JPS62105370A - Manufacture of cathode plate for alkaline storage battery - Google Patents

Abstract

PURPOSE:To increase the filling quantity of active material and to improve the utilization of active material by immersing a sintered nickle base body into specific active material salt aqueous solution of low temperature then of high temperature. CONSTITUTION:Since aqueous solution of active material salt has storing acidity, it is held under low temperature to weaken the oxidizing force, thus relieving corrosion of sintered nickle during immersion so that the immersing time is lengthen. Consequently, since salt can be permeated sufficiently into the thin holes of the sintered base body the filling quantity of the active matrial is improved. Then it is immersed into salt aqueous solution having strong oxidizing force under high temperature for short time, thereby the sintered nickle is slightly dissolved and the surface of the nickle particle is activated. Therefore, the electrical conductivity of the nickle particle and the active material is en hanced so that it is possible to improve the utilization of active material.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an improvement in the manufacturing method of anode plates for alkaline storage batteries.

Conventional technology Conventionally, the anode plate of an alkaline storage battery is generally produced by dipping a nickel sintered substrate in an aqueous solution of a specified active material salt, and then substituting and depositing PVC hydroxide in the pores of the substrate in the alkaline aqueous solution. This is being done. Sh) Shi, due to the recent market needs for higher capacity, it is desired to improve the capacity and weight of Yogon plates.
It has become essential to increase the active material loading and improve the active material utilization rate. Therefore, what is the porosity of the nickel sintered substrate used to produce high capacity plates? A method of increasing the active material filling amount and a method of increasing the utilization rate by depositing cobalt hydroxide on the surface of an active material mainly composed of nickel hydroxide containing cobalt hydroxide have been proposed.

Problems to be Solved by the Invention Among the above preparation methods, the method of increasing the porosity of the sintered substrate to increase the amount of active material filled in the sintered substrate reduces the mechanical strength of the sintered substrate, resulting in repeated photodischarges. This method has the disadvantage that the sintered substrate peels off from the porous metal core due to the swelling of the active material that occurs.

In addition, in the method of depositing cobalt hydroxide on the surface of the active material as a nickel hydroxide component containing cobalt hydroxide 7 to improve the utilization rate of the active material, the content of cobalt hydroxide in the active material is high. Therefore, there are problems such as promoting the expansion of the active material.

Means for Solving the Problems The present invention eliminates the above drawbacks by immersing a nickel sintered substrate in a predetermined active material salt aqueous solution at low and then high temperatures. Since the aqueous solution f1 has strong acidity, the low temperature 1
By maintaining iH to weaken the oxidizing power and alleviate corrosion of the sintered nickel during immersion, it is possible to lengthen the immersion time and ensure sufficient penetration of the salt into the pores in the sintered substrate. Therefore, the amount of active material filled can be improved. Next, by immersing the sintered nickel in an aqueous salt solution with strong oxidizing power at high temperature for a short period of time, the sintered nickel is dissolved in water, and the surface of the nickel particles becomes an active material. It is possible to increase the electrical conductivity of the active material and improve the utilization rate.

Example An embodiment of the present invention will be described.

1 nickel sintered substrate (L50XW50XtO, 50)
~5 wt% of cobalt nitrate Y was immersed in a nickel nitrate aqueous solution with a liquid temperature of 50°C and a specific gravity of 1.70 for 30 minutes, and then immersed in the nickel nitrate aqueous solution with a liquid temperature of 85°C and a specific gravity of 1.70 for 5 minutes. After immersion, the operation of filling the active material in an alkaline aqueous solution and washing the alkali with water was repeated until a predetermined active material 'tt was obtained. Next, this electrode plate was used as a counter electrode with a nickel plate 7, and 0,2
After being photophotosensitive for 10 hours at 0 mA current, 0.20 m1
Figure 1 shows a comparison of the amount of active material filled when the impregnation operation was repeated four times. FIG. 2 shows a comparison of the active material utilization rate for the same amount of active material.

Effects of the Invention As stated above, the present invention has extremely great industrial value, such as being able to increase the total amount of active material loaded and improve the active material utilization rate.

[Brief explanation of drawings]

FIG. 1 is a comparison diagram of the amount of active material filled in an embodiment of the present invention and the conventional method, and FIG. 2 is a comparison diagram of the active material utilization rate in the field electrode plate obtained by each method.

Claims (1)

[Claims] In the impregnation process of an anode plate for an alkaline storage battery in which an active material is filled into a nickel sintered substrate, the sintered substrate is immersed in an aqueous solution of a predetermined active material salt at a low temperature, and then further immersed in the aqueous solution at a high temperature. 1. A method for producing an anode plate for an alkaline storage battery, the method comprising: then replacing salts in the sintered substrate with hydroxides in an alkaline aqueous solution.