JPH02262257A - 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 selenium in a lead acid battery restricted in the content of antimony as impurities. CONSTITUTION:In an anode absorption type lead acid battery, the content of antimony as impurities is restricted to be antimony 100ppm or less, and one or all of an anode grating including a plate lug part, a plate group connection part and a polar column are constituted of lead or lead alloy containing 50 to 300ppm of selenium. According to the aforesaid construction, selenium works as an effective crystalline nucleus during the solidification of lead and the refining of crystals can he maintained, thereby strengthening the bonding of crystals and improving corrosion resistance.

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 during charging or self-discharging, which prevents the internal pressure of the battery from increasing due to gas generation.
! It has the function of suppressing the decrease in solution solution. In order to achieve this function, we selected the alloy for the lattice body, electrode plate group joints, and electrode columns.

The hydrogen overvoltage is high and water decomposition in the electrolyte occurs when the battery is charged.

The added elements do not move to the cathode and cause self-discharge.

The alloy composition is determined with this in mind.

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 that 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 can cause corrosion and breakage of the cathode components. It is assumed that Various studies have been conducted based on this assumption, but no clear cause has been identified.

A detailed analysis of a conventional cathode absorption lead-acid battery in which corrosion of the cathode material progressed during 2-standby use, leading to breakage of the material, revealed that the areas and parts that had been corroded had not been corroded. It was found that more antimony, which was not intentionally added, was contained than in areas where no antimony was added, and that the alloy crystal grains were large in those areas, and corrosion was progressing along the grain boundaries. Furthermore, as the amount of antimony increased, the amount of corrosion increased at an accelerated pace. Therefore, in addition to controlling the amount of antimony, which has traditionally been thought to have no particular effect as a trace amount, it is necessary to refine the crystal grains of the first alloy and add a second trace element that strengthens the bonds between crystals, or to contain that element. The use of lead and lead alloys as cathode members has been found to be important to prevent corrosion.

Therefore, in the present invention, the antimony content as an impurity in a lead-acid battery to which a cathode absorption type is applied is 100 ppI! 1
The cathode grid body including the electrode plate ears, the electrode plate group joints, and the pole columns, or all of these, shall be regulated as follows:
The above-mentioned drawbacks are improved by constructing the lead or lead alloy containing 300 ppm of selenium.

50 to 3% selenium to the working cathode grid, electrode plate group joints, and pole columns.
001) I) When m is added, the amount of antimony is 100 p.
Up to pm+1, selenium acts as an effective crystal nucleus during solidification of lead, maintains the fineness of the crystals, strengthens the bonds between crystals, improves corrosion resistance, and protects against the harsh oxygen atmosphere during use of cathode absorption lead-acid batteries. Even under these conditions, the cathode member is not susceptible to corrosion and will not break. 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, 6 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 antimony contained in i100m)pm is taken as oppm (below the detection limit), and the amount of selenium is 26ppm.

50 ppm, 150 ppm and 1,300 ppm, and the time until this part broke due to corrosion was measured. In the test, a cathode absorption type lead-acid battery with a voltage of 12 V and a capacity of 24 μh was used, and while charging at a constant voltage of 13.8 V was performed, changes in the battery capacity and internal resistance were measured every month. Note that the ambient temperature was 40°C.

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

As can be seen from Figure 2, a rapid increase in internal resistance occurs in 1 month for selenium fioppm and 3 months for selenium at 26 ppm. When these batteries were disassembled and the cause of the increase in internal resistance was investigated, it was discovered that the cathode plate group was broken due to corrosion. However, 50ppH1,150pp
At 300 ppm, no rapid increase in internal resistance was observed even after 18 months. However, the capacity decreased, and when we investigated the cause, we found that it was due to a short circuit caused by the elongation of the anode lattice, and no corrosion fracture was observed at the joints of the cathode plate group. Furthermore, in order to see the limit of the amount of antimony, the amount of selenium was set to 300 ppm, and the amount of antimony was set to %10pplO250ppm.
, 1100 ppm, and 150 ppm, and similar tests were conducted.

The results are shown in FIGS. 4 and 5.

As can be seen from Figure 3, a rapid increase in internal resistance occurred in 12 months when the antimony content was 150 ppm.The results of disassembling the storage battery showed that, similar to the above results, corrosion rupture occurred at the joint of the cathode plate group. there were.

In addition, if the amount of selenium exceeds 300 ppm, the selenium will oxidize at the top of the melting surface during blending, and the amount of selenium will exceed 300 ppm.
It was not possible to create an alloy with a diameter exceeding m. Furthermore, selenium fl (
3001) I) m, antimony amount % 1100pp
Similar tests were conducted between 150 ppm and 150 ppm, but a rapid increase in internal resistance was seen before 14 ppm, and no rapid increase in internal resistance was observed after 18 ppm.
It was found that I)m is the limit.

Observation of the crystals of Alloy 1 also supported the above results, and the crystal grains were smaller in those in which the period of rapid increase in internal resistance was longer. Therefore, it was found that the amount of antimony is preferably 1100 ppm or less, and the amount of selenium is preferably 50 to 300 ppm.

Effects of the Invention In the cathode absorption lead-acid battery according to the present invention, the antimony content as an impurity is regulated to 100 ppm or less,
Because the lead or lead alloy that makes up the cathode lattice body, electrode plate group joints, and pole columns contains selenium at a concentration of 50 to 300 ppH, the above members will not corrode or break during use of the storage battery, and the cathode absorption will be reduced. It also reduces electrolyte consumption and self-discharge, which are the most important functions for lead-acid batteries.

Therefore, it has the effect of significantly improving the reliability of the cathode absorption type lead-acid battery.

[Brief explanation of drawings]

Figure 1 is a partial sectional view of a cathode absorption type lead-acid battery according to an embodiment of the present invention, and Figures 2 to 5 show continuous charging tests in a 40°C atmosphere conducted to demonstrate the effects of the present invention. It is a figure showing a result. DESCRIPTION OF SYMBOLS 1... Electrode plate group joint part, 2... Cathode grid body, 3... Electrode plate lug, 4, pole column, 6, anode plate, 6
is a separator. Name of agent: Patent attorney Shigetaka Awano and 1 other person5.
- Rii Taneki 1 71- Kostomach)

Claims (1)

[Claims] In lead-acid batteries in which the antimony content as an impurity is regulated to 100 ppm or less, either or all of the cathode lattice plate group joints and pole columns are 50 to 3
A lead-acid battery characterized by being made of lead or a lead alloy containing 00 ppm of selenium.