JPS63168966A - Manufacture of lead storage battery - Google Patents

Abstract

PURPOSE:To restrict the temperature rise when a battery jar is formed chemically and to make it possible to form the battery jar without remaining a white portion in a simple equipment, by soaking anode plates in a dilute sulfuric acid to apply a lead-sulphatizing treatment, prior to the composition of a plate group. CONSTITUTION:Prior to the composition of a plate group, anode plates are soaked preliminarily in a dilute sulfuric acid to apply the lead-sulphatizing treatment. Since the anode plates are converted to a metallic lead as the formation of the anode plates proceeds, the preliminary lead-sulphatization of the anode plates to prevent to remain a white portion has no trouble. By lead- sulphatizing the anode plates preliminarily, the heating at the formation of a battery jar is generated mainly by cathode plates. Since the weight ratio of unformed active substances of a cathode and an anode is 1:1, the heating value can be reduced about 50% by lead-sulphatizing the anode active substance preliminarily. Therefore, the formation of the battery jar can be carried out remaining no white portion, with no cooling unit, or by using a simple cooling unit (a blower fan, for example) without a water tank.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing lead-acid batteries by carrying out battery cell formation.

[Prior Art] When carrying out the battery cell formation method, in which a group of electrode plates, each consisting of a cathode plate and an anode plate laminated with a separator interposed therebetween, is housed in a battery case and chemically formed, the cathode plate and the anode plate are used as the cathode plate and the anode plate. , an unformed electrode plate whose lattice body is filled with paste and dried is used as it is.

When chemically forming a container, dilute sulfuric acid is injected into the container and energized, and this dilute sulfuric acid has a relatively high specific gravity. The reason for this is that when the amount of electrolytic solution is small and the unformed active material becomes sulfated, the sulfuric acid is consumed and the electrolytic solution approaches water, resulting in a decrease in electrical conductivity. Dilute sulfuric acid having a specific gravity of 1.210 to 1.260 (20° C.) has been empirically used.

[Problems to be Solved by the Invention] When dilute sulfuric acid is injected into the rice tank, the dilute sulfuric acid reacts with the unformed active material and the battery temperature rises. Furthermore, since a relatively large current is often used, a high temperature is maintained even after the current is applied. When the electrode plate is kept at high temperature during the formation of the battery, a strong film of lead sulfate is formed on the surface of the electrode plate, and this lead sulfate remains even after formation, resulting in so-called white residue (a phenomenon in which lead sulfate remains). This results in poor chemical formation. This tendency is particularly remarkable for the anode plate. Furthermore, if dilute sulfuric acid with a high specific gravity is used, the rate of sulfate formation of the anode active material becomes faster, resulting in more noticeable white residue.

In order to prevent the above-mentioned zero residue from occurring, conventionally, battery cell formation was performed while cooling the battery in a water tank. In this way, in the past, a water tank was required to perform battery cell formation, which not only increased equipment costs, but also made the work troublesome as it required the effort to set the battery case in the water tank during battery case formation. There was a problem with becoming.

Furthermore, since it was necessary to use dilute sulfuric acid with a high specific gravity, there was also the problem of increased costs.

[Means for Solving the Problems] The present invention constitutes a group of electrode plates using unformed electrode plates filled with paste in a lattice body and dried, and stores the group of electrode plates in a battery case to form a group of electrode plates. In the method for manufacturing lead-acid batteries, temperature rise is suppressed and battery cell formation can be performed without producing zero residue.

Therefore, in the present invention, before constructing the electrode plate group, a step of immersing the cathode plate in dilute sulfuric acid and subjecting it to sulfuric acid lead treatment is performed.

[Operation of the Invention] Since the cathode plate becomes metallic lead as the chemical formation progresses, zero residue on the surface of the cathode plate, which is a problem with the anode plate, does not occur in the cathode plate. Therefore, there is no problem even if the cathode plate is previously converted into lead sulfate as described above.

If the cathode plate is converted into lead sulfate in advance, the heat generated during formation of the battery case will mainly occur from the anode plate. Normally, the weight ratio of the unformed active material of the anode and the cathode is 1:1, so if the cathode active material is previously converted to lead sulfate as in the method of the present invention, the calorific value can be reduced by 5.
It can be reduced by about 0%. Therefore, by omitting the cooling equipment or by using a simple cooling equipment (for example, a blower fan) that does not use a water tank, battery cell formation can be performed without producing zero residue.

Further, when the lead sulfate of the cathode active material turns into metallic lead, it releases sulfuric acid, so dilute sulfuric acid, which has a lower specific gravity than conventional ones, can be used as the electrolyte. In this case, since the rate at which the anode active material turns into lead sulfate is slowed down, the generation of zero residues on the anode plate is further suppressed.

[Example] Hereinafter, an example using an unformed electrode plate of a normal automobile battery will be described.

In the example, the unformed cathode plate that has been aged has a specific gravity of 1.260.
(20℃) diluted sulfuric acid, the liquid temperature was set to 40℃,
The sulfate lead reaction was carried out for 1 hour. As a result of this treatment, about 50 to 60 wt % lead sulfate was produced in the cathode plate. This cathode plate and unformed anode plate are combined to form an electrode plate group, and 12
V, 30. I made an Ah battery.

The unformed anode active material of the battery was 207Q/4 pieces, and the cathode active material was 386g/15 pieces. Since the cathode plate contains about 50% lead sulfate, the specific gravity of the sulfuric acid used for forming the battery case was set to 1.140 (20° C.). This means that the specific gravity of sulfuric acid after chemical conversion is 1.215 (2
This is to make it the same as 0℃).

Alternatively, add 450 mJ2/ of the above dilute sulfuric acid to the battery container.
This was done by placing each cell in the cell and applying electricity in the atmosphere.

The drawings show the results of measuring changes in battery temperature immediately after liquid injection for cases in which the battery case was formed using the conventional method and in cases where the case was formed using the method of the present invention. Immediately after injection, the battery temperature rose to around 70℃,
When left for 1 hour, the temperature dropped to around 50°C.

On the other hand, in the case of the method of the present invention, the rise in battery temperature immediately after injection is only 45°C;
The temperature dropped to 0°C. Furthermore, when using the method of the present invention, the battery temperature after energization was maintained at about 15° C. lower than when using the conventional method. At the end of the formation of the battery, the battery temperature rises again due to heat generation due to gas generation, but at this stage no problem arises because the formation has almost finished.

After completion of chemical formation, the specific gravity of the electrolytic solution was adjusted to 1.280 (25° C.), and a discharge of 6 A was performed in a water tank at 25° C. After completion of the discharge, charging was performed and the surface of the electrode plate was observed.

The results are shown in Table 1 on the next page, and the discharge duration of the storage battery manufactured by the method of the present invention was approximately 20 minutes longer than that of the battery manufactured by the conventional method. In this case the discharge was dominated by the anode. I also disassembled the battery and examined it.
In the battery prepared by the conventional method, zero residue was observed on the anode plate, but in the battery prepared by the method of the present invention, no residue was observed.

Table 1 [Effects of the Invention] As described above, according to the method of the present invention, it is possible to suppress the temperature rise during battery cell formation, so cooling equipment can be omitted or cooling equipment used in the past can be reduced. It is possible to perform battery cell formation without producing zero residue with much simpler equipment.

In addition, since dilute sulfuric acid, which has a lower specific gravity than conventional ones, can be used as the electrolyte, it is possible to slow down the rate at which the anode active material turns into lead sulfate, further suppressing the occurrence of 0 residues on the anode plate, resulting in poor chemical formation. It is possible to prevent this from occurring and produce high-quality batteries.

[Brief explanation of the drawing]

The drawing is a diagram showing changes in battery temperature from immediately after injection of electrolytic solution until completion of battery cell formation in the case of the conventional method and the case of the method of the present invention.

Claims (1)

[Claims] A method for manufacturing a lead-acid battery in which a grid body is filled with paste and dried unformed electrode plates are used to form a plate group, and the plate group is stored in a battery container and chemically formed. 1. A method for manufacturing a lead-acid battery, which comprises performing a step of pre-immersing a cathode plate in dilute sulfuric acid and subjecting it to sulfuric acid lead treatment before assembly.