JPH0426058A - Manufacture of nickel electrode plate - Google Patents

Abstract

PURPOSE:To improve the use efficiency of an active substance and production efficiency by oxidizing an active substance of a mixture of nickel hydroxide and a cobalt compound with an oxidizing agent, and using the resultant material. CONSTITUTION:CoO is mixed with spheroidal nickel hydroxide containing 5 wt.% of cadmium hydroxide in 5 : 95 weight ratio and the mixed active mass is thoroughly mixed in an aqueous solution with 1.25 specific gravity and containing mainly potassium hydroxide. Next, K2S2O8 with more than or equal to the molarity of the CoO is added until oxygen gas is generated and the mixed active mass is filtered, washed with water, dried, and a paste is prepared from the active mass and a nickel fiber porous body is impregnated with the paste. Then, after drying and pressing the nickel porous body, teflon coating is carried out on the surface to obtain a nickel electrode plate. Consequently, the use efficiency of the active mass is improve and production efficiency is heightened and electrode plates with low cost and no need of formation are obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing Nifke/l' plates for use in 7-potassium storage batteries.

Conventional technology and its problems Conventionally, paste acid didandruff ~ electrode plates were made from hydroxide didruff ~ 1
~30vt% cobalt monoxide (hereinafter referred to as Coo)
M combination, methyl cellulose (MC), power ~ Boki V Mechi ~
A paste was prepared using an aqueous solution of cellulose (OMG), and the paste was filled into a nickel fiber porous body. This nickel electrode plate is made by dissolving CoO in an electrolyte, β-00(OH)2
As = y μ μ fiber current collector and redeposited around the Nikke μ active material. For this reason, an aging step is usually required for about 1 to 3 days, in which the solution is left to stand after injection. Thereafter, a conductive network of β-0000H was formed by charging, resulting in a nickel electrode plate with excellent discharge performance. Without the aging step, the COO dissolution reaction (ml, β-
Co(OH)2 precipitation reaction (bl is hardly produced,
Formation reaction (C) of a conductive network, (the formation of a conductive network becomes difficult and the utilization rate of the active material decreases.

cOo+on-1 → acoo2 , -・・・・−
・(mlac0o2−+H2O→ β-co(OH)2 + Of −・−−−−−−(b
) ECo02−→C000H+ e −・−−−
--(clβ-co(OH)2→β-C000H+H2
O+6 ''= (+11) For this purpose, it is necessary to allow sufficient ashing time and then chemical formation by charging.However, since the solubility of cobalt ρF is low and the amount of electrolyte is small, sufficient dissolution cannot be achieved. Formation of a conductive network required repeated charging and discharging for several nitals, resulting in poor productivity.

Purpose of the Invention The present invention was made in view of the above-mentioned conventional problems, and an object thereof is to provide an inexpensive nickel electrode plate that has an excellent active material utilization rate, high production efficiency, and does not require chemical conversion. It is something.

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is a method for producing a nickel electrode plate, which is characterized in that a nickel electrode plate prepared by mixing nickel hydroxide μ with a cobalt compound is oxidized with an oxidizing agent.

Further, the method for producing the nickel electrode plate described above, in which the cobalt/I/) compound is cobalt monoxide;
This is a method for manufacturing the above-mentioned nickel electrode plate having 2s2oB.

Example The details of the present invention will now be explained by way of an example.

000 having a particle size of 1 mm and a surface area of 70'/9 was mixed in a weight ratio of 95:25 to spherical nickel hydroxide μ containing 5 vt% of hydroxide. This mixed active material has a specific gravity of 1.
No. 25 was added to an aqueous solution mainly consisting of potassium hydroxide and stirred thoroughly.

Next, ICK2S2O11 was added until the number of cracks of OoO or more was reached and oxygen gas was generated. The mixed active material was passed through, washed with water, and dried. This active material was made into a paste with a CMC solution and filled into a nickel fiber porous body. After that, it was dried at 80° C. for 1 hour and then pressed, and the surface was coated with Teflon to obtain a nickel electrode plate. A negative electrode plate made of a paste-type cadmium electrode plate, a polyamide nonwoven fabric, and the nickel electrode plate were combined, and an aqueous potassium hydroxide solution having a specific gravity of 1.25 was injected to obtain a battery with a nominal capacity of 2.0 μh.

For comparison, a similar nickel electrode plate was obtained by making a paste of spherical hydroxide (dandruff) containing 5 vt% of cadmium hydroxide in a CMC solution.

(Unoxidized active material) Using this unformed 27 μm electrode plate and the paste-type cadmium electrode plate described above, a conventional battery was obtained by assembling, injecting liquid, and chemically charging.

Using a battery using the nickel electrode plate of the present invention (the present invention) and a battery using the conventional nickel electrode plate (conventional product), the discharge characteristics of items 1 to 3 were investigated, and the results are shown in Figure 1. It was shown to.

In addition, after charging for 11 hours with a current of 0.1 Cm, the current of discharge was 0.
．． It was discharged at 2C.

In the present invention, the discharge capacity is constant from the first to the third, and the discharge time is excellent.

On the other hand, conventional products required stabilization of discharge capacity of IC3 or more.

This is because in the conventional product, when C00 is electrically charged, it does not become completely ICCoooH in the initial stage, and the conduction efficiency is low, so that the charging/discharging reaction cannot be performed sufficiently.

On the other hand, in the present invention, all C00 in the nickel electrode active material is changed to C60OH by the oxidizing agent, and a complete conductive network is formed.

In the above examples, 282 o@ was used as the oxidizing agent, but oxidizing agents with equivalent oxidizing power such as NazSz
Oa, CHEa) 25top II ttt>lever 1 similar effect i is obtained. [282O6 is the best because it has excellent oxidizing power, is safe, easy to handle, and inexpensive.

Effects of the Invention As described above, the present invention has great industrial value because it can provide an inexpensive nickel electrode plate with excellent active material utilization, high production efficiency, and no need for chemical conversion.

[Brief explanation of drawings]

FIG. 1 is a comparison diagram of the discharge characteristics of the battery of the present invention and a conventional battery. Lu Ganjin Intestine Co., Ltd. Figure 1 10 2O 30 40 50 60 70 80 9
0 100 (%) Utilization Rate Procedural Amendment (Voluntary) ] Name of the invention indicated in the case Process for manufacturing nickel electrode plates 3゜Relationship with the case

Claims (3)

[Claims] (1) A method for producing a nickel electrode plate, characterized in that a nickel electrode plate prepared by mixing nickel hydroxide with a cobalt compound is oxidized with an oxidizing agent. (2) Claim 1 wherein the cobalt compound is cobalt monoxide.
The method for producing the described nickel electrode plate. (3) The method for producing a nickel electrode plate according to claim 1, wherein the oxidizing agent is K_2S_2O_8.