Electrode drying device and electrode drying method using the same

Abstract

The present invention relates to an electrode drying device, which includes a drying chamber having an inlet on one side through which an electrode substrate is introduced and an outlet on the other side through which the electrode substrate is discharged, a piston rod located inside the drying chamber and extending in a vertical direction to apply pressure to both widthwise ends of the electrode substrate, a cylinder for moving the piston rod up and down in the thickness direction of the electrode substrate, and a plate coupled to an end of the piston rod facing the electrode substrate and extending in a direction perpendicular to the widthwise direction of the electrode substrate. Even if both widthwise ends of the electrode substrate transferred to the drying chamber are overdried, the piston rod applies pressure to the both ends to prevent the both ends from bending, and the plate coupled to the piston rod blocks hot air applied to the both ends to prevent overdrying by the hot air, thereby preventing deterioration of electrode quality.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0163998, filed November 30, 2022, and all contents disclosed in the documents of this Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an electrode drying device and an electrode drying method using the same. [Background technology]

[0003] In recent years, with the depletion of fossil fuels causing rising energy prices and increasing concerns about environmental pollution, the demand for environmentally friendly alternative energy sources has become an essential factor for future life. As a result, research into various power generation technologies such as nuclear, solar, wind, and tidal power has been ongoing, and there has also been great interest in power storage devices to more efficiently use the energy produced in this way.

[0004] In particular, with the increasing technological development and demand for mobile devices, the demand for batteries as an energy source is rapidly increasing, and accordingly, research is being conducted on batteries that can meet various demands.

[0005] Typically, in terms of battery shape, there is a high demand for prismatic secondary batteries and pouch-type secondary batteries that are thin and can be applied to products such as mobile phones, and 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 advantages such as high energy density, discharge voltage, and output stability.

[0006] Generally, such secondary batteries have an electrode assembly containing a positive electrode, a negative electrode, and a separator disposed between them inside a battery case, and positive and negative electrode tabs are welded to two electrode tabs and sealed so that they are exposed to the outside of the battery case. These electrode tabs are in contact with and electrically connected to an external device, and the secondary battery supplies power to or is supplied with power from the external device via the electrode tabs.

[0007] Meanwhile, to manufacture an electrode for a secondary battery, an electrode mixture, which is a mixture of an electrode active material, a binder, and a solvent, is coated on a current collector and dried. Then, the current collector coated with the electrode mixture is dried, and cut and notched to a required size to manufacture an electrode for a secondary battery.

[0008] In the electrode manufacturing process, the process of drying the electrode slurry is costly and time-consuming, and the drying process affects the overall efficiency of the electrode manufacturing process.

[0009] FIG. 1 shows a front view and a plan view of an electrode substrate dried by a conventional electrode drying method. Referring to FIG. 1, the electrode substrate 10 comprises an electrode current collector 12, which is a metal foil, and one side of the electrode current collector 12 is coated with an electrode mixture to form an electrode mixture layer 11. When the electrode substrate 10 is exposed to high temperatures, differences in physical properties, such as density and stress, occur between the portion coated with the electrode mixture and the portion not coated with the electrode mixture. Specifically, when the electrode current collector 12, which is a metallic material, is heated, the metal expands, whereas when the electrode mixture is heated, the solvent evaporates and the electrode mixture contracts.

[0010] Furthermore, even in the areas where the electrode composite is applied, a sliding phenomenon of the electrode composite can occur on both sides of the electrode substrate in the width direction where the electrode composite is applied, and the areas where the sliding phenomenon occurs have a relatively small amount of electrode composite applied to the electrode current collector compared to other areas, which dries more quickly and can cause the electrode composite to shrink rapidly. Therefore, when the electrode substrate 10 to which the electrode composite is applied undergoes a drying process, the edges of both ends b, b' in the width direction of the heated electrode substrate 10 may be bent (c), i.e., curled or wavy, unlike the central region a, which is the region excluding both ends b, b'. In severe cases, cracks d may occur around the boundary between the area where the electrode composite is applied and the area where it is not applied.

[0011] As described above, the surface of the electrode substrate that is excessively dried by the conventional drying device may develop curls, undulations, or cracks, which deteriorate the quality of the electrode surface and ultimately reduce the energy efficiency and safety of the secondary battery.

[0012] Therefore, there is a need to develop an electrode drying device and an electrode drying method using the same that can solve the above problems. Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an electrode drying device and an electrode drying method using the same that can prevent the electrode surface from bending or cracking during the process of drying an electrode having an electrode composite layer formed thereon. [Means for solving the problem]

[0014] The present invention provides an electrode drying apparatus. In one embodiment according to the present invention, the electrode drying apparatus includes a drying chamber having an inlet on one side through which an electrode substrate is introduced and an outlet on the other side through which the electrode substrate is discharged, and a piston rod located within the drying chamber, extending vertically, and applying pressure to both widthwise ends of the electrode substrate.

[0015] In another embodiment, the electrode drying device of the present invention further includes a cylinder that moves the piston rod up and down in the thickness direction of the electrode substrate.

[0016] In another example, the electrode drying device of the present invention further includes a plate coupled to an end of the piston rod facing the electrode substrate and extending in a direction perpendicular to the width direction of the electrode substrate.

[0017] In a specific example, the plate has a structure in which one side edge located toward the inlet of the drying chamber has a curvature and is bent upward.

[0018] In another specific example, the piston rods are arranged in a number n (n is an integer of 2 or more) in a direction perpendicular to the width direction of the electrode substrate, and the n piston rods are arranged in a row.

[0019] In another specific example, when the drying chamber is divided into k regions (k is an integer between 10 and 30) based on the direction in which the electrode substrate is transported, the piston rod is configured to be disposed behind a point one-third of the k regions forming the drying chamber.

[0020] In another embodiment, the electrode drying device of the present invention further includes a control unit that adjusts the pressure inside the cylinder to control the up and down movement of the piston rod.

[0021] In another example, the electrode drying device of the present invention further includes a sensor unit that measures one or more of the temperature, dryness, defect level, and volume of hot air applied to the electrode substrate; and a data processing unit that receives one or more of the temperature, dryness, defect level, and volume of hot air applied to the electrode substrate measured by the sensor unit and determines whether or not to operate the control unit when one or more of the transmitted temperature, dryness, defect level, and volume of hot air deviates from a reference value.

[0022] In a specific example, the plate has a structure in which the bottom surfaces of both ends are stepped in the width direction of the electrode substrate, and the bottom surface of the end toward the center of the electrode substrate is higher than the bottom surface of the end toward the opposite direction.

[0023] The plate has a width in the range of 10 to 100 mm in the width direction of the electrode base material, and a length in the range of 1 to 5 m in the direction perpendicular to the width direction of the electrode base material.

[0024] The plate has a thickness in the range of 5 to 50 mm.

[0025] In another specific example, the plate is made of a metal material having a thermal conductivity (kcal / m·h·° C.) of 20 or less.

[0026] The plate has a hollow structure in which a cooling fluid conduit through which a cooling fluid flows is formed, and one of the n (n is an integer of 2 or more) piston rods is provided with a cooling fluid supply channel that can supply cooling fluid into the plate, and the other is provided with a cooling fluid discharge channel that can discharge cooling fluid from the plate and is connected to the plate, and the cooling fluid conduit is connected in communication with the cooling fluid supply channel and the cooling fluid discharge channel.

[0027] In another specific example, the cylinder is selected from a pneumatic cylinder and a hydraulic cylinder.

[0028] The cylinder also moves the piston rod up and down within a range of 100 mm.

[0029] In one example, the electrode drying apparatus of the present invention further includes an upper trunk that is mounted in an upper space inside the drying chamber and includes a nozzle that discharges hot air downward at a position spaced upward from the upper surface of the electrode substrate, and a lower trunk that is mounted in a lower space inside the drying chamber and includes a nozzle that discharges hot air upward at a position spaced downward from the lower surface of the electrode substrate.

[0030] Meanwhile, the present invention provides a method for drying an electrode. In one embodiment of the present invention, the method includes the steps of: transferring an electrode substrate into an electrode drying device, the electrode drying device including a drying chamber having an inlet on one side through which the electrode substrate is introduced and an outlet on the other side through which the electrode substrate is discharged, and a piston rod located within the drying chamber, extending vertically, and applying pressure to both widthwise ends of the electrode substrate; measuring one or more of the temperature, dryness, and defect level of the electrode substrate at both widthwise ends, and the volume of hot air applied to the electrode substrate; and, if any of the measured values ​​deviates from a reference value, controlling the operation of a cylinder to apply pressure to both widthwise ends of the electrode substrate with the piston rod. [Effects of the Invention]

[0031] According to the electrode drying apparatus and the electrode drying method using the same of the present invention, a piston rod is provided inside a drying chamber for applying pressure to both widthwise ends of an electrode substrate. Even if both widthwise ends of an electrode substrate being transferred to the drying chamber are over-dried, the piston rod applies pressure to both ends of the electrode substrate, thereby preventing the both ends from bending. A plate coupled to the piston rod blocks hot air from being applied to both ends, preventing excessive drying due to the hot air, thereby preventing a deterioration in electrode quality. [Brief explanation of the drawings]

[0032] [Figure 1] 1A and 1B are a front view and a plan view showing an electrode dried by a conventional electrode drying method. [Figure 2] 1 is a front view showing an electrode drying device according to an example of the present invention. [Figure 3] 1 is a side view showing an electrode drying device according to one example of the present invention. [Figure 4] FIG. 2 is a front view showing a plate of an electrode drying device according to a specific example of the present invention. [Figure 5] FIG. 10 is a front view showing an electrode drying device according to another example of the present invention. [Figure 6] FIG. 10 is a side view showing a plate of an electrode drying device according to another specific example of the present invention. [Figure 7] 1 is a flowchart showing the steps of a method for drying an electrode according to one example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0033] Because the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0034] However, this is not intended to limit the invention to any particular embodiment, but rather to be understood as including all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0035] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0036] Furthermore, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion therebetween. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion therebetween. Furthermore, in this application, being "located on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0037] In addition, in the present invention, the two ends of the electrode substrate refer to one end and the other end in the width direction of the electrode substrate, and may refer to the right and left ends of the electrode substrate. The two ends may include a region where an electrode mixture layer is not formed on the electrode current collector (uncoated region) as well as a part of a region where an electrode mixture layer is formed (coated region), and may refer to a region where the electrode substrate bends upward or where cracks are formed as a result of the electrode substrate drying. Meanwhile, the central region of the electrode substrate may refer to the remaining region excluding the two ends.

[0038] The present invention will be described in detail below.

[0039] The present invention provides an electrode drying device and an electrode drying method using the same.

[0040] Generally, differences in physical properties, such as density and stress, exist between regions of an electrode current collector where an electrode mixture layer is formed and regions where it is not, and even in regions where an electrode mixture layer is formed, depending on the amount of electrode mixture applied. When an electrode with an electrode mixture layer formed thereon is dried using a conventional drying device, the edges of both ends in the width direction of the electrode may curl upward, unlike the center portion, forming curls or undulations, which may lead to cracks on the electrode surface. This deterioration in electrode quality ultimately reduces the energy efficiency and safety of secondary batteries. Therefore, the present invention provides a drying chamber equipped with a piston rod that presses both ends in the width direction of the electrode substrate. Even if both ends in the width direction of the electrode substrate being transferred to the drying chamber are overdried, the piston rod presses the ends to prevent the ends from bending, and a plate coupled to the piston rod blocks hot air from being applied to the ends, preventing overdrying due to the hot air, thereby preventing deterioration in electrode quality.

[0041] An electrode drying device and an electrode drying method using the same according to the present invention will be described in detail below.

[0042] In one example, the electrode drying device of the present invention includes a drying chamber having an inlet on one side through which an electrode substrate is introduced and an outlet on the other side through which the electrode substrate is discharged, and a piston rod located inside the drying chamber, extending in the vertical direction, and applying pressure to both widthwise ends of the electrode substrate.

[0043] The drying chamber is partitioned by a case on all four sides and provides a space for drying the electrode substrate that has been introduced into the case. The drying chamber has an inlet for inputting and an outlet for outputting the electrode substrate transported by the transport rollers, and a heat source is disposed inside the drying chamber to supply heat energy so that the electrode composite of the electrode substrate can be dried. Generally, heat sources used in the electrode drying process include various types such as hot air, infrared (IR), and mid-infrared (MIR), and the hot air, infrared, and mid-infrared may be used alone or in combination of two or more.

[0044] The piston rod is located in the drying chamber above the surface of the electrode substrate and moves up and down to pressurize the electrode substrate when it moves down. The shape of the piston rod may be circular or polygonal, and is not limited to a particular shape.

[0045] The electrode drying apparatus of the present invention may also include a cylinder that moves a piston rod up and down in the thickness direction of the electrode substrate. The cylinder provides power for linearly reciprocating the piston rod. Specifically, a portion of the piston rod is inserted into the cylinder and coupled to the cylinder, allowing the piston rod to slide back and forth within the cylinder due to pressure generated within the cylinder. The cylinder may be fixed to the outer upper surface of the drying chamber and move the piston rod up and down in the thickness direction of the electrode substrate. In some cases, the cylinder may be located within the drying chamber and fastened to the outer upper surface of an upper trunk including a heat source device. However, in this case, the air pressure generated within the cylinder may change due to exposure to high temperatures, making it difficult to accurately control the pressure within the cylinder. Therefore, a structure in which the main body is attached to the outer upper surface of the drying chamber is preferred.

[0046] In another embodiment, the electrode drying apparatus of the present invention further includes a plate coupled to an end of the piston rod facing the electrode substrate and extending in a direction perpendicular to the width direction of the electrode substrate. The plate, coupled to the piston rod, is disposed above the electrode substrate at a predetermined interval and moves up and down together with the piston rod when the piston rod moves up and down. The plate is located in an upper region of both widthwise ends of the electrode substrate, and when the piston rod moves down, the plate also moves down, so that both widthwise ends of the electrode substrate come into contact with the plate and are simultaneously pressed.

[0047] Furthermore, the plate is positioned between the upper heat source device and the electrode substrate and can partially block thermal energy such as hot air, infrared rays, and mid-infrared rays emitted from the upper heat source device. Specifically, the plate can adjust the amount of thermal energy such as hot air, infrared rays, and mid-infrared rays applied to a portion of the electrode substrate facing the plate by adjusting the gap between the electrode substrate and the plate. For example, if the gap between a portion of the electrode substrate and the plate is large, hot air will enter the space between the portion of the electrode substrate and the plate, increasing the amount of hot air applied to that portion. On the other hand, if the gap between a certain region of the electrode substrate and the plate is narrow, only a small amount of hot air will enter the space between the certain region of the electrode substrate and the plate, reducing the amount of hot air applied to that portion. Therefore, the amount of heat applied to the electrode substrate can be adjusted by adjusting the gap between the plate and the electrode substrate.

[0048] In a specific example, the plate of the present invention may have a structure in which one side edge facing the inlet of the drying chamber is curved and bent upward. If one side edge of the plate is flat, when the electrode substrate transported by the transport roller comes into contact with the plate, the electrode substrate may get caught on the edge of the plate, causing interference with the movement of the electrode substrate. On the other hand, if one side edge of the plate is rounded, the electrode substrate may come into contact with the processed plate with less interference than when it comes into contact with a plate having a flat structure, allowing for smoother transport of the electrode substrate. If necessary, the plate may have a structure in which not only one side edge of the plate facing the inlet of the drying chamber but also the other side edge facing the outlet of the drying chamber is curved and bent upward.

[0049] In another specific example, the piston rods of the present invention may be arranged in a number n (n is an integer of 2 or more) in a direction perpendicular to the width direction of the electrode substrate, and the n piston rods may be arranged side by side. In this case, each of the n piston rods may be connected to one plate, and two to four piston rods arranged sequentially may be connected to one plate. The more piston rods connected to a plate, the more firmly the plate may be connected to the piston rods, and the greater the structural stability.

[0050] In another example, in the electrode drying apparatus according to the present invention, when the drying chamber is divided into k regions (k is an integer between 10 and 30) based on the direction in which the electrode substrate is transported, the piston rod may be configured to be located one-third of the way through the k regions forming the drying chamber. For example, when the drying chamber is divided into 16 regions in the direction in which the electrode substrate is transported, when the electrode substrate passes through the sixth to eighth regions or the seventh to ninth regions, the solvent contained in the electrode composite layer may evaporate to a certain extent, causing bending or cracking of both widthwise ends of the electrode substrate. Therefore, one or more piston rods may be located below the sixth to eighth regions or the seventh to ninth regions, where defects in the electrode substrate may occur. If bending occurs at both widthwise ends of the electrode substrate, the piston rods connected to plates may apply pressure to forcibly straighten the bent portions. Alternatively, if bending does not yet occur at the both ends, the electrode substrate and plates may be positioned so that they come into contact with each other, thereby preventing bending of the electrode substrate even when over-dried.

[0051] On the other hand, if the piston rod is disposed before the 1 / 3 point of the drying chamber divided into the k regions, there is a problem that if solvent remains in the electrode composite layer and the plate comes into contact with the electrode base material, the electrode composite will adhere to the plate. Therefore, it is preferable to dispose the piston rod after the 1 / 3 point of the k regions.

[0052] In another example, the electrode drying apparatus according to the present invention further includes a control unit that adjusts the pressure inside the cylinder to control the up and down movement of the piston rod. The control unit can increase or decrease the pressure inside the cylinder to increase or decrease the extension, i.e., stroke, of the piston rod inserted inside the cylinder. For example, a target value for the pressure inside the cylinder or a target value for the stroke of the piston rod can be input to the control unit, and the control unit controls the operation of the cylinder so that the pressure inside the cylinder can be increased or decreased based on the input information. In other words, the control unit can control the up and down movement range of the piston rod by controlling the operation of the cylinder.

[0053] In another example, the electrode drying device according to the present invention further includes a sensor unit that measures one or more of the temperature, dryness, defect level, and volume of hot air applied to the electrode substrate. The sensor unit may include a sensor capable of sensing the surface condition of the electrode substrate, and the sensor may be located in an upper region of the electrode surface. Preferably, the sensor unit may include one or more sensors that sense one or more target points on an imaginary axis parallel to the width direction of the electrode substrate, and the one or more sensors may sense one or more of the temperature, dryness, defect level, and volume of hot air applied to the specific points at both ends and the center of the electrode substrate in the width direction. The dryness may be the amount of drying or the drying rate, and the defect level may refer to the degree of bending or cracking of the electrode substrate. The temperature, dryness, and volume of hot air applied to the measurement point can be indirect information for determining whether the electrode substrate at the measurement point is over-dried, while the defect level, which indicates the degree of bending or cracking on the surface of the electrode substrate, can be direct information for determining whether the electrode substrate is over-dried. The information sensed by the sensor can be detected by the sensor unit as a numerical value.

[0054] Meanwhile, the sensor unit is disposed inside the drying chamber and is therefore at high risk of being exposed to high temperatures, which may cause malfunction or breakdown of the device. To prevent this, the outer case of the sensor unit may be covered with a cooling jacket, or a cooling fan may be installed adjacent to the sensor unit to prevent the sensor unit from overheating, as needed.

[0055] In another example, the electrode drying apparatus according to the present invention may further include a data processing unit that receives one or more of the temperature, dryness, defect level, and volume of hot air applied to the electrode substrate measured by the sensor unit and determines whether to operate the control unit. The data processing unit may determine whether to operate the control unit if one or more of the temperature, dryness, defect level, and volume of hot air transmitted from the sensor unit deviate from a reference value. The reference value refers to the normal range of the temperature, dryness, defect level, and volume of hot air applied to a specific point on the electrode substrate at each time point during drying of the electrode substrate. For example, if the defect level measured by the sensor unit at one end of the electrode substrate at a specific drying time point deviates from the reference value, the data processing unit may determine that a defect has occurred on the electrode surface due to over-drying, and may determine to operate the control unit to either lower a plate disposed above one end of the electrode substrate so that the plate comes into contact with the electrode substrate or to pressurize the electrode substrate with the plate. As another example, when the sensor unit detects that the deviation between the dryness measured at one end of the electrode substrate and the dryness measured at the center of the electrode substrate at a specific drying time point is outside the reference value, the data processing unit may determine that the one end is excessively dried compared to the center, and may determine the operation of the control unit to lower a plate disposed above and spaced apart from the one end of the electrode substrate to narrow the gap between the plate and the electrode substrate and thereby reduce the amount of heat transferred to the electrode substrate.

[0056] In a specific example, the plate may have a stepped bottom at both ends in the width direction of the electrode substrate, with the bottom of the end toward the center of the electrode substrate being higher than the bottom of the end toward the opposite direction. The electrode substrate to be transported has a covered portion, which is a region on the electrode current collector where an electrode mixture layer is formed, and a plain portion, where no electrode mixture layer is formed, coexisting, with the covered portion being thicker than the plain portion, forming a step between the covered portion and the plain portion. Therefore, a plate that contacts both the covered portion and the plain portion may have a stepped structure that creates a height difference between the bottom surface of the plate that contacts the covered portion and the bottom surface of the plate that contacts the plain portion. When the bottom surface of the stepped plate is divided into an upper bottom surface and a lower bottom surface located at the top, the upper bottom surface may correspond to the covered portion of the electrode substrate, and the lower bottom surface may correspond to the plain portion of the electrode substrate.

[0057] Meanwhile, the step formed on the plate may correspond to the thickness of the electrode mixture layer due to the difference in thickness between the coated and uncoated portions. Since the thickness of the electrode mixture layer typically varies depending on the drying time, the step of the plate may preferably be formed within a range of ±10% of the thickness of the electrode mixture layer, more preferably within a range of ±5%, taking into account the thickness of the electrode mixture layer at different drying times, which varies depending on the drying time.

[0058] If the plate does not have a step, when the plate presses the widthwise end of the electrode substrate, the difference in thickness between the coated and uncoated portions may prevent the uncoated portion from coming into contact with the plate and being subjected to pressure. Therefore, by providing a step in the plate, pressure can be applied appropriately to the uncoated region, which is prone to bending, and bending in the uncoated region can be efficiently suppressed.

[0059] Meanwhile, the stepped plate also preferably has a structure in which one side edge facing the inlet of the drying chamber has a curvature and is bent upward, thereby reducing interference that occurs when the electrode substrate moves due to the plate when the electrode substrate is inserted into the drying chamber and comes into contact with the plate as described above.

[0060] In another specific example, the plate may have a width of 10 to 100 mm in the width direction of the electrode sheet and a length of 1 to 5 m in the longitudinal direction of the electrode sheet. If the plate width is less than 10 mm, the width is narrow and the thermal energy blocking efficiency of hot air, infrared rays, and mid-infrared rays is reduced. If the plate width exceeds 100 mm, it may be difficult to apply concentrated pressure to a localized region at one end of the electrode substrate, considering the width and length of a typical electrode substrate. On the other hand, if the length of the plate in the direction perpendicular to the width direction of the electrode substrate is less than 1 m, the thermal energy blocking efficiency is reduced. If it exceeds 5 m, there is a problem that a large load is placed on the cylinder to control the large plate.

[0061] The plate may have a thickness ranging from 5 to 50 mm. If the thickness of the plate is less than 5 mm, the plate may bend due to an external impact, and if the thickness exceeds 50 mm, the weight of the plate may increase, weakening the connection with the cylinder.

[0062] The plate may be made of a metal material with a thermal conductivity (kcal / m·h·°C) of 20 or less. The higher the thermal conductivity of a metal, the better it absorbs thermal energy, which can increase the temperature of the plate due to the high temperature inside the drying chamber. In this case, if a high-temperature plate presses against or is placed in close proximity to the electrode substrate, the surface temperature of the electrode substrate may increase, which can have the adverse effect of promoting excessive drying. Therefore, the plate may preferably be made of stainless steel, which may be classified into various types of stainless steel, such as Fe-Cr-Ni-based or Fe-Cr-based, based on its chemical composition, but is not limited to a specific type.

[0063] The plate may have a hollow structure in which a cooling fluid conduit is formed, through which a cooling fluid flows, and one of the n (n is an integer of 2 or more) piston rods may have a cooling fluid supply passage for supplying a cooling fluid into the plate, and another may have a cooling fluid discharge passage for discharging the cooling fluid from the plate and be coupled to the plate, and the cooling fluid conduit may be connected in communication with the cooling fluid supply passage and the cooling fluid discharge passage. Of the n (n is an integer of 2 or more) piston rods, the piston rod with the cooling fluid supply passage and the piston rod with the cooling fluid discharge passage may have a hollow structure to allow a cooling fluid to flow therethrough, and the cooling fluid supply passage of one piston rod may be connected to the cooling fluid conduit of the plate, and the cooling fluid discharge passage of the other piston rod may be connected to the cooling fluid conduit of the plate, so that the cooling fluid may circulate between the interior of the piston rod and the interior of the plate.

[0064] The cooling fluid supply channel is connected to a supply pump that provides power for supplying the cooling fluid, and the cooling fluid discharge channel is connected to a discharge pump that provides power for discharging the cooling fluid. In this case, the supply pump and the discharge pump may be configured as a single pump, and may simultaneously perform two functions: supplying and discharging the cooling fluid. The connection method between the cooling fluid supply channel and the supply pump and the connection method between the cooling fluid discharge channel and the discharge pump are not limited to a specific method, and various methods may be applied depending on the working environment. When the cooling fluid is introduced into the plate, the plate, whose temperature has increased inside the chamber, can be cooled through heat exchange with the cooling fluid flowing inside. When the plate, whose temperature has been reduced by the cooling fluid, is positioned adjacent to the electrode substrate, the temperature of the electrode substrate can be quickly reduced through heat exchange with the electrode substrate, which has a relatively high temperature. This can control the temperature of the electrode surface and prevent the electrode substrate from being overly dried.

[0065] The cylinder may be selected from a pneumatic cylinder and a hydraulic cylinder. The pneumatic cylinder converts the pressure energy generated by compressing air into linear motion, while the hydraulic cylinder converts the pressure energy generated by hydraulic oil flowing into a piston, which increases under load, into linear motion. The hydraulic cylinder has the disadvantages of a slower response speed than the pneumatic cylinder and a complex internal structure that poses a risk of explosion due to hydraulic oil leakage, but has the advantages of high precision and strong thrust force. On the other hand, the pneumatic cylinder has the advantages of using atmospheric air as an energy source, a fast response speed, and a relatively simple cylinder structure. It is preferable to use a pneumatic cylinder, considering that the drying process is performed at high temperatures and that it has a simple structure and is easy to install.

[0066] In addition, the cylinder can move the piston rod up and down within a range of 100 mm. That is, the stroke of the piston rod coupled with the cylinder is formed within 100 mm. If the stroke of the piston rod exceeds 100 mm, a large pressure is required inside the cylinder, which causes a problem in that the size of the cylinder increases.

[0067] In another embodiment, the electrode drying apparatus according to the present invention further includes an upper trunk mounted in an upper space within the drying chamber and including a nozzle spaced above the upper surface of the electrode substrate to discharge hot air downward, and a lower trunk mounted in a lower space within the drying chamber and including a nozzle spaced below the lower surface of the electrode substrate to discharge hot air upward, and may further include an infrared and / or mid-infrared heater, as necessary.

[0068] On the other hand, the present invention provides a method for drying an electrode using the above-mentioned electrode drying device.

[0069] In the present invention, the above description of the electrode drying device is also applicable to the electrode drying method, and a duplicated detailed description will be omitted.

[0070] Fig. 7 is a flowchart showing the steps of the electrode drying method according to the present invention. Referring to Fig. 7, the method includes a step (S10) of transferring an electrode substrate into a drying device of the present invention, a step (S20) of measuring one or more of the temperature, dryness, and defect level of both widthwise ends of the electrode substrate and the volume of hot air applied to those ends, and a step (S30) of controlling the operation of a cylinder to apply pressure to both widthwise ends of the electrode substrate with a piston rod if the measured value is outside the reference value.

[0071] In step S10, the electrode drying apparatus includes a drying chamber having an inlet on one side through which the electrode substrate is introduced and an outlet on the other side through which the electrode substrate is introduced, and a piston rod located inside the drying chamber, extending vertically, and applying pressure to both widthwise ends of the electrode substrate. If necessary, the electrode drying apparatus may further include a cylinder that moves the piston rod up and down in the thickness direction of the electrode substrate, and a plate that is connected to the end of the piston rod facing the electrode substrate and extends in a direction perpendicular to the width direction of the electrode substrate. The electrode substrate is introduced into the drying chamber by a transfer roller, and the electrode substrate is dried by a heat source supplying device, such as hot air and / or infrared rays, located inside the drying chamber.

[0072] The step S20 is a step of measuring one or more of the surface temperature, dryness, degree of defects, and the volume of hot air applied to the point of the electrode substrate during drying, and the temperature, dryness, degree of defects, and volume of hot air applied to the point may be measured by a sensor capable of detecting each or more of them. One or more sensors may be provided, and may be arranged in a row in the width direction of the electrode substrate in the upper region of the surface of the electrode substrate, and may detect the surface condition of both end portions in the width direction of the electrode substrate, and may also detect the surface condition of the central portion excluding the both end portions, as necessary.

[0073] Meanwhile, step S30 is a step of controlling the cylinder operation to pressurize both widthwise ends of the electrode substrate with the piston rod when the measured value deviates from a reference value. The reference value may refer to the normal range of temperature, dryness, defect level, and the amount of hot air applied to a specific point on the electrode substrate at each time point during drying of the electrode substrate. If the measured value deviates from the reference value, it may indicate that the measured point has been over-dried, resulting in a defect on the surface. If the electrode substrate is over-dried, both widthwise ends of the electrode substrate may bend, or defects such as cracks may occur. Therefore, if the measured value deviates from the reference value, it is determined that bending has occurred or will occur at both ends of the electrode substrate surface, and the piston rod located above both ends of the electrode substrate surface may be lowered to apply pressure to the surface portion of the electrode substrate where bending has occurred or will occur, thereby preventing bending of the electrode substrate.

[0074] Hereinafter, various embodiments of an electrode drying device and an electrode drying method using the same according to the present invention will be described with reference to the drawings.

[0075] (First embodiment) The present invention provides an electrode drying device according to an embodiment as a first embodiment.

[0076] Fig. 2 is a front view of an electrode drying apparatus according to one embodiment of the present invention, and Fig. 3 is a side view of an electrode drying apparatus according to one embodiment of the present invention. Referring to Figs. 2 and 3, an electrode drying apparatus 100 according to the present invention includes a drying chamber 120 having an inlet through which an electrode substrate 110 is introduced on one side and an outlet through which the heated and dried electrode substrate 110 is discharged on the other side, an upper trunk 160 mounted in an upper space inside the drying chamber 120 and including a nozzle 161 spaced above the upper surface of the electrode substrate 110 to discharge hot air supplied through an air supply duct 162 downward, and a lower trunk 170 mounted in a lower space inside the drying chamber 120 and including a nozzle 171 spaced below the lower surface of the electrode substrate 110 to discharge hot air upward through an air supply duct 172. Meanwhile, the electrode base material 110 is composed of a coated portion where an electrode mixture layer 111 is applied on an electrode current collector 112 and an uncoated portion where the electrode mixture layer 111 is not applied.

[0077] The drying chamber 120 also includes a cylinder 140 that is positioned inside the drying chamber 120, extends in the vertical direction, and is coupled to one end of a piston rod 130 that presses both widthwise ends b and b' of the electrode substrate 110, thereby moving the piston rod 130 up and down in the thickness direction of the electrode substrate 110. The cylinder 140 may be a pneumatic cylinder 140 that is compact and easy to operate. The cylinder 140 is coupled to the outer upper surface of the drying chamber 120, and the air pressure generated inside the cylinder 140 may cause the piston rod 130 coupled to the cylinder 140 to perform a linear reciprocating piston movement.

[0078] Meanwhile, a plate 150 may be coupled to an end of the piston rod 130 opposite to the end coupled to the cylinder 140, and the plate 150 may be formed to a predetermined length by extending in a direction perpendicular to the width direction of the electrode substrate 110. The piston rods 130 may be arranged in a plurality of units in a direction perpendicular to the width direction of the electrode substrate 110, and the plurality of piston rods 130 may be arranged side by side, and two consecutively arranged piston rods 130 may be coupled to one plate 150. The greater the number of piston rods 130 coupled to the plate 150, the stronger the structure of the plate 150 with the piston rods 130 may be, thereby improving structural stability.

[0079] The plate 150 may be made of a metal material with a thermal conductivity (kcal / m·h·°C) of 20 or less, and preferably made of stainless steel with a thermal conductivity in the range of 13 to 16. Metals with low thermal conductivity can maintain a relatively low temperature even under high temperature conditions created by hot air inside the drying chamber 120, thereby preventing the electrode substrate 110 adjacent to the plate 150 from being heated by the plate 150.

[0080] The plate 150 has a curved, upwardly curved edge on one side thereof facing the inlet of the drying chamber 120. When the electrode substrate 110 being transported contacts the flat edge of the plate 150, the electrode substrate 110 may get caught on the plate 150, causing interference with the movement of the electrode substrate 110. On the other hand, when the edge of the plate 150 is rounded, the electrode substrate 110 being transported contacts the rounded plate 150 with less interference than when the electrode substrate 110 contacts a plate 150 with a flat structure, allowing for smoother transport of the electrode substrate 110. If necessary, the plate 150 may have a curved, upwardly curved edge on not only the edge of the plate 150 facing the inlet of the drying chamber 120 but also the other edge of the plate 150 facing the outlet of the drying chamber 120.

[0081] If the electrode substrate 110 is dried excessively, both ends b and b' in the width direction of the electrode substrate 110 may bend or crack compared to the center portion a of the electrode substrate 110. In this case, if bending or cracking of both ends b and b' in the width direction of the electrode substrate 110 is detected, the plate 150 disposed on the upper surface of both ends b and b' in the width direction of the electrode substrate 110 is lowered so that the plate 150 and the electrode substrate 110 come into contact with each other, thereby preventing bending or cracking of both ends b and b' in the width direction of the electrode substrate 110 that is introduced into the drying chamber 120. In some cases, the electrode substrate 110 that is introduced into the drying chamber 120 with both ends b and b' in the width direction already bent may be pressed by the plate 150 to forcibly straighten the bent portions.

[0082] Meanwhile, when the drying chamber 120 is divided into k regions (k is an integer between 10 and 30) based on the direction in which the electrode substrate 110 is transported, the piston rod 130 may be configured to be disposed one-third of the way through the k regions forming the drying chamber 120. For example, when the drying chamber 120 is divided into 16 regions in the direction in which the electrode substrate 110 is transported, when the electrode substrate 110 passes through the sixth to eighth regions or the seventh to ninth regions, the solvent contained in the electrode composite layer 111 may evaporate to a certain extent, causing bending or cracking of both ends b and b' in the width direction of the electrode substrate 110. Therefore, one or more piston rods 130 are disposed after the sixth to eighth regions or the seventh to ninth regions where defects occur in the electrode substrate 110, and when bending occurs at both ends b and b' in the width direction of the electrode substrate 110, the piston rods 130 connected to the plates 150 apply pressure to forcibly straighten the bent portions, or when bending has not yet occurred at both ends b and b', the electrode substrate 110 and the plates 150 are positioned so as to come into contact with each other, thereby preventing bending of the electrode substrate 110 even when over-dried.

[0083] (Second embodiment) The present invention provides an electrode drying device according to another embodiment as a second embodiment.

[0084] The first embodiment described above is configured with plates without steps, but the second embodiment is distinguished from the first embodiment in that it is configured with plates with steps.

[0085] 4 is a front view showing a stepped plate of an electrode drying device according to another embodiment of the present invention. Referring to FIG. 4, plate 250 of the electrode drying device according to the present invention is coupled to the end of piston rod 230, and has a structure in which the bottom surfaces of both ends in the width direction of electrode substrate 210 form a step e, and the bottom surface of the end toward center portion a of electrode substrate 210 is higher than the bottom surface of the end toward the opposite direction.

[0086] Specifically, the electrode substrate 210 comprises a coated portion where the electrode mixture layer 211 is applied on the electrode current collector 212, and an uncoated portion where the electrode mixture layer 211 is not applied. A central portion a in the width direction of the electrode substrate 210 comprises a coated portion, while both ends b and b' in the width direction of the electrode substrate may comprise only an uncoated portion, or may comprise both a coated portion and an uncoated portion. When the bottom surface of the plate 250 having the step e is divided into an upper bottom surface and a lower bottom surface located at the top, the upper bottom surface may correspond to the coated portion of the electrode substrate 210, and the lower bottom surface may correspond to the uncoated portion of the electrode substrate 210.

[0087] When compressing the widthwise end of the electrode base material 210 using a plate 250 without step e, as in the first embodiment described above, the difference in thickness between the coated and uncoated portions may prevent the uncoated portion from coming into contact with the plate 250 and being subjected to pressure. To solve this problem, the present invention provides step e in the plate 250, and by applying pressure to the uncoated region, which is prone to bending, between both widthwise end portions b, b' of the electrode base material 210, the occurrence of bending in the uncoated region can be efficiently suppressed.

[0088] Meanwhile, the step e formed on the plate 250 may be formed within a range of ±10% of the thickness of the electrode mixture layer 211, taking into account the thickness of the electrode mixture layer 211 at each drying point. In addition, the plate 250 having the step e preferably has a structure in which one side edge facing the inlet of the drying chamber has a curvature and is curved upward. This may reduce interference that occurs when the electrode substrate 210 moves due to the plate 250 when the electrode substrate 210 is inserted into the drying chamber and the plate 250 come into contact with each other, as described above.

[0089] (Third embodiment) The present invention provides an electrode drying device according to another embodiment as a third embodiment.

[0090] The first embodiment described above presents an electrode drying device including a cylinder and a plate. The third embodiment is distinguished from the first embodiment in that it determines whether or not to operate the cylinder depending on the temperature, dryness, and other conditions of the electrode substrate, and controls the operation of the cylinder to adjust the position of the plate.

[0091] 5 is a front view of an electrode drying apparatus according to another embodiment of the present invention. Referring to FIG. 4, an electrode drying apparatus 300 according to the present invention includes a drying chamber 320 having an inlet through which an electrode substrate 310 is introduced on one side and an outlet through which the heated and dried electrode substrate 310 is discharged on the other side, an upper trunk 360 mounted in an upper space inside the drying chamber 320 and including a nozzle 361 spaced above the upper surface of the electrode substrate 310 to discharge hot air supplied through an air supply duct 362 downward, and a lower trunk 370 mounted in a lower space inside the drying chamber 320 and including a nozzle 371 spaced below the lower surface of the electrode substrate 310 to discharge hot air upward through an air supply duct 372. The electrode substrate 310 includes a coated portion where an electrode mixture layer 311 is coated on an electrode current collector 312 and an uncoated portion where the electrode mixture layer 311 is not coated.

[0092] The drying chamber 320 also includes a piston rod 330 that is positioned inside the drying chamber 320, extends in the vertical direction, and applies pressure to both ends b, b' of the electrode substrate 310 in the width direction; a cylinder 340 that is connected to one end of the piston rod 330 and moves the piston rod 330 up and down in the thickness direction of the electrode substrate 310; and a plate 350 that is connected to the end of the piston rod facing the electrode substrate and extends in a direction perpendicular to the width direction of the electrode substrate.

[0093] Additionally, the electrode drying apparatus 300 according to the present invention may further include a control unit 382 that adjusts the pressure inside the cylinder 340 coupled to the piston rod 330 and controls the up and down movement of the piston rod 330. When a target value for the internal pressure of the cylinder 340 or a target stroke value indicating the movable range of the piston rod 330 is input, the control unit 382 may increase or decrease the pressure inside the cylinder 340 according to the input value, thereby increasing or decreasing the stroke of the piston rod 330.

[0094] The electrode substrate 310 may further include a sensor unit 380 that measures one or more of the temperature, dryness, degree of defects, and volume of hot air applied to the electrode substrate 310. The sensor unit 380 may be provided as one or more sensors that sense target points on an imaginary axis parallel to the width direction of the electrode substrate 310, and the one or more sensors may sense one or more of the temperature, dryness, degree of defects, and volume of hot air applied to the points at specific points on both ends b and b' in the width direction of the electrode substrate 310. The sensor unit 380 may digitize the level of the information sensed by the one or more sensors. If necessary, the sensor unit 380 may sense and measure one or more of the temperature, dryness, degree of defects, and volume of hot air applied to the points at a specific point in the center region a of the electrode substrate 310.

[0095] In addition, the electrode drying apparatus 300 according to the present invention further includes a data processing unit 381 that receives one or more of the temperature, dryness, and defect level of the electrode substrate 310 measured by the sensor unit 380, and the volume of hot air blown to the electrode substrate 310, and determines whether to operate the control unit 382. The data processing unit 381 determines whether to operate the control unit 382 when one or more of the temperature, dryness, and defect level of the electrode substrate 310 measured by the sensor unit 380, and the volume of hot air blown to the electrode substrate 310, are outside of a reference value. The dryness may be the amount of dryness or the drying rate, the defect level may refer to the degree of bending or cracking of the electrode substrate 310, and the reference value may refer to the normal range of the temperature, dryness, and defect level of the electrode substrate 310, and the volume of hot air blown to the electrode substrate 310 at different drying times. As one example, if the degree of defect measured by the sensor unit 380 at either end b or b' of the width direction of the electrode substrate 310 at a specific drying time point is outside the reference value, or if the deviation of the dryness measured at either end b, b' of the width direction of the electrode substrate 310 from the dryness measured at the center portion a of the electrode substrate 310 is outside the reference value, the sensor unit 380 may determine that either end b, b' of the electrode substrate 310 has been over-dried, and may determine to operate the control unit 382 to command the piston rod 330 to pressurize the electrode substrate 310 or to come into contact with the electrode substrate 310.

[0096] (Fourth embodiment) The present invention provides an electrode drying device according to another embodiment as a fourth embodiment.

[0097] The first to third embodiments described above have a structure in which no hollow space is formed inside the plate, but the fourth embodiment is distinguished from the first to third embodiments in that a hollow space is formed inside the plate and a cooling fluid is injected into the hollow space, so that the plate can maintain a low temperature even when exposed to hot air, and the surface temperature of the electrode substrate that is in contact with or adjacent to the plate can be reduced.

[0098] 6 is a side view showing a plate of an electrode drying apparatus according to another embodiment of the present invention. Referring to FIG. 6, electrode drying apparatus 400 of the present invention includes a piston rod 430, a cylinder 440, and a plate 450 coupled to the end of piston rod 430. Plate 450 of the present invention has a structure in which one side edge facing the inlet of the drying chamber has a curvature and is bent upward, and has a hollow structure in which cooling fluid conduit 451 is formed inside plate 450 so that a cooling fluid can flow through it. The plate 450 having the hollow structure is connected to two piston rods 430, one of which includes a cooling fluid supply path 431 that can supply cooling fluid to the inside of the plate 450, and the other includes a cooling fluid discharge path 432 that can discharge the cooling fluid inside the plate 450, and the cooling fluid pipe 451 is connected in communication with the cooling fluid supply path 431 and the cooling fluid discharge path 432, so that the cooling fluid can flow through the cooling fluid pipe 451, the cooling fluid supply path 431, and the cooling fluid discharge path 432.

[0099] Meanwhile, a pump is provided to control the flow of the cooling fluid, and the cooling fluid can be supplied to the cooling fluid supply path 431 or discharged from the cooling fluid discharge path 432 by the pump.

[0100] When a cooling fluid is introduced into the plate 450, the temperature of the plate 450 can be reduced through heat exchange between the plate 450 and the cooling fluid. Since the plate 450 containing the cooling fluid maintains a temperature lower than the internal temperature of the drying chamber, the plate 450 can be positioned adjacent to or in contact with the electrode substrate to facilitate rapid heat exchange between the electrode substrate and the plate 450, thereby preventing the surface of the electrode substrate from being over-dried.

[0101] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, at the time of filing this application, there may be various equivalents and modifications that can replace them. [Explanation of symbols]

[0102] 100, 200, 300, 400: Electrode drying device 10, 110, 210, 310: Electrode base material 11, 111, 211, 311: Electrode composite layer 12, 112, 212, 312: Electrode current collector 120, 320: Drying chamber 130, 230, 330, 430: Piston rod 140, 340, 440: Cylinder 150, 250, 350, 450: Plate 160, 360: Upper trunk 161, 171, 361, 371: Nozzle 162, 172, 362, 372: Air supply duct 170, 370: Lower trunk 380: Sensor section 381: Data processing section 382: Control unit 431: Cooling fluid supply path 432: Cooling fluid discharge path 451: Cooling fluid line

Claims

1. a drying chamber having an inlet for inputting an electrode substrate on one side and an outlet for discharging the electrode substrate on the other side; a piston rod located inside the drying chamber, extending in a vertical direction, and applying pressure to both ends of the electrode base material in a width direction; a cylinder coupled to the piston rod and configured to move the piston rod up and down; a plate coupled to the piston rod and in contact with both widthwise ends of the electrode substrate; the electrode base material has a coated portion to which an electrode mixture layer is applied and an uncoated portion to which the electrode mixture layer is not applied, Both widthwise end portions of the electrode substrate include the uncoated portion, The electrode drying device, wherein the plate has a hollow structure in which a cooling fluid duct is formed inside, through which a cooling fluid flows.

2. An electrode drying device as described in Claim 1, wherein the cylinder moves the piston rod up and down in the thickness direction of the electrode substrate.

3. An electrode drying device as described in claim 1, wherein the plate is connected to the end of the piston rod facing the electrode substrate and extends in a direction perpendicular to the width direction of the electrode substrate.

4. The electrode drying apparatus according to claim 3 , wherein the plate has a structure in which one side edge facing the inlet of the drying chamber has a curvature and is bent upward.

5. 4. The electrode drying device according to claim 3, wherein n piston rods (n is an integer of 2 or more) are arranged in a direction perpendicular to the width direction of the electrode base material, and the n piston rods are arranged in a line.

6. 2. The electrode drying apparatus according to claim 1, wherein the drying chamber is divided into k regions (k is an integer between 10 and 30) based on a direction in which the electrode substrate is transported, and the piston rod is disposed behind one-third of the k regions forming the drying chamber.

7. The electrode drying device according to claim 2 , further comprising a control unit that adjusts the pressure inside the cylinder to control the up and down movement of the piston rod.

8. a sensor unit for measuring one or more of the temperature, dryness, defect level, and volume of hot air applied to the electrode substrate; 8. The electrode drying device according to claim 7, further comprising: a data processing unit that receives at least one of the temperature, dryness, defect level, and volume of hot air blown onto the electrode substrate measured by the sensor unit, and that determines whether to operate the control unit when at least one of the temperature, dryness, defect level, and volume of hot air blown onto the electrode substrate falls outside a reference value.

9. the plate has a structure in which bottom surfaces at both ends in the width direction of the electrode base material are stepped, The electrode drying device according to claim 3 , wherein the bottom surface of the end portion facing the center of the electrode base material is higher than the bottom surface of the end portion facing the opposite direction.

10. 4. The electrode drying device according to claim 3, wherein the plate has a width in the range of 10 to 100 mm in the width direction of the electrode substrate and a length in the range of 1 to 5 m in a direction perpendicular to the width direction of the electrode substrate.

11. 4. The electrode drying device according to claim 3, wherein the plate has a thickness in the range of 5 to 50 mm.

12. The electrode drying device according to claim 3 , wherein the plate is made of a metal material having a thermal conductivity (kcal / m·h·° C.) of 20 or less.

13. Any one of the n piston rods (n is an integer of 2 or more) has a cooling fluid supply path that supplies cooling fluid to the inside of the plate, and another piston rod has a cooling fluid discharge path that discharges cooling fluid inside the plate and is connected to the plate, and The electrode drying apparatus according to claim 5 , wherein the cooling fluid conduit is connected in communication with the cooling fluid supply path and the cooling fluid discharge path.

14. The electrode drying device according to claim 2 , wherein the cylinder is selected from a pneumatic cylinder and a hydraulic cylinder.

15. The electrode drying device according to claim 2 , wherein the cylinder moves the piston rod up and down within a range of 100 mm or less.

16. an upper trunk that is installed in an upper space inside the drying chamber and includes a nozzle that is spaced above the upper surface of the electrode substrate and that discharges hot air downward; 2. The electrode drying apparatus of claim 1, further comprising: a lower trunk mounted in a lower space inside the drying chamber and including a nozzle spaced downward from the lower surface of the electrode substrate to discharge hot air upward.

17. A step of transporting an electrode substrate into the electrode drying device according to claim 1; measuring one or more of the temperature, dryness, defect rate, and volume of hot air applied to both ends of the electrode substrate in the width direction; and when one or more of the measured temperature, dryness, defect level, and hot air volume are outside the reference values, controlling the operation of the cylinder to apply pressure to both ends of the electrode substrate in the width direction with the piston rod.

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