JPH0479111B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a sealed lead-acid battery in which the electrolyte is substantially non-fluidized, and its purpose is to improve discharge capacity and life.

Conventional sealed lead-acid batteries have a structure in which the electrolyte is virtually non-fluid, so there is no risk of leakage regardless of the orientation of the battery, and oxygen gas generated from the anode plate during charging is absorbed and recovered by the cathode plate. It has the feature of being maintenance free.

In order to make the electrolyte non-fluid, methods have been proposed that generally use a silica colloid mainly composed of silica or an impregnating material made of a mat of fine glass fibers with a diameter of 1 μm or less. However, in conventional sealed lead-acid batteries, the amount of electrolyte is very small because the electrolyte is essentially non-fluidized, and as a result, overcharging beyond the cathode absorption reaction rate or when the battery is used in a high temperature atmosphere may cause exhaust plugging. This has the disadvantage that the amount of electrolyte tends to decrease due to electrolysis or evaporation when the valve operation of the electrolyte decreases.

This has the disadvantage that the volume that can make the electrolyte non-fluid is small compared to the battery capacity, and as a result, the battery capacity and life deteriorate rapidly due to a slight decrease in water content. be.

The present invention eliminates the above-mentioned drawbacks, and by embedding glass fibers in the space outside the electrode group, the capacity for holding electrolyte is increased, which significantly improves the discharge capacity and life of the sealed lead-acid battery. The aim is to bring about a positive effect.

An embodiment of the present invention will be described.

Anode substrate (height:
115mm, width 110mm, thickness 3.4mm) and cathode substrate (height
115 mm in width, 110 mm in width, and 3.0 mm in thickness) were each filled with paste in accordance with a conventional method, dried, and heated, and then chemically formed in a specific gravity of 1.060 to obtain positive and negative electrode plates.
Next, we used 4 anode plates with a capacity of 10Ah each and 5 cathode plates with the same capacity, and in order to make the electrolyte non-fluid, we used a thickness of glass fibers mainly composed of fine glass fibers with a diameter of 1μ or less. Positive and negative electrode plates are stacked alternately through 2.15 mm separators to form an electrode plate group, which is stored in a container and diluted sulfuric acid with a specific gravity of 1.340 is injected so that there is no free electrolyte, and the capacity is increased at a rate of 10 hours. produced a 40Ah single cell battery and called it Battery A.

Furthermore, other batteries manufactured using the same method were filled with glass fibers with a diameter of 1μ or less through the injection port.
After filling the space outside the electrode group in the battery with glass fine fibers, dilute sulfuric acid with a specific gravity of 1.340 was reinjected to prepare test battery B.

After injection, each cell was charged at a constant voltage of 2.5 V for 10 hours, and then a 10-hour rate discharge test was conducted at 25°C.

Figure 1 shows the discharge voltage change during 10 hour rate discharge at 25°C. Conventional battery A reached its final voltage in about 10 hours, but battery B according to the present invention could be discharged for about 13 hours.

Figure 2 shows the capacity change as a percentage of the initial capacity when a floating charge test was performed at 2.30V/cell in an atmosphere at 50°C after recovery charging at 2.5V per cell after the above test. It is.

The capacity test was conducted once a month at 25°C for 10 hours.

As a result, while conventional battery A decreased to about 80% of its initial capacity after about 9 months, battery B according to the present invention showed amazing capacity characteristics, maintaining 90% of its initial capacity even after about 24 months. .

According to the present invention, it is possible to improve the discharge capacity of a sealed lead-acid battery in which the electrolyte is substantially non-fluidized by about 30%, and the battery life can also be significantly improved. There is.

In addition, in this example, an example was shown in which glass fine fibers were used as a means for making the electrolyte non-fluid, but the present invention is not limited to this. Alternatively, interposing a microporous sheet can be arbitrarily determined and used. Furthermore, the present invention can also be applied to applications of sealed lead-acid batteries, such as starting, float, cycle service, etc.

As mentioned above, the present invention has great industrial value, such as being able to improve the discharge capacity and life of sealed lead-acid batteries.

[Brief explanation of the drawing]

FIG. 1 is a discharge characteristic diagram of a conventional battery and a battery according to the present invention, and FIG. 2 is a comparison diagram of the same floating charge life test.

Claims (1)

[Claims] 1 In a sealed lead-acid battery in which fine glass fibers are filled in the space outside the electrode group, the diameter is 1μ after injecting dilute sulfuric acid.
A method for manufacturing a sealed lead-acid battery, which comprises filling the following glass fine fibers into the battery and then reinjecting dilute sulfuric acid.