JPS6288274A - Manufacture of button type alkaline cell - Google Patents

Abstract

PURPOSE:To prevent swelling out of negative electrode black mix from a container by filling the negative electrode container with negative electrode black mix and gelatinizing then pressuring by means of a jig having a thin section of such outer diameter as approximately same with the inner diameter of the negative electrode container. CONSTITUTION:A negative electrode container 2 comprising a pan-shaped sealing board fixed at the circumference with an insulation gasket 1 is filled with negative electrode black mix composed of gelation zinc powder and gelatinizer then alkaline electrolyte is injected to produce a gelatinous zinc negative electrode 5 thus to form the negative electrode section of a button type alkaline cell. Upon gelation of negative electrode black mix, the negative electrode 5 is pressurized by means of a pressurizing jig 11 provided with a thin section 11a having the outer diameter approximately same with the inner diameter of the container 2. Then it is removed upward to maintain the negative electrode 5 in horizontal surface condition. Since the outermost circumferential section of the negative electrode 5 is completely surrounded by the thin section 11a and pressurized, swelling out of the negative electrode 5 is eliminated resulting in improvement of the productionability.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing button-type alkaline batteries using a gelled zinc negative electrode, such as alkaline manganese batteries, mercury batteries, and silver oxide batteries.

BACKGROUND OF THE INVENTION In recent years, button-type alkaline batteries have been widely used as power sources for small electronic devices. When forming the gelled zinc negative electrode for this button-type alkaline battery, as shown in FIG.
After filling the negative electrode mixture 3 consisting of zinc hydrate powder and gelling agent, the alkaline electrolyte 4 is poured into the negative electrode mixture 3 as shown in Figure 3, and after the injection is finished, it is left for the required time. That's the third
As shown in Figure C, a gelled zinc negative electrode 5 was formed.

Problems to be Solved by the Invention However, in the above-described forming method, the injection pressure applied to the central part of the mixture surface is large, and as shown in FIG. 3C, the gelled zinc negative electrode formed after injection. In No. 6, a portion of the inner periphery of the negative electrode container was bulged. Even if the injection speed is lowered to weaken the injection pressure, the same swelling still occurs, and in this state, a battery configured in combination with a positive electrode will have a gelled zinc negative electrode inside the battery. Since it protrudes from inside the container, there is a problem in that it comes into contact with the positive electrode and causes voltage deterioration.

In view of the above-mentioned problems, the present invention is a manufacturing method for improving the characteristics of a button-type alkaline battery in which the filling rate of gelled zinc negative electrode is relatively high and it is difficult to form a horizontal surface state in the negative electrode container. .

Means for Solving the Problem In order to solve this problem, the present invention creates a gel by injecting an alkaline electrolyte into a negative electrode mixture consisting of zinc chloride powder and a gelling agent filled in a negative electrode container. A method for forming a gel-like zinc negative electrode, in which after the liquid is poured into a gel-like state, the gel-like zinc negative electrode is formed using a pressurizing jig provided with a thin-walled part having an outer diameter that approximates the inner diameter of the negative electrode container. The surface is made horizontal by applying pressure.

Function: According to this manufacturing method, the problems of conventional methods can be solved.
Even when combined with a positive electrode to form a battery, the gelled zinc negative electrode does not protrude from the inside of the negative electrode stone. Therefore, the gelled zinc negative electrode does not come into contact with the positive electrode inside the battery, which solves the problem of voltage deterioration. Examples Examples of the present invention will now be described with reference to the drawings. FIG. 2 is a half-sectional view of a button-type mercury battery (height: 9.2 mm, outer diameter: 15 m++) obtained conventionally and according to the present invention. A general method for manufacturing this battery is to insert the positive electrode mixture 6 together with the positive electrode ring 8 into the positive electrode container γ and compression mold it. Then, an alkali-resistant separator 9 and an electrolyte-impregnated material 10 are placed on the molded positive electrode mixture 6, and a predetermined amount of gelled zinc negative electrode 5 is placed on top of the molded positive electrode mixture 6, and a negative electrode container consisting of an insulating ring 1 and a sealing plate 2 is placed. The insulating ring 1 is tightened around the opening edge of the positive electrode container 7 to form a battery. Among these methods, the feature of the present invention lies in the method of forming a gelled zinc negative electrode.A predetermined amount of a negative electrode mixture consisting of zinc chloride powder and a gelling agent is filled into a negative electrode container consisting of an insulating gasket 1 and a sealing plate 2. After that, a predetermined amount of alkaline electrolyte is injected onto this surface, and after the alkaline electrolyte permeates uniformly into the mixture, a gelled zinc negative electrode 5 is formed as shown in FIG. 3C. Thereafter, as shown in FIG. 1a, the gelled zinc negative electrode is pressurized using a pressurizing jig 11 provided with a thin wall portion 11a having an outer diameter close to the inner diameter of the negative electrode container.

Thereafter, as shown in FIG. 1, the pressing jig 11 is removed upward from the surface of the gelled zinc negative electrode, and the gelled zinc negative electrode is formed in the negative electrode container with a horizontal surface.

The pressurizing jig applied to the present invention has a large effect on the thin walled part at the tip, and can apply pressure while completely surrounding the outermost part of the gelled zinc negative electrode. The gelled zinc negative electrode does not protrude.

The thickness of the thin portion is preferably as thin as possible. This is because the grooves formed in the gelled zinc negative electrode after pressure forming become larger and the area of contact with the electrolyte-impregnated material 1° as shown in FIG. 2 decreases. In addition, the longer the length of the thin wall part, the more securely the protrusion of the gelled zinc negative electrode is suppressed, but it depends on the swelling and gelling state of the gelled zinc negative electrode and the filling ratio of the gelled zinc negative electrode to the internal volume of the negative electrode container. It is preferable to adjust the length to an appropriate length.

According to the pressure forming method of the present invention, 1000 batteries of the example were assembled, and 15 days after completion of the batteries at room temperature and 60°
The number of open circuit voltage deteriorations (less than 1.50 V) of each SOO after being stored at C for 20 days is compared with the conventional product, and the results are shown in the following table.

As a result, the product of the present invention can be used at room temperature for 16 days after completion of the battery.
It is also better than conventional products in terms of the number of open circuit voltage deteriorations after being stored at 60'C for 20 days.

When the inlet periphery of the negative electrode container was checked by disassembling the battery, there was no protrusion of the gelled zinc negative electrode in the products of the present invention, and protrusion of the gelled zinc negative electrode was observed in all conventional products with voltage degradation.

Effects of the Invention As described above, the present invention can provide a battery that is free from voltage deterioration and has excellent mass productivity by pressurizing a gelled zinc negative electrode so that its surface becomes horizontal.

[Brief explanation of drawings]

Figures 1a and 1b are cross-sectional views illustrating the manufacturing process of the present invention, d is a cross-sectional view of the gelled zinc negative electrode being formed by lowering the pressurizing jig, and b is a cross-sectional view of the gelled zinc negative electrode formed after the pressurizing process is completed. A cross-sectional view when the pressing jig is raised; FIG. 2 is a half-sectional view of button-type batteries obtained by the conventional method and the present invention; FIG. 3 a, b, and c are cross-sectional views illustrating the conventional manufacturing process. In this figure, a is a cross-sectional view of the negative electrode mixture filled in the negative electrode container, b is a cross-sectional view of the alkaline electrolyte poured onto the surface of the negative electrode, and C is the gelled zinc negative electrode after being left for a predetermined period of time. FIG. 3 is a cross-sectional view showing the formed state. 1...Insulating gasket, 2...Sealing plate (1+2...Negative electrode container), 3...-Negative electrode mixture, 4...Alkali Electrolyte, 5...
Gel-like zinc negative electrode, 6... Positive electrode mixture, 7...
...Positive electrode container, 8...Positive electrode ring, 9...
... Separator, 1Q ... Electrolyte impregnated material, 11
. . . Pressure jig, 11a . . . Thin end portion of the pressure jig. Name of agent: Patent attorney Toshio Nakao and one other person
---56 Gokakure 1fα-...Toge Torinokigun l-1lC,-

Claims (1)

[Claims] A negative electrode mixture consisting of zinc chloride powder and a gelling agent is filled into a negative electrode container consisting of a dish-shaped sealing plate with an insulating ring attached to the periphery via a sealant, and then an alkaline electrolyte is poured into the negative electrode mixture. A method of forming a gelled zinc negative electrode by liquidizing the gelled zinc negative electrode. A method for producing a button-type alkaline battery, which is characterized by applying pressure and forming the surface horizontally.