JPS6324547A - Lead storage battery - Google Patents

Abstract

PURPOSE:To minimize dropout of a positive electrode material due to its softening and prolong a battery service life by containing either a positive plate or a negative plate in a bag made of a separator that a glass mat is sticked on a porous thin film with fine holes. CONSTITUTION:A separator consists of a glass mat 2 sticked on a porous thin film 1. A bag is made of this separator by using its sticking part 3. And at least one of a positive plate and a negative plate is contained in this bag. In a battery formed in such a way, softened active material can be kept by the glass mat 2 and little deposit remains in its bottom. Because the separator is made in bag-shape, short circuits on the side part of the electrode plate group and through the thin film 1 are prevented. Therefore, the service life of the battery can be prolonged.

Description

[Detailed description of the invention] Industrial applications The present invention is an improvement on lead-acid batteries.

BACKGROUND OF THE INVENTION In recent years, expanded lead-acid batteries using a calcium-lead alloy for the lattice have become popular. Since this type of battery does not have a vertical frame for the electrode plates, there is a risk that the active material may fall off and cause a short circuit, so a bag-shaped separator is used to prevent this. As shown in Figure 2, bag-shaped separators are usually made of sheets made mainly of polyethylene or sheets made of a mixture of synthetic fibers and pulp, which are then made into bags with a lip made of polyethylene. I am using it.

Problems to be Solved by the Invention However, this type of separator presses the electrode plates only at the lips, and does not have a structure in which group pressure is uniformly applied to the active material of the electrode plates. Therefore, the function of preventing the cathode active material from falling off due to softening is extremely low, and the life of the battery is significantly reduced, especially when used in applications that involve repeated deep charging and discharging.

The present invention overcomes the drawbacks of the bag-shaped separator described above, and by equalizing the pressure applied to the positive electrode plate, it is possible to minimize the falling off of the positive electrode active material due to softening, thereby providing a battery with a longer life. .

Means for Solving the Problems The basic structure of the present invention is to attenuate a combination of a microporous thin film and a glass mat, and include either a positive electrode plate or a negative electrode plate therein. Features.

Further, it is characterized in that the adhesive margin for weakening is only a thin film.

Embodiment FIG. 1A is a developed view of a separator to which the present invention is applied, and FIG.

The microporous thin film 1 must be hydrophilic and have acid resistance and oxidation resistance, as well as the presence of an internal short circuit when the softened and thinned active material of the housed positive electrode plate reaches the negative electrode side. It must be extremely microporous to prevent
It is desirable that the maximum pore diameter is 100 μm or less. Specific materials include microporous sheets mainly made of polyethylene and mixtures of synthetic fibers and pulp.

The glass mat 2 may be made of 100% glass fiber or a mixture of glass fiber and synthetic fiber.

When a separator is used in the form of a plate, the active material may fall off due to softening or shock and vibration during use, leading to the risk of bottom shorting and side sheets. This risk is extremely high when using expanded plate plates without vertical frame ribs. In order to prevent such seams, it is extremely important to weaken the separator.

Examples of bonding methods for weakening the separator include methods using adhesives, thermal welding, ultrasonic welding, and the like.

As shown in Fig. 3, if the lateral dimensions of the glass mat 2 and the thin film 1 are the same, no matter which of the above bonding methods is used to weaken the bag-like separator, the bag-like separator with reliable bond strength will remain stable. Therefore, it is desirable that the bonding area 3 does not include a glass mat as shown in FIG.

In order to make this effect more clear, we will discuss a battery with the configuration of the present invention, a battery with a conventional configuration, that is, a battery B with lips 4 set up here and there on the thin film, and applying pressure to the positive electrode plate only with the lips. A comparative test was also conducted with Battery C, which had not deteriorated using a conventional separator with a glass mat.

In the test, a 36B20 equivalent battery was prototyped with the above configuration, and the JIS lifespan was determined as a deep charge/discharge test pattern.

A test (capacity confirmed by repeating the pattern of discharging for 1 hour at 20 meters and charging for 6 hours with 6 people 26 times) was conducted.

The results are shown in FIG.

As for the lifespan, B:C (head of A).When examining the condition of the battery that reached the end of its lifespan, it was found that the softened cathode active material of battery B had settled considerably at the bottom of the bag, and the separator lip had fallen. In addition, in battery C, the softened active material was attached to the glass mat, but there was a short circuit on the side of the electrode plate group. In the inventor's battery, the softened active material was sufficiently retained by the glass mat, and there was little sediment at the bottom.Also, because it had weakened, short circuits on the side of the electrode plate group, as shown in C, were observed. , and no short circuit through the thin film was observed.

Effects of the Invention As described above, the present invention can eliminate the drawbacks of conventional bag-shaped separators and contribute to extending the life of batteries.

[Brief explanation of drawings]

Figure 1 shows an example of the present invention. Figure 1& is a developed view of a separator, Figure 1, b is a view of a separator weakened and an electrode plate inserted inside it, and Figure 2 is a view of a conventional lip plate. FIG. 3 is a diagram showing a separator with a glass mat disposed up to the adhesive margin that deteriorates. FIG. 4 is a diagram showing a battery constructed according to the present invention and a battery B constructed using conventional technology. , C is a diagram showing the results of a comparison test of JIS lifespan of C. 1... Microporous thin film, 2... Glass mat, 3... Glue, 4... Lip, 5
・・・・・・Ear part of the electrode plate.

Claims (2)

[Claims] (1) In a lead-acid battery using a bonded material of a microporous thin film and a glass mat as a separator, the separator is made into a bag, and at least one of the positive electrode plate or the negative electrode plate is wrapped in the lead-acid battery. Storage battery. (2) The lead-acid battery according to claim 1, wherein the width of the adhesive margin for bagging is 1 to 10 mm, and no glass mat is interposed in that portion. 3. The lead-acid battery according to claim 1, wherein the microporous thin film has a maximum pore diameter of 100 μm or less.