JP2001185203A - Manufacturing method of sealed type lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of lead-acid battery having superior productivity and battery performance, in the case where a solution in which granular silica and dilute sulfuric acid are dispersed is injected into the battery, and where only excess electrolyte is discharged from a drain hole. SOLUTION: In this manufacturing method of granular type sealed lead-acid battery where a solution in which granular silica is dispersed in dilute sulfuric acid s injected from the inlet of the battery and the excess dilute sulfuric acid in the battery from drain hole, where the filling of granular silica and injection of sulfuric acid are carried out simultaneously, the concentration of granular silica and dilute sulfuric acid in the dispersed solution is granular silica/sulfuric acid=0.15-0.25 g/cc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for manufacturing a sealed lead-acid battery.

[0002]

2. Description of the Related Art There has been a so-called retainer type in which an electrolyte is impregnated and held in a mat-like separator made of fine glass fibers as an electrolyte as a liquid holding system for a sealed lead-acid battery. The battery of this type has a good initial capacity, but has a problem in that the separator has a weak force to press the active material, and the life performance deteriorates early due to the deterioration of the active material and the expansion of the lattice.

For this reason, in recent years, there has been proposed a granular silica battery in which granular silica is densely filled between the electrodes and around the electrode group so that the electrode plate, the separator and the granular silica retain an electrolyte. I have. As a result, the silica that is densely filled in the battery presses the electrode plate from all directions, so that the life performance is significantly improved.

For example, Japanese Patent Laid-Open Publication No. Hei 3-252
No. 063 describes a sealed lead-acid battery in which a battery is filled with silica powder having a diameter of 10 to 500 μm, and an electrode plate, a separator, and an electrolyte are held in the silica powder. Moreover, silica powder is a very inexpensive material as compared with conventional glass fiber separators, and can be said to be an important material that enables batteries that are inexpensive and have excellent performance.

[0005]

As the silica powder used for the electrolyte holding material of the battery, it is necessary to hold as much electrolyte as possible, so porous silica is used. When the silica is made porous, the fluidity of the silica deteriorates, and it is necessary to give strong vibration to the filling of the battery with a vibrator.

Further, such a silica powder has a high specific surface area, and it is necessary to apply a reduced-pressure injection in which the inside of the battery is reduced by a vacuum pump in order to inject the electrolytic solution. Therefore,
There are drawbacks such as high equipment costs such as a vibrator and a reduced pressure injection device, and considerable time required for filling and injecting granules, resulting in low productivity and high production cost.

For this reason, in order to combine vibration filling and vacuum injection into one process, an uninjected battery using a battery case provided with a hole on the side or bottom surface and a filter for covering the hole is provided with granular silica and diluted sulfuric acid. There is a production method in which a solution in which is dispersed is injected, and only the surplus electrolytic solution is discharged from a discharge port (Japanese Patent Application Laid-Open No. 7-122288). Also in this manufacturing method, the discharge rate of the surplus electrolyte may be extremely slow, and the manufacturing cost may be rather increased. In addition, a battery having a low discharge rate has a shortage of battery capacity, which may adversely affect battery performance.

[0008] The problem to be solved by the present invention is that when a solution in which granular silica and dilute sulfuric acid are dispersed is injected and only the surplus electrolyte is discharged from the discharge port, a sealed package having excellent productivity and battery performance is obtained. An object of the present invention is to provide a method for manufacturing a lead-acid battery.

[0009]

According to a first aspect of the present invention, there is provided a method of manufacturing a sealed lead-acid battery according to the first aspect of the present invention, comprising the steps of: In the method for producing a granular sealed lead-acid battery, in which the excess diluted sulfuric acid in the battery is discharged from the outlet and the filling of the granular silica and the injection of sulfuric acid are simultaneously performed, the granular silica to be injected into the battery and It is characterized in that the concentration of the dilute sulfuric acid dispersion solution is granular silica / sulfuric acid = 0.15 to 0.25 g / cc.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below, but the present invention is not limited to the following description.

[0011] In the method for manufacturing a sealed lead-acid battery according to the present invention, a solution in which granular silica is dispersed in diluted sulfuric acid is injected from an inlet of the battery, and excess diluted sulfuric acid in the battery is discharged from an outlet on the other surface. , And the filling of granular silica and the injection of sulfuric acid are carried out simultaneously, and the concentration of the dispersed solution of granular silica and dilute sulfuric acid to be injected into the battery is such that the ratio of granular silica / sulfuric acid = 0.15 ０．２0.25 g / cc.

When the concentration of the dispersion of granular silica and diluted sulfuric acid is in the range of 0.15 to 0.25 g / cc of granular silica / sulfuric acid, the injection into the battery is completed quickly and the excess diluted sulfuric acid is added. Since sulfuric acid discharge can be remarkably accelerated, battery manufacturing costs can be significantly reduced.

Furthermore, since the distribution of the electrolyte solution in the battery after discharging the excess diluted sulfuric acid becomes uniform, good battery performance can be stably obtained.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments.

First, a group of electrodes consisting of unformed paste-type positive and negative electrodes and a separator made of a synthetic resin is inserted into a battery case provided with an outlet having a filter through which silica does not pass. Welding was performed.

Thereafter, as shown in FIG. 1, a granular silica-dispersed dilute sulfuric acid solution 5 was prepared by adding granular silica having an average particle size of about 60 μm (measured by a Coulter counter method) to dilute sulfuric acid having a specific gravity of 1.31 (20 ° C.). Injection was performed through an injection port 6 provided in the battery lid 2 through a hopper 7.

The concentration of the solution is granular silica / sulfuric acid = 0.10
0 g / cc (A), 0.125 g / cc (B), 0.1
50 g / cc (C), 0.175 g / cc (D), 0.
200 g / cc (E), 0.225 g / cc (F),
0.250 g / cc (G), 0.275 g / cc (H)
And After filling the inside of the battery with granular silica and injecting the electrolytic solution at the same time while removing excess dilute sulfuric acid by reducing the pressure with the vacuum pump 8 from the outlet 4 at the bottom, the outlet 4 at the bottom of the battery is thermally welded. Sealed more airtight, rated capacity 60Ah
A (3hR) -2V battery was produced.

Each of the batteries is charged with a predetermined amount,
The specific gravity of the electrolyte was adjusted to 1.32 (20 ° C.), and after charging, a safety valve was attached according to a conventional method.

Table 1 shows the time required for discharging the electrolyte.
When the concentration of the dispersion solution is lower than 0.15 g / cc, the required time is as long as 7 minutes or more.
In the case of 5 g / cc, the time was as short as 2 to 4 minutes, and the higher the dispersion concentration, the shorter the time.

However, when the concentration was increased to 0.25 g / cc, the fluidity of the dispersion solution was lost, and it was impossible to inject the solution into the battery. The required time is an average value of the time required for the manufacturing of ten batteries.

[0021]

[Table 1]

Note that the concentration of the dispersion solution after the discharge of the surplus electrolytic solution is smaller than that at the time of injection. Although the value varies depending on the configuration of the battery, the sulfuric acid (c
c) / granular silica (g) was 2.20 to 2.60 cc / g. Further, the concentration of the dispersion solution after the completion of charging is further lower than that, which also depends on the configuration of the battery, but in the present invention product of this embodiment, the sulfuric acid (cc) / granular silica (g) is 2.
It was 18 to 2.58 cc / g, and there was no problem in any case. Although the numerical value of the concentration of the dispersion solution after the injection varies depending on the configuration of the battery, the concentration of the dispersion solution at the time of injection may be within the range of the present invention even if the configuration of the battery changes.

The above battery was discharged at a current of 10 hR to 1.7 V and a cycle of charging at 135% of the discharged amount at a current of 10 hR was repeated ten times, and the performance of the battery was evaluated at the capacity of the tenth cycle. Table 2 shows the test results. The capacity of the battery of the present invention was about 4% higher than that of the battery using the dilute dispersion solution. The low capacity of a battery with a low concentration of the dispersion solution is not uniform because the electrolyte is not uniformly distributed throughout the battery, as expected from the fact that it takes time to inject the electrolyte. It seems to be because.
On the other hand, it seems that the battery of the present invention has a more uniform distribution of the electrolytic solution.

[0024]

[Table 2]

Although the outlet is provided on the bottom surface, the same effect can be obtained by providing the outlet on the side of the battery case.

[0026]

As described above, the method for producing a sealed lead-acid battery of the present invention is superior to the conventional production method in that the obtained sealed lead-acid battery has excellent battery performance and excellent productivity. , Its industrial value is extremely large.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a method for producing a granular sealed lead-acid battery according to the present invention.

[Description of Signs] 1 Battery 2 Lid 3 Filter 4 Outlet 5 Granular silica dispersed diluted sulfuric acid solution 6 Inlet 7 Hopper 8 Vacuum pump 9 Discharged diluted sulfuric acid

Continued on the front page F term (reference) 5H028 AA01 AA06 BB02 BB03 HH02 HH03

Claims (1)

[Claims] 1. A solution in which granular silica is dispersed in dilute sulfuric acid,
Injection from the injection port of the battery, discharging the excess dilute sulfuric acid in the battery from the outlet, filling the granular silica and injecting sulfuric acid at the same time, the method of manufacturing a granular sealed lead-acid battery,
A method for producing a sealed lead-acid battery, wherein the concentration of a dispersion of granular silica and dilute sulfuric acid to be injected into the battery is from 0.15 to 0.25 g / cc of granular silica / sulfuric acid.