JPH0997604A - Aging of electrode plate for lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To strengthen the bonding between active materials and that between the active material and a current collector in a short time by adding water to an electrode plate of a lead-acid battery on the way of an aging process. SOLUTION: Electrode plates 1 for a lead-acid battery prepared by filling a pasty active material in a current collector made of lead or a lead alloy are suspended at constant intervals to an aging dedicated frame 2, then the frame 2 is put in an aging chamber 3 for aging. After the specified time elapsed, water 5 is sprayed to the electrode plates 1 from a nozzle 4 arranged in the ceiling of the aging chamber 3, then aging is continued for the specified time. By spraying water 5 to the electrode plate 1 plural times during the aging process, the oxidation reaction is performed again by using water as a medium, metallic lead in the active material and the current collector is converted into lead oxide. Thereby, the bonding between active materials and that between the active material and the current collector are strengthened in a short time.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Generally, a lead-acid battery electrode plate is manufactured as follows. First, lead powder containing lead oxide as a main component, diluted sulfuric acid, and water are kneaded to form a paste-like active material,
A undried electrode plate is prepared by filling a current collector made of lead or a lead alloy with the paste-like active material. Next, a large number of these undried electrode plates are brought into close contact with each other, placed on a frame for exclusive use for aging, and placed in an atmosphere of high temperature and high humidity for 2 days to perform aging. After that, a dry treatment is performed to manufacture an unformed lead-acid battery electrode plate. In the aging step, lead metal in the paste-like active material is oxidized with water as a medium to generate lead oxide, and tribasic lead sulfate is grown to increase the binding force between the active material particles.
Then, the metallic lead on the surface of the current collector is oxidized to lead oxide, and the lead oxide and the lead oxide in the active material are combined to enhance the adhesion between the current collector and the active material. Therefore, as aging proceeds, the amount of metallic lead in the active material decreases, generally to about 4% by mass or less, and when the proportion of water in the active material is 1% by mass or less, the aging step ends. .

[0003]

In the conventional method, since the undried electrode plate was closely adhered to the maturing and aging, it was difficult to evaporate the water, and it took two days to complete the maturing. Therefore, it has been attempted to shorten the aging time by aging the undried electrode plates one by one while suspending them. In this method, the aging reaction rate was increased, and the heat of reaction accelerated evaporation of water in the active material, and the aging reaction (oxidation reaction) was completed in about 1/4 of the time required by the conventional method. However, the amount of metallic lead in the active material after aging exceeds 4% by mass, that is, the oxidation reaction of metallic lead is not sufficiently performed, and the binding force between the active materials and the active material and the current collector There was a problem that the bonding strength was inferior to the conventional one.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a binding force between active materials, which is the same as the conventional one, and an active material and a current collector in a short time. It is an object of the present invention to provide a method for obtaining a lead storage battery electrode plate having a binding force.

[0005]

In order to achieve the above object, the present invention provides a method for aging a lead-acid battery electrode plate, which comprises filling a current collector made of lead or a lead alloy with a paste-like active material, It is characterized by adding water to the electrode plate during the aging process.To add water, mist-like water is applied to the electrode plate, or the electrode plate is rapidly cooled to attach water in the atmosphere. There is a way.

[0006]

[Function] Since water is added to the electrode plate during aging, the oxidation reaction using water as a medium, that is, aging can be performed again, and the metallic lead of the active material and the current collector can be converted to lead oxide. Further, the bond between the active material and the current collector can be strengthened.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, an electrode plate 1 in which a current collector is filled with a paste-like active material is suspended in a frame 2 for aging at regular intervals. This frame 2 is placed in an aging chamber 3 having an ambient temperature of 55 ° C. and a relative humidity of 70%. Then, keeping this atmosphere, after 10 hours, the mist-like water 5 is sprayed from the nozzle 4 provided on the ceiling of the aging chamber 3 to the electrode plate 1 for about 1 minute and left still for a while. Next, the atmosphere temperature in the aging chamber 3 was set to 55 ° C. and the atmospheric humidity was set to 50%, and the aging was performed again for 3 hours. afterwards,
The atomized water 5 is again sprayed from the nozzle 4 onto the electrode plate 1 for about 1 minute and left still, and the atmosphere in the aging chamber 3 is kept at a temperature of 55 ° C. and a humidity of 40%.
Was aged for 3 hours. After that, water 5 is further sprayed on the electrode plate 3 in the same manner as above, and the plate is left to stand still under the same conditions as above.
Aged for hours. The total aging step time was 22 hours, and the water content (%) of the active material of the electrode plate 1 was measured during this time.
The result is shown in FIG.

From the 6th hour after starting ripening from FIG. 2, 7
It can be seen that the water content decreased sharply over the time, and the oxidation reaction was intense during this time. Then, it can be seen that there is almost no water at the 10th hour, and the aging is hardly performed. Furthermore, after adding water 5 to the electrode plate 3, it was found that the aging reaction was violently performed for about 10 minutes after a lapse of about 1 hour. After that, even if water 5 is added, the aging reaction is hardly performed.

Further, in the aging step, the number of oxidation reactions was four times, and it was investigated how the amount of metallic lead in the active material changed each time. The result is shown in FIG. From FIG. 3, the residual mass% of lead oxide is about 4% in the first oxidation reaction, which is larger than the conventional amount, but the mass% of lead oxide is about 2% in the second oxidation reaction, It can be seen that the amount is less than the conventional amount. Therefore, in this embodiment, an electrode plate having a quality equal to or higher than the conventional one can be obtained by adding water only once and aging, that is, aging for about 13 hours. Further, how the oxidation reaction start time changes depending on the relative humidity of the aging chamber 3 was investigated. The result is shown in Figure 4.
Shown in When the humidity is higher than in FIG. 4, the oxidation reaction start time is delayed, which is not preferable in shortening the aging time. However, if the humidity is lowered, the water content of the electrode plate is quickly lost and the oxidation reaction time is shortened, which is not desirable, and the number of times of adding water to the electrode plate must be increased. Therefore, it is necessary to set the humidity appropriately. In particular, it is desirable to increase the humidity during the first oxidation reaction to accelerate the oxidation reaction and prevent shrinkage (cracks) in the next step.

[0010]

As described above, according to the present invention, it is possible to obtain an electrode plate having the same quality as conventional ones by aging for a short time.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the elapsed time and the water content in the active material according to the embodiment of the present invention.

FIG. 3 is a graph showing the relationship between the number of oxidation reactions and the proportion of metallic lead in the active material according to the embodiment of the present invention.

FIG. 4 is a graph showing the relationship between relative humidity and oxidation reaction start time in the aging chamber according to the present invention.

[Explanation of symbols]

 1 plate 5 water

Claims (1)

[Claims] 1. A method of aging an electrode plate for a lead storage battery, which comprises filling a current collector made of lead or a lead alloy with a paste-like active material, wherein water is added to the electrode plate during the aging step. Aging method for lead-acid battery plates.