JPS61163618A - Manufacture of 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 a method for manufacturing an electric double layer capacitor.

[Conventional technology]

As shown in Fig. 2, an electric double layer capacitor consists of two opposing current collector plates 1, a pair of electrodes 3 and 3 separated by a separator 2, and an insulating ring outside the periphery. 4
．． 4 is arranged, but in manufacturing it, first the current collecting plate 1 and the insulating ring 4 are welded together using an ultrasonic welder, and a container-shaped container for accommodating the electrodes as shown in Fig. 3 is made. Grommet 5 is produced.

In manufacturing this grommet 5, from the viewpoint of mass production, conventionally, as shown in FIG. After lowering the horn 11 for ultrasonic oscillation above and welding a large number of insulating rings 4 to the long current collector plate l at predetermined intervals,
The grommet 5 was produced by punching it into a predetermined shape (for example, Japanese Patent Application No. 59-28147).

[Problem that the invention seeks to solve]

However, in the case of the above method, the ultrasonic energy applied for welding escapes laterally through the long current collector plate 1 located on the horn 1 side, resulting in more energy than necessary to obtain reliable welding. I had to put it on.

In addition, when producing the grommet 5, the current collector plate 1 is formed into a smooth sheet shape in order to improve the closeness with the insulating ring 4, so when the electrode is housed in the grommet 5, the electrolyte solution There was a problem in that the current collector plate l was poorly wetted, and the resulting electric double layer capacitor had a high internal resistance.

[Means for solving problems]

The present invention was made in order to solve the problems of the prior art described above, and the current collector plate is punched out in advance into a predetermined shape and welded to the insulating ring in the mold to prevent energy loss and to prevent the welding. At this time, an annular groove with a depth slightly shallower than the thickness of the insulating ring is provided in the lower mold, the insulating ring is placed in this groove, a current collector plate is placed on top of the insulating ring, and welding is performed using an ultrasonic welder. As a result, the lower mold side surface of the central part of the current collector plate is brought into contact with the lower mold and roughened by the vibrations caused by the ultrasonic waves emitted from the ultrasonic oscillation horn, and the electrolyte solution and the current collector plate are roughened. This provides an electric double layer capacitor with low internal resistance and good compatibility with.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

Example 1 The current collector plate was made of an organic material based on polypropylene with a small amount of rubber mixed with conductive carbon black and kneaded to form a sheet with a thickness of 0.1 + wm.
A sheet with a diameter of 10.0 mm was punched out.

The insulation ring is made of polypropylene and has a thickness of 0.4 mm.

The inner diameter is 9.0+u+ and the outer diameter is 10.0+u+.

An annular groove having a depth of 0.3 ms+ and having the same shape as the insulating ring was provided in the lower mold, and the insulating ring and current collector plate were inserted as shown in FIG.

That is, as shown in FIG. 1, the insulating ring 4 is fitted into the groove 12a of the lower mold 12, the side mold 13 is set, the current collector plate 1 is placed on the insulating ring 4, and the The horn 11 is lowered and comes into contact with the current collector plate 1, and the frequency is 49k.
Hz, amplitude 50μm1, gauge pressure 2゜0kgf
/cd, and the peripheral edge of the current collector plate 1 and the insulating ring 4 were welded for a welding time of 0.3 seconds. The pressure surface of the horn 11 has a diameter of 10.
It has a circular shape of 0+m-, and the welded part is the periphery of the current collector plate 1 and the insulating ring 4, but the center part inside the welded part of the current collector plate L also receives vibration at the same time, and the lower mold side The surface was roughened by contact with the lower mold.

An electrolyte solution consisting of a 33% sulfuric acid aqueous solution and an activated carbon fiber cloth are inserted into the recess 5a of the grommet 5 prepared as described above, and the activated carbon fiber cloth is impregnated with the electrolyte solution in the mixed slurry to form an electrode. 3 was produced.

The electrode grommet 5 was covered with a separator 2 made of a microporous polypropylene film with a thickness of 0.025 ms, and the electrodes 3.3 were placed on an electrode grommet made in the same manner as described above. After stacking them facing each other with a separator 2 in between, they were welded using an ultrasonic welder. Welding conditions are frequency 40kHz, amplitude 25μ
+11, gauge pressure 2. Okgf/cA, welding time 0.
It is 5 seconds.

Comparative Example 1 The material of the current collector plate l and the material of the insulating ring 4 were the same as in Example 1, and the long current collector plate 1 was placed on the insulating ring 4, and the frequency was 40 kHz, the amplitude was 60 μm, and the gauge pressure was 3.
After welding the insulating ring 4 and the current collector plate 1 at Okgf /cj and welding time O8.7 seconds, the electric double layer was fabricated in the same manner as in Example 1, except that the grommet 5 was produced by punching it to a diameter of 10.0+u+. Manufactured a capacitor.

1? +71% 4 to 1 wing -14A%LVeu+hh1M
Table 1 shows the results of measuring the internal resistance at 25°C for 100 pieces of each of the 1ml F 1ml 25h 1eJ 1h-1 rigid air double layer capacitors. Table 1 also shows the results of measuring the roughness of the current collector plate surface on the inner side of the grommet using a roughness meter during the manufacture of the grommet. This was done by running a roughness meter on the surface of the current collector plate, drawing the unevenness on a chart, and measuring it.

Table 1 As shown in Table 1, the electric double layer capacitor manufactured by Example 1 of the present invention had a lower internal resistance than the electric double layer capacitor manufactured by Comparative Example 1, which was a conventional method. . This is considered to be because, in the present invention, the surface of the current collector plate was roughened during the production of GLONO 7), which improved the compatibility between the electrolyte solution and the current collector plate. Further, the energy required for producing the grommet was also less in the case of the example of the present invention than in the case of comparative example 1, which is a conventional method.

In the above embodiment, the thickness was 0.4. The depth of the groove provided in the lower mold for the insulating ring of am was set to 0.3IllIl, but when the thickness of the insulating ring is 0.411°Cm, the depth of the groove provided in the lower mold is 0.3IllIl. It may be about 1 to 0.3 am. The depth of the groove provided in the lower mold varies slightly depending on the material and size of the current collector plate, but in general, the depth of the groove is about 25 to 75% of the thickness of the insulating ring. Bye.

Furthermore, welding conditions when making a grommet vary depending on the thickness of the current collector plate, the material of the current collector plate and the insulating ring, etc., but usually the frequency is 20 to 40 kHz, the amplitude is 30 to
60μ clear, gauge pressure 1.0-3.0 kgf/c+7
, the welding time is preferably selected from the range of 0.1 to 0.5 seconds. However, the welding time is not limited to the above range; for example, when the current collector plate is thick, the welding time may be increased to about 1.0 seconds.

Also, if the surface on the inner circumferential side of the lower mold groove is roughened,
This is preferable because the inner surface of the central portion of the current collector plate, that is, the surface that comes into contact with the electrolyte solution, can be more easily roughened when the current collector plate and the insulating ring are welded together to produce a grommet.

In addition, when the electric double layer capacitor obtained as described above is used, the electric double layer capacitor 1111 or two or more are laminated and sealed in a suitable case according to a conventional method.

〔Effect of the invention〕

As explained above, in the present invention, when producing a grommet, the current collector plate is punched into a predetermined shape and then welded to the insulating ring, which reduces energy loss and enables welding with lower energy than conventional methods. Furthermore, by roughening the surface of the central portion of the current collector plate on the side that comes into contact with the electrolyte solution by the above welding, it was possible to obtain good compatibility between the electrolyte solution and the current collector plate.

[Brief explanation of drawings]

1 and 2 are diagrams showing the electric double layer capacitor according to the present invention, FIG. 1 is a sectional view showing the state at the time of manufacturing the grommet, and FIG. 2 is a sectional view showing the state after manufacturing. It is. FIG. 3 is a sectional view showing a grommet, and FIG. 4 is a sectional view showing a state in which a current collector plate and an insulating ring are welded together when manufacturing an electric double layer capacitor by a conventional method. 1... Current collector plate, 2... Separator, 3...
Electrode, 4... Heavy color edge ring, 5... Grommet, 11... Horn, 12... Lower mold, 12a.
...Groove, 13...Side type patent applicant Hitachi Maxell Co., Ltd. Figure 1 Figure 2 Figure 3 Reciprocal No. 40 1...Hayabusa! class

Claims (2)

[Claims] (1) A pair of electrodes 3, 3 separated by a separator 2 are arranged between two opposing current collector plates 1, 1, and an insulating ring 4, 4 is arranged outside the periphery. In manufacturing a multilayer capacitor, when producing a grommet 5 for accommodating an electrode by welding the current collecting plate 1 and the insulating ring 4 using an ultrasonic welder, a groove 12a whose depth is slightly shallower than the thickness of the insulating ring is formed in the lower die 12. , and the insulation ring 4 is attached to the lower mold 1.
A current collector plate 1 punched into a predetermined shape is placed on the insulating ring 4, and a horn 11 for ultrasonic oscillation is brought into contact with the current collector plate 1. Periphery and insulation ring 4
are welded in the mold, and the lower mold side surface of the central part of the current collector plate 1 is fixed to the lower mold 1 by the ultrasonic vibration from the horn 11.
2. A method for manufacturing an electric double layer capacitor, comprising roughening the surface by contacting the capacitor. (2) The method for manufacturing an electric double layer capacitor according to claim 1, wherein the surface of the lower mold 12 that comes into contact with the lower mold side surface of the current collector plate 1 during welding for producing the grommet is a rough surface.