JPH05211111A - Electric double layer capacitor - Google Patents

Abstract

PURPOSE:To obtain an electric double layer capacitor capable of easily reducing equivalent series resistance without applying high pressure to an element. CONSTITUTION:In a recessed part formed by compression-bonding a ring type gasket 4 to a conducting separator, powder active carbon and phenol are mixed, heated, and cured, and a polarizable electrode 1 impregnated with electrolyte is arranged. A pair of said electrodes are so unified in a body that the polarizable electrodes 1 face each other, and subjected to covulcanization bonding, thereby obtaining an electric double layer capacitor whose equivalent series resistance is small. The equivalent series resistance can be further decreased by forming a conducting layer composed of butyl rubber and conductive carbon on one surface of the polarizable carbon. By applying active carbon/polyacene based compound material to the polarizable electrode, the equivalent series resistance can be easily reduced. When a conducting layer is formed on one surface of the polarizable electrode, an element whose equivalent series resistance is smaller can be formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electric double layer capacitors, and more particularly to polarizable electrodes of electric double layer capacitors.

[0002]

2. Description of the Related Art FIG. 4 shows a sectional view of a basic element (hereinafter referred to as a basic cell) of a conventional electric double layer capacitor. In the basic cell, powdered activated carbon is used as a polarizable electrode 12 to be impregnated with an electrolytic solution, and then a pair of polarizable electrodes 12 are opposed to each other with an ion-permeable, non-electron-conductive porous separator 3 interposed therebetween, and a conductive separator 2 is provided. The non-conductive gasket 4 has a structure in which the polarizable electrode 12 and the electrolytic solution are held.
Since this basic cell uses powdered activated carbon for the polarizable electrode 12, in order to reduce the contact resistance between the activated carbon particles, a pressure of several tens kg / cm ² is applied from the vertical direction of the basic cell, and this state is It was held and used as an electric double layer capacitor.

[0003]

Since the conventional electric double layer capacitor uses powdered activated carbon, there is a problem that the equivalent series resistance cannot be lowered unless a high pressure is applied to the basic cell.

An object of the present invention is to provide an electric double layer capacitor which can easily reduce the equivalent series resistance without applying a high pressure to the element like the conventional element.

[0005]

The electric double layer capacitor of the present invention comprises an ion-permeable, non-electroconductive porous separator, a pair of polarizable electrodes separated by the porous separator, and a pair of polarizable electrodes. An electrically conductive separator consisting of an ion-impermeable and electronically conductive material disposed via a polarizable electrode, and a non-conductive gasket interposed between the conductive separators at the periphery of a pair of polarizable electrodes. In an electric double layer capacitor using a double layer capacitor element, activated carbon / polyacene composite material was used for the polarizable electrode, and butyl rubber, butadiene rubber, polyisoprene or their co-weight was used on one side of the polarizable electrode. It is characterized by forming a conductive layer in which conductive carbon is dispersed in a rubber material whose main component is a dielectric material.

[0006]

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a basic cell according to an embodiment of the present invention.

First, the phenol-based activated carbon powder and the powdered phenol resin were weighed so that the weight ratio was 70/30,
After dry mixing with a ball mill, 100 in the mold
The activated carbon-containing phenol resin plate having a diameter of 30 mm and a thickness of 1 mm was prepared by heat-curing at 150 ° C. for 10 minutes while applying a pressure of kg / cm 2. This is heat-treated for 2 hours at 900 ° C under N ₂ atmosphere (temperature rising / falling rate 10 ° C / h)
By doing so, a polarizable electrode 1 was obtained.

Next, the pair of polarizable electrodes 1 was immersed in 30 wt% sulfuric acid, the whole was evacuated and left for 1 hour to impregnate the polarizable electrodes 1 with an electrolytic solution. The polarizable electrode 1 which has been impregnated with this electrolytic solution has an inner diameter of 31 m.
m, non-vulcanized butyl rubber with a thickness of 1 mm, punched into a ring shape with an outer diameter of φ37 mm The separator is placed in a recess formed by pressure bonding to obtain a pair of electrode sheets (not shown). The pair of electrode sheets are arranged and united on a concentric circle in a direction in which the polarizable electrodes 1 face each other via a polypropylene porous separator 3 having a thickness of 0.025 mm and a diameter of 34 mm, and then a temperature of 125 ± 5 ° C. By leaving it in the atmosphere for 3 hours, the unvulcanized butyl rubbers were co-vulcanized and bonded together to obtain a basic cell 5 of Example 1 of the present invention.

A width of 3 mm is provided above and below the basic cell 5 of the present invention.
The electrode plates 6 and 7 having terminals with a length of 15 mm are arranged,
A pressure of 0.1 to 1 kg / cm ² is applied in the vertical direction of the basic cell 5, and an outer packaging is performed by an injection molding method using a PBT (polybutylene terephthalate) resin 8 so as to hold the pressure. An electric double layer capacitor was prototyped.

FIG. 3 is a sectional view of a basic cell according to another embodiment of the present invention. As shown in FIG. 3, the same polarizable electrode 1 as in Example 1 with butyl rubber dissolved in xylene on one side 1
A mixture of 15 g of conductive carbon and 0 g of the conductive carbon was printed to a thickness of 50 μm using a 325 mesh stainless screen, and the mixture was placed in an atmosphere of 100 ± 5 ° C.
A basic cell 11 according to Example 2 of the present invention was obtained in the same manner as in Example 1 except that the conductive layer 10 was formed by leaving it for 0 minutes to dry.

An electric double layer capacitor according to a second embodiment of the present invention was manufactured by using the basic cell 11 and applying an outer cover in the same manner as in the first embodiment.

The polarizable electrode 1 is composed of powdered activated carbon and 30 w.
An electric double layer capacitor of a conventional example was manufactured in the same manner as in Example 1 except that the conventional paste electrode mixed with t% sulfuric acid was used.

Table 1 shows the results obtained by measuring the equivalent series resistance and capacitance of each of the 10 electric double layer capacitors of Examples 1 and 2 of the present invention and the conventional example, and obtaining the average value.

Compared to the conventional example, the equivalent series resistance of the first embodiment of the present invention is reduced to about 1/36, and the equivalent series resistance of the second embodiment is further reduced.
Then, it was reduced to about 1/90.

[0015]

[Table 1]

[0016]

As described above, according to the present invention, an activated carbon / polyacene composite material is used for a polarizable electrode and it is simply incorporated into an electric double capacitor element having a conventional structure, and an equivalent series is obtained without applying a high pressure to the element. The resistance can be easily reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an electric double layer capacitor element according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the electric double layer capacitor element of the embodiment shown in FIG. 1 of the present invention after being packaged.

FIG. 3 is a sectional view of an electric double layer capacitor element according to another embodiment of the present invention.

FIG. 4 is a sectional view of an example of a conventional electric double layer capacitor element.

[Explanation of symbols]

 1 Polarizable electrode of the present invention 2 Conductive separator 3 Porous separator 4 Non-conductive gasket 5 Basic cell according to Example 1 of the present invention 6,7 Electrode plate 8 PBT resin 9 Electric double layer capacitor according to the present invention 10 Conductive layer 11 Example 2 of the invention Basic cell 12 Conventional polarizable electrode 13 Conventional basic cell

Claims (2)

[Claims] 1. An ion-permeable, non-electron-conductive porous separator, a pair of polarizable electrodes separated by the porous separator, and an ion-impermeable material disposed by the pair of polarizable electrodes. An electric double layer capacitor element including an electrically conductive separator that is permeable and electronically conductive and a non-conductive gasket interposed between the conductive separators at the periphery of the pair of polarizable electrodes is used. An electric double layer capacitor in a multi-layer capacitor, wherein activated carbon / polyacene composite material is used for the polarizable electrode. 2. A conductive layer in which conductive carbon is dispersed in a rubber material containing butyl rubber, butadiene rubber, polyisoprene or a copolymer thereof, or a dielectric material as a main component on one surface of a polarizable electrode. The electric double layer capacitor according to claim 1, wherein