JPH06283191A - Sealed lead-acid battery - Google Patents

Abstract

PURPOSE:To improve charging/discharging cycle life of a sealed lead-acid battery for absorbing oxygen gas formed during charging into a negative electrode, by using a positive electrode lattice consisting of a lead-antimony alloy, and by providing an organic high polymer having an ion exchanging functional group between a positive electrode plate and a negative electrode plate. CONSTITUTION:The diameter of the primary particle of silica very fine powder used for an electrolyte holder is 10-40nm, and the surface area is 20m<2>/g. A powder-form cation exchange resin of 200-400 mesh is used as an ion exchange resin, and the capacity of the exchange group of the resin is no less than 4.4meg/g-R. The lifetime is thus extended while the current decreasing is reduced. Since a lead-antimony alloy is used for a positive electrode lattice, degradation of positive electrode active material and the extension of the lattice are expected to be reduced. The movement of antimony from a positive electrode to a negative electrode is considered to be inhibited by the ion exchange resin. In the diagram indicating the result, the curves 1-3, of the curves indicating transition of discharging capacity and transition of the amount of reduced liquid, indicate the characteristic of the battery used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved sealed lead acid battery.

[0002]

2. Description of the Related Art At present, there are gel type, retainer type, and granular silica type sealed lead-acid batteries of the type in which the negative electrode absorbs oxygen gas generated during charging of the battery. In the gel type, gel silica is arranged between a positive electrode plate and a negative electrode plate to hold a sulfuric acid electrolyte necessary for discharging. In the retainer type, a mat-like separator (glass separator) made of fine glass fibers is inserted between the positive electrode plate and the negative electrode plate to hold a sulfuric acid electrolytic solution necessary for discharging and separate the two electrodes.
The granular silica method is a method of filling and arranging silica fine powder in the gap between the positive electrode plate and the negative electrode plate to retain the sulfuric acid required for discharge, and is expected to improve battery life performance at the same time as reducing battery cost. .

In all of the conventional gel type, retainer type and granular silica type sealed lead-acid batteries, a lead-calcium alloy containing no antimony in the lattice is used.

However, when a lead-calcium alloy is subjected to a charge / discharge cycle including deep discharge, the lead-calcium alloy has a lattice-like structure during discharge.
Lead sulfate, which is a dense insulator, is generated at the active material interface to reduce the capacity early, and the bond between the lead dioxide particles, which is the active material, is weakened and the active material is likely to fall off. In addition, since the lead-calcium alloy is much softer than the lead-antimony alloy, a short circuit due to lattice expansion is likely to occur.

If a lead-antimony alloy is used for the positive electrode lattice, the corrosion layer formed by the antimony at the lattice-active material interface becomes porous, and the binding force between the lead dioxide particles is strengthened, resulting in early capacity decrease and The active material does not fall off, and short-circuiting due to lattice expansion hardly occurs.

However, when a lead-antimony alloy is used in these batteries, antimony elutes from the positive electrode grid during charge / discharge and moves in the electrolytic solution to deposit on the negative electrode plate to reduce hydrogen overvoltage. As a result, the amount of hydrogen generated due to water decomposition increases, and as a result, dead air is fatally dried up in the sealed lead-acid battery, leading to the end of its life. In the case of the granular silica battery, the silica fine powder filled in the gap between the positive electrode plate and the negative electrode plate adsorbs antimony, but the same phenomenon occurs due to the small adsorption amount. Therefore, in the conventional sealed lead-acid battery, a lead-calcium alloy is used for the positive electrode grid.

If a lead-antimony alloy can be used in the positive electrode grid to prevent the transfer of antimony from the positive electrode to the negative electrode, a sealed lead acid battery with excellent cycle life performance can be manufactured.

[0008]

In view of the above matters, the present invention uses a lead-antimony alloy for both the positive and negative plates or only the positive plate, and is a maintenance-free type having an excellent charge-discharge cycle life. Provided is a lead-acid battery, the gist of which is a positive electrode grid made of a lead-antimony alloy, and an organic polymer having an ion-exchange functional group in the gap between the positive electrode plate and the negative electrode plate (hereinafter referred to as an ion-exchange resin). Called)).

[0009]

[Operation] First, the antimony adsorption power of the ion exchange resin was examined. Granular silica, TiO ₂ (rutile type) for comparison
Also tested at the same time. The test has a specific gravity of 1.30 including antimony
Silica fine powder, TiO ₂ (rutile type), and ion-exchange resin were added to the diluted sulfuric acid, and the mixture was stirred for a certain period of time, and the amount of antimony reduction in the diluted sulfuric acid was examined and used as the adsorption amount. The results are shown in Table 1.

[0010]

[Table 1]

It is generally known that a metal oxide having a tetragonal crystal structure adsorbs antimony in a solution, and particularly TiO ₂ (rutile type) and silica fine powder are β-PbO ₂
Has a higher antimony adsorption power. However, the amount of antimony adsorbed is small, and antimony eluted from the positive electrode grid cannot be adsorbed. In particular, since TiO ₂ (rutile type) is expensive, adding a sufficient amount to prevent antimony migration into the battery will result in a significant cost increase.

On the other hand, the ion-exchangeable resin has much higher antimony adsorption power than these materials, and can adsorb a large amount of antimony even in a small amount. By using a lead-antimony alloy for the positive electrode grid, it is possible to prevent the capacity of the positive electrode plate from decreasing early, the active material from falling off, and the elongation of the grid to be prevented.If an ion-exchangeable resin is placed between the positive electrode plate and the negative electrode plate, antimony Since it does not cause an increase in water decomposition as described above by capturing between the electrodes, the characteristics of the sealed lead-acid battery, which are the main features of no maintenance and no rehydration, are not impaired.

[0013]

EXAMPLES The present invention will be described below based on examples.

The primary particles are 10 to 40 nm and the surface area is about 1.
Using a granular silica-type sealed battery having a 20 m ² / g silica fine powder as an electrolyte holder, a powdered cation exchange resin having an exchange group capacity of 4.4 meq / gR or more and 200 to 400 mesh is used as an ion exchange resin. Was used to carry out the test.

[0015]

[Table 2]

For comparison, a battery was prepared using lead-antimony-based alloys and lead-calcium-based alloys as the positive electrode grid alloy and silica fine powder as the electrolytic solution holder as shown in Table 2. A lead-calcium alloy was used for the negative electrode grid. JIS using these batteries
A life test of D-5301 was performed to examine the transition of discharge capacity and the amount of liquid reduction. The results are shown in Fig. 1. The discharge capacity was compared with the capacity before the test as 100%, and the liquid reduction amount was shown as 0% before the test and the liquid reduction amount was shown by weight%.

No. The battery of No. 2 had the shortest life and had a large amount of liquid reduction. This is because antimony eluted from the positive electrode grid is deposited on the negative electrode plate to increase water decomposition and reduce the amount of the electrolytic solution. No. No. 3 battery has a small amount of liquid reduction, The battery had a shorter life than the No. 1 battery.
This is because the positive electrode active material was likely to deteriorate because it did not contain antimony, and the lead-calcium alloy was softer than the lead-antimony alloy, so the lattice extended and a short circuit occurred. Has become.

On the other hand, the products of the present invention No. 1
In the battery using the lead-antimony alloy in the positive electrode grid and the ion-exchange resin disposed between the positive and negative electrodes, the result was that the number of lifespan was longest and the amount of liquid reduction was very small. This is because the deterioration of the positive electrode active material and the elongation of the lattice were small due to the use of a lead-antimony alloy in the positive electrode grid, and the ion exchange resin prevented the transfer of antimony from the positive electrode to the negative electrode. The reason is that the liquid volume has decreased.

In this example, a powdered cation exchange resin having an exchange group capacity of 0.8 or more and a mesh size of 200 to 400 was used as the ion exchange resin, but the same effect can be obtained by using the anion exchange resin. it can. In addition, a lead-antimony alloy is used for the positive electrode grid, a gel-type lead-acid battery that uses a gel-type silica gel for the electrolyte holder, and a retainer-type lead-acid battery that uses a glass mat. Also for the storage battery, by disposing the ion-exchange resin between the positive and negative electrode plates, the same effect as that of the present embodiment, that is, the performance of a small amount of reduced liquid and a long life can be expected.

[0020]

As is apparent from the above embodiments, the sealed lead-acid battery according to the present invention uses the positive electrode grid made of the lead-antimony alloy and has the ion-exchange resin in the gap between the positive electrode plate and the negative electrode plate. It is possible to overcome the disadvantages of the conventional sealed lead-acid battery by arranging, and its industrial value is enormous.

[Brief description of drawings]

FIG. 1 is a diagram showing a change in capacity and a liquid reduction amount during a cycle life test.

Claims (1)

[Claims] 1. A sealed lead-acid battery in which oxygen gas generated during charging is absorbed by a negative electrode, a positive electrode grid made of a lead-antimony alloy is used, and an ion-exchangeable functional group is provided in a gap between the positive electrode plate and the negative electrode plate. A sealed lead-acid battery in which an organic polymer having a group is arranged.