JPH1126325A - Coin-shaped electrochemical element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable coin-shaped electrochemical element which is excellent in sealing characteristic, even under a high-temperature and high- humidity environment. SOLUTION: This element comprises a pair of polarizable electrodes 11a and 11b, a separator 12 provided between them, an electrolyte impregnated in the pair of polarizable electrodes 11a and 11b and the separator 12, a dish-like metal case 13 where the pair of polarizable electrodes 11a and 11b and the separator 12 are housed, and a metal lid 15 which seals up an opening part of the metal case 13 via a sealer 14. Here, between the part of an interface where the dish-like metal case 13 makes contact the filler 14 and the part of an interface where the metal lid 15 contacts the sealer 14, at least the latter is provided with a resin coat layer 17 of electrically-insulating characteristics, while the resin coat layer 17 is constituted with a rubber denaturated hydrocarbon resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coin-type electrochemical device used for various electronic devices.

[0002]

2. Description of the Related Art As shown in FIG. 2, a conventional coin-type electric double-layer capacitor as a coin-type electrochemical element of this type has a pair of polarizable electrodes 1a and 1b and a pair of polarizable electrodes 1a and 1b. A pair of polarizable electrodes 1a, 1b and an electrolytic solution impregnated in the separator 2; and a pair of polarizable electrodes 1a, 1b.
Carbon-based conductive layers 5 a and 5 b are provided between the metal case 1 b and the dish-shaped metal case 3 and the metal lid 4, and the opening of the dish-shaped metal case 3 is sealed with the metal lid 4 via the sealing body 6. The sealing auxiliary agent 7 is interposed between the interface between the dish-shaped metal case 3 and the sealing body 6 and the interface between the metal lid 4 and the sealing body 6. And this seal auxiliary agent 7 is disclosed in JP-A-63-190.
In Japanese Patent No. 32, a sealing aid obtained by mixing asphalt pitch and polybutene is used.

[0003] In addition, propylene carbonate is used as a main solvent in an electrolytic solution, and a quaternary ammonium salt is generally used as an electrolyte.

[0004]

However, in the structure of the above-mentioned conventional coin-type electric double-layer capacitor, the opening of the dish-shaped metal case 3 is sealed with the metal lid 4 through the sealing body 6 and the dish is closed. The structure is such that a sealing aid 7 in which asphalt pitch and polybutene are mixed is interposed at an interface between a portion where the metal case 3 and the sealing member 6 are in contact with each other and an interface between a portion where the metal lid 4 and the sealing member 6 are in contact with each other. When this coin-type electric double layer capacitor is used in a high-temperature, high-humidity environment, the seal auxiliary agent 7 interposed at the interface between the metal lid 4 and the sealing body 6 contacts the pair of polarizable electrodes 1a, 1b
And the separator 2 had a problem of sealing property with respect to the electrolytic solution impregnated in the separator 2.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a highly reliable coin-shaped electrochemical element having excellent sealing properties even when used in a high-temperature, high-humidity environment. It is assumed that.

[0006]

In order to achieve the above object, a coin-shaped electrochemical device according to the present invention comprises a pair of polarizable electrodes, a separator interposed between the pair of polarizable electrodes, Electrolyte impregnated in the polarizable electrode and the separator, a dish-shaped metal case for accommodating the pair of polarizable electrodes and the separator, and a metal lid for sealing the opening of the metal case via a sealing body. And at least an interface between a portion where the metal lid and the sealing body are in contact with an interface between a portion where the dish-shaped metal case and the sealing body are in contact and an interface between a portion where the metal lid and the sealing body are in contact with each other. An electrically insulating resin coating layer is provided, and this resin coating layer is made of a rubber-modified hydrocarbon resin. According to this configuration, even when used in a high-temperature, high-humidity environment, the sealing property is improved. Good and reliable coin In which it is possible to obtain an electrochemical element.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention comprises a pair of polarizable electrodes, a separator interposed between the pair of polarizable electrodes, and a pair of polarizable electrodes and the separator. An impregnated electrolytic solution, a dish-shaped metal case for housing the pair of polarizable electrodes and the separator, and a metal lid for sealing an opening of the metal case via a sealing body, the dish-shaped An electrically insulating resin coating is provided on at least an interface between a portion where the metal lid and the sealing body are in contact with an interface between a metal case and the sealing body and a portion where the metal lid and the sealing body are in contact with each other. Layer, and this resin coating layer is composed of a rubber modified hydrocarbon resin,
According to this configuration, due to the presence of the resin coating layer, even when used in a high-temperature, high-humidity environment, the problem of sealing performance with respect to the electrolyte impregnated in the pair of polarizable electrodes and the separator is significantly reduced. In addition, the life of the coin-shaped electrochemical element is prolonged, whereby a highly reliable coin-shaped electrochemical element can be obtained.

According to a second aspect of the present invention, the rubber-modified hydrocarbon resin is composed of a mixed resin obtained by mixing a styrene-butadiene rubber, an aliphatic saturated hydrocarbon and a methylstyrene resin. The use of the mixed resin has an effect that the water absorption and the water permeability can be reduced as compared with the case where the styrene-butadiene rubber is used alone. The reason for this is that the bonds of the main chains of the rubber-modified hydrocarbon resin are constituted almost entirely by single bonds.

Next, a specific embodiment of the present invention and a comparative example will be described. (Embodiment) FIG. 1 is a sectional view of a coin-type electric double layer capacitor as a coin-type electrochemical element according to an embodiment of the present invention.
Reference numerals 1a and 11b denote a pair of polarizable electrodes in the coin-type electric double layer capacitor.
1b is activated carbon powder 80wt% and carbon black 10w
It has a cylindrical shape with a diameter of 4.5 mm and a thickness of 1.0 mm. Further, a separator 12 is interposed between the pair of polarizable electrodes 11a and 11b. Further, the pair of polarizable electrodes 11a and 11b and the separator 12 are impregnated with an electrolytic solution in which 10% by weight of tetraethylammonium tetrafluoroborate is dissolved in propylene carbonate. 13 is the pair of polarizable electrodes 11a,
The opening of the metal case 13 is sealed by a metal cover 15 serving as a current collector through a sealing body 14. Also, the one polarizable electrode 11a and the metal cover 15
And between the other polarizable electrode 11b and the dish-shaped metal case 13 are provided current collecting layers 16a and 16b.

The external dimensions of the coin-type electric double layer capacitor according to the embodiment of the present invention have a diameter of 9.
0 mm and height is 2.0 mm.

An electrically insulating resin coating layer 17 is provided at the interface between the dish-shaped metal case 13 and the sealing member 14 and at the interface between the metal lid 15 and the sealing member 14. Is provided. The resin coating layer 17 is made of a rubber-modified hydrocarbon resin. The resin is applied to a dish-shaped metal case 13 and a metal lid 15 with a brush and dried to be cured. . The rubber-modified hydrocarbon resin is composed of a mixed resin obtained by mixing three components of a styrene-butadiene rubber, an aliphatic saturated hydrocarbon, and a methylstyrene resin.

In the above-described embodiment of the present invention, the resin coating layer 17 is provided on the dish-shaped metal case 13 and the metal lid 15. The coating layer 17 may be provided.

COMPARATIVE EXAMPLE In the coin-type electric double-layer capacitor shown in FIG. 2, asphalt is formed at the interface between the dish-shaped metal case 3 and the sealing member 6 and at the interface between the metal lid 4 and the sealing member 6. A coin-shaped electric double layer capacitor was formed with a sealing aid 7 in which pitch and polybutene were mixed.

Table 1 shows ten samples of a coin-type electric double-layer capacitor according to an embodiment of the present invention and ten samples of a coin-type electric double-layer capacitor of a comparative example, respectively.
A comparison was made between the time during which the sealability of the coin-type electric double-layer capacitor failed when a DC voltage of 2.8 V was applied to the coin-type electric double-layer capacitor in a high-temperature atmosphere at 70 ° C. and the electrical characteristics. FIG.

[0015]

[Table 1]

As is clear from Table 1, in the coin type electric double layer capacitor of the comparative example, a defect of the sealing property was observed after about 5000 hours, and 1000 times.
After 0 hour, the change in the electrical characteristics of the internal resistance and the capacitance was larger than in the initial stage, but the coin-shaped electric double-layer capacitor according to one embodiment of the present invention has:
Even after 5,000 hours and 10,000 hours, there was no occurrence of a defect in the sealing property, and changes in the electrical characteristics of the internal resistance and the capacitance were smaller than those in the comparative example.

In the above-described embodiment of the present invention, the electrically insulating resin coating layer 17 is covered with the dish-shaped metal case 1.
Although a description has been given of the case where the metal cover 15 and the sealing member 14 are provided at both the interface where the metal lid 15 and the sealing body 14 are in contact with each other, it is not always necessary to provide them both. What is necessary is just to provide at the interface of the part which the body 14 contacts.

Further, in the above-described embodiment of the present invention, a case where the present invention is applied to a coin-type electric double layer capacitor has been described. However, the present invention is not limited to this. The present invention is also applicable to the coin-type electrochemical element described above.

[0019]

As described above, the coin-shaped electrochemical device of the present invention comprises a pair of polarizable electrodes, a separator interposed between the pair of polarizable electrodes, and a pair of polarizable electrodes and the separator. An impregnated electrolytic solution, a dish-shaped metal case for housing the pair of polarizable electrodes and the separator, and a metal lid for sealing an opening of the metal case via a sealing body, the dish-shaped An electrically insulating resin coating is provided on at least an interface between a portion where the metal lid and the sealing body are in contact with an interface between a metal case and the sealing body and a portion where the metal lid and the sealing body are in contact with each other. A layer is provided, and this resin coating layer is made of a rubber-modified hydrocarbon resin. According to this configuration, a pair of resin coating layers is used even in a high-temperature, high-humidity environment due to the presence of the resin coating layer. Impregnated in polarizable electrode and separator Since the failure of the seal against the electrolyte is depleted, the life of the coin-shaped electrochemical device also becomes longer, but this makes it possible to obtain a highly reliable coin type electrochemical device.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a coin-type electric double-layer capacitor according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional coin-type electric double-layer capacitor.

[Explanation of symbols]

 11a, 11b A pair of polarizable electrodes 12 Separator 13 Dish-shaped metal case 14 Sealing body 15 Metal cover 17 Resin coating layer

Claims (2)

[Claims] 1. A pair of polarizable electrodes, a separator interposed between the pair of polarizable electrodes, an electrolytic solution impregnated in the pair of polarizable electrodes and the separator, and a pair of the polarizable electrodes and A dish-shaped metal case for storing the separator, and a metal lid for sealing the opening of the metal case via a sealing body, and an interface between a portion where the dish-shaped metal case and the sealing body are in contact with each other, An electrically insulating resin coating layer is provided on at least the interface between the metal lid and the sealing body at the interface between the metal lid and the sealing body, and the resin coating layer is rubber-modified carbonized. A coin-shaped electrochemical element made of hydrogen resin. 2. The rubber-modified hydrocarbon resin comprises a mixed resin obtained by mixing three components of a styrene-butadiene rubber, an aliphatic saturated hydrocarbon and a methylstyrene resin.
4. The coin-shaped electrochemical device according to claim 1.