JPH0355765A - Sealed lead storage battery - Google Patents

Abstract

PURPOSE:To obtain a battery having an electrolyte holding body which is highly economical and has a high liquid holding ability and sulfur diffusing ability by providing a separator including fine powders between a positive and a negative pole plate, and filling silica granulated grains of a specified grain size between the pole plates and around the group of pole plates. CONSTITUTION:For a seale lead battery in which oxygen gas produced at the time of charging is absorbed by a negative pole, a separator including silica fine powders in part of its composition is put between a positive and negative electrode, and silica grains granulated in a grain size of 50-200mu are filled between the pole plates and around the group of pole plates, where sulfuric electrolyte of a necessary and sufficient quantity for discharging is impregnated. A high characteristic sealed lead battery including an electrolyte holding body which is highly economical and has a high liquid holding ability and sulfur diffusing ability can thus be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a sealed lead-acid battery, and in particular to improvements in its electrolyte holder.

BACKGROUND OF THE INVENTION In recent years, sealed lead-acid batteries have become widely used as backup power sources for portable devices and computers. This type of sealed lead-acid battery is classified into a retainer type and a gel type depending on the electrolyte retention method. The retainer type is a method in which the dilute sulfuric acid electrolyte is held in a porous separator made of paper mainly made of fine glass fibers, and the gel type is a method in which the dilute sulfuric acid electrolyte is turned into a gel using silicic acid and filled into the battery. be. Problems to be Solved by the Invention In the case of a retainer type separator, the fine glass fibers that make up the main part of the separator are expensive, so the separator itself is also very expensive. For this purpose, separators replaced with synthetic resin fibers have been developed, but they do not have sufficient liquid retention properties.

On the other hand, in the case of a gel type, preparing and filling the gel is complicated, and since it is necessary to fill all spaces except the space above the element with gel, there is a drawback that extra electrolyte must be filled. Ta.

Furthermore, due to the slow diffusion of sulfate ions within the gel, the performance of conventional open type liquid type J9 storage batteries was inferior to that of sealed type lead acid batteries.

In order to solve these problems, we investigated the use of silica as an electrolyte retaining material in sealed storage batteries (11). I found that it could be applied. However, as I continued to experiment, I found some drawbacks. One of them is that if the floors and floors are not sufficiently isolated, the In batteries with narrow electrode plates, the active material particles penetrate through the gaps between the silica sheets and cause a short circuit.In order to prevent short circuits, a thin glass separator made of 1M fine glass fiber is used to prevent short circuits. When used in contact with the plate surface, it shows better performance than C as long as there is sufficient electrolyte, but if the electrolyte decreases in applications where overcharging occurs, the electrolyte contained in the glass separator will disappear. It was found that the electrolyte in the glass separator was absorbed by the silica granules and the electrolyte in the glass separator was reduced, making it impossible to supply electrolyte to the electrode plates and further increasing the resistance.

Means for Solving the Problems The present invention solves a series of problems by providing an electrolyte holder that is inexpensive, has good liquid retention properties, and has excellent sulfuric acid diffusivity.
Zurushino offers sealed lead acid batteries. The gist of this is that a horizontal plate group consisting of a separator containing fine silica powder as a part of the composition is interposed between the Masaomi plate and the negative and other plates, and the horizontal plate group is housed in a battery case. Fill and arrange silica powder granulated to 50 to 200 microns around the bamboo plate group, and impregnate and hold the RA acid electrolyte in the amount necessary and sufficient for discharge into the above-mentioned powder and separator. There is a particular thing. The present invention will be explained below based on examples.

Example: A certain positive and negative electrode grid made of pb-Qi-Sn alloy was filled with ordinary positive and negative electrode pastes, respectively, and then wet-processed with about 50% of silica fine powder together with inorganic fibers, organic fibers and a small amount of binder. Paper-made thickness approximately 0.2■
The separators were brought into contact with both sides of the negative electrode plate, and an electrode plate group was prepared with three positive electrode plates and four negative electrode plates, and the electrode plate group was inserted into the battery case. Here, the spacing between the two electrode plates was maintained using a synthetic resin plate having a thickness of about 11 mm, but any material that is harmless to the battery and capable of maintaining the spacing between the two electrode plates may be used. It is preferable to use a material that occupies a small volume between the two electrode plates.

Next, water was added to the silica powder to make a paste, dried at about 200°C, and then crushed to make a diameter 2.
Granulated silica powder of 0 to 500 μm was densely packed between the two electrode plates and around the base plate group while applying vibration.

The silica powder filled here is about 90% in the filled state.
By itself, it had a porosity of about 85%.

After filling the granulated powder in this way, glue the lid,
A sealed lead-acid battery A with a nominal capacity of 4.5 Ah was assembled with an exhaust valve installed. For comparison, a sealed lead-acid battery B using the same electrode plates and a glass separator of the same thickness made of fine glass fibers instead of the separator containing fine silica powder of the present invention, and a fine glass fiber between the two electrode plates. Conventional closed type retainer type 1 that uses only a glass separator consisting of a glass separator and does not fill the periphery of the electrode plate with silica granules.
;] Storage battery C was also assembled. Table 1 shows the initial capacity test results of these three types of batteries, and FIG. 1 shows the cycle life test results. The cycle life test was conducted under the conditions of discharging 50% of the nominal capacity in one hour and charging it to 135% over four hours. Note that the quality is 40°C.

Table 1 As is clear from Table 1, the method in which a separator containing fine silica powder was used to separate the two electrode plates (A) also used a glass separator of the same thickness made of fine glass fibers. Type (B) also showed almost the same performance, and showed better performance than the conventional cage-type sealed lead-acid battery (C). This seems to be due to the smooth movement of the electrolyte and the ability to inject a large amount of electrolyte. On the other hand, as shown in Fig. 1, a thin glass separator made of fine glass fiber was brought into contact with the surface of the negative electrode plate, and silica powder was filled between the electrodes and around the electrode group. Although the product (F3) had a longer life cycle than the conventional product (C), the capacity suddenly decreased from around 300 cycles. When this battery was disassembled and examined, it was found that although the silica powder contained a sufficient amount of electrolyte, the glass separator in contact with the negative electrode plate contained almost no electrolyte. It is thought that this rapid capacity drop was due to the fact that the electrolyte 7^ could no longer be supplied to the negative electrode plate, and the resistance of the glass separator also increased. On the other hand, in a battery using a separator containing the silica micropowder of the present invention in contact with the surface of a negative electrode plate and filling the space between the electrodes and the periphery of the electrode plate group with the silicate powder, the capacitance rises rapidly. No deterioration was observed, and the life performance was significantly improved. This battery was also disassembled and examined after the life test. Sufficient electrolyte was contained not only in the silica granulated powder but also in the separator.

In addition, in the above example, a case was shown in which a separator containing fine silica powder was used in contact with the surface of the n-electrode plate, but it could be used in contact with the surface of a tEm plate, etc., containing fine silica + a powder. The present invention is not limited to the above embodiments, as long as the separator is a branch structure interposed between the positive and negative flea plates.

Effects of the Invention As is clear from the above-mentioned Practical Example 1, the sealed J9 storage battery according to the present invention 1 has a separator containing fine silica powder interposed between the positive and negative electrode plates, and between the electrode plates and between the electrode plate groups. By filling the surrounding area with silica powder, the performance of conventional sealed marine storage batteries can be greatly improved, and its industrial value is great.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the results of a cycle life test.

Claims (1)

[Claims] 1. In a sealed lead-acid battery in which the negative electrode absorbs oxygen gas generated during battery charging, an electrode plate group in which a separator containing fine silica powder as part of the composition is interposed between the positive and negative electrode plates. is stored in a battery case, and silica powder granulated to a size of 50 to 200 microns is filled and arranged between the electrode plates and around the electrode plate group, and a sufficient amount of sulfuric acid electrolyte necessary for discharge is applied. A sealed lead-acid battery characterized by being impregnated and held in granular powder and a separator.