JPH10162804A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent internal short-circuiting, lengthen the service life, and improve battery characteristics by bending and forming both side parts of a separator in a bag shape, and containing a plate group where a positive electrode and a negative electrode are opposed to each other in a lead-acid battery constituted so as to wrap a plate in it by forming the separator in a bag shape. SOLUTION: Both side parts 2 of a microporous sheet separator 1 composed of polyethylene resin are bent inside, and are press-fitted in a belt shape, and are formed in a bag shape, and a plate group constituted by opposing a positive electrode plate 3 and a negative electrode plate to each other is wrapped inside. When a lead-acid battery is constituted in this way, both end parts of the positive electrode plate are contained in a double separator, and a lattice ribe is prevented from breaking through the separator by corrosional deformation, and an internal short circuit by contact with a negative electrode is prevented. Since a microporous material is used as the separator, generated gas is smoothly blown off without staying it in the separator, and an increase in internal resistance is avoided, and the deterioration of a voltage characteristic at discharge time can be restrained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead storage battery using a bag-shaped separator.

[0002]

2. Description of the Related Art Conventionally, in a lead storage battery for an automobile, a positive electrode plate or a negative electrode plate filled with a predetermined active material paste by an expanded grid or a cast grid is accommodated in a bag-like separator made of a microporous synthetic resin. Some have been used. In this case, as shown in Japanese Utility Model Laid-Open No. 58-155759, a bag-like separator is manufactured by pressing both sides of a microporous synthetic resin sheet.

[0003] Thus, the positive and negative electrodes are separated from each other, and the active material that has fallen off from the electrodes as the battery is used is kept in a bag to prevent an electrical short circuit between the positive and negative electrodes.

Further, in order to prevent oxidative deterioration at the bottom end or side portion of the grid due to contact between the positive electrode plate and the separator, a combined type separator in which a glass mat is arranged inside a bag-shaped separator is also used. I have.

[0005]

However, in recent years, the interior of the engine room of an automobile has become extremely hot due to the mounting of a high-performance engine and the compactness of the body shape. When this occurs, corrosion of the positive electrode plate proceeds, causing deformation of the active material and the lattice.
Then, the ends of the frame bone of the deformed lattice body pierced both ends of the bag-shaped separator, and the ends of the positive electrode plate and the negative electrode plate were in contact with each other, causing an internal short circuit.

In the case of using a combined type separator in which a glass mat is superimposed on the inside of a bag-shaped separator, the separator is prevented from breaking through due to deformation of the lattice,
This has the effect of preventing internal short circuits. However, in a lead-acid battery with an electrolyte, the voids in the glass mat are filled, so oxygen gas generated from the positive electrode plate during charging cannot escape smoothly through the voids in the glass mat during charging. The battery stays between the electrodes, and the internal resistance of the battery increases. As a result, there is a problem that the voltage characteristics at the time of discharging decrease.

SUMMARY OF THE INVENTION The present invention solves these problems, and prevents the separator from being broken by the corrosive deformation of the grid of the positive electrode plate, and efficiently removes oxygen gas generated from the positive electrode plate during charging. It is an object of the present invention to provide a lead-acid battery that can reach a negative electrode plate through the battery.

[0008]

According to the present invention, there is provided a lead-acid battery in which a separator made of a microporous synthetic resin sheet is formed into a bag and encloses an electrode plate. Is used to form a bag-shaped separator. It is desirable that the side of the separator to be bent faces the side that contacts the positive electrode plate.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the lead storage battery of the present invention, both sides of the separator are bent inward to form a bag. Of the separator, it is possible to prevent the corroded and deformed lattice bone from breaking through the side of the separator, and to prevent an internal short circuit due to contact with the counter electrode.

Further, when a glass mat is not used as in the present invention, the ribs of the separator and the side surfaces of the bag-shaped separator can smoothly discharge oxygen gas generated from the positive electrode plate during charging without accumulating in the separator. Therefore, there is no stagnation of gas in the separator, and an increase in internal resistance can be prevented.

[0011]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the structure of a positive electrode plate and a bag-shaped separator according to this embodiment. 1 is a sheet made of polyethylene resin having a thickness of 0.2 mm and a width of 135 mm. The both sides of the microporous sheet separator are bent 10 mm inward. This is a separator in which both sides are formed in a bag shape by being pressure-bonded in a band shape by passing through. Reference numeral 2 denotes a bent portion of the separator surrounding both ends of the electrode plate, and reference numeral 3 denotes a positive electrode plate.

[0013] Five positive electrodes are positioned on the bag-shaped separator, and a negative electrode having a nominal capacity of 12 V4
An 8 Ah lead-acid battery was manufactured, and this was designated as a lead-acid battery A according to the example of the present invention. In addition, as a comparative example, a battery using a combined type separator in which a glass mat containing glass fiber as a main component was laminated on the inside of a microporous bag-like separator, and a microporous bag-like separator made of polyethylene resin were used as the separator. Batteries were manufactured, and these were used as conventional batteries B and C, respectively.

In order to accelerate these batteries, 7
A SAE pattern life test was performed at 5 ° C. at 20 A for 4 minutes and charging at a constant voltage of 14.8 V at a maximum of 25 A for 10 minutes. The result is shown in FIG.

As is apparent from FIG. 2, the battery B of the conventional battery did not break through the bag-shaped separator with the positive electrode grid and had a good life, but the battery voltage at the time of discharging was lower than that of the battery A of the present invention. Was lowered. In the conventional battery C, the positive electrode grid corrodes and expands to penetrate the frame body of the grid body at the side of the bag-shaped separator made of polyethylene resin.

The reason why the battery has a high voltage characteristic during discharging is as follows.
Compared with the conventional battery, in the battery A of the present invention, the oxygen gas generated from the positive electrode plate can be smoothly degassed from the inside of the bag via the separator, and the internal resistance of the battery is prevented by preventing the accumulation of bubbles in the separator. This was because it was possible to reduce Further, since the side portion of the bag was reinforced, long-life battery characteristics could be obtained.

[0017]

As is apparent from the above description, according to the present invention, since the both sides of the microporous synthetic resin sheet are bent to form a bag and wrap the electrode plate, the bottom end of the positive electrode and the Since only the portion is wrapped in the double separator, the corrosion-expanded positive grid lattice can be prevented from breaking through the separator, and a long-life battery can be obtained.

Furthermore, the side surface of the bag-shaped separator at the center of the lattice body is a microporous synthetic resin sheet, and oxygen gas generated from the positive electrode plate can be smoothly degassed without accumulating in the separator. Good discharge voltage characteristics can also be obtained because the discharge can be easily performed from the side portions and an increase in internal resistance can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a positive electrode plate wrapped with a bag-shaped separator of a lead storage battery according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between the number of life cycles of a battery and a voltage at 30 seconds in an example of the present invention and a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bag-shaped separator 2 Separator bending part 3 Positive electrode plate

Claims (2)

[Claims] 1. A lead-acid battery having a configuration in which a separator made of a microporous synthetic resin sheet is formed into a bag and enclosing an electrode plate, wherein a separator formed by bending both sides of the separator inward is used. Characteristic lead storage battery. 2. The lead-acid battery according to claim 1, wherein the side of the separator that is bent faces the side that contacts the positive electrode plate.