JP2942451B2 - Manufacturing method of organic electrolyte battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of manufacturing a coin-type (button-type) organic electrolyte battery using an aprotic organic solvent solution as an electrolyte.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No.
JP-A-170163 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 liquid is used as an electrolyte.

[0003] In the battery, the material of the gasket for keeping the battery airtight and liquid-tight and insulating the positive and negative electrode cans is extremely important. Conventional gasket materials include chemical resistance,
Inexpensive polypropylene, which is excellent in elasticity and creep resistance, has good moldability, and can be injection molded, has been used.

The positive / negative electrode cans, separators, organic semiconductors having a polyacene skeleton structure, and electrolytes of the battery all have high melting points or boiling points and excellent heat resistance.
However, the polypropylene used for the gasket has a low heat-resistant temperature, so that the conventional battery has a disadvantage that the heat resistance is inferior.

A coin-type (button-type) organic electrolyte battery is
It is mainly used as a memory backup power supply.
In this case, after the soldering terminal is welded to the battery, it is often soldered together with the memory element onto a printed circuit board. Conventionally, soldering on a printed circuit board has been performed using a soldering iron, but with the miniaturization and higher functionality of equipment, it is necessary to increase the number of electronic components mounted on the same area of the printed circuit board. Therefore, it has become difficult to secure a gap for inserting a soldering iron for soldering.

Therefore, solder is applied in advance to a portion of the printed circuit board where soldering is to be performed, and a component is mounted on the portion, or after the component is mounted, small solder balls are supplied to the soldered portion and soldered. A method of performing soldering by melting a solder by passing a printed board on which components are mounted in a furnace in a high-temperature atmosphere set at a temperature equal to or higher than the melting point of the solder, for example, 200 to 230 ° C. (Hereinafter referred to as reflow soldering). Conventional coin-type (button-type) organic electrolyte batteries using gaskets made of polypropylene have the problem that polypropylene melts or deforms during reflow soldering, and the positive and negative electrode cans made of stainless steel or aluminum come into contact and short-circuit. there were.

In order to improve heat resistance, it is effective to use a gasket made of a polyamide resin having excellent heat resistance and to mold the battery with a thermosetting resin, but the polyamide resin absorbs moisture. There is a problem that the battery absorbs moisture in the manufacturing process up to molding, and the electrical characteristics are deteriorated.

[0008]

In order to solve the above-mentioned problems, the inventors of the present invention have replaced a conventional gasket made of polypropylene with a gasket made of a polyamide-based resin and a positive electrode and / or a negative electrode made of polyacene. Used in a coin-type organic electrolyte battery made of an organic semiconductor having a system skeletal structure, and by performing the entire process up to molding the battery with a thermosetting resin in a dehumidifying environment, heat resistance is improved and reflow soldering is used. Is possible,
It has been found that the electrical characteristics are improved.

[0009]

That is, the present invention relates to an organic electrolyte battery provided with a positive electrode, a negative electrode, a separator, and a gasket and using an aprotic organic solvent solution as an electrolyte. A method of manufacturing a coin-type organic electrolyte battery comprising an organic semiconductor having a base skeletal structure, a gasket made of a polyamide resin, and molding with a thermosetting resin. A method of manufacturing a coin-type organic electrolyte battery, wherein all steps are performed in a dehumidifying environment.

In the battery of the present invention, 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 sheet 2 made of a polyacene organic semiconductor is used.
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 is opposed to each other via the separator 5. The gasket 4 is compressed by the positive electrode can 1 and the negative electrode can 6 to maintain airtightness, liquid tightness, and insulation of the positive and negative electrode cans. It may be in the space inside and partly in the space 7.

The thermosetting resin 8 completely covers the positive and negative electrode can surfaces. The positive electrode terminal 9 and the negative electrode terminal 10 are resistance-welded or laser-welded to the positive electrode can 1 and the negative electrode can 6, respectively, and a part thereof is exposed to the outside of the thermosetting resin 8. The positive electrode can and the negative electrode can are conventional, and are made of, for example, stainless steel or aluminum.

The separator is commonly used in batteries or capacitors, for example, a porous synthetic resin film,
It is a material obtained by hardening inorganic fibers with a resin, paper, or the like, and is preferably made of a glass fiber nonwoven fabric.

The organic electrolyte is a solution in which an aprotic organic solvent dissolves a salt that forms ions. Usually, as the electrolytic solution of this type of organic electrolyte battery, aprotic organic solvents such as propylene carbonate and γ-butyrolactone are preferably used as a solvent, and a tetraalkylammonium salt as a salt, for example,

Embedded image (R1, R2, R3 and R4 each represent an alkyl group;
To R4 may be the same or different. X represents ClO ₄ or BF ₄ ) is preferably used. Salt is usually 0.5
It is dissolved in the above-mentioned solvent in a concentration range of 1.51.5 mol / l and used as an electrolytic solution.

The terminals are commonly used in batteries or capacitors and are made of, for example, stainless steel nickel or the like, and are preferably made of stainless steel of the same material as the positive and negative electrode cans. Organic semiconductors having a polyacene skeleton structure used in the present invention are known per se, and are disclosed in, for example, JP-A-61-21.
No. 8060.

The organic semiconductor is pulverized using a ball mill or the like to obtain a powder, a binder and a conductive material are added to the powder, mixed, and then pressed to form a polyacene sheet to form a positive electrode and / or a negative electrode. .

The gasket is located between the positive and negative electrode cans and is used to keep the positive and negative electrode cans insulated and to maintain the airtightness and liquid tightness of the battery. The material must have chemical resistance to aprotic organic solvent liquids, and must have excellent elasticity and creep resistance because it is placed between the positive and negative electrode cans and compressed. is there. Further, it is more preferable that the composition has good moldability and is suitable for mass production and can be injection molded.

In the present invention, the polyamide resin refers to an amide bond -CO in a main chain generally called a nylon resin.
It is a polymer having —NH—. Typically, a resin synthesized by polycondensation of a dicarboxylic acid and a diamine, polycondensation of an ω-aminocarboxylic acid, or ring-opening polymerization of a lactam, is not only excellent in heat resistance but also in chemical resistance. It is excellent in heat resistance, creep resistance and elasticity, has good moldability, can be injection molded and is inexpensive, and is suitable for a gasket of a battery. Among them, nylon 46 is more preferable in terms of heat resistance.

The thermosetting resin in the present invention is a resin having the property of being cured by the reaction of unreacted groups remaining in the polymer by heating to increase the degree of polymerization and to proceed with crosslinking to form a network structure. That is, epoxy resin and phenol resin are more preferable. The resin has excellent heat resistance and solvent resistance, and is suitable for a coin-type (button-type) organic electrolyte battery mold.

All the steps in the present invention include a step of assembling the battery, a step of resin molding, and a step of storing the battery during the step. The dehumidifying environment in the present invention is a dehumidifying environment conventionally used when assembling an organic electrolyte battery, and includes, for example, a dehumidifying room, a dry box replaced with dry nitrogen, and the like.

The aforementioned gasket made of a polyamide resin is used for an organic electrolyte battery using an organic semiconductor having a polyacene skeleton structure for the positive electrode and / or the negative electrode instead of the conventional gasket made of polypropylene. By molding with a curable resin, and performing all the steps described above in a dehumidifying environment, the heat resistance of the battery is improved and reflow soldering becomes possible,
The electrical characteristics are improved.

[0021]

Example 1 First, a polyacene sheet was produced as follows. JP-A-61-2180 according to the applicant of the present invention
According to the manufacturing method described in Example 1 of JP-A-60,
Insoluble and infusible polyacene films were synthesized. When the electric conductivity of the substance was measured at room temperature by a DC four-terminal method,
It was 10 ^-4 Ω ^-1 · cm ^-1 . According to elemental analysis, the atomic ratio of hydrogen atoms / carbon atoms was 0.27. The specific surface area by the BET method was an extremely large value of 2100 m ² / g. Next, the polyacene film was ground using a ball mill for 3 hours to obtain a powder.

5% by weight of polytetrafluoroethylene and 10% by weight of carbon black were added to the powder, mixed, and then pressed to obtain a polyacene sheet having a thickness of 0.2 mm. Next, this polyacene sheet and a separator made of a borosilicate glass fiber non-woven fabric were punched out into a disk shape at 200 ° C.
After drying under vacuum for 3 hours, the mixture was stored in a jam pot.

Nylon which is the polyamide resin of the present invention
The gasket obtained by injection molding No. 46 was dried by vacuum drying at 100 ° C. for 3 hours and stored in a jam pot. Next, a conductive paste was applied to the bottom of the inside of the positive electrode can made of stainless steel, the above-described polyacene sheet was placed thereon, pressed from above, and dried at 100 ° C. for 30 minutes. Similarly, a conductive paste was applied to the inner bottom surface of a negative electrode can made of stainless steel, a polyacene sheet was placed thereon, and after pressing, 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 mounted. After a predetermined amount of the electrolytic solution was similarly injected into the negative electrode, a coin-type (button-type) organic electrolyte battery having a diameter of 6.8 mm and a height of 0.96 mm as shown in FIG. 1 was assembled.

Next, after stacking two coin-type (button-type) batteries, a stainless steel terminal is laser-welded to the positive electrode can of one battery and the negative electrode can of the other battery, and an epoxy resin (Matsushita Electric Works, Ltd.) Co., Ltd. CV5032), diameter 8.
Molded to 5mm height 3.5mm. The above-mentioned assembling work was all performed in the dehumidifying room.

The organic electrolyte battery of the present invention prepared as described above has an AC internal resistance (1 kHz, 1 mA) when the reflow soldering is performed so that the surface of the positive and negative electrodes has the temperature transition shown in FIG. Table 1 shows the changes, after reflow soldering,
Table 2 shows the internal resistance after applying a voltage of 5.0 v for 10 days in a constant temperature bath at 70 ° C.

[0027]

[Table 1]

[0028]

[Table 2]

[0029]

COMPARATIVE EXAMPLE 1 An organic electrolyte battery was assembled in a dehumidifying room in the same manner as in the example, and thereafter, terminals were similarly welded and molded in air. Table 1 shows the change in AC internal resistance (1 kHz, 1 mA) when the organic electrolyte battery fabricated as described above was subjected to reflow soldering so that the surface of the positive and negative electrodes had the temperature transition shown in FIG. After reflow soldering,
Table 2 shows the internal resistance after applying a voltage of 5.0 v for 10 days in a constant temperature bath at 70 ° C.

[0030]

Comparative Example 2 An organic electrolyte battery was assembled in a dehumidifying room in the same manner as in the above example using a gasket obtained by injection molding of polypropylene, and thereafter, the terminal was similarly welded and molded in the air in the same manner as above. An AC internal resistance (1 kHz) when the fabricated organic electrolyte battery was subjected to reflow soldering so that the surface of the positive and negative electrodes had the temperature transition shown in FIG.
Table 1 shows the changes in (z, 1 mA).

In Tables 1 and 2, the product of the present invention and the conventional product are compared. The product of the present invention does not cause a short circuit in the reflow soldering, has no change in the AC internal resistance, has improved heat resistance, can be reflow soldered, and has improved electrical characteristics.

[Brief description of the drawings]

FIG. 1 shows a coin type (button type) according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view of a battery.

FIG. 2 shows the change in the surface temperature of the positive and negative electrodes when reflow soldering is used.

[Explanation of symbols]

 1: Positive electrode can 2, 2 ': Sheet made of polyacene organic semiconductor 3, 3': Conductive paste 4: Gasket made of polyamide resin 5: Separator 6: Negative can 7: Electrolyte 8: Mold resin 9: Positive electrode Terminal 10: Negative terminal

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toyorou Harada 5-30-1, Nishitaga, Taihaku-ku, Sendai-shi (72) Inventor Isamu 5-30-1, Nishitaga, Taihaku-ku, Sendai City Examiner Susumu Ogawa (56 References: JP-A-5-325925 (JP, A) JP-A-5-96842 (JP, A) JP-A 2-98455 (JP, U) JP-A 54-29324 (JP, U) JP-A 58-83760 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) H01M 6/16 H01M 2/10 H01M 4/60

Claims (1)

(57) [Claims] 1. An organic electrolyte battery comprising a positive electrode can, a negative electrode can, a positive electrode, a negative electrode, a separator and a gasket, wherein the positive electrode and / or the negative electrode comprises an organic semiconductor having a polyacene skeleton structure, and the gasket comprises a polyamide resin. In a method for manufacturing a coin-type organic electrolyte battery, comprising: molding with a thermosetting resin, all steps from assembly to resin molding are performed in a dehumidifying environment. Of manufacturing a type organic electrolyte battery.