JPH09223502A - Sealed lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the dispersion of the electrode plate thickness, and lessen the dispersion of high rate discharge capacity and trickle life by providing a portion where cut widths are changed and the sum of the widths of two continuing parts as nearly equal to the electrode plate thickness in a lead-acid battery grid body. SOLUTION: Since adjoining cut widths are joined at the node portions 2 to 11, the cross section thickness of the portion is nearly equal to the sum of the adjoining cut widths, the thickness of the node portions 4, 10, in which the adjoining cut widths are large, determine; the maximum thickness of the grid body. At a paste filling time against the grid body, a scraper is regulated by the node portion where the sum of the cut widths is maximum so that the dispersion of a filled amount of paste is little, and as the result, the dispersion of the thickness of a completed electrode plate is also little.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealed lead-acid battery. More specifically, the present invention relates to improvement of a lattice body formed by the expanding process used for the electrode plate.

[0002]

2. Description of the Related Art As a grid of a lead storage battery, an expanded processed product in which an antimony-free lead or lead alloy sheet is developed into a grid to form a grid is widely used for the purpose of improving productivity and maintenance-free. It has also come to be used in sealed lead-acid batteries. The setting of the cutting width of the sheet forming the lattice bone in the conventional expanding process is made uniform from the upper part to the lower part, or as disclosed in JP-A-56-159065.
For the purpose of weight reduction and cost reduction without impairing battery performance and production efficiency, the cutting width of the sheet is changed, the part in contact with the upper rib is approximately equal to the sheet thickness, and gradually becomes narrower toward the lower rib. There was an example concerning sheet cutting width.

[0003]

However, in the step of filling the active material in the form of a paste into the lattice using the expand method, an excessive amount of paste is applied to the reticulated development part and adjusted to a specified amount by a scraper. , Expanding type electrode plate of the conventional configuration that changes the sheet cutting width during processing does not have a standard to adjust the scraper opening, and it is difficult to regulate the electrode plate thickness when filling the paste, so the electrode plate thickness and paste filling There was a problem that the variation in the amount became large. Furthermore, in the case of a so-called over-pasted electrode plate in which the electrode plate thickness after the paste is thicker than that of the grid, adjustment of the scraper for the electrode plate at the time of filling is similarly difficult, and the electrode plate thickness and paste filling amount vary. Was occurring. On the other hand, in the sealed lead-acid battery, since the electrolyte is contained in the separator and in the electrode plate, if there is a variation in the electrode plate thickness, the force of pressing the electrode plate group with the cell partition wall varies, There is a problem in that uniform adhesion cannot be obtained between the electrode and the electrode plate, which adversely affects the capacity and the trickle life particularly at high rate discharge.

The present invention solves these problems, and in a sealed lead-acid battery using an expanded grid, suppresses variations in the active material filling amount of the grid, and further improves the storage battery using it. The purpose is to improve the rate discharge capacity and the trickle life.

[0005]

In order to solve the above-mentioned problems, in the present invention, in a lattice body obtained by subjecting a sheet material made of lead or a lead alloy to an expansion process, the total of the cut widths at two continuous points forming the knots is formed. Is the maximum, and at least one portion, which is set to have a thickness substantially equal to the thickness of the electrode plate after the active material is filled, is present in at least one position in the longitudinal cross-sectional direction of the grid. Thus, when the paste is filled, the scraper can be regulated by the knotted portion having the maximum thickness of the lattice body, so that the filling amount can be made constant and the variation of the electrode plate thickness can be reduced. Further, this is effective for maintaining a uniform close contact between the separator and the electrode plate and leveling the capacity and the trickle life at the time of high rate discharge.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the sealed lead-acid battery of the present invention, a sheet material made of lead or a lead alloy is expanded and used as a lattice. The cut width in the expanding process is changed in the width direction of the sheet material, and at least one position where the sum of the cut widths of two adjacent positions is the maximum is provided in the width direction.

FIG. 1 shows an example of the embodiment. Reference numeral 1 is a lower frame bone, and 2 to 11 are nodules of each lattice. FIG.
(A) shows the aa 'cross section of the grating | lattice body of FIG. As can be seen from FIGS. 1 and 2 (a), since the adjacent cut widths of the respective knot portions are joined, the thickness of the cross section at that portion is approximately equal to the sum of the adjacent cut widths. The thickness of the widened nodules 4 and 10 determines the maximum thickness of the grid. More strictly, as shown in FIG. 5, in consideration of the angle θ formed by the sheet material surface at the knot portion with the cross-sectional direction of the lattice, in the normal expanding process, it becomes about 1.03 times the sum of cutting widths. . In the present invention, since the scraper is regulated at the knotted portion having the maximum sum of cutting widths when the paste is filled in the grid body, the variation in the paste filling amount is small, and the variation in the thickness of the resulting electrode plate is also small. small.

[0008] Even if the electrode plate thickness after filling with the active material is larger than the maximum value of the sum of the cutting widths, that is, the paste is slightly over-pasted, if the ratio is more than 1.08, the filling amount varies. Grows from 1.08 to 1.0
It is preferable to set it to 3 (that is, the thickness of the lattice).

[0009]

EXAMPLES Next, specific examples of the present invention and manufacturing methods thereof will be described. As an example of the present invention, 0.08 wt% Ca,
A 1.1 mm thick lead alloy sheet containing 1.1 wt% Sn was expanded and cut to prepare a grid plate for a positive electrode plate having a height of 43 mm and a width of 24.5 mm as shown in FIG. The sum of the cutting widths was the maximum at the lattice nodes 4 and 10, and the value was 2.0 mm.

A scraper was pressed against the grid nodes 4 and 10 to fill the grid with the positive electrode active material paste and dried to obtain a positive electrode plate having a thickness of 2.06 mm.

For comparison, the same lead alloy sheet as in the above example was used for expanding under the condition that the cutting width was constant, and cut to the same size as in the above example to produce a grid plate for a positive electrode plate according to the conventional example. did. The sum of the cutting widths in the conventional lattice body was constant at 1.9 mm at any lattice node.
The conventional grid was filled with the active material with the same opening of the scraper as the paste filling in the above-mentioned example, to prepare a positive electrode plate of the conventional example having a thickness of 2.06 mm.

Positive electrode plate 150 of these examples and conventional examples
The thickness t and the weight Wt were measured for each sheet and the variation thereof was obtained. At this time, the thickness of the electrode plate was measured at three points in the electrode plate with a micrometer, and the average value of the three points was taken as the thickness of the electrode plate. As a measure of variation, the thickness standard deviation tσ calculated from the measurement results and the electrode plate weight standard deviation w
σ was obtained and summarized in Table 1).

[0013]

[Table 1]

As is clear from Table 1, both the values of tσ and wσ of the positive electrode plate according to the example are lower than those of the conventional example. The decrease in the σ value is because the filling amount at the time of filling the paste can be regulated at the two knot portions.

Two positive electrode plates of the above-mentioned example and the conventional example are used three per cell, respectively, and four conventional negative electrode plates and glass mats are interleaved and alternately laminated to form six cells in a monoblock battery. The sealed lead-acid batteries according to the example and the conventional example were respectively placed in a tank. FIG. 3 shows a comparison between the present invention and the conventional example battery in the discharge capacities of the 20 test batteries at 3.0 CA (6 A) discharge. The one according to the present invention has an average duration of 11.5 minutes and a standard deviation of 0.2 minutes.
In the conventional example, the standard deviation was 10.5 minutes, and the standard deviation was 0.5 minutes, and the variation in capacity was also reduced as compared with the conventional example. This is because the variation in thickness of the positive electrode plate is reduced and the adhesion between the glass mat separator and the positive and negative electrode plates forming the electrode plate group becomes uniform, which stabilizes the supply and concentration of the electrolytic solution. It seems that

FIG. 4 shows the results of the trickle life of the above battery. The test battery composed of the above 12V was tested at 40 ° C.
In the atmosphere, trickle charging was performed at a constant voltage of 13.8 V, and 3.0 CA discharge capacity was measured every three months. As is clear from this result, the variation of the capacity reduction with the lapse of the trickle period is smaller in the device according to the present invention than in the conventional example. This is because, as described above, the variation in the thickness of the positive electrode plate affects the close contact between the positive electrode plate and the positive electrode plate and the negative electrode plate in the positive electrode plate group. It is considered that the increase of the internal impedance due to the dissipation is large and that it is the cause of the capacity decrease.

Although the present embodiment has been described with reference to the plate lattice alone,
When a lead alloy sheet is expanded to form a lattice, it is common that a lead alloy solid portion is usually present in the central portion, and the lead alloy sheet is unfolded in a net shape on both sides thereof. If there is a knot in which the sum of the cutting widths at least at one place and at two places is set to be approximately equal to the thickness of the electrode plate after filling with the active material in the left and right reticulated development parts, when paste is continuously applied, By using this knot, the paste can be uniformly filled.
Furthermore, although the effects of the positive electrode plate have been described in the present embodiment, the same effects as those described can be obtained for the negative electrode plate.

[0018]

As described above, according to the present invention, in the lead-acid battery grid formed by the expanding process, the cutting width is changed and the sum of the cutting widths at two consecutive positions is substantially equal to the electrode plate thickness. By providing the above, it is possible to reduce the variation in electrode plate thickness even when the active material paste is filled, and it is possible to supply a sealed lead-acid battery with high rate discharge capacity and little variation in trickle life.

[Brief description of drawings]

FIG. 1 is a plan view of a lattice according to an embodiment of the present invention.

FIG. 2A is a cross-sectional view of a grating body according to an embodiment of the present invention. FIG. 2B is a cross-sectional view of a grating body according to a conventional example.

FIG. 3 is a diagram showing a comparison of high rate discharge capacities of a battery according to an example of the present invention and a battery according to a conventional example.

FIG. 4 is a diagram showing a relationship between a trickle charge period at 40 ° C. and a high rate discharge capacity of a battery according to an example of the present invention and a battery according to a conventional example.

FIG. 5 is a view showing a cross section of a lattice node portion.

[Explanation of symbols]

 1 Lower frame bone 2-11 Lattice node

Claims (3)

[Claims] 1. A sealed lead-acid battery using an electrode plate filled with an active material in a lattice body formed by an expanding process in which a sheet material made of lead or a lead alloy is changed in a widthwise cutting width, The lattice type has a maximum value of the sum of the cut widths of two adjacent portions, and at least one portion, which is approximately equal to the thickness of the electrode plate after filling the active material, is arranged in the longitudinal cross-sectional direction of the lattice element in a sealed type. Lead acid battery. 2. The thickness of an electrode plate obtained by filling a grid body with an active material is 1. The maximum value of the sum of the cut widths of two adjacent portions is 1.
The electrode plate set in the range of 03 to 1.08 is used.
A sealed lead-acid battery as described. 3. The sealed type according to claim 1, wherein two portions are set in the longitudinal cross section of the lattice so that the sum of the cut widths of two adjacent portions is set to be substantially equal to the thickness of the electrode plate after filling with the active material. Lead acid battery.