JP2002280269A - Electrode structure for electric double-layer capacitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge the capacitance of a capacitor unit. SOLUTION: Positive poles and negative poles for the same number are alternately laminated, while interposing a separator between them and while using one part of each of positive poles and each of negative poles as planar rectangular lead parts 10a and 20a, the overlapped parts of the same poles are respectively bonded to short terminal plates 30a and 30b. Then, the respective terminal plates 30a and 30b are drawn from an outer body housing, such laminates together with an electrolyte to the outside, and this outer body is sealed into vacuum state. In such an electric double-layer capacitor, the overlapped parts of the same poles in the lead parts 10a and 20a are divided into two couples and each of overlapped parts of two couples is formed with a cut part 40, so that these overlapped parts can share the portion bonded with the terminal plates 30a and 30b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electrode structure of a capacitor (electric double layer capacitor).

[0002]

2. Description of the Related Art In recent years, attention has been focused on an application technique of an electric double layer capacitor that 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 are immersed in the electrolyte,
Housed in an exterior body (case) (Japanese Patent Laid-Open No. 2000-200)
No. 738).

FIG. 4 illustrates an example of the electrode structure of an electric double layer capacitor.
Is a collector electrode of a negative electrode body, which is formed of an aluminum foil of the same shape and size, and an activated carbon electrode (polarizable electrode) is formed on one side of the rectangular plane. Lead portions 1a and 2a are formed on these electrode plates 1 and 2 so as to approach one side of one side of the rectangular plane.

The lead portions 1a and 2a bundle the same poles, and terminal plates 3a and 3b (capacitor electrodes) are joined to the overlapping portions. For joining with the terminal plates 3a and 3b, lead portions 1a and 2 of aluminum foil are secured while maintaining good electrical conductivity.
Ultrasonic welding, spot welding, etc. are used so as not to damage a. The black circles in the figure represent the welding sites.

[0006]

When the present invention is applied to a drive power source for an electric vehicle, many electric double layer capacitors are connected in series and parallel to form an assembled battery having a required capacity. Since the mounting capacity of the vehicle is limited, it is necessary to increase the capacity of the capacitor alone. Therefore, it is conceivable to increase the number of stacked positive electrode bodies, separators, and negative electrode bodies (the number of capacitor cells) in one capacitor.

As the number of layers increases, the number of layers of the lead portions 1a and 2a naturally increases. However, for ultrasonic welding and spot welding, the lead 1
There is a limit to the number of pieces a and 2a that can be welded, and when the number of pieces exceeds 2a, it is difficult to secure an appropriate joining state.
Therefore, in the conventional electrode structure, the capacity of the single capacitor is limited to the number of weldable layers of the lead portions 1a and 2a.

An object of the present invention is to provide an effective means for solving such a problem.

[0009]

According to a first aspect of the present invention, the same number of positive electrode bodies and negative electrode bodies are alternately laminated with a separator interposed therebetween, and a part of each positive electrode body and each negative electrode body is connected to a lead portion. The overlapping parts of the same pole are joined to the terminal board respectively,
In an electric double-layer capacitor formed by pulling a pair of terminal plates out of an exterior body containing these laminates together with an electrolytic solution and sealing the exterior body in a vacuum state, a lead layer of the same polarity is stacked. Divide the part into multiple sets,
A cut portion is formed in a plurality of overlapping portions so that these portions can be shared with the terminal plate.

According to a second aspect of the present invention, the same number of positive and negative electrodes are alternately stacked with a separator interposed therebetween, and a part of each of the positive and negative electrodes is formed as a flat rectangular lead portion. Each of the overlapping portions is joined to a short terminal plate, and each terminal plate is pulled out from an exterior body containing these laminates together with the electrolytic solution, and the exterior body is sealed in a vacuum state. In the double-layer capacitor, the overlapping portion of the same polarity of the lead portion is divided into two sets,
A cut portion is formed in the overlapping portion of the set so that these portions can be shared with the terminal plate.

According to a third aspect, in the electrode structure of the electric double layer capacitor according to the second aspect, one set of cut portions includes:
Two sides intersecting one corner are cut obliquely from the tip side of the flat rectangular lead portion, and another cut section is formed so as to obliquely cut two sides intersecting the opposite corner. And

According to a fourth aspect of the present invention, in the electrode structure of the electric double layer capacitor according to the second aspect of the present invention, the pair of terminal plates are formed as a cut portion for polarity discrimination from the shorter end to the same plane at the same corner. The part is cut off diagonally.

[0013]

According to the first aspect of the present invention, the overlapping portions of the same polarity of the lead portions are divided into the number of overlapping layers which can obtain a proper joining with the terminal plate, and one terminal plate is provided for each set of overlapping portions. Since the junctions of these layers do not overlap (overlap) with the cuts, each junction with the terminal board is processed efficiently, and the capacity of a single capacitor can be doubled to the number of divisions of the lead Becomes In addition, since the cut portion is set so as to divide the joining portion with respect to the terminal plate, it is not necessary to increase the width of the terminal plate.

In the second invention, the same effect as in the first invention can be obtained by the cut portion. Since the same polarity of the lead portion is divided into two sets, the capacity of the single capacitor can be increased to about twice.

In the third invention, two sets of cut portions provide:
There is also obtained an effect that two sets of multilayer portions can be easily joined to alternate portions on one terminal plate.

According to the fourth aspect of the present invention, when forming a plurality of capacitors into an assembled battery, the polarity of the anode terminal and the cathode terminal of the capacitor can be determined by determining whether the cut portion is rightward or leftward. Will not be mistakenly wired. In addition, the weight and the like of the terminal plate can be reduced by the cut portion for polarity identification.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 illustrate an embodiment of the present invention.
Represents a collector electrode of a negative electrode body. These are formed in the same shape and size by punching a predetermined number of laminated aluminum foils. Activated carbon electrodes (polarizable electrodes) are formed on one side of a rectangular plane of each aluminum foil, and lead portions 10a,
20a is formed integrally with one side of one side of the rectangular plane.

In an electric double layer capacitor as a product, the same number of positive electrodes and negative electrodes are laminated with a separator interposed therebetween, and a part of these electrodes is formed into a flat rectangular lead portion 1.
The same electrodes are joined to short terminal plates 30a and 30b (capacitor electrodes) as 0a and 20a, respectively. After that, these laminates are accommodated in an outer package together with an electrolytic solution, each terminal plate 30a, 30b is pulled out from the outer package, and the outer package is sealed in a vacuum state.

FIG. 2 shows that the lead portions 10a and 20a of the collector electrodes 10 and 20 (the positive electrode body and the negative electrode body) are
This shows the process of bonding to the electrodes 0a and 30b, and the collecting electrodes 10 and 20 are divided into two groups A and B. Lead part 10
a, 20a are also divided into two sets,
A cut portion 40 is formed in the overlapping portion of the set so that these portions can be shared with the terminal plates 30a and 30b.

One set of cut portions 40 obliquely cuts two sides intersecting one corner from the distal ends of the flat rectangular lead portions 10a and 20b, while another set of cut portions 40 is formed at the opposite corner. It is set so that two intersecting sides are cut off diagonally. The punching dies of the collecting electrodes 10 and 20 require two types (corresponding to different directions of the cut portions 40) for the lead portions 10a and 20b of the same polarity. The same collector electrode 20 can be used by reversing the front and back sides.

As shown in FIG. 1, the lead portions 10a and 20a having the same polarity have a multi-layer portion for each pair of the terminal plates 30a and 30a.
30b. Ultrasonic welding, spot welding, or the like is used for joining with the terminal plates 30a, 30b so as not to damage the lead portions 10a, 20a of the aluminum foil.
Number of stacked collector electrodes 10 and 20 per group A and B (that is, number of stacked lead portions 10a and 20a per set)
Is connected to the terminal plate 30 by ultrasonic welding or spot welding.
a, 30b are set within a range in which an accurate joining with 30b can be obtained. The black circles in the figure represent the welding sites.

In this case, a portion (area) that does not overlap (overlap) efficiently occurs between the two sets of multilayer portions (lead portions 10a and 20a having the same polarity) due to the cut portion 40 in the opposite direction. One terminal plate 30a, 30
b, two sets of multilayer portions can be easily and easily joined to alternate portions.

As for the capacity of a single capacitor, if the number of layers per set is set to the maximum (approximately 16 sheets) at which accurate welding with the terminal plates 30a and 30b can be obtained, the current value is 2
It can be increased about twice. By these cut portions 40, it is not necessary to increase the width at the joint portion with the terminal plates 30a and 30b.

When an electric double layer capacitor as a product is applied to a drive power source of an electric vehicle, many electric double layer capacitors are connected in series / parallel to constitute a battery pack having a required capacity. By increasing the capacity of a single capacitor in this way, the volumetric efficiency of mounting a power supply is greatly improved.

For the pair of terminal plates 30a and 30b,
A cut portion 50 is provided for obliquely cutting two sides intersecting one corner from the short distal end side, and an effect of reducing the weight and the like can be expected similarly to the cut portion 40 in the lead portions 10a and 20a. As shown in FIG. 3, when these cut portions 50 are obliquely cut at the same corner at the same plane from the short end side for polarity identification as shown in FIG. 3, the front and back of the capacitor are determined depending on whether both cut portions 50 face right or left. Since it is possible, it is also possible to prevent a wiring error in which the polarity is wrong.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an electrode coupling of an electric double layer capacitor according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a process of electrode bonding.

FIG. 3 is an explanatory view showing the shape of a terminal plate.

FIG. 4 is an explanatory diagram of a conventional technique.

[Description of Signs] 10 Collector electrode of positive electrode body 10a Lead part of positive electrode body 20 Collector electrode of negative electrode body 20a Lead part of negative electrode body 30a, 30b Terminal plate (capacitor electrode) 40 Cut part of lead part 50 Cut part of terminal plate

Claims (4)

[Claims] A positive electrode body and a negative electrode body of the same number are alternately laminated with a separator interposed therebetween, and a part of each positive electrode body and each negative electrode body is used as a lead portion to form a multi-layered part having the same polarity as a terminal. A pair of terminal boards is pulled out from an exterior body containing these laminates together with an electrolytic solution, and the exterior body is sealed in a vacuum state. An electrode structure for an electric double layer capacitor, wherein the overlapping portions of the same pole are divided into a plurality of sets, and cut portions are formed in the plurality of sets of overlapping portions so as to divide joint portions with a terminal plate. . 2. The same number of positive electrode bodies and negative electrode bodies are alternately laminated with a separator interposed therebetween, and a part of each of the positive electrode bodies and each of the negative electrode bodies is formed as a flat rectangular lead portion. Are connected to short terminal plates, respectively, and each terminal plate is pulled out from an exterior body containing these laminates together with the electrolytic solution, and the exterior body is sealed in a vacuum state to form an electric double layer capacitor. An electric double layer, wherein an overlapping portion of the same polarity of the lead portion is divided into two sets, and cut portions are formed in the two sets of overlapping portions so that they can be joined to the terminal plate. Electrode structure of capacitor. 3. A set of cut portions cuts two sides intersecting one corner diagonally from the tip side of a flat rectangular lead portion,
The other set of cut portions is formed so as to diagonally cut two sides crossing one corner on the opposite side.
The electrode structure of the electric double layer capacitor according to the above. 4. The electric device according to claim 2, wherein the pair of terminal plates are formed by cutting the same corners of the same plane obliquely from the short end side as cut portions for polarity identification. Electrode structure of double layer capacitor.