JP2002025602A - Lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen the life of a lead-acid battery by retarding the stratification of an electrolyte in the battery adopting expanded grid electrode plates, and enhance high rate discharge characteristics in the initial stage in use. SOLUTION: An electrode group is constituted by alternately stacking expanded grid positive electrode plates 2 each housed in a synthetic resin (polyethylene) bag-shaped separator 1 and expanded grid negative electrode plates 4 whose surface is attached with a glass fiber mat 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a lead-acid battery using an expanded grid electrode plate.

[0002]

2. Description of the Related Art A lead storage battery is a secondary battery having a good balance between performance and cost. As such a lead storage battery, there is one that employs an expanded grid electrode plate. For example, it is a lead storage battery provided with an electrode group in which an expanded lattice positive electrode plate and an expanded lattice negative electrode plate housed in a synthetic resin bag-like separator are alternately laminated via a glass fiber mat. The negative electrode plate has a paste paper made of cellulose fibers adhered to the surface thereof. This paste paper has a role of preventing adhesion of the negative electrode plates in the battery manufacturing process and preventing active material from falling off the negative electrode plate. The paste paper is gradually oxidized and decomposed by sulfuric acid as an electrolytic solution during use of the battery, and finally dissolved in the electrolytic solution.

[0003]

In the above lead storage battery, the negative electrode plate is contained in a bag-like separator, and the surface of the negative electrode plate is covered with paste paper in the early stage of use of the battery. There is a problem that the hydrogen gas generated from the plate surface does not sufficiently contribute to the stirring of the electrolyte, and the electrolyte tends to be stratified. In the early stage of battery use, paste paper not only causes an increase in electrical resistance,
It hinders the supply of the electrolytic solution to the negative electrode active material and lowers the high rate discharge characteristics. In particular, when the battery is used at a low temperature, the supply of the electrolyte is likely to be hindered because the viscosity of the electrolyte is high.

[0004] The problem to be solved by the present invention is to suppress the stratification of the electrolyte and prolong the battery life in a lead-acid battery employing an expanded grid electrode plate. It is another object of the present invention to improve the high-rate discharge characteristics at the beginning of use of the battery.

[0005]

In order to solve the above-mentioned problems, a first lead-acid battery according to the present invention has an expanded grid positive electrode plate housed in a synthetic resin bag-shaped separator and a glass fiber mat on the surface. It is characterized by comprising an electrode plate group in which the attached expanded grid negative electrode plates are alternately stacked.

In the lead-acid battery having such a configuration, since the negative electrode plate is not housed in the bag-shaped separator, the hydrogen gas generated from the negative electrode plate is not hindered by the presence of the separator and is sufficiently sufficient for stirring the electrolyte. Contribute. Further, since the electrolytic solution sufficiently penetrates into the glass fiber mat adhered to the surface of the negative electrode plate, the electric resistance is reduced and the high-rate discharge characteristics are improved.

A second lead-acid battery according to the present invention comprises an expanded grid positive electrode plate housed in a synthetic resin bag-shaped separator, and an expanded grid negative electrode plate having paste paper made of cellulose fibers adhered to the surface thereof. It is characterized by comprising an electrode group alternately laminated via a glass fiber mat.

[0008] In the lead-acid battery having such a structure, the electrode plate is not housed in the bag-shaped separator as in the case of the first lead-acid battery, so that the hydrogen gas generated from the negative electrode plate sufficiently contributes to the stirring of the electrolyte. I do. Further, although the paste paper is adhered to the surface of the negative electrode plate, the supply of the electrolytic solution is sufficient because the paste paper is not stored in the bag-like separator, and the high-rate discharge characteristics are improved.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The following embodiments of the present invention are examples in which an expanded lattice obtained by expanding a sheet of a calcium-lead alloy is used as a lattice of a positive electrode plate and a negative electrode plate. The synthetic resin bag-shaped separator uses polyethylene.
For example, a polyethylene sheet folded in a U-shape is formed into a bag shape by heat welding both sides. The paste paper made of cellulose fiber uses pulp as a raw material. It does not hinder the supplementary addition of other fibers such as synthetic resin fibers to make the paste paper.

Example 1 An expanded lattice obtained by expanding a lead alloy sheet containing 0.08% by mass of calcium and 1.1% by mass of tin was filled with 85 g of a paste-like positive electrode active material. This was aged for 18 hours in an atmosphere at a temperature of 50 ° C. and a humidity of 95%, and then dried at 110 ° C. for 2 hours to prepare an unformed positive electrode plate. An expanded lattice obtained by expanding a lead alloy sheet containing 0.08% by mass of calcium and 0.8% by mass of tin was filled with 73 g of a paste-like negative electrode active material. This filling was carried out by laying a mat formed by accumulating and entangled glass fibers having a diameter of 19 μm under an expanded lattice. Then, after filling the paste-like negative electrode active material, a glass fiber mat was also placed on the upper surface thereof and pressed with a roller to obtain an expanded grid negative electrode plate having the glass fiber mat adhered to the surface. The glass fiber mat is in a state of being cut into the negative electrode plate surface.
This was aged and dried in the same manner as the above positive electrode plate to prepare an unformed negative electrode plate. As the glass fiber mat, a material having a small thickness (glass paper) is used similarly to the paste paper. Figure 1
As shown in FIG. 1, the unformed positive electrode plate 2 housed in the polyethylene bag-like separator 1 and the unformed negative electrode plate 4 having the glass fiber mat 3 adhered to the surface thereof are alternately laminated to form an electrode group. Was configured. This is an electrode plate group including seven positive electrode plates and eight negative electrode plates. The above electrode group was housed in a battery case, an electrolytic solution having a specific gravity of 1.225 (at 20 ° C.) was injected, and formed with a current of 9 A for 42 hours to complete a lead storage battery.

Embodiment 2 In Embodiment 1, the glass fiber mat 3 is adhered to the surface of the negative electrode plate. In this embodiment, instead of this glass fiber mat, paste paper (0. 0
A non-formed negative electrode plate was prepared in the same manner as in Example 1 except that the thickness was 5 mm. As shown in FIG. 2, an unformed positive electrode plate 2 (Example 1) stored in a polyethylene bag-like separator 1
An unformed positive electrode plate similar to that described above) and the unformed negative electrode plate 4 having the paste paper 5 adhered to the surface thereof were alternately laminated via a glass fiber mat 6 to form an electrode plate group. This is an electrode plate group including seven positive electrode plates and eight negative electrode plates. The electrode group was housed in a battery case, and a lead-acid battery was completed in the same manner as in Example 1.

Conventional Example In the above-mentioned Example 2, instead of accommodating the unformed positive electrode plate 2 in the polyethylene bag-like separator 1, an unformed negative electrode plate 4 is housed. did. FIG. 3 shows the configuration of the electrode group.

In order to confirm the characteristics of the lead storage batteries of the above examples, three batteries were each subjected to a charge / discharge cycle test and a high rate discharge test. The charge / discharge cycle test was performed at an ambient temperature of 75
At 25 ° C., charge and discharge are repeated with one cycle of discharging at 25 A for 4 minutes and charging at 14.8 V for 10 minutes, and then left for 480 cycles for 56 hours. Thereafter, discharge is performed for 582A for 30 seconds, and the above-described charge / discharge cycle is repeated. 582A-discharge for 30 seconds, voltage at the 30th second is 7.2V
Table 1 shows the total number of charge / discharge cycles at that time when the battery life decreased to the average (average value of three batteries). In the high rate discharge test, the battery in the initial stage of use was set to the
After being left at 5 ° C. for 16 hours, a 300 A discharge was performed, and the voltage was measured 5 seconds and 30 seconds after the start of the discharge. In addition, the discharge duration time until the voltage dropped to reach 6 V was measured. These are shown in Table 1 (average value of three batteries).

[0014]

[Table 1]

From Table 1, it can be understood that the batteries of the examples have excellent battery life characteristics and high-rate discharge characteristics at low temperatures. The reason that the battery of Example 1 has a longer life than the battery of Example 2 is that the stirring of the electrolytic solution is performed more actively.
This is because stratification of the electrolytic solution is less likely to occur.
The reason why the battery of Example 1 is superior to the battery of Example 2 in the high rate discharge characteristics is that the electrolyte solution sufficiently penetrates into the glass fiber mat adhered to the surface of the negative electrode plate, so that the paste paper adheres. This is because the electric resistance is lower than in the case of being restricted, and the supply of the electrolytic solution to the active material is sufficiently performed.

[0016]

As described above, in the lead-acid battery according to the present invention, the glass fiber mat or the paste paper adhered to the negative electrode plate surface prevents the negative electrode plates from adhering to each other and the negative electrode active material from falling off in the battery manufacturing process. In addition, the battery life characteristics and the high-rate discharge characteristics at the beginning of use of the battery are excellent.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an electrode plate group in an embodiment of the present invention.

FIG. 2 In another embodiment of the present invention,
It is explanatory drawing which shows the structure of an electrode group.

FIG. 3 is an explanatory view showing a configuration of an electrode group in a conventional lead storage battery.

[Explanation of symbols]

 1 is a bag-like separator 2 is a positive electrode plate 3 is a glass fiber mat 4 is a negative electrode plate 5 is a paste paper 6 is a glass fiber mat

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuya Sasaki, 2-8-7 Nihonbashi Honcho, Chuo-ku, Tokyo Inside Shin-Kobe Electric Co., Ltd. (72) Yasushi Uraoka 2-87 Nihonbashi Honcho, Chuo-ku, Tokyo F term in Shin-Kobe Electric Co., Ltd. (reference) 5H021 AA06 CC01 CC04 CC18 EE11 EE28 5H028 AA05 BB03 CC01

Claims (2)

[Claims] 1. An electrode group comprising an expanded grid positive electrode plate housed in a synthetic resin bag-shaped separator and an expanded grid negative electrode plate having a glass fiber mat adhered to its surface, which are alternately laminated. Characteristic lead storage battery. 2. An expanded lattice positive electrode plate housed in a synthetic resin bag-shaped separator and an expanded lattice negative electrode plate having paste paper made of cellulose fiber adhered to the surface thereof alternately via a glass fiber mat. A lead-acid battery comprising a set of electrode plates.