JPS5994371A - Alkaline battery and its manufacturing method - Google Patents

Abstract

PURPOSE:To increase the effect of suppressing gas generation and the effect of battery performance by using the amalgamated zinc ally powder in which one or more kinds of cadmium, tin, thallium, lead, and bismuth is/are allowed to coexist with indium or zinc-mercury alloy powder as the cathode active material. CONSTITUTION:The amalgamated zinc alloy powder in which one or more kinds of cadmium, tin, thallium, lead, and bismuth is/are allowed to coexist with indium or zinc-mercury alloy powder is used as the active material of a cathode 4. It is recommended that the volume of each element in the said powder should be listed below: The content of indium is 0.005-1wt%, the content of cadmium is 0.001-0.05wt%, the content of tin is 0.001-1wt%, the content of thallium is 0.001-1wt%, the content of lead is 0.005-1wt%, the content of bismuth is 0.001-1wt%, and the content of mercury is less than 5wt%.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an alkaline battery and a method for manufacturing the same, and more specifically, an amalgamated zinc alloy powder or a zinc- The present invention relates to an alkaline battery using mercury alloy powder as a cathode active material for batteries, and a method for manufacturing the same.

In alkaline batteries using zinc as a cathode active material, the battery must be sealed tightly because a strong alkaline electrolyte such as an aqueous potassium hydroxide solution is used. This sealing of the battery is particularly important when trying to downsize the battery, but it also traps hydrogen gas generated by corrosion of zinc during battery storage. Therefore, during long-term storage, the gas pressure inside the battery increases, and the more completely the battery is sealed, the greater the risk of explosion. As a countermeasure against this problem, various efforts have been made to improve the structure of the battery and selectively guide the generated gas to the outside of the battery, but these efforts are still not perfect.

Therefore, research has been conducted to prevent the corrosion of the zinc cathode active material itself and reduce gas generation inside the battery, and the use of mercury-containing zinc powder, which utilizes the hydrogen overvoltage of mercury, as the cathode active material has been carried out exclusively. .

However, the cathode active materials of alkaline batteries commercially available today contain mercury in an amount of 5 to 15% by weight, which poses a danger to humans and other living organisms, and is highly likely to cause environmental pollution.

Therefore, a method has been proposed in which gas generation is suppressed by using a zinc electrode to which lead or the like is added instead of using mercury.

However, although such elements have a gas generation suppressing effect to some extent, they are currently far from being able to replace mercury. In addition, a method has been proposed in which zinc powder is immersed in an acidic solution containing mercury ions to which lead ions, cadmium ions, etc. have been added, and amalgamation is performed by the substitution method, and at the same time lead and cadmium are added to the zinc powder. Regardless of the method used, it has not been possible to reduce the mercury content while effectively suppressing gas generation.

In view of the above-mentioned current situation, the present invention provides an alkaline battery using a cathode active material that significantly reduces the content of mercury necessary to suppress hydrogen gas generation from the cathode active material and also improves battery characteristics. The purpose is to provide a manufacturing method thereof.

As a result of intensive research in line with this objective, the present inventors found that in addition to mercury, cadmium,
When indium coexists with at least one selected from tin, thallium, lead, and bismuth, mercury and at least one selected from cadmium, tin, thallium, lead, and bismuth and indium act synergistically to suppress gas generation. Even though the amount of mercury is significantly reduced compared to the conventionally used cathode active material made of mercury-containing zinc powder, it is equivalent to the case where mercury-containing zinc powder is used as the cathode active material. It has been discovered that the above-mentioned gas generation suppressing effect and battery performance effect can be achieved, and the present invention has been achieved.

That is, the alkaline battery of the present invention contains cadmium, tin,
The alkaline battery is characterized in that an amalgamated zinc alloy powder or a zinc-mercury alloy powder containing indium and at least one selected from thallium, lead, and sumas is used as a cathode active material for the battery.

The conventional cathode active material consisting of simple mercury-containing zinc powder is
In contrast, the cathode active material used in the alkaline battery of the present invention has a mercury content of 5% by weight or less, or even 1% by weight or less, compared to the conventional one. It is possible to suppress gas generation to a greater extent than that of conventional methods.

Of course, it is also possible to increase the mercury content and increase the gas generation suppressing function accordingly. Practically, the preferable mercury content of the cathode active material in the present invention is 5% by weight or less, and the cathode active material made of conventional mercury-containing zinc powder is
It has a sufficiently greater suppressive effect than IJ quality.

Further, the indium content of the amalgamated zinc alloy powder or zinc-mercury alloy powder in the present invention is 0.005
The content is preferably 1% by weight, and even if the content is more than that, the effect will be small.

Amalgamated zinc alloy powder or zinc in the present invention
The mercury alloy powder contains at least one or more selected from cadmium, tin 1, -1 thallium, lead, and bismuth, and the content ratio of each is cadmium 0.
001-0.05 weight M%, soot o, oo1-1 weight%
, thallium is o, ooi ~ 1% by weight, lead is 0.005 ~
At least one type of bismuth is contained in a proportion of o, o-oi to 1% by weight, and even if it is contained more than that, the effect is small (it only needs to be contained in a small amount).

The alkaline battery of the present invention can be obtained by various methods, but the preferred manufacturing method is (1) alloying indium and mercury with at least one selected from cadmium, tin, thallium, lead, and pith. , a method of using an amalgamated zinc alloy powder obtained by amalgamating zinc powder using the alloy as a cathode active material for a battery; (2) at least one member selected from cadmium, tin, thallium, lead, and bismuth in molten zinc; A method of using an amalgamated zinc alloy powder obtained by mixing the above with indium and amalgamating the powder as a cathode active material for batteries, (3) molten zinc with cadmium, tin, thallium, lead, For example, at least one selected from bismuth, indium, and mercury are mixed and alloyed, and the resulting powder is used as a cathode active material for batteries.

In addition to these methods, for example, there is a method in which at least one member selected from cadmium, tin, thallium, lead, and bismuth is alloyed with mercury, and the alloy is used to amalgamate zinc-indium alloy powder; Zinc can be alloyed with one or more of cadmium, tin, thallium, lead, and bismuth selected from cadmium, tin, thallium, lead, and bismuth, and the resulting powder is amalgamated with an alloy of indium and mercury. do not have.

The manufacturing method (1) is carried out, for example, as follows: Example First, zinc powder is added to an alkaline solution such as an aqueous potassium hydroxide solution, and preliminary stirring is performed for 1 to 30 minutes. Then,
An alloy of at least one selected from cadmium, tin, thallium, lead, and bismuth mixed with indium and mercury is gradually dropped into the above alkaline solution containing zinc powder through the pores while After stirring for a minute, the mixture is washed with water and dried at a low humidity of 30 to 60°C to obtain a predetermined amalgamated zinc alloy powder. Mercury has the property of forming an alloy not only with zinc but also with cadmium, indium, etc. at relatively low temperatures. For example, while the cadmium/mercury or indium/mercury ratio in the alloy remains the same, the alloy is mixed into zinc powder. Contains. Therefore, by changing the content of cadmium, indium, etc. in the alloy, the content of cadmium, indium, mercury, etc. in the zinc powder can be freely changed.

In the second manufacturing method, first, at least one selected from cadmium, tin, thallium, lead, and bismuth and indium are added to molten zinc, and after homogeneous alloying with stirring, the molten metal is A predetermined amalgamated zinc alloy powder is obtained by air atomizing and pulverizing the powder in the same manner as described above, that is, by adding mercury to an alkaline solution containing the alloy powder.

Further, as the third method, at least one selected from cadmium, tin, thallium, lead, and bismuth, indium, and mercury are added to molten zinc, and after homogeneous alloying with stirring, the molten zinc is is air atomized to obtain a specified zinc alloy powder.

By using the thus obtained amalgamated zinc alloy powder or zinc-mercury alloy powder or zinc alloy powder as a cathode active material, an alkaline battery with suppressed gas generation and excellent battery performance can be provided. Ru. - Hereinafter, the present invention will be specifically explained based on Examples and Comparative Examples.

Example 1 (a) ~ (() > 1:10 in a hydrochloric acid bath, cadmium i, o @ 1 part, lead 5.
By mixing 1 part by weight, 2.1 parts by weight of indium, and 91.8 parts by weight of mercury, the proportions of cadmium, lead, and indium were 1.0% by weight, 5.1% by weight, and 2.1% by weight, respectively. A cadmium-lead-indium amalgam was prepared. Next, 0.5% of a 10% by weight potassium hydroxide solution prepared in advance was added. 35 to 100 meshes of commercially available battery zinc powder (250°) were added to the solution, and preliminarily stirred at 20° C. for 5 minutes. Next, a predetermined amount of the cadmium-lead-indium amalgam was gradually dropped through the pores and stirred at 20° C. for 60 minutes to perform amalgamation.

After completing the amalgamation, it was washed with water and dried at 45°C overnight. In this way, the content of cadmium, lead, indium, and mercury was reduced to 0.01% by weight and 0.01% by weight, respectively.
．． Zinc-cadmium lead-indium-mercury powder (Example 1(a)
) was obtained.

Cadmium-lead-indium amalgam or cadmium mousse-subismuth-indium amalgam was also obtained in a similar manner, and finally amalgamated zinc alloy powder having the following content of each element was obtained.

(1) Cadmium o, oi weight%, lead 0.05 weight%
, 0.02% by weight of indium and 1.5% by weight of mercury zinc-cadmium lead-indium-mercury powder (Example 1 (
b)).

(2) Cadmium 0.01% by weight, lead 0.05% by weight,
Zinc-hydrodium lead-indium-mercury powder containing 0.02% by weight of indium and 3% by weight of mercury (Example 1(c))
.

(3) Cadmium 0.01% by weight, lead 0.05% by weight,
Zinc-cadmium lead-indium-mercury powder containing 0.02% by weight of indium and 5% by weight of mercury (Example 1(d))
.

(4) Cadmium 0.01% by weight, lead 0.05% by weight,
Zinc-cadmium lead-indium-mercury powder containing 0.02% by weight of indium and 7% by weight of mercury (Example 1(e))
.

(5) Cadmium 0.03% by weight, lead 0.05% by weight,
Zinc-cadmium lead-indium-mercury powder containing 0.1% by weight of indium and 0.9% by weight of mercury (Example 1(f)
).

(6) Cadmium 0.01% by weight, tin 0.01% by weight
, bismuth 0.01% by weight, indium 0.02% by weight
, 0.09% mercury by weight zinc-hydrogen mousse-bismuth-indium-mercury powder (Example 1 (0)).

A hydrogen gas generation test was conducted using the thus obtained amalgamated zinc alloy powder as a cathode active material. The results are shown in Table 1. In the gas generation test, zinc oxide was saturated in a potassium hydroxide aqueous solution with a concentration of 40% by weight as the electrolytic solution 511! and 10 g of each cathode active material consisting of amalgamated zinc alloy powder at 45°C.
The gas generation rate (TIIg/g·day) was measured.

Further, the battery performance of the cathode active material made of this amalgamated zinc alloy powder was evaluated using an alkaline manganese battery having the structure shown in FIG. The alkaline manganese battery shown in Fig. 1 includes a positive electrode can 1, a positive electrode 2, a separator 3, a negative electrode 4 made of amalgamated zinc alloy powder or zinc-mercury alloy powder gelled with carboxymethyl cellulose, a negative electrode current collector 5, a rubber packing 6, and a presser. It is composed of a plate 7.

Using this alkaline manganese battery, the discharge load is 4Ω, 20Ω.
The discharge duration up to the final voltage of 0.9 V was measured under the discharge conditions of 100° C., and expressed as an index with the measured value of Comparative Example 1(d) using a conventional cathode active material described below as 100. The results are shown in Table 2.

Example 2 a) ~ (C) Tin, lead, and indium are added to molten zinc to produce approximately 450
This molten alloy was then stirred at a temperature of 4 ka
Powdered with compressed air at a pressure of / cm, with a particle size of 20 to 200 mesh and a content of tin, lead, and indium of 0.0
Zinc-tin-lead-indium alloy powders of 5% by weight, 0.1% by weight, and 0.02% by weight were obtained. Using this alloy powder and mercury, amalgamation was performed in the same manner as in Example 1, so that the tin, lead, indium, and mercury contents were 0.05% by weight, 0.1% by weight, and 0.02% by weight, respectively. 0,
A 9% by weight zinc-tin-lead-indium-mercury powder (Example 2(a)) was obtained.

In addition, by the same method, zinc-thallium-indium-mercury powder with thallium, indium, and mercury contents of 0.03% by weight, 0.1% by weight, and 0.9% by weight, respectively (Example 2 (b)) as well as cadmium, tin, thallium,
Content of lead, bismuth, indium, and mercury is 0 each
．． 01% by weight, 0.01% by weight, 0.01% by weight, 0.
05% by weight, 0.01% by weight, 0.02% by weight, 0.9
A zinc-hydrodium mousse-zoothallium-lead-bismuth-indium-mercury powder (Example 2(C)) was obtained in weight percent.

Using these amalgamated zinc alloy powders as a cathode active material, a gas generation test and a battery performance test were conducted in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

! "Lid" - molten zinc is charged with cadmium, thallium, lead, indium, and mercury, stirred at a temperature of about 450°C, and then the molten alloy is pulverized with compressed air at a pressure of 4ka/cnf,
Cadmium, thallium, with a particle size of 20 to 200 mesh
The content of lead, indium, and mercury is 0.02% by weight, 0.02% by weight, 0.05% by weight, and 0.02% by weight, respectively.
, 0.9% by weight of zinc-cadmium thallium-lead-indium-mercury powder was obtained.

Using this zinc-mercury alloy powder as a cathode active material, a gas generation test and a battery performance test were conducted in the same manner as in Example 1, and the results are shown in Tables 1 and 2.

Comparative Examples 1(a) to (e) Conventionally used mercury content: 0.9% by weight (Comparative Example 1(a)), 1.5% by weight (Comparative Example 1(b)), 3% by weight (Comparative Example 1(c)), 5% by weight (Comparative Example 1(d))
, 7% by weight (Comparative Example (e)) zinc-mercury powder was used as the cathode active material, and a gas generation test and a battery performance test were conducted in the same manner as in Example 1. The results are shown in Tables 1 and 2. Shown in the table.

As shown in Tables 1 and 2, Examples 1 (a) to (g), Examples 2 (a) to (C), and Example 3 related to the present invention are all related to Comparative Example 1 (a). ) to (e),
Even if the mercury content is significantly reduced, the gas generation suppressing effect remains at a high level. In addition, the battery performance was also improved (Comparative Example 1(d)) in which zinc-mercury powder containing 5% by weight of mercury was used as the cathode active material.
It is understood that it is superior to

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of an alkaline manganese battery according to the present invention. 1: Positive electrode can, 2: Positive electrode, 3: Separator, 4: Negative electrode made by gelling amalgamated zinc alloy powder or zinc-mercury alloy powder with carboxymethyl cellulose, 5: Negative electrode current collector, 6: Rubber packing, 7: Holder plate Procedures Amendment Written by Kazuo Wakasugi, Commissioner of the Patent Office, November 26, 19822 Name of the invention Alkaline battery and its manufacturing method3 Relationship with the case of the person making the amendment Patent application Place of residence Chuo, Tokyo 2-1 Muromachi, Nihonbashi-ku, 1 Name (618) Mitsui Kinzoku Mining Co., Ltd. Representative: Setsuo Takashima 4, Agent: 〒105 Address: 2-8-1 Toranomon, Minato-ku, Tokyo Voluntary amendment 6, subject of amendment Attachment Street 8, Attached documents (1) Application for correction 1 copy (2) Drawing 1 copy No. 1 1 = Soup Noa\-6 □1 11-4

Claims (1)

[Claims] 1. Amalgamated zinc powder or zinc-mercury alloy powder containing at least one member selected from cadmium, tin, thallium, lead, and bismuth and indium as a cathode active material for batteries. An alkaline battery characterized in that it is used. 2. The alkaline battery according to claim 1, wherein the amalgamated zinc powder or zinc-mercury alloy powder has an indium content of 0.005 to 1%. 3. The cadmium content of the flax, rugumized zinc powder or zinc-mercury alloy powder is o, ooi to 0.05 weight M
%, tin content is 0.001 to 1% by weight, thallium content is o, ooi to 1% by weight, lead content is 0.00%.
The alkaline battery according to claim 1 or 2, wherein the alkaline battery contains at least one kind of bismuth at a ratio of 5 to 1 weight % and a bismuth content of 0.001 to 1 weight %. 4. The alkaline battery according to claim 1, 2 or 3, wherein the mercury content of the amalgamated zinc powder or zinc-mercury alloy powder is 5% by weight or less. 5. The alkaline battery according to claim 4, wherein the amalgamated zinc powder or zinc-mercury alloy powder has a mercury content of 1% by weight or less. 6. Amalgamated zinc alloy powder obtained by alloying indium and mercury with at least one selected from cadmium, sulphur, thallium, lead, and bismuth, and amalgamating zinc powder using the alloy, can be used as a cathode active material for batteries. A method for producing an alkaline battery, characterized in that it is used as a substance. 7. Amalgamated zinc alloy powder obtained by alloying molten zinc with at least one selected from cadmium, tin, thallium, lead, and bismuth and indium, and amalgamating the powder. A method for producing an alkaline battery, characterized in that it is used as a cathode active material for a battery. 8. An alkali characterized by mixing molten zinc with at least one member selected from cadmium, tin, thallium, lead, and bismuth, indium, and mercury to form a powder, and using the powder as a cathode active material for batteries. How to manufacture batteries.