JPS6054167A - Divalent silver oxide battery - Google Patents

Abstract

PURPOSE:To decrease consumption of cellophene which is composed of separator and prevent internal short by forming a negative electrode by adding metal silver or amalgamated silver to amalgamated zinc powder. CONSTITUTION:Zinc powder having a particle size of 50-150 mesh is amalgamated to form amalgamated zinc powder. Metal silver or amalgamated silver having a particle size of 1-50mum is added to amalgamated zinc powder. By de- creasing particle size in the above range, surface area is increased and catalytic action to the reaction of oxygen and zinc is increased. Addition of 0.05-5pts.wt., preparably about 1pt.wt., silver or amalgamated silver to 100pts.wt. amalgamated zinc powder is effective. By using this mixture as negative mix 7, generation of internal short of battery is decreased.

Description

[Detailed description of the invention] This invention is amalgamated! 11j This invention relates to a ferric oxide battery using a negative electrode material prepared by adding metallic silver or amalgamated metallic silver to lead powder.

In a ferric oxide battery, during storage, ferric oxide decomposes and generates oxygen as shown in the chemical formula; This causes a problem in that the silver ion trapping effect of cellophane is reduced, and the silver ions move toward the negative electrode, causing an internal short circuit.

In order to avoid such problems, the applicant (j) has developed a method in which oxygen generated by the decomposition of silver oxide is preferentially reacted with zinc powder as a negative electrode active material, thereby allowing the reaction between cellophane and oxygen. How to stop 111L (Unexamined Japanese Patent Publication No. 5
No. 8-4269] was proposed. In other words, this method improves the amalgamated zinc powder used as the negative electrode material,
By using zinc powder whose surface is planed and alloyed with mercury and zinc, the reaction between oxygen and zinc is promoted by the catalytic action of silver, thereby reducing the disappearance of cellophane by oxygen. There is.

However, in the above-mentioned method No. There was also the problem that it was difficult to achieve sufficient performance commensurate with the amount of alloying.

As a result of further investigation from the viewpoints mentioned above, the inventors found that when metallic silver or amalgamated metallic silver was simply mixed with amalgamated zinc powder without alloying the surface of the zinc powder. Also, the catalytic effect of metallic silver on the reaction between oxygen and zinc powder is effectively exerted by the atmospheric contact between zinc and silver, and the effect of reducing consumption of cellophane is comparable to that of the proposed method described in 1jiJ. The present invention was completed based on the knowledge that the effect of preventing the occurrence of internal short circuits is 1 (1).

That is, the present invention relates to a silver oxide battery characterized in that a negative electrode material is formed by adding metallic silver or amalgamated metallic silver to amalgamated zinc powder. According to the present invention, there is no need to alloy the surface of the zinc powder with the t-positive means as in the previously proposed method, which is very advantageous in terms of battery manufacturing workability. In addition, since it is possible to easily obtain an effective reaction area for exerting a catalytic action according to the addition of metallic silver or amalgamated metallic silver, the consumption of cellophane can be reduced. Good results can be obtained in preventing the occurrence of

In this invention, zinc powder of about 50 to 150 meshes is first amalgamated to obtain amalgamated zinc powder. This method is not particularly different from the conventional method of producing amalgamated zinc powder, and the degree of amalgamation is such that the amount of mercury used is 5 to 1 part by weight per 100 parts by weight of zinc powder.
The proportion may be 5 parts by weight.

1. Add a small amount of gold to the above zinc powder. As silver or amalgamated metallic silver, particulate matter with a particle size of about 1 to 5 Q pm is used, and by reducing the particle size as described above and increasing the surface area, good results can be obtained in the catalytic action of

The addition of the above metallic silver or amalgamated metallic silver is 0.005 parts by weight per 100 parts by weight of amalgamated zinc powder.
The amount is preferably about 1 part to 5 parts, preferably about 1 part. If a few of these B-men come, the effect of υ1 cannot be obtained,
Also, if the amount of S is removed, the amount of negative electrode active material decreases and the amount of electricity decreases, which is not preferable.

The method for amalgamating metallic silver is the same as in the case of instant lead powder described in 1j. As for the degree of amalgamation, the use of mercury ↓ is 50
The proportion may be set to 150 parts by weight.

The amalgamated zinc powder and metallic silver or amalgamated metallic silver described above are uniformly mixed in a predetermined ratio to form a negative electrode material, and the silver oxide battery of the present invention is produced by storing this in a battery using a conventional method. can get. This battery uses only conventional amalgam zinc powder as the negative electrode material. , has the characteristic that internal short circuits occur less during storage, and in this respect +) results as good as those of the previously proposed battery described in iJ can be obtained. r,ij
It has the advantage that it does not cause any problems in manufacturing operations such as Ikei.

Examples for clarifying the above-mentioned effects of the present invention will be described below in comparison with comparative examples. In addition, in the following, parts shall mean 11 parts.

Example 1 1 part of metallic silver with a particle size of 1.0 pnr was added to 99 parts of amalgamated zinc powder (99 parts of zinc powder JO011'f4+i to a part of mercury; amalgamated using IS), and Mixture L7 was used as a negative electrode material, and this was housed in the following four batteries to produce a phothane type silver oxide battery as shown in the drawing.

That is, the electrolytic solution is 131≦t]: Into the positive electrode can 1, 475 pieces of ferric oxide powder and 477 pieces of ferrous oxide powder are added.
260 t of a mixture consisting of 5 parts of lead dioxide powder and 5 parts of lead dioxide powder
Diameter 9 obtained by pressure forming 7ty at 5 tons/c1rf
A positive electrode material 2 with a thickness of 0.7 tllll is inserted, and a separator 3 and an electrolyte absorber 4 are placed on this positive electrode material 2.
were placed one after another.

On the other hand, 75 my of the negative electrode agent 7 obtained by the method described in item d and most of the remaining electrolyte were added to the negative electrode can 6 which had an annular gasket 5 attached to the peripheral edge, and the By aligning the positive electrode can 1 in this state, the open part of the positive electrode can 1 is tightened inward, and the open part is bent inward, and the open part of the positive electrode can 1 is pressed against the chestnut-shaped gasket 5 to seal it. A silver oxide battery as shown was obtained.

The positive electrode 1111 used was made of iron with a nickel-plated surface, and the negative electrode 6 was made of copper-stainless steel.
Made of nickel clad plate. As the separator 3, a composite J model is used in which a graft film (a craft film made by graft polymerizing methacrylic acid to a cross-linked low-density polyethylene film) is laminated on both sides of cellophane.
The electrolyte absorber 4 was made of polypropylene nonwoven fabric.

Further, as the electrolytic solution, a 25% thorium hydroxide aqueous solution in which zinc oxide was dissolved was used. The diameter of this battery is 9
．． Example 2 Metallic silver with a particle diameter of 10/1 m], mercury 5 to 00 parts
Add 1 part of amalgamated metallic silver amalgamated using 0 parts to 99 parts of amalgamated zinc powder (same as described in Example J), mix well to prepare a negative electrode material, to 1.1° as in Example 1 using C button fi.
A first silver oxide battery of 1J was fabricated.

1) Add 111 cotton 1) powder to a 5% thorium aqueous solution and visualize it. Metallic silver was deposited on the surface of the zinc powder. This layer:) 1 was coated with 100 parts of zinc powder]:
jl≦. Next, mercury is added at a ratio of 9 parts to 100 nB of zinc powder to a solution containing zinc powder on which metallic silver has been precipitated to form an amalgam, and then washed with water and dried to form an alloy of silver-mercury-zinc on the surface. A negative electrode material made of zinc powder was obtained. Example 1 except that this negative electrode material was used
A button-shaped ferric oxide battery was produced in exactly the same manner as described above.

Comparative Example 2 A button-shaped ferric oxide battery was produced in exactly the same manner as in Example 1, except that conventional amalgamated aluminum (F/) was used as the negative electrode material.

Each of the batteries according to the above examples and comparative examples was stored at 60°C for a predetermined period of time, and the number of batteries in which a short circuit occurred among 1000 samples was determined.The results are summarized in the table below. It was there. 41. The occurrence of an internal i, l, i circuit was determined by a sudden drop in the closed circuit voltage.

As is clear from the above results, according to this invention, I'
It can be seen that it is possible to easily produce a silver oxide battery in which the occurrence of l isl ≦ short circuit is suppressed and is comparable to the battery of the previously proposed method (Comparative Example 1) in this respect.

[Brief explanation of the drawing]

FIG. 11 is a partially cutaway view showing an example of the silver oxide battery of the present invention. 7 Negative 1/υ4 agent.

Claims (1)

[Claims] +1+ A ferric oxide battery characterized in that a negative electrode material is formed by adding metallic silver or amalgamated metallic silver to amalgamated zinc powder.