KR19990008639A - Anode Manufacturing Method of Alkaline Secondary Battery - Google Patents

Abstract

PURPOSE: The present invention relates to a negative electrode manufacturing method of an alkaline secondary battery, in which the weight of the current collector on which the negative electrode paste is supported is reduced, so that the weight of the battery is realized and the short with the positive electrode is prevented.

Composition: Alkaline secondary battery manufactured by hydrogen absorbing alloy or cadmium, conductive agent, thickener and binder are mixed, pure water is added to the anode paste prepared on the surface of the current collector, dried, rolled and cut In the negative electrode manufacturing method, the current collector is made of a synthetic resin film, and in order to improve the flow of current, a plurality of unspecified holes are perforated, characterized in that formed on the surface of the conductor is doped.

Effect: A non-sintered negative electrode having a light, flexible and reduced internal resistance is produced by a collector made of a synthetic resin film.

Description

Anode Manufacturing Method of Alkaline Secondary Battery

The present invention relates to a method for manufacturing a negative electrode of an alkaline secondary battery, and more particularly, to a method for manufacturing a non-sintered negative electrode, which is suitably used to make a current collector of a negative electrode active material made of a synthetic resin film so as to realize a lightweight plate. .

Alkaline secondary batteries are rechargeable, compact and capable of large capacity, and nickel-cadmium (Ni-Cd) batteries and nickel-hydrogen (Ni-MH) batteries are mainly used.

While the former Ni-Cd battery has a low cost and has a memory effect, the charge capacity of the Ni-Cd battery is reduced, and cadmium, which is a pollution material, is used.

In the latter Ni-MH battery, a metal oxide is used as a positive electrode and a hydrogen storage alloy is used as a negative electrode. As a result, the hydrogen generated at the negative electrode is absorbed into the hydrogen absorbing alloy during charging, and the required hydrogen is discharged into the electrolyte during discharge. The discharge is repeated.

Such an alkaline secondary battery is wound by a separator interposed between a positive electrode and a negative electrode, assembled into a can of a predetermined size, and filled with an electrolyte solution therein and sealed.

Here, the method of manufacturing the non-sintered negative electrode in the production of the electrode plate of the alkaline secondary battery is, first, a micrometal-based hydrogen storage alloy as an active material of the negative electrode, a material having excellent conductivity such as Ni and artificial graphite as a conductive agent, and a thickener. Methyl cellulose (MC), carboxy methyl cellulose (CMC) and the like are used as a binder, and a paste is prepared using PVA, PTFF or rubber latex as a binder, and then the paste is plated with Ni on a steel sheet. It is manufactured by the method of apply | coating or filling in and cutting after rolling.

In the method of manufacturing a non-sintered negative electrode described in the prior art, the current collector is made of a thin sheet or a three-dimensional network structure using Ni or Ni plated steel sheet to support the active material and to charge and discharge current. To improve the flow.

However, the current collector of the metallic material has a problem of increasing the total weight of the battery.

In addition, a current collector made of a metal material has a problem in that a short occurs when an end thereof penetrates a separator and contacts a positive electrode when the electrode plate is cut.

The present invention has been made to overcome the problems of the prior art described above, the object is to lower the weight of the current collector to reduce the weight of the battery, and to prevent the short with the positive electrode.

Accordingly, in the present invention, in the manufacture of the negative electrode, the current collector supporting the negative electrode paste is made of a synthetic resin film, and in order to form an unspecified plurality of holes in order to improve the flow of current so that the conductor is formed on the surface thereof. Therefore, the present invention proposes a method of manufacturing a negative electrode of a non-sintered alkaline secondary battery which is light and flexible and has reduced internal resistance.

Here, the negative electrode paste is prepared by mixing a hydrogen storage alloy or a cadmium active material, a conductive agent, a thickener and a binder, and adding pure water.

Hereinafter, preferred embodiments for realizing the present invention will be described.

The method for producing a non-sintered negative electrode of an alkaline secondary battery according to the present invention includes a process of preparing a paste by mixing a hydrogen storage alloy or a Cd active material, a thickener, a conductive agent and a binder, stirring for 30 minutes, and collecting the paste. It consists of the process of apply | coating or filling the whole surface, the process of drying in 180 degreeC drying furnace, and the process of cutting to predetermined size after rolling.

Here, the negative electrode paste is based on 0.15 to 0.3% by weight of carboxymethyl cellulose, which is a hydrophilic binder, as a thickener, using 100% by weight of a micrometallic hydrogen storage alloy or a Cd active material, and 0.1 to 0.4% by weight as a conductive agent. Carbon black and a latex of 2% by weight of carboxy acrylate butadiene copolymer as a binder ) Is prepared by adding and stirring.

The negative electrode paste prepared as described above is supported by the current collector of the present invention made of a synthetic resin film in order to reduce the internal resistance, light and flexible.

The present invention is to use a synthetic resin film to produce a lighter and more flexible current collector than the current collector of a metallic material, as a result of the technical idea of manufacturing a light weight non-sintered negative electrode.

However, the present invention proposes a method of drilling a plurality of unspecified holes in a synthetic resin film and doping a conductor on the surface of the synthetic resin film in order to increase the binding force of the negative electrode paste and improve the flow of current during charging and discharging. .

Example 1

In this embodiment, the current collector is made of polyvinyl chloride (PVC) or polyvinyl acetate (PVA) to be flame-retardant (non-flammable) and manufactured to a thickness of 0.04 ton, and holes with a diameter of 2 mm are rectangular at intervals of 4 mm. It is made of a structure in which a hole having a diameter of 2 mm is drilled into the center of the shape.

Example 2

In the present embodiment, the current collector is made of polypropylene (PP) and polyethylene (PE), and is made of a flame retardant (non-flammable) process and manufactured to a thickness of 0.04 ton, and a hole having a diameter of 2 mm has a rectangular shape at intervals of 4 mm. And a hole having a diameter of 2 mm in the center of the shape.

Example 3

The current collector according to the present embodiment is made of polyvinyl chloride (PVC) or polyvinyl acetate (PVA), and made of a flame-retardant (non-flammable) treated material having a thickness of 0.04 ton, and a hole having a diameter of 2 mm has a diameter of 4 mm. Perforated in the form of a square at intervals, a hole with a diameter of 2 mm is drilled in the center of the form, and an alternative of nickel (Ni), copper (Cu), cobalt (Co), and chromium (Cr) is dissolved. The synthetic resin film is deposited in an aqueous hydrochloric acid solution, and the conductor is prepared by doping the surface.

Example 4

The current collector according to the present embodiment is made of polypropylene (PP) and polyethylene (PE) as a material, and flame-retardant (non-flammable) treated to a synthetic resin film manufactured to a thickness of 0.04 t, with holes having a diameter of 2 mm and a gap of 4 mm. It is perforated in the form of a square, a hole having a diameter of 2 mm is drilled in the center of the form, and a paint in which one selected from nickel (Ni), copper (Cu), cobalt (Co), and chromium (Cr) is dissolved. The synthetic resin film is deposited in a solution, and the conductor is prepared by doping the surface.

Each of the current collectors manufactured as described above was coated and filled with the same negative electrode paste including the hydrogen storage alloy or the Cd active material described above, and then dried in a drying furnace at 180 ° C., rolled, and then 30 * 30 * 0.4 By cutting to the size of, it is made of a non-sintered negative electrode.

Here, the negative electrode is mixed with a nickel hydroxide and a methyl cellulose as a thickener, cobalt monoxide as a conducting agent, and pure water, and then mixed with a sintered positive electrode prepared by filling a current collector and then dried, with a nylon nonwoven fabric interposed therebetween. 1,500 in size of * 60 Assembled to a theoretical capacity of.

In the present invention, the granules prepared as described above were placed in an acrylic container, 35 wt% of an electrolyte solution was added thereto, and charging and discharging were repeated at a current of 0.1 C to measure the capacity at this time. [Table 1] is the average result calculated by the applicant through a number of experiments, in order to clarify the effect, the prior art using a grid (hole) with a hole having a porosity of 50% in the Ni-plated steel sheet as a current collector Will be described in comparison.

Item Discharge capacity (%) Capacity density ( / cc) Plate weight (g) Example 1 79 compared to theoretical capacity 1,650 0.25 Example 2 78% of theoretical capacity 1,650 0.25 Example 3 100 to theoretical capacity 1,600 0.35 Example 4 100 to theoretical capacity 1,600 0.35 Prior art 100 to theoretical capacity 1,450 One

As can be seen from Table 1, the weight of the negative electrode was found to be reduced by 65 to 75% compared to the prior art. In addition, it can be seen that the capacity density of the battery is further increased compared with the prior art.

As can be seen through the configuration and operation described above, it can be seen that the negative electrode manufacturing method of the alkaline secondary battery according to the present invention substantially solves the problems of the prior art.

That is, according to the present invention, it is possible to obtain the effect that the current collector becomes light and the overall weight of the battery is reduced.

In addition, since the negative electrode according to the present invention is made flexible by the current collector made of a synthetic resin film, tearing of the nonwoven fabric during the assembly with the positive electrode can be prevented, and the occurrence of short can be obtained.

On the other hand, the present invention is not limited to the above-described specific preferred invention, any person having ordinary skill in the art to which the invention belongs without departing from the gist of the invention claimed in the claims. It will be possible.

Claims (7)

A hydrogen paste alloy or cadmium, a conductive agent, a thickener and a binder are mixed, and a cathode paste prepared by adding pure water is applied to the surface of the current collector, followed by drying in a high temperature atmosphere, rolling and cutting. In the negative electrode manufacturing method of the alkaline secondary battery, the current collector is a negative electrode manufacturing method of an alkaline secondary battery, characterized in that made of a synthetic resin film. The negative electrode manufacturing method of claim 1, wherein the synthetic resin film is made of one of polyvinyl chloride, polypropylene, polyethylene, and polyvinyl acetate. The method of claim 1, wherein the current collector is formed by forming a plurality of unspecified holes. A hydrogen paste alloy or cadmium, a conductive agent, a thickener and a binder are mixed, and a cathode paste prepared by adding pure water is applied to the surface of the current collector, followed by drying in a high temperature atmosphere, rolling and cutting. In the negative electrode manufacturing method of the alkaline secondary battery, the current collector is a negative electrode manufacturing method of the alkaline secondary battery, characterized in that the non-specific number of holes are formed in the synthetic resin film, the surface is doped with a conductor. 5. The method of claim 4, wherein the synthetic resin film is made of one of polyvinyl chloride, polypropylene, polyethylene, and polyvinyl acetate. 5. The method of claim 4, wherein the conductor is one of nickel, copper, cobalt and chromium. 5. The negative electrode manufacturing method of an alkaline secondary battery according to claim 4, wherein the current collector has a synthetic resin film deposited in an aqueous hydrochloric acid solution in which a conductor is dissolved, and the conductor is doped.