JPH05325952A - Zinc plate for alkaline zinc storage battery - Google Patents

Abstract

PURPOSE:To provide an alkaline zinc storage battery excellent in a charge/ discharge cycle by preventing a fluctuation of thickness of a zinc plate and a decrease of pressure in the inside of the battery to fixedly hold the pressure, even in the case of decreasing the volume of active material of the zinc plate for the alkaline zinc storage battery due to a shape change or densification. CONSTITUTION:A collector 1 is punched into honeycomb shape, to provide the thickness equal to that of a plate, and this space part is filled with an active material 2 mainly composed of zinc and zinc oxide. In this way, even when the active material 2 is decreased, the pressure inside a battery is fixedly maintained by fixedly holding the thickness of the plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core metal shape of a zinc electrode plate for an alkaline zinc storage battery.

[0002]

2. Description of the Related Art Conventionally, a core plate of a zinc electrode plate is obtained by punching a thin plate of copper or copper alloy by punching, a net of copper wire or silver wire, or arranging them in a radial pattern at a terminal portion. It is a summary of these, and the sheet-shaped active material using Teflon as a binder is preliminarily pressure-bonded to both of these cores, or a paste prepared with a binder such as carboxymethyl cellulose is applied, or powdered active materials are used. It is common to form a zinc electrode plate by arranging a substance on the upper and lower sides of a core metal and pressing it to form it.

Therefore, the active material is formed on both surfaces of the cored bar in the battery with a predetermined thickness, and the tension in the battery is also kept constant.

[0004]

However, as is well known in the above-mentioned conventional zinc electrode plate, a so-called shape change in which the active material moves to the center by repeated dissolution and precipitation,
The thickness changes as the charge and discharge cycle progresses due to the so-called densification, in which the active material is densified by the growth of the zinc metal crystals, and the pressure inside the battery decreases or the pressure does not become constant, so However, there is a drawback that the internal resistance of is increased.

Incidentally, a core metal shape having a honeycomb structure has heretofore been known as seen in Japanese Utility Model Laid-Open No. 63-184562. However, the present invention has been described as an example of a lead battery current collector, and the effects and objectives of the present invention are completely different.

The present invention solves the above-mentioned drawbacks of the prior art and prevents the variation in the thickness of the zinc electrode plate even when the active material of the zinc electrode plate is reduced in volume due to shape change or densification. The purpose is to prevent the internal pressure of the battery from decreasing and to keep the internal pressure constant, and to supply an alkaline zinc storage battery having an excellent charge-discharge cycle.

[0007]

To achieve the above object, the present invention is directed to forming a frame body by punching copper or a copper alloy into a honeycomb shape, the frame body portion having the same thickness as the electrode plate, and the space portion By filling the active material into a zinc electrode plate,
Even when the volume of the active material is reduced due to the densification due to the movement of the active material and the crystal growth, the thickness of the zinc electrode plate is suppressed by using the thickness of the core metal of the electrode plate.

[0008]

[Function] Even if the active material moves or decreases due to shape change or densification, the core metal is a honeycomb-shaped frame body, so that the thickness of the electrode plate is guaranteed and the tension inside the battery is reduced. Can be prevented. By preventing the decrease in the tension, the internal resistance of the battery can be prevented from increasing and the life of the battery can be extended.

[0009]

EXAMPLES Examples will be described below for the details of the present invention.
This will be described in comparison with the comparative example.

First, a method for manufacturing a zinc electrode plate for a storage battery according to the present invention will be described. Zinc oxide and metallic zinc were mixed in advance, and a sheet-shaped zinc active material layer with a thickness of 1 mm was created by the calender roll method. And pressurize filling,
A zinc electrode plate having a size of 10 cm × 9 cm and a thickness of 1 mm was obtained. The active material may be applied by a pasting method.

A battery A using the zinc electrode plate thus obtained is shown in FIG. Although only a part of the honeycomb portion of the zinc electrode plate in FIG. 1 is shown, the details are shown in FIG.
Further, FIG. 3 shows a cross section of the electrode plate. 1 to 3, reference numeral 1 denotes a core metal portion of the honeycomb electrode plate, and 2 denotes an active material portion of the honeycomb electrode plate.

A battery A of 15 AH was prepared by combining 7 sheets of the zinc electrode plates according to the present invention and 6 sheets of sintered nickel electrode plates of the same size which were packed in a bag shape with a microporous film separator and a non-woven fabric. did.

For comparison, the conventional thickness is 0.1 mm.
A battery B was manufactured by using a 1 mm thick zinc electrode plate obtained by press-molding the above sheet-like active material against a copper punching metal current collector having an opening ratio of 50%.

Next, using 10 batteries A each having the structure of the present invention and 10 batteries B using a conventional punching core metal,
A discharge current of 7.5 A was discharged for 12 Ah (80% of the actual capacity), a charging current was 1.5 A, and a charge amount was 105% of the discharge amount.

The results are shown in FIG. In each case, the initial discharge capacity was set to 100 and the relationship between the charge / discharge cycle and the capacity change was shown. At the beginning of the cycle, battery A and battery B are almost the same, but it can be seen that the discharge capacity of battery B decreases faster as the charging / discharging cycle progresses. It is considered that this is because the discharge voltage dropped due to the drop in the tension in the storage battery, causing the capacity to decrease.

[0016]

As shown in the examples, the zinc electrode plate of the present invention keeps the electrode plate thickness constant even when the active material is reduced,
Since the tension in the battery can be maintained constant, it is possible to provide a long-life alkaline zinc storage battery that can prevent deterioration of discharge characteristics and capacity decrease due to charge / discharge cycles over a long period of time.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a storage battery using a honeycomb type zinc electrode plate of the present invention.

FIG. 2 is a partially enlarged front view of the honeycomb type zinc electrode plate of the present invention.

FIG. 3 is a partially enlarged plan view of the honeycomb type zinc electrode plate of the present invention.

FIG. 4 is a diagram showing a change in battery capacity during a charge / discharge cycle.

[Explanation of symbols]

 1 Core metal part of honeycomb type zinc electrode plate 2 Active material part of honeycomb type zinc electrode plate

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takehito Bogai 6-6 Josaimachi, Takatsuki City, Osaka Prefecture Yuasa Battery Co., Ltd.

Claims (2)

[Claims] 1. A zinc electrode plate for an alkaline zinc storage battery, wherein the current collector has a shape punched into a honeycomb shape, and the space portion is filled with an active material containing zinc and zinc oxide as main components. 2. The zinc electrode plate for an alkaline zinc storage battery according to claim 1, wherein the thickness of the honeycomb current collector is the same as the thickness of the electrode plate.