JP2000243670A - Electrical double-layer capacitor and manufacture of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrical double-layer capacitor that has improved reliability with respect to vibration. SOLUTION: This capacitor is composed of a coiling member 1 that is formed by coiling a pair of electrodes, with a separator interposed between such electrodes, structured by forming a polarizable electrode layer consisting of mixture of activated carbon, a binding agent and conductive agent to form the exposed portions 2a, 2b of the current collecting material that is formed of a metal foil or conductive polymer, current collecting members 5a, 5b joined to the exposed portions 2a, 2b of at least one current collecting material at the end face of the coiling member 1 and a cylindrical metal case 7 to accommodate the coiling member 1 with the electrolyte. The inner circumferential surface of the metal case 7 of a squeezed process part 7a is placed in contact with the external circumference surface of the coiling member 1, by providing the annular squeezed process part 7a to the external circumference surface of the metal case 7. Thereby, the strength with respect to vibration can be improved extensively.

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 used for various electronic devices and a method for manufacturing the same.

[0002]

2. Description of the Related Art A conventional electric double layer capacitor of this type will be described with reference to FIGS.

FIG. 6 is an exploded perspective view showing the structure of a winding member constituting an electric double layer capacitor. In FIG. 6, reference numerals 3a and 3b denote a pair of electrodes.
a and 3b are each made of a mixture of activated carbon, a binder and a conductive agent such that exposed portions 2a and 2b of the current collector are formed on a current collector made of a metal foil or a conductive polymer, respectively. This is one in which a polar electrode layer is formed. Reference numeral 4 denotes a separator, which is wound between the pair of electrodes 3a and 3b to form a winding member 1.

FIG. 7 is a sectional view showing the structure of a conventional electric double-layer capacitor using the winding member 1. In FIG. 7, reference numerals 5a and 5b denote external connection terminals 6a and 6b, respectively. A current collecting member joined to the winding member 1 so as to be electrically connected to the exposed portions 2a and 2b of the current collector of the winding member 1, and a bottomed cylinder 20 for housing the winding member 1 A metal case, 8 is a sealing member, 9a and 9b are nuts, 10a and 10b are O-rings, and 11 is an O-ring for sealing.

As described above, in the conventional electric double layer capacitor, the winding member 1 is fixed to the metal case 20 by the nuts 9a and 9b via the current collecting members 5a and 5b joined to the winding member 1.
It was configured to be fixed inside.

[0006]

However, in the structure of the conventional electric double layer capacitor, the winding member 1 in the metal case 20 is fixed to the current collecting members 5a and 5b joined to the winding member 1. Since only the nuts 9a and 9b are tightened to the external connection terminals 6a and 6b, respectively, when a large vibration is applied to the electric double layer capacitor, the outer peripheral surface of the winding member 1 and the metal case Since there is a gap between the winding member 1 and the inner peripheral surface of the winding member 20, vibration is applied to the winding member 1, and as a result, the connection between the exposed portions 2a and 2b of the current collector of the winding member 1 and the current collecting members 5a and 5b In the worst case, the winding member 1 and the current collecting members 5a, 5
There is also a problem that the joint with b may be detached, and it is difficult to sufficiently guarantee the vibration resistance.

The present invention solves such a conventional problem,
An object of the present invention is to provide an electric double layer capacitor excellent in vibration resistance and a method for manufacturing the same.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, an annular drawing is performed on an outer peripheral surface of a metal case accommodating a winding member, and the inner peripheral surface of the drawn forming portion is wound. It comes into contact with the outer peripheral surface of the member.

According to the present invention, the winding member in the metal case can be fixed not only at both ends of the winding member but also at the outer peripheral surface, so that the strength against vibration can be greatly improved. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION According to the first aspect of the present invention, activated carbon and a binder are used so that an exposed portion of a current collector is formed on a current collector made of a metal foil or a conductive polymer. And a winding member formed by winding a pair of electrodes formed of a mixture of a conductive agent and a polarizable electrode layer with a separator interposed therebetween, and at least one of the end faces of the winding member A current collecting member joined to the exposed portion of the current collector on the surface, a cylindrical metal case for storing the winding member together with the electrolytic solution, and a sealing member for sealing an opening of the metal case; By applying an annular drawing process to the outer peripheral surface of the metal case, the inner peripheral surface of the metal case in the drawn portion comes into contact with the outer peripheral surface of the winding member. The turning member has no degree of freedom inside the metal case Therefore, the strength of the electric double-layer capacitor can be improved due to the displacement of the exposed portion of the current collector on the end face of the winding member and the current collecting member, or the disconnection of the current collecting member. Internal resistance rise,
Short circuit and open circuit can be prevented. Further, for example, when the electric double layer capacitor is used as a bank densely arranged in series and parallel, if the bank of the electric double layer capacitor is repeatedly charged and discharged with a current of several tens of A or more, the inside of the electric double layer capacitor becomes However, in the present invention, since the inner peripheral surface of the metal case is in direct contact with the outer peripheral surface of the winding member, an effect of obtaining a large heat radiation effect to the outside is obtained.

According to a second aspect of the present invention, in the first aspect of the present invention, a current collector is provided on a surface of the winding member on the side where the current collecting member is not joined, using a bottomed cylindrical metal case. According to this configuration, the exposed portion of the current collector on the end surface of the winding member is directly connected to the inner bottom surface of the bottomed cylindrical metal case. Since the connection is made, the number of parts is reduced, thereby improving productivity and reducing costs by reducing man-hours.
Further, it has an effect that a large heat radiation effect to the outside can be obtained.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the current collecting member is provided with an external connection terminal. Since the external connection terminals are integrated, the number of components is reduced, which has the effect of improving productivity and reducing costs by reducing man-hours.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the current collecting member and the sealing member are integrally formed, and according to this configuration, the number of parts is reduced. It is possible to reduce the number of processes, thereby improving productivity and reducing costs by reducing the number of steps. Further, since the dead space inside the metal case is reduced, it is possible to increase the capacity density. In addition, since both the upper surface and the bottom surface of the exposed portion of the current collector on the end surface of the winding member are in contact with the metal directly in contact with the outside, a large heat radiation effect can be obtained.

According to a fifth aspect of the present invention, in the invention of the fourth aspect, the outer peripheral portion of the current collecting member integrated with the sealing member is curled at the same time as the open end of the metal case. The configuration is such that the opening is sealed. According to this configuration, the number of components can be reduced, thereby improving productivity and reducing costs by reducing man-hours. In addition, since the dead space inside the metal case is reduced, a higher capacity density can be achieved. In addition, since both the upper surface and the bottom surface of the exposed portion of the current collector on the end surface of the winding member are in contact with the metal directly in contact with the outside, a large heat radiation effect can be obtained.

According to a sixth aspect of the present invention, in the method for manufacturing an electric double layer capacitor according to any one of the first to fifth aspects, the annular drawing process performed on the outer peripheral surface of the metal case is performed by winding. The winding member is inserted into the metal case, and is performed before or after sealing the opening of the metal case. According to this manufacturing method, the diameter of the winding member is reduced. The inner peripheral surface of the metal case can reliably and strongly contact the outer peripheral surface of the winding member regardless of the variation.
In addition, if the annular drawing process performed on the outer peripheral surface of the metal case is performed before the winding member is inserted into the metal case and the opening of the metal case is sealed, the centering of the winding member is performed. This has the effect that it can be performed reliably and easily.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG.

(Embodiment 1) FIG. 1 is a sectional view showing a configuration of an electric double layer capacitor according to a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a winding member. The member 1 is the same as the winding member 1 described with reference to FIG. 5 in the section of the related art, and a detailed description thereof will be omitted.

Reference numerals 5a and 5b denote external connection terminals 6a and 6b, respectively.
b, the exposed portions 2a and 2 of the current collector of the winding member 1 are provided.
b, a current collecting member joined to the winding member 1 so as to be electrically connected to the metal member 7; a cylindrical metal case 7 for storing the winding member 1; and a peripheral surface 7a of the metal case 7 , 8 is a sealing member, 9a and 9b are nuts, 10a and 10b are O-rings, and 11 is an O for sealing.
It is a ring.

As described above, the electric double layer capacitor according to the present embodiment includes the current collecting members 5a,
The winding member 1 is fixed in the metal case 7 by nuts 9a and 9b via the nut 5b, and furthermore, the drawn portion 7a is provided by an annular drawn portion 7a provided on the outer peripheral surface of the metal case 7.
Since the inner peripheral surface of a is configured to be in contact with the outer peripheral surface of the winding member 1, the winding member 1 is fixed so as to have no degree of freedom inside the metal case 7. The strength of the winding member 1 can be greatly improved.
The exposed portions 2a and 2b of the current collector on the end face of the
It is possible to prevent problems such as an increase in the internal resistance of the electric double layer capacitor, a short circuit, and an open circuit due to the displacement or disconnection of 5b. Further, for example, when an electric double layer capacitor is used as a bank densely arranged in series and parallel,
When the bank of the electric double layer capacitor is repeatedly charged and discharged with the current of the above level, heat is generated inside the electric double layer capacitor, but in the present invention, the inner peripheral surface of the metal case 7 is directly connected to the outer peripheral surface of the winding member 1. Because of this, there is also an effect that a large heat radiation effect to the outside can be obtained.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 2 is a sectional view showing the structure of the electric double layer capacitor according to the present embodiment. In this embodiment, the current collecting member of the first embodiment is joined to only one of the winding members. The structure is such that the exposed portion of the current collector of the winding member on the side where the current collecting member is not joined is joined to the inner bottom surface of the metal case, and other configurations are the same as those of the first embodiment. Therefore, the same portions are denoted by the same reference numerals, detailed description thereof will be omitted, and only different portions will be described.

In FIG. 2, reference numeral 1 denotes a winding member, and the exposed portion 2a of one current collector of the winding member 1 has the first
The current collecting member 5a having the external connection terminal 6a is joined and fixed to the metal case 7 in the same manner as in the embodiment, but the exposed portion 2b of the other current collector of the winding member 1 is 7 are directly joined to the inner bottom surface.

Therefore, by adopting such a configuration, the number of parts is reduced, the number of assembling steps is reduced, and the cost can be reduced and the productivity can be improved.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a sectional view showing the structure of an electric double layer capacitor according to the present embodiment. In this embodiment, the current collecting member of the first or second embodiment and an external connection terminal are integrated. The other configuration is the first
Alternatively, since the configuration is the same as that of the second embodiment, the same reference numerals are given to the same portions, detailed description is omitted, and only different portions are described.

In FIG. 3, reference numeral 12 denotes a current collecting member, and the current collecting member 12 has a structure in which an external connection terminal 12a is integrally provided, thereby reducing the number of parts and the number of assembling steps, reducing cost. The productivity can be improved.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a sectional view showing the structure of an electric double layer capacitor according to the present embodiment. In this embodiment, the current collecting member and the sealing member of the first to third embodiments are integrally formed. Since other configurations are the same as those of the first to third embodiments, the same portions are denoted by the same reference numerals, detailed description is omitted, and only different portions will be described.

In FIG. 4, 13 is a current collecting member also serving as a sealing member, 14a and 14b are terminals for external connection, 15 is an insulating member, and the insulating member 15 is provided with the current collecting member 13 also serving as the sealing member. This is necessary to prevent a short circuit due to contact with the metal case 7.

As described above, since the electric double layer capacitor according to the present embodiment uses the current collecting member 13 also serving as the sealing member, the number of parts can be reduced, and thus the productivity can be reduced by reducing the number of steps. Improvement and cost reduction are possible. Further, since the dead space inside the metal case 7 is reduced, it is possible to increase the capacity density. Further, since both the upper surface and the lower surface of the exposed portions 2a and 2b of the current collector on the end surface of the winding member 1 are in contact with the metal directly in contact with the outside, a large heat radiation effect can be obtained.

(Embodiment 5) Hereinafter, a fifth embodiment of the present invention will be described with reference to the drawings.

FIG. 5 is a sectional view showing the structure of an electric double layer capacitor according to the present embodiment. In the present embodiment, the outer peripheral portion of the current collecting member also serving as a sealing member according to the fourth embodiment is made of metal. The configuration is such that the opening of the metal case is sealed by curling at the same time as the opening end of the case, and the other configuration is the same as that of the fourth embodiment. The same reference numerals are given and detailed description is omitted, and only different portions will be described.

In FIG. 5, 16 is a metal case, 16a
Is an annular drawn portion provided on the metal case 16, 17 is a current collecting member also serving as a sealing member, 18 is a metal case side insulating member, 19 is a current collecting member side insulating member, and the metal case side insulating member is shown. 18 and the current-collecting-member-side insulating member 19 are necessary to prevent a short circuit caused by contact between the current-collecting member 17 also serving as a sealing member and the metal case 16.

As described above, in the electric double layer capacitor according to the present embodiment, the outer peripheral portion of the current collecting member 17 integrated with the sealing member is curled at the same time as the open end of the metal case 16, thereby opening the metal case 16. The configuration is such that the parts are sealed, and according to this configuration, the number of parts can be reduced, thereby improving productivity and reducing costs by reducing man-hours. In addition, since the dead space inside the metal case 16 is reduced, it is possible to increase the capacity density. Further, since both the upper surface and the lower surface of the exposed portions 2a and 2b of the current collector on the end surface of the winding member 1 are in contact with the metal directly in contact with the outside, a large heat radiation effect can be obtained.

[0035]

As described above, in the electric double layer capacitor according to the present invention, the outer peripheral surface of the metal case in which the winding member is housed is subjected to the annular drawing process, whereby the inner peripheral portion of the metal case in the drawn portion is processed. Since the surface comes into contact with the outer peripheral surface of the winding member, the winding member is fixed without any degree of freedom inside the metal case, thereby greatly improving the strength against vibration. In addition, it is possible to prevent problems such as an increase in the internal resistance of the electric double layer capacitor, a short circuit, and an open circuit due to a displacement or separation of the current collector from the exposed portion of the current collector on the end face of the winding member.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing a configuration of an electric double layer capacitor according to a second embodiment of the present invention.

FIG. 3 is a sectional view showing a configuration of an electric double layer capacitor according to a third embodiment of the present invention.

FIG. 4 is a sectional view showing a configuration of an electric double layer capacitor according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view showing a configuration of an electric double layer capacitor according to a fifth embodiment of the present invention.

FIG. 6 is an exploded perspective view showing a configuration of a winding member of a conventional electric double layer capacitor including an embodiment of the present invention.

FIG. 7 is a sectional view showing a configuration of a conventional electric double layer capacitor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Winding member 2a, 2b Exposed part of current collector 5a, 5b Current collecting member 6a, 6b Terminal for external connection 7 Metal case 7a Drawing part 8 Sealing member 9a, 9b Nut 10a, 10b O-ring 11 O for sealing Ring 12 Current collecting member 13 Current collecting member 14a, 14b Terminal for external connection 15 Insulating member 16 Metal case 16a Drawing portion 17 Current collecting member 18 Metal case side insulating member 19 Current collecting member side insulating member

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Makoto Fujiwara 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A polarizable electrode layer made of a mixture of activated carbon, a binder and a conductive agent is formed on a current collector made of a metal foil or a conductive polymer so that an exposed portion of the current collector is formed. And a current collector joined to the exposed portion of the current collector on at least one of the end faces of the wound member, the pair of electrodes being wound with a separator interposed therebetween. Member, a cylindrical metal case for accommodating the winding member together with the electrolytic solution, and a sealing member for sealing the opening of the metal case, by subjecting the outer peripheral surface of the metal case to an annular drawing process An electric double layer capacitor in which an inner peripheral surface of a metal case in a drawn portion is in contact with an outer peripheral surface of the wound member. 2. A metal case having a bottomed cylindrical shape, wherein an exposed portion of a current collector on a surface of the winding member on a side to which the current collecting member is not bonded is bonded to an inner bottom surface of the metal case. 3. The electric double layer capacitor according to claim 1. 3. The electric double layer capacitor according to claim 1, wherein an external connection terminal is provided on the current collecting member. 4. The electric double layer capacitor according to claim 1, wherein the current collecting member and the sealing member are integrally formed. 5. The electric device according to claim 4, wherein an opening of the metal case is sealed by curling an outer peripheral portion of the current collecting member integrated with the sealing member simultaneously with an open end of the metal case. Double layer capacitor. 6. An annular drawing process to be performed on the outer peripheral surface of the metal case is performed before or after sealing the opening of the metal case by inserting the winding member into the metal case. The method for manufacturing an electric double layer capacitor according to any one of claims 1 to 5, wherein