JP2002203565A - Sealed lead-acid battery - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a sealed lead storage battery having excellent overcharge resistance. SOLUTION: A sheet in which a lead-tin alloy plate is integrated on at least one surface of a lead or lead-calcium alloy plate,
A sealed lead-acid battery using a positive electrode plate with a grid formed by punching or elongating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positive electrode grid of a sealed lead-acid battery.

[0002]

2. Description of the Related Art At present, a method called a retainer type is generally employed for a sealed lead-acid battery utilizing a so-called oxygen cycle in which oxygen gas generated during charging of a battery is absorbed by a negative electrode plate. Retainer-type sealed lead-acid battery is a mat-shaped separator made mainly of fine glass fibers inserted between the positive electrode plate and the negative electrode plate (hereinafter referred to as a glass separator), which holds the sulfuric acid electrolyte required for battery charging and discharging. And the two poles are isolated.

[0003] The sealed lead-acid battery is used as a portable power source, a backup power source for a computer, and the like by utilizing features such as maintenance-free, liquid-leakage, and position-free.

[0004] Retainer-type sealed lead-acid batteries are classified into a square sealed lead-acid battery and a cylindrical sealed lead-acid battery in terms of external shape. The latter has excellent high-rate discharge performance by using a thin electrode plate, and is particularly suitable for applications where high-rate discharge performance is important.

[0005] In a rectangular sealed lead-acid battery, a high strength electrode plate is required because an electrode plate after filling with paste is stacked in several stages in the order of a positive electrode plate, a separator and a negative electrode plate to form an element. Therefore, a rigid lattice body made of a lead-calcium-tin alloy is usually used.

[0006] On the other hand, in a cylindrical sealed lead-acid battery, a soft grid body is used in order to immediately spirally wind the electrode plate after filling with the paste. For example, U.S. Pat. S. Pat. No. No. 3,862,861 describes the use of a grid formed by processing a pure lead sheet. However, in this case, the grid body processed from a pure lead sheet has a problem in charge acceptability at the time of deep discharge. S. Pa
t. No. No. 5,120,620 describes the use of a lattice formed by punching or extruding a lead-tin alloy sheet to which about 1% of tin is added in order to improve charge acceptability.

[0007] In the case of a square sealed lead-acid battery, the thickness of the positive electrode plate is 2
On the other hand, the diameter of the cylindrical lead-acid storage battery is as thin as 1 mm or less, whereas the overcharge resistance is not always good. In recent years, longer life has been required, and this has become a problem. It is effective to increase the tin concentration in the alloy of the positive electrode grid to improve the overcharge resistance performance of the prismatic sealed lead-acid battery, and the same can be said for a grid that does not contain Ca, such as a cylindrical sealed lead-acid battery. Can be However, there has been a problem that if the tin content is simply increased, the hydrogen overvoltage of the negative electrode is reduced, and the amount of the electrolyte solution during use is greatly reduced.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to improve the overcharge resistance of a sealed lead-acid battery as described above.

[0009]

According to the first aspect of the present invention, a sheet in which at least one surface of a lead or lead-calcium alloy plate is integrated with a lead-tin alloy plate is punched or extruded. A sealed lead-acid battery characterized in that the formed grid is used for a positive electrode plate.

[0010] According to a second aspect of the present invention, in the sealed lead-acid battery according to the first aspect, the tin content of the lead alloy is 1% to 30%.

[0011]

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a grid used in a sealed lead-acid battery, wherein a lead-tin alloy plate is integrated with at least one surface of a lead or lead-calcium alloy plate to form a sheet, and then punched. Alternatively, by using a grid body formed by an etching process for the positive electrode plate, a layer containing a large amount of tin is provided at the interface between the grid body and the active material to provide a sealed lead-acid battery with excellent overcharge resistance. Things.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

First, a 0.2 mm-thick lead-10% tin alloy plate is superimposed on a 10 mm-thick 99.99% lead plate and rolled to be integrated into a 0.8 mm-thick plate. A sheet was prepared. By punching this sheet, a lattice having squares of 5 mm × 7 mm was produced.

The grid plate is coated with a commonly used paste to provide a positive electrode plate and a negative electrode plate with 99.99.
A paste prepared by applying a paste to a grid manufactured from a% lead sheet was used. The thickness of the electrode plate was 1 mm for both the positive electrode plate and the negative electrode plate. Then, these electrode plates and a glass separator were combined and wound to form an element, thereby producing a cylindrical sealed lead-acid battery having a capacity of 10 Ah at a rate of 5 hours. In addition,
A commonly used separator mainly composed of glass fiber having an average diameter of about 1 μm and having a porosity of about 94% and a thickness of 0.8 mm under a load of 50 kgf / dm ² was used. The gap was set to 0.8 mm.

Experiment 1 In addition, 99.0 was used as a conventional grating.
For comparison, a sheet obtained by rolling a sheet of 10% lead-1.0% tin, a sheet obtained by rolling a sheet of 95.0% lead-5.0% tin, and a sheet obtained by rolling 99.99% lead were used for comparison. Sheet,
0.2m thick on 90.0% lead-1.0% tin plate
A battery using, as a positive electrode plate, a grid body manufactured by using sheets obtained by stacking and rolling rolled sheets of lead-10% tin alloy having a thickness of m and conducting an experiment was performed in the same manner as described above. Table 1 shows the relationship between the combination of the plates used and the battery using the grid manufactured from them. In the experiment, a current of 1 A was applied and 100
The capacity of each battery was checked at an hourly current (10 A) every hour. The experiment was performed in the gas phase at 30 ° C.

[0016]

[Table 1]

FIG. 1 shows the results. As described above, the battery of Battery No. 5 of the present invention exhibited excellent overcharge resistance. When the conventional product (battery No. 1) and the battery of battery No. 4 were dismantled and inspected at the end of their life, intergranular corrosion occurred in the grid of the positive electrode, and the battery was broken when pressed slightly by hand.
Battery No. 2 had a large amount of liquid reduction. This is considered to be due to the large amount of tin in the positive grid, which caused tin dissolved from the grid to precipitate on the negative plate and reduce the hydrogen overvoltage. Therefore, it is considered that the electrolytic solution was reduced by the electrolysis of water, and the performance was remarkably lowered due to the increase in the specific gravity of the electrolytic solution.

When a lead plate having a high purity was used (battery No. 3), the corrosion resistance was improved, but the capacity was reduced at an early stage. The overcharge resistance deteriorates due to poor contact between the lattice and the active material interface. In this case, it happened early.

In general, by adding tin to a lead-calcium alloy, it is possible to prevent the life from being significantly shortened.
In the case of the product of the present invention (battery No. 5), it is presumed that the combination of an alloy layer having a high tin concentration and a pure lead plate having excellent corrosion resistance greatly extended the life. 99.9 in this test
A 90% lead-10% tin alloy plate was stacked on only one side of the 9% lead plate, but the effect was still sufficient.

As described above, a 99.99% lead plate is provided with lead-
In a battery using a grid body made of a sheet integrated by laminating 10% tin alloy plates and rolling, the overcharge resistance was significantly improved. A test was also conducted on the charge acceptability at the time of deep discharge, but no difference was recognized between the battery number 1 of the conventional product and the battery number 5 of the product of the present invention. By using a grid obtained by superimposing a lead-10% tin alloy plate on a 99.99% lead plate, it is possible to reduce the charge acceptability during deep discharge, which is a drawback when using a pure lead grid. Had the effect of preventing it.

Further tests were conducted by changing the tin content of the superposed lead tin alloy plates.
It was found that within the range, the battery performance was improved.

[0022] The lead-tin alloy plate to be superimposed has a thickness of 0.1 mm.
Even if less than 2% Ca and other alkali metals, alkaline earth metals or Sb were included, the performance was not impaired.

In the above embodiment, a cylindrical sealed lead-acid battery using pure lead as the electrode substrate has been described. However, the present invention is applied to a prismatic sealed lead-acid battery using a lead-calcium alloy as the electrode substrate. The same operation and effect were obtained.

[0024]

As described above, at least one of a lead or a lead-calcium alloy plate and a lead-tin alloy plate are integrated to form a sheet, and then a grid formed by punching or expanding is used as a positive electrode. The use as a plate can improve the overcharge resistance of a sealed lead-acid battery, and its industrial value is extremely large.

[Brief description of the drawings]

FIG. 1 is a diagram showing a comparison of overcharge life performance.

Claims (2)

[Claims] A sheet in which a lead-tin alloy plate is integrated on at least one surface of a lead or lead-calcium alloy plate,
A sealed lead-acid battery characterized in that a grid body formed by punching or etching is used for a positive electrode plate. 2. The lead-tin alloy sheet has a tin content of 1%.
The sealed lead-acid battery according to claim 1, wherein the content of the sealed lead-acid battery is from 30% to 30%.