JPH11185762A - Electrode for lead-acid battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed lead-acid battery inhibiting accumulation of lead sulfate and having a long life and excellent weight efficiency. SOLUTION: This electrode for a lead-acid battery is constituted by laminating resin sheets 3 having a great number of perforated holes 4 and metal sheets 1 having perforated holes 2 smaller than the perforated holes 4, and by filling an active material into the perforated holes 2,4. Here, the number of the perforated holes 2 of the metal sheets 1 communicating to the perforated holes 4 is set to be a plural number per one of the perforated holes 4 of the resin sheets 3.

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, and more particularly to an electrode for a sealed lead-acid battery, and more particularly, to a lead-acid battery electrode plate having excellent energy density and charge / discharge cycle life characteristics. It is.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for high-energy-density and long-life quality improvement in sealed lead-acid batteries, as typified by batteries for electric vehicles.
However, the tuber (cladding) type, which has been used for many years, can meet the demand for a relatively long life but cannot meet the demand for a high energy density.
A lead-acid battery using a paste-type electrode can easily meet the demand for a relatively high energy density, but the life property is greatly impaired by improving the energy density. That is, at present, there is a limit in achieving both high energy density and long life, and there is a problem that a material that sufficiently satisfies the requirements cannot be obtained.

[0003] As a method for solving such a problem, a resin sheet having a large number of through holes and a metal sheet having a through hole smaller than the through holes are laminated in Japanese Patent Application Laid-Open No. 7-254408. There is disclosed an electrode characterized in that a through hole is filled with an active material.

[0004]

In order to maintain a high energy density even in an electrode in which a resin sheet having a large number of through holes and a metal sheet are laminated and the through holes are filled with an active material. In addition to reducing the weight of the electrode, it is necessary to increase the utilization rate of the positive and negative electrode active materials. There is a problem in that lead sulfate accumulates in the substance and the life is extended.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sealed lead-acid battery which suppresses accumulation of lead sulfate, has a long life and is excellent in weight efficiency. To provide.

[0006]

In order to solve the above problems, the present invention provides a resin sheet 3 having a large number of through holes 4.
And a metal sheath having a through hole 2 smaller than the through hole 4.
In the lead-acid battery electrode in which the active material 5 is filled in the through holes 2 and 4, each of the through holes 4 of the resin sheet 3 has a metal sheet 1 communicating with the through hole 4. The number of the through holes 2 is plural.

[0007]

According to the present invention, a plurality of through-holes 2 of the metal sheet 1 communicating with the through-holes 4 of the resin sheet 3 are provided, so that the low-resistance metal sheet 1 which is a current collector and the high-resistance active material 5 are formed. For example, the distance a between the point A and the metal sheet 1 in FIG. 4 can be reduced as the distance b between the point A and the metal sheet 1 in FIG. Since the contact area increases, the electrode resistance can be reduced and the charging efficiency of the electrode can be improved. Therefore, accumulation of lead sulfate in the active material can be suppressed.

The distance can be shortened by reducing the number of the through holes 2 of the metal sheet 1 communicating with the through holes 4 of the resin sheet 3 to one, but the area of the metal sheet 1 increases. Since the amount of the active material 5 filled in the through holes 2 decreases, the capacity decreases and the weight increases.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an electrode showing an embodiment of the present invention before filling with an active material, FIG. 2 is a partially enlarged plan view of FIG. 1, and FIG. FIG. 2 is a partially enlarged plan view of the filled electrode, 1 is a metal sheet made of a Pb—Ca—Sn-based alloy, 2 is a circular through hole formed in the metal sheet 1, and 3 is a resin sheet made of ABS. Reference numeral 4 denotes a circular through hole formed in the sheet 3, and reference numeral 5 denotes an active material mainly composed of metallic lead or lead oxide. The metal sheet 1 is
The resin sheet 3 is laminated on each of the front and back sides, and these sheets are bonded together with an adhesive. As shown in FIG. 2, a plurality of through holes 2 of the metal sheet 1 communicate with the through holes 4 of the resin sheet 3, and the through holes 2 and 4 are filled with the active material 5.

In this embodiment, four through-holes 2 of the metal sheet 1 overlap with the through-holes 4 of the resin sheet 3 so that the number of the through-holes can be as long as the active material can be filled and processed. Preferably, it is large.

Next, the manufacturing method of the present invention will be described.

(Example) A resin sheet 3 having a thickness of 1.0 mm and a thickness of 0.8 mm was used as a positive electrode and a negative electrode, respectively.
After processing the through hole 4 with a hole opening ratio of 75%,
As shown in FIG. 2, the resin sheet 3 has four through holes 2 each having a diameter of 1.0 mm with respect to the through holes 4 and has a thickness of 0.2
A metal sheet 1 mm was placed on both sides as an intermediate layer and bonded with an adhesive. Next, the active material 5 is inserted into the through holes 2 and 4.
, And aged and dried to produce a positive electrode and a negative electrode of the present invention.

A group of five positive electrodes and six negative electrodes is formed between the positive electrode and the negative electrode with a separator made of a fine glass fiber mat having a thickness of 1.0 mm therebetween.
And charged for the first time after injecting the electrolyte, to produce a sealed lead-acid battery A having a nominal capacity of 38 Ah.

(Comparative Example) After processing a resin sheet 3 as in Example 1 as a positive electrode and a negative electrode, the resin sheet 3 was 2.0 mm in diameter with respect to the through hole 4 as shown in FIGS. The metal sheet 1 having a thickness of 0.2 mm and having the through holes 2 was disposed on both sides as an intermediate layer. Thereafter, a positive electrode and a negative electrode were produced in the same manner as in Example 1.

Using such a positive electrode and a negative electrode, a sealed lead-acid battery B was produced in the same manner as in Example 1.

(Test) The cycle life characteristics of the battery A produced in the example and the battery B produced in the comparative example were examined under the same test conditions. Table 1 shows the results.

The discharge is carried out at a temperature of 25 ° C. with a discharge current at a rate of 3 hours and a DOD of 80%. %
In this case, uniform charging was appropriately performed according to the decrease in battery capacity. The life was determined when the discharge capacity became 80% or less of the initial capacity, and the charge / discharge cycle was repeated until the life was reached.

[0019]

[Table 1]

From the results in Table 1, it can be seen that the through holes 2
Battery A in which a plurality of
It was confirmed that the life of the battery B was about 1.4 times longer than that of the conventional battery B. In addition, when each of the lead storage batteries A and B was disassembled at the end of their life, almost the same accumulation of lead sulfate was observed in both, and it was confirmed that the decrease in discharge capacity due to the accumulation of lead sulfate was the cause of the life, Battery A using electrode structure of the present invention
Showed that the accumulation of lead sulfate was suppressed and excellent charge-discharge cycle life characteristics were obtained.

In this embodiment, the through holes 2 and 4 of the metal sheet 1 and the resin sheet 3 are circular. However, the present invention is not limited to this.

[0022]

As described above, according to the present invention, since the distance between the current collector and each active material is shortened, the accumulation of lead sulfate can be suppressed, and the through hole of the metal sheet communicating with the through hole of the resin sheet can be suppressed. Since the area can be increased, a sealed lead-acid battery having a long life and excellent weight efficiency can be provided.

[Brief description of the drawings]

FIG. 1 is a plan view of an electrode showing an embodiment of the present invention before filling an active material.

FIG. 2 is a partially enlarged plan view of FIG.

3 is a partially enlarged cross-sectional view in which an active material is filled in a through hole of FIG. 1;

FIG. 4 is a partially enlarged plan view of a comparative example before filling with an active material.

FIG. 5 is a partially enlarged cross-sectional view of a comparative example after filling with an active material.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal sheet 2 Through hole of metal sheet 3 Resin sheet 4 Through hole of resin sheet 5 Active material

Claims (1)

[Claims] 1. A resin sheet (3) having a large number of through holes (4) and a metal sheet (1) having a through hole (2) smaller than the through holes (4) are laminated. In the lead-acid battery electrode wherein the through holes (2, 4) are filled with the active material (5), the through holes (4) of the resin sheet (3) are replaced with the through holes (2) of the metal sheet (1). Characterized by having a plurality of communicating with each other.