JPS62126553A - Manufacture of cathode plate for sealed alkaline storage battery - Google Patents

Abstract

PURPOSE:To make quick charge possible by impregnating nickel oxide serving as active material in a sintered nickel substrate, immersing in an acidic solution to dissolve a part of active material and to expose a part of sintered substrate, then using as a cathode plate. CONSTITUTION:A sintered nickel substrate is immersed in nickel nitrate solution, an electrolytically reduce in potassium hydroxide solution to deposit nickel hydroxide. After impregnating a specified amount of active material, the substrate is immersed in sulfuric acid to dissolve 5-10% of active material and to expose a part of the sintered substrate. After that, formation is applied to the substrate in sodium hydroxide solution to form a cathode plate for sealed alkaline storage battery. The exposed part of the substrate evolves a small amount of oxygen gas from the initial stage of charge, and oxygen gas absorbing reaction in an anode plate is advanced and temperature within a battery is increased. Thereby, quick charge can be performed without operation of a safety vent.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing an anode plate for a nickel-cadmium storage battery (hereinafter referred to as rN i -Od battery) using a sealed alkaline storage battery method.

Conventional technology In general, anode plates for Ni-Cd batteries are manufactured using a cycle in which a sintered nickel substrate is immersed in an aqueous nickel nitrate solution, and then the same substrate is immersed in an aqueous potassium hydroxide solution while being electrolytically reduced to precipitate nickel hydroxide. After repeating 3 to 4 times,
It is obtained through chemical conversion in an aqueous sodium hydroxide solution, followed by washing with water and drying. In a Ni-Cd battery using this anode plate and a cathode plate made by the normal manufacturing method, o, t
A charging current of ~0.2 crnA is common and dusty.
The oxygen gas absorption performance of the cathode plate was also commensurate with this.

Problems to be Solved by the Invention Ni-
0d@When the battery is quickly charged at 1 to 1.5 nn N,
At the end of charging, oxygen gas generated from the anode plate is not completely absorbed by the cathode plate and accumulates inside the battery, causing an increase in internal pressure and causing the safety valve to operate. Further, the charging of the cathode plate progresses by the amount of oxygen gas released by the activation of the safety valve, and as it reaches a fully charged state, hydrogen gas is generated, and the safety valve is activated due to the increase in internal pressure. If the safety valve operates in this way and °C oxygen and hydrogen gas are repeatedly released to the outside of the battery, the life of the battery will eventually come to an end due to a decrease in the amount of electrolyte.

In view of the above, an object of the present invention is to obtain a novel positive one-electrode plate that does not operate the safety valve even during rapid charging and has a longer lifespan than conventional Ni-Cd batteries.

Means for Solving the Problems In order to achieve the above object, the present invention involves immersing an anode plate in which a nickel sintered substrate is filled with nickel oxide as an active material in an acidic aqueous solution to remove the active material on the surface of the electrode plate. The feature is that the nickel sintered substrate is exposed by melting.

The sintered nickel substrate exposed on the surface of the working anode plate generates a small amount of oxygen gas from the beginning of charging, which advances the oxygen gas absorption reaction at the cathode plate, and since this is an exothermic reaction, it increases the temperature inside the battery. Therefore, by the time the anode plate is fully charged at the end of charging and a large amount of °C oxygen gas is generated, the internal temperature of the battery has already risen, making it easy for the oxygen gas absorption reaction to proceed on the cathode plate. Therefore, faster charging is possible.

Example Next, one embodiment of the present invention will be described.

A slurry consisting of a methylcellulose binder solution and carbonyl nickel sintering metal powder is applied to a porous metal plate and then sintered in a hydrogen reducing atmosphere. This sintered substrate was placed in a nickel nitrate aqueous solution at a nickel concentration of 1O~204 and a temperature of 6.
0-70 "C)" and then immersed in an aqueous potassium hydroxide solution (concentration 10 to 15 winter, temperature 40 to 50 °C) while electrolytically reducing the current I with a trowel of 5 to LOA/d. The cycle of precipitating nickel hydroxide is repeated to secure a predetermined amount of active material.This substrate is bubbled in 1-2 N sulfuric acid and immersed in gamma for 15 minutes to deposit 50% of the active material.
After dissolving ~10 μm and exposing the sintered substrate, add a sodium hydroxide aqueous solution (concentration 20~30%, temperature 10 ~
After chemical conversion at 15°C, washing with water and drying, the anode plate was made into an anode plate.

The anode plate prepared by the above method was put through a separator made of synthetic fiber non-woven fabric and used as an electrode plate group together with the cathode plate prepared by a normal method.
Figure 1 shows a comparison of the quick charging performance of the inventive product and the conventional product using the standard model 几-8C (nominal capacity fi 1.2 Ah) as an example. 20°C)
It is charging. The product of the present invention has a battery internal pressure that is about one-third lower than that of conventional products, and can be said to have excellent rapid charging performance, that is, excellent oxygen gas absorption performance.

In addition, the life test results are shown in Figure C@2.

The test conditions were 1 cm A x 1 at an ambient temperature of 20"C.
After 5 h charging, the final voltage 1.1 cm at l cm A. The cycle of discharging up to Ov is repeated. It can be seen that the product of the present invention is superior to the conventional product in terms of life performance.

Effects of the Invention As described above, according to the present invention, by dissolving the active material on the surface of the anode plate and exposing the nickel sintered substrate, a battery can be charged more rapidly than conventional batteries. The fact that this makes it possible is of great industrial value.

[Brief explanation of drawings]

! Figure 1 is a comparative curve diagram showing the quick charging performance of the product of the present invention and the conventional product, and Figure 2 is a comparative characteristic diagram showing the life test results.

Claims (1)

[Claims] 1. A method for manufacturing an anode plate for a sealed alkaline storage battery, which comprises immersing an anode plate in which a nickel sintered substrate is filled with nickel oxide as an active material in an acidic aqueous solution to dissolve the active material on the surface of the electrode plate.