JPS58126671A - Manufacture of cathode plate for alkaline storage battery - Google Patents

Abstract

PURPOSE:To improve capacity density by adding a benzene derivative to a nickel salt aqueous solution of an electrolyte. CONSTITUTION:About 3% carboxymethylcellulose aqueous solution is added to carbonyl nickel powder to make paste. This paste is applied to a nickel plated perforated steel plate and dried, and sintered in a reducing atmosphere at about 900 deg.C to obtain a substrate having about 80% porosity. When 2,7 sodium naphthalenedisulfonate is added to a solution in an active mass filling process, a fine nickel hydroxide active mass 4 is formed and filled in order from the innermost pore of the substrate, and filled densely in pores of the substrate. Therefore, capacity density is increased. Sodium saccharinate as well as sodium 2,7- naphthalenedisulfonate is used as a benzene derivative.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to improve the capacity density of an anode plate for an alkaline storage battery.

The method for producing an anode plate for an alkaline storage battery includes (a) impregnating nickel salt into the pores of the substrate, and then decomposing the nickel salt in an aqueous solution of potassium hydroxide or hydroxide to form nickel hydroxide. (c) A method of impregnating nickel salt into the pores of the substrate and then thermally decomposing it at about 230° to 240°C to form nickel hydroxide; (c) Injecting nickel salt into the pores of the substrate. There is a method in which nickel hydroxide is formed by a chemical reaction by impregnating it with salt and then impregnating it with an aqueous solution of potassium hydroxide or sodium hydroxide. All of these required repeating the impregnation-reaction operation several times, and considering economic efficiency, the capacity density was about 330 mAh/crn3.

On the other hand, as a method for eliminating repetition of operations, there is a method (d) in which nickel hydroxide is formed by decomposing the substrate in an aqueous solution of nickel salt, using the substrate as a cathode. In this method, nickel hydroxide is formed in the pores of the substrate in an aqueous solution of dikel salt as a material, and since the material is continuously supplied, repetition is unnecessary. However, when this method was carried out under favorable conditions, the capacity density was about 330 mAh/1-rn3, similar to the other three methods. The present invention is (d
) is an attempt to improve capacity density.

Carbonyl nickel powder is made into a paste with an approximately 3% aqueous solution of carpoxymethyl cellulose.

Thickness: 80μ, pore diameter: 15φ, L″
A nickel-plated perforated steel plate from Tsuchi 25 Kaku is used as the core material, and after coating and drying, it is sintered at approximately 900℃ in a reducing atmosphere.
The substrate has a porosity of about 80%.

Next, the active material is filled under the following conditions.

That is, an electrolytic solution in which 2,7 naphthalene/sodium nosulfonate is added to a nickel nitrate solution having a specific gravity of 1.30 (80° C.) at 0, and 10 m9 of nickel nitrate aqueous solution 11 is used for B is used. Then, using a nickel plate as a mating plate, the mold was demolded for 30 minutes at a current density of 8 A/dm2. Thereafter, it is washed with water, dried, and chemically converted by a well-known method to form an anode plate.

Regarding the electrode plates A and B that have undergone chemical formation, the specific gravity is 1.26 (
The capacity was measured in a potassium hydroxide aqueous solution at 20° C. using a nickel plate as a counter plate.

Full K: 0. I CmAX 16h discharge: 0.2
The results up to CmA, -1, OV are shown below.

From the above, the capacity density of electrode plate B in which 2,7-naphthalene-nosulfonic acid sodium was added to the electrolytic solution was improved by about 10 cm. To explain this point, Figures 1 to 3
The figure shows how the active material is filled into the pores of the substrate. Figure 1 is the substrate, 1 is the hole, 2 is the core material, 3 is the nickel powder, and Figure 2 is the filling of the active material. When not added, FIG. 3 shows the filling situation of each active material 4 when a benzene derivative is added. As can be seen from this figure, when 2,7-naphthalene/sodium nosulfonate is added, it becomes fine nickel hydroxide as shown in Figure 3, and the filling progresses from the depths of the pores of the substrate, filling them densely into the pores of the substrate. On the other hand, if 2,7 naphthalene/nosulfonic acid sodium is not added, there will be a portion that adheres to the surface of the substrate as shown in Figure 2, and the pores of the substrate will only be roughly filled. Since the capacitance density is not increased, the capacitance density becomes small.

Although sodium 2,7-naphthalinosulfonate has been described as the benzene derivative, sodium saccharinate may also be used, or both may be added.

As described above, according to the present invention, capacity density can be improved by adding a benzene derivative to an aqueous solution of a nickel salt.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the substrate, Figure 2 is a diagram showing the active material filling situation when no additives are added, and Figure 3 is a diagram showing the active material filling status when additives are added. . 1... Hole, 2... Core material, 3... Nickel powder, 4
...Active material.

Claims (1)

[Claims] (1) Make carbonyl nickel powder into a paste,
After coating and drying a core material made of a perforated steel plate, the sintered porous substrate is decomposed in an aqueous solution of salt that forms the active material.
A method for producing an anode plate for an alkaline storage battery, which is produced by forming nickel hydroxide in the pores of a porous substrate, characterized in that a benzene derivative is added to an aqueous solution of a nickel salt. . A method for producing an anode plate for an alkaline storage battery according to claim (1), characterized in that one or both of these are added together.