JPH0794206A - Sealed type lead-acid battery - Google Patents

Abstract

PURPOSE:To shorten the time necessary to pour an electrolytic liquid and improve the cycle life properties of a sealed type lead-acid battery. CONSTITUTION:Regarding a sealed type lead-acid battery, a retainer consisting of mainly glass fibers with 6mum or larger average fiber diameter and having 30-50mum maximum hole diameter is used for an electrode group retaining material. An acid resistant inorganic powder is added to the electrolytic liquid at 2% as the maximum and a group of electrodes consisting of a positive pole plate, a negative pole plate, and the retainer are pressed at 10-50kg/dm<2> pressure in dry state before the electrolytic liquid is poured. As a result, the time necessary to pour the electrolytic liquid is shortened and layer formation is prevented for a long time and cycle life properties are improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved sealed lead acid battery.

[0002]

2. Description of the Related Art Conventionally, as a sealed lead-acid battery, a mixed material of a fibrous body mainly composed of fine glass fibers having an average fiber diameter of 5 μm or less and an inorganic powder having acid resistance is provided between a positive electrode plate and a negative electrode plate. The method of inserting the product as a retainer (inorganic powder-containing retainer type) and the method of adding the acid resistant inorganic powder to the electrolytic solution (gel type) are often used, using the retainer mainly composed of the fine glass fibers. Has been done.

[0003]

However, in the above-mentioned conventional sealed lead-acid battery, in order to improve the adhesion to the electrode plate and prevent stratification, an inorganic powder capable of holding the electrolytic solution with acid resistance is retained. Although the effect can be seen by including it in or adding it to the electrolytic solution, since a fiber body mainly composed of glass fibers having an average fiber diameter of 5 μm or less is used,
Since the fiber density is high, it takes time to inject the electrolytic solution. Further, the elastic force of the retainer itself becomes small, and the pressure pressing the electrode plate group cannot be maintained for a long period of time. In addition, if inorganic powder is present in the retainer, it becomes harder than the hardness of the retainer itself, and due to repeated charging and discharging, a gap gradually forms between the electrode plate that repeats expansion and contraction, and the retainer, resulting in long stratification. There was a problem that the period could not be prevented.

An object of the present invention is to provide a sealed lead acid battery capable of shortening the time for injecting an electrolyte and maintaining cycle life characteristics and prevention of stratification for a long period of time.

[0005]

In order to solve the above-mentioned problems, the present invention provides a sealed lead-acid battery mainly comprising glass fibers having an average fiber diameter of 6 μm or more between a positive electrode plate and a negative electrode plate and having a maximum pore size of A maximum of 2% of acid resistant inorganic powder that can retain the electrolytic solution is added to the electrolytic solution with a retainer of 30 to 50 μm interposed, and the electrolytic solution is injected into the electrode plate group including the positive electrode plate, the negative electrode plate and the retainer. 10-5 in the previous dry state
It is characterized by being compressed at a pressure of 0 kg / dm ² .

[0006]

[Function] In a sealed lead-acid battery, by increasing the average fiber diameter of the retainer, which is a separator for the electrode plate group, there are large pores between the fibers, and when an electrolyte containing acid-resistant inorganic powder is injected, Since the electrolytic solution spreads from these holes, the injection time can be shortened. Further, since the elastic force of the retainer becomes large, the pressure that presses the electrode plate group is maintained, and even if the hardness of the retainer itself becomes hard due to the presence of the inorganic powder, a gap is created between the electrode plate and the retainer. It's hard to do. By adding acid resistant inorganic powder to the electrolytic solution, the contact area with the active material increases and the inorganic powder itself has electrolytic solution retention properties, preventing stratification for a long period of time and cycle life characteristics. Also improves.

[0007]

EXAMPLE An example of the present invention will be described. In order to confirm the effect of this experiment, a sealed lead acid battery in which the retainer shown in Table 1 is interposed between the positive electrode plate and the negative electrode plate is used.

[0008]

[Table 1]

The electrode group of the sealed lead-acid battery used in the test was composed of three positive electrode plates, four negative electrode plates, and the retainer interposed between these electrode plates was the above retainer.

Inorganic powder was added to the electrolytic solution based on the specifications of the sealed lead-acid battery shown in Table 2. SiO ₂ was used as the added inorganic powder. The inorganic powder is not limited to SiO ₂ but S
Oxides such as i, Al, Ti, and Zr, or a mixture thereof may be used.

[0011]

[Table 2]

A cycle life test was conducted using each sealed lead acid battery shown in Table 2, and the results are shown in FIG. The test battery was 2 V-30 Ah, the cycle life test conditions were a discharge current of 7.5 A and a discharge time of 3 hours, and the charge condition was 5.
115% of the discharged amount was charged by constant current charging of 2A.
From this, it is understood that the products A, B and C of the present invention have a longer cycle life as the amount of the inorganic powder added increases. This is because the addition of the inorganic powder to the electrolytic solution increases the contact area with the active material and the inorganic powder itself has the electrolytic solution retaining property, thus preventing stratification. However, when the addition amount of the comparative product b is 3%, the diffusion of the electrolytic solution deteriorates as the electrolytic solution gels, and the cycle life characteristics deteriorate.

Next, the cycle life test of the products D and E of the present invention and the comparative product c was conducted by changing the pressure for pressing the electrode plate group, and the results are shown in FIG. 2% SiO ₂ in sulfuric acid electrolyte
Was added. Table 3 shows the pressure applied to the electrode plate group of the test battery.
The relationship between the pressure on the electrode plate group and the cycle life is shown in FIG.

[0014]

[Table 3]

In a sealed lead-acid battery using a retainer having a large average fiber diameter and a large maximum pore diameter, the cycle life characteristics are improved as the pressure pressing the electrode plate group is increased. This is because by pressing the electrode plate group, a gap is less likely to be formed between the electrode plate and the retainer, and stratification is prevented.
Moreover, since the retainer itself has a large elastic force, the pressure can be maintained for a long period of time. On the other hand, in the case of a sealed lead-acid battery using a retainer with a small average fiber diameter or a retainer with a small maximum pore diameter, the cycle life characteristics do not improve much even if the pressure that presses the electrode plate group is increased. This is because the retainer itself has a high hardness and a small elastic force due to the high fiber density, so the pressure that presses the electrode plate group cannot be maintained for a long period of time, and a gradual gap is created between the electrode plate and the retainer. In the product of the present invention, since it becomes impossible to prevent stratification,
When the pressure pressing the electrode plate group is less than 10 kg / dm ² , the difference in the specific gravity of the electrolyte solution between the battery upper part and the battery lower part after 200 cycles is shown in Table 4 by the products D and E of the present invention and the comparative product c. , Stratification cannot be prevented. On the other hand, if the electrode plate group is pressed with a pressure exceeding 50 kg / dm ² , the battery container will swell and it will be impossible to apply uniform pressure.

[0016]

[Table 4]

[0017]

As described above, the sealed lead-acid battery according to the present invention is mainly composed of fibers having an average fiber diameter of 6 μm or more and uses a retainer having a maximum pore diameter of 30 to 50 μm, and is electrolytically resistant to an electrolytic solution. Add up to 2% of inorganic powder that can hold the liquid, 10 to 50 kg in a dry state before injecting the electrolytic solution to the electrode plate group consisting of the positive electrode plate, the negative electrode plate and the retainer.
By pressing with a pressure of / dm ² , the injection time of the electrolytic solution is shortened, stratification can be prevented for a long period of time, and cycle life characteristics are improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a cycle life test result of a sealed lead-acid battery using an electrode plate group according to an embodiment of the present invention, in which the addition amounts of a retainer and an inorganic powder are changed.

FIG. 2 is a diagram showing a cycle life test result of a sealed lead-acid battery using an electrode plate group according to an embodiment of the present invention, the cycle life test being performed while changing the pressure pressing the electrode plate group.

FIG. 3 is a diagram showing a cycle life test result of a sealed lead-acid battery using a retainer according to an example of the present invention, the pressure being applied to an electrode plate group being changed.

Claims (3)

[Claims] 1. In a sealed lead-acid battery, a retainer mainly composed of glass fibers having an average fiber diameter of 6 μm or more is used as an electrode plate group separator, and a sulfuric acid electrolytic solution is made of an inorganic powder that is acid-resistant and can retain the electrolytic solution at the maximum. A sealed lead-acid battery characterized by being added at 2% by weight. 2. An electrode group consisting of a positive electrode plate, a negative electrode plate, and a retainer in a dry state before injecting an electrolytic solution for 10
The sealed lead acid battery according to claim 1, wherein the sealed lead acid battery is compressed at a pressure of 50 kg / dm ² . 3. The retainer for separating the positive electrode plate and the negative electrode plate has a maximum hole diameter of 30 to 50 μm.
Or the sealed lead-acid battery according to 2.