JPH0421310B2

JPH0421310B2 -

Info

Publication number: JPH0421310B2
Application number: JP60177668A
Authority: JP
Inventors: Nobuyori Kasahara; Toyohide Uemura; Keiichi Kagawa; Ryoji Okazaki; Kanji Takada; Akira Miura
Original assignee: Mitsui Mining and Smelting Co Ltd; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp; Mitsui Kinzoku Co Ltd
Priority date: 1985-08-14
Filing date: 1985-08-14
Publication date: 1992-04-09
Also published as: JPS6240162A

Description

[Detailed description of the invention]

〔産業上の利用分野〕本発明は亜鉛アルカリ電池に関し、詳しくは鉛
とインジウムとタリウム、カドミウム、ビスマ
ス、銀より選ばれる１種以上とアルミニウムを特
定範囲で含有した亜鉛合金をそのまま、もしくは
汞化して電池用負極活物質として用いた亜鉛アル
カリ電池に関する。〔従来の技術〕亜鉛を負極活物質として用いたアルカリ電池等
においては、水酸化カリウム水溶液等の強アルカ
リ性電解液を用いるため電池を密閉しなければな
らない。この電池の密閉は電池の小型化を図る際
には特に重要であるが、同時に電池保存中の亜鉛
の腐食により発生する水素ガスを閉じ込めること
になる。従つて長期保存中に電池内部のガス圧が
高まり、密閉が完全なほど爆発等の危険が伴な
う。その対策としてて、負極活物質である亜鉛の腐
食を防止して、電池内部の水素ガス発生を少なく
することが研究され、水銀の水素過電圧を利用し
た汞化亜鉛を負極活物質として用いることが専ら
行なわれている。このため、今日市販されている
アルカリ電池の負極活物質は５〜10重量％度の多
量の水銀を含有しており、社会的ニーズとして、
より低水銀のもの、あるいは無水銀の電池の開発
が強く期待されるようになつてきた。そこで、電池内の水銀含有量を低減させるべ
く、亜鉛に各種金属を添加した亜鉛合金粉末に関
する提案が種々なされている。例えば、亜鉛に鉛
を添加した亜鉛合金粉末、あるいは本発明者等に
よる亜鉛に鉛とインジウムを添加した亜鉛合金粉
末（特開昭58−181266号公報）等がある。しか
し、これらの亜鉛合金粉末はある程度のガス発生
抑制効果を奏するが、まだ十分とは言えない。このように、負極活物質である亜鉛合金粉末を
低汞化としつつ、水素ガス発生量を低減し、しか
も電池性能である放電性能を高い水準に維持する
電池は未だ得られていない。〔発明が解決しようとする課題〕本発明はかかる現状に鑑み、水銀の含有率を著
しく減少させつつ、水素ガス発生を抑制し、しか
も放電性能を高い水準に維持する負極活物質を用
いた亜鉛アルカリ電池を提供することを目的とす
る。〔課題を達成するための手段〕本発明者らはこの目的に沿つて鋭意研究の結
果、亜鉛からなる負極活物質において、鉛とイン
ジウムとタリウム、カドミウム、ビスマス、銀よ
り選ばれる１種以上とアルミニウムを特定範囲の
量添加することにより、これら添加元素の相乗的
な効果によつて、従来の低汞化した亜鉛合金粉末
よりも更に水素ガス発生量を低下させ、しかも放
電性能に優れた亜鉛アルカリ電池が得られること
を見出し本発明に到達した。すなわち本発明は、鉛を0.01〜0.5重量％、イ
ンジウムを0.01〜0.5重量％、タリウム、カドミ
ウム、ビスマス、銀より選ばれる１種以上の合計
量を0.01〜0.5重量％、アルミニウムを0.005〜0.5
重量％含有する亜鉛合金を負極活物質として用い
たことを特徴とする亜鉛アルカリ電池にある。本発明において、鉛とインジウムとタリウム、
カドミウム、ビスマス、銀より選ばれる１種以上
とアルミニウムとを特定量添加した亜鉛合金は、
そのまま負極活物質として用いるか、亜鉛合金を
汞化した後に負極活物質として用いる。汞化する
場合の水銀含有率は、従来の負極活物質の水銀含
有率よりも少ない量、すなわち、5.0重量％未満
であるが、より汞化率を低くし、低公害性を考慮
すると3.0重量％以下である。また、1.0重量％前
後またはそれ以下の少量であつてもガス発生を抑
制することが可能である。特に、排気機構を備え
た空気電池や水素吸収機構を備えた亜鉛アルカリ
電池等においては、水素ガスの発生許容量は比較
的大きいので、このような電池に本発明を適用す
る場合は、1.0重量％以下の低汞化率または無汞
化の亜鉛合金が負極活物質として好ましく用いら
れる。この負極活物質に用いられる亜鉛合金の鉛の含
有率は0.01〜0.5重量％、インジウムの含有率は
0.01〜0.5重量％、タリウム、カドミウム、ビス
マス、銀より選ばれる１種以上の合計量の含有率
は0.01〜0.5重量％、アルミニウムの含有率は
0.005〜0.5重量％と少量で添加効果が発揮され
る。鉛とインジウムとタリウム、カドミウム、ビ
スマス、銀より選ばれる１種以上とアルミニウム
の含有率がそれぞれ下限未満で本発明の効果が得
られず、上限を越えると、不純物を含有した亜鉛
のように、自己放電が進み、ガス発生抑制および
放電性能にとつて良好な結果が得られない。なお、アルミニウムの含有率は0.005〜0.2重量
％の範囲が特に好ましく、0.2重量％を越えた場
合にはそれほどの含有効果は見られない。〔作用〕これら各添加元素の作用効果は充分に解明され
ていないが、推定するに亜鉛合金中に含まれてい
る鉛、インジウムおよびタリウム、カドミウム、
ビスマス、銀は水素過電圧を高める作用あるいは
アルカリ電解液中での亜鉛の腐食を抑制する作用
を有すると考えられる。一方、アルミニウムは亜
鉛合金表面を平滑化させる効果があり、これによ
つて反応表面積を減少させ、耐食性の向上に役立
つと考えられる。本発明は、これら各作用の相乗効果により、放
電特性を劣化させることなく、耐食性のよい亜鉛
合金が得られたものである。このように本発明の亜鉛アルカリ電池は、電解
液に苛性カリ、苛性ソーダ等を主成分とするアル
カリ水溶液を用い、負極活物質に上記した亜鉛合
金または汞化した亜鉛合金、正極活物質に二酸化
マンガン、酸化銀、酸素等を用いることにより得
られる。〔実施例〕以下、実施例および比較例に基づいて本発明を
具体的に説明する。実施例１〜13および比較例１〜８純度99.997％以上の亜鉛地金を約500℃で溶融
し、これに第１表に示すごとく鉛、インジウム、
タリウム、アルミニウムの含有率がそれぞれ0.05
重量％となるように添加して亜鉛合金を作成し、
これを高圧アルゴンガス（噴出圧５Kg／cm²）を使
つて粉体化した。次に水酸化カリウム10％のアル
カリ性溶液中にて上記粉末に1.0重量％になるよ
うに水銀を添加して、汞化処理を行ない亜鉛合金
粉末（実施例１）を得た。また、第１表に示すごとく、下記の組成でそれ
ぞれ、１）鉛0.05重量％、インジウム0.05重量％、カ
ドミウム0.05重量％、アルミニウム0.05重量％
（実施例２）２）鉛0.05重量％、インジウム0.05重量％、ビ
スマス0.05重量％、アルミニウム0.05重量％
（実施例３）３）鉛0.05重量％、インジウム0.05重量％、銀
0.05重量％、アルミニウム0.05重量％（実施例
４）４）鉛0.01重量％、インジウム0.01重量％、タ
リウム0.01重量％、アルミニウム0.05重量％
（実施例５）５）鉛0.01重量％、インジウム0.01重量％、カ
ドミウム0.01重量％、アルミニウム0.005重量
％（実施例６）６）鉛0.01重量％、インジウム0.01重量％、ビ
スマス0.01重量％、アルミニウム0.005重量％
（実施例７）７）鉛0.01重量％、インジウム0.01重量％、銀
0.01重量％、アルミニウム0.005重量％（実施
例８）８）鉛0.5重量％、インジウム0.5重量％、タリ
ウム0.5重量％、アルミニウム0.2重量％（実施
例９）９）鉛0.5重量％、インジウム0.5重量％、カド
ミウム0.5重量％、アルミニウム0.2重量％（実
施例10） 10）鉛0.5重量％、インジウム0.5重量％、ビス
マス0.5重量％、アルミニウム0.2重量％（実施
例11） 11）鉛0.5重量％、インジウム0.5重量％、銀0.5
重量％、アルミニウム0.2重量％（実施例12） 12）鉛0.5重量％、インジウム0.5重量％、タリ
ウム0.5重量％、アルミニウム0.5重量％（実施
例13） 13）鉛0.05重量％（比較例１） 14）鉛0.05重量％、インジウム0.05重量％（比
較例２） 15）鉛0.05重量％、インジウム0.05重量％、タ
リウム0.05重量％（比較例３） 16）鉛0.05重量％、インジウム0.05重量％、カ
ドミウム0.05重量％、（比較例４） 17）鉛1.0重量％、インジウム0.05重量％、タ
リウム0.05重量％、アルミニウム0.05重量％
（比較例５） 18）鉛0.05重量％、インジウム1.0重量％、タ
リウム0.05重量％、アルミニウム0.05重量％
（比較例６） 19）鉛0.05重量％、インジウム0.05重量％、カ
ドミウム1.0重量％、アルミニウム0.05重量％
（比較例７） 20）鉛0.05重量％、インジウム0.05重量％、カ
ドミウム0.05重量％、アルミニウム1.0重量％
（比較例８）からなる亜鉛合金をそれぞれ作成し、これを前記
と同様な方法で粉体化し、汞化処理を行なつて水
銀含有率が1.0重量％の亜鉛合金粉末（実施例２
〜13および比較例１〜８）を得た。このようにして得られた亜鉛合金粉末を使つて
水素ガス発生試験を行ない、その結果を第１表に
示す。なお、ガス発生試験は、電解液として濃度
40重量％の水酸化カリウム水溶液に酸化亜鉛を飽
和させたものを５ml用い、亜鉛合金粉末を10g用
いて45℃で50日間のガス発生量（ml／ｇ）を測定
した。また、これらの亜鉛合金粉末を負極活物質とし
て第１図に示すアルカリマンガン電池を用いて電
池性能を評価した。第１図のアルカリマンガン電
池は、正極缶１、正極２、負極３、セパレーター
４、封口体５、負極底板６、負極集電体７、キヤ
ツプ８、熱収縮性樹脂チユーブ９、絶縁リング１
０，１１、外装缶１２で構成されている。このア
ルカリマンガン電池を用いて放電負荷4Ω、20℃
の放電条件により終止電圧0.9Vまでの放電持続
時間を測定し、従来の負極活物質を用いた後述す
る比較例９の測定値を100とした指数で示した。
結果を第１表に示す。比較例９実施例１と同様の方法で亜鉛に水銀を5.0重量
％添加した従来より用いられている汞化亜鉛合金
粉末（比較例９）を得た。これを実施例１と同様
の方法で水素ガス発生試験と電池性能試験を行な
い、その結果を第１表に示した。 [Industrial Field of Application] The present invention relates to a zinc-alkaline battery, and more specifically, a zinc alloy containing lead, indium, one or more selected from thallium, cadmium, bismuth, and silver, and aluminum within a specific range, either as it is or in the form of a starch. This invention relates to a zinc-alkaline battery used as a negative electrode active material for batteries. [Prior Art] In an alkaline battery using zinc as a negative electrode 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 attempting to miniaturize the battery, but it also traps hydrogen gas generated due to 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, research has been conducted to prevent corrosion of zinc, which is an active material for the negative electrode, and to reduce the generation of hydrogen gas inside batteries. It is carried out exclusively. For this reason, the negative electrode active materials of alkaline batteries commercially available today contain a large amount of mercury, ranging from 5 to 10% by weight.
There are strong expectations for the development of lower mercury or mercury-free batteries. Therefore, various proposals have been made regarding zinc alloy powders in which various metals are added to zinc in order to reduce the mercury content in batteries. For example, there is a zinc alloy powder made by adding lead to zinc, or a zinc alloy powder made by the present inventors by adding lead and indium to zinc (Japanese Patent Laid-Open No. 181266/1983). However, although these zinc alloy powders have a certain degree of gas generation suppressing effect, it is still not sufficient. As described above, a battery has not yet been obtained in which the zinc alloy powder, which is the negative electrode active material, has a low resistance, reduces the amount of hydrogen gas generated, and maintains the discharge performance, which is the battery performance, at a high level. [Problems to be Solved by the Invention] In view of the current situation, the present invention provides a zinc electrode active material that significantly reduces the mercury content, suppresses hydrogen gas generation, and maintains discharge performance at a high level. The purpose is to provide alkaline batteries. [Means for achieving the object] As a result of intensive research in line with this purpose, the present inventors have found that a negative electrode active material made of zinc contains lead, indium, and one or more selected from thallium, cadmium, bismuth, and silver. By adding aluminum in a specific range, the synergistic effect of these added elements reduces the amount of hydrogen gas generated even more than the conventional low-strength zinc alloy powder, and the zinc alloy powder has excellent discharge performance. The inventors have discovered that an alkaline battery can be obtained and have arrived at the present invention. That is, the present invention contains 0.01 to 0.5% by weight of lead, 0.01 to 0.5% by weight of indium, 0.01 to 0.5% by weight of one or more selected from thallium, cadmium, bismuth, and silver, and 0.005 to 0.5% of aluminum.
A zinc-alkaline battery characterized by using a zinc alloy containing % by weight as a negative electrode active material. In the present invention, lead, indium and thallium,
A zinc alloy containing a specific amount of aluminum and one or more selected from cadmium, bismuth, and silver is
It can be used as a negative electrode active material as it is, or it can be used as a negative electrode active material after a zinc alloy is made into a starch. The mercury content when converted into water is lower than the mercury content of conventional negative electrode active materials, that is, less than 5.0% by weight, but if the mercury content is lowered and low pollution is taken into account, it will be 3.0% by weight. % or less. In addition, gas generation can be suppressed even with a small amount of around 1.0% by weight or less. In particular, in air batteries equipped with an exhaust mechanism or zinc-alkaline batteries equipped with a hydrogen absorption mechanism, the hydrogen gas generation capacity is relatively large, so when applying the present invention to such batteries, 1.0 weight Zinc alloys with a low or non-grading rate of less than 10% are preferably used as the negative electrode active material. The lead content of the zinc alloy used in this negative electrode active material is 0.01 to 0.5% by weight, and the indium content is
The total content of one or more selected from thallium, cadmium, bismuth, and silver is 0.01 to 0.5% by weight, and the content of aluminum is 0.01 to 0.5% by weight.
The effect of addition is exhibited at a small amount of 0.005 to 0.5% by weight. If the content of lead, indium, one or more selected from thallium, cadmium, bismuth, silver, and aluminum is below the lower limit, the effect of the present invention cannot be obtained, and if the content exceeds the upper limit, zinc containing impurities, etc. Self-discharge progresses, and good results cannot be obtained in terms of gas generation suppression and discharge performance. Note that the content of aluminum is particularly preferably in the range of 0.005 to 0.2% by weight, and if it exceeds 0.2% by weight, no significant effect will be seen. [Function] The effects of each of these additive elements are not fully elucidated, but it is estimated that the effects of lead, indium, thallium, cadmium, and
Bismuth and silver are thought to have the effect of increasing hydrogen overvoltage or suppressing corrosion of zinc in an alkaline electrolyte. On the other hand, aluminum has the effect of smoothing the zinc alloy surface, thereby reducing the reaction surface area and is thought to be useful for improving corrosion resistance. In the present invention, due to the synergistic effect of these respective actions, a zinc alloy with good corrosion resistance is obtained without deteriorating the discharge characteristics. As described above, the zinc-alkaline battery of the present invention uses an alkaline aqueous solution containing caustic potash, caustic soda, etc. as the main component as an electrolyte, the above-mentioned zinc alloy or aqueous zinc alloy as a negative electrode active material, and manganese dioxide, as a positive electrode active material, Obtained by using silver oxide, oxygen, etc. [Example] The present invention will be specifically described below based on Examples and Comparative Examples. Examples 1 to 13 and Comparative Examples 1 to 8 Zinc ingots with a purity of 99.997% or more are melted at about 500°C, and lead, indium,
Thallium and aluminum content are each 0.05
Create a zinc alloy by adding it to be % by weight,
This was pulverized using high-pressure argon gas (ejection pressure 5 Kg/cm ² ). Next, mercury was added to the above powder to give a concentration of 1.0% by weight in an alkaline solution containing 10% potassium hydroxide, and a hydrochloric treatment was performed to obtain a zinc alloy powder (Example 1). In addition, as shown in Table 1, each of the following compositions: 1) 0.05% by weight of lead, 0.05% by weight of indium, 0.05% by weight of cadmium, and 0.05% by weight of aluminum.
(Example 2) 2) Lead 0.05% by weight, Indium 0.05% by weight, Bismuth 0.05% by weight, Aluminum 0.05% by weight
(Example 3) 3) 0.05% by weight of lead, 0.05% by weight of indium, silver
0.05% by weight, aluminum 0.05% by weight (Example 4) 4) 0.01% by weight lead, 0.01% by weight indium, 0.01% by weight thallium, 0.05% by weight aluminum
(Example 5) 5) Lead 0.01% by weight, Indium 0.01% by weight, Cadmium 0.01% by weight, Aluminum 0.005% by weight (Example 6) 6) Lead 0.01% by weight, Indium 0.01% by weight, Bismuth 0.01% by weight, Aluminum 0.005%. weight%
(Example 7) 7) 0.01% by weight of lead, 0.01% by weight of indium, silver
0.01% by weight, aluminum 0.005% by weight (Example 8) 8) 0.5% by weight lead, 0.5% by weight indium, 0.5% by weight thallium, 0.2% by weight aluminum (Example 9) 9) 0.5% by weight lead, 0.5% by weight indium , cadmium 0.5% by weight, aluminum 0.2% by weight (Example 10) 10) Lead 0.5% by weight, indium 0.5% by weight, bismuth 0.5% by weight, aluminum 0.2% by weight (Example 11) 11) Lead 0.5% by weight, indium 0.5% Weight%, silver 0.5
weight%, aluminum 0.2% by weight (Example 12) 12) Lead 0.5% by weight, indium 0.5% by weight, thallium 0.5% by weight, aluminum 0.5% by weight (Example 13) 13) Lead 0.05% by weight (Comparative Example 1) 14 ) Lead 0.05% by weight, Indium 0.05% by weight (Comparative Example 2) 15) Lead 0.05% by weight, Indium 0.05% by weight, Thallium 0.05% by weight (Comparative Example 3) 16) Lead 0.05% by weight, Indium 0.05% by weight, Cadmium 0.05 Weight%, (Comparative Example 4) 17) Lead 1.0% by weight, Indium 0.05% by weight, Thallium 0.05% by weight, Aluminum 0.05% by weight
(Comparative Example 5) 18) Lead 0.05% by weight, indium 1.0% by weight, thallium 0.05% by weight, aluminum 0.05% by weight
(Comparative Example 6) 19) Lead 0.05% by weight, Indium 0.05% by weight, Cadmium 1.0% by weight, Aluminum 0.05% by weight
(Comparative Example 7) 20) Lead 0.05% by weight, Indium 0.05% by weight, Cadmium 0.05% by weight, Aluminum 1.0% by weight
(Comparative Example 8) Zinc alloys consisting of 1.0% by weight of mercury were prepared and powdered in the same manner as described above.
-13 and Comparative Examples 1-8) were obtained. A hydrogen gas generation test was conducted using the zinc alloy powder thus obtained, and the results are shown in Table 1. In addition, in the gas generation test, the concentration of electrolyte was
Using 5 ml of a 40% by weight potassium hydroxide aqueous solution saturated with zinc oxide and 10 g of zinc alloy powder, the amount of gas generated (ml/g) was measured at 45° C. for 50 days. Further, battery performance was evaluated using an alkaline manganese battery shown in FIG. 1 using these zinc alloy powders as a negative electrode active material. The alkaline manganese battery shown in FIG. 1 includes a positive electrode can 1, a positive electrode 2, a negative electrode 3, a separator 4, a sealing body 5, a negative electrode bottom plate 6, a negative electrode current collector 7, a cap 8, a heat-shrinkable resin tube 9, and an insulating ring 1.
0, 11, and an outer can 12. Discharge load 4Ω, 20℃ using this alkaline manganese battery
The discharge duration up to the final voltage of 0.9V was measured under the following discharge conditions, and expressed as an index with the measured value of Comparative Example 9, which will be described later, using a conventional negative electrode active material as 100.
The results are shown in Table 1. Comparative Example 9 A conventionally used zinc chloride alloy powder (Comparative Example 9) in which 5.0% by weight of mercury was added to zinc was obtained in the same manner as in Example 1. This was subjected to a hydrogen gas generation test and a battery performance test in the same manner as in Example 1, and the results are shown in Table 1.

【表】第１表に示されるごとく、亜鉛に鉛とインジウ
ムとタリウム、カドミウム、ビスマス、銀より選
ばれる１種以上とアルミニウムを特定量添加して
汞化させた汞化亜鉛合金粉末を負極活物質に用い
た実施例１〜13は、比較例１〜８や亜鉛に水銀の
みを添加した従来より用いられている汞化亜鉛合
金粉末を負極活物質に用いた比較例９に比べて、
水素ガス発生抑制効果が大きく、放電性能も優れ
ていることがわかる。〔発明の効果〕以上説明のごとく、鉛とインジウムとタリウ
ム、カドミウム、ビスマス、銀より選ばれる１種
以上とアルミニウムを特定範囲で含有した亜鉛合
金をそのまま、もしくは汞化して負極活物質とし
て用いた本発明の亜鉛アルカリ電池は、水素ガス
発生率を抑制しつつ、電池性能を向上させること
が可能であり、また水銀が低含有率もしくは含有
しないことから、社会的ニーズにも沿つたもので
ある。従つて、本発明の亜鉛アルカリ電池は広範
な用途に使用可能である。[Table] As shown in Table 1, zinc chloride alloy powder, which is made by adding specific amounts of lead, indium, one or more selected from thallium, cadmium, bismuth, and silver, and aluminum to oxide, is used as a negative electrode. Examples 1 to 13 used as the material were compared to Comparative Examples 1 to 8 and Comparative Example 9 in which the conventionally used zinc chloride alloy powder, in which only mercury was added to zinc, was used as the negative electrode active material.
It can be seen that the hydrogen gas generation suppressing effect is large and the discharge performance is also excellent. [Effects of the Invention] As explained above, a zinc alloy containing lead, indium, one or more selected from thallium, cadmium, bismuth, and silver and aluminum within a specific range is used as a negative electrode active material as it is or after being made into a liquid. The zinc-alkaline battery of the present invention can improve battery performance while suppressing the hydrogen gas generation rate, and also meets social needs because it contains low or no mercury. . Therefore, the zinc-alkaline battery of the present invention can be used in a wide range of applications.

[Brief explanation of drawings]

第１図は本発明に係わるアルカリマンガン電池
の原理図を示す。１：正極缶、２：正極、３：負極、４：セパレ
ーター、５：封口体、６：負極底板、７：負極集
電体、８：キヤツプ、９：熱収縮性樹脂チユー
ブ、１０，１１：絶縁リング、１２：外装缶。 FIG. 1 shows a principle diagram of an alkaline manganese battery according to the present invention. 1: Positive electrode can, 2: Positive electrode, 3: Negative electrode, 4: Separator, 5: Sealing body, 6: Negative electrode bottom plate, 7: Negative electrode current collector, 8: Cap, 9: Heat-shrinkable resin tube, 10, 11: Insulation ring, 12: Exterior can.

Claims

[Claims] 1. Lead: 0.01 to 0.5% by weight, Indium: 0.01 to 0.5% by weight
0.5% by weight, thallium, cadmium, bismuth,
A zinc alkaline battery characterized in that a zinc alloy containing a total amount of 0.01 to 0.5% by weight of one or more types selected from silver and 0.005 to 0.5% by weight of aluminum is used as a negative electrode active material. 2. The zinc-alkaline battery according to claim 1, wherein the zinc alloy is made of aluminum.