Dry electrode manufacturing equipment

Abstract

Disclosed is a dry electrode manufacturing apparatus. According to the present invention, the electrode manufacturing apparatus comprises: a powder tabletting device configured to shape a dry material including an electrode active material into a sheet; the rolling device comprises at least one rolling unit, and each rolling unit comprises a pair of rolling rollers so as to roll the electrode sheets supplied from the powder sheet pressing device; and a single lamination roller configured to laminate the current collector and the electrode sheet having the target thickness rolled by the rolling device to form an electrode, in which the lamination roller is disposed facing one of the pair of rolling rollers of the last rolling electrode sheet of the rolling unit.

Description

Technical Field

[0001] The present invention relates to a dry electrode manufacturing apparatus, and more particularly, to a dry electrode manufacturing apparatus that measures and adjusts the tension of an electrode sheet during a calendaring process to stably manufacture the electrode sheet and minimize the possibility of the electrode sheet breaking after the calendaring process.

[0002] This application claims the priority of Korean Patent Application No. 10-2022-0137646 filed in Korea on October 24, 2022, and the disclosure of the Korean Patent Application is incorporated into this application by reference. Background Art

[0003] The electrodes used in lithium secondary batteries are usually manufactured by stacking an electrode active material layer on a current collector, the electrode active material layer including an electrode active material, a conductive material and a binder to bond them together if necessary. Wet manufacturing methods are usually used to manufacture electrodes, and include applying a coating slurry including an electrode active material, a binder and a conductive material to a current collector and heat treating to remove the solvent. However, these methods require additional energy and procedures to dry the polymer film or effectively remove the solvent from the coating slurry, and have low process efficiency and economic efficiency.

[0004] Therefore, many dry manufacturing methods have been proposed to manufacture electrodes without using a coating slurry. These methods mix electrode active materials, binders, and conductive materials without a liquid medium or dispersion medium such as a solvent, and pass the powder mixture through a roller to manufacture an electrode sheet.

[0005] However, in a rolling process of allowing an electrode sheet to pass through rolling rollers to manufacture an electrode having a target thickness, there are small differences in feeding and conveying speeds of the electrode sheet, rotation speeds between rolling rollers, etc., frequently causing clogging of the electrode sheet.

[0006] In addition, the calendering process may be repeated up to three times, depending on the type of active material and process conditions. For example, to produce an electrode with a target thickness, such as Figure 1 As shown in FIG. 1 , the calendering process can be performed in sequence (first, second, third). However, when the calendering process is performed in this manner, the electrode sheet gradually becomes thinner, and thus the fracture strength decreases, and the possibility of the electrode sheet breaking is higher. In particular, as Figure 1 As indicated by "E1" in the figure, after the last calendering, the electrode sheet moves to the laminating device in air, at which time the possibility of electrode sheet breakage is the greatest. Summary of the invention

[0007] Technical issues

[0008] The present invention aims to solve the above-mentioned problems, and therefore the present invention aims to provide an electrode manufacturing apparatus for minimizing the possibility of breakage of the electrode sheet after the final rolling process after the calendering process.

[0009] The present invention is also directed to providing an electrode manufacturing apparatus for preventing clogging of electrode sheets during a calendaring process.

[0010] Problems to be solved by the present invention are not limited to the above-mentioned problems, and those skilled in the art will clearly understand these and other problems from the following description.

[0011] Technical Solution

[0012] In order to solve the above problems, the electrode manufacturing equipment according to the present invention includes: a powder tableting device, configured to form a dry material including an electrode active material into a sheet; a calendering device, including at least one rolling unit, each rolling unit including a pair of rolling rollers to roll the electrode sheet supplied from the powder tableting device; and a single laminating roller, configured to laminate the collector and the electrode sheet with a target thickness rolled by the calendering device to form an electrode, wherein the laminating roller is arranged facing one of the pair of rolling rollers of the rolling unit that rolls the electrode sheet last.

[0013] The rolling unit may include an upper rolling roller; and a lower rolling roller located below the upper rolling roller, and the thickness of the electrode sheet may be adjusted to be the same as a gap between the upper rolling roller and the lower rolling roller.

[0014] The laminating roller may be disposed facing the lower rolling roller, and the electrode sheet and the current collector may be pressed together while passing between the laminating roller and the lower rolling roller.

[0015] The electrode manufacturing apparatus may further include a cutting unit to cut an edge of the electrode sheet, and the cutting unit may be disposed facing the lower pressing roller facing the laminating roller.

[0016] The cutting unit may be configured to cut both end portions of the electrode sheet in a width direction passing between the upper and lower rolling rollers.

[0017] The at least one rolling unit may include a plurality of rolling units arranged to be spaced apart from each other, and the calendaring device may further include a tension control unit to measure tension applied to the electrode sheet conveyed between the rolling units and control a rotation speed of the rolling roller.

[0018] The tension control unit may be configured to control a rotation speed of a rolling roller of a rolling unit provided in front of the electrode sheet or behind the electrode sheet or in front of and behind the electrode sheet.

[0019] Under high tension in the electrode sheet, the tension control unit can be configured to slow down the rotation speed of the rolling roller arranged behind the tension control unit (or accelerate the rotation speed of the rolling roller arranged in front of the tension control unit), and under low tension in the electrode sheet, it can be configured to accelerate the rotation speed of the rolling roller arranged behind the tension control unit (or slow down the rotation speed of the rolling roller arranged in front of the tension control unit).

[0020] The tension control unit may include a tension maintaining roller located on the electrode sheet and rotating; and a displacement detector to measure the displacement of the tension maintaining roller. The tension control unit may be configured to measure the tension of the electrode sheet according to the displacement measured by the displacement detector, and control the rotation speed of the rolling roller based on the tension.

[0021] The tension control unit may further include a guide member including a guide slit coupled to two rotating shafts of the tension maintaining roller to guide the tension maintaining roller to move up and down; and a loading member connected to the tension maintaining roller to apply a constant load to the tension maintaining roller.

[0022] The tension control unit can be configured to decelerate the rotation speed of the roller located behind the tension holding roller (or accelerate the rotation speed of the roller located in front of the tension holding roller) based on the displacement when the tension holding roller changes its position upward, and to accelerate the rotation speed of the roller located behind the tension holding roller (or decelerate the rotation speed of the roller located in front of the tension holding roller) based on the displacement when the tension holding roller changes its position downward.

[0023] In another example, the tension control unit may include a tension sensing roller located on the electrode sheet and rotating; and a sensor to measure a load change of the tension sensing roller, and may be configured to control a rotation speed of the rolling roller according to the load change measured by the sensor.

[0024] The tension control unit can be configured to decelerate the rotation speed of the rolling roller located behind the tension sensing roller (or accelerate the rotation speed of the rolling roller arranged in front of the tension sensing roller) based on the load change when the load of the tension sensing roller increases, and can be configured to accelerate the rotation speed of the rolling roller located behind the tension sensing roller (or decelerate the rotation speed of the rolling roller arranged in front of the tension sensing roller) based on the load change when the load of the tension sensing roller decreases.

[0025] The powder tableting device may include a pair of feed rollers to roll the dry material into sheets, and the electrode manufacturing equipment may also include a preliminary tension control unit to measure the tension applied to the electrode sheet conveyed between the powder tableting device and the rolling unit, and control the rotation speed of the feed rollers or the rolling rollers.

[0026] The at least one rolling unit may be a single rolling unit.

[0027] The electrode manufacturing apparatus may further include a winding roller on which the electrode is wound.

[0028] Beneficial Effects

[0029] According to the present invention, it is possible to provide an electrode manufacturing apparatus for stably manufacturing a dry electrode by minimizing the possibility of cracking of an electrode sheet finally rolled after a calendaring process.

[0030] In addition, the present invention can manufacture a dry electrode with improved process efficiency and economic efficiency by preventing clogging of the electrode sheet.

[0031] In addition, the present invention can have many other effects, and these effects will be described in each embodiment.Regarding the effects that can be easily inferred by those skilled in the art, the corresponding description is omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the conventional electrode manufacturing equipment.

[0033] Figure 2 is a schematic diagram of an electrode manufacturing apparatus according to a first embodiment of the present invention.

[0034] Figure 3 yes Figure 2 Perspective view of the tension control unit.

[0035] Figure 4 : is a diagram showing an operation example of the tension control unit according to the first embodiment of the present invention.

[0036] Figure 5 yes Figure 4 Control flow chart of the tension control unit.

[0037] Figure 6 yes Figure 2 An enlarged view of the third rolling unit.

[0038] Figure 7 is a schematic diagram of an electrode manufacturing apparatus according to a second embodiment of the present invention.

[0039] Figure 8 yes Figure 7 Perspective view of the tension control unit.

[0040] Fig. 9 yes Figure 8 Control flow chart of the tension control unit.

[0041] Fig.10 is a schematic diagram of an electrode manufacturing apparatus according to a third embodiment of the present invention.

[0042] Fig.11 is a schematic diagram of an electrode manufacturing apparatus according to a fourth embodiment of the present invention.

[0043] Fig.12 is a schematic diagram of an electrode manufacturing apparatus according to a fifth embodiment of the present invention. DETAILED DESCRIPTION

[0044] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the present invention and the appended claims should not be interpreted as limited to the general and dictionary meanings, but are interpreted based on the meanings and concepts corresponding to the technical aspects of the present invention based on the principle that the inventor is allowed to appropriately define the terms for the best description. The embodiments described herein and the illustrations in the accompanying drawings are exemplary embodiments of the present invention for describing the technical aspects of the present invention, and are not restrictive, so it should be understood that various other equivalents and modifications may be made when submitting this application.

[0045] Figure 2 is a schematic diagram of an electrode manufacturing apparatus according to a first embodiment of the present invention.

[0046] like Figure 2 As shown, the electrode manufacturing apparatus according to the present invention includes a powder tableting device 100 , a calendering device 200 and a laminating roller 300 .

[0047] The powder tableting apparatus 100 manufactures the electrode sheet 10 by roll-pressing the dry material 1 until the electrode sheet 10 reaches a target porosity.

[0048] The powder tableting device 100 includes a hopper 110 containing a dry material 1 including an electrode active material, and a pair of feed rollers 120 facing each other and disposed below the hopper 110 and rotating, the dry material 1 is fed into the pair of feed rollers 120, and is rolled in the pair of feed rollers 120 to obtain a film-shaped electrode sheet 10. In this case, in addition to the electrode active material, the dry material 1 may include various types of additives, for example, a conductive material and a binder may also be included.

[0049] The electrode active material may include any material commonly used in positive and negative electrodes of lithium secondary batteries.

[0050] The conductive material is used to improve the conductivity of the electrode, and may include any conductive material commonly used in the technical field of lithium secondary batteries.

[0051] The binder helps to bind the electrode active material and the conductive material together and adhere to the current collector 20 , and may include any binder commonly used in the technical field of lithium secondary batteries.

[0052] The dry material 1 in a mixed state is fed into a pair of feed rollers 120 arranged side by side in a horizontal or vertical direction (in the present invention, the horizontal direction for ease of understanding), and is compacted by rolling. This process is performed to form the dry material 1 mixed in a powder state into a sheet, so the gap between the pair of feed rollers 120 included in the powder tableting device 100 can be larger than the gap between the pair of rollers 211, 212 included in the calendering device 200. In addition, by applying shear force at different rotation speeds of a pair of feed rollers 120, the dry material can be formed into a sheet. As the speed ratio of the pair of feed rollers 120 increases, the thickness of the sheet decreases and the density decreases. Therefore, by appropriately setting the speed ratio and the gap between the feed rollers, the dry material 1 is formed into a sheet with a desired thickness and density.

[0053] The electrode sheet 10 rolled by a pair of feed rollers 120 moves downward and is supported by a plurality of guide rollers 30, and changes direction to a horizontal direction. The guide rollers 30 are not operated by a driving motor and rotate at a fixed position to support the film with minimum friction, thereby allowing the film to move smoothly.

[0054] The edge portion of the electrode sheet 10 that has been rolled by the feed roller 120 is generally very rough and irregular, so the two edge portions of the electrode sheet 10 in the width direction are cut by the cutting unit 40 to make the length of the electrode sheet in the width direction uniform. Here, the cutting unit 40 may include, for example, a predetermined cutting blade to cut the two edge portions of the electrode sheet 10 in the width direction, and a motor to drive the cutting blade.

[0055] like Figure 2 As shown, the cutting unit 40 may be disposed between the feed roller 120 and the calendering device 200 to cut the two edge portions of the electrode sheet before the calendering process. In addition, the cutting unit 40 may be disposed facing the lower rolling roller 212 of the third rolling unit 210C as described below to cut the two edge portions of the electrode sheet again before the lamination process after the calendering process.

[0056] The calendaring device 200 is configured to perform multi-stage rolling on the electrode sheet 10 supplied from the powder tableting device 100 to obtain a target thickness before laminating the electrode sheet 10 and the current collector 20 .

[0057] In the following, reference will be made to Figures 2 to 5 A calendering device 200 according to a first embodiment of the present invention is described.

[0058] The calendering device 200 includes a plurality of roller pressing units 210 spaced apart from each other and a tension control unit 220, each of the roller pressing units 210 including a pair of rollers disposed facing each other and rotating. Figure 2As shown, the rolling unit 210 may include a first rolling unit 210A, a second rolling unit 210B, and a third rolling unit 210C, and each of the rolling units may include a pair of rolling rollers 211 and 212 and be spaced apart from each other by a predetermined distance in a horizontal direction.

[0059] The rolling unit 210 may include a pair of rolling rollers 211 and 212 rotating with a predetermined gap between them, and when the electrode sheet 10 passes between the rolling rollers 211 and 212, the thickness of the electrode sheet 10 can be adjusted to be the same as the gap between the rolling rollers. Specifically, the pair of rolling rollers 211 and 212 are arranged side by side in a vertical or horizontal direction (in the present invention, the vertical direction is for ease of understanding) and rotate in different directions to squeeze the electrode sheet 10 passing between them, thereby reducing the thickness of the electrode sheet 10 and stretching the electrode sheet 10 in the length direction. Through extrusion, the particles contained in the electrode sheet 10 can be elongated, and the electrode sheet 10 can become denser.

[0060] More specifically, the rolling unit 210 includes an upper rolling roller 211 and a lower rolling roller 212 located below the upper rolling roller 211, and the upper rolling roller 211 and the lower rolling roller 212 face each other. Either the upper rolling roller 211 or the lower rolling roller 212 can move toward the opposite rolling roller. That is, the gap between the rolling rollers can be adjusted by the movement of the rolling rollers. In this case, the thickness of the electrode sheet 10 passing through the corresponding rolling unit 210 is adjusted to be the same as the gap between the upper rolling roller 211 and the lower rolling roller 212. When the electrode sheet 10 is conveyed only in the right direction, the upper rolling roller 211 rotates counterclockwise and the lower rolling roller 212 rotates clockwise. For example, the first rolling unit 210A or the second rolling unit 210B can convey the electrode sheet 10 in the right direction by the counterclockwise rotation of the upper rolling roller 211 and the clockwise rotation of the lower rolling roller 212, and the third rolling unit 210C can convey the electrode sheet 10 in the left direction by the clockwise rotation of the upper rolling roller 211 and the counterclockwise rotation of the lower rolling roller 212.

[0061] In the present invention, the rotation speed of the upper pressing roller 211 and the rotation speed of the lower pressing roller 212 can be adjusted to be equal to or different from each other. For example, when the rotation speed of the upper pressing roller 211 and the rotation speed of the lower pressing roller 212 are adjusted to be equal, the density of the electrode sheet 10 can be increased, and when the rotation speed of the upper pressing roller 211 and the rotation speed of the lower pressing roller 212 are adjusted to be different from each other, the thickness of the electrode sheet 10 can be reduced.

[0062] The plurality of rolling units 210 may have a smaller gap between a pair of rolling rollers in the conveying direction of the electrode sheet 10. That is, the gap between the upper rolling roller 211 and the lower rolling roller 212 of the third rolling unit 210C that squeezes the electrode sheet 10 last may be smaller than the gap between the upper rolling roller 211 and the lower rolling roller 212 of the first rolling unit 210A that squeezes the electrode sheet 10 first. This is because when the electrode sheet 10 in the initial state is formed into a desired thickness by a single extrusion when the calendering process is introduced, the electrode sheet 10 may be broken or wrinkled in the process. On the contrary, when multi-stage extrusion is applied to the electrode sheet 10, the burden applied to the electrode sheet 10 is reduced, thereby stably manufacturing the electrode sheet 10 with the desired thickness.

[0063] Return to reference Figure 2 It can be seen that the calendering device 200 of the present invention includes a tension control unit 220 to measure the tension applied to the electrode sheet 10 transported between the rolling units 210 and control the rotation speed of the rolling rollers.

[0064] The tension control unit 220 may be configured to control a rotation speed of each rolling roller included in the rolling unit 210 disposed in front of the electrode sheet 10 or behind the electrode sheet 10 or before, after and behind the electrode sheet 10 .

[0065] For example, when the tension in the electrode sheet 10 is high, the tension control unit 220 decelerates the rotation speed of the rolling roller disposed behind the electrode sheet 10 (or accelerates the rotation speed of the rolling roller disposed in front of the electrode sheet 10), and when the tension in the electrode sheet 10 is low, the tension control unit 220 accelerates the rotation speed of the rolling roller disposed behind the electrode sheet 10. In this case, the rotation speed ratio of the rolling rollers rotating in pairs can be maintained.

[0066] Specifically, the tension control unit 220 included in the calendering device 200 according to the first embodiment of the present invention includes a tension holding roller 221 located on the electrode sheet 10 and rotating and a displacement detector 225 for measuring the displacement of the tension holding roller 221, and controls the rotation speed of the rolling roller based on the displacement of the tension holding roller 221 detected by the displacement detector 225. Here, the tension holding roller 221 may be a floating roller.

[0067] Will refer to Figures 3 to 5 The structure, operation, and control system of the tension control unit 220 that controls the rotation speed of the rolling roller are described in more detail.

[0068] Reference Figure 3 , it can be seen that the tension maintaining roller 221 is located on the electrode sheet 10 to transfer a constant load to the electrode sheet 10 .

[0069] In addition, the tension control unit 220 may also include a guiding member 222 and a loading member 224, wherein the guiding member 222 includes a guiding slit 223 coupled to two rotating axes of the tension maintaining roller 221 to guide the tension maintaining roller 221 to move up and down, and the loading member 224 is connected to the rotating axis of the tension maintaining roller 221 to apply a constant load (force (F)) to the tension maintaining roller 221.

[0070] The tension holding roller 221 is rotatably coupled to the rotating shaft. For example, the tension holding roller 221 and the rotating shaft may be connected by a bearing (not shown). Each rotating shaft extending from each side of the two sides of the tension holding roller 221 may be coupled to the guide member 222. Specifically, the rotating shaft may 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 ground, and the rotating shaft moves up and down along the guide slit 223 and supports the tension holding roller 221.

[0071] The tension holding roller 221 can be maintained under a constant load (force (F)) in the direction of gravity, and the electrode sheet 10 is subjected to the constant force F through the tension holding roller 221. The load can be directly transmitted to the rotating shaft connected to the tension holding roller 221. Specifically, the load can be generated by a loading member 224 connected to the rotating shaft. The loading member 224 may include, for example, a spring, a cylinder (not shown), a weight (not shown), etc. When taking a spring as an example, one end of the spring may be coupled to the rotating shaft, and the other end may be fixed to the ground. The load may be limited by the restoring force and length of the spring fixed to the ground.

[0072] As a result, the tension maintaining roller 221 continuously applies a constant load as much as the restoring force of the spring to the electrode sheet 10 .

[0073] The displacement detector 225 is configured to measure a position change of the tension maintaining roller 221. The displacement detector 225 may include any detector generally used to measure the displacement of a dancing roller, and in the present invention, the measuring method is not limited to a specific method.

[0074] Then, refer to Figure 4, it can be seen that each rolling unit 210 including an upper rolling roller 211 and a lower rolling roller 212 is arranged in front of the tension holding roller 221 and behind the tension holding roller 221, and the electrode sheet 10 passing through the rolling unit 210 located in front of the tension holding roller 221 passes through the rolling unit 210 located behind the tension holding roller 221 via the tension holding roller 221. A pair of support rollers R1 may be further provided between the two rolling units 210 to support the electrode sheet 10 and change the conveying direction. Specifically, the electrode sheet 10 conveyed from the rolling unit 210 located in front of the tension holding roller 221 is guided by the support roller R1 to move downward and pass under the tension holding roller 221. Subsequently, the electrode sheet 10 passing through the tension holding roller 221 moves upward, and is guided by another support roller R2 to move forward and conveyed to the rolling unit 210 located behind the tension holding roller 221. In this case, the electrode sheet 10 passing under the tension holding roller 221 is subjected to a constant load from the tension holding roller 221.

[0075] That is, the tension holding roller 221 is subjected to a constant force F by a spring whose part is fixed to the ground, and the tension holding roller 221 applies an equal force F to the electrode sheet 10 below. For example, when the electrode sheet 10 becomes loose, the electrode sheet 10 is weakly supported on the tension holding roller 221, and the tension holding roller 221 changes its position downward. On the contrary, when the electrode sheet 10 becomes tight, the electrode sheet 10 is strongly supported on the tension holding roller 221, and the tension holding roller 221 changes its position upward.

[0076] Then, refer to Figure 5 The tension control unit 220 of the present invention may further include a control unit 229 to control the rotation speed of the pair of rolling rollers 211 and 212 of the rolling unit 210 .

[0077] The control unit 229 may control the rotation speed of each rolling roller based on the displacement of the tension maintaining roller 221 detected by the displacement detector 225 .

[0078] For example, when the tension maintaining roller 221 changes its position upward, the tension control unit 220 can slow down the rotation speed of a pair of rolling rollers located behind the tension maintaining roller 221 or accelerate the rotation speed of a pair of rolling rollers located in front of the tension maintaining roller 221 based on the displacement so as to keep the tension applied to the electrode sheet 10 constant.

[0079] For example, when the tension changes due to the difference in rotation speed between each rolling roller included in the rolling unit 210, the electrode sheet may be looser or tighter than normal. The tension holding roller may move up and down, and the control unit 229 may control the rotation speed of each rolling roller based on the displacement detected by the displacement detector 225.

[0080] In addition, in the calendering process, due to the difference in the feeding and conveying speed of the electrode sheet, the rotation speed between the rolling rollers, etc., the electrode sheet may become loose or too tight, and then the tension holding roller 221 may move up and down, and the tension holding roller 221 may change its position. In this case, the displacement of the tension holding roller 221 is detected by the displacement detector 225, and the displacement data of the tension holding roller 221 detected is transmitted to the control unit 229. The control unit 229 adjusts the rotation speed of the rolling roller included in any one of the rolling unit 210 located in front of the tension holding roller 221 and the rolling unit 210 located behind the tension holding roller 221 based on the displacement of the tension holding roller 221. In this case, the rotation speed can be adjusted by controlling the driving motors M1, M2, M1′, M2′ connected to each rolling roller.

[0081] For example, when the tension holding roller 221 changes the position between the first rolling unit 210A and the second rolling unit 210B downward, the control unit 229, for example, decelerates the rotation speed of a pair of rolling rollers included in the first rolling unit 210A, or accelerates the rotation speed of a pair of rolling rollers included in the second rolling unit 210B. Then, the electrode sheet 10 under the constant tension of the tension holding roller can be conveyed at an optimal speed without becoming loose.

[0082] For example, when the tension holding roller 221 changes the position between the first rolling unit 210A and the second rolling unit 210B downward, the control unit 229, for example, decelerates the rotation speed of a pair of rolling rollers included in the first rolling unit 210A or accelerates the rotation speed of a pair of rolling rollers included in the second rolling unit 210B. Then, while the tension is maintained at an optimal level by the tension holding roller 221, the electrode sheet 10 can be conveyed at an optimal speed without becoming loose.

[0083] In another example, when the tension holding roller 221 changes position upward, the control unit 229 accelerates the rotation speed of a pair of rolling rollers included in the first rolling unit 210A or decelerates the rotation speed of a pair of rolling rollers included in the second rolling unit. Then, while the tension is maintained at an optimal level by the tension holding roller 221, the electrode sheet 10 can be conveyed without becoming too tight.

[0084] As described above, the tension maintaining roller 221 together with the control unit 229 plays the role of detecting the tension change of the electrode sheet 10 by moving upward and downward, controlling the rotation speed of the rolling roller included in the rolling unit 210 located in front of the electrode sheet 10 or behind the electrode sheet 10, and maintaining a constant tension on the electrode sheet 10.

[0085] Then, refer to Figure 6The electrode manufacturing apparatus according to the present invention includes a laminating roller 300 to laminate the current collector 20 and the electrode sheet 10 having a target thickness rolled by the calendering device to form an electrode. The single laminating roller 300 is arranged facing one of the pair of rolling rollers of the third rolling unit 210C that rolls the electrode sheet 10 last.

[0086] For example, Figure 6 As shown in the exemplary configuration of FIG. 1 , the laminating roller can be directly disposed facing the lower rolling roller 212 of the third rolling unit 210C, so that in the calendering process (i.e., the last calendering process (e.g., Figure 1 The electrode sheet 10 having a reduced thickness is not transported in the air until it is joined to the current collector 20 (laminated) after the conventional technology of the present invention. That is, according to the above configuration of the present invention, the electrode sheet 10 is not transported in the air until it is joined to the current collector 20 (laminated) after the final calendering process, and thus tension is hardly applied to the electrode sheet 10, thereby minimizing the possibility of breakage of the electrode sheet 10, and thus the lamination process can be stably performed, thereby improving electrode production.

[0087] More specifically, the calendering process through the third rolling unit 210C, that is, the final calendering process and the laminating process can be continuously performed by three rollers arranged in the vertical (top-bottom) direction. Here, the three rollers refer to the upper rolling roller 211 and the lower rolling roller 212 of the third rolling unit 210C and the laminating roller 300. In addition, the upper rolling roller 211 of the third rolling unit 210C can be configured to rotate in a clockwise direction, the lower rolling roller 212 can be configured to rotate in a counterclockwise direction, and the laminating roller 300 can be configured to rotate in a clockwise direction.

[0088] Through the above configuration, the electrode sheet 10 can move in the clockwise direction along the circumference of the upper pressing roller 211 and pass between the upper pressing roller 211 and the lower pressing roller 212, and can finally be rolled at a target thickness, and as the conveying direction changes, it is conveyed along the circumference of the lower pressing roller 212 in the counterclockwise direction.

[0089] The cutting process may be performed again in the process of conveying the electrode sheet 10 in the counterclockwise direction along the circumference of the lower rolling roller 212. This is to cut the two irregular edges of the electrode sheet 10 in the width direction after rolling through the final calendering process, so as to make the length of the electrode sheet 10 in the width direction uniform. Therefore, the cutting unit 40 may be arranged facing the lower rolling roller 212 at a position further forward than the laminating roller 300, and is configured to cut both ends of the electrode sheet 10 in the width direction. The cutting unit 40 may be a rotatable disc-shaped cutting blade.

[0090] The electrode sheet 10 whose both ends in the width direction have been cut by the cutting process moves in the counterclockwise direction along the circumference of the lower rolling roller 212 and passes between the lower rolling roller 212 and the laminating roller 300. In this case, the electrode sheet 10 and the current collector 20 supplied from the current collector feeding roller 50 can be laminated by heat and pressure while both pass through the lower rolling roller 212 and the laminating roller 300. Since the current collector feeding roller 50 is located below the electrode sheet 10 being conveyed, the current collector 20 is bonded to the lower surface of the electrode sheet 1.

[0091] Here, the current collector 20 may be made of stainless steel, aluminum, nickel, titanium, sintered carbon, copper, stainless steel treated with copper / carbon / nickel / titanium / silver on the surface, aluminum alloy, etc. The current collector 20 may include any current collector 20 commonly used in the technical field of lithium secondary batteries.

[0092] Generally, an electrode is manufactured by coating an electrode slurry prepared by dispersing an electrode material in a solvent on a current collector 20 and drying the electrode slurry. However, the present invention does not require a drying process because the electrode sheet 10 manufactured by rolling the dried material 1 without using a solvent is directly bonded to the current collector 20 (lamination).

[0093] As described above, the electrode sheet 10 having a target thickness, density, porosity, etc. can be manufactured through the calendaring process and the cutting process, and the dry electrode film can be completed through the lamination process of laminating the electrode sheet 10 and the current collector 20. The dry electrode film wound on the winding roll 60 can be stored or transported.

[0094] Meanwhile, an electrode sheet may be bonded to the opposite surface of the single-sided laminated electrode film produced as described above to produce a double-sided laminated electrode (in this case, Figure 6 The current collector of the current collector feed roller 50 may be replaced with a single-sided laminated electrode film). Alternatively, for example, a double-sided laminated electrode may be manufactured by installing another calendering device and another cutting device facing the above calendering device and the above cutting device.

[0095] Subsequently, an electrode manufacturing apparatus according to a second embodiment of the present invention will be described with reference to the drawings.

[0096] The same reference numerals as those of the first embodiment denote the same elements, and redundant description of the same elements is omitted, and differences between this embodiment and the previous embodiment will be described.

[0097] That is, Figure 7 As shown, the electrode manufacturing apparatus according to the second embodiment of the present invention is substantially the same as the above-described first embodiment except for the tension control unit 230 of the rolling device 200. Therefore, the tension control unit 230 according to the second embodiment will be described in detail.

[0098] The tension control unit 230 included in the calendering device 200 according to the second embodiment of the present invention includes a tension sensing roller 231 rotating in contact with one surface of the electrode sheet 10 and a sensor 233 for measuring the load change of the tension sensing roller 231, and controls the rotation speed of the rolling roller according to the load change measured by the sensor 233.

[0099] Figure 8 is a schematic perspective view of a tension control unit 230 of the present invention.

[0100] Reference Figure 8 , the tension control unit 230 of the present invention may include a support block 234 to support the tension sensing roller 231 on both sides of the tension sensing roller 231 and measure the load change of the tension sensing roller 231. Specifically, it can be seen that the tension sensing roller 231 supports the electrode sheet 10 while rotating in contact with one surface of the electrode sheet 10, and the rotating shaft 232 passes through the tension sensing roller 231. The tension sensing roller 231 can be supported on the rotating shaft 232 and rotate around the rotating shaft 232. The rotating shaft 232 extending from each of the two sides of the tension sensing roller 231 can be coupled to the support block 234. Specifically, the rotating shaft 232 can be inserted into and supported by a groove (not shown) formed on one side of the support block 234. The sensor 233 can be set at a portion of the groove that contacts the rotating shaft 232 to detect a weight change of the rotating shaft 232 (for reference, the sensor 233 can be installed below the support block 234 and configured to measure the weight change).

[0101] The sensor 233 disposed at the groove detects a weight change of the rotation shaft 232 supporting the tension sensing roller 231 , in a principle similar to an electronic scale generally used to measure weight.

[0102] The tension sensing roller 231 is located below the electrode sheet 10, and transmits a constant tension from the electrode sheet 10. In this case, when the tension of the electrode sheet 10 is high, the pressing force F applied to the tension sensing roller 231 below increases, and the load of the tension sensing roller 231 recorded in the sensor 233 increases. On the contrary, when the tension of the electrode sheet 10 is low, the pressing force F applied to the tension sensing roller 231 below decreases, and the load of the tension sensing roller 231 recorded in the sensor 233 decreases.

[0103] The sensor 233 measures the load change of the tension sensing roller 231 transmitted through the rotating shaft 232. The sensor 233 may be replaced with a load cell generally used to measure the change of the force F and pressure applied to the roller.

[0104] In a similar manner to the first embodiment, the tension control unit 230 according to the second embodiment may include a control unit 229 to control the rotation speed ratio of the pair of rolling rollers.

[0105] The control unit 229 controls the rotation speed of the rolling roller to accelerate or decelerate according to the load variation of the tension sensing roller 231 measured by the sensor 233 .

[0106] Reference Figure 8 and 9 , the load of the tension sensing roller 231 subjected to the load in the gravity direction caused by the tension of the electrode sheet 10 changes in proportion to the change in the tension of the electrode sheet 10. The load change of the tension sensing roller 231 is detected by the sensor 233, and the load change of the tension sensing roller 231 is transmitted to the control unit 229. The control unit 229 adjusts the rotation speed of the rolling roller included in any one of the first rolling unit 210A located in front of the tension sensing roller 231 and the second rolling unit 210B located behind the tension sensing roller 231, for example, based on the load change of the tension sensing roller 231. In this case, the rotation speed of the rolling roller is adjusted by controlling the rotation speeds of the driving motors M1, M2, M1', M2' respectively connected to the rolling rollers 211, 212.

[0107] In the example, when the tension of the electrode sheet 10 is reduced and the load of the tension sensing roller 231 is reduced, the control unit 229 accelerates the rotation speed of a pair of rolling rollers included in the second rolling unit 210B, for example. In this case, if the tension reduction of the electrode sheet 10 is not detected and the process continues, the electrode sheet 10 may not be properly conveyed due to a loose electrode sheet 10, or the electrode sheet 10 wound on the rolling roller may be stuck or wrinkled.

[0108] In another example, when the tension of the electrode sheet 10 increases and the load of the tension sensing roller 231 increases, the control unit 229, for example, decelerates the rotation speed of a pair of rolling rollers included in the second rolling unit 210B. In this case, if the increase in the tension of the electrode sheet 10 is not detected and the process continues, the electrode sheet 10 may be broken during the process due to the stretched electrode sheet 10.

[0109] As described above, the tension control unit 230 can play the following roles: detecting the tension change of the electrode sheet 10 through the load change of the tension sensing roller 231, controlling the rotation speed of the rolling roller included in the rolling unit located in front of the electrode sheet 10 or behind the electrode sheet 10, and adjusting the tension of the electrode sheet 10.

[0110] Fig.10 is a schematic diagram of an electrode manufacturing apparatus according to a third embodiment of the present invention.

[0111] Subsequently, an electrode manufacturing apparatus according to a third embodiment of the present invention will be described.

[0112] The same reference numerals as those of the previous embodiment denote the same elements, and redundant description of the same elements is omitted, and the differences between this embodiment and the previous embodiment will be described.

[0113] When compared with the first and second embodiments, the electrode manufacturing apparatus according to the third embodiment of the present invention is characterized in that the number of the rolling unit 210 included in the calendering device is one. That is, by the electrode manufacturing apparatus according to the third embodiment, the electrode sheet 10 having a target thickness is manufactured by performing a calendering process once, such as Fig.10 As shown, each of the cutting unit and the laminating roller 300 is disposed facing the lower rolling roller 212 to perform a cutting process and a laminating process, respectively, while the electrode sheet 10 moves along the circumference of the lower rolling roller 212 .

[0114] When compared with the electrode manufacturing apparatus according to the first or second embodiment, the electrode manufacturing apparatus according to the third embodiment includes a rolling unit, and other additional equipment including tension control units 220, 230 can be omitted, thereby making it easy to install and operate the apparatus and significantly reducing the equipment installation cost.

[0115] Fig.11 is a schematic diagram of an electrode manufacturing apparatus according to a fourth embodiment of the present invention.

[0116] like Fig.11 As shown, the electrode manufacturing apparatus according to the fourth embodiment of the present invention may include a powder tableting device 100, a calendering device 200 and a laminating roller 300. Specifically, a plurality of rolling rollers of the calendering device 200 according to the present embodiment may be continuously arranged at predetermined intervals in the horizontal direction. In this case, when compared with the electrode manufacturing apparatus according to the first embodiment or the second embodiment, other additional equipment including the tension control unit 220, 230 may be omitted. In addition, compared with the third embodiment, the electrode film may be additionally rolled.

[0117] Fig.12 is a schematic diagram of an electrode manufacturing apparatus according to a fifth embodiment of the present invention.

[0118] The same reference numerals as those of the previous embodiment denote the same elements, and redundant description of the same elements is omitted, and the differences between this embodiment and the previous embodiment will be described.

[0119] The electrode manufacturing apparatus according to the present invention may further include a preliminary tension control unit 400 between the powder tableting device 100 and the rolling unit 210 of the calendering device 200. The preliminary tension control unit 400 may have substantially the same configuration and function as the tension control unit 220. The preliminary tension control unit 400 may be disposed at a position of the guide roller 30 between the powder tableting device 100 and the rolling unit 210 of the calendering device 200, such as Figure 2 , 7 , 10 and 11. In this case, the guide roller 30 can be omitted.

[0120] Specifically, Fig.12 As shown, the electrode manufacturing apparatus according to the fifth embodiment of the present invention may include a preliminary tension control unit 400 between the powder tableting device 100 and the rolling unit 210 of the calendaring device 200 .

[0121] The preliminary tension control unit 400 can be configured to control the rotation speed of a pair of feed rollers 120 arranged in front of the electrode sheet 10 or a pair of rolling rollers 211, 212 arranged behind the electrode sheet 10, or control the rotation speed ratio of the pair of feed rollers 120 and / or the pair of rolling rollers 211, 212.

[0122] In addition, the preliminary tension control unit 400 may include a tension maintaining roller 410 rotating on the electrode sheet 10 and a displacement detector (not shown) for measuring the displacement of the tension maintaining roller 410, and may be configured to control the rotation speed of the feed roller 120 or the pressing rollers 211, 212 based on the displacement of the tension maintaining roller 221 detected by the displacement detector.

[0123] For example, when the tension of the electrode sheet 10 is high, the preliminary tension control unit 400 decelerates the rotation speed of the pair of rolling rollers 211, 212 disposed behind the electrode sheet 10 (or accelerates the rotation speed of the pair of feed rollers 120 disposed in front of the electrode sheet 10), and conversely, when the tension of the electrode sheet 10 is low, the preliminary tension control unit 400 accelerates the rotation speed of the pair of rolling rollers 211, 212 disposed behind the electrode sheet 10. In this case, the rotation speed ratio of the pair of rotating rolling rollers 211, 212 can be maintained. The other elements of the preliminary tension control unit 400 are replaced by the description of the tension control unit 200 described above.

[0124] By the preliminary tension control unit 400 according to the fifth embodiment of the present invention, the electrode sheet 10 rolled by the pair of feed rollers 120 and moving downward can be guided to move upward by the support of the tension holding roller 410 of the preliminary tension control unit 400. In addition, the feeding problem such as jamming of the electrode sheet 10 between the powder tableting device 100 and the calendering device 200 can be eliminated, thereby improving the electrode manufacturing process.

[0125] Although the present invention has been described above based on a limited number of embodiments and drawings, the present invention is not limited thereto, and it is apparent that those skilled in the art may make various changes and modifications within the technical aspects of the present invention and the scope of the appended claims and their equivalents.

[0126] For convenience of description, terms indicating directions such as up, down, left, right, front, and rear are used, but it is obvious to those skilled in the art that these terms may change according to the positions of the elements or observers.

Claims

1. An electrode manufacturing device for manufacturing a dry electrode, comprising: a powder tableting device configured to form a dry material including an electrode active material into a sheet; A calendering device, comprising at least one rolling unit, each rolling unit comprising a pair of rolling rollers for rolling the electrode sheet supplied from the powder tableting device; as well as a single laminating roller configured to laminate the current collector and the electrode sheet having a target thickness rolled by a calendering device to form an electrode, The laminating roller is arranged to face one of a pair of rolling rollers of the rolling unit that roll the electrode sheet last.

2. The electrode manufacturing apparatus according to claim 1, wherein the rolling unit comprises: Upper roller pressure roller; as well as a lower roller located below the upper roller, and The thickness of the electrode sheet is adjusted to be the same as the gap between the upper pressing roller and the lower pressing roller.

3. The electrode manufacturing apparatus according to claim 2, wherein the laminating roller is arranged facing the lower laminating roller, and The electrode sheet and the current collector are pressed together while passing between the laminating roller and the lower laminating roller.

4. The electrode manufacturing apparatus according to claim 2, further comprising: A cutting unit to cut the edge of the electrode sheet, The cutting unit is arranged facing the lower pressing roller, and the lower pressing roller faces the laminating roller. 5 . The electrode manufacturing apparatus according to claim 4 , wherein the cutting unit is configured to cut both end portions of the electrode sheet in a width direction passing between the upper rolling roller and the lower rolling roller.

6. The electrode manufacturing apparatus according to claim 1, wherein the at least one rolling unit comprises a plurality of rolling units arranged to be spaced apart from each other, and The calendaring device further includes a tension control unit to measure the tension applied to the electrode sheet conveyed between the rolling units and control the rotation speed of the rolling rollers.

7. The electrode manufacturing apparatus according to claim 6, wherein the tension control unit is configured to control the rotation speed of each rolling roller of the rolling unit provided in front of the electrode sheet or behind the electrode sheet or in front of and behind the electrode sheet, or The tension control unit is configured to control a rotation speed ratio of the pair of rolling rollers of the rolling unit.

8. The electrode manufacturing apparatus according to claim 6, wherein under high tension in the electrode sheet, the tension control unit decelerates the rotation speed of the rolling roller disposed behind the tension control unit (or accelerates the rotation speed of the rolling roller disposed in front of the tension control unit), and Wherein under low tension in the electrode sheet, the tension control unit accelerates the rotation speed of the rolling roller arranged behind the tension control unit (or decelerates the rotation speed of the rolling roller arranged in front of the tension control unit).

9. The electrode manufacturing apparatus according to claim 6, wherein the tension control unit comprises: a tension-maintaining roller located on the electrode sheet and rotating; as well as a displacement detector to measure the displacement of the tension maintaining roller, The tension control unit measures the tension of the electrode sheet according to the displacement measured by the displacement detector, and controls the rotation speed of the rolling roller based on the tension.

10. The electrode manufacturing equipment according to claim 9, wherein the tension control unit further comprises: a guide member including a guide slit coupled to two rotation shafts of the tension maintaining roller to guide the tension maintaining roller to move up and down; as well as A loading member is connected to the tension maintaining roller to apply a constant load to the tension maintaining roller.

11. The electrode manufacturing apparatus according to claim 9, wherein the tension control unit decelerates the rotation speed of the roll-down roller located behind the tension holding roller (or accelerates the rotation speed of the roll-down roller disposed in front of the tension holding roller) based on the displacement when the tension holding roller changes position upward, When the tension maintaining roller changes position downward, the tension control unit accelerates the rotation speed of the rolling roller located behind the tension maintaining roller (or decelerates the rotation speed of the rolling roller arranged in front of the tension maintaining roller) based on the displacement.

12. The electrode manufacturing apparatus according to claim 6, wherein the tension control unit comprises: a tension sensing roller located on the electrode sheet and rotating; as well as A sensor to measure the load change of the tension sensing roller, The rotation speed of the rolling roller is controlled according to the load change measured by the sensor.

13. The electrode manufacturing device according to claim 12, wherein the tension control unit decelerates the rotation speed of the rolling roller located behind the tension sensing roller (or accelerates the rotation speed of the rolling roller arranged in front of the tension sensing roller) based on the load change when the load of the tension sensing roller increases, and accelerates the rotation speed of the rolling roller located behind the tension sensing roller (or decelerates the rotation speed of the rolling roller arranged in front of the tension sensing roller) based on the load change when the load of the tension sensing roller decreases.

14. The electrode manufacturing apparatus according to claim 6, wherein the powder tableting device comprises a pair of feed rollers to roll the dry material into a sheet shape, and The electrode manufacturing apparatus further includes a preliminary tension control unit to measure the tension applied to the electrode sheet conveyed between the powder tableting device and the rolling unit, and to control the rotation speed of the feed roller or the rolling roller.

15. The electrode manufacturing apparatus of claim 1, wherein the at least one rolling unit is a single rolling unit.

16. The electrode manufacturing apparatus according to claim 1, further comprising: The winding roller is where the electrode is wound.

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