JPH1064602A - Alkaline button battery - Google Patents

Abstract

(57) [Problem] An alkaline button type battery in which a positive electrode power generation element and a separator are arranged inside a positive electrode case, and these are pressed and sealed by a gasket attached to an outer periphery of the negative electrode case, and the variation in internal resistance is small. An object of the present invention is to stably provide an alkaline button battery. SOLUTION: Between a power generating element of a positive electrode and a gasket 3,
By interposing the ring 11 partially having a defective portion 11a, air present in a state of being interposed between the air electrode 5 and the separator 4 in the process of assembling the battery is released when the battery is closed. As a result, the formation of an air layer is prevented, and a stable battery with small variations in internal resistance can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline button in which a positive electrode power generation element and a separator disposed in a positive electrode case are liquid-tightly sealed via a gasket attached to the outer periphery of the negative electrode case. It relates to a shape battery.

[0002]

2. Description of the Related Art With the miniaturization, weight reduction and power saving of electronic equipment, the use of small button-type batteries as power supplies has been widespread. Silver oxide batteries are used for precision equipment such as watches because of their long-term reliability, and relatively inexpensive alkaline button batteries are used as power supplies for small electronic equipment such as calculators and game machines. In addition, zinc-air batteries use oxygen in the air as the active material of the positive electrode, and therefore have a higher energy density than other primary batteries.Not only in conventional hearing aid power supplies but also in communication equipment such as pagers. Its demand is growing.

[0003] The prior art related to the present invention will be described below using a button-type zinc-air battery as an example. FIG. 3 shows the structure of a button-type zinc-air battery, and FIG.
It is the figure which showed the principal part enlarged cross section in the state which generated the air layer. 3 and 4, reference numeral 1 denotes a dish-shaped negative electrode case also serving as a sealing plate, and 2 denotes a negative electrode, which is made of zinc powder and an alkaline electrolyte. Reference numeral 3 denotes a ring-shaped gasket attached to the outer periphery of the negative electrode case 1, and 4 denotes a separator for preventing a short circuit between the positive and negative electrodes. 5
Is an air electrode which is a reaction field of oxygen as a positive electrode active material, and is composed of an oxygen reduction catalyst layer and a water repellent layer. 6 is an air electrode 5
A water-repellent film 7 for supplying oxygen to the battery and preventing the electrolyte from leaking out of the battery, and a diffusion paper 7 for uniformly diffusing the air. Reference numeral 8 denotes a positive electrode case, in which an air hole 9 is provided at the bottom for the purpose of taking in oxygen, which is a positive electrode active material.

Generally, when a button-type battery using an alkaline aqueous solution of potassium hydroxide, sodium hydroxide or the like as an electrolytic solution is stored for a long period of time, the battery components such as the negative electrode case 1 and the gasket 3 or the gasket 3 and the positive electrode case 8 are joined. The electrolyte oozes out of the gap between the parts and leaks out of the battery. Preventing the generation of this liquid leakage is one of the important issues in manufacturing a battery using an alkaline electrolyte. The zinc-air battery curls the opening edge of the positive electrode case 8 inward, thereby tightening the outer periphery of the negative electrode case 1 via the gasket 3 and simultaneously compressing the separator 4, the air electrode 5, and the water-repellent film 6. With this, liquid-tight sealing is performed and liquid leakage resistance is secured.

[0005]

However, in the battery having the above structure, a battery having a high internal resistance that deviates from the normal distribution may be generated.

[0006] In the process of constructing the battery, the air existing between the air electrode 5, which is a positive electrode power generation element laminated inside the positive electrode case 8, and the separator 4 is pressed at the peripheral edge by the gasket 3 during sealing. As a result, it moves to the center, and forms an air layer 10 between the air electrode 5 and the separator 4, which serves as an insulating layer. A battery having such a high internal resistance is strongly affected by the IR drop at the time of discharging, so that the discharge voltage becomes low, the operating voltage of the device cannot be reached, and the device cannot be operated normally. Furthermore, if the internal resistance is abnormally high, current may flow into the wrong circuit, causing the device to operate abnormally.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to solve these conventional problems. In the alkaline button type battery of the present invention, a ring having a defective portion is interposed between a gasket and an air electrode or a positive electrode. And sealed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
In the process of assembling the battery by interposing the ring,
Air present in a state sandwiched between the air electrode and the separator stacked in the positive electrode case is pressed by a gasket attached to the negative electrode case at the time of battery sealing,
Because it is pushed out of the battery through the missing part of the ring,
The formation of an air layer in the battery is prevented, and a stable battery with small variation in internal resistance can be provided. In addition,
The ring is suitably made of a plastic material such as nylon which does not adversely affect the battery reaction inside the battery, and the shape may be a circular ring with a part missing.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to an R44 size, that is, a zinc-air battery having a diameter of 11.5 mm and a height of 5.4 mm. Note that the same components as those of the conventional product shown in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description is omitted.

In FIG. 1 and FIG.
5 to 1.50 mm, width W of the defective portion 11a is 0 to 1.50
A ring 11 of mm was prepared, and batteries A to L shown in Tables 1 and 2 were prototyped.

[0011]

[Table 1]

[0012]

[Table 2]

The ring 11 is made of nylon which is resistant to an alkaline aqueous solution, and is disposed between the separator 4 and the air electrode 5 as shown in FIG. 1. The number of occurrences of the upper limit failure of the internal resistance at this time is shown in FIG. Table 3 shows the results as compared with the conventional product.

[0014]

[Table 3]

If the ring 11 has no deficient portion 11a and the width W is 0.05 mm or less, no effect is obtained. This is because the ring 11 was deformed by the pressurization for sealing the battery, and the defective portion 11a was closed.

Table 4 shows the results of the liquid leakage resistance test of the batteries A to L shown in Tables 1 and 2.

[0017]

[Table 4]

The test was conducted at 60 ° C. and 90% R.V. H. The results obtained when the battery was accelerated and stored under the environment described above are shown. The liquid leakage progress of the battery stored under these conditions for 250 hours corresponds to that stored under normal temperature and normal humidity for one year.

From the results shown in Tables 3 and 4, the thickness of the ring 11 is 0.10 to 1.00 mm,
In the examples where the width W is 0.05 to 1.00 mm, the effect of preventing the occurrence of the upper limit failure of the internal resistance due to the formation of the air layer is observed, and the liquid leakage resistance is as high as that of the conventional product. Was obtained.

Next, a trial production of a battery was performed by changing the mounting position of the ring 11. The size of the ring 11 is 0.20 m in thickness
The following three examples and one kind of comparative example were prepared by setting m and the interval between the defective portions 11a of the ring 11 to be 0.10 mm, and compared with the conventional example shown in FIG.

(Example M) A ring arranged between a gasket and a separator (Example N) A ring arranged between a separator and a separator (Example O) A ring is arranged between a separator and an air electrode (Comparative Example P) Ring placed between air electrode and positive electrode case Table 5 shows the number of occurrences of internal resistance upper limit failure for a prototype battery.

[0022]

[Table 5]

As apparent from Table 5, the same effect was obtained when such a ring was disposed in any layer between the air electrode (or the positive electrode) and the bottom of the gasket. On the other hand, no effect was obtained in the comparative example in which the ring was disposed between the air electrode and the positive electrode case.

[0024]

As described above, according to the present invention,
Alkaline button type battery with small variation in internal resistance by preventing the formation of an air layer between the air electrode and the separator by arranging and sealing a ring having a partially defective portion between the air electrode and the gasket Can be provided stably.

[Brief description of the drawings]

FIG. 1 is an enlarged sectional view of a main part of an air zinc battery in one embodiment of the present invention.

FIG. 2 is a plan view of a ring having the same defect.

FIG. 3 is a half sectional side view of a conventional zinc-air battery.

FIG. 4 is an enlarged sectional view of a main part of the zinc-air battery.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Negative electrode case 3 Gasket 4 Separator 5 Air electrode 6 Water repellent film 8 Positive electrode case 10 Air layer 11 Ring 11a Ring missing part W Width of missing part

Claims (2)

[Claims] 1. An alkaline button-type battery in which a positive electrode power generating element and a separator are disposed inside a positive electrode case, and the positive electrode power generating element and the separator are pressed and sealed by a gasket attached to an outer periphery of the negative electrode case. An alkaline button-type battery characterized in that a ring having a partially defective portion is interposed between the power generating element and the gasket. 2. The thickness of the ring is 0.10 to 1.00 m.
The alkaline button type battery according to claim 1, wherein m and the width of the defective portion are 0.05 to 1.00 mm.