JP4102896B2 - Zinc alkaline battery and method for producing zinc negative electrode thereof - Google Patents

Description

【００１６】
表１から明らかなように、実施例の電池は６０日貯蔵後までの漏液発生はなく、９０日貯蔵後で２個あるに過ぎないのに対し、比較例の電池では６０日貯蔵後から漏液が発生し始め、９０日貯蔵後では１３〜１９個と明らかな差が現れた。
【００１７】
以上より、酸素ガス濃度１％以下の不活性ガス雰囲気中の無汞化亜鉛合金粉末を同雰囲気中でゲル状負極に調製したものを使用したことによって、低公害かつ安全で高性能な亜鉛アルカリ電池を製造することができる。
【００１８】
【発明の効果】
以上説明したように、本発明のゲル状亜鉛負極を用いることにより、無汞化亜鉛合金粉末使用による電池の低公害化を達成しつつ、長期貯蔵中のガス発生量を抑制することが可能となり、耐漏液特性を改善した安全で高性能な亜鉛アルカリ電池を提供することができる。
【図面の簡単な説明】
【図１】本発明の一実施例である亜鉛アルカリ電池の断面図。
【符号の説明】
１…金属缶、２…正極合剤、３…セパレータ、４…ゲル状亜鉛負極、５…負極集電棒、６…絶縁ガスケット、７…リング状の金属板、８…負極端子を兼ねる金属封口板。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mercury-free zinc alkaline battery and a method for producing the zinc negative electrode.
[0002]
[Prior art]
Conventionally, zinc-halide alloy powders have been used as negative electrode active materials for zinc-alkaline batteries for the purpose of suppressing gas generation due to corrosion of zinc and improving electrical characteristics. As it has become regarded as a problem, low pollution has become a social demand, and research on zinc alloy compositions and anticorrosives (inhibitors) to make zinc alloy powder non-glazed (anhydrous silver) has progressed. Finally, a gelled negative electrode for mercury-free alkaline batteries has been developed which has no practical problem of gas generation.
[0003]
By the way, it was found that batteries that simply used zinc-free zinc alloy powder had less impact resistance than batteries that used zinc-halide alloy powder. Thus, measures have been taken to increase the viscosity of the gelled zinc negative electrode and improve the impact resistance.
[0004]
[Problems to be solved by the invention]
However, when the viscosity of the gelled zinc negative electrode is increased to improve the impact resistance of the battery, the proportion of the alkaline electrolyte in the gelled zinc negative electrode absorbed by the gelling agent increases, and the non-glazed zinc alloy powder Insufficient wetting. Therefore, air is likely to remain between the non-zincified zinc alloy powder, and an oxidation-reduction reaction occurs at the gas-liquid interface on the surface of the non-zincified zinc powder in the presence of oxygen gas, increasing the amount of gas generated during long-term storage, and finally It was found that liquid leakage could occur.
[0005]
The present invention has been made in view of the above situation, and an object of the present invention is to suppress the amount of gas generated in a zinc-alkaline battery using a non-annealed zinc alloy powder, thereby improving the leakage resistance.
[0006]
[Means for Solving the Problems]
To solve the above problems, the present invention was an improvement over the method of manufacturing a mercury-free gelled zinc anode zinc alkaline batteries, a non-amalgamated zinc alloy powder is filled with an inert gas after the vacuum treatment The oxygen gas concentration between the powders is reduced to 1% or less, and the non-zincified zinc alloy powder is mixed with a gel alkaline electrolyte in an inert gas atmosphere , and again degassed and stirred . The
[0007]
In the present invention, the oxygen gas in the air between the denitrified zinc alloy powders is replaced with an inert gas (for example, nitrogen gas) in advance so that the oxygen gas concentration is 1% or less, and then the gel is formed in an inert gas atmosphere. Therefore, the presence of oxygen at the gas-liquid interface on the surface of the non-zincified zinc powder is reduced, and generation of hydrogen gas due to the oxidation-reduction reaction of zinc can be suppressed. Therefore, a zinc alkaline battery using such a gelled zinc negative electrode is a high-performance battery having low pollution and improved leakage resistance during long-term storage.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
(Example 1)
First, after reducing the pressure of the non-hatched zinc alloy powder to 1 Torr to remove air, the inert gas was filled, and oxygen between the non-hatched zinc alloy powder was replaced with the inert gas. Inert gas includes nitrogen gas, helium gas, argon gas, etc., but this time nitrogen gas was used. The oxygen gas concentration in the inert gas atmosphere was measured by gas chromatography and found to be 0.1%. Next, the mixture was mixed with a gel alkaline electrolyte in the same atmosphere and stirred while degassing again to prepare an inert gas-substituted gelled zinc negative electrode.
[0009]
(Example 2)
It was prepared in the same manner as in Example 1 except that the reduced pressure level of the non-zincified zinc alloy powder was 30 Torr. The oxygen gas concentration in the inert gas atmosphere at this time was 1% when measured by the gas chromatrophy method.
[0010]
(Comparative Example 1)
It was prepared in the same manner as in Example 1 except that the reduced pressure level of the non-zincified zinc alloy powder was 190 Torr. The oxygen gas concentration in the inert gas atmosphere at this time was 5% when measured by the gas chromatrophy method.
[0011]
(Comparative Example 2)
It was prepared in the same manner as in Example 1 except that the reduced pressure level of the unzinced zinc alloy powder was 380 Torr. The oxygen gas concentration in the inert gas atmosphere at this time was 10% when measured by the gas chromatrophy method.
[0012]
(Comparative Example 3)
It was prepared in the same manner as in Example 1 except that the atmosphere during the inert gas substitution of the non-zincified zinc alloy powder and the preparation of the gelled zinc negative electrode was not changed to the inert gas atmosphere. The oxygen gas concentration in the atmosphere at this time was 20% when measured by the gas chromatrophy method.
A JIS standard LR6 type (AA) alkaline battery shown in FIG. 1 was assembled using the five types of gelled zinc negative electrodes thus obtained.
[0013]
In FIG. 1, reference numeral 1 denotes a bottomed cylindrical metal can also serving as a positive electrode terminal, and the metal can is filled with a positive electrode mixture 2 that is pressure-formed in a cylindrical shape. The positive electrode mixture 2 is a mixture of manganese dioxide powder and carbon powder, which is housed in a metal can 1 and pressed into a hollow cylinder at a predetermined pressure. The hollow portion of the positive electrode mixture 2 is filled with the gelled zinc negative electrode 4 produced by the above method through a bottomed cylindrical separator 3 made of a nonwoven fabric of acetalized polyvinyl alcohol fibers. A brass negative electrode current collector rod 5 is mounted in the gelled zinc negative electrode 4 so that the upper portion protrudes from the gelled zinc negative electrode 4. An insulating gasket 6 made of a double annular polyamide resin is disposed on the outer periphery of the protruding portion of the negative electrode current collector rod 5 and the upper inner peripheral surface of the metal can 1. A ring-shaped metal plate 7 is disposed between the double annular portions of the insulating gasket 6, and a hat-shaped metal sealing plate 8 that also serves as a negative electrode terminal is attached to the head of the current collecting rod 5. It arrange | positions so that it may contact | abut. The inside of the metal can 1 is sealed with the gasket 6 and the metal sealing plate 8 by bending the opening edge of the metal can 1 inward.
[0014]
About each LR6 type | mold alkaline battery assembled as mentioned above, 100 each was stored on the storage conditions of temperature 60 degreeC and humidity 93%, and the generation | occurrence | production number of the liquid leakage was investigated. The results are shown in Table 1. The numerical value in the table is the number of leaked liquids out of 100.
[0015]
[Table 1]

[0016]
As is clear from Table 1, the batteries of the examples did not leak until 60 days after storage, and there were only two after 90 days of storage, whereas the batteries of the comparative examples had been stored after 60 days of storage. Leakage began to occur, and after 19 days storage, there was a clear difference of 13-19.
[0017]
As described above, low-pollution, safe, and high-performance zinc alkali is obtained by using a non-zincified zinc alloy powder in an inert gas atmosphere with an oxygen gas concentration of 1% or less prepared as a gelled negative electrode in the same atmosphere. A battery can be manufactured.
[0018]
【The invention's effect】
As described above, by using the gelled zinc negative electrode of the present invention, it is possible to reduce the amount of gas generated during long-term storage while achieving low pollution of the battery by using non-annealed zinc alloy powder. Thus, it is possible to provide a safe and high-performance zinc-alkaline battery with improved leakage resistance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a zinc alkaline battery according to an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Metal can, 2 ... Positive electrode mixture, 3 ... Separator, 4 ... Gel-like zinc negative electrode, 5 ... Negative electrode collector rod, 6 ... Insulating gasket, 7 ... Ring-shaped metal plate, 8 ... Metal sealing plate which serves as a negative electrode terminal .

Claims (2)

After the vacuum-treated zinc-free alloy powder is filled with an inert gas, the oxygen gas concentration between the powders is reduced to 1% or less, and the zinc-free zinc alloy powder is subjected to gel alkaline electrolysis in an inert gas atmosphere. A method for producing an anhydrous silver-gelled zinc negative electrode for a zinc-alkaline battery, characterized by mixing with a liquid and degassing and stirring again .   The zinc alkaline battery provided with the anhydrous silver gel-like zinc negative electrode manufactured with the manufacturing method of Claim 1.

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