JPH02215055A - Sealed lead storage battery - Google Patents

Abstract

PURPOSE:To improve discharge performance by holding electrolyte and separating a positive electrode plate from a negative electrode plate using both a perforated plate mainly made of fine powder of silicon dioxide in a sheet form and glass separators mainly made of fine glass fiber. CONSTITUTION:A binder is made, in a sheet form, of fine powder of silicon dioxide kneaded water, thereby obtaining a perforated plate. Normal pastes of positive and negative electrodes are filled into grids of positive and negative electrodes made of Pb-Ca-Sn alloy, respectively, followed by aging. Consequently obtaining non-forming plates. Between the non-forming positive and negative plates, glass separators are inserted in contact with both surfaces of the perforated plate, to serve as a plate group. The plate group is accommodated in a battery jar, and then, it is covered with a cap and provided with an exhaust valve, resulting in assembly of a sealed lead battery. Therefore, each capacity in a 5-hour rate discharge and a high rate discharge can be increased, and a low rate discharge can be enhanced.

Description

[Detailed description of the invention] Industrial applications The present invention relates to improvements in sealed lead-acid batteries.

Conventional technology and its problems There are two types of sealed lead-acid batteries, the retainer type and the gel type, in which the negative electrode absorbs oxygen gas generated during battery charging. In the retainer type, a matte separator (glass separator) made of m-fine glass 1It4 fiber is inserted between the positive and negative electrode plates, and this holds the sulfuric acid electrolyte necessary for discharge and isolates the two electrodes. In recent years, it has become widely used as a backup power source for portable devices and computers. However, the cage type has the drawback that the discharge capacity is limited by the amount of electrolyte at low rate discharge because the glass separator is expensive and cannot hold a sufficient amount of electrolyte, and this type of sealed battery is becoming popular. has become an obstacle.

On the other hand, although the gel type is cheaper than the retainer type, it has the disadvantage that its battery performance is inferior to the liquid type and retainer type.

Therefore, as a separator for sealed lead-acid batteries, we proposed a perforated plate made of fine powder of silicon dioxide and a binder formed into a sheet. This porous plate, which is mainly made of fine powder of silicon dioxide, has the advantage of being cheap and easy to manufacture, but it also has poor elasticity and therefore does not make sufficient contact with the surface of the electrode plate, making it difficult to incorporate it into a battery. The discharge capacity was superior to the retainer type, but the discharge voltage was slightly inferior.

Means for Solving the Problems The present invention eliminates the drawbacks of the conventional sealed lead-acid batteries mentioned above and provides an inexpensive sealed lead-acid battery with excellent discharge performance. A perforated plate formed into a sheet using a binder mainly made of fine silicon dioxide powder was inserted between the plate and the negative electrode plate, and a thin glass separator made mainly of fine glass fibers was inserted in contact with both sides of the porous plate. The electrode plate group is housed in a battery container, and the porous plate and glass separator are impregnated with and retained in a sufficient amount of sulfuric acid electrolyte necessary for discharge.

The present invention will be explained below based on examples.

EXAMPLE 80 weight percent of water was added to 20 weight percent of fine powder of silicon dioxide and thoroughly kneaded, and 1 weight percent of carboxymethyl cellulose was added as a binder. Form this into a sheet and dry it at 120℃ to a thickness of 2
．． Porous plates with a thickness of 0 nm and 1.6 nn (under a pressure of 20 Kg/d, hereafter the thickness indicates the value under a pressure of 1/dl12) were prepared.The porosity was about 82%. A sealed lead-acid battery was assembled using plates.

That is, after filling positive and negative electrode grids made of pb-Ca-3n alloy with normal positive and negative electrode pastes, aging is performed to produce unformed electrode plates, and then these positive and negative electrode unformed plates are using the above thickness 1.
．． Glass separators with a thickness of 0°2nn are brought into contact with both sides of a 6nn perforated plate and inserted between the two electrode plates to form a group of electrode plates, which is then stored in a battery case, a lid is glued on, and an exhaust valve is attached to produce the present invention. A sealed lead-acid battery with a nominal capacity of 4.5 Ah was assembled. Similarly, using positive and negative electrode plates from the same lot, the thickness was 2.
Regarding the 0ni porous plate, it was inserted alone between the two electrode plates to form a conventional sealed lead-acid battery.

For comparison, a retainer type battery and a gel type battery were also assembled using positive and negative electrode plates from the same lot. these 4
A 5-hour rate discharge test and a low-temperature high rate discharge test were conducted on the various types of batteries. The results are shown in Table 1.

From this test result, when the retainer type and the gel type were compared, the retainer type had a slightly higher electrolyte specific gravity, so the high rate discharge performance was superior to the gel type. In addition, the conventional product, in which only a porous plate made mainly of fine powder of silicon dioxide was inserted between the two electrode plates, had a higher discharge capacity than the retainer type, but the 5th second voltage during low-temperature high-rate discharge was inferior to the retainer type. The product of the present invention, in which a porous plate mainly made of fine powder of silicon dioxide and glass separators in contact with both sides of the plate are inserted between the two electrode plates, has a high capacity for both 5-hour rate discharge and high rate discharge. The increased voltage at the 5th second of low rate discharge also exceeded that of the retainer type.

Furthermore, even if a glass separator was brought into contact with only one side of the perforated plate and inserted between the two electrodes, it was effective in increasing the voltage during low-temperature, high-rate discharge compared to inserting only the perforated plate.

Effects of the Invention As is clear from the above embodiments, the sealed lead-acid battery according to the present invention uses a porous plate formed into a sheet shape mainly made of fine powder of silicon dioxide and a glass separator mainly made of fine glass fiber. This technology has great industrial value because it can greatly improve the discharge performance of conventional sealed lead-acid batteries by simply holding the electrolyte and isolating the positive and negative plates.

Claims (1)

[Claims] 1. In a sealed lead-acid battery in which the negative electrode absorbs oxygen gas generated during battery charging, a porous plate formed into a sheet using a binder mainly composed of fine powder of silicon dioxide is used between the positive and negative electrode plates. A group of electrode plates made up of a thin glass separator mainly made of fine glass fibers that is in contact with both sides of the plate is housed in a battery case, and a sufficient amount of sulfuric acid electrolyte necessary for discharge is applied to the porous plate and the plate. A sealed lead-acid battery characterized by impregnation and retention in a glass separator.