JPS60161611A - Electric double layer capacitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electric double layer capacitor that utilizes an electric double layer formed by a polarizable electrode and an electrolyte interface.

Conventionally, most polarizable electrodes for electric double layer capacitors have been made of activated carbon, which has a large surface area per unit volume. However, when activated carbon is used as a polarizable electrode, since a binder is used to support the activated carbon, the conductivity inside the electrode is very poor, resulting in energy loss. In addition, methods of adding conductive agents such as conductive carbon black together with activated carbon, or applying pressure and sintering have been adopted to improve conductivity, but none of these methods are perfect and there is a resistance component inside the polarizable electrode. There was a loss of energy.

On the other hand, in order to improve the conductivity of polarizable electrodes due to the above-mentioned circumstances, electrode materials that do not use activated carbon and have good conductivity and a large surface area are being sought.

However, the present invention provides an electric double layer capacitor using stainless steel fibers as polarizable electrodes. In particular, in the present invention, by using pressure-vacuum sintered stainless steel fibers with a diameter of 20 μm or less as a polarizable electrode, the internal resistance of the electrode when configured as a capacitor element is almost ignored. It is possible to provide as much as possible, and also to reduce the size of the product.

First, a polarizable electrode of an electric double layer capacitor and a manufacturing method thereof according to the present invention will be explained. For example, stainless steel fiber with a diameter of 12 μm (SU8316L; 18%Cr・1
Felt of 2% Ni/2.5% MO1 ultra-low carbon type steel was placed in a vacuum sintering furnace at a vacuum degree of 1 O-5 Torr and a temperature of 1
Vacuum sintering is carried out under the conditions of 000℃ and pressure lt/crA. The conditions for this vacuum sintering vary depending on the diameter of the stainless steel fiber, and the degree of vacuum, temperature, and pressure also vary relative to each other. For example, if the temperature is high, the pressure may be low. Here, since the melting point of stainless steel is about 1350°C, the temperature range must be below the melting point and the degree of vacuum must be greater than 10-"'rorr to prevent deterioration of the stainless steel. In addition, during vacuum sintering, pressure may not be applied, but the polarizable electrode may be obtained by applying pressure to obtain an appropriate hardness and volume after vacuum sintering.

Next, an example of an electric double layer capacitor according to the present invention using the polarizable electrode thus obtained will be described with reference to FIG. One polarizable electrode (11) and the other polarizable electrode (11) were obtained by vacuum sintering stainless steel fibers with a diameter of 12 μm.
) and an ion-permeable separator made of synthetic fiber (2
) is impregnated with a highly conductive organic electrolyte to obtain a single capacitor element (3). This element (3) is connected between the elements by a conductor (
4), For example, a stainless steel plate is arranged, several layers are laminated to increase the withstand voltage, and finally it is sealed with a sealing body (5) to isolate it from the outside air, creating an electric double layer with a high withstand voltage. Capacitor (
6) was obtained. In the figure, (force is a lead. The capacity determined from the DC current charging time of this capacitor (6) is
It was 10,000 μF in the external dimensions of the 8-pharynx.

Table 1 shows a comparison of the characteristics of the embodiment of the present invention and the conventional example. Prior to the comparison, the conventional electric double layer capacitor will be explained with reference to FIG. 325 Metsu Sea Pass Activated Carbon 5
III? A polarizable electrode (I
get the benefits. Similar to the above-mentioned embodiment of the present invention, a separator is interposed between two polarizable electrodes a"a (121) and impregnated with an electrolytic solution to obtain a capacitor element α. This element αa is connected to a conductor (one A sealing body 161 is formed by laminating several layers with
The capacitor was sealed with aluminum to obtain an electric double layer capacitor aD having a capacitance of 10°000 μF. In the figure, Q8) is a lead.

Table 1 Comparison of Characteristics As can be seen from Table 1, the embodiments of the present invention can reduce internal resistance and leakage current compared to the conventional example, and can provide a compact electric double layer capacitor. be.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a sectional view showing a conventional example. In the figure, (1), a-polarizable electrode, (2), (I3
) Separator, (3)Q4)-Key y Hashita element, ('4), (151・i it body, (5), ae・
...Sealing body, (6), (1η...Electric double layer capacitor, (7), α~...Lead, (1])...Current collector. Patent applicant Elna Co., Ltd. Figure 2

Claims (1)

[Claims] (1) An electric double layer capacitor that utilizes an electric double layer formed by a polarizable electrode and an electrolyte interface, characterized in that stainless steel fibers are used as the polarizable electrode. Electric double layer capacitor. (2. In claim (1), the electric double layer capacitor is characterized in that the stainless steel fiber has a diameter of 20 μm or less. (3) In claim (1), polarizable An electric double layer capacitor characterized by using pressurized and vacuum sintered stainless steel fibers as electrodes.