JPH10242011A - Method for manufacturing solid activated carbon electrode - Google Patents

Abstract

(57) [Problem] To provide a method for producing solid activated carbon capable of obtaining sufficiently high mechanical strength. In a rapid temperature raising step (ie, a binder removal step) in a heat treatment step of heat treating a molded body, 300 (° C.)
An activated carbon electrode is manufactured by raising the temperature at a predetermined temperature raising rate of (/ hr) or more. For this reason, since the heating rate in the heating process in the heat treatment is set to be sufficiently high, the excess amount of the phenol resin is quickly decomposed and removed, and a sufficiently high mechanical strength is obtained.

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 an improvement in a heat treatment process.

[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. This solid activated carbon electrode is a composite of activated carbon and carbon. For example, after mixing activated carbon powder with a thermosetting resin to form a desired shape, for example, a non-oxidizing atmosphere in which the furnace gas is replaced with nitrogen gas is used. It is manufactured by heat-treating at a predetermined temperature to carbonize (carbonize) the thermosetting resin. As a result, a solid activated carbon electrode in which the activated carbon powder is bonded to each other by carbon without significantly reducing the specific surface area thereof can be obtained.

In the electric double layer capacitor, a pair of charge layers (ie, electric double layers) having different signs are provided at an interface between a conductor forming a pair of electrodes and an electrolyte solution.
This is characterized by the fact that rapid charging is possible and the life cannot be deteriorated 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. Have been. Since the above-mentioned solid activated carbon electrode has a large specific surface area and electrical contact between activated carbon powders can be obtained without particularly applying pressure, the capacitance and the discharge current value are maintained while keeping the dimensions of the electric double layer capacitor relatively small. Is raised,
It is suitable for such applications.

[0004] Incidentally, the capacitance of the electric double layer capacitor is determined by the amount of electric charge stored in the electric double layer, and the larger the surface area of the electrode, the larger the capacitance can be obtained.
Conventionally, activated carbon having high conductivity and high specific surface area has been 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, pressurization is required to obtain electrical contact between the powder or fiber. Therefore, in order to obtain a large capacitance, 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. Extremely large. Therefore, a capacitance of only about several F can be obtained at most as a practically-sized electric double-layer capacitor, and its use for memory backup as described above has been limited.

[0005]

By the way, in an electric double layer capacitor using solid activated carbon as an electrode,
In order to reduce the effective internal resistance, the solid activated carbon electrode is made as thin as possible, for example, about a few (mm) or less, preferably 1 (mm) or less. Therefore, it is desired that the solid activated carbon electrode has as high a mechanical strength as possible in order to suppress breakage due to vibration or shock during use in the manufacturing process or during use.
It is considered that a transverse rupture strength of 50 (kgf / cm ² ) or more is required.
However, the bending strength of the activated carbon electrode manufactured by the above-mentioned conventional manufacturing method is, for example, the standard defined by Japan Powder Metallurgy Industry Association standard J.
10 to 14 in the measurement method based on “Measuring method of strength of metal compact by bending strength” specified in PMA P 10-1992
(kgf / cm ² ), which is not enough.

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 obtaining a sufficiently high mechanical strength.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the first invention is to form a molded body in which activated carbon powder is bonded by a thermosetting resin under a non-oxidizing atmosphere. A method for producing a solid activated carbon electrode, comprising a heat treatment step of carbonizing the thermosetting resin to obtain a solid activated carbon electrode by heat treatment, wherein (a) the heat treatment step comprises:
A rapid temperature raising step of raising the temperature at a predetermined temperature raising rate of 0 (° C./hr) or more.

[0008]

[Effect of the first invention] In this manner, in the rapid temperature rising step in the heat treatment step of heat treating the compact, 300 (° C./hr)
The solid activated carbon electrode is manufactured by increasing the temperature at the above-mentioned predetermined rate. Therefore, since the heating rate in the heating process of the heat treatment is sufficiently fast,
The excess amount of the thermosetting resin is quickly decomposed and removed, and a sufficiently high mechanical strength is obtained. The rapid temperature raising step may be performed in a part of the temperature raising step of the heat treatment, or may be performed in the entire temperature raising step. By the way, thermosetting resin is
Since an amount much larger than an amount corresponding to the amount of carbon (carbon) necessary for bonding activated carbon powders in the solid activated carbon electrode is added for the purpose of obtaining a molded article having a desired shape, the ratio of the solid activated carbon electrode In order to keep the surface area sufficiently high, it is considered necessary to decompose and remove as much excess thermosetting resin as possible during the heat treatment process.

[0009]

A second aspect of the present invention to achieve the above object is to provide a molded article in which activated carbon powder is bonded by a thermosetting resin under a non-oxidizing atmosphere. A method of manufacturing a solid activated carbon electrode including a heat treatment step of carbonizing the thermosetting resin to obtain a solid activated carbon electrode by heat treatment, wherein (a) the heat treatment step is 150 (° C. / hr) or a rapid temperature raising step of raising the temperature at a predetermined rate.

[0010]

According to the second aspect of the present invention, the temperature can be raised at a predetermined temperature rising rate of 150 (° C./hr) or more while evacuating in the rapid temperature rising step in the heat treatment step of heat treating the compact. Thereby, a solid activated carbon electrode is manufactured. for that reason,
Since the decomposed gas of the thermosetting resin is forcibly exhausted by evacuation, the decomposed gas of the thermosetting resin is prevented from staying near the surface of the molded body, the decomposition is accelerated, and the strength is reduced. Insufficient carbonization, which causes the above, is removed and the material is hardened, so that sufficiently high mechanical strength is obtained. The rapid temperature raising step may be performed in a part of the temperature raising step of the heat treatment, or may be performed in the entire temperature raising step.

[0011]

In another preferred embodiment of the present invention, in the method for producing a solid activated carbon electrode according to the first and second aspects of the present invention, the step of rapidly raising the temperature includes a step of causing thermal decomposition of the thermosetting resin. In this range, the temperature is raised at the predetermined rate. In this case, since the temperature is rapidly raised in the thermal decomposition temperature range of the thermosetting resin, burnout due to oxidation is suppressed, so that higher mechanical strength is obtained.
The temperature range in which the thermal decomposition of the thermosetting resin proceeds depends on the type of the thermosetting resin.For example, in the case of a phenol resin, it is about 450 to 550 (° C.). At least a temperature range including this, for example, 400 to
It is desirable to carry out the process in the range of about 600 (° C).

[0012] Preferably, the molded body further includes an organic molding aid for molding the activated carbon powder and the thermosetting resin into a predetermined shape, and the rapid temperature raising step comprises: The temperature is raised at the predetermined rate in the temperature range in which the thermal decomposition of the agent and the thermosetting resin proceeds. In this case, the temperature is rapidly raised in the thermal decomposition temperature range of the organic molding aid and the thermosetting resin, so that higher mechanical strength is obtained. The temperature range in which the thermal decomposition of the organic molding aid proceeds varies depending on the type as in the case of the thermosetting resin.
C), when the main component is polyvinyl alcohol (PVA), acrylic resin, or the like, the temperature is 300 (° C.) or less. Therefore, for example, when a phenol resin is used as the thermosetting resin and a material mainly composed of MC, PVA, acrylic resin, or the like is used as the organic molding aid, the rapid temperature raising step is at least 200 to 600 ( (° C).

Preferably, the heating rate in the rapid heating step is 900 (° C./hr) or less. In this case, since the rate of temperature rise is not too high, after the decomposed components of the thermosetting resin are sufficiently dissipated, the residue is carbonized and the molded body is hardened, so that the residual decomposed gas remains. The occurrence of blisters and cracks, which are considered to be caused by the above, is suppressed.

[0014]

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 and 16, a pair of terminal plates 18 and 18, a pair of fixing plates 20 and 20, and a gasket provided on the side of the activated carbon electrodes 10 and 10 to support the current collectors 16 and 16. 22, and fixing plates 20, 20 provided on both sides of the gasket 22.
Is provided with a pair of supports 24, 24. The inside surrounded by the current collectors 16, 16 and the gasket 22, for example, a 30 (wt%) sulfuric acid aqueous solution is injected as an electrolytic solution. ing.

The pair of activated carbon electrodes 10, 10 is, for example, about 1 (mm) in thickness, and is a porous activated carbon-carbon composite in which activated carbon is bound by a carbon tissue. The separator 14 has, for example, a thickness of 0.
It is made of glass fiber of about 1 to 0.2 (mm) and has a slightly larger area than the activated carbon electrode 10. This prevents an electrical short circuit due to contact between the activated carbon electrodes 10, 10 and allows the electrolyte to freely flow. It is formed porous so that it can be distributed.

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 flat 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 a number of activated carbon particles 28 to have a positive or negative ion in an 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 activated carbon particles 28 to each other by a carbon structure (not shown) derived from a thermosetting resin described later. Road).

The activated carbon electrode 10 is manufactured, for example, according to the process shown in FIG. First, in the first mixing step of the step 1, for example, the particle size is 5 to 30 (μ).
m) and the specific surface area measured by the BET method is 700 to 2000
(m ² / g) activated carbon powder to about 70 (wt%), for example, phenol resin powder having a particle size of about 10 to 50 (μm) to 30 (wt.
%), And 60 (wt.) Relative to 100 (wt.%) Of the mixture.
%) Of water and a molding binder mainly composed of, for example, MC, PVA, acrylic resin, etc., as a mixture 100 (wt.
%) And about 60 (wt%). In addition, all of these mixing steps are performed by, for example, a dry mixer or the like, whereby the raw materials and the additives are uniformly mixed. The amount of addition of the phenol resin is an amount required to form a composite material of activated carbon and carbon (an amount required to obtain sufficient mechanical strength of the activated carbon electrode 10). This is determined in consideration of the moldability necessary to obtain a desired molded body in the extrusion molding step of the following step 3. In this embodiment, the phenol resin corresponds to a thermosetting resin, and the molding binder corresponds to an organic molding aid.

Next, in the kneading step of step 2, by kneading the above mixture using, for example, a kneader, plasticity suitable for molding is given. And step 3
In the extrusion molding step, the kneaded product is continuously formed into a sheet-like molded body having a width of about 100 (mm) and a thickness of about 1 (mm) by an extruder. The extruded sheet-like molded body is dried with hot air of, for example, 100 (° C.) in the drying step of step 4.

In the binder removal step and the heat treatment step of Steps 5 and 6, for example, in a state in which a sheet-shaped molded body is placed on a predetermined setter, for example, in a box furnace, a stream of N ₂ gas or a vacuum atmosphere is used. Below, 300 (℃ / hr)
Degreasing (debindering) is performed while increasing the temperature at the sufficiently high rate, and heat treatment is continuously performed for about 900 (° C.) × 2 hours. That is, the heat treatment is performed in the furnace with, for example, the heat profile shown in FIG. 4 (a).
_H corresponds to the rapid temperature raising step, and the period H _K corresponds to the heat treatment step. Therefore, in the present embodiment, the entire heating process is constituted by the rapid heating process. Thereby, a part of the phenol resin is carbonized and the excess is sufficiently dissipated to obtain the solid activated carbon electrode, that is, the activated carbon electrode 10. In the present embodiment, the debinding step and the heat treatment step correspond to the “heat treatment step” in the claims.

Table 1 below shows the results of tests conducted by changing the conditions of the debinding step in various ways. In the table, “Comparative Example” indicates a comparative example implemented for conventional heat treatment conditions and comparison, and “Example” indicates this example. In the firing furnace column, “box” indicates a batch-type box furnace, and “continuous furnace” indicates a continuous furnace in which heat treatment is performed in a process of being conveyed along one direction by, for example, a mesh belt or the like. In the atmosphere column, “N ₂ ” is obtained by heat treatment in a nitrogen gas stream, and “vacuum” is obtained by heat treatment while evacuating.
“H _H ” is the time of the temperature raising step, that is, the debinding step in the profile of FIG. 4 (a), but for the comparative example of No. 2, the heat treatment was performed with the profile of FIG. Therefore, each period of H _{H1 to} H _H3 was set to the time shown in the margin. Both the maximum temperature T _K and the holding time H _K are 900
(° C) and 2 hours. Therefore, H _H = 9 (hr)
Means that the heating rate is 100 (° C./hr), and for the other heating time steps H _H = 3, 2, 1, 0.5 (hr), the heating rate is similarly 300, 450, 900, 1800 (℃ / h
r). The flexural strength is determined by the JPMA P
It is measured by the method specified in 10-1992, and the capacitance is constant at a current value of about 0.1 (A) until it reaches 0.45 (V) after charging at a constant voltage of, for example, 0.9 (V) for 30 minutes. The capacitance at the time of current discharge is represented by C = (i △ t) / △ V [where the capacitance is C (F), the discharge current is i (A), and the time required for the voltage drop is △ t. (sec), and the voltage drop is ΔV (V)].

[Table 1] No. Firing furnace atmosphere H _H (hr) Flexural strength Capacitance 1. Comparative example box N ₂ 924 (kgf / cm ² ) 184 (F) 2. Comparative example box N ₂ * 24 186 3. Example box N ₂ 3 56 191 4. Example continuous furnace N ₂ 1 92 203 5. Example continuous furnace N ₂ 0.5 116 213 6. Comparative example box vacuum 9 44 198 7. Example box vacuum 3 80 212 8. Example box Vacuum 2 126 217 * H _H1 = 0.67, H _H2 = 4, H _H3 = 1

As is clear from the above table, in both the N ₂ gas atmosphere and the vacuum atmosphere, when the heating time is 3 hours or less, that is, when the heating rate is 300 (° C./hr) or more,
The flexural strength is 50 (kgf / cm ² ) or more, and the activated carbon electrode 10 having sufficient mechanical strength can be obtained. On the other hand, in the case of the conventional heat treatment condition in which the heating rate is about 100 (° C./hr), about 24 (kgf / cm ² ) in an N ₂ gas atmosphere and about 44 (kgf / cm ² ) in a vacuum atmosphere. ² ) The degree and practical mechanical strength cannot be obtained. In the comparative example No. 2, the period H
_The heating rate of _H1 and _HH3 is set to 300 (° C./hr). On the other hand, the period H during which the temperature is increased from 200 (° C.) to 600 (° C.)
_{For H2} , the heating rate is 100 (° C./hr). for that reason,
Since the heating rate in the range of 200 to 600 (° C.) is as slow as before, the mechanical strength is not improved at all. That is, in order to improve the mechanical strength in the present embodiment in the case of the N ₂ gas atmosphere, at least 200 to 600
It is necessary to raise the temperature in the range of (° C) at a rate of 300 (° C) or more. This temperature range includes a temperature range in which the thermal decomposition of the phenolic resin proceeds (about 400 to 600 ° C.) and a temperature range in which the thermal decomposition of the molding binder proceeds (about 300 ° C.). When the temperature is rapidly increased in a temperature range in which such thermal decomposition proceeds, the activated carbon electrode 10
The mechanical strength of is increased.

FIG. 5 is a graph showing the relationship between the heating rate and the bending strength in the test results shown in Table 1 above. As shown in the figure, in both the N ₂ gas atmosphere and the vacuum atmosphere, the bending strength tends to increase as the heating rate is increased, but at the same heating rate, the bending strength is higher in vacuum. Strength is obtained. Generally, in the binder removal step (step 5) of the heat treatment, the phenol resin and the molding binder contained in the molded body are thermally decomposed to generate a decomposed gas in the furnace, but the discharge of the decomposed gas is not sufficient. It is conceivable that stagnation stays on the surface of the molded product to hinder the progress of thermal decomposition. The higher the efficiency of the decomposition gas discharge, the faster the thermal decomposition proceeds. Therefore, a higher bending strength can be obtained when heat treatment is performed in a vacuum. Due to this, as shown in the figure, when the heat treatment is performed in a vacuum, the improvement effect by increasing the heating rate is more remarkable. As is clear from the figure, when heat treatment is performed in a vacuum, the transverse rupture strength (50 [kgf / c
m ² ] or more is 150 (° C / hr)
About.

Although not shown in the table, the heating rate was
In the case of No. 5 which is as fast as 1800 (° C./hr), a good activated carbon electrode 10 is not necessarily obtained, and swelling and cracking may occur. It is considered that this is because the surface of the molded product is carbonized and hardened before the decomposition gas of the phenol resin is sufficiently dissipated due to the excessively high temperature rising rate, and the generated decomposition gas remains inside. Therefore, it is considered that the ease with which the decomposed gas escapes depends on the thickness of the compact, and it can be said that the rate of temperature rise has an upper limit determined for each thickness. For example, when the thickness is about 1 (mm) as in this embodiment,
The heating rate is desirably about 900 (° C./hr) or less.

Further, as shown in Table 1, according to the present embodiment, the capacitance is slightly improved. The activated carbon electrode 10 of the embodiment has a tendency to slightly shrink during firing compared to the case of heat treatment under the conventional heat treatment conditions, but has a lighter weight and the same density as the conventional one. However, it is considered that the shrinkage and the change in weight are mainly due to the progress of decomposition and dissipation of the phenolic resin. Accordingly, the proportion of macropores formed by carbonization of the phenolic resin in the activated carbon electrode 10 is formed. Is considered to be reduced, the specific surface area is improved, and the capacitance is increased.

As described above, No. 3 of this embodiment
According to ~ 5, in the rapid heat-up step (ie, the binder removal step of step 5) in the heat treatment steps 5 and 6 for heat-treating the formed body, the temperature is raised at a predetermined rate of 300 (° C / hr) or more. The activated carbon electrode 10 is manufactured by being heated. For this reason, since the heating rate in the heating process in the heat treatment is set to be sufficiently high, the excess amount of the phenol resin is quickly decomposed and removed, and a sufficiently high mechanical strength is obtained.

Further, in Nos. 7 and 8 of this embodiment, in the rapid temperature rise step in the heat treatment step of heat treating the compact, a predetermined temperature rise rate of 150 (° C./hr) or more was performed while evacuating. Activated carbon electrode 10 is manufactured. Therefore, since the decomposition gas of the phenol resin is forcibly exhausted by the vacuum evacuation, the decomposition gas of the phenol resin is suppressed from staying in the vicinity of the surface of the molded body, the decomposition is accelerated, and the strength is reduced. Since the insufficiently carbonized portion is removed and baked, a sufficiently high mechanical strength is obtained.

In the present embodiment, the rapid heating step is performed at a temperature of about 300 (° C./hr) or more in the temperature range in which the thermal decomposition of the phenol resin proceeds (when heat treatment is performed in a nitrogen gas stream) or 150 ° C. The temperature is raised at a rate of about (° C./hr) or more (when heat treatment is performed in a vacuum). In this case, the temperature is rapidly raised in the thermal decomposition temperature range of the phenol resin, so that higher mechanical strength can be obtained.

Further, in this embodiment, the molded body further includes a molding binder for molding the activated carbon powder and the phenol resin into a predetermined shape, and the rapid heating step includes a step of heating the molded binder and the phenol resin. Within the temperature range where decomposition proceeds, about 300 (° C / hr) or more (when heat treatment is performed in a nitrogen gas stream) or 150 (° C / h)
r) The temperature is raised at a temperature rising rate of about or more (when heat treatment is performed in a vacuum). In this case, since the temperature is rapidly raised in the thermal decomposition temperature range of the molding binder and the phenol resin, burnout thinning due to oxidation is suppressed, so that higher mechanical strength is obtained.

While the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be embodied in still another embodiment.

For example, in the embodiment, nitrogen gas is used as the non-oxidizing gas. However, heat treatment may be performed in an inert gas stream such as argon, helium, or neon.

In the examples, the particle size is 5-30.
(μm), specific surface area of 700 to 2000 (m ^Two/ g) activated carbon
Activated carbon electrode 10 was made using powder, but it was used.
The size of the activated carbon powder is, for example, a specific surface area of several hundred (m^Two/ g)
Degree to several thousand (m^Two/ g) is appropriately changed in the range.

In the examples, 30 (wt%) of a phenol resin was added as a thermosetting resin, but the type and amount of the thermosetting resin to be added depend on the conditions of each step, the equipment used,
It is appropriately changed according to the target sintered density of the activated carbon electrode 10 and the like. For example, another thermosetting resin such as a urea resin or a melamine resin may be used, and the amount added may be more or less than 30 (wt%).

In the examples, a molded article having a predetermined shape is formed by extrusion in the molding step, but the molding method is not particularly limited. For example, cold pressing, hot pressing such as hot pressing, injection molding, powder rolling,
The molding may be performed by a doctor blade method or the like. In the case of press molding or the like, it is desirable to granulate a mixture of activated carbon powder and thermosetting resin in advance, and the type of a molding binder added to enhance moldability depends on the molding method and molding dimensions. It is changed as appropriate.
For example, when sufficient plasticity can be imparted with water alone and there is no problem in moldability, the molding binder need not be added.

The maximum holding temperature T _K during the heat treatment is not limited to about 900 (° C.) as shown in the embodiment.
It may be about 600 (° C) or about 1000 (° C).
That is, the temperature during the heat treatment is appropriately changed within a range in which the activated carbon is not oxidized and the thermosetting resin is sufficiently dissipated and carbonized.

Further, in the embodiment, the entire temperature raising step is constituted by the rapid temperature increasing step, but only a part may be constituted by the rapid temperature increasing step. In this case, a temperature range in which the temperature is rapidly raised is appropriately set according to the thermal decomposition temperature determined for each type of the resin and the binder used.

Although not specifically exemplified, the present invention can be appropriately 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 method for producing the activated carbon electrode of FIG.

4 (a) and 4 (b) are views showing heat profiles in a heat treatment step of step 4 in FIG.

FIG. 5 is a diagram showing a relationship between a heating rate and a transverse rupture strength in the manufacturing process of FIG. 3;

[Explanation of Signs] 10: Activated carbon electrode

Continued on the front page (72) Inventor Yukari Kibi 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Inventor Takayuki Saito 5-7-1 Shiba, Minato-ku, Tokyo NEC Corporation In company

Claims (4)

[Claims] 1. A solid activated carbon comprising a heat treatment step of heat-treating, in a non-oxidizing atmosphere, a molded body in which activated carbon powder is bound by a thermosetting resin to carbonize the thermosetting resin to obtain a solid activated carbon electrode. A method for producing an electrode, wherein the heat treatment step includes a rapid temperature increasing step of increasing the temperature at a predetermined temperature increasing rate of 300 (° C./hr) or more. 2. A solid activated carbon comprising a heat treatment step of heat-treating, in a non-oxidizing atmosphere, a molded body in which activated carbon powder is bound by a thermosetting resin to carbonize said thermosetting resin to obtain a solid activated carbon electrode. A method for manufacturing an electrode, wherein the heat treatment step includes a rapid heating step of heating at a predetermined heating rate of 150 (° C./hr) or more while evacuating to a vacuum. Method. 3. The method for producing a solid activated carbon electrode according to claim 1, wherein said rapid temperature raising step raises the temperature at said predetermined temperature raising rate in a temperature range in which thermal decomposition of said thermosetting resin proceeds. Method. 4. The molded article further includes an organic molding aid for molding the activated carbon powder and the thermosetting resin into a predetermined shape, and the rapid heating step includes the organic molding aid and the thermosetting resin. 3. The method for producing a solid activated carbon electrode according to claim 1, wherein the temperature is raised at the predetermined rate in a temperature range in which the thermal decomposition of the curable resin proceeds.