JPH0869811A - Lead-acid battery - Google Patents

Abstract

PURPOSE: To prevent damage of a separator, and prevent shortening of the service life caused by a shortage of charging by setting a negative plate total active material quantity in a plate group in the prescribed ratio to a positive plate total active material quantity. CONSTITUTION: Lead-calcium-tin alloy is used in both grid bodies of a positive electrode and a negative electrode, and a negative plate is wrapped in a bag- shaped separator. The ratio of a negative plate total active material quantity in a plate group to a positive plate total active material quantity is set in 0.80 to 1.10. Therefore, pole changing speed of negative electrode electric potential in charging is optimized, and reduction in a charging current is restrained until a positive electrode is sufficiently charged, and a polarity change of the negative electrode electric potential is delayed, and a charging shortage of the positive electrode is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead acid battery for an automobile, and more particularly to an improvement of a battery in which a cathode-plate is wrapped with a bag-like separator using a lead-calcium-tin alloy for both the anode and cathode grids. It is a thing.

[0002]

2. Description of the Related Art In a lead-acid battery for an automobile, an electrode plate in which a grid is filled with a predetermined active material paste, particularly an anode plate, is generally used by being housed in a bag-shaped separator made of microporous polyethylene. It is becoming a reality.

With this structure, the positive and negative plates are separated from each other, and the active material dropped from the grid when the battery is used is stored in a bag to prevent an electrical short circuit between the positive and negative plates due to the dropped active material. .

In recent years, as the performance of automobile engines has increased, the ambient temperature of automobile batteries has become extremely high.

When the battery is used at such a high temperature,
Corrosion of the anode plate may be accelerated and the lattice may be largely expanded and deformed, and the bag-shaped separator may be broken and the anode plate and the cathode plate may come into contact with each other to cause a short circuit.

In order to prevent this, there is a battery having a structure in which the cathode plate is wrapped with a bag-shaped separator instead of the anode plate to prevent the separator from coming off.

[0007]

However, in recent automobiles, the number of electric components inside the automobile has increased remarkably as the engine performance has increased, and the battery for automobiles has a high ambient temperature and a very deep load, resulting in a very deep discharge depth. It is getting deeper.

When a battery is used under such a high temperature and high load condition, a battery having a structure in which a cathode plate is wrapped with a bag-shaped separator instead of the conventional anode plate, particularly, a positive-cathode grid is leaded. In a battery using a -calcium-tin alloy, it is effective in suppressing the cracking of the separator, but the charge acceptability is reduced due to deterioration of the diffusion of the electrolyte solution near the cathode plate, There has been a problem that the entire battery reaches the end of life due to insufficient charging at an early stage due to insufficient charging of the anode plate.

The present invention solves these problems, and prevents the separator from breaking through due to the corrosion extension of the grid of the anode plate, and improves the short life due to insufficient charging due to a decrease in charge acceptability. It provides a lead storage battery.

[0010]

In order to solve the above problems, in the lead acid battery of the present invention, the ratio of the total amount of the active material of the negative electrode plate to the total amount of the active material of the positive electrode plate in the electrode plate group is 0.80 or more 1 .1
It is characterized by being set to 0 or less.

[0011]

In the lead-acid battery of the present invention, a lead-calcium-tin alloy is used for both the anode and cathode grids, and the cathode plate is wrapped with a bag-shaped separator. The ratio to the total active material amount of the anode plate is 0.80 or more 1.
By setting the ratio to 10 or less, it is possible to prevent the separator from breaking through due to use at high temperature, improve the charge acceptability due to use under high load, and prolong the life.

That is, in the conventional structure, the concentration of the electrolytic solution near the cathode plate increases early during charging due to the deterioration of the diffusion of the electrolytic solution, and apparently the charging progresses, so that the cathode potential is rapidly switched. As a result, the charging current decreased before the anode plate was sufficiently charged, resulting in insufficient charging.

On the other hand, the present invention optimizes the reversal speed of the cathode potential during charging by setting the ratio of the total active material amount of the cathode plate to the total active material amount of the anode plate to 0.80 or more. In order to suppress the decrease of the charging current until the anode is sufficiently charged, the reversal of the cathode potential is delayed, thereby improving the insufficient charging of the anode.

When the ratio of the total active material amount of the cathode plate to the total active material amount of the anode plate exceeds 1.10, the cathode potential is switched too slowly, and the anode plate is overcharged to the contrary and the grid is generated. Corrosion is accelerated, resulting in a shorter life.

[0015]

Embodiments of the present invention will be described below.

First, various anode and cathode plates were prepared by using a lead-calcium-tin alloy for the anode and cathode grids and applying different amounts of paste thereto.

Next, using these plates, the nominal capacity is 12V.
55 Ah, battery A in which the ratio of the total active material of the cathode plate in the electrode plate group to the ratio of total active material of the anode plate was 0.70, battery B in which the ratio was 0.80, and battery in which the ratio was 1.10. A battery D containing C and 1.20 was prepared.

These batteries were charged at 14.0 V (maximum charging current 25 A) for 10 minutes and discharged at 25 A for 4 minutes in an atmosphere of 75 ° C., and each discharge was performed at 582 A for 30 seconds at 480 cycles. Then, a test was conducted to determine the end of life at the time when the terminal voltage at 30 seconds became 7.2 V or less.

The results are shown in FIG. As shown in FIG. 1, the ratio of the total active material of the cathode plate was 0.70 for battery A and 1.2.
Battery D of 0 has reached the end of its life early, while 0.80
Battery B of 1. and Battery C of 1.10 had very long life cycles and good results.

Then, when the batteries after these tests were disassembled and the electrode plate group was observed, it was found that the battery A had an anode plate,
Almost no deterioration was seen in the cathode plate, but the state of the active material of the anode plate showed a discharging tendency, and it is considered that the charge was insufficient during the cycle.

In Battery D, the grid of the anode plate was significantly deformed due to corrosion, and it is considered that overcharge was likely to occur during the cycle.

On the other hand, in the batteries B and C, both the anode plate and the cathode plate were in a deteriorated state corresponding to the number of cycles,
It showed that the charge-discharge balance during the cycle was favorable.

[0023]

As described above, the lead-acid battery of the present invention uses the lead-calcium-tin alloy for both the anode and cathode grids,
In the structure in which the cathode plate is wrapped with the bag-shaped separator, the ratio of the total amount of the active material of the cathode plate to the total amount of the active material of the anode plate in the electrode plate group is 0.80 or more and 1.10 or less, and it corrodes when the battery is used. It is intended to prevent the separator from breaking through due to the expansion of the anode plate due to the above, and to improve the short life due to insufficient charge due to the decrease in charge acceptability in the conventional configuration in which the cathode plate is wrapped in the bag-shaped separator.

[Brief description of drawings]

FIG. 1 is a diagram showing the results of a life test of the present invention and a conventional battery.

Claims (1)

[Claims] 1. A lead-calcium-containing material for both the anode and cathode grids.
In a battery having a structure in which a cathode plate is wrapped with a bag-like separator using a tin-based alloy, the ratio of the total amount of active material of the negative electrode plate to the total amount of active material of the positive electrode plate in the electrode plate group is 0.80 or more and 1.10 or less. A lead acid battery characterized by being present.