Drying device for electrode manufacturing and method for manufacturing electrodes using the same

Abstract

The present invention relates to a drying apparatus for manufacturing an electrode and a method for manufacturing an electrode using the same. The drying apparatus for manufacturing an electrode includes a transfer section that transfers dried electrode substrates, and a floating section that uses air to levitate and transfer the electrode substrates, and simultaneously cools the coated section coated with electrode slurry and the uncoated section not coated with electrode slurry. This improves the thermal expansion difference between the electrode substrates, thereby preventing wrinkles and / or folding problems that may occur in the uncoated section of the electrode substrate. Furthermore, the floating section has an air floating plate with a discharge port that can be replaced depending on the specifications of the electrode to be manufactured, which has the advantage of excellent processability.

Description

[Technical field]

[0001] The present invention relates to a drying device for use in the manufacture of electrodes and a method for manufacturing electrodes using the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0103377 filed on August 5, 2021, and Korean Patent Application No. 10-2022-0083725 filed on July 7, 2022, and all contents disclosed in the documents of the relevant Korean patent applications are incorporated herein by reference. [Background technology]

[0003] Lithium secondary batteries have electrodes containing an active material that exhibits electrical activity, and such electrodes are manufactured by coating an electrode substrate with an active material slurry to form a composite layer and drying the layer. In the manufacturing process of such electrodes, a slurry coating device and a drying device are usually used when manufacturing the electrode, and the drying device includes a drying section that dries the composite layer of the electrode substrate, and a running roller that is provided outside the outlet of the drying section and runs the electrode substrate with the dried composite layer.

[0004] Here, since the drying section removes the solvent in the slurry using high heat, the electrode substrate exiting the drying section has a thermal expansion difference between the coating section where the composite layer is formed and the uncoated section where the composite layer is not formed. This thermal expansion difference causes problems such as wrinkles or folds in the running direction from the uncoated section while the electrode substrate is running.

[0005] To solve these problems, conventional coating / drying equipment has been developed that uses a cooling device to cool the electrode substrate or a wrinkle roller to smooth out wrinkles and folds. However, these equipment requires additional space to install the cooling device and rollers, and once the equipment is installed, it is difficult to change the specifications of the electrode width, etc., resulting in low processability. In addition, when a plain area is formed between multiple coating areas, the effect of improving wrinkles and folds formed in the plain area is minimal, or there is a limit to the possibility of damaging the coating area. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent No. 10-1810146 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a drying apparatus for manufacturing an electrode, which can improve a thermal expansion difference of an electrode substrate between a coated portion and an uncoated portion, regardless of the shape or number of coated portions where electrode slurry is applied, thereby preventing wrinkles and / or folding phenomena induced in the uncoated portion. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, in one embodiment, the present invention comprises: a drying unit that dries the coating portion of the electrode substrate having at least one surface coated with the electrode slurry and a non-coated portion not coated with the electrode slurry; and a conveying unit coupled to an outlet of the drying unit and conveying the dried electrode substrate in a traveling direction, The conveying unit provides a drying apparatus for manufacturing an electrode, the drying apparatus including: a floating unit having an air floating plate for floating the electrode substrate by using air; and a traveling unit for moving the floating electrode substrate in a traveling direction.

[0009] In this case, the air floating plate includes an outlet that ejects air onto the surface on which the electrode substrate runs, and the outlet may be included on the entire surface of the air floating plate; or may be included only in the area on which the coating portion of the electrode substrate runs.

[0010] The discharge port in the region where the coating portion of the electrode base material runs may have an average diameter of 0.005 mm to 10 mm.

[0011] In addition, when the air floating plate includes outlets over the entire surface thereof, the diameter and / or frequency of the outlets can be controlled to a constant value in order to adjust the pressure of the air ejected in each region where the coated and uncoated portions of the electrode substrate run.

[0012] As one example, the discharge opening in the region where the coated portion of the electrode substrate runs may have an average diameter that is 50 to 99% of the discharge opening in the region where the uncoated portion of the electrode substrate where the electrode slurry is not applied runs.

[0013] As another example, the number of outlets per unit area in the region where the coated portion of the electrode substrate runs may be 50 to 99% of the number of outlets per unit area in the region where the uncoated portion of the electrode substrate runs.

[0014] The discharge port may be provided so as to form an inclination angle of 30° to 80° with the surface of the air floating plate in the running direction of the electrode base material.

[0015] In addition, the air floating plate may include an outlet for blowing air onto a surface on which the electrode substrate runs, and a vacuum suction hole for sucking the blown air at a position adjacent to the outlet.

[0016] Meanwhile, the running part may include a tilting machine for tilting the air floating plate; or conveyors disposed at the upper and lower ends of the floating part to slide the electrode substrate in the running direction.

[0017] In one embodiment, the present invention further comprises: Drying the electrode substrate having the electrode slurry applied to at least one surface of the electrode substrate at a high temperature; and The present invention provides a method for manufacturing an electrode, comprising the step of levitating and transporting an electrode substrate that has been dried at a high temperature using air.

[0018] In this case, in the step of transferring the electrode substrate, the electrode substrate may be floated by air ejected from an outlet provided in the air floating plate.

[0019] The pressure of the air ejected from the outlet may be 0.01 MPa to 0.5 MPa.

[0020] Specifically, when the entire surface of the air floating plate includes outlets, the pressure of the air ejected from the area where the coated portion of the electrode substrate runs can be 0.05 MPa to 0.4 MPa, and the pressure of the air ejected from the area where the uncoated portion of the electrode substrate runs can be 0.01 MPa to 0.2 MPa.

[0021] In addition, the air used in the step of transporting the electrode base material may have a temperature of -10°C to 30°C.

[0022] In addition, the step of transporting the electrode substrate may be performed at a transport speed of 1 mm / s to 20 mm / s. Effect of the Invention

[0023] The drying apparatus for manufacturing an electrode according to the present invention is provided with a floating unit that can cool the electrode substrate while floating it using air in a transport unit that transports the dried electrode substrate, thereby preventing wrinkles and / or folding problems induced in the non-coated portion of the electrode substrate. In addition, the floating unit can be replaced with an air floating plate in which the average diameter and / or number of outlets per unit area are controlled according to the specifications of the electrode to be manufactured, which is advantageous in terms of excellent processability. [Brief description of the drawings]

[0024] [Figure 1] 1 is a schematic diagram showing a drying apparatus for electrode production according to the present invention; [Diagram 2] 4 is a cross-sectional structural view illustrating a floating part of a transfer part provided in the drying apparatus for manufacturing an electrode according to the present invention; FIG. [Diagram 3] 2 is an example illustrating a surface structure of an air floating plate according to the present invention having a single plate-like structure. [Figure 4] 2 is an example illustrating a surface structure of an air floating plate according to the present invention having a single plate-like structure. [Diagram 5] 2 is an example illustrating a surface structure of an air floating plate according to the present invention having a single plate-like structure. [Figure 6] 1 is a diagram illustrating an example of the structure of an air floating plate according to the present invention having a structure in which a plurality of rod shapes are assembled. [Figure 7] 1 is a diagram illustrating an example of the structure of an air floating plate according to the present invention having a structure in which a plurality of rod shapes are assembled. [Figure 8] 2 is a perspective view illustrating an example of a transfer unit provided in the drying apparatus for electrode manufacturing according to the present invention; FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Although the present invention can be modified in various ways and can have various embodiments, a specific embodiment will be described in detail in the detailed description.

[0026] However, it is not intended that this be construed as limiting the invention to the particular embodiments, but rather to include all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

[0027] In the present invention, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are to be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0028] 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" may include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0029] The present invention will now be described in more detail.

[0030] <Drying equipment for electrode production> In one embodiment, the present invention comprises: a drying section for drying the coating section of the electrode substrate, which has at least one surface coated with the electrode slurry and a non-coated section not coated with the electrode slurry; and a conveying unit coupled to an outlet of the drying unit and conveying the dried electrode substrate in a traveling direction, The conveying unit includes a floating unit having an air floating plate for floating the electrode substrate by air; and a traveling unit for moving the floating electrode substrate in a traveling direction.

[0031] FIG. 1 is a perspective view showing a schematic configuration of a drying apparatus for manufacturing an electrode according to the present invention. Referring to FIG. 1, the drying apparatus for manufacturing an electrode according to the present invention includes a drying unit 100 for drying an electrode slurry applied to an electrode substrate to form an electrode composite layer, and a transport unit 200 for moving the electrode substrate 1, on which the applied electrode slurry has been dried, in a traveling direction D after the electrode substrate 1 exits the drying unit 100.

[0032] Here, the drying unit 100 may include a housing and a plurality of heating elements provided within the housing. An inlet (not shown) is provided on one side of the housing for receiving the electrode substrate (or electrode collector, 1) having a surface coated with electrode slurry containing one or more electrode active materials after passing through a coater, and an outlet 110 is provided on the other side of the housing for the electrode substrate (or electrode collector) to exit. The electrode substrate 1 that passes through the inside of the housing and is discharged to the outside of the housing through the outlet advances along a conveying unit 200 coupled to the rear of the outlet 110, and is wound up on an electrode recovery roller.

[0033] The heating elements generate heat by supplying electric energy and are installed inside the housing. Specifically, the heating elements are arranged on the electrode substrate 1 along the running direction D of the electrode substrate 1. When the heating elements generate heat, the electrode slurry applied to the upper surface of the electrode substrate, i.e., the coating portion, is dried and hardened by the radiant heat. Specifically, the coating portion is dried and hardened by heating with the radiant heat of the heating elements to remove the solvent in the electrode slurry. For this reason, the internal temperature of the space in the housing where the heating elements are arranged may be adjusted to a temperature at which the solvent can be volatilized, specifically, to 120°C to 150°C. The heating elements may be, for example, halogen lamps, and if necessary, a heat reflector surrounding the upper surface of each heating element may be installed inside the housing so that the radiant heat realized by the heating elements is transferred to the electrode substrate while minimizing heat loss.

[0034] In addition, the drying apparatus 10 for manufacturing an electrode according to the present invention has a structure in which a conveying unit 200 for moving the dried electrode substrate 1 in a traveling direction D is continuously connected to the outlet 111 of the drying unit. The conveying unit 200 includes a floating unit 210 for floating the electrode substrate 1 by using air, and a traveling unit 220 for moving the floating electrode substrate 1 in the traveling direction D.

[0035] Here, the floating part 210 is installed perpendicular to the running direction D of the electrode substrate, and includes an air floating plate 214 having a number of outlets along the running direction D for blowing air onto the surface of the electrode substrate 1 .

[0036] The air floating plate 214 not only can float the dried electrode substrate 1 by discharging air onto the surface of the electrode substrate 1 through the provided outlet, but also can prevent wrinkles and / or folding phenomena occurring in the uncoated areas where the electrode slurry is not applied.

[0037] Specifically, when the electrode substrate 1 coated with the electrode slurry is dried at a high temperature, the difference in thermal expansion between the coated portion coated with the electrode slurry and the non-coated portion not coated with the electrode slurry may cause wrinkles and / or folds in the non-coated portion. In particular, in a surface contact type transport method such as a roll-to-roll method, tension is generated in the running direction of the electrode substrate 1. When such tension is applied to the electrode substrate 1 that is dried at a high temperature and has a high temperature, wrinkles and / or folds may occur between the coated portion and the non-coated portion of the electrode substrate 1. However, the present invention can promote cooling of the electrode substrate 1 by blowing air onto the surface of the electrode substrate 1 that has been dried at a high temperature. In addition, since the electrode substrate 1 can be lifted and moved while cooling, the tension applied to the electrode substrate 1 can be minimized, and wrinkles and / or folds may be suppressed between the coated portion coated with the electrode slurry and the non-coated portion not coated with the electrode slurry.

[0038] In addition, since the air-floating plate 214 has a plate-like shape, it is possible to prevent vibration of the electrode substrate caused by twisting between rollers or bearings due to rotation generated in an air-floating system in which a plurality of rollers or a plurality of bearings are combined, and it is possible to minimize the generation of dust during processing, and it is advantageous in that safe operation and maintenance of the equipment are easy.

[0039] In addition, the air floating plate 214 is connected to an air supply unit 216 at its lower end for supplying air to the outlet, and the air supply unit 216 may include an air blower (not shown) for generating air. In this case, the air blower may be composed of a motor for providing a driving force and an impeller rotated by the driving of the motor, and may further include an air compressor and an air control unit for controlling the flow rate and pressure of the air in addition to the air blower.

[0040] 2 is a cross-sectional view showing a schematic structure of the floating part 210. Referring to FIG. 2, the floating part 210 has an air floating filter 213 between the air supply part 216 and the air floating plate 214, and can remove foreign matter in the air while reducing the difference in the amount of air supplied to the outlet 215 of the air floating plate 214. For this reason, the air floating filter 213 can have a mesh-sized net structure, and the open pores inside can include a fine flow path structure that guides and discharges air. The air floating filter 213 can be made of an insulating material to maintain insulation. Specifically, the air floating filter 213 can be made of a heat-resistant porous engineering plastic material or a porous ceramic material.

[0041] In addition, a gasket 212 is further included between the air supply unit 216 and the air floating filter 213 to prevent air from leaking to the outside, thereby making it possible to keep the pressure of air supplied to the air floating plate 214 constant.

[0042] In addition, the air floating plate 214 has an outlet 215 for ejecting air on the side along which the electrode substrate 1 runs, and the outlet 215 can be formed on the entire surface of the air floating plate 214, i.e., the entire surface, or can be formed only in the area along which the coating applied to the electrode substrate 1 runs.

[0043] Specifically, Figures 3 to 5 are images illustrating the surface of the air-floating plate 214 according to the present invention, and the air-floating plates 214a, 214b, and 214c may include outlets 215a only in the area where the coating portion C of the electrode substrate runs, as in Figure 3, or may include outlets 215b, 215b', 215c, and 215c' on the entire surface, as shown in Figures 4 and 5.

[0044] 3, when the air floating plate 214 includes the outlet 215a only in the area where the coating part C of the electrode substrate runs, it can minimize the loss of air discharged onto the surface of the electrode substrate 1, thereby increasing the floating efficiency of the electrode substrate 1. In addition, the air floating plate 214 can induce rapid cooling of the coating part, thereby minimizing the temperature difference between the electrode current collector and the active material layer (i.e., the dried electrode slurry layer) located in the coating part, thereby preventing a decrease in the adhesive strength between them.

[0045] In addition, when the air floating plate 214 includes the discharge ports 215b, 215b', 215c and 215c' on the entire surface of the electrode substrate 1 as shown in Figures 4 and 5, the difference in the cooling rate perpendicular to the direction in which the electrode substrate 1 travels, i.e., the cooling rate in the width direction of the electrode substrate 1, can be minimized, thereby preventing bending of the electrode substrate 1.

[0046] Here, when the air floating plate 214 has the outlets 215b, 215b', 215c, and 215c' included on the entire surface of the air floating plates 214b and 214c, the outlets in the region C where the coated portion of the electrode substrate runs may have a smaller average diameter or a smaller number of outlets per unit area than the outlets in the region S where the uncoated portion of the electrode substrate where the electrode slurry is not applied runs.

[0047] As an example, when the air floating plates 214b and 214c include the outlets 215a, 215b, 215b', 215c, and 215c' over the entire surface, the outlets in the region C where the coated portion of the electrode substrate runs may have an average diameter that is 50 to 99% of the outlets in the region S where the uncoated portion of the electrode substrate where the electrode slurry is not applied runs. Specifically, the air floating plates 214b and 214c may have an average diameter that is 50 to 95%, 50 to 90%, 50 to 85%, 50 to 80%, 50 to 75%, 50 to 70%, 60 to 90%, 70 to 95%, 80 to 99%, or 75 to 90% of the outlets in the region S where the uncoated portion of the electrode substrate runs.

[0048] Here, the discharge port of the region C through which the coating portion of the electrode base material runs is not particularly limited as long as it has an average diameter that can eject sufficient air to levitate the electrode base material including the coating portion, but specifically, it can have an average diameter of 0.005 mm to 10 mm, and more specifically, it can have an average diameter of 0.005 mm to 5 mm; 0.005 mm to 3 mm; 0.005 mm to 2 mm; 0.005 mm to 1 mm; 0.005 mm to 0.9 mm; 0.00 It may have an average diameter of 5mm~0.5mm; 0.005mm~0.1mm; 0.005mm~0.05mm; 0.005mm~0.01mm; 0.01mm~0.03mm; 0.025mm~0.05mm; 0.06mm~0.09mm; 0.01mm~3mm; 0.05mm~2mm; 0.05mm~1mm; 0.1mm~1mm; 0.5mm~2mm; 0.5mm~0.9mm; or 0.01mm~0.1mm.

[0049] As another example, when air floating plates 214b and 214c include outlets 215b, 215b', 215c and 215c' over their entire surfaces, the number of outlets per unit area in region C where the coated portion of the electrode substrate runs may be 50 to 99% of the number of outlets per unit area in region S where the uncoated portion of the electrode substrate runs, specifically, 50 to 90%; 60 to 90%; 70 to 90%; 60 to 80%; 50 to 70%; or 65 to 85% of the number of outlets per unit area in region S where the uncoated portion of the electrode substrate runs.

[0050] In the present invention, by controlling the average diameter and the number per unit area of ​​the outlets 215b, 215b', 215c, and 215c' introduced into the air floating plates 214b and 214c according to their positions within the above ranges, the electrode substrate 1 coated with the electrode slurry can be stably floated. Furthermore, the uncoated areas not coated with the electrode slurry can be heated to a high temperature and then rapidly cooled to a temperature lower than room temperature, so that the substrate structure of the uncoated areas can be rapidly solidified, thereby improving the thermal expansion difference of the electrode substrate 1.

[0051] Furthermore, the outlets 215a, 215b, 215b', 215c, and 215c' introduced into the surfaces of the air floating plates 214a, 214b, and 214c may have a porosity (opening rate) of 20 to 80%, specifically 30 to 70%. By controlling the porosity (opening rate) of the outlets introduced into the air floating plates 214a, 214b, and 214c within the above range, the present invention can smooth the flow of air sprayed onto the surfaces of the air floating plates 214a, 214b, and 214c, while blocking the inflow of fine particles that may be present in the air.

[0052] In addition, the outlets 215a, 215b, 215b', 215c, and 215c' of the air-floating plates applied in the present invention may be formed perpendicular to the direction D in which the electrode base material 1 travels, or may be provided to form an inclination angle (α) of 30° to 80° with the surfaces of the air-floating plates 214a, 214b, and 214c in the direction D in which the electrode base material 1 travels, as shown in Fig. 5. Specifically, the outlets 215a, 215b, 215b', 215c, and 215c' may be formed perpendicular to the direction D in which the electrode base material 1 travels, or may be provided to form an inclination angle (α) of 30° to 70°, 30° to 60°, 30° to 50°, 45° to 70°, 60° to 80°, 30° to 45°, or 40° to 60° with the surfaces of the air-floating plates 214a, 214b, and 214c.

[0053] In the present invention, by adjusting the angles of the outlets 215a, 215b, 215b', 215c and 215c' to satisfy the above range, the electrode substrate can be moved by the jetted air with less energy.

[0054] In addition, the air floating plates 214a, 214b, and 214c include outlets 215a, 215b, 215b', 215c, and 215c' that blow air onto the surface on which the electrode substrate runs, and may include vacuum suction holes 117 at positions adjacent to the outlets 215a, 215b, 215b', 215c, and 215c' that re-suck in the air blown out through the outlets.

[0055] The air floating plates 214a, 214b and 214c may be provided with vacuum suction holes 117 for re-sucking the sprayed air, without any particular limitation, as long as they are located adjacent to the outlets provided on the surface. Specifically, as shown in FIG. 5, the vacuum suction holes 117 may be provided between region C where the coated portion of the electrode substrate 1 runs and region S where the uncoated portion of the electrode substrate runs; or rows of outlets and rows of vacuum suction holes 117 may be provided alternately in the direction D in which the electrode substrate 1 runs.

[0056] The vacuum suction hole 142 is for stably transporting the dried electrode substrate 1 and is located adjacent to the discharge ports 215a, 215b, 215b', 215c and 215c' to facilitate the exhaust of air, thereby minimizing the bending phenomenon of the electrode substrate 1 and easily adjusting the fluctuation, floating flatness and height.

[0057] In addition, since the floating part 210 can be replaced by separating the air floating plates 214a, 214b, and 214c, it is possible to apply air floating plates with an average diameter and number of outlets adjusted according to the specifications of the electrode to be manufactured.

[0058] In this case, the air floating plates 214a, 214b and 214c may have a structure in which outlet ports having an average diameter, number per unit area and / or porosity controlled by the coated and uncoated parts of the electrode substrate 1 are provided on one plate-shaped substrate as shown in Figs. 3 to 5.

[0059] 6 to 7, the air-floating plates 214a, 214b, and 214c can have a structure in which a plurality of rod-shaped substrates can be assembled according to the positions of the coated and uncoated portions of the electrode substrate 1. In this case, the air-floating plates are highly processable and easy to assemble, which has the advantage of improving the freedom and responsiveness in terms of the design of the electrode substrate.

[0060] Meanwhile, the transfer unit 200 includes a running unit 220 as a means for moving the electrode substrate 1 levitated by the floating unit 210. The running unit 220 is not particularly limited as long as it can move the levitated electrode substrate 1, and specifically, it may include a tilting machine that tilts the air floating plates 214a, 214b, and 214c; or conveyors that are disposed at the upper and lower ends of the floating unit 210 and slide the electrode substrate 1 in the traveling direction D.

[0061] Here, the tilting machine is a device that tilts and inclines the air-floating plates 214a, 214b, and 214c, thereby allowing the levitated electrode substrate 1 to move in the tilted direction, and a tilting frame is located on the other side of the surface of the air-floating plates 214a, 214b, and 214c on which the electrode substrate 1 travels, so that the air-floating plates 214a, 214b, and 214c can be set up so as to be tilted.

[0062] The tilting machine is a device that applies an external force so that the electrode substrate 1 levitated by the air floating plates 214a, 214b, and 214c moves at an appropriate speed according to gravity and a tilt angle, and the tilt angle realized by the tilting machine may be 1 to 20°, more specifically, 1 to 15°; 1 to 10°; 5 to 15°; 8 to 12°; or 3 to 8°.

[0063] In addition, the conveyor may be disposed at the upper and lower ends of the floating part 210 to move the electrode substrate 1, and the conveyor may include at least one of a belt conveyor type and / or a roller type.

[0064] Specifically, FIG. 8 is a perspective view illustrating the transfer unit 200 when a conveyor is provided as the running unit 220. Referring to FIG. 8, the conveyor may include a first conveyor 221 located at the upper end of the floating unit 210 and a second conveyor 222 located at the lower end of the floating unit, and the first conveyor 221 and the second conveyor 222 are formed to be flush with the air floating plate 214 of the floating unit 210, thereby preventing snagging during the movement of the electrode substrate 1.

[0065] Optionally, the conveying unit 200 may further include an unwinder (not shown) which supplies the electrode substrate 1 to the drying unit 100, and a winder (not shown) which winds up the electrode substrate after passing through the drying unit. The unwinder may supply the electrode substrate 1 to the drying unit and thereby move the electrode substrate 1 by applying a pushing force in the running direction D, and the winder may move the dried electrode substrate 1 by applying a pulling force in the running direction D. For this purpose, the unwinder may be located at an upper end of the drying unit 100, and the winder may be located at a lower end of the floating unit 210.

[0066] The drying apparatus 10 for manufacturing an electrode according to the present invention has the above-mentioned configuration, and therefore can improve the thermal expansion difference of the electrode substrate 1 dried at high temperature, thereby preventing wrinkles and / or folding problems induced in the uncoated portion of the electrode substrate. In addition, the floating part 210 can be replaced with an air floating plate 214 in which the average diameter and / or the number per unit area of ​​the outlets 215 is controlled according to the specifications of the electrode to be manufactured, which is advantageous in terms of excellent processability.

[0067] <Electrode manufacturing method> In one embodiment, the present invention further comprises: Drying the electrode substrate having the electrode slurry applied to at least one surface of the electrode substrate at a high temperature; and The present invention provides a method for manufacturing an electrode, comprising the step of levitating and transporting an electrode substrate that has been dried at a high temperature using air.

[0068] The method for manufacturing an electrode according to the present invention includes the steps of applying an electrode slurry to at least one surface of an electrode substrate to form an electrode mixture layer, drying the electrode substrate coated with the electrode slurry at a high temperature, and levitating and transporting the dried electrode substrate using air, and may be performed using the drying apparatus for manufacturing an electrode according to the present invention described above.

[0069] Specifically, in the step of drying the electrode substrate, when the electrode substrate (or electrode collector) having the surface coated with the electrode slurry containing one or more electrode active materials through a coater is introduced into the drying section of the drying device, the electrode slurry coated on the electrode substrate has the solvent removed by a plurality of heating elements provided in the drying section, and is hardened to form an electrode composite layer. At this time, the temperature inside the drying section due to the radiant heat of the heating elements may be specifically adjusted to 120°C to 150°C.

[0070] In addition, the step of transporting the dried electrode substrate may be performed by a transport unit connected to the outlet of the drying unit. Specifically, the dried electrode substrate exits through the outlet of the drying unit and enters the transport unit connected to the outlet. The electrode substrate that has entered is floated by the air floating plate of the transport unit and moves in the traveling direction in the floated state. Here, the air floating plate includes an outlet that ejects air onto the surface of the electrode substrate in the traveling direction, and the air ejected through the outlet may satisfy a specific range of pressure and / or temperature to float the dried electrode substrate and improve the wrinkling and / or folding phenomenon that occurs in the non-coated portion of the electrode substrate due to the electrode slurry heated to a high temperature.

[0071] Specifically, the pressure of the air ejected through the outlet may be adjusted to 0.01 MPa to 0.5 MPa, more specifically, 0.01 MPa to 0.4 MPa; 0.01 MPa to 0.3 MPa; 0.01 MPa to 0.2 MPa; 0.01 MPa to 0.1 MPa; 0.05 MPa to 0.2 MPa; 0.1 MPa to 0.5 MPa; 0.2 MPa to 0.4 MPa; 0.01 MPa to 0.09 MPa; or 0.05 MPa to 0.09 MPa.

[0072] As one example, when the entire surface of the air floating plate includes outlets, the pressure of the air ejected from the area where the coated portion of the electrode substrate runs may be 0.05 MPa to 0.4 MPa or 0.1 MPa to 0.15 MPa, and the pressure of the air ejected from the area where the uncoated portion of the electrode substrate runs may be 0.01 MPa to 0.2 MPa or 0.04 MPa to 0.07 MPa.

[0073] In addition, the temperature of the air discharged through the outlet may be adjusted to -10 to 30°C, specifically, -10 to 20°C; -10 to 10°C; -10 to 5°C; 0 to 30°C; 5 to 20°C; or 10 to 20°C.

[0074] As one example, when the entire surface of the air floating plate includes outlets, the temperature of the air ejected from the area where the coated portion of the electrode substrate runs may be 10 to 20°C, and the temperature of the air ejected from the area where the uncoated portion of the electrode substrate runs may be -5 to 5°C.

[0075] In the present invention, the pressure and temperature of the air ejected from the outlet of the air floating plate are adjusted within the above-mentioned ranges, so that the dried electrode substrate can be stably floated, and the high-temperature electrode slurry can rapidly harden the structure of the electrode substrate in the uncoated area, thereby reducing the thermal expansion difference with the coated area.

[0076] In addition, in the step of transporting the dried electrode substrate, the transport speed of the electrode substrate can be appropriately controlled to stably transport the electrode substrate in a levitated state. To this end, the transport speed of the electrode substrate can be adjusted to 1 mm / s to 20 mm / s, specifically, 5 mm / s to 15 mm / s; or 8 mm / s to 12 mm / s.

[0077] The manufacturing method of an electrode according to the present invention has the above-mentioned configuration, and therefore, can improve the thermal expansion difference of an electrode substrate dried at a high temperature, thereby preventing wrinkles and / or folding problems induced in the uncoated portion of the electrode substrate.

[0078] The present invention will now be described in more detail with reference to examples and experimental examples.

[0079] However, the following examples and experimental examples are merely illustrative of the present invention, and the aspects of the present invention are not limited to the following examples and experimental examples.

[0080] <Experimental Example> In order to evaluate the performance of the drying device for electrode production according to the present invention, the following experiment was carried out.

[0081] Specifically, a steel plate measuring 1500 cm wide x 600 cm long x 0.6 cm thick was prepared, and an air floating plate was produced by forming outlet ports having the average diameter and number per unit area shown in Table 1 on the surface of the steel plate.

[0082] Separately, a first roller-type conveyor, a floating part, and a second roller-type conveyor were connected to the outlet of a drying part, the internal temperature of which was about 130°C by a halogen lamp, and the air floating plate manufactured as described above was attached to the upper part of the floating part, thereby preparing a drying apparatus for manufacturing electrodes. At this time, the floating part has a structure in which a gasket 212, an air floating filter 213, and an air floating plate 214 are sequentially stacked on a lower table 211 having an air supply hole 211a, as shown in FIG. 2, and an air supply part 216 is connected to the air supply hole 211a of the lower table 211 to supply air to the air floating plate 214.

[0083] [Table 1]

[0084] The electrode substrate coated with the electrode slurry was dried and transported (transport speed: approximately 11 mm / s) using the prepared drying device for electrode manufacturing, and the temperature of the air ejected from the air floating plate was adjusted to 20°C in the area where the coated part of the electrode substrate ran, and 10°C in the area where the uncoated part of the electrode substrate ran. In addition, the degree of floating of each electrode and the presence or absence of wrinkles and / or folds in the uncoated part of the electrode substrate were confirmed. The evaluation criteria were as follows, and the results are shown in Table 2 below: (1) Evaluation of the presence or absence of floating of the electrode substrate: -○: The electrode substrate is stably levitated - △: The electrode substrate is lifted, but the shaking is so severe that it is not suitable for the process. -x: The electrode substrate is not lifted at all (2) Presence or absence of wrinkles / folds in the plain area of ​​the electrode substrate -○: The area of ​​the plain area where wrinkles / folds occurred is less than 5% of the total area - △: The area of ​​the plain area where wrinkles / folds occurred is 5% to less than 50% of the total area - ×: The area of ​​the plain area where wrinkles / folds occurred is 50% or more of the total area

[0085] [Table 2]

[0086] As shown in Table 2 above, the drying apparatus for manufacturing an electrode according to the present invention can not only safely move an electrode substrate dried at a high temperature by suspending it in air, but also reduce the thermal expansion difference between the coated portion and the uncoated portion of the electrode substrate caused by high-temperature drying, thereby showing an excellent effect of improving the wrinkling and / or folding phenomenon of the uncoated portion.

[0087] From these results, it can be seen that the drying apparatus for manufacturing an electrode according to the present invention not only can stably lift and move the electrode substrate coated with electrode slurry after drying it at a high temperature, but also can prevent the wrinkling and / or folding phenomenon of the uncoated portion caused by the difference in thermal expansion between the coated portion and the uncoated portion of the electrode substrate during movement without damaging the coated portion, thereby exhibiting excellent processability.

[0088] Although the present invention has been described above with reference to preferred embodiments, it will be understood that a person skilled in the art or having ordinary knowledge in the art can make various modifications and variations to the present invention without departing from the spirit and technical scope of the present invention as described in the claims below.

[0089] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims. [Explanation of symbols]

[0090] 1: Electrode base material 10:Drying equipment for electrode production 100:Drying section 110: Exit of drying section 200:Transfer section 210: Floating section 211: Lower table 211a: Air supply hole 212: Gasket 213: Air floating filter 213a: Micropore 214, 214a, 214b, 214c: Air floating plate 215, 215a, 215b, 215b', 215c: Air floating plate outlet 216: Air supply unit 217: Air intake hole 220: Running part 221: First conveyor 222: Second conveyor D: Electrode running direction S: Coating area of ​​electrode substrate C: Uncoated running area of ​​electrode substrate

Claims

1. a drying unit for drying the coating portion of the electrode substrate having at least one surface coated with the electrode slurry and a non-coated portion not coated with the electrode slurry; and a conveying unit coupled to an outlet of the drying unit to convey the dried electrode substrate in a conveying direction; The transport unit includes: A floating portion including an air floating plate that floats the electrode base material by using air; and a running section that runs the levitated electrode base material in a running direction, the air floating plate includes an outlet port for ejecting air onto a surface on which the electrode base material travels, The outlet is included in the entire surface of the air floating plate, or is included only in the area where the coating portion of the electrode base material runs, The discharge port in the region where the coating portion of the electrode substrate runs has an average diameter of 0.005 mm to 10 mm, The pressure of the air ejected from the region where the coating portion of the electrode base material runs is 0.05 MPa to 0.4 MPa; wherein, when the discharge ports are included over the entire surface of the air floating plate, the number of discharge ports per unit area in a region where a coated portion of the electrode substrate runs is 50 to 99% of the number of discharge ports per unit area in a region where an uncoated portion of the electrode substrate runs.

2. 2. The drying apparatus for manufacturing an electrode according to claim 1, wherein the discharge ports are included on an entire surface of the air floating plate, and the discharge ports in a region where a coated portion of the electrode substrate runs have an average diameter that is 50 to 99% of that of the discharge ports in a region where an uncoated portion of the electrode substrate where the electrode slurry is not applied runs.

3. 2. The drying device for electrode production according to claim 1, wherein the discharge port is provided so as to form an inclination angle of 30° to 80° with respect to the surface of the air floating plate in the running direction of the electrode base material.

4. 2. The drying apparatus according to claim 1, wherein the air floating plate includes a vacuum suction hole adjacent to the outlet for sucking in the air ejected from the air outlet.

5. The running part is A tilting machine for tilting the air floating plate; or 2. The drying apparatus for manufacturing an electrode according to claim 1, further comprising conveyors disposed at upper and lower ends of the floating section, respectively, for sliding the electrode base material in a traveling direction.

6. drying the electrode substrate having the electrode slurry applied to at least one surface of the electrode substrate; and and transporting the dried electrode substrate by levitating it using air; The electrode substrate is floated by air ejected from an outlet provided in an air floating plate, the air floating plate includes an outlet port for ejecting air onto a surface on which the electrode base material travels, The outlet is included in the entire surface of the air floating plate, or is included only in the area where the coating portion of the electrode base material runs, The discharge port in the region where the coating portion of the electrode substrate runs has an average diameter of 0.005 mm to 10 mm, The pressure of the air ejected from the region where the coating portion of the electrode base material runs is 0.05 MPa to 0.4 MPa; when the discharge ports are included over the entire surface of the air floating plate, the number of discharge ports per unit area in a region where a coated portion of the electrode substrate runs is 50 to 99% of the number of discharge ports per unit area in a region where an uncoated portion of the electrode substrate runs.

7. The entire surface of the air floating plate includes the outlet port, 7. The method for producing an electrode according to claim 6, wherein the pressure of the air ejected from the region where the uncoated portion of the electrode base material runs is 0.01 MPa to 0.2 MPa.

8. The method of claim 6, wherein the air used in the step of transporting the electrode substrate has a temperature of -10 to 30°C.

9. The method of claim 6, wherein the step of transporting the electrode substrate is performed at a transport speed of 1 mm / s to 20 mm / s.

Images