JPH1126322A - Electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cost of a large-capacitance electric double layer capacitor, by disposing a terminal board which contacts the entire lead face at the top of a capacitor element, and contacting the entire bottom lead face of the element to the bottom of a metal case to connect them in parallel. SOLUTION: An electrolyte is disposed between electrodes. Extrudent leads are swaged to turn them inwards to the center of a capacitor element 2 having an anode lead face at the top and cathode lead face at the bottom. Such six capacitor elements 2 disposed on the same plane are housed in a metal case 10. The anode lead face of the element 2 contacts the entire surface of an Al terminal board 12 disposed thereon. The cathode lead face of the element 2 contacts the entire bottom surface 11 of the case 10. Lead bars 12a protruding from the board 12 pierce an insulative seal 13 which closes an opening of the case 12 and extrudes outside.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric double layer capacitor.

[0002]

2. Description of the Related Art An electric double layer capacitor is manufactured by kneading, for example, activated carbon, carbon, and polytetrafluoroethylene (PTFE) as a binder. A metal plate-shaped or mesh-shaped current collector is bonded with a conductive adhesive to form an electrode body, and a pair of the electrode bodies is wound through a separator to form a capacitor element, which is impregnated with an electrolytic solution. After that, one capacitor element is put in a bottomed metal case, and the lead leads respectively connected to both electrode bodies are connected to the inner end of an external terminal attached to an insulating sealing body. Then, the opening of the case is sealed with a sealing body.

However, a large current cannot be taken out instantaneously due to the small current capacity of the lead, so that the width of the current collector is made wider than that of the sheet-like polarizable electrode. There is proposed a dry battery type electric double layer capacitor in which a protruding part is provided and the protruding lead part is swaged so as to be in surface contact as a lead surface (Japanese Patent Laid-Open No. 4-15 / 1990).
2616 and Japanese Patent Application No. 9-96516).

This is, for example, a protruding lead in which the upper edge of the anode current collector and the lower edge of the cathode current collector protrude from the sheet-shaped polarizable electrode and the separator, respectively. The anode current collector and the cathode current collector are placed facing each other, and a separator is interposed between them to form a capacitor element and impregnated with the electrolytic solution. Each of the lead portions is turned down by swaging to form an anode lead surface on the upper surface of the capacitor element and a cathode lead surface on the lower surface. One of the capacitor elements is housed in a metal case, and a terminal plate is disposed on the anode lead surface side so as to make surface contact with the anode lead surface, and the protruding portion of the terminal plate is an opening of the metal case. The cathode lead surface protrudes to the outside through a sealing body for hermetically sealing, while the cathode lead surface is in surface contact with the bottom of the metal case.

[0005]

In order to obtain a large capacitance using such a dry cell type electric double layer capacitor, a plurality of electric double layer capacitors must be arranged and connected in parallel. Wiring is difficult and troublesome. Moreover, since the electric double layer capacitors are housed in different metal cases one by one, the cost is high. Further, when a large capacitance is to be obtained with one electric double layer capacitor, the number of windings of the capacitor element increases, and there is a problem that winding deviation is likely to occur.

An object of the present invention is to provide an inexpensive large-capacity electric double layer capacitor.

[0007]

According to the electric double layer capacitor of the present invention, a sheet-like polarizable electrode is arranged so as to be offset to an upper side edge portion of a wider metal current collector. An electrode body having a protruding lead portion formed below the current collector; and a polarizable electrode disposed offset to a lower side edge portion of the current collector so as to protrude above the current collector. Are wound so that the polarizable electrodes are arranged to face each other and an electrolyte is formed between the opposing electrode bodies.
The two or more capacitor elements each having a lead portion inwardly inwardly swaged to form a lead surface on an upper surface and a lower surface are arranged in the same plane, and the same metal is formed. One terminal plate which is housed in the case and is in surface contact with the lead surface above each capacitor element is disposed on the upper surface side of each capacitor element, and the protruding portion of this terminal plate is formed of a metal case. It penetrates through an insulating sealing body that seals the opening and protrudes to the outside.
The metal surface is in surface contact with the bottom of the metal case and is connected in parallel.

[0008]

FIG. 1 is a longitudinal sectional view showing an example of an electric double layer capacitor according to the present invention, FIG. 2 is a view showing a state where a part of the capacitor element is unwound, and FIG. It is a cross-sectional view of a multilayer capacitor. As shown in FIG. 2, the capacitor element 2 is formed by winding a cathode-side electrode body 3 and an anode-side electrode body 4 with separators 5 and 6 interposed therebetween.

The cathode-side electrode body 3 has a thickness of, for example, 20 to 100.
For example, a sheet-like polarizable electrode 3b having a thickness of 400 to 800 μm is attached to both sides of a tape-shaped current collector 3a made of a μm aluminum foil. The polarizable electrode is formed by kneading, for example, activated carbon, carbon, and polytetrafluoroethylene (PTFE) as a binder.
It is in the shape of. The current collector 3a is made of foil,
It may be a metal plate or mesh.

The current collector 3a is wider than the polarizable electrode 3b, and the polarizable electrode 3b is arranged along the upper edge of the current collector 3a, so that it is located on the lower edge of the current collector 3a. Protrudes from the polarizable electrode 3b to form a protruding lead portion 3c.

On the other hand, the anode-side electrode body 4 has, for example, a thickness of 20 to
For example, a sheet-like polarizable electrode 4b having a thickness of 400 to 800 μm is attached to both sides of a tape-shaped current collector 4a made of 100 μm aluminum foil with a conductive adhesive. Polarizing electrodes include, for example, activated carbon, carbon, and polytetrafluoroethylene (PT) as a binder.
FE) to form a sheet. Current collector 4
a may be a metal plate or mesh in addition to the foil.

The current collector 4a is wider than the polarizable electrode 4b, and the polarizable electrode 4b is arranged along the lower edge of the current collector 4a, so that it is located on the upper edge of the current collector 4a. Protrudes from the polarizable electrode 4b to form a protruding lead portion 4c.

In FIG. 2, the polarizable electrodes 3b, 4b of the cathode-side electrode body 3 and the anode-side electrode body 4 are connected to the current collector 3 respectively.
Although they are provided on both surfaces a and 4a, they may be provided only on one surface.

The separators 5 and 6 have a thickness of, for example, 50 to 20.
It is made of a sheet made of 0 μm polypropylene or Manila hemp, and is wider than the width of the polarizable electrodes 3b and 4b.
The width is smaller than the width of the current collectors 3a and 4a.

The cathode-side electrode body 3 and the anode-side electrode body 4 are arranged such that the polarizable electrode 3b and the polarizable electrode 4b face each other, and the separators 5 and 6 are arranged therebetween. At this time, the protruding lead portion 3c of the cathode-side electrode body 3 is located below the lower edge of the separators 5, 6, and the protruding lead portion 4c of the anode-side electrode body 4 is provided with the separator 5, 6
Is arranged to protrude above the upper edge.

Thereafter, the cathode side electrode body 3 and the anode side electrode body 4
And the outer periphery is stopped by a tape 2a, and the capacitor element 2
It is said. An electrolyte is arranged between the electrode bodies facing each other across the separator. The electrolyte can be an electrolyte, an electrolyte consisting of a gel or a solid electrolyte, in the case of an electrolyte,
The capacitor element is immersed (preferably vacuum immersed) in the electrolytic solution to impregnate the electrolytic solution. As the solid electrolyte, for example, an organic semiconductor such as TCNQ (tetracyanoquinodimethane) or a conductive polymer solid electrolyte such as polypyrrol can be used. These gel electrolytes or solid electrolytes are sols, liquids or monomers.
Impregnated in the capacitor element in the state of, then hydrolysis,
It is formed into an electrolyte consisting of a gel or a solid electrolyte by cooling or polymerization. When a solid electrolyte or an electrolyte composed of a gel is used as the electrolyte, the separators 5 and 6 are preferably carbonized after winding. When a solid electrolyte or an electrolyte made of gel is used as the electrolyte, the separator 5,
6 may be omitted.

Next, the protruding leads 3c, 4c are swaged so as to fall inward toward the center of the capacitor element 2, respectively. By this swaging, an anode lead surface 7 is formed on the upper surface of the capacitor element 2, and a cathode lead surface 8 is formed on the lower surface.

As shown in FIGS. 1 and 3, the electric double layer capacitor 1 of the present invention has six such capacitor elements 2,
They are arranged on the same plane and housed in a metal case 10. The metal case 10 is formed of a bottomed cylinder of aluminum, and the cathode lead surface 8 on the lower surface of each capacitor element 2 is in surface contact with the bottom 11 of the metal case 10. Note that a conductive adhesive may be used to ensure contact.

The anode lead surface 7 on the upper surface of each capacitor element 2 is connected to an aluminum terminal plate 12 disposed thereon.
Is in surface contact with Therefore, each capacitor is connected in parallel. In this case, a conductive adhesive may be used to ensure the contact. A lead rod 12a is provided at the center of the terminal plate 12 so as to protrude therethrough. The lead rod 12a penetrates an insulating sealing body 13 which seals an opening above the metal case 10. It protrudes to the outside. The sealing body 13 is made of, for example, rubber or phenol resin.

In the vicinity of the opening of the metal case 10, a lateral drawing groove 14 is formed in the metal case 10 to lock the sealing body 13.
After the sealing body 13 is placed on the lateral drawing groove 14, the opening edge 10a of the metal case 10 is curled inward to fix the sealing body 13. In order to enhance the sealing performance, the open edge 10 of the curled metal case is used.
“a” has entered the annular rubber portion 13 a provided with the sealing body 13. A sleeve 15 made of a heat-shrinkable synthetic resin is covered on the outside of the metal case 10.

The number of capacitor elements 2 housed in the metal case 10 is not limited to six, but may be more or less. Further, the shape of the metal case can be arbitrarily set, for example, as shown in FIG.

[0022]

According to the present invention, a large-capacity electric double-layer capacitor housed in one metal case is obtained, and wiring is performed so as to connect the electric double-layer capacitors contained in the individual metal cases in parallel. It is easier to handle than when you do.
Further, the cost can be reduced as compared with the case of using the electric double layer capacitor contained in each metal case.

In the present invention, any capacitance can be easily handled by increasing the number of capacitor elements. In addition, since a plurality of small-capacity capacitor elements having the same capacitance are used, an electric double-layer capacitor having a plurality of capacitances can be manufactured with one type of capacitor element, so that manufacturing equipment costs can be reduced.

Further, in order to obtain a large capacity with one capacitor element, it is necessary to increase the number of windings to increase the diameter. However, in this case, winding deviation easily occurs and the yield is poor. In that regard, the electric double layer capacitor of the present invention does not have such a problem. The shape of the metal case can be any shape, such as a square, according to the place of use.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an electric double layer capacitor of the present invention.

FIG. 2 is a diagram showing a capacitor element.

FIG. 3 is a schematic cross-sectional view of the electric double layer capacitor of FIG.

FIG. 4 is a cross-sectional view of another electric double layer capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric double layer capacitor 2 Capacitor element 2a tape 3 Cathode side electrode body 3a Current collector 3b Polarizing electrode 3c Protruding lead part 4 Anode side electrode body 4a Current collector 4b Polarizing electrode 4c Protruding lead part DESCRIPTION OF SYMBOLS 5 Separator 6 Separator 7 Anode lead surface 8 Cathode lead surface 10 Metal case 10a Opening edge 11 Bottom 12 Terminal plate 12a Lead rod 13 Sealing body 13a Ring rubber 14 Horizontal drawing groove 15 sleeve 20 metal case

Claims (1)

[Claims] 1. A sheet-shaped polarizable electrode is disposed at a position closer to an upper side edge of at least one surface of a wider metal current collector, and extends out below the current collector. And a similar electrode body in which a polarizable electrode is arranged offset to the lower side edge of the current collector and a lead portion is formed above the current collector. However, each polarizable electrode is arranged and wound so as to face each other, an electrolyte is formed between the opposing electrode bodies, and the upper and lower protruding leads are swaged to form inner portions. A plurality of capacitor elements, each having a lead surface formed on the upper and lower surfaces, are housed in the same metal case in a state where they are arranged in the same plane, and are placed on the upper surface side of each capacitor element. Is one end in surface contact with the upper lead surface of each capacitor element A plate is disposed, and a protruding portion of the terminal plate protrudes outside through an insulating sealing member for sealing the opening of the metal case, while a lead surface on the lower surface of each capacitor element is formed of a metal case. An electric double layer capacitor connected in parallel with the bottom of the contact in surface contact.