JPH06231808A - Air battery and sealant for air battery - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a sealing material that prevents a decrease in battery capacity due to an electrochemical reaction with oxygen in the air accumulated in a convex portion provided on the bottom surface of a case. [Constitution] A sealing material composed of a base material 4 and an adhesive agent 5. A convex member provided on the bottom surface of the case by interposing an oxygen absorber 6 in the adhesive agent covering the air intake hole on the bottom surface of the case and its surroundings. Oxygen in the air staying in the chamber is completely removed to prevent the decrease in battery capacity due to the electrochemical reaction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air battery, and more particularly to a sealant for an air battery in which an air intake hole is closed with a sealant, and an air battery using this type of sealant.

[0002]

2. Description of the Related Art The positive electrode active material of an air battery is oxygen in the air. Therefore, it is necessary to provide the positive electrode case (hereinafter referred to as the case) with a vent hole for taking in oxygen in the air.

In general, an air battery has a structure shown in FIG. 1, and an air intake hole 2 provided on the inner bottom surface of a convex portion 1a for introducing air in the case 1 for introducing oxygen in the air.
(Hereinafter, it is described as a hole) and is taken as a positive electrode active material. When the battery is stored in a state where it is not used, the electrolytic solution (caustic alkaline aqueous solution) in the battery evaporates from the hole 2 or the electrolytic solution absorbs carbon dioxide gas in the air to generate carbonate. In order to prevent the deterioration of the battery storage performance, it is necessary to close the hole 2 with the sealing material 3 having a high gas barrier property. Therefore, a sealing material as described in Japanese Utility Model Publication No. 2-18524 is used. This sealing material usually has a total thickness of several hundreds to several tens of microns, and has a synthetic resin film, synthetic rubber sheet, and special surface treatment that has an adhesive and non-adhesive adhesive on one side and has excellent gas barrier properties. The used paper is a laminated material that is a composite of these papers. When the battery is used, this sealing material is peeled off from the outer bottom surface of the case 1 to expose the hole 2 for use.

[0004]

As described above, the role of the sealing material is important in the construction of the air battery. Further, in order to smoothly carry out the electromotive reaction of the air battery, it is necessary to remove the sealing material from the bottom surface of the case and uniformly supply oxygen to the positive electrode catalyst. Especially when a large current is required, the convex portion provided on the bottom surface of the case needs a sufficient volume necessary for air diffusion. However, if a sufficient amount of volume of the convex portion provided on the bottom surface of the case is secured, oxygen in the air staying in this portion and the positive electrode catalyst react electrochemically, and the capacity of the battery decreases to a considerable extent. there were.

[0005]

SUMMARY OF THE INVENTION The present invention provides a sealing material that solves these problems, and an air battery using the sealing material.

That is, the portion of the sealing material that is in contact with the air intake hole is made to have a deoxidizing property. Specifically, the sealing material provided in the case has an oxygen absorber attached to the portion that is in contact with the air intake hole, and the other surface is Use a material with a gas barrier property.

[0007]

According to this structure, since the oxygen scavenger in the sealing material absorbs and removes the oxygen in the air staying in the convex portion provided on the bottom surface of the case, the positive electrode catalyst and the oxygen in the air staying in the convex portion are electrically charged. It reacts chemically and prevents the battery capacity from decreasing,
An air battery having an excellent electric capacity can be provided.

[0008]

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

FIG. 1 shows an air battery using the sealing material according to the present embodiment, 1 is a positive electrode case, and an air diffusion convex portion 1a for air intake and an air diffusion convex portion 1 on the bottom surface thereof.
An air intake hole 2 is provided on the bottom surface of a. 3 is a sealing material of the present invention, which is composed of a base material 4 and an adhesive agent 5.
Specifically, the oxygen scavenger 6 is interposed in the air intake hole on the bottom surface of the case and the adhesive that covers the surrounding area.
The oxygen absorber 6 may be used as it is in the case of a powder, and may be used by encapsulating it in a microcapsule or impregnating it with an adsorbent such as a powder or a fiber in the case of a liquid. Reference numeral 7 is a positive electrode catalyst layer having an oxygen reducing ability such as manganese dioxide. 8
Is a negative electrode zinc, 9 is a separator made of a polyolefin microporous film, 10 is a Teflon membrane which allows gas to pass but does not allow liquid to pass, and 11 is diffusion paper made of pulp fiber. 12 is a sealing packing that is nylon 11 with excellent insulation and airtightness
Made of polyamide resin. A negative electrode case 13 is made of, for example, a metal material obtained by plating iron with nickel.

Next, the structure of the sealing material 3 shown in FIG. 2 will be described. The sealing material 3 is composed of the base material 4 and the adhesive 5 as described above, and the base material 4 is usually a polyester having a thickness of 20 to 100 microns. Generally, a synthetic resin film having excellent gas barrier properties such as polypropylene, polyethylene, or polyvinylidene chloride is used alone, or a laminated material with a paper material, a fiber material, a rubber material, or the like is used. Adhesive 5
Examples of the adhesive adhesive composition include polyacrylic acid ester, chlorinated polyethylene, SBR (styrene-butadiene rubber), polyisobutylene and the like having a thickness of 5 to 20 μm.

In the present invention, the thickness of the base material of the sealing material 3 is 3
A 5 micron polyester film was used, a polyacrylic acid ester having a thickness of 20 microns was used as an adhesive, and Rongalit was interposed as a deoxidizer 6 in a predetermined portion of the adhesive. Using the thus constructed sealant, the diameter is 16.0 mm, the height is 6.2 mm, and the electric capacity is 1100 m.
Table 1 shows the results of comparing the electric capacities of the Ah button type air battery PR1662 when 50 batteries were respectively discharged at a constant current of 5 mA.

[0012]

[Table 1]

As the oxygen scavenger, Rongalit intervened in a predetermined portion of the pressure-sensitive adhesive was used. , And / or its salt, sorbose, glucose, lignin, dibutylhydroxytoluene, or butylhydroxyanisole have been found to have the same effect as this experiment.

[0014]

As is apparent from Table 1, the sealant of the present invention uses the oxygen absorber in the sealant to absorb and remove oxygen in the air accumulated in the convex portion provided on the bottom of the case. It is possible to prevent the capacity of the battery from decreasing due to electrochemical reaction between oxygen in the air that stays in the positive electrode catalyst and the convex portion. In addition, the oxygen scavenger of the sealant has a gas barrier material on the outer surface exposed to the outside, so it absorbs only oxygen in the convex parts of the case, so that the oxygen scavenging effect can be very efficiently exhibited. Is.

[Brief description of drawings]

FIG. 1 is a sectional view showing the structure of an air battery of the present invention.

FIG. 2 is a sectional view of the sealing material of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode case 1a Convex part 2 Air intake hole 3 Sealing material 4 Base material 5 Adhesive 6 Deoxidizer 7 Positive electrode catalyst layer 8 Negative electrode zinc 9 Separator 10 Teflon film 11 Diffusion paper 12 Sealing packing 13 Negative electrode case

Claims (3)

[Claims] 1. A sealant for an air battery in which an air intake hole provided in a battery case is closed with a sealant, wherein the sealant has a deoxidizer in a portion in contact with the air intake hole, and the other surface is a gas. Sealant for air batteries with barrier material. 2. An air battery in which a deoxidizer is provided in a portion in contact with an air intake hole provided in a battery case, and the other surface is covered with a sealing material having a gas barrier material. 3. An oxygen scavenger is a nithionite salt, ferrous salt salt, hydroquinone, catechol, resorcinol, pyrogallol,
The sealing material for an air battery according to claim 1, which is gallic acid, ascorbic acid, rongalit and / or a salt thereof, sorbose, glucose, lignin, dibutylhydroxytoluene, or butylhydroxyanisole, and an air battery using the sealing material. .