JPH1074672A - Electric dual layer capacitor and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the mechanical strength of terminals furthermore lessening the inner resistance while precisely laminating the electrode plates composing an electric dual layer capacitor for increasing the electrostatic capacity. SOLUTION: Positive and negative side electrodes having notch parts 104 are alternately laminated. The positions of each electrode plate can be precisely aligned by aligning the sides a, b, c of these electrode plates. After the lamination, the side d as a part excluding the parts constituting the terminals 112 and 113 is removed so as to form the terminals 112 and 113. In such a constitution, the terminals 112 and 113 are laminated in the numbers equivalent to the total numbers of the positive and negative sides electrode plates so that the thickness thereof may be made almost twice of the ordinary one, thereby enabling the inner resistance thereof to be lessened almost at 1/2 level.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an electric double layer capacitor device. In particular, an electric double layer capacitor capable of increasing the capacitance and reducing the electric resistance of the lead portion by precisely laminating the current collector portions constituting the electric double layer capacitor body. Related to the device.

[0002]

2. Description of the Related Art Since an electric double layer capacitor device can realize an extremely large capacitance, it is often used not only as a capacitor but also as a battery. In particular, in recent years, electric double layer capacitor devices have been widely used as backup power supplies for electronic devices.

[0003] In many cases, the main body of the electric double layer capacitor is formed by laminating a plurality of electrode plates having a current collecting portion, for example. This is called a laminated electric double layer capacitor. FIG. 6 is a schematic diagram of an electrode plate including a current collector used in a conventional multilayer electric double layer capacitor. As shown in FIG. 6, a conventional electrode plate includes a current collector 10 provided with an active material (printed) to form a capacitor, and the current collector 10 and an external circuit. And a lead part 12 to be an electric terminal for connecting The electrode plate shown in FIG. 6 forms the positive electrode of the electric double layer capacitor.

On the other hand, the negative electrode of the electric double layer capacitor is an electrode plate having substantially the same configuration as the electrode plate shown in FIG. Used. FIG. 7 shows a schematic diagram of such an electrode plate constituting the negative electrode side. As shown in FIG. 7, the electrode plate constituting the negative electrode side is covered with a bag-shaped separator 14. This separator 14
For example, the bag is formed by heat welding. The positive electrode and the negative electrode are insulated by the separator 14.

[0005] By alternately stacking the electrode plates constituting the positive electrode side as shown in FIG. 6 and the electrode plates constituting the negative electrode side as shown in FIG. An electric double layer capacitor having a large surface area and a large capacitance can be formed. 6 and 7
After the electrode plates shown in FIG. 6 are stacked, all the leads 12 of the positive electrode plate (shown in FIG. 6) are electrically connected to form the positive terminal of the electric double layer capacitor. Is done. Similarly, by electrically connecting all the leads 12 of the negative electrode plate (shown in FIG. 7), the negative terminal of the electric double layer capacitor is formed. As means for electrically connecting, the lead portion 1 is used.
2, a method of providing a through hole and fixing it by bolting or the like is adopted.

A conventional multilayer electric double layer capacitor has been manufactured as described above.

[0007]

In such a laminated electric double layer capacitor, it is necessary to surely prevent the terminal of the positive electrode from contacting the terminal of the negative electrode. As described above, a technique for preventing a short circuit between the positive electrode side and the negative electrode side terminal is described in, for example, Japanese Utility Model Laid-Open No. 6-36210. The publication discloses a configuration for preventing a short circuit between a positive electrode side and a negative electrode side of an oil-immersed secondary battery. The publication discloses a technique in which a cut is made in a portion corresponding to a lead wire above a separator surrounding a positive electrode, and the portion is folded obliquely.

In an electric double layer capacitor, a lead wire take-out portion is generally provided above a separator, and a lead portion of an electrode coming out of the lead wire take-out portion is usually formed integrally with a current collector portion. ing. For example, as shown in FIGS. 6 and 7, the current collector 10 and the lead 12 are often formed as one electrode plate. The current collector 10 is printed with an active material to form an electrode portion of a capacitor or a battery. In order to increase the capacity per unit volume of the electric double layer capacitor, the current collector 10 is used. The thinner the better, the better.

However, if the current collector portion 10 is too thin, the tensile strength of the terminal is reduced when a plurality of the lead portions 12 are stacked to form an electric terminal of the capacitor, and when the terminal is connected to an external circuit. There is a possibility that the lead part 12 constituting the terminal is separated from the current collector part 10 and cut off. Furthermore, as the current collector 10 becomes thinner, the electric resistance of the current collector 10 and the lead 12 increases, which causes an increase in the internal resistance of the formed electric double layer capacitor.

As described above, in the multilayer electric double layer capacitor, one of the positive and negative electrode plates is covered with the separator 14, and this is laminated with the other polarity electrode plate. For example, when the separator 14 is attached to the electrode plate constituting the negative electrode and the separator 14 is not attached to the electrode plate constituting the positive electrode, the size of the separator 14 is increased when the electrode plates are laminated. And the size of the electrode plate is larger than that of the first electrode plate, and when lamination is performed, a positional shift easily occurs between the current collector on the positive electrode side and the current collector on the negative electrode side. When such a displacement occurs, the capacitance is reduced by the displacement.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an electric double layer capacitor capable of reducing electric resistance. Another object of the present invention is to provide a method for manufacturing an electric double layer capacitor capable of precisely laminating a positive electrode plate and a negative electrode plate during lamination in a multilayer electric double layer capacitor. To provide.

[0012]

According to a first aspect of the present invention, there is provided a current collector portion forming an electric double layer capacitor main body and a lead portion forming terminals of the electric double layer capacitor. A plurality of positive electrode plate groups comprising: a plurality of negative electrode plate groups comprising the current collector portion and the lead portion, similarly to the positive electrode plate group; The electric double layer capacitor device is formed by alternately laminating the groups by covering the groups with bag-shaped separators so that the leads of the positive electrode plate group and the leads of the negative electrode plate group do not contact with each other. The thickness of the lead portion of each of the positive electrode plate group and the negative electrode plate group is greater than the thickness of the current collector portion. .

Since the lead portion is thicker than before,
The strength of the lead is improved. Therefore, the strength of the terminal of the electric double layer capacitor device increases, and the electric resistance of the terminal decreases.

According to a second aspect of the present invention, there is provided a method for manufacturing an electric double layer capacitor device according to the first aspect of the invention, wherein the substantially rectangular electrode plate has an active material on a surface thereof. An electrode plate including the provided current collector portion and the lead portion forming the terminal of the electric double layer capacitor, and provided with a cut portion for separating the current collector portion and the lead portion. A laminating step of laminating the lead portions in a plane perpendicular to a laminating direction and laminating, and a removing step of removing a portion of the laminated lead portions other than the portion constituting the terminal of the electric double layer capacitor. In the laminating step, the opening portion of the cut portion of the electrode plate of the positive side electrode plate group is in a direction substantially opposite to the opening portion of the cut portion of the electrode plate of the negative side electrode plate group, Said A first method of manufacturing the electric double layer capacitor device of the present invention characterized by having an electrode plate laminate step, performing a stack of plates.

In the present invention, in the rectangular electrode plate, since the current collector portion and the lead portion are separated only by the cut portion, the lead portion of the positive electrode plate and the lead portion of the negative electrode plate are separated. And have substantially the same shape. Therefore,
By stacking the electrode plates in the stacking step with the lead portions aligned in a plane perpendicular to the stacking direction, the electrode plates can be stacked precisely.

In the present invention, since the lead portion of the positive electrode plate and the lead portion of the negative electrode plate have substantially the same shape, the positive terminal and the negative terminal are electrically connected as they are. Short-circuited to another state. Therefore, in the removing step, the positive terminal and the negative terminal of the electric double layer capacitor device are separated by removing portions other than the portion where the terminal is formed.

According to a third aspect of the present invention, there is provided a method of manufacturing an electric double layer capacitor device according to the first aspect of the invention, wherein the substantially rectangular electrode plate has an active material on a surface thereof. An electrode plate including the provided current collector portion and the lead portion forming the terminal of the electric double layer capacitor, and provided with a cut portion for separating the current collector portion and the lead portion. A laminating step of laminating the lead portions in a plane perpendicular to the laminating direction and laminating, and a portion of a lead portion forming a positive terminal and a portion of a lead portion forming a negative terminal of the electric double layer capacitor. A cutting step of cutting the stacked lead portions in the stacking direction in order to separate the lead portions from each other, and winding the portions of the lead portions other than the portions forming the terminals around the portions forming the terminals. And the laminating step is such that the opening of the cutout of the electrode plate of the positive electrode plate group is in the opposite direction to the opening of the cutout of the electrode plate of the negative electrode plate group. An electrode plate laminating step of laminating the electrode plates.
Is a method for manufacturing an electric double layer capacitor device of the present invention.

In the present invention, the electrode plates can be precisely laminated as in the second invention. That is,
In the rectangular electrode plate, the current collector portion and the lead portion are separated only by the cut portion, so that the lead portion of the positive electrode plate and the lead portion of the negative electrode plate have substantially the same shape. I have. Therefore, by stacking the electrode plates by aligning the positions of the lead portions in a plane perpendicular to the stacking direction in the stacking step, the electrode plates can be stacked accurately.

In the third aspect of the present invention, similarly to the second aspect of the present invention, it is necessary to separate the positive terminal and the negative terminal. In the third aspect of the present invention, the lead portion is cut in the cutting step for such separation.

In the third aspect of the present invention, portions of the lead portion other than the portion constituting the terminal are wound around the terminal. By employing such a configuration, the resistance of the terminal portion is further reduced.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are schematic diagrams showing the positive and negative electrode plates of the multilayer electric double layer capacitor according to the present embodiment, respectively.

FIG. 1 is a schematic diagram showing a state of the negative electrode plate. As shown in FIG. 1, the electrode plate according to the present embodiment also includes a current collector 100 that forms a capacitor and a lead 102 that forms a positive terminal.

A characteristic feature of this embodiment is that the electrode plate is formed by making a cut into a substantially rectangular sheet material of a predetermined length, whereby the current collector portion 100 and the lead portion 102 are separated by the cut. It is being done. Further, as shown in FIG. 2, a notch 104 is also provided on the negative electrode plate, and the current collector 100 and the lead 102 are formed by the notch 104.
And are distinguished. The feature of this embodiment is that the cut portion 104 on the positive side and the cut portion 104 on the negative side
Are provided in the opposite direction. FIG.
When the electrode plate shown in FIG. 2 and the electrode plate shown in FIG. By cutting out portions other than the portion constituting the above, it is possible to insulate the positive terminal and the negative terminal from each other.

According to the present embodiment, since the lead portions 102 of the positive electrode plate and the negative electrode plate have the same shape, the positions of the lead portions 102 can be accurately determined when they are laminated. It becomes possible to match. 5 and 6
In the conventional electrode plate as shown in (1), since the lead portions 12 are provided at different places for electrical insulation, it is difficult to position the electrode plates when laminating the electrode plates. However, in the present embodiment, as shown in FIGS. 1 and 2, the lead portions 102 have the same shape as each other, and therefore, unlike the conventional multilayer electric double-layer capacitor, the position of the electrode plate is different. Can be laminated accurately. As a result, there is an effect that the capacitance can be increased.

Furthermore, the lead portion 102 of the electrode plate in the present embodiment ultimately forms the terminal of the electric double layer capacitor device. In this case, since the shape of the lead portion 102 is substantially the same, The number of layers 102 is
This is the total number of positive electrode plates and negative electrode plates. On the other hand, in the conventional electrode plates as shown in FIGS. 5 and 6, the lead portions 12 of the positive electrode plate are laminated by the number of the positive electrode plates, and the negative electrode plate is connected to the negative electrode plate. The lead portions 12 of the electrode plates are laminated by the number of negative electrode plates. As described above, according to the present embodiment, the number of the lead portions 102 to be stacked can be increased, so that the electric resistance of the terminal when the terminal is formed can be reduced.

Hereinafter, a method of manufacturing the electric double layer capacitor according to the present embodiment will be described in detail.

FIG. 3 is a schematic diagram showing a case where the positive electrode plate shown in FIG. 1 and the negative electrode plate covered with the separator 106 shown in FIG. It is shown.

As shown in FIG. 3, in this embodiment, since the shape of the lead portion 102 is substantially the same between the positive electrode plate and the negative electrode plate, the position of each side is determined. By aligning, it is possible to accurately position the electrode plate. That is, as shown in FIG. 3, by aligning the positions of the sides a, b, and c, the current collector 100 of the electrode plate can be accurately laminated. More specifically, it is possible to stack the current collectors 100 by matching the positions in a plane perpendicular to the stacking direction with each other. As a result, according to the present embodiment, it is possible to increase the capacitance of the multilayer electric double layer capacitor.

Next, after the positioning of the current collectors 100 is completed and the layers are precisely laminated, as shown in FIG. 5 described later, the current collectors 100 are stacked by a metal case 120 or the like. Fix 100.

Thereafter, the through holes 110 penetrate through each electrode plate.
Are provided as shown in FIG. And this through hole 1
The bolts 10 are used to fasten the bolts 102 to fix the lead portions 102 of the laminated electrode plates, specifically, to fix the portions of the lead portions 102 that form the terminals. Next, after the fixing, the hatched portion shown in FIG. 3D is deleted. By removing the d portion, the positive terminal 112 and the negative terminal 113 are formed insulated from each other.

As described above, the positive terminal 112 includes not only the lead 102 of the positive electrode plate but also a part of the lead 102 of the negative electrode plate. for that reason,
It is possible to form a thicker terminal than a conventional multilayer electric double layer capacitor. The same applies to the terminal 113 on the negative side, and it is possible to form a terminal almost twice as thick as a conventional electric double layer capacitor. Therefore, the electric double layer capacitor according to the present embodiment has a terminal thickness approximately twice that of the conventional capacitor, so that the strength of the terminal itself can be improved and the electric resistance can be reduced. it can.

In this manner, the terminals 112 and 113 can achieve a sufficient tensile strength even when connected to an external circuit, and are formed as terminals that are difficult to cut.

The electrode plate used in this embodiment is preferably made of, for example, aluminum. The active material as shown by hatching in FIG. 1 includes powdered activated carbon, a conductive material (10 to 30 wt%) such as carbon black or graphite, and PTFE (polystyrene) for binding these materials. An active material including a binder (5 to 30 wt%) such as tetrafluoroethylene is used. Such an active material is attached to the current collector 100 of FIGS. 1 and 2 by printing.

Specifically, for example, a mixture of 60% by weight of activated carbon having a specific surface area of 2000 m ² / g, 20% by weight of carbon black, and 20% by weight of PTFE is wet-blended to form a 20 μm thick aluminum foil current collector. It is conceivable to form (one side 50 × 47 × 0.1 (mm)). Then, in order to form the lead portion 102 on the electrode plate thus formed, a cutout portion 104 is provided in the electrode plate.

The separator 106 covering the negative electrode plate is made of, for example, porous polyethylene. The electrode plate is covered with a sheet made of porous polyethylene, and the periphery of the electrode plate of this sheet is thermally welded to form a bag-shaped separator. Is formed.

Using the numerical values of the above-described example, the inventors actually tried to produce a multilayer electric double layer capacitor.
The capacitance of the electric double layer capacitor in the case where 50 electrode plates were laminated by determining the position of the electrode plate by a conventional configuration was, for example, 313F on average. Here, five conventional electric double layer capacitors were prepared. On the other hand, the multilayer electric double layer capacitor according to the present embodiment
When it was made, the average was 320F. As described above, according to the experiments performed by the inventors of the present application, it was found that the present embodiment increased the capacitance by about 2%.

Further, since the thickness of the terminal is twice as large as that of the conventional electric double layer type capacitor, the failure rate due to the defective cutting of the terminal of the electric double layer type capacitor is reduced.
Specifically, the failure rate due to the disconnection failure of the terminal of the electric double layer capacitor according to the conventional configuration is 10%, whereas according to the present embodiment, the failure rate is reduced to 0%. That is, when 20 electric double-layer capacitors according to the conventional configuration and 20 electric double-layer capacitors according to the present embodiment were respectively manufactured, according to the conventional configuration, 2 out of 20 capacitors had poor terminal disconnection. Thus, in the electric double layer capacitor according to the present embodiment, there was no disconnection failure.

When the resistance of the terminal was measured, it was found that the electric double layer capacitor of the conventional configuration had a resistance of 0.7.
mΩ, whereas the electric double layer capacitor according to the present embodiment resulted in a reduction in terminal resistance to 0.4 mΩ.

In the embodiment shown in FIG.
The portion where the terminals 112 and 113 are not formed (the portion indicated by d in FIG. 3) of the cutout portion 104 is shown as being removed. But not just removing,
It is also preferable to wind it around the terminals 112 and 113. FIG. 4 is a diagram illustrating the configuration of such terminals.

As shown in FIG. 4, for example, the cut portions 104 are cut at the center after being laminated. Then, by bending the lead portion along the broken lines indicated by e, f, g, and h in FIG. 4, it becomes possible to wind the surplus portion in the cut portion 104 around the terminals 112 and 113. . For example, about 15 μm is adopted as the thickness of the electrode plate, and the thickness becomes 750 μm when 50 sheets are laminated. Then, these 50 sheets can be collectively bent at the locations indicated by broken lines e and f and wound around the positive terminal 112. The same applies to the periphery of the negative terminal 113.

In the above example, an example in which the surplus portion in the cut portion 104 is wound around the portion where the terminals 112 and 113 are formed is described. However, it is also preferable to fold around the surplus portion. Specifically, first, f and g in FIG.
Next, e and h in FIG. 4 are folded inward. As a result, folding is performed about the surplus portion in the cutout portion 104, and the finally folded portion is the terminal 11
2 and 113. Even with such a configuration, it is possible to reduce the electric resistance of the terminals 112 and 113.

As described above, the portion of the cut portion 104 where the terminals 112 and 113 are not formed is not simply removed, but is wound around the terminals 112 and 113 to form the terminals 112 and 113 of the electric double layer capacitor. Can be further reduced.

As described above, according to the present embodiment, in the multilayer electric double layer capacitor, the accuracy of lamination of the electrode plates can be further improved, and as a result, the capacitance can be improved. It has become possible.

Further, since the cut portions 104 of the positive electrode plate and the negative electrode plate have the same shape, the thickness of the terminals 112 and 113 is approximately doubled by stacking them. It became possible. As a result,
The strength of the terminals 112 and 113 can be increased, and the electrical resistance of the terminals 112 and 113 can be reduced.

FIG. 5 is an explanatory diagram showing a state where the electric double layer capacitor is incorporated in the electronic device. After being laminated as shown in FIG. 3, the electric double layer capacitor is housed in a metal case 120, and terminals 112 and 113 are provided with leads 122 for external extraction, respectively. The external lead 122 is attached to the lid 126 via an insulating plate 124.

[0047]

As described above, according to the first aspect of the present invention, since the thickness of the terminal portion is larger than the thickness of the current collector portion, the mechanical strength of the terminal portion is improved. Therefore, when connected to an external extraction electrode or the like, a terminal that is hard to be cut due to high tensile strength is formed. Further, since the thickness of the terminal portion is large, it is possible to reduce the electric resistance in the terminal portion.

According to the second aspect of the present invention, it is possible to improve the positioning accuracy when laminating the electrode plates, and to produce an electric double layer capacitor having an increased capacitance. Furthermore, since the thickness of the terminal portion is about twice as large as that of the conventional electric double layer capacitor, the strength of the terminal portion is increased, and the electric resistance at the terminal portion is reduced to about half of the conventional value. Becomes possible.

According to the third aspect of the present invention, of the lead portions,
Since the portion other than the terminal is wound around the lead portion forming the terminal, it is possible to manufacture an electric double layer capacitor with further reduced electric resistance of the terminal.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a structure of a positive electrode plate according to a preferred embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state in which a negative electrode plate is covered with a separator in a preferred embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a state where the electrode plates shown in FIGS. 1 and 2 are stacked.

FIG. 4 is an explanatory diagram illustrating a configuration in a case where a portion where a terminal is not formed in a lead portion is wound around a portion where a terminal is formed, thereby further reducing the electric resistance of the terminal.

FIG. 5 is an explanatory diagram illustrating a case where the electric double layer capacitor is attached to an actual electronic device.

FIG. 6 is an explanatory diagram showing a conventional positive electrode plate.

FIG. 7 is an explanatory diagram illustrating a state in which a conventional electrode plate is covered with a separator.

[Explanation of symbols]

10 current collector part, 12 lead part, 100 current collector part,
102 lead part, 104 cut part, 106 separator, 110 through hole, 112, 113 terminal, 120
Metal case, 122 Lead for external extraction, 124
Insulating plate, 126 lid.

Claims (3)

[Claims] 1. A plurality of positive electrode plate groups each including a current collector portion forming an electric double layer capacitor main body and a lead portion forming terminals of the electric double layer capacitor, and a positive electrode plate group. Similarly, a plurality of negative electrode plate groups including the current collector portion and the lead portion, one of the electrode plate groups is covered with a bag-shaped separator, and the lead portion of the positive electrode plate group. In the electric double layer capacitor device configured by being alternately stacked so that the lead portions of the negative electrode plate group do not contact with each other, The electric double layer capacitor device, wherein the thickness of the lead portion is larger than the thickness of the current collector portion. 2. The method for manufacturing an electric double layer capacitor device according to claim 1, wherein the current collector section is a substantially rectangular electrode plate, and has an active material provided on a surface thereof; An electrode plate provided with a cut portion for separating the current collector portion and the lead portion, the position of the lead portion in a plane perpendicular to the stacking direction. A stacking step of stacking together, and a removing step of removing a portion of the stacked lead portions other than a portion constituting the terminal of the electric double layer capacitor, wherein the stacking step includes: The opening part of the cut part of the electrode plate of the group is
The electric device according to claim 1, further comprising: an electrode plate laminating step of laminating the electrode plates so as to be in a direction substantially opposite to an opening of a cut portion of the electrode plate of the negative electrode plate group. A method for manufacturing a multilayer capacitor device. 3. The method for manufacturing an electric double layer capacitor device according to claim 1, wherein the current collector section is a substantially rectangular electrode plate, and has an active material provided on a surface thereof; An electrode plate provided with a cut portion for separating the current collector portion and the lead portion, the position of the lead portion in a plane perpendicular to the stacking direction. A stacking step of stacking together, and separating the stacked lead portions in order to separate a portion of the lead portion forming the positive terminal of the electric double layer capacitor from a portion of the lead portion forming the negative terminal. A cutting step of cutting in a stacking direction; and a winding step of winding a portion of the lead portion other than a portion forming the terminal around a portion forming the terminal. , Cut opening portion of the positive electrode plate group of the electrode plates,
The electric double layer according to claim 1, further comprising: an electrode plate laminating step of laminating the electrode plates so as to be in a direction opposite to an opening of a cut portion of the electrode plate of the negative electrode plate group. A method for manufacturing a capacitor device.