JP2001223142A - Method of manufacturing solid activated-carbon electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which an extremely thin solid activated- carbon electrode can be manufactured stably. SOLUTION: In this method, the electrostatic latent image of an activated- carbon electrode 10 is formed by projecting light 76 upon the surface of a photosensitive drum 73 electrostatically charged in an electrostatically charging step 60 in an exposing step 62, and the latent image is visualized by sticking powder material 30 for electrode containing activated-carbon powder 32 manufactured in a powder material manufacturing step 48 and a thermosetting rein 34 which couples the powder 32 to the latent image on the surface of the drum 73 in a developing step 64. Then the powder material 30 forming the visual image is transferred to thin paper 84 in a transferring step 66, and the extremely thin activated-carbon electrode 10 is obtained by coupling the activated-carbon powder 32 with each other by using glass-like carbon derived from resin 34 contained in the powder material 30, by carbonizing the resin 36 by heat-treating the thin paper 84 carrying the transferred material 30 in a carbonizing step 70.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a solid activated carbon electrode, and more particularly, to a method suitable for manufacturing a thin-film solid activated carbon electrode.

[0002]

2. Description of the Related Art Solid activated carbon is known in which activated carbon powder is solidified into a predetermined shape while maintaining a high specific surface area. For example, a solid activated carbon electrode (hereinafter, referred to as a solid activated carbon electrode) constituting an electrode of a large-capacity electric double-layer capacitor described in Japanese Patent Publication No. 7-91449 or the like is an example thereof. The solid activated carbon electrode is a composite of activated carbon and carbon. The activated carbon powder is formed by binding activated carbon powder with carbon derived from a thermosetting resin or the like without greatly reducing the specific surface area.

The above-mentioned electric double-layer capacitor utilizes the fact that a pair of charge layers (that is, electric double layers) having different signs are formed at the interface between a conductor constituting a pair of electrodes and an electrolyte solution. It is characterized by being capable of quick charging and not being able to cause a life deterioration due to charging and discharging. Therefore, for example, an electric double-layer capacitor is connected in parallel with a battery or a commercial AC power supply that is converted to DC, and various components are backed up by the electric charge stored in the electric double-layer capacitor when the power supply is momentarily interrupted. Used in In recent years, by making such an electric double-layer capacitor capable of discharging a large capacity and a large current, it is considered that the electric double-layer capacitor is used for, for example, a regenerative energy storage device of an electric vehicle, a cell motor drive of the vehicle, a solar cell voltage leveling, and the like. However, the above-mentioned solid activated carbon electrode is an important electrode material constituting an electric double layer capacitor for such an application. This is because the solid activated carbon electrode has a large specific surface area and electrical contact between the activated carbon powders is ensured without any particular pressurization. This is because the discharge current value can be increased.

Incidentally, since the capacitance of the electric double layer capacitor is determined by the amount of electric charge stored in the electric double layer, the larger the surface area of the electrode, the larger the capacitance. Therefore, activated carbon having high conductivity and high specific surface area is preferably used as an electrode material.However, in a conventional electric double layer capacitor in which powdered or fibrous activated carbon is stored in a metal case or the like, powder or powder is used. Pressurization was required to obtain electrical contact between the fibers. Therefore, in order to obtain a large capacitance with such a structure, it is necessary to increase the surface area by increasing the amount of activated carbon and to increase the pressing force in order to further ensure the electrical contact of the activated carbon. Therefore, the metal case becomes extremely large. For this reason, an electric double-layer capacitor of a practical size can obtain only a capacitance of about several F at most, and it has been difficult to apply it to a large-capacity and large-current application as described above. On the other hand, according to the solid activated carbon electrode, since pressurization for ensuring electrical contact is not required,
The dimensional expansion of the electric double layer capacitor can be suitably suppressed.

[0005]

By the way, the above-mentioned solid activated carbon electrode is formed, for example, by mixing a thermosetting resin with activated carbon powder and molding it into a desired shape, and then converting the vacuum or furnace gas to nitrogen gas. It is manufactured by heat-treating a molded article at a predetermined temperature in a non-oxidizing atmosphere such as a substituted atmosphere to carbonize (carbonize) the thermosetting resin. At this time, the electric double layer capacitor has a structure in which two electrodes are stacked with a separator interposed therebetween to form one cell, and a plurality of cells are stacked as necessary.
The shape of the electrode, that is, the shape of the molded body is a thin plate shape or the like that can be easily laminated. Conventionally, as a molding method for obtaining such a thin plate-shaped molded body, for example, a powder pressing method described in Japanese Patent Application Laid-Open No. 9-36004, which was previously filed and published by the present applicant, etc. And an extrusion molding method.

In the above-mentioned powder pressing method, since the process is a dry process, the process is simple and mass production is easy. On the other hand, it is difficult to uniformly fill the raw material into a shallow molding die for molding a thin plate. However, there is a problem that it is difficult to obtain a solid activated carbon electrode having a uniform density and a uniform thickness. In this case, the thickness can be made uniform by polishing after firing, but the process is complicated and the manufacturing cost is increased, and the strength and electric double layer capacitor are increased due to the uneven density. Characteristics such as capacitance may also be reduced. On the other hand, according to the extrusion molding method, since a thin plate is formed by extruding a raw material kneaded substantially uniformly in a molding machine from a die, a uniform density and a uniform thickness according to the shape accuracy of the die. Thus, it is possible to obtain a molded article provided with Moreover, since the extruded thin plate is formed while its surface is rubbed with a die, there is an advantage that a smooth surface can be obtained as compared with the case of the powder pressing method. In electric double layer capacitors,
Since two or more electrodes stacked via a separator to form one or more cells are further sandwiched by current collectors, if the electrode surface is low in smoothness, contact between the electrodes and the current collector may occur. Failure occurs, and the internal resistance, which is desired to be as small as possible to obtain high capacitance, increases.

In order to reduce the effective internal resistance as much as possible in order to further reduce the size and increase the capacity of the electric double-layer capacitor, it is necessary to improve the surface smoothness as described above and to use a solid activated carbon electrode. It is necessary to increase the mobility of ions into the electrode during charging and discharging as much as possible. Because, as described above, the solid activated carbon electrode is porous because the activated carbon powder is bonded without greatly reducing its specific surface area, but even though it is porous, ions pass through This is because the longer the internal route, the lower the mobility. However, the lower limit of the molding thickness at which the solid activated carbon electrode can be stably manufactured by the powder press molding or extrusion molding as described above is, for example, about 1 (mm).

Further, by using the doctor blade method described in Japanese Patent Application Laid-Open No. 11-171523, filed by the present applicant, the solid activated carbon electrode having a thickness of, for example, about 0.1 mm can be stabilized. Can be manufactured.
However, even thinner solid activated carbon electrodes cannot be manufactured stably by the doctor blade method. Therefore, a method capable of stably producing a thinner solid activated carbon electrode has been desired.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a solid activated carbon electrode capable of stably producing an extremely thin solid activated carbon electrode. It is in.

[0010]

The present inventors have made various studies to achieve the above object, and as a result, have applied electrophotographic technology to a method of manufacturing a solid activated carbon electrode, and have developed a toner used in an electrophotographic process. Instead of using activated carbon and a fine powder containing a thermosetting resin for bonding the activated carbon to each other, it has been found that an extremely thin solid activated carbon electrode can be stably manufactured. The present invention has been made based on such findings.

That is, the gist of the present invention for achieving the above object is a method for producing a solid activated carbon electrode using static electricity to produce a relatively thin solid activated carbon electrode. A charging step of charging the surface of the
(b) electrostatically depositing an electrode powder material containing activated carbon powder and a thermosetting resin for bonding the activated carbon powder to each other on the surface of the charged body charged in the charging step; An electrostatic adhesion step, (c) a transfer step of transferring the electrode powder material attached to the charged body surface in the electrostatic adhesion step to a substrate, and (d) an electrode powder material by the transfer step. A carbonization step of heating the substrate to which the carbon black is transferred to carbonize the thermosetting resin contained in the powdery material for electrodes to bond the activated carbon powder.

[0012]

According to the above, in the electrostatic adhesion step, the activated carbon powder produced in the powder raw material production step and the activated carbon powder are mutually bonded on the surface of the charged body charged in the charging step. The electrode powder material containing the above thermosetting resin is attached by electrostatic adsorption, and in the transfer step, the electrode powder material attached on the charged body surface is transferred to the substrate. Subsequently, in a carbonization step, the substrate on which the electrode powder raw material has been transferred is subjected to a heat treatment, whereby the thermosetting resin contained in the electrode powder raw material is carbonized, and the activated carbon powder is interlinked. And a very thin solid activated carbon electrode is obtained.

[0013]

In another preferred embodiment of the present invention, the substrate is a thin sheet made of an organic material such as paper made of an organic fiber material such as natural fiber or synthetic fiber. In this way, in the carbonization step, the substrate itself is also carbonized, so that it can be used as a solid activated carbon electrode without peeling the substrate.

Preferably, the charging step, the electrostatic adhering step, and the transferring step are repeated a predetermined number of times, so that the thickness of the electrode powder raw material transferred onto the base is a predetermined thickness. After that, the carbonization step is performed. In this case, the thickness of the solid activated carbon electrode can be easily adjusted.

Preferably, a heating / kneading step of kneading while heating the mixed raw material having the activated carbon powder, the thermosetting resin and the binder resin, and cooling the mixed raw material kneaded in the heating / kneading step. The powder raw material for an electrode is manufactured by a powder raw material manufacturing step including a cooling step and a pulverizing step of pulverizing the raw material cooled in the cooling step into fine powder.
In this way, the powder raw material manufacturing step produces an electrode powder raw material in which the activated carbon powder and the thermosetting resin are uniformly dispersed in the binder resin. The binder resin is degreased or decomposed, and the activated carbon powder is mutually bonded by the carbide of the thermosetting resin. Therefore, a thin activated carbon electrode having a uniform (uniform) structure can be obtained.

[0016] Preferably, the method further includes an oxidizing heat treatment step of heat-treating, in an oxygen-containing atmosphere, a carbide to which the activated carbon is bonded by carbonizing the thermosetting resin in the carbonization step. If you do this,
The carbonized carbonized in the carbonization step is subjected to heat treatment in an atmosphere containing oxygen by the oxidation heat treatment step,
The carbonized thermosetting resin and the activated carbon powder bound thereby are activated, and the capacitance of the solid activated carbon electrode is increased.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following examples, the dimensional ratios and the like of each part are not necessarily drawn accurately.

FIG. 1 is a diagram schematically showing a cross-sectional structure of an electric double layer capacitor 12 using an activated carbon electrode 10 manufactured by a method for manufacturing a solid activated carbon electrode according to one embodiment of the present invention. The capacitor 12 has a box shape as a whole, and is provided in order on a pair of plate-like activated carbon electrodes 10, 10, a separator 14 sandwiched between the pair of activated carbon electrodes 10, 10, and outside the activated carbon electrodes 10, 10. A pair of current collectors 16, 16, a pair of terminal plates 18, 18, a pair of fixing plates 20, 20, and a gasket provided on the side of the activated carbon electrodes 10, 10 to support the current collectors 16, 16 22, and fixing plates 20, 20 provided on both sides of the gasket 22.
Is provided with a pair of supports 24, 24, which support the liquid crystal. A 30 (wt%) sulfuric acid aqueous solution, for example, is injected as an electrolytic solution into the interior surrounded by the current collectors 16, 16 and the gasket 22. I have. Although the pair of activated carbon electrodes 10 and 10 are provided via the separator 14 in the figure, a larger number of activated carbon electrodes 10 may be stacked via the separator 14.

The pair of activated carbon electrodes 10, 10 has a thickness of, for example, about 0.03 (mm). One of the porous carbon layers formed by carbonizing the thin paper 84 used as the substrate is formed. Alternatively, it has a structure in which a porous activated carbon-carbon composite layer in which activated carbon particles are bonded by vitreous carbon obtained by carbonizing a thermosetting resin is formed on both surfaces. The separator 14 is made of glass fiber having a thickness of, for example, about 0.1 to 0.2 (mm) and having a slightly larger area than the activated carbon electrode 10, and prevents an electrical short circuit caused by contact between the activated carbon electrodes 10, 10. In addition, the electrolyte is formed porous so that the electrolyte can flow freely.

The current collectors 16, 16 are made of, for example, conductive rubber containing carbon and have a thickness of, for example, 0.1 to 0.2.
(mm), and is a partition between cells by being sandwiched between the gasket 22 and the supports 24 at the periphery. That is, it has a bipolar electrode structure.

The terminal plates 18, 18 provided outside the current collectors 16, 16 are, for example, aluminum plates having a thickness of about 0.2 (mm) and an area similar to that of the activated carbon electrodes 10, 10. By applying a voltage to a pair of terminals (not shown) provided on the terminal plates 18, 18, the current collector 16,
Electric power is supplied to the activated carbon electrodes 10, 10 via 16. In addition, fixing plate 20, gasket 2
2. Each of the supports 24, 24 is made of a resin that can be injection molded.

The above electric double layer capacitor 12 is assembled as follows. That is, first, each of the above-mentioned constituent members is sequentially laminated, and at this time, a sulfuric acid-resistant adhesive is applied between the gasket 22 and the supports 24, and fixed. Next, after the terminal plates 18, 18 are crimped to the current collectors 16, from both sides, the fixing plates 20, 20 are
It is fixed from both sides by bolts and nuts 26 in places. Finally, the electric double layer capacitor 12 is obtained by injecting a predetermined amount of the electrolytic solution through an injection hole (not shown) provided in the gasket 22 and sealing the same.

As shown schematically in FIG. 2, the electric double layer capacitor 12 configured as described above, when a voltage is applied, causes the surface of many activated carbon particles 28 to have positive or negative ions in the electrolyte solution. (Ie H ⁺ or SO
₄ ^2- ) is adsorbed to form an electric double layer, and charging is performed. At this time, the activated carbon electrode 10
Is formed by bonding the activated carbon particles 28 to each other with glassy carbon (not shown) derived from a thermosetting resin 34 or the like described below, so that the above ions are formed by the glassy carbon and the activated carbon particles 28. It moves through the gap (flow path) that is formed.

The activated carbon electrode 10 is produced, for example, in accordance with a powder raw material production step 48 shown in FIG. 3 and a activated carbon electrode production step shown in FIG. First, the powder raw material 30 for an electrode shown in FIG. 5 is manufactured by the powder raw material manufacturing step 48 of FIG.

In the mixing step 50 of FIG. 3, the activated carbon powder 32, the thermosetting resin 34, the binder resin 36, and the charge control agent 38 are weighed, and the mixing ratio is 4 to 40 (wt%).
, 4 to 40 (wt%), 70 to 40 (wt%), and 10 (wt%)
%) And activated carbon powder 32 and thermosetting resin 34
The mixed raw material is prepared so that the mixing ratio with the mixture becomes 8: 2 to 2: 8. The activated carbon powder 32 has a particle size of 0.1 to 30.
(μm), preferably about 1 (μm), and the specific surface area measured by the BET method is about 700 to 2000 (m ² / g), preferably 1700
As the thermosetting resin 34 having a particle size of about (m ² / g), for example, a water-insoluble phenol resin powder having a particle size of about 0.1 to 50 (μm) is used. In addition, the binder resin 36 includes
Similar to those contained in toners for electrophotographic copying machines, thermoplastic resins having a glass transition point of around 60 ° C. and being brittle at room temperature are used, for example, a copolymer of styrene and acrylate, Polyester having a molecular weight (molecular weight of 10,000 or less) or the like is used. Further, as the charge control agent 38, a quaternary ammonium salt, a pyridinium salt, a nigrosine dye or the like is used. The particle size of the thermosetting resin 34 and the charge control agent 38 is set to a value sufficiently larger than the pore diameter of the activated carbon powder 32 so as not to enter the pores (open pores) and block the pores. Have been.

Next, in the heating / kneading step 52,
Using a kneader or the like, the mixed raw materials are kneaded while being heated to uniformly disperse the materials. At this time, the heating temperature is set to a temperature at which the thermoplastic resin is in a semi-molten state and the thermosetting resin is not cured, for example, around 80 ° C.

In the subsequent cooling step 54, the mixed raw material kneaded in the heating / kneading step 52 is cooled to room temperature or water temperature. In the subsequent pulverizing step 56, the cooling step 54
After the raw material cooled in step (1) is roughly pulverized (several mm square), it is further pulverized into a fine powder of about 10 μm by a mechanical pulverization method such as a pulverization by collision between particles in a jet stream such as a jet mill.
As a result, the electrode powder raw material 30 is obtained. In the subsequent surface modification step 58, as the surface modifier 40, a fine powder of colloidal silica, titanium oxide, alumina or the like (primary particle diameter of about 10 to 30 nm) is used. ) Is added to the electrode powder raw material 30 by a dry blending method. As shown in the schematic sectional view of FIG. 5, the electrode powder raw material 30 obtained as described above has an activated carbon powder 32, a thermosetting resin 34, and a charge control agent 38 in a binder resin 36. It is evenly distributed.

Next, the activated carbon electrode 10 is manufactured according to the activated carbon electrode manufacturing process shown in FIG. 6 and 7 are conceptual diagrams of each step of the activated carbon electrode manufacturing process of FIG. The manufacturing process of the activated carbon electrode shown in FIG. 4 is the same as the electrophotographic process except that the powder raw material for electrode 30 is used instead of the toner, and the carbonization process 70 and the oxidation heat treatment process 72 are provided. A similar process,
An apparatus similar to that used in the electrophotographic process is used.

In the charging step 60, the surface (peripheral surface) of the photosensitive drum 73 in the form of a circular roller which functions as a charged body and is continuously rotated around a horizontal axis, is attached with ions or electrons to generate static electricity. This is a step of uniformly charging to a constant potential. In this case, for example, a high voltage of about 5 to 10 kV is applied to the charger 74 in a state where the opening surface of the charger 74 is arranged to face the photosensitive drum 73, and the positive or negative ions (FIG. 6, negative ions are moved to the surface of the photosensitive drum 73, and the surface of the photosensitive drum 73 is charged.

The subsequent exposure step 62, that is, the latent image forming step is a step of forming a latent image of the activated carbon electrode 10 on the surface of the photosensitive drum 73 by using electric charges by utilizing the photoconductive phenomenon. In order to form a latent image, the photosensitive drum 73 has a property of an insulator when light does not shine, and needs to have a property of becoming conductive when light shines and releasing charged charges. The surface layer 73 includes, for example, a blocking layer for preventing injection of charges from the substrate on a conductive substrate such as aluminum, a carrier transporting layer for transporting optical carriers, a carrier generating layer for generating optical carriers by light irradiation, and a carrier generating layer. A surface protection layer for protecting the layers is sequentially provided. The activated carbon electrode 1 is formed on the surface of the photosensitive drum 73 configured as described above by a copying optical system (not shown).
When the light 76 is applied to a portion other than the image portion of the light 0, the light 76
Electron-hole pairs are generated in the carrier-generating layer in the irradiated portion of the active carbon electrode 10 except for the image portion, and the electron-hole pairs are combined with the charges charged on the surface of the photosensitive drum 73. To release surface charges. This allows
An electrostatic latent image of the activated carbon electrode 10 is formed.

The next developing step 64 is a step of electrostatically adhering the electrode powder raw material 30 to the electrostatic latent image formed on the surface of the photosensitive drum 73 to form a visible image. It corresponds to a process. For example, a developer 80 is conveyed by a developing roller 79 provided with a rotatable non-magnetic sleeve 78 on a magnet roller 77 to develop the electrostatic latent image. The developer 80 is a mixture of a carrier 82, which is an iron powder having a diameter of about 100 μm, and a powder raw material 30 for an electrode at a fixed ratio, and the powder raw material 30 for an electrode is charged by friction with the carrier 82. Then, it adheres to the surface of the carrier 82 by electrostatic force. The developer 80 is deposited on the developing roller 79 by a magnetic force to form a chain-shaped magnetic brush. When this magnetic brush is lightly brought into contact with the surface of the photosensitive drum 73, the powder material 30 for an electrode is
2 moves onto the electrostatic latent image on the surface of the photosensitive drum 73 to form a visible image. The carrier 82 is collected by a collecting device (not shown).

The subsequent transfer step 66 is a step of moving the visible image formed on the surface of the photosensitive drum 73, that is, the powdery raw material for electrode 30 adhered to the surface of the photosensitive drum 73, to the surface of the substrate and attaching it. . There, for example, a thickness of 20μ
m thin paper 84 is used as a substrate, the thin paper 84 is superimposed on the visible image, and a charge opposite to the charge of the electrode powder raw material 30 is given by a corona charger 86 provided on the back side of the thin paper 84. Or by applying a predetermined pressure,
The electrode powder raw material 30 that forms the visible image is transferred onto the thin paper 84.

The following fixing step 68 is a step of fixing the electrode powder raw material 30 adhered to the thin paper 84 with a small force by electrostatic transfer to the thin paper 84. Here, for example, the electrode powder raw material 30 is heated and pressed by a heating roller 88 and a pressure roller 89. When the electrode powder raw material 30 is heated and pressed, the binder resin 36 contained in the component is melted and permeates or adheres to the fibers of the thin paper 84, so that the electrode powder raw material 30 has a uniform thickness. Then, it is fixed on the thin paper 84. The photosensitive drum 73
The electrode powder raw material 30 remaining on the upper surface is removed by the cleaner 90, and the electrostatic latent image is erased by the neutralizer 92.

In the subsequent carbonization step 70, a portion of the thin paper 84 to which the electrode powder raw material 30 is fixed is punched or cut into a predetermined size in advance, and the molded body 94 obtained by punching or cutting is cut out. For example, a heat treatment (firing) is performed at a temperature of 700 ° C. or more (eg, 900 ° C.) for about 2 hours in a box furnace 96 which is made an inert atmosphere by N ₂ gas or the like. In the carbonization step 70, the thin paper 84 is carbonized to form a porous carbon layer, and the thin paper 8
4. Binder resin 36 contained in electrode raw material 30 on electrode
Is degreased or decomposed to be sufficiently dissipated, and at the same time, the thermosetting resin 34 is carbonized, and the activated carbon powder 32 is bonded to each other with vitreous carbon derived therefrom, and has a substantially uniform structure. A porous activated carbon-carbon composite layer is formed. That is, the activated carbon electrode 10 which is a carbonized molded body in which the activated carbon-carbon composite layer is formed on the porous carbon layer is obtained. Although the activated carbon electrode 10 thus obtained can be used as it is, in this embodiment, an oxidation heat treatment step 72 is further performed.

In the oxidation heat treatment step 72, in order to increase the capacitance of the activated carbon electrode 10 obtained in the carbonization step 70, the activated carbon electrode 10 is placed in the air or in a nitrogen atmosphere in which oxygen is actively added. In an atmosphere containing oxygen such as
By performing a heat treatment in a temperature range of 200 to 700 ° C., for example, 400 ° C., the activated carbon electrode 10 is activated, that is, activated. Thus, the activated carbon electrode 10 having a thickness of 0.03 to 0.05 mm can be manufactured. The heating temperature is 200
If the temperature is lower than ℃, it is difficult to sufficiently obtain the effect of increasing the capacitance. If the temperature is higher than 700 ℃, the oxidation proceeds excessively and becomes brittle or burns out.

FIG. 8 shows the performance of the activated carbon electrode 10 manufactured as described above and the fact that only the thin paper 84 was used.
The performance of the porous carbon electrode treated as porous carbon was compared with the measurement by measuring the capacitance (F / g) when an electric double layer capacitor was constructed using each electrode. It is a figure showing a result. The capacitance is, for example, the capacitance obtained when a constant voltage discharge (for example, about 0.1 (A)) is performed until the voltage reaches 0.45 (V) after charging at a constant voltage of, for example, 0.9 (V) for 30 minutes.
(I △ t) / △ V [where the capacitance is C (F), the discharge current is i (A), the time required for the voltage drop is △ t (sec), and the voltage drop is △ V (V) And converted to a value per unit weight. As shown in FIG. 8, when a porous carbon electrode derived from thin paper 84 is used, the capacitance is about
In contrast to 24 (F / g), the capacitance when the activated carbon electrode 10 is used is approximately 50 (F / g), which is a marked improvement in performance.

As described above, according to this embodiment, in the developing step 64, the activated carbon powder 32 produced in the powder material producing step 48 is placed on the surface of the photosensitive drum 73 charged in the charging step 60. The electrode powder raw material 30 containing the thermosetting resin 34 for binding the activated carbon powder 32 to each other is attached, and in the transfer step 66, the electrode powder raw material 30 attached to the surface of the photosensitive drum 73. Is thin paper 84
Is transferred to Subsequently, in the carbonization step 70, the thin paper 84 to which the electrode powder material 30 has been transferred is subjected to a heat treatment, so that the thermosetting resin 34 contained in the electrode powder material 30 is carbonized. Extremely thin activated carbon electrode 1
0 is obtained.

Further, according to the present embodiment, since the thin paper 84 is also carbonized in the carbonization step 70,
Before or after, the thin paper 84 can be used as the activated carbon electrode 10 without peeling.

According to this embodiment, the activated carbon powder 3
2. a heating / kneading step 52 of kneading while heating a mixed raw material including the thermosetting resin 34 and the binder resin 36;
A powder raw material manufacturing step 4 including a cooling step 54 for cooling the mixed raw material kneaded in the heating / kneading step 52 and a pulverizing step 56 for pulverizing the raw material cooled in the cooling step 54 into fine powder;
8, the powder raw material for electrode 30 is manufactured by the powder raw material manufacturing process 48, and the powder raw material for electrode 40 in which the activated carbon powder 32 and the thermosetting resin 34 are uniformly dispersed in the binder resin 36 is manufactured. Then, in the carbonization step 70, the binder resin 36 in the electrode powder raw material 30 is degreased or decomposed, and the activated carbon powder 32 is mutually bonded by the carbide of the thermosetting resin 34. Therefore, a thin activated carbon electrode 10 having a uniform (uniform) structure can be obtained.

Further, according to this embodiment, in the oxidation heat treatment step 72, the activated carbon electrode 10 carbonized in the carbonization step 70 is subjected to heat treatment in an atmosphere containing oxygen, so that the carbonized thermosetting The resin 34 and the activated carbon powder 32 bound by the resin 34 are activated, and the capacitance of the activated carbon electrode 10 is increased.

Further, according to the present embodiment, the photosensitive drum 73 in the form of a circular roller rotating continuously is used as a charging member, and a part of the outer peripheral surface of the photosensitive drum 73 is charged in the charging step 6.
0, the exposure step 62, the development step 64, the transfer step 66, and the fixing step 68, so that high processing efficiency can be obtained and the production cost can be reduced, and uniform quality in thickness, density, capacitance and the like can be obtained. Is obtained. Further, when a tunnel-type continuous firing path is used, the fixing step 68 is performed.
Subsequently, the carbonization step 70 is continuously performed, so that the efficiency is further improved.

FIG. 9 shows a thin paper 84 which is formed without passing through the oxidizing heat treatment step 72 of the above-described step of FIG.
From the binder resin 36 and the raw material for the electrode (here, the activated carbon powder 32 and the thermosetting resin 34) are mixed at a mixing ratio of 7: 2.
And sample 1, sample 2, and sample 3 in which the mixing ratio between the activated carbon powder 32 and the thermosetting resin 34 is 8: 2, 5: 5, and 2: 8, and a thin paper (white paper) 84 Only in the same manner as those samples, the performance with the sample 4 which is a porous carbon electrode made into porous carbon was compared with the capacitance (F /
It is a figure which shows the result of having compared by measuring g). In the sample 1, a high capacitance is obtained because the ratio of the activated carbon powder 32 is high. However, when the ratio is higher than this, the bonding due to the carbonization of the thermosetting resin 34 becomes insufficient, and the mutual fixing force is reduced. The activated carbon powder 32 falls off. In the above sample 3, the activated carbon powder 32 contains the thermosetting resin 3
4 is firmly bonded by the carbonization, the falling off is eliminated, but if the ratio is lower than this, the capacitance (10 F / g or more) required for practical use cannot be obtained due to the shortage of the activated carbon powder 32. After all, the mixing ratio between the activated carbon powder 32 and the thermosetting resin 34 is desirably 8: 2 to 2: 8.

While one embodiment of the present invention has been described with reference to the drawings, the present invention can be implemented in another mode different from the above embodiment.

For example, in the above embodiment, the exposure step 6
In step 2, the surface of the photosensitive drum 73 charged in the charging step 60 is irradiated with light 76 to form an electrostatic latent image on the activated carbon electrode 10. In a subsequent developing step 64, the electrostatic latent image is The powder raw material 30 was electrostatically deposited,
The exposure step 62 is not provided, and the electrode powder raw material 30 may be electrostatically attached to the entire surface of the photosensitive drum 73. When the electrode powder raw material 30 is adhered to the entire surface of the photosensitive drum 73, in the subsequent transfer step 66, the electrode powder raw material 30 is continuously transferred to the thin paper 84. After, after the carbonizing step 70, or after the oxidation heat treatment step 72, a forming step of forming the powdered raw material for electrode 30 or the carbonized molded body into the shape of the activated carbon electrode 10 by cutting or punching is provided.

In the above-described embodiment, the compact 94 in a state where the powdered raw material 30 for an electrode is fixed to the thin paper 84 functioning as a base is carbonized in an inert atmosphere. Alternatively, only the thin plate-like electrode powder raw material 30 may be carbonized. Alternatively, the thin paper 84 may be burned out by heat-treating the molded body 94 in an atmosphere containing oxygen. When the substrate is peeled before the carbonization step 70, the substrate may not be made of an organic fiber material and may not be thin.

In the above-described embodiment, following the transfer step 66, the fixing step 68 is executed to fix the electrode powder raw material 30 to the thin paper 84, and the binder contained in the electrode powder raw material 30 is Although the resin 30 was melted by heating, the powder raw material for electrode 30 can be fixed to the surface of the thin paper 84 by being appropriately heated and pressed in the transfer step 66, so that the fixing step 68 is not necessarily performed. You may.

In the above embodiment, the charging step 60,
The exposure step 62, the development step 64, the transfer step 66, and the fixing step 68 have been performed only once, but the charging step 60
After the fixing step 68 is repeated a predetermined number of times, and the thickness of the electrode powder raw material 30 for forming the visible image of the activated carbon electrode 10 transferred onto the thin paper 84 is set to a predetermined thickness, the carbonization step 70 is executed. May be done. By doing so, the thickness of the solid activated carbon electrode 10 can be easily adjusted. Incidentally, when the charging step 60 to the fixing step 68 were repeatedly performed, the thickness of the electrode powder raw material 30 on the thin paper 84 increased by about 0.05 mm each time the charging step was repeated.

In the fixing step 68 of the above embodiment,
The powder raw material 30 for an electrode is fixed on the thin paper 84 by heating and pressing using a heating roller 88 and a pressing roller 89. However, the heating is performed only by heating using a heating lamp such as an infrared lamp or a xenon lamp. The powder raw material 30 may be fixed on the thin paper 84.

Further, in the above-described embodiment, the circular roller-shaped photosensitive drum 73 is used as the charging member, but a plate-shaped charging member may be used. In this case, for example, the electrode powder raw material 30 uniformly electrostatically adsorbed on one surface of the plate-shaped charged body is transferred by being pressed onto a substrate such as a sheet of paper. Further, as the charged body, various materials can be used as long as the insulator can be charged with static electricity.

The thin paper 84 of the above-described embodiment is usually
Fine paper used in electrostatic copying machines may be used,
It may be a paper or a nonwoven fabric in which natural fibers, synthetic fibers, and carbon fibers are intertwined. In particular, when a Japanese paper or a nonwoven fabric made of a natural fiber obtained from a trident or kozo having high flexibility and strength is used as the base, the solid activated carbon electrode 10 becomes more flexible.
By winding the solid activated carbon electrode 10 including the current collector, the separator, and the substrate made of a sheet-like metal in a laminated state, a wound electric double-layer capacitor can be formed.

If the above-described method for manufacturing a solid activated carbon electrode is applied, a circuit or the like can be manufactured as follows. That is, in the electrostatic adhering step, the raw material is adhered to a predetermined pattern on the surface of the charged body, and in the transfer step, the raw material for forming the predetermined pattern is transferred onto the insulating substrate, and in the heat treatment step, When the raw material is carbonized, only the raw material portion has conductivity, so that a circuit or the like can be manufactured.

What has been described above is merely an embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a view showing a cross-sectional structure of an electric double layer capacitor to which an activated carbon electrode manufactured by a manufacturing method according to an embodiment of the present invention is applied.

FIG. 2 is a schematic diagram for explaining the operation of the electric double layer capacitor of FIG.

FIG. 3 is a process chart showing a powder raw material manufacturing process for manufacturing an electrode powder raw material for the activated carbon electrode of FIG. 1;

FIG. 4 is a process chart showing a manufacturing process of the activated carbon electrode of FIG. 1;

FIG. 5 is a conceptual cross-sectional view of an electrode powder raw material manufactured by the powder raw material manufacturing process of FIG.

6 is a conceptual diagram showing each step of the activated carbon electrode manufacturing process of FIG. 4, and is a diagram showing a process from a charging process to a fixing process.

FIG. 7 is a conceptual diagram showing each step of the activated carbon electrode manufacturing process of FIG. 4, and is a diagram showing a carbonizing step and an oxidation heat treatment step.

FIG. 8 is a diagram showing the capacitance of an activated carbon electrode manufactured by the manufacturing method of the present example in comparison with that of a porous carbon electrode manufactured only from thin paper.

FIG. 9 shows samples 1, 2, and 3 manufactured without passing through the oxidation heat treatment step and changing the ratio between the activated carbon powder and the thermosetting resin.
FIG. 3 is a diagram showing the capacitance of Sample No. 3 in comparison with Sample 4 which is a porous carbon electrode manufactured from thin paper only.

[Explanation of symbols]

 10: (Solid) activated carbon electrode 30: Powder raw material for electrode 32: Activated carbon powder 34: Thermosetting resin 36: Binder resin 48: Powder raw material production step 60: Charging step 62: Exposure step 64: Development step (electrostatic Attachment step) 66: transfer step 70: carbonization step 73: photosensitive drum (photoreceptor) 76: light 84: thin paper (substrate)

Claims (1)

[Claims] 1. A method for manufacturing a solid activated carbon electrode for producing a relatively thin solid activated carbon electrode using static electricity, comprising: a charging step of charging a surface of a charged body; and a charged body charged by the charging step. An electrostatic adhesion step of electrostatically adhering an electrode powder material containing activated carbon powder and a thermosetting resin for bonding the activated carbon powder to each other, A transfer step of transferring the electrode powder raw material adhered to the charged body surface to the substrate; and heating the substrate on which the electrode powder raw material has been transferred in the transfer step to be included in the electrode powder raw material. And carbonizing the thermosetting resin to bond the activated carbon powder.