JPH05325919A - Manufacture of button type alkaline battery - Google Patents

Abstract

PURPOSE:To solve a problem that the liquid is prone to leak when the positive electrolyte quantity is increased and to manufacture a button type alkaline battery with no leakage of liquid even if the positive electrolyte quantity is increased. CONSTITUTION:A positive electrode case 2 is formed into such a shape as to partly project outward at the bottom surface thereof, where a capacity of the projection 2a exceeds a positive electrolyte quantity. In a final stage, the projection 2a is pressurized into a flat plan. By this manufacturing method, it is possible to obtain a button type alkaline battery excellent in low temperature characteristic without leakage of liquid.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a button type alkaline battery.

[0002]

2. Description of the Related Art Button-type alkaline batteries are widely used as power sources for wristwatches, calculators, game machines, etc. as small and high-performance batteries, and recently, small, thin and high-capacity batteries are required. There is.

A conventional button type alkaline battery will be described below. FIG. 3 shows a sectional structure of a button type alkaline battery.

In FIG. 3, 1 is a positive electrode mixture, 2 is a positive electrode case, 3 is a separator, 4 is a negative electrode mixture, 5 is a sealing plate, 6
Is a sealing packing.

As the positive electrode mixture, a metal oxide such as silver oxide, manganese oxide, or mercury oxide and graphite as a conductive auxiliary agent are mixed,
A disc-shaped one is used. Zinc fluoride is used as the negative electrode mixture. An aqueous solution of potassium hydroxide or sodium hydroxide is used as the electrolytic solution.

[0006] The manufacturing process of the conventional button type alkaline battery will be briefly described. The steps of the positive electrode part include (1) a step of injecting a predetermined amount of electrolytic solution onto the bottom surface of the positive electrode case.

(2) A step of inserting the disk-shaped positive electrode mixture 1 into the positive electrode case 2. (3) A step of inserting a separator having a predetermined size on the positive electrode mixture.

The steps of the negative electrode section are: (1) Filling the sealing plate 5 configured beforehand with the sealing packing 6 with the zinc hydride powder 4 as the negative electrode mixture.

(2) A step of injecting an electrolytic solution onto the negative electrode mixture. Then, the positive electrode portion and the negative electrode portion are coupled and the crimp is sealed to form a button-type alkaline battery.

[0010]

In the above conventional structure, since the positive electrode mixture is inserted on the positive electrode electrolytic solution, the electrolytic solution bounces out when the positive electrode mixture is inserted or sealed, and the positive electrode mixture and the case are separated. There was a problem in that the liquid leaked immediately after the battery was sealed by leaking up to the upper part of the case through the gap and immediately after the battery leaked.

Further, as shown in FIG. 2, the larger the amount of the positive electrode electrolyte, the more stable the battery characteristics (in particular, the battery internal resistance at low temperature is proportional to the pulse characteristics). Injecting 100% or more of the void volume of the mixture) improves the battery performance, but the above problems are more likely to occur as the amount of the electrolytic solution increases.

The present invention solves the above-mentioned conventional problems and is a method for producing a button-type alkaline battery in which the electrolytic solution does not splash or creep up when the positive electrode mixture is inserted or sealed, and immediately after which the leakage does not occur. The purpose is to provide.

[0013]

In order to achieve this object, the button type alkaline battery of the present invention has a shape in which a part of the bottom surface has a protrusion protruding outward and the volume of the recessed portion caused thereby is The method has a step of using a positive electrode case having a volume larger than the volume of the electrolytic solution to be injected into the positive electrode side, injecting the electrolytic solution into the recessed portion, and pressing the convex portion on the bottom surface to flatten it when the battery is sealed.

Therefore, the manufacturing method of the button type alkaline battery of the present invention is as follows: (1) A step of injecting a predetermined amount of electrolytic solution to be injected into the positive electrode side into the concave portion formed by the convex portion on the bottom surface of the positive electrode case.

(2) A step of inserting a disk-shaped positive electrode mixture into the positive electrode case. (3) A step of punching out the separator and inserting it into the surface of the positive electrode mixture.

(4) A step of coupling with the negative electrode. (5) A step of flattening the convex portion on the bottom surface of the positive electrode case while sealing the crimp.

A battery is constructed through the above steps.

[0018]

With this structure, when the positive electrode mixture is inserted into the positive electrode case, the positive electrode mixture is held on the surface other than the convex portion on the bottom surface of the case, so that the electrolytic solution is pushed and splashes, or the case and the positive electrode mixture are mixed. It doesn't crawl up through the gap between
Immediately after, there is no leakage.

Further, since the protrusion of the bottom of the positive electrode case is pressed into a flat surface when the battery is sealed, there is no problem in appearance.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an example of the positive electrode case used in the present invention. As can be seen from the figure, a part of the bottom surface of the positive electrode case 2 projects outside. Although the volume of the convex portion 2a varies depending on the type of battery, it has a volume equal to or larger than the void volume of the positive electrode mixture of the battery.

Also, the planar shape of the convex portion of the positive electrode case is circular,
Although it may have any shape such as a quadrangle or a triangle, a circle is generally used.

The case of a silver oxide battery SR626SW will be described below as a specific example of the present invention.

SR626SW has a diameter of 6.8 mm and a height of 2.
It is a 6mm button type battery. The void volume of the positive electrode mixture is 3.
Comparison of the occurrence rate of liquid leakage immediately after changing the amount of the positive electrode electrolyte using the positive electrode case of the present invention and the conventional positive electrode case having a flat bottom surface under the condition of 8 μl and the positive electrode electrolyte injection volume of 4 μl did.

For the positive electrode case of the present invention, three kinds of bottom projections having a volume of 3 μl, 4 μl and 5 μl were used.

The results are shown in (Table 1).

[0027]

[Table 1]

As can be seen from (Table 1), when the conventional case is used, the amount of electrolyte solution is 3.5 μl or more and leakage occurs immediately thereafter. Even if the amount is 3 μl, leakage does not occur immediately after the amount of electrolyte reaches 4 μl.

This is because the positive electrode mixture absorbs the electrolytic solution, and even if the amount of the electrolytic solution is more than the volume of the convex portion and is less than a certain amount, it is a free electrolysis that creeps up from the gap between the positive electrode mixture and the case. It is thought that this is because the liquid runs out.

This is also the case when the volume of the convex portion is 4 μl or 5 μl. Therefore, it can be seen that the use of the positive electrode case of the present invention significantly improves the occurrence rate of liquid leakage immediately after. Further, it can be seen that the larger the volume of the convex portion on the bottom surface, the greater the effect.

However, in order to obtain a battery having stable low-temperature characteristics, in order to inject the positive electrode electrolyte solution in an amount of 100% or more of the positive electrode mixture void volume, considering the variation in the injection amount, the bottom of the positive electrode case is considered. The volume of the convex portion is preferably equal to or larger than the volume of the positive electrode electrolyte solution.

As described above, by using the manufacturing method of this embodiment, a battery having excellent low-temperature characteristics can be manufactured immediately without leakage.

In this embodiment, the silver oxide battery SR626 is used.
Although only SW is described, similar effects can be obtained in other sizes and other button type alkaline batteries such as alkaline manganese battery and mercury battery.

[0034]

As described above, the present invention uses the positive electrode case in which a part of the bottom surface is protruded to the outside and the volume of the convex portion is equal to or more than the amount of the positive electrode electrolyte to be injected, and finally the convex portion is used. By adopting a manufacturing method in which the positive electrode is pressurized to a flat surface, it is possible to provide a button-type alkaline battery having excellent low-temperature characteristics without leaking immediately after pouring the positive electrode electrolyte solution at 100% or more of the positive electrode mixture void volume. It is a thing.

[Brief description of drawings]

FIG. 1 is a sectional view of a positive electrode case according to an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the ratio of the positive electrode electrolyte solution injection volume to the positive electrode mixture void volume and the battery internal resistance.

FIG. 3 is a sectional view of a conventional button-type alkaline battery and the present invention.

[Explanation of symbols]

 1 Positive Electrode Mixture 2 Positive Electrode Case 3 Separator 4 Negative Electrode Mixture 5 Sealing Plate 6 Sealing Packing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Korenori Morita 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (2)

[Claims] 1. A positive electrode mixture is poured into a positive electrode case, and then a positive electrode material mixture and a separator molded in a disk shape are sequentially inserted and placed.
On the other hand, a negative electrode mixture and an electrolytic solution are filled in a sealing plate provided with a sealing packing on the periphery, and the positive electrode case is coupled,
Then, in the manufacturing method of the button battery in which the sealing portion is crimped by the crimp sealing, a part of the bottom surface of the positive electrode case is previously formed with a convex portion on the outside, and the electrolytic solution is injected into the recess formed by the convex portion. , A method for manufacturing a button-type alkaline battery in which the convex portion on the bottom surface of the positive electrode case is flattened when the caulking is performed. 2. The method for manufacturing a button type alkaline battery according to claim 1, wherein the volume of the recessed portion formed by the convex portion on the bottom surface of the positive electrode case is not less than the volume of the positive electrode electrolyte.