JPS59194361A - Air cell - Google Patents

Abstract

PURPOSE:To prevent electrolyte leakage even during long storage by decreasing porosity in the periphery of an air electrode than that in its center in an air cell prepared by accommodating an air electrode comprising porous material and an anode in a can having air supply holes. CONSTITUTION:A cup-shaped cathode can 1 which also serves as a cathode terminal consists of nickel plated steel plate and has air supply hole 11 in its bottom. An air electrode 3 is placed through a water repellent material 2 comprising polytetrafluoroethylene inside the can 1, and a separator 4 comprising a barrier and polypropylene nonwoven fabric is placed on the air electrode 3. In this state, the circumference of the air electrode is pressed against the can 1 to reduce the porosity of the circumference to 7% or less. An anode sealing plate, comprising copper clad nickel plated steel with copper placed inside, filled with an anode material 5 is inserted into the opening 1a of the can 1 through an insulating gasket, and the opening 1a is bent inward to seal a cell. The circumference of the air electrode may be spreaded or impregnated with adhesive. Thereby, electrolyte leakage even during long storage is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air cell with improved leakage resistance.

Conventionally, as an air battery, an air electrode consisting of an air electrode sheet attached to a core body through a water repellent material is placed inside an anode can with an air supply hole on the bottom, and a sheet of paper or other liquid-containing material is placed. ,
After that, a cathode sealing plate filled with gelled zinc was installed at the opening of the anode can via an insulating packing, and the opening was bent inward to seal the opening to complete the battery.

By the way, the air electrode in such an air battery has a porous structure 1 having a large number of pores in order to have good air permeability.
The so-called porosity, which is generally expressed as the ratio of the total volume of the pores of the material to the total volume of the material including the pores, is 30.
Sizes from 1 to 70 inches are used.

However, in conventional air batteries, when there is a large amount of electrolyte in the entire air electrode, the electrolyte on the liquid-containing side may pass through the pores at the periphery of the air electrode to the positive electrode can, and this can lead to leakage during long-term storage. There was a possibility that this could be the cause.

This invention was made to eliminate the above-mentioned drawbacks, and provides an air battery that can reliably prevent electrolyte leakage even during long-term storage by making the porosity of the air electrode periphery smaller than that of the center. The purpose is to

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a cup-shaped anode can made of a nickel-plated steel plate which also serves as an anode terminal, and this anode can 1 has an air supply hole 11 on the bottom surface.

Inside the anode can 1, a C air electrode 3 is disposed via a water repellent body 2 made of polytetrafluoroethylene, and further a separator 4 made of a nonwoven fabric of polypropylene such as cellophane or the like is disposed.

In this state, a pressing force is applied to these peripheral parts toward the anode can 1 side, so that the porosity of the peripheral part of the crushed air electrode 3 becomes smaller than that of the central part. Specifically, it is desirable that the porosity of the peripheral portion of the air electrode 3 be 7% or less. This is 7
If the temperature is above Excellent, leakage may still occur through the pores in the periphery of the air electrode 3 during long-term storage, and in addition, the pressure of the periphery of the air electrode 3 to the anode can 1 side may not be sufficient, resulting in slight leakage. For example, liquid leakage may occur due to unevenness.

Thereafter, a gelled zinc 5 which will become a cathode is inserted into the opening 1a of the anode can 1.
A cathode sealing plate 6 made of nickel-plated steel and clad with a copper plate is provided on the inner side filled with a copper plate via an insulating packing 7, and in this state, the opening 1a is bent inward to apply a tightening force and seal the battery. has been completed.

With this configuration, the porosity of the periphery of the air electrode can be reduced, so leakage through the pores in the periphery can be reliably prevented, and at the same time, the porosity of the periphery of the air electrode on the anode can side can be reduced. The pressure contact condition is also good, and leakage from this part can be reliably prevented.

By the way, the battery of this invention configured as described above [A]
and conventional product CB), 50 pieces each were stored at room temperature for 1 month, 6 days.
When the number of leakages was investigated after storage for several months and one year, the results shown in the table below were obtained. In this case, an A44 button type air battery is used as the battery. In addition, one invention battery (
In A), the porosity of the central part of the air electrode is 30%, and the porosity of the peripheral part is 30%, and in the conventional battery CB), the porosity of the entire air electrode is 30%.

From the results shown in the table above, it was found that the product of the present invention can reliably prevent electrolyte leakage even during long-term storage compared to the conventional product.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be implemented with appropriate modifications without changing the gist.

For example, in addition to the above-mentioned embodiment, a means for reducing the porosity of the peripheral edge of the air electrode 3 is to crush the peripheral edge of the air electrode 3 by using the tightening force when bending the opening 1a of the positive electrode can 1. The porosity may be reduced.

Furthermore, a chloroprene rubber-based rubber adhesive may be applied or impregnated onto the peripheral edge of the air electrode 3 as the adhesive. Furthermore, the periphery of the air electrode may be crushed in advance to reduce the porosity and then incorporated into the anode can. Even in this case, leakage of liquid through the pores in the peripheral portion can be prevented, and a considerable effect can be expected.

As described above, according to the present invention, it is possible to provide an air battery that can reliably prevent electrolyte leakage even during long-term storage by making the porosity of the air electrode periphery smaller than that of the center.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing an embodiment of the present invention. 1...Anode can 1a...Opening part 11...
Air supply hole 2... Water repellent body 3... Air electrode
4... Separator 5-... Gel zinc
6...Cathode sealing plate 7...Insulating packing

Claims (4)

[Claims] (1) An air battery in which an air electrode and a cathode made of a porous material are laminated and filled inside a can body having air supply holes, wherein the porosity of the periphery of the air electrode is smaller than that of the center. . (2) The air cell according to claim 1, wherein the air electrode has a peripheral edge having a porosity of 7 inches or less. (3) The air cell according to claim 1 or 2, wherein the air electrode has a crushed peripheral portion. (4) The air cell according to any one of claims 1 to 3, wherein the air electrode has a peripheral portion coated or impregnated with an adhesive.