JP4560849B2 - Control valve type lead storage battery manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a lead-acid battery, and more particularly to a method for manufacturing a control valve-type lead-acid battery that undergoes a process for forming a battery case.
[0002]
[Prior art]
Lead storage batteries are composed of both unformed positive and negative electrode plates in a chemical conversion tank and manufactured using these formed electrode plates, and unformed positive and negative electrode plates. After that, there is a method of manufacturing by so-called battery case formation (case formation) in which chemical conversion and initial charging are performed simultaneously.
[0003]
[Problems to be solved by the invention]
In any of the above methods, the amount of gas generated increases at the end of the chemical conversion step. This gas generation is more remarkable in the positive electrode plate than in the negative electrode plate. The positive electrode plate requires an amount of electricity of about 200% of the theoretical capacity from the unformed state to full charge, but it is more than that of the negative electrode plate (about 130%). This is because as the positive electrode plate approaches the end of chemical conversion, the amount of electricity consumed for oxygen gas generation becomes larger than the amount of electricity consumed for charging.
[0004]
In the former method described in the prior art, since both the positive electrode plate and the negative electrode plate are formed in a chemical conversion tank filled with a dilute sulfuric acid solution, the negative electrode plate is almost in contact with oxygen gas generated from the positive electrode plate. Absent. Therefore, the negative electrode plate hardly absorbs oxygen gas, and power consumption associated with the oxygen gas absorption reaction is not performed. However, when the control valve type lead-acid battery that regulates the amount of electrolyte and holds the electrolyte in a fine glass mat separator is formed by the conventional battery formation method, the negative electrode is exposed. The generated oxygen gas touches the negative electrode plate, an oxygen gas absorption reaction occurs in the negative electrode plate, and power is consumed. For this reason, the negative electrode plate is not fully charged, and the positive electrode plate is first fully charged. When the formation is completed in this state, the lead sulfate remains on the negative electrode plate. If left as it is, the lead sulfate becomes coarse and inactivated, and cannot be restored even after charge / discharge. It was. When the amount of such inactivated lead sulfate increases, there is a problem that the ratio of the active active material decreases, and the discharge capacity of the negative electrode plate, in particular, the high rate discharge performance decreases.
[0005]
In addition, when a battery containing a large amount of lead sulfate deactivated on the negative electrode plate is float (trickle) charged at a specified voltage, the potential of the negative electrode does not reach the potential at which hydrogen is generated, but at a charging reaction potential that is nobler than the hydrogen generation potential. Stabilize. On the other hand, since the potential of the positive electrode is polarized to a noble potential, oxygen gas generation is accelerated and the float (tricle) charging current is increased. As a result, the negative electrode plate further absorbs oxygen gas and remains in an uncharged state, the electrolytic solution decreases due to the water splitting reaction, and the discharge performance and life performance of the battery are degraded.
[0006]
As a means of suppressing such problems, a method of fully charging the negative electrode plate before reducing the active material capacity of the negative electrode plate than that of the positive electrode plate and generating gas from the positive electrode plate or before reducing the amount of electrolyte In this case, since the discharge capacity of the negative electrode plate, particularly the high rate discharge capacity, is lowered, the battery performance is not sufficiently satisfied.
[0007]
Moreover, although the method of increasing the formation degree of a negative electrode plate by adding battery case formation time is used, the formation degree was not able to be raised for the sacrifice of production efficiency.
[0008]
As described above, when a valve-regulated lead-acid battery is produced by battery case formation, it is difficult to fully charge the negative electrode plate, and it is difficult to control the voltage applied to each electrode plate during float (trickle) charging. there were.
[0009]
Accordingly, an object of the present invention is to provide a control valve type lead acid battery manufacturing method capable of fully charging a negative electrode plate in a battery case forming method capable of simplifying the manufacturing process, and to provide a control valve with excellent high rate discharge characteristics and life performance. It is to obtain a lead-acid battery.
[0010]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a method for manufacturing a control valve type lead storage battery according to the present invention is a manufacturing method for manufacturing a control valve type lead storage battery by battery case formation, preparing an unformed positive electrode plate and a negative electrode plate, After charging only the unformed negative electrode plate, a battery is formed using the unformed positive electrode plate and the charged negative electrode plate, and the battery is formed into a battery case. As described above, when the negative electrode plate is charged in advance to form a battery case, the negative electrode plate can be fully charged before a large amount of oxygen gas is generated from the positive electrode plate. And the control valve type lead acid battery produced in this way has almost no inactivated lead sulfate on the negative electrode plate, so that the float current is not increased, and the discharge current and life performance are excellent.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Examples of the present invention will be described below.
[0012]
First, an unformed negative electrode plate prepared by a known method is prepared. This negative electrode plate was charged in a sulfuric acid aqueous solution having a specific gravity of 1.10 (25 ° C.) to 5, 50, and 100% of its theoretical capacity at a constant current for 0.5, 5 and 10 hours, respectively. Thereafter, the electrode plate was washed with water and dried by a known method. Control valve type lead acid batteries A, B, and C were constructed using these negative electrode plates, an unformed positive electrode plate produced by a known method, and a sulfuric acid aqueous solution having a specific gravity of 1.26 (25 ° C.) as an electrolytic solution. Next, the battery was charged (battery formation) over 40 hours at a constant current up to 200% in terms of theoretical capacity of the positive electrode plate.
[0013]
The above manufacturing method (hereinafter abbreviated as “Example”) and a conventional manufacturing method were compared. A conventional manufacturing method (hereinafter abbreviated as a conventional example) comprises a control valve type lead-acid battery using an unformed positive electrode plate and negative electrode plate and a sulfuric acid aqueous solution having a specific gravity of 1.26 (25 ° C.) as an electrolyte. The battery is charged (battery formation) at a constant current for 50 hours up to 250% of the theoretical capacity of the positive electrode plate. FIG. 1 shows the float (tricle) charging characteristics during the 50 ° C. acceleration test after the battery formation in the example and the conventional example, and FIG. 2 shows the high rate during the 50 ° C. acceleration test after the battery formation in the example and the conventional example. Shows the discharge characteristics. The battery D is a control valve type lead storage battery manufactured by a conventional manufacturing method.
[0014]
As is clear from FIGS. 1 and 2, the batteries A, B, and C according to the present invention have less decrease in the float current rate and the discharge capacity with respect to the elapsed days than the battery D according to the conventional method.
The float current rate (%) is a relative value when the float current at the initial 4 hours of the battery D is 100 (%).
[0015]
1 and 2 will be described in detail. FIG. 1 shows the float charging current characteristics of batteries A to D, and the reason why the float current rate increases rapidly except for the initial period is that the high rate discharge characteristics were tested on the corresponding day. This is because the float current temporarily increased during the restart.
[0016]
FIG. 2 shows a change in discharge capacity when the battery in the float test of FIG. 1 is periodically discharged at a high rate discharge rate (3CA).
[0017]
As can be seen from FIGS. 1 and 2, the batteries A, B, and C, in which the negative electrode plate was charged before the formation of the battery case, had a lower float current and maintained that low value for a long time compared to the battery D by the conventional method. Has been. Furthermore, it can be seen that the initial discharge capacity is high for high rate discharge performance, and that discharge capacity is maintained for a long period of time. Charging before forming the battery case with respect to the negative electrode plate had an effect of sufficiently improving the battery characteristics even when the amount of electricity was not charged 100% of the theoretical capacity, even if it was about 5% (battery A). On the other hand, in the conventional method, the float current is large and the high rate discharge capacity is small even though the total amount of charge is 250% more than that of the batteries A to C. This is probably because the negative electrode plate is not completely charged. That is, in the conventional battery case formation, a large amount of oxygen is absorbed by the negative electrode plate when the oxygen gas is generated from the positive electrode plate described above, and as a result, the amount of electricity charged in the negative electrode plate is mainly generated by the oxygen gas absorption reaction. It is thought that it was used for charging lead sulfate.
[0018]
【The invention's effect】
As described in detail above, the production method of the present invention can fully charge the negative electrode plate until oxygen gas is generated from the positive electrode plate, so that the deactivated lead sulfate does not remain on the negative electrode plate. Therefore, the control valve type lead storage battery manufactured according to the present invention is excellent in high rate discharge characteristics and float life performance.
[Brief description of the drawings]
FIG. 1 is a graph showing float (tricle) charging characteristics of a battery according to the present invention and a conventional method.
FIG. 2 is a graph showing high rate discharge characteristics of a battery according to the present invention and a conventional method.

Claims (1)

In a manufacturing method for producing a valve-regulated lead-acid battery by battery case formation, after preparing an unformed positive electrode plate and a negative electrode plate, charging only the unformed negative electrode plate, and then charging the unformed positive electrode plate and A method for producing a control valve type lead-acid battery, comprising: forming a battery using a negative electrode plate; and forming the battery in a battery case.

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