JPS58164173A - Button type zinc air cell - Google Patents

Abstract

PURPOSE:To provide a sealing material which seals air supply holes of a button type zinc air cell to give a good storage life by using as a sealing material a double sheet formed by combining a resin sheet mainly comprising polyester or polypropylene with humidity-proof resin impregnated paper. CONSTITUTION:A sealing material is formed with a sticking layer 11-1, humidity-proof paper obtained by impregnating polypropylene, and a polyester sheet 11-3, and the sticking layer 11-1 is sticked to a positive case 1. Sealing performance of this sealing material at high humidity is substantially improved compared with that of the sealing material obtained by combining a polyester sheet and paper not impregnating resin, and capacity deterioration is also improved. Resin used to impregnate in paper is polyester, fluorine resin, polyester, and others.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a sealing material for sealing the air supply hole of a button type air battery.

In general, a button-type air battery consists of: 1. An air electrode (positive electrode) mainly consisting of a catalyst using oxygen in the air as an active material, and an electrolyte that is an alkaline aqueous solution. It consisted of a zinc negative electrode and an air supply hole in the pond container, which supplied oxygen to the positive electrode when the battery was in use.

In addition, when storing or discontinuing battery use, the air supply hole was sealed with a sealant to cut off the outside air.
If the sealing condition is incomplete or the sealing material is easily gas permeable, the electrolyte will evaporate, resulting in a shortage of electrolyte, or conversely, carbon dioxide gas will flow in from the outside air and cause damage to the air electrode. This reduced the catalytic ability and caused an adverse effect on battery performance.

Conventionally used sealing material for air supply holes.

There are polyester single sheets, polypropylene sheets, polyester and paper double layer sheets, etc.

Among these, those mainly composed of polyester have excellent gas impermeability and good sealing properties.

However, when a battery is stored for a long period of time, hydrogen gas is generated little by little due to self-depletion of the negative electrode. This accumulation of hydrogen gas can cause the internal pressure of the battery to rise, causing the sealing material made of polyester to swell, or breaking the adhesive layer of the sealing material, resulting in complete electrical conduction between the inside of the battery and the outside air. Ta. Therefore, as an improvement measure, we pasted together polyester and paper and provided an adhesive layer on one side of the paper.

Some battery cases come with a sticker that serves as a sealant□. ``In this case, the paper layer allows the slightly generated hydrogen gas to gradually dissipate to the outside.

The swelling of the sealant as described above is eliminated.

In addition, while a single polyester sheet is not alkali-resistant, paper is alkali-resistant, so if electrolyte leaks from the air supply hole, it will absorb the liquid and protect the polyester layer. There is. However, if left in humidity for a long time, the paper deteriorates or softens, and the paper layer becomes a conductive layer between the inside of the battery and the outside air, so it cannot withstand long-term use.

Therefore, an object of the present invention is to eliminate these drawbacks and provide a sealing material that has excellent long-term storage stability.

That is, a composite sheet made by laminating a resin sheet mainly made of polyester or polypropylene and moisture-resistant resin-impregnated paper is used as the sealing material. Paper alone is sensitive to moisture, but paper impregnated with resin has significantly improved moisture resistance. The impregnating resin is sufficient as long as it is moisture resistant, and polypropylene, polyethylene, fluorine resin + 1L polyester, etc. can be used.

In addition, since the sealing material of the present invention has a layer of polyester or polypropylene, it has good insulation properties from the outside air, and only a small amount of hydrogen generated from inside the battery can be gradually dissipated to the outside through the resin-impregnated layer. can.

Examples of the present invention will be described below.

w, Figure 1 is a half-cut sectional view of the button-type air battery according to the present invention. In the figure, 1 is the positive electrode case, 2 is the air supply hole, and 3 is the positive electrode case.
is air diffusion paper, 4 is a water-repellent membrane, 6 is a positive electrode catalyst layer, 6 is a separator, 7 is an electrolyte impregnated material, 8 is a sealing ring, 9 is a sealing plate, 10 is a negative electrode zinc, 111 is an air supply hole 2 It is a closed seal.

FIG. 2 is a sectional view of a sealing material that is a feature of the present invention. In the figure, 11-1 is an adhesive layer, 11-2 is a polybutyl sheet, and the particle adhesion layer 11-1 is pasted on the positive electrode case 1.

The sealing material of the present invention was a polyester sheet (11-3) having a thickness of 26 μm and a polypropylene-impregnated paper 11-2 having a thickness of approximately 100 μm, and using these, SOO cells were made. For comparison, 300 'Batteries B' were made using a sealing material made by laminating the same polyester sheet as above and paper not impregnated with resin. Store 100 pieces of each at room temperature for 6 months.
It was stored at a temperature of 46° C. and a humidity of 90% for 1 month and 60' CI for 60 months, and a comparison test was conducted with an open circuit voltage in a sealed state and a continuous discharge of 300Ω.

The open circuit voltage is 1.3 V or less in a sealed state, but if the seal is defective, the oxygen potential is generated due to the intrusion of oxygen from the outside air, so it is the same as in the open state (1.40 V or more. Therefore, 1.40
Those showing a value of V or more were considered to be defective, and the number of them was investigated.

In addition, in the case of continuous discharge of 300Ω, good products that showed 1.30 V or less were discharged to examine the degree of capacity deterioration from the initial stage. The results are shown in the table below.

In terms of open circuit voltage, product B of the present invention has zero defects even when stored at room temperature and at 80℃ for one month, and only two at 90% at 46℃, whereas conventional product B has many defects, especially when stored at 80℃ for one month. 4
Most common when stored at 6°C and 90%.

For these reasons, the product of the present invention had a good sealing condition, and the sealing effect was significantly improved, especially in high humidity.

The product of the present invention is also clearly superior in terms of capacity deterioration rate.

For these reasons, the product of the present invention has excellent storage stability, especially moisture resistance, and has the effect of drastically reducing defects.

In addition to the polyester sheet, a similar effect was obtained when a sheet mainly composed of polypropylene was used, and as the resin to be impregnated into the paper, other than polypropylene, polyethylene, fluororesin, polyester, etc. can be similarly used.

Furthermore, an adhesive layer may be present between each layer to form a composite sheet.

[Brief explanation of the drawing]

FIG. 1 is a half-cut sectional view of a button-type air cell according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a sealing material of the present invention. 1...Positive electrode case, 2...Air supply hole, 3...Air diffusion paper, 4...Air electrode water-repellent film, 6... ... Positive electrode catalyst layer, 6 ... Separator, 7 ... Impregnated paper, 8 ... Sealing ring, 9 ... Sealing plate, 10 ... ... Negative electrode zinc, 11 ... Sealing material, 11-1 ... Adhesive layer, 11-2 ... Volip, lopylene-impregnated paper,
1)-3...Polyester sheet. Name of agent, patent attorney Toshio Nakao TL or one person Figure 1, 21θ ~ 3 2 1 Figure 2

Claims (2)

[Claims] (1) A button characterized in that the air supply hole of a battery case containing a power generation element is sealed with a sealing material made by laminating a resin sheet mainly made of polyester or polypropylene and paper impregnated with moisture-resistant resin. type air battery. (2) The moisture-resistant resin-impregnated paper is impregnated with a resin selected from the group consisting of polypropylene, polyethylene, fluorine resin, and polyester.
Button type air battery as described in section.