JPH08329948A - Lead acid battery - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a lead-acid battery having good life performance even at high temperatures. A lead storage battery comprising a negative electrode plate obtained by adding a trace amount of a metal having a hydrogen overvoltage lower than that of lead or a compound such as an oxide or a sulfate of the metal to an active material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improving the life performance of lead acid batteries, and more particularly to improving the life performance of negative electrode plates.

[0002]

2. Description of the Related Art Lignin, which is an organic additive made from pulp waste liquid, has been conventionally added to a negative electrode plate of a lead storage battery. This is very effective in increasing the surface area of the negative electrode active material and increasing the discharge capacity.

In recent years, as the performance of automobiles has advanced, the batteries in the engine room are surrounded by more devices, and the cooling space thereof is decreasing. In addition, the heat generation of the engine is increasing due to the higher performance of the engine itself. Therefore, the temperature of the battery in the engine room tends to become higher and higher. Especially in summer, the battery temperature may be 90 ° C. or higher.

The increase in temperature of the battery is not limited to that for automobiles, and in UPS as well, due to the progress of downsizing, the cooling space around the battery is reduced, and similar increase in temperature occurs.

Under such a high temperature, even in the case of the lead storage battery, the deterioration of the performance occurs earlier than before.
Naturally, it is naturally expected to be mainly the deterioration of the negative electrode plate. Because the solubility of lignin added to the negative electrode plate increases as the temperature rises, the amount of elution into the electrolytic solution increases and it is reduced and decomposed in the negative electrode plate. This is because the amount of lignin remaining in the product will decrease.

Therefore, although lignin has been improved for a long time, the one having good high temperature resistance has not been developed yet.

Therefore, an object of the present invention is to provide a negative electrode plate for high temperature resistance by suppressing the decomposition of lignin in the negative electrode by adding the additive of the present invention to the negative electrode active material, and to provide a long life of the lead acid battery at high temperature. It is to improve performance.

[0008]

The present invention is characterized in that a metal having a hydrogen overvoltage lower than that of lead or a compound of the metal is added to the negative electrode active material of a lead storage battery.

[0009]

[Function] The lignin added to the negative electrode plate of the lead acid battery is significantly reduced by undergoing reduction at the negative electrode during charging and discharging at high temperature.

However, if a small amount of a metal having a hydrogen overvoltage lower than that of lead or a compound of the metal is added to the negative electrode plate in advance as in the present invention, the end-of-charge voltage can be suppressed to a low level, so that the decomposition of lignin is significantly reduced. Can be reduced.

Therefore, if the above additives are added,
It is possible to provide a lead storage battery that has excellent life performance at high temperatures.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples.

In addition to lignin, barium and carbon which are usually added to the negative electrode active material in the negative electrode grid made of an alloy of 0.06% Ca-1% Sn-the balance of lead, Sb which is a metal having a hydrogen overvoltage lower than that of lead, Ni, Co, Mo, Bi, Pt,
Filled with 0.002% Au paste, 1.7 mm
Seven types of negative electrode plates having different thicknesses were manufactured. The batteries using the respective electrode plates are A, B, C, D, E, F, and G. A battery (H) using a conventional negative electrode plate containing no such additives was also manufactured. The positive electrode plate was manufactured by filling a grid having the same composition as the negative electrode grid with a normal paste.

After assembling a battery using 11 of these negative plates, 10 of the positive plates having a thickness of 2.3 mm and a glass mat separator made of fine glass fibers, predetermined liquid injection and charging are performed to obtain a liquid specific gravity. 1.32 (20 ℃), capacity about 6
A retainer type sealed lead acid battery of 3Ah (3hR) -12V was manufactured.

The initial capacity of these batteries was first examined.
The initial capacity was almost the same regardless of the presence or type of the additive. Next, in a water bath at 50 ° C., discharge depth 80
%, The charging / discharging was repeated in a pattern of charging 110% of the discharge amount at a constant current, and the life performance of the battery was examined. Table 1 shows the relative values of the number of cycles that reached the end of life, the end-of-charge voltage at the 200th cycle, and after 200 cycles, another battery subjected to the same test was disassembled and the amount of lignin was analyzed.

The term "lifetime" as used herein means that the 3CA capacity has reached 70% or less of the initial capacity. In addition, the performance is evaluated by the 3CA capacity because the performance when discharging at 3CA, that is, a large current is dominated by the performance of the negative electrode plate, and is suitable for the evaluation, and whether it is for an automobile or an electric vehicle. This is because the performance when discharged with a large current is important.

[0017]

[Table 1] As is clear from this result, all the batteries using the negative electrode plate to which the metal having a low hydrogen overvoltage was added had the end-of-charge voltage lower than that of the conventional battery (H) without addition, as expected. The amount of residual lignin after 200 cycles was large, and the life was longer than that of the conventional battery (H).

It is considered that when a metal having a low hydrogen overvoltage is added, the lignin in the negative electrode active material is less likely to be reduced because the voltage of the negative electrode plate at the time of hydrogen generation is lowered.

When a metal having a low hydrogen overvoltage is added, self-discharge increases, but the amount added, the charging method, the recovery charging method, etc. may be optimized.

Further, it is clear that the material to be added works effectively if the material has a hydrogen overvoltage lower than that of lead at the potential of the negative electrode. Therefore, a compound that becomes a metal at the potential during charging of the negative electrode plate of a lead battery is effective. Is.

When an Sb alloy is used for the negative electrode grid, a small amount of Sb is eluted and deposited in the negative electrode active material, so that the end-of-charge voltage is low and the capacity is not significantly reduced. According to the test results so far, when the Sb concentration of the negative electrode lattice alloy is 1.2% or more, the above additive is not necessary.

In this embodiment, Pb-Ca-Sn is used for the positive electrode grid.
Although an alloy was used, when Sb alloy was used, some S
b is eluted, diffused and deposited on the negative electrode plate. Therefore, the above additive exerts the greatest effect when the lattice alloy of the positive electrode is Sb-free. From the results of the tests so far, it is known that even when the positive electrode lattice is made of the Sb alloy, the additive is unnecessary when the Sb amount in the lattice alloy is 1.2% or more.

Finally, in this example, the evaluation was carried out by applying to a retainer type sealed battery, but a liquid type battery such as an automobile battery or a gel type battery prevailing in Europe is also being developed. Even with a silica-type sealed battery, the effect is
Obviously the same.

[0024]

As described above, according to the present invention, by adding a metal having a hydrogen overvoltage lower than that of lead or a compound of the metal to the negative electrode active material, the life performance of a lead storage battery, particularly a negative electrode plate, can be greatly improved. And its industrial value is extremely high.

Claims (3)

[Claims] 1. A lead-acid battery comprising a negative electrode plate obtained by adding a trace amount of a metal having a hydrogen overvoltage lower than that of lead or a compound such as an oxide or a sulfate of the metal to the active material. 2. The amount of antimony used as the negative electrode grid is 1.2%.
The lead acid battery according to claim 1, wherein a grid made of the following lead-antimony alloy or lead alloy containing no antimony is used. 3. The amount of antimony in the positive electrode grid is 1.2%.
The lead-acid battery according to claim 1 or 2, wherein a grid made of the following lead-antimony alloy or lead alloy containing no antimony is used.