JPH02262253A - Lead-acid battery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an improvement in a so-called cathode absorption type lead-acid battery, in which the cathode absorbs oxygen gas generated from the anode during charging.

Conventional technology In cathode absorption type lead-acid batteries, metal lead, which is the cathode active material, absorbs oxygen gas generated from the anode during charging or self-discharge, and an electrolytic solution is used to prevent the internal pressure of the battery from increasing due to gas generation. It has the function of suppressing the decrease in In order to achieve this function, we selected alloys for the lattice, plate group joints, and pole pillars because they have a high hydrogen overvoltage and are difficult to generate oxygen when the battery is charged. The alloy composition was determined with the consideration that it would not cause electrical discharge.

In this way, cathode absorption type lead-acid batteries have less loss of electrolyte during use, so the troublesome work of adding water is no longer necessary, and the storage battery can now be sealed. Furthermore, by sealing the battery, there is no need to emit harmful gases outside the battery during use, and the battery can now be easily used indoors.

Problems to be Solved by the Invention However, when using a conventional cathode absorption type lead-acid battery, especially in situations where it is constantly being charged such as in standby use, the cathode pole, cathode grid body, and cathode grid ear There was a phenomenon in which rapid corrosion progressed at the joints of the cathode plates or the joints of the cathode plates, causing some of the members to break. During use, a cathode absorption lead-acid battery is always filled with oxygen gas generated from the anode.

Therefore, not only the cathode active material, which has the function of absorbing oxygen gas, but also the cathode grid, electrode plate group joints, and pole columns are constantly exposed to oxygen, which can lead to corrosion and breakage of the cathode members. is assumed. Based on this assumption, various studies have been conducted, but no clear cause has been identified.

A detailed analysis of this conventional cathode absorption lead-acid battery in which corrosion of the cathode material progressed during standby use, leading to the material breaking, revealed that the one area that had been corroded was not corroded. It was found that there was a large amount of tellurium (which was not intentionally added) compared to other parts.

Furthermore, as the amount of tellurium increases, the amount of corrosion increases at an accelerated pace, and it is important to control the amount of tellurium, which was previously considered to be a very small amount with no particular effect, in order to prevent corrosion of cathode members. I understand.

Means for Solving the Problems Therefore, the present invention provides a lead-acid battery to which a cathode absorption type is applied, in which either or all of the cathode grid body including the electrode plate ears, the electrode plate group joints, and the pole columns are made of tellurium. content 2
01) It is made of lead or lead alloy and has a length of 9 m or less.

The amount of tellurium contained as an impurity in the lead or lead alloy constituting the working cathode grid, electrode plate group joints, and pole columns is reduced to 20pp.
By keeping it below lIl, the cathode member is less susceptible to corrosion and will not break even in the harsh oxygen atmosphere during use of the cathode absorption lead-acid battery. Therefore, the reliability of the cathode absorption type lead-acid battery can be significantly improved.

Example The present invention will be explained in detail below.

Figure 1 shows the configuration of a negative electrode absorption lead-acid battery. In the figure, 1 is a negative electrode plate group joint, 2 is a negative electrode grid, 3 is an electrode tab, 4 is a negative pole, 5 is a positive electrode plate, and 6 is a U-shaped separator.

In order to clarify the effects of the present invention, the cathode plate group joint 1
The amount of tellurium contained in is 150ppm, 50pp+n
.

The concentration was changed to 30 ppm, 20 ppm, and 5 ppm, and the time until this part broke due to corrosion was measured. In the test, a cathode absorption lead-acid battery with a voltage of 12 V and a capacity of 24 Ah was used, and the battery was charged at a constant voltage of 13.8 V. Changes in battery capacity and internal resistance were measured every month. Note that the ambient temperature was 40°C.

The above results are shown in FIGS. 2A and B.

As can be seen from Figure 2, the rapid rise in internal resistance occurred in 1 month at a tellurium content of 150 ppu+, and 3 months at a tellurium content of 50 ppu+.
It occurs in Rikizuki and 6 Rikizuki in 30ppIIl. When these batteries were disassembled to investigate the cause of the increase in internal resistance, it was discovered that all of the batteries had broken due to corrosion at the joints of the cathode plates.

However, at 20 ppm and 5 pp+ll, no rapid increase in internal resistance was observed even after 18 months. However, capacity is decreasing. When we investigated the cause, we found that
In both cases, the cause was a short circuit due to elongation of the anode grid, and no corrosion fracture was observed at the joints of the cathode plate groups.

Effects of the Invention As described above, the cathode absorption type lead-acid battery according to the present invention does not contain tellurium in excess of 20 pplI+ as an impurity in the lead or lead alloy constituting the cathode grid, the electrode plate group joints, and the pole columns. - The above-mentioned members do not corrode or break during use, and the amount of electrolyte and self-discharge, which are the most important functions for cathode absorption lead-acid batteries, can be reduced. Therefore, it has the effect of significantly improving the reliability of the cathode absorption type lead-acid battery.

[Brief Description of the Drawings] Fig. 1 is a partial cross-sectional view of a cathode absorption type lead-acid battery according to an embodiment of the present invention, and Fig. 2 shows continuous charging in a 40°C atmosphere to demonstrate the effects of the present invention. It is a figure showing the result of a test. ■... Plate group joint, 2... Cathode grid body, 3... Plate lug, 4... Pole column, 5...
... Anode plate, 6 ... Separator. Name of agent: Patent attorney Shigetaka Awano 1 idiot 1- vaginariyoseigunsaibanbu 2- 柘木 1 溪 3- ○FJix杆 4- 柘柘柘社 5-罎宎柘oriC-一で八' Shi-da

Claims (1)

[Claims] A lead-acid battery characterized in that either or all of the cathode lattice, the electrode plate group joints, and the pole columns are made of lead or a lead alloy with a tellurium content of 20 ppm or less.