JPH0317208B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an electric double layer capacitor, and particularly to a casing structure of an electric double layer capacitor element laminate.

(Prior Art) As one means of obtaining a large capacity capacitor by utilizing the electric double layer phenomenon, as disclosed in U.S. Pat. No. 3,536,963, carbon powder is brought into contact with an electrolytic solution. There are some that utilize the generation of an electric double layer.

FIG. 1 is a sectional view of an example of a conventional electric double layer capacitor. In Figure 1, 1 and 2 are top and bottom plates made of conductive elastic material (e.g. conductive rubber), 3 is a carbon paste electrode made of activated carbon powder and an electrolyte solution (e.g. sulfuric acid aqueous solution), and 4 is a carbon paste electrode made of activated carbon powder and an electrolyte solution (e.g. sulfuric acid aqueous solution). Ion-permeable and non-conductive porous separator, 5 is an electrically insulating elastic body (e.g. rubber)
The side wall is made of.

Therefore, the above-mentioned top cover 1 and bottom plate 2 serve as the electrodes of the capacitor. However, in the electric double layer capacitor having this structure, the withstand voltage as a capacitor is controlled by the electrolytic voltage of the electrolyte solution, so in order to obtain a capacitor with a high withstand voltage, the above-mentioned capacitors are stacked and connected in series to form a multilayer type capacitor.

FIG. 2 is a sectional view of an example of a laminated electric double layer capacitor. In FIG. 2, 6 represents the single electric double layer capacitor (hereinafter referred to as a basic cell) shown in FIG. 1, and n represents the number of stacked basic cells 6 required to achieve the required withstand voltage.

In the above-described laminated structure, the contact resistance between the basic cells 6 and the contact resistance between activated carbon particles within the basic cells 6 becomes large, and the internal resistance becomes large as a whole. In order to prevent an increase in internal resistance, it is necessary to apply appropriate pressure to the upper and lower surfaces of the laminate and to provide a casing that maintains this pressure.

FIG. 3 is a sectional view showing the casing structure of a conventional self-supporting electric double layer capacitor. As shown in FIG. 3, while pressing the first electrode plate 7 through the resin insulating case 8 and the second electrode plate 9 to the stacked body of basic cells 6, the upper end of the metallic outer case 10 is pressed inside. It is bent and caulked. However, this conventional casing structure has (a) a lead wire structure in which the terminal electrodes protrude, making it difficult to provide a chip-shaped electric double layer capacitor. (b) There is a drawback that the height of the capacitor is high compared to the demand for lower height when mounted on a board.

(Object of the Invention) An object of the present invention is to provide an electric double layer capacitor having a casing structure that eliminates such conventional drawbacks.

(Structure of the Invention) According to the present invention, a pair of mixed electrode layers are vertically separated through an ion-permeable and non-electron-conductive porous separator, and ions are arranged vertically in close contact with the mixed electrode layer. an impervious conductive separator;
A laminate consisting of electric double layer capacitor elements made of a non-conductive gasket interposed between conductive separators at the periphery of a mixed electrode layer is electrically conductive, and is arranged in parallel on a conductive plate. , a conductive plate, a pair of conductive reinforcing plates arranged outside the upper part of the laminate while maintaining electrical insulation, the reinforcing plates, and an electrode plate placed on the upper part of the reinforcing plates. An electric double layer capacitor is obtained which is characterized by having a structure in which the ends of the plates are caulked and housed in a pressurized state in a substantially U-shaped insulating coated plate body. Further, an electric double layer capacitor is obtained, which is characterized in that the width of the stacked electrode plates in the direction in which they are arranged is changed.

(Example) Hereinafter, an example of the present invention will be described with reference to FIGS. 4 and 5.

Embodiment 1 As shown in FIG. 4, a laminate 11 in which a required number of basic cells 6 are stacked is formed to have the same structure as the conventional structure shown in FIGS. 2 and 3 described above. A conductive metal reinforcing plate 12 is arranged at one end, that is, the upper part of this laminate 11, and the laminate 1
An electrode plate 13 such as an iron plate having a convex portion 13a at the center is arranged so as to be in contact with the surface opposite to the surface in contact with the upper end of the electrode plate 13. Next, a pair of laminates 11 are arranged in parallel on a conductive metal plate 14. At this time, one electrode 13L, reinforcing plate 12L, and laminate 11L are different from the other electrode plate 13R, reinforcing plate 12.
R and the laminated body 11R so that there is no electrical short-circuit contact, or a layer of insulating material such as synthetic resin is provided between them. For example, 3
If a laminate 11 in which six basic cells 6 are stacked in series is placed in parallel on a conductive metal plate 14, a capacitor with the same withstand voltage as a conventional capacitor with a casing structure in which six basic cells 6 are stacked in series can be obtained. It will be done. In other words, a capacitor with the same breakdown voltage can be obtained with half the stacking height. As mentioned above, this electric double layer capacitor needs to maintain a predetermined pressing force on the laminate 11 in order to obtain various characteristics as a capacitor.
For this purpose, for example, a metal plate 15 having a U-shaped cross section and having an insulating layer of synthetic resin or the like on the inner surface is pressed by a known pressure means (not shown) such as a hand press.
An electric double layer capacitor is formed by bending the left and right ends of the capacitor inward and fixing the capacitor while maintaining the pressing force.

Embodiment 2 Most of the structure is the same as in Embodiment 1, but the width of the electrode plate 13 in the long axis direction is changed by making one side (electrode plate 13L) wider than the other side (electrode plate 13R). This configuration has the advantage that the polarity can be automatically determined using a sensor such as a photoelectric switch.

Note that (a) the structure may be such that the insulating layer on the outside of the plate is not provided.

(b) An insulating layer may be provided on one side of the conductive plate.

(c) If a sufficient insulating layer is provided on only one side of the conductive plate, it is possible to use a plate that is not covered with an insulating layer.

(d) The electrode, reinforcing plate, and plate body do not need to be made of metal; they may be made of any material as long as it has the desired conductivity and strength.

(e) The entire electrode may be covered with a hardening resin such as epoxy resin, leaving a part of the electrode, that is, the electrical contact surface.

(Effects of the Invention) As described above, the electric double layer capacitor according to the present invention has the following effects.

() The terminal electrode has a flat plate shape, and there is no need to provide a through hole for inserting the lead wire on the mounting board.

() The height of the capacitor when mounted on the board becomes lower.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a basic cell of a conventional electric double layer capacitor. Figure 2 is a cross-sectional view of a multilayer electric double layer capacitor. FIG. 3 is a sectional view showing the state of a conventional electric double layer capacitor after casing. FIG. 4 and FIG. 5 are a perspective view and a sectional view showing an electric double layer capacitor according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Top lid, 2... Bottom plate, 3... Carbon paste electrode, 4... Porous separator, 5... Side wall, 6... Basic cell, 7... First electrode plate, 8...
...Insulating case, 9...Second electrode plate, 10...Exterior case, 11, 11L, 11R...Laminated body, 1
2, 12L, 12R... Reinforcement plate, 13... Electrode plate, 14... Metal plate, 15... Plate body.

Claims (1)

[Scope of Claims] 1. A pair of mixed electrode layers vertically separated by an ion-permeable, non-electronically conductive porous separator, and ion-impregnable electrode layers disposed closely above and below the mixed electrode layers. A laminate formed by laminating an electric double layer capacitor element consisting of a conductive separator and a non-conductive gasket interposed between the conductive separators around the mixed electrode layer is placed on a conductive plate. a pair of conductive reinforcing plates arranged in parallel to each other, and disposed on the outer sides of the laminate, the conductive plate, and the upper part of the laminate, respectively, while maintaining electrical insulation; An electric double layer capacitor characterized by having a structure in which a placed electrode plate is housed in an insulating coated plate body having a substantially U-shaped cross section with the plate ends caulked under pressure. 2. The electric double layer capacitor according to claim 1, wherein the width of the electrode plate in the direction in which the laminates are arranged in parallel is changed.