JPH0475313A - Electric double layer capacitor - Google Patents

Abstract

PURPOSE:To obtain a square-shaped electric double layer capacitor whose electrostatic capacity corresponding to its size is high by a method wherein one pair of electrode bodies formed by attaching each sheetlike polarizing electrode to one face of each belt-shaped current collector are laminated in such a way that a separator is sandwiched between both polarizing electrodes and this laminated electrode body is folded in a zigzag manner to obtain a square-shaped capacitor element. CONSTITUTION:Individual electrode bodies 1, 2 are formed by attaching sheetlike polarizing electrodes 1b, 2b to one face of current collectors 1a, 2a. In this case, the current collectors 1a, 2a display a belt shape having a prescribed length; their material may be a metal foil of stainless steel, aluminum or the like or its mesh-shaped body. The polarizing electrodes 1b, 2b are formed to be a sheet shape by kneading activated charcoal, carbon and polyteteraflurorthylene as a binder. When the electrode bodies 1, 2 are laminated in such a way that a separator 3 is sandwiched between the polarizing electrodes 1b 2b, an electrode laminated body 4 is obtained. The electrode laminated body 4 is folded in a zigzag manner to obtain a square-shaped capacitor element 5. The element is housed inside a square-shaped outer-package case 6.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric double layer capacitor that can obtain a large capacitance.

[Prior Art] An electric double layer capacitor is equipped with a polarizable electrode formed into a sheet by kneading, for example, activated carbon, carbon, and polytetrafluoroethylene (PTFE) as a binder. In order to obtain high capacity, conventionally, this sheet-like polarizable electrode is bonded to a plate-like or mesh-like metal current collector to form an electrode body, and a pair of the same electrode bodies is wound with a separator in between to form a cylindrical shape. A capacitor element is obtained and the capacitor element is housed in an exterior case.

[Problem to be solved by the invention]

Since the capacitor element is cylindrical, if the outer case that houses it is cylindrical, it can be stored efficiently by minimizing dead space, but if it is a square case, the space between the parts is Since it is a dead space, there is a problem that the capacitance is low considering its size.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned conventional drawbacks, and its structural features include a sheet-like polarizable electrode on one side of a strip-like current collector. It has a capacitor element made by folding a pair of electrode bodies in a zigzag shape with a separator sandwiched between the polarizable electrodes, and the capacitor element is housed in a bottomed rectangular cylindrical outer case. The opening of the outer case is sealed with a sealing body having a terminal connected to each current collector of the electrode body. In this case, a metal foil or a metal mesh made of stainless steel or aluminum is used as the current collector.

[For production]

Since this capacitor element has a rectangular shape, it can be stored efficiently in a rectangular case, and a rectangular electric double layer capacitor having a high capacitance commensurate with its size can be obtained.

【Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an electrode laminate 4 in which electrode bodies 1 and 2 used in this electric double layer capacitor are laminated with a separator 3 in between.
A perspective view is shown in which the parts are peeled apart in a stepped manner so that each member can be clearly seen.

Each electrode body 1.2 consists of a current collector 1a, 2a with a sheet-like polarizable electrode 41b, 2b attached to one side. In this case, the current collectors 1a, 2a have a band shape (tape shape) having a predetermined length, and the material thereof may be a metal foil such as stainless steel or aluminum, or a mesh thereof. Further, the polarizable electrodes 1b and 2b are made of a sheet formed by kneading activated carbon, carbon, and polytetrafluoroethylene (PTFE) as a binder, as described above. Current collector 1a.

The polarizable electrodes 1b, 2b may be attached to the electrodes 2a by using a conductive adhesive or by pressing with a roller.

This electrode body 1.2 is used as the polarizable electrode 1b.

The electrode laminate 4 is obtained by stacking the electrodes with the separator 3 interposed between them, but in the present invention,
As shown in FIG. 2, the electrode laminate 4 is folded in a zigzag pattern to form a rectangular capacitor element 5, which is then housed in a similarly rectangular exterior case 6. After a predetermined electrolytic solution (for example, tetraethylphosphonium tetrafluoroboric acid) is injected into the case 6, the opening thereof is sealed with a sealing body 7. A pair of lead terminals 7a and 7b are implanted in the sealing body 7, and each current collector 1a and 2a of the electrode bodies 1 and 2 is connected to the lead terminal 7 before sealing.
a and 7b, respectively, by welding, for example.

〔Effect of the invention〕

As explained above, according to the present invention, a pair of electrode bodies each having a sheet-like polarizable electrode attached to one side of a band-like current collector are laminated with a separator interposed between the polarizable electrodes. However, by folding this laminated electrode body in a zigzag shape to obtain a rectangular capacitor element, a rectangular electric double layer capacitor having a high capacitance commensurate with its size can be provided.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the laminated electrode body used in the electric double layer capacitor of the present invention peeled off in a stepped manner, and Fig. 2 shows a square capacitor element formed by folding the laminated electrode body in a zigzag shape. FIG. 3 is a sectional view showing a state where the device is housed in a case. In the figure, 1.2 is the electrode body, la, 2a is the current collector, lb, 2
b is a polarizable electrode, 3 is a separator, 4 is a laminated electrode body, 5
is a capacitor element, 6 is an outer case, 7 is a sealing body, 7a
, 7b are lead terminals.

Claims (2)

[Claims] (1) It has a capacitor element formed by folding a pair of electrode bodies, each consisting of a sheet-shaped polarizable electrode attached to one side of a band-shaped current collector, into a zigzag shape with a separator sandwiched between the polarizable electrodes. The capacitor element is housed in a bottomed rectangular cylindrical outer case, and the opening of the outer case is sealed with a sealing body having terminals connected to each current collector of the electrode body. An electric double layer capacitor featuring: (2) The electric double layer capacitor according to claim 1, wherein the current collector is made of metal foil or metal mesh.