JPH07183029A - Manufacture of lead-acid battery - Google Patents

Abstract

PURPOSE:To enable a lead-acid battery to be preserved for a long period without performance degradation by sealing and storing an assembly of alternately stacked, unformed positive and negative plates inside a battery jar, and opening the jar before use of the battery, for injection of dilute sulfuric acid. CONSTITUTION:An assembly of plates, in which unformed positive plates each comprising a Pb-Sb alloy lattice filled with a positive paste and unformed negative plates each comprising a Pb-Sb alloy lattice filled with an additive and lead are stacked alternately, is stored inside a battery jar, which is sealed after a battery is assembled. The battery is preserved in that state, and before the battery is used the battery jar is opened to inject dilute sulfuric acid for forming. By this method of preservation, the lead-acid battery can be preserved for a long period without performance degradation.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art At present, lead-acid batteries are used in all fields including automobiles, electric vehicles, portable devices and the like, and among them, the amount of automobile batteries produced is the largest.

The most important performance of an automobile battery is to fully rotate a starter motor, which requires a large current and a high voltage, to start the engine.
This starting performance, that is, the high rate discharge performance is a criterion for judging the quality of the lead acid battery for automobiles.

The high rate discharge performance of a lead storage battery has a strong temperature dependency, and its performance decreases as the temperature decreases. for that reason,
A lead-acid battery for automobiles that has been used for a long time and is nearing the end of its life can manage to start the engine from spring to early autumn when the temperature is relatively high, but high rate discharge from the end of autumn to winter when the temperature begins to drop. Performance is significantly reduced, and the engine often fails to start and reaches the end of its life.

As described above, in the case of automobile batteries, the engine cannot be started in winter and the service life is often long, and demand tends to be concentrated.

For battery manufacturers, it is desirable that the demand for batteries be stable throughout the year, and if it is attempted to have equipment capable of producing the batteries required during the demand period, the production will become excessive during the non-demand period or the production facilities Will have to keep playing.

[0007] Therefore, various ideas have been conceived for storing the batteries produced during the non-demand period and shipping the batteries during the demand period.
It is actually adopted.

The method of manufacturing a lead storage battery is classified into a battery case formation and a tank formation when the electrode plate formation method is classified. The battery case formation is a method in which diluted sulfuric acid, which is an electrolytic solution, is injected into a battery assembled by using an unformed positive electrode plate and an unformed negative electrode plate, and a predetermined current is applied for a predetermined time to perform formation.
In this method, if the battery after forming the battery case is stored, the capacity and the specific gravity of the electrolyte will decrease due to self-discharge, and when the battery is actually installed in the vehicle, supplementary charging corresponding to the storage period will be performed. However, if the battery is left for too long, it will not recover to the original capacity even if it is supplemented.

It is also conceivable to store the assembled battery in an unformed state and inject it with dilute sulfuric acid during the demand period to perform the formation. However, if the battery is stored unformed,
Lead monoxide, which is the main component of the unformed electrode, reacts with carbon dioxide in the air during storage to produce lead carbonate, and when dilute sulfuric acid is injected, this reacts with dilute sulfuric acid to form lead sulfate. At that time, there is a defect that the electrode is dropped from the electrode plate to lose the capacity, or a short circuit occurs at the lower part of the electrode plate.

On the other hand, the tank formation is a method of forming the electrode plate in dilute sulfuric acid as it is. After the formation, a battery is assembled by using a positive electrode plate and a negative electrode plate which are washed with water and dried in an inert gas.
Just inject the electrolyte just before mounting it in the car and use it as it is. In this case, it does not cause self-discharge like the battery that has undergone battery case formation during storage from the time the battery is assembled to the time it is installed in the car, and it produces lead carbonate as if the battery had not been formed. There is nothing to do. However, the negative electrode plate that has undergone electrode plate formation reacts with oxygen in the air to produce lead oxide in the presence of a slight amount of water, and when dilute sulfuric acid, which is the electrolyte, is injected, lead oxide becomes lead sulfate and discharge. I can not do it.

Further, in the positive electrode plate subjected to the electrode plate formation, lead, which is also a lattice, reacts with lead dioxide, which is an active material, in the presence of a slight amount of water, and lead monoxide is present at the interface between the lattice and the active material. Is generated, and when dilute sulfuric acid as an electrolytic solution is injected, it becomes lead sulfate, which becomes a resistance at the time of discharge and causes a phenomenon that discharge cannot be performed.

[0012]

DISCLOSURE OF THE INVENTION The present invention eliminates the above-mentioned problems, and its contents are an electrode plate in which an unformed positive electrode plate and an unformed negative electrode plate are alternately laminated with a separator interposed therebetween. The group is stored in a battery case, the battery case is sealed after the battery is assembled, the container is opened before use and diluted sulfuric acid is injected to perform chemical conversion, and it is stored for a long time without degrading the performance. The present invention provides a lead acid battery that can be used.

[0013]

EXAMPLES The present invention will be described below based on examples.

A positive electrode paste prepared by adding dilute sulfuric acid to lead powder and kneading the mixture was filled in a Pb-Sb alloy grid, aged and dried to prepare an unformed positive electrode plate. On the other hand, a small amount of an additive was added to lead powder, mixed with dilute sulfuric acid, kneaded, filled in a Pb-Sb alloy lattice, aged, and dried to prepare an unformed negative electrode plate. .

A battery-type lead acid battery for automobiles (nominal capacity 28 Ah, a nominal capacity of 28 Ah, with a capacity of 28 Ah (5 hour rate) was assembled, a sealing liquid stopper having no holes was attached to the liquid injection port, and a sealing treatment was performed so that the atmosphere did not enter the battery, thereby producing a lead acid battery A. In this embodiment, a sealing liquid stopper having no holes was used to seal the battery, but the entire battery may be put in a synthetic resin bag to be sealed, or an aluminum seal or the like may be welded to the liquid injection port. May be sealed.

The battery A thus prepared was stored in a room at 40 ° C., taken out every three months and opened, and after dilute sulfuric acid was injected, battery case formation was carried out to obtain a 5-hour rate capacity and a low temperature high rate capacity. Examined. For comparison, the battery B which was not assembled and sealed using the unformed positive and negative electrode plates of the same lot was also stored in a room at 40 ° C., taken out every three months, and injected with dilute sulfuric acid. After that, battery case formation was performed and the 5-hour rate capacity and the low temperature high rate capacity were examined.

The battery C, which was assembled using unformed positive and negative electrode plates of the same lot and was injected with dilute sulfuric acid immediately after assembly to perform battery case formation, was also stored in a room at 40 ° C. After being taken out every month and fully supplemented, the 5-hour rate capacity and the low temperature high rate capacity were examined.

Further, after the batteries A and B were stored for 6 months, the batteries A6 and B6 subjected to battery case formation were subjected to a light load life test stipulated in JIS-D5301. For comparison, the battery C, which has been subjected to battery case formation immediately after battery assembly, is not left as it is (battery C0), and is stored for 6 months and then subjected to supplemental charging, and is a battery C6.
Was also subjected to the same life test.

FIG. 1 shows the relationship between the storage period and the 5-hour rate capacity, and FIG. 2 shows the relationship between the storage period and the low temperature high rate capacity.
Figure 3 shows the results of the light load life test.

Battery C, which had been subjected to battery case formation immediately after battery assembly, had a longer storage period and a decrease in both the 5-hour rate capacity and the low-temperature high-rate capacity, and especially when the storage period was 6 months or more, the performance deteriorated significantly. It is considered that this is because lead sulfate generated by self-discharge during storage grew greatly as the storage period became longer, and did not completely return to PbO2 in the positive electrode and Pb in the negative electrode even if excessive supplementary charging was performed. .

The JIS C light load life performance of the battery C6 which has been stored for 6 months and then subjected to supplementary charge is about 2000 cycles or less, and the life performance of the battery C0 (about 3500) subjected to a life test by performing battery case formation immediately after assembly. Cycle) was much worse. This is probably because the lead sulfate described above could not be fully charged.

On the other hand, although the battery B stored without being sealed without being sealed was not as good as the battery C stored after being subjected to battery case formation, the 5 hour rate capacity and the low temperature high rate capacity of this cell were saved. Declined over time. When the battery B6, which had been stored for 6 months without sealing treatment and then subjected to battery case formation, was subjected to a JIS light load life test, it had a life of about 1700 cycles. Remarkably, this seemed to be the cause of the short life. It is considered that when the battery is stored in an unformed state without being sealed, carbon dioxide in the atmosphere reacts with the unformed active material to produce lead carbonate, which causes deterioration of the active material.

Battery A, which had been sealed and stored in an unformed state, showed almost no decrease in both the 5-hour rate capacity and the low temperature high rate capacity after the cell formation even after being stored for about 1 year. Further, the battery A6 according to the present invention, which was subjected to a sealing treatment and stored for 6 months and then formed into a battery case, was subjected to a light load life test stipulated in the JIS standard. The battery exhibited almost the same life performance as the battery C0 used for the light load life test without storing. It is considered that the battery assembled by using the unformed positive and negative electrode plates could be stored for a long period of time without causing deterioration of the active material by performing the sealing treatment.

In this embodiment, Pb is used for both the positive and negative electrodes.
A -Sb alloy grid was used. This shows the case where the self-discharge during standing is the largest and the effect of the present invention is most prominent, and in the case where the Pb-Ca alloy is used for the positive and / or negative electrode plates. Even if there was, it was possible to suppress deterioration of the active material during storage by assembling and sealing the battery using the unformed electrode plate and storing.

[0025]

As is apparent from the above-described embodiments, the present invention provides a battery assembled by using the unformed positive and negative electrode plates with a sealing treatment so that the battery performance is not deteriorated for a long period of time. It can be preserved, the product quality is stabilized, and it can be stably produced throughout the year, and its industrial value is enormous.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a storage period and a 5-hour rate capacity.

FIG. 2 is a diagram showing a relationship between a storage period and a low temperature high rate capacity.

[Fig. 3] JIS D5301 light load life test result diagram

Claims (1)

[Claims] 1. An electrode group, in which an unformed positive electrode plate and an unformed negative electrode plate are alternately laminated with a separator in between, is housed in a battery case, and after the battery is assembled, the battery container is sealed and used. A method for manufacturing a lead acid battery, which comprises unsealing before and injecting dilute sulfuric acid to perform chemical conversion.