JP2001229958A - Sealed lead-acid storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealed lead-acid storage battery, that is maintenance-free and superior in high-efficient discharge characteristics and cycle-life characteristics. SOLUTION: By laminating clad-type cathode plates 1 and paste-type anode- plates 3 via retainers, a closed-type lead-acid storage battery is produced. Then, in the space 8 between the clad-type cathode plates 1 and the retainers 2, a sticklike porous body 9, which has an approximately triangular cross section and is superior in oxidation-resistance, is arranged.

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 using a clad-type positive electrode plate.

[0002]

2. Description of the Related Art A clad type positive electrode plate is generally used as a positive electrode plate for a lead storage battery such as a forklift which repeats deep charging and discharging. The clad-type positive electrode plate has a feature that the active material is long and has a long life because it is wrapped in a tube made of glass or synthetic resin fibers. That is, in a general paste-type positive electrode plate, the binding between active material particles is broken by repeated charge and discharge, and the discharge capacity is reduced due to softening and falling off of the active material. On the other hand, in the case of the clad type positive electrode plate, since the active material is wrapped in the tube, it is possible to prevent the active material from falling off due to charge and discharge.

Recently, there has been a strong demand for maintenance-free and high-capacity lead-acid batteries using clad-type positive plates. As a method of maintaining and freeing lead-acid batteries using clad-type positive plates, there is already a technology for manufacturing sealed lead-acid batteries by using lead-calcium-tin alloy for the core metal and impregnating the retainer with electrolyte. Established However, when this method is used, as shown in FIG. 2, a portion where the tube 6 of the clad type positive electrode plate does not contact the retainer 2, that is, a space 8 is formed. Therefore, the positive electrode active material in contact with the space 8 has a problem that the supply of the electrolytic solution is insufficient, the high-rate discharge characteristics are reduced, and the life is shortened at an early stage.

[0004] In view of the above, a method of preparing and using a separator having an uneven portion in accordance with the shape of the clad type positive electrode plate is considered. However, there are problems that it is technically difficult to manufacture such a separator and that the manufacturing cost increases.

On the other hand, as a means for solving the above-mentioned problems, Japanese Patent No. 2855693 discloses a method of filling fine silica powder around a clad type positive electrode plate. However, filling a fine inorganic powder around the clad-type positive electrode plate has a problem that it takes a lot of man-hours.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sealed lead-acid battery using a clad type positive electrode plate which is easy to manufacture and has excellent high rate discharge characteristics and cycle life characteristics. .

[0007]

In order to solve the above-mentioned problems, the present invention provides a rod-like porous material having excellent oxidation resistance and a substantially triangular cross section between a clad type positive electrode plate and a retainer. It is characterized by the presence of a body.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Preparation of clad type positive electrode plate A clad type positive electrode plate was prepared by a conventional method. That is,
A lead-calcium-tin alloy core metal is manufactured, the core metal is wrapped in a tube having a circular cross section in which glass fiber is woven, a powder mainly composed of lead monoxide is filled, and the lower end of the tube is made of resin. by closing Made in the lower complicity 7 to injection molding, dimensions, to prepare a cladding-type positive electrode plate 1 of ^{l 220mm × w 145mm × t 7.5mm} ( Fig. 3).

[0009] 2. Production of Sealed Lead-Acid Battery Between the tubes 6 of the clad-type positive electrode plate, a porous body 9 made of foamed polyethylene having a porosity of 90% and having a rod-like shape and a substantially triangular cross section is sandwiched (FIG. 1). Then, one clad-type positive electrode plate 1 and two 1.6 mm-thick retainers 2 made of glass fiber on both surfaces thereof are combined and arranged. On the outside thereof, the dimensions are ^l 220 mm × ^w 145 mm × ^t 3.0 mm.
An electrode plate group (FIG. 3) is prepared using two of the paste type negative electrode plates 3 described above, and the electrode plate group is inserted into a battery case. Thereafter, an electrolyte was injected to produce a sealed lead-acid battery having a nominal capacity of 36 Ah-2V.

The manufacturing conditions of the paste type negative electrode plate 3 and
The assembling conditions and the like of the sealed lead-acid battery are exactly the same as the conventional one. According to the present invention, as shown in FIG. 1, between the tubes 6 of the clad-type positive electrode plate, there is a porous body 9 having a substantially triangular cross section. Can be created.

3. Discharge rate test After the fabricated lead-acid battery was fully charged, it was discharged at 25 ° C at 0.1CA, 0.2CA, 0.5CA and 1.0CA, respectively (discharge end voltage: 1.6
V) and the discharge capacity was measured.

4. Life test The sealed lead-acid battery whose initial discharge capacity was measured was subjected to a cycle life test at 25 ° C. Discharge condition: 0.23CA for 3 hours Charge condition: 2.45V constant voltage for 8 hours (Limit current is 0.
3CA) These sealed lead-acid batteries were fully charged every 100 cycles, and then discharged at a constant current of 0.1 CA to 1.8 V (discharge end voltage) to measure the discharge capacity.

[0013]

An embodiment of the present invention will be described.

Example 1 A sealed lead-acid battery having a structure in which a porous body 9 was sandwiched outside a tube 6 having a circular cross section according to the present invention was prepared and tested (FIG. 1). In addition, the manufacturing conditions and test conditions of the sealed lead-acid battery are as described above.

Comparative Example 1 A conventionally used closed lead-acid battery was prepared and tested (FIG. 2). That is, the porous body 9 is not provided outside the tube 6. In addition, the manufacturing conditions and test conditions of the sealed lead-acid battery are as described above.

FIG. 4 shows the discharge rate test results of these batteries. When the present invention is used, the high rate discharge capacity is particularly excellent as compared with Comparative Example 1.

FIG. 5 shows the results of the cycle life test. The life of Comparative Example 1 was about 1000 cycles, but the capacity of 70% or more of the initial capacity was maintained after 1600 cycles using the present invention.

By using the present invention, the space 8 between the clad-type positive electrode plate 1 and the retainer 2 can be reduced, and the diffusion of the electrolytic solution is improved. It is thought to be easier. Since the present invention is a sealed lead-acid battery, it goes without saying that it is maintenance-free.

[0019]

As described above, the use of the present invention is excellent because it can provide a sealed lead-acid battery which is maintenance-free and has excellent high rate discharge characteristics and cycle life characteristics.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a sealed lead-acid battery using the present invention.

FIG. 2 is a sectional view of a main part of a conventional sealed lead-acid battery.

FIG. 3 is a schematic diagram showing a configuration of a clad-type sealed lead-acid battery.

FIG. 4 is a discharge rate test result of a sealed lead-acid battery.

FIG. 5 shows a cycle life test result of the sealed lead-acid battery.

[Explanation of symbols]

1: clad type positive electrode plate, 2: retainer, 3: paste type negative electrode plate, 4: cored bar, 5: positive electrode active material, 6: tube, 7: lower joint 8: space, 9: porous body

Claims (2)

[Claims] 1. A sealed lead-acid battery in which a clad-type positive electrode plate and a paste-type negative electrode plate are stacked via a retainer, wherein a porous body having excellent oxidation resistance is provided between the clad-type positive electrode plate and the retainer. A sealed lead-acid battery characterized by the presence of: 2. A sealed lead-acid battery according to claim 1, wherein said porous body is a rod-shaped one having a substantially triangular cross section.