JPH09129198A - Flat organic electrolyte battery - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To supply a battery excellent in leakage resistance at a low cost by improving an assembly sealing plate of a flat type organic electrolyte battery. SOLUTION: In the assembled sealing plate, first, an adhesive 7a containing modified PP as a main component is applied to the sealing plate 1 in advance, and then the sealing plate is housed in a molding die to pour synthetic resin 6a and integrally molded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a flat organic electrolyte battery, and more particularly to an improvement in liquid leakage resistance.

[0002]

2. Description of the Related Art The structure of a conventional flat type organic electrolyte battery is shown in FIG. In the figure, 1 is a metal sealing plate that also serves as a negative electrode case, 2 is a negative electrode made of metallic lithium, 3 is a cup-shaped separator, 4 is a mixed powder of an active material such as manganese dioxide, and a conductive agent such as graphite and a binder. Is a pressure-molded positive electrode in the form of a pellet, 5 is a metal battery case that also serves as a positive electrode terminal, and 6b is a synthetic resin gasket having a substantially L-shaped cross section.

As an example of the structure of the battery, first, after injecting a sealing agent 7b such as blown asphalt into the L-shaped portion of the synthetic resin gasket 6b, the sealing plate 1 is inserted and the sealing plate 1 and the synthetic resin gasket 6b are assembled. . Hereinafter, this is referred to as an assembly sealing plate. Next, the negative electrode 2 is pressure-bonded to the assembled sealing plate, and the separator 3 is inserted while shaping it into a cup shape.
After injecting the electrolytic solution, the positive electrode 4 is inserted, and the battery case 5 in which the sealant 7b such as blown asphalt is applied to the inner surface side of the battery case 5 in advance is covered and sealed to form a battery.
The sealant applied to the sealing plate side and the battery case side improves the leakage resistance.

As another method, FIG. 3 shows a structure of a battery using a synthetic resin gasket which is improved from the above example. As shown in the figure, the sealing plate 1 and the synthetic resin gasket 6a are integrally molded to simplify the assembly process and reduce the manufacturing cost.

[0005]

According to the above technique, the sealing plate and the synthetic resin gasket must be assembled in separate steps, and coating defects such as coating unevenness may occur in the sealing agent coating step. Since synthetic resin gaskets are very thin, they are prone to distortion and the like, which causes process defects and increases the cost of battery manufacturing.

In the above-mentioned improved battery, the metal sealing plate and the polypropylene synthetic resin gasket are basically not bonded,
There is a problem in liquid leakage resistance just by increasing the adhesion by shrinking the synthetic resin gasket.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to solve these problems. The sealing agent is applied to the sealing plate in advance, and then the sealing plate and the synthetic resin gasket are fixedly molded to obtain the leakage resistance property. The purpose is to improve the manufacturing process and simplify the process to reduce the manufacturing cost.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION By using the assembled sealing plate according to the present invention, the manufacturing process can be simplified and the cost is low, and the adhesive force between the sealing plate and the synthetic resin gasket is improved, so that the battery has excellent leakage resistance. Can be supplied.

[0009]

EXAMPLE One example of the present invention will be described below with reference to a flat type organic electrolyte battery.

FIG. 1 (a) is a sectional view of an assembled sealing plate according to the present invention. The structure is such that an adhesive containing olefinic synthetic resin such as polypropylene or polyethylene as a main component in advance inside and outside the end of the sealing plate 1 and having a functional group by acid modification with maleic acid (hereinafter Modified PP
An adhesive) is applied, dried at room temperature, and then dried at 130 ° C. for 30 seconds to form a film. After that, it is integrally molded with polypropylene synthetic resin.

FIG. 1 (b) is a schematic view of a flat organic electrolyte battery according to the present invention. The structure is almost the same as the conventional structure shown in FIG. 3, and 1 is a sealing plate which also serves as a negative electrode case,
2 is a negative electrode made of metallic lithium, 3 is a separator, 4 is a positive electrode formed by pressing a mixed powder of an active material such as manganese dioxide and a conductive agent and a binder such as graphite into a pellet,
Reference numeral 5 is a metal battery case that also serves as a positive electrode terminal, 6a is a synthetic resin gasket, and 7a is a modified PP adhesive.

Next, in order to see a concrete effect, the height 1.
Flat type organic electrolyte battery (CR2
016) was constructed.

The assembled sealing plate is made of Toray Kasei Co., Ltd.'s product name Hardlen, which has excellent heat resistance and adhesiveness, as a modified PP adhesive, and has a synthetic resin gasket with a side thickness of 0.2 m.
m was used.

As a positive electrode active material, 100 parts by weight of manganese dioxide heat-treated at 400 ° C. was mixed with 7 parts by weight of graphite to prepare a positive electrode mixture. 430 mg of this mixture was weighed and a molding die having a diameter of 15.7 mm. Molding pressure using 4t / cm
Molding was performed at ² , and pellets dried at 250 ° C. were used as the positive electrode 4. As the negative electrode 2, metallic lithium having a thickness of 0.
It was punched out to have a diameter of 25 mm and an outer diameter of 15 mm, and this was used by being pressure bonded to the inner surface of the assembled sealing plate of the present invention. Also, as the electrolytic solution, a solution obtained by dissolving 0.5 mol / l concentration of lithium perchlorate in a mixed solvent of propylene carbonate and dimethyoethan was used, and a separator made of polypropylene non-woven fabric was arranged in a flat shape to form a battery. I went.

Using the above batteries, the liquid leakage resistance characteristics were compared. As a condition of the liquid leakage test, it is left in a tank at 60 ° C. for 1 hour and then left in a tank at −10 ° C. for 1 hour. After storing this for 120 cycles (10 days) as one cycle,
The leakage was confirmed. Also, the battery manufacturing costs were compared. The results are shown in (Table 1).

[0016]

[Table 1]

In the table, A indicates the above-mentioned embodiment, a battery constructed by integrally molding the sealing plate after applying the modified PP adhesive, B is a battery having a conventional structure, and C is a conventional improved battery. The sealing plate and synthetic resin gasket are simply molded together.

The battery manufacturing costs were compared with each other, assuming that the cost of the conventional battery B assembly and sealing plate was 1. As is clear from (Table 1), the battery using the synthetic resin gasket of the present invention is cheaper than the battery having the conventional structure, and the leakage resistance is improved as compared with the battery without the sealant applied.

Next, the adhesive coating thickness of the assembly sealing plate of the present invention is 10, 20, 30 respectively with respect to the gasket side thickness.
Those having a thickness of 40, 50, 60% were manufactured, and the results of molding defects such as short mold are shown in (Table 2).

[0020]

[Table 2]

From the results of (Table 2), it can be seen that in the region where the coating thickness exceeds 60% of the gasket side thickness, the flow of the synthetic resin becomes poor and short molding occurs.

[0022]

As is apparent from the above embodiments, by using the integrally molded sealing plate and synthetic resin gasket of the present invention, the manufacturing process can be simplified and pre-coated on the sealing plate. The adhesive that was used improved the adhesive strength between the sealing plate and the synthetic resin gasket, and improved the liquid leakage resistance. Therefore, it is possible to supply the flat organic electrolyte battery having excellent liquid leakage resistance at low cost.

[Brief description of the drawings]

FIG. 1 (a) is a sectional view of an assembled sealing plate of the present invention. (B) is a sectional view of a flat organic electrolyte battery according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional flat type organic electrolyte battery.

FIG. 3 is a cross-sectional view of another conventional flat organic electrolyte battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing plate 2 Negative electrode 3 Separator 4 Positive electrode 5 Battery case 6a Synthetic resin gasket integrally molded 6b Conventional synthetic resin gasket 7a Adhesive (modified PP) 7b Sealing agent (Bron asphalt)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Fumio Oo 1006 Kazuma Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A negative electrode using a light metal as an active material, a positive electrode mainly using a metal oxide, a sulfide and a halide as an active material, and a separator interposed between these positive and negative electrodes.
A battery consisting of a battery case that also serves as the positive and negative terminals, a sealing plate, and a synthetic resin gasket interposed between them. A flat type organic electrolyte battery, characterized in that an adhesive having a functional group is applied in advance and then integrally molded with a synthetic resin gasket. 2. The thickness of the adhesive applied to the sealing plate is
60% of the side thickness of synthetic resin gasket molded integrally
The flat type organic electrolyte battery according to claim 1, which does not exceed