JPH07142082A - Retainer type sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To provide a retainer type sealed lead-acid battery having a trickle service life characteristic, a cycle service life characteristic and an excellent overcharge characteristic. CONSTITUTION:A powder layer 11 arranged around a plate group and a continuous foam body 2 arranged between a powder layer 4 and a storage battery cover, are provided, and the average pore diameter of the powder layer 4 is set larger than the average hole diameter of a separator, and the average hole diameter of the continuous foam body 2 is set larger than the average pore diameter of the powder layer 4. Through electrolyte inside of a battery is reduced by steam permeation as a trickle service life test makes progress, when the average pore diameter of the powder layer 4 is larger than the average hole diameter of the separator, the reduction in the electrolyte is caused from the powder layer 4, and an IR loss is not caused in the separator. Since the powder layer does not move freely, the expansion of a positive electrode plate by corrosion is restrained, and since the pressure degree of a plate group 3 is increased, service life performance is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a retainer type sealed lead acid battery.

[0002]

2. Description of the Related Art There are two types of retainer type and gel type sealed lead-acid batteries that use a so-called oxygen cycle, in which a negative electrode plate absorbs oxygen gas generated during charging of the battery.
Currently, the retainer type is mainly used.

The retainer type is a mat-like separator (glass separator) made of fine glass fibers inserted between a positive electrode plate and a negative electrode plate for holding a sulfuric acid electrolytic solution necessary for charging and discharging and for separating both electrodes. This is the method to do. The retainer type has the advantages of no maintenance, no leakage, position-free, etc., and in recent years it has been used for portable devices, cordless devices, backup power sources for computers, large stationary batteries, and for starting the engine of automobiles. Has become.

[0004]

However, in the sealed lead-acid battery, when the overcharge or the use atmosphere is 40 ° C. or higher, the water content of the electrolytic solution permeates as water vapor, so that the electrolytic solution is gradually removed. Decrease to. For this reason, there is a problem that the electrolytic solution in the separator decreases and the IR loss increases.
Therefore, especially at the time of high-rate discharge such as UPS application, the performance may be significantly reduced.

In order to prevent this problem, it is sufficient to make the electrolyte excessively exist from the beginning, but this will destroy the position-free characteristic of the retainer type sealed lead acid battery, and is not a sufficient solution. I'm sorry.

As another method, it is possible to fill the inside of the storage battery with a powder layer having an average pore size larger than the average pore size of the separator, but it is extremely difficult to fill the inside of the storage battery with the powder because of the structure of the storage battery. Difficult to do.

The present invention has been made in order to solve the above problems, and its purpose is to:
A retainer-type sealed lead-acid battery that can prevent the occurrence of a large IR loss due to an increase in electrical resistance at the separator due to a decrease in water content during overcharge or high temperature use, as well as excellent cycle life characteristics and overcharge characteristics. Is to provide.

[0008]

[Means for Solving the Problems] Therefore, the powder layer disposed around the electrode plate group and the open-cell body disposed between the powder layer and the storage battery lid are provided. The pore size is larger than the average pore size of the separator, and the average pore size of the open-cell body is larger than the average pore size of the powder layer.By using the retainer type sealed lead-acid battery, the conventional problems can be solved. is there. In addition, in the present invention, the open-cell body is a general term for members having open cells therein.

[0009]

EXAMPLES The present invention will be described in detail below with reference to examples. The separator has a glass fiber average diameter of about 1 μm,
Using a commonly used one with porosity of about 94%, 20
A storage battery with a 2V rated capacity of 8Ah (20hR) is used, which has a thickness of 1.5mm under a load of kg / dm ² and is combined with a positive electrode plate and a negative electrode plate (between the electrode plates is 1.5mm). I made it. Then, powder was filled from the opening of the lid to form a powder layer, and then foamable resin was filled from the opening of the lid to foam inside the storage battery. Also, as powder,
Glass beads made of soda-lime glass, which is close to a true sphere and has almost no holes, were used. Also, for comparison,
Although a storage battery in which a non-cellular resin is arranged in place of the foamable resin having open cells in the space behind the lid and a powder layer are provided,
A storage battery having a free space above it was also manufactured. Further, the average pore diameter of the powder layer was set to 1, 20, 50, and 100 μm by using powders having various particle diameters. In this example, the average pore size of the foam having open cells was about 200 μm, but it is necessary to make the average pore size of the open cells larger than the average pore size of the powder layer in view of the liquid retention function. is there.

The average pore diameter of the powder layer was measured using a micrometric pore sizer 9310 manufactured by Shimadzu Corporation.

A schematic sectional view of such a storage battery is shown in FIG.
In the figure, 1 is a battery case, 2 is an open cell body, 3 is an electrode plate group, 4 is a powder layer, 5 is powder, and 6 is a jogo for filling powder. FIG. 4 is a diagram showing the types of components other than the average pore diameter of the powder layer.

Specific gravity of these storage batteries is 1.32 (20 ° C.)
After diluting the diluted sulfuric acid of No. 1, it was subjected to the test. As the first test, the battery was placed in a thermostatic chamber (gas phase) kept at a temperature of 40 ° C with a trickle voltage of 2.3 V / cell, and a final voltage of 1.65 V / cell was obtained by constant power discharge of 50 W every 3 months. Discharge was performed and the discharge duration was measured. The result when the average pore diameter of the powder layer is 100 μm is shown in FIG. Retainer-type sealed lead-acid battery No. 1 in which a granular layer was arranged around the electrode plate group. Nos. 2 to 4 were superior in trickle life performance to the conventional products. This tendency was the same for those having an average pore diameter of 20 and 50 μm, but no difference was observed for the one having an average pore diameter of 1 μm from the conventional product. The following are possible reasons for this. That is, as the trickle life test progresses, the liquid permeates the battery cell wall due to water vapor permeation and goes out, so the amount of electrolytic solution inside the battery decreases, but the powder layer arranged around the electrode plate group Since the electrolyte is impregnated and the average pore diameter of the powder layer is larger than the average pore diameter of the separator, the electrolyte solution decreases from the powder layer, IR loss does not occur in the separator, and the trickle life performance is excellent. It seems that

Next, the storage battery having the above structure was subjected to a cycle life test. The cycle life test conditions were as follows: the battery was discharged at 0.25 CA to 1.7 V / cell and 2.45
V / cell, 6 at maximum current 0.25 CA constant current constant voltage
The time charging and the temperature atmosphere of 25 ° C. were repeated. The result when the average pore diameter of the powder layer is 100 μm is shown in FIG.
Battery No. not filled with powder Battery No. 1 in which the electrode plate group was simply buried with 1 or particles. The battery No. 2 reached the end of its life in about 300 cycles, but the battery No. Nos. 3 and 4 had a life of about 600 cycles. This tendency was the same regardless of the average pore size of the powder layer. The following are possible reasons for this. That is, as the cycle life test progresses, expansion due to corrosion of the positive electrode plate and decrease in binding force of the active material occur, and battery No. Battery No. 1 and 2 reached the end of their service life early, but battery No. In Nos. 3 and 4, since the powder is filled in the entire space in the battery, expansion due to corrosion of the positive electrode plate is suppressed, and it is considered that the life is extended. The reason why the latter capacity transition was good is considered that the elongation of the lattice was limited by the surrounding glass beads, the stress was applied to the electrode plate, and the degree of compression of the electrode plate group increased. Traditionally,
It is said that the life performance will improve if the battery is assembled by increasing the degree of pressure on the electrode plates. However, since the assembly is actually difficult, the degree of pressure cannot be increased so much. However, when the powder is placed around the electrode plate group, as described above, the electrode plate group is eventually pressed, and it is considered that the capacity transition was good. Further, even if the lattice stretches, if glass beads are arranged around the electrode plate group as in the present invention, the force is dispersed and stress is applied to the entire wall of the battery case, so that it is considered that the battery case is less likely to break. .

Further, the storage batteries having these structures are installed upside down so that the powder injection port is on the bottom surface, and the small seal lead storage battery J is installed.
IS standard JIS-C-8702 (1988), 8.3.
According to 6 "Overcharge characteristics", continuous charging was performed for 48 hours at a constant current of 0.1 CA. As a result, after the test No. In the storage battery of No. 3, overflow of the electrolytic solution was observed regardless of the size of the average pore diameter of the granular layer. The following are possible reasons for this. In the above-mentioned constant current charging, a part of the electrolytic solution held in the electrode plate group was discharged by gassing and moved to the injection port portion at the bottom. In the storage battery of No. 3, there is no escape because the non-cellular resin is arranged on the back of the lid, and it is considered that the storage battery overflowed from the inlet.

From the above test results, the trickle life performance,
In order to obtain a storage battery having excellent cycle life performance and overcharge characteristics, a powder layer disposed around the electrode plate group and an open-cell body disposed between the powder layer and the storage battery lid are used. It is understood that the retainer-type sealed lead-acid battery in which the average pore diameter of the body layer is larger than the average pore diameter of the separator and the average pore diameter of the open-cell body is larger than the average pore diameter of the powder layer is sufficient.

[0016]

As described above in detail, the retainer type sealed lead acid battery according to the present invention is arranged between the powder layer disposed around the electrode plate group and the powder layer and the battery lid. And the average pore size of the powder layer is larger than the average pore size of the separator, and the average pore size of the open cell is larger than the average pore size of the powder layer.

As a result, it is possible to provide a retainer-type sealed lead-acid battery which does not leak even if the storage battery is used in an inverted state and has excellent trickle life, cycle life and overcharge characteristics. .

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of a sealed lead acid battery of the present invention.

FIG. 2 is a diagram showing 40 ° C. trickle life performance.

FIG. 3 is a diagram showing a 25 ° C. cycle life performance diagram.

FIG. 4 is a diagram showing a battery configuration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery case 2 Open cell body 3 Electrode plate group 4 Powder layer 5 Powder 6 Jogo for filling powder 7 Space where powder is not filled in battery case

Claims (1)

[Claims] 1. A powder layer disposed around the electrode plate group and an open-cell body disposed between the powder layer and a storage battery lid, wherein the average pore diameter of the powder layer is the average pore diameter of the separator. Greater than
Retainer-type sealed lead acid battery in which the average pore diameter of the open-cell body is larger than the average pore diameter of the powder layer.