JPH01294369A - Sealed clad type lead battery - Google Patents

Abstract

PURPOSE:To obtain a sealed clad type lead battery with excellent discharging capacity and cycle lifetime by installing a group of electrode plates composed of specified separators, positive and negative plates into an electrolytic cell with pressure more than a specified value under the state of being dry before putting electrolyte into the electrolytic cell. CONSTITUTION:Glass fiber formed into sheet with uniform fiber diameter of less than 10mum is used for a separator 3 and gelled dilute sulfuric acid for electrolyte. A group of electrode plates composed of separators, positive and negative plates 2 with pressure more than 20kg/dm<2> per apparent surface are (longitudinal and transverse dimensions of a plate) of the positive plate is accommodated in an electrolytic cell under the state of being dry before putting electrolyte into the electrolytic cell. The glass separator 3 extremely increase its surface contacting with the positive plate 1 by strong pressing and has the construction in which the separator easily absorbs H2SO4 formed at charging. Thus, the gap of the clad type positive plate and the separator becomes about half compared with a conventional battery not being pressed. Therefore, discharging capacity and cycle lifetime are extremely improved.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a sealed lead-acid battery using a clad positive electrode plate, and particularly aims to provide a sealed lead-acid battery with excellent discharge capacity and cycle life performance. It is something to be done on your own.

Conventional technology In general, batteries that use a clad type positive electrode plate wrap the positive electrode active material in a tube and compress it, so the active material does not fall off even after repeated charging and discharging. It is known that they have a superior lifespan compared to batteries. Conventionally, when sealing this clad lead-acid battery, there are three methods A:

B and C have been carried out.

The first type A is glass fiber with an average fiber diameter of 10 μm or more,
A method in which a sol-like dilute sulfuric acid containing non-precipitating oxides such as SiO2 and Al2O3 is added to a battery using a non-liquid-absorbing separator such as pulp or synthetic resin, and the battery is gelled and sealed inside the battery. The second method B is to use a liquid-absorbing glass@fiber separator with a thinner fiber diameter in a state where it is hardly compressed within the electrode plate group, and inject sol-form dilute sulfuric acid into the battery using the same method as above. How to make it gel. The third C, like the second one, uses a liquid-absorbing separator compressed within the electrode group,
This is a so-called retainer clad type battery in which only the separator and the electrode plate group are impregnated with dilute VA acid.

Problem to be Solved by the Invention In the battery according to method A, the separator has poor liquid absorption properties, so if the battery is repeatedly charged and discharged, H2SO, which is generated on the positive electrode plate during charging, easily passes through the bore of the gel electrolyte. H2S accumulates at the bottom of the battery and
This causes a so-called electrolyte stratification phenomenon in which a large difference in O4 concentration occurs. As a result, a large amount of PBSO accumulates at the bottom of the electrode plate, resulting in a disadvantage that the battery performance is significantly degraded.

In the battery according to method B, since the separator is liquid-absorbing, the degree of deterioration of the battery due to the above-mentioned drawbacks can be reduced. However, in this battery, since the electrode plate group is constructed with almost no pressure applied as shown in the cross-sectional view of FIG. 2, a large gap is created between the clad type positive electrode plate and the separator.

Since this part is filled with gel electrolyte, it does not affect the discharge capacity much, but when deep discharge is performed and the specific gravity of the electrolyte decreases, the gel electrolyte softens significantly, so the H2O generated at this time is easily removed. The electrolyte then progresses to the top, causing what is called a stratification phenomenon of the electrolyte and deteriorating the battery. A similar phenomenon occurs with method A.

In addition, in the battery using method C, no matter how much pressure is applied to the electrode plate group,
Furthermore, even if a flat tube is used as the cladding type positive electrode plate, there will always be a gap between the cladding type positive electrode plate and the separator, so the discharge capacity will be significantly lower than in the former battery where the gap is filled with gel electrolyte. It had the disadvantage that it deteriorated.

Means for Solving the Problems The present invention is a closed clad type! The purpose is to improve the discharge capacity and cycle life performance of 9 batteries, and the gist is that the separator has an average fiber diameter of 10 μm.
The following glass fibers were made into a sheet, and gel-like dilute sulfuric acid was used as the electrolyte, and the separator,
The apparent surface area of the positive electrode plate (vertical dimension of the electrode plate x
It is characterized by being housed in a battery case with a compression force of 20 kg/di2 or more per horizontal dimension).

EXAMPLE Hereinafter, a closed type clad 2B pond according to the present invention will be explained with reference to the drawings.

The battery has a capacity of approximately 35 Ah, and is composed of three clad positive plates and four paste negative plates.The separator has average fiber diameters of 1 μm and 10 μm, and for comparison, conventional 2
Three types of separators made of 0 μm glass fiber sheets were used.

The compression force for these is 0, 10.20.30.40.50
and 60 k (1/dl12 (per apparent surface area of the positive electrode plate)).The electrolyte had a specific gravity of 1.24 (at 20°C) and contained about 7% S;02.
of dilute sulfuric acid, and after charging, the specific gravity was 1.30 (at 20℃).
). These batteries have a discharge depth of 75%
A cycle life test was conducted under the condition that the charge amount was 110%.

FIG. 3 shows the relationship between the compressive force and the number of life cycles of batteries with different average fiber diameters of the glass separators.

A battery using a separator with an average fiber diameter of 10 μm or less (
The compression force is 20 kg/di2 (curve A and mouth).
(per apparent surface area of the positive electrode plate) or more (product of the present invention), it can be seen that the life performance is significantly improved.

In other words, it can be seen that it is not possible to obtain the same life performance as the battery according to the present invention with conventional products that do not apply compressive force.

FIG. 1 shows a cross-sectional view of an electrode plate group according to the present invention.

As is clear from the figure, by applying strong pressure to the glass separator, the area in contact with the positive electrode plate increases significantly, and H2SO generated during charging increases.

It can be seen that the gap between the clad positive electrode plate and the separator is approximately 172 mm compared to the conventional product that does not apply pressure as shown in Figure 2.

In a battery using a separator with an average fiber diameter of 20 μm (curve C), no matter how much pressure was applied, no longer life performance than the product of the present invention could be obtained.

In this way, by improving the electrolyte absorption capacity of the separator, stratification of the electrolyte can be prevented and the life of the battery can be extended.

We also manufactured a cage-type sealed clad battery (conventional product) in which dilute sulfuric acid not containing 5102 was injected into a battery using a glass fiber separator with an average fiber diameter of 1 μm and held in the separator. The discharge capacity was compared with the case where a gel electrolyte was used like the invented product. FIG. 4 shows the results of measuring the discharge capacity of gel clad battery A (including the product of the present invention) and conventional retainer type clad battery B by varying the compressive force.

In both the gel clad battery A and the retainer type clad battery B, the discharge capacity increases as the compressive force increases. However, no matter how much pressure is applied to the retainer type battery B, the discharge capacity is lower than that of the product of the present invention.

This is because no matter how much pressure is applied, the gap between the clad positive electrode plate and the separator cannot be eliminated, and gel-type clad batteries, which fill the gap with gel, have a higher discharge capacity. Of course it's big.

Although the present invention has been described using only a glass fiber separator as a separator, since the purpose is to increase the water absorption capacity of the separator in contact with the positive electrode plate, for example, the average fiber diameter according to the present invention is 10 μm only on the positive electrode plate side. The same effect can be obtained even if two or more types of separators are used in combination, such as a glass fiber separator shown below is brought into contact with the negative electrode plate, and a synthetic resin separator such as polyethylene is brought into contact with the negative electrode plate.

Furthermore, in the battery according to the present invention, the inside of the electrode plate and the separator do not contain SiO□ or Al2O, and only the gap between the positive electrode plate and the separator contains a gel electrolyte containing a large amount of S;02 and At20. If it is allowed to enter, H2SO4
It is thought that the discharge capacity is further improved because the moving speed of

Effects of the Invention As described above, the sealed clad lead-acid battery according to the present invention can significantly improve discharge capacity and cycle life performance compared to conventional sealed clad lead-acid batteries, and its industrial value is extremely large. It can be said.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the electrode plate group of the battery of the present invention, Fig. 2 is a cross-sectional view of the electrode plate group of the conventional battery, and Fig. 3 is the relationship between the average fiber diameter and compression force of the glass separator and battery life performance. FIG. 4 is a diagram showing the relationship between the difference in electrolyte (gel or liquid) and the relationship between compression force and discharge capacity in gel-clad batteries. 1... Clad type positive electrode plate, 2 paste type negative electrode plate, 3.
...Glass separator tsubo 1 times -5 ayθ 2θ 3θ 〃 Copying
W repetition 77 (脣/dn)

Claims (1)

[Claims] 1. In a clad lead-acid battery using a gel electrolyte,
A separator made of a sheet of glass fiber with an average fiber diameter of 10 μm or less is interposed between the positive electrode plate and the negative electrode plate, and the electrode plate group consisting of the separator, the positive electrode plate, and the negative electrode plate is placed in a A sealed clad lead-acid battery, characterized in that it is housed in a battery case with a compression force of 20 kg/dm^2 or more per apparent surface area of the positive electrode plate in a dry state.