JPH11251190A - Electric double layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve reliability to vibration by putting a winding core in a metallic case together with a winding element body without being separated from a winding element body and fixing directly or indirectly an end part of a winding core to at least one of a bottom or a sealing lid body of a metallic case or a side of a metallic case. SOLUTION: In an electric double layer capacitor, a winding element body 50 wherein band-like electrode bodies 25, 25' wherein positive electrode layers 22, 22' are formed in both sides of one metallic current collector 20 and negative electrode layers 24, 24' are formed in both sides of another metallic current collector 20 are wound on a hollow or solid winding core 40 with band-like separators 30, 30' between is contained in a bottomed tubular metallic case 60 and an opening part of the metallic case 60 is sealed by a sealing lid body 80 forming electrode terminals 72, 74. A plurality of current collecting leads 52, 52'... and 54, 54'....are dn out of the metallic current collectors 20, 120' in the winding element body 50 and are electrically connected to the electrode terminals 72, 74, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric double layer capacitor including a wound element body, and more particularly, to a structure in which a wound element body can be firmly fixed to a case and a sealing lid, thereby improving reliability against vibration. Large-capacity electric double layer capacitor.

[0002]

2. Description of the Related Art Recently, attention has been paid to large-capacity, high-output electric double-layer capacitors intended for application to driving power supplies for vehicles and the like, and their development has been promoted.

Conventionally, as one configuration of a large-sized electric double layer capacitor suitable for such a large current discharge application, Japanese Patent Application Laid-Open Nos. 4-154106, 7-307250, and
As described in JP-A-8-45795 and the like, those having a cylindrical structure are known. This is, as shown in FIG. 1, a pair of strip-shaped electrode bodies, specifically, a strip-shaped positive electrode body 2 in which electrode layers mainly composed of activated carbon are formed on both surfaces of a metal current collector, and a negative electrode electrode. A body 3 and a band-shaped separator 4;
The current collector drawn out from the positive electrode body 2 and the negative electrode body 3 after accommodating the wound element body wound via 4 ′ in a bottomed cylindrical metal case 5 and impregnating with an electrolytic solution. The leads 6, 6 'are connected to the electrode terminals 9, 9' provided on the electrically insulating sealing lid 8, respectively, and the sealing lid is fitted to a metal case.

[0004]

An electric double layer capacitor as a driving power supply for a vehicle is, like a battery for a vehicle, capable of withstanding at least steady vibrations and shocks. It is considered that there is a need for durability that does not cause abnormalities even when subjected to vibrations or the like in the placed state. Of course, it should not cause the electrolyte to leak due to vibration or impact.

[0005] However, when the present inventors conducted a vibration test on such a cylindrical capacitor using a vibration tester, the structure disclosed in FIG.
The wound element body easily swings or rotates inside the capacitor case. For this reason, the current collecting lead pulled out from the oscillating winding element body is twisted or pulled between the electrode terminal fixed to the sealing lid,
It has been found that the connection can be broken. In particular, in order to obtain a large-capacity element, in the case of a wound element body having a large winding diameter wound many times, the number of current collection leads to be drawn is large,
It is difficult to mechanically and equally connect all the leads from the inside to the outside with the electrode terminals. Moreover, the larger the diameter of the rotating element body, for example, the larger the amount of displacement on the outside thereof, the more the current collecting lead located on the outside is more susceptible to external force, and the higher the possibility that the connection is broken. I found it.

An object of the present invention is to solve such a problem and to provide a large-capacity electric double layer capacitor in which a wound element body can be firmly fixed in a case and reliability against vibration is improved. I do.

[0007]

According to the present invention, positive and negative electrode strips each having an electrode layer formed on both surfaces of a metal current collector are hollow or solid through a strip separator. A wound element body wound around a winding core is housed in a bottomed cylindrical metal case, and the opening of the metal case is sealed with a sealing lid, and each of the positive electrode terminal and the negative electrode terminal At least one is taken out through the sealing lid, and the end of the core is fixed to at least one of the bottom surface of the metal case, the sealing lid, or the side of the metal case. An electric double layer capacitor is provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows a preferred embodiment of the present invention. That is, the positive electrode layers 22 and 22 'are formed on both surfaces of one metal current collector 20, and the negative electrode layers 24 and 24' are formed on both surfaces of another metal current collector 20 '. , 25 ′ are wound around a hollow or solid winding core 40 via band-shaped separators 30, 30 ′, and a wound element body 50 is housed in a bottomed cylindrical metal case 60, The opening of the metal case 60 is connected to the electrode terminals 72 and 7.
4 is an electric double-layer capacitor sealed by a sealing lid body 80 on which is formed. Note that a plurality of current collecting leads 52, 52 ', 52 ",..., 54, and 5 are respectively provided from the metal current collectors 20 and 20' in the wound element body 50.
4 ', 54 ",... Are drawn out and electrically connected to the electrode terminals 72 and 74, respectively.

A feature of the present invention is that, in such an electric double layer capacitor, the winding core 40 is not separated from the wound element body and is attached to the metal case 60 together with the wound element body 50. And the ends 41 and 43 of the winding core are directly or indirectly fixed to at least one of the bottom surface 61, the sealing lid 80, or the side surface 63 of the metal case. It is in the point.

As the material of the hollow or solid core used in the present invention, a material having corrosion resistance to an electrolytic solution and having high mechanical strength is preferable. For example, polyethylene, polypropylene, urea resin, phenol resin, polyacetal, poly (meth) acrylic, nylon resin, polyimide, polyurethane, fluorine resin (for example, polytetrafluoroethylene,
Hexafluoropropylene copolymer, polyvinylidene fluoride
), Polyetheretherketone, polyethersulfone, resins such as polyparaphenylene sulfide may be used, but metals such as aluminum, aluminum alloy, cast iron, stainless steel, copper, nickel, titanium, tantalum, monel, hastelloy, and the like are particularly preferable. Light aluminum is preferred.

Further, as the material of the sealing lid, it is preferable that the material has corrosion resistance to the electrolytic solution and has high mechanical strength, like the core. An insulating resin may be used like the winding core, but a metal such as aluminum is also preferable. When using metal, it is necessary to insulate the metal case and the lid, or the lid and the electrode terminals.

In the present invention, the winding core housed in the metal case together with the winding element body is fixed to the sealing lid 80 and the case bottom surface 61. Basically, the end of the core is brought into direct contact with the sealing lid, etc., and the contact part is welded and fixed, or a female screw is attached to the surface of the sealing lid and the bottom of the case that faces the end of the core. Once formed, male screws formed at both ends of the winding core can be screwed into the core, or they can be similarly fitted and fixed using fitting holes.

However, the plurality of current collecting leads 52, 52 ',... And 54, 54',. In order to secure the connection, the insulating fixing plates 92 and 94 shown in FIG. 2 and the current collecting disks 96 and 98 shown in FIG.
It is preferable that the fixing be performed via a fixing member such as.

In FIG. 2, using an insulating fixing plate,
An example is shown in which a hollow core is fixed to the sealing lid and the case bottom surface. Here, as the insulating fixing plate, a lower insulating fixing plate 92 installed in contact with the bottom surface of the metal case and an upper insulating fixing plate 94 installed in a space between the sealing lid 80 and the wound element body 50 are appropriately used. Is preferred.

The structure of the insulating fixing plate is substantially the same in the upper part and the lower part, and will be described together. (In the following description, () indicates a portion of the upper fixed plate corresponding to the lower fixed plate.)
Regarding the lower (upper) insulating fixing plate 92 (94), the fixing plate is made of an insulating material such as polyethylene, polypropylene, urea resin, phenol resin, polyacetal, poly (meth) acrylic, nylon resin, polyimide, polyurethane, and the like. Fluorine resin (for example, polytetrafluoroethylene, tetrafluoroethylene, hexafluoropropylene copolymer, polyvinylidene fluoride), polyetheretherketone, polyethersulfone, polyparaphenylene sulfide, etc. It is a molded body, and basically includes a support portion 92a (94a) and a fitting portion 92a.
b (94b).

The support portions 92a (94a) are bonded, welded,
The entire insulating fixing plate is brought into contact with the bottom surface 61 by any means such as fitting.
(Sealing lid body 80), and is a part that provides a base for securely holding and fixing the winding core together with the winding element body. In this case, the supporting portion 92a has its peripheral edge portion 92a 'in contact with the inner surface of the case, and the outer periphery of the case can be narrowed inward in a bead shape slightly below the contact edge portion. By squeezing the contact edge portion through the packing or the gasket in this manner, the position of the wound element body is fixed by the support portion.

The fitting portion 92b (94b) is a portion for receiving and fixing the lower end portion 41 (upper end portion 43) of the winding core, which is located substantially at the center of the insulating fixing plate. The fixing means is not particularly limited. The fitting portion 92b (94b) is formed thick, the lower end (upper end) of the core is brought into contact with the fitting portion, and the contact portion is welded. Or the fitting portion is made to protrude in a rod shape, and a hollow core is used to fit and fix the hollow portion of the winding core. Means such as forming a thread which is screwed to each other in the portion, and screwing and fixing the thread are adopted.

In the case of the configuration shown in FIG. 2, the electrode terminals 72 and 74 protrude from the inner surface of the sealing lid 80 (the surface facing the upper insulating fixing plate), and the entire insulating fixing plate is sealed. Because it is difficult to make the upper insulating fixing plate 94a ′ protrude, for example, at the center, and this protruding portion is fitted (or screwed) into the sealing lid 80, the upper insulating fixing plate is attached. It is preferable to fix to the sealing lid. In order to secure this fixation, the outer edge portion 94a ″ of the support portion 94a is bent as shown in the figure and locked on the case side surface 63, thereby fixing the insulating fixing plate to the sealing lid. It is also preferable to provide an auxiliary.
Further, the tip of the outer edge portion 94a "is in contact with the inner side surface of the case, and the outer periphery of the case can be narrowed inwardly in a bead shape slightly above the case via a packing or the like. Is fixed.

FIG. 2 shows an example in which a male screw is formed at the fitting portion and a female screw is formed at the end of the winding core, and the two are screwed together and fixed. In addition, the support part 92a and the fitting part 92b are
It is not always necessary to form them integrally, and they may be configured separately. In this case, the fitting portion 92b is a rod-shaped element having a thread or the like at both ends, and a screw at one end thereof is screwed with a screw groove of a winding core, and a screw at the other end is formed as a support portion 92a.
It will be obvious that it may be screwed with the thread groove.

In FIG. 2, a plurality of positive electrode leads 52,
52 ′, 52 ″,... And a plurality of negative electrode leads 54,
54 ', 54 ", ... are drawn out, respectively.
Preferably, the winding phase of the wound body is within 30 degrees,
It is more preferably within 20 degrees, and it is desirable that the current collecting leads of the same pole are extracted with a phase as small as possible. That is, it is preferable that the plurality of current collecting leads be arranged so as to be substantially linearly arranged in the radial direction when viewed from above the wound body.

In the upper insulating fixing plate, for example, as shown in FIG. 4, the portion where the current collecting lead is taken out from the wound element body is cut out as A1 and A2 to form a concave portion. It is preferable that the electric lead is taken out to the upper part through the notch. As described above, it is preferable to provide a protruding portion or the like that can fit into the hollow portion of the core on the surface of the insulating fixing plate facing the core end.

The upper insulating fixing plate may have a current collecting lead lead-out insertion hole having a circular shape, a square shape, a slit shape or the like. The current collecting leads are collected on the insulating fixing plate through the insertion holes. In particular, the shape of this insertion hole may be a shape close to the cross-sectional shape of the lead. In the case of a slit shape, each lead is pulled out while being stably held by the slit. The plurality of leads taken out from the upper portion of the upper insulating fixing plate are overlapped and integrated with each other, and are electrically connected to the electrode terminals by means such as welding. By doing so, much more reliable connection is realized than connecting the current collecting lead taken out of the wound element body directly to the electrode terminal.

After the current collecting lead is connected to the electrode terminal, an electrolytic solution is supplied into the metal case, and the upper end portion 82 of the side surface of the metal case is closed with a sealing lid, and then the sealing lid is closed. To form an electric double layer capacitor.

FIG. 3 shows another preferred embodiment of the present invention.

The electrode terminal 72 is formed on the sealing lid 80 in the same manner as in FIG. 2, but the other electrode terminal 74 is formed on the bottom surface 61 of the metal case 60. different. In addition, without forming the electrode terminal on the bottom,
The entire bottom surface may have the function of an electrode terminal.

Therefore, the metal current collector 2 in the wound element body 50
0, 20 ′, a plurality of current collecting leads 52, 5
2 ′, 52 ″,... And 54, 54 ′, 54 ″,
Are drawn out, but the positive electrode current collecting leads 52, 5
Are pulled out from the upper part of the wound element body and electrically connected to the upper positive electrode terminal 72, while the negative leads 54, 54 ', 54 ",. It is pulled out from the lower part of the wound element body and is electrically connected to the lower negative electrode terminal 74.

In such an electrode configuration as shown in FIG. 3, since the electrode terminals are symmetrically located at the upper and lower portions, respectively, two current collecting disks (lower current collecting disk 9) are provided.
6 and the upper current collecting disk 98) are arranged, and the current collecting leads are collectively and electrically connected to the current collecting disk. In this case, if the current collecting lead is crushed in the direction perpendicular to the axis of the winding core and is brought into contact with the current collecting disk, the contact area between the disk and the lead increases and the contact resistance may decrease. It is preferable. In addition, by maintaining the current collecting disk and the current collecting lead by spot welding or full-surface welding, or by fixing with a conductive adhesive, even if the capacitor is subjected to vibration, swing, or tilt, the increased contact area is maintained. Can be. The two current collection disks are
It may be configured in a substantially similar manner.

The material of the current collecting disk may be the same as the current collector forming material, and for example, aluminum, aluminum alloy, cast iron, stainless steel, copper, nickel, titanium, tantalum, monel, hastelloy, etc. are preferably used. . Although the shape of the current collecting disk is not particularly limited, for example, a disk-shaped foil or the like is suitable.

Since the upper and lower current collecting disks are almost the same, they will be described together. (In the following description, () indicates the portion of the upper current collecting disk corresponding to the lower current collecting disk.) . Except for the current collecting function, the current collecting disk has the same shape as the insulating fixing plate described in FIG. 2 and is the same in the function of holding and fixing the winding core. An analogy can be applied, and a brief description will be given to avoid inconvenience.

Lower (upper) current collecting disk 96 (98)
Is basically composed of a support portion 96a (98a) and a fitting portion 96b.
(98b). Support part 96a (9
8a) is a supporting portion 92a of the lower insulating fixing plate shown in FIG.
In the same manner as described above, the lower (upper) current collecting disk 96 (
98) The entirety is securely fixed to the bottom surface 61 or to the electrode terminal 74 (72) provided on the sealing cover (80) provided on the bottom surface, and the winding core is securely fixed together with the wound element body. Holding and fixing, the fitting portion 96b (98b) receives and fixes the lower end 41 (upper end 43) of the winding core. As the fixing means, the same means as the insulating fixing plate of FIG. 2 can be adopted. When a metal core is used, the lower end of the core is fixed in a state of being electrically connected to the bottom of the metal case via the lower current collecting disk.

It is also possible to process the lower current collecting disc into a disk shape whose outer diameter is slightly smaller than the inner diameter of the side face near the bottom of the case, and fit and fix it with almost no gap in the case. is there. At this time, if the knurls are formed on the outer periphery of the disk in a direction parallel to the center line of the disk, the current collecting disc can be more easily fixed to the inner surface of the case.

The shape of the current collecting disk is basically a disk shape, but it is not a simple disk, and in some cases, it is preferable to form holes or cutouts in the disk.
The number of notches is arbitrary, for example, two, three, four,
... and can be selected according to the purpose. For example,
If three notches are provided, a Y-shaped current collecting disk
If provided, it becomes a cross-shaped current collecting disk.

As will be described later, when assembling the capacitor of the present invention, for example, the wound element body is housed in a metal case, sealed with a sealing lid, and then the electrolyte is poured from a liquid inlet provided in the sealing lid. An operation of injecting and impregnating the element body is performed. By using a current collecting disk having the above-described shape, high liquid injection property (sufficient liquid injection and a shortened liquid injection time) can be secured. That is, the electrolytic solution injected from the liquid inlet is distributed to the entire current collecting disk, and quickly flows downward from each cutout portion of the Y-shaped or cross-shaped current collecting disk, so that the wound element body From the upper end face and the lower end face, it passes through the gap between the electrodes constituting the strip-shaped electrode body, penetrates into the inside of the element body, and the entire element body is immediately impregnated with the electrolytic solution.

In the configuration shown in FIG. 3, upper and lower insulating plates are used to insulate between the wound element body and the current collecting disk. The insulating plate preferably has an insertion hole or a notch as shown in FIG. 4 for drawing out the current collecting lead. However, only one notch is required in the insulating fixing plate.
A plurality of negative electrode current collecting leads 54, 54 ', 54 ",... (Positive electrode current collecting leads 52, 52', 52",...) Stably pulled out from the lower part (upper part) of the wound element. Are taken out through the respective notches and are collectively electrically connected to the current collecting disk by means such as welding or caulking. Since the current collecting disk is electrically connected to the negative electrode (positive electrode) electrode terminal, the electric connection to the electrode terminal is completed by this.

In the configuration shown in FIG. 3, the diameter of the insulating plate is preferably larger than the diameter of the wound element body in order to prevent a short circuit due to the electrode layer, the current collecting lead, etc. coming into contact with the side of the case.

As described above, the upper part of the metal core is electrically connected to the positive electrode element, and the lower part of the core is electrically connected to the negative electrode element and the bottom of the metal case. Therefore, in this case, in order to prevent a short circuit, the winding core is divided into an upper part and a lower part, and both are insulated by a winding core insulating coupler 40a made of an insulating material. It is preferable that the upper part of the winding core and the insulating coupling tool, and the lower part of the winding core and the insulating coupling tool are firmly connected by screws and / or fitting. As the insulating coupler, a high-strength resin excellent in heat resistance is preferable, and for example, a polyimide resin, polyparaphenylene sulfide, or the like is preferable.

Hereinafter, the method of assembling the capacitor of the present invention will be briefly described.

The current collector used in the present invention may be any conductor that is electrochemically and chemically resistant, and may be graphite, corrosion resistant metal, etc., especially non-aqueous (organic solvent). When a solution is used, a metal foil such as aluminum, stainless steel, nickel, and tantalum is used, and an aluminum foil is particularly preferable. In the present invention, the metal current collector made of such a metal foil has a thickness of 10 μm to 0.1 μm.
It is preferably about 5 mm, and the surface is preferably roughened.

An electrode layer is formed on both sides of the metal current collector.
The electrode layer is made of a carbon material having a large specific surface area such as activated carbon powder and polyacene (specific surface area of about 800 to 3500 m ³ / g).
) As a main component, carbon black, carbon whiskers, etc. as conductive substances, and polytetrafluoroethylene, polyvinylidene fluoride, carboxymethyl cellulose, etc. as binders, and in the presence of a liquid lubricant such as alcohol. The sheet is formed by kneading, forming into a sheet by roll rolling or the like, and drying the sheet, and then bonding the sheet to both surfaces of the metal current collector by thermocompression bonding or via a conductive adhesive or the like. The thickness of the electrode layer is not limited, but is usually 10
It is about μm to 0.5 mm.

Instead of kneading, the above binder is mixed with a solvent (water, N-methylpyrrolidone, etc.) to form a slurry, which is applied to both surfaces of the metal current collector and dried to form an electrode layer. May be. Here, as proposed by the present applicants, it is also a preferred embodiment to stretch the dried product of the sheet-like molded product in a uniaxial or multiaxial direction (Japanese Patent Publication No. 7-105306).

A plurality of current collecting leads (52, 52 ', 52 ",... Or 54,
54 ′, 54 ″,...) Are preferably formed in advance. As the current collecting lead, an electrode layer is formed by welding a conductive tab terminal, wire, tape, ribbon, or the like. Although it may be attached to the portion of the metal current collector that does not have, it is more preferable to provide a tape-shaped or ribbon-shaped portion where the electrode layer is not formed on a part of the metal current collector and use this as a current collecting lead When the current collecting lead is attached by welding or the like, it is preferable that the current collecting lead is made of a foil thinner than the metal current collector.

The separator may be a porous separator that transmits ions, and may be a microporous polyethylene film, a microporous polypropylene film, a polyethylene nonwoven fabric, a polypropylene nonwoven fabric, a glass fiber mixed nonwoven fabric,
Glass mat filters, cellulose-based nonwoven fabrics, rayon-based nonwoven fabrics and the like can be suitably used.

The winding core 40 used in the present invention includes:
A slit 45 as shown in FIG. 5 is formed, and an end of the band-shaped separator 30 or the like is inserted and fixed in the slit, or the end of the separator is fixed to the surface of the winding core by directly bonding or the like. preferable. By doing this,
The winding core and the winding element body are integrated, and the winding element body is prevented from idling around the winding core.

When a metal winding core is used, winding is performed so that the separator is arranged on the innermost periphery of the winding element body.
Further, it is preferable to form a wound element body by winding a band-shaped electrode body through the separator so that the separator is also arranged on the outermost periphery of the wound element body.

On the other hand, according to the configuration of the electrodes shown in FIGS. 2 and 3, a lower insulating fixing plate and a lower current collecting disk are previously installed in the metal case, and electrode terminals are provided on the bottom surface of the metal case. It is preferable to attach it. If the lower insulating fixing plate or the like is to be fixed by screwing or the like, a screw is provided, and a screw thread to be screwed is formed in the winding core.

The material of the metal case is not particularly limited, but may be aluminum, aluminum alloy, cast iron, stainless steel, copper, nickel, titanium, tantalum,
Metals such as Monel and Hastelloy are preferred, and particularly lightweight aluminum is preferred.

On the other hand, it is preferable to attach an electrode terminal to the sealing lid in advance.

In such a state, the winding element body is housed in a capacitor metal case together with the winding core, and the lower end of the winding core is fixed to a lower insulating fixing plate or a lower current collecting disk previously installed at the bottom of the case. Let me do it.
Thus, the wound element body is fixed in the metal case.

Subsequently, a plurality of current collecting leads drawn out from the wound element body are drawn out from the insertion holes or cutouts of the upper insulating fixing plate, and are formed into one current collecting lead by caulking or welding. It is electrically connected to the electrode terminals installed on the lid by welding or the like.

Finally, an electrolytic solution is supplied into the case, the electrodes are immersed in the electrolytic solution, the upper end of the metal case is swaged with a sealing lid, and the capacitor is sealed to form an electric double layer capacitor. When caulking, silicon rubber, butyl rubber, ethylene / propylene rubber,
It is preferable to use a gasket made of an insulator such as polypropylene.

Here, the supply of the electrolytic solution may be performed from a liquid inlet of a sealing lid (not shown) after sealing.

In the case of the electrode configuration as shown in FIG. 3, the connection of the electrode lead (in this case, the negative electrode lead) drawn out from the lower part of the wound element body to the lower current collecting disk is performed first.
Thereafter, it is preferable that the core is housed in a metal case and the winding core is fixed.

The electrolytic solution to be used may be a known one. Examples of the aqueous solution include aqueous solutions of sulfuric acid, sodium sulfate, sodium hydroxide, potassium hydroxide, ammonium hydroxide, potassium chloride, and the like. Potassium carbonate aqueous solution and the like can be mentioned.

Examples of the organic solvent-based compounds include compounds represented by the general formulas R ¹ R ² R ³ R ⁴ N ⁺ and R ¹ R ² R ³ R ⁴ P ⁺ (where R ¹ , R ² , R ³ , R ^{3 4} represents an alkyl group having about 1 to 6 carbon atoms which may be the same or different.), Such as a BF ₄ salt, a ClO ₄ salt or a PF ₆ salt such as a quaternary ammonium ion or a quaternary phosphonium ion; And
LiBF ₄ , LiClO ₄ , NaPF ₆ or LiP
Salts such as F _6, propylene carbonate, ethylene carbonate, .gamma.-butyrolactone, acetonitrile, dimethylformamide, sulfolane, 1,2-dimethoxyethane, nitromethane, dimethyl carbonate, diethyl carbonate, diethyl methyl carbonate, one or more such as dimethyl ethyl carbonate Are preferred.

[0056]

[Example 1]

(Assembly of the wound element body) The electrode element configuration shown in FIG. 2 was used.

Length 2500 mm, width 150 mm, thickness 5
Using 0 μm aluminum foil as a metal current collector,
In the part of this both sides 2500mm in length and 100mm in width,
Activated carbon powder 80% by weight, carbon black 10% by weight,
A slurry containing N-methylpyrrolidone containing a solid content and kneaded with 10% by weight of PTFE as a binder was applied and dried to form electrode layers of 100 μm each. From the uncoated part (length 2500mm, width 50mm), about 15
Current collecting leads having a width of 12 mm and a length of 50 mm were formed at 16 points at intervals of 0 mm to obtain strip-like positive and negative electrode bodies.

As a winding core, a diameter of 10 mm and a length of 110
A screw groove was formed on the inner surface of both ends of an aluminum tube of mm.

As the separator, two nonwoven fabrics made of polypropylene having a length of 2700 mm and a width of 110 mm were used, and had a layer structure of positive electrode body / separator / negative electrode body / separator.
Winding around the core of aluminum tube, diameter 4
A wound element body of 5 mm was obtained.

(Accommodation and attachment of the wound element body) The container has a diameter of 51 mm, a height of 130 mm, and a thickness of 0.8 m.
m cylindrical aluminum can, and a polyimide disc (2 mm thick,
(Diameter: 49 mm). This central part is 10m in diameter
m and a height of 15 mm, and a screw was formed in this protrusion.

The wound element body was housed in an aluminum can, and the screw of the bottom insulating fixing plate was screwed into an aluminum tube at the center of the wound element body and screwed.

As the sealing lid, a phenol resin disk having a diameter of 49 mm and a thickness of 5 mm, having a positive electrode terminal and a negative electrode terminal insert-molded therein and having a liquid injection hole (liquid injection port), was used.

As an upper insulating fixing plate, a polyimide disk (thickness: 2 m) in which the central portions of both surfaces are projected to a diameter of 10 mm and a height of 15 mm, and a screw is formed in the projected portion.
m, diameter 49 mm). On this surface, two notches are formed as shown in FIG. Sixteen positive current collecting leads and sixteen negative current collecting leads from the wound element body were pulled out through different notches A1 and A2, respectively, and further fixed to the respective electrode terminals by welding.

The end of the sealing lid and the opening of the aluminum case were caulked and sealed, and a 2 molar concentration of propylene carbonate solution of triethylmonomethylammonium tetrafluoroborate was injected from the injection port to impregnate the wound element body. And further sealed to obtain a cylindrical capacitor.

(Vibration test) Discharge capacity of this capacitor
Table 1 shows the average discharge output obtained from the average discharge voltage between 1 V at a constant current of 200 A after charging at 2.5 V and 2.5 A.

Next, a capacitor was attached to the vibration tester, and vibration was applied for 1 hour while changing the vibration cycle (reciprocal fluctuation between 13 Hz and 30 Hz for 5 minutes) at a vibration acceleration of 3 G (X, Y, Z directions). No leakage of the electrolyte was observed.

Table 1 shows the discharge capacity of the capacitor after the vibration test and the average discharge output obtained from the average discharge voltage between 1 V at a constant current of 200 A after charging at 2.5 V. It showed the same performance.

As a precautionary measure, the inside of the capacitor was examined by removing the sealing portion by caulking. However, the winding core was still fixed to the upper and lower insulating fixing plates, and the wound element body also maintained the sealed state. It was found that all the current collecting leads were kept fixed to the electrode terminals.

[0070]

[Table 1]

[Comparative Example 1] (Assembly of a wound element body)
The same experiment as in Example 1 was performed except that a wound element body was obtained using an aluminum tube having a length of 110 mm and a length of 110 mm, and the core was removed and housed in a cylindrical aluminum can.

(Vibration test) Table 1 shows the results of measuring the discharge capacity and average discharge output of this capacitor before and after the vibration test in the same manner as in Example 1.

Although no electrolyte leakage was observed, the discharge capacity and the average discharge output after the vibration test were considerably reduced.
When the inside of the capacitor was inspected by removing the sealing part by caulking, the wound element body was pressed against the bottom of the case in a twisted state, and several current collecting leads were pulled by the wound element body and came off the electrode terminals. I understood that.

[Example 2] (Assembly of wound element body) The same test as in Example 1 was conducted except that the electrode element configuration shown in Fig. 3 was used. However, the following points were changed in accordance with the element configuration.

In the layer structure of the positive electrode body / separator / negative electrode body / separator, the current collecting lead of the positive electrode body is drawn out from the upper part of the wound element body, and the current collecting lead of the negative electrode body is drawn out from the lower part. Wound.

In place of the lower insulating fixing plate, a thickness of 2 m
m aluminum disk (diameter 49 mm) was used as the lower current collecting disk. The current collecting disk and the aluminum winding core are screwed and fixed using aluminum screws,
Further, the current collecting disk was screwed and fixed to the negative electrode terminal with screws and electrically connected. The negative electrode current collecting lead was welded to the lower current collecting disk.

The upper and lower insulating plates were slightly larger in diameter and were press-fitted into an aluminum case and fixed to the side surfaces thereof. Further, one notch was formed in each of the insulating plates, and the current collecting leads were drawn out through the cutouts. As shown in FIG. 3, the winding core was joined by screwing two aluminum tubes each having a diameter of 10 mm and a length of 50 mm with a polyimide insulating connector as shown in FIG. One used.

As the upper current collecting disk, a disk having the same shape as that of the lower current collecting disk was used. The center of the disk was similarly connected and fixed to the positive electrode terminal, and the positive current collecting lead was welded to the upper current collecting disk.

(Vibration test) Table 1 shows the results of measuring the discharge capacity and the average discharge output of this capacitor before and after the vibration test in the same manner as in Example 1.

As a precautionary measure, the inside of the capacitor was inspected by removing the sealing portion by caulking. However, the winding core was fixed to the upper and lower current collecting disks, and the wound element body maintained the sealed state. It was found that all the current collecting leads were kept fixed to the electrode terminals.

[Comparative Example 2] (Assembling of the wound element body)
The same experiment as in Example 2 was performed except that a wound element body was obtained using an aluminum tube having a length of 120 mm and a length of 120 mm, and the core was removed and housed in a cylindrical aluminum can.

(Vibration Test) Table 1 shows the results of measuring the discharge capacity and the average discharge output of this capacitor before and after the vibration test in the same manner as in Example 2.

Although no leakage of the electrolyte was observed, the discharge capacity and the average discharge output after the vibration test were considerably reduced.
When the inside of the capacitor was examined by removing the sealing part by caulking, the wound element body was pressed against the side of the case in a twisted state, and several of the positive current collecting lead and the negative current collecting lead were pulled by the wound element body. As a result, it was found that the current collecting lead was cut at the root portion near the wound element body, and that some of the current collecting leads were separated from the current collecting disk.

[0084]

According to the present invention, by utilizing the winding core, the wound element body can be firmly fixed to the metal case and the sealing lid, and the reliability of the capacitor against vibration and shock can be improved. Greatly improved.

Further, by using the current collecting disk, the resistance relating to the current collecting can be reduced, and a large current can flow.

Furthermore, according to the present invention, the efficiency of housing the wound element body in the cylindrical container can be increased, and the volume density can be increased.

That is, according to the present invention, a large-capacity, high-output, and suitable power supply for driving an electric vehicle or the like is provided.
An electric double layer capacitor resistant to vibration and shock is provided.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a conventional cylindrical electric double layer capacitor.

FIG. 2 is a sectional view of a cylindrical electric double layer capacitor according to the present invention.

FIG. 3 is a sectional view of a cylindrical electric double layer capacitor according to the present invention.

FIG. 4 is a plan view showing a cutout formed in an insulating fixing plate or the like;

FIG. 5 is a perspective view showing a slit of a winding core.

[Explanation of symbols]

 20, 20 'Metal current collector 22, 22' Positive electrode layer 24, 24 'Negative electrode layer 25, 25' Electrode body 30, 30 'Separator 40 Core 40a Insulating connector 41 Core lower end 43 Core upper end Part 45 Slit 50 Winding element body 52, 52 ', 52 "Current collecting lead 54, 54', 54" Current collecting lead 60 Metal case 61 Metal case bottom 63 Metal case side 72 Positive electrode terminal 74 Negative electrode terminal 80 Sealing lid Body 81 aperture 82 part to be swaged 92 lower insulating fixing plate 92a its supporting part 92a 'its peripheral part 92b its fitting part 93 lower insulating plate 94 upper insulating fixing plate 94a its supporting part 94b its fitting part 94a' of supporting part 94a Center protrusion 94a "Outer edge of support portion 94a 95 Upper insulating plate 96 Lower current collecting disk 96a Support portion 96b Fitting part 98 Upper collecting disk 98a Support part 98b Fitting part A1, A2 Notch formed in insulating fixed plate etc.

Continuing on the front page (72) Inventor Ken Ken Kawari 1150 Hazawacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Inside Asahi Glass Co., Ltd. (72) Inventor Tomonori Aoki 1-1 1-1 Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Asahi Glass Co., Ltd. 72) Inventor Makoto Inoue 1-1, Suehirocho, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Asahi Glass Co., Ltd. (72) Inventor Yoshihiro Hozumi 1150 Hazawacho, Kanagawa-ku, Yokohama-shi, Kanagawa Prefecture Asahi Glass Co., Ltd.

Claims (6)

[Claims] 1. A winding in which a strip-shaped electrode body of a positive electrode and a strip-shaped negative electrode obtained by forming electrode layers on both surfaces of a metal current collector is wound around a hollow or solid core through a strip-shaped separator. The element body is housed in a bottomed cylindrical metal case, and the opening of the metal case is sealed with a sealing lid, and at least one of the positive electrode and the negative electrode terminals is the sealing lid. And an end portion of the winding core is fixed to at least one of a bottom surface of the metal case, a sealing lid, or a side surface of the metal case. . 2. The capacitor according to claim 1, wherein the winding core is made of a metal, and the separator is in contact with the winding core at the innermost periphery of the wound element body. 3. The capacitor according to claim 1, wherein the end of the winding core is fixed to the bottom surface of the metal case, the sealing lid, and / or the side surface of the metal case via a fixing member. 4. A plurality of current collecting leads are drawn from the wound element body and connected to the electrode terminals or a current collecting disk electrically connected to the electrode terminals by caulking and / or welding. The capacitor according to any one of claims 1 to 3. 5. The capacitor according to claim 1, wherein a plurality of current collecting leads formed of a part of the metal current collector are drawn from the wound element body. 6. An electrode terminal is attached to a sealing lid, the other electrode terminal is formed on a bottom surface of a metal case, and a core made of metal is separated into an upper part and a lower part. The capacitor according to any one of claims 1 to 5, wherein the upper and lower parts are insulated from each other by an insulating connector.