KR20090111290A - Active carbon for an electric double layer capacitor electrode and process for manufacturing the same - Google Patents

Abstract

PURPOSE: An active carbon for an electric double layer capacitor electrode and a method for manufacturing the same are provided to use an active carbon whose average particle size is mall and whose non surface size is relatively large in an electrode, thereby improving electrostatic capacity per a unit volume. CONSTITUTION: A carbon material which can be graphitized is plastic-processed. The carbon material is revived by alkali metal hydroxide. The revived carbon material is wetly crashed by using two kinds of balls having different diameters. A plastic processing temperature is between 500 and 700°C. A diameter of a larger ball between two kinds of balls having different diameters is from 1 to 30 mm and a diameter of a smaller ball is from 1/10 to 1/2 of a diameter of a large ball.

Description

ACTIVE CARBON FOR AN ELECTRIC DOUBLE LAYER CAPACITOR ELECTRODE AND PROCESS FOR MANUFACTURING THE SAME}

The present invention relates to activated carbon which is a carbon material for electric double layer capacitor electrodes and a method of manufacturing the same.

Activated carbon is made of porous structure by reviving carbon materials such as carbonized palm coke, petroleum coke and coal coke. Porous activated carbon having a large surface area is widely used in electrode materials such as adsorbents or catalyst carriers, electric double layer capacitors, and lithium secondary batteries. In particular, in an electric double layer capacitor used in a hybrid car or the like, in order to increase the energy density, that is, the capacitance, activated carbon having a high crystallinity and a large surface area in which micropores are effectively formed as the electrode material is required.

In industrial production of activated carbon having micropores effectively formed in the electrode material of such an electric double layer capacitor, carbon materials such as petroleum coke and alkali metal compounds such as potassium hydroxide are heated in an inert gas atmosphere, for example, in a range of 600 to 1200 ° C. The activating method which invades and reacts alkali metal between a graphite crystal layer is generally used. In this revival, alkali metal invades the layered structure in which the layered condensed polycyclic carbon compound is laminated to form micropores.

Activated carbon obtained by alkaline activation treatment has a relatively large specific surface area, and furthermore, when producing an electrode for an electric double layer capacitor, it is required that the average particle diameter of the activated carbon is small and the particle size of the activated carbon is matched so as not to contain coarse large particles.

In patent document 1, when manufacturing the electrode for electric double layer capacitors, in order to match the particle size of activated carbon, the activated carbon is grind | pulverized by the ball mill, and the specific surface area by BET method is 1300 m <2> / g or more and 2200 m <2> / g or less, average particle diameter 1 micrometer. Activated carbon of 7 µm or less is obtained. In patent document 2, the activated carbon whose average particle diameter is 100 nm-10 micrometers is obtained by the ball mill grinding method. In addition, in patent document 3, the activated carbon after reactivation is wet-pulverized in the presence of washing | cleaning liquid coexistence for the purpose of high purity of activated carbon. However, the specific surface area was large, and the production of electrodes for electric double layer capacitors was still insufficient in view of the fact that the average particle diameter of activated carbon was small, so that it was necessary to match the particle size of activated carbon.

Patent Document 1: Japanese Patent Application Laid-Open No. 2000-182904

Patent Document 2: Japanese Patent Application Laid-Open No. 2006-324183

Patent Document 3: Japanese Patent Application Laid-Open No. 2008-7387

As a method of reducing the particle diameter of activated carbon, there are a method of pulverizing activated carbon to a desired particle size and a method of activating fine particles of a raw material to obtain activated carbon. However, the former causes the pore to be broken by pulverization, resulting in a decrease in specific surface area. For this reason, it is not preferable. In the latter case, since the fusion of the particles occurs at the time of activation, the particle diameter of the obtained activated carbon has a problem that becomes larger than the diameter of the raw material. The present inventors have completed the present invention by finding that activated carbon after alkali activation is wet-pulverized, and furthermore, by combining the ball mill ball with a large diameter and a small diameter, the activated carbon having a large specific surface area and a small particle size can be easily obtained.

That is, the present invention is characterized in that the carbon material which can be easily graphitized is calcined, then activated by using an alkali metal hydroxide, and then wet pulverized using two kinds of balls having different diameters. The present invention relates to a method for producing activated carbon for an electric double layer capacitor electrode having a particle diameter of 0.5 to 5 m and a BET specific surface area of 1500 to 2500 m 2 / g.

The present invention also relates to a method for producing activated carbon for an electric double layer capacitor electrode, wherein the average particle diameter of the easily graphitizable carbon material is 0.5 to 8 µm.

In addition, the present invention is the electric double layer capacitor electrode, characterized in that the diameter of the large ball of two kinds of balls having different diameters is 1 to 30mm, and the diameter of the small ball is 1/10 to 1/2 of the diameter of the large ball. It relates to a method for producing molten activated carbon.

The present invention also relates to activated carbon for electric double layer capacitor electrodes obtained by the above production method.

The present invention also relates to an electric double layer capacitor using activated carbon for the electric double layer capacitor electrode.

According to the present invention, activated carbon for an electric double layer capacitor having a small specific particle diameter and a relatively large specific surface area having a matching particle size can be produced easily and at a lower cost. In addition, by using the activated carbon obtained according to the present invention for the electrode, activated carbon having a large capacitance per unit volume is provided.

Hereinafter, the present invention will be described in detail.

Easily graphitizable carbon materials used as starting materials in the present invention include carbonized petroleum coke or coal coke, insoluble and carbonized mesophase pitch or mesophase pitch fibers spun therein, and the like. Although an example is mentioned, petroleum coke is preferable and petroleum coke is especially preferable in this invention.

Petroleum raw coke preferably used as a starting material in the present invention is an aggregate in which a polycyclic aromatic compound having an alkyl side chain is laminated, and is a solid that is not thermally dissolved.

Petroleum coke is a product composed mainly of solid carbon obtained by pyrolyzing (coking) heavy oil of petroleum at a high temperature of about 500 ° C, and is called petroleum coke in response to ordinary coal-based coke. Petroleum coke is based on the delayed caulking method and the flow caulking method, and the former is mostly used by the former. In this invention, it is preferable to use petroleum coke (raw coke) as it is from the coker as this petroleum coke. The raw coke produced by the delayed coking method has a volatile matter normally 6-13 mass%, and the fresh coke produced by the flow coking method has a volatile matter normally 4-7 mass%. Although the raw coke by any method may be used in this invention, the fresh coke produced by the delayed coking method which can be obtained easily and is stable in quality is especially preferable.

The heavy oil fraction of the petroleum is not particularly limited, but heavy oil obtained as a residue when petroleum is distilled under reduced pressure, heavy oil obtained by fluid catalytic cracking of petroleum, heavy oil obtained by hydrodesulfurization of petroleum, and mixtures thereof This includes.

In the present invention, the graphitizing easy carbon material is calcined, and then activated by an activating step using an alkali metal hydroxide.

At this time, the average particle diameter of the graphitizing easy carbon material at least before an activation process is adjusted to 0.5-8 micrometers, Preferably it is 1-6 micrometers. If the particle diameter of the graphitizing carbon material is less than 0.5 µm, it is not preferable because the particle diameter is increased by fusion of the particles. If the particle diameter of the graphitizing carbon material exceeds 8 µm, It is not preferable because it becomes larger than the particle diameter.

Although it does not specifically limit as a method of adjusting the particle diameter of a graphitizing easy carbon material, Usually, it grinds by grinding means, such as a jet mill. Grinding is usually carried out after the firing treatment described later, but may be carried out before the firing treatment.

The firing conditions of the graphitizing easy carbon material have a firing temperature of 500 to 700 ° C, preferably 520 to 680 ° C, and the firing time is about 10 minutes to 2 hours as a holding time from reaching the target temperature.

The reaction conditions of the activating process in the activating step are not particularly limited as long as the reaction can proceed sufficiently, and the activating reaction can be carried out under the same reaction conditions as those of the known activating process performed in normal activated carbon production. For example, in the activating process, the activating reaction is carried out by mixing alkali metal hydroxides carried out in the production of ordinary activated carbon with the carbide after firing, preferably at least 400 ° C, more preferably at least 600 ° C, particularly preferably at 700 It may be carried out by heating to a temperature condition of high temperature or more. The upper limit of this heating temperature is not particularly limited as long as the activation reaction proceeds without any problems, but is usually 900 ° C. or lower.

Examples of alkali metal hydroxides used for the activation reaction in the activation process include KOH, NaOH, RbOH, and CsOH. Among these, KOH is preferable from a viewpoint of an activating effect.

The alkali activation method is usually performed by mixing and heating an activating agent such as an alkali metal hydroxide and a carbide. Although the mixing ratio of a carbide and an activator is not specifically limited, Usually, the mass ratio (carbide: activator) of both is preferably in the range of 1: 0.5 to 1: 5, and more preferably in the range of 1: 1 to 1: 3. Do.

In the present invention, a method of obtaining activated carbon by preferably adding the activated product thus obtained into water to make an alkali slurry, wet grinding the alkali slurry, and then performing washing, can preferably be employed. After that, wet grinding may be performed from the water slurry.

The slurry concentration is preferably in the range of 2 to 40%, more preferably in the range of 5 to 20%. When the slurry concentration is less than 2%, the grinding efficiency is deteriorated, which is not preferable. When the slurry concentration is more than 40%, the fluidity is deteriorated and the impact force due to the balls is not preferable.

The apparatus used for the wet grinding is not particularly limited as long as the object of the present invention is achieved. For example, a ball mill, an attritor, a sand mill, a bead mill and the like are used, but a ball mill is preferably used.

Hereinafter, the example of wet grinding by a ball mill is demonstrated.

Examples of the balls include alumina balls, zirconia balls, stainless balls, silicon nitride balls, tungsten carbide balls, and the like.

In this invention, in order to alleviate the impact at the time of grinding | pulverization, it is necessary to use at least 2 types of ball from which a ball diameter differs. In this case, it is important to combine the balls so that the crushed particles are mainly disintegrated and the particles are pulverized relatively little.

The diameter of the large ball is preferably 1 to 30 mm, more preferably 5 to 20 mm, and the diameter of the small ball is preferably in the range of 1/10 to 1/2 to the ball diameter of the large ball.

The ratio of the total weight of the large balls to the total weight of the small balls is preferably in the range of 1/10 to 10/1, more preferably in the range of 2/8 to 8/2.

Since the milling time is too long or too short, activated carbon having a desired particle diameter and surface area is not obtained, preferably from 30 minutes to 5 hours, more preferably from 60 minutes to 3 hours. Moreover, 10-100 rpm is preferable and 30-60 rpm is more preferable.

As the washing method of the activator, a method of washing the activator with a washing liquid and separating the solid solution is preferably employed. For example, a method of immersing the activator in a washing liquid, stirring and heating as necessary to mix with the washing liquid, and then removing the washing liquid is exemplified.

As a washing | cleaning liquid, it is preferable to use water and / or an acidic aqueous solution, For example, washing | cleaning with water, the washing with an acidic aqueous solution, the washing with water, etc. can be combined suitably, and can be used.

As an aqueous acid solution, inorganic acids, such as hydrochloric acid, such as hydrochloric acid, hydroiodic acid, and hydrobromic acid, sulfuric acid, a carbonic acid, are mentioned as a preferable example. The concentration of the acid aqueous solution is, for example, 0.01 to 3N. Washing with these cleaning liquids can be repeated several times as needed.

The amount of alkali metal remaining in the carbide is not particularly limited as long as it is lower than the level which may adversely affect the electric double layer capacitor (preferably 1000 mass ppm or less). It is preferable to wash to about 8 to 8 while washing to remove the alkali metal powder if possible. After washing, a target activated carbon can be obtained through a drying process usually performed.

The activated carbon obtained by the present invention has an average particle diameter of 0.5 to 5 µm, a specific surface area of 1500 to 2500 m 2 / g, and a pore volume of 0.1 to 50 nm by a nitrogen gas adsorption method of activated carbon after the activation process. The pore volume of 3 ml / g, the pore diameter of 0.05-300 micrometers by a mercury porosimetry is 0.4-5 ml / g, and the amount of alkali metals is 200 mass ppm or less.

Next, the electric double layer capacitor of this invention is demonstrated.

The electric double layer capacitor of this invention is characterized by including the electrode containing the activated carbon prepared as mentioned above.

The electrode may be configured by, for example, adding activated carbon and a binder, more preferably a conductive agent, and further integrated with a current collector.

As a binder used here, a well-known thing can be used, For example, Fluorinated polymers, such as polyolefin, such as polyethylene and a polypropylene, polytetrafluoroethylene, polyvinylidene fluoride, and a fluoroolefin / vinyl ether copolymer crosslinked polymer And celluloses such as carboxymethyl cellulose, vinyl polymers such as polyvinylpyrrolidone and polyvinyl alcohol, and polyacrylic acid. Although content of a binder in an electrode is not specifically limited, Usually, it selects suitably within the range of about 0.1-30 mass% with respect to the total amount of activated carbon and a binder.

As the conductive agent, powders such as carbon black, powdered graphite, titanium oxide, ruthenium oxide and the like are used. Although the compounding quantity of a electrically conductive agent in an electrode is suitably selected according to the compounding purpose, it is suitably selected within the range of 1-50 mass% normally, Preferably it is about 2-30 mass% with respect to the total amount of activated carbon, a binder, and a electrically conductive agent.

In addition, as a method of mixing activated carbon, a binder, and a conductive agent, a well-known method is appropriately applied, and for example, a solvent having a property of dissolving the binder is added to the component to make a slurry on the current collector uniformly. The method of apply | coating, or the method of pressure-molding under normal temperature or heating after kneading the said component without adding a solvent is employ | adopted.

Moreover, as a collector, what is well-known material and a shape can be used, For example, metals, such as aluminum, titanium, tantalum, and nickel, or alloys, such as stainless steel, can be used.

The unit cell of the electric double layer capacitor of the present invention generally uses a pair of the above electrodes as a positive electrode and a negative electrode, and faces them through a separator (polypropylene fiber nonwoven fabric, glass fiber nonwoven fabric, synthetic cellulose paper, etc.) and immerses them in an electrolyte solution. Is formed.

As an electrolyte solution, although well-known aqueous electrolyte solution and organic electrolyte solution can be used, it is more preferable to use organic electrolyte solution. As such an organic electrolyte solution, one used as a solvent of an electrochemical electrolyte solution can be used, and for example, propylene carbonate, ethylene carbonate, butylene carbonate, γ-butyrolactone, sulfolane, sulfolane derivatives, and 3-methyl sulfolane , 1,2-dimethoxyethane, acetonitrile, glutaronitrile, valeronitrile, dimethylformamide, dimethylsulfoxide, tetrahydrofuran, dimethoxyethane, methyl formate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate Etc. can be mentioned. In addition, you may mix and use these electrolyte solutions.

In addition, the supporting electrolyte in the organic electrolytic solution is not particularly limited, but various kinds of salts, acids, alkalis and the like commonly used in the electrochemical field or the battery field can be used. For example, inorganic ion salts such as alkali metal salts and alkaline earth metal salts can be used. , Quaternary ammonium salts, cyclic quaternary ammonium salts, quaternary sulfonium salts, and the like, (C ₂ H ₅ ) ₄ NBF ₄ , (C ₂ H ₅ ) ₃ (CH ₃ ) NBF ₄ , (C ₂ H ₅ ) ₄ PBF ₄ , (C ₂ H ₅ ) ₃ (CH ₃ ) PBF _4, and the like are preferable. The concentration of these salts in the electrolyte is usually appropriately selected within the range of about 0.1 to 5 mol / l, preferably about 0.5 to 3 mol / l.

A more specific configuration of the electric double layer capacitor is not particularly limited, but a coin-shaped, pair of coins housed in a metal case via a separator between a pair of electrodes (positive electrode and negative electrode) on a thin sheet or disk of 10 to 500 μm in thickness, for example. The winding type which wound an electrode through a separator, and the laminated type which laminated | stacked many electrode groups via the separator are mentioned.

Example

Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited only to these Examples.

In addition, hydrogen / carbon atomic ratio, volatile matter, true density, specific surface area, particle size distribution measurement, and capacitance were obtained by the following method.

(1) hydrogen / carbon atomic ratio

Using the organic element analyzer (SUMIGRAPH HCN-22F, manufactured by Coin Analysis Center), carbon mass% and hydrogen mass% in the sample were obtained, and the hydrogen / carbon atomic ratio was calculated.

(2) volatiles

It measured according to the method described in JIS M8812 "Oil and coke industrial analysis method."

(3) true density

It measured according to JISK2151.

(4) specific surface area

It measured by nitrogen gas adsorption method (BET method).

(5) Particle size distribution measurement

Using a laser diffraction particle size distribution measuring device (manufactured by KLC, Model LA-950), water was used as a dispersion medium, and a small amount of surfactant was added and ultrasonic measurement was performed. 10% particle size (D10), 50% particle size (average particle diameter (D50)), and 90% particle size (D90) were obtained from the obtained particle size integral curve.

(6) capacitance

The coin-type cell was charged to 2.7V at a constant current of 2mA per 1F. After the charge was maintained at 2.7 V for 30 minutes, a constant current discharge of 1 mA was performed at 20 ° C. In the discharge curve, when ΔT and the discharge current value I are the time taken for the voltage to fall from 80% of the charging voltage to V1, 40% to V2, and 80% to 40%, the following equation is obtained. When capacitance C [F] is calculated and divided by the mass of the activated carbon contained in the electrode (the sum of the positive and negative electrodes), the capacitance per mass [F / g] is calculated. This F / g was multiplied by the electrode density [g / cc] to calculate F / cc.

Capacitance C [F] = I △ T / (V1-V2)

Example 1

Petroleum raw coke was used as a raw material. The physical properties are shown in Table 1.

The raw coke was calcined at 550 ° C. for 1 hour in a nitrogen gas atmosphere. At that time, the temperature increase rate was 200 degreeC / hour. The physical properties of the carbide after firing are shown in Table 1. The particle size distribution when this carbide is pulverized with a jet mill is shown in FIG. The average particle diameter (D50) of the milled product was 2.5 μm. Subsequently, it mixed so that potassium hydroxide might be 220 weight part with respect to 100 mass parts of this pulverized products, and the activating reaction was performed at 700 degreeC in nitrogen gas atmosphere for 1 hour. After the reaction, the reaction was added to water to obtain an alkali slurry.

500 g of this slurry (solid content / water = 1/20 weight ratio) were charged together with an alumina ball (5 kg having a diameter of 17 mm and 5 kg having a diameter of 5 mm) into a ball mill pot having an inner diameter of 234 mm and a height of 234 mm, and rotating at 60 rpm for 1 hour. Grinding treatment. The pulverized product was repeatedly washed with water and acid washed (using hydrochloric acid) to remove residual potassium, and dried to obtain activated carbon. The particle size distribution of the obtained activated carbon is shown in FIG. The average particle diameter of this activated carbon was 3.9 micrometers, and the specific surface area was 2220 m <2> / g. The results are shown in Table 2.

10 parts by mass of carbon black and 10 parts by mass of polytetrafluoroethylene powder were added to 80 parts by mass of the activated carbon, and the mixture was kneaded until it became a paste in a mortar. Subsequently, the obtained paste was rolled by the roller press of 180 kPa, and the electrode sheet of thickness 200micrometer was produced.

Two disc-shaped disks of 16 mm in diameter were punched out using the electrode sheet, and vacuum dried at 120 DEG C and 13.3 Pa (0.1 Torr) for 2 hours, followed by organic electrolyte solution (triethylmethylammonium) in a glove box under nitrogen atmosphere at -85 DEG C. Propylene carbonate solution of tetrafluoroborate, concentration: 1 mol / liter) was vacuum impregnated. Subsequently, two electrodes were used as a positive electrode and a negative electrode, respectively, and the cellulose separator (made by Nippon Kogyo Kogyo Co., Ltd., brand name: TF40-50, thickness: 50 micrometers), the current collector of aluminum foil is attached to both ends, An electric double layer capacitor (coin-type cell) was fabricated by assembling in a two-pole cell manufactured by Okcheon Corporation. The capacitance was measured for each capacitor obtained. The results are shown in Table 3.

Example 2

The raw raw coke used in Example 1 was baked at 650 degreeC for 1 hour. The temperature increase rate or atmospheric gas was the same as that of Example 1. The physical properties of the carbide after firing are shown in Table 1.

This carbide was ground with a jet mill. The particle size distribution of the milled product is shown in FIG. 2. The average particle diameter (D50) was 0.9 micrometer. This pulverized product was activated in the same manner as in Example 1 to obtain an alkali slurry.

500 g of this slurry (solid content / water = 1/10 weight ratio) were pulverized for 3 hours at a rotational speed of 60 rpm using a ball mill in the same manner as in Example 1. This pulverized product was repeatedly washed with water and acid washed (using hydrochloric acid) to remove residual potassium, and dried to obtain activated carbon. The particle size distribution of the obtained activated carbon is shown in FIG. 2. The average particle diameter of this activated carbon was 1.0 micrometer, and the specific surface area was 1680 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Example 3

The raw coke fired product used in Example 1 was ground with a jet mill. The particle size distribution of the milled product is shown in FIG. 3. The average particle diameter (D50) was 4.7 micrometers. This pulverized product was activated in the same manner as in Example 1 to obtain an alkali slurry.

500 g of this slurry (solid content / water = 1/20 weight ratio) were pulverized for 4 hours at a rotational speed of 60 rpm using a ball mill in the same manner as in Example 1. This pulverized product was repeatedly washed with water and acid washed with hydrochloric acid to remove residual potassium, and dried to obtain activated carbon. The particle size distribution of the obtained activated carbon is shown in FIG. The average particle diameter of this activated carbon was 4.0 micrometers, and the specific surface area was 2120 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Example 4

The jet mill pulverized product of the raw raw coke used in Example 1 was activated in the same manner as in Example 1 to obtain an alkali slurry.

Water washing and acid washing (using hydrochloric acid) were repeated for this slurry to remove residual potassium, thereby obtaining a washing slurry. 500 g of this slurry (solid content / water = 1/20 weight ratio) were pulverized for 1 hour at a rotational speed of 60 rpm using a ball mill in the same manner as in Example 1. The average particle diameter of the obtained activated carbon was 3.6 micrometers, and the specific surface area was 2260 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Comparative Example 1

The jet mill pulverized product of the raw raw coke used in Example 1 was activated in the same manner as in Example 1 to obtain an alkali slurry.

Water washing and acid washing (using hydrochloric acid) were repeated for this slurry to remove residual potassium and dried to obtain activated carbon. The particle size distribution of the obtained activated carbon is shown in FIG. 4. The average particle diameter of this activated carbon was 15.1 micrometers, and the specific surface area was 2320 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Comparative Example 2

20 g of dried activated carbon obtained in Comparative Example 1 was charged into a ball mill pot and an alumina ball used in Example 1, and ground at a rotational speed of 60 rpm for 3 hours. The average particle diameter of the obtained activated carbon was 3.8 micrometers, and the specific surface area was 1460 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Comparative Example 3

500 g of the cleaning slurry obtained by the same operation as in Example 4 was subjected to the wet grinding treatment in the same manner except that 10 kg of a diameter of 17 mm was used as the alumina ball. The average particle diameter of the obtained activated carbon was 6.7 micrometers, and the specific surface area was 2190 m <2> / g. The results are shown in Table 2.

Then, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

[Comparative Example 4]

500 g of the cleaning slurry obtained by the same operation as in Example 4 was subjected to the wet grinding treatment in the same manner except that 10 kg of the alumina ball having a diameter of 5 mm was used. The average particle diameter of the obtained activated carbon was 7.4 micrometers, and the specific surface area was 2040 m <2> / g. The results are shown in Table 2.

Next, using this activated carbon, the electric double layer capacitor was produced like Example 1, and the capacitance was measured. The results are shown in Table 3.

Firing temperature ℃ Hold time hr H / C atomic ratio- Volatile Mass% True density g / cm3 Raw material 0.422 6.7 1.41 Example 1 550 One 0.410 4.6 1.40 Example 2 650 One 0.380 3.8 1.45

1 shows particle size distribution curves of activated carbon of Example 1 and carbides before activation.

FIG. 2 shows particle size distribution curves of activated carbon of Example 2 and carbides before activation.

FIG. 3 shows particle size distribution curves of activated carbon of Example 3 and carbides before activation.

4 shows particle size distribution curves of activated carbon of Comparative Example 1 and carbides before reactivation.

Claims (6)

Calcining the easily graphitizable carbon material; Activating the carbon material with an alkali metal hydroxide; And Wet grinding the activated carbon material by using two kinds of balls of different diameters, the average particle diameter of 0.5 to 5㎛, BET specific surface area of 1500 to 2500m 2 / g, electric Method for producing activated carbon for a double layer capacitor electrode. The method for producing activated carbon for electric double layer capacitor electrodes according to claim 1, wherein the average particle diameter of the easily graphitizable carbon material is 0.5 to 8 mu m. The manufacturing method of the activated carbon for electric double layer capacitor electrodes of Claim 1 or 2 whose baking process temperature is 500-700 degreeC. The method of any one of claims 1 to 3, wherein, among two kinds of balls having different diameters, the diameter of the large ball is 1 to 30 mm and the diameter of the small ball is 1/10 to 1/2 of the diameter of the large ball. Method for producing activated carbon for electric double layer capacitor electrode. Activated carbon for electric double layer capacitor electrodes produced by the manufacturing method according to any one of claims 1 to 4. An electric double layer capacitor using the activated carbon for electric double layer capacitor electrodes of Claim 5.

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