JPS62278755A - Manufacture of cathode plate for alkaline storage battery - Google Patents

Abstract

PURPOSE:To increase quick discharge performance of a cathode by washing out concentrated raw salt in pores in a substrate after finishing intermediate drying process in cathode plate impregnation process to retard blockage of pores, and impregnating active materials. CONSTITUTION:A sintered nickel substrate is immersed in a raw salt solution, dried at temperature higher than heat decomposition temperature of the raw salt to concentrate the raw salt solution. The surfaces of the sintered nickel particles are corroded with concentrated heated salt and the corroded layer is converted into active material layer. The substrate is immersed in warm water or warm dilute raw salt solution to wash out the concentrated raw salt solution left in pores in the substrate. Thereby, the amount of hydroxide of the raw salt to be produced in the next alkali-immersion process is controlled to retard blockage of pores. After that, active material is impregnated to continue impregnation process of a cathod plate for alkaline storage battery. Therefore, formation of coarse active material is prevented, and quick discharge performance of the cathode can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a method for manufacturing an anode plate for a rapid discharge type alkaline storage battery.

Conventional technology The anode plate of a conventional alkaline storage battery is made by impregnating a sintered nickel substrate with an aqueous raw salt solution, and then immersing it in an alkaline aqueous solution to remove the raw salt in the pores of the substrate from the water containing the raw salt, which is the anode active material. It is produced by converting it into an oxide.

Problems to be solved by the inventionIn recent years, Alka 11 storage for toys and power tools has been developed.
? As demand for batteries increases, improvements in rapid discharge performance are desired. It has become essential to increase the utilization rate of active materials during rapid discharge. However, it has been found that with conventional active material manufacturing methods, rapid discharge performance does not improve even if the capacity is increased.

The anode plate manufactured by the above manufacturing method has shortcomings such as a short capacity during rapid discharge and a decrease in discharge N'M and pressure at the end of discharge.

Means for Solving the Problems The present invention eliminates the above-mentioned drawbacks by washing out the concentrated raw material salt remaining in the pores of the substrate after the intermediate drying in the anode plate impregnation process, and cleaning the pores in the pores. This is to regulate the amount of active material filled.

By washing out the thick raw material salt remaining in the pores after the intermediate drying of the working anode plate impregnation process, only the raw material salt deposited in solid form is present in the pores, and this raw material salt is used for the next process. Since it replaces the alkaline aqueous solution in the process and becomes hydroxide, many fine voids are formed in the active material layer within the pores, which increases the amount of electrolyte retained in the electrode plate and closes the pores. Diffusion of the electrolyte into the interior can be facilitated.

Furthermore, since the formation of a coarse active material is suppressed, the diffusion distance of protons in the active material is shortened, and the diffusion resistance of protons can be reduced.

The raw material salt aqueous solution of the example was a nickel nitrate aqueous solution containing L~twt% of cobalt nitrate or cadmium nitrate (ratio M1.70.pH2 at a liquid temperature of 50°C), and the raw material salt aqueous solution with a low concentration was a liquid temperature of 6o'. Specific gravity at c: 1.20. An aqueous solution with a pH of 4 was used, and even in the case of hot water, the liquid temperature was 60'C. In addition, immersion was performed for 2 to 5 minutes. Moreover, 2QWtl of sodium hydroxide aqueous solution was used as the alkaline aqueous solution. For intermediate drying, the furnace atmosphere temperature was set to t2o'c, and the drying time was 10 minutes.

Figure 1 shows the observation results of the active material inside the pores when a sintered nickel substrate (P50Kw50XtO, 55°C) was used and the active material was filled into the substrate according to the conventional manufacturing method and the manufacturing method according to the present invention. . From FIG. 111, it can be seen that the active material produced using the production method according to the present invention is smaller than that produced by the conventional production method, and that voids exist in each active material.

Next, a part of this electrode plate (/312xw12) was charged in an excess potassium hydroxide aqueous solution of C131,2VVtl using a platinum mesh as a counter electrode at a theoretical volume of 1.50 for 1ζ, and then discharged at 100. The anode potential was measured. From this result, it can be seen that the C-th discharge capacity is large and the discharge potential also remains high.

Effects of the Invention As described above, according to the present invention, the amount of active material filled in the pores of the sintered nickel substrate is regulated, voids are formed in the active material layer, and formation of coarse active material is suppressed. This has great industrial value, as it can improve the rapid discharge characteristics of the anode.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the observation results of active materials of the anode plate obtained by the present invention and the anode plate obtained by the conventional manufacturing method, and Fig. 2 is an explanatory diagram showing the active material observation results of the anode plate obtained by the present invention and the anode plate obtained by the conventional manufacturing method. FIG. 3 is a comparison diagram showing the rapid discharge characteristics of anode plates. 1 is an anode plate manufactured by the manufacturing method of the present invention, and 2 is an anode plate manufactured by the conventional manufacturing method for the patent in Shin-Kobe TFF! Co., Ltd. Representative Director Yasuo Sakurai Figure 2

Claims (1)

[Claims] A sintered nickel substrate is immersed in a raw salt aqueous solution, intermediately dried, then immersed in an alkaline aqueous solution to deposit the hydroxide of the raw salt as an active material within the substrate, followed by washing with water several times to obtain a specified amount. In the anode plate impregnation operation in which active material is filled into a substrate to form an anode plate, the substrate is immersed in a raw salt aqueous solution, and then intermediate drying is performed at a temperature higher than the thermal decomposition temperature of the raw salt to concentrate the raw salt aqueous solution and sintered. After corroding the surface layer of the nickel particles with the concentrated hot raw material salt and turning the corroded layer into an active material, the substrate is immersed in warm water or a hot aqueous solution of the raw material salt with a low concentration, so that it remains in the pores of the substrate without solidifying. This method is characterized by washing out the concentrated raw material salt, regulating the amount of hydroxide in the raw material salt produced in the next step of alkaline immersion, suppressing pore clogging, and filling the pores of the substrate with active material. A method of manufacturing an anode plate for a storage battery.