JP3178160B2 - Method for producing negative electrode for button-type alkaline battery and button-type alkaline battery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a negative electrode for a mercury-free button-type alkaline battery and to an improvement of the button-type alkaline battery.

[0002]

2. Description of the Related Art Conventionally, for a negative electrode of a silver oxide battery, an air battery, and an alkaline button battery using an alkaline electrolyte, zinc-melted zinc obtained by adding about 3 to 10% by weight of mercury to zinc powder has been used. However, efforts to eliminate the addition of mercury to zinc from the viewpoint of environmental issues have been promoted as a top priority for the entire battery industry.

When the amount of mercury added to the negative electrode is reduced to 0%, the following technical problems must be mainly solved.

1) Suppression of hydrogen gas generation from zinc electrode in alkaline electrolyte 2) Suppression of hydrogen gas generation by leaving the zinc electrode after partial discharge 3) Hydrogen gas by contact of zinc electrode with dissimilar metal Prevention of generation Unless the issues of hydrogen gas generation of 1-3 above are solved,
Many problems such as swelling of the battery, increase in internal resistance, abnormal discharge, deterioration of discharge capacity, and liquid leakage due to generation of hydrogen gas occur frequently, and the battery cannot be configured.

[0005] Many studies have been made on the suppression of the generation of hydrogen gas. For the negative electrode and zinc material,
One or more of indium, lead, thallium, bismuth, etc. are added to zinc to complete a zinc alloy that suppresses hydrogen gas generation.This zinc alloy generates hydrogen gas equivalent to the conventionally used zinc aluminide. No battery characteristics were obtained.

Therefore, in order to obtain a zinc material which is similar to zinc zinc oxide and generates less hydrogen gas, a method of attaching indium metal to the surface of zinc and zinc alloy particles has been disclosed in Japanese Patent Laid-Open No. 48-773.
No. 33, JP-A-50-98636, JP-A-4-286
No. 865 has been proposed.

However, when a recently developed corrosion-resistant zinc alloy powder is treated by the above-described method, there is a problem that hydrogen gas generation increases. A button-type alkaline battery using this zinc alloy powder as a negative electrode has not been obtained in a storage test in which the internal resistance is increased and the electric capacity is remarkably deteriorated to satisfy the electric characteristics.

[0008]

The present invention relates to a method for producing a mercury-free zinc anode for a button-type alkaline battery and to a button-type alkaline battery. It is an object of the present invention to provide a zinc negative electrode in which hydrogen gas generation equivalent to that of zinc is suppressed, and to obtain a battery having stable storage characteristics.

[0009]

According to the present invention, there is provided a zinc alloy powder comprising water containing at least one alcohol selected from methyl alcohol, ethyl alcohol, isopropyl alcohol and normal propyl alcohol, and containing indium ions. This is a production method in which a zinc alloy powder is separated and dried after being immersed in a mixed solution of, and dried, whereby zinc composite particles capable of suppressing the generation of hydrogen gas in an alkaline electrolyte solution to the same level as zinc calomel can be provided. Furthermore, the zinc alloy powder treated by the above-mentioned manufacturing method is used as a negative electrode active material of a button-type alkaline battery, and the inner surface of a sealing plate, which is a current collector, is coated with tin or indium. An object of the present invention is to solve the problem of storage characteristics of a button-type alkaline battery by adding an organic anticorrosive.

[0010]

The zinc alloy powder for mercury-free silver can be coated more uniformly with indium than the conventional indium treatment method, and as a result, generation of hydrogen gas in an alkaline solution is suppressed.

A button-type alkaline battery composed of the indium-coated zinc alloy powder, a sealing plate having an inner surface coated with tin and indium, and an alkaline electrolyte to which a special organic anticorrosive is added, has a synergistic effect. There is no problem such as battery swelling, liquid leakage, and abnormal discharge caused by hydrogen gas generated inside the battery during storage, and the same storage characteristics as a battery using zinc aluminide can be obtained.

[0012]

The details and effects of the present invention will be described below with reference to examples.

A method for preparing the corrosion-resistant zinc alloy used in the present invention, a method for producing composite particles in which the zinc alloy powder is coated with indium metal, a sealing plate in which the zinc alloy composite particles and the inner surface are coated with tin or indium, The structure and evaluation of an alkaline button battery using an alkaline electrolyte to which an organic anticorrosive is added will be described.

The zinc alloy powder is obtained by melting zinc having a purity of 99.97%, adding 500 ppm of lead and uniformly melting, and adding bismuth, indium and calcium to each of 400 and 40 parts.
Add 0,200 ppm and homogenously melt and pulverize with compressed air. It was prepared by the so-called atomizing method, which was classified by a sieve and adjusted.

(Example 1) A method for producing composite particles in which the surface of the zinc alloy powder is uniformly coated with indium metal will be described.

1 g of indium chloride is dissolved in 15 ml of water,
Next, 1 kg of the above zinc alloy powder was added to an indium chloride solution having a total volume of 600 ml by adding ethyl alcohol, and the solution was added for about 3 minutes.
Stir and mix for 0 minutes. After completion of the stirring, the zinc alloy powder is taken out and dried with hot air at 60 ° C. to obtain composite particles of the zinc alloy powder. In this experiment, zinc-lead alloy powder was used as the zinc type (A), and zinc-bismuth-indium-
The one using calcium alloy powder is referred to as (B).

As a comparative example, zinc alloy composite particles are obtained in the same process as above except that an aqueous solution of indium chloride in which 1 g of indium chloride is dissolved in 600 ml of water is used. In this experiment, the one using zinc-lead alloy powder was (C)
What used the bismuth-indium-calcium alloy powder is designated as (D).

(Example 2) A mixed solution 58 of 89% by weight of ethyl alcohol and 11% by weight of methyl alcohol in 15 ml of water.
5 ml was added, and zinc alloy composite particles were obtained in the same steps as in Example 1 except that an indium chloride solution obtained by dissolving 1 g of indium chloride in this three-component solution was used. In this experiment, zinc-
(E) using the lead alloy powder and (F) using the zinc-bismuth-indium-calcium alloy powder.

Example 3 86.6% by weight of ethyl alcohol and 13.4% by weight of isopropyl alcohol in 15 ml of water
Is added, and zinc alloy composite particles are obtained in the same steps as in Example 1 except that an indium chloride solution obtained by dissolving 1 g of indium chloride in this three-component solution is used.

In this experiment, a sample using a zinc-lead alloy powder was designated as (G), and a sample using a zinc-bismuth-indium-calcium alloy powder was designated as (H).

Example 4 In 15 ml of water, 90.4 wt% of ethyl alcohol and 9.6 wt% of normal propyl alcohol
% Of a mixed solution was added, and zinc alloy composite particles were obtained in the same process as in Example 1 except that an indium chloride solution in which 1 g of indium chloride was dissolved was used.

In this experiment, the one using the zinc-lead alloy powder was designated as (I), and the one using the zinc-bismuth-indium-calcium alloy powder was designated as (J).

EXAMPLE 5 A mixed solution of 85.5% by weight of ethyl alcohol, 4.9% by weight of isopropyl alcohol and 9.6% by weight of normal propyl alcohol in 15 ml of water 58
5 ml was added, and zinc alloy composite particles were obtained in the same steps as in Example 1 except that an indium chloride solution obtained by dissolving 1 g of indium chloride in this four-component solution was used.

In this experiment, a sample using a zinc-lead alloy powder was designated as (K), and a sample using a zinc-bismuth-indium-calcium alloy powder was designated as (L).

Example 6 To 15 ml of water was added 585 ml of a mixed solution of 85.5 wt% of ethyl alcohol, 4.9 wt% of methyl alcohol and 9.6 wt% of normal propyl alcohol, and 1 g of indium chloride was dissolved in the four-component solution. The zinc alloy composite particles are obtained in the same steps as in Example 1 except that the indium chloride solution is used.

In this experiment, a sample using the zinc-lead alloy powder was designated as (M), and a sample using the zinc-bismuth-indium-calcium alloy powder was designated as (N).

Example 7 76.8 wt% of ethyl alcohol
%, Methyl alcohol 1.3 wt%, isopropyl alcohol 1.3 wt%, water 20.6 wt% A quaternary solution containing 1 g of indium chloride dissolved in an indium chloride solution was used. Obtain composite particles.

In this experiment, the one using the zinc-lead alloy powder was designated as (O), and the one using the zinc-bismuth-indium-calcium alloy powder was designated as (P).

The untreated zinc-lead alloy powder used alone in the above examples was (Q) zinc-bismuth-indium-
Untreated calcium alloy powder alone (R), 10wt%
The calcined zinc powder is designated as (S).

The results of evaluating the hydrogen gas performance of the powders A to S are shown in Table 1. In addition, the evaluation was made of 40 wt% KO.
Using 10 ml of an electrolyte solution saturated with zinc oxide in an H solution, dipping 5 g of the zinc powder of the above A to S into this electrolyte solution,
The results measured after storage in the atmosphere for 7 days are shown in hydrogen gas generation rate (I).

The hydrogen gas generation rate (II) shows the result of measurement under the same conditions except that 120 ppm of an organic anticorrosive having the following structural formula was added to the electrolytic solution.

[0032]

Embedded image

[0033]

[Table 1]

As is clear from Table 1, (A), (B) and (E) obtained by the method for producing zinc alloy composite particles of the present invention.
In (P) to (P), the generation of hydrogen gas is suppressed as compared with (C) and (D) obtained by the conventional production method and (Q) and (R) which are untreated products of the raw material zinc alloy powder alone.

FIG. 1 is a structural sectional view of an alkaline button battery LR44 used in this embodiment. In FIG. 1, 1
Is a positive electrode case, 2 is a positive electrode active material mainly composed of manganese dioxide, 3 is a separator, 4 is a liquid-containing material, 5 is a negative electrode active material of the present invention, 6 is a sealing plate, 7 is a positive electrode base, and 8 is a positive electrode case 1
L-shaped packing that closes the opening of FIG.

(Embodiment 8) The sealing plate 6 of FIG.
A plate material consisting of three layers of stainless steel-copper is pressed, and an inner copper sealing plate is prototyped. Next, the sealing plate was subjected to the steps of degreasing, washing with water, acid washing, and washing with water, and subjected to electroless galvanizing with a solution containing tin chloride or indium chloride as a main component. Of tin or indium.

Zinc composite particles (A) obtained in Example 1, Comparative Example (C), raw zinc powder (Q), zinc aluminide (S) were applied to the above-mentioned tin, indium-plated sealing plate and conventional copper sealing plate. The mixture was quantitatively filled with a negative electrode mixture obtained by mixing 3 wt% of a gelling agent (CMC), and the negative electrode was added to a 42 wt% KOH solution saturated with zinc oxide without adding the above organic anticorrosive agent, or with 120 ppm added. Using each type of electrolyte, 100 batteries each having the configuration shown in FIG. 1 were prototyped.

The test battery was subjected to a storage test at 60 ° C. for 60 days, and the swelling, internal resistance, deterioration of discharge capacity, abnormal discharge rate, etc. of the battery caused by hydrogen gas generation were evaluated. The results are shown in (Table 2).

[0039]

[Table 2]

As is clear from Table 2, when the hydrogen gas generation in the alkaline solution of the zinc alloy powder is different, even if the same zinc alloy powder is used, the collector metal and the electrolytic solution that come into contact with the zinc are transferred to the metal. The storage characteristics of the battery greatly differ depending on whether or not an organic anticorrosive is added, and the combination of these.

The batteries 4 and 6 of the battery configuration of the present invention (Table 2) have no difference in storage performance such as battery swelling, internal resistance and capacity deterioration rate from the current battery 19 using zinc aluminide, and are used as negative electrodes. It has been found that a mercury-free button-type alkaline battery equivalent to a mercury-containing battery using zinc mercurized can be obtained.

In the examples, the zinc alloy composite particles (A) shown in Example 1 of the method for producing a negative electrode for an alkaline button battery were described, but the zinc alloy composite particles (A) obtained by another production method of the present invention were used. It has been confirmed that the same battery characteristics can be obtained for B) and (E) to (P).

The battery configuration of the present invention is not limited to an alkaline button battery, and the same effect can be obtained with an air battery or a silver oxide battery.

[0044]

As described above, it has been found that the method for producing zinc alloy composite particles according to the present invention significantly suppresses the generation of hydrogen gas from anhydrous mercury zinc.

Although the cause is not clear at present, it is estimated that the result is that the surface of the zinc alloy composite particles is not roughened and indium is uniformly coated.

A zinc alloy composite particle obtained by the production method of the present invention is used as a negative electrode, and a sealing plate whose inner surface is plated with tin or indium;
Batteries using a solution obtained by adding a special organic anticorrosive to the electrolyte significantly suppress the generation of hydrogen gas at the negative electrode due to the combined effect of the above three factors, and improve the storage characteristics of mercury-free batteries to the level of mercury. It became clear.

When the organic anticorrosive agent used in the present invention is added to a strongly alkaline solution at room temperature, the organic anticorrosive agent dissolves insufficiently and shows a phenomenon of floating on the liquid surface. When this solution is injected into a battery, the effect of suppressing the generation of hydrogen gas by zinc varies and the battery characteristics become non-uniform. However, it was confirmed that a uniform effect can be obtained by heating this solution to 60 ° C. or higher.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an alkaline button battery used in one embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Positive electrode case 2 Positive electrode active material 3 Separator 4 Liquid material 5 Negative electrode active material 6 Sealing plate 7 Positive electrode pedestal 8 L-shaped cross section packing

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01M 6/12 H01M 6/12 A (56) References JP-A-4-26062 (JP, A) (58) Fields surveyed ( Int.Cl. ⁷ , DB name) H01M 4/42 H01M 4/06-4/12

Claims (4)

(57) [Claims] 1. A zinc alloy powder immersed in a mixed solution of at least one alcohol selected from methyl alcohol, ethyl alcohol, isopropyl alcohol and normal propyl alcohol, and water containing indium ions.
A method for producing a negative electrode for a button-type alkaline battery, in which the zinc alloy powder is separated and dried after stirring. 2. Methyl alcohol, ethyl alcohol,
A button-type alkaline battery comprising, as a negative electrode active material, a zinc alloy powder mainly containing at least one alcohol of isopropyl alcohol and normal propyl alcohol and treated with a mixed solution with water containing indium ions. 3. An inner surface of a sealing plate, which is a current collector in contact with a negative electrode active material, is coated with tin or indium.
A button-type alkaline battery as described. 4. The button-type alkaline battery according to claim 2, wherein an organic anticorrosive having the following structural formula is added to the alkaline electrolyte. Embedded image