Vacuum drying equipment and vacuum drying method for electrodes in roll-to-roll state

Abstract

An apparatus for vacuum drying an electrode in a roll-to-roll state according to the present technology includes: a low-vacuum pumping device configured to pump the vacuum chamber to a low-vacuum level; a medium-high vacuum pumping device connected to the vacuum chamber through a medium-high vacuum pipeline separated from the low-vacuum pipeline and configured to pump the vacuum chamber to a medium-vacuum level or a high-vacuum level; and a control unit connected to the low-vacuum pumping device and the medium-high vacuum pumping device and configured to gradually adjust the vacuum level in the vacuum chamber to dry the electrode.

Description

Technical Field

[0001] The present invention relates to a vacuum drying apparatus and a vacuum drying method for drying an electrode in a roll-to-roll state.

[0002] More specifically, the present invention relates to a vacuum drying apparatus and a vacuum drying method that can improve the wetting performance of an electrode and dry an electrode having a high moisture content by performing evacuation to various vacuum pressures according to set process conditions.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0027817, filed on March 3, 2021, the entire contents of which are incorporated herein by reference as part of this application. Background Art

[0004] With the development of technology and the increasing demand for mobile devices, the demand for secondary batteries has rapidly increased. Among secondary batteries, lithium secondary batteries are widely used as an energy source for various electronic products and various mobile devices due to their high energy density, high operating voltage, and excellent storage and life cycle characteristics.

[0005] A lithium secondary battery is manufactured through the following processes: an electrode process in which a positive electrode active material and a negative electrode active material are respectively coated on a positive electrode conductor foil and a negative electrode conductor foil serving as current collector sheets; an assembly process including slitting, lamination, and encapsulation, where slitting is for forming electrode tabs in an uncoated area where no electrode active material is applied, lamination is for laminating an electrode and a separator to produce an electrode assembly, and encapsulation is for stacking or folding the electrode assembly, encapsulating the electrode assembly in a bag or can, and injecting an electrolyte, etc.; and an activation process in which the assembled battery is charged or discharged to impart battery characteristics.

[0006] In addition, in an electrode manufacturing process or an assembly process, etc., an electrode is conveyed and processed in a so-called roll-to-roll state between an unwinder and a rewinder. Since a paste mixture composed of an active material, a conductive material, an adhesive, etc. is applied to a metal foil serving as a base material, such a rolled electrode sheet has high hygroscopicity. Therefore, it is necessary to remove moisture during the electrode manufacturing process.

[0007] However, when drying an electrode in a rolled state, a temperature difference is generated between the inside and the outside of the roll, making it difficult to dry the electrode uniformly. Therefore, a method of vacuum drying an electrode in a roll-to-roll state has been proposed.

[0008] In addition, recently, there have been electrodes in which it is difficult to exhibit desired battery characteristics due to high formation of moisture in the electrodes according to the composition of the active material, the particle size of the active material constituting the active material, etc. For example, a positive electrode coated with a high-nickel positive electrode material or an electrode having an active material with a small particle size structure, which is proposed to increase the battery capacity and reduce the manufacturing cost, deviates from the desired moisture specification (spec) because it is vulnerable to the external environment and has a high moisture absorption rate in the atmosphere.

[0009] However, conventional electrode vacuum drying equipment dries the electrodes by evacuating the vacuum chamber to a low vacuum level of 1 Torr or higher, and thus has limitations in removing moisture from the electrodes. In particular, in the case of electrodes having a high moisture content as described above, it is difficult to sufficiently remove moisture using such a vacuum drying equipment that performs vacuum drying at a low vacuum level.

[0010] In addition, even if moisture is removed to a certain extent, conventional low vacuum drying equipment is not sufficient to improve the wetting performance of the electrodes. The wetting performance of the electrodes refers to the performance in which, when the electrode assembly is encapsulated in a container and an electrolyte is injected into the container, the electrolyte can easily penetrate into the active material of the electrodes and be impregnated. Since the wetting performance of such electrodes is further improved because the electrolyte is more easily impregnated into the air bubbles inside the electrodes, it is necessary to appropriately form air bubbles so that the electrolyte can be impregnated into the electrodes. However, conventional low vacuum drying equipment has limitations in improving the wetting performance of the electrodes, especially the wetting performance of electrodes having a high moisture content.

[0011] In order to remove moisture from the electrodes and improve the performance of the electrodes, it can be conceived to dry the electrodes by evacuating the vacuum chamber using a medium vacuum device or a high vacuum device. However, due to the structure of the vacuum equipment or pipelines, it is not easy to evacuate the vacuum chamber from a low vacuum level to a medium-high vacuum level through a single pipeline, and its control will also be very complicated. In addition, when the vacuum chamber is directly evacuated to a high vacuum level, so-called vacuum damage in which the electrodes are damaged by the vacuum may occur.

[0012] In addition, when the electrodes are continuously vacuum dried in the vacuum chamber, foreign substances generated from the electrodes may be suspended in the vacuum chamber or remain in the vacuum chamber. When continuous vacuum drying is carried out in the vacuum chamber, the foreign substances may adhere to the electrodes of the electrode roll subsequently introduced into the vacuum chamber, and thus the electrodes will be contaminated in the vacuum chamber.

[0013] Based on this, it is desirable to develop a vacuum drying technology that can remove moisture from the electrodes and improve the wetting performance of the electrodes without causing vacuum damage to the electrodes.

[0014] In addition, it is desirable to develop a vacuum drying technology that can prevent electrode contamination by effectively removing foreign substances from the vacuum chamber.

[0015] [Related Technical Literature]

[0016] [Patent Literature]

[0017] Japanese Patent No. 5984643 (September 6, 2016) Summary of the Invention

[0018] Technical Problem

[0019] The present invention is dedicated to solving the above problems, and aims to provide a device for vacuum-drying electrodes in a roll-to-roll state. Even when the electrodes have a high moisture content, the device can effectively remove moisture from the electrodes while preventing vacuum damage and improving the wetting performance of the electrodes.

[0020] In addition, the present invention aims to provide a device for vacuum-drying electrodes in a roll-to-roll state, which can prevent foreign matter contamination in the vacuum chamber.

[0021] In addition, the present invention aims to provide a method for vacuum-drying electrodes in a roll-to-roll state, which can effectively remove moisture from the electrodes and improve the wetting performance of the electrodes.

[0022] Technical Solution

[0023] To solve the above problems, the device for vacuum-drying electrodes in a roll-to-roll state according to the present invention includes: a vacuum chamber in which the electrodes are arranged in a roll-to-roll state to be dried; a low-vacuum pumping device which is connected to the vacuum chamber through a low-vacuum pipeline and is configured to pump the vacuum chamber to a low-vacuum level; a medium-high vacuum pumping device which is connected to the vacuum chamber through a medium-high vacuum pipeline separated from the low-vacuum pipeline and is configured to pump the vacuum chamber to a medium-vacuum level or a high-vacuum level; and a control unit which is connected to the low-vacuum pumping device and the medium-high vacuum pumping device and is configured to gradually adjust the vacuum level in the vacuum chamber to dry the electrodes.

[0024] As an example, the low-vacuum level may be a vacuum level in the range from 1 Torr to 600 Torr, the medium-vacuum level may be a vacuum level in the range from 10 -2 Torr to less than 1 Torr, and the high-vacuum level may be a vacuum level in the range from 10 -8 Torr to less than 10 -2 Torr.

[0025] As a preferred example, the low-vacuum pipeline and the medium-high vacuum pipeline may be connected to the bottom of the vacuum chamber.

[0026] Specifically, when observing the vacuum chamber from the top, at least one of the low-vacuum pipeline and the medium-high vacuum pipeline can be arranged adjacent to the corner of the vacuum chamber symmetrically up and down, symmetrically left and right, or symmetrically up, down, left, and right.

[0027] As an example, a low-vacuum gauge for measuring the low-vacuum level and a medium-high vacuum gauge for measuring the medium-vacuum level or the high-vacuum level can be installed in the vacuum chamber.

[0028] As a specific example, the low-vacuum pumping device includes: a low-vacuum pump connected to the vacuum chamber through the low-vacuum pipeline; and a low-vacuum switching valve configured to open and close the low-vacuum pipeline.

[0029] As a more specific example, the low-vacuum pump can be a rotary pump or can further include a Roots pump connected to the rotary pump.

[0030] As a specific example, the low-vacuum switching valve can include: an on / off valve installed in the low-vacuum pipeline on one side of the low-vacuum pump; and a multi-stage switching valve installed in the low-vacuum pipeline on the side of the vacuum chamber and configured to adjust the opening degree.

[0031] As a more specific example, the multi-stage switching valve can be one of a servo valve, an SMC two-stage valve, and a throttle valve.

[0032] Specifically, the medium-high vacuum pumping device can include: a medium-high vacuum pump connected to the vacuum chamber through the medium-high vacuum pipeline; and a medium-high vacuum switching valve configured to open and close the medium-high vacuum pipeline.

[0033] As a specific example, the medium-high vacuum pump can include a dry pump and a turbo molecular pump (TMP), and the turbo molecular pump is connected to the dry pump through the medium-high vacuum pipeline and installed in the medium-high vacuum pipeline adjacent to the vacuum chamber.

[0034] As a more specific example, the medium-high vacuum switching valve can include: an on / off valve installed in the medium-high vacuum pipeline on one side of the dry pump; and an adaptive pressure control (APC) valve installed in the medium-high vacuum pipeline between the TMP and the vacuum chamber and configured to adjust the opening degree.

[0035] As an example, the medium-high vacuum pipeline on one side of the dry pump can include a bypass pipeline, a first on / off valve and a second on / off valve can be respectively installed in the bypass pipeline and the medium-high vacuum pipeline on one side of the dry pump, and the first on / off valve and the second on / off valve can be opened sequentially.

[0036] As an example, the control unit can control the low-vacuum pumping device and the medium-high vacuum pumping device to pump the vacuum chamber to a low vacuum level, a medium vacuum level, or a high vacuum level according to the set process conditions, and when pumping the vacuum chamber to the medium vacuum level or the high vacuum level, the control unit can control the low-vacuum pumping device and the medium-high vacuum pumping device to gradually pump the vacuum chamber from the low vacuum level to the medium vacuum level or the high vacuum level.

[0037] As another example, when a predetermined number of electrode rolls are dried in the vacuum chamber in a roll-to-roll state and then removed from the vacuum chamber, the control unit can gradually control the vacuum level to pump the vacuum chamber to a predetermined medium vacuum level or high vacuum level to remove foreign matters in the vacuum chamber.

[0038] As another aspect of the present invention, a method for vacuum drying electrodes in a roll-to-roll state includes the following steps: pumping the vacuum chamber to a low vacuum level according to the set process conditions for vacuum drying the electrodes arranged in the vacuum chamber in a roll-to-roll state; and drying the electrodes in the vacuum chamber at the low vacuum level, and further includes the following steps: after drying a predetermined number of electrode rolls in the vacuum chamber in a roll-to-roll state, in a state where the electrodes are removed from the vacuum chamber, setting the vacuum chamber to a predetermined medium vacuum level or high vacuum level to remove foreign matters in the vacuum chamber.

[0039] Specifically, the predetermined medium vacuum level or high vacuum level can be obtained by pumping the vacuum chamber to a low vacuum level and then gradually pumping from the low vacuum level until reaching the predetermined medium vacuum level or high vacuum level.

[0040] A method for vacuum drying electrodes in a roll-to-roll state according to another embodiment of the present invention includes the following steps: gradually pumping the vacuum chamber from a low vacuum level to a medium vacuum level or a high vacuum level according to the set process conditions for vacuum drying the electrodes arranged in the vacuum chamber in a roll-to-roll state; and drying the electrodes in the vacuum chamber at the medium vacuum level or the high vacuum level.

[0041] As an example, the method may further include the following steps: after drying a predetermined number of electrode rolls in the vacuum chamber in a roll-to-roll state, in a state where the electrodes are removed from the vacuum chamber, setting the vacuum chamber to a predetermined medium vacuum level or high vacuum level to remove foreign matters in the vacuum chamber.

[0042] Beneficial effects

[0043] According to the present invention, moisture can be effectively removed by applying various vacuum pressures while preventing vacuum damage to an electrode having a high moisture content.

[0044] In addition, the wetting performance of the electrode can be further improved.

[0045] According to the present invention, an electrode can be continuously vacuum-dried while preventing foreign matter contamination in a vacuum chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram showing a vacuum drying apparatus according to an embodiment of the present invention.

[0047] Figure 2 including a perspective view and a plan view, which show the Figure 1 connection structure of a vacuum pipeline of the vacuum drying apparatus.

[0048] Figure 3 is a schematic diagram showing an example of a vacuum heating device of a vacuum drying apparatus to which the present invention is applied in order to perform vacuum drying after an electrode is cut.

[0049] Figure 4 is a flowchart showing a vacuum drying method according to an embodiment of the present invention.

[0050] Figure 5 is an overview diagram of the vacuum level showing the change in the vacuum level of a plurality of battery cells over time when vacuum pumping is performed by a pumping device.

[0051] Figure 6 is a flowchart showing a vacuum drying method according to another embodiment of the present invention. DETAILED DESCRIPTION

[0052] Hereinafter, the detailed configuration of the present invention will be described in detail with reference to the drawings and according to several embodiments. To assist in understanding the present invention, the following embodiments are illustratively shown, and the drawings are not drawn to scale to assist in understanding the present invention, and the dimensions of some components may be exaggerated.

[0053] The present invention can be variously modified and have several forms, and the specific embodiments will be shown in the drawings and described in detail below. However, this is not intended to limit the present invention to the specific embodiments, but it should be understood that the present invention encompasses any modifications, equivalents, and substitutions included in the spirit and scope of the present invention.

[0054] The apparatus for vacuum drying an electrode in a roll-to-roll state according to the present invention includes: a vacuum chamber in which the electrode is disposed in a roll-to-roll state to be dried; a low-vacuum pumping device that is connected to the vacuum chamber through a low-vacuum pipeline and configured to pump the vacuum chamber to a low-vacuum level; a medium-high vacuum pumping device that is connected to the vacuum chamber through a medium-high vacuum pipeline separated from the low-vacuum pipeline and configured to pump the vacuum chamber to a medium-vacuum level or a high-vacuum level; and a control unit that is connected to the low-vacuum pumping device and the medium-high vacuum pumping device and configured to gradually adjust the vacuum level in the vacuum chamber to dry the electrode.

[0055] A conventional vacuum drying apparatus for vacuum drying an electrode in a roll-to-roll state heats and dries the electrode at a low-vacuum level of 1 Torr or higher, and thus has limitations in removing moisture from high-moisture electrodes such as electrodes coated with a high-nickel cathode material or electrodes coated with an active material having a small particle size structure, which have recently received attention. In addition, vacuum drying at the low-vacuum level as described above has limitations in improving the bubble-forming ability of the wetting performance.

[0056] To solve this conventional problem, the present invention aims to remove moisture from high-moisture electrodes and improve the wetting performance by including a low-vacuum pumping device configured to pump the vacuum chamber to a low-vacuum level and a medium-high vacuum pumping device connected to the vacuum chamber through a pipeline separated from the low-vacuum pumping device. In addition, by providing a control unit connected to the low-vacuum pumping device and the medium-high vacuum pumping device and configured to gradually adjust the vacuum level in the vacuum chamber to dry the electrode, the vacuum chamber can be quickly pumped to a medium-vacuum degree or a high-vacuum degree, and thus vacuum damage to the electrode in the vacuum chamber can be prevented.

[0057] In addition, the degree of vacuum described herein is also referred to as vacuum pressure (force) and will be expressed in Torr. The magnitude of the vacuum level used during the vacuum drying of the electrodes may be different from the magnitude of the vacuum levels classified in the field of normal vacuum pumping. In one embodiment, a low vacuum level is a vacuum level in the range from 1 Torr to 600 Torr, i.e., a vacuum level of 1 Torr or higher. The low vacuum level is not applied to the high-nickel positive electrode or the electrode having a small particle size structure, but to the vacuum pressure of the electrodes of a conventional lithium secondary battery. Even when vacuum drying a conventional electrode other than the above-mentioned high-moisture electrode at a low vacuum level, moisture can be sufficiently removed from the electrode. However, for example, an electrode in which the nickel content of the positive electrode is increased or an electrode having a small particle size structure in which the particle size of the active material contained in the electrode is fine is vulnerable to the external environment, and thus this electrode has a higher moisture content than a conventional electrode. In order to dry such an electrode having a higher moisture content and improve the wetting performance, it is preferably to evacuate the vacuum chamber to a higher vacuum level. For this purpose, in the present invention, a medium vacuum level of less than 1 Torr is applied, and if necessary, a high vacuum level of less than 10 -2 Torr is also applied. The preferred range of the medium vacuum level applied to the present invention may be from 10 -2 Torr to less than 1 Torr, and the range of the high vacuum level may be, for example, 10 -8 Torr to less than 10 -2 Torr. If necessary, an ultra-high vacuum level of less than 10 -8 Torr may be applied, but this will increase the manufacturing cost of the electrode. Therefore, it is desirable to select the vacuum level in consideration of the available vacuum equipment and manufacturing cost. In addition, as will be described later, according to an embodiment of the present invention, the vacuum chamber may be evacuated to a medium vacuum level or a high vacuum level in order to clean the vacuum chamber in addition to performing vacuum drying. Thus, the range of the medium vacuum level or the high vacuum level for cleaning may be appropriately selected within the above-mentioned range of vacuum levels for efficiency. However, the magnitude of the medium vacuum level or the high vacuum level for the vacuum drying of the electrodes does not have to be the same as the magnitude of the medium vacuum level or the high vacuum level for the vacuum chamber cleaning, and the vacuum level may be determined within the range that can best achieve the respective purposes of vacuum drying and cleaning.

[0058] Detailed description of the preferred embodiment

[0059] Hereinafter, the present invention will be described in more detail with reference to the drawings and specific embodiments of the present disclosure.

[0060] Figure 1 is a schematic diagram showing a vacuum drying apparatus 100 according to an embodiment of the present invention, Figure 2 including a perspective view and a plan view, which show the Figure 1 connection structure of the vacuum pipelines of the vacuum drying apparatus 100.

[0061] The vacuum drying device 100 of the present invention includes a vacuum chamber 10 for drying electrodes in a roll-to-roll state. In Figure 1 and Figure 2 For ease of description, only the vacuum drying device 100 is shown without showing the electrodes. However, the electrodes can be arranged in the vacuum chamber 10 in a roll-to-roll state.

[0062] In order to vacuum-dry the electrodes arranged in the vacuum chamber 10 in a roll-to-roll state, the vacuum drying device 100 of the present invention includes a low-vacuum pumping device 20 connected to the vacuum chamber 10 through a low-vacuum pipeline 21.

[0063] In addition, according to the present invention, the vacuum drying device 100 includes a medium-high vacuum pumping device 30, and the medium-high vacuum pumping device 30 is connected to the vacuum chamber 10 through a medium-high vacuum pipeline 31 separated from the low-vacuum pipeline 21.

[0064] According to the present invention, two types of pumping devices (low-vacuum pumping device and medium-high vacuum pumping device) are connected to the vacuum chamber 10 through separate vacuum pipelines. Considering the simplification of the device, it is desirable to be able to perform pumping from low vacuum to high vacuum using a single pumping pump. However, for example, a turbomolecular pump (TMP: Turbomolecular Pump) used to pump to a high vacuum level has a structure suitable for high-speed rotation due to the structure of the pump device. Therefore, when the pump rotates at a low speed to achieve a low vacuum level, there is a risk of damaging the rotating shaft or pump components. Therefore, it is technically difficult to design a vacuum pump that can perform pumping from a low vacuum level even to a medium vacuum level, let alone to a high vacuum level. In addition, when the low-vacuum pumping device 20 and the medium-high vacuum pumping device 30 are connected to a single pipeline, it is difficult to adjust the vacuum level, and the vacuum control is also very complex. In addition, when the adjustment of the vacuum level fails, the electrodes in the vacuum chamber 10 will be damaged by vacuum due to pumping to a medium vacuum level or a high vacuum level.

[0065] Therefore, according to the present invention, the low-vacuum pumping device 20 and the medium-high vacuum pumping device 30 are connected to the vacuum chamber 10 through separate dedicated pipelines. However, in the case of the medium-high vacuum pumping device 30, a device capable of performing pumping within the range of the medium vacuum level to the high vacuum level defined in the present invention can be adopted. It will be understood that the medium-high vacuum pumping device 30 is divided into a medium vacuum pumping device and a high vacuum pumping device that are respectively connected to the vacuum chamber through separate pipelines. However, in this case, the structure of the vacuum drying device 100 is too complex, resulting in an increase in manufacturing cost and an increase in the complexity of the vacuum control process. In addition, when the vacuum level is gradually increased from the medium vacuum level to the high vacuum level through the medium-high vacuum pumping device 30, vacuum damage to the electrodes can be more effectively prevented.

[0066] Referring to Figure 2 , according to an embodiment of the present invention, the low-vacuum pipeline 21 and the medium-high vacuum pipeline 31 are respectively connected from the bottom of the vacuum chamber 10. When the vacuum pipelines are connected from the side of the vacuum chamber 10, the air flow in the vacuum chamber 10 is concentrated on both sides, which makes the internal air flow unstable, thus causing appearance defects in the manufactured battery. In addition, when the vacuum pipeline is connected to the top of the vacuum chamber 10, the vacuum tube inevitably extends to reach the top of the vacuum chamber 10. In this case, additional devices such as regulators should be installed on the extended pipeline to perform pressure regulation. Therefore, in order to stabilize the air flow in the vacuum chamber 10 and prevent pipeline loss, the vacuum pipelines are connected from the bottom of the vacuum chamber 10, as shown in the perspective view of (a) of Figure 2 .

[0067] Figure 2 The plan view of (b) of Figure 2 is a plan view of the vacuum chamber 10 observed from the top. In this embodiment, when the vacuum chamber 10 is observed from the top, at least one of the low-vacuum pipeline 21 and the medium-high vacuum pipeline 31 is formed in pairs by being symmetrically arranged vertically, horizontally, or vertically and horizontally, and is disposed adjacent to the corner of the vacuum chamber 10. In order to uniformly maintain the vacuum level in the vacuum chamber 10, one or both of the low-vacuum pipeline 21 and the medium-high vacuum pipeline 31 are symmetrically installed in the vacuum chamber 10. Preferably, as shown in (b) of

[0068] When the pipelines are installed adjacent to the corner of the vacuum chamber 10 such that the pipelines are symmetrically arranged vertically and horizontally in the vacuum chamber 10, the vacuum level in the vacuum chamber 10 can become more uniform. In the illustrated embodiment, the medium-high vacuum pipeline 31 is installed outside the low-vacuum pipeline 21. However, the medium-high vacuum pipeline 31 can be installed inside the low-vacuum pipeline 21. Figure 1 And Figure 2 In

[0069] As the low vacuum gauge A, for example, a capacitance manometer (CA) that converts the pressure change movement of a thin film into an electrical signal proportional to the pressure can be used. The CA gauge can measure a wide range from 1 Torr to 1000 Torr, and generates a signal through physical changes in the vacuum gauge rather than changes in the gas characteristics in the chamber. Thus, the CA gauge can measure values independently of the gas composition in the measurement chamber and has the advantage of relatively high accuracy.

[0070] Examples of the medium-high vacuum gauge B may include an ionization vacuum gauge that ionizes gas, amplifies, and measures the ion current. Among the ionization vacuum gauges, the Bayard-Alpert ion gage is preferred, which is suitable for measuring lower vacuum levels by reducing the X-rays generated from the ionization vacuum gauge.

[0071] For ease of description, in Figure 1 and Figure 2 the low vacuum gauge A and the medium-high vacuum gauge B are shown placed in the center of the vacuum chamber. However, in order not to interfere with various devices (unwinder, rewinder, heating device, vacuum components, etc.) installed in the vacuum chamber 10, it will be understood that these vacuum gauges can be installed in the vacuum chamber 10 by coupling members such as brackets or bolt-nut pairs not shown herein.

[0072] The low vacuum pumping device 20 connected to the vacuum chamber 10 of the vacuum drying apparatus 100 of the present invention through the low vacuum pipeline 21 includes: a low vacuum pumping pump connected to the vacuum chamber 10 through the low vacuum pipeline 21; and a low vacuum switching valve configured to open and close the low vacuum pipeline 21.

[0073] As an example of the low vacuum pumping pump 22, a rotary pump that sucks, compresses, and discharges gas by the rotation of blades can be used. As another example, a roots pump connected in series with the rotary pump can be used as an auxiliary pump. The roots pump is a pump that discharges the gas entering the intake port by two rotors rotating in opposite directions. Connecting the roots pump to the rotary pump can increase the discharge speed and prevent contamination caused by the backflow of lubricating oil in the rotary pump. The above-mentioned rotary pump or roots pump is used in the rough vacuum region of the range from 760 Torr to 1 Torr. The rotary pump and the roots pump are commonly used pumps in the field of vacuum technology, and thus their detailed descriptions will be omitted.

[0074] As Figure 1As shown, a low-vacuum switching valve according to an embodiment of the present invention includes: a on / off valve 23 installed in a low-vacuum pipeline 21 on one side of a low-vacuum pumping pump 22; and a multi-stage switching valve 24, the multi-stage switching valve 24 being installed in the low-vacuum pipeline 21 on one side of a vacuum chamber 10 and configured to adjust the opening degree. To evacuate the vacuum chamber 10 to a low-vacuum level, the on / off valve 23 is opened and the multi-stage switching valve 24 in the low-vacuum pipeline 21 installed on one side of the vacuum chamber is opened. In this case, evacuation to a predetermined low-vacuum level can be performed. In the present embodiment, in order to achieve a desired low-vacuum level, a multi-stage switching valve 24 is installed in the low-vacuum pipeline 21 on one side of the vacuum chamber 10 to change and adjust the vacuum level in the vacuum chamber 10 by adjusting the opening degree. For example, as the multi-stage switching valve 24, a servo valve, an SMC two-stage valve, or a throttle valve can be used. A servo valve is a valve that can utilize a servo motor to control the opening position of the valve to adjust the vacuum pressure. An SMC two-stage valve is a two-stage valve using two valves, a large valve and a small valve. The SMC two-stage valve can open and close the small valve to adjust the vacuum pressure within a small range and can open and close the large valve to adjust the vacuum pressure within a large range. A throttle valve is a valve that changes the pressure by adjusting the opening angle of the valve body in the throttle valve body.

[0075] As described above, in the present embodiment, by installing a multi-stage switching valve 24 in the low-vacuum pipeline 21 on one side of the vacuum chamber 10, the vacuum chamber 10 can be gradually evacuated until a desired low-vacuum level is reached. In addition, for example, by adjusting the opening degree of the servo valve, a specific low-vacuum level can be maintained, or the corresponding vacuum level can be changed to another vacuum level.

[0076] After evacuating the vacuum chamber 10 to a predetermined low-vacuum level to dry the electrodes, in order to restore the vacuum chamber 10 to atmospheric pressure, a ventilation pipe 25 and a ventilation valve 26 are installed in the low-vacuum pipeline 21. The ventilation valve 26 can be closed when the on / off valve 23 is opened and can be opened when the on / off valve 23 is closed to restore the pressure in the vacuum chamber 10.

[0077] The vacuum drying apparatus 100 of the present invention includes a medium-high vacuum pumping device 30, and the medium-high vacuum pumping device 30 is connected to the vacuum chamber 10 through a medium-high vacuum pipeline 31 separated from the low-vacuum pipeline 21. Specifically, the medium-high vacuum pumping device 30 includes: a medium-high vacuum pumping pump connected to the vacuum chamber 10 through the medium-high vacuum pipeline 31; and a medium-high vacuum switching valve configured to open and close the medium-high vacuum pipeline.

[0078] In Figure 1 the embodiment, a dry pump 32 and a TMP 37 constitute the medium-high vacuum pumping pump, and the TMP 37 is connected to the dry pump 32 through the medium-high vacuum pipeline 31 and is installed in the medium-high vacuum pipeline 31 adjacent to the vacuum chamber 10.

[0079] The dry pump 32 is a pump that does not use oil to rotate the rotor in the pump. In the present embodiment, in order to prevent vacuum damage from occurring when the vacuum chamber 10 is suddenly evacuated to a high vacuum level and to prevent damage to the TMP components, the dry pump 32 is provided as part of the medium-high vacuum evacuation pump.

[0080] The TMP 37 is a turbomolecular pump that can achieve a vacuum level of 10 -3 Torr (medium vacuum level) and a vacuum level of 10 -10 Torr (ultra-high vacuum level) through the alternating arrangement of a rotating shaft that rotates at high speed and a fixed shaft that is inclined in the opposite direction along the rotating shaft.

[0081] In Figure 1 the embodiment, as the medium-high vacuum switching valve, an on / off valve 33 installed in the medium-high vacuum pipeline 31 on one side of the dry pump 32 and an adaptive pressure control (APC) valve 34 installed in the medium-high vacuum pipeline 31 between the TMP 37 and the vacuum chamber 10 to adjust the opening degree are provided. The APC valve 34 is a valve that can perform fine vacuum control by controlling the opening position and angle of the valve within the range of 1 to 1000 points, and thus is suitable for vacuum control of the medium vacuum level and the high vacuum level.

[0082] Therefore, the medium-high vacuum evacuation device 30 according to the present embodiment can evacuate the vacuum chamber 10 step by step until the desired vacuum level is reached by installing the APC valve 34 in the medium-high vacuum pipeline 31 on the vacuum chamber side. For example, by adjusting the opening degree of the APC valve 34, a specific medium vacuum level or high vacuum level can be maintained, or the corresponding vacuum level can be changed to another vacuum level.

[0083] After evacuating the vacuum chamber 10 to a predetermined medium vacuum level or high vacuum level to dry the electrodes, in order to increase the pressure in the vacuum chamber 10 of the medium-high vacuum evacuation device 30, a vent pipe 35 and a vent valve 36 are installed in the medium-high vacuum pipeline. The vent valve 36 can be closed when the on / off valve 33 is open, and can be opened when the on / off valve 33 is closed to restore the pressure in the vacuum chamber 10.

[0084] In Figure 1In the embodiment, in order to prevent vacuum damage to the electrodes and prevent damage to the TMP components, the medium-high vacuum line 31 on the dry pump 32 side includes a bypass line 31-1. That is, by branching the medium-high vacuum line into two lines, namely, the medium-high vacuum line 31 on the dry pump side and the bypass line 31-1, the low vacuum pressure is prevented from being applied to the TMP 37 all at once. In addition, by installing a first on / off valve 33S and a second on / off valve 33F in the bypass line 31-1 and the medium-high vacuum line 31 on the dry pump side respectively and opening the first on / off valve 33S and the second on / off valve 33F sequentially, the impact on the TMP 37 is minimized. Here, the first on / off valve 33S corresponds to a slow start valve, and the second on / off valve 33F corresponds to a fast start valve.

[0085] As described above, according to the present invention, a low vacuum pumping device 20 and a medium-high vacuum pumping device 30 connected to the vacuum chamber 10 through separate vacuum tubes are provided, and these pumping devices are connected to the control unit 40. By controlling the low vacuum pumping device and the medium-high vacuum pumping device so as to gradually adjust the vacuum level in the vacuum chamber 10 to dry the electrodes, the control unit 40 controls according to the set process conditions to pump the vacuum chamber 10 to a low vacuum level, a medium vacuum level or a high vacuum level without applying vacuum damage to the electrodes. In particular, when pumping the vacuum chamber 10 to a medium vacuum level or a high vacuum level, the control unit 40 of the present invention controls the low vacuum pumping device and the medium-high vacuum pumping device to gradually pump the vacuum chamber 10 from a low vacuum level to a medium vacuum level or a high vacuum level instead of immediately pumping to a medium vacuum level or a high vacuum level.

[0086] In addition, according to the present invention, since a medium-high vacuum pumping device 30 is provided in addition to the low vacuum pumping device 20, the medium-high vacuum pumping device 30 can be used to remove foreign substances in the vacuum chamber 10. When repeating the process of introducing the electrode roll into the vacuum chamber 10 and vacuum drying the electrodes in a roll-to-roll state, foreign substances originating from the electrodes are generated in the vacuum chamber 10. The conventional low vacuum level for vacuum drying the electrodes has limitations in removing foreign substances. When a predetermined number of electrode rolls are dried in the vacuum chamber 10 in a roll-to-roll state and then the electrodes are removed from the vacuum chamber 10, the control unit 40 of the present invention can gradually control the vacuum level to pump the vacuum chamber 10 to a predetermined medium vacuum level or high vacuum level to remove foreign substances in the vacuum chamber 10.

[0087] Figure 3FIG. 0 is a schematic diagram showing an example of a vacuum heating device of the vacuum drying apparatus 100 of the present invention applied for performing vacuum drying after electrode cutting. Even if an electrode of a high-nickel cathode material or an electrode having a small particle size electrode structure is vacuum dried and moisture is removed in a so-called electrode process, since the electrode still contains moisture exceeding a set specification, it is still necessary to remove moisture again after a cutting process which is an assembly process. Figure 3 FIG. shows an example of performing vacuum drying by introducing an electrode into a vacuum chamber 10 after a cutting process. In Figure 3 FIG., not shown Figure 1 and Figure 2 of the vacuum drying apparatus 100 (only the vacuum pipelines 21 and 31 are shown), a specific process of vacuum drying an electrode after a cutting process is shown.

[0088] After a cutting process, an electrode 1 is wound around a core, and an electrode roll 1a in which the electrode is wound around the core is installed in a loader 2a outside the vacuum chamber 10. The electrode roll 1a is installed in an unwinder 2b in the vacuum chamber by a robot (not shown). Subsequently, the electrode roll 1b is unwound from the unwinder 2b, and the electrode 1 is connected to a rewinder 2c installed in the vacuum chamber 10. When such an electrode is set in a roll-to-roll state between the unwinder 2b and the rewinder 2c, the vacuum chamber 10 is evacuated to dry the electrode. When the unwinder 2b and the rewinder 2c are driven, the electrode 1 travels in the vacuum chamber 10 in a roll-to-roll state, and while the tension is adjusted and skewing is prevented by a skew adjustment unit 3 and a tension adjustment unit 4 installed in the vacuum chamber 10, the electrode 1 in the roll-to-roll state travels to the rewinder 2c. While evacuating the vacuum chamber 10 in a roll-to-roll state by the vacuum drying apparatus 100 shown in Figure 1 and Figure 2 FIG., the electrode is heated and dried by a heating unit 5 at a predetermined vacuum level, or vacuum dried by hot air jetted by a nitrogen jet unit 6 and circulated by a high-speed fan 7. The dried electrode 1 is wound by the rewinder 2c. Then, the evacuation of the vacuum chamber is stopped, and the wound electrode roll 1c is moved to an unloader 2d outside the vacuum chamber 10 by a robot or the like. Thus, the vacuum drying is completed. For the electrode 1 conveyed in a roll-to-roll state in the vacuum chamber 10 in the above process after a cutting process, a control unit 40 of the present invention gradually adjusts the vacuum level in the vacuum chamber 10, that is, adjusts to a low vacuum level, a medium vacuum level or a high vacuum level, while using a low vacuum pumping device 20 and a medium-high vacuum pumping device 30 connected to the vacuum chamber 10 through separate pipelines, so that the electrode is heated and dried, thereby removing moisture from the electrode and improving the wetting performance. The control unit 40 of the present invention can be connected not only to the pumping device, but also to Figure 3The unwinder 2b, rewinder 2c, heating unit 5, tension adjustment unit 4, skew adjustment unit 3, etc., to organically control air extraction and heat drying.

[0089] The operation of the vacuum drying apparatus 100 of the present invention and the vacuum drying method will be described in detail below with reference to Figures 4 to 6 The operation of the vacuum drying apparatus 100 of the present invention and the vacuum drying method will be described in detail below with reference to

[0090] Figure 4 is a flowchart showing a vacuum drying method according to an embodiment of the present invention.

[0091] A vacuum drying method for electrodes in a roll-to-roll state according to an embodiment of the present invention includes the steps of: evacuating a vacuum chamber to a low vacuum level according to set process conditions in order to perform vacuum drying on the electrodes disposed in the vacuum chamber in a roll-to-roll state ( Figure 4 step (a)); and drying the electrodes in the vacuum chamber at the low vacuum level ( Figure 4 step (b)), and further includes the steps of: after drying a predetermined number of electrode rolls in a roll-to-roll state in the vacuum chamber, in a state where the electrodes have been removed from the vacuum chamber, setting the vacuum chamber to a predetermined medium vacuum level or high vacuum level to remove foreign substances in the vacuum chamber ( Figure 4 step (d)).

[0092] In step (a), when the electrode rolls 1b and 1c are disposed between the unwinder 2b and the rewinder 2c in the vacuum chamber 10 as shown in Figure 3 to form a roll-to-roll state, the vacuum chamber 10 can be evacuated to a predetermined low vacuum level by the low vacuum pumping device 20 of the vacuum drying apparatus 100 of Figure 1 . In this case, the target electrode 1 to be vacuum dried is a conventional type of electrode with a low moisture content, and the process conditions (recipe) for vacuum drying such a conventional electrode are preset and input to the control unit 40. According to the preset process conditions, for example, when the low vacuum pump 22 (rotary pump or a combination of a rotary pump and a Roots pump) of the low vacuum pumping device 20 of the vacuum drying apparatus 100 of Figure 1 is started, the on / off valve 23 installed in the low vacuum pipeline 21 is opened. In this case, the vent valve 26 of the vent pipe 25 is closed. After opening the on / off valve 23, the multi-stage switch valve 24 installed in the low vacuum pipeline 21 on one side of the vacuum chamber is opened. Further, for example, by adjusting the opening degree of the multi-stage switch valve 24 which is a servo valve, the vacuum degree can be adjusted and the vacuum degree can be stably maintained.

[0093] In step (b), when the low vacuum level corresponding to the process conditions is stable and maintained in the vacuum chamber 10, the control unit 40 can operate Figure 3The heating unit 5, etc., dries the electrodes in a roll-to-roll state. According to the set process conditions, the electrodes are dried by heating the electrodes for a predetermined time while maintaining the vacuum level for a predetermined time. During the vacuum drying, the electrodes 1 are heated and dried while moving from the unwinder 2b to the rewinder 2c at a predetermined rate.

[0094] In step (c), the dried electrodes are wound by the rewinder 2c, and then the wound electrode roll 1c is discharged to the outside of the vacuum chamber 10. Before discharging the electrodes to the outside of the vacuum chamber, the low-vacuum switching valve (on / off valve and servo valve) of the low-vacuum pumping device 20 is closed, and the vent valve 26 is opened, so that the internal pressure in the vacuum chamber 10 becomes atmospheric pressure. The electrode roll 1d discharged to the outside of the vacuum chamber is mounted on the unloader 2d. Subsequently, by repeating steps (a) to (c), the electrodes are vacuum-dried in a roll-to-roll state in the vacuum chamber 10.

[0095] In step (d), the vacuum drying method according to an embodiment of the present invention further includes a cleaning process for removing foreign matter in the vacuum chamber 10. When vacuum-drying a predetermined number of electrode rolls in a roll-to-roll state in the vacuum chamber 10 by repeating step (a) and (b) or steps (a) to (c), foreign matter derived from the electrodes or introduced from the outside accumulates in the vacuum chamber. When vacuum-drying subsequent electrode rolls in the vacuum chamber 10 in the presence of such foreign matter, the electrodes are contaminated by the foreign matter, and the electrode characteristics or wetting performance deteriorate. Therefore, the vacuum drying method of the present invention further includes the following steps: after vacuum-drying a predetermined number (for example, 50) of electrode rolls in the vacuum chamber 10, in a state where the electrodes are removed from the vacuum chamber, the vacuum chamber 10 is set to a predetermined medium vacuum level or high vacuum level to remove foreign matter in the vacuum chamber 10.

[0096] In this case, the predetermined medium vacuum level or high vacuum level is obtained by pumping the vacuum chamber 10 to a low vacuum level and then gradually pumping from the low vacuum level until the predetermined medium vacuum level or high vacuum level is reached. As described above, when the vacuum chamber 10 is immediately pumped to the medium vacuum level or high vacuum level, the rotating shaft or components of the TMP 37 of the medium-high vacuum pumping device 30 may be damaged. Therefore, before setting the inside of the vacuum chamber 10 to the predetermined medium-high vacuum level, it is necessary to first make the inside of the vacuum chamber 10 a low vacuum level environment. Specifically, when there are no electrodes in the vacuum chamber 10 and the vacuum chamber 10 returns to atmospheric pressure, by Figure 1While the low-vacuum pump 22 (e.g., a rotary pump) is started, the on / off valve 23 and the multi-stage switching valve 24 are opened to evacuate the vacuum chamber 10 to a low-vacuum level. In a state where the low-vacuum level is stabilized by adjusting the opening degree of the servo valve, the medium-high vacuum pumping device 30 is started. Generally speaking, the medium-high vacuum pump of the medium-high vacuum pumping device 30 is started, so the first on / off valve 33S of the bypass line 31-1 is first opened, and then the APC valve 34 is opened. By sequentially opening the second on / off valve 33F after opening the first on / off valve 33S, the TMP 37 can be prevented from being loaded. By opening the APC valve 34, the TMP 37 evacuates the vacuum chamber until it reaches the medium-vacuum level or the high-vacuum level. After the APC valve 34 is opened, the on / off valve 23 and the multi-stage switching valve 24 of the low-vacuum pumping device 20 are closed. The TMP 37 of the medium-high vacuum pumping device 30 can evacuate the vacuum chamber step by step starting from the low-vacuum environment formed by the low-vacuum pumping device 20, so internal component damage can be prevented. When the medium-vacuum level or the high-vacuum level in the vacuum chamber 10 is stabilized by adjusting the opening degree of the APC valve 34, the vacuum chamber is evacuated to remove foreign matters in the vacuum chamber.

[0097] Figure 5 is an overview diagram of the vacuum level showing the change of the vacuum level of multiple battery cells over time when vacuum pumping is performed by the pumping device. It is proposed Figure 5 is to show the trend of the vacuum level that can be verified when pumping with the pumping device, rather than the change of the vacuum level of the electrode. As Figure 5 shown, when the pumping device evacuates the vacuum chamber, it can be seen that the vacuum level rises rapidly over time during vacuum pumping (evacuation) using the vacuum pump, and the vacuum level remains at a constant value after being stabilized for a certain period of time. Subsequently, it can be seen that when the vacuum valve is closed and the vent valve is opened, the vacuum level decreases and returns to atmospheric pressure. In the vacuum drying method of the present invention, by adjusting the multi-stage switching valve of the low-vacuum switching valve to rapidly stabilize the vacuum level, the vacuum level can be maintained at a constant value. Similarly, in the case of the medium-high vacuum switching valve, the medium-vacuum level or the high-vacuum level can be stabilized and maintained by adjusting the opening degree of the APC valve.

[0098] In addition, it can be achieved by using Figure 1 and Figure 2 the low-vacuum gauge (A) shown in to measure the low-vacuum level and using the medium-high vacuum gauge (B) to measure the medium-high vacuum level to check whether the target vacuum level (low-vacuum level and medium-high vacuum level) is reached in the vacuum chamber.

[0099] Figure 6 is a flowchart showing the vacuum drying method according to another embodiment of the present invention.

[0100] The vacuum drying method of this embodiment includes the following steps: gradually evacuating the vacuum chamber from a low vacuum level to a medium vacuum level or a high vacuum level according to the set process conditions, so as to perform vacuum drying on the electrodes arranged in the vacuum chamber in a roll-to-roll state; and drying the electrodes in the vacuum chamber at the medium vacuum level or the high vacuum level.

[0101] This embodiment is applicable to electrodes with a high moisture content or those that require improved wetting performance, and relates to a method of gradually evacuating the vacuum chamber to a medium vacuum level or a high vacuum level for drying.

[0102] In step (a), when the electrode roll is Figure 3 arranged between the unwinder 2b and the rewinder 2c in the vacuum chamber 10 as shown in Figure 1 to form a roll-to-roll state, the vacuum chamber 10 can be evacuated to a predetermined low vacuum level by the low vacuum pumping device 20 of the vacuum drying equipment 100. In this case, the target electrode to be vacuum dried is an electrode of a model with a high moisture content, and the process conditions (recipe) for vacuum drying such an electrode with a high moisture content are preset and input into the control unit 40. According to the preset process conditions, for example, when Figure 1 the low vacuum pump 22 of the low vacuum pumping device 20 of the vacuum drying equipment starts, the on / off valve 23 installed in the low vacuum pipeline 21 is opened. In this case, the vent valve of the ventilation pipe is closed. After opening the on / off valve, the multi-stage switch valve in the low vacuum pipeline installed on one side of the vacuum chamber is opened. In addition, for example, by adjusting the opening degree of the multi-stage switch valve that is a servo valve, the vacuum degree can be adjusted and the vacuum degree can be stably maintained.

[0103] In step (a-1), in this embodiment, by starting while the vacuum chamber 10 is maintained at a low vacuum level Figure 1The medium-high vacuum pumping device 30 gradually pumps air from the vacuum chamber 10 until it reaches the medium vacuum level or high vacuum level input as process conditions. That is, in a state where the low vacuum level is stable, the first on / off valve 33S of the bypass pipeline 31-1 is first opened, and then the APC valve 34 is opened. By sequentially opening the second on / off valve 33F after opening the first on / off valve 33S, the TMP 37 can be prevented from being loaded. By opening the APC valve, the TMP pumps air from the vacuum chamber until it reaches the medium vacuum level or high vacuum level. After the APC valve 34 is opened, the on / off valve 23 and the multi-stage switching valve 24 of the low vacuum pumping device are closed. The TMP 37 of the medium-high vacuum pumping device 30 can gradually pump air from the low vacuum environment formed by the low vacuum pumping device to the vacuum chamber, thus preventing damage to internal components. When the medium vacuum level or high vacuum level in the vacuum chamber 10 is stabilized by adjusting the opening degree of the APC valve 34, the control unit 40 operates the heating unit 5, etc. to perform vacuum drying on the electrodes.

[0104] In step (b)’, at the medium vacuum level or high vacuum level corresponding to the process conditions, the control unit 40 operates Figure 3 the heating unit 5, etc. to dry the electrodes in a roll-to-roll state. According to the set process conditions, the electrodes are dried by heating the electrodes for a predetermined time while maintaining the vacuum level for a predetermined time. During vacuum drying, the electrodes are heated and dried while moving from the unwinder 2b to the rewinder 2c at a predetermined rate.

[0105] In step (c), the dried electrodes are wound by the rewinder 2c and discharged to the outside of the vacuum chamber 10. Before discharging the electrodes to the outside of the vacuum chamber 10, the medium-high vacuum switching valves (on / off valves and servo valves) of the medium-high vacuum pumping device 30 are closed, and the vent valve 36 (primary ventilation) is opened. In addition, in this state, the vent valve 26 of the low vacuum pumping device is opened to quickly restore the vacuum chamber 10 to atmospheric pressure (secondary ventilation). Subsequently, by repeating steps (a) to (c), the electrodes are vacuum dried in a roll-to-roll state in the vacuum chamber 10.

[0106] In step (d), the vacuum drying method according to an embodiment of the present invention may further include a cleaning process for removing foreign substances in the vacuum chamber 10. When vacuum drying a predetermined number of electrode rolls in a roll-to-roll state in the vacuum chamber by repeating steps (a) and (b)’ or steps (a) to (c), foreign substances derived from the electrodes or introduced from the outside will accumulate in the vacuum chamber. The vacuum drying method of the present invention further includes the following steps: after vacuum drying a predetermined number (for example, 50) of electrode rolls in the vacuum chamber 10, in a state where the electrodes are removed from the vacuum chamber, the vacuum chamber 10 is set to a predetermined medium vacuum level or high vacuum level to remove foreign substances in the vacuum chamber 10.

[0107] The predetermined medium vacuum level or high vacuum level for removing foreign substances in the vacuum chamber does not have to be the same as the medium vacuum level or high vacuum level for drying electrodes with a high moisture content. Since the purposes of electrode drying and foreign substance removal are different, the medium vacuum level or high vacuum level can be selected within the optimal range suitable for each purpose. Since the vacuum drying apparatus 100 of the present invention employs an APC valve 34 capable of adjusting the opening degree, the desired medium vacuum level or high vacuum level can be achieved by adjusting the opening degree. The process of gradually performing evacuation starting from a low vacuum level until reaching the predetermined medium vacuum level or high vacuum level for removing foreign substances is the same as Figure 4 that of the embodiment, and thus additional description thereof will be omitted.

[0108] Based on the above description, the vacuum drying apparatus of the present invention is used for various vacuum levels in the range from several tens to hundreds of Torr to 10 -8 Torr by providing a low vacuum pumping device and a medium-high vacuum pumping device. Therefore, the vacuum drying apparatus can be used to dry electrodes of models with a low moisture content and high-nickel electrodes with a high moisture content.

[0109] In addition, as described above, by applying various vacuum pressures (vacuum levels), not only can the electrode moisture removal ability be improved, but also the wetting performance can be improved.

[0110] In addition, even in each vacuum mode of low vacuum or medium vacuum, the vacuum level can be gradually and finely adjusted by using a servo valve or an APC valve, and thus the vacuum level can be very conveniently stabilized or adjusted.

[0111] In addition, since a low vacuum pumping device and a medium-high vacuum pumping device are provided, foreign substances in the vacuum chamber can be advantageously removed by the medium-high vacuum pumping device without vacuum damage.

[0112] In addition, in addition to the above advantages, the vacuum drying method of the present invention can also effectively perform vacuum drying of the electrodes in the vacuum chamber in a roll-to-roll state.

[0113] So far, the present invention has been described in detail with reference to the drawings, embodiments, etc. However, the structures described in the drawings or embodiments described herein are only examples of the present invention and do not represent all the technical spirits of the present invention. It should be understood that various equivalents and modifications can replace the structures at the time of filing this application.

[0114] (Reference numeral description)

[0115] 1: Electrode

[0116] 1a, 1b, 1c, 1d: Electrode roll

[0117] 2a: Loader

[0118] 2b: Unwinder

[0119] 2c: Rewinder

[0120] 2d: Unloader

[0121] 3: Skew Adjustment Unit

[0122] 4: Tension Adjustment Unit

[0123] 5: Heating Unit

[0124] 6: Nitrogen Injection Unit

[0125] 7: Fan

[0126] 10: Vacuum Chamber

[0127] A: Low Vacuum Gauge

[0128] B: Medium-High Vacuum Gauge

[0129] 20: Low Vacuum Pumping Device

[0130] 21: Low Vacuum Pipeline

[0131] 22: Low Vacuum Pump

[0132] 23: On / Off Valve

[0133] 24: Multi-Stage Switching Valve

[0134] 25: Vent Pipe

[0135] 26: Vent Valve

[0136] 30: Medium-High Vacuum Pumping Device

[0137] 31: Medium-High Vacuum Pipeline

[0138] 31-1: Bypass Pipeline

[0139] 32: Dry Pump

[0140] 33S: First On / Off Valve

[0141] 33F: Second On / Off Valve

[0142] 34: APC Valve

[0143] 35: Vent Pipe

[0144] 36: Vent Valve

[0145] 37: TMP

[0146] 40: Control Unit

[0147] 100: Vacuum drying equipment.

Claims

1. An apparatus for vacuum drying an electrode in a roll-to-roll state, the apparatus comprising: A vacuum chamber in which electrodes are arranged in a roll-to-roll state to be dried; A low-vacuum pumping device that is connected to the vacuum chamber through a low-vacuum pipeline and configured to pump the vacuum chamber to a low-vacuum level; A medium-high-vacuum pumping device that is connected to the vacuum chamber through a medium-high-vacuum pipeline separated from the low-vacuum pipeline and configured to pump the vacuum chamber to a medium-vacuum level or a high-vacuum level; And A control unit that is connected to the low-vacuum pumping device and the medium-high-vacuum pumping device and configured to gradually adjust the vacuum level in the vacuum chamber to dry the electrodes, wherein, after drying a predetermined number of electrode rolls in a roll-to-roll state in the vacuum chamber, in a state where the electrodes are removed from the vacuum chamber, the control unit gradually controls the vacuum level to pump the vacuum chamber to a predetermined medium-vacuum level or high-vacuum level to remove foreign matters in the vacuum chamber.

2. The apparatus according to claim 1, wherein: The low-vacuum level is a vacuum level in the range from 1 Torr to 600 Torr, The medium vacuum level is a vacuum level within the range from 10 -2 torr to less than 1 torr, and The high vacuum level is a vacuum level in the range from 10 -8 Torr to less than 10 -2 Torr.

3. The apparatus according to claim 1, wherein the low-vacuum pipeline and the medium-high vacuum pipeline are connected to the bottom of the vacuum chamber.

4. The apparatus according to claim 3, wherein when the vacuum chamber is viewed from the top, at least one of the low-vacuum pipeline and the medium-high vacuum pipeline is disposed adjacent to a corner of the vacuum chamber symmetrically up and down, symmetrically left and right, or symmetrically up, down, left, and right.

5. The apparatus according to claim 1, wherein a low-vacuum gauge for measuring the low-vacuum level and a medium-high vacuum gauge for measuring the medium-vacuum level or the high-vacuum level are installed in the vacuum chamber.

6. The apparatus according to claim 5, wherein the low-vacuum pumping means comprises: A low-vacuum pump connected to the vacuum chamber through the low-vacuum pipeline; And a low-vacuum switch valve configured to open and close the low-vacuum pipeline.

7. The apparatus according to claim 6, wherein the low-vacuum pump is a rotary pump or further comprises a Roots pump connected to the rotary pump.

8. The apparatus according to claim 6, wherein the low-vacuum switching valve comprises: An on / off valve in the low-vacuum pipeline installed on one side of the low-vacuum pump; And a multi-stage switch valve that is installed in the low-vacuum pipeline on one side of the vacuum chamber and configured to adjust the opening degree.

9. The apparatus according to claim 8, wherein the multi-stage switching valve is one of a servo valve, an SMC two-stage valve, and a throttle valve.

10. The apparatus according to claim 5, wherein the medium-high vacuum pumping means comprises: A medium-high-vacuum pump connected to the vacuum chamber through the medium-high-vacuum pipeline; And a medium-high-vacuum switch valve configured to open and close the medium-high-vacuum pipeline.

11. The apparatus according to claim 10, wherein the medium-high vacuum pump comprises a dry pump and a turbo molecular pump, and the turbo molecular pump is connected to the dry pump through the medium-high vacuum pipeline and is installed in the medium-high vacuum pipeline adjacent to the vacuum chamber.

12. The apparatus according to claim 11, wherein the medium-high vacuum switching valve comprises: An on / off valve in the medium-high-vacuum pipeline installed on one side of the dry pump;And an adaptive pressure control valve that is installed in the medium-high-vacuum pipeline between the turbo molecular pump and the vacuum chamber and configured to adjust the opening degree.

13. The device according to claim 12, wherein: The medium-high-vacuum pipeline on one side of the dry pump includes a bypass pipeline, A first on / off valve and a second on / off valve are respectively installed in the bypass pipeline and the medium-high-vacuum pipeline on one side of the dry pump, and The first on / off valve and the second on / off valve are opened sequentially.

14. The device according to claim 1, wherein the control unit controls the low-vacuum pumping device and the medium-high vacuum pumping device to pump the vacuum chamber to a low-vacuum level, a medium-vacuum level or a high-vacuum level according to set process conditions, and when pumping the vacuum chamber to the medium-vacuum level or the high-vacuum level, the control unit controls the low-vacuum pumping device and the medium-high vacuum pumping device to gradually pump the vacuum chamber from the low-vacuum level to the medium-vacuum level or the high-vacuum level.

15. A method for vacuum drying an electrode in a roll-to-roll state, the method comprising the following steps: Pump the vacuum chamber to a low-vacuum level through a low-vacuum pumping device according to set process conditions so as to perform vacuum drying on electrodes arranged in a roll-to-roll state in the vacuum chamber, and the low-vacuum pumping device is connected to the vacuum chamber through a low-vacuum pipeline; And Dry the electrodes in the vacuum chamber at the low-vacuum level, wherein the method further includes the following steps: after drying a predetermined number of electrode rolls in a roll-to-roll state in the vacuum chamber, in a state where the electrodes are removed from the vacuum chamber, pump the vacuum chamber to a predetermined medium-vacuum level or high-vacuum level through a medium-high-vacuum pumping device to remove foreign matters in the vacuum chamber, and the medium-high-vacuum pumping device is connected to the vacuum chamber through a medium-high-vacuum pipeline separated from the low-vacuum pipeline.

16. The method according to claim 15, wherein the predetermined medium-vacuum level or high-vacuum level is obtained by pumping the vacuum chamber to a low-vacuum level and then gradually pumping from the low-vacuum level until the predetermined medium-vacuum level or high-vacuum level is reached.

17. A method for vacuum drying an electrode in a roll-to-roll state, the method comprising the following steps: The vacuum chamber is evacuated to a low vacuum level by a low vacuum pumping device according to set process conditions, and starting from the low vacuum level, the vacuum chamber is gradually evacuated by a medium-high vacuum pumping device until a medium vacuum level or a high vacuum level is reached, so as to vacuum-dry the electrodes arranged in the vacuum chamber in a roll-to-roll state. The low vacuum pumping device is connected to the vacuum chamber through a low vacuum pipeline, and the medium-high vacuum pumping device is connected to the vacuum chamber through a medium-high vacuum pipeline separated from the low vacuum pipeline; Dry the electrodes in the vacuum chamber at the medium vacuum level or the high vacuum level; And After drying a predetermined number of electrode rolls in the roll-to-roll state in the vacuum chamber, in a state where the electrodes are removed from the vacuum chamber, the vacuum chamber is evacuated to a predetermined medium vacuum level or high vacuum level by the medium-high vacuum pumping device to remove foreign matters in the vacuum chamber.

18. The method according to claim 17, wherein the predetermined medium-vacuum level or high-vacuum level is obtained by pumping the vacuum chamber to a low-vacuum level and then gradually pumping from the low-vacuum level until the predetermined medium-vacuum level or high-vacuum level is reached.

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