JPH1064530A - Manufacture of electrode plate for lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an electrode plate for a lead-acid battery with high capacity recovery capability and high quick charge performance by filling a pasty active material in a grid, aging, drying, and forming a non-formed positive plate and a non-formed negative plate at the same time by interposing the suspension between charge and discharge. SOLUTION: A pasty active material comprising lead oxide, dilute sulfuric acid, water, and an additive is filled in a grid made of a lead alloy, aged, and dried. A non-formed electrode plates for a positive electrode and a negative electrode obtained are placed in an electrolyte, and a constant current is applied to the electrode plates to form the electrode plates at the same time. Suspension is interposed between charge and discharge. As suspension, it is preferable to stop discharge until voltage reaches 2.1V/cell after charge across the positive and negative electrode plates formed at the same time is finished. The conversion of lower lead oxide into lead sulfate is retarded, and formation of the electrode plates is uniformly advanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrode plate for a lead-acid battery, and more particularly to a chemical conversion method.

[0002]

2. Description of the Related Art An unformed electrode plate of a lead-acid battery is conventionally filled with a grid-like body made of a lead alloy and filled with a paste-like active material in which lead oxide, dilute sulfuric acid, water and various additives are mixed, and then aged and dried. Was manufactured by that. The unformed electrode plates for the positive electrode and the negative electrode obtained in this manner were arranged in an electrolytic solution and were formed by continuous energization with a constant current. Was not.

[0003] In order to improve the progress of the formation of the electrode plate, as described in JP-A-59-139563,
A method has been adopted in which an on-off pulse current is supplied by a constant current at an early stage of formation.

[0004]

When a predetermined current is applied to the positive electrode plate, electrolytic oxidation occurs, and the lead oxide of the active material becomes lead dioxide (PbO ₂ ). Therefore, when the unformed active material becomes lead dioxide, the formation charge ends. However, the formation reaction in the electrode plate does not proceed uniformly, and a partial difference occurs. In other words, electrolysis of water occurs from the chemical conversion end portion, and oxygen gas is generated, which prevents diffusion of the electrolytic solution into the non-chemical conversion portion, thereby deteriorating the efficiency of electrolytic oxidation. As a result, the lead oxide in the active material of the unpolarized electrode plate is not oxidized to lead dioxide, but becomes PbO or PbO.Pb.
Since the chemical conversion process ends with the electrochemically unstable lower lead oxide such as SO ₄ , and then discharge is performed, these lower lead oxides easily generate lead sulfate. , Resulting in a passive state that is difficult to be charged. In this state, even if the next charge is performed in order to recover the discharge capacity, the recovery is difficult, and there is a problem that it cannot be used for applications requiring rapid discharge.

An object of the present invention is to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a battery which uniformly improves the progress of formation of an electrode plate and has excellent capacity recovery and rapid discharge.

[0006]

According to the present invention, in order to solve the above-mentioned problems, the charging and discharging are performed until the voltage between the positive and negative electrodes after the charging in the chemical conversion step reaches 2.1 V / cell or less. It is characterized by performing a pause. This suppresses the conversion of the lower lead oxide into lead sulfate, and the progress of the formation of the electrode plate is uniformly improved. As a result, a battery with excellent capacity recovery can be obtained.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is a method for producing a lead storage battery electrode plate in which the formation of an unformed electrode plate is made to proceed uniformly by suspending the charging and discharging in the formation step.
FIG. 1 shows an example of a charge / discharge pattern according to the chemical conversion method of the present invention. At this time, assuming that the post-charging voltage between the positive and negative electrodes that have undergone simultaneous formation reaches a voltage of 2.1 V / cell or less, the non-forming portion of the electrode plate, that is, unstable and uneven Since the active material existing in a stable state is stabilized in an electrochemically uniform state, the progress of chemical formation is improved, and it is effective to suppress the active material from easily becoming lead sulfate by discharge.

That is, if the discharge step is started at a voltage of 2.1 V / cell or more, the next charge acceptance is insufficient. On the other hand, if the pause is longer than that, it takes a long time for the entire chemical conversion process, which is not efficient.

[0009]

EXAMPLE An example of the present invention will now be described with reference to a nominal 6 V, 3.2 V
An AH sealed lead-acid battery will be described with reference to the drawings. Eleven unformed electrode plates for the positive electrode for the test battery were similarly disposed between 22 unformed electrode plates for the negative electrode, and formed in a dilute sulfuric acid tank having a specific gravity of 1.100 (20 ° C.).
As shown in FIG. 1, continuous formation was performed at a constant current of 1.3 A / dm ² (10 hours, charge 1) and a current density of 0.9 A / dm ² (10 hours, charge 2). A pause was performed until the voltage between the positive and negative electrodes subjected to simultaneous formation reached 2.1 V / cell or less, and then discharge was performed at a constant current of 0.9 A / dm ² for 1 hour. After the formation, a positive electrode plate according to the production method of the present invention was obtained through a washing and drying process. Further, formation was carried out in the pattern shown in FIG. 2 with the same arrangement and current density as in the above-mentioned embodiment without pausing between charging and discharging, to obtain a positive / negative electrode plate by a conventional manufacturing method. Each of the positive and negative electrode plates was housed in a battery case in combination with a separator, etc., charged with an electrolytic solution, charged, and assembled as a sealed lead storage battery. Each of these conventional examples and the sealed lead-acid batteries of the present invention was 2
Table 1 shows the results of the initial capacity test in which constant current discharge was performed at 0 hour rate, 10 hour rate, 3 hour rate, and 30 minute rate, and the discharge duration was measured.

[0010]

[Table 1]

From Table 1, it can be seen that in the case of the present invention, the initial capacity is improved as compared with the conventional example. this is,
In the case of the present invention, it is considered that the progress of the formation of the electrode plate active material was improved, and the lead dioxide required for the battery reaction was uniformly present during the discharge.

Further, with respect to the conventional lead-acid battery and the sealed lead-acid battery of the present invention, each was left at 25 ° C. for 90 days, discharged at a constant current at a rate of 3 hours, and the results of the remaining capacity test were measured. After discharging for 3 hours, 1
Table 2 shows the results of the recovery capacity test after constant voltage charging under the conditions of 4.7 V and 8 hours.

[0013]

[Table 2]

From Table 2, it can be seen that in the case of the present invention, the capacity remaining ratio is higher and the capacity recovery is excellent as compared with the conventional example. This is considered to be because in the case of the present invention, the chemical conversion reaction of the active material was improved, and the lower lead oxide in the electrode plate active material was less likely to be converted to lead sulfate.

[0015]

As described above, according to the present invention, the progress of the formation of the positive electrode plate is improved by suspending between the charge and discharge in the chemical conversion step, and the lower lead oxide in the electrode plate active material remains. The amount could be reduced. Therefore, according to the present invention, not only the initial capacity can be improved, but also the problem of poor charge recovery in long-term storage in the market can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a charge / discharge pattern according to a chemical conversion method of the present invention.

FIG. 2 is a diagram showing a charge / discharge pattern according to a conventional chemical conversion method.

Claims (2)

[Claims] 1. A lead characterized in that, after filling a paste-like active material into a lattice and simultaneously forming unformed positive and negative electrode plates through an aging and drying step, a pause is performed between charging and discharging. A method for manufacturing an electrode plate for a storage battery. 2. The production of an electrode plate for a lead-acid battery according to claim 1, wherein the discharge is stopped until the voltage between the positive and negative electrode plates simultaneously formed reaches 2.1 V / cell or less after charging. Method.