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 dated November 30, 2022, and all contents disclosed in the documents of said 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, as the depletion of fossil fuels has led to rising energy prices and concerns over 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 atomic, solar, wind, and tidal power has been ongoing, and there has also been great interest in power storage devices to use the energy produced in this way more efficiently.

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

[0005] Typically, in terms of battery shape, there is a high demand for square-type 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] In general, such a secondary battery has an electrode assembly including a positive electrode, a negative electrode, and a separator disposed between them, built into a battery case, and has a structure in which positive and negative electrode tabs are welded to two electrode tabs and sealed so as to be 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 the external device or is supplied with power from the external device through the electrode tabs.

[0007] Meanwhile, in order 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 on which the electrode mixture is applied 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 is composed of an electrode current collector 12, which is a metal foil, and an electrode mixture layer 11 is formed by applying an electrode mixture to one side of the electrode current collector 12. When the electrode substrate 10 is exposed to high temperatures, differences in physical properties such as density and stress occur between the part where the electrode mixture is applied and the part where the electrode mixture is not applied. Specifically, when the electrode current collector 12, which is a metal material, is heated, the metal expands, whereas when the electrode mixture is heated, the solvent evaporates and the electrode mixture shrinks.

[0010] In addition, even in the portion where the electrode composite is applied, a sliding phenomenon of the electrode composite occurs at both sides in the width direction of the electrode substrate where the electrode composite is applied, and the region where the sliding phenomenon occurs has a relatively small amount of the electrode composite applied on the electrode current collector compared to the other region, and dries quickly, so that the electrode composite may 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 portion a, which is the portion excluding both ends b, b', or in severe cases, cracks d may occur around the boundary between the region where the electrode composite is applied and the region where it is not applied.

[0011] As described above, the surface of the electrode substrate that is excessively dried by the conventional drying device has a problem that curling, undulation, or cracks occur, degrading the quality of the electrode surface, and ultimately reducing 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 is made to solve the above problems, and has an object to provide an electrode drying device and an electrode drying method using the same, which can prevent the electrode surface from bending or cracking during the process of drying an electrode having an electrode mixture 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 at one side through which an electrode substrate is inserted and an outlet at the other side through which the electrode substrate is discharged, and a piston rod located inside the drying chamber, extending in a vertical direction, and applying pressure to both ends in a width direction 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 base material.

[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 structured to be disposed behind 1 / 3 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] Moreover, 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] In addition, the plate has a hollow structure in which a cooling fluid pipeline 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 passage capable of supplying cooling fluid to the inside of the plate, and the other is provided with a cooling fluid discharge passage capable of discharging the cooling fluid in the inside of the plate and is connected to the plate, and the cooling fluid pipeline is connected in communication with the cooling fluid supply passage and the cooling fluid discharge passage.

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

[0028] In addition, the cylinder 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 in a downward direction 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 in an upward direction 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 for drying an electrode includes the steps of: transferring an electrode substrate into an 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 inside the drying chamber, extending vertically, and applying pressure to both ends in a width direction of the electrode substrate; measuring one or more of the temperature, dryness, and defect level of both ends in the width direction of the electrode substrate and the amount of hot air applied to the portions; and, when the measured values ​​are outside of reference values, controlling the operation of a cylinder to apply pressure to both ends in the width direction of the electrode substrate with the piston rod. Effect 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 that applies pressure to both widthwise ends of an electrode substrate is provided inside a drying chamber, and even if both widthwise ends of an electrode substrate transported to the drying chamber are overdried, the piston rod applies pressure to both ends of the electrode substrate to prevent the both ends from bending, and a plate coupled to the piston rod blocks hot air applied to both ends to prevent the electrode from being overdried by the hot air, thereby preventing deterioration of electrode quality. [Brief description 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. [Diagram 2] 1 is a front view showing an electrode drying device according to one example of the present invention. [Diagram 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. [Diagram 5] FIG. 11 is a front view showing an electrode drying device according to another example of the present invention. [Figure 6] FIG. 11 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 embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Since 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 it should be understood to include 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] In addition, 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 in between. 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 in between. In addition, in the present application, being "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, both 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 end and the left end of the electrode substrate. The both ends may include a part of the area (uncoated area) where the electrode mixture layer is formed on the electrode current collector, including an area (coated area) where the electrode mixture layer is formed, and may refer to an area where the electrode substrate bends upward during the drying process of the electrode substrate, or where cracks are formed as a result. Meanwhile, the center portion of the electrode substrate may refer to the remaining area excluding the both 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] In general, there are physical property differences such as density and stress between the area where the electrode mixture layer is formed on the electrode current collector and the area where the electrode mixture layer is not formed, and even in the area where the electrode mixture layer is formed, depending on the amount of the electrode mixture applied. When an electrode on which an electrode mixture layer is formed is dried using a conventional drying device, the edges of both ends in the width direction of the electrode may bend upwards, unlike the center portion, and curl or ripple may be formed, which may cause cracks on the electrode surface. Such a deterioration in electrode quality ultimately reduces the energy efficiency and safety of the secondary battery. Therefore, the present invention is characterized in that a piston rod is provided inside a drying chamber to pressurize both ends in the width direction of the electrode substrate, and even if both ends in the width direction of the electrode substrate transferred to the drying chamber are excessively dried, the piston rod presses the both ends to suppress the phenomenon of the both ends being bent, and a plate coupled to the piston rod blocks hot air applied to the both ends to prevent excessive drying by the hot air, thereby preventing deterioration of the electrode quality.

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

[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 inserted 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 ends of the electrode substrate in the width direction.

[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 is provided with an inlet for inputting and an outlet for outputting the electrode substrate transported by the transport roller, and a heat source for supplying heat energy so that the electrode composite of the electrode substrate can be dried is disposed inside the drying chamber. In general, heat sources used in the electrode drying process can be various, such as hot air, infrared (IR), and mid-infrared (MIR), and the hot air, infrared, and mid-infrared can be used alone or in combination of one or more of them.

[0044] The piston rod is located in the upper region of the electrode substrate surface while being located inside the drying chamber, and may move vertically to pressurize the electrode substrate when it descends. The shape of the piston rod may be circular or polygonal columnar, and is not limited to a particular shape.

[0045] The electrode drying device of the present invention may further include a cylinder that moves the piston rod up and down in the thickness direction of the electrode substrate. The cylinder provides power so that the piston rod can move back and forth linearly. Specifically, a part of the piston rod is inserted into the cylinder, and the piston rod may slide back and forth within the cylinder due to the pressure generated within the cylinder when the piston rod is coupled to the cylinder. The cylinder may be fixed to the outer upper surface of the drying chamber, and the piston rod may be moved 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 to be located within the drying chamber. However, in this case, the air pressure generated within the cylinder may change depending on the temperature due to exposure to high temperatures, and it may be difficult to accurately control the pressure within the cylinder. Therefore, a structure in which the main body is mounted on the outer upper surface of the drying chamber is preferable.

[0046] In another embodiment, 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. The plate is disposed at a predetermined interval in an upper direction of the electrode substrate while being coupled to the piston rod, 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 ends in the width direction of the electrode substrate, and when the piston rod moves down, the plate also moves down, so that both ends in the width direction of the electrode substrate come into contact with the plate and are simultaneously pressurized.

[0047] Furthermore, the plate is located 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 the portion of the electrode substrate and the plate is large, hot air enters the space between the portion of the electrode substrate and the plate, increasing the amount of hot air applied to that portion, whereas if the gap between a certain portion of the electrode substrate and the plate is narrow, a small amount of hot air enters the space between the certain portion of the electrode substrate and the plate, decreasing 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 located toward the inlet of the drying chamber is curved upward with a curvature. 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 is caught by the edge of the plate, causing interference in the movement of the electrode substrate. On the other hand, if one side edge of the plate is rounded, the electrode substrate is less interfered with when the processed plate comes into contact with the transported electrode substrate than when the processed plate comes into contact with a plate having a flat structure, so that the electrode substrate can be transported more smoothly. If necessary, the plate may have a structure in which not only one side edge of the plate located toward the inlet of the drying chamber but also the other side edge located toward the outlet of the drying chamber is curved upward with a curvature.

[0049] In another specific example, the piston rods of the present invention may be arranged in a number of 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 coupled to one plate, and two to four piston rods arranged in sequence may be coupled to one plate. The more piston rods are coupled to a plate, the more firmly the plate may be coupled 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 of 10 to 30) based on the direction in which the electrode substrate is transported, the piston rod may be arranged behind 1 / 3 of 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 6th to 8th regions or the 7th to 9th regions, the solvent contained in the electrode mixture layer may evaporate to a certain extent, causing bending or cracking of both ends in the width direction of the electrode substrate. Therefore, one or more piston rods are arranged below the 6th to 8th regions or the 7th to 9th regions where defects of the electrode substrate occur, and when bending occurs at both ends in the width direction of the electrode substrate, the piston rods connected to the plates are pressed to forcibly straighten the bent portions, or when bending does not yet occur at both ends, the electrode substrate and the plates are positioned to come into contact with each other, thereby preventing bending of the electrode substrate even when it is overdried.

[0051] On the other hand, if the piston rod is placed 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 mixture layer and the plate comes into contact with the electrode base material, the electrode mixture will adhere to the plate. Therefore, it is preferable to place the piston rod after the 1 / 3 point of the k regions.

[0052] In another embodiment, 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 formed inside the cylinder to increase or decrease the extension, i.e., stroke, of the piston rod inserted inside the cylinder. For example, a target pressure value inside the cylinder or a target stroke value 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. That is, 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 amount of hot air applied to the electrode substrate. The sensor unit includes a sensor that can sense the surface condition of the electrode substrate, and the sensor can be located in an upper region of the electrode surface. Preferably, the sensor unit includes one or more sensors that sense one or more target points on a virtual axis parallel to the width direction of the electrode substrate, and the one or more sensors can sense one or more of the temperature, dryness, defect level, and amount of hot air applied to the points at specific points at both ends and a center portion in the width direction of the electrode substrate. The dryness may be a dry amount or a drying rate, and the defect level may mean a degree of bending or a degree of cracking of the electrode substrate. The temperature, dryness, and the amount of hot air applied to the point can be indirect information for determining whether the electrode substrate at the measurement point is over-dried, and the defect level means the degree of bending or cracking on the surface of the electrode substrate, and can be direct information for determining defects caused by the electrode substrate being over-dried. The information sensed through the sensor can be detected by the sensor unit as a numerical value.

[0054] Meanwhile, since the sensor unit is disposed inside the drying chamber, there is a high risk of it being exposed to high temperatures, and the sensor unit exposed to high temperatures may cause malfunction or failure of the device. To prevent this, if necessary, the outer case of the sensor unit may be covered with a cooling jacket or a cooling fan may be provided adjacent to the sensor unit to prevent the sensor unit from overheating.

[0055] In another example, the electrode drying device according to the present invention may further include a data processing unit that receives at least one of the temperature, dryness, defect level, and hot air volume applied to the electrode substrate measured by the sensor unit and determines whether or not to operate the control unit. The data processing unit may determine whether or not to operate the control unit when at least one of the temperature, dryness, defect level, and hot air volume transmitted from the sensor unit is outside of a reference value. The reference value means a normal range of the temperature, dryness, defect level, and hot air volume applied to the point at a specific point of the electrode substrate according to a time point when the electrode substrate is dried. For example, when the defect level measured by the sensor unit at one end of the electrode substrate at a specific drying time point is outside of a reference value, the data processing unit may determine that a defect has occurred on the electrode surface due to overdrying, and may determine to operate the control unit so that a plate disposed above and spaced apart from one end of the electrode substrate is lowered so that the plate is in contact with the electrode substrate, or the electrode substrate is pressurized by 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 at a specific drying time point falls outside a 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 spaced apart above 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 structure in which the bottom surfaces of both ends in the width direction of the electrode substrate are stepped, and the bottom surface of the end toward the center of the electrode substrate among the both ends may be higher than the bottom surface of the end toward the opposite direction. The electrode substrate to be transferred has a landed portion, which is a region where an electrode mixture layer is formed on an electrode current collector, and a non-coated portion where no electrode mixture layer is formed, and the landed portion has a thickness greater than the non-coated portion, forming a step between the landed portion and the non-coated portion. Thus, the plate in contact with both the landed portion and the non-coated portion may have a structure in which a step is provided so that a height difference is formed between the bottom surface of the plate in contact with the landed portion and the bottom surface of the plate in contact with the non-coated portion. When the bottom surface of the plate having the step is divided into an upper bottom surface and a lower bottom surface located at the upper part, the upper bottom surface may correspond to the landed portion of the electrode substrate, and the lower bottom surface may correspond to the non-coated 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 parts. Since the thickness of the electrode mixture layer usually varies depending on the drying time, the step of the plate may 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 each drying time, 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 base material, the uncoated portion may not come into contact with the plate due to the difference in thickness between the coated portion and the uncoated portion, and may not be pressed. Therefore, by providing a step in the plate, the uncoated portion area, which is prone to bending, can be appropriately pressed, and bending of the uncoated portion area 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 curved upward, thereby reducing interference that occurs when the electrode substrate is moved by the plate when the electrode substrate is inserted into the drying chamber and the plate contacts each other 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 width of the plate 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, and if it exceeds 100 mm, it may be difficult to concentrate pressure on a local area at one end of the electrode substrate when considering the width and length of a general 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, and if it exceeds 5 m, there is a problem that a large load is applied to the cylinder to control the large-scale plate.

[0061] In addition, 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] Also, the plate may be made of a metal material having 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, so the temperature of the plate may rise due to the effect of high temperature in the drying chamber. In this case, when a high-temperature plate presses the electrode substrate or is placed in close proximity, the surface temperature of the electrode substrate may rise, which may have the adverse effect of promoting excessive drying. Therefore, preferably, the plate may 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 stainless steels based on chemical composition, but is not limited to a specific type.

[0063] Also, the plate may have a hollow structure in which a cooling fluid duct is formed inside through which a cooling fluid flows, and any one of the n (n is an integer of 2 or more) piston rods may be provided with a cooling fluid supply passage capable of supplying a cooling fluid to the inside of the plate, and the other may be provided with a cooling fluid discharge passage capable of discharging the cooling fluid in the inside of the plate and coupled to the plate, and the cooling fluid duct may be connected in communication with the cooling fluid supply passage and the cooling fluid discharge passage. Among the n (n is an integer of 2 or more) piston rods, the piston rod provided with the cooling fluid supply passage and the piston rod provided with the cooling fluid discharge passage may have a hollow structure so that a cooling fluid can flow through them, and the cooling fluid supply passage provided in one piston rod may be connected to the cooling fluid duct of the plate, and the cooling fluid discharge passage provided in the other piston rod may also be connected to the cooling fluid duct of the plate, so that the cooling fluid may circulate between the inside of the piston rod and the inside of the plate.

[0064] The cooling fluid supply passage is connected to a supply pump that provides power for supplying the cooling fluid, and the cooling fluid discharge passage is connected to a discharge pump that provides power for discharging the cooling fluid. In this case, the supply pump and the discharge pump are configured as one pump, and can simultaneously perform two functions of supplying or discharging the cooling fluid. Meanwhile, the connection method between the cooling fluid supply passage and the supply pump and the connection method between the cooling fluid discharge passage and the discharge pump are not limited to a specific method, and various methods can be applied according to the working environment. When the cooling fluid is introduced into the plate as described above, the plate whose temperature is increased inside the chamber can be lowered through heat exchange with the cooling fluid flowing into the chamber. When the plate whose temperature is lowered by the cooling fluid is positioned adjacent to the electrode substrate, the temperature of the electrode substrate can be quickly lowered through heat exchange with the electrode substrate having a relatively high temperature. This can control the temperature of the electrode surface to 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, which increases due to the load when hydraulic oil flows into the piston, into linear motion. The hydraulic cylinder has a relatively slower reaction speed than the pneumatic cylinder, and has a disadvantage that the internal structure of the cylinder is complicated and there is a risk of explosion due to hydraulic oil leakage, but has an advantage of high precision and strong thrust force. On the other hand, the pneumatic cylinder has a relatively low precision and a weak thrust force, but has an advantage of using air in the atmosphere as an energy source, a fast reaction speed, and a relatively simple cylinder structure. It is preferable to use a pneumatic cylinder when considering that the drying process is performed at a high temperature 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 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 that is installed in an upper space inside the drying chamber and includes a nozzle spaced upward from an upper surface of the electrode substrate to discharge hot air in a downward direction, and a lower trunk that is installed in a lower space inside the drying chamber and includes a nozzle spaced downward from a lower surface of the electrode substrate to discharge hot air in an upward direction, and may further include an infrared and / or mid-infrared heater as necessary.

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

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

[0070] Fig. 7 is a flow chart showing the procedure of the electrode drying method according to the present invention. Referring to Fig. 7, the method includes a step (S10) of transporting 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 ends of the electrode substrate in the width direction and the amount of hot air applied to the portions, and a step (S30) of controlling the operation of a cylinder to pressurize both ends of the electrode substrate in the width direction with a piston rod when 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 discharged, and a piston rod located inside the drying chamber, extending in a vertical direction, and applying pressure to both ends in the width direction 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 an 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 transport roller, and the electrode substrate is dried by a heat source supplying device, such as hot air and / or infrared rays, located in 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 amount of hot air applied to the point of the electrode substrate during drying, and the temperature, dryness, degree of defects, and the amount of hot air applied to the point may be measured by a sensor capable of sensing each or one or more of them. The sensor may be provided in one or more, 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 sense the surface condition of both ends in the width direction of the electrode substrate, and may also sense the surface condition of the central portion excluding the both ends, as necessary.

[0073] Meanwhile, the step S30 is a step of controlling the cylinder operation to pressurize both ends in the width direction of the electrode substrate with the piston rod when the measured value is outside the reference value. The reference value may mean the normal range of temperature, dryness, defect degree, and the amount of hot air applied to a specific point of the electrode substrate at each time point when the electrode substrate is dried, and when the measured value is outside the reference value, it may mean that the measured point is overdried and a defect occurs on the surface. When the electrode substrate is overdried, both ends in the width direction of the electrode substrate may bend, or defects such as cracks may occur. Therefore, when the measured value is outside the reference value, it is determined that bending occurs or will occur immediately at both ends of the electrode substrate surface, and the piston rod located in the upper region of both ends of the electrode substrate surface is lowered to pressurize the surface part of the electrode substrate where bending occurs or will occur, thereby suppressing 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 showing an electrode drying apparatus according to an embodiment of the present invention, and Fig. 3 is a side view showing an electrode drying apparatus according to an embodiment of the present invention. Referring to Figs. 2 and 3, the electrode drying apparatus 100 according to the present invention includes a drying chamber 120 having an inlet at one side through which an electrode substrate 110 is introduced and an outlet at the other side through which the heated and dried electrode substrate 110 is discharged, an upper trunk 160 mounted in an upper space inside the drying chamber 120 and including a nozzle 161 at a position spaced upward from the upper surface of the electrode substrate 110 to discharge hot air supplied through an air supply duct 162 in a downward direction, and a lower trunk 170 mounted in a lower space inside the drying chamber 120 and including a nozzle 171 at a position spaced downward from the lower surface of the electrode substrate 110 to discharge hot air in an upward direction through an air supply duct 172. Meanwhile, the electrode base material 110 includes 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] In addition, the drying chamber 120 includes a cylinder 140 that is connected to one end of a piston rod 130 that is located inside the drying chamber 120 and extends in a vertical direction, pressurizes both ends b and b' of the electrode substrate 110 in the width direction, and moves 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 not large in volume and is easy to operate. The cylinder 140 is connected to an outer upper surface of the drying chamber 120, and the piston rod 130 connected to the cylinder 140 may perform a linear reciprocating piston movement by the air pressure generated inside the cylinder 140.

[0078] Meanwhile, a plate 150 may be coupled to an end of the piston rod 130 located in a direction 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 piston rods 130 arranged in sequence 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, and the structural stability may be improved.

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

[0080] The plate 150 has a structure in which one side edge located toward the inlet of the drying chamber 120 is curved upward with a curvature. When the electrode substrate 110 being transported contacts the flat edge of the plate 150, the electrode substrate 110 is caught by the plate 150, causing interference in the movement of the electrode substrate 110. Meanwhile, when one side edge of the plate 150 is processed to be round, the electrode substrate 110 being transported contacts the processed plate 150 with less interference than when the processed plate 150 contacts the plate 150 with a flat structure, so that the electrode substrate 110 can be transported more smoothly. If necessary, the plate 150 may have a structure in which not only one side edge of the plate 150 located toward the inlet of the drying chamber 120 but also the other side edge located toward the outlet of the drying chamber 120 is curved upward with a curvature.

[0081] If the electrode substrate 110 is excessively dried, both ends b, 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, when bending or cracking of both ends b, b' in the width direction of the electrode substrate 110 is detected, the plate 150 disposed on the upper surface of both ends b, 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, b' in the width direction of the electrode substrate 110 introduced into the drying chamber 120, and in some cases, the electrode substrate 110 introduced into the drying chamber 120 with both ends b, b' in the width direction of the electrode substrate 110 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 from 10 to 30) based on the direction in which the electrode substrate 110 is transported, the piston rod 130 may be structured to be disposed behind 1 / 3 of 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 6th to 8th regions or the 7th to 9th regions, the solvent contained in the electrode mixture layer 111 may evaporate to a certain extent, causing bending or cracking of both ends b, b' of the electrode substrate 110 in the width direction. Therefore, one or more piston rods 130 are disposed after the 6th to 8th regions or the 7th to 9th regions where defects occur in the electrode substrate 110, and when bending occurs at both ends b, b' in the width direction of the electrode substrate 110, the piston rods 130 to which the plates 150 are connected apply pressure to forcibly straighten the bent portions, or when bending has not yet occurred at both ends b, 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 it is overdried.

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

[0084] The above-mentioned first embodiment is configured with a plate without a step, but the second embodiment is distinguished from the first embodiment in that it is configured with a plate having a step.

[0085] Fig. 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, a plate 250 of the electrode drying device according to the present invention is coupled to an end of a piston rod 230, and has a structure in which the bottom surfaces of both ends in the width direction of the electrode substrate 210 form a step e, and the bottom surface of the end toward the center part a of the electrode substrate 210 among the both ends is higher than the bottom surface of the end toward the opposite direction.

[0086] Specifically, the electrode substrate 210 is composed of a ground portion in which the electrode mixture layer 211 is applied onto the electrode current collector 212, and an uncoated portion in which the electrode mixture layer 211 is not applied. A central portion a in the width direction of the electrode substrate 210 is composed of a ground portion, while both ends b, b' in the width direction of the electrode substrate may be composed of only an uncoated portion or may be composed of a ground 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 upper portion, the upper bottom surface may correspond to the ground 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 with the plate 250 without the step e as in the first embodiment described above, the difference in thickness between the coated and uncoated portions may result in the uncoated portions not coming into contact with the plate 250 and not being compressed. To solve this problem, the present invention provides the step e in the plate 250 and preferably applies pressure to the uncoated regions of both widthwise ends b, b' of the electrode base material 210 that are prone to bending, thereby efficiently suppressing bending of the uncoated regions.

[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 consideration the thickness of the electrode mixture layer 211 at each drying point. In addition, the plate 250 having the step e also preferably has a structure in which one side edge located toward the input port of the drying chamber has a curvature and is curved upward. This can reduce interference that occurs when the electrode substrate 210 moves by the plate 250 when the electrode substrate 210 input 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 the position of the plate is adjusted by determining whether or not the cylinder is operating depending on the temperature, dryness, and other conditions of the electrode substrate and controlling the operation of the cylinder.

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

[0092] The drying chamber 320 further includes a piston rod 330 extending in a vertical direction and applying pressure to both ends b, b' of the electrode substrate 310 in the width direction, and a cylinder 340 connected to one end of the piston rod 330 and moving the piston rod 330 up and down in the thickness direction of the electrode substrate 310. The drying chamber 320 further includes a plate 350 connected to the end of the piston rod facing the electrode substrate and extending in a direction perpendicular to the width direction of the electrode substrate.

[0093] Additionally, the electrode drying device 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 an internal pressure target value of the cylinder 340 or a stroke target 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 for measuring one or more of the temperature, dryness, degree of defects, and the amount of hot air applied to the electrode substrate 310. The sensor unit 380 may be provided as one or more sensors for sensing a target point on a virtual 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 the amount of hot air applied to the point at a specific point on both ends b and b' in the width direction of the electrode substrate 310. The sensor unit 380 may digitize the degree from information sensed by the one or more sensors. If necessary, the electrode substrate 110 may sense and measure one or more of the temperature, dryness, degree of defects, and the amount of hot air applied to the point at a specific point in the center portion a of the electrode substrate 110.

[0095] In addition, the electrode drying device 300 according to the present invention further includes a data processing unit 381 that receives at least one of the temperature, dryness, and defect level of the electrode substrate 310 measured by the sensor unit 380, and the amount of hot air applied to the electrode substrate 310, and determines whether or not to operate the control unit 382. The data processing unit 381 is characterized in that it determines whether or not to operate the control unit 382 when at least one of the temperature, dryness, and defect level of the electrode substrate 310 measured by the sensor unit 380, and the amount of hot air applied to the electrode substrate 310, is outside of a reference value. The dryness may be a dryness amount or a drying rate, the defect level may mean the degree to which the electrode substrate 310 is bent or the degree to which cracks are generated, and the reference value may mean a normal range of the temperature, dryness, and defect level of the electrode substrate 310, and the amount of hot air applied to the electrode substrate 310 at different drying times. As one example, if the degree of defect measured by the sensor unit 380 at both ends b or b' in the width direction of the electrode substrate 310 at a specific drying time point falls outside a standard value, or if the deviation of the dryness measured at both ends b and b' in the width direction of the electrode substrate 310 from the dryness measured at the center portion a of the electrode substrate 310 falls outside a standard value, the sensor unit 380 may determine that both ends b and b' of the electrode substrate 310 have been overdried, 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 base material that is in contact with or adjacent to the plate can be reduced.

[0098] Fig. 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, an electrode drying apparatus 400 of the present invention includes a piston rod 430, a cylinder 440, and a plate 450 coupled to an end of the piston rod 430. The plate 450 of the present invention has a structure in which one side edge located toward the inlet of the drying chamber has a curvature and is bent upward, and has a hollow structure in which a cooling fluid duct 451 is formed so that a cooling fluid can flow through the inside of the plate 450. The plate 450 having the hollow structure is connected to two piston rods 430, one of which includes a cooling fluid supply passage 431 that can supply cooling fluid to the inside of the plate 450, and the other of which includes a cooling fluid discharge passage 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 passage 431 and the cooling fluid discharge passage 432, and the cooling fluid can flow through the cooling fluid pipe 451, the cooling fluid supply passage 431 and the cooling fluid discharge passage 432.

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

[0100] When a cooling fluid is introduced into the inside of 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 rapidly exchange heat 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 described in the drawings or embodiments, etc. in this specification are merely one embodiment of the present invention and do not fully represent the technical ideas of the present invention, and therefore there may be various equivalents and modifications that can replace them at the time of filing this application. [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 through which the electrode substrate is introduced on one side and an outlet through which the electrode substrate is discharged 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.

2. The electrode drying device according to claim 1 , further comprising a cylinder for moving the piston rod up and down in a thickness direction of the electrode base material.

3. The electrode drying device according to claim 1 , further comprising a plate coupled to an end of the piston rod facing the electrode substrate and extending in a direction perpendicular to a 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 located toward the inlet of the drying chamber has a curvature and is curved upward.

5. The electrode drying device according to claim 3, wherein 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 base material, and the n piston rods are arranged in a line.

6. 2. The electrode drying apparatus according to claim 1, wherein when 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, the piston rod is disposed behind a ⅓ point of the k regions forming the drying chamber.

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

8. a sensor unit for measuring one or more of a temperature, a dryness, a defect degree, and a 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 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.

9. The plate has a structure in which a bottom surface at both ends in a width direction of the electrode base material has a step, The electrode drying device according to claim 3 , wherein, of the two end portions, a bottom surface of the end portion facing a central portion of the electrode base material is positioned higher than a 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 a 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. The electrode drying apparatus 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. The plate has a hollow structure in which a cooling fluid duct is formed inside through which a cooling fluid flows, Any one of the n piston rods (n is an integer of 2 or more) is provided with a cooling fluid supply passage for supplying a cooling fluid to an inside of the plate, and another piston rod is provided with a cooling fluid discharge passage for discharging the cooling fluid in the inside of the plate and is coupled to the plate; and The electrode drying apparatus of claim 5 , wherein the cooling fluid conduit is coupled in flow communication with the cooling fluid supply passage and the cooling fluid discharge passage.

14. The electrode drying apparatus of 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 upward from an upper surface of the electrode substrate and that discharges hot air downward; 2. The electrode drying apparatus according to claim 1, further comprising: a lower trunk mounted in a lower space inside the drying chamber and including a nozzle spaced downward from a lower surface of the electrode substrate to eject hot air in an upward direction.

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

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