JPS59160953A - Manufacture of alkaline battery - Google Patents

Abstract

PURPOSE:To improve resistance to leakage of liquid while removing the gap part and heightening tightness of the closely contacting part by a emthod in which a metal case is provided with salient parts projecting inwardly, while being bent for sealing by using gaskets in which the salient parts are formed in the projecting parts in the positions opposing thereto after sealing. CONSTITUTION:A positive pole black mixture 1 mainly composed of silver oxide, manganese dioxide and nickel dioxide is placed inside a positive pole can 2 made of a metal case 2. Next, a separator, which consists of a minute hole film made of synthetic resin and a semitransparant film, is placed on the positive pole black mixture while injecting an electrolyte. While using the gaskets, each of which has a projecting part 5 thicker than the other part in the position which is to closely contact with a salient part 3 provided on the positive pole cna 2, said gaskets 4 are fitted to the negative pole can 8 made of a metal sealing plate 8 filled with the negative pole black mixture 7 mainly composed of zinc and cadmium for being placed on the separator 4. Further, the opening ends of the positive pole can 2 are bent inwardly for sealing in the state in which the upper-and-lower parts are pressed in.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an alkaline battery, which improves leakage resistance by improving the sealing method. 1-', 1lli lead, dioxide, kel-
For alkaline batteries such as cadmium batteries, organic electrolyte batteries such as manganese dioxide-lithium oxide batteries, and especially button-type batteries, the positive electrode can is fitted with a cross-sectional gas cap, 1, and the end of the positive electrode can is inserted inward. It was folded and sealed by applying pressure. However, in the above method, a gap is formed between the positive electrode can, the gasket, and the negative filler, so that the electrolyte leaks out through the gap during use or storage of the battery, damaging the equipment used. I had something to do.

In order to eliminate these drawbacks, the bending pressure during sealing may be increased, or adhesive may be applied to the surface of the gasket.
Attempts have been made to eliminate the gap, but since the battery itself is small, it is extremely difficult to work in the manufacturing process.

The present invention eliminates the above drawbacks.

The manufacturing method of one embodiment will be explained in detail below with reference to the drawings.

In FIG. 1, a cathode can 2 consisting of a metal case 2 having a protrusion 3 protruding inward near the open end contains silver oxide and nitride dioxide.

A positive electrode mixture 1 containing nickel oxide as a main component is placed. Next, as shown in FIG. 6, a separator 6 made of a synthetic resin microporous membrane, a semipermeable membrane, etc. is placed on the positive electrode mixture 1, and an il electrolyte is poured into the separator 6. On the other hand, as shown in FIG. 2, the gasket 4 has a cross-sectional shape including a protrusion 6 provided on the positive electrode can 2 and a protrusion 5 that is thicker at the position where it abuts after sealing than at other parts.

This gasket 4 is fitted into an electrode can 8 made of a metal sealing plate 8 filled with a negative electrode mixture 7 mainly containing zinc and cadmium, and placed on the seventh pallet 4. Next, with the upper and lower parts pressed, the open end of the positive electrode can 2 is bent inward and sealed, thereby producing a battery having the shape shown in FIG. 4.

As described above, in the present invention, the protrusion 5 provided on the positive electrode can 2 increases the contact pressure between the gasket 4 and the positive electrode can 2 and the electrode can 8, and the protrusion 6 causes more compression than other parts. Therefore, the gap generated around the protrusion 6 is thickened by the protrusion 5 of the gasket 4, so that the close contact between the positive electrode can 2 and the gasket 4 is good, and it is difficult for the electrode can 8 to form a gap.
The pressing force on the gasket 4 is made uniform with the surface that comes into contact with the gasket 4. Therefore, the entire surface of the gasket 4 is brought into close contact with the positive electrode can 2 and the electrode can 8, completely preventing leakage of the electrolyte from inside the battery.Next, the positive electrode can is placed at the height B of the protrusion by the gas gate 7. The present invention uses a gasket in which the thickness of the gasket is 50% of the thickness of the gasket (cross section A where no projection is formed), and the thickness A' of the projection is 50% of the thickness of the gasket (cross section A where no projection is formed). In order to increase the contact pressure between the battery, the gasket, and the positive electrode can, the improved conventional battery A and 9 have a normal positive electrode can and gasket in which the protrusion on the positive electrode can is made 50% higher than the thickness A of the gasket. Concerning the conventional battery B used, 100 silver-zinc oxide batteries each having a diameter of 7° and a height of 2.6 mm and using a caustic potassium electrolyte were fabricated.

The leak resistance performance was compared. The test conditions were a temperature of 45° C., a humidity of 90%, and the product was left for 60 days.

The results are shown in Table 1.

From the above results in Table 1, it is understood that the leakage resistance performance of the battery according to the present invention is greatly improved. In addition, the leakage of conventional battery A is
A gap may form around the protrusion on the inner surface of the positive electrode can and a part of the contact area with the gasket, resulting in leakage.Also, because the battery shape itself is very small, the height of the protrusion may vary. If the gasket was higher than 50%, the compressibility of the gasket would become too high and its elastic force would weaken, making it impossible to obtain the necessary sealing compression and weakening the contact pressure, resulting in leakage.

In addition, as a result of various studies regarding the height of the protrusion of the positive electrode can and the height of the protrusion of the gasket, it was found that the appropriate protrusion of the positive electrode can should be 20 to 80% of the thickness of the gasket, and the protrusion of the gasket should not be too thick. Then, the appropriate height is up to the normal thickness of [gas care because a gap is formed around the protrusion of F] (total is twice the normal thickness). Furthermore, the shape of the protrusions is not limited to the embodiments, as long as the protrusions come into contact with each other when the end of the positive electrode can is bent inward. Also, the polarity of the positive electrode can may be reversed.

As described above, the present invention provides a metal case with a protrusion that protrudes inward, and after sealing the metal case, the gasket and the metal seal are bent using a gasket with a protrusion formed at a position opposite to the protrusion. This is an alkaline battery that increases the contact pressure with the plate, eliminates the gap, improves the adhesion of the contact area, and improves leakage resistance, and has great industrial value.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the metal case, Fig. 2 is a sectional view of the Gaskent, and Fig. 6 is a sectional view of the battery before sealing. FIG. 4 is a sectional view of the battery after sealing. 2...Metal case 6...Protrusion 4...Gaskent 5...Protrusion ('dI8...Metal sealing plate Applicant Yuasa Battery Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1) A metal wooce having an inward protrusion formed on its side surface. After placing the active material on one side of the power generation element and placing the separator on the active material, a gasket with a protrusion formed on the outer surface at the position where it contacts the protrusion of the metal case after sealing and the active material of the capacity are placed. A method for manufacturing an alkaline battery, in which a filled metal sealing plate is placed, and the open end of the metal case is bent inward to seal it. 2) The internal force protrusion of the metal case is 20~20mm thicker than the gasket.
A method for manufacturing an alkaline battery according to claim 1, wherein the height is 80%. 6) The method for manufacturing an alkaline battery according to claim 1, wherein the protruding portion of the gasket has a height less than or equal to the thickness of the gasket.