JPS61163620A - 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]

In general, electric double layer capacitors, as shown in Figure 2,
A pair of electrodes 3.3 are arranged between two opposing current collector plates 1.1 with a separator 2 in between, and an insulating ring 4.4 is arranged outside the periphery of the electrodes 3.3. There is. and,
For example, the manufacturing process begins with the current collector plate 1 and the insulating ring 4.
are welded using an ultrasonic welder to produce a container-shaped grommet, an electrode 3 is arranged in the recess of this grommet, a pair of such electrode-type grommets is prepared, one of them is covered with a separator 2, Lay it on the other electrode grommet with the separator 2 in between so that the electrodes 3 and 3 are facing each other, and place it on one current collector plate l for ultrasonic oscillation. This is done by bringing the ring-shaped honin 1) into contact with each other, heating the insulating ring 4.4 and the separator 2 through the current collecting plate l, and welding the separator 2 and the insulating ring 4.4.

For the above sealing, the horn 1) of the ultrasonic welder concentrates energy and uses a ring-shaped horn with a ring-shaped tip so as not to affect the contents such as electrodes, so as to apply pressure only to the area to be welded. However, conventionally, the inner diameter of this ring-shaped horn 1) was set to be larger than the inner diameter of the insulating ring 4, as shown in Fig. 3, with emphasis only on energy concentration and prevention of influence on the contents. (For example, Japanese Patent Application No. 59-28147).

[Problem that the invention seeks to solve]

However, when using the ring-shaped horn 1) as described above, it is not possible to cover the entire surface of the insulating ring 4 with the horn 1), and when welding, the ring-shaped horn 1) is guided to the outer circumference of the insulating ring 4 as shown in FIG. 12 is placed, the insulating ring 4 escapes to the inner circumferential side due to pressurization, the inner circumferential side of the insulating ring 4 protrudes upward, and the thin current collector plate 1 is thereby pierced and the current collector plate 1 There was a problem that cracking occurred.

[Means for solving problems]

The present invention solves the problems of the prior art described above.
During ultrasonic welding during the sealing process, the inner diameter of the ring-shaped horn is made smaller than the inner diameter of the insulating ring to prevent the current collector plate from cracking as described above.

That is, by making the inner diameter of the ring-shaped horn smaller than the inner diameter of the insulating ring as described above, the ring-shaped horn can press the entire surface of the insulating ring during welding, and therefore,
The insulating ring does not escape toward the inner circumference during welding, and the current collector plate is prevented from cracking.

〔Example〕

Next, the present invention will be explained in more detail by giving examples.

Example 1 Thickness 0.1 mm and diameter 10. Thickness 0 for current collector plate 1 of Omm
．． 4nv+, inner diameter 9.0 +1)m, outer diameter 10.0m+
A container-shaped grommet was produced by welding the insulating ring 4 of W with an ultrasonic welder. The above current collector plate l is made by adding a conductive carbon blank to an organic material mainly made of polypropylene and kneading it into a sheet with a diameter of 10.0 m.
The insulating ring 4 is made of polypropylene, and the welding conditions for making the grommet are a frequency of 40 kHz, an amplitude of 45μ steel, and a gauge pressure of 2. O
kgf/d, welding time 0.7 seconds.

A mixed slurry of an electrolyte solution consisting of a 33% sulfuric acid aqueous solution and activated carbon powder was injected into the recess of the grommet prepared as described above, and then a circular activated carbon fiber cloth punched to a diameter of 8 m was inserted from above. . By inserting the activated carbon fiber cloth, the mixed slurry, especially the electrolyte solution contained therein, is absorbed by the activated carbon fiber cloth, and the fluidity of the mixed slurry is completely lost and it does not spread beyond the periphery of the activated carbon fiber cloth. Therefore, a gap of approximately 0.5 mm was left between the electrode 3 thus formed and the inner peripheral surface of the insulating ring 4.

Prepare a pair of electrode grommets as described above, one of which has a thickness of 0.025 +u+ and a diameter of 10.0 mm.
Separator 2 made of microporous polypropylene film of
1), and place it over the other electrode grommet with the separator 2 in between so that the electrodes 3 and 3 face each other, and as shown in Figure 1, attach the horn 1) of the ultrasonic welder to one current collector plate. 1, the horn 1) emits ultrasonic waves, the horn 1) applies pressure, heats the insulating ring 4 and the separator 2 through the current collector plate 1, and the separator 2
An electric double layer capacitor as shown in FIG. 2 was manufactured by welding the insulating ring 4.4 and the insulating ring 4.4. The horn 1) used for the above welding is a ring-shaped horn with an outer diameter of 10.0 mm and an inner diameter of 8.5 mm, and its inner diameter is 0.5 mm larger than the inner diameter of the insulating ring 4.
am small, therefore the horn 1) covered the entire surface of the insulating ring 4 via the current collector plate l. The welding conditions for the above welding were a frequency of 4QkHz, an amplitude of 45μ, and a gauge pressure of 2. Okgf /aJ, the welding time was 0.6 seconds, and the obtained electric double layer capacitor was stacked one or two or more and sealed in an appropriate case according to the usual method, and the voltage was is applied, one electrode becomes negatively charged and the other electrode becomes positively charged.

When 100 electric double layer capacitors were manufactured as described above, and according to the conventional method, a ring-shaped horn with an inner diameter of 9.0 + wm was used, the frequency was 40 kHz, the amplitude was 45 μm, and the gauge pressure was 2. Okgf/cd, welding time is 0.5 seconds to seal the electric double layer capacitor.
Table 1 shows the results of investigating the occurrence of cracks in the current collector plate when 0 pieces were manufactured.

Table 1 As shown in Table 1, the electric double layer capacitor manufactured by the method of the present invention had fewer cracks in the current collector plate than the electric double layer capacitor manufactured by the conventional method. In the present invention, the ring-shaped horn 1) having an inner diameter smaller than the inner diameter of the insulating ring 4 is pressurized and welded, so the ring-shaped horn 1) covers the entire surface of the insulating ring 4 during welding, so the insulating ring 4 This is thought to be due to the fact that the particles did not escape to the inner circumferential side and break through the current collector plate l.

In the above embodiment, the inner diameter of the ring-shaped horn 1) was o, s m- smaller than the inner diameter of the insulating ring 4;
It is decided based on the balance with the outer diameter of.

In other words, when sealing is performed by ultrasonic welding, the electrode 3
If the activated carbon is filled to the point that it is in close contact with the inner circumferential wall of the insulating ring 4, the activated carbon will scatter due to vibration during welding, and the activated carbon will enter the joint surface between the separator 2 and the insulating ring 4, causing a decrease in sealing performance. become. Therefore, in the embodiment, the outer diameter of the electrode 3 is 1 mm smaller than the inner diameter of the insulating ring 4, but if there is a difference of 1 mm, the inner diameter of the ring-shaped horn 1) is In consideration of,
It is preferable to make the outer diameter of the electrode 3 as large as possible in order to achieve high capacity. The outer diameter of the electrode 3 is 1 to 2 smaller than the inner diameter of the insulating ring 4.
Since the diameter of the ring-shaped horn 1) is to be reduced to only about m + The outside diameter of the shaped horn 1) is the same as the outside diameter of the insulating ring 4, or slightly larger than the outside diameter, as in the conventional case.

Regarding the welding conditions, when comparing the welding conditions of the above embodiment and the welding conditions of the conventional example, there is almost no significant difference, although the embodiment requires slightly more energy.

Furthermore, in carrying out the present invention, welding is generally performed at a frequency of 20 to 4
0kHz, 15 width 20-50μ wire, gauge pressure 2.
0~3゜0 ktf/crl, welding time 0.2~1.
It can be done in 0 seconds. As is clear from the comparison of the welding conditions of the above example and the conventional example, when the insulating rings, separators, etc. are the same, in the present invention, a ring-shaped horn with an inner diameter of 9.0 l1) m is used for welding. Although it requires slightly more energy than welding using a welding method, it can be carried out under almost the same welding conditions.

[Effects of the Invention] As explained above, in the present invention, when performing ultrasonic welding to Japan, by using a ring-shaped horn having an inner diameter smaller than the inner diameter of the insulating ring, the insulating ring can be welded by pressure during welding. It was possible to prevent the insulating ring from escaping toward the inner periphery, and to prevent the current collector plate from cracking, which would otherwise have occurred due to the insulating ring escaping toward the inner periphery.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing an example of the electric double layer capacitor according to the present invention, with Figure 1 being a cross-sectional view showing the state in the sealing process during manufacturing, and Figure 2 being a cross-sectional view showing the state after manufacturing. It is. 3 and 4 are cross-sectional views showing the state in the sealing process when manufacturing an electric double layer capacitor by a conventional method, with FIG. 3 being an overall schematic view and FIG. 4 being a partially detailed view. ■...Current plate, 2...Separator, 3...Electrode, 4...Insulating ring, 1)...Ring-shaped horn patent applicant Hitachi Maxell Co., Ltd. 1st concave 4...Toiro Next Q link. 1) °-'+>y-; *t-y 2nd I2]
Figure 3

Claims (1)

[Claims] (1) A pair of electrodes separated by a separator are placed between two opposing current collector plates, and an insulating ring is placed outside the periphery of the electrode, and the seal is insulated from the separator by ultrasonic welding. In the manufacturing of electric double layer capacitors by welding a ring and a ring, during the sealing process, a ring-shaped horn for ultrasonic oscillation of an ultrasonic welder is smaller than the inner diameter of the insulating ring so that the entire surface of the insulating ring can be pressurized. A method for manufacturing an electric double layer capacitor, characterized in that it has an inner diameter.