JP3262785B2 - Method for producing wet capacitor using organic semiconductor - Google Patents

Abstract

PURPOSE:To restrain the reduction in inner resistance in the initial phase of manufacture as well as the notable increase in inner resistance after storage by a method wherein, within a capacitor using an organic semiconductor in polyacetal base skeletal structure as an electrode, a nonwoven fabric comprising glass fiber of borosilicate is used as a separator. CONSTITUTION:A positive polarity can 1 is made of e.g. a clad material of aluminum-stainless steel plated with nickel on a stainless steel surface. A conductive paste 3 is laid between a polyacetal sheet 2 and the positive polarity can 1. A negative polarity can 6 serving both as a negative polarity terminal is made of e.g. a stainless steel plated with nickel and another conductive paste 3' is laid between another polyacetal sheet 2' and the negative polarity can 6 similar to the positive polarity side. A glass fiber separator 5 of a socket 4 serving both as an insulator is laid between the positive polarity can 1 and the negative polarity can 6. The separator 5 is made of borosilicate glass mainly comprising silicon dioxide and boric acid to be processed into a nonwoven fabric after turning in a staple state. In order to attain the most practical nonwoven fabric thickness of 50-500mum, 0.1-50mm of staple diameter is recommended.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

The present invention relates to a wet capacitor, and more particularly, to a small-sized and large-capacity capacitor using an organic semiconductor having a polyacene skeleton structure as an electrode.

[0002]

[Prior art]

Japanese Patent Application Laid-Open No. 60-170163, filed by the joint applicant of the present application, discloses an organic electrolyte battery in which an organic semiconductor having a polyacene skeleton structure is used as a positive electrode and a negative electrode, and an aprotic organic solvent solution is used as an electrolyte. It has been disclosed. This organic electrolyte battery (secondary battery) can be expressed as a "capacitor" when considered as a capacitor.

[0003] In practical use of the capacitor, in order to reduce the internal resistance and reduce the change, the material and characteristics of the separator (electrolyte impregnation, liquid retention, stability, and ion permeability) are extremely high. is important. Conventionally, nonwoven fabric made of polypropylene, porous membrane made of polypropylene, composite fiber of polyethylene and polypropylene, etc. are used for the separator.
Alternatively, 〜 was appropriately used as a laminate.

That is, in a conventional capacitor using an organic semiconductor, as shown in FIG. 1, a conductive paste 3, 3 ′ is applied to the inner bottoms of a positive electrode can 1 and a negative electrode can 6, and a polyacene sheet 2,
2 ′ is inserted into the positive electrode can 1 and the negative electrode can 6 so as to be in contact with the conductive pastes 3 and 3 ′, and faces each other via the separator 5 described above. The gasket 4 is compressed by the positive electrode can 1 and the negative electrode can 6 to maintain airtightness, and propylene carbonate containing tetraethylammonium borofluoride is typically used as an electrolytic solution.
It may be in the space inside 2 ′ and partly in the space 7.

However, the capacitor using the separator described above has a slightly higher internal resistance in the initial stage of manufacturing ((9.5 m in outer diameter).
m, battery with 2.1mm thickness, 30-50Ω, AC resistance) After accelerating test at high temperature and high humidity (60 ℃, 95% RH), battery of the same size rises to 100-30Ω. Had.

[0006]

[Means for Solving the Problems]

The present invention, in order to solve the above-described problems, a positive electrode and a negative electrode made of an organic semiconductor having a polyacene-based skeleton structure, a separator that separates the positive electrode and the negative electrode, a method of manufacturing a wet capacitor made of an organic electrolyte, the positive electrode The negative electrode and the negative electrode are produced by powdering an organic semiconductor having a polyacene skeleton structure, adding polytetrafluoroethylene and carbon black to the powder and press-molding the same, and the separator is made by heating a glass fiber nonwoven fabric in a vacuum. And dried and manufactured.

In the present invention, a nonwoven fabric made of ultrafine borosilicate glass fiber is used as a separator instead of the conventional organic separator, thereby reducing the internal resistance at the initial stage of production and the internal resistance after storage. Has been found to be able to suppress a remarkable increase in the temperature.

[0008] The borosilicate glass of the present invention is a glass containing silicon dioxide and boric acid as main components, and includes CaO,
This is a glass in which a part of SiO ₂ is substituted with B ₂ O ₃ . Usually SiO ₂ is 65
80%, the B ₂ O ₃ 5~25, CaO glass is preferably used having a composition of 5-8% weight fraction.

The separator used in the present invention is obtained by forming the above-mentioned borosilicate glass into a staple shape and then processing it into a nonwoven fabric. The diameter and length of the stipple depend on the intended nonwoven fabric, but in order to obtain the most practical nonwoven fabric thickness of 50 to 500 μm used in the present invention, the staple fiber diameter is preferably 0.1 to 50 μm. Fiber diameter 0.1 μm
It is extremely difficult to produce the following glass stipple, and when a stipple of 50 μm or more is used, it is difficult to produce a nonwoven fabric having the above-mentioned thickness with little entanglement between the staples.

[0010] The above-described method for producing a borosilicate glass nonwoven fabric is performed by a usual wet papermaking machine. At this time, the borosilicate glass stipple alone can be processed into a nonwoven fabric, but an organic binder may be added to the staple in an amount of 0.1 to 10% in order to improve the binding between the staples. For example, PTFE known as an organic binder of Teflon-water dispersion system
In the case of using slag, 5 to 10% is added to the above-mentioned borosilicate glass stipple, and papermaking is performed to obtain a nonwoven fabric.

[0011] Organic semiconductors having a polyacene-based skeleton structure used in the present invention are known per se, and are described, for example, in JP-A-60-170163 and JP-A-61-218060. The collecting of the can and the polyacene is performed by applying a conductive paste to the bottom surfaces of the inside of the positive electrode can and the negative electrode can and inserting the polarizable electrode into the negative electrode can and the positive electrode can such that the polarizable electrode comes into contact with the conductive paste. The organic electrolytic solution used in the present invention is a solution in which a salt that forms ions by electrolysis is dissolved in an aprotic organic solvent. Usually, the electrolytic solution of this type of capacitor includes propylene carbonate, ethylene carbonate, γ-
An aprotic organic solvent such as butyl lactone is preferably used, and a tetraalkylammonium salt as a salt,
For example

[0012]

(Equation 1)

Is preferably used.

Incidentally, R ₁ , R ₂ , R ₃ and R ₄ represent an alkyl group, and R _{1 to} R ₄ may be the same or different. X represents ClO ₄ or BF ₄ .
The salt of the present invention is usually dissolved in the above-mentioned solvent in a concentration range of 0.5 to 1.5 mol / l and used as an electrolyte.

In this specification, a “condenser” can be expressed as a “secondary battery” if it is considered as one of the power sources capable of charging and discharging.

[0016]

【Example】

Hereinafter, examples of the present invention will be described. FIG. 1 shows a wet condenser of this embodiment, having an outer diameter of 9.5 mm and a height of 2.1 m.
m, nominal capacity 0.5F (Farad). In the drawing, reference numeral 1 denotes a positive electrode can, for example, a stainless steel surface of a clad material of aluminum-stainless steel plated with nickel. Reference numeral 2 denotes a polyacene sheet, and a conductive paste 3 is interposed between the sheet and a positive electrode can. Reference numeral 6 denotes a negative electrode can which also serves as a negative electrode terminal, for example, a nickel-plated stainless steel, and a conductive paste 3 'is interposed between the negative electrode can and the polyacene 2' similarly to the positive electrode side. Between the positive electrode can 1 and the negative electrode can 6 are a gasket 4 also serving as insulation and a separator 5 which is a glass fiber of the present invention. (Example 1) First, a polyacene sheet was manufactured as follows.
An insoluble and infusible polyacene film was synthesized by the production method described in Example 1 of Japanese Patent Application Laid-Open No. 61-218060 according to the joint applicant of the present invention. When the electric conductivity of the substance was measured at room temperature by a DC four-terminal method, it was found to be 10 ^-4 Ω ^-1 .cm ^-1.
Met. According to elemental analysis, the atomic ratio of hydrogen atoms / carbon atoms was 0.27. The specific surface area by the BET method is 2100 m ² /
It was an extremely large value of g. Next, the polyacene film was pulverized for 3 hours using a ball mill to obtain a powder. 5% by weight of polytetrafluoroethylene and 10% by weight of carbon black were added to this powder, mixed, and then molded under pressure to a thickness of 0.
A 7 mm polyacene sheet was obtained. Next, the polyacene sheet and the separator made of the borosilicate glass fiber nonwoven fabric of the present invention (GC-50 manufactured by Advantech) were punched out in a disk shape, vacuum-dried at 200 ° C. for 3 hours, and stored in a jam pot. The gasket was dried by vacuum drying at 100 ° C for 3 hours and stored in a jam pot. Next, after applying a conductive paste to the bottom inside the positive electrode can, the above-described polyacene sheet was placed and pressed from above, and then pressed at 100 ° C. for 3 hours.
Dried for 0 minutes.

Further, a liquid sealant containing rubber as a main component was applied to the inner peripheral portion of the above-described positive electrode can, and then the sealant was applied to a gasket groove portion, and dried for several minutes.

Similarly, a conductive paste was applied to the inner bottom surface of the negative electrode can, a polyacene sheet was placed and pressed, and then dried at 100 ° C. for 30 minutes.

To the positive electrode thus obtained, a predetermined amount of propylene carbonate containing tetraethylammonium borofluoride as an electrolytic solution was injected, and a separator was placed. Also, after injecting a predetermined amount of the electrolytic solution into the negative electrode in the same manner,
A button-type wet condenser as shown in FIG. 1 was assembled. The above-mentioned assembling operations were all performed in the dehumidifying room. (Example 2) 50% PTFE as a binder in borosilicate glass fiber
A button-type wet capacitor was assembled in the same manner as in Example 1 except that the mixture (Advantech PG-60) was used as a separator.

Table 1 shows the AC internal resistance (1 kHz, 1 mA) immediately after assembling of the wet capacitor of the present invention produced as described above.
In addition, 2.4V applied, 60 ℃, 95% RH10days, 10days for another 10days
The AC internal resistance after storage (0 days) is also shown.

Table 1 Comparison table of electrical characteristics

[0022]

[Table 1]

(Comparative Example) As a separator, one polypropylene porous membrane (Dielaguard 2500, manufactured by Polyplastics Co., Ltd.) (Comparative Example 1) and one polyethylene polypspyrene-glass mixed membrane (Comparative Example 2) Were used to assemble button-type wet capacitors similar to those in Example 1. Table 1 shows the values of the AC internal resistance before and after storage. In Table 1, the present invention is compared with a conventional product. Regarding the AC internal resistance, the battery of the present invention shows 1/2 of the conventional battery (comparative example) and 1/3 to 5 after storage, indicating that the wet capacitor of the present invention is greatly improved.

[Brief description of the drawings]

FIG. 1 is a partially broken sectional view showing an example of the present invention and a conventional wet condenser.

[Description of Signs] 1 ... Positive electrode can 2,2 '... Polyacene sheet 3,3' ... Conductive paste 4 ... Gasket 5 ... Glass fiber alone or glass fiber containing organic binder Conventionally non-woven fabric made of polypropylene 6 …… Negative electrode can 7 …… Space

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Koji Yamaguchi, Inventor 1-6-2-406, Tomobuchi-cho, Miyakojima-ku, Osaka-shi, Osaka (72) Inventor Shizukuni Yada 2-6-13, Miyanishi, Harima-cho, Kako-gun, Hyogo Prefecture (72) Inventor Toyo Hayasaka 5-30-1, Nishitaga, Taihaku-ku, Sendai City, Miyagi Prefecture Seiko Electronic Components Co., Ltd. (56) References JP-A-60-170163 (JP, A) JP-A-63-261819 ( JP, A) JP-A-59-12561 (JP, A) JP-A-60-146464 (JP, A) JP-A-62-127341 (JP, A)

Claims (3)

(57) [Claims] 1. A method for manufacturing a positive electrode and a negative electrode comprising an organic semiconductor having a polyacene-based skeleton structure, a separator for separating the positive electrode and the negative electrode, and a wet capacitor comprising an organic electrolyte, wherein the positive electrode and the negative electrode comprise: The organic semiconductor having the polyacene-based skeletal structure is made into a powder, and polytetrafluoroethylene and carbon black are added to the powder to produce a powder, which is then produced by pressure molding. And a method for producing a wet condenser. 2. The method according to claim 1, wherein the heating is performed at 200 ° C. 3. The method according to claim 1, wherein the glass fiber is made of borosilicate glass.