JPS6358365B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an electric double layer capacitor and a method for manufacturing the same, and particularly to an electric double layer capacitor cell.
The present invention relates to a means for maintaining insulation between an exterior case and an electric double layer capacitor element in which one or more electric double layer capacitor elements are housed in a stacked manner. Generally, an electric double layer capacitor using paste electrodes has a structure shown in FIG. 1, as seen in US Pat. No. 3,536,963. In the figure, 1 is a conductive separator that is electronically conductive and impermeable to ions, 2 is a paste electrode made of activated carbon powder and an electrolyte solution, and 3 is an ion-permeable separator provided to prevent conduction between the electrodes. 4 is a porous separator that blocks electron conduction, and 4 is a non-conductive gasket provided to hold the paste electrode and isolate it from the outside world. An electric double layer capacitor is formed by enclosing a stack of basic cells in which multiple basic cells with such a structure are stacked in a metal exterior case, and when a DC voltage is applied, the voltage increases in proportion to the insulation resistance of each basic cell. voltage is distributed. In this case, when the basic cell, especially the plurality of conductive separators that make up the basic cell, come into contact with the inner wall side of the metal exterior case, the basic cell becomes short, and the voltage held by the basic cell in the short part remains. Basic cell 1 is redistributed to the basic cell of
The voltage applied to each increases. If the voltage increased in this manner becomes higher than the designed value and exceeds the withstand voltage of the basic cell, the basic cell is destroyed and the electric double layer capacitor loses its function. Therefore, in order to improve the conventional drawbacks, it is necessary to maintain insulation between the basic cell and the inner wall side of the outer case. Therefore, the conventional insulation structure between the basic cell and the outer case is (a) one in which an insulating film is wrapped around the outer periphery of a single basic cell or a stack of basic cells, which is a stack of multiple basic cells. Insert an insulating tube made of resin or other material between it and the outer case. This was done with the following configuration. However, the above-mentioned conventional structure (a) has the disadvantage that it requires a very large number of steps to wrap the insulating film around the basic cell or a laminate. On the other hand, in the conventional structure (b), If the dimensional difference between the tubes is small, it will be difficult to insert the tube, and if the dimensional difference is large, there will be large variations in the placement position of the insulating tube within the outer case, making it difficult to insert the basic cell into the outer case. At this time, the insertion position cannot be determined. Additionally, because there is a gap between the outer case and the resin tube, the finished product shape also becomes larger. There are drawbacks such as. SUMMARY OF THE INVENTION An object of the present invention is to provide an electric double layer capacitor and a method for manufacturing the same which eliminates such conventional drawbacks. According to the present invention, one electric double layer capacitor cell
In an electric double layer capacitor in which one or more of the capacitors are laminated and sealed in a conductive outer case, and in a manufacturing method thereof, a sheet having restoring elasticity cut into strips is inserted along the inner wall side of the outer case. An electric double layer capacitor and a method for manufacturing the same are obtained, which are characterized by including a step of providing the same. An embodiment of the present invention will be described in detail below. Embodiment FIGS. 2A to 2D are cross-sectional views of an assembly process of an electric double layer capacitor according to an embodiment of the present invention. An insulating sheet with increased elasticity is made by bonding both sides of high-quality paper with a thickness of 0.1 mm with polypropylene resin.
Cut into strips of 8.0 mm and length of 50 mm, and spread this sheet into a tube shape of about 12 to 10 mm in diameter. Next, as shown in Figure 2 A, the inner diameter is 15 mm and the height is 13.1 mm.
A sheet 7 spread in a tubular shape is inserted into a bottomed cylindrical outer case 6 made of metal such as iron with a diameter of 1 mm. The sheet 7 inserted in this way is pushed back by the outer case 6 as shown in FIG. 2B due to its own restoring force.
An insulating layer is provided extending along the side surface of the inner wall. After that, as shown in FIG.
A laminated body 8 is put into the stack. Next, electrodes are taken out from the conductive separators at the upper and lower ends of the laminate 8 placed in the outer case 6 via the first electrode plate 9 and the outer case 6, respectively, and the laminate 8 is subjected to a process such as pressing. A pressure of 15 to 20 kg/cm ² is applied to caulk the outer case 6 and the second electrode plate 10, and the laminate 8 is pressurized with a constant pressure to form an electric double layer capacitor while maintaining this state ( Figure 2D). Table 1 shows the general electrical characteristics of the electric double layer capacitor formed according to the present invention described above. Table 1 also shows the general electrical characteristics of an electric double layer capacitor manufactured by wrapping an insulating film around the outer peripheral surface of a laminate as a conventional comparative example. As is clear from this conventional comparative example, it can be seen that the desired electrical characteristics can be sufficiently maintained even when the present invention is used. On the other hand, Table 2 shows the number of man-hours required to put the sheet cut into strips of the present invention into an exterior case and the number of man-hours required to wrap the conventional example of insulating film, expressed in time per 1000 sheets. However, according to the present invention, the number of steps can be reduced to about 1/5.

【table】

[Table] In the embodiments of the present invention, the insulating sheets are shown in an overlapping state, but the overlapping state is not necessary as long as the end surfaces of the sheets can be brought into close contact with each other with almost no gaps. As described above, the electric double layer capacitor according to the present invention has the effect that insulation of the inner wall side surface of the outer case can be easily mass-produced, and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electric double layer capacitor element used in the present invention. FIGS. 2A to 2D are cross-sectional views of the assembly process of the electric double layer capacitor according to the present invention. DESCRIPTION OF SYMBOLS 1... Conductive separator, 2... Paste electrode, 3... Porous separator, 4... Non-conductive gasket, 5... Basic cell, 6... Exterior case,
7... Sheet, 8... Laminate, 9... First electrode plate, 10... Second electrode plate.

Claims (1)

[Scope of Claims] 1. An electric double layer capacitor in which one or more electric double layer capacitor cells are laminated and sealed in a conductive outer case, in which the electric double layer capacitor cells are stacked against the inner wall side of the outer case due to its own repulsive force. An electric double layer capacitor characterized by having an insulating layer made of a wound restoring elastic sheet in contact with the insulating layer. 2. A step of cutting a sheet having restoring elasticity into strips on the inner wall side of the outer case, winding the sheets, and inserting the sheets in a temporarily formed state into a tubular body having an outer diameter smaller than the inner diameter of the outer case; The method is characterized by comprising the steps of: disposing the sheet in contact with the inner wall side of the case due to the repulsive force of the tubular body's self-restoring property; and disposing an electric double layer capacitor cell within the tubular body. Method for manufacturing electric double layer capacitors.