JP2000251899A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the stratification of an electrolyte and to improve the service life performance of a battery by applying a lead alloy containing at least Sb to the lower end part of a negative electrode grid board formed of a Pb-Ca-based alloy. SOLUTION: A Pb-Sb-based alloy is fused and kept at 350-400 deg.C. An application film 3 is formed by dipping each foot part 2 of a negative electrode grid board 1 cast by using a Pb-Ca-based alloy in the fused alloy for 5 sec. For instance, a Pb-Sb-Sn-As-Se (3.0% Sb-0.2% Sn-0.3% As-0.01% Se-remainder of Pb) alloy is used as the Pb-Sb-based alloy. The application area of the application film to the total area of the foot parts 2 is set to be in the range of 70-95% of the total area of the outside surfaces of the foot parts 2. After the application film 3 is formed, a negative electrode plate is completed by filling the grid board 1 with paste. The hydrogen overvoltage in the application part of the application film 3 is lowered, the gas generated amount from the foot parts 2 is increased, and an electrolyte becomes thereby thoroughly stirred, so that the stratification of the electrolyte is prevented and the service life performance of a battery is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead-acid battery mounted on an automobile or the like.

[0002]

2. Description of the Related Art In lead-acid batteries for automobiles, there has been a growing demand for maintenance-free batteries due to the complexity of inspection and maintenance of electrolytes. P on grid substrate
A hybrid battery using a b-Sb-based alloy and a Pb-Ca-based alloy for the negative grid substrate, and a Pb-
A calcium battery using a Ca-based alloy and a Pb-Ca-based alloy for a grid substrate of a negative electrode is provided, and the calcium battery is currently the mainstream.

[0003]

However, in such a maintenance-free battery, since a Pb-Ca-based alloy is used for the grid substrate of the negative electrode, the hydrogen overvoltage increases, and the battery is charged during constant-voltage charging. Then, the charging current value becomes small, and the amount of generated gas decreases. As a result, the electrolyte inside the battery is not sufficiently agitated, stratification occurs, the charge / discharge reaction in the low-concentration part where the electrolyte diffuses well is activated, the electrode plates are used unevenly, and the life performance of the battery is reduced. There is a problem of causing a decrease.

The present invention has been made in view of such a point, and an object of the present invention is to suppress the hydrogen overvoltage to appropriately increase the amount of gas generated, and to increase the amount of gas generated by the electrolytic solution. An object of the present invention is to stir moderately and sufficiently, thereby preventing stratification of an electrolytic solution and improving the life performance of a battery.

[0005]

In order to achieve the above object, the present invention provides a lead-acid battery using a grid substrate made of a Pb-Ca-based alloy as a negative electrode, wherein at least the lower end of the grid substrate has The lead alloy containing Sb is applied.

The portion to which the lead alloy is applied is, for example, a foot formed on the lower edge of the grid substrate of the negative electrode.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a lead-acid battery of the present invention, a Pb-Ca-based alloy is used as a grid substrate for a positive electrode and a negative electrode, as in a conventional calcium battery. For example, at least Sb
Is applied.

FIG. 1 shows a grid substrate 1 of a negative electrode cast using a Pb—Ca alloy.
The foot 2 is integrally formed on the lower end edge of the body. The vertical width of this lattice substrate 1 is 110 mm, the horizontal width is 100 mm,
The vertical width of the foot 2 is 3 mm and the horizontal width is 10 mm.

Each foot 2 of the lattice substrate 1 is provided with Sb
Pb-Sb-based alloy (an alloy containing Pb-Sb as a main component and trace amounts of other elements) as a lead alloy containing, for example, Pb-Sb
-Sn-As-Se (3.0% Sb-0.2% Sn-0.3% A
A coating film 3 of an (s-0.01% Se-Pb residue) alloy is formed.

This coating film 3 is formed by casting the lattice substrate 1 and then dissolving Pb-Sb-Sn-As-Se.
(3.0% Sb-0.2% Sn-0.3% As-0.01% Se-P
b Residue) The foot 2 of the lattice substrate 1 is immersed in the alloy.

The melted alloy is maintained at a temperature of 350 to 400 ° C., and the foot 2 of the lattice substrate 1 is immersed in the alloy for 5 seconds to form a coating film 3. The coating area of the coating film 3 on the foot 2 is 70 to 95 with respect to the total area of the outer surface of the foot 2.
% Range. And a coating film 3 on the foot 2
After that, the grid substrate 1 is filled with a predetermined paste to complete the negative electrode plate.

The means for forming the coating film 3 includes:
In addition to the immersion method, it is also possible to adopt a method by spraying or a method by plating.

As described above, in a lead-acid battery using a negative electrode plate in which a coating film made of a Pb-Sb-based alloy is applied to the foot of a lattice substrate, the hydrogen overvoltage at the coating portion of the coating film decreases, The amount of gas generated from the electrolyte is appropriately increased, and the entire electrolytic solution in the battery is sufficiently stirred, so that the stratification of the electrolytic solution is suppressed and the life performance of the battery is improved.

Here, if the application area of the coating film to the foot portion is too large, the amount of gas generated from the foot portion becomes excessive, the stirring of the electrolytic solution exceeds a proper range, and the electrolytic solution decreases, On the other hand, if the application area is too small, the stirring of the electrolyte is insufficient and the electrolyte is stratified, so that the application area of the coating film to the foot is the total area of the outer surface of the foot. On the other hand, it is preferable to be within the range of 70 to 95%.

In order to confirm the effects of the present invention, the 5-hour rate capacity of the product of the present invention using a Pb-Ca alloy lattice substrate for the positive electrode plate and a Pb-Ca alloy lattice substrate for the negative electrode plate was 28%.
An Ah automotive lead-acid battery was prototyped, subjected to a light load life test in accordance with JIS D5301, and compared with a conventional product having the same capacity. As shown in FIG. 2, the product of the present invention has a longer life performance than the conventional product. It was confirmed that it was improved about 1.5 times.

In the above embodiment, Pb-Sb-Sn-As-Se (3.0% Sb-0.2%
Although the Sn-0.3% As-0.01% Se-Pb residue) alloy is exemplified, it is possible to suppress the hydrogen overvoltage with a simple Pb-Sb alloy. In short, if a lead alloy containing at least Sb is used as the material of the coating film, the hydrogen overvoltage in the coating portion is suppressed, the amount of gas generated is increased appropriately, the stratification of the electrolyte is prevented, and the battery life performance is improved. Can be improved.

In the above-described embodiment, a lead alloy containing Sb for suppressing hydrogen overvoltage is applied to the foot at the lower edge of the grid substrate. The same effect can be obtained by applying a lead alloy containing Sb to the lower end with an area equivalent to that of the foot.

[0018]

As explained above, according to the present invention,
Suppresses hydrogen overvoltage to increase gas generation moderately, and this increase in gas generation allows the electrolyte to be stirred appropriately and sufficiently, thus preventing stratification of the electrolyte and improving battery life. Can be done.

[Brief description of the drawings]

FIG. 1 is a front view showing a grid substrate of a negative electrode of a lead storage battery according to an embodiment of the present invention.

FIG. 2 is a graph showing the results of a light load life test of the product of the present invention and a conventional product.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Lattice substrate 2 ... Foot 3 ... Coating film

Claims (2)

[Claims] 1. A lead-acid battery using a grid substrate made of a Pb-Ca-based alloy as a negative electrode, wherein a lead alloy containing at least Sb is applied to the lower end of the grid substrate. 2. The lead-acid battery according to claim 1, wherein the portion to which the lead alloy is applied is a foot formed on the lower edge of the grid substrate of the negative electrode.