JP2002305021A - Manufacturing method and storing method of lead-acid battery of ready use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a lead-acid battery having a superior performance of ready use. SOLUTION: The manufacturing method of the lead-acid battery of ready is provided with a first process of assembling a lead-acid battery of not-yet chemically converted, a second process of injecting an electrolytic solution into the lead-acid battery to chemically convert a battery case, a third process of draining the electrolytic solution after the chemical conversion of the battery case, and a fourth process of storing the lead-acid battery after the drainage, and after the third process or in the fourth process, a plug with a valve is provided the lead-acid battery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-acid battery which can be used immediately by injecting an electrolytic solution and has an immediate performance.

[0002]

2. Description of the Related Art Lead-acid batteries use lead dioxide as the positive electrode active material, lead as the negative electrode active material, and dilute sulfuric acid as the electrolytic solution. It changes and returns to the original state by charging.

The positive and negative electrode active materials are lead dioxide and lead, respectively, and the raw materials are both lead powder. In the case of clad type batteries, the positive electrode is called a clad type electrode plate.A lead alloy core made by casting is passed through a tube made of glass fiber or synthetic fiber, and lead is inserted into the gap between the tube and the core. It is filled with powder. The negative electrode is referred to as a paste-type electrode plate, and is formed by filling a grid of a lead alloy formed by casting with a paste kneaded with lead powder and a predetermined diluted sulfuric acid. At the stage of filling with this lead powder or paste, there is no electric capacity yet, a constant amount of electricity is supplied in dilute sulfuric acid, the positive electrode becomes lead dioxide, and the negative electrode becomes lead, resulting in a lead storage battery with electric capacity . This step is called chemical formation.

In the case of normal mass-produced batteries, including batteries that serve as power sources for battery-powered forklifts, an electrode group is assembled by using unformed positive and negative plates and separators before formation, put into a battery case, and put into a battery case. Lead-acid battery in the state. Dilute sulfuric acid is injected as an electrolytic solution into the lead storage battery in an unformed state, and a predetermined amount of electricity is supplied to obtain a converted battery (this formation method is referred to as battery forming). Once a lead storage battery is a completed battery that has been charged, it self-discharges and has a limited storage period. In addition, since it contains dilute sulfuric acid that flows, there are many safety problems in transporting such as transport abroad.

[0005] Therefore, a lead-acid battery of immediate use, whose capacity can be immediately taken out by injecting dilute sulfuric acid immediately before use, has been used, particularly for storage and transport applications, or suitable for them. In this battery, positive and negative plates are arranged in a tank containing diluted sulfuric acid, and an electrode plate that has been formed by applying a predetermined amount of electricity is used. The positive electrode plate after chemical formation is often washed with water and dried, but the negative electrode plate is required to be thoroughly washed with water and then dried in a vacuum to suppress oxidation. The ready-to-use lead-acid battery assembled using the formed electrode plates has a disadvantage that the cost is high because a large number of steps are required to form each electrode plate.

On the other hand, a method for producing a lead-acid battery having the same immediate performance without using a chemically converted electrode plate for producing a conventional immediate-type lead-acid battery has been found. That is, instead of performing chemical formation on a single electrode plate, a lead-acid battery is manufactured by battery case formation, and then the electrolyte is extracted.

A normal liquid lead-acid battery loses about 0.2% of its rated capacity per day at room temperature due to self-discharge. Lead sulfate accumulates in the electrode plate due to long-term storage,
So-called sulfation, which is difficult to recover even by charging, is caused, and the life is significantly shortened. As a result of detailed analysis, it was found that the amount of self-discharge was proportional to the specific gravity of the electrolytic solution, and was large at a high specific gravity and small at a low specific gravity. Since the discharge reaction of the lead storage battery is a reaction between the positive / negative active material and sulfuric acid as the electrolyte, the specific gravity of the electrolyte decreases according to the amount of discharge. By extracting the electrolyte, the total amount of the solution is reduced, and the amount of decrease in the specific gravity of the electrolyte due to self-discharge is increased. The specific gravity is largely reduced, and when the specific gravity is lowered, the self-discharge amount is remarkably reduced, the amount of lead sulfate in the electrode plate is suppressed, and a mechanism that leads to the prevention of sulfation is not used.

[0008] According to this manufacturing method, since no chemical conversion is performed for each electrode plate, the man-hour and cost required for manufacturing can be reduced.

However, there is a problem in this type of lead-acid battery manufacturing method. That is, when the liquid is drained, the electrode plate is exposed, and when there is oxygen around, the lead of the negative electrode active material is oxidized and discharged.

[0010]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing a lead-acid battery of a ready-to-use type in which the electrolyte of a lead-acid battery manufactured by battery case formation is drained. The present invention provides a method of manufacturing a ready-to-use lead-acid battery having the same immediate performance as a ready-to-use lead-acid battery in which batteries are manufactured. It is to provide a storage method.

[0011]

Means for Solving the Problems The present inventor has found that the amount of self-discharge when left for a long period of time can be suppressed by draining the liquid from a battery manufactured by battery case formation and installing a valve for preventing the invasion of outside air. . That is, the invention according to claim 1, which solves the above-mentioned problem, is a method for manufacturing a lead-acid battery for immediate use, comprising a first step of assembling an unformed lead-acid battery, and pouring an electrolyte into the lead-acid battery. To form a battery case
And the third step of extracting the electrolytic solution after the formation of the battery case.
And a fourth step of storing the lead storage battery after the extraction, wherein the valve having an on-off valve pressure of 0 to 50 kPa is connected to the lead after the third step or the fourth step. A method for producing a ready-to-use lead-acid battery, which is provided in a storage battery.

According to the present invention, the lead storage battery is provided with a valve, that is, a check valve for preventing outside air from entering the inside of the battery case, during the manufacturing process, especially after extracting or storing the electrolyte. Air-tightness due to self-discharge and damage to the battery case can be suppressed, and an instant-use lead-acid battery having excellent immediate-use performance can be manufactured. By setting the opening valve pressure of the valve to 0 kPa or more, self-discharge can be prevented by at least preventing outside air from entering, that is, oxidation discharge of the negative electrode active material due to oxygen can be prevented. Insufficient airtightness such as breakage due to battery case swelling can be suppressed.

The valve is closed when the pressure inside the battery is equal to or less than the pressure outside the battery,
The internal pressure is released at a positive pressure that is higher than the external pressure. The pressure outside the battery is usually atmospheric pressure.
As the valve having an on-off valve pressure of 0 kPa, a valve that opens when the battery internal pressure becomes higher than the atmospheric pressure outside the battery can be used. Further, as the valve having an opening / closing valve pressure of 50 kPa, a valve that opens when the battery internal pressure exceeds a pressure 50 kPa higher than the atmospheric pressure outside the battery can be used. Then, a valve that closes when the internal pressure of the battery falls below a pressure obtained by adding the above-described on-off valve pressure to the pressure outside the battery can be used. Preferably, a valve that closes when the internal pressure of the battery becomes equal to or smaller than the pressure obtained by adding the above-mentioned prescribed on-off valve pressure to the pressure outside the battery is preferable.

The valve is preferably provided in a liquid port used for injecting or withdrawing the electrolytic solution, and is preferably a plug with a valve.

The valve provided in the lead storage battery may be provided when the battery is used, or may be removed. When using the plug with a valve in the liquid port for electrolyte injection, remove the plug with the valve at the time of re-injecting the electrolyte immediately before use of the lead storage battery, and after injecting the electrolyte, with the valve A stopper may be attached, or the liquid port may be covered with a separate stopper.

According to a second aspect of the present invention to solve the above-mentioned problems, after extracting the electrolyte of a ready-to-use lead-acid battery formed by a battery case, a valve having an on-off valve pressure of 0 to 50 kPa is attached to the lead-acid battery. This is a method for storing a ready-to-use lead-acid battery, characterized in that it is stored in a state where it is stored.

According to the above-mentioned invention, self-discharge and poor airtightness can be stored as in the case of a ready-to-use lead-acid battery using a converted electrode plate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A ready-to-use lead-acid battery is a lead-acid battery in which dilute sulfuric acid, which is an electrolytic solution, is injected into a battery case immediately before use, and the capacity can be immediately taken out. After the electrolyte is injected, the battery may be charged once.

The method for manufacturing a ready-to-use lead-acid battery according to the present invention is a ready-to-use lead-acid battery, particularly of the type formed by a battery case. According to the manufacturing method, a lead storage battery is assembled by inserting an unformed positive / negative electrode plate into a battery case, and after injecting an electrolytic solution, the battery is first charged to form a battery, that is, a battery case is formed. After completion of the formation, the electrolytic solution is withdrawn. (At this time, it is impossible to completely remove the electrolyte because the electrolyte is impregnated in the electrode plate or the separator or exists between these power generating elements.) The method for removing the electrolyte is not particularly limited. The liquid may be sucked from the liquid port, or the lead storage battery may be inverted and drawn out such that the liquid port faces down. In this way, a lead-acid battery that can be used and can have a sufficient electric capacity only by injecting the electrolytic solution is obtained.

Hereinafter, the present invention will be described based on examples and comparative examples with reference to the drawings.

The cladding battery, which is initially charged by battery case formation, inverted, and the electrolyte is drawn out, suppresses the invasion of air from the outside as shown in FIG. A battery with a rated capacity of 280 Ah (5 hour rate) -2 V, in which a plug with a rubber valve capable of allowing the air to escape was attached to the liquid port as shown in Fig. 2, was manufactured. 1 is a rubber valve, 2 is a valve seat,
Reference numeral 3 denotes a valve presser, 4 denotes a valve hole, 5 denotes a packing for maintaining airtightness between a plug with a valve and a lid, 6 denotes a projection for fixing between a plug with a valve and a lid, 7 denotes a plug with a valve, and 8 denotes a lead storage battery. The opening / closing valve pressure of the rubber valve is 0 kPa (battery A), 5 kPa (battery B), 25 kPa (battery C), and a liquid stopper (battery D) having a vent hole of about 5 mm that allows outside air to enter the battery (battery D). The attached test batteries A to D were prepared. Among these batteries, batteries A to C are examples of the present invention, and battery D is a comparative example.

These batteries were allowed to stand in a 40 ° C. atmosphere for 6 months, and the self-discharge performance was evaluated. FIG. 3 shows the relationship between the idle period and the open circuit voltage.

Generally, the open circuit voltage correlates with the amount of self-discharge, and a decrease in the open circuit voltage indicates an increase in the amount of self-discharge. In the batteries A to C (Examples) having an on-off valve pressure of 0 to 25 kPa, the self-discharge amounts are considered to be substantially the same, since all show the same tendency of the decrease in the open circuit voltage.

On the other hand, φ which allows outside air to enter the battery
In the battery D having the air hole of about 5 mm, the decrease in the open circuit voltage increases with the lapse of the standing period. This is considered to be because ambient oxygen penetrates into the battery through the air holes and oxidizes the exposed lead of the negative electrode active material to accelerate discharge.

Next, the battery is charged for the first time by battery case formation, the battery is inverted, and the electrolytic solution is withdrawn to a rated capacity of 280 Ah (5
(Time rate)-2V clad type battery is manufactured and 0k
Pa (battery F), 5kPa (battery G), 25kPa (battery H), 30k
A pressure standing test was performed in which the battery was left at a set pressure of Pa (battery I) and 50 kPa (battery J). The test period was one year, which is the storage limit.

FIG. 4 shows the relationship between the internal pressure of the batteries F to J and the deformation of the battery case. If the battery internal pressure exceeds 25 kPa, the amount of battery case deformation increases.

Table 1 shows a period until the airtight failure occurs in the pressure test. It can be seen that a battery having a pressure of 50 kPa or less can be stored without airtightness failure for a relatively short period of 4 months. Preferably, batteries FH of 0-25 kPa
Therefore, poor airtightness does not occur after one year of standing.

[0028]

[Table 1] Battery internal pressure and timing of poor airtightness

In this embodiment, the effect of the present invention has been described by taking a clad type battery as an example, but the effect is not changed even in a paste type battery.

[0030]

According to the method for manufacturing a ready-to-use lead-acid battery of the present invention, the number of steps required for manufacturing can be reduced as compared with the method for manufacturing a ready-to-use lead-acid battery using assembled electrode plates.
The cost can be easily reduced. Also,
The self-discharge of the battery in the preservation step until the electrolyte is injected and used can be suppressed, and poor airtightness due to damage to the battery case due to gas generation from inside the battery can also be suppressed.

According to the method for storing a lead-acid battery of the present invention, self-discharge of the battery can be suppressed, and poor airtightness can be suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a valve structure according to the present invention.

FIG. 2 is a schematic view showing an example of a ready-to-use lead storage battery according to the present invention.

FIG. 3 is a diagram showing a relationship between a leaving period and an open circuit voltage in Examples and Comparative Examples of the present invention.

FIG. 4 is a diagram showing the relationship between battery internal pressure and battery case deformation in Examples and Comparative Examples of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 rubber valve 2 valve seat 3 valve retainer 4 valve hole 5 packing with valve to keep air tight between lid and lid 6 projection with plug to fix between lid and lid 7 plug with valve 8 lead storage battery

Claims (2)

[Claims] 1. A method for manufacturing a ready-to-use lead-acid battery, comprising: a first step of assembling an unformed lead-acid battery; and a second step of injecting an electrolytic solution into the lead-acid battery to form a battery case. A third step of extracting the electrolytic solution after the battery case formation, and a fourth step of storing the lead storage battery after the extraction, and after the third step or the fourth step Sometimes, a valve having an on-off valve pressure of 0 to 50 kPa is provided in the lead storage battery.
A method for producing a ready-to-use lead-acid battery. 2. The method according to claim 1, wherein after extracting the electrolyte from the ready-to-use type lead-acid battery formed in a battery case, a valve having an on-off valve pressure of 0 to 50 kPa is attached to the lead-acid battery and stored. How to store lead-acid batteries.