Electrode roll cleaning method and cleaning device

Abstract

A method for automatically cleaning a mill roll used in an electrode rolling process according to one embodiment of the present invention includes a step of determining whether the mill roll is in an out-of-operation state, and if the mill roll is in an out-of-operation state, a step of cleaning the mill roll in a first cleaning mode, wherein the first cleaning mode is a mode in which cleaning of the mill roll is performed while a process of rolling an electrode with the mill roll is stopped.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0125135 filed on September 30, 2022 and Korean Patent Application No. 10-2023-0127648 filed on September 25, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a method and an apparatus for cleaning rolls used in an electrode manufacturing process, and more particularly to a method and an apparatus for automatically cleaning rolls when the rolls are in operation and when they are not in operation. [Background technology]

[0003] As the cost of energy sources rises due to the depletion of fossil fuels and concerns about environmental pollution grow, the demand for environmentally friendly alternative energy sources is becoming an essential factor for future life. In particular, with technological development and increased demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing.

[0004] In terms of battery shape, there is a high demand for thin prismatic and pouch-type secondary batteries that can be used in mobile phones, etc., while in terms of materials, there is a high demand for lithium secondary batteries such as lithium-ion batteries and lithium-ion polymer batteries that have high energy density, discharge voltage, and output stability.

[0005] In general, a secondary battery is manufactured by forming a cathode and an anode by applying an electrode mixture layer containing an electrode active material to the surface of a current collector, and then interposing a separator between them to form an electrode assembly. The electrode assembly is then mounted inside a cylindrical or rectangular metal can or a pouch-type case made of an aluminum laminate sheet, and the electrode assembly is then injected or impregnated with a liquid electrolyte or a solid electrolyte.

[0006] Secondary batteries can also be classified according to the structure of their electrode assembly, which has a positive electrode / separator / negative electrode structure. Representative examples include a jelly-roll (wound-type) electrode assembly in which long sheet-like positive and negative electrodes are wound up with a separator interposed between them; a stacked (laminate-type) electrode assembly in which multiple positive and negative electrodes cut into units of a predetermined size are stacked one after the other with a separator interposed between them; and a stacked / folded electrode assembly in which a bi-cell or full cell in which a predetermined number of positive and negative electrodes are stacked with a separator interposed between them is wound up with a separator sheet.

[0007] On the other hand, the electrodes generate current through the exchange of ions, and the positive and negative electrodes that make up the electrodes are configured such that an electrode active material is applied to an electrode current collector made of metal.

[0008] The separator is located between the positive and negative electrodes of the battery to provide insulation, retain the electrolyte, and provide a path for ion conduction.

[0009] Rolling processes, slitting processes, notching processes, lamination processes, folding processes, etc. for manufacturing the electrodes and separators are mostly performed using roll-to-roll processing, where roll-to-roll processing refers to a process in which processes such as coating and printing are performed while multiple flexible metal foils are moved between rollers.

[0010] For example, a roll of flexible, thin sheet-like material is unwound to supply the material, which is then coated or printed on another roll, after which the material is processed and rewound again for collection. In particular, positive and negative electrodes for secondary batteries are formed by applying a positive or negative active material to a sheet and rolling it.

[0011] In this rolling process, rolling is performed repeatedly, and if the remaining active material or other foreign matter adheres to the rolls during rolling, the foreign matter will adhere to the electrode in the subsequent rolling process, reducing the quality of the electrode and the battery including the electrode. Therefore, a rolling roll cleaning device is used to remove contamination from the rolling rolls.

[0012] In contrast to this, conventional rolling roll cleaning devices have used a method in which a cleaning liquid is sprayed onto a cleaning section such as a cleaning roller through a nozzle while the rolling roll is driven to manufacture electrodes, and the rolling roll is cleaned in the cleaning section where the cleaning liquid is sprayed.

[0013] Nevertheless, if contaminants are found on the surface of the rolling roll, the rolling roll must be stopped and workers must remove the contaminants using wipers or the like, which reduces the production efficiency of electrode manufacturing.

[0014] On the other hand, when the rolling rolls are cleaned during the electrode manufacturing process while the rolling rolls are in operation, there are limitations on the type and amount of cleaning solution used in order to maintain the amount of residual moisture in the electrode, so oil-based cleaning solutions containing oil components are mainly used.

[0015] However, when using such oil-based cleaning solutions, there are limitations to the removal of contaminants. For example, in the case of a negative electrode rolling roll for rolling the negative electrode of a secondary battery, the solvent for the negative electrode is water, so there is a limit to the removal of contaminants from the negative electrode rolling roll using only the oil component. As a result, the contaminants are not completely removed and tend to remain. When an electrode is rolled using a rolling roll with contaminants remaining on it, the contaminants on the rolling roll surface leave marks on the electrode surface, resulting in problems such as electrode detachment.

[0016] Therefore, there is a need for a method and apparatus for more efficiently cleaning mill rolls to address these problems. Summary of the Invention [Problem to be solved by the invention]

[0017] The present invention relates to a method and apparatus for more efficiently cleaning rolls used in the electrode manufacturing process, and aims to provide a method and apparatus therefor that can clean the rolls used in electrode manufacturing even when the rolls are not in operation, while automatically cleaning the rolls.

[0018] However, the problems to be solved by the embodiments of the present invention are not limited to the above-mentioned problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Means for solving the problem]

[0019] A method for automatically cleaning a mill roll used in an electrode rolling process according to one embodiment of the present invention includes a step of determining whether the mill roll is in an out-of-operation state, and if the mill roll is in an out-of-operation state, a step of cleaning the mill roll in a first cleaning mode, wherein the first cleaning mode may be a state in which cleaning of the mill roll is performed while a process of rolling an electrode with the mill roll is stopped.

[0020] The method may further include a step of cleaning the rolling roll in a second cleaning mode when the rolling roll is in an operating state, and the second cleaning mode may be a step in which cleaning of the rolling roll is performed simultaneously with the step of rolling the electrode with the rolling roll.

[0021] The first cleaning mode and the second cleaning mode may differ from each other in at least one of the type of cleaning liquid, the number of times and amount of cleaning liquid supplied, and the moving speed of the cleaning cloth.

[0022] The step of determining whether the rolling roll is in an out-of-operation state may include the steps of receiving an input of the rotational speed of the rolling roll, counting a standby time of the rolling roll if the rotational speed of the rolling roll is 0, and determining that the rolling roll is in an out-of-operation state if a first predetermined time has elapsed while the rotational speed of the rolling roll is 0.

[0023] The step of determining whether the rolling roll is out of operation can include the steps of receiving an input of the position of the rolling roll, counting a standby time of the rolling roll when the rolling roll is in a predetermined standby position, and determining that the rolling roll is out of operation when a second predetermined time has elapsed while the rolling roll is in the predetermined standby position.

[0024] The step of determining whether the rolling roll is in an out-of-operation state can include the steps of respectively receiving input of the rotational speed and position of the rolling roll, counting a standby time of the rolling roll when the rotational speed of the rolling roll is 0, counting a standby time of the rolling roll when the rolling roll is in a predetermined standby position, and determining that the rolling roll is in an out-of-operation state when a first predetermined time has elapsed while the rotational speed of the rolling roll is 0 and a second predetermined time has elapsed while the rolling roll is in the predetermined standby position.

[0025] The step of cleaning the rolling roll in a first cleaning mode may include the steps of measuring a brightness value of a surface of the rolling roll, and cleaning the rolling roll for a third predetermined time if the brightness value of the surface of the rolling roll is equal to or less than a first predetermined brightness value.

[0026] The step of cleaning the mill roll in a first cleaning mode may further include a step of measuring a brightness value of the surface of the cleaned mill roll and determining whether the brightness value is equal to or greater than a second predetermined brightness value, and if the brightness value of the surface of the mill roll is equal to or greater than the second predetermined brightness value, the step of cleaning in the first cleaning mode may be automatically terminated.

[0027] The step of cleaning the mill roll in a first cleaning mode may further include a step of measuring a brightness value of the surface of the cleaned mill roll and determining whether the brightness value is equal to or greater than a second predetermined brightness value, and if the brightness value of the surface of the mill roll is less than the second predetermined brightness value, the step of cleaning the mill roll for the third predetermined time may be repeated.

[0028] The third predetermined time may be selected from the range of 3 to 10 minutes.

[0029] The second predetermined brightness value may be greater than the first predetermined brightness value.

[0030] The first predetermined brightness value may be 40% and the second predetermined brightness value may be 80%.

[0031] The number of times and the amount of cleaning liquid supplied in the first cleaning mode may be greater than the number of times and the amount of cleaning liquid supplied in the second cleaning mode.

[0032] The cleaning fluid provided in the first cleaning mode may be an oil-based cleaning agent.

[0033] The cleaning liquid provided in the first cleaning mode may be selected from the group consisting of water, acetone, a water-based cleaning liquid, and a combination of at least two selected from these.

[0034] The cleaning fluid provided in the second cleaning mode may be an oil-based cleaning agent.

[0035] An apparatus for automatically cleaning a rolling roll for carrying out the method according to the above-described embodiment may include a sensor unit for measuring the brightness value of the surface of the rolling roll, a cleaning liquid supply unit for supplying the cleaning liquid to the rolling roll, a cleaning unit for cleaning the surface of the rolling roll, and a control unit for receiving data input from the sensor unit and controlling whether or not the cleaning liquid supply unit and the cleaning unit are operated.

[0036] The cleaning liquid supply unit may be provided in plurality, and some of the cleaning liquid supply units may supply an oil-based cleaning agent, and the remaining cleaning liquid supply units may supply water, acetone, a water-based cleaning liquid, or a combination of at least two selected from these.

[0037] The cleaning device may be provided in a plurality, some of the plurality of cleaning devices may be devices for the first cleaning mode, and the remaining of the plurality of cleaning devices may be devices for the second cleaning mode. [Effects of the Invention]

[0038] According to an embodiment of the present invention, the rolls for electrode production are cleaned even when the rolls are not in operation, and the cleaning of the rolls is started and ended automatically, thereby increasing the efficiency of cleaning the rolls. This also improves the manufacturing efficiency of the electrode process. Furthermore, because electrodes are produced using rolls cleaned by the improved cleaning method, battery performance can be improved. [Brief explanation of the drawings]

[0039] [Figure 1] 1 is a diagram showing a rolling roll cleaning apparatus for carrying out a rolling roll cleaning method according to an embodiment of the present invention. [Figure 2] 1 shows a flow chart of a method for cleaning a mill roll according to an embodiment of the present invention. [Figure 3] 1 shows a flow chart of a method for cleaning a mill roll according to an embodiment of the present invention. [Figure 4] 1 shows a flow chart of a method for cleaning a mill roll according to an embodiment of the present invention. [Figure 5] 1 shows a flow chart of a method for cleaning a mill roll according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily carry out the present invention. The present invention may be embodied in several different forms and is not limited to the embodiments described herein.

[0041] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0042] In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. In the drawings, thicknesses are exaggerated to clearly show multiple layers and regions. In the drawings, thicknesses of some layers and regions are exaggerated for the convenience of explanation.

[0043] Furthermore, when a layer, film, region, plate, or other part is said to be "on" or "above" another part, this includes not only the case where it is "directly above" that other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in the middle. Furthermore, being "on" or "above" a reference part means being located above or below the reference part, and does not necessarily mean being located "above" or "above" the direction opposite to gravity.

[0044] Furthermore, throughout the specification, when a part "comprises" a certain element, it does not mean that it excludes other elements, but that it may further include other elements, unless otherwise specified.

[0045] Also, throughout the specification, "on a plane" means when the target part is viewed from above, and "on a cross section" means when the target part is cut vertically and viewed from the side.

[0046] Hereinafter, an apparatus and a method for automatically cleaning a roll used in an electrode rolling process according to one embodiment of the present invention will be described with reference to FIG. 1 and FIGS. 2 to 5, respectively.

[0047] First, the automatic cleaning device and method for the roll used in the electrode rolling process according to one embodiment of the present invention roughly includes cleaning in a first cleaning mode and cleaning in a second cleaning mode.

[0048] The first cleaning mode is a mode in which cleaning is performed on the mill roll 100 while the process of rolling an electrode with the mill roll 100 is stopped. The second cleaning mode is a mode in which cleaning is performed on the mill roll 100 simultaneously with the process of rolling an electrode with the mill roll 100. Supplementally, the first cleaning mode is a mode in which the mill roll 100 is cleaned when the electrode rolling process is stopped and the equipment is not operating.

[0049] The first cleaning mode includes cases where the electrode rolling process is stopped irregularly and cases where the electrode rolling process is stopped regularly. For example, an irregular stop refers to a case where the electrode rolling equipment is stopped due to a defect in the electrode rolling equipment or in the pre- or post-process, or a case where the operation of the mill roll 100 is stopped for reasons such as equipment inspection or replacement. Alternatively, a regular stop refers to a case where a time for completing the electrode rolling process is separately set and the equipment does not operate for a predetermined period of time after the electrode rolling process is completed.

[0050] The second cleaning mode is a mode in which electrode rolling is performed while the rolling roll 100 is rotating during the electrode rolling process, i.e., while the equipment is operating, and foreign matter 110 that occurs on the surface of the rolling roll 100 is simultaneously cleaned in real time.

[0051] FIG. 1 shows a roll 100 used in the electrode rolling process and an apparatus for automatically cleaning the roll (hereinafter referred to as a "rolling roll cleaning apparatus" for convenience) 200.

[0052] The rolling roll cleaning device 200 roughly comprises a sensor unit 210 that measures the brightness value of the surface of the rolling roll 100, a cleaning unit 220 that cleans the surface of the rolling roll 100, a cleaning liquid supply unit 230 that supplies cleaning liquid to the cleaning unit 220, and a drying unit 240 that dries the surface of the rolling roll 100 that has been cleaned with the cleaning liquid. The cleaning unit 220 is composed of a supply roll 221 that feeds a cleaning cloth 224 and a take-up roll 222 that rewinds the cleaned cleaning cloth 224, and is also composed of a cleaning roll (e.g., nip roll) 223 that improves the adhesion between the rolling roll 100 and the cleaning cloth 224 in order to increase the cleaning power of the rolling roll 100.

[0053] The sensor unit 210 measures the brightness value of the surface of the mill roll 100. The brightness value can be calculated by sensing the entire surface of the mill roll 100, that is, by sensing the half of the outer circumferential surface of the cylindrical mill roll 100 on which the sensor unit 210 is located. Although one sensor unit 210 is shown in FIG. 1 for convenience, the present invention is not limited thereto. Two sensor units 210 can be disposed on both sides of the mill roll 100 facing each other, and the sensor units 210 on both sides can sense each half of the mill roll 100 to calculate the brightness value.

[0054] Alternatively, the sensor unit 210 can scan while moving in the length direction or along the circumference of the cylindrical rolling roll 100, or can scan while moving in a spiral around the outer circumferential surface of the cylindrical rolling roll 100, and various modifications and variations are possible.

[0055] Alternatively, the sensor unit 210 can also detect the foreign matter 110 by determining that a portion whose brightness value is particularly lower than that of the surrounding portion is the foreign matter 110.

[0056] The cleaning unit 220 must first remove foreign matter attached to the mill roll 100 after rolling, and is therefore located closest to the point where the mill roll 100 rolls the electrode in the direction of rotation of the mill roll 100.

[0057] The cleaning cloth 224 is taken up from the supply roll 221 and transferred to the cleaning roll 223. The cleaning roll 223 is adjacent to the surface of the mill roll 100, and one side of the cleaning cloth 224 can contact the mill roll 100. After passing through the cleaning roll 223, the cleaning cloth 224 is collected by the take-up roll 222. The cleaning roll 223 generally has a roll shape to facilitate smooth transfer of the cleaning cloth 224. In this case, the cleaning roll 223 can rotate simultaneously with the movement of the cleaning cloth 224. If the contact portion between the cleaning roll 223 and the mill roll 100 is rounded as described above, damage to the mill roll 100 caused by the cleaning cloth 224 when the cleaning cloth 224 contacts the mill roll 100 can be prevented. Meanwhile, the shape and structure of the cleaning roll 223 are not limited as long as it can guide the transfer of the cleaning cloth 224 and bring the cleaning cloth 224 into contact with the mill roll 100.

[0058] The cleaning cloth 224 is not limited to any particular type as long as it can smoothly absorb or remove foreign matter adhering to the rolling roll 100 and does not damage the surface of the rolling roll 100, but nonwoven fabric is preferred in terms of cleaning ability. In addition, the material of the nonwoven fabric is not limited to any particular type as long as it can absorb or remove foreign matter, and nonwoven fabrics made of cotton fiber, polyethylene fiber, polypropylene fiber, polyester, aramid fiber, cellulose fiber, rayon fiber, or a mixture thereof can be used.

[0059] The cleaning liquid supply unit 230 sprays cleaning liquid onto the cleaning cloth 224. A plurality of cleaning liquid supply units 230 may be provided. For example, a cleaning liquid supply unit that supplies water and a cleaning liquid supply unit that supplies acetone may be provided. Although not shown in detail in FIG. 1 , the cleaning liquid supply unit 230 may include a cleaning liquid storage tank, cleaning liquid transfer piping, a pump, valves, pumps, and / or nozzles. The structure, shape, and number of the detailed components of the cleaning liquid supply unit 230 may be variously modified or changed depending on the environment in which the present invention is implemented.

[0060] There are no limitations on the type of cleaning liquid as long as it can smoothly remove foreign matter, etc. For example, the cleaning liquid may include water, acetone, dimethyl carbonate, dimethylformamide, N-methylformamide, sulfolane (tetrahydrothiophene-1,1-dioxide), 3-methylsulfolane, N-butylsulfone, dimethylsulfoxide, pyridinone (HEP), dimethylpiperidone (DMPD), N-methylpyrrolidinone (NMP), N-methylacetamide, dimethylacetamide (DMAc), dimethylformamide (DMF), diethylacetamide (DEAc), dipropyleneacetamide (DPAc), ethanol, propanol, butanol, hexanol, ethylene glycol, tetrachloroethylene, propylene glycol, toluene, tolpentine, methyl acetate, ethyl acetate, phenol ether, cresol, and glycerol.

[0061] Furthermore, the mill roll cleaning device 200 according to the present invention can use a water-based cleaning liquid, specifically, one or more selected from the group including water or alcohol-based compounds.

[0062] More specifically, the cleaning solution may be a mixture of water and an alcohol-based compound, and the alcohol-based compound may be one or more selected from the group including ethanol, propanol, butanol, pentanol, hexanol, isopropanol, heptanol, decanol, octanol, isotecanol, ethylene glycol, diethylene glycol, triethylene glycol, ethylene glycol methyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, ethylene glycol ethyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol monopropyl ether, diethylene glycol monopropyl ether, triethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, and triethylene glycol monohexyl ether. More preferably, the alcohol-based compound may be one or more selected from the group including pentanol, hexanol, heptanol, octanol, and decanol.

[0063] The cleaning solution may contain 10 to 40 wt %, 20 to 30 wt %, or 30 wt % of acetone based on the total weight of the cleaning solution.Similarly, the cleaning solution may contain 60 to 90 wt %, 70 to 80 wt %, or 70 wt % of water based on the total weight of the cleaning solution.

[0064] The drying unit 240 dries the surface of the mill roll 100 that has been washed with the washing liquid. The drying unit 240 serves to dry the surface of the mill roll 100 by heating and / or blowing air. Foreign matter can be dried and removed from the roll surface by heating and / or blowing air, and remaining liquid foreign matter can be removed by evaporating by heating and / or blowing air. The drying unit 240 may be a heater type that directly applies heat to the surface of the mill roll 100, or may be a hot air drying type that applies hot air to the surface of the mill roll 100.

[0065] The rolling roll cleaning device 200 further includes a control unit (not shown) that controls the sensor unit 210, the cleaning unit 220, the cleaning liquid supply unit 230, the drying unit 240, etc. The control unit receives data input from the sensor unit 210 and controls whether or not the cleaning unit 220, the cleaning liquid supply unit 230, and the drying unit 240 are operated.

[0066] Meanwhile, in the first cleaning mode, as in the second cleaning mode, the rolling roll cleaning device 200 is fixed, and the first cleaning mode can be performed while rotating the rolling roll 100 as needed. Alternatively, in the first cleaning mode, the rolling roll 100 does not necessarily have to rotate for electrode production, so various modifications and variations are possible, such as the sensor unit 210, cleaning unit 220, cleaning liquid supply unit 230, drying unit 240, and other components of the rolling roll cleaning device 200 moving simultaneously or individually over the surface of the rolling roll 100.

[0067] Meanwhile, in the second cleaning mode, the surface of the mill roll 100 is cleaned while the electrode is being rolled by the mill roll 100, so the use of water and aqueous cleaning solutions is limited so as not to affect the quality of the rolled electrode. However, in the first cleaning mode, since the electrode is not being rolled by the mill roll 100, water, acetone, aqueous cleaning solution, or a mixture thereof can also be used. In this case, after cleaning in the first cleaning mode, the surface of the mill roll 100 is dried with a cloth or dryer, and the water is drained from the bottom of the equipment before the electrode rolling process is performed again, so that the quality of the produced electrode is not affected.

[0068] It is also possible to provide a plurality of rolling roll cleaning apparatuses 200, with a rolling roll cleaning apparatus 200 for the first cleaning mode and a rolling roll cleaning apparatus 200 for the second cleaning mode. Alternatively, a single rolling roll cleaning apparatus 200 may be provided, but with a plurality of cleaning liquid supply units 230, which may supply an oil-based cleaning liquid or a water-based cleaning liquid as needed. That is, some of the multiple cleaning liquid supply units 230 may supply an oil-based cleaning liquid in the second cleaning mode or in both the first cleaning mode and the second cleaning mode, and the remaining some may supply a water-based cleaning liquid in the first cleaning mode.

[0069] Hereinafter, a method for automatically cleaning a rolling roll used in an electrode rolling process according to one embodiment of the present invention (hereinafter referred to as a "roll cleaning method") will be described.

[0070] 2 to 5 show a flowchart of a method for cleaning a mill roll according to an embodiment of the present invention.

[0071] The method for cleaning a rolling roll includes a step of determining whether the rolling roll is in an out-of-operation state (S100); if the rolling roll 100 is in an out-of-operation state, a step of cleaning the rolling roll 100 in a first cleaning mode (S200); and if the rolling roll 100 is in an operating state, a step of cleaning the rolling roll 100 in a second cleaning mode (S300).

[0072] The step of cleaning in the first cleaning mode (S200) and the step of cleaning in the second cleaning mode (S300) can be performed by the cleaning unit 220, cleaning liquid supply unit 230, drying unit 240, control unit, etc. of the mill roll cleaning apparatus 200. The mill roll cleaning apparatus 200 may be composed of a plurality of components, and may be provided with a device 200 for cleaning in the first cleaning mode and a device 200 for cleaning in the second cleaning mode separately. Alternatively, the step of cleaning in the first cleaning mode (S200) and the step of cleaning in the second cleaning mode (S300) may be performed by the mill roll cleaning apparatus 200. The step of cleaning in the second cleaning mode (S300) may be performed using a cleaning method used in the electrode rolling process during normal electrode manufacturing.

[0073] As described above, the first cleaning mode is a mode in which cleaning is performed on the mill roll 100 while the process of rolling an electrode on the mill roll 100 is stopped. The second cleaning mode is a mode in which cleaning is performed on the mill roll 100 simultaneously with the process of rolling an electrode on the mill roll 100. In the first cleaning mode, the electrode rolling process is stopped and the mill roll 100 is separated from the electrode sheet and is not being rolled. Therefore, the section of the electrode sheet adjacent to the mill roll 100 is tagged as a defective section and then discarded as defective. Therefore, cleaning the mill roll 100 in the first cleaning mode does not affect the quality of the final electrode. In some cases, such as when an electrode sheet is not positioned on the mill roll 100, cleaning the mill roll 100 can be performed without affecting the quality of the rolled electrode. In such cases, cleaning can be performed by changing at least one of the type of cleaning solution, the number and amount of supply of cleaning solution, the moving speed of the cleaning cloth, and the type of cleaning solution, which are typically used in the second cleaning mode performed during the electrode rolling process. However, this is not necessarily the case with the present invention, and cleaning can also be performed in the first cleaning mode while the electrode rolling process is stopped by keeping the same type of cleaning liquid, number of times and amount of cleaning liquid supplied, cleaning cloth movement speed, and type of cleaning liquid used in the second cleaning mode.

[0074] There are two main conditions for determining whether the mill roll 100 is in an out-of-operation state. The conditions for determining whether the equipment including the mill roll 100 for electrode manufacturing has stopped operating and is on standby, i.e., is in an out-of-operation state, are as follows. One is that a predetermined time has passed during which the rotation speed of the mill roll 100 is maintained at 0. The other is that a predetermined time has passed while the mill roll 100 is in a predetermined standby position. The mill roll 100 being in a predetermined standby position means that the mill roll 100 is in a position where it cannot apply pressure to the electrode (electrode sheet). For example, the mill roll 100 may be in a position where it maintains a predetermined distance from the traveling position of the electrode sheet. For example, in an electrode rolling process, when an electrode is rolled using a pair of mill rolls 100, the distance between the pair of mill rolls 100 may be greater than the thickness of the electrode. However, the present invention is not limited to this, and can be modified and altered in various ways, such as in some cases meaning that the operation of the equipment is completely completed and the rolling roll 100 is located in a pre-designated location (a location to which it has been automatically moved) for cleaning, inspection, etc., and that this position is maintained.

[0075] On the other hand, if both of the conditions of the rotation speed of the rolling roll 100 and the standby position of the rolling roll 100 are met, it can be determined that the rolling roll 100 is in a non-operating state, but depending on the environment in which the present invention is implemented, it can also be determined that the rolling roll 100 is in a non-operating state if either one of the two conditions is met.

[0076] More specifically, referring to FIG. 3, the step (S100) of determining whether the mill roll 100 is in an idle state includes: a step (S110-1) of receiving an input of the rotational speed (driving speed) of the mill roll 100; a step (S120-1) of counting a standby time of the mill roll 100 if the rotational speed of the mill roll 100 is 0; and a step (S130) of determining that the mill roll 100 is in an idle state if a first predetermined time has elapsed while the rotational speed of the mill roll 100 is 0. Here, the standby time refers to the time during which the rotational speed of the mill roll 100 remains 0. In steps S110-1 and S120-1, the rotational speed of the mill roll 100 may be detected by a speed sensor, or the time may be counted based on the time when a control unit (not shown) connected to the mill roll 100 sends a drive stop command to the mill roll 100. The present invention can be applied in various ways.

[0077] Alternatively, referring to FIG. 4, the step (S100) of determining whether the mill roll 100 is in an idle state includes: a step (S110-2) of receiving input of the position of the mill roll 100; a step (S120-2) of counting the standby time of the mill roll 100 when the mill roll 100 is in a predetermined standby position; and a step (S130) of determining that the mill roll 100 is in an idle state when a second predetermined time has elapsed while the mill roll 100 is in the predetermined standby position. Here, the standby time refers to the time during which the mill roll 100 remains in the predetermined standby position. In steps S110-2 and S120-2, the position of the mill roll 100, such as whether it has moved toward the electrode or away from the electrode, can be detected using a position detection sensor or the like. Alternatively, the standby position of the mill roll 100 can be indirectly detected by detecting the pressure applied by the mill roll 100 using a pressure detection sensor such as a load cell.

[0078] Alternatively, if both of the two conditions are met, it can be determined that the roll 100 is out of operation.

[0079] For example, the steps shown in Fig. 3 may be performed first, followed by the steps shown in Fig. 4. That is, after a first predetermined time has elapsed with the rotation speed of the rolling roll 100 at 0, it may be determined that the rolling roll 100 is in a non-operating state when a second predetermined time has elapsed with the rolling roll 100 again at a predetermined standby position.

[0080] Conversely, the steps shown in Fig. 4 may be performed first, followed by the steps shown in Fig. 3. That is, after a second predetermined time has elapsed with the roll 100 in a predetermined standby position, it may be determined that the roll 100 is finally in an out-of-operation state when a first predetermined time has elapsed with the rotational speed of the roll 100 at 0 again.

[0081] Alternatively, the steps shown in FIGS. 3 and 4 may be performed simultaneously. Steps (S110-1) and (S110-2) may be performed simultaneously, and then steps (S120-1) and (S120-2) may be performed simultaneously. If a first predetermined time has elapsed with the rotational speed of the mill roll 100 at 0 and a second predetermined time has elapsed with the mill roll 100 at a predetermined standby position, it may be determined (S130) that the mill roll 100 is in an out-of-operation state. Specifically, the rotational speed and position of the mill roll 100 are received as input. If the rotational speed of the mill roll 100 is 0, the standby time of the mill roll 100 is counted. At the same time, if the mill roll 100 is at the standby position, the standby time of the mill roll 100 is counted. If a first predetermined time has elapsed with the rotational speed of the mill roll 100 at 0 and a second predetermined time has elapsed with the mill roll 100 at the standby position, it may be determined that the mill roll 100 is in an out-of-operation state.

[0082] Each of the first predetermined time and the second predetermined time is, for example, a time selected from a range of more than 0 minutes to 100 minutes or less, but the present invention is not limited to the above, and each of the first predetermined time and the second predetermined time can be appropriately selected to suit various environments to which the present invention is applied.

[0083] Referring to FIG. 5, when the rolling roll 100 is not in operation, the step of cleaning the rolling roll 100 in the first cleaning mode (S200) includes: a step of measuring the brightness value of the surface of the rolling roll 100 with the sensor unit 210 (S210); and if the brightness value of the surface of the rolling roll 100 is equal to or less than a first predetermined brightness value, a step of cleaning the rolling roll 100 for a third predetermined time with the cleaning unit 220 (S220); and a step of measuring the brightness value of the surface of the cleaned rolling roll 100 and determining whether the brightness value is equal to or greater than a second predetermined brightness value (S230).

[0084] In this case, the second predetermined brightness value is greater than the first predetermined brightness value. The higher the brightness value, the cleaner the rolling roll. The first predetermined brightness value and the second predetermined brightness value are each any one of brightness values ​​between 0 and 100% and can be appropriately selected according to various environments to which the present invention is applied. For example, the first predetermined brightness value may be 40% and the second predetermined brightness value may be 80%. The third predetermined time is, for example, any one of 3 to 10 minutes, for example, 5 minutes, but the present invention is not limited to the above, and the third predetermined time can be appropriately selected according to various environments to which the present invention is applied.

[0085] In relation to step S210, in the second cleaning mode, there may be limitations on the type and amount of cleaning solution used because cleaning may degrade the quality of the electrode. In some cases, foreign matter, residues, or contaminants 110 that were not removed even in the second cleaning mode may remain on the surface of the mill roll 100. As a result, the brightness value of the surface of the mill roll 100 may be somewhat low. An operator may preset a first predetermined brightness value of the surface of the mill roll 100 at which the first cleaning mode should be started, depending on the environment in which the present invention is implemented (i.e., depending on the type of active material of the electrode rolled by the mill roll 100, the degree of cleaning in the second cleaning mode, etc.).

[0086] On the other hand, in step (S210), if the brightness value of the surface of the rolling roll 100 exceeds the first predetermined brightness value, the first cleaning mode is not performed and is immediately ended.

[0087] After the mill roll 100 is cleaned for a third predetermined time in step (S220), the brightness value of the mill roll 100 is measured in step (S230) to determine whether the brightness value is equal to or greater than a second predetermined brightness value.

[0088] When the surface of the roll 100 is cleaned and the brightness value is increased, i.e., when the brightness value of the surface of the roll 100 is equal to or greater than the second predetermined brightness value, the step of cleaning in the first cleaning mode is automatically terminated. However, if foreign matter, residue, or contaminants 110 still remain on the surface of the roll 100 and the brightness value of the surface of the roll 100 is less than the second predetermined brightness value, step (S220) of cleaning the roll 100 for a third predetermined time is performed again. That is, step (S220) is repeatedly performed until the end of the first cleaning mode is declared in step (S230), i.e., until the step of cleaning in the first cleaning mode is automatically terminated.

[0089] As a result, when the mill roll 100 is not in operation, unlike the conventional case where an operator manually cleans the mill roll 100 each time, the mill roll 100 can be automatically cleaned. In addition, by continuously repeating the same process of measuring the brightness value and cleaning the mill roll 100 for a third predetermined time, measuring the brightness value again, and if the desired brightness value (i.e., the second predetermined brightness value) is not achieved, cleaning the mill roll 100 again for the third predetermined time, it is possible to realize automation of cleaning of the mill roll 100 when the mill roll 100 is not in operation.

[0090] Furthermore, according to an embodiment of the present invention, the electrode manufacturing roll is cleaned even when the roll is not in operation, and the cleaning of the roll is started and ended automatically, thereby improving the cleaning efficiency of the roll. This also improves the manufacturing efficiency of the electrode process. Furthermore, because the electrode is rolled using the roll that has been cleaned by the improved cleaning method, the performance of the battery can be improved.

[0091] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0092] 100 Rolls 110 Foreign object 200 Mill roll cleaning equipment 210 Sensor section 220 Cleaning section 230 Cleaning liquid supply unit 240 Drying section

Claims

1. A method for automatically cleaning a rolling roll used in an electrode rolling process, comprising: determining whether the roll is out of service; and cleaning the roll in a first cleaning mode when the roll is out of service; In the first cleaning mode, the cleaning of the mill roll is performed while the process of rolling the electrode with the mill roll is stopped.

2. If the rolling roll is in operation, cleaning the rolling roll in a second cleaning mode; The cleaning method according to claim 1 , wherein in the second cleaning mode, cleaning of the mill roll is performed simultaneously with the step of rolling the electrode with the mill roll.

3. The cleaning method according to claim 2 , wherein at least one of the type of cleaning liquid, the number of times and amount of cleaning liquid supplied, and the moving speed of the cleaning cloth is different between the first cleaning mode and the second cleaning mode.

4. The step of determining whether the rolling roll is out of operation includes: receiving an input of the rotational speed of the rolling roll; When the rotation speed of the rolling roll is 0, counting the waiting time of the rolling roll; and The cleaning method according to claim 1 , further comprising the step of determining that the roll is out of service if a first predetermined time has elapsed with the rotational speed of the roll remaining at zero.

5. The step of determining whether the rolling roll is out of operation includes: receiving an input of the position of the rolling roll; When the rolling roll is at a predetermined standby position, counting the standby time of the rolling roll; and The method of claim 1 , further comprising determining that the mill roll is out of service if a second predetermined time period elapses with the mill roll in a predetermined standby position.

6. The step of determining whether the rolling roll is out of operation includes: receiving inputs of the rotational speed and position of the rolls; a step of counting a waiting time of the rolling roll when the rotation speed of the rolling roll is 0; When the rolling roll is at a predetermined standby position, counting the standby time of the rolling roll; and 2. The cleaning method according to claim 1, further comprising the step of determining that the rolling roll is out of operation when a first predetermined time has elapsed with the rotational speed of the rolling roll at 0 and a second predetermined time has elapsed with the rolling roll in a predetermined standby position.

7. The step of cleaning the rolling roll in a first cleaning mode includes: measuring the brightness value of the surface of the rolling roll; and The cleaning method of claim 1 , further comprising the step of cleaning the mill roll for a third predetermined time if the brightness value of the surface of the mill roll is equal to or less than a first predetermined brightness value.

8. The step of cleaning the rolling roll in a first cleaning mode includes: measuring a brightness value of the surface of the cleaned mill roll to determine whether the brightness value is equal to or greater than a second predetermined brightness value; The cleaning method according to claim 7, wherein the step of cleaning in the first cleaning mode is automatically terminated when the brightness value of the surface of the rolling roll is equal to or greater than a second predetermined brightness value.

9. The step of cleaning the rolling roll in a first cleaning mode includes: measuring a brightness value of the surface of the cleaned mill roll to determine whether the brightness value is equal to or greater than a second predetermined brightness value; 8. The cleaning method of claim 7, further comprising repeating the step of cleaning the mill roll for the third predetermined time if the brightness value of the surface of the mill roll is less than a second predetermined brightness value.

10. 10. The cleaning method according to claim 7, wherein the third predetermined time is selected from the range of 3 minutes to 10 minutes.

11. 10. The cleaning method according to claim 8, wherein the second predetermined brightness value is greater than the first predetermined brightness value.

12. 10. The cleaning method according to claim 8 or 9, wherein the first predetermined brightness value is 40% and the second predetermined brightness value is 80%.

13. The cleaning method according to claim 2 , wherein the number of times and the amount of supply of the cleaning liquid in the first cleaning mode are greater than the number of times and the amount of supply of the cleaning liquid in the second cleaning mode.

14. The cleaning method according to claim 1 , wherein the cleaning fluid provided in the first cleaning mode is an oil-based cleaning agent.

15. The cleaning method of claim 1 , wherein the cleaning liquid provided in the first cleaning mode is selected from the group consisting of water, acetone, a water-based cleaning liquid, and a combination of at least two of them.

16. The cleaning method according to claim 2 , wherein the cleaning fluid provided in the second cleaning mode is an oil-based cleaning agent.

17. 10. An apparatus for automatically cleaning a rolling roll for carrying out the cleaning method according to claim 1, comprising: a sensor unit for measuring the brightness value of the surface of the rolling roll; a cleaning liquid supply unit that supplies a cleaning liquid to the rolling roll; a cleaning unit that cleans the surface of the rolling roll; and a control unit that receives data input from the sensor unit and controls whether or not the cleaning liquid supply unit and the cleaning unit are activated;

18. the cleaning liquid supply unit is a plurality of cleaning liquid supply units, some of the plurality of cleaning liquid supply units supply an oil-based cleaning agent; The cleaning apparatus of claim 17 , wherein the remaining ones of the plurality of cleaning liquid supplies supply water, acetone, an aqueous cleaning liquid, or a combination of at least two of these.

19. the cleaning device is a plurality of cleaning devices; 18. The cleaning apparatus of claim 17, wherein some of the plurality of cleaning apparatuses are apparatuses for a first cleaning mode and the remaining of the plurality of cleaning apparatuses are apparatuses for a second cleaning mode.

Images