JP2003178794A - Production process of sealed lead acid storage battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a production process of a sealed lead acid storage battery improved in life performance in a system that a gel electrolyte is charged into a space between a plate group of a retainer type sealed battery and a battery jar. <P>SOLUTION: A prescribed amount of diluted sulfuric acid is charged into a battery to conduct initial charge, and a sol solution obtained by mixing diluted sulfuric acid having a higher concentration than the electrolyte contained in a liquid-absorbing separator after the initial charge with silica powder is charged into the space between the plate group and a battery jar to gelatinize it, thereby inhibiting excellent life performance without accumulating the electrolyte at a lower portion of the separator. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a lead storage battery.

[0002]

2. Description of the Related Art In recent years, in automotive applications, an example of applying a sealed lead acid battery instead of a conventional open type lead acid battery has been increasing. This is because in sealed lead-acid batteries, oxygen gas generated in the positive electrode plate is absorbed by the negative electrode plate, so there is little decrease in the electrolyte solution and there is no need to replenish water, or the battery can be installed in various directions and locations. This is because there are various merits such as free use.

Three types of sealed lead-acid batteries are known as shown in the schematic structure of FIG. It is a gel type in which the electrolytic solution is gelled with fine silica, a retainer type in which the electrolytic solution is held in a separator made by processing fine liquid absorbing fibers into a mat, and the gap between the positive electrode plate and the negative electrode plate and the electrode. Granular silica type 3 in which the electrolytic solution is held inside the granular silica filled in the gap between the plate group and the battery case and in the silica particle gap.
It is a kind.

However, the gel method has a drawback in that the electrolytic solution is gelled, so that the diffusion performance of the electrolytic solution is deteriorated and the performance of the battery is deteriorated. In addition, although the retainer type has good electrolytic solution diffusion performance, it has the drawback that the amount of electrolytic solution decreases and the area in which the electrolytic solution contacts the battery case is small, so the temperature of the battery in use increases greatly. . Therefore, there were problems such as lattice corrosion and an excessive decrease in the amount of electrolyte. And, the granular silica type has no problem in performance because the diffusion of the electrolytic solution is good and the heat capacity of the electrolytic solution is large, but it takes time to fill the silica and inject the electrolytic solution, resulting in an increase in cost. There was a flaw.

[0005]

Therefore, in order to reduce the cost, accelerate the diffusion of the electrolytic solution, and suppress the rise in the battery temperature, the electrode plate group of the retainer type sealed battery shown in FIG. A sealed lead-acid battery, in which a gel electrolyte is injected into the gap between the battery and the battery case, was studied.

However, in our test, the life performance of the sealed lead-acid battery was not improved as expected. From the results of the disassembly study of those test batteries, the cause is that the fluid electrolyte gradually liberated from the gel migrates to the bottom through the glass separator, and the electrolyte accumulates at the bottom of the separator, and as a result, It is considered that the amount of charge / discharge reaction at the bottom of the battery was locally increased and accelerated the deterioration of the active material.

In the conventional gel-type sealed lead-acid battery, since the amount of the retained liquid in the separator is small, the amount of the released electrolytic solution migrating to the lower portion through the separator is small, and the above-mentioned problems are hardly present.

Therefore, an object of the present invention is to accumulate the electrolyte solution in the lower part of the separator in the sealed lead acid battery of the type in which the gel electrolyte solution is injected into the gap between the electrode plate group of the retainer type seal type battery and the battery case. It is an object of the present invention to provide a method of manufacturing a lead storage battery having improved life performance.

[0009]

In order to solve the above-mentioned problems, in the method for manufacturing a sealed lead-acid battery according to the first aspect of the present invention, an electrolytic solution is held by using a liquid-absorbing separator, and an electrode plate group is used. A method for manufacturing a sealed lead-acid battery having a structure in which a gelled electrolytic solution is placed in the gap between the battery and a battery case, in which a predetermined amount of dilute sulfuric acid is injected into the battery for initial charging in the first step. In the second step, a mixed sol solution of dilute sulfuric acid and silica powder having a concentration higher than the sulfuric acid concentration of the electrolytic solution contained in the absorbent separator after the initial charge is injected into the battery to cause gelation in the battery. It is characterized by

According to a second aspect of the present invention, there is provided a method for producing a sealed lead acid battery according to the first aspect, which is the same as the method for producing a sealed lead acid battery according to the first aspect. The difference from the sulfuric acid concentration of the electrolytic solution held by the liquid-absorbent separator is 0.01 or more and 0.05 or less (converted to 20 ° C.) in terms of sulfuric acid specific gravity.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A separator formed by forming a sheet of a liquid-absorbent fine fiber is used to hold an electrolytic solution and gelled in a gap between an electrode plate group and a battery case. In the manufacture of gel-retainer hybrid seal type lead-acid batteries with a structure in which an electrolytic solution is arranged, first a predetermined amount of dilute sulfuric acid is injected into the battery for initial charging, and then the electrolysis contained in the separator after the initial charging. It was found that the above problem can be solved by injecting a predetermined amount of a sol solution obtained by mixing dilute sulfuric acid having a higher sulfuric acid concentration than the liquid and silica powder to cause gelation in the battery.

Generally, the higher the concentration of sulfuric acid retained in the gel, the harder the gelled electrolytic solution and the slower the rate of liberation. As a result, the amount of electrolyte released from the gel is small,
Accumulation of fluid electrolyte in the lower part of the separator is reduced, and the charge / discharge reaction is not locally increased.

When the difference between the sulfuric acid concentration of the gelled electrolytic solution and the sulfuric acid concentration of the electrolytic solution held by the separator exceeds 0.05 (converted at 20 ° C.) in terms of sulfuric acid specific gravity, it is liberated. Because the concentration of the electrolyte solution supplied to the separator becomes too high and the charge acceptance performance deteriorates, and the life performance deteriorates. Therefore, the difference in sulfuric acid concentration is 0.01 or more and 0.05 or less (converted at 20 ° C). Specific gravity is desirable.

[0014]

EXAMPLES Examples of the present invention will be described below. (Example 1) First, Pb- which is a base material and has a thickness of 10 mm
A continuous cast plate of 0.07 wt% Ca-1.3 wt% Sn alloy is rolled with a rolling roller to have a thickness of 1.0 mm.
After producing the rolled sheet of, the rolled sheet was developed into a mesh using a rotary expander to form a lattice. These grids were filled with a paste prepared by plastering lead powder, red lead and dilute sulfuric acid, aged and dried to prepare a positive electrode plate.

Lignin sulfone was formed on a grid of five positive plates and a rolled Pb-0.07wt% Ca-1.3wt% Sn alloy sheet having a thickness of 1.0mm in a mesh-like shape using a rotary expander. Negative electrode plate 6 prepared by filling a paste prepared by plastering lead powder mixed with acid, BaSO ₄ and carbon and dilute sulfuric acid, aging and drying
The sheet and the sheet were alternately laminated via a fine glass fiber separator to form an electrode plate group.

These electrode plate groups were inserted into a battery case, a predetermined amount of dilute sulfuric acid was injected, and initial charging was performed to produce a 2V30Ah sealed lead acid battery. After completion of the first charge, inject into the battery a sol solution in which each type of dilute sulfuric acid having a concentration higher than the sulfuric acid concentration of the electrolytic solution contained in the separator and 5% of colloidal silica (weight percentage of silica in dilute sulfuric acid) are mixed. Then, gel-retainer hybrid seal type lead-acid batteries were produced by gelling in the batteries. Finally, the battery was fitted with a normal safety valve.

These batteries are discharged at 10 A (1/3 C
In A), a charge / discharge cycle test was conducted in which the battery was charged up to 1.70 V at the end and 110% of the discharge amount was charged at a constant current of 10 A. The test was carried out in a water tank at 40 ° C. The life was determined when the discharge capacity of 10 A reached 80% of the initial value. For comparison, a conventional retainer battery without gel injection around the electrode plate group was also manufactured and evaluated.

Table 1 shows the structure of the battery and the result of the life test.
Gel-retainer hybrid seal type in which the concentration of sulfuric acid contained in the gel is 0.01 to 0.05 (converted at 20 ° C.) higher than the sulfuric acid concentration of the electrolytic solution held by the separator of the present invention in terms of specific gravity The lead-acid battery has a significantly improved life performance compared to the retainer-type sealed lead-acid battery. As a result of disassembling and investigating the battery, no accumulation of electrolyte solution under the separator was observed.

However, if the difference between the sulfuric acid concentration of the gel electrolyte and the sulfuric acid concentration of the electrolyte held in the separator is 0.05 or more (converted to 20 ° C.) in terms of sulfuric acid specific gravity, the life performance is rather deteriorated.

In this example, the test was carried out by limiting the amount of colloidal silica to 5% by weight with respect to sulfuric acid.
The results were the same when the amount of colloidal silica was larger or smaller than that.

[0021]

[Table 1] Test battery composition and life performance

[0022]

As described above, by using the present invention, it is possible to obtain a lead storage battery having an improved life performance without the electrolytic solution accumulating in the lower part of the separator.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a schematic configuration of various sealed lead acid batteries of a conventional example.

FIG. 2 is a schematic diagram showing a schematic configuration of a sealed lead acid battery according to the manufacturing method of the present invention.

[Explanation of symbols]

1 Gelled electrolyte 2 Fine glass fiber separator containing electrolyte 3 Granular silica containing electrolyte 4 battery case 5 exhaust 6 Water-absorbing separator containing electrolyte

Claims (2)

[Claims] 1. A method of manufacturing a sealed lead-acid battery having a structure in which an electrolytic solution is held by using a liquid-absorbing separator and a gelled electrolytic solution is disposed in a gap between an electrode plate group and a battery case. In the first step, a predetermined amount of dilute sulfuric acid is injected into the battery for initial charging, and in the second step, the diluted sulfuric acid concentration is higher than the sulfuric acid concentration of the electrolytic solution contained in the absorbent separator after the initial charging. A method for manufacturing a sealed lead-acid battery, which comprises injecting a mixed sol solution of sulfuric acid and silica powder into a battery to cause gelation in the battery. 2. The difference between the sulfuric acid concentration of the gelled electrolytic solution and the sulfuric acid concentration of the electrolytic solution retained in the liquid-absorbent separator after initial charging is 0.01 or more 0.05 in terms of sulfuric acid specific gravity. The method for producing a sealed lead-acid battery according to claim 1, wherein the following (20 ° C. conversion) is satisfied.