits a constant load to the electrode sheet 10.

[0055] Furthermore, the tension adjustment mechanism 220 further includes a guide member 222 which includes guide slits 223 that are connected to the rotation shafts on both sides of the tension holding roll 221 and guide the tension holding roll 221 so that it can move up and down, and a load member 224 which is connected to the rotation shaft of the tension holding roll 221 and applies a constant 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 bearing or other member (not shown). The rotating shaft, which protrudes through both sides of the tension-holding roll 221, can each be coupled to a guide member 222. Specifically, the rotating shaft can be inserted into and supported by a guide slit 223 formed along the height direction of the guide member 222. The guide member 222 is fixed to the bottom surface or the like, and the rotating shaft supports the tension-holding roll 221 while moving up and down along the guide slit 223.

[0057] The tension-holding roll 221 can be held under a constant load (force F) in the direction of gravity, and this load transmits a constant force F to the electrode sheet 10 via the tension-holding roll 221. The load can be transmitted directly to a 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, pneumatics (not shown), a weight (not shown), etc., and the load member 224 can apply a load of a certain magnitude to the tension-holding roll 221. Taking a spring as an example, one end of the spring can be connected 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 continuously applies a constant load to the electrode sheet 10 that is equivalent to the spring's return force.

[0059] The displacement detector 225 is a device for measuring changes in the position of the tension-holding roll 221. The displacement detector 225 can be any ordinary detector that measures the displacement of the dancer roll, and the measurement method is not necessarily limited in this invention.

[0060] Next, referring to Figure 4, it can be seen that rolling units 210, including an upper rolling roll 211 and a lower rolling roll 212, are positioned in front of and behind the tension-holding roll 221, respectively, and that the electrode sheet 10 that has passed through the rolling unit 210 located in front passes through the tension-holding roll 221 and then through the rolling unit 210 located behind. Between the two rolling units 210, a pair of support rolls R1 may be provided to support the electrode sheet 10 and switch the direction of transport. Specifically, the electrode sheet 10 transported from the rolling unit 210 located in front of the tension-holding roll 221 is guided downward by the support rolls R1 and passes under the tension-holding roll 221. After this, the electrode sheet 10 that has passed through the tension-holding roll 221 moves upward and is then guided forward by another support roll R2 and transported to the rolling unit 210 located behind the tension-holding roll 221. At this time, the electrode sheet 10, which passes below the tension-holding roll 221, receives a constant load from the tension-holding roll 221.

[0061] In other words, the tension-holding roll 221 is subjected to a constant force F via a spring to which a portion is fixed on the bottom surface, and the tension-holding roll 221 applies the same force F to the electrode sheet 10 passing below it. For example, if the electrode sheet 10 is loose, the support for the tension-holding roll 221 weakens, causing the tension-holding roll 221 to be displaced downward. Conversely, if the electrode sheet 10 is taut, the support for the tension-holding roll 221 strengthens, causing the tension-holding roll 221 to be displaced upward.

[0062] Next, referring to Figure 5, the tension adjustment mechanism 220 of the present invention may further include a control unit 229 that controls the rotational speed of a pair of rolling rolls 211 and 212 provided on the rolling unit 210.

[0063] The control unit 229 can sense the displacement of the tension-holding roll 221 via the displacement detector 225 and control the rotational speed of each rolling roll.

[0064] For example, when the tension-holding roll 221 is displaced upward, the tension adjustment mechanism 220 reduces 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, the tension may change due to the difference in rotational speed of each rolling roll included in the rolling unit 210, potentially causing the electrode sheet to become looser or tighter than normal. 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 speed of each rolling roll.

[0066] In other words, during the calendering process, slight differences in the supply and transport speed of the electrode sheet, the rotational speed between the rolling rolls, etc., can cause the electrode sheet to become loose or excessively taut. This can cause the tension-holding roll 221 to move up and down, potentially displacing the position of the tension-holding roll 221. 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 adjusts the rotational speed of the rolling rolls included in either the rolling unit 210 located in front of or 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 speed of the drive motors M1, M2, M1', and M2' connected to each of the 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 will, for example, reduce the rotational speed of the pair of rolling rolls included in the first rolling unit 210A, or accelerate the rotational speed of the pair of rolling rolls included in the second rolling unit 210B. As a result, the electrode sheet 10 can be transported at an appropriate speed without slackening while maintaining 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 will, for example, reduce the rotational speed of the pair of rolling rolls included in the first rolling unit 210A, or accelerate the rotational speed of the pair of rolling rolls included in the second rolling unit 210B. As a result, the electrode sheet 10 will maintain the appropriate tension with the tension-holding roll 221 and will be transported at an appropriate speed without sagging.

[0069] To give another example, if the tension-holding roll 221 is displaced upward, the control unit 229 may, for example, accelerate the rotational speed of the pair of rolling rolls included in the first rolling unit 210A, or decelerate the rotational speed of the pair of rolling rolls included in the second rolling unit. As a result, the electrode sheet 10 can be transported while maintaining the appropriate tension with the tension-holding roll 221, without becoming excessively taut.

[0070] As described above, the tension-holding roll 221, by moving up and down, works in conjunction with the control unit 229 to detect 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] Referring next to Figure 6, the electrode manufacturing equipment according to the present invention includes one lamination roll 300 that forms an electrode by bonding the electrode sheet 10, which has been rolled to a desired thickness via the calendering apparatus, with a current collector 20. The one lamination roll 300 is positioned to face one of a pair of rolling rolls of a third rolling unit 210C that ultimately rolls the electrode sheet 10.

[0072] For example, as shown in the embodiment configuration of Figure 6, by arranging the lamination rolls to face the lower rolling roll 212 of the third rolling unit 210C directly, it is possible to prevent the electrode sheet 10, which has the thinnest thickness after the calendering process by the third rolling unit 210C, from being transported while suspended in mid-air until it is bonded to the current collector 20 (as in Figure 1 of the conventional technology). In other words, according to the above configuration of the present invention, since the electrode sheet 10 is not transported while suspended in mid-air between the time the final calendering process is performed and the electrode sheet 10 is bonded to the current collector 20, almost no tension is applied to the electrode sheet 10, and as a result, the possibility of wire breakage is minimized. This allows the lamination process to be performed stably and improves the yield of electrode production.

[0073] More specifically, the calendering process by the third rolling unit 210C, i.e., the final calendering and lamination process, is configured to be performed continuously by three rollers arranged vertically. Here, the three rollers refer to the upper rolling roll 211, the lower rolling roll 212, and the lamination roll 300 of the third rolling unit 210C. The upper rolling roll 211 of the third rolling unit 210C may be configured to rotate clockwise, the lower rolling roll 212 to rotate counterclockwise, and the lamination roll 300 to rotate clockwise.

[0074] According to the above configuration, the electrode sheet 10 is wound clockwise around the upper rolling roll 211, passes between the upper rolling roll 211 and the lower rolling roll 212, and is finally rolled to the desired thickness. After this, the transport direction is switched, and the electrode sheet 10 is transported counterclockwise around the lower rolling roll 212.

[0075] Thus, as the electrode sheet 10 is wound and conveyed in a counterclockwise direction around the lower rolling roll 212, a slitting process may be performed again. This is to equalize the width of the electrode sheet 10 by cutting off the parts where the edges on both sides in the width direction have an irregular, uneven shape due to the rolling of the electrode sheet 10 in the final calendering process. For this reason, the slitting unit 40 may be positioned further forward than the lamination roll 300 and facing the lower rolling roll 212, and configured to cut both ends of the electrode sheet 10 in the width direction. Such a slitting unit 40 can be realized by a rotatable disc-shaped cutting blade.

[0076] As described above, the electrode sheet 10, after undergoing a slitting process and having both ends in the width direction cut, is wound counterclockwise around the lower rolling roll 212 and passes between the lower rolling roll 212 and the lamination roll 300. At this time, the electrode sheet 10, together with the current collector 20 supplied from the current collector supply roll 120, passes between the lower rolling roll 212 and the lamination roll 300 and can be bonded to each other by heat and pressure. The current collector 20 is located in the lower part of the electrode sheet 10 that the current collector supply roll 50 is conveying and is bonded to the lower surface of the electrode sheet 10.

[0077] Here, the current collector 20 can be made from materials such as stainless steel, aluminum, nickel, titanium, calcined carbon, copper, or stainless steel and aluminum alloys surface-treated with copper / carbon / nickel / titanium / silver. In addition to these, any current collector 20 commonly used in the field of lithium secondary batteries is acceptable.

[0078] Generally, electrodes are manufactured by dispersing electrode materials in a solvent to produce an electrode slurry, coating the current collector 20 with the slurry, and then drying it. However, in the present invention, since the electrode sheet 10, manufactured by rolling the dry material 1, is directly bonded to the current collector 20 without using a solvent, a separate drying process is unnecessary.

[0079] As described above, an electrode sheet 10 is manufactured through a calendering process and a slitting process to achieve the desired thickness, tissue density, and porosity. A dry electrode film can then be completed by a lamination process to bond the electrode sheet 10 and the current collector 20. The dry electrode film can be wound onto a winding roll 60 for storage or transport.

[0080] On the other hand, a double-sided laminated electrode can be manufactured by laminating an electrode sheet to the back surface of a single-sided laminated electrode film manufactured using the method described above. (In this case, the current collector of the current collector supply roll 50 in Figure 6 can be replaced by the single-sided laminated electrode film.) Alternatively, a double-sided laminated electrode can be manufactured by constructing other calendering and slitting equipment, for example, that are positioned opposite the calendering and slitting equipment described above.

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

[0082] The same component numbers as in the previously described embodiments refer to the same components, and redundant explanations of the same components will be omitted. The explanation will focus on the differences from the previously described embodiments.

[0083] In other words, as shown in Figure 7, the electrode manufacturing equipment according to the second embodiment of the present invention differs from the first embodiment described above in the tension adjustment mechanism 230 of the calendering apparatus 200, with the remaining configuration being 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 calendering apparatus 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 changes in the load of the tension-sensing roll 231, and controls the rotation speed of the rolling roll according to the changes in load measured by the sensor 233.

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

[0086] Referring to Figure 8, the tension adjustment mechanism 230 of the present invention may include support blocks 234 that support the tension sensing roll 231 on both sides of the tension sensing roll 231 and measure changes 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 simultaneously contacting one side of the electrode sheet 10 and supporting the electrode sheet 10, and that a rotating shaft 232 passes through the tension sensing roll 231. The tension sensing roll 231 can be rotated while being supported by the rotating shaft 232. The rotating shafts 232 that protrude through both sides of the tension sensing roll 231 can each be coupled to a support block 234. Specifically, the rotating shafts 232 can be fitted and supported in grooves (not shown) formed on the side surface of the support block 234. The portion of the groove that contacts the rotating shaft 232 may further include a sensor 233 capable of sensing changes in the weight of the rotating shaft 232. (For reference, the sensor 233 may also be configured to be positioned beneath the support block 234 to measure changes in weight.)

[0087] The sensor 233 provided in the groove detects the change in 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 balance used to measure weight.

[0088] The tension-sensing roll 231 is located below the electrode sheet 10 and receives a constant tension from the electrode sheet 10. When the tension of the electrode sheet 10 is strong, the force F pressing down on the tension-sensing roll 231 located below it becomes stronger, and the load of the tension-sensing roll 231 recorded by the sensor 233 increases. Conversely, when the tension of the electrode sheet 10 weakens, the force F pressing down on the tension-sensing roll 231 located below it weakens, and the load of the tension-sensing roll 231 recorded by the sensor 233 decreases.

[0089] The sensor 233 measures the change in load on the tension-sensing roll 231 transmitted via the rotating shaft 232. Such a sensor 233 can be replaced with a conventional load cell that measures changes in 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 rotational speed ratio of a pair of rolling rolls.

[0091] The control unit 229 controls the rotation speed of the rolling mill 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 Figures 8 and 9, the load on the tension-sensing roll 231, which is subjected to a load in the direction of gravity due to the tension of the electrode sheet 10, changes proportionally to the change in the tension of the electrode sheet 10. Then, the sensor 233 senses the change in the load on the tension-sensing roll 231, 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 rolls included in either the first rolling unit 210A or the second rolling unit 210B, which are located in front of and behind the tension-sensing roll 231. 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', and M2' connected to the respective rolling rolls 211 and 212.

[0093] For example, if 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 the pair of rolling rolls included in the second rolling unit 210B. If the process continues without detecting that the tension of the electrode sheet 10 has weakened, there is a risk that the electrode sheet 10 may become loose and unable to be transported normally, or that the electrode sheet 10 may get caught in the rolling rolls, causing congestion or crushing.

[0094] To give another example, if the tension of the electrode sheet 10 increases and the load on the tension sensing roll 231 increases, the control unit 229 will, for example, reduce the rotational speed of the pair of rolling rolls included in the second rolling unit 210B. In this case, if the process continues without detecting that the tension of the electrode sheet 10 has increased, there is a risk that the electrode sheet 10 may break during the process due to becoming too taut.

[0095] As described above, the tension adjustment mechanism 230 detects changes in the tension of the electrode sheet 10 using changes in the load of 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 playing a role in adjusting the tension of the electrode sheet 10.

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

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

[0098] The same component numbers as in the previously described embodiments refer to the same components, and redundant explanations of the same components will be omitted. The explanation will focus on the differences from the previously described embodiments.

[0099] The electrode manufacturing equipment according to the third embodiment of the present invention is characterized in that, compared to the first and second embodiments described above, the rolling unit 210 included in the calendering apparatus is a single unit. That is, according to the electrode manufacturing equipment according to the third embodiment, an electrode sheet 10 of the desired thickness is manufactured in a single calendering process, and as shown in Figure 10, the slitting unit and the lamination roll 300 are arranged 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 around the lower rolling roll 212.

[0100] Compared to the electrode manufacturing equipment according to the first and second embodiments, this third embodiment has a single rolling unit and eliminates other incidental devices such as tension adjustment mechanisms 220 and 230, making it easier to construct and operate the equipment, and also significantly reducing equipment construction costs.

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

[0102] An electrode manufacturing apparatus according to a fourth embodiment of the present invention may include a powder sheet processing apparatus 100, a calendering apparatus 200, and a lamination roll 300, as shown in Figure 11. In particular, the rolling rolls constituting the calendering apparatus 200 according to this embodiment may be configured such that a large number of rolling rolls are arranged continuously in the horizontal direction (lateral direction) at predetermined intervals from each other. In this case, compared to the electrode manufacturing apparatus according to the first and second embodiments, other incidental devices such as tension adjustment mechanisms 220, 230, etc., can be omitted. Furthermore, compared to the third embodiment, it is possible to perform further rolling of the electrode film.

[0103] Figure 12 is a schematic diagram of an electrode manufacturing facility according to a fifth embodiment of the present invention.

[0104] The same component numbers as in the previously described embodiments refer to the same components, and redundant explanations of the same components will be omitted. The explanation will focus on the differences from the previously described embodiments.

[0105] The electrode manufacturing equipment according to the present invention may further include a pre-tension adjustment mechanism 400 between the powder sheet processing apparatus 100 and the rolling unit 210 of the calendering apparatus 200. The pre-tension adjustment mechanism 400 may be configured to have substantially the same configuration and operation as the tension adjustment mechanism 220 described above. The pre-tension adjustment mechanism 400 may be positioned at the location of the guide roll 30 located between the powder sheet processing apparatus 100 and the rolling unit 210 of the calendering apparatus 200, as shown in Figures 2, 7, 10, and 11, respectively. In this case, the guide roll 30 is optional.

[0106] Specifically, as shown in Figure 12, in the electrode manufacturing equipment according to the fifth embodiment of the present invention, a pre-tension adjustment mechanism 400 may be placed between the powder sheet processing apparatus 100 and the rolling unit 210 of the calendering apparatus 200.

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

[0108] Furthermore, the pre-tension adjustment mechanism 400 may include a tension-holding roll 410 that rotates at the top of the electrode sheet 10 and a displacement detector (not shown) that measures the displacement of the tension-holding roll 410, and may be configured to control the rotational speed of the supply roll 120 or rolling rolls 211, 212 based on the amount of displacement 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 reduces the rotational speed of the pair of rolling rolls 211 and 212 located behind the electrode sheet 10 (or accelerates the rotational speed of the pair of supply rolls 120 located in front of it), and conversely, when the tension of the electrode sheet 10 decreases, it accelerates the rotational speed of the pair of rolling rolls 211 and 212 located behind the electrode sheet 10. At this time, the rotational speed ratio of the pair of rolling rolls 211 and 212 rotating together can be maintained. Other components of the pre-tension adjustment mechanism 400 will be replaced by the description of the tension adjustment mechanism 220 described above.

[0110] According to the pre-tension adjustment mechanism 400 of this fifth embodiment of the present invention, the electrode sheet 10, which is 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. Furthermore, the phenomena of stagnation and congestion of the electrode sheet 10 between the powder sheet processing apparatus 100 and the calendering apparatus 200 can be eliminated, making the electrode manufacturing process even smoother.

[0111] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited in any way thereto, and it goes without saying that it can be implemented by persons with ordinary skill in the art to which the present invention belongs, with various modifications and variations within the equivalent scope of the technical idea of ​​the present invention and the appended claims.

[0112] On the other hand, while terms indicating directions such as up, down, left, right, front, and back have been used in this specification, these terms are used merely for ease of explanation, and it will be obvious to those skilled in the art that they may vary depending on the position of the object in question, the observer's position, etc.

Claims

1. Equipment for manufacturing dry electrodes, A powder sheet processing apparatus for processing dry materials containing electrode active materials into a sheet, A calendering apparatus including at least one rolling unit that rolls an electrode sheet supplied from the powder sheet processing apparatus, each equipped with a pair of rolling rolls, The device includes a lamination roll that forms an electrode by bonding an electrode sheet, rolled to a desired thickness via the aforementioned calendering apparatus, with a current collector. Electrode manufacturing equipment, wherein the lamination rolls are positioned to face each other with one of a pair of rolling rolls of the rolling unit that ultimately rolls the electrode sheet.

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

3. The lamination roll is positioned opposite the lower rolling roll, The electrode manufacturing apparatus according to claim 2, wherein the electrode sheet and the current collector are pressed together while simultaneously passing 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 apparatus according to claim 2, wherein the slitting unit is arranged to face the lower rolling roll which faces the lamination roll.

5. The electrode manufacturing apparatus according to claim 4, wherein the slitting unit is provided to cut both ends in the width direction of the electrode sheet that has passed 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 apparatus according to claim 1, further comprising a tension adjustment mechanism that measures the tension applied to the electrode sheet being conveyed between the plurality of rolling units and controls the rotational speed of the rolling rolls.

7. The electrode manufacturing apparatus according to claim 6, wherein the tension adjustment mechanism controls the rotational speed of each rolling roll of a rolling unit arranged in front of or behind the electrode sheet, or the rotational speed ratio of a 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 located behind the tension adjustment mechanism is reduced, or the rotational speed of the rolling roll located in front of it is accelerated. The electrode manufacturing apparatus according to claim 6, wherein when the tension of the electrode sheet weakens, the rotational speed of the rolling rolls located behind the tension adjustment mechanism is accelerated, or the rotational speed of the rolling rolls located in front of it is decelerated.

9. The tension adjustment mechanism is, A tension-holding roll that rotates located at the top of the electrode sheet, Includes a displacement detector for measuring the displacement of the tension-holding roll, The electrode manufacturing apparatus according to claim 6, wherein the tension of the electrode sheet is measured according to the displacement derived by the displacement detector, and the rotation speed of the rolling roll is controlled based on the tension.

10. The tension adjustment mechanism is, A guide member including guide slits that are connected to the rotation axes on both sides of the tension-holding roll and guide the tension-holding roll so that it can move up and down, The electrode manufacturing apparatus according to claim 9, further comprising a load member connected to the tension-holding roll and applying a constant load to the tension-holding roll.

11. The tension adjustment mechanism reduces the rotational speed of the rolling rolls located behind the tension holding roll, or accelerates the rotational speed of the rolling rolls located in front of it, based on the amount of displacement when the tension holding roll is displaced upward. The electrode manufacturing apparatus according to claim 9, wherein, based on the amount of displacement when the tension-holding roll is displaced downward, the rotational speed of the rolling roll located behind the tension-holding roll is accelerated, or the rotational speed of the rolling roll located in front of the tension-holding roll is decelerated.

12. The tension adjustment mechanism is, A tension-sensing roll that rotates while positioned on an electrode sheet, Includes a sensor for measuring changes in the load of the tension-sensing roll, The electrode manufacturing apparatus according to claim 6, wherein the rotation speed of the rolling roll is controlled in accordance with the change in load measured by the sensor.

13. The tension adjustment mechanism is, When the load on the tension-sensing roll increases, the rotational speed of the rolling rolls positioned behind the tension-sensing roll is reduced, or the rotational speed of the rolling rolls positioned in front of it is accelerated, based on the amount of change in the load. The electrode manufacturing apparatus according to claim 12, wherein when the load on the tension-sensing roll decreases, the rotational speed of the rolling roll located behind the tension-sensing roll is accelerated, or the rotational speed of the rolling roll located in front of the tension-sensing roll is decelerated, based on the amount of change in the load.

14. The powder sheet processing apparatus includes a pair of feed rolls for rolling the dry material into a sheet. The electrode manufacturing equipment according to claim 6, further comprising a pre-tension adjustment mechanism that measures the tension applied to the electrode sheet being transported between the powder sheet processing apparatus and the rolling unit and controls the rotational speed of the supply roll or the rolling roll.

15. The electrode manufacturing apparatus according to claim 1, wherein the at least one rolling unit is one rolling unit.

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

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