JP2000200738A - High power type electric double layer capacitor, electrode and method of manufacturing the same - Google Patents

Abstract

(57) [Problem] To provide a high packing density as a capacitor unit, and to take out a current from each electrode layer without causing a tab shift, and further, without generating a death volume without an electrode. Provided are a high power type electric double layer capacitor, an electrode, and a method for manufacturing the same. SOLUTION: A laminate 11, such as a positive electrode and a negative electrode, an electrolytic solution,
In the high-power type electric double layer capacitor 1 including the case 6 and the like, each of the positive electrode and the negative electrode 2 has a current extracting portion 21 provided around the lateral side of the electrode. The positive electrode current extraction unit 21 is located on the opposite side of the electrode lateral direction from the negative electrode current extraction unit 21. The positive electrode and the negative electrode 2 are displaced in the lateral direction of the electrodes such that the current extracting portions 21 are outward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high power type electric double layer capacitor, an electrode and a method for manufacturing the same, and more particularly, to a high power type electric double layer capacitor characterized by a current extracting portion from stacked electrodes. The present invention relates to an electrode and a method for manufacturing the electrode.

[0002]

2. Description of the Related Art An electric double layer capacitor (EDLC) is
This is a capacitor using an electric double layer formed at the interface between the activated carbon and the electrolyte by impregnating the activated carbon powder with the electrolyte. The withstand voltage and the maximum operating temperature depend on the decomposition voltage and temperature of the electrolytic solution, and the rated voltage is as low as several volts. However, since the capacitance in the farad order can be easily obtained, a semiconductor memory is used instead of a battery. It has been widely used for low current density applications such as backup of (D-RAM), and has recently been studied for use in applications having higher current densities, for example, in place of in-vehicle lead-acid batteries. ing.

A conventional high-power electric double layer capacitor has a wound structure in which both electrodes are integrally wound to increase the electrode area. In the case of the wound type, it is necessary to attach a large number of tabs for taking out current in order to cope with a large current. Therefore, there is a drawback that the tab mounting interval becomes severe and tab displacement easily occurs. Further, since the shape of a product is rounded, when several capacitors are used as banks, the packing density has been reduced.

As means for solving these problems, a stacked type in which a positive electrode, a negative electrode, and the like are alternately stacked has been proposed (FIG. 5B).
And FIGS. 6c, d). In this case, since the product shape is square, the packing density as the capacitor unit can be increased. In addition, there is no need to worry about tab displacement because current is extracted from each layer. However, since the current collecting foil for current extraction needs to be thickened so as not to be cut by the handling during manufacturing, the packing density as an element has to be reduced. Furthermore, in order to attach the current collecting foil to the upper part of the electrode, it is necessary to secure a space for collecting a plurality of current collecting foils in the upper space of the electrode laminate. Because the amount of deformation of the area to be collected increases when stress is collected and stress is applied and the foil breaks, it is necessary to make the current collecting foil easily deformable to some extent, and it is necessary to use a long current collecting foil , The space above the electrode stack becomes larger,
There has been a problem that a death volume in which no electrode exists is generated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art described above. The object of the present invention is to provide a capacitor unit with a high packing density and to extract a current from each electrode layer. There is no worry about tab displacement,
An object of the present invention is to provide a high power type electric double layer capacitor which does not cause a death volume without an electrode, an electrode, and a method of manufacturing the same.

[0006]

The present invention relates to a high-power type electric double-layer capacitor comprising a laminate of a positive electrode and a negative electrode, an electrolyte, a case, and the like.
Each is a high-power electric double layer capacitor in which a current extracting portion is provided around the electrode in the lateral direction.

The present invention is also a high power type electric double layer capacitor in which the current extracting portion of the positive electrode is located on the opposite side of the electrode in the lateral direction from the current extracting portion of the negative electrode.

[0008] In the present invention, the positive electrode and the negative electrode include:
These are high-power type electric double layer capacitors which are shifted in the lateral direction of the electrodes so that the current extracting portions are outwardly projected.

Further, the present invention is a high power type electric double layer capacitor in which the positive electrode and the negative electrode each have a lead member attached to a current extracting portion.

Further, the present invention is a high power type electric double layer capacitor in which the positive electrode and the negative electrode have a rectangular or square shape.

The present invention provides an electrode used for a high-power type electric double layer capacitor comprising a laminated body such as a positive electrode and a negative electrode, an electrolytic solution, a case, and the like, wherein a current extracting portion is provided around the electrode in the lateral direction. Of the high power type electric double layer capacitor.

Further, the present invention provides a method of manufacturing an electrode for a high-power type electric double layer capacitor, in which an active material slurry is applied to a substrate, dried or the like to form an electrode body, the electrode body is cut, and a current extracting member is attached. A high-power type electric double-layer capacitor in which a slurry-uncoated portion is provided when applying an active material slurry to a substrate, and when the electrode body is cut, the slurry-uncoated portion is cut around the electrode. Is a method of manufacturing an electrode for use.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described. Embodiments of a high-power type electric double layer capacitor, an electrode and a method of manufacturing the same according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram of an electrode unit of a high power type electric double layer capacitor according to an embodiment. FIG.
It is explanatory drawing of attachment of the lead member of the high power type electric double layer capacitor of an Example. FIG. 3 is an explanatory view of assembling the high power type electric double layer capacitor of the embodiment. FIG.
FIG. 1 is an explanatory diagram of the appearance of a high-power type electric double layer capacitor of an example. FIG. 5 is an explanatory diagram of an electrode laminate of an electric double layer capacitor of an example and a conventional example. FIG. 6 is an explanatory view of the vertical and horizontal cross sections of the electric double layer capacitor of the embodiment and the conventional example.

An embodiment will be described. A method for manufacturing a high-power electric double layer capacitor will be described. First, an activated carbon slurry is applied to an aluminum foil serving as a base so as to partially provide an uncoated portion, and the slurry is dried to solidify the slurry, thereby manufacturing an electrode body. The obtained electrode body was cut so that the portion where the slurry was applied became a rectangle of 80 × 50 mm, and the outside of one side of the rectangle became the portion where the slurry was not applied, to obtain an electrode 2. Subsequently, the lead member 4 was attached to the current extracting portion 21 of the electrode by ultrasonic welding to obtain an electrode with a lead. Since the lead member 4 has flexibility,
It is possible to change the shape to an inverted L-shape. next,
As shown in FIG. 1, two leaded electrodes serving as a positive electrode and a negative electrode and a separator (not shown) are arranged such that the lead member 4 is on the opposite side of the electrode in the lateral direction, and the current extracting portion 21 of the electrode is One set of the electrode units was made by shifting the electrodes so as to come out. The three sets of electrode units are laminated so that the lead members of the same pole are on the same side to form an electrode laminate 11 (see FIG. 2). Then, the lead member 4 is ultrasonically welded to the extraction terminal 51 of the lid 5. Then, the elliptical lid 5 and the electrode laminate 11 were integrated, and this was placed in an aluminum case 6 having an oval cross section (see FIG. 3). After being impregnated with the electrolytic solution, it was swaged to produce the intended high-power type electric double layer capacitor 1 (see FIG. 4).

FIG. 5 shows the electrode laminate 11 in this embodiment.
(A). The electrode laminate 11 of the present embodiment includes positive and negative electrodes 2 and a separator 3, and the shape of the electrodes 2 and the separator 3 is rectangular or square. The current extracting portion 21 of the electrode is a portion of the substrate not coated with the slurry at the time of manufacturing, is provided around the electrode in the lateral direction, and the lead member 4 is attached in a later step. The positive and negative electrode current extraction portions 21 are located on opposite sides of the electrode in the lateral direction, and the lead members 4 of the same polarity are on the same side. FIG. 5B shows a conventional laminated type. The conventional electrode laminate 11 'also includes the electrode 2' and the separator 3 ', but the lead member 4' is provided above the electrode.

Next, a description will be given of the structure and cross section of the capacitor when it is packaged. FIGS. 6A and 6B show the case of this embodiment, and FIG.
(C) and (d). The lead member 4 of the capacitor according to the present embodiment has a narrow width but a long length, and has flexibility, so that the shape is easily deformed into an inverted L-shape, and the lead member 4 is connected to the case next to the electrode laminate 11. Since it is possible to arrange in the space 13, the space 12 above the electrode stack 11 can be reduced. On the other hand, the lead member 4 'of the conventional example has an I-shape and is wide but short in length, and the space 13' with the case beside the electrode unit laminate 11 'is not used. , And the upper space 1
2 'is wider. This is because, in the capacitor 1 of the present embodiment, the current extracting portion 21 of the electrode is located in the periphery in the lateral direction of the electrode, and the length of the portion where the lead member 4 is attached to the electrode 2 can be increased in the longitudinal direction. Lead member 4
Even if the width of is reduced, the mounting area can be secured. In addition, since the lead member 4 protrudes outside the electrode laminate 11, the space 13 with the horizontal case can be used. On the other hand, in the conventional capacitor 1 ', the current extracting portion 21' of the electrode is located above the electrode, and the length of the portion where the lead member 4 'is attached to the electrode 2' cannot be increased. This is because it is necessary to widen the width of. As a result, in the capacitor 1 of the present embodiment, the lead member is disposed and used in the space 13 which is wasted in the conventional structure, and the space 12 above the electrode stack is reduced because the width of the lead member is narrow. Therefore, the reduced portion can be used as a space for the electrode laminate. The size of the activated carbon coated portion of one electrode that can be inserted into the same capacitor case 5 is 75 × 50 mm in the conventional type, whereas it is 8 in the product of the present embodiment.
0 × 50 mm, the capacity was 440F in the conventional product and 5% in the product of the present embodiment.
20F and the internal resistance is 1.4mΩ in the conventional product
On the other hand, the value was 1.0 mΩ in the product of this example, and the characteristics were improved in the product of this example. Furthermore, since the current extracting portion 21 of the electrode and the lead member 4 are outside the electrode laminate 11, the thickness of the current extracting portion 21 of the electrode and the lead member 4 can be increased, so that no foil break occurs. Did not.

As described above, by providing the current extracting portion of the electrode at the periphery in the lateral direction of the electrode, the foil cross-sectional area can be increased to prevent the foil from being cut off. By using it for improving the packing density, it is possible to obtain a high-power type electric double layer capacitor having an increased capacity and a reduced resistance.

[0018]

According to the present invention, the packing density as a capacitor unit is high, and current is taken out from each electrode layer, so that there is no fear of tab displacement, and further, a death volume without electrodes is produced. And a high-power type electric double layer capacitor and electrodes free of the problem.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an electrode unit of a high-power type electric double layer capacitor according to an embodiment.

FIG. 2 is an explanatory view of attaching a lead member of the high power type electric double layer capacitor of the embodiment.

FIG. 3 is an explanatory view of assembling the high-power type electric double layer capacitor of the embodiment.

FIG. 4 is an explanatory diagram of the appearance of a high-power electric double-layer capacitor according to an embodiment.

FIG. 5 is an explanatory view of an electrode laminate of an electric double layer capacitor according to an embodiment and a conventional example.

FIG. 6 is an explanatory view of a vertical and a horizontal section of an electric double layer capacitor of an embodiment and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Capacitor 11 Electrode laminated body 12 Space on electrode laminated body 2 Electrode 21 Current extraction part 3 Separator 4 Lead member 41 Weld part 5 Lid 51 Extraction terminal 6 Case

Claims (7)

[Claims] 1. A high-power electric double-layer capacitor comprising a laminate of positive and negative electrodes, an electrolytic solution, a case, and the like, wherein each of the positive electrode and the negative electrode has a current extracting portion provided in the periphery in the lateral direction of the electrode. A high-power type electric double layer capacitor characterized by the above-mentioned. 2. The high-power type electric double layer capacitor according to claim 1, wherein the current extracting portion of the positive electrode is located on the side opposite to the current extracting portion of the negative electrode in a lateral direction of the electrode. High power type electric double layer capacitor. 3. The high-power type electric double-layer capacitor according to claim 2, wherein the positive electrode and the negative electrode are shifted in a lateral direction of the electrodes so that a current extracting portion is protruded outside. Electric double layer capacitor. 4. The high power type electric double layer capacitor according to claim 1, wherein each of the positive electrode and the negative electrode has a lead member attached to a current extracting portion. Power type electric double layer capacitor. 5. The high power type electric double layer capacitor according to claim 1, wherein said positive electrode and said negative electrode have a rectangular or square shape. Electric double layer capacitor. 6. An electrode used for a high-power type electric double layer capacitor comprising a laminate such as a positive electrode and a negative electrode, an electrolytic solution, a case, and the like, wherein a current extracting portion is provided on a periphery in a lateral direction of the electrode. Characteristic high power type electric double layer capacitor electrode. 7. A method for producing an electrode for a high-power type electric double layer capacitor, in which an active material slurry is applied to a substrate and dried to form an electrode body, the electrode body is cut, and a current extracting member is mounted. When applying the active material slurry, a high-power type electric double layer is provided in which a slurry-uncoated portion is provided, and when the electrode body is cut, the slurry-uncoated portion is cut so as to be around the electrode. A method for manufacturing a capacitor electrode.