JP2002299191A - Electric double-layer capacitor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply an electric double-layer capacitor of high quality at a low cost. SOLUTION: This electric double-layer capacitor is provided with a capacitor body, constituted by alternately laminating the same number of positive electrode bodies and negative electrode bodies and interposing separators in between, and a vessel which accommodates the capacitor body together with electrolyte, and is hermetically shielded. In the electric double-layer capacitor, collector electrodes 21 of the respective positive electrode bodies and negative electrode bodies are formed collectively in unified bodies with rectangular protruding chips being lead parts 21a by punching work of a metal foil 20, and bundling parts 24 where the same poles of the lead parts 21a are overlapped with each other and bonded are formed. In a manufacturing process of the electric double-layer capacitor, a seal 25 is stuck on the metal foil 20 so as to be freely peelable, and burrs or the like, which are generated when the punching work is performed, can be eliminated by sticking them on the seal 25. After a prescribed number of the collector electrodes 21 are combined in a laminated state, a spacer 25a, which can be peeled, is stuck on the metal foil 20 in order to generate a gap corresponding to widths of a pair of polarizable electrodes and the separator, between the respective laminates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric double layer capacitor (electric double layer capacitor) and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, attention has been focused on an application technique of an electric double layer capacitor which can be rapidly charged and has a long charge / discharge cycle life as various power storage devices (e.g., a driving power source for an electric vehicle).

[0003] An electric double layer capacitor is constituted by alternately stacking the same number of positive and negative electrode bodies with a separator interposed therebetween. These laminates (capacitor body)
Is immersed in an electrolytic solution, housed in a container, and sealed (see JP-A-7-94374).

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive electric double layer capacitor and a reasonable manufacturing method thereof based on the prior art of such an electric double layer capacitor.

[0005]

According to a first aspect of the present invention, there is provided a capacitor body formed by alternately stacking the same number of positive and negative electrode bodies with a separator interposed therebetween, and a capacitor body and an electrolytic solution. And a container to be housed and sealed, in the electric double-layer capacitor comprising: the collector electrode of each positive electrode body and the collector electrode of each negative electrode body, by die-cutting metal foil,
The present invention is characterized in that a binding portion is formed integrally with a rectangular projecting piece as a lead portion and overlaps and joins the same poles of these lead portions.

According to a second aspect of the present invention, a capacitor body is formed by alternately stacking the same number of positive and negative electrode bodies with a separator interposed therebetween, and the capacitor body is housed and sealed together with an electrolyte. In an electric double layer capacitor including a container and a pair of terminals that are partially drawn out of the container, the collector electrode of each positive electrode body and the collector electrode of each negative electrode body are formed by cutting a metal foil into a lead. And a connecting portion that is integrally formed with a rectangular protruding piece as a portion and overlaps and joins the same polarity of these lead portions, and a connecting portion that joins a terminal portion having a polarity corresponding to the binding portion. Features.

According to a third aspect of the present invention, a capacitor body is formed by alternately stacking the same number of positive and negative electrode bodies with a separator interposed therebetween, and the capacitor body is housed together with an electrolyte and sealed. And a container, wherein the step of forming the capacitor body includes a step of integrally forming the collectors of the positive electrode body and the negative electrode body together with the lead portion by die cutting from a metal foil, and Assembling the collecting electrodes in a stacked state and joining them in a binding state in which the same poles of the lead portions are overlapped, and a polarizing electrode of the positive electrode body, a polarizing electrode of the negative electrode body, and a separator between the stacked layers of the collecting electrodes. And a step of interposing.

According to a fourth aspect of the present invention, in the method for manufacturing an electric double layer capacitor according to the third aspect of the invention, the metal foil has a seal releasably attached thereto, and burrs and the like generated at the time of die cutting can be removed by attaching to this. It is characterized by having.

According to a fifth aspect of the present invention, in the method for manufacturing an electric double layer capacitor according to the third aspect, when a predetermined number of collector electrodes are assembled in a laminated state, a pair of a polarizable electrode and a separator are interposed between these laminated layers. A sheet-like spacer is releasably attached to a metal foil to generate an interval corresponding to the thickness of the metal foil.

[0010]

According to the first aspect of the present invention, the collector electrode including the lead portion is easily and efficiently formed by stamping a metal foil. A predetermined number of collector electrodes are integrated by a binding portion of these rectangular projections (lead portions). As a result, a predetermined number of collector electrodes and their integration are rationally processed, and the electric double layer capacitor can be supplied at low cost.

According to the second aspect, in addition to the same effects as those of the first aspect, a bonding state (having good electrical conductivity) between the respective rectangular projections (lead portions) and the terminal portions can be obtained accurately.

In the third aspect of the present invention, the collecting electrode is easily and efficiently formed including the lead portion by die cutting from a metal foil. Then, a predetermined number of collector electrodes are integrated by a binding portion of these rectangular projections (lead portions), and a pair of polarizable electrodes and a separator are interposed between these stacked layers. Through these steps, the capacitor body is rationally formed, and the electric double layer capacitor can be supplied at low cost.

In the fourth aspect of the present invention, burrs and the like at the time of die-cutting work adhere to the cut surface of the seal. By removing this, the burrs and the like can be effectively removed. Therefore, in the electric double layer capacitor, problems caused by floating such as burrs (damage to the separator, etc.) are prevented, and a high quality electric double layer capacitor can be supplied at low cost.

According to the fifth aspect of the present invention, when a predetermined number of collector electrodes are assembled in a laminated state by a spacer attached to a metal foil, an interval corresponding to the thickness of a pair of polarizable electrodes and a separator is provided between each of these laminated layers. Since a space is generated, in the same assembled state as that of the capacitor body (a pair of polarizable electrodes and a separator are interposed between the collecting electrodes), the respective lead portions can be joined to these bound states. The length of the lead portion (distance from the connection side with the collecting electrode to the binding portion) that is different depending on the lamination position of the collecting electrode is naturally adjusted by each spacer, so that the joining of the lead portions (integration of a predetermined number of collecting electrodes) ) Can be properly and efficiently processed. In addition, during the composition of the capacitor body, each lead portion is not forced or wrinkled. The collector electrode spacer is peeled off before interposing a pair of polarizable electrodes and a separator between these laminations.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 10 denotes a container for accommodating a capacitor body (not shown) together with an electrolytic solution, and 11 denotes a pair of terminal plates (capacitor electrodes) drawn out of the container 10. The terminal plates 11a and 11b are joined to the corresponding multilayered lead portions of the polarity inside the container 10.

The capacitor body is formed by laminating the same number of positive and negative electrode bodies with a separator interposed therebetween. The collector electrodes of each positive electrode body and each negative electrode body are formed of metal foil (for example, aluminum foil), and activated carbon electrodes (polarizable electrodes) are formed on both surfaces thereof (the metal foils located at both ends of the laminate are one side). You. Lead portions are integrally formed on these collector electrodes, and terminal plates 11a and 11b (for example, aluminum electrodes) are joined to the overlapping portions of these same electrodes.

The capacitor body is immersed in an electrolytic solution,
Set to 0. The container 10 is formed in a bag shape from a resin film (in this example, an aluminum laminate) having a laminated structure including a metal intermediate layer, and a pair of terminal plates 11a and 11b (part thereof) are drawn out from one side thereof. . Container 10
Is sealed by a heat seal in a vacuum state while extracting excess electrolyte by vacuuming.

A welding agent (not shown) for heat sealing is attached to each of the terminal plates 11a and 11b in advance in order to compensate for the fusion with the resin film. A PE (polyethylene) material containing an adhesive is used for this welding agent. Bag 10 (container)
When a heat seal is added to the opening, the welding agent is melted, and the resin film is satisfactorily welded to the terminal plate 11.

FIG. 2 is a view for explaining a manufacturing process (part) of the electric double layer capacitor. In FIG. 2 (a), a predetermined number of metal foils 20 to be laminated are punched out (22 is a punching die). By doing so, the collector electrodes 21 of the positive electrode body and the negative electrode body are formed in the same shape and the same size. Each collector electrode 21 is led to one side of one side of the rectangular plane (rectangular projection).
Are integrally formed. Burrs 23 generated during this die cutting process
Are removed from each collector electrode by an appropriate method.
FIG. 3 is a perspective view for further supplementarily explaining the die cutting process of FIG. 2A, and the same reference numerals are given to the same portions as FIG. Reference numeral 21a denotes a lead portion of the collecting electrode 21.

In FIG. 2B, a positive electrode collector electrode and a negative electrode collector electrode 21 are alternately superposed, and a predetermined number (the same number of positive electrode collector electrodes 21 and negative electrode collector electrodes 21) of the laminates 21 are provided.
A. The laminated body 21A is formed by bonding the overlapping portions of the lead portions 21a of the same polarity in a bound state, and providing a pair of activated carbon electrodes (the polarizable electrode of the positive electrode body and the polarizable Electrode) and separator (1
Sandwiched between a pair of activated carbon electrodes).

Through these steps, the production of the collector electrode 21 and the integration thereof are efficiently processed, the capacitor body is rationally configured, and the electric double layer capacitor can be supplied at a low cost. When an electric double layer capacitor as a product is applied to a drive power source of an electric vehicle, a large number of the electric double layer capacitors are connected in series and parallel to form a battery pack having a required capacity.

The capacitor body has terminal plates 11a and 11b attached to a binding portion 24 (joining portion) of a lead portion 21a of the same polarity.
Are further joined, and are housed in the container 10 which is sealed as described above. The joining of the lead portions 21a and the joining of the binding portions 24 to the terminal plates 11a and 11b are performed by ultrasonic welding and spot welding so as to ensure good conductivity and not to damage the lead portions 21a of the metal foil. , Etc. are used.

FIG. 4 illustrates a process (part) of manufacturing an electric double layer capacitor in another embodiment. 1A, a seal 25 is attached to one surface of a metal foil 20 in an easily peelable adhesive state. By punching this metal foil (with a seal), the collector electrodes 21 of the positive electrode body and the negative electrode body are formed in the same shape and the same size.
A lead portion (rectangular projection) is integrally formed on one side of the rectangular plane toward one side.

The burrs 23 and the like generated during the die cutting process are attached to the cut surfaces of the seals 25. Therefore, by removing these seals 25 from the metal foil after the die-cutting process, it is possible to easily and effectively remove burrs and the like.

Thereafter, in (b), the collector electrodes of the positive electrode body and the collector electrodes 21 of the negative electrode body are alternately overlapped to form a predetermined number of laminates 21A. In the laminated body 21A, the overlapping portions of the lead portions 21a of the same polarity are joined in a binding state, and one set of the activated carbon electrode and the separator is interposed between each lamination of the collecting electrodes 21.

As described above, the seal 25 attached to the metal foil 20
Thereby, burrs and the like at the time of die cutting can be easily and effectively removed. Therefore, in the electric double layer capacitor, troubles (such as damage to the separator) caused by floating such as burrs are also prevented, and a high quality electric double layer capacitor can be supplied at low cost.

The seal 21 affixed to the metal foil 20 is provided with a pair of activated carbon electrodes (a polarizable electrode of a positive electrode body and a pair of activated carbon electrodes) so as to have a spacer function so that the integration of the collecting electrode 21 can be performed accurately and efficiently. The thickness is set to a thickness corresponding to the thickness of the polarizable electrode of the negative electrode body) and the thickness of the separator (between the pair of activated carbon electrodes). In addition, a break is provided in the seal at the boundary between the region of the collector electrode 21 and the region of the lead portion 21a.

The sealing portion of the lead portion 21a is peeled off before the bonding process (b). In (b), when a predetermined number of collecting electrodes 21 are assembled in a laminated state, the sealing portions of these collecting electrodes 21 generate a predetermined space (space) between the respective laminations.

Specifically, as shown in FIG. 5, a predetermined number of collecting electrodes 21 are set in a stacked state using a jig 30. Due to the sealing portion 25a (spacer) of the collecting electrode 21,
Since a space corresponding to the thickness of the pair of polarizable electrodes and the separator is generated between each stack, the capacitor body (1 between each collector electrode).
In the same assembled state as in the case where the pair of polarizable electrodes and the separator are interposed), the respective lead portions 21a can be joined to these bound states by the joining machine 31 (for example, a welding machine).

The length of the lead portion 21a (distance from the connection side to the collecting electrode 21 to the binding portion 24) differs depending on the lamination position of the collecting electrode 21 due to the spacer 25a of each collecting electrode 21.
Is naturally adjusted, so that the leads 21a are not forced or wrinkled during the composition of the capacitor body. The spacer 25a of each collector electrode 21 is peeled off before the composition of the capacitor body (a pair of polarizable electrodes and a separator is interposed between each collector electrode).

By setting such a spacer function in the seal 25 of the metal foil 20, not only the integration of a predetermined number of collector electrodes 21 (joining of the lead portions 21a) but also the composition of the capacitor body is appropriate and appropriate. It can process efficiently. In addition, since the seal 25 can effectively remove burrs and the like, the electric double layer capacitor can be reasonably mass-produced, and a high quality electric double layer capacitor can be supplied at low cost.

Instead of setting the spacer 25a on the seal 25 for removing burrs or the like, these may be attached alone.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view of a manufacturing process.

FIG. 3 is an explanatory diagram of a die cutting process.

FIG. 4 is an explanatory view of a manufacturing process in another embodiment.

FIG. 5 is an explanatory diagram of a process of integrating collector electrodes (joining of lead portions).

[Explanation of symbols]

 Reference Signs List 20 metal foil (for example, aluminum foil) 21 collector 21A laminated body of collector 21a lead 24 binding part (joining) of lead 25 seal 25a spacer

Claims (5)

[Claims] 1. A capacitor body constituted by alternately laminating the same number of positive and negative bodies with a separator interposed therebetween, and a container which is sealed by containing the capacitor body together with an electrolyte. In the electric double-layer capacitor provided, the collector electrode of each positive electrode body and the collector electrode of each negative electrode body are formed integrally with a rectangular protruding piece as a lead part by die-cutting a metal foil. An electric double layer capacitor comprising a binding portion that is overlapped and joined. 2. A capacitor body constituted by alternately laminating the same number of positive and negative electrode bodies with a separator interposed therebetween, a container which houses and seals the capacitor body together with an electrolyte, and a container Part of which is pulled out to the outside 1
In the electric double layer capacitor including a pair of terminal portions, the collector electrode of each positive electrode body and the collector electrode of each negative electrode body are formed integrally with a rectangular projection as a lead portion by die cutting of a metal foil. An electric double layer capacitor, comprising: a binding portion for overlapping and joining the same polarity of the lead portions; and a connection portion for joining a terminal having a polarity corresponding to the binding portion. 3. A capacitor body constituted by alternately laminating the same number of positive and negative electrode bodies with a separator interposed therebetween, and a container containing the capacitor body together with an electrolytic solution and hermetically sealed. In the method for manufacturing an electric double-layer capacitor provided, as a step of forming the capacitor body, a step of integrally forming the collector electrodes of the positive electrode body and the negative electrode body together with the lead portion by die-cutting from a metal foil, and a predetermined number of collector electrodes. Assembling them in a laminated state and joining them in a bound state in which the same poles of these lead portions are overlapped, and interposing a polarizable electrode of a positive electrode body, a polarizable electrode of a negative electrode body, and a separator between each lamination of these collector electrodes And a method for manufacturing an electric double layer capacitor. 4. The electric double layer capacitor according to claim 3, wherein the metal foil has a seal releasably attached thereto, and burrs and the like generated at the time of die cutting are attached to the metal foil so as to be removable. Production method. 5. When a predetermined number of collecting electrodes are assembled in a laminated state, a sheet-like spacer is formed on the metal foil so as to generate an interval corresponding to the thickness of a pair of polarizable electrodes and a separator between these laminated layers. The method for manufacturing an electric double layer capacitor according to claim 3, wherein the electric double layer capacitor is detachably attached.