JP5984643B2 - Electrode sheet drying apparatus and electrode sheet drying method - Google Patents

Description

  The present invention relates to an electrode sheet drying apparatus and an electrode sheet drying method for drying a roll-shaped electrode sheet used for a lithium battery or the like.

  For example, in a secondary battery such as a lithium ion secondary battery used for an automobile storage battery, an electrode having a necessary length is manufactured by cutting a rolled electrode sheet. This roll-shaped electrode sheet has a very high hygroscopicity because a paste-like activator is applied to a metal stay as a base material.

  For this reason, it is necessary to dry the roll-shaped electrode sheet in order to remove moisture and the like before the processing. Conventionally, the roll-shaped electrode sheet is put in a drying apparatus as it is and dried by heating.

JP2011-134545A

  However, when heated and dried with a roll electrode as in the past, drying takes a very long time, and even with the drying time, a temperature difference occurs between the inner side near the center of the roll and the outer side far from the center, resulting in uniform drying. There is a problem that cannot be done. In addition, if the electrode is heated and dried while the roll electrode is used, the electrode material is curled due to the heat history during the drying process, and the curl near the center of the roll becomes strong and often cannot be used.

  There is also a drying device that unwinds a roll-shaped electrode sheet and winds the sheet while heating and drying it. For example, Patent Document 1 provides an infrared light source inside a drying apparatus, unwinds a roll-shaped electrode sheet outside the drying apparatus, takes it into the drying apparatus, and heat-drys it with infrared light. The electrode sheet is wound up outside the drying device.

  However, if unwinding and winding of the roll-shaped electrode sheet are performed outside the drying device as in Patent Document 1, moisture may be reattached during winding even if the inside of the drying device is dried. There is.

  Moreover, since the light source of infrared light is arrange | positioned inside a drying apparatus in patent document 1, in order to prevent deterioration of the electrode sheet by the heat | fever of light source itself, in patent document 1, the light source is cooled with cooling gas. Further, a drying gas is also introduced into the drying device in order to promote moisture removal. For this reason, in Patent Document 1, even if the inside of the drying apparatus is depressurized in order to increase the water removal efficiency, a sufficient vacuum pressure cannot be obtained because the cooling gas or the drying gas is introduced.

  In addition, since the cooling efficiency decreases as the pressure is lowered, the cooling effect of the heat source by the cooling gas is greatly reduced if the pressure is lowered as the vacuum pressure is increased, and the influence of heat on the electrode sheet is also increased.

  Therefore, the present invention has been made in view of such problems, and the object of the present invention is to make the inside of the chamber a vacuum atmosphere sufficient to enhance the moisture removal effect and to recycle the moisture. It is an object to provide an electrode sheet drying apparatus and the like that can uniformly dry the entire electrode sheet while suppressing curling without adhering, and can significantly reduce the drying time more than before without causing thermal deterioration of the electrode sheet.

  In order to solve the above-described problems, according to an aspect of the present invention, an electrode sheet drying apparatus that unwinds a roll-shaped electrode sheet and dries while winding the electrode sheet, and can accommodate the roll-shaped electrode sheet. An unwinding side accommodating portion and a winding side accommodating portion are provided apart from each other, an airtight chamber having a communication portion that communicates the inside of the unwinding side accommodating portion and the inside of the winding side accommodating portion, and exhausting the inside of the chamber An evacuation apparatus connected to an exhaust port for making the inside of the chamber have a vacuum pressure, an unwinding shaft provided in the unwinding side accommodating portion, a winding shaft provided in the unwinding side accommodating portion, A plurality of guide rollers for guiding the electrode sheet unwound from the unwinding-side housing portion to the winding-side housing portion through the communicating portion, and provided outside the chamber and passing through the communicating portion. For the electrode sheet, An infrared irradiation unit for irradiating infrared rays through a transparent window provided in the middle of the section, the electrode sheet drying apparatus comprising the provided.

  In order to solve the above problems, according to another aspect of the present invention, there is provided an electrode sheet drying method in which a roll-shaped electrode sheet is unwound using an electrode sheet drying apparatus and dried while being wound. In the sheet drying apparatus, the unwinding side accommodating portion and the winding side accommodating portion that can accommodate the roll-shaped electrode sheet are provided apart from each other, and the inside of the unwinding side accommodating portion and the inside of the winding side accommodating portion are communicated with each other. An airtight chamber having a communication part, an evacuation device connected to an exhaust port for exhausting the inside of the chamber and making the inside of the chamber have a vacuum pressure, an unwinding shaft provided in the unwinding side accommodating part, A plurality of guide rollers for guiding the winding shaft provided in the winding side accommodating portion and the electrode sheet unwound from the winding side accommodating portion to the winding side accommodating portion through the communication portion And outside of the chamber An infrared irradiation unit that irradiates the electrode sheet passing through the communication part with an infrared ray through a transmission window provided in the middle of the communication part, and the chamber is evacuated by the vacuum exhaust device. Reducing the pressure to a predetermined vacuum pressure, and heating and drying the electrode sheet by irradiating infrared rays from the infrared irradiation unit while unwinding the electrode sheet from the unwinding shaft and winding the electrode sheet on the winding shaft; A method for drying an electrode sheet is provided.

  The vacuum pressure in the chamber is preferably 30000 Pa or less to dry the electrode sheet.

  Further, one or both of the unwinding shaft and the winding shaft may be provided with a shaft driving unit that performs rotational driving and sliding driving in the axial direction. In this case, when the electrode sheet unwound by the unwinding shaft is wound by the winding shaft, a meandering detection sensor for detecting the meandering in the axial direction of the electrode sheet is provided, and the detection result of the meandering detection sensor It is preferable to calculate a meandering correction amount in the axial direction of the electrode sheet based on the control, and to control the slide driving of the shaft driving unit based on the meandering correction amount.

  Further, a plurality of roll-shaped electrode sheets may be arranged in the axial direction of the unwinding shaft, and the plurality of roll-shaped electrode sheets may be simultaneously unwound and dried. In this case, the winding shaft may be provided separately for each of the electrode sheets, and the winding shafts may be arranged to be shifted.

  Also, a temperature sensor for detecting the temperature of the electrode sheet is provided, and either or both of the output of the infrared irradiation unit and the feed speed of the electrode sheet are set so that the temperature of the electrode sheet becomes a predetermined set temperature. You may make it adjust.

  According to the present invention, the inside of the chamber can be set to a vacuum pressure atmosphere sufficient to enhance the moisture removal effect, and the roll-shaped electrode sheet can be heated from outside the chamber while being unwound and wound in the vacuum pressure atmosphere. By doing so, the entire electrode sheet can be uniformly dried while curling is suppressed without reattaching moisture, and the drying time can be significantly shortened more than before while preventing thermal deterioration of the electrode sheet.

It is an external appearance perspective view which shows the structural example of the electrode sheet drying apparatus concerning 1st Embodiment of this invention. It is a cross-sectional perspective view which shows schematic structure at the time of cut | disconnecting in the AA cross section shown in FIG. It is sectional drawing for demonstrating operation | movement of the electrode sheet drying apparatus concerning the embodiment. It is a flowchart which shows the specific example of the electrode sheet drying process concerning the embodiment. It is sectional drawing which shows schematic structure of the shaft drive part which drives the unwinding shaft in the embodiment. It is sectional drawing which shows the modification of the electrode sheet drying apparatus concerning the embodiment. It is a cross-sectional perspective view which shows the structural example of the electrode sheet drying apparatus concerning 2nd Embodiment of this invention. It is a cross-sectional perspective view which shows the modification of the electrode sheet drying apparatus concerning the embodiment. It is sectional drawing for demonstrating operation | movement of the electrode sheet drying apparatus shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and drawings, components having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

(Configuration example of electrode sheet drying apparatus according to the first embodiment)
First, an electrode sheet drying apparatus according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view showing a schematic configuration of the electrode sheet drying apparatus according to the first embodiment, and FIG. 2 is a cross-sectional perspective view taken along the line AA shown in FIG. FIG. 3 is a cross-sectional view for explaining the operation of the electrode sheet drying apparatus.

  The electrode sheet drying apparatus 100 according to the present embodiment unwinds a roll-shaped electrode sheet in a vacuum pressure atmosphere chamber, irradiates infrared rays from the outside of the chamber, heats and drys the electrode sheet, and places it in the chamber. It is comprised so that it can wind up by.

  Specifically, as shown in FIG. 1, an electrode sheet drying apparatus 100 according to the first embodiment includes an airtight chamber 102 made of a metal such as stainless steel or aluminum. The chamber 102 includes an unwinding side accommodating portion 110 that accommodates the roll-shaped electrode sheet W, a winding side accommodating portion 120 that is provided apart from the accommodating portion 110, and the accommodating portions 110, 120. And a communication unit 130 that communicates with each other.

  An opening 103 is provided in the ceiling of the chamber 102, and the opening 103 is hermetically closed by a lid 104. As shown in FIG. 1, the lid 104 may pivotally support the opening 103 in the chamber 102 so that it can be opened and closed, or may be configured separately from the chamber 102. Moreover, the cover part 104 may be comprised with a transparent member as shown in FIG. 1, and may be comprised with the member which is not transparent.

  Openings 111 and 121 through which the roll-shaped electrode sheet W is taken in and out are provided on the front surfaces of the housing portions 110 and 120, respectively, and the openings 111 and 121 are closed by doors 112 and 122, respectively. The doors 112 and 122 are pivotally supported in the chamber 102 so that the openings 111 and 121 can be opened and closed.

  As shown in FIG. 1, the chamber 102 may be provided with transparent windows 106 on both side surfaces thereof so that the respective accommodating portions 110 and 120 can be observed from the outside. Instead of providing these transparent windows 106 on both sides of the chamber 102, they may be closed with side plates.

  As shown in FIG. 2, the unwinding side accommodating portion 110 includes a unwinding shaft 114, and the winding side accommodating portion 120 includes a winding shaft 124. When the roll-shaped electrode sheet W is set on the unwinding shaft 114, the center of the roll-shaped electrode sheet W is supported by being inserted into the unwinding shaft 114.

  Each of the unwinding shaft 114 and the winding shaft 124 extends from the back plate 102a of the chamber 102 toward the front surface and is rotatably supported. A plurality of guide rollers 108 for conveying the electrode sheet W are provided on the back plate 102 a of the chamber 102. The electrode sheet W set on the unwinding shaft 114 is stretched through the communicating portion 130 to the winding shaft 124 via the plurality of guide rollers 108.

  The unwinding shaft 114 and the winding shaft 124 are provided with rotational drive motors 105 and 125 for rotating them, respectively. Here, the case where the rotation drive motors 105 and 125 are provided on the unwinding shaft 114 and the winding shaft 124 is described as an example, but the present invention is not limited to this, and only the winding shaft 124 is rotationally driven. A motor may be provided.

  The guide roller 108 shown in FIG. 2 is an example in which two guide rollers 108 are arranged in each of the accommodating portions 110 and 120. The number and arrangement of the guide rollers 108 are not limited to those illustrated. As shown in FIG. 2, a tension roller 109 for adjusting the tension of the electrode sheet W may be provided between the two guide rollers 108 provided in the unwinding side accommodating portion 110. The number and arrangement of the tension rollers 109 are not limited to those illustrated.

  The communication portion 130 is provided with a light transmission window 134 that transmits infrared rays for heating the electrode sheet W. Specifically, as shown in FIG. 2, a plurality of openings 132 are provided on the lower surface of the communication part 130, and a light transmission window 134 is provided so as to close the openings 132.

  An infrared irradiation unit 136 that irradiates infrared rays toward each light transmission window 134 is provided outside the chamber 102, that is, outside the communication unit 130. The infrared irradiation unit 136 is formed of, for example, a halogen lamp, and the light transmission window 134 is formed of quartz glass that transmits infrared light from the halogen lamp.

  The material of the light transmission window 134 is not limited to quartz glass, and any material that can transmit the infrared rays from the infrared irradiation unit 136 and heat the electrode sheet W may be used. A reflector may be provided below the infrared irradiation unit 136 such as a halogen lamp in order to increase the efficiency of infrared irradiation to the electrode sheet W. The infrared irradiation unit 136 is an example of a heat ray irradiation unit that can radiate heat rays that heat the electrode sheet W from outside the chamber 102, and is not limited to a halogen lamp.

  The communication unit 130 is provided with an exhaust port 142 to which a vacuum exhaust device 140 (not shown in FIG. 1) such as a vacuum pump shown in FIG. 3 is connected. The inside of the chamber 102 can be evacuated by the evacuation device 140 to be a predetermined vacuum pressure.

  In order to sufficiently enhance the moisture removal effect, the vacuum pressure in the chamber 102 during the drying process is preferably at least 30000 Pa or less, and more preferably 10000 Pa or less. For example, when the vacuum pressure during drying is set to 10,000 Pa, water boils even at about 46 ° C., so that the moisture removal efficiency can be increased even by heating the electrode sheet W at a relatively low temperature of at least about 46 ° C. . As described above, according to the present embodiment, a sufficient vacuum pressure in the chamber 102 can be obtained, so that the water removal efficiency can be greatly increased.

  By the way, when the electrode sheet W is dried, the moisture can be efficiently removed as it is heated at a high temperature and high pressure. However, when the electrode sheet W used for a lithium ion battery or the like having a limited temperature condition is dried, the temperature is lower. It is desirable to dry efficiently.

  Specifically, in an electrode material used for a lithium ion battery or the like, the temperature at which the electrode material can be heated is, for example, about 130 ° C. to 150 ° C., and the temperature at which the electrode material after the heat treatment (after the drying treatment) can be taken out from the drying apparatus is Considering prevention and safety, for example, there is a severe temperature limit such as about 50 ° C. to 60 ° C. or less.

  For this reason, such an electrode sheet W cannot be dried at a high temperature of 150 ° C. or higher, and as it is heated at a high temperature, it takes time to cool to a temperature where it can be subsequently taken out. There are disadvantages. In this respect, in the electrode sheet drying apparatus 100 according to the present embodiment, the chamber 102 can be set to a sufficient vacuum pressure, and thus can be dried more efficiently at a low temperature.

  Moreover, although the moisture contained in the porous material used for the electrode sheet can be effectively removed as the vacuum pressure in the chamber 102 is decreased (the degree of vacuum is increased), the vacuum pressure is reduced to 600 Pa or less. Then, since the water will freeze, an extra amount of heat such as heat of fusion and heat of vaporization is required to dry it. Therefore, in order to efficiently remove moisture at a low temperature, for example, it is preferable to dry in a pressure range of 60 ° C. water vapor pressure (approximately 20000 Pa) to 0 ° C. water vapor pressure (approximately 613 Pa). Therefore, practically, the vacuum pressure in the chamber 102 is preferably set in the pressure range of 20000 Pa to 1000 Pa, and more preferably set in the pressure range of 10,000 Pa to 1000 Pa.

  The exhaust port 142 is preferably provided in a range where the electrode sheet W is heated. Thereby, moisture evaporated from the electrode sheet W can be efficiently exhausted from the exhaust port 142. In FIG. 1, the case where the exhaust port 142 is provided in the back plate 102a of the chamber 102 that constitutes the communication portion 130 where the electrode sheet W is heated is taken as an example.

  As shown in FIG. 3, the electrode sheet drying apparatus 100 includes a control unit 200 that controls each component. Connected to the control unit 200 is an operation unit 210 including a keyboard, a display, and the like for an operator to input commands in order to operate the electrode sheet drying apparatus 100. The operation unit 210 may be configured with a touch panel.

  Further, the control unit 200 includes a program for realizing a drying process executed by the electrode sheet drying apparatus 100 under the control of the control unit 200 and recipe data necessary for executing the program (for example, a vacuum in the chamber 102). A storage unit 220 in which the pressure, the winding speed of the electrode sheet W, etc.) are stored is connected.

  These recipes may be stored in a hard disk or semiconductor memory, and set in a predetermined position of the storage unit 220 while being stored in a portable computer-readable storage medium such as a CD-ROM or DVD. You may come to do.

  The control unit 200 executes a desired process in the electrode sheet drying apparatus 100 by reading out a desired process recipe from the storage unit 220 based on an instruction from the operation unit 210 and controlling each unit. Further, the recipe can be edited by an operation from the operation unit 210.

(Rolled electrode sheet)
Next, the roll-shaped electrode sheet which performs a drying process with the electrode sheet drying apparatus 100 will be described. Here, a roll-shaped electrode sheet used when manufacturing a lithium ion secondary battery is taken as an example.

  A lithium ion secondary battery is configured, for example, by laminating a positive electrode and a negative electrode with a separator interposed between them and storing them in a battery container and injecting an electrolyte. These electrodes, such as a positive electrode and a negative electrode, are manufactured by cutting an electrode sheet in which a paste-like activator is applied to a metal stay such as a copper foil as a current collector and processing it into a required length and shape.

  Specifically, the positive electrode is manufactured from an electrode sheet obtained by applying a positive electrode active material to a metal foil, and the negative electrode is manufactured from an electrode sheet obtained by applying a negative electrode active material to a metal foil. These positive electrode or negative electrode sheets are coated with an electrode active material on a metal foil, dried and formed into a roll, and stored in this state in a storage room. Then, if necessary, a roll-shaped electrode sheet is taken out and cut into a required length and shape to produce an electrode.

  In a battery such as a lithium ion secondary battery in which an electrolyte component easily reacts with moisture to cause deterioration, it is required that moisture of the electrodes constituting the battery is sufficiently removed. However, since the electrode sheet is often made of a porous material and is very easy to absorb moisture, the roll electrode sheet is taken out of the storage room and dried to remove moisture before processing into an electrode. There is a need to.

  The electrode sheet drying apparatus 100 according to the present embodiment can be used for drying before processing such a rolled electrode sheet into an electrode. The electrode sheet may be one having an electrode active material applied on one side, or one having an electrode active material applied on both sides. Furthermore, the electrode sheet drying apparatus 100 according to the present embodiment is not limited to the drying process before processing the roll-shaped electrode sheet, but also when the roll-shaped electrode sheet is manufactured or before the storage (for example, remains in the electrode active material). It can also be used in a drying step for removing impurities such as moisture.

(Electrode sheet drying process)
Next, the drying process at the time of drying such a roll-shaped electrode sheet W using the electrode sheet drying apparatus 100 concerning this embodiment is demonstrated, referring drawings. The control unit 200 executes the electrode sheet drying process by controlling each unit of the electrode sheet drying apparatus 100 based on a predetermined program. FIG. 4 is a flowchart showing a specific example of the electrode sheet drying process according to the present embodiment.

  This drying process is started by setting the roll-shaped electrode sheet W in the electrode sheet drying apparatus 100 and pressing a drying start button provided on the operation unit 210, for example. Specifically, the roll core 115 of the roll-shaped electrode sheet W is inserted and fixed to the unwinding shaft 114, and the electrode sheet W is unwound and passed around the guide roller 108 and the tension roller 109 as shown in FIG. Attached to the roll core 125 set on the shaft 124. Then, the lid 104 and the doors 112 and 122 are all closed, and the drying process is started.

  When starting the drying process, the controller 200 first evacuates the chamber 102 in step S110. Specifically, the vacuum exhaust device 140 is driven to exhaust the inside of the chamber 102, and the pressure is reduced to a predetermined vacuum pressure.

  Subsequently, in step S120, it is determined whether or not the inside of the chamber 102 has reached a predetermined vacuum pressure. Specifically, for example, the pressure in the chamber 102 is monitored by a pressure sensor (not shown) to determine whether or not a predetermined vacuum pressure (for example, 10,000 Pa or less) has been reached.

  If it is determined in step S120 that the predetermined vacuum pressure has been reached, the infrared irradiation unit 136 is turned on in step S130 while controlling the vacuum exhaust device 140 to maintain the vacuum pressure, and infrared irradiation is performed. Start.

  Next, unwinding and winding of the electrode sheet W is started in step S140. Specifically, the rotation drive motors 105 and 125 are driven to start the rotation of the winding shaft 124 and the unwinding shaft 114. In this way, as shown in FIG. 3, the roll-shaped electrode sheet W is unwound from the unwinding storage unit 110, and is wound around the winding shaft 124 of the winding storage unit 120 through the communication unit 130. Then, when the electrode sheet W passes through the communication portion 130, infrared rays are irradiated from the infrared irradiation unit 136, and the electrode sheet W is heated from below. As a result, moisture is removed from the electrode sheet W, and the electrode sheet W is wound around the winding shaft 124 without being exposed to the atmosphere.

  In step S150, it is determined whether or not the winding of the electrode sheet W has been completed. Whether or not the winding is completed is determined by detecting the winding diameter of the electrode sheet W on one or both of the winding side and the winding side using a winding diameter sensor or the like, and determining the winding end based on the detection result. May be. Details of such a winding diameter sensor will be described later.

  Further, when the winding of the electrode sheet W is completed, all the electrode sheet W is wound in a roll shape around the winding shaft 124, so that no tension is applied, and the torque of the winding shaft 124 changes sharply. Therefore, the end of winding may be detected by monitoring the torque output of the winding shaft 124 by a torque sensor (not shown) and detecting the change in torque output. Note that the method for determining the end of winding is not limited to the above.

  If it is determined in step S150 that the winding has been completed, the unwinding and winding of the electrode sheet W are stopped in step S160. Specifically, the rotation drive motors 105 and 125 are stopped, and the rotation of the winding shaft 124 and the unwinding shaft 114 is stopped.

  In step S170, the infrared irradiation unit 136 is turned off to stop infrared irradiation. In step S180, the chamber 102 is returned to atmospheric pressure, and a series of drying processes is completed. Specifically, for example, a purge valve (not shown) capable of opening and closing communication with the atmosphere may be provided in the chamber 102, and the interior of the chamber 102 may be returned to atmospheric pressure by opening the purge valve. When the return to the atmospheric pressure is completed, the door 122 shown in FIG. 1 can be opened to take out the dried roll electrode sheet.

  As described above, since the electrode sheet drying process according to the present embodiment is performed in the chamber 102 maintained in a predetermined vacuum pressure atmosphere, the boiling point of water is significantly lowered as compared with the case of the atmospheric pressure atmosphere. For this reason, since moisture can be efficiently and rapidly removed from the electrode sheet W by infrared heating, the drying time can be greatly shortened.

  Moreover, since the unwinding and winding of the electrode sheet W can all be performed in a vacuum pressure atmosphere in the chamber 102, moisture is not only removed when the electrode sheet W is unwound but also when the electrode sheet W is wound. Can be very effectively prevented from re-adhering. In addition, when the electrode sheet W is dried while being unwound on one side and wound on the other side, the curling (rounding) of the electrode sheet W is greatly generated as compared with the case where the electrode sheet W is dried in a roll shape. Can be suppressed.

  Further, since the infrared irradiation unit 136 is provided outside the chamber 102, the electrode sheet W is not affected by the heat even if the infrared irradiation unit 136 itself generates heat. For this reason, since it is not necessary to introduce a gas for cooling the infrared irradiation unit 136 into the chamber 102, the inside of the chamber 102 can be set to a sufficient vacuum pressure (for example, 10,000 Pa or less) to enhance the moisture removal effect.

  On the other hand, if an infrared irradiation unit is provided in the chamber 102, the electrode sheet W becomes very susceptible to heat when the infrared irradiation unit generates heat. In order to prevent this, since it is necessary to cool the infrared irradiation section itself with a cooling gas or the like, the vacuum pressure environment as in the present embodiment cannot be created in the chamber 102.

  Further, the electrode sheet drying apparatus 100 according to the present embodiment is provided with a communication portion 130 that communicates the unwinding-side storage portion 110 and the winding-side storage portion 120, and the electrode sheet W passes through the communication portion 130. To heat up. As a result, the communication portion 130 can be made thick enough for the electrode sheet W to pass therethrough, so that the internal space of the chamber 102 to be evacuated can be reduced as much as possible as compared with the case where the chamber 102 is simply box-shaped. it can.

  In addition, even if the infrared irradiation unit 136 is disposed outside the chamber 102, it can be disposed at a position close to the electrode sheet W by disposing the infrared irradiation unit 136 below the thin communication unit 130, so that heating efficiency is improved. Can do.

  In addition, the number and arrangement positions of the infrared irradiation units 136 are not limited to those illustrated. For example, the number of infrared irradiation units 136 may be one, or three or more. When increasing the number of infrared irradiation parts 136, it is preferable to arrange | position along the conveyance direction of the electrode sheet W of the communication part 130. FIG. When a plurality of infrared irradiation units 136 are provided, the same number of light transmission windows 134 as that of the infrared irradiation units 136 may be arranged opposite to each other, and one light transmission window 134 may be disposed up to the arrangement range of the infrared irradiation units 136. You may make it expand and provide.

  Further, when a plurality of infrared irradiation units 136 are arranged, the infrared output (light emission intensity) by each infrared irradiation unit 136 may be the same or may be changed. When changing the light emission intensity, for example, it may be adjusted so that the light emission intensity becomes weaker as it is arranged on the winding side.

  Furthermore, the arrangement position of the infrared irradiation unit 136 may be an upper part of the communication unit 130. Further, the infrared irradiation unit 136 may be provided on both the upper part and the lower part of the communication part 130. The arrangement position of the infrared irradiation unit 136 may be determined according to the configuration of the electrode sheet W. For example, when the activator is applied to both surfaces of the electrode sheet W, the infrared irradiation portions 136 are provided on both the upper and lower portions of the communicating portion 130 so that the infrared rays are directly irradiated to the active agents on both surfaces. You may do it.

  In such a drying process using the electrode sheet drying apparatus 100 according to the present embodiment, the roll-shaped electrode sheet W is unwound and dried while being wound, so that the electrode sheet W may meander. In this case, it is effective to correct the meandering of the electrode sheet W by allowing the roll-shaped electrode sheet W to be wound, that is, the winding shaft 124 to be slidable in the axial direction. Therefore, it is preferable that at least the winding shaft 124 is configured to be slidable in the axial direction as well as driven in the rotational direction. Not only the winding shaft 124 but also the unwinding shaft 114 is configured to be slidable in the axial direction so that the meandering of the electrode sheet W can be corrected by either the winding shaft 124 or the unwinding shaft 114. Also good.

  In the electrode sheet drying apparatus 100 according to the present embodiment, both the winding shaft 124 and the unwinding shaft 114 are slide-driven so that the meandering of the electrode sheet W can be corrected by either the winding shaft 124 or the unwinding shaft 114. A specific example in the case of freely configuring will be described. FIG. 5 is a cross-sectional view for explaining a shaft driving unit that rotationally drives and slides the unwinding shaft 114. The unwinding shaft 114 shown in FIG. 5 penetrates the back plate 102 a of the chamber 102 and is attached to a shaft driving unit 150 provided outside the chamber 102. The shaft driving unit 150 is configured so that the unwinding shaft 114 can be driven to rotate and slide in the axial direction.

  Specifically, the shaft driving unit 150 is configured as shown in FIG. 5, for example. That is, the unwinding shaft 114 is inserted into the orthogonal reduction gear 156 while being pivotally supported by the bearing 154 via the guide roller mounting plate 152 on the back plate 102a. That is, the guide roller mounting plate 152 includes a plate-like portion 152a disposed inside the back plate 102a and a cylindrical portion 152b protruding in the axial direction from the plate-like portion 152a. The cylindrical portion 152b is inserted into a shaft hole provided in the back plate 102a, and an unwinding shaft 114 is pivotally supported in the cylindrical portion 152b.

  The orthogonal speed reducer 156 is provided with a rotation drive motor 105, and the rotation drive motor 105 rotates the unwinding shaft 114. Further, the orthogonal reduction device 156 is configured to be slidable in the axial direction of the unwinding shaft 114 along the slide guide 162 by the slide drive motor 160.

  Specifically, the orthogonal reduction device 156 is attached to the slide member 158. The slide member 158 is slid along the slide guide 162 by a slider 159 provided below the slide member 158. The slider 159 is screwed into a ball screw 164 that is rotated by a slide drive motor 160.

  According to this, the orthogonal speed reducer 156 can be slid by driving the slider 159 along the slide guide 162 by rotating the ball screw 164 by the slide drive motor 160.

  A bellows 157 is provided between the slide member 158 and the back plate 102 a of the chamber 102 so as to surround the unwinding shaft 114 and the cylindrical portion 152 b of the guide roller mounting plate 152. According to this, when the orthogonal speed reducer 156 slides back and forth, the bellows 157 expands and contracts.

  The unwinding shaft 114 is pivotally supported by the bearing 154 on the back plate 102a via the guide roller mounting plate 152, but is not limited thereto. When the guide roller mounting plate 152 is not provided, it may be supported by the bearing 154 on the back surface 102 a of the chamber 102.

  Such a shaft driving unit 150 is also provided on the winding shaft 124. Also in the case of the winding shaft 124, when the guide roller mounting plate 152 is not provided, the shaft 102 may be supported by the bearing 154 on the back surface 102 a of the chamber 102.

  According to such a shaft drive unit 150, while the unwinding shaft 114 and the unwinding shaft 124 are rotated by the rotation drive motor 105, either the unwinding shaft 124 or the unwinding shaft 114 is moved to the other by the slide drive motor 160. Can be slid freely in the axial direction. Thereby, the meandering of the electrode sheet W can be corrected. As described above, it is most effective to correct the meandering of the electrode sheet W by slidingly driving only the winding electrode sheet W, that is, only the winding shaft 124 in the axial direction.

  At this time, it is more preferable to provide a sensor for detecting the meandering of the electrode sheet W to monitor the meandering and correct the meandering when meandering. The meandering correction amount is controlled by the slide correction amount in the axial direction, for example. Specifically, for example, as shown in FIG. 6, a meandering monitoring window 172 may be provided on the ceiling of the chamber 102 and a meandering detection sensor 170 may be provided outside the meandering monitoring window 172.

  The meandering detection sensor 170 is preferably arranged at a position close to the shaft (the unwinding shaft 114 or the winding shaft 124) to be slid to correct the meandering. For example, when the winding shaft 124 side is slid and driven, it is arranged at a position close to the winding shaft 124 as shown in FIG.

  In this case, in order to perform meandering correction until the end of winding of the electrode sheet W, it is preferable to arrange the meandering detection sensor 170 in consideration of the diameter of the electrode sheet W at the end of winding. Specifically, for example, as shown in FIG. 6, a position separated from the center of the winding shaft 124 toward the winding shaft 114 by the radius of the outer periphery (dashed line) of the electrode sheet W expected at the end of winding. , It is preferably disposed within a range d between the guide roller 108 closest to the winding shaft 124. The arrangement position of the meandering detection sensor 170 is not limited to the position shown in the figure, and the meandering detection sensor 170 may be arranged other than the ceiling of the chamber 102.

  When monitoring the meandering of the electrode sheet W from the ceiling of the chamber 102, the lid 104 of the ceiling is divided into two parts on the left and right of the attachment part of the meandering monitoring window 172 like the lids 104a and 104b shown in FIG. , These may be opened and closed separately.

  Further, a monitoring window 174 may be provided on the lower surface of each of the accommodating portions 110 and 120, and a winding diameter measurement sensor 175 for measuring the winding diameter of the electrode sheet W from the outside of the monitoring window 174 may be provided. According to this, the end of drying can be detected by detecting the end of winding of the electrode sheet W.

  By the way, when performing the drying process while winding the electrode sheet W as in the present embodiment, the temperature of the electrode sheet W depends not only on the output of the infrared irradiation unit 136 but also on the feeding speed (winding speed) of the electrode sheet W. Also changes. For example, even if the output of the infrared irradiation unit 136 is the same, the smaller the feed rate of the electrode sheet W, the slower the electrode sheet W. Therefore, the amount of heat received when the electrode sheet W passes through the infrared irradiation unit 136 also increases. For this reason, the temperature of the electrode sheet W can be raised as the feeding speed of the electrode sheet W is reduced.

  Therefore, the electrode sheet drying apparatus 100 according to the present embodiment is provided with a temperature sensor for detecting the temperature of the electrode sheet W, and the output (light emission) of the infrared irradiation unit 136 so that the temperature of the electrode sheet W becomes a predetermined set temperature. (Strength) and / or the feeding speed of the electrode sheet W may be adjusted. In this case, the feeding speed of the electrode sheet W can be adjusted by adjusting the rotational speed of one or both of the unwinding shaft 114 and the winding shaft 124.

  Thus, by adjusting one or both of the output of the infrared irradiation unit 136 and the feeding speed of the electrode sheet W, the temperature of the electrode sheet W can be adjusted more accurately. Further, the temperature of the electrode sheet W can be adjusted by the feed speed of the electrode sheet W without increasing the output of the infrared irradiation unit 136.

  The temperature sensor described above is configured by a non-contact thermometer such as a radiation thermometer, for example, so that the temperature of the electrode sheet W being wound can be measured in a non-contact manner. Specifically, for example, a radiation thermometer is disposed outside the chamber 102 toward the electrode sheet W through a quartz window (not shown), and the temperature of the electrode sheet W is detected from the outside of the chamber 102 in a non-contact manner.

  In this case, by measuring the thermal resistance of the electrode sheet W in advance, the radiation thermometer can measure the temperature of the electrode sheet W only by being arranged on one side of the electrode sheet W. For this reason, the radiation thermometer may be arranged on either the upper side or the lower side of the electrode sheet W. For example, as shown in FIG. 6, when the infrared irradiation unit 136 irradiates infrared rays from the lower side of the electrode sheet W, a radiation thermometer is arranged on the upper side of the electrode sheet W to measure the temperature of the electrode sheet W. It may be.

  Further, non-contact thermometers such as a radiation thermometer may be arranged on both the upper and lower sides of the electrode sheet W. According to this, for example, when both the upper surface and the lower surface of the electrode sheet W are separately irradiated with infrared rays by the infrared irradiation unit 136, or when the temperature difference between the upper surface and the lower surface increases due to the large thermal resistance of the drying object. In addition, the temperatures on both sides of the electrode sheet W can be accurately measured. The arrangement of the non-contact thermometer is not limited to that described above, and the non-contact thermometer is not limited to the radiation thermometer.

(Configuration Example of Electrode Sheet Drying Device According to Second Embodiment)
Next, the structural example of the electrode sheet drying apparatus concerning 2nd Embodiment of this invention is demonstrated, referring drawings. In 2nd Embodiment, the electrode sheet drying apparatus comprised so that the several roll-shaped electrode sheet W could be dried simultaneously is mentioned as an example. In addition, about the part which has the same function as 1st Embodiment, the same code | symbol is attached | subjected and the detailed description is abbreviate | omitted.

  FIG. 7 is a configuration example of an electrode sheet drying apparatus 101 according to the second embodiment. The electrode sheet drying apparatus 101 is configured to be able to dry two roll-shaped electrode sheets W simultaneously. Specifically, as shown in FIG. 7, the roll-out shaft 114, the winding shaft 124, each guide roller 108, and the tension roller 109 are extended in front of the chamber 102, so that two rolls are provided in the front and rear in the chamber 102. A shaped electrode sheet W can be attached.

  According to this, by rotating the common unwinding shaft 114 and the winding shaft 124, the two roll-shaped electrode sheets W can be unwound simultaneously and dried in a vacuum atmosphere while being wound. Moreover, according to this configuration, by extending the lengths of the unwinding shaft 114 and the winding shaft 124 further forward, three or more roll-shaped electrode sheets W can be attached and dried simultaneously.

  Note that the electrode sheet drying apparatus 101 that can simultaneously dry a plurality of roll-shaped electrode sheets W is not limited to the configuration shown in FIG. 7. For example, the winding shaft 124 is provided separately shifted. It may be. For example, FIG. 8 shows a case where only the winding shaft 124 and the guide roller 108 on the winding side are separately shifted. Specifically, as shown in FIG. 9, the winding shaft 124 and the guide roller 108 on the winding side are respectively shifted in the horizontal direction. Each winding shaft 124 may be provided with the above-described shaft driving unit 150 so that the meandering correction can be performed.

  Also by the electrode sheet drying apparatus 101 shown in FIGS. 8 and 9, two roll-shaped electrode sheets W can be simultaneously unwound and dried in a vacuum atmosphere while being wound. In addition, the meandering correction of the two electrode sheets W can be adjusted separately by providing the winding shaft 124 separately and providing the shaft driving unit 150 for each.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above-described embodiment, the case of drying an electrode sheet used in a lithium ion secondary battery has been described as an example. However, the present invention is not limited to this, and a roll-like shape that requires removal of impurities such as moisture is necessary. Any electrode sheet can be dried as long as it is an electrode sheet. For example, not only an electrode sheet used for a battery but also an electrode sheet used for an electronic component such as a capacitor may be used.

  The present invention can be applied to an electrode sheet drying apparatus and an electrode sheet drying method for drying a roll-shaped electrode sheet used for a lithium battery or the like.

DESCRIPTION OF SYMBOLS 100,101 Electrode sheet drying apparatus 102 Chamber 102a Back plate 103 Opening part 104 Cover part 104a, 104b Cover part 105 Rotation drive motor 105,125 Rotation drive motor 106 Transparent window 108 Guide roller 109 Tension roller 110 Unwinding side accommodating part 112 Door 114 114 Unwinding shaft 115 Roll core 120 Winding side accommodating portion 121 Opening 122 Door 124 Winding shaft 125 Roll core 130 Communication portion 132 Opening 134 Light transmission window 136 Infrared irradiation unit 140 Vacuum exhaust device 142 Exhaust port 150 Shaft Drive portion 152 Guide roller mounting plate 152a Plate portion 152b Tube portion 154 Bearing 156 Orthogonal reduction gear 157 Bellows 158 Slide member 159 Slider 160 Slide drive motor 162 Slide guide 164 Ball screw 170 Meander detection sensor 172 meandering monitoring window 174 monitor window 175 wound diameter measuring sensor 200 control unit 210 operation unit 220 storage unit W electrode sheet

Claims (9)

An electrode sheet drying apparatus for unwinding and drying a rolled electrode sheet,
The unwinding side accommodating portion and the winding side accommodating portion capable of accommodating the roll-shaped electrode sheet are provided separately from each other, and a communication portion is provided that communicates the inside of the unwinding side accommodating portion and the inside of the winding side accommodating portion. An airtight chamber,
An evacuation apparatus connected to an exhaust port for exhausting the interior of the chamber, and for evacuating the interior of the chamber;
An unwinding shaft provided in the unwinding-side accommodation portion;
A take-up shaft provided in the take-up side accommodating portion;
A plurality of guide rollers for guiding the electrode sheet unwound from the unwinding side accommodating portion to the unwinding side accommodating portion through the communicating portion;
An infrared irradiation unit that is provided outside the chamber and that irradiates infrared rays through a transmission window provided in the middle of the communication part with respect to the electrode sheet passing through the communication part;
An electrode sheet drying apparatus comprising: 2. The electrode sheet drying apparatus according to claim 1, wherein the electrode sheet is dried at a vacuum pressure of 30000 Pa or less in the chamber. The electrode sheet drying apparatus according to claim 1, wherein a shaft driving unit that performs rotational driving and axial driving is provided on one or both of the unwinding shaft and the winding shaft. A meandering detection sensor for detecting meandering in the axial direction of the electrode sheet when the electrode sheet unwound by the unwinding shaft is wound by the winding shaft;
The meandering correction amount in the axial direction of the electrode sheet is calculated based on the detection result of the meandering detection sensor, and the slide drive of the shaft driving unit is controlled based on the meandering correction amount. The electrode sheet drying apparatus as described. 5. The electrode according to claim 1, wherein a plurality of roll-shaped electrode sheets are arranged in an axial direction of the unwinding shaft, and the plurality of roll-shaped electrode sheets are simultaneously unwound and dried. Sheet drying device. 6. The electrode sheet drying apparatus according to claim 5, wherein the winding shaft is provided separately for each of the electrode sheets, and the winding shafts are arranged to be shifted. A temperature sensor for detecting the temperature of the electrode sheet is provided, and either or both of the output of the infrared irradiation unit and the feeding speed of the electrode sheet are adjusted so that the temperature of the electrode sheet becomes a predetermined set temperature. The electrode sheet drying apparatus according to any one of claims 1 to 6. An electrode sheet drying method in which a roll-shaped electrode sheet is unwound using an electrode sheet drying apparatus and dried while being wound.
The electrode sheet drying device is provided with an unwinding side accommodating portion and a winding side accommodating portion that can accommodate the roll-shaped electrode sheet spaced apart, and the inside of the unwinding side accommodating portion and the inside of the winding side accommodating portion are provided. An airtight chamber having a communicating portion, a vacuum exhaust device connected to an exhaust port for exhausting the inside of the chamber and making the inside of the chamber have a vacuum pressure, and an unwinding shaft provided in the unwinding side accommodating portion A plurality of winding shafts provided in the take-up side accommodating part, and a plurality of the electrode sheets unwound from the unwinding-side accommodation part through the communicating part to the take-up side accommodating part. A guide roller, and an infrared irradiation unit that is provided outside the chamber and irradiates the electrode sheet passing through the communication part with infrared rays through a transmission window provided in the middle of the communication part;
Evacuating the chamber with the evacuation device to reduce the pressure to a predetermined vacuum pressure;
Unwinding the electrode sheet from the unwinding shaft and winding the electrode sheet while heating the electrode sheet by irradiating infrared rays with the infrared irradiation unit; and
A method for drying an electrode sheet, comprising: The electrode sheet drying method according to claim 8, wherein the predetermined vacuum pressure in the chamber is 30000 Pa or less.

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