JPS63244839A - 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] (Industrial application field) The present invention relates to an electric double layer capacitor.

(Prior Art) Electric double layer capacitors are used as backup power sources for computers during power outages, and as power sources for solar clock batteries and motor drives.

Conventionally, such an electric double layer capacitor has a structure in which polarizable electrodes are separated by a separator, a current collector is formed on the other surface of the polarizable electrode, and the current collector is impregnated with an electrolytic solution.

(Problems to be Solved by the Invention) However, activated carbon and the like used as polarizable electrodes have a relatively high resistance and have a drawback of high ESR.

For this reason, some inventions use conductive carbon black instead of activated carbon, but although the ESR is lowered, the capacity is difficult to produce.

SUMMARY OF THE INVENTION An object of the present invention is to improve the above drawbacks and provide an electric double layer capacitor which has a low ESR and a relatively large capacity n.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides an electric double layer capacitor that utilizes an electric double layer formed by a polarizable electrode and an electrolyte interface. This invention provides an electric double layer capacitor characterized by having a polarizable electrode mainly composed of conductive carbon black and activated carbon having a particle size of 10 μm or less and having a larger specific surface area than the 3# conductive carbon black. be.

(Function) According to the present invention, the polarizable electrode is made of conductive carbon black with a particle diameter of 40 mμ or less and a particle diameter of 10 mμ with a large specific surface area.
Because it is mainly composed of activated carbon of less than μ,
It has the advantages of both components, and can have low ESR and large capacity. .

Incidentally, it is preferable that the amount of S-electrocarbon black is at least 15% or more of the activated carbon, and if it is less than this, the ESR lowering effect will be lowered.

(Example) Hereinafter, the present invention will be explained based on illustrated embodiments.

The polarizable electrode 1 is made of a) conductive carbon black with a particle size of 16 mμ, and a BET method surface ratio of 4111500 d/g.
There are two types of activated carbon: one with a particle diameter of 40 mμ and a specific surface area of 1000 rt/g. b) Using activated carbon with a particle diameter of 1 μm and a specific surface area of 2000 rlL/9, polytetrafluoroethylene with 10 convex portions is added to this, and it is press-molded to obtain a thick 600
It is made into a sheet with a diameter of 12 μm and a disk shape.

The at body 2 is made of Ni expanded metal and is laminated in a circular shape with a diameter of 5.4M on the surface of the polarizable electrode.

The separator 3 is made of polypropylene with a thickness of 100 μm, and polarizable electrodes are laminated on both sides thereof.

Then, the laminate of the polarizable electrode 4fi1, the current collector 2, and the separator 3 is housed in a Ni-clad stainless steel case 4 and sealed.

In the above examples, the weight and ESR when the mixing ratio of conductive carbon black and activated carbon of the polarizable electrode is changed.
are shown in the table. As conventional examples, a case using only conductive carbon black and a case using only activated carbon are also shown. Also,
As a comparative example, use specific surface instead of current collecting carbon black!
161m/9 acetylene black or particle size 50m
The case where carbon black with μ and specific surface area of 50rt/9 is used is shown.

As is clear from the table, according to the present invention, the capacity is approximately 13% compared to conventional examples 1 and 2, which only use conductive carbon black.
Moreover, the ESR is reduced by more than 60% compared to Conventional Examples 3 and 4, which only use activated carbon. As is clear from Comparative Examples 1 and 2, when acetylene black or carbon black is used, the capacity is about 33% compared to the present invention.
This will also decrease.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain an electric double layer capacitor that has the advantages of conductive carbon black and activated carbon, has a relatively large capacity, and has a low ESR.

[Brief explanation of drawings]

The figure shows a front sectional view of an embodiment of the invention. 1... Polarizable electrode, 2... Current collector. 3...Separator. Patent Applicant Hitachi Capacitor Co., Ltd. Procedural Amendment (Voluntary) November 24, 1932 Patent Application No. 79080, 1988 Address 31-1 Nishigotanda-chome, Parts Ward, Tokyo (1) Letter No. The unit of particle diameter in the table on page 5 [μm] is [mμ]
and correct it. (2) “10m, μ” on page 3, line 11 of Ming aS is “1”
0 μm”.

Claims (2)

[Claims] (1) In an electric double layer capacitor that utilizes an electric double layer formed between a polarizable electrode and an electrolyte interface, a particle size of 4
An electric double layer capacitor characterized by having a polarizable electrode mainly composed of conductive carbon black having a particle size of 0 mμ or less and activated carbon having a particle size of 10 μm or less and having a larger specific surface area than the conductive carbon black. (2) The electric double layer capacitor according to claim 1, wherein the amount of conductive carbon black is at least 15% or more of the activated carbon.