JPS5999663A - Production method of silver (ii) oxide cell - Google Patents

Abstract

PURPOSE:To obtain a cell with low internal resistance and excellent discharge characteristics by using a mixture of lead dioxide and silver (II) oxide both oxidized and synthesized in the same reaction system as a raw material for a positive electrode black mix. CONSTITUTION:One (1) of a mixture of a lead nitrate aqueous solution and a silver nitrate aqueous solution with a predetermined density is heated at 80 deg.C, then 80g of potassium persulfate and 35g of potassium hydroxide are added and stirred, and the precipitate is water-washed and dried to obtain a mixture of silver (II) oxide and lead dioxide. Silver (II) oxide is added to this mixture so that the weight ratio between silver (II) oxide and lead dioxide becomes 95/5, and it is pressurized and molded at 5t/cm<2> to obtain a molded positive electrode black mix 1. This black mix 1 is inserted into a positive electrode can 2 injected with part of an alkaline electrolyte, a separator 3 and an electrolyte absorber 4 are mounted in sequence, an annular gasket 7 is inserted in the peripheral section and is coupled with a negative electrode terminal plate 5 filled with a negative electrode 6 using amalgamated zinc as an active material and most of the remaining alkaline electrolyte, and the opening section of the positive electrode can 2 is tightened and bent inward so that its inner periphery is brought into contact by pressure with the annular gasket 7 for sealing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a silver oxide battery using silver oxide (APO) as the main active material for the anode and lead dioxide (pbo2) as a conductive agent.

Conventionally, this type of power supply is made by press-molding an anode mixture of silver oxide and lead dioxide and storing it inside the battery, but this method relies on the conductive function of lead dioxide. Perhaps because the internal resistance could not be sufficiently exerted, the internal resistance could not be lowered much, and satisfactory discharge characteristics could not be obtained.

In the process of research to improve the above-mentioned discharge characteristics, the inventors synthesized silver oxide and lead dioxide together in the same reaction system, and used this as part or all of the raw material for forming the anode mixture. It was discovered that when used as a battery, a silver oxide battery with low internal resistance and excellent discharge characteristics can be obtained, leading to the completion of this invention.

That is, this invention involves pressure-molding an anode mixture containing silver oxide as the main active material of the anode and lead dioxide as a conductive agent, and storing this in a battery to produce a ferric oxide battery. In the manufacturing method, Ay ions and Pb2+ ions are simultaneously oxidized with persulfate in an alkali aqueous solution to create a mixture of ferric oxide and lead dioxide, which is added to the anode composition. The present invention relates to a method for manufacturing a ferric oxide battery, which is characterized in that the present invention is used as part or all of the raw material for the agent.

In this invention, first, Ay in an alkaline earth metal is
+ ion and pb ion are simultaneously combined with persulfate.
This oxidation produces a mixture of ferric oxide and lead dioxide.

In this method, for example, potassium persulfate (K2S208) is added to a heated mixture of a silver nitrate aqueous solution and a lead nitrate aqueous solution.
This can be carried out by adding and stirring reaction with potassium hydroxide.

The ferric oxide and lead dioxide produced by this method are in the form of fine particles of lead dioxide deposited uniformly on the surface of the ferric oxide particles, and this is due to the conductive function of lead dioxide. In addition, according to the above method, the crystallization rate of lead dioxide becomes faster, and the crystal particles tend to become smaller. Since it becomes an α-type suitable for suppressing the increasing phenomenon (this makes it possible to further improve the function as a conductive aid).

In this invention, a mixture of ferric oxide and lead dioxide produced by the above method is used as a raw material for the anode mixture, but in this case, it is also common to use the above mixture as a modified conductive additive. It is a usage mode. In this case, usual silver oxide and, if necessary, silver oxide are mixed with the above mixture, and this is pressure-molded to obtain a molded anode mixture.

As another mode of use, when the above mixture already consists of ferric oxide and lead dioxide in an appropriate ratio as an anode mixture, it may be used as it is or, if necessary, a prescribed component such as ferric oxide may be added. There is no problem in using it as a raw material for forming anode mixture.

Of course, usage modes other than these may be used, and the point is that any method in which the mixture is used as part or all of the anode mixture for molding is arbitrary.

In addition, in any usage mode, the final 1
The content of lead dioxide in the anode mixture to be formed or silver oxide (if this and silver oxide are used together, the total amount) 1
It is adjusted so that 3 to 10 parts of market weight per 1 part of 0.00 parts of market weight.

As described above, according to the method of this invention, a mixture of lead dioxide and ferric oxide synthesized in the same reaction system is used as a raw material for the anode mixture (this allows good discharge characteristics with low internal resistance to be obtained. The following silver oxide battery can be obtained.

EXAMPLES Below, examples of the present invention will be described in more detail.

Example A mixture 11 of a lead nitrate aqueous solution with a predetermined concentration and a silver nitrate aqueous solution with a predetermined concentration was heated to 80° C., and then 80 y of potassium persulfate and 35 y of potassium hydroxide were added and stirred for 1 hour. The precipitate was washed with water and then dried in a vacuum dryer at 8°C to obtain a mixture of ferric oxide and lead dioxide.

This mixture has a weight ratio of 95% silver oxide and lead dioxide.
Silver oxide was added so that the amount was 15.

The 260cm was press-formed at 5 tons/d to a diameter of 9mm.
A molded anode mixture having a thickness of 0.7 mm was obtained. Using this mixture, a silver oxide battery as shown in the figure was prepared by a conventional method.

That is, the anode can 2 into which a part of alkaline electrolyte is injected
The above-mentioned molded anode mixture 1 was inserted, and the separator 3 and electrolyte absorber 4 were placed on this mixture 1 in this order.

Next, the anode can 2 in this state is connected to the same edge portion (the cathode 6 in which the annular gasket 7 is fitted and the cathode 6 containing 75ffIg amalgamated zinc as an active material and the remaining majority of the alkaline electrolyte). A button type having the structure shown in Fig. 1 is formed by fitting into the terminal plate 5, tightening the opening of the electrode can 2 inward and bending it, and pressing the inner solid surface against the annular gasket 7 to seal it. A silver oxide battery was fabricated.

The anode can 2 used was made of iron and had its surface plated with nickel, and the cathode terminal plate 5 was made of a copper-stainless steel-nickel clad plate. As the separator 3, a composite membrane is used in which a graft film (a graft film obtained by graft polymerizing methacrylic acid to a cross-linked low-density polyethylene film) is laminated on both sides of cellophane, and the electrolyte absorber 4 is made of a polypropylene nonwoven fabric.

As the alkaline electrolyte, a 25% by weight caustic soda aqueous solution in which zinc oxide was dissolved was used. Also, the diameter of the battery (button type) is 9. ” 5 mm, height is 2.7 mm.

Regarding this silver oxide battery, the results of investigating the relationship between the weight ratio of ferric oxide (converted to silver metal) and lead dioxide (converted to metal lead) in the mixture and the internal resistance characteristics of the battery are as follows. , as shown in the accompanying table. Note that the internal resistance characteristic of a battery is expressed as a resistance component when an alternating current of 1KH2 is applied.

As is clear from the above table, by simultaneously oxidizing and synthesizing ferric oxide and lead dioxide in the same reaction system, the internal resistance of the ferric oxide battery obtained using this can be lowered and the discharge characteristics improved. It can be seen that it is possible to achieve the following.

[Brief explanation of drawings]

The drawing is a cross-sectional view showing an example of a silver oxide battery obtained by the method of the present invention. 1. Anode mixture.

Claims (1)

[Claims] (1) A method of manufacturing a ferric oxide battery by press-molding an anode mixture containing ferric oxide as the main active material of the anode and lead dioxide as a conductive agent, and storing this in a battery. In this step, +, hy io/ and Pb2+ ions are simultaneously oxidized with persulfate in an alkaline aqueous solution to create a mixture of ferric oxide and lead dioxide, and this is added to some or all of the Va electrode associating agent raw material. A method for manufacturing a ferric oxide battery, characterized in that it is used as a battery.