JPH02262249A - 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 Industrial Field of Application The present invention uses a cathode to absorb oxygen gas generated from an anode during charging. This paper relates to the improvement of so-called cathode absorption lead-acid batteries.

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 electrolyte. A lattice body to achieve this function.

When selecting alloys for the electrode plate group joints and electrode columns.

・Hydrogen overvoltage is high, causing water decomposition in the electrolyte when charging the battery.

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

Taking this into consideration, one alloy composition is determined and A.

In this way, cathode absorption type lead-acid batteries have little loss of electrolyte during use, which eliminates the need for tedious water replenishment work, and it has become possible to seal the storage battery. Furthermore, by sealing the battery, no harmful gases are discharged outside the battery during heavy use, and the battery can be easily used indoors.

Problems to be Solved by the Invention However, during heavy use of conventional cathode absorption lead-acid batteries, especially in situations where they are constantly being charged, such as in standby use, it is difficult to solve the problem that the single round pole column, cathode lattice body, and cathode lattice ear There was a phenomenon in which rapid corrosion progressed at the parts or the joints of the metal electrode plate groups, causing some of the above members to break. The interior of the i-cathode absorption lead-acid battery is always filled with oxygen gas generated from the anode during use.

Therefore, not only the cathode active substance 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 11C&H, which causes corrosion and breakage of the cathode members. 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 standby use, leading to one member breaking, revealed that corrosion was observed in one part of the battery that had undergone one cooking process. Compared to areas that were not affected, it contained more antimony, which was not intentionally added, and the alloy crystal grains were large in those areas, and corrosion was progressing along the grain boundaries. I understand. 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 was previously considered to be a small amount and having no particular effect, we also made the crystal grains of alloy 1 finer.
It is possible to add a second trace element that strengthens the bond between crystals, or to use lead and lead alloys containing that element as the cathode material.

It was found to be important to prevent corrosion.

Means for Solving the Problems Therefore, the present invention provides a lead-acid battery using a cathode/primary absorption type, in which the content of antimony as an impurity is regulated to 1 ooppm or less, and the cathode lattice body including the electrode plate lugs, the electrode plate group joints, etc. and the combination of pole pillars, or all of these 20 to 3
00m)9m7) The above-mentioned drawbacks have been improved by constructing the lead or lead alloy containing copper.

Add 20 to 300% copper to the working cathode grid, electrode plate group joints, and pole pillars.
When ppm is added, copper acts as an effective crystal nucleus during solidification of lead until the amount of antimony reaches 1100 pp, maintaining the fineness of the crystals, strengthening the bonds between crystals, improving corrosion resistance, and improving the cathode absorption type lead. Even in the harsh oxygen atmosphere during use of a storage battery, 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 Hereinafter, one aspect of the present invention will be explained in detail.

Figure 1 shows the configuration of a negative, return 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 drawing column, 6 is a positive electrode plate, and 6 is a ζ-shaped separator.

In order to clarify the effects of the present invention,
The amount of antimony contained in O is 1100 pp, and the amount of copper is O.
ppm (below detection limit), sppm.

The concentration was changed to 20 ppm, 100 ppm, and 300 ppm, and the time until this part broke due to corrosion was measured.

For the test, a cathode absorption lead-acid battery with a voltage of 12V and a capacity of 24μH was used, and while charging at a constant pressure of 13.8'i,
Changes in storage battery capacity and internal resistance were measured every month.

Note that the ambient temperature was 40°C.

Figures 2 and 3 show the coleoptiles of this species.

From Figure 2, a rapid increase in internal resistance occurs in 1 month when the copper amount is oppm, and after 3 months when the copper content is 5 ppm. When these batteries were disassembled and the cause of the increase in internal resistance was investigated, it was discovered that the joints of the electrode plates had broken due to corrosion. However, 20ppm・100ppm,
At 300 ppm, there was no sudden rise in internal resistance 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 grid, and no corrosion fracture was observed at the joints of the cathode plate group. Also, check the limit of antimony amount.

The amount of copper is 300 ppm, and the amount of antimony is o ppm.
(detection limit), 1oppm, soppm,
1ooppm.

A similar test was conducted with the concentration changed to 150 ppm. The results are shown in FIGS. 4 and 6.

As can be seen from Figure 3, a sudden rise in the internal resistance occurs at an antimony level of 15 (12 lpm at lpm), which is 1 M
The result of disassembling the battery was that the cathode plate group joint was corroded and fractured, as described above.

Further, when the amount of copper exceeds 30Oppm, self-discharge increases significantly, causing a problem in practical use. Therefore, the amount of copper is 3o
Oppm was the limit. Furthermore, the amount of antimony
A similar test was conducted between 1100pp and 150ppm, but a rapid increase in internal resistance occurred before 1500ppm.
The reason why the internal resistance does not show a sudden rise for more than 18 months is because
It was found that 1100pp was the limit. In addition, inspection of alloy 1 crystals also supports the above results, indicating that the internal resistance increases rapidly and the rise time becomes longer, and the crystal grains of A are smaller and are fake. Therefore, the amount of antimony is less than 100 pp'ff1, and the amount of copper is 20 to 3
It was found that 0 ppm was good.

Effects of the Invention As described above, in the linear color absorption lead-acid battery according to the present invention,
Antimony content as impure proboscis - fil Q 1100
ppm or less and contains 20 to 300 ppm of lead or lead alloy in the cathode lattice body, electrode plate group joints, and pole pillars, so that the parts mentioned above may corrode or break during use. Furthermore, the electrolyte loss and self-discharge amount, which are the most important functions for cathode absorption lead-acid batteries, are also small.

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 cross-sectional view of a cathode absorption type lead-acid battery according to an embodiment of the present invention, and Figures 2 to 5 show the results of continuous charging tests in a 40"C atmosphere conducted to demonstrate the effects of the present invention. 1: Plate group joint, 2: Cathode grid body, 3: Valve plate lugs, 4: Pole column, 6.
...Intestinal plate, e...Separator. Name of agent: Patent attorney Shigetaka Awano and 1 other person1-
4 go and 2・-ichisui≧F; Σi road! I

Claims (1)

[Claims] In a lead-acid battery with an antimony content of 100 ppm or less as an impurity, any or all of the cathode lattice, electrode plate group joint, and pole column has a content of 20 to 300 ppm.
A lead-acid battery characterized by being made of lead or a lead alloy containing pm of copper.