JP2012146848A - Electrode manufacturing device, electrode manufacturing method, program, and computer storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately and efficiently form an active material layer on a surface of a belt-like substrate when manufacturing an electrode.SOLUTION: An electrode manufacturing device comprises an unwind roll 10 unwinding a belt-like metal foil M, a coating part 11 coating an active material compound on both sides of the metal foil M, a dehydration part 12 dehydrating the active material compound coated on the metal foil M to form an active material layer, and a wind roll 13 winding the metal foil M. The dehydration part 12 is arranged in line in a length direction of the metal foil M and includes a plurality of rod heaters 30 emitting infrared rays. The dehydration part 12 is divided into a plurality of regions Ta, Tb, Tc. A temperature of the rod heater 30 in one of the regions Ta, Tb, Tc is set, with respect to a film thickness of water in the active material compound in the one of the regions Ta, Tb, Tc, at a temperature within a range in which the active material compound does not boil and at a temperature in which an infrared ray absorption ratio of water becomes maximum.

Description

  The present invention relates to an electrode manufacturing apparatus that manufactures an electrode by forming an active material layer on both surfaces of a belt-shaped substrate, an electrode manufacturing method using the electrode manufacturing apparatus, a program, and a computer storage medium.

  In recent years, a lithium ion capacitor (LIC), an electric double layer capacitor (EDLC) and a lithium ion have been utilized by taking advantage of the small size, light weight, high energy density, and the ability to repeatedly charge and discharge. Demand for electrochemical elements such as batteries (LIB: Lithium Ion Battery) is rapidly expanding.

  Lithium ion batteries have a relatively high energy density and are used in fields such as mobile phones and notebook personal computers. In addition, since the electric double layer capacitor can be rapidly charged and discharged, it is used as a memory backup compact power source for personal computers and the like. Furthermore, the electric double layer capacitor is expected to be applied as a large power source for electric vehicles. In addition, lithium ion capacitors that combine the advantages of lithium ion batteries and the advantages of electric double layer capacitors are attracting attention because of their high energy density and power density.

  For example, an electrode of such an electrochemical element is formed by applying an active material mixture containing an active material or a solvent to the surface of a metal foil that is a current collector as a base material, and then drying the active material mixture. It is manufactured by forming a material layer. For example, an electrode manufacturing apparatus in which a coating apparatus and a dryer are disposed between an unwinding roll and a winding roll is used for manufacturing the electrode. The coating apparatus has a coating head in which a coating port for coating the active material mixture is formed. The dryer has a plurality of heaters arranged at predetermined intervals. Then, while transporting the strip-shaped metal foil between the unwinding roll and the winding roll substantially vertically upward, the coating material and the dryer apply and dry the active material mixture on the surface of the metal foil, respectively. (Patent Document 1).

JP 2010-186782 A

  Here, when the active material mixture coated on the surface of the metal foil is dried, if the drying is performed rapidly, the solvent may boil inside the active material mixture, and convection or bubbles may be generated. In such a case, irregularities are formed on the surface of the active material layer on the metal foil, and the active material layer is not properly formed. Moreover, there is a possibility that peeling occurs at the boundary between the metal foil and the active material layer.

  However, in the dryer described in Patent Document 1, only a plurality of heaters are arranged at a predetermined interval, and the measures for avoiding the above-described rapid drying are not considered. For this reason, the active material layer could not be appropriately formed on the surface of the metal foil.

  On the other hand, it is also conceivable to arrange a large number of the heaters so as to secure a sufficient drying time and gradually dry the active material mixture. However, in such a case, the length of the dryer becomes long and the active material mixture cannot be efficiently dried.

  This invention is made | formed in view of this point, and when manufacturing an electrode, it aims at forming an active material layer in the surface of a strip | belt-shaped base material appropriately and efficiently.

  In order to achieve the above object, the present invention provides an electrode manufacturing apparatus for manufacturing an electrode by forming an active material layer on both surfaces of a strip-shaped base material, the unwinding unit for unwinding the base material, and the unwinding An active material mixture prepared by winding the base material unwound at the part and between the unwinding part and the wind-up part and mixed with an active material and a solvent; A coating part to be worked, and a drying part which is provided between the coating part and the winding part, and which forms the active material layer by drying the active material mixture coated in the coating part; The drying unit is arranged side by side in the longitudinal direction of the substrate, and has a plurality of rod heaters that irradiate infrared rays, and the drying unit is divided into a plurality of regions where the temperatures of the rod heaters are different. The temperature of the rod heater in the one region is the active material relative to the film thickness of the solvent on the substrate in the one region. Agent is a temperature in the range that does not boil, infrared absorptivity of the solvent is characterized in that it is set to a temperature of maximum. In the present invention, the phrase “the active material mixture does not boil” means that the solvent in the active material mixture does not boil.

  According to the present invention, the drying section is divided into a plurality of regions, and the temperature of the rod heater in one region is set to a temperature within a range where the active material mixture does not boil. Unevenness is not formed on the surface of the material layer, and an active material layer having a smooth surface can be formed with a uniform thickness. Moreover, peeling does not occur at the boundary between the base material and the active material layer. Moreover, since the temperature of the rod heater in one region is set to a temperature at which the infrared absorption rate of the solvent is maximized, the active material mixture can be efficiently heated and dried. And since the temperature setting of such a rod heater is performed for every area | region, the drying time of an active material mixture can be shortened rather than before, and the length of a drying part can also be shortened. As described above, according to the present invention, the active material layer can be appropriately and efficiently formed on the surface of the substrate.

  The rod heater may include a ceramic outer cylinder and a heating element provided inside the outer cylinder.

  The solvent may be water.

  The drying unit is divided into three regions, an upstream region, a midstream region, and a downstream region from the unwinding unit side, and the temperature of the rod heater disposed in the upstream region is set to 200 ° C. and disposed in the downstream region. The temperature of the rod heater to be set is set to 600 ° C., and the rod heater set to a temperature higher than 200 ° C. and lower than 600 ° C. may be arranged in the midstream region.

  The drying unit is divided into three regions, an upstream region, a midstream region, and a downstream region from the unwinding unit side, and the temperature of the rod heater disposed in the upstream region is set to 200 ° C. The temperature of the arranged rod heater may be set to 600 ° C., and the upstream region rod heater and the downstream region rod heater may be mixed and disposed in the midstream region.

  The drying unit may include an air supply mechanism that supplies air between the plurality of rod heaters and the base material.

  The unwinding unit and the winding unit may be arranged so as to convey the substrate in a direction in which the longitudinal direction of the substrate is the horizontal direction and the short direction of the substrate is the vertical direction. .

  The electrode may be an electrode used for a lithium ion capacitor, an electric double layer capacitor, or a lithium ion battery.

  Another aspect of the present invention is an electrode manufacturing method for manufacturing an electrode by forming an active material layer on both surfaces of a base material while conveying a belt-shaped base material between an unwinding unit and a winding unit. In the coating part, an active material mixture in which an active material and a solvent are mixed is applied to both surfaces of the base material, and then the active material applied in the coating process in the drying part A drying step of drying the mixture to form an active material layer, and the drying unit is arranged in the longitudinal direction of the base material and includes a plurality of rod heaters that irradiate infrared rays, and the drying unit Is divided into a plurality of regions having different temperatures of the rod heater, and the temperature of the rod heater in one region is the active material relative to the film thickness of the solvent on the substrate in the one region. The temperature of the mixture does not boil, and the infrared absorption rate of the solvent is maximized. It is characterized in that it is set each time.

  The rod heater may have a ceramic outer cylinder and a heating element provided inside the outer cylinder.

  The solvent may be water.

  The drying unit is divided into three regions, an upstream region, a midstream region, and a downstream region from the unwinding unit side, and the temperature of the rod heater disposed in the upstream region is set to 200 ° C., and the downstream region The temperature of the rod heater to be arranged is set to 600 ° C., and a rod heater having a temperature set to be greater than 200 ° C. and less than 600 ° C. may be arranged in the midstream region.

  The drying unit is divided into three regions, an upstream region, a midstream region, and a downstream region from the unwinding unit side, and the temperature of the rod heater disposed in the upstream region is set to 200 ° C. The temperature of the arranged rod heater may be set to 600 ° C., and the upstream region rod heater and the downstream region rod heater may be mixed and disposed in the midstream region.

  The drying unit includes an air supply mechanism that supplies air between the plurality of rod heaters and the base material, and in the drying step, radiation heating by infrared rays from the plurality of rod heaters, and the air supply mechanism The active material mixture may be dried by convection heating with air supplied from the above.

  The coating process and the drying process may be performed on the substrate being conveyed in a direction in which the longitudinal direction of the substrate is the horizontal direction and the short direction of the substrate is the vertical direction.

  The electrode may be an electrode used for a lithium ion capacitor, an electric double layer capacitor, or a lithium ion battery.

  According to another aspect of the present invention, there is provided a program that runs on a computer of a control unit that controls the electrode manufacturing apparatus in order to cause the electrode manufacturing apparatus to execute the electrode manufacturing method.

  According to another aspect of the present invention, a readable computer storage medium storing the program is provided.

  ADVANTAGE OF THE INVENTION According to this invention, when manufacturing an electrode, an active material layer can be appropriately and efficiently formed on the surface of a strip | belt-shaped base material.

It is a schematic side view which shows the outline of a structure of the electrode manufacturing apparatus concerning this Embodiment. It is a top view which shows the outline of a structure of the electrode manufacturing apparatus concerning this Embodiment. It is a side view of the electrode manufactured with an electrode manufacturing apparatus. It is a top view of the electrode manufactured with an electrode manufacturing apparatus. It is a perspective view which shows the outline of a structure of a coating head. It is a side view which shows the outline of a structure of a drying part. It is a top view which shows the outline of a structure of a drying part. It is explanatory drawing which shows the outline of a structure of a rod heater. It is the flowchart which showed the process of setting the temperature of a rod heater. It is a graph which shows the 1st correlation with the wavelength of the infrared rays which a rod heater radiates | emits, and the absorption factor of the infrared rays of water. It is a graph which shows the 2nd correlation with the temperature of a rod heater, and the wavelength of the infrared rays which a rod heater radiates | emits. It is a graph which shows the 3rd correlation with the film thickness of the water in an active material mixture, and the temperature of a rod heater when the boiling of an active material mixture starts. It is a top view which shows the outline of a structure of the coating part concerning other embodiment. It is a schematic plan view which shows the outline of a structure of the electrode manufacturing apparatus concerning other embodiment. It is a side view which shows the outline of a structure of the electrode manufacturing apparatus concerning other embodiment.

  Embodiments of the present invention will be described below. FIG. 1 is a schematic side view showing an outline of a configuration of an electrode manufacturing apparatus 1 according to the present embodiment. FIG. 2 is a plan view schematically showing the configuration of the electrode manufacturing apparatus 1. In addition, in the electrode manufacturing apparatus 1 of this Embodiment, the electrode of a lithium ion capacitor is manufactured.

  In the electrode manufacturing apparatus 1, an electrode E in which an active material layer F is formed on both surfaces of a metal foil M as a strip-shaped base as shown in FIGS. 3 and 4 is manufactured. The active material layers F on both sides of the metal foil M are formed to face each other. Moreover, the active material layer F is formed in the center part of the transversal direction (Z direction in FIG. 3) of the metal foil M, and plural in the longitudinal direction (Y direction in FIGS. 3 and 4) of the metal foil M. It is formed.

  The metal foil M is a porous current collector, for example. When a positive electrode is manufactured as the electrode E, for example, an aluminum foil is used as the metal foil M. On the other hand, when manufacturing a negative electrode, copper foil is used as the metal foil M, for example.

  Further, in order to form the active material layer F, a slurry-like active material mixture is applied to the surface of the metal foil M as described later. The positive electrode active material mixture used in the production of the positive electrode includes, for example, conductive materials such as activated carbon as an active material, an acrylic binder as a binder, carboxymethyl cellulose as a dispersant, and acetylene black as a conductive additive. It is produced by mixing carbon powder, adding water as a solvent thereto, and kneading. On the other hand, the negative electrode active material mixture used in the production of the negative electrode includes, for example, amorphous carbon as an active material capable of occluding and releasing lithium ions, polyvinylidene fluoride as a binder, and conductive additive. It is produced by mixing a conductive carbon material such as acetylene black, adding water as a solvent thereto, and kneading.

  As described above, the positive electrode and the negative electrode are different in material, but the width, thickness and the like of the metal foil M and the active material layer F are not significantly different. For this reason, the electrode manufacturing apparatus 1 can manufacture both the positive electrode and the negative electrode of the lithium ion capacitor. Hereinafter, the positive electrode and the negative electrode will be referred to as an electrode E for explanation.

  As shown in FIGS. 1 and 2, the electrode manufacturing apparatus 1 includes an unwinding roll 10 as an unwinding unit for unwinding the metal foil M, and a coating unit that applies an active material mixture to both surfaces of the metal foil M. 11, a drying unit 12 for drying the active material mixture on the metal foil M to form the active material layer F, and a winding roll 13 as a winding unit for winding the metal foil M. The unwinding roll 10, the coating part 11, the drying part 12, and the winding roll 13 are arranged in this order from the upstream side in the transport direction of the metal foil M (the Y direction in FIGS. 1 and 2). A driving mechanism (not shown) is provided between the unwinding roll 10 and the winding roll 13, and the metal foil M unwound from the unwinding roll 10 is conveyed by this driving mechanism to be wound up. The roll 13 is wound up.

  The unwinding roll 10 is arrange | positioned in the direction from which the axial direction turns into a perpendicular direction (Z direction in FIG. 1). An untreated metal foil M is wound around the unwinding roll 10, and the unwinding roll 10 is configured to be rotatable around a vertical axis. The metal foil M is unwound from the unwinding roll 10 as it is pulled in the longitudinal direction.

  The winding roll 13 is also arranged in such a direction that its axial direction becomes the vertical direction. The take-up reel 13 is configured to be rotatable about a vertical axis. Then, the metal foil M on which the active material layer F is formed is wound around the winding roll 13.

  The unwinding roll 10 and the winding roll 13 are arranged at the same height. And as for the unwinding roll 10 and the winding roll 13, the longitudinal direction of the metal foil M is a horizontal direction (Y direction in FIG.1 and FIG.2), and the transversal direction of the metal foil M is a vertical direction (FIG. 1 is arranged so as to convey the metal foil M in a direction (Z direction in FIG. 1).

  The coating unit 11 has a coating head 20 that coats the surface of the metal foil M with an active material mixture. The coating head 20 is disposed opposite to both sides of the metal foil M being conveyed between the unwinding roll 10 and the winding roll 13.

  As shown in FIG. 5, the coating head 20 has a substantially rectangular parallelepiped shape extending in the vertical direction (Z direction in FIG. 5). The coating head 20 is formed longer than the short side direction of the metal foil M, for example. On the surface of the coating head 20 facing the metal foil M, a slit-shaped coating port 21 for discharging the active material mixture is formed. The coating port 21 is formed to extend in the vertical direction (Z direction in FIG. 5). Further, the coating port 21 is formed at a position where the active material mixture can be supplied to the central portion of the metal foil M in the short direction. Further, a supply pipe 23 communicating with an active material mixture supply source 22 is connected to the coating head 20. The active material mixture is stored inside the active material mixture supply source 22 so that the active material mixture can be supplied from the active material mixture supply source 22 to the coating head 20.

  As shown in FIGS. 1, 2, and 6, the drying unit 12 includes a plurality of, for example, three regions Ta, Tb, and Tc in the longitudinal direction of the metal foil M (the Y direction in FIGS. 1, 2, and 6). It is divided. Hereinafter, these three regions Ta, Tb, and Tc are referred to as “upstream region Ta”, “middle stream region Tb”, and “downstream region Tc” from the unwinding roll 10 side, that is, from the upstream side in the conveying direction of the metal foil M. There is a case. Note that these three regions Ta, Tb, and Tc are divided into regions having different temperatures of the rod heater 30 described later.

  Moreover, the drying part 12 has the some rod heater 30 which irradiates infrared rays, as shown in FIG. The rod heater 30 is arranged side by side in the longitudinal direction of the metal foil M (Y direction in FIG. 7). These rod heaters 30 are arranged on both sides of the metal foil M being conveyed between the unwinding roll 10 and the winding roll 13.

  As shown in FIG. 8, the rod heater 30 includes an inner cylinder 31 and an outer cylinder 32 provided so as to surround the inner cylinder 31. A nichrome wire heater 33 having a nichrome wire as a heating element is spirally provided on the outer peripheral portion of the inner cylinder 31. The nichrome wire heater 33 is provided longer than the length in the short direction of the metal foil M in the vertical direction (Z direction in FIG. 8). In other words, the rod heater 30 can irradiate infrared rays on the entire short direction of the metal foil M. The material of the outer cylinder 32 is ceramic. The inner cylinder 31 has heat resistance, and the material thereof is, for example, ceramic or alumina.

  As described above, the drying unit 12 is divided into three regions Ta, Tb, and Tc where the temperature of the rod heater 30 is different. Therefore, for convenience, among the plurality of rod heaters 30, the rod heater 30 disposed in the upstream region Ta is referred to as “upstream rod heater 30 a” and the rod heater disposed in the midstream region Tb, as shown in FIGS. 1, 2, and 6. 30 may be referred to as “middle stream rod heater 30b”, and the rod heater 30 disposed in the downstream region Tc may be referred to as “downstream rod heater 30c”. A method for setting the temperatures of the upstream rod heater 30a, the midstream rod heater 30b, and the downstream rod heater 30c will be described in detail later.

  Further, as shown in FIG. 7, the drying unit 12 is disposed to face the surface of the metal foil M with the rod heater 30 interposed therebetween, and has a reflector 40 that reflects infrared rays from the rod heater 30 toward the metal foil M side. ing. The reflecting plate 40 extends in the vertical direction so as to cover the rod heater 30 and extends in the longitudinal direction of the metal foil M (Y direction in FIG. 7) so as to cover the plurality of rod heaters 30. The infrared rays radiated from the rod heater 30 to the opposite side of the metal foil M are reflected by the reflector 40 and radiated to the metal foil M. In addition, this reflecting plate 40 is arrange | positioned at the both sides of the metal foil M currently conveyed between the unwinding roll 10 and the winding roll 13. FIG.

  A plurality of air supply ports 41 for supplying air to the drying region D formed between the reflection plate 40 and the metal foil M are formed in the reflection plate 40. Each air supply port 41 is provided with a supply pipe 42 for supplying air to the air supply port 41. The supply pipe 42 communicates with the air supply source 43. Air, for example, dry air, is stored in the air supply source 43. Then, the air supplied from the air supply port 41 into the drying region D flows along the surface of the metal foil M and is then exhausted from the end of the drying region D. The air supply port 41, the supply pipe 42, and the air supply source 43 constitute an air supply mechanism of the present invention.

  The above electrode manufacturing apparatus 1 is provided with a control unit 50 as shown in FIG. The control unit 50 is, for example, a computer and has a program storage unit (not shown). The program storage unit stores a program for controlling processing for manufacturing the electrode E in the electrode manufacturing apparatus 1. The program is recorded on a computer-readable storage medium H such as a computer-readable hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnetic optical desk (MO), or a memory card. May have been installed in the control unit 50 from the storage medium H.

  Next, a method for setting the temperatures of the upstream rod heater 30a, the midstream rod heater 30b, and the downstream rod heater 30c described above will be described. The temperature of the rod heaters 30 a to 30 c refers to the temperature of the outer cylinder 32 heated by the nichrome wire heater 33.

  First, a method for setting the temperature of the upstream rod heater 30a will be described. FIG. 9 shows a flow for setting the temperature of the upstream rod heater 30a. The temperature of the upstream rod heater 30a is a temperature in a range where the active material mixture does not boil with respect to the solvent in the active material mixture dried in the upstream region Ta, that is, the film thickness of water, and the infrared ray of water The temperature is set to a temperature at which the absorption rate of the gas becomes maximum. In addition, that an active material mixture does not boil means that the water in the said active material mixture does not boil.

  Specifically, as shown in FIG. 10, the relationship between the wavelength of infrared rays radiated from the rod heater 30 (horizontal axis in FIG. 10) and the infrared absorption rate of water (vertical axis in FIG. 10) is represented. The first correlation is derived in advance. A 1st correlation is derived | led-out for every film thickness of the water in an active material mixture (process A1 of FIG. 9). In addition, the film thickness of water is substantially the same as the film thickness of the active material mixture itself. In the illustrated example, there are two types of water film thicknesses of 10 μm and 2 μm, but in practice, the first correlation with respect to other film thicknesses is also derived in advance.

  Further, as shown in FIG. 11, the second correlation representing the relationship between the temperature of the rod heater 30 (horizontal axis in FIG. 11) and the wavelength of infrared rays radiated by the rod heater 30 (vertical axis in FIG. 11). Is derived in advance (step A1 in FIG. 9).

  Further, as shown in FIG. 12, the film thickness of water in the active material mixture (horizontal axis in FIG. 12) and the temperature of the rod heater 30 when the boiling of the active material mixture starts (the vertical axis in FIG. 12). The third correlation representing the relationship with the axis) is derived in advance (step A1 in FIG. 9). In FIG. 12, the active material mixture boils above the third correlation, that is, when the temperature of the rod heater 30 is higher than the temperature of the third correlation. On the other hand, in FIG. 12, when the temperature of the rod heater 30 is lower than the third correlation, that is, when the temperature of the rod heater 30 is lower than the temperature of the third correlation, the boiling of the active material mixture does not boil.

  And the film thickness of the water in the active material mixture dried in the upstream area | region Ta is estimated (process A2 of FIG. 9). In the present embodiment, the film thickness of the water is estimated to be 10 μm, for example.

  Then, based on the film thickness of water estimated in step A2, the first correlation is used to determine the infrared wavelength (hereinafter sometimes referred to as “peak wavelength”) corresponding to the maximum infrared absorption rate of water. Derived (step A3 in FIG. 9). In the present embodiment, the peak wavelength for water having a film thickness of 10 μm is 3 μm.

  Then, based on the peak wavelength derived in step A3, the temperature of the upstream rod heater 30a is derived using the second correlation (step A4 in FIG. 9). In the present embodiment, the temperature of the upstream rod heater 30a with respect to the peak wavelength of 3 μm is 600 ° C.

  Thereafter, based on the water film thickness estimated in step A2 and the temperature of the upstream rod heater 30a derived in step A4, it is determined whether or not the active material mixture is boiled using the third correlation. (Step A5 in FIG. 9).

  When it is determined in step A5 that the active material mixture does not boil, the temperature of the upstream rod heater 30a is set to the temperature derived in step A4 (step A6 in FIG. 9). On the other hand, when it determines with an active material mixture boiling in process A5, it returns to process A3 mentioned above and performs process A3-A5. And it repeats these processes A3-A5 until it determines with the active material mixture not boiling in process A5.

  In the present embodiment, in step A5, the temperature in the third correlation is 500 ° C. with respect to the water film thickness of 10 μm. In contrast, the temperature of the upstream rod heater 30a derived in step A4 is 600 ° C. Therefore, the active material mixture boils.

  Thus, in this Embodiment, since it determines with an active material mixture boiling in process A5, it returns to process A3. In step A3, a peak wavelength corresponding to the next absorption rate of the maximum absorption rate is derived using the first correlation. In the present embodiment, the peak wavelength is 6 μm. Thereafter, in step A4, the temperature of 200 ° C. of the upstream rod heater 30a with respect to the peak wavelength of 6 μm is derived using the second correlation. Thereafter, in step A5, it is determined whether or not the active material mixture boils using the third correlation. In the present embodiment, when the temperature of the upstream rod heater 30a is 200 ° C., the active material mixture does not boil.

  As described above, when it is determined in step A5 that the active material mixture does not boil, the temperature of the upstream rod heater 30a is set to the temperature derived in step A4 (step A6 in FIG. 9). In the present embodiment, the temperature of the upstream rod heater 30a is set to 200 ° C.

  Similarly, the temperatures of the midstream rod heater 30b and the downstream rod heater 30c are set by performing the above-described steps A1 to A6. And in this Embodiment, the temperature of the downstream rod heater 30c is set to 600 degreeC. The temperature of the midstream rod heater 30b is set to, for example, 500 ° C., which is a temperature higher than 200 ° C. and lower than 600 ° C.

  The electrode manufacturing apparatus 1 according to the present embodiment is configured as described above. Next, the process for manufacturing the electrode E performed by the electrode manufacturing apparatus 1 will be described.

  The metal foil M is unwound from the unwinding roll 10 and conveyed to the coating unit 11. In the coating unit 11, the slurry-like active material mixture S is applied from the coating head 20 to the surface of the metal foil M being conveyed. At this time, the active material mixture S is simultaneously applied to both surfaces of the metal foil M with a uniform film thickness by supplying the active material mixture S from the coating heads 20 and 20 disposed on both sides of the metal foil M. Is done. Further, the active material mixture S supplied from the coating head 20 is applied to the central portion of the metal foil M in the short direction. Furthermore, the active material mixture S is applied to a plurality of regions in the longitudinal direction of the metal foil M by intermittently supplying the active material mixture S from the coating head 20.

  Thereafter, the metal foil M coated with the active material mixture S is conveyed to the drying unit 12. In the drying unit 12, the active material mixture S on both surfaces of the metal foil M is dried by radiation heating with infrared rays from the plurality of rod heaters 30 and the plurality of reflectors 40 arranged on both sides of the metal foil M. At this time, as described above, the temperature of the upstream rod heater 30a is set to 200 ° C., the temperature of the midstream rod heater 30b is set to 500 ° C., and the temperature of the downstream rod heater 30c is set to 600 ° C. Then, the active material mixture S absorbs infrared rays to the maximum without boiling the active material mixture S, and the active material mixture S is sequentially dried at the above temperature.

  Further, in the drying unit 12, the active material mixture S on both surfaces of the metal foil M is dried by convection heating with air supplied from the air supply port 41 into the drying region D on both sides of the metal foil M. Furthermore, the water evaporated from the active material mixture S smoothly flows to the end of the dry region D by the air flow from the air supply port 41 generated in the dry region D to the end of the dry region D, and the evaporated water Is removed without reattaching to the metal foil M. Thus, the active material mixture S on both surfaces of the metal foil M is dried, and an active material layer F having a predetermined thickness is formed on both surfaces of the metal foil M.

  Thereafter, the metal foil M on which the active material layer F is formed is conveyed to the take-up roll 13 and taken up by the take-up roll 13. Thus, a series of processes in the electrode manufacturing apparatus 1 is completed, and the electrode E is manufactured.

  According to the above embodiment, the drying unit 12 is divided into three regions Ta, Tb, and Tc, and the temperature of the rod heater 30 in one region Ta, Tb, and Tc is in a range where the active material mixture S does not boil. Since the temperature is set, unevenness is not formed on the surface of the active material layer on the metal foil as in the prior art, and the active material layer F having a smooth surface can be formed with a uniform film thickness. . Further, no peeling occurs at the boundary between the metal foil M and the active material layer F. Moreover, since the temperature of the rod heater 30 in one region Ta, Tb, Tc is set to a temperature at which the infrared absorption rate of water is maximized, the active material mixture S can be efficiently heated and dried. . And since the setting of the temperature of such a rod heater 30 is performed for every area | region Ta, Tb, Tc, the drying time of the active material mixture S can be shortened rather than before, and the length of the drying part 12 is also comprised. Can be shortened. As described above, according to the present embodiment, the active material layer F can be appropriately and efficiently formed on the surface of the metal foil M.

  Further, in the drying unit 12, the active on the metal foil M is performed by radiant heating by infrared rays from the plurality of rod heaters 30 and the reflecting plate 40 and convection heating by air supplied from the air supply port 41 into the drying region D. The material mixture S is dried. As described above, since two kinds of drying methods of radiation heating using infrared rays and convection heating using air are used, the active material mixture S can be dried more appropriately. Furthermore, when radiant heating by infrared rays is used, infrared radiant heat is transferred without depending on the distance between the rod heater 30 and the reflector 40 and the metal foil M. Therefore, the active material mixture S can be appropriately heated without being affected by the warp or inclination of the metal foil M.

  In the drying unit 12, an air flow from the air supply port 41 to the end of the drying region D can be generated in the drying region D. By this air flow, the water evaporated when the active material mixture S on the metal foil M is dried is discharged from the end of the drying region D, so that the evaporated water is reattached to the surface of the metal foil M. There is no. Therefore, the active material mixture S on the metal foil M can be dried more appropriately.

  Further, since the reflecting plate 40 is disposed so as to face the surface of the metal foil M with the rod heater 30 in between, the infrared rays radiated from the rod heater 30 to the opposite side of the metal foil M are reflected by the reflecting plate 40. Is emitted to the metal foil M. Therefore, all of infrared rays can be used, and the active material mixture S on the metal foil M can be efficiently dried.

  Moreover, in the coating part 11, since the metal foil M is conveyed in the direction in which the longitudinal direction of the metal foil M becomes the horizontal direction, the active material mixture S applied on the surface of the metal foil M is the metal foil M. It does not flow upstream or downstream in the transport direction. Furthermore, since the metal foil M is conveyed in the direction in which the short direction of the metal foil M is the vertical direction, the active material mixture S can be uniformly applied to both surfaces of the metal foil M. Thus, since the active material mixture S can be applied appropriately in the coating part 11, the active material layer F can be more appropriately formed on the metal foil M.

  Moreover, since the metal foil M is conveyed between the unwinding roll 10 and the winding roll 13 in the direction in which the longitudinal direction is the horizontal direction, the height of the metal foil M can be reduced to a constant level. Maintenance of the manufacturing apparatus 1 becomes easy. Therefore, the active material layer F can be efficiently formed on the surface of the metal foil M.

  In the above embodiment, the temperature of the midstream rod heater 30b is set to 500 ° C. in the midstream region Tb, but the upstream rod heater 30a set to 200 ° C and the downstream set to 600 ° C in the midstream region Tb. The rod heater 30c may be mixed and arranged. In such a case, the upstream rod heater 30a and the downstream rod heater 30c in the midstream region Tb can be arbitrarily arranged within a range where the active material mixture S does not boil. Specifically, the adjustment so that the active material mixture S does not boil may be adjusted, for example, by changing the ratio of the number of the upstream rod heater 30a and the downstream rod heater 30c, or, for example, with the upstream rod heater 30a. You may adjust by changing the space | interval which arrange | positions the downstream rod heater 30c. In any case, since the active material mixture S does not boil, the active material mixture S can be appropriately dried. Therefore, the active material layer F can be appropriately formed on the surface of the metal foil M.

  In the above embodiment, the drying unit 12 is divided into three regions Ta, Tb, and Tc. However, the number of regions that divide the drying unit 12 is not limited to the present embodiment, and is arbitrarily set. can do. For example, the drying unit 12 may be divided into two regions, or may be divided into four or more regions. In any case, if the temperature of the rod heater 30 in each region is set by performing the above-described steps A1 to A6, the active material mixture S is appropriately dried without boiling the active material mixture S. Can do.

  Moreover, although the above embodiment demonstrated the case where the solvent of the active material mixture S was water, this invention is applied also when the solvent of an active material mixture is another material, for example, an organic solvent. Can do. In such a case, the first correlation shown in FIG. 10 and the third correlation shown in FIG. 12 are derived in advance in step A1 according to the type of solvent. And by performing process A2-A6, the temperature of the rod heater 30 of the drying part 12 can be set appropriately, and the active material mixture S can be dried appropriately.

  In the electrode manufacturing apparatus 1 according to the embodiment described above, the unwinding roll 10 is provided as the unwinding unit. However, the configuration of the unwinding unit is not limited to the present embodiment, and the metal foil M is unwound. Various configurations can be used if necessary. Similarly, the winding roll 13 is provided as the winding unit, but the configuration of the winding unit is not limited to the present embodiment, and various configurations can be adopted as long as the metal foil M is wound up.

  Moreover, although the coating head 20 was provided in the coating part 11 of the above embodiment, the structure of the coating part 11 is not limited to this Embodiment, An active material combination is carried out on the surface of the metal foil M. Various configurations can be adopted as long as the agent S can be applied.

  For example, in the above embodiment, the coating heads 20 and 20 are provided opposite to both sides of the metal foil M, but either one of the coating heads 20 is disposed downstream of the other coating head 20. May be. Further, the number of coating heads 20 is not limited to the present embodiment, and a plurality of coating heads 20 may be disposed on both sides of the metal foil M, respectively.

  For example, in the coating part 11, you may apply the active material mixture S to the surface of the metal foil M by an inkjet system.

  For example, as shown in FIG. 13, the coating unit 11 is in contact with the surface of the metal foil M and applies a slurry-like active material mixture S to the metal foil M, and the surface of the roller 100. And a nozzle 101 for supplying the active material mixture S. These rollers 100 and nozzles 101 are arranged opposite to both sides of the metal foil M being conveyed between the unwinding roll 10 and the winding roll 13.

  The roller 100 is configured such that its axial direction extends in the vertical direction and is rotatable about the vertical axis. The roller 100 extends at the same length as the length of the active material layer F formed on the metal foil M in the vertical direction, and is at a position where the active material mixture S can be supplied to the central portion of the metal foil M in the short direction. Has been placed.

  The nozzle 101 also extends in the vertical direction like the roller 100. Further, a discharge port (not shown) that extends in the vertical direction and discharges the active material mixture S to the roller 100 is provided on the surface of the nozzle 101 on the roller 100 side. The discharge port is formed at a length and a position where the active material mixture S can be supplied to the entire surface of the roller 100. In addition, the supply pipe (not shown) connected to the active material mixture supply source (not shown) is connected to the nozzle 101 similarly to the coating head 20 shown in FIG.

  In such a case, in the coating unit 11, the roller 100 to which the active material mixture S is attached is brought into contact with the surface of the metal foil M while supplying the active material mixture S from the nozzle 101 to the surface of the roller 100. Then, the active material mixture S adhering to the surface of the roller 100 is transferred to the surface of the metal foil M, and the active material mixture S is applied to the surface of the metal foil M.

  According to the present embodiment, when the active material mixture S is applied from the roller 100 to the surface of the metal foil M, by adjusting the distance between the surface of the roller 100 itself and the surface of the metal foil M, The film thickness of the active material mixture S can be adjusted. Therefore, the active material mixture S can be applied to the surface of the metal foil M with a more uniform film thickness.

  In the electrode manufacturing apparatus 1 of the above embodiment, the metal foil M is transported in a direction in which the longitudinal direction is the horizontal direction and the short direction is the vertical direction. As shown in FIG. 4, the metal foil M is oriented so that its longitudinal direction is the horizontal direction (Y direction in FIGS. 14 and 15) and its short direction is the horizontal direction (X direction in FIG. 14). It may be conveyed. In such a case, the unwinding roll 10 and the winding roll 13 are arranged at the same height. Moreover, the unwinding roll 10 and the winding roll 13 are each arrange | positioned in the direction from which the axial direction turns into a horizontal direction (X direction in FIG. 14). Even when the electrode manufacturing apparatus 1 of the present embodiment is used, the effects of the above-described embodiments can be enjoyed.

  In the above embodiment, a plurality of active material layers F are formed in the longitudinal direction of the metal foil M, but the electrode manufacturing apparatus of the present invention is also used when forming the electrode E provided with one active material layer F. 1 is useful.

  Moreover, in the above embodiment, the active material layer F was formed on both surfaces of the metal foil M in the electrode manufacturing apparatus 1, but other processes such as pressing and cutting of the metal foil M are also performed in order to form the electrode E. Done. The electrode manufacturing apparatus 1 may continuously perform these other processes between the unwinding roll 10 and the winding roll 13.

  Moreover, although the above embodiment demonstrated the case where the electrode E of a lithium ion capacitor was manufactured, also when manufacturing the electrode used for an electric double layer capacitor and a lithium ion battery, the electrode of this invention is used. The manufacturing apparatus 1 can be used. In this case, what is necessary is just to change the material of the metal foil M, the material of the active material mixture S, etc. according to the kind of electrode manufactured.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the idea described in the claims, and these naturally belong to the technical scope of the present invention. It is understood.

DESCRIPTION OF SYMBOLS 1 Electrode manufacturing apparatus 10 Unwinding roll 11 Coating part 12 Drying part 13 Winding roll 30 Rod heater 30a Upstream rod heater 30b Middle flow rod heater 30c Downstream rod heater 31 Inner cylinder 32 Outer cylinder 33 Nichrome wire heater 40 Reflector 41 Air supply Port 42 Supply pipe 43 Air supply source 50 Control unit D Drying area E Electrode F Active material layer M Metal foil S Active material mixture Ta Upstream area Tb Midstream area Tc Downstream area

Claims (18)

An electrode manufacturing apparatus for manufacturing an electrode by forming an active material layer on both sides of a belt-shaped substrate,
An unwinding section for unwinding the substrate;
A winding unit for winding the substrate unwound at the unwinding unit;
A coating part that is provided between the unwinding part and the winding part, and that applies an active material mixture in which an active material and a solvent are mixed to both surfaces of the substrate;
A drying unit that is provided between the coating unit and the winding unit and that forms an active material layer by drying the active material mixture coated in the coating unit;
The drying unit is arranged side by side in the longitudinal direction of the substrate, and has a plurality of rod heaters that irradiate infrared rays,
The drying unit is divided into a plurality of regions having different temperatures of the rod heater,
The temperature of the rod heater in one region is a temperature in a range where the active material mixture does not boil with respect to the film thickness of the solvent on the substrate in the one region, and the infrared ray of the solvent The electrode manufacturing apparatus is characterized in that the temperature is set to a temperature at which the absorption rate of the electrode becomes maximum. 2. The electrode manufacturing apparatus according to claim 1, wherein the rod heater includes a ceramic outer cylinder and a heating element provided inside the outer cylinder. The electrode manufacturing apparatus according to claim 1, wherein the solvent is water. The drying unit is divided into three regions of an upstream region, a midstream region, and a downstream region from the unwinding unit side,
The temperature of the rod heater arranged in the upstream region is set to 200 ° C.,
The temperature of the rod heater arranged in the downstream region is set to 600 ° C.,
The electrode manufacturing apparatus according to claim 3, wherein a rod heater set at a temperature greater than 200 ° C. and less than 600 ° C. is disposed in the midstream region. The drying unit is divided into three regions of an upstream region, a midstream region, and a downstream region from the unwinding unit side,
The temperature of the rod heater arranged in the upstream region is set to 200 ° C.,
The temperature of the rod heater arranged in the downstream region is set to 600 ° C.,
4. The electrode manufacturing apparatus according to claim 3, wherein a rod heater in the upstream region and a rod heater in the downstream region are mixed and disposed in the middle flow region. The electrode manufacturing apparatus according to claim 1, wherein the drying unit has an air supply mechanism that supplies air between the plurality of rod heaters and the base material. The unwinding unit and the winding unit are arranged so as to convey the substrate in a direction in which the longitudinal direction of the substrate is the horizontal direction and the short direction of the substrate is the vertical direction. The electrode manufacturing apparatus according to claim 1, wherein the electrode manufacturing apparatus is characterized. The said electrode is an electrode used for a lithium ion capacitor, an electric double layer capacitor, or a lithium ion battery, The electrode manufacturing apparatus in any one of Claims 1-7 characterized by the above-mentioned. An electrode manufacturing method for manufacturing an electrode by forming an active material layer on both surfaces of a base material while conveying a belt-shaped base material between an unwinding part and a winding part,
In the coating part, a coating process in which an active material mixture in which an active material and a solvent are mixed is coated on both surfaces of the substrate;
Thereafter, in the drying section, a drying step of drying the active material mixture coated in the coating step to form an active material layer,
The drying unit is arranged side by side in the longitudinal direction of the substrate, and has a plurality of rod heaters that irradiate infrared rays,
The drying unit is divided into a plurality of regions having different temperatures of the rod heater,
The temperature of the rod heater in one region is a temperature in a range where the active material mixture does not boil with respect to the film thickness of the solvent on the substrate in the one region, and the infrared ray of the solvent The electrode manufacturing method is characterized in that the temperature is set to a temperature at which the absorption rate of the electrode becomes maximum. The electrode manufacturing method according to claim 9, wherein the rod heater includes a ceramic outer cylinder and a heating element provided inside the outer cylinder. The electrode manufacturing method according to claim 9 or 10, wherein the solvent is water. The drying unit is divided into three regions of an upstream region, a midstream region, and a downstream region from the unwinding unit side,
The temperature of the rod heater arranged in the upstream region is set to 200 ° C.,
The temperature of the rod heater arranged in the downstream region is set to 600 ° C.,
The electrode manufacturing method according to claim 11, wherein a rod heater having a temperature set to be greater than 200 ° C. and less than 600 ° C. is disposed in the midstream region. The drying unit is divided into three regions of an upstream region, a midstream region, and a downstream region from the unwinding unit side,
The temperature of the rod heater arranged in the upstream region is set to 200 ° C.,
The temperature of the rod heater arranged in the downstream region is set to 600 ° C.,
The electrode manufacturing method according to claim 11, wherein a rod heater in the upstream region and a rod heater in the downstream region are mixedly disposed in the middle flow region. The drying unit has an air supply mechanism for supplying air between the plurality of rod heaters and the base material,
The said active material mixture is dried in the said drying process by the radiant heating by the infrared rays from these rod heaters, and the convection heating by the air supplied from the said air supply mechanism, It is characterized by the above-mentioned. The electrode manufacturing method in any one of -13. The coating step and the drying step are performed on the substrate being conveyed in a direction in which the longitudinal direction of the substrate is the horizontal direction and the short direction of the substrate is the vertical direction. The electrode manufacturing method according to any one of claims 9 to 14. The electrode manufacturing method according to claim 9, wherein the electrode is an electrode used for a lithium ion capacitor, an electric double layer capacitor, or a lithium ion battery. A program that operates on a computer of a control unit that controls the electrode manufacturing apparatus in order to cause the electrode manufacturing apparatus to execute the electrode manufacturing method according to any one of claims 9 to 16. A readable computer storage medium storing the program according to claim 17.

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