JPH0654680B2 - Sealed lead acid battery - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a sealed lead-acid battery.

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 charging of the battery. The retainer type inserts a mat-shaped separator (glass separator) made of fine glass fibers between the positive electrode plate and the negative electrode plate, thereby holding the sulfuric acid electrolyte necessary for discharge and separating the two electrodes. In recent years, it has been widely used as a backup power source for portable devices and computers. However, the retainer type has a drawback that the discharge capacity is limited by the amount of the electrolytic solution at low rate discharge because the glass separator is expensive and cannot hold a sufficient amount of the electrolytic solution. Is an obstacle.

On the other hand, the gel type is less expensive than the retainer type, but has a drawback that the battery performance is inferior to that of the retainer type.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks of the conventional sealed lead-acid battery, and provides an inexpensive sealed lead-acid battery having excellent discharge performance. This is to impregnate and hold a sufficient amount of sulfuric acid electrolyte necessary for charging / discharging in a powder of a porous body in which silica fine powder is granulated using a binder, which is placed around the electrode plate group. The present invention will be described below based on examples.

EXAMPLE A positive and negative electrode grid made of Pb-Ca-Sn alloy was filled with ordinary positive and negative electrode pastes, and then 0.1 mm thick glass paper made from fine glass fibers with a diameter of 0.5 to 1.0 micron was filled. Attached to both sides. After that, both the positive and negative electrode plates were aged, and then a positive electrode group consisting of three positive electrode plates and four negative electrode plates was prepared using a low resistance synthetic separator having a thickness of 0.5 mm, and was inserted into a battery case. Then, add 15% of methyl methacrylate as a binder to a fine silica powder with a particle size of 10-40 mm and knead with water to obtain a particle size of 100-20.
What was dried after being granulated to 0 micron was densely packed while applying vibration between the battery cell wall and the electrode plate group. The granules filled here are secondary particles of 100-200 microns that are formed by agglomeration of fine silica primary particles, and the porosity in the filled state is about
It was 85%. The porosity of the granulated product itself was 90% or more.

After filling the granulated material in this way, the lid was adhered, an exhaust valve was attached, and a sealed lead-acid battery having a nominal capacity of 4.5 Ah was produced and subjected to a capacity test. For comparison, a conventional retainer battery and gel battery using the same lot of electrode plates were also tested at the same time. Table 1 shows the test results.

From this test result, when comparing the retainer type and the gel type, the retainer type was superior in high rate discharge performance to the gel type because the electrolytic solution specific gravity was slightly high. On the other hand, the product of the present invention has improved performance by 10 to 20% in both low rate discharge and high rate discharge as compared with these conventional sealed lead acid batteries. This was because the amount of electrolyte was larger than that of the retainer type, the specific gravity of the liquid was higher than that of the gel type, the diffusion of acid was better than that of the retainer type and gel type, and it was attached on both sides of the positive electrode plate and the negative electrode plate. It is believed that there is a synergistic effect such as the glass paper effectively acting to replenish the electrolyte.

By the way, when a prototype of a battery in which glass paper was not attached to the surface of the electrode plate was prototyped and examined, the battery performance was about the same as the conventional product. From this, the effect of sticking the glass paper is clear.

EFFECTS OF THE INVENTION As is apparent from the above-described examples, the sealed lead-acid battery according to the present invention uses a granulated product of silica fine powder for holding the electrolytic solution, and a simple method of pasting glass paper on the surface of the electrode plate. The industrial value is extremely high in that the discharge performance of the conventional sealed lead-acid battery can be greatly improved by operation.

Claims (1)

[Claims] 1. A sealed lead-acid battery in which oxygen gas generated during charging of the battery is absorbed by a negative electrode, and a positive electrode plate and a negative electrode plate each having a thin glass paper made of fine glass fibers attached to both sides thereof and a low resistance plate. The electrode plate group consisting of the separator is stored in the battery case, and
Filling and arranging a porous powder obtained by granulating 10-40 millimicron silica fine powder using a binder, and impregnating and holding the above-mentioned granulated powder with a sufficient amount of sulfuric acid electrolyte necessary for discharge. A sealed lead-acid battery that is characterized by: