Electrode sheet drying device that can prevent heat wrinkles on non-coated areas

Abstract

The present invention relates to an electrode sheet drying device capable of preventing thermal wrinkles in uncoated portions, and relates to a device for drying an electrode sheet including a pair of coating portions in which an electrode active material is coated on one side of a metal foil, and an uncoated portion located between the pair of coating portions and not coated with the electrode active material. The electrode sheet drying device includes a rectangular chamber that is a space for drying the electrode sheet, a heating means provided above the chamber and that adjusts the temperature inside the chamber to a temperature for drying the electrode sheet, and one or more guide rolls that guide movement of the electrode sheet inside the chamber and maintain tension of the electrode sheet, wherein a portion of the electrode sheet moves while being spaced apart from the guide rolls by a predetermined distance.

Description

[Technical field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0153675 dated November 10, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an electrode sheet drying device capable of preventing thermal wrinkles in uncoated areas, and more particularly to an electrode sheet drying device capable of preventing thermal wrinkles in uncoated areas by separating a guide roll and the uncoated areas by a predetermined distance and by selectively cooling the uncoated areas so as to prevent the phenomenon of thermal wrinkles occurring in the uncoated areas when drying an electrode sheet. [Background technology]

[0003] As technological development and demand for mobile devices such as smartphones, notebook PCs, and digital cameras increases, there has been active research into technologies related to rechargeable secondary batteries. Secondary batteries are an alternative energy source to fossil fuels, which generate air pollutants, and are used in electric vehicles (EVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (P-HEVs), and energy storage devices (ESSs).

[0004] Currently widely used types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries.

[0005] Such secondary batteries are generally formed by housing an electrode assembly, an electrolyte, and the like in a battery case.

[0006] Here, the electrode assembly is generally made up of a jelly roll type electrode assembly having a structure in which a separator is interposed between long sheet-like positive and negative electrodes and then wound up; a stack type electrode assembly having a structure in which rectangular positive and negative electrodes are stacked with a separator interposed therebetween; a stack-folding type electrode assembly in which a unit cell is wound up with a long separator film; or a lamination-stack type electrode assembly in which battery cells are stacked with a separator interposed therebetween and attached to each other.

[0007] In addition to the commonly used liquid electrolyte, the electrolyte may be replaced with a solid electrolyte or a gel-like quasi-solid electrolyte having an intermediate form between a liquid and a solid by adding an additive to the solid electrolyte.

[0008] The electrode assembly as described above is housed in a battery case. Depending on the type of battery case, the battery case can be classified into a cylindrical battery or a prismatic battery in which the electrode assembly is housed in a cylindrical or prismatic metal can, and a pouch battery in which the electrode assembly is housed in a pouch-type case made of an aluminum laminate sheet.

[0009] Meanwhile, in a method for manufacturing an electrode for such a secondary battery, a slurry prepared by dispersing an active material, a conductive material, a binder, etc. in a solvent is applied onto an electrode current collector, followed by drying.

[0010] Here, as a method for drying the electrodes, there is a method in which the sheet-like electrodes are wound on a roll and then placed in a drying device to dry them. However, in this case, the electrodes are dried in a stacked state, which causes a problem of difference in the degree of dryness between the inside and the outside.

[0011] FIG. 1 is a front view showing the schematic structure of a conventional electrode drying device, and FIG. 2 is a diagram showing the state of the uncoated area before (a) and after (b) the electrode sheet is inserted into a chamber when using the conventional electrode drying device.

[0012] As shown in FIG. 1, a conventional electrode drying device includes an open chamber 11, a heating means 12, and a guide roll 13, and dries an electrode sheet 20 passing through the inside.

[0013] Such an apparatus has the advantage that the electrode sheet 20 can be dried uniformly. However, since the entire electrode sheet 20 is heated, heat wrinkles may occur in the uncoated areas, i.e., areas where the electrode current collector is exposed because no active material is applied, as shown in FIG. 2(b).

[0014] The reason for the occurrence of such heat wrinkles is that when the electrode sheet enters the chamber maintained at a relatively high temperature, the rigidity of the electrode current collector using metal foil decreases. In particular, the temperature of the uncoated area where there is no active material becomes relatively higher than that of the area where the active material is applied, resulting in the occurrence of wrinkles intensively in the uncoated area.

[0015] Meanwhile, as a method for suppressing the occurrence of such heat wrinkles, Patent Document 1 discloses an electrode drying device that includes an air conditioner that cools the outside air near the outlet from which the electrode sheet of the chamber is discharged, and a cold air discharge nozzle that blows the cooled air onto the uncoated area.

[0016] However, the device in Patent Document 1 supplies cold air to the plain areas where heat wrinkles have already occurred inside the high-temperature chamber, which has the advantage of allowing cooling to be performed a little faster than natural cooling outside the chamber, but has the problem of not being able to fundamentally prevent the occurrence of heat wrinkles. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] Korean Patent No. 1810146 Summary of the Invention [Problem to be solved by the invention]

[0018] In order to solve the above problems, an object of the present invention is to provide an electrode sheet drying device capable of preventing heat wrinkles occurring in non-coated areas when drying an electrode sheet. [Means for solving the problem]

[0019] In order to achieve the above object, the electrode sheet drying apparatus according to the present invention is an apparatus for drying an electrode sheet (S) including a pair of coating parts (Sc) in which an electrode active material is applied to one side of a metal foil, and a non-coating part (Sn) located between the pair of coating parts (Sc) and not coated with an electrode active material, the apparatus comprising: a rectangular chamber (100) which is a space for drying the electrode sheet (S); a heating means (200) provided above the chamber (100) for adjusting the temperature inside the chamber (100) to a temperature for drying the electrode sheet (S); and one or more guide rolls (300) for guiding the movement of the electrode sheet (S) inside the chamber (100) and maintaining the tension of the electrode sheet (S), wherein a portion of the electrode sheet (S) moves while being spaced a predetermined distance from the guide rolls (300).

[0020] In the electrode sheet drying device according to the present invention, the guide roll (300) is cylindrical and is characterized in that it is provided with a first groove portion (310) having a predetermined depth and width along the circumferential surface.

[0021] In the electrode sheet drying device according to the present invention, the first groove portion (310) is located at the center based on the longitudinal direction of the guide roll (300).

[0022] In the electrode sheet drying device according to the present invention, a non-coated portion (Sn) is located above the first groove portion (310) in a spaced relationship therewith.

[0023] In addition, in the electrode sheet drying device according to the present invention, the boundary between the coated portion (Sc) and the uncoated portion (Sn), and the uncoated portion (Sn) are located above the first groove portion (310).

[0024] In the electrode sheet drying device according to the present invention, the first groove portion (310) further includes a second groove portion (320) having a predetermined depth and width.

[0025] In addition, in the electrode sheet drying device according to the present invention, a cooling pipe (330) arranged in a direction perpendicular to the central axis of the guide roll (300) is positioned in the second groove portion (320).

[0026] In the electrode sheet drying apparatus according to the present invention, the non-coated portion (Sn) is located away from the cooling pipe (330).

[0027] In the electrode sheet drying device according to the present invention, both ends of the cooling pipe (330) are located outside the chamber (100).

[0028] In the electrode sheet drying device according to the present invention, the heating means (200) is any one of an infrared lamp, a heating coil, and a hot air blower. Effect of the Invention

[0029] According to the electrode sheet drying device of the present invention capable of preventing thermal wrinkles in the uncoated portion, by providing a groove portion in the guide roll, the guide roll is separated from the uncoated portion of the electrode sheet by a predetermined distance, which has the advantage of reducing the occurrence of thermal wrinkles in the uncoated portion.

[0030] In addition, according to the electrode sheet drying device capable of preventing thermal wrinkles in the non-coated portion of the present invention, since a cooling means is provided under the non-coated portion, it has the advantage that the occurrence of thermal wrinkles in the non-coated portion during the drying process can be minimized. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a front view illustrating a schematic structure of a conventional electrode sheet drying device. [Diagram 2] 1A and 1B are diagrams showing the state of a non-coated portion of an electrode sheet before (a) and after (b) the electrode sheet is placed in a chamber in a conventional electrode sheet drying device. [Diagram 3] 1 is a perspective view showing a schematic structure of an electrode sheet drying device according to an embodiment of the present invention; [Figure 4] 1 is a front view showing a schematic structure of an electrode sheet drying device according to an embodiment of the present invention; [Diagram 5] FIG. 4 is a cross-sectional view taken along the line BB' in FIG. 3, illustrating the structure of the guide roll. [Figure 6] FIG. 11 is a cross-sectional view showing a modified example of the guide roll. [Figure 7] FIG. 4 is a cross-sectional view taken along line AA' in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] In this application, the terms "comprise", "have", "include" and the like are intended to specify the presence of features, numbers, steps, components, parts or combinations thereof described in the specification, but should 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.

[0033] In addition, the same reference numerals are used throughout the drawings for parts having similar functions and actions. Throughout the specification, when a part is said to be connected to another part, this includes not only the case where the part is directly connected to another part, but also the case where the part is indirectly connected via another element between the two parts. In addition, when a part includes a certain component, it does not mean that the other component is excluded, but that the part may further include the other component, unless otherwise specified.

[0034] Hereinafter, an electrode sheet drying device according to the present invention will be described with reference to the accompanying drawings.

[0035] FIG. 3 is an oblique view showing the structure of an electrode drying device according to one embodiment of the present invention, FIG. 4 is a front view showing the structure of an electrode drying device according to one embodiment of the present invention, and FIG. 5 is a cross-sectional view taken along line B-B' in FIG. 3, and is a diagram for explaining the structure of the guide roll.

[0036] The electrode sheet drying apparatus 1000 of the present invention will be described with reference to Figures 3 to 5. The electrode sheet drying apparatus 1000 is an apparatus for continuously drying a long sheet-like electrode, i.e., an electrode sheet S, and includes a chamber 100, a heating means 200, a guide roll 300, and a cooling means 400.

[0037] First, the electrode sheet S to be dried is composed of a coated portion Sc where an electrode active material is applied to one side of a metal foil, and a non-coated portion Sn where no electrode active material is applied.

[0038] Here, the coating portion Sc may be a pair separated by a predetermined distance. Here, the uncoated portion Sn is located between the pair of coating portions Sc. Although the drawings show the coating portion Sc formed on only one side of the metal foil, it is clear that the coating portion may be provided on both sides.

[0039] Meanwhile, electrode active materials can be divided into positive and negative active materials. A conductive material and a binder are added to the active material to prepare a slurry, which is then applied to the surface of a metal foil.

[0040] The positive electrode active material is a layered compound such as lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), or a compound substituted with one or more transition metals; the chemical formula is Li 1+x Mn 2-xLithium manganese oxides such as LiMnO4 (where x is 0 to 0.33), LiMnO3, LiMn2O3, and LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxides such as LiV3O8, LiV3O4, V2O5, and Cu2V2O7; and the chemical formula LiNi 1-x Ni-site type lithium nickel oxide represented by MxO2 (where M=Co, Mn, Al, Cu, Fe, Mg, B or Ga, and x=0.01-0.3); chemical formula LiMn 2-x M x Examples of the lithium manganese composite oxides include, but are not limited to, lithium manganese oxides represented by the formula LiMn2O2 (wherein M is Co, Ni, Fe, Cr, Zn, or Ta, and x is 0.01 to 0.1) or Li2Mn3MO8 (wherein M is Fe, Co, Ni, Cu, or Zn); LiMn2O4 in which part of the Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; and Fe2(MoO4)3.

[0041] The conductive material is usually added in an amount of 1 to 30% by weight based on the total weight of the mixture including the positive electrode active material.

[0042] Such a conductive material is not particularly limited as long as it is conductive while not causing a chemical change in the battery, and examples that can be used include graphite such as natural graphite and artificial graphite; carbon black such as carbon black, acetylene black, ketjen black, channel black, fanace black, lamp black, and thermal black; conductive fibers such as carbon fiber and metal fiber; metal powders such as carbon fluoride, aluminum, and nickel powder; conductive whiskers such as zinc oxide and potassium titanate; conductive metal oxides such as titanium oxide; and conductive materials such as polyphenylene derivatives.

[0043] The binder is a component that promotes the binding of active materials and conductive materials, etc., and the binding to the current collector, and is usually added in an amount of 1 wt% to 30 wt% based on the total weight of the mixture containing the positive electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, various copolymers, and the like.

[0044] In addition, as the negative electrode active material, for example, carbon such as graphitizable carbon and graphite-based carbon; Li x Fe2O3(0≦x≦1), Li x WO2(0≦x≦1), Sn x Me 1-x Me’ y O z (Me: Mn, Fe, Pb, Ge; Me’: Al, B, P, Si, Group 1, Group 2, and Group 3 elements of the periodic table, halogen; 0 < x ≦ 1; 1 ≦ y ≦ 3; 1 ≦ z ≦ 8) and other metal composite oxides; lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Si-based materials that are Si, SiO, SiO2 alone or a mixture thereof, etc. can be used, but are not limited thereto.

[0045] In addition, the negative electrode active material can also be selectively further included with the above-described conductive material, binder, etc. for production.

[0046] The chamber 100 is for housing the electrode sheet S composed of the coated portion Sc coated with the electrode active material as described above and the uncoated portion Sn without the electrode active material and drying the coated portion Sc, and can have a rectangular structure.

[0047] Specifically, the inside is hollow, with parts of the front and rear surfaces open so that the electrode sheet S can be continuously supplied and discharged, and the remaining surfaces, i.e., the bottom surface, top surface, and a pair of side surfaces, are sealed.

[0048] Therefore, it is possible to maintain the internal temperature within a predetermined range and to prevent foreign matter from entering from the outside.

[0049] The heating means 200 is configured to maintain the internal temperature of the chamber 100 within a predetermined range. Specifically, the heating means 200 maintains the internal temperature of the chamber 100 within a predetermined range so as to dry the coating portion Sc of the electrode sheet S. Although the heating means 200 is shown in the drawings as being provided on the upper inside of the chamber 100, it is clear that the heating means 200 may also be provided on the side.

[0050] The heating means 200 for performing the above-mentioned functions may be any of various known heat sources, such as heat, hot air, or a light source, capable of heating the inside of the chamber 100 or the electrode sheet S and maintaining the heated temperature constant. For example, any one or a combination of two or more of an infrared lamp, a heating coil, or a hot air blower may be used.

[0051] Next, the guide roll 300 is positioned inside the chamber 100, including near the entrance and exit of the chamber 100, to guide the movement of the electrode sheet S and maintain a constant tension so that the electrode sheet S being dried in the chamber 100 does not sag.

[0052] As described above, the guide roll 300 supports the electrode sheet S so that the entire electrode sheet S has a constant tension, regardless of the division between the coated portion Sc and the uncoated portion Sn of the electrode sheet S. Therefore, in the chamber 100 heated to a predetermined temperature, the uncoated portion Sn of the electrode sheet S, which is not coated with an active material, stretches relatively greatly and thus wrinkles are generated.

[0053] However, the guide roll 300 located inside the chamber 100 of the present invention is cylindrical and has a first groove portion 310 having a predetermined depth and width along its circumferential surface, thereby minimizing the occurrence of wrinkles in the non-coated portion Sn.

[0054] Specifically, the inside of the chamber 100 is maintained at a temperature in the range of about 100 to 200°C to dry the coating portion Sc, and the guide roll 300 is made of a heat-resistant metal or ceramic material and is in a high-temperature state. Therefore, when the uncoated portion Sn, which is not coated with the active material, comes into close contact with the guide roll 300, it is relatively more likely to stretch than the coating portion Sc, causing wrinkles.

[0055] However, in the present invention, the first groove portion 310 is located at the center based on the longitudinal direction of the guide roll 300, so the coated portion Sc is transported in a closely contacted state, while the uncoated portion Sn, where wrinkles are likely to occur, is separated. As a result, the transfer of hot air from the guide roll 300 to the uncoated portion Sn can be reduced, thereby reducing the occurrence of wrinkles in the uncoated portion Sn.

[0056] Here, it is most preferable that the entire area of ​​the uncoated portion Sn is located above the first groove portion 310 and is not in close contact with the guide roll 300, but the boundary between the coating portion Sc and the uncoated portion Sn may be located above the first groove portion 310.

[0057] Further, the depth of the first groove portion 310 is not particularly limited, but it is preferable that it is deep enough so that the uncoated portion Sn does not come into contact with it.

[0058] 6 is a diagram showing a modified example of the guide roll. As shown in FIG. 6, in the modified example of the guide roll 300, the first groove portion 310 may further include a second groove portion 320 having a predetermined depth and width. Here, a cooling pipe 330 arranged in a direction perpendicular to the central axis of the guide roll 300 is located in the second groove portion 320.

[0059] Although the uncoated portion Sn is positioned vertically above the first groove portion 310 of the guide roll 300 and does not come into direct contact with the first groove portion 310, wrinkles may occur because the inside of the chamber 100 is at a relatively high temperature.

[0060] However, in this modification, the cooling pipe 330 in which a low-temperature refrigerant circulates is provided in the second groove portion 320, so that the temperature of the non-coated portion Sn can be prevented from increasing.

[0061] Here, the cooling pipe 330 and the uncoated portion Sn are slightly spaced apart, and the cooling pipe 330 extends long along the second groove portion 320 of each guide roll 300, and both ends are connected to a refrigerant circulation supply device (not shown) located outside the chamber 100.

[0062] Fig. 7 is a cross-sectional view taken along line AA' in Fig. 3. Description will be given with reference to Figs. 3 and 4.

[0063] In addition, the electrode sheet drying apparatus 1000 of the present invention further includes a cooling means 400 capable of reliably lowering the temperature of the non-coating portion Sn to minimize elongation.

[0064] Specifically, the cooling means 400 can be provided near the bottom of the electrode sheet drying device 1000 so as to face the back surface of the electrode sheet S on which the coating portion Sc is not formed, and supplies cold air toward the uncoated portion Sn.

[0065] The cooling means 400 may be any of various known cooling means, and may be manufactured in a desired form using an air cooling device, a nozzle for spraying cooling air to a desired position, etc.

[0066] In addition, the cooling means 400 may be configured to continuously supply cold air to the uncoated portion from near the interior entrance of the chamber 100 to near the exit of the chamber 100, i.e., from the time the electrode sheet S enters the interior of the chamber 100 to the time it is discharged to the outside of the chamber 100, to cool the uncoated portion.

[0067] In addition, when the cooling means 400 is a nozzle that sprays cold air, a height adjusting means for adjusting the height of the nozzle may be provided, and a separate cooling air adjusting means may be further provided to adjust the temperature and amount of sprayed air.

[0068] Furthermore, it is also possible to control the cooling means 400 while continuously measuring the temperature of the uncoated portions Sn with a thermometer, for example, a non-contact infrared thermometer, for measuring the temperature of the uncoated portions Sn.

[0069] In this way, when the temperature of the uncoated portion Sn is lowered to a predetermined range, the localized elongation in the uncoated portion Sn can be reduced, and thus the formation of wrinkles can be suppressed.

[0070] On the other hand, as described above, the binder contained in the active material is a component that promotes the bonding between the active material and the conductive material and the like and the bonding to the metal foil.

[0071] However, if the temperature of the metal foil increases during the drying process, the binder distributed on the contact surface with the metal foil may migrate to the inside or top layer (surface) of the coating portion Sc.

[0072] When such a migration phenomenon occurs, the amount of binder remaining on the surface of the foil decreases, which can lead to defects (such as electrode detachment) due to a decrease in the interfacial adhesion between the active material and the metal foil. However, in the present invention, by applying cold air to the uncoated Sn area using the cooling means 400, the temperature of not only the uncoated Sn area but the entire metal foil can be lowered compared to existing devices that do not have the cooling means 400, which has the advantage of suppressing such a migration phenomenon.

[0073] Meanwhile, although not shown in the drawing, the electrode sheet drying device 1000 may further include a humidity adjusting unit for adjusting the humidity in the chamber 100, a temperature sensor for measuring the temperature in the chamber 100, and a control unit for controlling the heating means 200.

[0074] Hereinafter, a method for drying the electrode sheet S using the electrode sheet drying device 1000 of the present invention will be described.

[0075] The drying method according to the present invention includes the steps of: a) inserting the electrode sheet S into a chamber 100 and heating and drying it; and b) cooling the non-coated portion Sn of the electrode sheet S.

[0076] Here, step b) is a step of continuously supplying cold air to the non-coated portion Sn from the bottom of the electrode sheet S until the drying of the electrode sheet S is completed, thereby maintaining the temperature of the non-coated portion Sn at a certain temperature or lower.

[0077] Also, steps a) and b) may be performed simultaneously. Here, performing simultaneously means that when the electrode sheet S enters the chamber 100, the cold air starts to be supplied to the non-coating portion Sn almost at the same time.

[0078] A battery cell can be manufactured including an electrode manufactured by such a drying method, and a battery module or a battery pack can be manufactured using such a battery cell.

[0079] Such a battery module or battery pack can be used as a power source for various devices.

[0080] Although certain parts of the contents of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific techniques are merely preferred embodiments and do not limit the scope of the present invention. Various changes and modifications are possible within the scope of the scope and technical ideas of the present invention, and it goes without saying that such changes and modifications are also included in the scope of the attached claims. [Explanation of symbols]

[0081] 1000 Electrode sheet drying device 100 Chambers 200 Heating means 300 Guide Roll 310 First groove part 320 Second groove part 330 Cooling pipe 400 Cooling means S Electrode Sheet Sc coating section Sn Plain area

Claims

1. An electrode sheet drying device for drying an electrode sheet including a pair of coating parts in which an electrode active material is applied to one surface of a metal foil, and a non-coating part located between the pair of coating parts and not coated with an electrode active material, A rectangular chamber which is a space for drying the electrode sheet; a heating means provided above the chamber and regulating a temperature inside the chamber to a temperature for drying the electrode sheet; one or more guide rolls for guiding movement of the electrode sheet within the chamber and for maintaining tension on the electrode sheet; a portion of the electrode sheet moves in a state spaced apart from the guide roll by a predetermined distance; The guide roll is cylindrical and has a first groove portion having a predetermined depth and width along a peripheral surface thereof, The non-coating portion is positioned above the first groove portion in a spaced-apart state.

2. The electrode sheet drying device according to claim 1 , wherein the first groove portion is located at a center with respect to a longitudinal direction of the guide roll.

3. The electrode sheet drying device according to claim 2 , wherein the uncoated portion and a boundary between the coating portion and the uncoated portion are located above the first groove portion.

4. The electrode sheet drying device according to claim 1 , wherein the first groove portion further includes a second groove portion having a predetermined depth and width.

5. The electrode sheet drying device according to claim 4 , wherein a cooling pipe is positioned in the second groove portion and is arranged in a direction perpendicular to a central axis of the guide roll.

6. The electrode sheet drying apparatus according to claim 5 , wherein the non-coated portion is located apart from the cooling pipe.

7. The electrode sheet drying device according to claim 5 , wherein both ends of the cooling pipe are located outside the chamber.

8. The electrode sheet drying device according to claim 1 , wherein the heating means is any one of an infrared lamp, a heating coil, and a hot air blower.

9. 1. A method for drying an electrode sheet including a pair of coating portions in which an electrode active material is applied to one side of a metal foil, and a non-coating portion located between the pair of coating portions and not coated with an electrode active material, comprising: moving the electrode sheet into the chamber by the guide roll while maintaining tension on the electrode sheet in a state where a portion of the electrode sheet is spaced a predetermined distance from an opposing portion of the guide roll located inside the chamber; heating the metal foil coating in the chamber by a heating means at or above a minimum temperature for drying the electrode sheet; The guide roll has a cylindrical shape and includes a first groove portion extending along a peripheral surface thereof, the electrode sheet moves in a state in which the uncoated portion of the metal foil is spaced upward from the first groove portion of the guide roll.

10. The electrode sheet drying method according to claim 9 , wherein the first groove portion is located at a center with respect to a longitudinal direction of the guide roll.

11. 11. The electrode sheet drying method according to claim 10, wherein the electrode sheet moves in a state in which an uncoated portion of the metal foil and a boundary surface between the coating portion of the metal foil and the uncoated portion of the metal foil are positioned above the first groove portion of the guide roll.

12. The electrode sheet drying method according to claim 9 , wherein the guide roll includes a second groove portion located within the first groove portion and extending to an exposed surface of the guide roll within the first groove portion.

13. the guide roll includes a cooling pipe disposed in the second groove portion and extending in a direction perpendicular to a central axis of the guide roll, The method of claim 12, further comprising the step of cooling an uncoated portion of the metal foil while heating the coated portion of the metal foil.

14. The electrode sheet drying method according to claim 13 , wherein the electrode sheet moves in a state in which an uncoated portion of the metal foil is spaced from the cooling pipe.

15. The method for drying an electrode sheet according to claim 13 , wherein both ends of the cooling pipe are located outside the chamber.

16. The electrode sheet drying method according to claim 9 , wherein the heating means is any one of an infrared lamp, a heating coil, and a hot air blower.

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