JP2000003838A - Electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric double layer capacitor, whose ESR(equivalent series resistance) is low and which is durable to a large current and is easily connected in series. SOLUTION: A capacitor element 12, wherein a plurality of the positive electrode lead-out leads 18 are led out from end and a plurality of the negative electrode lead-out leads 19 are led out from another end, is accommodated into a cylindrical metal case 11, whose opinions at the upper and lower ends are sealed by insulating sealing bodies 13 and 14. A plurality of electrodes 15 and 16 are provided at every sealing body so that the plurality of electrodes can penetrate the sealing bodies. Metal conductive plates 20 and 21 are laid out and fixed respectively at the sides facing the capacitor element inside of the every sealing bodies so that the inner ends of the terminals which penetrate the sealing bodies can be connected mutually. The positive lead-out leads 18 and the negative lead-out leads 19 are connected to the inner ends of terminals 15 and 16, which are close to the lead-out leads.

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 In an electric double layer capacitor, a capacitor element, that is, a polarizable electrode formed into a sheet by kneading activated carbon, carbon and a binder is formed by using a conductive adhesive.
An electrode body was formed by attaching a lead wire to a metal plate or mesh current collector to which a lead was previously fixed, and a pair of this electrode body was wound as a positive electrode body and a negative electrode body via a separator. After impregnating the capacitor element with the electrolytic solution, FIG.
A capacitor element 1 is placed in a bottomed cylindrical metal case 2 like an electric double-layer capacitor A shown in FIG. 1 and a lead 3 connected to an anode electrode of the capacitor element 1 and a cathode electrode. Are fixed to the inner ends of the anode terminal 6 and the cathode terminal 7 attached so as to penetrate the insulating sealing member 5, respectively.
Is sealed by a sealing body 5. In FIG. 8,
Reference numeral 8 denotes a tape wound around the outer periphery of the capacitor element 1 to prevent the wound capacitor element 1 from unwinding, and 9 denotes an explosion-proof valve.

[0003]

In an electric double layer capacitor, particularly an electric double layer capacitor for a large current, as shown in FIG. 8, two lead wires 3 and 4 are respectively drawn out from the anode electrode body and the cathode electrode body. It is pulled out and connected to the anode terminal 6 and the cathode terminal 7 arranged on the sealing body 5 above the metal case 2, but has a disadvantage that the equivalent series resistance (ESR) is large.

In order to reduce the equivalent series resistance, it is necessary to further increase the number of lead-out leads. However, when many lead-out leads are connected to one terminal, a large current is required from the viewpoint of connection reliability and heat generation. It was hard to connect to endure. In addition, it is difficult to increase the number of terminals because the area of the sealing body is limited, and even if it is increased, the anode terminal and the cathode terminal come close to each other, which is extremely dangerous. is there.

Further, since the electric double layer capacitor has a low withstand voltage, it is necessary to use a series connection when a high withstand voltage is required. However, the conventional electric double layer capacitor is difficult to connect in series.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electric double layer capacitor which can achieve a low ESR, withstand a large current and can be easily connected in series.

[0007]

An electric double layer capacitor according to the present invention has a plurality of cylindrical metal casings whose upper and lower ends are respectively sealed by insulating sealing members. A capacitor element in which a plurality of cathode lead leads are drawn from the other end of the anode lead lead is housed,
A plurality of terminals are arranged on each sealing body so as to pass through the sealing body, and the inner ends of the terminals penetrating the sealing body are arranged on the side facing the capacitor element inside each sealing body. The metal conductive plate is arranged and fixed so as to connect,
Anode lead out from both ends of the capacitor element
The cathode and the cathode lead are respectively connected to the inner ends of the terminals of the sealing body close to the cathode and the cathode lead.

[0008] Further, the invention is characterized in that at least one of the upper and lower sealing members or the metal conducting plate is provided with an element fixing rod inserted into the center of the capacitor element for holding and fixing the capacitor element.

The element fixing rod may be provided on one of the upper and lower sealing members, and may extend to the other sealing member and be connected thereto.

Also, the element fixing rod may be a round bar, a cone,
A round bar may be formed halfway and then spread in a conical shape, or a horizontal bar which supports the capacitor element may be provided in the middle of the round bar.

[0011]

1, an electric double layer capacitor 10 according to the present invention comprises a capacitor element 12 housed in an aluminum cylindrical metal case 11 having upper and lower ends opened. Are sealed by insulating sealing members 13 and 14 made of Bakelite.
Edges 11a of upper and lower openings of metal case 11 and sealing body 1
Rubber packings 13a and 14a are arranged at the places where the parts 3 and 14 are in contact with each other in order to enhance the sealing performance. The sealing bodies 13 and 14 made of Bakelite were used as the sealing bodies.
Instead, another material, for example, the whole sealing body may be made of rubber.

Two screw-type anode terminals 15 (15a, 15b) are disposed on the upper sealing body 13, and two screw-type cathode terminals 16 (16a, 16b) are also provided on the lower sealing body 14.
Are arranged, and the anode terminals 15a and 15b and the cathode terminal 1
Inner screws (not shown) are formed in 6a and 16b, respectively. The explosion-proof valve 1 made of synthetic resin is provided on the upper sealing body 13.
7 is provided, and a similar explosion-proof valve 17 (FIG. 2) is provided on the lower sealing body 14.

The capacitor element 12 is formed by kneading activated carbon, carbon and polytetrafluoroethylene (PTFE) as a binder to form a sheet-shaped polarizable electrode (eg, 400 to 800 μm thick) using a conductive adhesive. A pair of anode-side electrode bodies and cathode-side electrodes respectively attached to both sides of a current collector made of aluminum foil (for example, having a thickness of 20 to 100 μm) are wound via a separator made of paper or glass-mixed paper. It is made of a material impregnated with an electrolyte. A tape 12a is wound to prevent rewinding.

Four lead-out leads 18 and 19 are fixed to the anode-side electrode body and the cathode-side electrode body of the capacitor element 12, respectively, and two lead-out leads 18 and 19 are respectively connected to the anode terminals 15a and 15b and the cathode terminals. Terminals 16a, 16b
Are fixed to the inner ends by caulking or ultrasonic welding, respectively.

Metal conductive plates 20 and 21 made of aluminum are arranged inside the sealing members 13 and 14 facing the capacitor element 12, respectively. When the cathode side is taken as an example, the metal conductive plates 21 (the same applies to the metal conductive plate 20) Fig. 2
As shown, the inner ends of the cathode terminals 16a and 16b penetrate and protrude. The cathode terminals 16a and 16b and the metal conductive plate 2
1 may be integrally formed. Metal conductive plate 2
An element fixing bar 22 is provided integrally with the metal conductive plate 21 at the center of the device 1.

The shape of the metal conductive plates 20 and 21 is not limited to the oval shape, but may be any shape such as a circle as shown in FIG. In the metal conductive plate 21 of FIG. 3, holes 21a and 21b are provided at locations corresponding to the element fixing rod 22 and the explosion-proof valve 17. The element fixing bar 22 may be fixed to the sealing body 14 as in the case of FIG. 3 and may not be in contact with the metal conductive plate 21.

The element fixing rod 22 is inserted into a space surrounded by a separator which is generally formed at the beginning of winding of the separator at the center of the capacitor element 12, but the element fixing rod is inserted. The cavity may be specially formed for ease of operation.

The shape of the element fixing bar 22 is not only a round bar, but also a conical shape capable of supporting the capacitor element 12 as shown at 22a in FIG. 4 or a conical shape from the middle of the round bar as shown at 22b in FIG. You may. In addition, various shapes such as a round bar-like shape having a supporting horizontal bar 22d in the middle as shown at 22c in FIG. 6 can be used.

The element fixing rod 22 is short in both the lower and upper sealing plates in FIGS.
Only one of the lower or upper sealing body or the metal conductive plate may be provided with a short element fixing rod extending to the vicinity of the other metal conductive plate. Further, as shown in FIG. 7, for example, the lower part of the element fixing rod 22f is fixed to the lower sealing plate 14,
The upper end may be connected to the sealing body 13 through the center of the capacitor element 12. In this case, the element fixing bar 22f is configured not to contact the metal conductive plates 20, 21.

In the electric double layer capacitor of the present invention,
Three or four or more lead leads on the anode and cathode sides may be provided, respectively, and the number of terminals may be two or more for one sealing body. In order to connect a plurality of electric double layer capacitors in series, a threaded socket is screwed into each of the screw terminals to be connected, etc., and a male screw jack is fitted to each of the other screw terminals in the socket. Is preferably provided by screwing. Further, the terminals are not limited to the screw type terminals, and other types of terminals such as lug terminals and lead terminals may be used.

If the use of the electric double layer capacitor is not specified, it is preferable to provide the explosion-proof valve on both of the sealing members, but it may be provided only on one of them. When the explosion-proof valves are provided on both sealing bodies, they may be provided on the same vertical axis or may be provided shifted.

The electric double-layer capacitor of the present invention is not limited to the above-mentioned wound electric double-layer capacitor, but also to a multilayer electric double-layer capacitor in which strip-shaped polarizable electrodes and separators are laminated in multiple layers. Applicable.

[0023]

<Embodiment 1> The openings at the upper and lower ends of a metal case as shown in FIG.
Electric double layer capacitor (2.3V4
000F, diameter 89 mm, height 150 mm). Aluminum was used for the metal case, the conductive plate and the element fixing rod. A polarizable electrode (400 μm thick) formed by kneading activated carbon, carbon and polytetrafluoroethylene (PTFE) for the capacitor element
Is electrically etched in advance using a commercially available conductive adhesive, and attached to both surfaces of a current collector made of aluminum foil (thickness: 50 μm) to which a lead made of aluminum is fixed. A pair of anode-side electrode bodies and a cathode-side electrode are wound through a separator made of manila paper, and impregnated with a non-aqueous electrolyte in which tetraethylammonium tetrafluoroborate is dissolved in propylene carbonate. used. Four lead wires were drawn from the anode electrode body and the cathode electrode body, respectively.

<Comparative Example> An electric double-layer capacitor (same rating and size) as shown in FIG. 8 was placed in a bottomed cylindrical aluminum case using the same capacitor element and electrolytic solution as in Example 1. Created. Two lead wires were drawn from the anode electrode body and the cathode electrode body, respectively.

The equivalent series resistance (1 KHz) was measured using the electric double layer capacitors of Example 1 and Comparative Example. As a result, the equivalent series resistance of the electric double layer capacitor of the first embodiment is 5 mΩ, while the equivalent series resistance of the electric double layer capacitor of the comparative example is 10 mΩ. The equivalent series resistance was reduced to half compared with the conventional electric double layer capacitor (comparative example).

[0026]

According to the electric double layer capacitor of the present invention, the number of lead leads is large, the leads are dispersed and connected to the terminals, and the terminals are connected by the metal conductive plate.
The ESR (equivalent series resistance) can be reduced, and an electric double layer capacitor that can withstand a large current can be obtained.

Further, in the electric double layer capacitor of the present invention, the anode terminal and the cathode terminal are arranged vertically, so that they can be arranged in the vertical direction to easily connect in series and have a high breakdown voltage. Furthermore, since the drawer lead and the anode terminal and the cathode terminal are completely separated from each other, there is no danger of contact between the drawer lead and the external conductor.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a metal conductive plate inside a sealing body.

FIG. 3 is a view showing another metal conductive plate.

FIG. 4 is a view showing an element fixing rod.

FIG. 5 is a view showing another element fixing rod.

FIG. 6 is a view showing another element fixing rod.

FIG. 7 is a view showing another element fixing rod.

FIG. 8 is a sectional view of a conventional electric double layer capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Electric double layer capacitor 11 Metal case 12 Capacitor element 13 Sealing body 14 Sealing body 15 Anode terminal 16 Cathode terminal 17 Explosion-proof valve 18 Extraction lead 19 Extraction lead 20 Metal conduction plate 21 Metal conduction plate 22 Element fixing rod

Claims (8)

[Claims] 1. A plurality of anode lead-outs from one end and a plurality of cathodes from the other end are placed in a cylindrical metal case whose upper and lower openings are sealed by insulating sealing members. A capacitor element from which a drawer lead is drawn is housed, and a plurality of terminals are arranged in each of the sealing members so as to pass through the sealing member, and face the capacitor element inside each of the sealing members. On the side, a metal conductive plate is arranged and fixed so as to connect the inner ends of the terminals penetrating the sealing body, and an anode lead and a cathode lead led from both ends of the capacitor element are provided. An electric double layer capacitor which is connected to an inner end of a terminal of a sealing body which is close to each of them. 2. The electric double layer capacitor according to claim 1, wherein at least one of the sealing members is provided with an element fixing rod inserted into the center of the capacitor element for holding and fixing the capacitor element. 3. The electric double layer capacitor according to claim 1, wherein at least one of the metal conductive plates is provided with an element fixing rod inserted into the center of the capacitor element to hold and fix the capacitor element. 4. The electric double-layer capacitor according to claim 1, wherein an element fixing bar is provided on one of the upper and lower sealing members, and the element fixing bar extends to the other sealing member and is connected thereto. 5. The electric double-layer capacitor according to claim 1, wherein the element fixing rod has a round rod shape. 6. The electric double-layer capacitor according to claim 1, wherein the element fixing rod has a conical shape. 7. The electric double-layer capacitor according to claim 1, wherein the element fixing rod is partially round and then conically widens. 8. The electric double-layer capacitor according to claim 1, wherein the element fixing rod has a round bar shape and a horizontal bar for supporting the capacitor element is provided on the way.