JPS61203568A - Lead storage battery - Google Patents

Abstract

PURPOSE:To make a lead storage battery maintenance free and improve the deterioration of the cycle life of the battery during deep discharge by using a lead alloy grid which is composed of lead and given proportions by weight of antimony, selenium, arsenic, tin and bismuth. CONSTITUTION:The lead storage battery of this invention includes a lead alloy grid composed of 0.8-0.3wt% of antimony, 0.005-0.1wt% of selenium, 0.025-0.3wt% of arsenic, at most 0.2wt% of tin and 0.005-0.1wt% of bismuth. As a result, the battery can be made maintenance free. Furthermore, it is possible to inhibit the deterioration of the cycle life of the battery during deep discharge.

Description

DETAILED DESCRIPTION OF THE INVENTION INDUSTRIAL UTILIZATION PUBLIC FUND The present invention relates to lead-acid batteries, and more particularly to improvements in maintenance IF lead-acid batteries for automobiles.

In recent years, in the lead-acid battery market, Kikusui's efforts can be saved.
There is a growing trend toward MF (maintenance-free) due to the advantages of low self-discharge and long-term storage in an injected state.

Since this type of battery generates a small amount of gas, there is almost no corrosion of its terminals, and it also has the advantage that it can be installed in any location because it does not require water replenishment.

Generally, a ferro-calcium alloy or a ferro-low antimony alloy with a low antimony content is used as the grid alloy of an MF battery. When a lead-calcium alloy is used for the lattice of the positive electrode plate, it has the disadvantage of short life in charge/discharge cycles under relatively deep discharge conditions.

In addition, when a lead-antimony alloy is used for the lattice body, the above-mentioned drawbacks are improved, but batteries using a lattice body with an antimony content of 3% or less for the purpose of achieving MF cannot be used with conventional antimony 4 % or more, the cycle life will decrease compared to the battery. Furthermore, the lower the antimony content, the greater this decrease in life tends to be.

OBJECTS OF THE INVENTION An object of the present invention is to provide a lead-acid battery that uses a lattice body made of a lead-low antimony alloy and is easy to maintain and has improved cycle life reduction due to deep discharge.

Structure of the Invention The first aspect of the present invention is 0.8 to 3. Owt% antimony, o, oos~0.1wt% selenium, 0.025~0
．． 3wt% arsenic, O', 2wt% or less tin, o, oo
This is a lead-acid battery using a lead alloy lattice body consisting of bismuth of s~0.1 wt% and the balance lead.

The second aspect of the present invention is 0.8 to 3. Owt% Ann, Timon, O, oos ~ 0.1 wt% Selenium, 0.025
~0.3 wt% arsenic, 0-2 wt% or less tin, 0.0
05-0.1 wt% bismuth, 0.01-0.5w
This is a lead-acid battery using a lead alloy grid consisting of t% cadmium and the balance lead.

In a lead-antimony alloy, if the antimony content is less than 3 wt%, cracks are likely to occur during solidification in a normal casting process. This has a wide solidification temperature range (temperature from the start to the end of solidification), and the crystals are shaped like dendrites.
This occurs because the molten metal is not sufficiently supplied to the unsolidified areas between the crystals. To prevent this, British Patent No. 6
The addition of selenium as shown in US Pat. No. 22,512 is effective. The addition of selenium suppresses the growth of dendrite crystals, creating a fine crystal structure and eliminating the occurrence of cranks. However, if the amount of selenium added is less than 0.005 wt%, there is no effect, and if it is more than 0.1 wt%, non-uniform phases are likely to be formed, resulting in defects.

By adding 0.005 to 0.1 wt% of selenium in this manner, the occurrence of cracks is suppressed and a uniform structure is obtained, but selenium has little effect on the age hardening of the alloy.

Also, in order to accelerate age hardening, it is effective to add a small amount of arsenic.

However, when the amount of arsenic added is 0.025 wt% or less, age hardening does not occur much. If the amount of arsenic added is 0.3 wt% or more, the mechanical strength will decrease due to the formation of a heterogeneous phase, and corrosion will also increase.

When the antimony content is reduced, castability is reduced. This can be improved by adding an anchor, which is known from the past. However, if the amount of tin added exceeds 0.2 wt%, the viscosity of the molten metal will increase and the workability during casting will deteriorate.
It is desirable that it is less than wt%.

As mentioned above, by adding a small amount of selenium, arsenic, and anchor to a lead-low antimony alloy, a uniform structure can be obtained, and a good lattice body without defects can be obtained.

However, lowering the antimony content tends to shorten the charge/discharge cycle life under conditions of relatively deep discharge. As a result of investigating various alloy additives to the lattice alloy, we found that bismuth and cadmium are effective in improving this problem.

Example An embodiment based on the present invention will be described below.

Example 1 Lead-1.5vt% anti-sodium 0.02wt% selenium-
A 5 6 B, 2 0 R type battery was prototyped using a lattice made of an alloy to which 0.1 vt 0.15 wt % of bismuth was added, and a life test was conducted using JIf9 D 5301 (automobile storage battery). The results obtained are shown in Table 1.

In addition, the JIS life test is a cycle of discharging at 20 μm for 1 hour at 40 to 50°C and charging at 5 A for 5 hours, and the life is defined as the point in time when the discharge duration reaches 42 minutes at 20 A discharge. As can be seen from Table 1, life performance can be improved by adding bismuth to the lattice alloy. If the amount of bismuth added is less than o, oos%, there is no effect. Moreover, if the content exceeds 1%, the special performance will deteriorate and the self-release weight will increase rapidly, so it is preferable that the content is 0.1% or less.

Example 2 A JIS life test similar to that described above was conducted by adding roughly 0.01 to 0.5 wt% of cadmium to the bismuth-added ito, 0.5 wt% lattice alloy of Example 1.

The results obtained are shown in Table 2.

As can be seen from the second review, adding bismuth and cadmium to the lattice alloy at the same time can further improve the life span properties. If the amount of cadmium added is less than 0.01 wt%, there is no effect.

Further, since cadmium precipitates on the negative electrode plate and causes dendrite-like crystals to grow, causing a short through the separator, the amount added is preferably 0.5 wt % or less.

The addition of cadmium forms a 5 baa intermetallic compound and also improves the strength loss of lead-low antimony alloys.

In the above example, a lattice body made of an alloy of the same composition was used for both the positive and negative electrode plates, but using a lattice body made of a ship-force alloy for the negative electrode plate would have less self-discharge and be more effective. .

Effects of the Invention As described above, according to the present invention, in a lead-acid N battery using a lattice made of a lead-low antimony alloy, it is possible to improve the deterioration of cycle life due to deep discharge without maintenance, and its industrial value is improved. is extremely large.

Izuhara Yuasa Battery Co., Ltd.

Claims (2)

[Claims] (1) 0.8-3.0wt% antimony, 0.005
~0.1wt% selenium, 0.025-0.3wt% arsenic, 0.2wt% or less tin, 0.005-0.1wt
A lead-acid battery characterized by using a lead alloy lattice body consisting of % bismuth and the balance lead. (2) 0.8-3.0 wt% antimony, 0.005
~0.1wt% selenium, 0.025-0.3wt% arsenic, 0.2wt% or less tin, 0.005-0.1wt
1. A lead-acid battery characterized by using a lead alloy lattice body consisting of % bismuth, 0.01 to 0.5 wt% cadmium, and the balance lead.