JPS58169770A - Manufacturing method of alkaline battery - Google Patents

Abstract

PURPOSE:To reduce the generation of hydrogen gas, by purifying the copper or copper alloy make inner surface of a cathode collector body with gydrogen peroxide and sulfuric acid chemical polishing solution and then processing it with a rust preventive solution containing mercury ion, while carrying out amalgamation and antirust treatment at the same time. CONSTITUTION:If the copper or copper alloy make inner surface of a cathode case removing all foreign substances from inside so far is left intact, it tends to oxidate, so that when it makes contact with amalgamated zinc in a state that a little alkali electrolyte to be contained in a battery remains there, it takes much time till amalgamation and galvanization are performed, causing the generation of hydrogen gas till that time elapses, and therefore impedance or internal pressure becomes increased. From this reason, after purifying the inner surface by means of chemical polishing, it is treated with a rust preventive solution containing mercury ion. After amalgamation and antirust treatment are simultaneously carried out, the amalgamated zinc and the alkali electrolyte are used to fill up the space whereby the generation of the hydrogen gas is prevented. In this case, a thoriasol derivative is used as a rust preventive.

Description

Detailed Description of the Invention This invention uses silver oxide, manganese dioxide, etc. as a positive electrode active material.
The present invention relates to a method for manufacturing an alkaline battery using zinc or the like as a negative electrode active material and an alkaline electrolyte.

In general, alkaline batteries are made by filling a positive electrode active material in a metal positive electrode container that also serves as a positive electrode terminal, a negative electrode active material and an alkaline electrolyte in a metal negative electrode container that also serves as a negative electrode terminal, and then inserting a separator between the two. The two containers are fitted together via an insulating gasket, and the opening of the positive electrode container is bent inward to form a hermetically sealed opening.

For example, in the case of button-type silver oxide batteries, the negative electrode container is generally
Two-layer clad plate of stainless steel and steel or steel alloy, or two! It is manufactured by drawing a three-layer clad plate of KEL stainless steel, steel or steel alloy so that the steel or steel alloy side becomes the inner surface of the container.

The steel or steel alloy surface of the negative electrode container manufactured in this manner is subjected to processes such as cladding plate manufacturing, slitting, punching, drawing, etc. The formation of chemical substances, the adhesion of dirt and dust, and the adhesion of minute pieces of metal such as stainless steel and nickel cannot be avoided. Before assembling the battery, pretreatment such as degreasing and cleaning is performed, but if these foreign substances get into scratches on the AT or steel alloy surface, or if they are pressed after adhesion, it is impossible to completely remove them with normal cleaning or other means. It is difficult to remove it.

Due to the presence of an alkaline electrolyte, the steel or steel alloy surface of the negative electrode container comes into contact with the negative electrode active material, zinc hydride, to undergo amalgamation and galvanization.

Therefore, even though steel or steel alloy is more dangerous than zinc, hydrogen gas generation is suppressed even when it comes into contact with zinc, so the battery can be sealed.

However, foreign substances such as stainless steel and nickel remain on the copper or steel alloy surface; these foreign substances are difficult to freeze and galvanize.

It remains exposed. These metals have a small water turbine overvoltage, so when the negative electrode container is filled with alkaline solution and zinc, they generate hydrogen gas.

Therefore, a structure in which hydrogen gas easily fills inside the battery after one assembly is a serious defect as a battery.

This invention was made based on the above circumstances.

The surface of the steel or steel alloy in contact with the negative electrode active material of the negative electrode current collector is polished and cleaned with a chemical polishing solution based on hydrogen peroxide or sulfuric acid, and then treated with a steel or steel alloy rust preventive solution containing mercury ions. However, by performing amalgamation and rust prevention treatment at the same time, less hydrogen gas is generated, resulting in leakage and increased impedance.

It is an object of the present invention to provide a method for manufacturing alkaline batteries that is free from bursting, has a longer service life, and can improve work efficiency.

In other words, it is difficult to remove fine particles of metal adhering to the steel or steel alloy of the negative electrode container using normal cleaning methods, so these harmful foreign particles are removed by scraping off the surface of the steel or steel alloy to a certain thickness. This is the solution from number ζ.

The thickness to be removed by this polishing is determined by the degree of dirt or foreign matter adhering to one surface and the thickness of the copper or copper alloy. The thickness of the steel or steel alloy surface is 10 of the total thickness of the clad plate.
I1111F is standard, so if the clad plate is thin, the steel or steel alloy layer will also be thin, limiting the thickness to which it will chip.

When the thickness of the clad plate is Q, 3mm, the thickness of steel or steel alloy is generally 30III41 degrees, and 10s.
Although there is no risk of exposing the inner stainless steel layer even if it is chipped away, it is not practical because the cost of chipping away increases. The depth to which foreign matter such as copper or steel alloy mK stainless steel, nickel, etc. is attached or implanted in the negative electrode container is about 3 to 5 depths at most, and it is possible to fill it by cutting it by 6 μm. Confirmed.

In this case, chemical polishing is suitable as a means for sharpening the steel or copper alloy surface, since the thickness of the surface to be scratched can be controlled relatively easily. More specifically, the advantage of using hydrogen peroxide and sulfuric acid type chemical molding agents is that the thickness of the scratch can be precisely controlled by selecting the composition of hydrogen peroxide and hydrochloric acid, treatment temperature and time. There is.

If the steel or copper alloy surface is brought into contact with the steel or copper alloy surface after the foreign matter has been removed, it will take some time for the steel or copper alloy surface to freeze and galvanize, and in the meantime hydrogen gas will be generated from the steel or steel alloy surface. Since the battery is assembled immediately after filling the negative electrode container with zinc hydrate and alkaline electrolyte, hydrogen gas generation continues until after the battery is assembled. When hydrogen gas is generated inside the battery, it increases its impedance or causes leakage due to an increase in internal pressure.

Therefore, in this invention, after cleaning by chemical polishing, this clean surface is treated with a rust preventive solution of copper or copper alloy containing mercury ions, and amalgamation and rust prevention treatment are simultaneously performed. The generation of hydrogen gas is prevented by filling the tank with an alkaline electrolyte. In this case, triazole derivatives commonly used as rust preventive agents for steel or steel alloys can be used as the rust preventive agent.

In addition, the negative electrode container is generally formed into a shape with a folded part around the periphery by drawing processing, and when forming this folded part, the area near the folded part is stretched due to the high degree of processing of the copper or steel alloy. It is thinner than the . Therefore, if this part is scraped with a chemical polishing solution, the stainless steel will be exposed, which may generate hydrogen gas.

However, in this invention, chemical polishing is performed while avoiding the folded portion, so this is a problem! Consideration has been given to preventing the generation of hydrogen gas.

Next, an embodiment of the present invention will be described with reference to the drawings.

As shown in Figure 1, the overall thickness is Q, nickel l, stainless steel 2, steel 3 with a steel thickness of 3 mm and 30 μm.
The negative electrode container 4 is manufactured by drawing a three-layer clad plate made of the following materials.

A jig 6 made of synthetic resin is attached to the peripheral folded part 5 of this negative electrode container 4.
After contacting and covering the surface with a chemical polishing solution containing about 10 moles of hydrogen peroxide and about 45 moles of sulfuric acid and a molar ratio of sulfuric acid to hydrogen peroxide of 0.045, the polishing solution was treated at room temperature for about 2 minutes. Wash with water and sulfuric acid.

Water washing, neutralization, and water washing are repeated to chemically scrape off the exposed surface of the copper 3 to remove foreign matter and clean it. Approximately 0, tmg per 51 negative electrodes is applied to this clean surface.
of mercury ion and benzotriazole as a rust inhibitor 0.2
Immerse it in an aqueous solution containing 11G.

After processing at 80° C. for about 1 second to simultaneously form amalgam and form a rust-preventing broken film, the jig 6 was removed and washed with water and dried. The average thickness of the steel surface is about 6μ.

8 is a short cylindrical positive electrode with a bottom made of a nickel-plated steel plate, 8 is an anode mixture formed by adding graphite as a conductive agent to an oxidized active material, 9 is an ion-permeable separator, IO
1 is an electrolyte holding material made of a porous fibrous material impregnated with a γ-alkaline electrolyte, and 11 is zinc chloride as a negative electrode active material. Reference numeral 12 denotes an insulating puffing for insulating and sealing the gap between the positive electrode container 57 and the negative electrode container 4, and the opening of the positive electrode container 1 is bent inward and fastened.

In the figure, 13 is a ring.

A conventional battery η assembled using only various treatments, including the battery 0 produced in this way, was compared with respect to leakage. In other words, Table 1 is.

These batteries were stored in a test chamber at a temperature of 6011:, 51 degrees and 90 degrees, and each 100
The number of leaked samples is shown for 0 samples.

Table 2 also shows the changes in height due to hydrogen gas generation, etc. of batteries stored for 3 months at a temperature of 45°C and humidity of 90°C. This shows the number of batteries whose height has increased by 5 mm or more.

Table 2 below is a blank space.
In the case of , a small number of liquids start leaking after 30 days of storage, and even if the number of days increases, the number of liquids leaking is significantly smaller than in the case of the conventional product η.

Also, according to Table 2, compared to the number of defective units in the case of the conventional product η, the number of defective units in the case of the battery capacitor (6) according to the present invention is approximately 1/7
You can do it by keeping it below.

In addition, through the first expression and Table 2, hydrogen peroxide is 8 to 10 mol, sulfuric acid is 0.25 to 0.6 mol, and the molar ratio of sulfuric acid to hydrogen peroxide is in the range of 0.03 to 0.06. (6
) to 0, it can be seen that particularly favorable test results are obtained.

As described above, according to the present invention, after polishing and cleaning the surface of the steel or steel alloy in contact with the negative electrode active material of the electrode current collector with hydrogen peroxide and sulfuric acid-based chemical polishing liquid, mercury ions are removed. By treating the steel or steel alloy with a rust preventive solution that contains amalgamation and rust prevention treatment at the same time, less hydrogen gas is generated, resulting in less leakage, increased impedance, and
It is possible to provide a method for manufacturing an alkaline battery that can prolong its life without bursting, and can improve work efficiency.

Note that the present invention is not limited to the above-mentioned embodiments, and various modifications have been made without changing the gist thereof, but the rust preventive agent is not limited to these.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of the manufacturing process of one embodiment of the present invention;
The figure is a longitudinal cross-sectional view showing a mercury oxide battery obtained in the same example. 1... Nickel 2... Stainless steel 3... Steel 4... Negative electrode container 5... Peripheral folding 1116... Jig 7... Positive electrode container
8.-Anode mixture 9...Separator 1G--Electrolyte holding material 11...Zinc chloride 12-Insulating packing! 3...Ring, total of 14 ri/double - Figure 1 $2 Figure

Claims (4)

[Claims] (1) After polishing and cleaning the end of the negative electrode current collector in contact with the electrode active material or the surface of the steel alloy with a chemical polishing solution based on hydrogen peroxide or sulfuric acid, rust prevention of steel or steel alloy containing mercury ions is performed. 1. A method for producing an alkaline battery characterized by having the right to perform amalgamation and rust prevention treatment at the same time by treating it with a chemical solution. (2) The above chemical polishing liquid contains 8 to 10 moles of hydrogen peroxide,
2. The method for producing an alkaline battery according to claim 1, wherein the alkaline battery contains 0.25 to 0.6 moles of sulfuric acid. (3) The method for manufacturing an alkaline battery according to claim 2, wherein the chemical polishing liquid has a molar ratio of sulfuric acid to hydrogen peroxide in a range of 0.03 to 0.06. (4) A method for producing an alkaline battery as set forth in any one of claims 1 to 3, characterized in that a triazole derivative is used as the rust preventive agent.