Automatic electrode drying control system and automatic electrode drying control method

Abstract

The system for automatically controlling electrode drying according to the present invention includes: an oven that provides a space for moving and drying electrode sheets, includes a drying device that applies hot air and / or radiant heat to the electrode sheets, and is divided into a plurality of drying sections; a measuring unit that collects information about the drying amount of the electrode sheets and transmits the collected information to a controller; and a controller that determines the drying level of the electrode sheets based on the information about the drying amount received from the measuring unit, and controls the drying intensity of the oven according to the determined drying level. Here, the controller independently controls the plurality of drying sections.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2020-0154295 filed on November 18, 2020 and Korean Patent Application No. 10-2021-0157703 filed on November 16, 2021, and the contents of these Korean patent applications are incorporated herein as part of this specification.

[0002] The present invention relates to a system and method for automatically controlling electrode drying, and more particularly, to a system and method for automatically controlling electrode drying, which is capable of identifying the drying level from information about the drying amount such as the solid content and surface temperature of an electrode sheet, and accordingly adjusting the drying amount of the electrode in real time by automatically operating a drying device. Background Art

[0003] Recently, secondary batteries that can be charged and discharged have been widely used as energy sources for wireless mobile devices. In addition, secondary batteries have attracted attention as energy sources for electric vehicles, hybrid electric vehicles, and the like that are proposed as air pollution solutions for existing gasoline vehicles and diesel vehicles that use fossil fuels. Therefore, due to the advantages of secondary batteries, various applications using secondary batteries are currently very diverse, and it is expected that secondary batteries will be applied to many fields and products in the future.

[0004] According to the composition of electrodes and electrolytes, such secondary batteries can be divided into lithium ion batteries, lithium ion polymer batteries, lithium polymer batteries, etc., among which the use of lithium ion polymer batteries, which are less likely to leak electrolytes and are easy to manufacture, has increased. Generally, according to the shape of the battery housing, secondary batteries are divided into cylindrical batteries and prismatic batteries in which the electrode assembly is built into a cylindrical or square metal can, and pouch-type batteries in which the electrode assembly is built into a pouch-type housing of an aluminum laminate. The electrode assembly built into the battery housing is composed of a positive electrode, a negative electrode, and a separator inserted between the positive electrode and the negative electrode, and is a power generating element capable of charging and discharging. The electrode assembly is divided into: a jelly roll type wound with a separator inserted between the positive electrode and the negative electrode in a long sheet shape and coated with an active material; and a stacked type in which a plurality of positive and negative electrodes of predetermined sizes are stacked sequentially while a separator is inserted between them.

[0005] The positive electrode and the negative electrode are formed by applying a positive electrode slurry containing a positive electrode active material and a negative electrode slurry containing a negative electrode active material to a positive electrode collector and a negative electrode collector to form a positive electrode active material layer and a negative electrode active material layer, respectively, and then drying and roll-pressing them.

[0006] At this time, the drying conditions of the electrode affect the quality and physical properties of the electrode. In particular, during the drying process, the adhesion and coupling levels of the electrode surface can be significantly changed according to the control of the drying deviation in the width direction of the electrode and the time point when the drying is completed. Traditionally, the electrode is dried by predetermining the initial process conditions, and after the drying is completed, the drying amount is evaluated by measuring the physical properties of the sample, and then the process conditions are adjusted. However, this method requires a lot of time to measure the physical properties, and it is difficult to reflect the drying amount evaluation results in real time to the process. Therefore, this method is not suitable for roll-to-roll continuous production processes.

[0007] Therefore, a method for drying an electrode is needed, which can keep the dryness of the finished electrode constant by monitoring the drying amount of the electrode in real time and reflecting the monitoring result to the process in time. Summary of the invention

[0008] Technical issues

[0009] It is believed that the present invention solves at least some of the above problems. For example, one aspect of the present invention provides a system and method for automatically controlling electrode drying, which can keep the final electrode drying level constant by automatically controlling the electrode drying level in real time, thereby reducing product deviation.

[0010] Technical Solution

[0011] The system for automatically controlling electrode drying according to the present invention includes: an oven, which provides a space for moving and drying electrode sheets, the oven includes a drying device for applying hot air and / or radiant heat to the electrode sheets, and is divided into a plurality of drying sections; a measuring unit, which collects information about the drying amount of the electrode sheets and transmits the collected information to a controller; and a controller, which determines the drying level of the electrode sheets based on the information about the drying amount received from the measuring unit, and controls the drying intensity of the oven according to the determined drying level. Here, the controller independently controls the plurality of drying sections.

[0012] In one embodiment of the present invention, the measuring unit is configured to periodically collect information about the drying amount of the electrode sheet at fixed time intervals, and whenever the information about the drying amount is received from the measuring unit, the controller periodically controls the drying intensity of the oven by determining the drying level of the electrode sheet.

[0013] In one embodiment of the present invention, the measuring unit collects information on the drying amount 1 to 5 minutes before a time point at which the controller is expected to control the drying intensity.

[0014] In one embodiment of the present invention, the information on the drying amount includes information on at least one of a solid content and a surface temperature of the electrode sheet.

[0015] In one embodiment of the present invention, the controller includes: a data input unit, which receives input of information about the drying amount collected by the measuring unit and a reference set value about the drying amount; a determination unit, which determines the drying level of the electrode sheet by comparing the information about the drying amount with the set value, and determines whether to adjust the drying intensity in the oven according to the determined drying level; and a command unit, which controls the drying intensity of the oven based on the determination result of the determination unit.

[0016] In one embodiment of the present invention, the controller determines the drying level of the electrode sheet as one of five levels: a normal level, an over-dry level, an under-dry level, an excessive over-dry level, and an excessive under-dry level.

[0017] In one embodiment of the present invention, when the drying level of the electrode sheet is determined to be an over-dry level or an excessively over-dry level, the controller controls to reduce the drying intensity of the oven, and when the drying level of the electrode sheet is determined to be an undried level or an excessively undried level, the controller controls to increase the drying intensity of the oven.

[0018] In one embodiment of the present invention, when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the controller controls to adjust the drying intensity of one drying section, and when the drying level of the electrode sheet is determined to be an excessively over-drying level or an excessively under-drying level, the controller controls to adjust the drying intensity of two or more drying sections together.

[0019] In one embodiment of the present invention, the controller controls the drying intensity of the drying sections among the plurality of drying sections except the drying section at the front end of the oven.

[0020] In one embodiment of the present invention, the measuring unit transmits an average value or a median value of the collected information on the drying amount to the controller.

[0021] In one embodiment of the present invention, each of the plurality of drying sections includes a drying device, and the drying device includes at least one of a hot air nozzle applying convection heat by supplying hot air to the electrode sheet and a heater applying radiant heat to the electrode sheet.

[0022] In one embodiment of the present invention, the controller controls at least one selected from the group consisting of a hot air velocity of a hot air nozzle, a hot air volume of a hot air nozzle, a temperature of a heater, and a moving speed of a conveying roller moving the electrode sheet.

[0023] In one embodiment of the present invention, the measuring unit includes at least one of a web-gauge and a temperature measuring instrument for measuring the load amount of the electrode sheet.

[0024] In one embodiment of the present invention, the measuring unit further includes a calculating unit, and the calculating unit calculates the solid content of the electrode sheet according to the load amount measured by the web gauge.

[0025] A method for automatically controlling electrode drying, comprising: (a) supplying an electrode sheet into an oven, the oven being divided into a plurality of drying sections and having a drying device; (b) collecting information on the drying amount of the electrode sheet through a measuring unit; and (c) determining the drying level of the electrode sheet by comparing the collected information on the drying amount with a reference value, and controlling the drying intensity of the oven according to the determined drying level. Here, the determination of the drying level includes independently controlling a plurality of drying sections.

[0026] In one embodiment of the present invention, in step (b), the information on the drying amount includes information on at least one of a solid content and a surface temperature of the electrode sheet.

[0027] In one embodiment of the present invention, step (b) includes periodically collecting information about the drying amount of the electrode sheet at fixed time intervals, and step (c) includes periodically controlling the drying intensity of the oven by determining the drying level of the electrode sheet whenever the information about the drying amount is received through step (b).

[0028] In one embodiment of the present invention, step (c) comprises determining the dryness level of the electrode sheet to be one of five levels: a normal level, an overdry level, an underdry level, an excessive overdry level, and an excessive underdry level.

[0029] In one embodiment of the present invention, during step (c), when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the drying intensity of one drying section is controlled and adjusted, and when the drying level of the electrode sheet is determined to be an excessively over-drying level or an excessively under-drying level, the drying intensities of two or more drying sections are controlled and adjusted together.

[0030] Beneficial Effects

[0031] According to the present invention, the drying level of the electrode can be automatically controlled in real time by collecting information on the drying amount of the electrode sheet and determining the drying level of the electrode from the collected information on the drying amount to control the drying amount of the oven in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a block diagram showing the configuration of an electrode automatic drying control system according to the present invention.

[0033] Figure 2 is a schematic diagram showing the structure of an automatic electrode drying control system according to one embodiment of the present invention.

[0034] Figure 3 is a block diagram showing the configuration of an automatic electrode drying control system according to one embodiment of the present invention.

[0035] Figure 4 is a schematic diagram showing the structure of an automatic electrode drying control system according to another embodiment of the present invention.

[0036] Figure 5 is a flow chart showing the sequence of the automatic electrode drying control method according to the present invention.

[0037] Figure 6 The figure is a picture taken by using a thermal imaging camera to take pictures of an electrode sheet dried by the automatic control method according to one embodiment of the present invention. DETAILED DESCRIPTION

[0038] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The terms and words used in this specification and claims should not be interpreted as limited to common terms or dictionary terms, and the inventors can appropriately define the concepts of the terms in order to best describe their inventions. The terms and words should be interpreted as meanings and concepts consistent with the technical concept of the present invention.

[0039] In the present application, it should be understood that terms such as "including" or "having" are intended to indicate that the described features, quantities, steps, operations, components, parts or combinations thereof are present in the present application, and they do not preclude the possibility of the presence or addition of one or more other features or quantities, steps, operations, components, parts or combinations thereof. In addition, when a part such as a layer, a film, a region, a plate, etc. is referred to as being "on" another part, this includes not only the case where the part is "directly" "on" the other part, but also the case where other parts are inserted between the part and the other part. On the other hand, when a part such as a layer, a film, a region, a plate, etc. is referred to as being "under" another part, this includes not only the case where the part is "directly" "under" the other part, but also the case where other parts are inserted between the part and the other part. In addition, to be set "on" in the present application may include the case where it is set at the bottom as well as the top.

[0040] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

[0041] Figure 1 is a block diagram showing the configuration of an electrode automatic drying control system according to the present invention, Figure 2 1 is a schematic diagram showing the structure of an automatic electrode drying control system according to one embodiment of the present invention. Referring to these drawings, the system 100 for automatically controlling electrode drying includes: an oven 110, which provides a space for moving and drying electrode sheets, includes a drying device for applying hot air and / or radiant heat to the electrode sheets, and is divided into a plurality of drying sections; a measuring unit 120, which collects information about the drying amount of the electrode sheets 10 and transmits the collected information to a controller 130; and a controller 130, which determines the drying level of the electrode sheets 10 based on the information about the drying amount received from the measuring unit 120, and controls the drying intensity of the oven 110 according to the determined drying level. Here, the controller 130 independently controls the plurality of drying sections.

[0042] As mentioned above, the drying conditions of the electrode significantly affect the quality and physical properties of the electrode. Usually, after the electrode is dried by predetermining the initial process conditions, the process conditions are then adjusted by evaluating the dryness and physical properties of the product. However, in this case, it is difficult to control the drying of the electrode in real time.

[0043] According to the system for automatically controlling electrode drying of the present invention, the drying level is determined by collecting information about the drying amount of the electrode sheet in real time and independently controlling multiple drying sections accordingly. The drying amount is appropriately adjusted according to the drying level of the electrode sheet, and the drying level of the electrode drying section can be automatically controlled.

[0044] In addition, in the present invention, the x-axis refers to the direction in which the electrode is transported, the y-axis refers to the direction perpendicular to the transport direction of the electrode on the electrode surface, as the width direction of the electrode, and the z-axis corresponds to the direction in which hot air is sprayed or infrared rays are irradiated, as the direction perpendicular to the electrode surface.

[0045] Hereinafter, the configuration of the automatic electrode drying control system according to the present invention will be described in detail.

[0046] Reference Figure 2 The automatic electrode drying control system 100 according to the present invention includes an oven 110. The oven 110 has a chamber shape and provides a space for drying the electrode sheet 10 and preventing the escape of internal heat, wherein the electrode sheet 10 to be dried can move in the oven 110.

[0047] In addition, the electrode sheet 10 may have a structure in which the electrode active material layer 12 is formed by coating a slurry for electrode formation including an electrode active material on the current collector sheet 11. The electrode slurry may be applied to at least one surface of the current collector.

[0048] In this case, the current collector may be a positive electrode current collector or a negative electrode current collector, and the electrode active material may be a positive electrode active material or a negative electrode active material. In addition, the electrode slurry may further include a conductive material and a binder in addition to the electrode active material.

[0049] In the present invention, the positive electrode collector generally has a thickness of 3 to 500 μm. The positive electrode collector is not particularly limited as long as it has high conductivity and does not cause chemical changes in the battery. Examples of positive electrode collectors include stainless steel; aluminum; nickel; titanium; sintered carbon; or aluminum or stainless steel whose surface is treated with carbon, nickel, titanium, silver or the like. The collector may have fine concave-convex on its surface to increase the adhesion of the positive electrode active material, and may be in various forms such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics.

[0050] The sheet material used for the negative electrode current collector generally has a thickness of 3 to 500 μm. The negative electrode current collector is not particularly limited as long as it has conductivity without causing chemical changes in the battery, and examples thereof include copper; stainless steel; aluminum; nickel; titanium; sintered carbon; copper or stainless steel whose surface is treated with carbon, nickel, titanium, silver or the like; aluminum-cadmium alloy; or the like. In addition, as with the positive electrode current collector, fine concave-convex can be formed on the surface to enhance the adhesion of the negative electrode active material, and can be used in various forms such as films, sheets, foils, nets, porous bodies, foams, and non-woven fabrics.

[0051] In the present invention, the positive electrode active material is a material capable of inducing an electrochemical reaction, is a lithium transition metal oxide, and contains two or more transition metals. Examples thereof include: layered compounds such as lithium cobalt oxide (LiCoO 2 ) and lithium nickel oxide (LiNiO 2 ); lithium manganese oxide substituted by one or more transition metals; LiNi 1-y M y O 2 (wherein M = Co, Mn, Al, Cu, Fe, Mg, B, Cr, Zn or Ga, and contains at least one of the above elements, 0.01≤y≤0.7) represented by lithium nickel oxide; 1+z Ni b Mn c Co 1-(b+c+d) M d O (2-e) A e , such as Li 1+z Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 , Li 1+z Ni 0.4 Mn 0.4 Co 0.2 O 2 Lithium nickel cobalt manganese composite oxide represented by (wherein -0.5≤z≤0.5, 0.1≤b≤0.8, 0.1≤c≤0.8, 0≤d≤0.2, 0≤e≤0.2, b+c+d<1, M=Al, Mg, Cr, Ti, Si or Y, and A=F, P or Cl); Lithium nickel cobalt manganese composite oxide represented by molecular formula Li 1+x M 1-y M′ y PO 4-z X z (wherein M = transition metal, preferably Fe, Mn, Co or Ni, M′ = Al, Mg or Ti, X = F, S or N, and -0.5≤x≤0.5, 0≤y≤0.5, 0≤z≤0.1) represented by olivine-based lithium metal phosphate.

[0052] Examples of negative electrode active materials include: carbon such as non-graphitizable carbon and graphitizable carbon; metal composite oxides such as Li x Fe 2 O 3 (0≤x≤1), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me' y Oz (Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of groups 1, 2 and 3 in the periodic table, halogens; 0<x≤1; 1≤y≤3; 1≤z≤8); lithium alloys; silicon alloys; tin alloys; metal oxides such as SnO, SnO 2 、PbO、PbO 2 , Pb 2 O 3 , Pb 3 O 4 , Sb 2 O 3 , Sb 2 O 4 , Sb 2 O 5 、GeO、GeO 2 、Bi 2 O 3 、Bi 2 O 4 and Bi 2 O 5 ; conductive polymers such as polyacetylene; and Li-Co-Ni based materials.

[0053] The conductive material is generally added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive electrode active material. Such conductive material is not particularly limited as long as it has conductivity without causing chemical changes in the battery, and examples thereof include: graphite, such as natural graphite and artificial graphite; carbon black, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, and summer black; conductive fibers, such as carbon fibers and metal fibers; metal powders, such as carbon fluoride powder, aluminum powder, and nickel powder; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and conductive materials such as polyphenylene derivatives; and the like.

[0054] As a component that assists the bonding between the active material and the conductive material and the bonding with the current collector, the binder is added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butadiene rubber, fluororubber, various copolymers, and the like.

[0055] At the same time, the electrode slurry can be prepared by dissolving the electrode active material, the conductive material and the binder in a solvent. The type of solvent is not particularly limited, as long as it can disperse the electrode active material, and an aqueous solvent or a non-aqueous solvent can be used. For example, the solvent can be a commonly used solvent in the art, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methyl pyrrolidone (NMP), acetone or water, and one or a mixture of two or more thereof can be used alone. The amount of solvent used can be considered to be the coating thickness, yield and processability of the slurry, so that the slurry can be adjusted to have an appropriate viscosity, and there is no particular restriction.

[0056] The oven 110 is divided into a plurality of drying sections 111, 112, and 113, each of which includes a drying device for drying the electrode sheet 10 therein. The drying device includes a hot air nozzle 114 for applying convection heat by supplying hot air to the electrode sheet 10 and a heater 115 for applying radiant heat to the electrode sheet 10. Figure 2 The hot air nozzles 114 and the heaters 115 may be arranged at regular intervals along the conveying direction (MD direction, x direction) of the electrode sheet 10, and apply hot air or radiant heat in a direction perpendicular to the electrode sheet 10. Figure 2 , the hot air nozzle 114 and the infrared heater 115 are shown to be located at the upper part of the electrode sheet 10, that is, the lower surface of the top plate of the oven 110, but when the electrode active material layer is formed on both surfaces of the collector, the hot air nozzle 114 and the heater 115 can be located at the upper and lower parts of the electrode sheet 10, respectively. Figure 2 A case where both the hot air nozzle and the heater are included as the drying means is shown, but the present invention is not limited to this example, and only one of the hot air nozzle and the heater may be included as the drying means.

[0057] On the other hand, the hot air nozzle 114 includes a main body unit and a spray unit. The main body unit constitutes the main body of the hot air nozzle and fixes the hot air nozzle 114 to the top of the oven. In addition, the main body unit is empty inside and transfers hot air transferred from a hot air supply source (not shown) to the spray unit. On the other hand, the spray unit is provided on the lower surface of the main body unit. The spray unit is connected to the main body unit, and a spray hole portion for spraying hot air is formed on the lower surface of the spray unit. The spray hole portion may have a structure in which a plurality of holes are arranged at regular intervals.

[0058] In addition, in a specific example of the present invention, the heater 115 may be an infrared heater, and the infrared heater may include an infrared lamp for irradiating infrared rays to the electrode and a bracket for supporting the infrared lamp. The shape of the infrared lamp is not particularly limited, for example, a rod-shaped lamp may be arranged side by side along the conveying direction of the electrode while extending in the width direction of the electrode.

[0059] The hot air nozzles 114 and the heaters 115 may be alternately arranged in the moving direction of the electrode sheet 10 so as to uniformly supply hot air and infrared rays to the surface of the electrode sheet 10. However, the type of arrangement is not particularly limited, and the arrangement scheme of the hot air nozzles 114 and the infrared heaters 115 may be appropriately changed by a person of ordinary skill in the art according to drying conditions.

[0060] In addition, the oven 110 may include a conveying roller 116 for conveying the electrode. A plurality of conveying rollers 116 may be arranged at regular intervals along the conveying direction of the electrode sheet 10, and the conveying rollers 116 support the electrode sheet 10 during the drying process and convey the electrode sheet 10 to the outside of the oven 110. In addition, the drying amount of the electrode sheet may be controlled by adjusting the rotation speed of the conveying rollers.

[0061] The oven 110 may be divided into a plurality of drying zones. When overdrying or underdrying occurs during the drying process of the electrode sheet 10, it may be necessary to properly dry the electrode sheet 10 while changing the drying intensity. In this case, the drying intensity of each drying section may be independently controlled by dividing the oven 110 into a plurality of drying sections. Figure 2 1 shows that the oven 110 is divided into three drying sections, but the oven may also be divided into 3 to 20 drying sections or 5 to 15 drying sections, and the present invention is not limited to this example. In the specification of the present invention, the three drying sections are referred to as the first drying section 111, the second drying section 112, and the third drying section 113.

[0062] The first drying section 111, the second drying section 112, and the third drying section 113 may physically divide the space by installing inner walls between the drying sections, or may also abstractly divide the space according to drying conditions.

[0063] The system 100 for automatically controlling electrode drying according to the present invention includes a measuring unit that collects information on the drying amount of the electrode sheet and transmits the collected information to a controller.

[0064] In a specific example of the present invention, the information about the drying amount includes information about at least one of the solid content and the surface temperature of the electrode sheet. The system for automatically controlling electrode drying of the present invention determines the drying level of the electrode sheet by information about the solid content and / or temperature collected by a measuring unit. The measuring unit may include at least one of a web-gauge and a temperature measuring instrument for measuring the load amount of the electrode sheet to collect information about the solid content and the surface temperature of the electrode sheet.

[0065] Reference Figure 2 , the measuring units 120a and 120b include a web-gauge for measuring the loading amount of the electrode sheet, and the measuring units 120 may be installed at the entrance and exit of the oven 110, respectively, and measure the loading amount before drying the electrode sheet and the loading amount after drying the electrode sheet. The measuring unit may further include a calculation unit to derive the solid content, and the calculation unit may derive the solid content of the electrode active material layer 12 from the measured loading amount using a pre-input calculation formula. The solid content may be derived from the loading amount using a formula known in the relevant art.

[0066] When the drying level of the electrode sheet is excessive (overdrying), the solid content becomes greater than the reference value, and when the drying level of the electrode sheet is insufficient, the solid content becomes less than the reference value. Therefore, the solid content can be an indicator for identifying the drying level of the electrode sheet.

[0067] The system 100 for automatically controlling electrode drying according to the present invention includes a controller 130. The controller 130 can determine the drying level of the electrode sheet according to the information on the drying amount received from the measuring units 120a and 120b, and control the drying intensity of the oven 110 according to the determined drying level, thereby adjusting the drying amount of the electrode sheet in real time.

[0068] In order to adjust the drying amount of the electrode sheet in real time, the measuring unit is configured to periodically collect information about the drying amount of the electrode sheet at fixed time intervals, and whenever the information about the drying amount is received from the measuring unit, the controller periodically controls the drying intensity of the oven by determining the drying level of the electrode sheet.

[0069] Figure 3 is a block diagram showing the configuration of a system for automatically controlling electrode drying according to one embodiment of the present invention. Figure 3The controller 130 of the present invention includes: a data input unit 131, which receives information about the drying amount collected by the measuring unit and an input about a reference setting value of the drying amount; a determination unit 132, which determines the drying level of the electrode sheet by comparing the information about the drying amount with the setting value, and determines whether to adjust the drying intensity in the oven according to the determined drying level; and a command unit 133, which controls the drying intensity of the oven based on the determination result of the determination unit 132.

[0070] The data input unit 131 can receive information about the load amount and / or the drying amount before / after the electrode sheet is dried, such as the temperature of the surface of the electrode, from the measuring unit 120, and receive an input of a reference value for determining whether the drying level of the electrode sheet is excessive or insufficient. In addition, the information about the drying amount and the reference value input through the data input unit is transmitted to the determining unit 132.

[0071] The determination unit 132 determines whether the drying level of the electrode sheet is an overdrying level, an underdrying level, or a normal level by comparing the information about the drying amount received from the data input unit 131 with a reference value, and by comparing the information about the drying amount with the reference value, the determination unit 132 determines a method for controlling the drying intensity by quantitatively identifying the degree of overdrying or underdrying.

[0072] The controller controls at least one of the hot air speed of the hot air nozzle, the hot air volume of the hot air nozzle, the temperature of the heater, and the moving speed of the conveying roller moving the electrode sheet. In order for the controller to control the drying intensity of the oven, the command unit 133 sends a driving operation command to the oven according to the change of the drying intensity determined by the determination unit.

[0073] The oven may adjust the drying intensity in the oven according to a driving operation command received from a command unit of the controller. The oven includes a hot air nozzle for applying convection heat by supplying hot air to the electrode sheet and a heater for applying radiant heat to the electrode sheet as a drying device. Here, the drying amount of the electrode sheet may be adjusted by changing at least one of the temperature, speed, and volume of the hot air ejected from the hot air nozzle according to the driving operation command.

[0074] Furthermore, the drying amount may be adjusted by controlling the rotation speed of a conveying roller conveying the electrode sheet in addition to the driving operation of the hot air nozzle and / or the heater.

[0075] The controller controls the drying intensity periodically at fixed time intervals. In a specific example, the controller can repeatedly control the drying intensity of the oven in a cycle of 5 to 20 minutes, preferably a cycle of 6 to 15 minutes, but the present invention is not limited to these examples.

[0076] Further, the measuring unit is configured to periodically collect information about the amount of drying of the electrode sheet at fixed time intervals according to the drying intensity control of the controller. In a specific example, the measuring unit collects information about the amount of drying 1 to 5 minutes before the estimated time point when the controller controls the drying intensity. That is, the measuring unit does not collect information about the amount of drying of the electrode sheet in a timely manner after controlling the drying intensity of the oven, but collects information about the amount of drying of the electrode sheet after a predetermined time has passed since the controller started to control the drying intensity. This is because the effect of the drying amount adjustment takes a certain amount of time to manifest according to the change in the drying intensity of the oven.

[0077] The measuring unit sets an average value or a median value of the information on the drying amount collected within the predetermined time as a representative value of the information on the drying amount, and transmits the value to the controller.

[0078] In the system for automatically controlling electrode drying of the present invention, the controller controls the drying intensity of the drying sections except the drying section at the front end of the oven among the plurality of drying sections. The front drying section refers to the drying section located at the entrance of the oven. In a specific example, in the case where the oven is divided into the first drying section to the Nth drying section from the entrance to the exit, the front drying section may refer to the first drying section to the (N / 3)th drying section, but the present invention is not limited to this example.

[0079] In such a front drying section, since the electrode sheet has just been fed into the oven, even if the drying intensity is adjusted in the front drying section, the effect of adjusting the drying amount is not significant compared with the effect of the subsequent drying sections. Therefore, the controller of the present invention controls the adjustment of the drying intensity in the drying sections other than the front drying section among the plurality of drying sections of the oven.

[0080] In a specific example, the controller may determine the dryness level of the electrode sheet as one of five levels: a normal level, an overdryness level, an underdryness level, an excessive overdryness level, and an excessive underdryness level. The controller determines the dryness level of the electrode sheet based on a predetermined reference value. If the information on the dryness amount collected by the measuring unit exceeds the predetermined reference value but the difference is small, it is determined as an overdryness level and an underdryness level, but if the difference is large, it is determined as an excessive overdryness level or an excessive underdryness level.

[0081] The controller of the present invention also distinguishes between excessive over-drying level and excessive under-drying level by quantitatively identifying the degree of over-drying and under-drying. Therefore, optimized drying intensity control can be performed according to the drying level.

[0082] Specifically, when the drying level of the electrode sheet is normal, there is no need to change the drying intensity. Therefore, the controller does not perform control to adjust the drying intensity of the oven. That is, the command to adjust the drying intensity is not transmitted to the oven.

[0083] When the drying level of the electrode sheet is determined to be an over-dry level or an excessively over-dry level, the controller of the present invention controls to reduce the drying intensity of the oven, and when the drying level of the electrode sheet is determined to be an undried level or an excessively undried level, the controller controls to increase the drying intensity of the oven.

[0084] Further, when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the controller of the present invention controls to adjust the drying intensity of one drying section, and when the drying level of the electrode sheet is determined to be an excessively over-drying level or an excessively under-drying level, the controller controls to adjust the drying intensity of two or more drying sections together.

[0085] In the case where the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the difference from the reference value is small. Thus, if the drying intensity is adjusted uniformly for a plurality of drying sections, an opposite effect may be caused. For example, if the drying intensity of all drying sections is increased to adjust an under-dried state, an over-drying level may be caused. Therefore, the controller first controls to increase the drying intensity of only one drying section, receives feedback of information on the drying amount from the measuring unit, and then performs subsequent control.

[0086] Further, when performing subsequent control, if the received information on the drying amount exceeds the reference value and is still determined as the non-drying level, the controller controls to increase the drying intensity in the next part of the drying section where the drying intensity has been controlled in advance. In addition, if the received information on the drying amount is within the range of the reference value, the drying intensity does not need to be adjusted. Therefore, the control to adjust the drying intensity is not performed.

[0087] In addition, in the case where the drying level of the electrode sheet is determined to be an over-drying level, the controller of the present invention can sequentially reduce the drying intensity from the rear drying section to the middle drying section. Conversely, in the case where the drying level of the electrode sheet is determined to be an under-drying level, the controller can sequentially increase the drying intensity from the middle drying section to the rear drying section. The order of controlling the drying intensity can be changed according to whether the electrode sheet has been over-dried or under-dried to improve the adjustment efficiency of the drying amount.

[0088] Similarly, when the drying intensity is controlled sequentially in time sequence, the drying intensity of the front drying section is not controlled. Since the adjustment effect of the drying amount of the front drying section is small, the control is performed sequentially from the middle drying section to improve the adjustment efficiency of the drying amount.

[0089] In addition, in the case where the drying level of the electrode sheet is an excessive over-drying level or an excessive under-drying level, the difference from the reference value is relatively large. In this case, if the drying intensity is adjusted for only one drying section, the drying amount adjustment effect is not obvious. Therefore, in this case, in order to relatively increase the change in drying intensity, the controller of the present invention controls the adjustment of the drying intensity of two or more drying sections.

[0090] Specifically, when the drying level of the electrode sheet is determined to be an excessively dry level and the drying intensity is controlled to be reduced, the drying intensity of the middle drying section and the rear drying section is controlled to be reduced simultaneously. On the other hand, when the drying level of the electrode sheet is determined to be an excessively under-dried level and the drying intensity is controlled to be increased, the drying intensity of the middle drying section and the rear drying section is controlled to be increased simultaneously.

[0091] Figure 4 FIG. 1 is a schematic diagram of the structure of an automatic electrode drying control system according to another embodiment of the present invention. Figure 4 , web gauges 221a and 221b for measuring the load of the electrode sheet are installed at the entrance and exit of the oven respectively, and a temperature measuring instrument 222 is installed between the first drying section 211 and the second drying section 212, between the second drying section 212 and the third drying section 213, and at the exit of the oven. The temperature measuring instrument can measure the temperature of the electrode surface. In addition, Figure 4 2 shows that the temperature measuring instrument 222 is located at the upper portion of the electrode sheet 10 , but when the electrode active material layer is formed on both surfaces of the current collector, the temperature measuring instrument 222 may be located at the upper and lower portions of the electrode.

[0092] In one example, the temperature measuring instrument 222 may be disposed in the oven 110 and measure the surface temperature of the electrode sheet 10. The type of the temperature measuring instrument is not limited as long as it can measure the surface temperature of the electrode. Specifically, the temperature measuring instrument may be a temperature sensor or a thermal imaging camera.

[0093] In the case where the temperature measuring instrument 222 is a thermal imaging camera, it can be arranged in a manner of penetrating the outer wall of the oven, and in order to prevent the thermal imaging camera from being exposed to excessively high temperatures, it is preferably arranged at a relatively low temperature position. In addition, the thermal imaging camera is preferably arranged at a position where the user's sight is not blocked by the hot air nozzle 214 and the heater 215 in the oven 210. Therefore, the thermal imaging camera can be arranged at a position where the hot air nozzle 213 and the infrared heater 215 are not arranged.

[0094] In addition, in order to prevent damage to the temperature measuring instrument installed in the oven, a cooling device (not shown) for cooling the temperature measuring instrument may be further included. The cooling device allows continuous measurement of the temperature of the electrode surface by preventing the temperature measuring instrument from being damaged by the high temperature environment in the oven.

[0095] The cooling device may be fixed or attached to the temperature measuring instrument from the outside of the oven to prevent temperature changes in the oven. The shape of the cooling device is not limited as long as it can cool the temperature measuring instrument. For example, the cooling device may be a cooling jacket that covers the temperature measuring instrument and contains a refrigerant therein.

[0096] In addition, the present invention provides a method for automatically controlling electrode drying.

[0097] Figure 5 is a flow chart showing the sequence of the automatic electrode drying control method according to the present invention.

[0098] Reference Figure 5 , a method for automatically controlling electrode drying includes: (a) supplying an electrode sheet to an oven, the oven being divided into a plurality of drying sections and having a drying device; (b) collecting information about the drying amount of the electrode sheet through a measuring unit; and (c) determining a drying level of the electrode sheet by comparing the collected information about the drying amount with a reference value, and controlling the drying intensity of the oven according to the determined drying level. Here, the determination of the drying level includes independently controlling a plurality of drying sections.

[0099] According to the method for automatically controlling electrode drying of the present invention, the information collection includes periodically collecting information about the drying amount of the electrode sheet at fixed time intervals, and the determination of the drying level includes periodically controlling the drying intensity of the oven by determining the drying level of the electrode sheet whenever the information about the drying amount is received during the information collection process. Therefore, according to the method for automatically controlling electrode drying of the present invention, after receiving real-time information about the drying amount of the electrode sheet, the drying amount can be automatically controlled to be uniform by adjusting the drying amount to meet a predetermined reference value.

[0100] Hereinafter, each step of the automatic electrode drying control system according to the present invention is described in detail.

[0101] <Preparation of Electrode>

[0102] First, an electrode sheet is manufactured by coating a slurry for electrode formation including an active material on a current collector sheet. The details of the electrode sheet are the same as those described above. If the electrode sheet is manufactured, drying is started by supplying the electrode sheet to the above-mentioned oven.

[0103] <Drying of Electrode Sheet and Collection of Information on Drying Amount>

[0104] When the electrode sheet is supplied to the oven, the solvent in the slurry is removed by a drying device such as a heater or a hot air nozzle when the electrode sheet moves in the oven, thereby drying the electrode sheet. In addition, the measuring unit collects information about the drying amount of the electrode sheet. The information about the drying amount includes information about at least one of the solid content and the surface temperature of the electrode sheet. The process of the measuring unit collecting information about the drying amount is performed by measuring the surface temperature of the electrode sheet by a temperature measuring instrument installed inside or outside the oven or by an electrode load measuring device (such as a web gauge) installed at the inlet and outlet of the oven.

[0105] In a specific example, the measuring unit may further include a calculating unit that calculates the solid content according to the loading amount of the electrode sheet before and after drying.

[0106] <Determination of drying level and control of drying intensity>

[0107] If information about the drying amount, such as the surface temperature or solid content of the electrode sheet, is obtained from the measuring unit, it is compared with a reference value, thereby performing an operation of determining the drying level of the electrode sheet. If the measured drying amount is less than the reference value, it is indicated that the drying is insufficient. Therefore, in order to increase the drying intensity, at least one of the temperature, velocity and volume of the hot air of the hot air nozzle and the temperature of the heater in the oven may be increased. Conversely, if the measured drying amount is greater than the reference value, it is indicated that the drying is overdrying. Therefore, in order to reduce the drying intensity, at least one of the temperature, velocity and volume of the hot air of the hot air nozzle and the temperature of the heater in the oven may be reduced.

[0108] In addition, as described above, the oven can be divided into a plurality of drying sections, and these drying sections can be divided into a front drying section, a middle drying section, and a rear drying section. The method for automatically controlling electrode drying of the present invention does not control the drying intensity in the front drying section. The front drying section is an initial drying section, in which the electrode sheet is dried immediately after the coating process is completed. In the initial drying section for stabilizing the electrode sheet, it is not desirable to periodically change the drying intensity, and from the viewpoint of drying amount adjustment efficiency, it is sufficient to adjust the drying amount in the middle drying section and the rear drying section.

[0109] Therefore, even in the case where it is necessary to control the drying intensity, the drying intensity can be controlled by changing the driving conditions of the hot air nozzles or heaters installed in the middle drying section and the rear end drying section without changing the driving conditions of the hot air nozzles or heaters included in the front end drying section.

[0110] In addition, the method of automatically controlling electrode drying of the present invention can be changed according to the change in the amount between the dryness level of the electrode sheet determined according to the above method and the target dryness level. Specifically, the determination of the dryness level includes determining the dryness level of the electrode sheet as one of the five levels of a normal level, an overdrying level, an undried level, an over-overdrying level, and an over-undried level.

[0111] According to the control method of the present invention, when the information on the drying amount of the electrode sheet collected by the measuring unit is compared with the target reference value, if the information on the drying amount of the electrode sheet meets the reference value, it is determined to be a normal level. When the information on the drying amount of the electrode sheet collected by the measuring unit is compared with the target reference value, if the difference is within a predetermined range, it is determined to be an over-drying level or an under-drying level. If the difference exceeds the predetermined range, the drying level of the electrode sheet is determined to be an over-drying level or an over-under-drying level.

[0112] For example, assuming that the dryness level of the electrode sheet is determined by the solid content, and the predetermined reference value of the solid content is 88% to 89%, if the information about the dryness of the electrode sheet collected by the measuring unit is within ±1% of the reference value, it is determined to be an over-dryness level or an under-dryness level; if the information about the dryness of the electrode sheet collected by the measuring unit exceeds ±1% of the reference value, it is determined to be an excessively over-dryness level or an excessively under-dryness level; and if the information about the dryness of the electrode sheet collected by the measuring unit is within the reference value range, it is determined to be a normal level.

[0113] In the method for automatically controlling electrode drying of the present invention, when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the controller controls to adjust the drying intensity of one drying section, and when the drying level of the electrode sheet is determined to be an over-over-drying level or an over-under-drying level, the controller controls to adjust the drying intensity of two or more drying sections together. In addition, when the drying level of the electrode sheet is determined to be normal, since the drying intensity of the oven is appropriate, the adjustment control of the drying intensity of the oven is not performed.

[0114] In the case where the drying level of the electrode sheet is at an over-drying level or an under-drying level, the drying intensity of a drying section can be increased first, and after a period of time, until the adjustment effect of the drying amount is shown according to the adjustment of the drying intensity, the drying level is determined again by receiving information about the drying amount from the measuring unit, and subsequent drying intensity control is performed based on the received information, so as to more accurately adjust the drying amount.

[0115] In addition, after determining whether the drying level of the electrode sheet is an overdrying level or an underdrying level, the method of adjusting the drying intensity of a drying section may be different depending on whether it is an overdrying level or an underdrying level. Specifically, when it is determined that the drying level of the electrode sheet is an overdrying level, a control to reduce the drying intensity should be performed. At this time, a control to reduce the drying intensity is performed starting from the drying section close to the oven outlet. In the case where the oven is divided into a plurality of drying sections, the drying sections from the entrance to the exit are numbered as the first drying section to the Nth drying section, and if it is determined that the drying level of the electrode sheet is an overdrying level, a control to reduce the drying intensity is performed in the Nth drying section closest to the oven outlet. Further, after a predetermined time, when the measuring unit collects information about the drying amount of the electrode sheet and compares the information with a reference value, if it is still determined that the drying level of the electrode sheet is an overdrying level, a control to reduce the drying intensity is performed in the (N-1)th drying section.

[0116] On the contrary, if the drying level of the electrode sheet is determined to be an undried level, a control to increase the drying intensity should be performed. At this time, a control to increase the drying intensity in sequence starting from the drying section close to the oven entrance is performed. In the present invention, the control to adjust the drying intensity is not performed in the initial drying section close to the oven entrance. Therefore, if the initial drying section corresponds to the first drying section to the eighth drying section, a control to increase the drying intensity is performed in the ninth drying section. Further, after a predetermined time, when the measuring unit collects information about the drying amount of the electrode sheet and compares the information with a reference value, if the drying level of the electrode sheet is still determined to be an undried level, a control to increase the drying intensity is performed in the tenth drying section.

[0117] In addition, when the drying level of the electrode sheet is determined to be an overdrying level or an overly overdrying level, changing the drying intensity in only one drying section may not be sufficient to adjust the drying amount. Thus, the drying intensity can be appropriately controlled by adjusting the drying intensity of two or more drying sections at the same time.

[0118] After the drying intensity adjustment control of the oven is performed as described above, the process of drying the electrode sheet at the adjusted drying intensity is performed within a predetermined time. In this way, the drying amount of the electrode sheet can be adjusted to a certain extent by the adjusted drying intensity. In addition, in order to identify the drying level of the electrode sheet again, the process of collecting information on the drying amount is performed in the same manner as described above.

[0119] At this time, the information about the drying amount can be collected 1 to 5 minutes before the time point of the subsequent control of the drying intensity. That is, the information about the drying amount of the electrode sheet can be collected 2 minutes before the time point of the subsequent control of the drying intensity, 3 minutes before the time point of the subsequent control of the drying intensity, or 4 minutes before the time point of the subsequent control of the drying intensity. In addition, the average value or median value of the information about the drying amount collected within a predetermined time can be identified as the information about the drying amount.

[0120] Similarly, based on the identified information about the drying amount, the process of determining the drying level of the electrode sheet and the process of controlling the drying intensity of the oven are performed in the same manner as described above, and by periodically performing the drying amount collection process, the drying level determination and the drying intensity control process, the drying level of the electrode sheet can be controlled to be uniform.

[0121] Hereinafter, the automatic control system of the present invention will be described in more detail through one embodiment of the present invention. Table 1 below shows reference values ​​for determining the dryness level of the electrode sheet, and the results determined therefrom and the control method.

[0122] [Table 1]

[0123]

[0124]

[0125] Referring to Table 1, the reference value of the solid content is 88%-89%. In the case where the measured solid content is less than the set value, since this means insufficient drying, the drying intensity needs to be increased, on the other hand, in the case where the measured solid content is greater than the set value, since this means excessive drying, the drying intensity needs to be reduced.

[0126] A plurality of drying sections sequentially arranged from the entrance to the exit of the oven are divided into a first drying section, a second drying section, ..., an (N-1)th drying section and an Nth drying section, and a method of controlling drying intensity will be described in detail.

[0127] First, if the measured solid content is within the range of 88%-89%, it means that the drying level is normal, so the existing drying intensity can be maintained. Therefore, there is no need to perform control to adjust the drying intensity.

[0128] If the measured solid content is lower than 87%, it is determined to be an excessively undried level, and therefore, drying sections other than the front drying section are controlled to increase the drying intensity. If the front drying section corresponds to the first drying section to the (N / 3)th drying section, the drying intensity increases from the next drying section to the Nth drying section. For ease of explanation, this is referred to as two-plus control.

[0129] If the measured solid content is greater than 90%, it is determined to be an excessive over-drying level, and accordingly, the drying sections other than the front-end drying section are controlled to reduce the drying intensity. For ease of explanation, this is called two-reduction control.

[0130] If the measured solid content is between 87% and 88%, it is determined to be an undried level, and accordingly, the drying intensity is increased in the next drying section of the front drying section. For ease of explanation, this is called one-plus control. One-plus control does not increase the drying intensity of the drying section in which the drying intensity has been increased, and increases the drying intensity of the next drying section. For example, by performing one-plus control in the 5th drying section, a control of increasing the drying intensity of the 5th drying section to a certain extent is performed. After a period of time, if the solid content collected from the measuring unit is 87.5%, it is still at an undried level, so one-plus control should be performed. At this time, a control of increasing the drying intensity of the 6th drying section after the 5th drying section is performed, and a control of changing the drying intensity of the 5th drying section is not performed.

[0131] Since the measured solid content is greater than 89% and equal to or less than 90%, it is determined to be an over-drying level, and accordingly, in the drying sections other than the front drying section, a control of reducing the drying intensity starting from the rear drying section close to the oven outlet is performed. For ease of explanation, this is called one-minus control. One-minus control does not reduce the drying intensity of the drying section where the drying intensity has been reduced, and reduces the drying intensity of the previous drying section. For example, by performing one-minus control in the 15th drying section, a control of reducing the drying intensity of the 15th drying section to a certain extent is performed, and after a period of time, if the solid content collected from the measuring unit is 89.8%, it is still at an over-drying level, so one-minus control should be performed. At this time, a control of reducing the drying intensity of the 14th drying section before the 15th drying section is performed, and a control of changing the drying intensity of the 15th drying section is not performed.

[0132] Hereinafter, the control system and control method of the present invention will be described in more detail with reference to Table 2 below.

[0133] [Table 2]

[0134]

[0135]

[0136] Referring to Table 2 above, the solid content is measured every 10 minutes from No. 1 to No. 15, and accordingly, control of adjusting the drying intensity is performed (here, the solid content of No. 3 is not measured because No. 3 corresponds to the non-coating portion). In addition, the control method according to the solid content measured for each No. is disclosed in the last column of Table 2. In addition, the numbers 0, 1, and 2 recorded in the columns of the 10th to 12th drying stages are arbitrary values ​​indicating changes in drying intensity.

[0137] The automatic control system and the automatic control method of the present invention are described in detail in conjunction with the above Table 2.

[0138] Since the solid content in No. 2 is 87.6%, the drying level of the electrode sheet is determined to be the undried level, and one-plus control is performed. In this way, by increasing the drying intensity of the 10th drying section only, without increasing the drying intensity of other drying sections, the drying intensity of the 10th drying section is increased by 1 from the drying intensity of No. 1 to 2, thereby maintaining the drying intensity of No. 1 at 1.

[0139] Since No. 3 corresponds to the non-coated portion, no control is performed.

[0140] Since the solid content of No. 4 is 91.8%, the drying level of the electrode sheet is determined to be an excessively dry level, and two-reduction control is performed. In this way, control of reducing the drying intensity by 1 is performed for each of the 10th to 12th drying sections. In this way, the drying intensity becomes 1, 0, and 0, which are respectively reduced by 1 from the drying intensity 2, 1, and 1 of each area of ​​No. 2.

[0141] Since the solid content of No. 5 is 88.2%, the drying level of the electrode sheet is determined to be a normal level, and no control is performed to adjust the drying intensity. Therefore, the drying intensity of the 10th to 12th drying sections is the same as that of each drying section of No. 4.

[0142] Since the solid content of sequence number 6 is 87.7%, the drying level of the electrode sheet is determined to be an undried level, and one-plus control is performed. Therefore, the drying intensity in the 11th drying section, which is a drying section after the 10th drying section, is increased, wherein the drying intensity of the 10th drying section has been increased in sequence number 2. Therefore, the drying intensity of the 10th drying section is maintained at the drying intensity of 1 in sequence number 5, and the drying intensity of the 11th drying section is increased by 1 to become 1 based on the drying intensity of 0 in the 11th drying section of sequence number 5.

[0143] Since the solid content of sequence number 7 is 87.4%, the drying level of the electrode sheet is determined to be an undried level, and one-plus control is performed. Therefore, the drying intensity is increased by 1 only in the 12th drying section, which is a drying section after the 11th drying section, in which the drying intensity has been increased in sequence number 6. Therefore, the drying intensity in each of the 10th to 12th drying sections is changed from the drying intensity 1, 1, and 0 in sequence number 6 to 1, 1, and 1.

[0144] Since the solid content of sequence number 8 is 87.2%, the drying level of the electrode sheet is determined to be an undried level, and one-plus control is performed. Since the drying intensity in the 10th drying section to the 12th drying section has been increased sequentially, only the drying intensity of the 10th drying section is increased again by 1. In this way, the respective drying intensities in the 10th drying section to the 12th drying section are changed from the drying intensities 1, 1, and 1 in sequence number 7 to 2, 1, and 1.

[0145] In sequence numbers 9 and 10, one plus control is performed. The specific method is the same as above.

[0146] Since the solid content of No. 11 is 87.3%, the drying level of the electrode sheet is determined to be the undried level and one-plus control is performed. However, since the drying intensity of the 10th drying stage to the 12th drying stage increases to the upper limit (2), no control is performed to no longer increase the drying intensity.

[0147] Since the control methods in sequence numbers 12 to 15 are the same as those described above, their detailed descriptions are omitted.

[0148] Figure 6 The figure shows a photo of an electrode sheet that has been dried according to the control of sequence number 2-15, taken by using a thermal imaging camera. Figure 6 , the electrode sheet dried by the automatic drying control system according to the embodiment of the present invention shows a uniform temperature along the longitudinal direction. Therefore, the automatic drying control system of the present invention shows the effect of manufacturing an electrode sheet with a uniform drying level.

[0149] The above description is only an example of the technical concept of the present invention, and those skilled in the art to which the present invention belongs may make various modifications and changes without departing from the essential features of the present invention. Therefore, the drawings disclosed in the present invention are not intended to limit the technical concept of the present invention, but to describe the present invention, and the scope of the technical concept of the present invention is not limited by these drawings. The scope of protection of the present invention shall be interpreted by the following claims, and all technical concepts within the scope equivalent thereto shall be interpreted as included in the scope of the present invention.

Claims

1. A system for automatically controlling electrode drying, the system include: an oven providing a space for moving and drying the electrode sheet, the oven including a drying device for applying hot air and / or radiant heat to the electrode sheet and being divided into a plurality of drying sections; a measuring unit that collects information about the drying amount of the electrode sheet and transmits the collected information to a controller; and a controller that determines a drying level of the electrode sheet based on the information about the drying amount received from the measuring unit, and controls a drying intensity of the oven according to the determined drying level, wherein the controller independently controls the plurality of drying sections, wherein the controller determines the dryness level of the electrode sheet to be one of five levels: a normal level, an overdry level, an underdry level, an overdry level, and an overunderdry level; wherein when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the controller controls to adjust the drying intensity of a drying section, and When the drying level of the electrode sheet is determined to be an excessively over-dried level or an excessively under-dried level, the controller controls to adjust the drying intensities of two or more drying sections together.

2. The system according to claim 1, wherein the measuring unit is configured to periodically collect information about the drying amount of the electrode sheet at fixed time intervals, and The controller periodically controls the drying intensity of the oven by determining the drying level of the electrode sheet whenever receiving information on the drying amount from the measuring unit. 3 . The system according to claim 2 , wherein the measuring unit collects information on the drying amount 1 to 5 minutes before a time point at which the controller is expected to control the drying intensity. 4 . The system according to claim 1 , wherein the information about the drying amount includes information about at least one of a solid content and a surface temperature of the electrode sheet.

5. The system of claim 1, wherein the controller include: a data input unit that inputs the information on the drying amount collected by the measuring unit and a reference set value on the drying amount; a determination unit, the determination unit determining a drying level of the electrode sheet by comparing the information on the drying amount with the set value, and determining whether to adjust the drying intensity in the oven and determining an adjustment amount according to the determined drying level; and A command unit controls a drying intensity of the oven based on the determination result of the determination unit.

6. The system according to claim 1, wherein when the drying level of the electrode sheet is determined to be an over-drying level or an excessive over-drying level, the controller controls to reduce the drying intensity of the oven, and When the drying level of the electrode sheet is determined to be an undried level or an excessive undried level, the controller controls to increase the drying intensity of the oven.

7. The system according to claim 1, wherein the controller controls the drying intensity of the drying sections among the plurality of drying sections except for the drying section at the front end of the oven. 8 . The system according to claim 1 , wherein the measuring unit transmits an average value or a median value of the collected information on the drying amount to the controller.

9. The system of claim 1, wherein each of the plurality of drying sections comprises a drying device, and The drying device includes at least one of a hot air nozzle for applying convection heat by supplying hot air to the electrode sheet and a heater for applying radiant heat to the electrode sheet.

10. The system according to claim 9, wherein the controller controls at least one selected from the group consisting of a hot air speed of the hot air nozzle, a hot air volume of the hot air nozzle, a temperature of the heater, and a moving speed of a conveying roller moving the electrode sheet to adjust the drying intensity of the oven.

11. The system according to claim 1, wherein the measuring unit comprises at least one of a web gauge and a temperature measuring instrument for measuring a load amount of the electrode sheet.

12. The system according to claim 11, wherein the measuring unit further comprises a calculating unit, and The calculation unit calculates the solid content of the electrode sheet according to the load amount measured by the web gauge.

13. A method for automatically controlling electrode drying, the method include: (a) supplying an electrode sheet into an oven, wherein the oven is divided into a plurality of drying sections and has a drying device; (b) collecting information about the drying amount of the electrode sheet by a measuring unit; and (c) determining a drying level of the electrode sheet by comparing the collected information on the drying amount with a reference value, and controlling the drying intensity of the oven according to the determined drying level, wherein the determination of the drying level includes independently controlling the plurality of drying sections, The determination of the dryness level includes determining the dryness level of the electrode sheet as one of five levels: a normal level, an overdryness level, an underdryness level, an overdryness level, and an overdryness level. Wherein, in the process of determining the drying level, when the drying level of the electrode sheet is determined to be an over-drying level or an under-drying level, the drying intensity of a drying section is controlled and adjusted, and When the drying level of the electrode sheet is determined to be an excessively over-dried level or an excessively under-dried level, the drying intensities of two or more drying sections are controlled and adjusted together. 14 . The method according to claim 13 , wherein in the information collection process, the information on the drying amount includes information on at least one of a solid content and a surface temperature of the electrode sheet.

15. The method according to claim 13, wherein the collection of the information comprises periodically collecting the information on the drying amount of the electrode sheet at fixed time intervals, and The determining of the drying level includes periodically controlling the drying intensity of the oven by determining the drying level of the electrode sheet whenever the information on the drying amount is received during the information collection process.

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