JPH02262256A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To prevent the corrosion and break of an anode material by constituting one or all of an anode grating, a plate group connection part and a polar column with lead or lead alloy having the specific content of antimony and zinc respectively. CONSTITUTION:In an anode absorption type lead-acid battery having one or all of an anode grating including a plate lug part, a plate group connection part and a polar column made of lead or lead alloy, the content of antimony as impurities in the aforesaid material is kept at 20ppm or less and the content of zinc also at 20ppm. According to the aforesaid construction, the concerned material is hardly subjected to corrosion and becomes free from a break, even in a severe oxygen atmosphere during the use of the battery.

Description

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

Conventional technology In a cathode absorption type lead-acid battery, during charging or self-discharging, oxygen gas generated from the anode is absorbed by the metal lead, which is the cathode active material, to prevent an increase in battery internal pressure due to gas generation, and to prevent the electrolyte from increasing. It has the function of suppressing the decrease in In order to achieve this function, when selecting alloys for the grid, plate group joints, and pole columns, we selected the following: ・High hydrogen overvoltage, less likely to cause water decomposition in the electrolyte when charging the battery, ・Added elements The composition of the first alloy was determined with consideration to the fact that no self-discharge would occur due to migration of the metal to the cathode.

In this way, cathode absorption type lead-acid batteries have little loss of electrolyte during use, eliminating the need for troublesome water replenishment work and allowing storage batteries to be sealed. Furthermore, by sealing the battery, harmful gases are no longer emitted outside the battery during use, making it easier to use the battery indoors.

Problems to be Solved by the Invention However, during use of conventional cathode absorption lead-acid batteries, especially in situations where they are constantly being charged, such as during standby use, the cathode pole and cathode lattice are damaged.

There was a phenomenon in which corrosion progressed rapidly at the cathode grid ears or the cathode plate group joints, causing some of the above 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, cathode plate group joints, and pole columns are constantly exposed to oxygen, which causes corrosion of the cathode members and
It is assumed that rupture will occur. Various studies have been conducted based on this assumption, 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 and resulted in one member breaking, revealed that the corrosion did not occur in the areas where the entire structure had been corroded. It was found that antimony and zinc, which were not intentionally added, were contained in large amounts compared to other areas.

Furthermore, as the amount of antimony and zinc increases, the amount of corrosion increases at an accelerated pace, and in order to prevent corrosion of cathode members, it is necessary to fully control antimony and zinc, which were previously thought to have no particular effect in small amounts. It turned out to be important.

Means to Solve All Problems Therefore, the present invention applies a cathode absorption type, and provides a cathode lattice body in which antimony and zinc are not added to the battery system and the electrode plate ears are entirely mounted.
In lead-acid batteries in which either or all of the electrode plate group joints and pole columns are made of lead or lead alloy, the antimony content of the above members (i720 ppm or less, zinc content f20 ppm or less) be.

The amount of antimony contained as an impurity in the working cathode grid, electrode plate group joints, and pole pillars is kept below 20 ppm.

Moreover, by setting the zinc content to i 20 ppm or less, the corresponding member is less susceptible to corrosion and will not break even in the harsh oxygen atmosphere during use of a cathode absorption lead acid battery. Therefore, the overall reliability of the cathode absorption type lead-acid battery can be dramatically improved.

Example The present invention will be explained in detail below.

Figure 1 shows the configuration of a cathode absorption lead-acid battery. In the figure, 1 is a cathode plate group joint, 2 is a cathode grid, 3 is an electrode tab, 4 is a cathode pole, 6 is an anode 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 antimony contained in and the total amount of zinc 160 ppm
, 50 m) I) m, 30 ppm, 2 oppm
, 5 ppm, and the time required for this part to break due to corrosion was measured. For testing, voltage 12V, capacity 2
A 4 μh cathode absorption type lead-acid battery was used, and while charging at a constant voltage of 13.8 V was performed, the change in battery capacity was measured every month. Note that the ambient temperature was 40°C.

The above results are shown in FIGS. 2 and 3.

FIG. 2 is a diagram showing the change in capacity of some storage batteries in the above test.

Further, FIG. 3 is a diagram showing the relationship between the period until the storage battery capacity sharply decreases and the amount of antimony contained in the joint portion of the cathode plate group in the above test. From Figure 3, it's Rekarutoo! l
With 1% antimony i at 150 Ppm, the capacity decreased in one month regardless of the amount of zinc.

Although there are some differences depending on the amount of zinc, when the amount of antimony was 60 ppm, the capacity decreased between 1 and 3 months. When these batteries were disassembled to investigate the cause of the decrease in capacity, it was found that the joints of the cathode plates in each battery had corroded and fractured.

However, in the area where the amount of antimony is 6 to 20 ppm,
As the amount of zinc decreases, the period until the capacity decreases becomes longer, and the amount of zinc is 5 ppm.

At 20 ppm, a decrease in capacity was observed after 18 months.

As a result of completely disassembling storage batteries with an antimony content of 5 pptn and 20 ppm and investigating the cause of their capacity reduction, corrosion and breakage of the cathode plate group joints were observed in all storage batteries with a zinc content of 30 to 1 soppm. .

However, in the storage batteries with zinc amounts of appm and 2 oppm, the cause of the decrease in capacity was a short circuit caused by the anode, and no corrosion breakage of the cathode member was observed.

Effects of the Invention As described above, the cathode absorption type lead-acid battery according to the present invention does not contain antimony exceeding 20 ppm in the cathode grid, electrode plate group joints, and pole pillars, and does not contain zinc exceeding 20 ppH'ii, making it easy to use as a storage battery. The above-mentioned members do not corrode or break, and the amount of electrolyte and self-discharge, which are the most important functions for single cathode absorption storage batteries, is also small. Therefore, it has the effect of significantly improving the reliability of the cathode absorption type lead-acid battery.

[Brief explanation of drawings]

FIG. 1 is a partial cross-sectional view of a cathode absorption lead-acid battery according to an embodiment of the present invention, and FIG. 2 is a change in battery capacity during a continuous charging test in a 40°C atmosphere conducted to demonstrate the effects of the present invention. Figure 3 shows the relationship between the amount of antimony and zinc contained in the cathode plate group assembly and the period until the storage battery capacity suddenly decreases, in the same continuous charging test in a 40℃ atmosphere. This is a diagram. DESCRIPTION OF SYMBOLS 1... Plate group joint, 2... Cathode lattice body, 3... Plate lug, 4... Pole column, 6...
... Anode plate, 6... Separator. Name of agent: Patent attorney Shigetaka Awano and 1 other person ■−
・Kengo Dance Lower Punishment Gi 葎金戒 2 --- T figure 2,000 sake cups 4 koi ii 1; 5- Yoseikai C'J Oki - Three Otsu 1141 Minami V Sakakiyama -: Kudo and ■ρ 〈Torusatsu E Omura Takeshi’s Wife

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 an antimony content of 20 ppm or less and a zinc content of 20 ppm or less.