JPH04115510A - Electric double-layer capacitor - Google Patents

Abstract

PURPOSE:To make it possible to reduce and stabilize the contact resistance of an electric double-layer capacitor to enhance its reliability and to make the capacitor smaller and thinner by providing the capacitor with lead electrode plates and a clamping section having a circular bottom and circular arc wall. CONSTITUTION:At both ends of an element laminated body 7, electrode disks 23 and 24 are laid out having electrode lead drawing sections 23a and 24a. The element laminated body 7 and electrode disks 23 and 24 caulk an end portion 15 of the clamping section that laminate insulating layers 17 and that has a bottom 8 and an arc-like wall 9 to hold a predetermined pressure that is applied to the element laminated body 7. Further, the outer circumference of the clamping body is coated with insulating resin 16 by means of molding or the like. With this, the electrodes and leads are integrated and electrode disks are in contact with all over the entire electrode surface of the element, so that the contact resistance of the capacitor can be reduced and stabilized and the capacitor can be made smaller and thinner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric double layer capacitor, and particularly to its exterior structure.

[Conventional technology]

One way to obtain a large capacity capacitor by utilizing the electric double layer phenomenon is to generate an electric double layer by bringing carbon powder into contact with an electrolyte, as disclosed in U.S. Pat. No. 3,536,963. There is something that takes advantage of this.

FIG. 4 is a sectional view of an example of a conventional electric double layer capacitor element. In the figure, numerals 1 and 2 are disk-shaped top and bottom plates made of conductive elastic material (e.g. conductive rubber), 3 is a carbon conductive paste electrode made of activated carbon powder and an electrolyte solution (e.g. sulfuric acid aqueous solution), 4 5 is an ion-permeable, non-conductive porous separator, and 5 is a side wall made of an electrically insulating elastic material (for example, rubber). Therefore, the top cover 1 and the bottom plate 2 serve as the electrodes of the capacitor. However, in an electric double layer capacitor with this structure, the withstand voltage of the capacitor is controlled by the electrolysis voltage of the electrolyte solution, so in order to obtain a capacitor with a high withstand voltage, the above electric double layer capacitors are stacked and connected in series to form a multilayer type. .

FIG. 5 is a cross-sectional view of an example of an element laminate of a conventional multilayer electric double layer capacitor. Reference numeral 6 corresponds to a single electric double layer capacitor (hereinafter referred to as an element) shown in FIG. 4, and n represents the number of laminated elements 6 required for the required withstand voltage.

In such a conventional laminated structure, the contact resistance between elements 6 and the contact resistance between activated carbon particles within element 6 are large, and the internal resistance as a whole is excessive. Therefore, in order to optimize the internal resistance, a structure is adopted in which an appropriate pressure is applied to the upper and lower surfaces of the laminate and the pressure is maintained.

As shown in FIGS. 6(a) to 6(e), the structure for maintaining the pressure is as shown in FIGS. 6(a) to 6(e).
As shown in FIG. 0 and FIG. 7, an insulating plate 12 having the same shape as the metal cover plate 11- is used, and as shown in FIG. First, the tips of the electrode leads are flattened at both ends of the body 7 so as not to damage the elements when they come into contact with the surface of the element stack 7. Second electrode lead flat parts 13 and 14 are arranged, a metal cover plate 1 is arranged outside the first lead flat part 13, and an insulating plate 12 is arranged outside the cover plate 1], and an element stack 7 is arranged. Insulating plate 1
2 and the second lead flat part 14, and while applying a predetermined pressure to the element stack 7, the ends 15 of the clamp part are crimped to keep the element stack 7 firmly in place. It has a structure that applies a predetermined pressure. After that, the element stack 7 is placed in the first. Lead extraction parts 13a and 14a of the second electrode lead
With the lead extension parts 13a and 1.4a facing upward, the entire part except for the lead pull-out parts 13a and 1.4a is immersed in an epoxy thermosetting resin solution to adhere the resin and harden it by heating in a constant temperature bath to form an insulating resin layer around the outer periphery of the product. 16 is formed.

[Problem to be solved by the invention]

In this conventional exterior structure, the electrode lead is inserted between the metal cover plate and the element stack, and between the circular bottom of the clamping part and the element stack, so the thickness of the electrode lead digs into the element stack at the insertion position. This solves the problem of easily damaging the device if the electrode leads meet the shape. In addition, if the contact area between the electrode lead and the element is sufficient, it is not possible to draw out the electrode uniformly from the entire electrode surface of the element, resulting in a high resistance value. Although the structure is such that the electrodes are drawn out uniformly from the entire electrode surface of the device, there is a drawback that poor contact is likely to occur between the electrode lead and the metal cover plate or clamping portion. Furthermore, since the metal cover plate is inserted, the height of the product increases due to the thickness of the cover plate.

An object of the present invention is to provide an electric double layer capacitor that eliminates the conventional drawbacks, reduces and stabilizes contact resistance, improves reliability in terms of quality, and is more compact and thin. It is in.

[Means to solve the problem]

The electric double layer capacitor of the present invention includes a circular element laminate of the electric double layer capacitor, and a first capacitor with leads provided on the upper and lower electrode surfaces of the circular element laminate having different polarities. It has a second leaded electrode plate, a holding part having a circular bottom surface and an arcuate wall surface, and the above-described element stack and the first. The second leaded electrode plate is connected to the above-mentioned clamping part and the above-mentioned first electrode plate. The structure is characterized in that at least one of the second leaded electrode plate or the clamping part is insulated and clamped under pressure in the stacking direction, and is externally coated with an insulating resin.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIGS. 1(a) and 1(b) are a sectional view and a front view of an electric double layer capacitor according to a first embodiment of the present invention. Figure 1 (a
), electrode leads made of solder-plated Fe material, SUS material, etc. are used to uniformly press the element laminate 7 at both ends of the element laminate 7, in which the number of elements required for the required withstand voltage is stacked. Disc-shaped electrode plates 23 and 24 having lead-out portions 23a and 24a are arranged. The electrode lead extension parts 23a and 24a are bent and formed so as to be lined up in the same plane perpendicular to the element stacking direction.

Then, the element laminate 7 and the electrode plates 23 and 24 are laminated with the insulating layer 1-7, and the end portion 15 of the clamping portion having a circular bottom surface 8 and an arcuate wall surface 9 is crimped to form the element laminate 7. A predetermined pressure is maintained. Thereafter, the outer periphery is coated with an insulating resin 16 by molding or the like.

Next, a second embodiment of the present invention will be described. Figure 2 (a>,
(b) is a sectional view and a front view of an electric double layer capacitor according to a second embodiment of the present invention. Compared to the first embodiment described above, the electrode lead extraction portions 23a, 2 on the clamping portion wall surface 9 are
Only the drawer position 4a is a notch, and the arc-shaped wall surface 9 is not divided into two parts as in the first embodiment, so there is an advantage that the pressure holding force is strong.

Next, a third embodiment of the present invention will be described. Figure 3(a),
(b) is a plan view and a sectional view of an electric double layer capacitor according to a third embodiment of the present invention. Compared to the first and second embodiments described above, the pressure holding structure and the resin exterior structure of the element are the same, but the difference is that the electrode lead extension parts 33a and 34a are drawn out from two directions. . It is used by forming leads to an appropriate lead pitch when mounting on a circuit board. This has the advantage of reducing the height of the product when mounted on a circuit board.

〔Effect of the invention〕

As explained above, in the present invention, the electrode plate and the lead are integrated, and the electrode plate is in contact with the front surface of the electrode surface of the element, thereby reducing and stabilizing the contact resistance and making the product smaller and thinner. It has an effect suitable for Furthermore, if the lead is made long, it can be used as a taped product, and by applying molding to the resin exterior, the advantages of a regular shaped part can be added, and it is also suitable for automatic mounting.

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are a cross-sectional structural diagram and a front view of a first embodiment of the present invention, and FIGS. 2(a) and (b) are a cross-sectional structural diagram and a front view of a second embodiment of the present invention. 3(a) and 3(b) are a plan view and a cross-sectional structure diagram of a third embodiment of the present invention, FIG. 4 is a cross-sectional view of an electric double layer capacitor element, and FIG. 5 is a cross-sectional view of an element laminate. Figures 6 (a), (b), and (c) are a plan view, front view, and expanded view of material removal of a clamping part with a circular bottom surface and an arcuate wall surface, and Figures 7 (a>, (b)) 8(a) and 8(b) are a plan view and a side view of an electrode plate and an insulating plate used in a conventional exterior structure, and FIGS. 8(a) and 8(b) are a cross-sectional structure diagram and a front view of a conventional electric double layer capacitor. 1... Top lid, 2... Bottom plate, 3... Conductive paste electrode, 4... Porous separator, 5... Side wall, 6...
- Element, 7... Element laminate, 8... Bottom surface of clamping part, 9
... Holding part arcuate side wall, 10... Holding part (whole),
11...Circular electrode plate, 12...Circular insulating plate, 13.
...First electrode lead flat part, 13a...First electrode lead extraction part, 14...Second electrode lead flat part, 1
4a...Second electrode lead extraction part, 15...Clinching part of the clamping part, 16...Coating resin layer, 17...Insulating layer of the clamping part, 23...First lead attachment Electrode plate, 23a
. . . 1st electrode lead extraction portion, 24 . . . 2nd leaded electrode plate, 24a . . . 2nd electrode lead extraction portion, 3
3... First electrode plate with leads, 33a... First electrode lead extraction part, 34... Second electrode plate with leads, 3
4a...Second electrode lead extraction part. (+) No.f review

Claims (1)

[Claims] A circular element laminate of an electric double layer capacitor, first and second leaded electrode plates with leads provided on upper and lower electrode surfaces of the circular element laminate having different polarities, a circular bottom surface and an arcuate wall surface. a holding part having a structure, wherein the element stack and the first and second leaded electrode plates are connected to the first and second leaded electrode plates at the holding part.
An electric double layer capacitor characterized in that at least one of the second leaded electrode plate or the clamping portion is insulated and clamped under pressure in the stacking direction, and the exterior is covered with an insulating resin.