JPH09289015A - Manufacture of electrode plate for lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrode plate in a short time aging process without deterioration in cycle life performance by filling paste prepared with the prescribed lead powder for a lead-acid battery in a grid, oxidizing lead, then conducting formation. SOLUTION: Lead powder whose surface is lead monoxide is heated under the existence of coke and/or carbon monoxide to reduce the surface of the lead monoxide into lead by the reaction of PbO+C→Pb+CO. Since coke or carbon monoxide directly react with lead monoxide in this reaction, the reaction starts from the surface of the lead monoxide, and reduced lead is selectively formed on the surface of the lead monoxide. Thereby, in a aging process, metallic lead can easily come in contact with oxygen and water, and the oxidation reaction of the metallic lead easily occur. As a result, time of the aging process is shortened, and since the metallic lead exists on the surface coming in contact with active material particles, bonding between active material particles is strengthened, and the cycle life is lengthened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a lead storage battery electrode plate.

[0002]

2. Description of the Related Art Lead powder used in the production of lead-acid battery electrode plates varies depending on the application of the battery used, but is produced by the ball mill method or the Burton pot method, and the lead powder has a particle diameter of about 0.1 to 10 μm and is oxidized. Those with physical properties of 70 to 90% are used.

This lead powder is mainly composed of lead and lead monoxide. However, no matter which manufacturing method is used, the surface of lead is always oxidized to lead monoxide, so lead is exposed on the surface. There is nothing to do, and lead monoxide is arranged around lead.

[0004]

In order to obtain sufficient cycle life performance in such a conventional lead powder for a lead storage battery, it is natural that the bonding between the active material particles is caused by the oxidation reaction of metallic lead. Need to be formed.

For this reason, in the conventional method of manufacturing the electrode plate for the lead storage battery, the lead powder containing a large amount of metallic lead and having an oxidation degree of 70 to 90% must be used for a long aging step. was there.

An object of the present invention is to provide a method for producing a lead storage battery electrode plate which can produce a lead storage battery electrode plate by a short aging step without deteriorating the cycle life performance.

Another object of the present invention is to provide a method for manufacturing a lead-acid battery electrode plate which can control the amount of lead reduced.

[0008]

DISCLOSURE OF THE INVENTION The present invention is to improve a method of manufacturing a lead storage battery electrode plate using lead powder for lead storage batteries, which surface is made of lead powder.

In the method of manufacturing a lead-acid battery electrode plate according to claim 1, at least a part of the surface of lead monoxide is reduced to lead, and the surface of the lead monoxide is reduced to lead. It is characterized in that the grid body is filled with a paste formed by using powder, and then lead is oxidized in a maturing step to perform chemical conversion.

In the method for manufacturing a lead-acid battery electrode plate according to claim 2, in the step of reducing at least a part of the surface of lead monoxide to lead, lead powder whose surface is lead monoxide is
It is characterized in that the heating is performed by coexisting with either or both of coke and carbon monoxide.

When lead powder whose surface is lead monoxide is coexistent with either or both of coke and carbon monoxide and heated, the surface of lead monoxide is reduced to lead by the following reaction.

PbO + C → Pb + CO PbO + CO → Pb + CO _{2 In} this reaction, since coke or carbon monoxide directly reacts with lead monoxide, the reaction starts from the surface of lead monoxide, and the reduced lead is the surface of lead monoxide. Are selectively formed. In such a step of reducing lead monoxide to lead, the amount of lead to be reduced can be controlled by limiting the amount of coexisting reducing means to an insufficient amount.

In the lead powder produced by such a process, lead monoxide is always present around lead in the conventional lead powder, while lead is present on the surface of lead monoxide. It has a shape. For this reason, in the aging step, metallic lead can easily come into contact with oxygen and water, and the oxidation reaction of metallic lead easily occurs. As a result, the aging process time can be shortened. Furthermore, since metallic lead is present on the surfaces in contact with the particles, the bonds between the active material particles are strengthened and the cycle life characteristics are improved.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an example of an embodiment of the method for manufacturing a lead-acid battery electrode plate according to the present invention will be described.

According to a conventional ball mill method, as a conventional lead powder, an average particle diameter is 1 μm and a specific surface area is about 60,000 cm ² / cm ^3.
A lead powder having the physical properties of 70% and 73% oxidation degree was prepared.

Next, the lead powder of the present invention has the above-mentioned oxidation degree of 73%.
Made from lead powder of coke and coke and carbon monoxide 80
It was heated to 0 ° C and subjected to a reduction treatment so that the degree of oxidation of lead powder would be 70%. The produced lead powder had the average particle diameter of 0.9 μm and the specific surface area of about 65,000 cm ² / cm ³ .

Next, using a total of two types of lead powder, the conventional lead powder having an oxidation degree of 70% and the lead powder of the present invention, an anode paste having a lead sulfate content of 10% and a water content of 11% was prepared according to a conventional method. Created respectively. These pastes were filled in lead alloy grids having the same composition.

A conventional lead alloy grid filled with a paste containing lead powder was aged under the usual aging process conditions and shortening aging process conditions to prepare an unformed electrode plate.

The lead alloy grid filled with the paste using the lead powder of the present invention is aged under the usual aging process conditions, shortening aging process conditions, and 15-hour shortening aging process conditions, respectively, to form unformed electrode plates. It was created.

In this case, the usual aging process conditions are 35 ° C.
Leave for 48 hours in 98% RH atmosphere. On the other hand, the conditions for the shortening aging process are to leave it in an atmosphere of 35 ° C. and 10% RH for 24 hours.

Next, the obtained five kinds of unformed electrode plates were formed by a conventional method and combined with the same cathode plate to prepare liquid type batteries having a nominal capacity of 28 Ah.

FIG. 1 shows the result of the cycle life test based on JIS of each of the prepared lead acid batteries. As is clear from FIG. 1, the battery using the lead powder of the present invention (the product of the present invention) is a battery using the conventional lead powder having substantially the same physical properties (conventional product) under the conditions of the usual aging process. It has a longer life. Further, in the battery prepared under the shortened aging process condition, the battery using the lead powder of the present invention has the same life performance as that of the battery prepared under the conventional aging process condition. It can be seen that the performance of the battery using lead powder has deteriorated.

Further, as is clear from the figure, if the lead powder of the present invention is used and the life performance is the same as that of the battery prepared under the conventional aging process conditions using the conventional lead powder, further aging is performed. Time can be reduced from 24 hours to 15 hours.

When reducing the surface of lead monoxide to lead, only one of coke and carbon monoxide may be used in addition to the method of using both coke and carbon monoxide.

[0025]

In the method for producing a lead-acid battery electrode plate according to the first aspect of the present invention, since lead powder in which at least a part of the surface of lead monoxide is reduced to lead is used, metallic lead is removed in the aging step. Since it can easily come into contact with oxygen and water, the oxidation reaction of metallic lead easily occurs, and as a result, the aging process time can be shortened. Further, the lead-acid battery electrode plate produced by the method of the present invention, since at least a part of the surface of lead monoxide is reduced to lead, compared to a battery using a conventional lead-acid battery lead powder active material The bond between particles becomes strong,
Therefore, there is an advantage that the cycle life characteristics can be improved, and even if the aging step is shortened, the cycle life characteristics equivalent to the conventional one can be provided.

In the method for manufacturing a lead-acid battery electrode plate according to claim 2, the step of reducing at least a part of the surface of lead monoxide to lead is carried out by using lead powder whose surface is lead monoxide,
Since the heating is performed by coexisting with either or both of coke and carbon monoxide, the amount of lead to be reduced can be controlled by limiting the amount of coexisting reducing means to an insufficient amount. There is.

[Brief description of drawings]

FIG. 1 is a comparative diagram showing cycle life characteristics when aging conditions are changed using a lead powder for a lead storage battery of the present invention and a conventional lead powder for a lead storage battery.

Claims (2)

[Claims] 1. A method for manufacturing an electrode plate for a lead storage battery using lead powder for a lead storage battery, which comprises lead powder having a surface made of lead monoxide, wherein at least a part of the surface of the lead monoxide is reduced to lead. Then, the paste formed by using the lead powder for lead-acid batteries, in which the surface of the lead monoxide has been reduced to lead, is filled in a grid, and then the lead is oxidized in the aging step before being formed. Manufacturing method of electrode plate for storage battery. 2. The step of reducing at least a part of the surface of the lead monoxide to lead, the lead powder having a surface of lead monoxide is allowed to coexist with either or both of coke and carbon monoxide. The method for producing a lead-acid battery electrode plate according to claim 1, wherein the method is performed by heating.