JPH0353448A - Manufacture of closed type alkaline storage battery - Google Patents

Abstract

PURPOSE:To shorten the injecting time for an electrolyte by receiving an electrode group prepared through the process of combining positive and negative- pole electrodes together, with a separator interposed therebetween, in a canning body and subsequently injecting the electrolyte into the canning body while applying ultrasonic waves to the canning body. CONSTITUTION:Ultrasonic waves are applied to a canning body 1 in injecting an electrolyte into the canning body 1 to be permeated into positive and negative-pole electrodes and also into a separator after receiving an electrode group 2 prepared through the process of combining the positive and negative- pole electrodes together, with the separator interposed therebetween, in the canning body 1. Since the surface tension of the electrolyte to the separator and to the like can be accordingly lowered, the electrolyte can be quickly permeated into both the separator and the electrodes. Since also air present in the electrodes and in the separator, both received in the canning body, can be speedily removed permeability of the electrolyte can be expedited. The injecting time for the electrolyte can thus be shortened to mass-produce a storage battery.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Industrial Application Field) This paper relates to a method for manufacturing a sealed alkaline storage battery, and in particular, a method for manufacturing a sealed alkaline storage battery that improves the electrolyte injection process. related to.

(Prior Art) Alkaline storage batteries are known to use nickel for the positive electrode and cadmium, zinc, hydrogen storage alloy, etc. for the negative electrode. Among these, 2.7 Kel cadmium batteries in particular have been studied for a long time and are currently widely used. Nickel-cadmium storage batteries use so-called sintered electrodes, which are made of sintered nickel powder impregnated with an active material, but as the demand for higher capacity and lower cost increases in recent years, sintered electrodes are used as electrodes for nickel-cadmium storage batteries. Paste type electrodes have been actively developed in place of bonded type electrodes.

A sealed alkaline storage battery using the above-mentioned paste type electrodes is constructed by sandwiching a separator between the positive and negative electrodes, winding or laminating them in a prescribed manner, and then inserting the battery into a case and subjecting it to a prescribed amount of electrolysis. It is manufactured by injecting a liquid and sealing it.

As a method of injecting the electrolytic solution, a method has conventionally been mainly adopted in which the electrolytic solution is injected little by little into the cavity inside the can so that it directly seeps into the separator and electrodes housed within the can. However, this method has a problem in that when a highly concentrated alkaline electrolyte having a particularly high viscosity is used, the permeation into the separator or electrode is slow, the time required for injection is long, and productivity is lacking.

For this reason, as a rectangular device that shortens the injection time of the electrolyte, a rectangular device that increases the porosity of the electrodes and separators,
A separator? Masahiro applying hydrophilic treatment to ffitffi,
Alternatively, a method of reducing the pressure inside the can when pouring the electrolyte is being considered.

However, the method of increasing the porosity of the separator or electrode may reduce the insulation properties of the separator, reduce the liquid retention capacity, and reduce the electrode volume of other electrodes, resulting in a decrease in the electrode capacity. There are 17 between. Furthermore, if the separator or the TiS electrode is subjected to hydrophilic treatment, there is a risk that the resistance of the separator or the electrode may increase or the charging/discharging performance may deteriorate. Furthermore, the method of injecting the electrolyte while reducing the pressure inside the can has the problem of complicating the manufacturing process and raising the cost.

(Issue 8 to be solved by the invention) The present invention was made to solve the above three conventional problems, and it is possible to shorten the injection time of electrolyte through an extremely simple process, and to mass-produce sealed alkaline storage batteries. The aim is to provide a method for manufacturing.

[1000 Steps to Solve the Problems] The present invention stores an electrode group in which positive and negative electrodes are combined with a separator interposed in a can body, and then applies ultrasonic waves to the can body while moving the electrodes into the can body. This is a method for producing a sealed alkaline storage battery characterized by injecting an electrolyte into the battery.

As the positive electrode and the negative electrode, for example, a paste type electrode in which a conductive porous substrate having a three-dimensional structure is filled with a paste containing an active material can be used.

Examples of the conductive porous material having the three-dimensional structure include foamed metal, nickel sintered fiber material, metal plated fiber material, and the like. The paste-like material includes, for example, (1) a positive electrode active material such as nickel hydroxide, a binder such as carboxymethyl cellulose (CMC), methylcellulose, or sodium polyacrylate, a binder such as polytetrafluoroethylene, and water; Examples include paste-like materials for positive electrodes consisting of a composition of a solvent such as (1) a negative-electrode active material such as oxidizing power dominium, a binder such as polyvinyl alcohol, and a solvent such as ethylene glycol; I can do it. Note that, in addition to the paste type electrode described above, cadmium or a hydrogen storage alloy can be used for the negative electrode. In addition, β-
Co(OH)2 may also be added.

Examples of the above-mentioned separator include nylon G, G fiber,
It is formed from nonwoven fabric of polyacetal fiber.

As the means for applying ultrasonic waves to the can body, for example, a method of applying ultrasonic waves to the can body using the limb as a medium, a method of applying ultrasonic waves directly to the can body, etc. can be adopted. It is desirable to use such ultrasound with a MJit number b in the range 20kHz - IMHz.

Examples of the electrolytic solution include sodium hydroxide aqueous solution,
An alkaline electrolyte such as an aqueous potassium hydroxide solution can be used. Alternatively, electrolytic i& may be prepared by adding lithium to the sodium hydroxide aqueous solution and potassium hydroxide aqueous solution as necessary.

(Function) According to the present invention, when an electrolytic solution is injected into the can body and the seven-square gel lfk is infiltrated into the positive and negative electrodes and the separator inside the can body, ultrasonic waves are applied to the can body. By Electric A
Since the surface tension of the /4 liquid against the separator etc. can be lowered, the electrolytic solution can be quickly penetrated into the separator and electrodes.

Moreover, since the air in the electrodes and separators housed in the can can be quickly removed by applying ultrasonic waves, the permeability of electrolytic components can be promoted. Therefore, electric angle! Since the injection time of liquid I can be significantly shortened, sealed alkaline storage batteries can be mass-produced.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Example First, nickel hydroxide is used as an active material, and predetermined amounts of nickel powder as a conductive material, carboxymethyl cellulose as a thickener, and polytetrafluoroethylene as a binder are added, and pure water is added and mixed. A paste-like material was prepared, and this paste-like material was filled into a nickel annealing fiber substrate, followed by drying and pressing to produce a paste-type nickel positive electrode. Subsequently, as shown in Fig. 1(a), the positive electrode and the cadmium negative electrode were placed in a cylindrical can of AA size (AA size), made of nylon 6.0 fiber, with an amount of 87 g/m2 and a wall thickness of 0. Electrode detail 2, which was wound with a .2■ sebarator (trade name, FT-21f3 manufactured by Nippon Vilene Fu) sandwiched in between, was stored. Next, the can body l is shown in Fig. 1 (
As shown in b), after most of the can body is immersed in distilled water 4 in the water tank 3, the can body l is immersed in water while applying 45kHz ultrasonic waves using an ultrasonic transducer (not shown) attached to the bottom of the water tank 3. From the upper opening of the KOH water solution to a concentration of 5'
& (electrolysis)! ．． GcC was added dropwise. The time required for all the dropped electrolyte solutions of different concentrations to permeate the surface electrode group was determined. Figure 2 shows the relationship between the degree of electrolyte and the permeation time. In addition, as a comparative example, FIG. 2 also shows the relationship between the concentration of the electrolyte and the penetration time when no ultrasonic waves are applied.

As is clear from FIG. 2, in this example, when the concentration of the electrolyte of the KOH aqueous solution was 6N, injection was completed in about 40 seconds, whereas in the comparative example it took about 90 seconds, and the ultrasonic wave of the present invention It can be seen that in a wide direction where . Furthermore, it can be seen from FIG. 2 that the higher the concentration of the electrolyte, the greater the effect of shortening the night time.

In addition, by attaching a sealing plate to the upper opening of the cylindrical can body by caulking after injecting the electrolyte in the above operation,
We were able to manufacture a high-capacity alkaline storage battery with excellent charge-discharge characteristics.

[Effects of the Invention] As described in detail above, according to the present invention, the electrode group housed in the can body can be housed without changing the properties of the electrodes and separators constituting the electrode group housed in the can body. It is possible to provide a method in which an electrolyte can be injected in a very simple process in a short time, and a high-capacity sealed alkaline storage battery can be mass-produced.

[Brief explanation of drawings]

Figures 1 (a) and (b) are perspective views showing the manufacturing process of the sealed alkaline storage battery in this example, and Figure 2 shows the concentration of the electrolyte in this example and a comparative example, and the It is a characteristic diagram showing a relationship. l... Cylindrical can body, 2... Electrode group, 3... Hydrology, 4... Distilled water. joining agent

Claims (1)

[Claims] A sealed alkaline storage battery characterized in that an electrode group consisting of positive and negative electrodes combined with a separator is housed in a can, and then an electrolytic solution is injected into the can while applying ultrasonic waves to the can. manufacturing method.