JPH0536402A - Negative plate for lead storage battery - Google Patents

Abstract

PURPOSE:To manufacture a negative plate whose performance is by no means inferior to the performance of the previous ones, which is good in life performance. CONSTITUTION:In the negative plate for lead storage battery, the content of lead sulfate in the charging state immediately after manufacture is 0.4% or more and the half-value width 2theta of a peak recognized near 25.5 deg. at the time of X-ray analysis of lead sulfate is 0.3 deg. or less, and the content of barium is 0.2% or less.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an improvement of a negative electrode plate for a lead storage battery.

[0002]

2. Description of the Related Art Negative electrodes for lead-acid batteries are added with some substances to improve their performance.
Examples thereof include carbon for improving the conductivity of the negative electrode plate, lignin that suppresses the growth of lead sulfate during discharge, and the like.

In addition to the above, barium may be added which becomes a crystal nucleus of lead sulfate generated during discharge and improves the discharge performance. However, when barium is added, barium added to the negative electrode plate may be eluted into the electrolytic solution and reach the positive electrode plate when the charge / discharge life cycle is repeated, which may cause performance deterioration of the positive electrode plate.

[0004]

In the present invention, the adverse effect of barium is removed by suppressing the barium content of the negative electrode plate to 0.2% or less, and the deterioration of performance due to the decrease of the barium content is suppressed. The conventional problems are solved by adding lead sulfate having high crystallinity, which is hard to be charged in the negative electrode plate, to the negative electrode plate.

[0005]

[Function] By reducing the amount of barium added to the negative electrode plate to suppress adverse effects on the positive electrode plate, and by adding inert lead-free and highly crystalline lead sulfate, which has the same function as barium, In addition, the performance of the negative electrode plate is comparable to the conventional one, and it is possible to manufacture a negative electrode plate having a long life.

[0006]

[Examples] As is conventionally practiced, a mixture of lead powder, carbon, lignin, and barium is continuously added with dilute sulfuric acid to form a paste into a grid to form an unformed negative electrode plate. Energize the negative electrode plate in dilute sulfuric acid,
After completion of charging, washing with water and vacuum drying are carried out to manufacture a negative electrode plate for immediate use. At this time, the addition amount of barium and the addition amount of the lead sulphate used in the present invention, which is inactive and difficult to be charged and has high crystallinity, are set to the four compositions shown in Table 1. Here, as the lead sulfate having high crystallinity which is inactive and difficult to be charged, a commercially available reagent lead sulfate was used.

[0007]

[Table 1]

[0008] One sheet of the negative electrode plate for immediate use manufactured in this way,
Two immediate-use positive electrode plates with theoretical capacity 1.6 times that of the negative electrode plate were placed in a battery case with a gap of 2 mm, and the specific gravity at 20 ° C was 1.2.
Test batteries A, B, C, and D filled in the tank with 80 diluted sulfuric acid are manufactured, and these test batteries are discharged at a discharge current of 5 hours. The transition of the terminal voltage at this time is shown in FIG. The discharge voltage and the discharge capacity of the test battery B using the electrode plate No. 2 were lower than those of the test batteries A, C and D using the electrode plates No. 1, 3 and 4 shown in Table 1. This is because the negative electrode plate contains a small amount of substances that become discharge nuclei.

Next, these test batteries are subjected to a charge / discharge cycle life test in which they are discharged at a discharge current of 5 hours for 3 hours and 120% of the discharge amount is charged in 5 hours. The transition of the discharge capacity at this time is shown in FIG. Compared to the test batteries C and D using the electrode plates No. 3 and 4, the test battery A using the electrode plate No. 1 has a large capacity decrease rate, and the test battery B using the electrode plate No. 2 has a small initial capacity. The life was early. here,
Since the deterioration of the positive electrode plate in the test battery A using the electrode plate No1 is more remarkable than that of the other test batteries, it can be said that the deterioration of the positive electrode plate is the cause of its life.

[0010]

[Effects of the Invention] By reducing the amount of barium added to the negative electrode plate and adding lead sulfate having high crystallinity, which is inert and difficult to be charged, the negative electrode plate performance is comparable to the conventional one, It is possible to manufacture a negative electrode plate having excellent life performance.

[Brief description of drawings]

FIG. 1 is a diagram comparing changes in terminal voltage during discharge.

FIG. 2 is a diagram comparing capacity transitions during charge / discharge cycle life tests.

Claims (1)

Claims: 1. The content of lead sulfate in a charged state immediately after production is 0.4% or more, and when X-ray analysis of the lead sulfate is performed,
The half value width 2θ of the peak observed near 25.5 ° is 0.
A negative electrode plate for a lead storage battery, which is 3 ° or less and the barium content is 0.2% or less.