JPH05307949A - Lead-acid battery - Google Patents

Abstract

PURPOSE:To restrict the elongation and the deformation of a grid body of a positive electrode plate of a lead-acid battery for automobile under the high temperature, and prevent the lowering of the lifetime characteristic of the battery and the internal short circuit under the high temperature. CONSTITUTION:A positive electrode plate 1, which is obtained by filling the paste-like active material in a grid body made of lead-calcium-tin (Pb-Ca-Sn) alloy including calcium (Ca) at 0.05-0.07weight% and tin (Sn) at 0.75-1.0weight%, is housed in a bag-like separator 2, which is obtained by folding the fine porous polyethylene film into the U-shape, providing longitudinal parallel ribs inside thereof, mechanically providing projecting parts and recessed parts in both of right and left ends, and being subjected to press-fitting.

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 automobiles,
Particularly, it relates to the positive electrode plate.

[0002]

2. Description of the Related Art Conventionally, a lead-antimony (Pb-Sb) -based alloy has been used for a grid of a positive electrode plate of a lead storage battery for SLI of an automobile. However, a battery using this alloy in a lattice has problems of reduction of electrolyte solution due to overcharge and self-discharge due to Sb (antimony), and in recent years, lead-calcium-tin (Pb-Ca-Sn) alloy has been used. It has come to be used as a lattice.

The Pb-Ca-Sn alloy lattice is filled with a paste-like active material to prepare an electrode plate, and the electrode plate thus prepared is housed in a bag-shaped separator for charging and discharging. The internal short circuit between the positive electrode plate and the negative electrode plate due to stretching or deformation of the body was prevented.

[0004]

However, recently, as the efficiency of an automobile engine is increased and the density of the engine room is increased, the ambient temperature of the battery for SLI of an automobile is increased to a high temperature of about 75 ° C to 90 ° C. May be.

In such a temperature environment, particularly, the amount of corrosion of the grid of the positive electrode plate of the lead storage battery is increased, and the positive electrode plate is greatly stretched and deformed.

Due to the expansion and deformation of the positive electrode plate, the bag-shaped separator accommodating the positive electrode plate may be torn or the positive electrode active material may fall off from the electrode plate, resulting in deterioration of battery life characteristics. Alternatively, an internal short circuit may occur due to the positive electrode active material deposited on the bottom of the battery case.

The present invention is intended to solve such a problem and prevents the expansion and deformation of the positive electrode plate of the lead storage battery for SLI of automobiles at high temperatures, thereby breaking the bag-shaped separator or dropping the positive electrode active material. It is intended to provide a lead storage battery capable of preventing deterioration of battery life characteristics and internal short circuit due to the above.

[0008]

In order to solve the above-mentioned problems, the lead-acid battery of the present invention uses calcium (Ca) of 0.
05-0.07 wt% and tin (Sn) 0.75-1.0
A positive electrode plate in which a paste-like active material is filled in a lattice of a lead-calcium-tin (Pb-Ca-Sn) -based alloy containing 1% by weight,
Fold a microporous polyethylene film into a U shape,
Vertically parallel ribs are provided on the inside, and the left and right ends are mechanically provided with protrusions and recesses and are housed in a pressure-bonded bag-shaped separator.

[0009]

In the present invention, the lead-calcium used in the lattice is
Calcium (Ca) as tin (Pb-Ca-Sn) alloy
0.05 to 0.07% by weight, and tin (Sn) 0.75 to
Since the one containing 1.0% by weight is used, the mechanical strength of the lattice, particularly the tensile strength, can be improved.

Then, Pb-C having improved tensile strength
By using the a-Sn alloy for the grid of the positive electrode plate, it is possible to suppress the expansion and deformation of the grid of the positive electrode plate even when the battery is at a high temperature exceeding 75 ° C. It can be prevented from falling off. Then, by housing the positive electrode plate of the present invention in a bag-shaped separator that is reliably formed into a bag, it is possible to prevent the active material of the positive electrode from falling off from the electrode plate and accumulating on the bottom of the battery case. It is possible to prevent the deterioration of the life characteristics of the battery and the internal short circuit.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows lead-calcium-tin (Pb-Ca).
-Sn) alloy with tin (Sn) and calcium (Ca)
The change in tensile strength when the content of is changed is shown.

As shown in FIG. 1, the tensile strength increases as the tin (Sn) content increases, but the tensile strength increases when the calcium (Ca) content exceeds 0.07% by weight. No big difference was seen.

Considering this result and the workability at the time of manufacturing the Pb-Ca-Sn alloy lattice, Pb-Ca-Sn is considered.
The content of Ca in the alloy is 0.05 to 0.07% by weight, S
It has been found that the content of n is preferably 0.75 to 1.0% by weight. And the Pb-Ca-S of the present invention
By using an n alloy, in particular, by using a Pb-Ca-Sn alloy containing 0.07% by weight of Ca and 1.0% by weight of Sn, a lattice of a positive electrode plate having improved mechanical strength is produced. I was able to.

Next, as shown in FIG. 2, the grid body of the present invention is filled with a predetermined paste-like active material to prepare a positive electrode plate 1, which is formed into a U-shaped separator of a microporous polyethylene film. It was folded into a bag-like separator 2, and the left and right ends thereof were mechanically pressure-bonded to be housed in a bag-shaped separator 2 in which irregularities were alternately formed. The separator 2 has a plurality of ribs vertically provided on its inner side surface. Then, a plurality of positive electrode plates 1 and negative electrode plates 3 housed in the bag-shaped separator 2 are stacked,
An electrode plate group as shown in FIG. 3 was produced and the nominal capacity was 48 Ah.
The lead acid batteries A and B of the present invention were manufactured.

As comparative examples, lead-acid batteries E to H having the positive and negative electrode plates having different alloy compositions C and D from the present invention and the negative electrode plate which is the electrode plate accommodated in the bag-like separator were prepared. ..

Lead acid batteries of the present invention and comparative examples are shown in (Table 1).

[0018]

[Table 1]

Next, using the batteries of the present invention and the comparative example, a charge / discharge cycle life test was conducted at a high temperature. here,
The charge / discharge cycle life test was carried out at 75 ° C. with constant voltage charging with a maximum current of 25 A at 14.8 V for 2 hours, then at 20 A for 1 hour.
It was discharged for an hour. And 75 ° C every 39 cycles
At 30 seconds, the voltage was measured after 300 A was discharged, and the life was defined when the voltage was 7.2 V or less.

The results are shown in FIG. As shown in FIG. 4, the lead-acid battery of the present invention was able to improve the charge / discharge cycle life characteristics at high temperatures.

[0021]

As described above, the lead-acid battery of the present invention contains 0.05 to 0.07% by weight of calcium (Ca) and tin (S).
n) 0.75 to 1.0% by weight of a lead-calcium-tin (Pb-Ca-Sn) alloy lattice filled with a paste-like active material, a positive electrode plate is filled with a microporous polyethylene film U. It folds in a letter shape, and it has ribs that are vertically parallel to the inside.
Since it is housed in a bag-shaped separator that is mechanically roughened at both ends on the left and right sides and crimped, it is possible to suppress the expansion and deformation of the positive electrode plate grid even when the battery is under high temperature. It is possible to prevent deterioration of life characteristics of the battery and internal short circuit.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the Ca and Sn contents in a Pb-Ca-Sn alloy and the tensile strength of a lattice.

FIG. 2 is a diagram showing a state where the positive electrode plate of the present invention is stored in a bag-shaped separator.

FIG. 3 is a diagram showing an electrode plate group using the positive electrode plate of the present invention.

FIG. 4 is a diagram showing charge / discharge cycle life characteristics at 75 ° C. of the batteries of the present invention and comparative examples.

[Explanation of symbols]

 1 Positive electrode plate 2 Bag-shaped separator 3 Negative electrode plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhiro Takahashi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. Calcium (Ca) 0.05 to 0.07
Lead containing 0.75 to 1.0% by weight of tin and Sn (Sn)-
A positive electrode plate in which a paste-like active material is filled in a lattice of a calcium-tin (Pb-Ca-Sn) alloy is folded into a U-shape with a microporous polyethylene film, and vertical parallel ribs are provided on the inside. Lead-acid battery stored in a bag-shaped separator that is mechanically textured at both ends and crimped.