JP2003059765A - Collector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a collector which has highly reliable electric properties of low internal resistance, being excellent in airtightness of the electrolyte in an electric component such as an electric double layer capacitor, a battery, etc., where an electrolyte of liquid is applied. SOLUTION: This collector is made of a double-layer structure consisting of a collector where priority is given to electrolyte sealing properties, in respect of the quantity of mixedly kneaded conductive particles, the grain diameter, and the kind, using a method of relatively lessening the quantity of conductive particles, or the like, and a collector where priority is given to reduce the contact resistance between the collector and armored components, using a method of relatively increasing the quantity of conductive particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component such as an electric double layer capacitor or a battery to which a liquid electrolytic solution is applied, and more specifically, a highly reliable and low internal resistance excellent in airtightness of the electrolytic solution. The present invention relates to electronic parts such as electric double layer capacitors and batteries having the electric characteristics of 1.

[0002]

2. Description of the Related Art The basic structure of an electric double layer capacitor is shown in FIG. As shown in FIG. 2, the structure of the basic element of this electric double layer capacitor is such that the sealing of the electrolytic solution in the element is performed by the sealing rubber on the side surface of the electrode and the upper and lower two current collectors on the back surface of the electrode. The sealing rubber and current collector are made of butyl rubber or a composite material that uses polyolefin resin as a polymer, but the purpose of the sealing rubber is to insulate the upper and lower current collectors and the electrodes inside the element. Therefore, it is not necessary to knead conductive particles into the inside of the polymer, and as a result, it has excellent electrolytic solution sealing properties. On the other hand, in the current collector, it is necessary to knead the conductive particles inside the polymer to impart conductivity to connect the electrodes in the element to the exterior parts, and the conductive particles seal the electrolyte solution. The characteristics are obstructed, and the reliability such as product life is reduced. In order to balance the sealing characteristics of the electrolytic solution and the contact resistance between the current collector and exterior parts, the kneading amount, particle size, and type of conductive particles are adjusted, but both the contact resistance and reliability are adjusted. It was difficult to make the characteristics compatible.

[0003]

DISCLOSURE OF THE INVENTION The present invention has a highly reliable and low internal resistance electrical characteristic which is excellent in airtightness of an electrolytic solution in electronic parts such as electric double layer capacitors and batteries to which a liquid electrolytic solution is applied. It is to provide an electronic component having.

[0004]

As shown in FIG. 1, the amount of conductive particles to be kneaded, the particle size, and the type are set to the electrolytic solution sealing property by using a method of relatively reducing the amount of conductive particles. A two-layer structure is used for the current collector with a focus on reducing the contact resistance between the current collector and the exterior parts by using a technique such as increasing the amount of conductive particles. The present invention provides an electronic component having high reliability with excellent airtightness of an electrolytic solution and electrical characteristics of low internal resistance.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an electric double layer capacitor of the present invention will be described with reference to the drawings. FIG. 1 shows an outline of a product of the electric double layer capacitor of the present invention.

In the description of the embodiment of the present invention, the basic element 1 described in the conventional example shown in FIGS. 2 and 3 is adopted.

Referring to FIG. 3, the electric double layer capacitor includes six basic elements 1 stacked in series with each other,
An upper circular electrode plate 2a on which the lowermost basic element 1 is placed,
The insulating material 3 having the circular electrode plate 2a placed thereon is provided. Further, in the electric double layer capacitor, the insulating material 3 is placed on the lower circular electrode plate 2b. The whole is housed in a bottomed cylindrical housing 4.

Referring to FIG. 2, the basic element 1 is a positive
Powdered activated carbon is used as the negative electrodes 12 and 12, and the powdered activated carbon is impregnated with dilute sulfuric acid as an electrolytic solution.
A porous film separator 13 is provided between the electrodes 12, 12.
have. The separator 13 has a structure that prevents a short circuit between the plus and minus electrodes, is impregnated with the electrolytic solution, and allows ions in the electrolytic solution to pass therethrough.

Since the basic element 1 employs powdered activated carbon as the pair of electrodes 12, 12, the electrodes 12, 1
A separator 13 that prevents short-circuiting between the two and allows only ions in dilute sulfuric acid as an electrolyte to pass is placed between the electrodes 12, 12. Further, it is necessary to stabilize the contact resistance between the powdered activated carbon electrodes of the electrodes 12, 12 by applying a constant pressure from the outside.

Furthermore, between the pair of electrodes 12, 12 and the current collectors 11, 11 on the respective back surfaces, between the plurality of basic elements 1, and between the current collector 11 and the circular electrode plate 2a and the cylindrical housing 4. Similarly, it is necessary to stabilize the contact resistance by applying a constant pressure from the outside. The pressure applied from the outside is maintained after the pressure is applied by crimping the opening edge 4a of the cylindrical casing 4 to the outer peripheral portion of the lower circular electrode plate 2b.

Prior to the description of the embodiments of the present invention, first,
A specific example of a conventional electric double layer capacitor serving as a comparative reference will be described. As dimensions of electric double layer capacitor, diameter D dimension (13.5 mm), height dimension (14.5 mm)
Weight (3.9 g) and internal resistance (9.
8 Ω) and capacitance (0.22 F) are shown in Table 1 below.

[Table 1]

Next, regarding the embodiment of the present invention,
This will be described with reference to FIG. Among the basic elements shown in FIG. 3, a further layer of relatively conductive particles is provided on the side of the circular electrode plate 2a and the circular casing 4 of the current collector connected to the circular electric plate 2a and the cylindrical casing 4. Current collectors using methods such as increasing the amount
The current collector 21 is inserted with an emphasis on reducing the contact resistance between the exterior parts.

The current collector 21 to be inserted may be handled as an integrated current collector by laminating the current collector 22 with the current collector 22 with emphasis placed on the electrolyte sealing characteristics at the time of manufacturing the current collector. Alternatively, it may be inserted between the current collector 22 and the circular electrode plate 2a and the cylindrical housing 4 which place emphasis on the electrolytic solution sealing property when assembling the electric double layer capacitor.

At the time of manufacturing the current collector, two current collectors are attached to each other to form a laminated structure to form an integrated current collector,
A specific example applied to the electric double layer capacitor of the present invention will be described. Diameter D as the dimension of the electric double layer capacitor
Dimensions (14.5 mm), height dimensions (18 mm), weight (3.92 g) and electrical resistance as internal resistance (6.3).
Ω) and capacitance (0.22F) are shown in Table 2 below.

[Table 2]

The current collectors applied at this time used butyl rubber as a base polymer, and the specific resistance of the electrode: the side in contact with the powdered activated carbon was 16 Ω · Cm and the thickness was 0.
20 mm 2, the specific resistance of the side in contact with the circular electrode plate and the circular case was 7.5 Ω · C m, and the thickness was 0.20 mm.

Further, in order to confirm the reliability of the electric double layer capacitor itself whose electric characteristics shown in Table 2 are maintained, a DC voltage of 0.917 V is applied to one basic element in an atmosphere of 85 ° C. A high temperature load test for 1000 hours was performed. Table 3 shows the measurement results of the electrical characteristics after the test.

[Table 3]

As a comparison, the conventional electric double layer capacitors shown in Table 1 were subjected to a high temperature load test under the same conditions as above. Table 4 shows the measurement results of the electrical characteristics after the test.

[Table 4]

It has been shown that the present invention reduces the internal resistance of the electric double layer capacitor without impairing the reliability.

[0019]

As described above with reference to the embodiments, according to the present invention, there is provided an electronic component which is excellent in airtightness of an electrolytic solution, has high reliability, and has low internal resistance. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of a product of an electric double layer capacitor of the present invention.

FIG. 2 is a sectional view showing a basic cell of a conventional electric double layer capacitor.

FIG. 3 is a schematic view of a product of the present invention and a conventional electric double layer capacitor.

[Explanation of symbols]

1 Basic element 2a, 2b Circular electrode plate 3 insulator 4 cylindrical housing 4a Opening edge of cylindrical housing 11 Current collector 12 electrodes 13 separator 14 Sealing rubber 21 Current collector focused on reducing contact resistance 22 Current collector with emphasis on electrolyte sealing characteristics

Claims (2)

[Claims] 1. An electric double layer capacitor comprising a plus / minus electrode and a basic element having a collector of a porous film sandwiched between the electrodes and a collector for connecting to an external electrode on the back surface of the electrode, In an electronic component such as a battery, the current collector has a two-layer structure, one of which is in contact with the electrode containing the electrolytic solution is a current collector of the electrolytic solution airtight design, and the other is in contact with the exterior component. An electronic component characterized by being a collector having a low contact resistance design with an exterior component. 2. The electronic component according to claim 1, further comprising a current collector that is made of butyl rubber as a base material and is kneaded with carbon particles to impart conductivity.