JPS607000Y2 - button air-zinc battery - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a button-type air-zinc battery, and aims to improve the leakage resistance and to sufficiently exhibit the current collecting effect.

In general, a button-type air-zinc battery ionizes oxygen in the air with an oxygen depolarization catalyst layer, which acts as a depolarizer for the battery.

Therefore, in this type of battery, a small hole is provided at the bottom of the anode case to allow air to flow through the small hole.

In addition, the catalyst layer that ionizes oxygen in the air is usually made of activated carbon, sintered nickel, etc. mixed with polytetrafluoroethylene powder, etc., which has a hydrophobic effect, and has a thickness of about 0.1 to 1.
mm is used.

In other words, the volume occupied by the zinc cathode in this type of battery system is about twice that of a mercury battery or a silver oxide battery, but the distance between the zinc cathode and the bottom of the anode case is very short.

Therefore, while the alkaline electrolyte in the zinc cathode is water-repellent by the oxygen depolarization catalyst layer and the hydrophobic porous membrane, some of it also flows from the separator to the hydrophobic porous membrane and the side wall of the anode case, and loses its hydrophilic properties from this side wall. reach the absorbent paper.

The alkaline electrolyte that has reached the moisture-absorbing paper further flows out of the battery system through the small hole at the bottom of the anode case, causing so-called leakage.

In order to prevent this liquid leakage phenomenon, conventionally, a hydrophobic resin or the like was filled between the hydrophobic porous membrane and the side wall of the anode case to prevent the liquid leakage.

That is, FIG. 2 shows a conventional button-type air-zinc battery, in which 21 is an anode case with a small hole 22 at the bottom, 23 is a hydrophilic moisture-absorbing paper, 24 is a hydrophobic porous membrane,
25 is an oxygen depolarization catalyst layer sandwiching an anode current collector network 26;
A sealing plate 7 has a gasket 28 on its peripheral edge, and seals the opening of the anode case 21.

29 is a zinc cathode containing an alkaline electrolyte, 30.30
' is a separator, and 31 is a hydrophobic resin filled between the hydrophobic porous membrane 24 and the side wall of the anode case 21.

However, in this structure, the hydrophobic resin 31 is pressed and deformed by the lower surface of the gasket 28 via the separator 30, 30' when the sealing plate 27 is applied to the date and time, so the adhesive force of the hydrophobic resin 31 is impaired. This will reduce the adhesion between the hydrophobic porous membrane 24 and the side wall of the anode case 21.

Therefore, in this structure as well, the alkaline electrolyte passes between the side wall of the anode case 21 and the hydrophobic porous membrane 24 and reaches the moisture absorbing paper 23, and then reaches the small holes 2 at the bottom of the anode case 21.
2 had the disadvantage that it leaked out of the battery system.

Furthermore, conventionally, as a current collecting means for the anode, an anode current collector network 26 is provided in the oxygen depolarization catalyst layer 25 as shown in FIG.
and the periphery of this current collector network 26 to the anode case 2.
The anode case 21 was brought into contact with the side wall of the anode case 21 to be electrically charged.

However, in this structure, the periphery of the current collector network 26 is brought into contact with the side wall of the anode case 21;
It is necessary to strictly control the dimensional accuracy of the outer diameter of the current collector network 26 and the inner diameter of the anode case 21, and the hydrophobic resin 31
Due to the pressing deformation during sealing, the contact between the peripheral edge of the current collector network 26 and the side wall of the anode case 21 is insufficient, resulting in an insufficient charging effect.

This invention eliminates the above-mentioned conventional drawbacks, has good leakage resistance,
The present invention also provides a button-type air-zinc battery with sufficient anode current collection effect.

Hereinafter, the present invention will be explained based on drawings showing embodiments thereof.

In FIG. 1, reference numeral 1 denotes a metal anode case having a small hole 2 at its bottom, and a hydrophilic moisture-absorbing paper 3 covering the small hole 2 is placed at the inner bottom of the anode case 1.

Reference numeral 4 denotes a hydrophobic porous membrane installed at the inner bottom of the anode case 1 so as to cover the moisture-absorbing paper 3, and this hydrophobic porous membrane 24 is made of a polytetrafluoroethylene film having a hydrophobic effect.

5 is an oxygen depolarization catalyst layer installed on the hydrophobic porous membrane 4;
An anode current collector network 6 is buried as a core material.

7 and 7' are separators installed on the oxygen depolarization catalyst layer 5; 8 is a metal sealing plate having a gasket 9 with an abbreviated cross section on its periphery; this sealing plate 8 is connected to the anode through the gasket 9; Seal the opening of case 1.

Further, the outer diameter of the moisture-absorbing paper 3 is smaller than the inner diameter of the gasket 9.

10 is a zinc cathode containing an alkaline electrolyte, and a sealing plate 8
is filled with.

Reference numeral 11 denotes a metal ring having an angular cross-section and arranged around the periphery of the oxygen depolarization catalyst layer 5. This metal ring 11 is caused by the sealing pressure from the sealing plate 8 to connect the separator 7.7 to the lower surface 9' of the gasket.
The outer wall of this metal ring 11 is brought into close contact with the inner wall of the anode case 1, and the bottom part is brought into close contact with the hydrophobic porous membrane 4.

That is, when sealing with the sealing plate 8, the sealing plate 8
Since the lower surface 9' of the gasket 9 is pressed against the metal ring 11 via the separator 7.7' by the sealing pressure caused by In addition, the bottom of the metal ring 11 acts to bring the hydrophobic porous membrane 4 into close contact with the inner bottom periphery of the anode case 1.

The hydrophobic porous membrane 4 in close contact with each other acts like a so-called backing, and the electrolyte flowing along the side wall of the anode case 1 is completely blocked by this close contact portion.

The following table shows a button-type air-zinc battery having the conventional structure shown in FIG. 2 and a button-type air-zinc battery having the structure of the present invention shown in FIG.

After being stored in an atmosphere with a relative temperature of 90% for 100 (turns), connected to an IKΩ load and discharged, the number of leaks from the small hole at the bottom of the anode case after 1 month has been compared. It is.

As is clear from the above embodiments, according to the present invention, the lower surface of the gasket is pressed by sealing pressure against the metal ring disposed around the periphery of the oxygen depolarization catalyst layer, and this metal ring is tightly attached to the inner wall of the anode case. At the same time, the metal ring allows the hydrophobic porous membrane to adhere to the inner bottom edge of the anode case, which further improves leakage resistance and prevents charging of the anode case. Since it firmly adheres to the wall, it can exhibit sufficient current collection effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a button-shaped air-zinc battery showing an embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of a button-shaped air-zinc battery showing a conventional example. 1...Anode case, 2...Small hole, 3.
... Moisture-absorbing paper, 4 ... Hydrophobic porous membrane, 5.
... Oxygen depolarization catalyst layer, 7,7' ... Separator, 8 ... Sealing plate, 9 ... Gasket, 10 ... Zinc Cathode, 11...metal ring.

Claims (1)

[Scope of utility model registration request] An anode case with small holes at the bottom, a moisture-absorbing paper installed in this anode case sequentially from the bottom, a hydrophobic porous membrane covering the moisture-absorbing paper, an oxygen depolarization catalyst layer, and an oxygen depolarization catalyst layer around the periphery of the oxygen depolarization catalyst layer. It has a metal ring, a separator, a zinc cathode, and a sealing plate that seals the opening of the anode case through a gasket having a cross-sectional shape, and the lower surface of the gasket is sealed by the sealing pressure of the sealing plate. A button-shaped air-zinc battery in which a metal ring is pressed through the periphery to bring the metal ring into close contact with the inner wall of the anode case, and a hydrophobic porous membrane is brought into close contact with the inner bottom rim of the anode case by the metal ring.