JPS5832369A - Air cell - Google Patents

Abstract

PURPOSE:To obtain an air cell having high reliability even for the long term storage, by thermally processing the metal chelate compound and carbon under the reduction ambience. CONSTITUTION:In the air cell the air pole is made by thermally processing the metal chelate compound and the carbon powder under the reduction ambient with the temperature in the range of 150-1,300 deg.C, where the catalyst will change into the conjugated bond through the thermal processing thus to maintain the activity stably. For example the cobalt-tetra-methoxy-porphyn C51H42O4N4Co will change into C47H25O4N4Co to reduce the elements C, H while to increase the number of the double and triple bonds thus to produce the stable metal chelate compound.

Description

[Detailed Description of the Invention] The present invention relates to the modification of the air electrode of an air battery, and is aimed at improving the storage performance of the battery.
``1'' Conventional Air Battery Co., Ltd., powdered activated carbon or granular activated carbon is mixed with a water-repellent binder such as Teflon powder, and the mixture is added to a conductor such as nickel net in the form of a thin plate. %A using a pressure-formed air electrode.

However, conventional air electrodes have drawbacks such as rounding, which deteriorates their activity toward oxygen due to the electrolyte during long-term storage, and the storage performance of the air battery, which significantly deteriorates.

The present invention aims to heat-treat a metal chelate compound and carbon in a reducing atmosphere, and to obtain an air cell with improved reliability even during long-term storage using the same air electrode.

Embodiments of the present invention will be described with reference to the drawings.

1 is a positive electrode can which also serves as a positive terminal tube and has an air supply hole 2 at the bottom. Reference numeral 3 denotes an air electrode, which is connected to the positive electrode can 1, and both sides are supplemented with conductive porous reinforcing bodies 4 such as stainless steel net, and the periphery is fixed by pressure contact with a gasket 5. Reference numeral 6 denotes an electrolyte retaining layer impregnated with a caustic alkaline electrolyte, which is a nonwoven fabric or porous material with excellent retention and liquid resistance, and is interposed between the negative electrode body 7 and the air electrode 3. Reference numeral 8 denotes a negative electrode can which also serves as a negative electrode terminal, and the opening S of the positive electrode can l is folded through the gasket 5 to seal the battery.

The air electrode 3 has a surface area of 800 to 300 by gas adsorption method.
0 m"/Ii activated carbon" was fully immersed in a solution of cobalt 7 thalocyanine 2 It dissolved in 300 FKml of concentrated sulfuric acid solvent, and then placed in 11 pure water in a liquid-holding state to precipitate cobalt phthalocyanine from the solvent onto the activated carbon. After washing with water, filter and dry. In this operation, approximately 1 Otl for activated carbon
After J weight of cobalt phthalocyanine catalyst is precipitated and dried, heat treatment fMt- is carried out within the range of 150 to 1300°C in a reducing atmosphere containing hydrogen gas. Next, the air electrode 3 was formed by water-repellent treatment with fine powder of tuff. Furthermore, it is sandwiched between both sides with a nickel porous reinforcing body 4 and used in an air battery.

In the air battery of the present invention, the air electrode is heated at 150°C to 130°C in an atmosphere containing a coexisting metal chelate compound and carbon powder.
The catalyst was heat-treated within a temperature range of 0° C. The heat treatment changes the catalyst into a highly covalent bond, and the activity remains stable. For example, cobalt tetra methoxy porphyrin 011Hg04N40o is 04v H,
04N400, O and H elements decrease, and the number of double and triple bonds increases, resulting in a stable metal chelate compound. However, at temperatures below 150° C., no effect was observed, and at temperatures above 1,300° C., the metal chelate compound significantly sublimated due to heat, and the expected effect could not be obtained.

In addition, as a result of various studies regarding the heating treatment atmosphere, it was found that the atmosphere containing hydrogen gas was the most effective. This is because oxygen, carbon dioxide, etc. adsorbed on the activated carbon surface are removed, and the surface activity increases in a reducing atmosphere. Various compounds are effective, for example, metal-7
nlne) Me: Metal Metal-tetra methoxy tzenyl φ porphyrin (
Me-1etra (p-methoxy phenyl
) porpbrim ) Meta~-Tetra@7E Hatakeru・
Porphyrins such as posiphyrin (Me-1c, pbemyl, pfistrphrim),
m) 13 or Borziraj: / (Porpb
yrazine) $1 as a substrate (Oo,
By coexisting Fe, Ni, Mal) compounds, it is possible to obtain a nine-air electrode having remarkable acid IJL1 element ability.

In addition, the species lI! of the central metal element! ItIc′)v2 is
Any transition element can be used effectively. Transition metals in this category generally have 8 electron orbitals in the outermost shell, or the number of electrons in the inner d shell is incomplete, so they are generally easily ionized into polyvalent %A*
As a solvent for precipitation on activated carbon,
In addition to sulfuric acid, quinoline, dimethylamide, etc. may also be used.Next, the product of the present invention (A) is a flat air cell with a diameter of 11.5 m and a height of 5.2 brocades using the air electrode according to the present invention.
and a conventional product (B) of the same type of air cell using an air cathode tube such as a conventional granular activated carbon. 40 pieces each were stored at 25°C, and 10 pieces each were stored every 6 months, 12 months, and 18 months. -1,5
The retention rate of the discharge capacity compared to the initial stage after discharging at a constant current for m people is shown in Table 90. From the table above, it can be seen that the air battery of the present invention has excellent storage performance.

As described above, the activated carbon containing the metal chelate compound of the present invention is heat-treated in a reducing atmosphere and used for the air electrode. The performance has been dramatically improved, and its industrial value is great.

[Brief explanation of drawings]

The figure is a sectional view of a button-type air battery, which is an embodiment of the air battery according to the present invention. l... Positive electrode can 2... Air supply hole 3... Air electrode 4... Name of porous reinforcement patent applicant

Claims (2)

[Claims] (1) An air cell in which a coexistence material of a metal chelated metal material and carbon is heat-treated in a reducing atmosphere and used as an air vibration electrode. (2) The #metal chelate compound has a tH structure centered around the ND, cobalt (Oo), toge (re)@' transition, and nitrogen (N) element. The air battery according to claim 1, characterized in that it has a cyanino ring or a porphyrin ring.
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