JPH03165021A - Electric double-layer capacitor - Google Patents

Abstract

PURPOSE:To prevent the corrosion of a case, to eliminate charging in cases and to avoid the occurrence of electric accidents by using a solid polarizing electrode as a basic cell, and using a resin case for an outer packaging case. CONSTITUTION:As a basic cell 6, a cell wherein a polarizing electrode is a solid polarizing electrode is used. Since active carbon powder is sintered in this solid polarizing electrode, the contact amount the active powder particles is very excellent, and pressure to be applied on the basic cell 6 is largely decreased. Several pieces of ht basic cells 6 are laminated. An electrode plate 1 is applied on one surface, and an electrode plate 2 is applied on the other surface. An insulating plate 5 is provided between a lead-out terminal 1A (2A) and the side surface of the basic cell 6. Thus the contact with a current collector 11 having the different polarity is prevented. Such a device is packaged with resin cases 3 and 4 from both sides. The inside is tightly sealed by thermal welding. When the resin cases such as these are used as an outer package, the device is not subjected to corrosion even if electrolyte leaks from the basic cell 6. Since the cases have insulating property, the cases are not charged, and electric accidents do not occur between the device and peripheral apparatuses.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an electric double layer capacitor with an improved outer case.

[Conventional technology]

FIG. 8 shows a conventional electric double layer capacitor. In FIG. 8, 81 is an exterior case, 82 is an insulating plate, and 8
3 is a caulked part of the outer case 81, 84 is an electrode plate, 84-
1 is a terminal port, 84A is a terminal integrated with the electrode plate 84, 85 is an electrode plate, 85A is a terminal integrated with the electrode plate 85, and 86 is a basic cell of an electric double layer capacitor. The outer case 81 is made of metal that can be caulked. Although four basic cells 86 are stacked, the number of stacked cells is determined as appropriate depending on the withstand voltage required by the application. An electrode plate 85 is brought into contact with the upper surface of the stack, and the bottom of the exterior case 81 is brought into contact with the lower surface. An insulating plate 82 is placed over the electrode plate 85, and the other electrode plate 84 is placed on top of the insulating plate 82. The electrode plate 84 is in contact with the caulking portion 83 of the outer case 81, and the caulking portion 83
3, it is pressed downward. The terminal 85A integrated with the electrode plate 85 is connected to the terminal port 8
4-1 and is drawn out to the outside. Note that the insulating plate 82
is for insulating the electrode plate 85 and the electrode plate 84. FIG. 9 shows a basic cell of an electric double layer capacitor using a paste-like polarizable electrode as a polarizable electrode. As the basic cell 86, such a basic cell is usually used. In FIG. 9, 11 is a current collector, 12 is a paste-like polarizable electrode, 13 is a separator, and 14 is a gasket. The paste-like polarizable electrode 12 is made by mixing activated carbon powder with an electrolytic solution (eg, dilute sulfuric acid) to form a paste. In order to reduce the contact resistance between the activated carbon powders in the paste-like polarizable electrode 12 and the contact resistance between the paste-like polarizable electrode 12 and the current collector 11, the current collector 11 is Pressure is applied from the outside. In the electric double layer capacitor shown in FIG. 8, the pressurizing force is generated by caulking the edge of the outer case 81. That is, the four basic cells 86 are pressurized by the pressing force applied by the caulking portion 83 via the electrode plate 84. The above is a case of an electric double layer capacitor using a pasty polarizable electrode as a polarizable electrode. Some devices use solid polarizable electrodes, as seen in Japanese Patent Application Laid-open No. 70622/1983. Conventionally, even in such electric double layer capacitors, a metal case has been used as the outer case. However, in this case, since the activated carbon powders have very good contact with each other, the pressing force only needs to be small enough to make good contact between the current collector and the solid polarizable electrode. In addition, as a conventional document regarding the exterior case of an electric double layer capacitor, there is, for example, Japanese Utility Model Application No. 61-138236.

[Problem to be solved by the invention]

Conventional electric double layer capacitors that use metal cases have the following problems. The first problem is that if the electrolyte leaks from the basic cell, the metal case will corrode. The second problem is that if the internal structure is damaged, the metal case may become charged and cause an electrical accident with surrounding equipment. This point is particularly serious when the basic cell is enlarged and the number of laminated layers is increased. An object of the present invention is to solve the above-mentioned problems.

[Means to solve the problem]

In order to solve the above problems, the electric double layer capacitor of the present invention includes a basic cell using a solid polarizable electrode as a polarizable electrode, and a lead terminal that is electrically contacted with the current collector of the basic cell. It was decided to include a sealed electrode plate and a resin case sealed by heat fusion.

[For production]

By using a basic cell whose polarizable electrode is a solid polarizable electrode, it becomes possible to make it unnecessary to apply almost no pressure to the basic cell from the outer case. Furthermore, by using resin as the material for the exterior case, it is possible to obtain a case that is not corroded by the electrolyte and has excellent sealing performance. In addition, it is easy to manufacture, inexpensive, and has excellent electrical safety.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. (First embodiment) Fig. 1 shows a perspective view of an electric double layer capacitor according to a first embodiment of the present invention, and Fig. 2 shows a cross-sectional view taken along line II-II in the first embodiment. shows. In these figures, 1.2 is an electrode plate, IA and 2A are lead terminals, 3.4 is a resin case, 5 is an insulating plate, and 6 is a basic cell. As the basic cell 6, one in which the polarizable electrode is a solid polarizable electrode is used. A basic cell of such an electric double layer capacitor is shown in FIG. In FIG. 4, the symbols correspond to those in FIG. 9, and 15 is a solid polarizable electrode. In the solid polarizable electrode 15,
Since the activated carbon powder is sintered or fired, the contact between the activated carbon powders is very good (and the contact resistance is small. Therefore, in order to reduce the internal resistance of the basic cell 6, the current collector 11 The force required to bring the cell into good contact with the solid polarizable electrode 15 is sufficient, and the pressure to be applied to the basic cell 6 is greatly reduced. Apply the electrode Fi1, and apply the electrode plate 2 to the other side. Fig. 3 is a perspective view of those electrode plates. Each electrode plate is provided with lead terminals IA and 2A. In the example, the lead terminals are provided in the same direction (above) on both IT electrode plates, but they may be drawn out in different directions if necessary.The lead terminal LA (2A) and the side surface of the basic cell 6 As shown in FIG. 2, an insulating plate 5 is interposed between the lead terminal IA (2A) and the current collector 11 having a different polarity from the lead terminal IA (2A). The above-described product is wrapped in resin cases 3 and 4 from both sides, and the inside is sealed by heat-sealing the two.
The shape is pulled out from the joint. In addition, pressure is applied to the basic cell 6 due to the contraction force during thermal fusion, and this pressure improves the contact between the current collector 11 of the basic cell 6 and the solid polarizable electrode 15. If the exterior is made of such a resin case, even if the electrolyte leaks from the basic cell 6, it will be completely sealed by heat fusion, so there is no risk of it leaking outside the case.
Moreover, since it is made of resin, there is no need to worry about it corroding. It is also easier to manufacture and cheaper than a metal case. Furthermore, since the case is insulating, it will not be charged with electricity, and there will be no electrical charge between it and peripheral equipment. No accidents will occur. (Second Embodiment) FIG. 5 shows a sectional view of an electric double layer capacitor according to a second embodiment of the present invention, and FIG. 6 shows an exploded view thereof. Once, it corresponds to the one in FIG. The difference from the first embodiment is that the basic cell 6 is one thin type, and the lead terminals IA of the electrode plates 1 and 2,
2A are drawn in opposite directions. The basic cell 6 is sandwiched between electrode plates 1.2, wrapped with resin cases 3 and 4 from both sides, and heat-sealed. If the basic cell 6 is thin, the resin case 3.4 may be flat, but if it is thick, the resin case 3.4 may be pre-molded with a concave center as shown in FIG. use.

【Effect of the invention】

As described above, in the electric double layer capacitor of the present invention,
Since a solid polarizable electrode is used as the basic cell and a resin case is used as the outer case, the following effects are achieved. ■ No leakage of electrolyte. Even if the electrolyte leaks from the basic cell, the resin case is completely sealed by heat sealing, so there is no risk of it leaking outside the case. Also, since it is made of resin, there is no need to worry about it corroding and creating holes. do not have. ■ Easier to manufacture and cheaper than metal cases. ■ Excellent safety. Since the case is insulating, even if there is some kind of internal failure, the case will not become charged, and therefore, even if it comes into contact with peripheral equipment, it will not cause an electrical accident.

[Brief explanation of the drawing]

Fig. 1: A perspective view of an electric double layer capacitor according to the first embodiment of the present invention Fig. 2: A sectional view taken along the line ■-■ in the first embodiment Fig. 3: 1 Perspective view of the electrode plate used in Example 4
Figure: Basic cell of an electric double layer capacitor using a solid polarizable electrode as a polarizable electrode. Figure 5: Cross-sectional view of an electric double layer capacitor according to the second embodiment of the present invention. ...An exploded view of the second embodiment Fig. 7...Another example of the resin case Fig. 8...Conventional electric double layer capacitor Fig. 9...
In the basic cell diagram of an electric double layer capacitor using a paste-like polarizable electrode as a polarizable electrode, 1. 2 is an electrode plate, IA, 2A are lead terminals, 3 and 4 are resin cases, 5 is an insulating plate, 6 is a basic cell, 11 is a current collector, 12 is a paste polarizable electrode, 13 is a separator, 14 is a gasket , 15 is a solid polarizable electrode, 81 is an exterior case, 82 is an insulating plate, 83 is a caulking part, 84 is an electrode plate, 84-1 is a terminal opening, 84A is a terminal, 8
5 is an electrode plate, 85A is a terminal, and 86 is a basic cell.

Claims (1)

[Claims] A basic cell using a solid polarizable electrode as a polarizable electrode, an electrode plate having a lead-out terminal and electrically contacted with the current collector of the basic cell, and a resin case sealed by heat fusion. An electric double layer capacitor characterized by: