JP2006324285A - Method for producing electrode of electrochemical capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing the electrode of an electrochemical capacitor having a higher volume capacitance. <P>SOLUTION: Since rolling direction of a lamination 20 by a first roll press portion 150 or a second roll press portion 160 is perpendicular to the border line of a portion on a collector 16 covered with a polarizable electrode layer 18 and a portion not covered with the polarizable electrode layer 18, deformation or creasing does not take place at the end of the collector 16. Since the surface of the polarizable electrode layer 18 is rolled in multiple step at first through fourth roll press portions 150-180, a high volume capacitance can be attained and since a portion becoming a lead-out electrode is flattened by rolling, deformation or creasing does not take place and joint of the lead-out electrodes can be made rigid when the capacitor electrodes are laid in multilayer. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an electrode for an electrochemical capacitor, and particularly relates to a method for manufacturing an electrode for an electrochemical capacitor having a polarizable electrode compressed by rolling such as a roll press.

  In recent years, electrochemical capacitors such as electric double layer capacitors have attracted attention as batteries that are small and lightweight and can provide a relatively large capacity. The electric double layer capacitor does not use a chemical reaction as in a normal secondary battery, but is a type of battery that directly accumulates charges on the electrodes, so that it can be charged and discharged at a very high speed. Have. Taking advantage of these features, for example, it is expected to be used as a backup power source for portable devices (small electronic devices), an auxiliary power source for electric vehicles and hybrid vehicles, etc. Consideration has been made. In particular, when a large capacity is required such as a power source for an electric vehicle, it is desired to develop an electrochemical capacitor having a high electrostatic capacity per unit volume (hereinafter referred to as “volume capacity”) of the electrode. .

The electrode used in such an electric double layer capacitor has a laminated structure including a current collector and a polarizable electrode layer, and becomes a material for the polarizable electrode layer on the surface of the sheet-shaped current collector. It can be prepared by applying a solution and drying (see Patent Document 1). However, simply applying such a solution to the surface of the current collector and drying it cannot provide a sufficient volume capacity because the density of the polarizable electrode layer formed is low. For this reason, in order to obtain a higher volume capacity, it is necessary to compress the polarizable electrode layer by roll press or the like after forming the polarizable electrode layer by coating.
JP 2000-106332 A

  In the production of the electrode for the electric double layer capacitor, when forming the polarizable electrode layer on the current collector, as shown in FIG. 12, the end in the width direction of the current collector 16 necessary for forming the lead electrode In other words, the polarizable electrode layer 18 is formed on the entire other surface by coating.

  However, when the roll press part 200 is arranged perpendicular to the longitudinal direction of the sheet-like current collector 16 on which such a polarizable electrode layer 18 is formed, the vicinity of the center of the current collector 16, that is, the distribution Although pressure is applied to the region where the polar electrode layer 18 is formed, no pressure is applied to the vicinity of the width direction end of the current collector 16, that is, the region W0 where the polarizable electrode layer 18 is not formed. As a result of the non-uniform rolling of the current collector 16 as described above, there is a problem that deformation and wrinkles occur near the width direction end of the current collector 16.

  Further, the surface of the current collector 16 may be roughened in advance for the purpose of improving the adhesion between the current collector 16 and the polarizable electrode layer 18. When such a current collector 16 is used, the region W0 serving as an extraction electrode remains in a roughened state. Therefore, compared with a case where a current collector that is not roughened is used, the electric double layer There is also a problem that the connection condition between the lead electrodes when the capacitor electrodes are stacked is deteriorated.

  Accordingly, an object of the present invention is to prevent deformation and wrinkling when compressing a polarizable electrode layer formed on a current collector by rolling such as a roll press, and for an electrochemical capacitor having a higher volume capacity. It is to provide a method for manufacturing an electrode.

  In addition, another object of the present invention is a method for producing an electrode for an electrochemical capacitor capable of relaxing the connection conditions between lead electrodes even when a current collector having a roughened surface is used. Is to provide.

  The method for manufacturing an electrode for an electrochemical capacitor according to the present invention includes a first step of forming a polarizable electrode layer on the entire surface of the sheet-like current collector excluding the widthwise end, and the current collector in the width direction. Rolling the current collector in a direction perpendicular to the boundary line between the second step of cutting and processing into a strip shape and the portion covered with the polarizable electrode layer on the current collector and the portion not covered And a third step.

  In the present invention, the third step preferably includes a step of rolling the current collector in multiple stages, and more preferably includes a step of rolling the current collector 4 to 6 times by a roll press.

  Thus, in the present invention, the current collector on which the polarizable electrode layer is formed is rolled in multiple stages, so that the polarizable electrode layer is effectively compressed, and as a result, a high volume capacity can be achieved. Become. Moreover, since the embossing is flattened after embossing, the porous particles contained in the polarizable electrode layer are prevented from falling off and high reliability can be ensured.

  In the present invention, the current collector is preferably an aluminum foil having a roughened surface. According to this, adhesiveness with a polarizable electrode layer can fully be improved.

  In the present invention, the first step is to apply a coating solution containing porous particles having electron conductivity, a binder capable of binding the porous particles, and a solvent capable of dissolving or dispersing the binder, It is preferable to carry out by coating along the longitudinal direction. According to this, the polarizable electrode layer can be easily formed on the current collector. In this case, it is preferable that the coating liquid further contains a conductive additive. Use of a conductive aid can facilitate the movement of electric charge between the current collector and the polarizable electrode layer.

  Thus, according to the present invention, the end of the current collector is rolled by rolling in a direction orthogonal to the boundary line between the portion covered by the polarizable electrode layer on the current collector and the portion not covered. Since no deformation or wrinkle occurs in the portion, it is possible to form a higher-density polarizable electrode layer. This makes it possible to produce a high-capacity and highly reliable electrochemical capacitor. In addition, even if the current collector is roughened, the region that becomes the lead electrode of the current collector is flattened by rolling, so that the connection between the lead electrodes when the electric double layer capacitor electrode is multilayered Will also be good.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic cross-sectional view showing a structure of an electrode for an electric double layer capacitor manufactured by a method according to a preferred embodiment of the present invention.

  As shown in FIG. 1, the produced electric double layer capacitor electrode 10 includes a current collector 16 having electron conductivity and a polarizable electrode layer 18 having electron conductivity formed on the current collector 16. Composed.

  The current collector 16 is not particularly limited as long as it is a good conductor that can sufficiently transfer charges to the polarizable electrode layer 18, and is used for a known electrode for an electric double layer capacitor. A material such as aluminum (Al) can be used. In the present invention, the surface of the current collector 16 is roughened, thereby improving the adhesion with the polarizable electrode layer 18. A method for roughening the surface of the current collector 16 is not particularly limited, but the current collector 16 can be roughened by chemical etching using a chemical such as an acid. The etching depth is preferably set to about 3 to 7 μm. This is because if the etching is too shallow, the effect of improving the adhesion is hardly obtained, and conversely, if the etching is too deep, it is difficult to uniformly apply the undercoat layer 14. The back surface of the current collector 16 does not need to be roughened. However, as will be described later, when the undercoat layer 14 and the polarizable electrode layer 18 are formed on both surfaces of the current collector 16. Needs to roughen both surfaces of the current collector 16.

  The thickness of the current collector 16 is not particularly limited, but in order to further reduce the size of the manufactured electric double layer capacitor, it is preferable to set the current collector 16 as thin as possible as long as sufficient mechanical strength is ensured. Specifically, when aluminum (Al) is used as the material of the current collector 16, the thickness is preferably set to 10 μm or more and 100 μm or less, and more preferably set to 15 μm or more and 50 μm or less. If the thickness of the current collector 16 made of aluminum (Al) is set within this range, it is possible to achieve miniaturization of the finally produced electric double layer capacitor while ensuring sufficient mechanical strength. It becomes.

  The polarizable electrode layer 18 is a layer formed on the current collector 16 and contributes to charge storage and discharge. The polarizable electrode layer 18 contains at least porous particles having electron conductivity as a constituent material thereof and a binder capable of binding the porous particles. Although not particularly limited, the content of the porous particles in the polarizable electrode layer 18 is preferably 84 to 92% by mass based on the total amount of the polarizable electrode layer 18, and the content of the binder is It is preferable to set it as 6.5-16 mass% on the basis of the polar electrode layer 18 whole quantity. In particular, based on the total amount of the polarizable electrode layer 18, it is composed of 84 to 92% by mass of porous particles, 6.5 to 16% by mass of binder, and 0 to 3.0% by mass of electrical conductivity assistant. It is preferable.

  The porous particles contained in the polarizable electrode layer 18 are not particularly limited as long as they are porous particles having electronic conductivity that contributes to charge storage and discharge. For example, granular or fibrous activated carbon that has been activated. Etc. As these activated carbons, phenol-based activated carbon, eggplant activated carbon, or the like can be used. The average particle diameter of the porous particles is preferably 3 to 20 μm, and the BET specific surface area obtained from the nitrogen adsorption isotherm using the BET isotherm adsorption formula is preferably 1500 m 2 / g or more, more preferably 2000 to 2500 m 2. / G. By using such porous particles, a high volume capacity can be obtained.

  The binder contained in the polarizable electrode layer 18 is not particularly limited as long as it is a binder capable of binding the porous particles. For example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyethylene (PE), polypropylene (PP), fluororubber, and the like can be used. Among these, it is particularly preferable to use fluororubber. This makes it possible to sufficiently bind the porous particles even if the content is small if fluororubber is used. This improves the coating strength of the polarizable electrode layer 18 and increases the double layer interface. This is because the volume capacity can be improved.

  Examples of the fluororubber include vinylidene fluoride-hexafluoropropylene-tetrafluoropropylene (VDF-HFP-TFE) copolymer, vinylidene fluoride-hexafluoropropylene (VDF-HFP) copolymer, and vinylidene fluoride. -Pentafluoropropylene (VDF-PFP) copolymer, vinylidene fluoride-pentafluoropropylene-tetrafluoroethylene (VDF-PFP-TFE) copolymer, vinylidene fluoride-perfluoromethyl vinyl ether-tetrafluoroethylene ( VDF-PFMVE-TFE) copolymer, vinylidene fluoride-chlorotrifluoroethylene (VDF-CTFE) copolymer, ethylene-tetrafluoroethylene copolymer, propylene-tetrafluoroethylene copolymer, etc. It is below. Among these, fluororubber formed by copolymerizing at least two selected from the group consisting of VDF, HFP, and TFE is preferable, and adhesion and chemical resistance tend to be further improved. A VDF-HFP-TFE copolymer obtained by copolymerization of seeds is particularly preferred.

  Further, the conductive auxiliary agent contained as necessary in the polarizable electrode layer 18 is an electron conduction capable of sufficiently proceeding the movement of charges between the current collector 16 and the polarizable electrode layer 18. If it has property, there will be no restriction | limiting in particular, For example, carbon black etc. are mentioned.

  Examples of the carbon black include acetylene black, ketjen black, and furnace black. In the present invention, acetylene black is preferably used. The average particle size of the carbon black is preferably 25 to 50 nm, and the BET specific surface area is preferably 50 m2 / g or more, more preferably 50 to 140 m2 / g.

  Further, the thickness of the polarizable electrode layer 18 is preferably 50 to 200 μm, and more preferably 80 to 150 μm, from the viewpoint of reducing the size and weight of the electric double layer capacitor electrode 10. In addition, when the thickness of the polarizable electrode layer 18 is not uniform (for example, when embossing remains on the surface), the above thickness means the maximum film thickness. By making the thickness of the polarizable electrode layer 18 in the above range, the electric double layer capacitor can be reduced in size and weight.

  The total thickness (maximum film thickness) of the electric double layer capacitor electrode 10 having such a structure is preferably 65 to 250 μm, and more preferably 90 to 150 μm. By setting it as such thickness, it becomes possible to achieve size reduction and weight reduction of the finally produced electric double layer capacitor.

  The above is the configuration of the electric double layer capacitor electrode 10 manufactured by the manufacturing method according to the preferred embodiment of the present invention. Next, a manufacturing method according to a preferred embodiment of the present invention will be described in detail.

  FIG. 2 is a flowchart for explaining a method of manufacturing an electrode for an electric double layer capacitor according to a preferred embodiment of the present invention. Hereinafter, the method for manufacturing the electrode for the electric double layer capacitor according to the present embodiment will be described with reference to this flowchart.

  First, the coating liquid used as the material of the polarizable electrode layer 18 is prepared (step S11). The application liquid can be adjusted as follows. First, as shown in FIG. 3, the above-mentioned porous particles P1, the above-mentioned binder P2, the above-mentioned solvent S1 and the above-mentioned conductive auxiliary agent P3 as necessary are put into a mixing device C1 equipped with a stirring unit SB1. , Stir. Thereby, the coating liquid L1 can be prepared. The preparation of the coating liquid preferably includes a kneading operation and / or a dilution and mixing operation. Here, “kneading” means kneading the materials by stirring the liquid in a relatively high viscosity state, and “diluted mixing” means adding a solvent to the kneaded liquid to It means mixing in a low viscosity state. The time for these operations and the temperature at the time of operation are not particularly limited. However, the kneading time is preferably about 30 minutes to 2 hours, and the temperature at the time of kneading is preferably about 30 to 80 ° C. The dilution mixing time is preferably about 1 to 5 hours, and the temperature during dilution mixing is preferably about 20 to 50 ° C.

  The solvent S1 shown in FIG. 3 is not particularly limited as long as it can dissolve or disperse the binder P2. For example, a ketone solvent such as methyl ethyl ketone (MEK) or methyl isobutyl ketone (MIBK) can be used. . Moreover, it is preferable that the compounding quantity of solvent S1 in the coating liquid L1 shall be 200-400 mass parts with respect to 100 mass parts of solid content whole quantity in the coating liquid L1. The content of the porous particles P1 in the coating liquid L1 is preferably set so that the content of the porous particles P1 after forming the polarizable electrode layer 18 is in the range described above.

  After preparing the coating liquid L1 in this manner, the coating liquid L1 is then applied onto the surface of the current collector 16 to form a coating film (step S12), and the solvent S1 contained in the coating film by drying. Is removed (step S13). As a result, the uncompressed polarizable electrode layer 18 is formed on the current collector 16. As a method of applying the coating liquid L1 on the surface of the current collector 16, various known coating methods can be used without particular limitation. For example, methods such as an extrusion lamination method, a doctor blade method, a gravure coating method, a reverse coating method, an applicator coating method, and a screen printing method can be employed. The coating film can be dried by heating for a predetermined time. Specifically, it is preferable to perform drying under conditions of 70 to 130 ° C. and 0.1 to 10 minutes.

  Here, when the polarizable electrode layer 18 is formed on the current collector 16, as shown in FIG. 11, the constant region W0 at the end in the width direction of the current collector 16 necessary for forming the extraction electrode is formed. The polarizable electrode layer 18 is formed on the entire remaining surface. Therefore, exposed portions that are not covered by the polarizable electrode layer 18 are formed at both ends in the width direction of the current collector 16.

  After forming the uncompressed polarizable electrode layer 18 on the current collector 16 in this way, next, as shown in FIG. 4, the sheet-shaped current collector 16 is cut in the width direction into a strip shape. Processing is performed (step S14). The cutting width W1 at this time may be appropriately set according to the final scale cut out as the electric double layer capacitor electrode.

  Next, the polarizable electrode layer 18 formed on the strip-shaped current collector 16 is rolled in multiple stages. Here, rolling the polarizable electrode layer 18 in multiple stages effectively compresses the polarizable electrode layer 18 without causing deformation or distortion in the polarizable electrode layer 18 and the current collector 16, thereby reducing the volume. This is to increase the capacity. The rolling frequency is more preferably 4 to 6 times. When the number of rolling is 3 times or less, the polarizable electrode layer is insufficiently compressed, and there is still room to compress, whereas when the number of compression is 7 times or more, the volume capacity is almost saturated, This is because there is almost no rolling effect. As a method for flattening the surface of the polarizable electrode layer 18, for example, a roller having a substantially smooth surface can be pressed against the surface of the polarizable electrode layer 18. By arranging such rollers in multiple stages, the current collector can be continuously rolled.

  Further, in rolling with a roller or the like, rolling is performed in a direction perpendicular to the boundary line between the portion covered by the polarizable electrode layer 18 on the current collector 16 and the portion not covered. This direction coincides with the cutting direction of the sheet-like current collector before processing. When the polarizable electrode layer 18 is rolled in such a direction, the end of the current collector 16 is not deformed or wrinkled, and the polarizable electrode layer 18 with higher density can be formed. Moreover, since the area | region used as the extraction electrode of the roughened electrical power collector is planarized by rolling, the connection of the extraction electrodes at the time of laminating | stacking the electrode for electric double layer capacitors also becomes favorable.

  Thus, the effectively compressed polarizable electrode layer 18 is formed on the current collector 16. Therefore, if this is cut out to a required size and shape (step S16), the electric double layer capacitor electrode 10 is completed. Furthermore, if this electric double layer capacitor electrode is laminated (step 17) and the lead electrodes 12 are ultrasonically connected to each other, a multilayered electric double layer capacitor electrode can be produced.

  FIG. 5 is a schematic view showing the configuration of the front stage portion of the apparatus for manufacturing an electrode for an electric double layer capacitor, and shows the structure of the apparatus capable of performing the above-described steps S12 to S4.

  An electric double layer capacitor electrode manufacturing apparatus 100 shown in FIG. 5 includes a supply roll 101 around which a sheet-like current collector 16 is wound, a coating unit 110 provided in this order downstream from the supply roll 101, and a drying unit. 120, a cutting unit 130, and a first transport unit 140. As described above, in the electric double layer capacitor electrode manufacturing apparatus 100, the coating unit 110, the drying unit 120, the cutting unit 130, and the first transport unit 140 are arranged from upstream (supply roll 101) to downstream (arrow A direction). It has the structure arranged in order.

  The application part 110 is a part for performing the process (step S12) of apply | coating the coating liquid L1 on the surface of the electrical power collector 16. FIG. The application unit 110 includes a container 111 that stores the application liquid L1 and an application liquid supply roll (gravure roll) 112 that supplies the application liquid L1 in the container 111 to the current collector 16. As shown in FIG. 5, the current collector 16 supplied from the supply roll 101 is conveyed by the rotating coating liquid supply roll 112, whereby the polarizable electrode layer 18 is formed on one surface of the current collector 16. A coating film L2 as a material is formed. The current collector 16 on which the coating film L <b> 2 is formed moves to the drying unit 120 by the guide roll 103.

  The drying part 120 is a part for performing the process (step S13) which removes the solvent S1 contained in the coating film L2. The electric double layer capacitor electrode manufacturing apparatus 100 shown in FIG. 5 includes two dryers 121 and 122 disposed so as to sandwich the current collector 16, and is coated by heating by these dryers 121 and 122. The solvent S1 contained in the film L2 is removed, and the polarizable electrode layer 18 is obtained. Thereby, the polarizable electrode layer 18 is formed on the surface of the current collector 16. However, in this state, the density of the polarizable electrode layer 18 is low, and a high volume capacity cannot be obtained in this state.

  The cutting part 130 is a part for performing the process (step S14) which cuts the sheet-like collector 16 in the width direction and processes it into a strip shape. The cutting unit 130 includes a cutting blade 131, a lifting device 132 for the cutting blade, and a base plate 133 that abuts the lowered cutting blade. Cut in the width direction and processed into strips. The laminated body 20 cut in this way is sequentially sent out to the next step indicated by the arrow A by the first transport unit 140.

  FIG. 6 is a schematic view showing the configuration of the rear part of the electric double layer capacitor electrode manufacturing apparatus 100, and is a top view showing the structure of the apparatus capable of performing the above-described steps S15 to S16.

  As shown in FIG. 6, the rear stage portion of the electric double layer capacitor electrode manufacturing apparatus 100 includes a second transport unit 142, a guide plate 146, a first roll press unit 150, and a second roll press unit. 160, a third roll press section, and a fourth roll press section. The second transport unit 142 includes a pair of transport rollers 143 and 144 and a transport belt 145 wound around the transport rollers 143 and 144. The first to fourth roll press units 150 to 180 are provided in the middle of the conveyance path by the second conveyance unit 142. The strip-shaped laminate 20 that has been transported on the first transport unit 140 is sent to the second transport unit 142 while being guided by the guide plate 146. As a result, the direction of the current collector relative to the traveling direction is changed by 90 degrees, and the strip-shaped laminate 20 proceeds with the portion not covered by the polarizable electrode layer 18 facing the top, and the first roll press Sent to the unit 150.

  FIG. 7 is a perspective view showing in detail the structure of the first to fourth roll press sections 150 to 180.

  As shown in FIG. 7, the 1st thru | or 4th roll press parts 150-180 are parts for performing the process (step S15) of rolling the surface of the polarizable electrode layer 18 in multiple steps. In other words, the electric double layer capacitor electrode manufacturing apparatus 100 shown in FIG. 7 includes four roll press sections. The first roll press section 150 includes a first roller 151 disposed on the polarizable electrode layer 18 side and a second roller 152 disposed on the current collector 16 side, and the rollers 151 and 152 form a strip shape. The laminate 20 is roll-pressed to compress the polarizable electrode layer 18 formed on the current collector 16. Here, the surfaces of the first and second rollers 151 and 152 are substantially smooth, and are uniformly pressed onto the surface of the polarizable electrode layer 18 by the passage of the first roll press unit 150. Thereby, the density of the polarizable electrode layer 18 is effectively increased. Further, as shown in FIG. 8, there is no step due to the polarizable electrode layer 18 in the width direction of the strip-shaped laminate 20 parallel to the axial direction of the first and second rollers 151 and 152, and the polarizable electrode layer The entire width direction is uniformly rolled, not only in the portion not covered with 18 but also in the portion covered with the polarizable electrode layer 18 and even in the vicinity of the boundary between them. Therefore, no deformation or wrinkle occurs at the end of the current collector 16.

  Each subsequent roll press section operates similarly to the first roll press section 150. That is, the second roll press unit 160 includes a third roller 161 disposed on the polarizable electrode layer 18 side and a fourth roller 162 disposed on the current collector 16 side, and the third roll press unit 170 includes a fifth roller 171 disposed on the polarizable electrode layer 18 side and a sixth roller 172 disposed on the current collector 16 side, and the fourth roll press unit 180 includes the polarizable electrode layer 18. The roll press units 160 to 180 are laminated under the same conditions as the first roll press unit 150. The seventh roller 181 is disposed on the side and the eighth roller 182 is disposed on the current collector 16 side. The body 20 is rolled. Thus, by rolling the laminated body 20 in multiple stages, the polarizable electrode layer 18 is effectively compressed without causing deformation or distortion of the polarizable electrode layer 18 and the current collector 16, and thereby the volume capacity. Can be sufficiently increased. Moreover, since the area | region used as the extraction electrode of the roughened electrical power collector is planarized by rolling, the connection of the extraction electrodes at the time of laminating | stacking the electrode for electric double layer capacitors also becomes favorable.

  Then, as shown in FIG. 9 (a), if the strip-shaped laminate 20 is cut into a required size and shape (step S17), the electric double layer capacitor electrode 10 is formed as shown in FIG. 9 (b). Complete. At this time, if a part of the current collector 16 not covered with the polarizable electrode layer 18 is taken out simultaneously as shown in FIG. 9B, it can be used as the lead electrode 12.

  In the electric double layer capacitor electrode 10 manufactured as described above, the rolling direction of the current collector 16 by the first to fourth roll press sections 150 to 180 is such that the polarizable electrode layer 18 on the current collector 16 is aligned. Since the direction is perpendicular to the boundary line between the portion covered with the electrode and the portion not covered with the polarizable electrode layer 18, the end of the current collector 16 is not deformed or wrinkled, and has a higher density. A polarizable electrode layer 18 can be formed. In particular, since the polarizable electrode layer 18 is rolled in multiple stages (step S15), not only a high volume capacity can be achieved, but also the porous particles P1 can be prevented from falling off and high reliability can be ensured. It becomes possible.

  Then, at least two electric double layer capacitor electrodes 10 manufactured as shown in FIG. 10 are prepared, and the separator 40 is sandwiched between the two electric double layer capacitor electrodes 10 so that the polarizable electrode layers 18 face each other. After that, as shown in FIG. 11, an electric double layer capacitor is obtained by further multilayering through the separator 40 and ultrasonically connecting the extraction electrodes 12 to each other and then housed in a case (not shown) and filled with an electrolyte solution in the case. Is completed. At this time, the extraction electrode 12 is flattened by rolling and is free from deformation and wrinkles, so that the connection between the extraction electrodes 12 can be strengthened.

  The separator 40 is a film for physically separating the polarizable electrode layers 18 and 18. The separator 40 is preferably formed of an insulating porous body. For example, the separator 40 is made of a laminate of films made of polyethylene, polypropylene or polyolefin, a stretched film of a mixture of the above resins, or a group consisting of cellulose, polyester and polypropylene. A fiber nonwoven fabric made of at least one selected constituent material can be used. The thickness of the separator 40 is not particularly limited, but is preferably 10 μm or more and 200 μm or less, and more preferably 15 μm or more and 50 μm or less.

  As the electrolyte solution, an electrolyte solution (electrolyte aqueous solution, electrolyte solution using an organic solvent) used in a known electric double layer capacitor can be used. However, the electrolyte aqueous solution used in the electric double layer capacitor is an electrolyte solution (non-aqueous electrolyte solution) using an organic solvent because the breakdown voltage of the capacitor is limited because the electrochemical decomposition voltage is low. preferable. The type of the specific electrolyte solution is not particularly limited, but is preferably selected in consideration of the solubility of the solute, the degree of dissociation, and the viscosity of the solution. The electrolyte has a high conductivity and a high potential window (high decomposition start voltage) It is particularly desirable that it is a solution. As a typical example, a quaternary ammonium salt such as tetraethylammonium tetrafluoroborate dissolved in an organic solvent such as propylene carbonate, diethylene carbonate, or acetonitrile is used. In this case, it is necessary to strictly manage the moisture content.

  The preferred embodiment of the present invention has been described in detail above, but the present invention is not limited to the above embodiment.

  For example, an apparatus for manufacturing an electrode for an electric double layer capacitor according to the present invention includes a coating unit 110, a drying unit 120, a first roll press unit 150, and a second roll press, as in the devices shown in FIGS. It is not necessary that the unit 160 is continuously and integrally arranged, and may be an assembly of two or more devices as long as the above order is ensured. For example, the sheet-like current collector 16 that has passed through the drying unit 120 may be temporarily wound and processed by another apparatus including the cutting unit 130, the first roll press unit 150, and the second roll press unit 160. Absent. Furthermore, the first roll press unit 150 and the second roll press unit 160 may be separate devices.

  Moreover, in the said embodiment, although the embossing and planarization to the polarizable electrode layer 18 are performed by roll press, it is not restricted to this, Even if it rolls using plate-shaped press apparatuses, such as a hot press. I do not care.

  Furthermore, the electrode for an electrochemical capacitor manufactured according to the present invention can be used as an electrode for an electric double layer capacitor, and also used as an electrode for various electrochemical capacitors such as a pseudo-capacitance capacitor, a pseudo capacitor, and a redox capacitor. Is possible.

It is a schematic sectional drawing which shows the structure of the electrode for electric double layer capacitors manufactured by the method by preferable embodiment of this invention. 5 is a flowchart for explaining a method of manufacturing an electrode for an electric double layer capacitor according to a preferred embodiment of the present invention. It is a schematic diagram for demonstrating the preparation method (step S11) of a coating liquid. 4 is a schematic perspective view for explaining a cutting process of the current collector 16. FIG. It is the schematic which shows the structure of the front | former part of the manufacturing apparatus of the electrode for electrochemical capacitors by preferable embodiment of this invention. It is the schematic which shows the structure of the back | latter stage part of the manufacturing apparatus of the electrode for electrochemical capacitors by preferable embodiment of this invention. It is a schematic perspective view which shows roughly the structure of the 1st thru | or 4th roll press part 150 thru | or 180. FIG. It is a schematic sectional drawing which shows the state of the laminated body 20 rolled by the 1st roll press part 150 (or 2nd roll press part 160). It is a figure for demonstrating the process (step S16) which cuts out the electrode 10 for electric double layer capacitors from the laminated body 20, (a) is a schematic plan view of the laminated body 20 from which the electrode 10 for electric double layer capacitors was cut out. (B) is a schematic plan view of the cut-out electrode 10 for an electric double layer capacitor. It is a schematic diagram for demonstrating the process of laminating | stacking the electrode 10 for single electric double layer capacitors. It is a schematic sectional drawing for demonstrating the process (step S17) of further multilayering the electrode for electric double layer capacitors. It is a schematic perspective view which shows the rolling state of the electrode for electric double layer capacitors.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric double layer capacitor electrode 12 Lead electrode 16 Current collector 18 Polarized electrode layer 20 Laminate body 40 Separator 100 Manufacturing apparatus 101 Supply roll 103 Guide roll 110 Application part 111 Container 112 Application liquid supply roll (gravure roll)
DESCRIPTION OF SYMBOLS 120 Drying part 121,122 Dryer 130 Cutting part 131 Cutting blade 132 Lifting apparatus 133 Base plate 140 1st conveyance part 142 2nd conveyance part 143,144 Conveyance roller 145 Conveyance belt 146 Guide rail 150 1st roll press part 151 1st roller 152 2nd roller 160 2nd roll press part 161 3rd roller 162 4th roller 170 3rd roll press part 171 5th roller 172 6th roller 180 4th roll press part 181 7th roller 182 8th roller 200 Roll press part C1 Mixing device L1 Coating liquid L2 Coating film P1 Porous particle P2 Binder P3 Conductive aid S1 Solvent SB1 Stirring part

Claims (5)

  A first step of forming a polarizable electrode layer on the entire surface of the sheet-like current collector excluding the widthwise end, and a second step of cutting the current collector in the width direction to form a strip shape And a third step of rolling the current collector in a direction orthogonal to a boundary line between a portion covered with the polarizable electrode layer on the current collector and a portion not covered with the current collector. A method for producing an electrode for an electrochemical capacitor, which is characterized.   The method for manufacturing an electrode for an electrochemical capacitor according to claim 1, wherein the third step includes a step of rolling the current collector in multiple stages.   The method for producing an electrode for an electrochemical capacitor according to claim 2, wherein the third step includes a step of rolling the current collector 4 to 6 times by a roll press.   The method for manufacturing an electrode for an electrochemical capacitor according to any one of claims 1 to 3, wherein the current collector is an aluminum foil having a roughened surface. In the first step, a coating liquid containing porous particles having electron conductivity, a binder capable of binding the porous particles, and a solvent capable of dissolving or dispersing the binder is used as the current collector. The method for producing an electrode for an electrochemical capacitor according to any one of claims 1 to 4, wherein the method is performed by coating along the longitudinal direction.

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