JPS60158555A - Manufacture of cadmium anode plate for alkaline storage battery - Google Patents

Abstract

PURPOSE:To prevent deposition of cadmium to the part to be used as the current collecting end when cadmium is electrochemically deposited in a porous body, by spreading synthetic resin in the part to be used as the current collecting end and drying it. CONSTITUTION:When cadmium is electrochemically deposited on the surface of a porous plate having conductivity, synthetic resin is spreaded and dried on the surface of a porous plate to form the current collecting end where cadmium is not deposited. For example, epoxy resin adhesive is spreaded on the part to be used as the current collecting end of nickel plate steel punched metal and dried. This plate is immersed in cadmium sulfate solution and is subjected to electrolysis. The electrode obtained is passed between a press roll, and cut in the center of the part where the synthetic resin adhesive is spreaded to obtain unit plate to be assembled to a battery.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for manufacturing a cadmium cathode plate for an alkaline storage battery.

Conventionally, typical manufacturing methods for cathode plates for alkaline storage batteries are as follows.

The first method is currently the most widely used.
As an active material holder that also serves as a current collector, a thin porous plate of nickel-plated iron or a net is coated with a slurry of nickel powder kneaded with an aqueous binder solution such as carboxymethyl cellulose, and after drying is placed in a hydrogen stream. For example, 90
Sintering is performed at a temperature of about 0° C. to obtain a porous substrate having a porosity of 70 to 85 inches. After that, this substrate is impregnated with a cadmium nitrate solution having a high concentration of 111&', dried, electrolyzed in a caustic alkaline solution kept at a high temperature, and then washed with water and dried, or simply immersed in a caustic alkaline solution, washed with water, and dried. 1 sintering type. These manufacturing methods require a complicated active material filling process and require repeated filling, resulting in relatively expensive electrode plates.

The second method is a method in which a paste-like active material containing cadmium oxide as a main component is directly applied to the core material made of the conductive perforated plate or net and dried and fixed. This method is extremely simple and is called the "paste method." In this manufacturing method, the mechanical strength of the active material is weaker than that of a sintered electrode plate in which the active material is firmly held in a nickel sintered porous body, and the active material may peel off from the core material during the assembly process, etc. It has the disadvantage of being classy.

A third method is to electrochemically deposit cadmium directly onto the nickel-plated thin plate by immersing the nickel-plated iron plate in a cadmium salt solution and then performing negative electrolysis. .

The present invention relates to a method for forming a current collecting end portion of an electrode plate according to a third method.

In an alkaline storage battery 1 with a spiral electrode body, for example a single cylindrical sealed nickel cadmium storage battery, the electrode current collecting end is generally formed as follows. In the case of the sintering type, when applying a slurry mainly composed of nickel powder to the above-mentioned porous plate, a non-slurry coating area is provided to expose both the front and back sides of the porous plate. After that, a predetermined active material filling is performed. The thus obtained electrode plate is cut at the aforementioned non-slurry coated portion to obtain a unit electrode plate ready to be incorporated into the i-pond. When actually assembled into a battery, the current collector I1 is welded to this non-slurry coated part, and this current collector is pressed or welded to the battery can which also serves as the cathode terminal.

In the case of the paste type, the current collecting end is formed by providing a non-paste coated part when applying a paste mainly composed of I and cadmium oxide to the surface of the porous plate, as in the sintering type. .

In the case where cadmium is electrochemically deposited on the surface of a porous body in the third production method, conventionally, the current collecting end is used to scrape off the deposited cadmium to a predetermined width, or to collect the current on the porous body. The former method was a waste of effort (scraping off the precipitated cadmium was wasteful, and furthermore, when scraping off the precipitated cadmium, there was a lot of waste). Due to the weak mechanical strength of cadmium, it has the disadvantage that one piece of cadmium is more likely to fall off than necessary.Also, the latter has the disadvantage that cadmium is easily removed from the area that should be the current collecting end, such as when the tape is insufficiently adhesive. It had the disadvantage that it precipitated.

The present invention is intended to eliminate the above-mentioned drawbacks, and requires that a synthetic resin be applied and dried on one area that should become the current collecting end.

Example: Nickel-plated iron punching metal with a thickness of 0.1 +nm, at intervals of 30++II++ in the longitudinal direction, 3+lI
After applying an epoxy resin adhesive to the +I1 width and drying it, electrolysis is performed at a current density of 250 mA/d while immersing the porous temporary in a 50y/β cadmium sulfate solution. The tentative feeding speed of the porous hole is 2 m/h. The electrode thus obtained had cadmium precipitated to a thickness of about 3III.

After passing it through a pressure roll to a length of 05 m, it was discharged with a current of 100 mk/d, and then cut at the center of the part coated with a synthetic resin adhesive on which no cadmium was deposited, to obtain a unit plate to be assembled into a battery.

As mentioned above, according to the present invention, it is possible to easily obtain a current collecting end in which cadmium does not precipitate at all by applying a synthetic resin to the place where the current collecting end is to be formed and drying it. The value base is a big thing.

Patent applicant Shin-Kobe Electric Co., Ltd.

Claims (1)

[Claims] A manufacturing method in which cadmium is electrochemically deposited on the surface of a perforated plate having conductivity, characterized in that a synthetic resin is coated on the surface of the perforated plate and dried to obtain a current collecting end in which cadmium is not deposited. A method for producing a cadmium cathode plate for alkaline storage batteries.