JPH067540B2 - Electric double layer capacitor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a large-sized electric double layer capacitor configured by laminating a plurality of basic cells.

(Prior Art) A vehicle equipped with an internal combustion engine, such as a passenger car, includes a starter motor for starting the internal combustion engine, a generator for generating electric power using the rotational force of the internal combustion engine, and a power generated by the generator temporarily. It is equipped with a lead battery or the like that stores the electric power and supplies the electric power to the starter motor or other electric devices at the time of starting.

On the other hand, in recent years, an electric double layer type large-capacity capacitor has been developed, and some of them have been used for battery applications, and a proposal to use the large-capacity capacitor for starting an internal combustion engine has been proposed for vehicles. As a power supply device for use, it is specified in Japanese Patent Application No. 329846 of 1988.

FIG. 7 shows an electric double layer capacitor generally formed by using a paste electrode. This is disclosed in U.S. Pat. No. 3,536,963, which is a current collector 1 of an electronic conductor serving as a pair of collector electrodes, a carbon electrode 2 made of activated carbon particles, a non-conductive gasket 3, A single basic cell is composed of the separator 4 for preventing electrons from moving between the electrodes 2.

The carbon electrode is manufactured as a concentrated slurry in which activated carbon in the form of powder or fine particles and an electrolyte are mixed.
The electrolyte here fulfills three functions. That is, it functions as an accelerator for ionic conduction, as an ion source, and as a binder for carbon particles.

In order to use such an electric double layer capacitor as a power source for a vehicle, a capacitor having a large capacitance value of 100 to 150 F (farad) is required. However, if an attempt is made to realize a required capacity value by increasing the number of cells integrated, the weight and volume increase, which is not suitable for loading on a vehicle. Therefore, in order to increase the energy density, that is, the capacitance value per unit volume or the capacitance value per unit weight, it is necessary to increase the size of the basic cell itself.

However, when the size of the basic cell is increased, the area of the collector electrode is increased, and as a result, when the laminated pressure applied to the basic cell is different between the central portion and the peripheral portion, a differential pressure is generated. Therefore, in order to stabilize the performance of the power source, the collector electrodes of the basic cells to be stacked need to be in contact with each other uniformly and with a sufficient adhesive force.

(Problem to be Solved by the Invention) In the structure of an ordinary electric double layer capacitor, a plurality of cells are pressurized by caulking in order to reduce the internal resistance thereof. For example, a self-standing capacitor described in Japanese Patent Laid-Open No. 56-2621 has a case structure shown in FIG. That is, the outer case 5 has the first
The second electrode plate 10 in which the electrode terminals 6 are provided upright from the first electrode plate 7 and the second electrode terminals 9 are upright via the insulating plate 8.
Are stacked and the required number of basic cells 12 to which pressure is applied by the reinforcing plate 11 is housed in the outer case 5, pressure is applied from above the electrode plate 7 at the two terminals 6 and 9 side to the outer case 5. The peripheral edge of the is bent inward to be caulked.

In such a conventional electric double layer capacitor, the pressure applied thereto depends on not only the size of the electrode but also the size of the particles of the carbon material, the type of electrolyte used, etc. A pressure of cm ² is required. However, in order to increase the pressure, it is necessary to increase the rigidity of the case, for example, by increasing the plate thickness of the case, and there is a limit in terms of overall weight and material cost. In addition, it is necessary to prepare a pressurizing means and a caulking device, which complicates the work process of applying an appropriate pressure.

The present invention has been made to solve the above problems,
An object of the present invention is to provide an electric double layer capacitor in which a plurality of electric double layer capacitor elements can be uniformly pressed and easily adjusted.

Another object of the present invention is to provide a structure of an electronic double layer capacitive element and a manufacturing method thereof for easily manufacturing a large capacitive element.

(Means for Solving the Problems) According to the present invention, in an electric double layer capacitor in which a plurality of electric double layer capacitive elements are laminated in a pressure-compressed state, a through hole formed in a central portion of each of the capacitive elements An electric double layer, comprising: fastening means for connecting the fixing plates respectively arranged at both ends of the capacitive element via the through holes to each other and clamping the capacitive element to press the laminated capacitive element. Capacitor can be provided.

(Operation) In the electric double layer capacitor of the present invention, when a plurality of electric double layer capacitive elements are stacked, the fixing plates can be connected and fastened to each other through the through hole at the center of each capacitive element. The pressurization can be made uniform and the pressure can be easily adjusted.

(Example) Hereinafter, one example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a partial cross-sectional view showing an electric double layer capacitor of the present invention, and FIG. 2 is an external perspective view showing an electric double layer capacitive element (basic element) constituting the electric double layer capacitor of FIG. .

The electric double layer capacitor 20 is configured by laminating a plurality of basic elements 30 each having a circular flat surface, and each of these basic elements 30 has a through hole 31 formed in a central portion thereof.

Reference numeral 21 is a compression plate on the upper and lower surfaces of the stacked basic elements, which also serves as the bipolar plates of the capacitor, and 22 is a cylindrical outer case that covers the outer periphery of the stacked basic elements 30. The compression plate 21 is made of a highly rigid metal such as stainless steel, and has a circular shape having the same size as the basic element 30 as a fixing plate of the basic element. Then, holes corresponding to the through holes 31 are formed therein, and the bolts 2 are used to connect the compression plates 21 to each other and tighten the basic element 30.
3 is inserted into the through hole 31 of the basic element 30, and the compression plate 21 at the other end is crimped by the nut 24. 25 is
These are a pair of collars made of resin or the like that are inserted into the through holes 31 from both ends thereof.
0 and the contact surface with the compression plate 21 are electrically insulated.

The basic element 30 has a structure in which a polarizable electrode 33 of a carbon paste separated into two layers by a separator 32 is enclosed between a pair of current collecting electrodes 34.
The ring-shaped gaskets 35 and 36 for sealing 3 are the through holes 3
It is provided on the inner peripheral portion on the first side and the outer peripheral portion of the collector electrode 34. That is, the gasket 35 that seals the polarizable electrode 33.
Thus, the configuration differs from the conventional electric double layer capacitive element shown in FIG. 7 in that a circular through hole 31 having a predetermined size is formed.

The electric double layer capacitor 20 having the above structure is laminated by inserting the bolt 23 in the order of the compression plate 21, the predetermined number of basic elements 30, and the compression plate 21, screwing and coupling the nut 24, and tightening them. It is possible to easily press the existing basic element 30.

FIG. 3 shows the clearance Δ set on the joint surface of the pair of collars 25.

That is, the collar 25 is divided into two parts in the longitudinal direction at the middle portion of the bolt 23, and the clearance Δ is set as a gap corresponding to the maximum compressive strain amount of the plurality of stacked basic elements 30. Therefore, when tightening the nut 24 in the assembly process, the internal resistance can be easily adjusted by setting a strain amount that does not damage the basic element 30.

FIG. 4 is a sectional view showing another embodiment of the electric double layer capacitor of the present invention.

In this embodiment, a partition wall 42a is formed outside the upper and lower compression plates 41 in the central portion of a resin outer case 42, and the basic element 30 is pressed from both sides of this partition wall 42a. Further, a conductive plate 43 for drawing out lead terminals is provided between the compression plate 41 and the basic element 30, and the bolt 44
Then, the compression plate 41 is connected and tightened by the nut 45 to fix it. These bolts 44 and nuts 45 are subjected to insulation processing by spraying resin mold or tar after assembly.

Here, the two lead terminals have the same polarity, and although not shown, the bolt 44 is electrically connected to the basic element 30 at an intermediate portion of the outer case 42 to form an electrode lead of the opposite polarity. To do. Then, each basic element of the capacitor is connected in paraseries by an external cable according to the application.

As described above, the partition wall fixed to the central portion of the outer case is provided, and pressure is applied from both sides, so that the stacking adhesive force of the basic element 30 is further improved as compared with the method of compressing from one side as shown in FIG. Be uniform. Further, when a large number of basic elements are stacked, the capacity value per unit weight can be increased by forming the through hole 31 in the central portion to be large even if the area of the collector electrode becomes large, and the bolt 44 can be used. , Nut 4
Since a differential pressure is less likely to occur when tightening 5, the contact resistance between the collector poles can be reduced.

5 (a) and 5 (b) are a partial cross section and a perspective view showing a modified example of the compression plate of the capacitor of FIG. Here, a compression plate 51 having a central portion formed to be thicker than a peripheral portion is used. As a result, the pressure on each basic element is evenly applied.

6 (a) to 6 (e) are explanatory views showing a manufacturing process of the electric double layer capacitive element of FIG.

First, prepare a disk of a predetermined size that forms the collector electrode 32, and put gaskets 3 on the outer peripheral portion and the central portion, respectively.
6 and 35 are adhered (a in the figure). The gasket is preferably made of hard rubber, for example. Next, a carbon paste serving as the polarizable electrode 33 is filled in the groove portion between the gaskets 35 and 36 (FIG. 8B). The polarizable electrode 33 thus prepared was enclosed by an ion-permeable separator 32 (FIG. 6C), and the polarizable electrode 33 prepared in the same manner was used.
And the separator 32 are joined via the separator 32 to form the capacitive element 30 (FIG. 3D). After that, the gasket 3 with a predetermined size is attached to the central portion of the collector electrode 34 of the joined capacitive element.
A through hole 31 penetrating 5 is formed (e in the figure).

Although the present invention has been described above in some detail with reference to its most preferred embodiments, the description of the preferred embodiments does not contradict the spirit of the present invention described in the modifications of the detailed configuration and the claims. It is obvious that various modifications can be made as long as possible, or a combination thereof can be changed.

(Effects of the Invention) As described above, according to the present invention, even if the basic element (cell) becomes large, a high pressure can be applied to the cell to reduce the internal resistance, and the central portion thereof can be reduced. It is possible to provide an electric double layer capacitor in which the degree of contact between the current collecting electrodes of the cells is made uniform by tightening and the contact resistance of the entire capacitor can be reduced.

Further, the cells can be stacked according to the required capacitance value, and the lengths of the bolt and the collar can be changed according to the stacked thickness, which facilitates the manufacturing.

Further, even if the internal resistances of a plurality of stacked cells vary, the internal resistance can be adjusted by performing an appropriate tightening operation while measuring the internal resistance when tightening the bolt.

Moreover, even if the force becomes excessive during the tightening work, the maximum strain amount is set by the collar, so that there is no risk of the cell being destroyed.

Even if the basic element (cell) becomes large, it is easy to reduce the weight of the entire capacitor by providing a void in the central portion of the cell.

[Brief description of drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention, FIG. 2 is an external perspective view showing an electric double layer capacitive element constituting the electric double layer capacitor of FIG. 1, and FIG. 3 is a bolt. Showing a connecting portion of an electrically insulating collar covering the outer peripheral surface of the
FIG. 5 is a partial sectional view showing another embodiment of the present invention, FIGS. 5 (a) and 5 (b) are partial sectional views and perspective views showing a modified example of the capacitor shown in FIG. 4, and FIG. 6 (a). ~ (E) is the second
Explanatory drawing which shows the manufacturing process of the electric double layer capacitive element of FIG.
FIG. 8 is a partial sectional view showing an example of an electric double layer capacitor formed by using a conventional paste electrode, and FIG. 8 is a sectional view showing a structure of a conventional capacitor case. 20 ... Electric double layer capacitor, 21 ... Compression plate, 23 ... Bolt, 24 ... Nut, 25 ... Collar, 30 ... Electric double layer capacitive element (basic element), 31 ... Through hole.

Claims (6)

[Claims] 1. An electric double layer capacitor in which a plurality of electric double layer capacitive elements are laminated in a pressure-compressed state, and a through hole formed in a central portion of each of the capacitive elements, and the capacitive element through the through hole. An electric double layer capacitor, comprising: fastening means for connecting the fixed plates respectively disposed at both ends to each other to fasten and press the laminated capacitive element. 2. The fastening means comprises a bolt reaching from a fixed plate serving as one current collecting pole of the stacked capacitive elements to a fixed plate serving as the other current collecting pole, and a nut screwed to the bolt. The electric double layer capacitor according to claim 1, wherein the electric double layer capacitor is configured. 3. The electric double layer capacitor according to claim 2, wherein the outer peripheral surface of the bolt is covered with an electrically insulating collar. 4. The collar covering the outer peripheral surface of the bolt is divided into two parts in the longitudinal direction of the bolt, and between these collars,
The electric double layer capacitor according to claim 3, wherein a gap corresponding to the maximum compressive strain amount of the laminated capacitive elements is set. 5. An electric double layer capacitive element constituting the electric double layer capacitor according to claim 1, wherein a polarizable electrode of carbon paste separated into two layers by a separator and the polarizable electrode. Collector electrodes arranged in parallel on both sides of the collector electrode, through holes penetrating the polarizable electrode and the collector electrode, and sealing the polarizable electrode at the inner peripheral portion of the through hole side and the outer peripheral portion of the collector electrode. An electric double layer capacitive element comprising: 6. A method of manufacturing an electric double layer capacitive element constituting the electric double layer capacitor according to claim 1, wherein gaskets are adhered to an outer peripheral portion and a central portion of a plate forming a collector pole. The step of filling the groove portion between these gaskets with a carbon paste to be a polarizable electrode, the step of joining two polarizable electrodes via a separator to form a capacitive element, A method of manufacturing an electric double layer capacitive element, which comprises a step of forming a through hole penetrating the gasket in the center of a current collecting electrode.