JPH09289013A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the life by placing a fiber mat and a synthetic resin separator between a positive plate formed by filling a pasty positive active material in a grid substrate made of the specified alloy and a negative plate so that the fiber mat is faced to the positive plate. SOLUTION: A glass fiber mat 3 is closely placed on both sides of a positive plate 1, a polyethylene separator 4 is stacked on the outside of the mat 3, and a negative plate 2 is stacked on the outside of the separator 4 between the positive plate 1 and the negative plate 2 to constitute an electrode plate group A. The positive plate 1 is manufactured by filling a pasty positive active material in a grid substrate cast with an alloy comprising 0.03-0.09wt.% Ca, 1.05-1.50wt.% Sn, and the balance lead. Since the lead grid substrate is easily cast from the specified Pb-Ca-Sn alloy, corrosion resistance is enhanced, a lead-acid battery having a long cycle life at high temperature can be obtained, and the life of the battery such as a car battery used under environment exposed to high temperature is lengthened.

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 applied to automobiles and the like.

[0002]

2. Description of the Related Art The applicant previously filed Japanese Patent Application No. 6-28447.
No. 8, Ca 0.03 to 0.09 wt%, Sn
A positive electrode plate having excellent corrosion resistance even under high temperature, which is prepared by filling a grid substrate made of a lead-calcium-tin alloy with 1.05 to 1.50% by weight and the balance lead with a paste-like positive electrode active material, is synthesized. A lead-acid battery having an improved battery life, which has an electrode plate group formed by combining and stacking a negative electrode plate housed in a bag-shaped separator without housing in a resin separator, is presented.

[0003]

However, since only the synthetic resin separator is interposed between the positive electrode plate and the negative electrode plate, the active material of the positive electrode plate is liable to fall off and the battery life is shortened. May lead to As a countermeasure for this, the positive electrode plate is housed in a bag-shaped polyethylene separator which is provided with vertical parallel ribs on the opposing inner surfaces folded in a U shape, and the left and right ends thereof are provided with protrusions and recesses, and these ribs and protrusions and recesses Therefore, it is possible to improve the mechanical strength of the active material by dropping the active material by pressure bonding to the positive electrode plate surface and breaking the bag-shaped separator due to the expansion of the positive electrode plate, but the objective cannot be sufficiently achieved. Therefore, it is desired to develop a lead-acid battery that eliminates the above inconvenience and has a longer life.

[0004]

SUMMARY OF THE INVENTION The present invention provides a lead acid battery that satisfies the above-mentioned needs, and has a Ca 0.03 to
A fiber mat is formed between a positive electrode plate and a negative electrode plate, which are obtained by filling a grid substrate cast with an alloy of 0.09% by weight, Sn 1.05 to 1.50% by weight, and the balance of lead with a paste-like positive electrode active material. And a synthetic resin separator, the electrode plate group comprising the fiber mat facing the positive electrode plate surface.

Since the fiber mat is pressure-bonded to the entire surface of the positive electrode plate, it prevents the active material from falling off, absorbs the elongation of the positive electrode plate, and the synthetic resin separator on the outer side thereof has a bag shape. Has a cushioning effect and prevents the bag from breaking. On the other hand, in the synthetic resin separator on the outer side of the fiber mat, Pb deposited on the negative electrode plate reaches the positive electrode plate through the fine holes of the fiber mat to prevent a short circuit between the positive and negative electrode plates. Thus, extending the life of the lead acid battery.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail. Ca 0.03 to 0.14% by weight, Sn 0.7 to 1.
At 50% by weight and the balance of lead, various alloys were produced by changing the alloy composition, and cast lattice substrates were produced by using each of them as a material. Each of the grid substrates thus prepared was filled with a paste-like positive electrode active material, and each positive electrode plate was prepared by a conventional method. Each of the positive electrode plates having different alloy compositions of the lattice substrate manufactured in this way was measured at 75 ° C. according to JIS.
A specified overcharge test was performed. That is, the battery is continuously charged at 4.5A for 110 hours, left for 48 hours, and then at 150A for 30 hours.
It was discharged for 3 cycles for 3 cycles. After that, the amount of corrosion (%) of each lattice substrate of the positive electrode plate was measured.
As a result, the relationship between the change in the compounding amount of each of the composition components Ca and Sn in the alloy of the alloy lattice substrate of the positive electrode plate and the corrosion amount (%) of each alloy lattice substrate was investigated. The result is shown in FIG. As is clear from FIG. 1, especially the corrosion amount of the lattice substrate is 20
It has been found that in order to make the content as low as 0.1% or less, it is necessary to add Ca in an amount of 0.09% by weight or less and Sn of 1.05% by weight or more. However, when Ca is 0.02% by weight,
The mechanical strength of the lattice substrate becomes weak, making it unsuitable for practical use. On the other hand, when Sn was 1.55% by weight, it was confirmed that the molten metal flow was deteriorated during casting, causing lattice defects such as breaks in the cast lattice substrate. Therefore, Ca is 0.03 to 0.
By using a lead-calcium-tin based alloy with the balance of 09% by weight, Sn in the range of 1.05 to 1.50% by weight, and the balance of lead, it is possible to ensure a good grid substrate with low corrosivity without loss. It can be smoothly cast, and the corrosion amount is 2
A positive electrode plate of 0% or less can be obtained.

[0007] However, Ca and S in the range specified above
Even if a lead alloy grid substrate is prepared by using a compounding amount with n, and a positive electrode active material is filled therein to manufacture a positive electrode plate, the positive electrode plate and the conventional method are used for manufacturing the lead acid battery. And a negative electrode plate made of a synthetic resin separator such as leaf-shaped polyethylene between them, or a positive electrode plate or a bag-shaped synthetic resin separator such as polyethylene containing the negative electrode plate interposed between them A lead storage battery manufactured by assembling the group and incorporating it in a battery case does not have a long life, and a leaf-shaped or bag-shaped fiber mat is interposed between the positive electrode plate and the separator. It was found that a lead-acid battery with a longer life can be obtained. As the fiber mat, any of a glass fiber mat, a synthetic fiber mat, or a mixed fiber mat of glass fiber and synthetic fiber may be used, but the glass fiber mat is most preferable.

2 and 3 show electrode plate groups A and A'constituting the lead-acid battery of the present invention, respectively. Reference numeral 1 denotes a positive electrode plate, 2 denotes a negative electrode plate, 3 denotes a fiber mat, and the illustrated example is a glass fiber mat. Reference numeral 4 denotes a synthetic resin separator, and the example shown is a polyethylene separator. The glass fiber mat 3 and the polyethylene separator 4 may be either leaf-shaped or bag-shaped. The electrode plate group A shown in FIG.
Each positive electrode plate 1 is a bag-shaped glass fiber separator 3 inside
And a bag-shaped polyethylene separator 4 on the outside thereof are housed in a double bag-shaped separator, and three negative electrode plates 2 are laminated on the outside thereof to form an electrode plate group. In the electrode plate group A ′ shown in FIG. 3, glass fiber mats 3 and 3 are laminated on both side surfaces of two positive electrode plates 1 and three negative electrode plates 2 are provided outside thereof in a bag-shaped polyethylene separator 4. It is a stack of the ones housed in. Thus, the electrode group A,
In any case of A ', each glass fiber mat 3 is face-to-face contacted between the positive electrode plate 1 and the negative electrode plate 2 adjacent to each other on both entire surfaces of the positive electrode plate 1, and the glass fiber separator 3 The polyethylene separator is laminated on the outer side, and the negative electrode plates 2 are laminated on the outer side to form an electrode plate group. The electrode plate group A or A'having the above-described structure is housed in a battery case (not shown) by a conventional method to be incorporated therein to form the lead acid battery of the present invention.

Next, from each of the positive electrode plates and lead-calcium-tin alloys prepared by using various grid substrates made of lead-calcium-tin alloys having different Ca and Sn compounding amounts shown in Table 1 below. Between the known negative electrode plate and a known negative electrode plate, for example, a bag-shaped glass mat 3 having a thickness of 0.4 mm and a bag-shaped polyethylene separator 4 are interposed in accordance with the form of the electrode plate group A shown in FIG. The electrode plate group of the present invention is housed in a battery case by a conventional method,
For comparison with the lead acid battery of the present invention, for comparison, a lead acid battery manufactured by incorporating an electrode plate group in which a bag-shaped polyethylene separator is interposed between the same positive electrode plate and a known negative electrode plate as described above into a battery case. , J at the following high temperature of 40 ℃ and 80 ℃
A light load life test according to IS D 5301 was carried out to test the presence or absence of the glass mat and the effect of cycle life characteristics due to changes in the Ca and Sn contents. Life is 4
It was determined that the voltage at the 30th second when 300 A was discharged every 80 cycles was below 7.2V. 4 and 5 show the results.
Shown in

[0010]

[Table 1]

As is clear from Table 1 and FIGS. 4 and 5, even if the alloy composition of the grid substrate of the positive electrode plate is within the range defined by the present invention, batteries a'and b without a glass fiber mat interposed therebetween. It can be seen that the life of ', c', and e'remarkably decreases as compared with the batteries a, c, e, and d of the present invention in which the glass fiber mat is interposed. In addition, when the alloy composition of the grid substrate of the positive electrode plate is out of the range limited by the present invention, even if the glass fiber mat is interposed on the surface of the positive electrode plate, as shown by the characteristics of the batteries e and f, It can be seen that no improvement is obtained, and in the case where the glass fiber mat is not interposed, the life is further shortened as shown by the characteristics of the batteries e'and f '.

A similar life test was conducted by using the electrode plate group A'of the type shown in FIG. 3 in place of the electrode plate group A of the type shown in FIG. 2, but the same tendency as shown in FIG. 4 and FIG. showed that.

In the above examples, the glass fiber mat was used as the fiber mat, but the synthetic fiber mat and the mixed fiber mat of the glass fiber and the synthetic fiber showed the same tendency.

[0014]

As described above, not only the lead grid substrate can be easily cast from the lead-calcium-tin alloy specified by the present invention, the corrosion resistance is improved, but also the paste type positive electrode plate using the same is used. Assemble the electrode plate group by interposing both the glass fiber mat and the synthetic resin separator between the negative electrode plate and the negative electrode plate, with the glass fiber mat facing the positive electrode plate surface, and assemble this into a battery case by a conventional method. In the case of the lead storage battery, a lead storage battery having an extremely improved cycle life even at high temperatures can be obtained, and the service life can be extended under the environment exposed to high temperatures such as automobile batteries.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between the change in the composition of lead-calcium-tin alloy and the amount of corrosion of the grid substrate of the positive electrode plate.

FIG. 2 is a cut side view of an example of an electrode plate group that constitutes the lead storage battery of the present invention.

FIG. 3 is a cut side view of another example of the electrode plate group constituting the lead storage battery of the present invention.

FIG. 4 is a comparative graph of the JIS light load life at 40 ° C. of the lead acid battery of the present invention and the control lead acid battery.

FIG. 5 is a comparative graph of the JIS light load life at 80 ° C. of the lead acid battery of the present invention and the control lead acid battery.

[Explanation of symbols]

1 Positive electrode plate 2 Negative electrode plate 3 Fiber mat 4 Synthetic resin separator

Claims (2)

[Claims] 1. 0.03 to 0.09% by weight of Ca, Sn
A fiber mat and a synthetic resin separator are provided between a positive electrode plate and a negative electrode plate, which are formed by filling a grid substrate cast with an alloy of 1.05 to 1.50% by weight and the balance of lead with a paste positive electrode active material. A lead acid battery comprising an electrode plate group including the fiber mat facing the positive electrode plate surface. 2. The lead acid battery according to claim 1, wherein one or both of the fiber mat and the synthetic resin separator are leaf-shaped or bag-shaped.