JP3518975B2 - Positive electrode for alkaline storage battery and alkaline storage battery - Google Patents

Positive electrode for alkaline storage battery and alkaline storage battery

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Publication number
JP3518975B2
JP3518975B2 JP21520397A JP21520397A JP3518975B2 JP 3518975 B2 JP3518975 B2 JP 3518975B2 JP 21520397 A JP21520397 A JP 21520397A JP 21520397 A JP21520397 A JP 21520397A JP 3518975 B2 JP3518975 B2 JP 3518975B2
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JP
Japan
Prior art keywords
surface layer
metal elements
positive electrode
oxide
active material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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JP21520397A
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Japanese (ja)
Other versions
JPH10149821A (en
Inventor
宏和 木宮
陽一 和泉
弘之 坂本
秀勝 泉
功 松本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Corp
Panasonic Holdings Corp
Original Assignee
Panasonic Corp
Matsushita Electric Industrial Co Ltd
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Priority to JP21520397A priority Critical patent/JP3518975B2/en
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Publication of JP3518975B2 publication Critical patent/JP3518975B2/en
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【発明の属する技術分野】本発明は、ニッケル・カドミ
ウム蓄電池、ニッケル・水素蓄電池などのアルカリ蓄電
池用正極、さらに詳しくは、複数の金属元素の酸化物か
らなる活物質に関する。TECHNICAL FIELD The present invention relates to a positive electrode for alkaline storage batteries such as nickel-cadmium storage batteries and nickel-hydrogen storage batteries, and more particularly to an active material composed of oxides of a plurality of metal elements.

【０００２】[0002]

【従来の技術】近年、アルカリ蓄電池、とくに小型の密
閉式蓄電池は、他の電池系と比べて、充放電特性、サイ
クル寿命および安全性・信頼性にバランス良く優れるこ
とから、通信機、事務機、家電および雑貨等の各種のポ
ータブル機器用主電源として著しく普及した。また、充
放電特性や信頼性に極めて優れることから、大型の電
源、例えば電気自動車等の移動用主電源としても注目さ
れている。このアルカリ蓄電池を代表する電池系は、長
い歴史を持つニッケル・カドミウム蓄電池である。最近
では、この電池のカドミウム負極の代わりに金属水素化
物を用いたニッケル・水素蓄電池が工業化され、ニッケ
ル・カドミウム蓄電池より高いエネルギー密度を有する
ことから、急激にその占有率を伸ばしている。このよう
なエネルギー密度および信頼性の向上のためには、従来
から行われてきたように、（１）電極における支持体と
添加物、セパレータ、電解液および電槽や蓋体の軽薄短
小化を図って正・負極の活物質を一定の容積内に多量に
詰めこむ工夫、（２）活物質の利用率を高める各種の添
加物や導電材等の改良、に加えて、（３）多様な使用条
件の下で高エネルギー密度を発揮する新たな活物質材料
を開発することが極めて重要になってきた。2. Description of the Related Art In recent years, alkaline storage batteries, especially small-sized sealed storage batteries, have excellent charge-discharge characteristics, cycle life and safety / reliability in a well-balanced manner compared to other battery systems. , Has become extremely popular as a main power source for various portable devices such as home appliances and sundries. Further, since it is extremely excellent in charge / discharge characteristics and reliability, it has been attracting attention as a large-scale power source, for example, a main power source for moving vehicles such as electric vehicles. The battery system that represents this alkaline storage battery is a nickel-cadmium storage battery with a long history. Recently, a nickel-hydrogen storage battery using a metal hydride in place of the cadmium negative electrode of this battery has been industrialized, and has a higher energy density than that of the nickel-cadmium storage battery, so that its occupancy rate is rapidly increasing. In order to improve such energy density and reliability, (1) the support and additives in the electrode, the separator, the electrolytic solution, and the light, thin, short, and miniaturization of the battery case and lid are used as has been conventionally done. In addition to devising a large amount of positive and negative electrode active materials within a certain volume, (2) Improvement of various additives and conductive materials that increase the utilization rate of active materials, (3) Various It has become extremely important to develop new active material materials that exhibit high energy density under the conditions of use.

【０００３】そこで、これらに関する近年の技術動向を
以下に記載する。工業的なニッケル・カドミウム蓄電池
やニッケル・水素蓄電池における正極の主活物質は古く
からのニッケル酸化物（ＮｉＯＯＨ）に変わりはない
が、電極の支持体は従来の高性能かつ長寿命の焼結式電
極に用いられてきた焼結基板に代わり、同じ三次元構成
ではあるが、より高い多孔度の網状基板、例えば発泡状
ニッケル基板などが適用され始めた。その結果、発泡状
ニッケル基板に活物質粉末を多量に充填した電極（以
後、発泡メタル式電極と呼称する）が工業化され、これ
によってニッケル正極のエネルギー密度は飛躍的に向上
した（米国特許第４，２５１，６０３号）。発泡状ニッ
ケル基板と同様な特徴を有するニッケルのフェルトを基
板に用いた電極なども知られている。これらの高多孔度
の基板を使用する際に共通する利点は、従来の微孔性の
焼結基板と異なり、孔径が大きくできることから、ニッ
ケル酸化物を粉末状態で直接基板に充填できるという簡
単な製法が採用できることである。反面、大粒径の粉末
を焼結基板より遥かに大孔径の基板に充填するため、活
物質粉末の導電性の低さと共に、それを支持する極板全
体の電子伝導度の低下が顕著に影響して活物質利用率の
低下を来す問題が生じた。このため、活物質粉末、つま
り、ニッケル酸化物粉末に加えて、Ｃｏやその酸化物、
Ｎｉ等を添加する方法で導電性を補い、あるいはまだ不
十分な導電性をニッケル酸化物中にＣｏなどのＮｉ以外
の金属元素を固溶させることによって補うなどがなされ
てきた。Therefore, recent technical trends relating to these are described below. The main active material for the positive electrode in industrial nickel-cadmium storage batteries and nickel-hydrogen storage batteries has been nickel oxide (NiOOH) for many years, but the electrode support is the conventional high-performance and long-life sintered type. Instead of the sintered substrates that have been used for electrodes, reticulated substrates with the same three-dimensional configuration but higher porosity, such as foamed nickel substrates, have begun to be applied. As a result, an electrode in which a foamed nickel substrate is filled with a large amount of active material powder (hereinafter referred to as a foamed metal electrode) has been industrialized, and thereby the energy density of the nickel positive electrode has been dramatically improved (US Patent No. 4). , 251,603). Electrodes using nickel felt as a substrate, which has the same characteristics as the foamed nickel substrate, are also known. The common advantage of using these high-porosity substrates is that, unlike conventional microporous sintered substrates, the pore size can be increased, which makes it possible to directly fill the substrate with nickel oxide in powder form. The manufacturing method can be adopted. On the other hand, since the powder having a large particle size is filled into the substrate having a pore size much larger than that of the sintered substrate, the conductivity of the active material powder is low, and the electron conductivity of the whole electrode plate supporting the active material powder is significantly lowered. This caused a problem that the utilization rate of the active material was lowered. Therefore, in addition to the active material powder, that is, the nickel oxide powder, Co and its oxides,
The conductivity has been supplemented by a method of adding Ni or the like, or the insufficient conductivity has been supplemented by solid-dissolving a metal element other than Ni such as Co in nickel oxide.

【０００４】ニッケル酸化物への他金属元素の固溶は、
充電効率の改良にも顕著な効果を発揮し、特にＣｏおよ
びＣｄの２元素の固溶が顕著な効果を持つことが見い出
された。その後、Ｃｄと似た性質のＺｎが注目されてＣ
ｄの代替元素として用いられたり、更に、Ｃｏ、Ｚｎお
よびＢａなどの３元素の固溶体も提案されている。この
ような充放電特性の高効率化を目的にした、ニッケル酸
化物への他元素の固溶は、焼結式電極では古くから知ら
れた技術である。Ｍｇ、Ｃａ、Ｂａ、Ｔｉ、Ｚｒ、Ｍ
ｎ、Ｃｏ、Ｆｅ、Ｃｕ、Ｓｃ、Ｙ等から選ばれた一種以
上の元素を固溶した固溶体を用いるなどの改良例が挙げ
られる。ニッケル酸化物へのＣｏ、Ｃｄ、Ｚｎなどの元
素の固溶は、充電受け入れ性の改善のほか、過充電時に
高次酸化物、すなわちγ相のニッケル高次酸化物の生成
を抑制する効果も併せ持っている。このため、前記元素
の固溶は、ニッケル酸化物の体積膨張を抑えることか
ら、堅牢な焼結式電極とは異なり、脆弱な発泡メタル式
電極等に適用する場合には、長寿命化のための有効な手
段でもあった（米国特許第５，３６６，８３１号）。ま
た、このような活物質の材料面からの改良と平行して、
活物質粉末の形状も高密度充填に適した球状に改良さ
れ、実用電池に用いられるようになった。The solid solution of other metal elements in nickel oxide is
It was also found that the effect of improving the charging efficiency was remarkable, and that the solid solution of two elements Co and Cd had a remarkable effect. After that, attention was paid to Zn, which has a property similar to Cd, and C
It is used as an alternative element to d, and a solid solution of three elements such as Co, Zn and Ba is also proposed. The solid solution of other elements to nickel oxide for the purpose of improving the efficiency of such charge / discharge characteristics is a technique that has been known for a long time in sintered electrodes. Mg, Ca, Ba, Ti, Zr, M
Examples of improvements include using a solid solution in which one or more elements selected from n, Co, Fe, Cu, Sc, Y, and the like are used as a solid solution. Solid solution of elements such as Co, Cd, and Zn in nickel oxide not only improves charge acceptability, but also suppresses the formation of higher-order oxides, that is, γ-phase nickel higher-order oxides during overcharge. I have both. Therefore, the solid solution of the above elements suppresses the volume expansion of nickel oxide, and therefore, unlike the robust sintered electrode, when applied to a fragile metal foam electrode or the like, it has a long life. (US Pat. No. 5,366,831). Further, in parallel with the improvement from the material side of such an active material,
The shape of the active material powder has also been improved to a spherical shape suitable for high-density packing, and has come to be used in practical batteries.

【０００５】前述のＣｏやその酸化物の添加方法にも更
に改良が加えられ、活物質粉末表面にＣｏ（ＯＨ）2の
被覆層を形成する方法、あるいはＣｏ酸化物の粉末層を
形成する方法等が提案されてきた。これらは、いずれも
導電剤の添加方法の効率化を行うことにより、活物質利
用の高効率化及び生産性の向上を目指したものである。
このような技術の進歩により、従来より遥かに高密度に
充填された活物質粉末の充放電効率を、優秀な焼結式電
極と同程度にまで高めることができ、正極のエネルギー
密度は飛躍的に向上し、現在ではエネルギー密度６００
ｍＡｈ／ｃｍ3程度のニッケル正極が実用化されてい
る。The above-mentioned method of adding Co or its oxide is further improved, and a method of forming a coating layer of Co (OH) 2 on the surface of the active material powder or a method of forming a powder layer of Co oxide. Etc. have been proposed. All of these aims to increase the efficiency of utilization of the active material and improve the productivity by improving the efficiency of the method of adding the conductive agent.
Due to such technological advances, the charge / discharge efficiency of the active material powder packed in a much higher density than in the past can be increased to the same level as that of an excellent sintered electrode, and the energy density of the positive electrode is dramatically increased. Energy density of 600
A nickel positive electrode of about mAh / cm 3 has been put to practical use.

【０００６】一方、負極では、従来のカドミウム負極に
代わり、高容量密度の金属水素化物（ＡＢ5系）の適用
により、エネルギー密度は大きく向上し、正極の倍以上
の単位体積当たりのエネルギー密度を有する負極が実用
化されるに至った。これに呼応してセパレータや電槽関
連部品の薄型化も急速に進歩して、電池のエネルギー密
度は増加の一途をたどってきた。しかしながら前述のよ
うに、特にポータブル機器用の電源としてのエネルギー
密度向上の要望は近年益々大きくなる一方である。この
様な要請に応え、電池のエネルギー密度の一層の向上を
実現するためには、正極を上回る負極などの高エネルギ
ー密度化技術の進展の中で、特に正極における一層の高
エネルギー密度化や高性能化が強く望まれ出した。さら
に、最近の用途面から見ると、電源として適用されるポ
ータブル電子機器の使用条件の多様化に伴い、従来以上
に広い温度範囲、特に４５〜６０℃程度の高温における
高エネルギー密度と長寿命および安全性を発揮すること
が一層強く求められている。これは、苛酷な作動環境条
件下で小型・軽量化が求められる大型の移動用主電源に
おいても同様である。On the other hand, in the negative electrode, the energy density is greatly improved by applying a high capacity density metal hydride (AB 5 system) in place of the conventional cadmium negative electrode, and the energy density per unit volume more than double that of the positive electrode is obtained. The negative electrode has been put to practical use. In response to this, the thinning of separators and battery case-related parts has made rapid progress, and the energy density of batteries has continued to increase. However, as described above, the demand for improving the energy density as a power source for portable devices in particular has been increasing in recent years. In order to meet these demands and further improve the energy density of the battery, in order to further improve the energy density of the negative electrode, which is higher than that of the positive electrode, in particular the higher energy density and Performance improvement was strongly desired. Further, from the viewpoint of recent applications, with the diversification of usage conditions of portable electronic devices applied as a power source, a higher energy density and a longer service life at a wider temperature range than before, particularly at a high temperature of about 45 to 60 ° C. and There is a strong demand for safety. This is also true for large-sized mobile main power supplies that are required to be small and lightweight under severe operating environment conditions.

【０００７】焼結式に比べて高エネルギー密度を有する
発泡メタル式やフェルト式電極においても、支持体の金
属量の低減や添加物の種類、添加量の見直しにも限度が
あり、活物質の充填密度もほぼ限界に達しつつある。一
般に言われているように、Ｎｉの一電子反応が利用され
ているとした場合の活物質利用率はほぼ限界（１００
％）に近づいているため、今のままでは飛躍的な高エネ
ルギー密度化は望めない。このような点から、一層の高
容量密度化や高性能化のためには、支持体や添加物の見
直しだけでなく、画期的な高エネルギー密度を有する活
物質自体の開発が必要である。ここで、現状の活物質材
料をもう少し具体的に説明する。前述したように、工業
的に使用されるアルカリ蓄電池の正極活物質には、現在
ニッケル酸化物（Ｎｉ（ＯＨ）2）主体の材料が用いら
れている。その反応は以下に示すようなβタイプの結晶
間におけるＮｉの２価と３価との間の一電子反応が主で
あるといわれている。Even in the foam metal type and felt type electrodes, which have a higher energy density than the sintering type, there is a limit to the reduction of the metal amount of the support, the kind of the additive and the review of the amount of the active material, The packing density is almost reaching the limit. As is generally said, the utilization rate of the active material is almost the limit (100
%), It is not possible to expect a dramatic increase in energy density as it is. From this point of view, in order to achieve higher capacity density and higher performance, it is necessary not only to review the support and additives, but also to develop the active material itself having a revolutionary high energy density. . Here, the current active material will be described more specifically. As described above, a nickel oxide (Ni (OH) 2 ) -based material is currently used as a positive electrode active material for industrially used alkaline storage batteries. It is said that the reaction is mainly one-electron reaction between divalent and trivalent Ni of β-type crystals as shown below.

【０００８】[0008]

【化１】 [Chemical 1]

【０００９】しかし、実際の電池においては、平均値で
２．２価付近と３．２価付近との間での反応が行われて
いるようである（この場合もβーＮｉ（ＯＨ）2とβー
ＮｉＯＯＨの反応と総称される場合が多い）。いずれに
してもほぼ１電子（１価）相当の反応である。そして、
充電状態のβ−ＮｉＯＯＨに関しては、低温雰囲気下で
充電したり、長期にわたって充電したり、あるいは過充
電を繰り返したりすると、その一部が高次酸化物である
γ−ＮｉＯＯＨにまで酸化される。γ−ＮｉＯＯＨに酸
化されると、体積膨張を来すので電極が膨張し易くな
る。また、γ−ＮｉＯＯＨは電気化学的に不活性な物質
である。このため、γ−ＮｉＯＯＨが生成すると、容量
の低減を来したり、過電圧の増大による電池電圧の低下
を招く等の弊害があった。従って、従来はγ−ＮｉＯＯ
Ｈの生成を抑制する工夫が講じられてきた。なお、γ−
ＮｉＯＯＨは、過去から、Ｎｉの３．５価〜３．８価付
近、具体的には化学式ＡxＨyＮｉＯ2・ｎＨ2Ｏ（Ｎｉと
Ｏで構成される層と層の間にアルカリ金属Ａが入り、
Ａ、Ｈ、Ｎｉ、およびＯの間でチャージバランスがとら
れている。）で表されると言われている。そして、Ｎｉ
の価数は３．６７や３．７５価とも言われ、非化学量論
的な価数を示す高次酸化物として知られている。However, in an actual battery, it seems that the reaction is performed between an average value around 2.2 and an average value around 3.2 (also in this case, β-Ni (OH) 2 ). Is often referred to as the reaction of β-NiOOH). In any case, the reaction is equivalent to approximately one electron (single valence). And
When β-NiOOH in a charged state is charged in a low temperature atmosphere, charged for a long period of time, or repeatedly overcharged, a part thereof is oxidized to γ-NiOOH which is a higher oxide. When oxidized to γ-NiOOH, the electrode expands easily because volume expansion occurs. Further, γ-NiOOH is an electrochemically inactive substance. Therefore, when γ-NiOOH is generated, there are problems such as a decrease in capacity and a decrease in battery voltage due to an increase in overvoltage. Therefore, conventionally, γ-NiOO
Measures have been taken to suppress the production of H 2. Note that γ−
NiOOH has been used since the past in the vicinity of 3.5 to 3.8 valence of Ni, specifically, chemical formula A x H y NiO 2 · nH 2 O (alkaline metal between layers composed of Ni and O). A enters,
There is a charge balance between A, H, Ni, and O. ) Is said to be represented. And Ni
The valence of is also called 3.67 or 3.75, and is known as a higher-order oxide exhibiting a non-stoichiometric valence.

【００１０】ニッケルの酸化物をベースにした材料を二
次電池の活物質に用いて、さらに高エネルギー密度化を
図るには、この高次酸化物γーＮｉＯＯＨを使いこなす
こと、言い換えれば一電子を越える反応をする材料を見
出すことが極めて重要である。このために、Ａｌ3+やＦ
ｅ3+などのように、３価の金属元素をニッケル酸化物に
固溶させて正に帯電した金属酸化物層を形成し、全体の
チャージバランスを取るためにアニオンをその金属酸化
物層間に入れることによって、βーＮｉ（ＯＨ）2相
（最も近接した層間距離：約４．６オングストローム）
ではなく、主に層間距離の広いαーＮｉ（ＯＨ）2相
（これは放電状態であるが、層間距離は充電状態である
γ−ＮｉＯＯＨの約７オングストロームに近く約８オン
グストロームである）を、初めから作成する方法などが
報告されている（米国特許第５，３４８，８２２号な
ど）。In order to achieve a higher energy density by using a material based on nickel oxide as an active material of a secondary battery, the higher oxide γ-NiOOH must be mastered, in other words, one electron must be emitted. It is extremely important to find a material that reacts beyond. For this reason, Al 3+ and F
For example, e 3+ , a trivalent metal element is solid-dissolved in nickel oxide to form a positively charged metal oxide layer, and anions are placed between the metal oxide layers to balance the overall charge. Β-Ni (OH) 2 phase (closest interlayer distance: about 4.6 Å)
Rather, mainly the α-Ni (OH) 2 phase having a wide interlayer distance (this is in a discharged state, but the interlayer distance is about 8 Å, which is close to about 7 Å of γ-NiOOH in a charged state), A method of producing the same from the beginning has been reported (US Pat. No. 5,348,822 etc.).

【００１１】この様な酸化物は、層間距離の変化が小さ
いため容易にγ−ＮｉＯＯＨ相に充電されて、充放電の
反応価数は増す。しかし、βーＮｉ（ＯＨ）2より層間
距離の広いαーＮｉ（ＯＨ）2相が存在することによ
り、材料自身の密度（物質密度、従ってタップ密度）が
極端に低下するという問題が生じる。タップ密度は、電
極作成時に充填密度と正の相関を持つため、高密度充填
が極めて困難となる。また、この材料を用いることによ
り、サイクル寿命が短くなったり、放電電圧が低下した
りするという新たな問題が生じる。さらに、着目すべき
点は、前記の様な材料を用いただけでは、Ｎｉベースの
酸化物の高温における充電効率の低下という問題は何ら
解決されないことである。高温特性は、電池使用条件の
多様化で、近年特に重要視されつつある性能であり、今
後の二次電池の発展の中で実用性の面からは無視するこ
とのできない課題である。Since such an oxide has a small change in the interlayer distance, it can be easily charged into the γ-NiOOH phase and the charge / discharge reaction valence increases. However, the existence of the α-Ni (OH) 2 phase having a wider interlayer distance than β-Ni (OH) 2 causes a problem that the density of the material itself (substance density, that is, tap density) is extremely lowered. Since the tap density has a positive correlation with the packing density at the time of forming the electrode, high density packing becomes extremely difficult. In addition, the use of this material causes new problems such as a short cycle life and a decrease in discharge voltage. Further, it should be noted that the use of the above materials alone does not solve the problem of the decrease in charging efficiency of Ni-based oxides at high temperatures. High-temperature characteristics are performances that have been particularly emphasized in recent years due to diversification of battery use conditions, and are issues that cannot be ignored in terms of practicality in the future development of secondary batteries.

【００１２】高温での充電効率の低下は、Ｎｉベースの
酸化物の充電電位が酸素発生電位と近接することによ
り、充電末期において酸素発生が充電反応との競争反応
として生じやすくなるためである。従って、高温での充
電効率を改善するために、特に高温になりやすい中・大
型のニッケル・水素蓄電池において、高温でも酸素発生
過電圧を高める元素をニッケル酸化物の中に固溶または
添加させる提案がなされている（米国特許第５，４５
５，１２５号）。しかし、この提案は、γ−ＮｉＯＯＨ
相の利用をも鑑みた電極エネルギー密度の向上の考え方
に根ざしたものではなかった。すなわちβーＮｉ（Ｏ
Ｈ）2とβ−ＮｉＯＯＨとの間の充放電反応における高
温時の充電効率の改善を目指したものであった。また、
酸素発生過電圧を高める元素の固溶は、充放電反応の主
な担い手であるＮｉの含有量を低下させる欠点をも有し
ていた。従って、エネルギー密度の向上を併せて考える
と、十分とは言えるものではなかった。The decrease in charging efficiency at high temperature is because the charging potential of the Ni-based oxide is close to the oxygen generation potential, so that oxygen generation easily occurs as a competitive reaction with the charging reaction at the end of charging. Therefore, in order to improve the charging efficiency at high temperatures, it has been proposed to solid-dissolve or add an element that enhances the oxygen generation overvoltage even at high temperatures in medium- and large-sized nickel-hydrogen storage batteries, which tend to reach high temperatures. (US Pat. No. 5,45
No. 5,125). However, this proposal does not address γ-NiOOH.
It was not based on the idea of improving the electrode energy density in consideration of the use of phases. That is, β-Ni (O
The aim was to improve the charging efficiency at high temperature in the charge / discharge reaction between H) 2 and β-NiOOH. Also,
The solid solution of an element that increases the oxygen generation overvoltage also has a drawback that the content of Ni, which is a main player of the charge / discharge reaction, is reduced. Therefore, considering the improvement of the energy density together, it cannot be said to be sufficient.

【００１３】[0013]

【発明が解決しようとする課題】以上の説明をまとめる
と、高エネルギー密度、かつ高性能なアルカリ蓄電池用
正極を提供するには、多様な使用条件、特に高温下での
使用においても、従来より遥かに高いエネルギー密度、
即ち高密度充填の下での高利用率を実現する新しい活物
質が必要である。そのためには、以下の課題を改善する
必要がある。 （１）充放電反応において一電子反応以上を有し、その
利用率の高い活物質材料であること。即ち、Ｎｉベース
の酸化物としては、従来材料の充電状態である主にβ−
ＮｉＯＯＨ（Ｎｉの価数は３．０付近）より高次の酸化
物であるγ−ＮｉＯＯＨ（Ｎｉの価数は３．５〜約３．
８）を通常の充放電における充電状態の活物質として使
用可能とすること。 （２）活物質材料は、電極作成時には、高密度充填に適
する材料であること。 （３）充放電反応は、高温下においても従来の材料より
高効率で行われること。 （４）高率放電においても、放電電圧は従来の材料と同
等またはそれ以上であること。 ここで重要であるのは、上記の問題を総て同時に解決を
図らなければならない点にある。即ち、高利用率を示す
活物質を、高密度に充填することができるＮｉをベース
にした酸化物であって、同時に充放電効率の高い材料を
開発することが必要である。SUMMARY OF THE INVENTION To summarize the above description, in order to provide a high energy density and high performance positive electrode for an alkaline storage battery, even under various use conditions, especially under high temperature, it is better than before. Much higher energy density,
That is, a new active material that realizes a high utilization rate under high density packing is required. To that end, it is necessary to improve the following issues. (1) An active material that has one or more electron reactions in a charge / discharge reaction and has a high utilization rate. That is, as the Ni-based oxide, β-based oxide, which is in the charged state of conventional materials, is mainly used.
Γ-NiOOH (the valence of Ni is 3.5 to about 3.) which is an oxide higher than NiOOH (the valence of Ni is around 3.0).
8) can be used as an active material in a charged state during normal charge / discharge. (2) The active material material should be a material suitable for high-density packing at the time of making an electrode. (3) The charge / discharge reaction should be performed with higher efficiency than conventional materials even at high temperatures. (4) Even in high-rate discharge, the discharge voltage should be equal to or higher than that of conventional materials. What is important here is that all of the above problems must be solved simultaneously. That is, it is necessary to develop a Ni-based oxide that can be densely packed with an active material exhibiting a high utilization rate, and at the same time, have a high charge / discharge efficiency.

【００１４】本発明の目的は、上記の条件（１）および
（２）を満たし、更に（３）、（４）が付与された実用
的な正極材料を提供することである。An object of the present invention is to provide a practical positive electrode material which satisfies the above conditions (1) and (2) and is further provided with (3) and (4).

【００１５】[0015]

【課題を解決するための手段】本発明は、Ｎｉを主とす
る複数金属元素の酸化物からなる活物質を具備するアル
カリ蓄電池用正極であって、前記複数金属元素の酸化物
は、少なくとも表面層には多数の微細孔を有し、その表
面層の平均組成とその内部の平均組成は異なるものであ
り、前記表面層には、Ｎｉのほかに、Ｃａ、Ｔｉ、Ｚ
ｎ、Ｓｒ、Ｂａ、Ｙ、Ｃｄ、Ｃｏ、Ｃｒ、Ｂｉ、および
Ｌａ族金属元素からなる群より選ばれた少なくとも一種
の元素が含まれているという点で、または前記元素が内
部より高濃度に含まれているという点で内部とは平均組
成が異なっているアルカリ蓄電池用正極を提供する。The present invention is a positive electrode for an alkaline storage battery, which comprises an active material composed of an oxide of a plurality of metal elements mainly containing Ni, wherein the oxide of the plurality of metal elements is at least on the surface. The layer has a large number of micropores, and the average composition of the surface layer is different from the average composition of the inside, and the surface layer contains Ca, Ti, Z in addition to Ni.
n, Sr, Ba, Y, Cd, Co, Cr, Bi, and at least one element selected from the group consisting of La group metal elements are contained, or the element has a higher concentration than the inside. Provided is a positive electrode for an alkaline storage battery, which has a different average composition from the inside in that it is included.

【００１６】本発明の好ましい態様において、前記複数
金属元素の酸化物の表面層に含まれたＮｉ以外の全金属
元素の平均的な含有割合ｘは、Ｎｉを含む全金属元素の
原子数を１としたとき、０．０１≦ｘ≦０．４で表され
る。本発明の好ましい他の態様において、前記複数金属
元素の酸化物の内部には、Ｎｉのほかに、Ａｌ、Ｖ、Ｃ
ｒ、Ｍｎ、Ｆｅ、Ｃｕ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ａ
ｇ、Ｓｎ、Ｓｂ、およびＷからなる群より選ばれた少な
くとも一種の元素が含まれているという点で、または前
記元素が表面層より高濃度に含まれているという点で、
表面層とは平均組成がさらに異なっている。In a preferred embodiment of the present invention, the average content ratio x of all metal elements other than Ni contained in the surface layer of the oxide of a plurality of metal elements is 1 in terms of the total number of metal elements including Ni. Is expressed as 0.01 ≦ x ≦ 0.4. In another preferable aspect of the present invention, in addition to Ni, Al, V, C is contained in the oxide of the plurality of metal elements.
r, Mn, Fe, Cu, Ge, Zr, Nb, Mo, A
In that it contains at least one element selected from the group consisting of g, Sn, Sb, and W, or that the element is contained in a higher concentration than the surface layer,
The average composition is further different from that of the surface layer.

【００１７】また、本発明は、Ｎｉを主とする複数金属
元素の酸化物からなる活物質を具備するアルカリ蓄電池
用正極であって、前記複数金属元素の酸化物は、少なく
とも表面層には多数の微細孔を有し、その表面層の平均
組成とその内部の平均組成は異なるものであり、前記複
数金属元素の酸化物の表面層を除く内部には、Ｎｉのほ
かに、Ａｌ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｕ、Ｇｅ、Ｚ
ｒ、Ｎｂ、Ｍｏ、Ａｇ、Ｓｎ、Ｓｂ、およびＷからなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が表面層より高濃度に含まれ
ているという点で、表面層とは平均組成が異なっている
アルカリ蓄電池用正極を提供する。前記複数金属元素の
酸化物の内部に含まれたＮｉ以外の全金属元素の平均的
な含有割合は、Ｎｉを含む全金属元素の原子数を１とし
たとき、０．０１≦ｙ≦０．３５で表される範囲が好ま
しい。Further, the present invention is a positive electrode for an alkaline storage battery, which comprises an active material composed of an oxide of a plurality of metal elements mainly containing Ni, wherein the plurality of oxides of the plurality of metal elements are present in at least a surface layer. And the average composition of the surface layer is different from the average composition of the inside thereof. Inside the surface except the surface layer of the oxide of a plurality of metal elements, in addition to Ni, Al, V, Cr, Mn, Fe, Cu, Ge, Z
The point that at least one element selected from the group consisting of r, Nb, Mo, Ag, Sn, Sb, and W is contained, or that the element is contained at a higher concentration than the surface layer. Then, a positive electrode for an alkaline storage battery having an average composition different from that of the surface layer is provided. The average content ratio of all metal elements other than Ni contained in the oxide of the plurality of metal elements is 0.01 ≦ y ≦ 0. The range represented by 35 is preferable.

【００１８】前記複数金属元素の酸化物は、通常前記Ｎ
ｉ以外の金属元素を固溶したニッケル酸化物、好ましく
は、水酸化ニッケル固溶体である。前記複数金属元素の
酸化物は、ＮｉおよびＮｉ以外の各金属元素の酸化物の
共晶で構成されることもありうる。前記複数金属元素の
酸化物の多数の微細孔は、孔径２００オングストローム
以下であり、表面層付近の微細孔同士は互いに連通して
いるのが好ましい。また、前記複数金属元素の酸化物に
おける表面層の厚さは、１０〜５００ｎｍであることが
好ましい。前記複数金属元素の酸化物は、平均径１００
μｍ以下の粉末であって、主に球状もしくは球状に近い
形状の粉末であり、タップ密度が１．５ｇ／ｃｃ以上で
あることが好ましい。本発明の活物質は、反応晶析法に
より作製した粉末、または多孔性の導電性支持体に電気
化学的に析出された活物質粉末として得られる。本発明
は、また上記の活物質を含む活物質混合物を導電性支持
体に支持させたアルカリ蓄電池用正極を提供する。The oxide of the plurality of metal elements is usually N
A nickel oxide in which a metal element other than i is solid-soluted, preferably a nickel hydroxide solid solution. The oxide of a plurality of metal elements may be composed of Ni and a eutectic of an oxide of each metal element other than Ni. It is preferable that the large number of micropores of the oxide of a plurality of metal elements have a pore diameter of 200 angstroms or less, and the micropores near the surface layer communicate with each other. The thickness of the surface layer of the oxide of the plurality of metal elements is preferably 10 to 500 nm. The oxide of the plurality of metal elements has an average diameter of 100.
It is preferable that the powder has a particle diameter of not more than μm and is mainly spherical or nearly spherical and has a tap density of 1.5 g / cc or more. The active material of the present invention is obtained as a powder produced by a reaction crystallization method or an active material powder electrochemically deposited on a porous conductive support. The present invention also provides a positive electrode for an alkaline storage battery, in which an active material mixture containing the above active material is supported on a conductive support.

【００１９】[0019]

【発明の実施の形態】本発明は、高エネルギー密度電極
を目指し、ニッケル酸化物をベースにした金属酸化物を
活物質とするニッケル電極における前述の課題を解決す
るため、以下の点に着目して改良を行った。 （１）Ｎｉ以外のある種の金属元素をニッケル酸化物に
固溶させることは、高温における性能を改善するのに有
益である。しかし、他元素の固溶による酸素発生過電圧
上昇の効果は、固−液界面、即ち活物質表面付近以外で
はその寄与が小さい。従って、従来行われてきたよう
に、活物質全体にわたってＮｉ以外の元素を固溶させた
場合には、固溶割合に比例した効果が得られにくい。BEST MODE FOR CARRYING OUT THE INVENTION The present invention aims at a high energy density electrode, and in order to solve the above-mentioned problems in a nickel electrode using a metal oxide based on nickel oxide as an active material, the following points are focused on. And improved. (1) The solid solution of a certain metal element other than Ni in nickel oxide is useful for improving the performance at high temperatures. However, the effect of increasing the oxygen generation overvoltage due to the solid solution of other elements has a small contribution except at the solid-liquid interface, that is, near the surface of the active material. Therefore, when elements other than Ni are solid-dissolved over the entire active material as has been conventionally performed, it is difficult to obtain the effect proportional to the solid-solution ratio.

【００２０】この点に鑑み、本発明では、活物質粉末の
表面層付近およびそこに近い粉末の微細孔に面した表面
層付近に上記の効果を持つ元素を固溶させる。または、
その固溶割合が内部より大きくなるようにする。本発明
者らは、この構成によって、酸素発生電位の向上に顕著
な効果が得られることを見出した。ここで言う表面層と
は、電気化学的に有効に働く表面であり、活物質表面よ
り深さ方向に約５００オングストローム程度の領域を指
すものである。この領域への元素固溶により、酸素発生
過電圧の上昇に顕著な効果を有することが確認された。
このことは、酸素発生過電圧向上の効果を有する元素
は、表面層のみに固溶させれば十分な効果を得ることが
でき、活物質粉末全体に固溶させた従来法に対し、より
少量の元素固溶により同等の効果を得られることを意味
する。言い換えれば、充放電反応の主な担い手である活
物質内のＮｉ量の減少を防ぐため、エネルギー密度の向
上の効果をも併せ持つのである。また、当然ではある
が、高価な元素を固溶させる場合には、材料コストの低
減にも極めて効果的となる。In view of this point, in the present invention, the element having the above-mentioned effect is solid-dissolved in the vicinity of the surface layer of the active material powder and in the vicinity of the surface layer facing the fine pores of the powder. Or
The solid solution ratio should be higher than that in the interior. The present inventors have found that this configuration has a remarkable effect in improving the oxygen generation potential. The surface layer mentioned here is a surface that works electrochemically effectively, and indicates a region of about 500 angstroms in the depth direction from the surface of the active material. It was confirmed that the elemental solid solution in this region has a remarkable effect on the increase of the oxygen generation overvoltage.
This means that the element having the effect of improving the oxygen generation overvoltage can obtain a sufficient effect if it is solid-soluted only in the surface layer, and a smaller amount than that in the conventional method in which it is solid-dissolved in the whole active material powder. It means that the same effect can be obtained by elemental solid solution. In other words, it also has the effect of improving the energy density in order to prevent the decrease of the amount of Ni in the active material, which is the main player of the charge / discharge reaction. In addition, as a matter of course, when an expensive element is solid-dissolved, it is very effective in reducing the material cost.

【００２１】このような作用を有する元素は、Ｃａ、Ｔ
ｉ、Ｚｎ、Ｂａ、Ｙ、Ｃｄ、Ｃｏ、Ｃｒ、Ｂｉ、および
Ｌａ族金属である。このうちＣａは、水酸化ニッケルに
固溶しやすい。そして、Ｃａを固溶した水酸化ニッケル
は、高温における充電効率が大きく向上し、利用率にも
優れている。したがって、固溶元素としてＣａは有用で
ある。Ｔｉは、酸素発生電位を上昇させるので、高温に
おける充電効率を向上させるのに効果がある。Ｃｏは、
高温における充電効率を向上させるだけでなく、導電性
をも向上させる。従って、他の元素と併せて固溶させる
のが望ましい。Ｙは、少量で高温における充電効率を大
きく向上させるので、Ｎｉの含有量を大きくとることが
でき有利である。最近、Ｃｏ酸化物やＭｎ酸化物、Ｃｄ
酸化物などのＮｉ酸化物以外の金属酸化物のみからなる
層で活物質表面を被覆する提案がなされている（米国特
許第５，５２３，１８２号）。しかし、この金属酸化物
層は、活物質粉末間または活物質と基体間の導電性を確
保するものであって、それ自体が酸化還元反応を行う活
物質ではないので、高エネルギー密度の材料としては不
利になる。これに対して本発明では、表面層はそれ自体
が酸化還元反応を行う活物質の一部であって、Ｎｉ含有
量を極力低下させずに酸素発生過電圧を増大させること
によって充電効率を向上させるものである。Elements having such an action are Ca, T
i, Zn, Ba, Y, Cd, Co, Cr, Bi, and La group metals. Of these, Ca easily dissolves in nickel hydroxide. The nickel hydroxide containing Ca as a solid solution has a significantly improved charging efficiency at high temperatures and is excellent in utilization rate. Therefore, Ca is useful as a solid solution element. Since Ti raises the oxygen generation potential, it is effective in improving the charging efficiency at high temperatures. Co is
It not only improves charging efficiency at high temperatures, but also improves conductivity. Therefore, it is desirable to form a solid solution together with other elements. A small amount of Y greatly improves the charging efficiency at high temperatures, so that the content of Ni can be made large, which is advantageous. Recently, Co oxide, Mn oxide, Cd
It has been proposed to coat the surface of the active material with a layer composed of only metal oxides other than Ni oxides such as oxides (US Pat. No. 5,523,182). However, since this metal oxide layer secures conductivity between the active material powders or between the active material and the substrate, and is not an active material itself that undergoes a redox reaction, it is used as a high energy density material. Is at a disadvantage. On the other hand, in the present invention, the surface layer itself is a part of the active material that carries out the redox reaction, and improves the charging efficiency by increasing the oxygen generation overvoltage without reducing the Ni content as much as possible. It is a thing.

【００２２】（２）γ−ＮｉＯＯＨは、これまでは不活
性であると考えられてきた。ところが、固溶元素によっ
ては、未充電状態ではβ相の水酸化ニッケルであって
も、常温または高温雰囲気下において、充電時にγ−Ｎ
ｉＯＯＨを生成し、これが通常の電池電圧の範囲で容易
に放電して再びβ相の酸化物に戻るものがあることがわ
かった。このような活物質は、電極構成時には有利な高
い密度を有しており、かつ充放電時には高次酸化物であ
るγ−ＮｉＯＯＨが利用される。従って、エネルギー密
度を向上する上で極めて有効である。ただし、Ａｌな
ど、固溶元素によっては、粉末作成時にα相の酸化物が
若干生じるのが認められる場合もある。しかし、それは
不安定であり、アルカリ中で長時間保持することにより
消滅してしまう。(2) γ-NiOOH has hitherto been considered to be inactive. However, depending on the solid solution element, even if it is β-phase nickel hydroxide in an uncharged state, γ-N is charged at the time of charging in normal temperature or high temperature atmosphere.
It has been found that there are some that generate iOOH, which easily discharges in the range of normal battery voltage and returns to the β-phase oxide again. As such an active material, γ-NiOOH which is a high-order oxide is used because it has a high density that is advantageous when forming an electrode, and during charge and discharge. Therefore, it is extremely effective in improving the energy density. However, depending on the solid solution element such as Al, some α-phase oxide may be observed to be generated during powder preparation. However, it is unstable and disappears when it is kept in alkali for a long time.

【００２３】ニッケル酸化物への他金属元素の固溶は、
充放電反応の主な担い手であるＮｉ量が減少することに
なるから、活物質の高容量化を行うには、他元素の固溶
によるＮｉ量の減少が、γ−ＮｉＯＯＨの利用による反
応次数の向上、即ち活物質利用率の向上のメリットを上
回らないように、固溶元素の選択および固溶量の適正化
に留意する必要がある。この他、固溶元素の種類によっ
て異なるが、固溶量が極端に低い場合あるいは固溶限界
を超えた場合には、充電時においてγ−ＮｉＯＯＨの生
成の促進の効果が得られ難くなることがある。ニッケル
酸化物へ他金属元素を固溶させるに際しては、複数種の
元素を固溶させることが幅広い性能の改善には有益であ
る。また、前述の固溶量の適正化は、固溶された元素の
全固溶量に関して行わなければならない。The solid solution of other metal elements in nickel oxide is
Since the amount of Ni, which is the main player of the charge / discharge reaction, will decrease, in order to increase the capacity of the active material, the decrease in the amount of Ni due to the solid solution of other elements depends on the reaction order by the use of γ-NiOOH. Therefore, it is necessary to pay attention to the selection of the solid solution element and the optimization of the amount of the solid solution so as not to exceed the merit of improving the efficiency, that is, improving the utilization rate of the active material. In addition, although depending on the type of solid solution element, if the amount of solid solution is extremely low or exceeds the solid solution limit, it may be difficult to obtain the effect of promoting the production of γ-NiOOH during charging. is there. When solid-dissolving other metal elements in nickel oxide, solid-solubilizing a plurality of kinds of elements is useful for improving a wide range of performance. Further, the optimization of the solid solution amount described above must be performed with respect to the total solid solution amount of the dissolved elements.

【００２４】このように充電時に低密度となる材料を用
いる場合には、充放電時の密度変化が大きくなり、サイ
クル寿命等で問題を来す恐れがある。これに対しては、
極板作成時に結着剤を少量用いること、および、後述す
るように、強固な導電性を電極に付与することによっ
て、現在求められる範囲では実用上差し支えない程度に
まで改善することができる。γ−ＮｉＯＯＨは、βーＮ
ｉＯＯＨより低い放電電位を有するから、γ−ＮｉＯＯ
Ｈを利用する上記のような材料を活物質に用いると、電
池の放電電圧の低下を招き、エネルギー密度低下の一因
となる。従って、γ−ＮｉＯＯＨの生成を促進させるよ
うな固溶元素は、活物質表面付近よりは内部に存在させ
た方が有利である。そのような目的に用いられる元素
は、Ａｌ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｕ、Ｇｅ、Ｚｒ、
Ｎｂ、Ｍｏ、Ａｇ、Ｓｎ、Ｓｂ、およびＷである。この
うち、Ｍｎは、他元素の場合より放電しやすいγ相の生
成量を大きくするので、活物質の利用率を高める。ま
た、β相の合成が容易であるため、適当な条件下で高密
度の結晶が得られる。Ａｌは、利用率を向上させるだけ
でなく、特異的に放電電位を上昇させる。Ｃｒは、高温
における充電効率を向上させる効果も有する。これらの
元素のなかには、Ｃｒなど溶出しやすい元素も含まれて
いる。従って、そのような元素は、活物質内部に配する
のが有効である。ただし、Ａｌは、放電電圧を引き上げ
る作用があるため、他の元素に比して表面付近に多く配
しても良い。この場合でも、他の固溶元素と併せた全固
溶量に関して表面より内部が多くなっていれば、前述の
効果を得ることができる。なお、Ｍｎ、Ｆｅ等はＮｉに
比して安価であり、材料コスト低減にも寄与する。When a material having a low density during charging is used as described above, the density change during charging and discharging becomes large, which may cause a problem in cycle life and the like. For this,
By using a small amount of a binder at the time of forming the electrode plate, and imparting strong conductivity to the electrode, as will be described later, it can be improved to a practically acceptable level in the currently required range. γ-NiOOH is β-N
Since it has a discharge potential lower than that of iOOH, γ-NiOO
The use of the above-mentioned materials using H as the active material causes a decrease in the discharge voltage of the battery, which is one of the causes of the decrease in the energy density. Therefore, it is advantageous that the solid solution element that promotes the formation of γ-NiOOH is present inside the active material rather than near the surface. Elements used for such purposes include Al, V, Cr, Mn, Fe, Cu, Ge, Zr,
Nb, Mo, Ag, Sn, Sb, and W. Of these, Mn increases the amount of γ-phase that is more easily discharged than other elements, and thus increases the utilization rate of the active material. Moreover, since the β phase is easily synthesized, a high-density crystal can be obtained under appropriate conditions. Al not only improves the utilization rate, but also specifically raises the discharge potential. Cr also has the effect of improving the charging efficiency at high temperatures. Among these elements, elements such as Cr that easily elute are included. Therefore, it is effective to dispose such an element inside the active material. However, since Al has a function of increasing the discharge voltage, Al may be arranged in a larger amount in the vicinity of the surface than other elements. Even in this case, the above effect can be obtained as long as the inside is larger than the surface in terms of the total amount of solid solution combined with other solid solution elements. It should be noted that Mn, Fe, etc. are cheaper than Ni and contribute to material cost reduction.

【００２５】（３）エネルギー密度の向上とともに、高
率放電特性および／または高温での充電特性の向上を図
るには、上記（１）、（２）の手段を組み合わせて用い
ることが極めて有効である。即ち、表面層と内部の材料
を変え、異なる機能を担わせることによって、前述の課
題の解決を同時に図ることができ、多様な使用条件の下
で高いエネルギー密度を有するアルカリ蓄電池用正極を
可能とする。 （４）これらの元素の状態に関しては、その作用上、Ｎ
ｉ（ＯＨ）2の結晶内に固溶したものであることが望ま
しい。しかし、特に高温充電特性を向上させる元素に関
しては、共晶状態であっても効果が認められる。 （５）粉末の形状に関しては、二次元または三次元の金
属多孔体への充填し易さを考え、球状または球状に近い
形状の粉末とすることがエネルギー密度向上のためには
有利である。(3) In order to improve the energy density and the high-rate discharge characteristics and / or the charging characteristics at high temperature, it is extremely effective to use the means of (1) and (2) in combination. is there. That is, by changing the materials of the surface layer and the inside and performing different functions, it is possible to simultaneously solve the above-mentioned problems, and it is possible to provide a positive electrode for an alkaline storage battery having a high energy density under various usage conditions. To do. (4) Regarding the states of these elements, due to their action, N
It is preferably a solid solution in the crystal of i (OH) 2 . However, the effect is recognized especially in the eutectic state for the element that improves the high-temperature charging property. (5) Regarding the shape of the powder, considering the ease of filling into a two-dimensional or three-dimensional porous metal body, it is advantageous to use a spherical or near-spherical shape powder for improving the energy density.

【００２６】（６）活物質粉体の構造に関しては、多数
の微細孔を有することにより電解液の液回りが良好とな
るほか、固−液界面の増大により反応面積が増大し、特
に高率放電時に速やかな電極反応が可能となる。速やか
な電極反応が行われない場合には、放電時の過電圧が増
大し、放電電圧が低下する。高次酸化物を利用する材料
では、充放電反応によってアルカリイオンの挿入・脱離
を伴うことから、この様にして電極表面の反応面積を増
大させる工夫を行うことが重要である。ただし、電極に
活物質を有効に詰め込むためには、粉体としての密度が
高いことが必須である。活物質の多数の微細孔は、孔径
２００オングストローム程度以下であり、粉末全体の表
面層付近の微細孔同士は連通していることが望ましい。(6) With respect to the structure of the active material powder, the presence of a large number of fine pores improves the liquid flow of the electrolytic solution, and the increase in the solid-liquid interface increases the reaction area, resulting in a particularly high rate. A prompt electrode reaction is possible during discharge. If a rapid electrode reaction is not performed, the overvoltage during discharge increases and the discharge voltage decreases. It is important to devise to increase the reaction area of the electrode surface in this way, since the material using the higher order oxide is accompanied by the insertion / desorption of alkali ions by the charge / discharge reaction. However, in order to effectively pack the active material in the electrode, it is essential that the powder has a high density. A large number of micropores in the active material have a pore diameter of about 200 angstroms or less, and it is desirable that the micropores near the surface layer of the entire powder be in communication with each other.

【００２７】（７）本発明によって活物質の特性は大幅
に改善するが、電極として使用するには、極板としての
導電性を確保しなければならない。前記のようにＮｉ
（ＯＨ）2に他元素を固溶させることによって副次的に
活物質自身の導電性の向上は見られる。しかし、活物質
を二次元または三次元の金属多孔体に充填して電極を構
成する際には、活物質粉末同士間、および活物質と電極
基体間の導電性を補填することが重要である。特に、こ
の材料のように充放電により膨張・収縮が大きい場合に
は、活物質粉末の表面に、導電性を有する金属酸化物ま
たは金属の微細な結晶からなる薄層で強固な被覆もしく
はネットワークを付与するのが有効である。(7) Although the characteristics of the active material are significantly improved by the present invention, the conductivity as an electrode plate must be secured in order to use it as an electrode. As mentioned above Ni
It can be seen that the conductivity of the active material itself is secondarily improved by solid-solving (OH) 2 with another element. However, when the active material is filled in a two-dimensional or three-dimensional metallic porous body to form an electrode, it is important to supplement the conductivity between the active material powders and between the active material and the electrode substrate. . In particular, when this material has large expansion and contraction due to charging and discharging, a strong coating or network is formed on the surface of the active material powder with a thin layer of conductive metal oxide or fine crystals of metal. It is effective to give it.

【００２８】本発明による正極は、多孔性の導電性支持
体に活物質を電気化学的に析出させる方法によって作製
することができるが、反応晶析法または電気化学的析出
法により得た活物質粉末を含む活物質混合物を導電性支
持体である三次元的に連続した空間を有する金属多孔
体、例えば発泡状メタル内に充填するか、または、二次
元的な多孔金属板に塗着一体化して作製するのが好まし
い。前記の活物質混合物中には、結着剤、好ましくはポ
リエチレン、ポリテトラフルオロエチレン、ポリスチロ
ール、カルボキシメチルセルロース、メチルセルロー
ス、ポリビニルアルコール、ポリエチレンオキサイドお
よびスチレンブタジエンラバーから選ばれた少なくとも
一種を活物質粉末の重量に対して０．１〜７ｗｔ％添加
されているのが好ましい。The positive electrode according to the present invention can be prepared by a method of electrochemically depositing an active material on a porous conductive support, and the active material obtained by a reactive crystallization method or an electrochemical deposition method. The active material mixture containing the powder is filled in a porous metal body having a three-dimensionally continuous space which is a conductive support, for example, a foamed metal, or is coated and integrated on a two-dimensional porous metal plate. It is preferable to make it. In the active material mixture, a binder, preferably at least one selected from polyethylene, polytetrafluoroethylene, polystyrene, carboxymethyl cellulose, methyl cellulose, polyvinyl alcohol, polyethylene oxide and styrene butadiene rubber is used as the active material powder. It is preferable that 0.1 to 7 wt% is added to the weight.

【００２９】[0029]

【実施例】以下、本発明を実施例により、詳細に説明す
る。図１は、表面層付近の平均組成と内部の平均組成が
異なる、本発明による活物質粉末を模式的に示したもの
である。ここで、表面層付近とは、粒子自体の表面層ば
かりでなく、微細孔に面する部分をも含めている。表面
層は、ＣａおよびＹを固溶させたＮｉ（ＯＨ）2からな
る。ＣａおよびＹは、酸素発生電位を上昇させる作用を
持っている。この作用により活物質表面における酸素発
生が抑制され、４５℃など特に高温雰囲気下において充
電効率が向上し、活物質の深い充電が可能となる。EXAMPLES The present invention will be described in detail below with reference to examples. FIG. 1 schematically shows an active material powder according to the present invention in which the average composition near the surface layer is different from the average composition inside. Here, the vicinity of the surface layer includes not only the surface layer of the particles themselves but also the portion facing the fine pores. The surface layer is made of Ni (OH) 2 in which Ca and Y are solid-dissolved. Ca and Y have the action of increasing the oxygen generation potential. Owing to this action, oxygen generation on the surface of the active material is suppressed, the charging efficiency is improved especially in a high temperature atmosphere such as 45 ° C., and the active material can be deeply charged.

【００３０】一方、粉末内部は、Ｍｎ、Ａｌ、およびＣ
ｒを固溶させたＮｉ（ＯＨ）2からなる。ＭｎおよびＡ
ｌは、高次酸化物であるγ−ＮｉＯＯＨの生成を促進さ
せる作用を持っているから、この活物質は、従来品に比
してより多くの容量を充電することができる。また、こ
れらの元素を固溶させたγ−ＮｉＯＯＨは、通常使用す
る電圧の範囲で速やかに放電する。従って、活物質利用
率が向上する。また、特にＭｎの固溶により放電電圧の
低下が著しいが、Ｍｎを固溶していない表面層によっ
て、電圧の低下および固溶成分（ここではＣｒ、Ａｌが
主）の溶出を防止する。ここでは、固溶元素として、Ｃ
ａ、Ｙ、Ｍｎ、Ａｌ、およびＣｒを用いた例について説
明したが、他の固溶元素についても同様に適用可能であ
る。活物質の形状については、金属多孔体への充填し易
さから球状が好しく、その場合を例示した。On the other hand, inside the powder, Mn, Al, and C
It consists of Ni (OH) 2 in which r is dissolved. Mn and A
Since l has a function of promoting the production of γ-NiOOH which is a higher order oxide, this active material can charge a larger capacity as compared with the conventional product. Further, γ-NiOOH in which these elements are solid-dissolved quickly discharges in the range of voltage normally used. Therefore, the utilization rate of the active material is improved. Further, although the discharge voltage is remarkably lowered due to the solid solution of Mn, the voltage drop and the elution of the solid solution components (here mainly Cr and Al) are prevented by the surface layer in which the Mn is not solid solution. Here, as the solid solution element, C
An example using a, Y, Mn, Al, and Cr has been described, but the same can be applied to other solid solution elements. Regarding the shape of the active material, a spherical shape is preferable because it is easy to fill the porous metal body, and the case is exemplified.

【００３１】図２および図３は、発泡状ニッケル基板
に、活物質を充填した例を示している。これらの図にお
いて、１は発泡状ニッケル基板の骨格を示している。こ
の基板の三次元的に連なる空隙部内に、ＣｏＯＯＨの導
電性多孔層３により被覆された活物質粉末２、Ｙ2Ｏ3粉
末４、および結着剤の四フッ化エチレン樹脂５からなる
活物質混合物が充填されている。６は電極をフッ素樹脂
の水分散液に浸漬処理して形成されたフッ素樹脂皮膜で
あり、７は空間部を示している。この電極においては、
活物質粉末間および活物質と基板間は、活物質を被覆し
ているＣｏＯＯＨによって導電的に連絡されている。ま
た、このＣｏＯＯＨと結着剤のフッ素樹脂が、極板の膨
張収縮による劣化を抑制している。さらに、添加された
Ｙ2Ｏ3によって、高温充電特性が補填される。2 and 3 show an example in which a foamed nickel substrate is filled with an active material. In these figures, 1 shows the skeleton of the foamed nickel substrate. An active material composed of an active material powder 2, Y 2 O 3 powder 4 coated with a conductive porous layer 3 of CoOOH, and a tetrafluoroethylene resin 5 serving as a binder in the three-dimensionally continuous voids of this substrate. The mixture is filled. Reference numeral 6 is a fluororesin film formed by dipping the electrode in an aqueous dispersion of fluororesin, and 7 is a space. In this electrode,
The active material powder and the active material and the substrate are electrically connected to each other by CoOOH coating the active material. Further, the CoOOH and the fluorocarbon resin as the binder suppress the deterioration due to the expansion and contraction of the electrode plate. Furthermore, the added Y 2 O 3 supplements the high temperature charging characteristics.

【００３２】ここで、以下の実施例１〜１３、および比
較例１〜１０で製作されたニッケル正極板の評価に使用
する電池の構成について述べる。正極板は、３５×３５
ｍｍの大きさに整形し、基板中にあらかじめ設けられた
リード接続部に電極リードをスポット溶接した後、スル
フォン化ポリプロピレン不織布からなるセパレータで包
み込み、セパレータの数ヵ所を熱溶着する。対極には、
正極に対しその容量が十分大である公知のアルカリ蓄電
池用負極を用いる。ここでは水素吸蔵合金ＭｍＮｉ3.55
Ｃｏ0.75Ｍｎ0.4Ａｌ0.3からなる負極を用いた。ここで
扱われる特性は、正極に起因するものであって、使用す
る負極によらない。従って、他のアルカリ蓄電池用負
極、例えばＺｒ−Ｍｎ−Ｖ−Ｃｏ−Ｎｉ系水素吸蔵合金
負極、Ｃｄ電極あるいはＺｎ電極を用いた場合にも同様
の効果が得られる。Here, the structure of the battery used for evaluation of the nickel positive electrode plates manufactured in the following Examples 1 to 13 and Comparative Examples 1 to 10 will be described. The positive plate is 35x35
After shaping to a size of mm and spot welding the electrode lead to a lead connecting portion previously provided in the substrate, the electrode lead is wrapped with a separator made of a sulfonated polypropylene nonwoven fabric, and several places of the separator are heat-welded. At the other end,
A known negative electrode for an alkaline storage battery, which has a capacity sufficiently larger than that of the positive electrode, is used. Here, hydrogen storage alloy MmNi 3.55
A negative electrode made of Co 0.75 Mn 0.4 Al 0.3 was used. The characteristics treated here are due to the positive electrode and not to the negative electrode used. Therefore, the same effect can be obtained when another negative electrode for an alkaline storage battery, for example, a Zr-Mn-V-Co-Ni-based hydrogen storage alloy negative electrode, a Cd electrode or a Zn electrode is used.

【００３３】上記の水素吸蔵合金は、所定の割合で混合
したＭｍ、Ｎｉ、Ｃｏ、Ｍｎ、およびＡｌをアーク溶解
炉にて溶解して作製した。この合金塊を不活性雰囲気中
で機械的に粉砕し、粒径３０μｍの粉末とした。この粉
末に結着剤のカルボキシメチルセルロースの水溶液を加
えて混練し、得られたペーストを電極支持体に加圧充填
し厚さ０．４５ｍｍ、容量密度１３５０ｍＡｈ／ｃｃの
水素吸蔵合金負極板を得た。この負極板を３５×３５ｍ
ｍに切断し、正極の場合と同様に電極リードをスポット
溶接し、スルフォン化ポリプロピレン不織布からなるセ
パレーターで包み込み、セパレータを数ヵ所で熱溶着し
た。この負極２枚の間に前記正極を挟み込み、電槽内に
挿入した後、３０ｗｔ％のＫＯＨ水溶液を４００ｍｌ注
入する。以下の実施例または比較例で得られたニッケル
正極板の特性は、この様にして製作された開放型ニッケ
ル−水素電池により評価されたものである。The above hydrogen storage alloy was prepared by melting Mm, Ni, Co, Mn, and Al mixed at a predetermined ratio in an arc melting furnace. This alloy block was mechanically crushed in an inert atmosphere to obtain a powder having a particle size of 30 μm. An aqueous solution of carboxymethylcellulose as a binder was added to this powder and kneaded, and the obtained paste was pressure-filled into an electrode support to obtain a hydrogen storage alloy negative electrode plate having a thickness of 0.45 mm and a capacity density of 1350 mAh / cc. . This negative plate is 35 x 35 m
Then, the electrode lead was spot-welded in the same manner as in the case of the positive electrode, wrapped with a separator made of sulfonated polypropylene nonwoven fabric, and the separator was heat-welded at several places. The positive electrode is sandwiched between two negative electrodes, inserted into a battery case, and 400 ml of a 30 wt% KOH aqueous solution is injected. The characteristics of the nickel positive electrode plates obtained in the following examples or comparative examples were evaluated by the open-type nickel-hydrogen battery thus manufactured.

【００３４】《比較例１》厚さ０．５ｍｍの白金板を大
きさ３５×３５ｍｍに切断し、電極リードをスポット溶
接した。この白金板からなる陰極と、同じく白金板から
なる対極を１ｍｏｌ／ｌのＮｉ（ＮＯ3 ）2水溶液中に
浸漬し、２５ｍＡの電流を３時間通電することにより、
陰極にＮｉ（ＯＨ）2を電気化学的に析出させた。Ｎｉ
（ＯＨ）2を析出させた白金板を６０℃の３０ｗｔ％苛
性カリ水溶液に４０時間浸漬するアルカリ処理をした
後、水洗、乾燥してニッケル正極板とした。Comparative Example 1 A platinum plate having a thickness of 0.5 mm was cut into a size of 35 × 35 mm, and electrode leads were spot-welded. By immersing the cathode made of this platinum plate and the counter electrode made of the same platinum plate in a 1 mol / l Ni (NO 3 ) 2 aqueous solution, and applying a current of 25 mA for 3 hours,
Ni (OH) 2 was electrochemically deposited on the cathode. Ni
The platinum plate on which (OH) 2 was deposited was immersed in a 30 wt% caustic potash aqueous solution at 60 ° C. for 40 hours for alkali treatment, then washed with water and dried to obtain a nickel positive electrode plate.

【００３５】《実施例１》０．８ｍｏｌ／ｌのＮｉ（Ｎ
Ｏ3）2および０．２ｍｏｌ／ｌのＣａ(ＮＯ3)2を含む混
合水溶液を１１準備した。この溶液に、比較例１と同様
にして得たニッケル極板と白金板からなる対極を浸漬
し、ニッケル極板を陰極として２５ｍＡの電流を１時間
通電した。次いで、前記のニッケル極板を６０℃の３０
ｗｔ％ＫＯＨ水溶液中に４０時間浸漬するアルカリ処理
を行った後、水洗、乾燥した。こうして、Ｃａを固溶し
たＮｉ（ＯＨ）2の表面層を有する、厚さ５００ｎｍの
Ｎアｉ（ＯＨ）2の析出層を持った正極板を得た。同様に
通電電気量を調節することにより、厚さが５０、１０
０、２００、５００、１０００ｎｍの、Ｃａを固溶した
Ｎｉ（ＯＨ）2の表面層を有するＮｉ（ＯＨ）2析出層を
持った正極板を作成した。Example 1 0.8 mol / l Ni (N
11 mixed aqueous solutions containing O 3 ) 2 and 0.2 mol / l Ca (NO 3 ) 2 were prepared. A counter electrode consisting of a nickel electrode plate and a platinum plate obtained in the same manner as in Comparative Example 1 was immersed in this solution, and a current of 25 mA was applied for 1 hour using the nickel electrode plate as a cathode. Then, the nickel plate is heated to 60 ° C. for 30 minutes.
After performing an alkali treatment of immersing in a wt% KOH aqueous solution for 40 hours, it was washed with water and dried. Thus, having a surface layer of Ni (OH) 2 was solid solution of Ca, to give a positive electrode plate having a deposit of N A i (OH) 2 having a thickness of 500 nm. Similarly, the thickness can be adjusted to 50, 10 by adjusting the amount of electricity supplied.
A positive electrode plate having a Ni (OH) 2 deposition layer having a surface layer of Ni (OH) 2 in which Ca was solid-solved was prepared at 0, 200, 500, and 1000 nm.

【００３６】《実施例２》厚さ０．５ｍｍの白金板を大
きさ３５×３５ｍｍに切断し、電極リードをスポット溶
接した。これを１ｍｏｌ／ｌのＮｉＳＯ4水溶液１ｌ中
に浸漬し、陰分極することにより、Ｎｉ（ＯＨ）2を析
出させた。これを３０ｗｔ％のＫＯＨ水溶液中に２４時
間浸漬するアルカリ処理を行った後、水洗、乾燥した。
ＮｉＳＯ4水溶液にエチレンジアミン四酢酸（以下ＥＤ
ＴＡで表す）を加え、錯体を形成させた。同様にＣａ
（ＮＯ3）2水溶液にＥＤＴＡを加え錯体を形成させた。
両者の溶液を所望の割合で混合し、その混合液中にｐＨ
調整のためイオン交換水、及びＮａＯＨ水溶液を加え、
Ｎｉ及びＣａを錯イオンの形でそれぞれ０．８ｍｏｌ／
ｌ及び０．２ｍｏｌ／ｌ含み、ｐＨ＝１１．５の混合液
を調製した。この様にして得られた混合液１ｌに、比較
例１と同様にして得られたニッケル極板を浸漬し、８０
℃に加熱した。次いで、前記のニッケル極板を３０ｗｔ
％のＫＯＨ水溶液中に２４時間浸漬するアルカリ処理を
行った後、水洗、乾燥した。こうして、Ｃａを固溶した
Ｎｉ（ＯＨ）2の表面層を有する、Ｎｉ（ＯＨ）2析出層
を持った正極板を得た。Example 2 A platinum plate having a thickness of 0.5 mm was cut into a size of 35 × 35 mm, and electrode leads were spot-welded. This was immersed in 1 liter of a 1 mol / l NiSO 4 aqueous solution and subjected to negative polarization to deposit Ni (OH) 2 . This was alkali-treated by immersing it in a 30 wt% KOH aqueous solution for 24 hours, then washed with water and dried.
NiSO 4 aqueous solution of ethylenediaminetetraacetic acid (hereinafter ED
(Denoted by TA) was added to form a complex. Similarly Ca
EDTA was added to the (NO 3 ) 2 aqueous solution to form a complex.
Mix both solutions at the desired ratio and add pH to the mixture.
Add ion-exchanged water and NaOH aqueous solution for adjustment,
Ni and Ca in the form of complex ions each 0.8 mol /
A mixed solution containing 1 and 0.2 mol / l and having a pH of 11.5 was prepared. The nickel plate obtained in the same manner as in Comparative Example 1 was immersed in 1 l of the mixed solution thus obtained,
Heated to ° C. Next, 30 wt% of the above nickel electrode plate
% Alkaline aqueous solution for 24 hours, washed with water and dried. Thus, having a surface layer of Ni (OH) 2 was solid solution of Ca, to give a positive electrode plate having a Ni (OH) 2 precipitate layer.

【００３７】図４は実施例１および比較例１の極板の酸
素発生電位と充電電位の差ηと、Ｎｉ（ＯＨ）2析出層
におけるＣａを含む表面層の厚みとの関係を示す。図４
から明らかなように、Ｃａを含む表面層を有しない比較
例１に比して、Ｃａを含む表面層を有する極板は、ηが
大きく、従って充電効率が向上している。一方、Ｃａを
含む表面層の厚みが５００ｎｍ以上では、ηはほぼ一定
となる。従って、充電効率の向上には、５００ｎｍ程度
の厚みのＣａを含む表面層を有していれば十分である。
実施例１の極板は、その表面が微細孔の少ない平板状の
薄膜によって被覆されていた。実施例２の極板は、微細
孔が多数存在した多孔質な表面を有していた。表１は、
実施例１、２、および比較例１の極板を２ｍＡで１０時
間充電した後、１０ｍＡで放電したときの平均放電電圧
を示している。FIG. 4 shows the relationship between the difference η between the oxygen generation potential and the charging potential of the electrode plates of Example 1 and Comparative Example 1 and the thickness of the surface layer containing Ca in the Ni (OH) 2 precipitation layer. Figure 4
As is apparent from the above, the electrode plate having the surface layer containing Ca has a larger η, and therefore the charging efficiency is improved, as compared with Comparative Example 1 having no surface layer containing Ca. On the other hand, when the thickness of the surface layer containing Ca is 500 nm or more, η is almost constant. Therefore, in order to improve the charging efficiency, it is sufficient to have the surface layer containing Ca having a thickness of about 500 nm.
The surface of the electrode plate of Example 1 was covered with a flat thin film having few fine holes. The electrode plate of Example 2 had a porous surface with many fine pores. Table 1 shows
The average discharge voltage when the electrode plates of Examples 1 and 2 and Comparative Example 1 were charged at 2 mA for 10 hours and then discharged at 10 mA is shown.

【００３８】[0038]

【表１】 [Table 1]

【００３９】実施例２の極板は、実施例１の極板に比し
て平均放電電圧が高かった。白金板上に、Ｎｉ（ＯＨ）
2に代えて、Ｍｎを固溶したＮｉ（ＯＨ）2を電気化学的
に析出させた他は、前記実施例２と同様にして作製した
正極板の場合は、更に平均放電電圧の向上の効果が高か
った。従って、活物質の表面層は、微細孔を多数有した
ものである方が好ましい。The electrode plate of Example 2 had a higher average discharge voltage than the electrode plate of Example 1. Ni (OH) on the platinum plate
In the case of the positive electrode plate produced in the same manner as in Example 2 except that Ni (OH) 2 in which Mn was dissolved as a solid solution was electrochemically deposited instead of 2 , the effect of further improving the average discharge voltage was obtained. Was high. Therefore, the surface layer of the active material preferably has a large number of fine pores.

【００４０】《実施例３》０．９ｍｏｌ／ｌのＮｉ（Ｎ
Ｏ3）2および０．１ｍｏｌ／ｌのＺｎ(ＮＯ3)2を含む混
合水溶液を１１準備し、実施例１と同様にしてＺｎを固
溶したＮｉ（ＯＨ）2の表面層を有する、厚さ５００ｎ
ｍのＮｉ（ＯＨ）2正極板を作成した。更にＮｉ（Ｎ
Ｏ3）2、Ｚｎ（ＮＯ3）2の濃度を変化させることにより
所望の量のＺｎを含有したＮｉ（ＯＨ）2の表面層を有
するＮｉ（ＯＨ）2の析出層を持った正極板を作成し
た。図５は実施例３および比較例１の極板の酸素発生電
位と充電電位の差ηと、Ｚｎを含有したＮｉ（ＯＨ）2
層のＺｎの固溶割合との関係を表したものである。ここ
で、固溶割合ｘは、ニッケルの原子数を（１−ｘ）で表
したときの値である。図５から明らかなように、表面層
に含まれるＺｎの固溶割合が０．０５程度からηの上昇
が明確に認められる。しかし、Ｚｎの固溶割合が０．３
以上の場合にはＺｎＯの生成が認められた。従って、表
面層におけるＺｎの固溶割合は０．０５から０．３程度
であることが望ましい。Example 3 0.9 mol / l Ni (N
A mixed aqueous solution containing O 3 ) 2 and 0.1 mol / l Zn (NO 3 ) 2 was prepared, and a surface layer of Ni (OH) 2 containing Zn as a solid solution was prepared in the same manner as in Example 1. 500n
m Ni (OH) 2 positive electrode plate was prepared. Furthermore, Ni (N
O 3) 2, Zn (NO 3) positive electrode plate having a deposited layer of Ni (OH) 2 having a surface layer of Ni (OH) 2 containing a Zn desired amount by varying the second concentration Created. FIG. 5 shows the difference η between the oxygen generation potential and the charging potential of the electrode plates of Example 3 and Comparative Example 1 and Ni (OH) 2 containing Zn.
It shows the relationship with the solid solution ratio of Zn in the layer. Here, the solid solution ratio x is a value when the number of nickel atoms is represented by (1-x). As is clear from FIG. 5, the increase of η is clearly recognized when the solid solution ratio of Zn contained in the surface layer is about 0.05. However, the solid solution ratio of Zn is 0.3
In the above cases, formation of ZnO was confirmed. Therefore, the solid solution ratio of Zn in the surface layer is preferably about 0.05 to 0.3.

【００４１】以上の実施例および比較例では、Ｎｉ（Ｏ
Ｈ）2の表面層に含有させる元素としてＣａまたはＺｎ
を取り上げたが、これらに代えてＴｉ、Ｚｎ、Ｓｒ、Ｂ
ａ、Ｙ、Ｃｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族元素か
らなる群より選ばれる１種または２種以上の金属元素を
用いることができる。そして、これら金属元素を含むＮ
ｉ（ＯＨ）2の表面層を形成するには、上記と同様の方
法を用いることができ、同様の効果を得ることができ
る。表２にこれらの金属元素を用い、実施例１と同様に
して製作した電極の酸素発生と電位充電電位の差ηを示
す。In the above examples and comparative examples, Ni (O
H) 2 Ca or Zn as an element contained in the surface layer
However, instead of these, Ti, Zn, Sr, B
One or more metal elements selected from the group consisting of a, Y, Cd, Co, Cr, Bi, and La group elements can be used. And N containing these metal elements
The same method as described above can be used to form the surface layer of i (OH) 2 , and the same effect can be obtained. Table 2 shows the difference η between the oxygen generation and the potential charging potential of the electrode manufactured using these metal elements in the same manner as in Example 1.

【００４２】[0042]

【表２】 [Table 2]

【００４３】《実施例４》１ｍｏｌ／ｌのＮｉＳＯ4水
溶液、２ｍｏｌ／ｌのＮａＯＨ水溶液、および２．１ｍ
ｏｌ ／ｌのＮＨ3水を準備し、撹拌翼を備えた反応晶析
装置にそれぞれ１ｍｌ／ｍｉｎの割合で連続的に供給し
た。そして、反応槽内で溶液の混合物を撹拌し、水酸化
ニッケルを生成させた。その生成反応が定常的となった
後に、懸濁液を採集した。これをデカンテーションによ
り水洗した後、４０℃に保った３０ｗｔ％ＫＯＨ水溶液
中に５時間浸漬した。次いで、水洗、乾燥して平均粒径
２０μｍの球状Ｎｉ（ＯＨ）2粉末を得た。次いで、Ｎ
ｉＳＯ4水溶液にＥＤＴＡを加えて錯体を形成させた。
同様にＣａ（ＮＯ3)2水溶液にＥＤＴＡを加えて錯体を
形成させた。各々の錯体を含む液を所望の割合で混合
し、混合液中にｐＨ調整のためイオン交換水、及びＮａ
ＯＨ水溶液を加え、Ｎｉ及びＣａを錯イオンの形でそれ
ぞれ０．８ｍｏｌ／ｌおよび０．２ｍｏｌ／ｌ含み、ｐ
Ｈ＝１１．５である混合液を調製した。この混合液１ｌ
に上記で得られたＮｉ（ＯＨ）2粉末５０ｇを混合し、
撹拌しながら８０℃に加熱した。得られた懸濁液を遠心
分離し、上澄液をイオン交換水で置換し、生じた微結晶
を流体分級によって除去した後、水洗、乾燥させた。こ
うして平均粒径２０．５μｍの球状粉末を得た。以下、
これを粉末Ａと称する。Example 4 1 mol / l NiSO 4 aqueous solution, 2 mol / l NaOH aqueous solution, and 2.1 m
NH 3 water of ol / l was prepared and continuously supplied to a reaction crystallizer equipped with a stirring blade at a rate of 1 ml / min. Then, the mixture of the solutions was stirred in the reaction tank to generate nickel hydroxide. The suspension was collected after the production reaction became steady. After this was washed with water by decantation, it was immersed in a 30 wt% KOH aqueous solution kept at 40 ° C. for 5 hours. Then, it was washed with water and dried to obtain spherical Ni (OH) 2 powder having an average particle diameter of 20 μm. Then N
EDTA was added to the aqueous solution of iSO 4 to form a complex.
Similarly, EDTA was added to the Ca (NO 3) 2 aqueous solution to form a complex. A liquid containing each complex is mixed at a desired ratio, and ion-exchanged water and Na for adjusting pH in the mixed liquid.
Aqueous OH solution was added to contain Ni and Ca in the form of complex ions at 0.8 mol / l and 0.2 mol / l, respectively, and p
A mixed solution with H = 11.5 was prepared. 1 liter of this mixture
50 g of the Ni (OH) 2 powder obtained above is mixed with
Heat to 80 ° C. with stirring. The obtained suspension was centrifuged, the supernatant was replaced with ion-exchanged water, and the generated fine crystals were removed by fluid classification, followed by washing with water and drying. Thus, a spherical powder having an average particle size of 20.5 μm was obtained. Less than,
This is referred to as powder A.

【００４４】この粉末Ａ１００ｇに、添加剤として１０
ｇのＣｏ（ＯＨ）2 粉末、０．５ｇの四フッ化エチレン
樹脂（以下ＰＴＦＥで表す。）粉末、３０ｇのエタノー
ル、および３０ｇの水を加え、混練してペースト状にし
た。このペーストを多孔度９５％の発泡ニッケル基板に
充填し、乾燥後、加圧成形して、厚さ０．６ｍｍ、多孔
度２５％のニッケル正極板を得た。To 100 g of this powder A was added 10% as an additive.
g Co (OH) 2 powder, 0.5 g tetrafluoroethylene resin (hereinafter referred to as PTFE) powder, 30 g ethanol, and 30 g water were added and kneaded to form a paste. This paste was filled in a foamed nickel substrate having a porosity of 95%, dried and pressure-molded to obtain a nickel positive electrode plate having a thickness of 0.6 mm and a porosity of 25%.

【００４５】《実施例５》実施例４において、ニッケル
のＥＤＴＡ錯体とカルシウムのＥＤＴＡ錯体の混合液の
調製時に、ＴｉＣｌ3水溶液にＥＤＴＡを加えて錯体と
したものを所望の割合で混合した。この混合液にｐＨ調
整のためイオン交換水、及びＮａＯＨ水溶液を加え、Ｎ
ｉ、Ｃａ及びＴｉを錯イオンの形で１ｌ中にそれぞれ
０．８ｍｏｌ、０．１ｍｏｌ、および０．１ｍｏｌ含
み、ｐＨ＝１１．５である混合液を調製した。これを用
いた他は実施例４と同様にして平均粒径２１μｍの球状
粉末を得た。以下これを粉末Ｂと称する。この粉末Ｂを
用い実施例４と同様にしてニッケル正極板を得た。Example 5 In Example 4, when a mixed solution of a nickel EDTA complex and a calcium EDTA complex was prepared, a TiCl 3 aqueous solution to which EDTA was added to form a complex was mixed at a desired ratio. Ion-exchanged water and NaOH aqueous solution were added to the mixed solution for pH adjustment, and N
A mixed solution containing 0.8 mol, 0.1 mol, and 0.1 mol of i, Ca, and Ti in the form of complex ions in 1 l and having a pH of 11.5 was prepared. A spherical powder having an average particle size of 21 μm was obtained in the same manner as in Example 4 except that this was used. Hereinafter this is referred to as powder B. Using this powder B, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００４６】《実施例６》０．９ｍｏｌ／ｌのＮｉＳＯ
4、０．０２ｍｏｌ／ｌのＣｏＳＯ4、および０．０２ｍ
ｏｌ／ｌのＺｎＳＯ4 を含む混合水溶液、２ｍｏｌ／ｌ
のＮａＯＨ水溶液、および２．１ｍｏｌ／ｌのＮＨ3水
を準備し、反応晶析装置にそれぞれ１ｍｌ／ｍｉｎの割
合で連続的に供給した。そして、反応槽で溶液の混合物
を撹拌し、反応が定常的となった後に、懸濁液を採集し
た。デカンテーションにより水洗した後、乾燥させてＣ
ｏおよびＣｄを含有した、平均粒径１８μｍの球状Ｎｉ
（ＯＨ）2粉末を得た。次いで、ＮｉＳＯ4、ＣｏＳ
Ｏ4、ＣｄＳＯ4を９２：４：２のｍｏｌ比で含む混合水
溶液にＥＤＴＡを加え錯体を形成させた。同様にＣａ
（ＮＯ3）2水溶液にＥＤＴＡを加え錯体を形成させた。
両者を所望の割合で混合した後、混合液中にｐＨ調整の
ためイオン交換水、及びＮａＯＨ水溶液を加え、Ｎｉ、
Ｃｏ、Ｃｄ及びＣａを錯イオンの形でそれぞれ０．９２
ｍｏｌ／ｌ、０．０４ｍｏｌ／ｌ、０．０２ｍｏｌ／
ｌ、および０．０２ｍｏｌ／ｌ含み、ｐＨ＝１１．５で
ある混合液を調製した。この混合液１ｌに、上記で得ら
れたＣｏおよびＺｎを含有したＮｉ（ＯＨ）2粉末５０
ｇを混合し、撹拌しながら８０℃に加熱した。得られた
懸濁液を遠心分離し、上澄液をイオン交換水で置換し、
生じた微結晶を流体分級によって除去した後、水洗、乾
燥させた。こうして平均粒径１８．５μｍの球状粉末を
得た。以下これを粉末Ｃと称する。この粉末Ｃを用い実
施例４と同様にしてニッケル正極板を得た。Example 6 0.9 mol / l NiSO
4 , 0.02 mol / l CoSO 4 , and 0.02 m
2 mol / l mixed aqueous solution containing ol / l ZnSO 4
NaOH aqueous solution and 2.1 mol / l NH 3 water were prepared and continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixture of the solutions was stirred in the reaction tank, and after the reaction became steady, the suspension was collected. After washing with water by decantation, drying and C
Spherical Ni containing O and Cd and having an average particle diameter of 18 μm
(OH) 2 powder was obtained. Next, NiSO 4 , CoS
EDTA was added to a mixed aqueous solution containing O 4 and CdSO 4 at a molar ratio of 92: 4: 2 to form a complex. Similarly Ca
EDTA was added to the (NO 3 ) 2 aqueous solution to form a complex.
After mixing both in a desired ratio, ion-exchanged water and an aqueous NaOH solution for pH adjustment are added to the mixed solution to obtain Ni,
Co, Cd and Ca in the form of complex ions are 0.92 each
mol / l, 0.04 mol / l, 0.02 mol /
1 and a mixed solution containing 0.02 mol / l and pH = 11.5 was prepared. 50 ml of the Ni (OH) 2 powder containing Co and Zn obtained above was added to 1 liter of this mixed liquid.
g were mixed and heated to 80 ° C. with stirring. The obtained suspension was centrifuged, and the supernatant was replaced with deionized water,
The generated fine crystals were removed by fluid classification, washed with water and dried. Thus, a spherical powder having an average particle size of 18.5 μm was obtained. Hereinafter this is referred to as powder C. Using this powder C, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００４７】《実施例７》０．９ｍｏｌ／ｌのＮｉＳＯ
4および０．１ｍｏｌ／ｌのＭｎＳＯ4を含む混合水溶
液、２ｍｏｌ／ｌのＮａＯＨ水溶液、および２．１ｍｏ
ｌ／ｌのＮＨ3水を準備し、これらを反応晶析装置にそ
れぞれ１ｍｌ／ｍｉｎの割合で連続的に供給した。そし
て、反応槽内の混合液を撹拌し、反応が定常的となった
後に、懸濁液を採集し、水洗、乾燥させた。得られた粉
末を３０ｗｔ％のＫＯＨ水溶液に浸漬し、撹拌しながら
４０℃に加熱し２０時間保持した後、水洗、乾燥させ
た。こうして平均粒径１９．５μｍの球状粉末を得た。
次いで、ＮｉＳＯ4水溶液にＥＤＴＡを加え錯体を形成
させた。更にｐＨ調整のためイオン交換水、及びＮａＯ
Ｈ水溶液を加え、Ｎｉを錯イオンの形で１ｍｏｌ／ｌ含
み、ｐＨ＝１１．５である溶液を調製した。この溶液１
ｌに先に得られたＮｉ（ＯＨ）2粉末５０ｇを混合し、
撹拌しながら８０℃に加熱した。得られた懸濁液を遠心
分離し、上澄液をイオン交換水で置換し、得られた微結
晶を流体分級によって除去した後、水洗、乾燥させた。
こうして平均粒径２０μｍの球状粉末を得た。以下これ
を粉末Ｄと称する。この粉末Ｄを用い実施例４と同様に
してニッケル正極板を得た。Example 7 0.9 mol / l NiSO
4 and 0.1 mol / l MnSO 4 mixed aqueous solution, 2 mol / l NaOH aqueous solution, and 2.1 mo
1 / l NH 3 water was prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixed solution in the reaction tank was stirred, and after the reaction became steady, the suspension was collected, washed with water, and dried. The obtained powder was immersed in a 30 wt% KOH aqueous solution, heated to 40 ° C. with stirring and held for 20 hours, then washed with water and dried. Thus, a spherical powder having an average particle size of 19.5 μm was obtained.
Then, EDTA was added to the NiSO 4 aqueous solution to form a complex. Further, ion-exchanged water and NaO for pH adjustment
An aqueous solution of H was added thereto to prepare a solution containing 1 mol / l of Ni in the form of complex ions and having a pH of 11.5. This solution 1
50 g of the Ni (OH) 2 powder obtained above was mixed with 1
Heat to 80 ° C. with stirring. The obtained suspension was centrifuged, the supernatant was replaced with ion-exchanged water, and the obtained fine crystals were removed by fluid classification, followed by washing with water and drying.
Thus, a spherical powder having an average particle size of 20 μm was obtained. Hereinafter this is referred to as powder D. Using this powder D, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００４８】《実施例８》実施例７において、ＮｉＳＯ
4−ＭｎＳＯ4混合水溶液の濃度を変化させることによ
り、Ｎｉ1-xＭｎx（ＯＨ）2（ｘ＝０．０５、０．２、
０．４）で表される、Ｍｎを含有する平均粒径１９．５
μｍの球状Ｎｉ（ＯＨ）2 粉末を作成した。これに実施
例７と同様の処理を行うことによって、平均粒径２０μ
ｍの球状粉末を得た。これを用い実施例４と同様にして
ニッケル正極板を製作した。Example 8 In Example 7, NiSO
By changing the concentration of the 4- MnSO 4 mixed aqueous solution, Ni 1-x Mn x (OH) 2 (x = 0.05, 0.2,
Mn-containing average particle size represented by 0.4) 19.5
A spherical Ni (OH) 2 powder of μm was prepared. By performing the same treatment as in Example 7 on this, an average particle size of 20 μm is obtained.
m spherical powder was obtained. Using this, a nickel positive electrode plate was manufactured in the same manner as in Example 4.

【００４９】《実施例９》０．９ｍｏｌ／ｌのＮｉＳＯ
4および０．０８ｍｏｌ／ｌのＭｎＳＯ4を含む混合水溶
液、０．０２ｍｏｌ／ｌのＣｒ（ＮＯ3）3水溶液、２ｍ
ｏｌ／ｌのＮａＯＨ水溶液、及び２．１ｍｏｌ／ｌのＮ
Ｈ3水を準備し、反応晶析装置にそれぞれ１ｍｌ／ｍｉ
ｎの割合で連続的に供給した。そして、反応槽内の混合
液を攪拌し、反応が定常的となった後に、懸濁液を採集
し、水洗した。これを４０℃の３０ｗｔ％ＫＯＨ水溶液
に５時間浸漬した後、水洗、乾燥した。こうしてＭｎお
よびＣｒを含有する、平均粒径２１μｍの球状Ｎｉ（Ｏ
Ｈ）2粉末を得た。次いで、この粉末に、実施例４と同
様の方法で、Ｎｉ（ＯＨ）2からなる表面層を付与して
平均粒径２１．５μｍの球状粉末を得た。以下これを粉
末Ｅと称する。この粉末Ｅを用い実施例４と同様にして
ニッケル正極板を得た。Example 9 0.9 mol / l NiSO
4 and 0.08 mol / l MnSO 4 mixed aqueous solution, 0.02 mol / l Cr (NO 3 ) 3 aqueous solution, 2 m
ol / l NaOH aqueous solution, and 2.1 mol / l N
H 3 water was prepared, and 1 ml / mi was added to each reaction crystallization device.
It was continuously fed at a rate of n. Then, the mixed solution in the reaction tank was stirred, and after the reaction became steady, the suspension was collected and washed with water. This was immersed in a 30 wt% KOH aqueous solution at 40 ° C. for 5 hours, washed with water and dried. Thus, spherical Ni (O) containing Mn and Cr and having an average particle diameter of 21 μm
H) 2 powder was obtained. Then, a surface layer made of Ni (OH) 2 was applied to this powder by the same method as in Example 4 to obtain a spherical powder having an average particle size of 21.5 μm. Hereinafter this is referred to as powder E. Using this powder E, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５０】《実施例１０》０．９ｍｏｌ／ｌのＮｉＳ
Ｏ4、０．０８ｍｏｌ／ｌのＭｎＳＯ4、０．０１ｍｏｌ
／ｌのＡｌ2（Ｓ Ｏ4）3、および０．０１ｍｏｌ／ｌの
Ｃｒ（ＮＯ3）3を含む混合水溶液、２ｍｏｌ／ｌのＮａ
ＯＨ水溶液、および２．１ｍｏｌ／ｌのＮＨ3水を準備
し、これらを反応晶析装置にそれぞれ１ｍｌ／ｍｉｎの
割合で連続的に供給した。そして、反応槽内で混合液を
攪拌し、反応が定常的となった後に、懸濁液を採集し、
水洗した。得られた粉末を４０℃の３０ｗｔ％ＫＯＨ水
溶液に５時間浸漬した後、水洗、乾燥した。こうして平
均粒径２３μｍの球状粉末を得た。一方、ＮｉおよびＡ
ｌをそれぞれ０．９５ｍｏｌ／ｌおよび０．０５ｍｏｌ
／ｌだけＥＤＴＡ錯イオンの形で含み、イオン交換水、
及びＮａＯＨ水溶液を加えることによってｐＨ＝１１．
５に調整された溶液を準備した。この溶液１ｌに、先に
得られた粉末５０ｇを混合し、撹拌しながら８０℃に加
熱し、得られた懸濁液を遠心分離し、上澄液をイオン交
換水で置換し、得られた微結晶を流体分級によって除去
した後、水洗、乾燥させた。こうして平均粒径１０．５
μｍの粉末を得た。Example 10 0.9 mol / l NiS
O 4 , 0.08 mol / l MnSO 4 , 0.01 mol
/ L Al 2 (SO 4 ) 3 and 0.01 mol / l Cr (NO 3 ) 3 mixed aqueous solution, 2 mol / l Na
An OH aqueous solution and 2.1 mol / l NH 3 water were prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixture is stirred in the reaction tank, and after the reaction becomes steady, the suspension is collected,
Washed with water. The obtained powder was immersed in a 30 wt% KOH aqueous solution at 40 ° C. for 5 hours, washed with water and dried. Thus, a spherical powder having an average particle size of 23 μm was obtained. On the other hand, Ni and A
0.95 mol / l and 0.05 mol respectively
/ L contained in the form of EDTA complex ion, deionized water,
And pH = 11.
A solution adjusted to 5 was prepared. 50 g of the powder obtained above was mixed with 1 liter of this solution, heated to 80 ° C. with stirring, the suspension obtained was centrifuged, and the supernatant was replaced with ion-exchanged water to obtain the solution. The fine crystals were removed by fluid classification, washed with water and dried. Thus the average particle size is 10.5
A μm powder was obtained.

【００５１】この粉末５０ｇを３０ｗｔ％のＫＯＨ水溶
液１ｌに混合し、撹拌しながら６０℃に加熱し、２０時
間保持した。これを遠心分離にかけ、黄色に着色した上
澄液をイオン交換水で置換した後、水洗、乾燥して、平
均粒径２４μｍの粉末を得た。以下これを粉末Ｆと称す
る。この粉末Ｆを用い実施例４と同様にしてニッケル正
極板を得た。50 g of this powder was mixed with 1 liter of a 30 wt% KOH aqueous solution, heated to 60 ° C. with stirring, and kept for 20 hours. This was subjected to centrifugation to replace the yellow colored supernatant with ion-exchanged water, followed by washing with water and drying to obtain a powder having an average particle size of 24 μm. Hereinafter this is referred to as powder F. Using this powder F, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５２】《実施例１１》０．９ｍｏｌ／ｌのＮｉＳ
Ｏ4および０．１ｍｏｌ／ｌのＭｎＳＯ4を含む混合水溶
液、２ｍｏｌ／ｌのＮａＯＨ水溶液、および２．１ｍｏ
ｌ／ｌのＮＨ3水を準備し、これらを反応晶析装置にそ
れぞれ１ｍｌ／ｍｉｎの割合で連続的に供給した。そし
て、反応槽内で混合液を攪拌し、反応が定常的となった
後に、懸濁液を採集し、水洗した。得られた粉末を４０
℃の３０ｗｔ％ＫＯＨ水溶液に５時間浸漬した後、水
洗、乾燥した。こうしてＭｎを含有する、平均粒径１２
μｍの球状Ｎｉ（ＯＨ）2粉末を得た。これに実施例４
と同様の処理を行い、Ｃａを含むＮｉ（ＯＨ）2の表面
層を付与した。以下これを粉末Ｇと称する。この粉末Ｇ
を用い実施例４と同様にしてニッケル正極板を得た。Example 11 0.9 mol / l NiS
Mixed aqueous solution containing O 4 and 0.1 mol / l MnSO 4 , 2 mol / l NaOH aqueous solution, and 2.1 mo
1 / l NH 3 water was prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixed solution was stirred in the reaction tank, and after the reaction became steady, the suspension was collected and washed with water. 40 of the powder obtained
After dipping in a 30 wt% KOH aqueous solution at 0 ° C. for 5 hours, it was washed with water and dried. Thus, Mn-containing particles having an average particle diameter of 12
A spherical Ni (OH) 2 powder of μm was obtained. Example 4
The same treatment as described in (1) above was performed to give a surface layer of Ni (OH) 2 containing Ca. Hereinafter this is referred to as powder G. This powder G
A nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５３】《実施例１２》０．９ｍｏｌ／ｌのＮｉＳ
Ｏ4、０．０１ｍｏｌ／ｌのＣｏＳＯ4、０．０８ｍｏｌ
／ｌのＭｎＳＯ4 、及び０．０１ｍｏｌ／ｌのＡｌ
2（ＳＯ4）3を含む混合水溶液、２ｍ ｏｌ／ｌのＮａＯ
Ｈ水溶液、および２．１ｍｏｌ／ｌのＮＨ3水を準備
し、これらを反応晶析装置にそれぞれ１ｍｌ／ｍｉｎの
割合で連続的に供給した。そして、反応槽内で混合液を
攪拌し、反応が定常的となった後に、懸濁液を採集し、
水洗した。得られた粉末を水洗、乾燥させて、Ｍｎ、Ｃ
ｏ、およびＡｌを含有する、平均粒径１８μｍのＮｉ
（ＯＨ）2粉末を得た。この粉末５０ｇを３０ｗｔ％の
ＫＯＨ水溶液１ｌに混合し、撹拌しながら８０℃に加熱
し、４０時間保持した。次いで、遠心分離を行い、澄明
な上澄液をイオン交換水で置換した後、水洗乾燥して、
平均粒径８μｍの粉末を得た。Example 12 0.9 mol / l NiS
O 4 , 0.01 mol / l CoSO 4 , 0.08 mol
/ L MnSO 4 and 0.01 mol / l Al
2 (SO 4 ) 3 mixed aqueous solution, 2 mol / l NaO
An H aqueous solution and 2.1 mol / l NH 3 water were prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixture is stirred in the reaction tank, and after the reaction becomes steady, the suspension is collected,
Washed with water. The obtained powder is washed with water and dried to obtain Mn, C
Ni containing o and Al and having an average particle size of 18 μm
(OH) 2 powder was obtained. 50 g of this powder was mixed with 1 liter of a 30 wt% KOH aqueous solution, heated to 80 ° C. with stirring, and kept for 40 hours. Then, centrifugation is performed, the clear supernatant is replaced with ion-exchanged water, washed with water and dried,
A powder having an average particle size of 8 μm was obtained.

【００５４】一方、ＮｉＳＯ4、ＣｏＳＯ4、およびＡｌ
2（ＳＯ4）3を含む混合水溶液、ならびにＣａ（ＮＯ3)2
水溶液にそれぞれＥＤＴＡを加えて錯体を形成させた。
両者を所望の割合で混合し、この混合液中にｐＨ調整の
ためイオン交換水、及びＮａＯＨ水溶液を加え、Ｎｉ、
Ｃｏ、Ａｌ及びＣａを錯イオンの形でそれぞれ０．９ｍ
ｏｌ／ｌ、０．０２ｍｏｌ／ｌ、０．０２ｍｏｌ／ｌ、
および０．０６ｍｏｌ／ｌ含み、ｐＨ＝１１．５である
混合液を調整した。この混合液１ｌに上記で得られたＮ
ｉ（ＯＨ）2粉末５０ｇを混合し、撹拌しながら８０℃
に加熱した。得られた懸濁液を遠心分離し、上澄液をイ
オン交換水で置換した後、流体分級によって微結晶を除
去した後、水洗、乾燥させた。こうして平均粒径１８．
５μｍの球状粉末を得た。以下これを粉末Ｈと称する。
この粉末Ｈを用い実施例４と同様にしてニッケル正極板
を得た。On the other hand, NiSO 4 , CoSO 4 , and Al
2 (SO 4 ) 3 mixed aqueous solution and Ca (NO 3) 2
EDTA was added to each aqueous solution to form a complex.
Both are mixed in a desired ratio, and ion-exchanged water and an aqueous NaOH solution are added to the mixed solution for pH adjustment, and Ni,
Co, Al and Ca in the form of complex ions each 0.9m
ol / l, 0.02 mol / l, 0.02 mol / l,
A mixed solution containing 0.06 mol / l and pH = 11.5 was prepared. 1 l of this mixed solution was used to obtain the N
50g of i (OH) 2 powder is mixed and stirred at 80 ° C
Heated to. The obtained suspension was centrifuged, the supernatant was replaced with ion-exchanged water, the fine crystals were removed by fluid classification, then washed with water and dried. Thus, the average particle size is 18.
5 μm spherical powder was obtained. Hereinafter this is referred to as powder H.
Using this powder H, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５５】《比較例２》１ｍｏｌ／ｌのＮｉＳＯ4溶
液、２ｍｏｌ／ｌのＮａＯＨ溶液、および２．１ｍｏｌ
／ｌのＮＨ3水を準備し、これらを反応晶析装置にそれ
ぞれ１ｍｌ／ｍｉｎの割合で連続的に供給した。そし
て、反応槽内で混合液を撹拌し、得られた懸濁液中の粒
子を流体中で分級した後、水洗、乾燥した。平均粒径が
２１μｍの球状Ｎｉ（ＯＨ）2粉末が得られた。この粉
末を用い実施例４と同様にしてニッケル正極板を得た。Comparative Example 2 1 mol / l NiSO 4 solution, 2 mol / l NaOH solution, and 2.1 mol
/ L NH 3 water was prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixed solution was stirred in the reaction tank, the particles in the obtained suspension were classified in a fluid, washed with water and dried. A spherical Ni (OH) 2 powder having an average particle size of 21 μm was obtained. Using this powder, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５６】《比較例３》０．９６ｍｏｌ／ｌのＮｉＳ
Ｏ4、０．０２ｍｏｌ／ｌのＣｏＳＯ4、および０．０２
ｍｏｌ／ｌのＺｎＳＯ4を含む混合水溶液、２ｍｏｌ／
ｌのＮａＯＨ水溶液およびイオン交換水を準備し、これ
らを反応晶析装置にそれぞれ１ｍｌ／ｍｉｎの割合で連
続的に供給した。そして、反応槽内で混合液を攪拌し、
得られた懸濁液を採集し、水洗、乾燥した。平均粒径が
２１μｍの球状Ｎｉ（ＯＨ）2粉末が得られた。この粉
末を用い実施例４と同様にしてニッケル正極板を得た。Comparative Example 3 0.96 mol / l NiS
O 4 , 0.02 mol / l CoSO 4 , and 0.02
Mixed aqueous solution containing 2 mol / l ZnSO 4
l NaOH aqueous solution and ion-exchanged water were prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixed solution is stirred in the reaction tank,
The obtained suspension was collected, washed with water and dried. A spherical Ni (OH) 2 powder having an average particle size of 21 μm was obtained. Using this powder, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５７】《比較例４》比較例１で得られた球状Ｎｉ
（ＯＨ）2粉末９９ｇに、添加剤として１０ｇのＣｏ
（ＯＨ）2粉末、１ｇのＣａ（ＯＨ）2粉末、３０ｇの
水、および３０ｇのエタノールを加え、混練してペース
ト状にした。このペーストを用い実施例４と同様にして
ニッケル正極板を得た。Comparative Example 4 Spherical Ni obtained in Comparative Example 1
99g of (OH) 2 powder and 10g of Co as an additive
(OH) 2 powder, 1 g Ca (OH) 2 powder, 30 g water, and 30 g ethanol were added and kneaded to form a paste. Using this paste, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００５８】《比較例５》０．９ｍｏｌ／ｌのＮｉＳＯ
4水溶液、０．１ｍｏｌ／ｌのＣａ（ＮＯ3）2水溶液、
２ｍｏｌ／ｌのＮａＯＨ水溶液、および２．１ｍｏｌ／
ｌのＮＨ3水を準備し、これらを反応晶析装置にそれぞ
れ１ｍｌ／ｍｉｎの割合で連続的に供給した。そして、
反応槽内で混合液を攪拌し、得られた懸濁液を採集し、
水洗、乾燥させた。Ｃａを固溶した、平均粒径１２μｍ
のＮｉ（ＯＨ）2粉末が得られた。これを用い実施例４
と同様にして ニッケル正極板を得た。Comparative Example 5 0.9 mol / l NiSO
4 aqueous solution, 0.1 mol / l Ca (NO 3 ) 2 aqueous solution,
2 mol / l NaOH aqueous solution, and 2.1 mol / l
1 l of NH 3 water was prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. And
Stir the mixture in the reaction tank, collect the resulting suspension,
It was washed with water and dried. An average particle size of 12 μm, which is a solid solution of Ca
Ni (OH) 2 powder was obtained. Example 4 using this
A nickel positive electrode plate was obtained in the same manner as in.

【００５９】《比較例６》０．９ｍｏｌ／ｌのＮｉＳＯ
4水溶液、０．１ｍｏｌ／ｌのＭｎＳＯ4水溶液、２ｍｏ
ｌ／ｌのＮａＯＨ水溶液、および２．１ｍｏｌ／ｌのＮ
Ｈ3水を準備し、これらを反応晶析装置にそれぞれ１ｍ
ｌ／ｍｉｎの割合で連続的に供給した。そして、反応槽
内で混合液を攪拌し、得られた懸濁液を採集し、デカン
テーションにより沈澱物を分離した。これを水洗、乾燥
した。Ｃａを含有した、平均粒径１２μｍのＮｉ（Ｏ
Ｈ）2粉末を得た。この粉末を用い実施例４と同様にし
てニッケル正極板を得た。Comparative Example 6 0.9 mol / l NiSO
4 aqueous solution, 0.1 mol / l MnSO 4 aqueous solution, 2 mo
1 / l NaOH aqueous solution, and 2.1 mol / l N
H 3 water was prepared, and 1 m of each was placed in the reaction crystallizer.
It was continuously supplied at a rate of 1 / min. Then, the mixed solution was stirred in the reaction tank, the obtained suspension was collected, and the precipitate was separated by decantation. This was washed with water and dried. Ni (O containing Ca and having an average particle diameter of 12 μm
H) 2 powder was obtained. Using this powder, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００６０】《比較例７》１ｍｏｌ／ｌのＭｎＳＯ4水
溶液にＨ3ＰＯ4水溶液を加えｐＨ＝２となるよう調整し
た。この溶液に、Ｈ2Ｏ2を加えた後、さらにＨ3ＰＯ4水
溶液を加えてＭｎの濃度を０．１ｍｏｌ／ｌとした。次
いで、０．９ｍｏｌ／ｌのＮｉＳＯ4水溶液、１．８ｍ
ｏｌ／ｌのＮａＯＨ水溶液、および２ｍｏｌ／ｌのＮＨ
3水を準備した。これらの溶液および前記のＭｎＳＯ4を
含む水溶液を反応晶析装置にそれぞれ１ｍｌ／ｍｉｎの
割合で連続的に供給した。そして、反応槽内で混合液を
攪拌し、得られた懸濁液を採集した。これを水洗、乾燥
して、Ｍｎを含有した、平均粒径２０μｍのＮｉ（Ｏ
Ｈ）2粉末を得た。Comparative Example 7 An H 3 PO 4 aqueous solution was added to a 1 mol / l MnSO 4 aqueous solution to adjust the pH to 2. After H 2 O 2 was added to this solution, an H 3 PO 4 aqueous solution was further added to adjust the Mn concentration to 0.1 mol / l. Next, 0.9 mol / l NiSO 4 aqueous solution, 1.8 m
ol / l NaOH aqueous solution, and 2 mol / l NH
3 prepared water. These solutions and the above-mentioned aqueous solution containing MnSO 4 were continuously supplied to the reaction crystallizer at a rate of 1 ml / min. Then, the mixed liquid was stirred in the reaction tank, and the obtained suspension was collected. This is washed with water and dried to obtain Ni (O) containing Mn and having an average particle size of 20 μm.
H) 2 powder was obtained.

【００６１】次に、ＮｉＳＯ4水溶液にＥＤＴＡを加え
錯体を形成させた。同様にＣａ（ＮＯ3）2水溶液にＥＤ
ＴＡを加え錯体を形成させた。両者の液を所望の割合で
混合し、その混合液中にｐＨ調整のためイオン交換水、
及びＮａＯＨ水溶液を加え、Ｎｉ及びＣａを錯イオンの
形でそれぞれ０．８ｍｏｌ／ｌおよび０．２ｍｏｌ／ｌ
含み、ｐＨ＝９．５である混合液を調製した。この混合
液１ｌに、上記で得られたＮｉ（ＯＨ）2粉末５０ｇを
混合し、撹拌しながら８０℃に加熱した。得られた懸濁
液を遠心分離し、上澄液をイオン交換水で置換し、得ら
れた微結晶を流体分級によって除去した後、水洗、乾燥
させた。平均粒径２０．５μｍの球状粉末が得られた。
この粉末を用い実施例４と同様にしてニッケル正極板を
得た。Next, EDTA was added to the NiSO 4 aqueous solution to form a complex. Similarly, ED was added to the Ca (NO 3 ) 2 aqueous solution.
TA was added to form a complex. Both liquids are mixed at a desired ratio, and ion-exchanged water for pH adjustment in the mixed liquid,
And an aqueous solution of NaOH are added, and Ni and Ca in the form of complex ions are 0.8 mol / l and 0.2 mol / l, respectively.
A mixed solution containing and having a pH of 9.5 was prepared. 50 g of the Ni (OH) 2 powder obtained above was mixed with 1 liter of this mixed solution, and heated to 80 ° C. with stirring. The obtained suspension was centrifuged, the supernatant was replaced with ion-exchanged water, and the obtained fine crystals were removed by fluid classification, followed by washing with water and drying. A spherical powder having an average particle size of 20.5 μm was obtained.
Using this powder, a nickel positive electrode plate was obtained in the same manner as in Example 4.

【００６２】《比較例８》０．９ｍｏｌ／ｌのＮｉＳＯ
4水溶液、０．１ｍｏｌ／ｌのＭｎＳＯ4水溶液、および
２ｍｏｌ／ｌのＮａＯＨ水溶液を準備し、これらを反応
晶析装置にそれぞれ１ｍｌ／ｍｉｎの割合で連続的に供
給した。そして、反応槽内で混合液を攪拌し、得られた
懸濁液を採集した。得られた粉末を水洗、乾燥、粉砕し
た後、篩にかけ粒径２００μｍ以上及び３０μｍ以下
の、Ｍｎを含有するＮｉ（ＯＨ）2粉末を得た。これら
の粉末をそれぞれ３０ｗｔ％のＫＯＨ水溶液１ｌに対し
５０ｇの割合で混合し、撹拌しながら８０℃に加熱し４
０時間保持した。次いで、遠心分離を行い、澄明な上澄
液をイオン交換水で置換した後、水洗、乾燥させた。こ
れらの粉末にそれぞれ実施例４と同様にＥＤＴＡ錯体溶
液による処理を行った後、粉末を得た。これらの粉末を
用いて実施例４と同様にしてそれぞれニッケル正極板を
作成した。Comparative Example 8 0.9 mol / l NiSO
4 aqueous solution, 0.1 mol / l MnSO 4 aqueous solution, and 2 mol / l NaOH aqueous solution were prepared, and these were continuously supplied to the reaction crystallizer at a rate of 1 ml / min, respectively. Then, the mixed liquid was stirred in the reaction tank, and the obtained suspension was collected. The obtained powder was washed with water, dried and pulverized, and then sieved to obtain Ni (OH) 2 powder containing Mn and having a particle size of 200 μm or more and 30 μm or less. These powders were mixed at a ratio of 50 g with 1 L of a 30 wt% KOH aqueous solution, and heated to 80 ° C. with stirring.
Hold for 0 hours. Then, centrifugation was carried out to replace the clear supernatant with ion-exchanged water, followed by washing with water and drying. Each of these powders was treated with the EDTA complex solution in the same manner as in Example 4 to obtain powders. Nickel positive electrode plates were prepared in the same manner as in Example 4 using these powders.

【００６３】図６に実施例４、５、６及び比較例２、
４、５の電極を用いた電池を４５℃において４０ｍＡの
電流で１５時間充電し、２０℃において８０ｍＡの電流
で電池電圧１．０Ｖ以下に低下するまで放電したときの
充放電曲線を示す。図６の充電曲線に示されるように、
実施例４、５の電極は、比較例２の電極に比して酸素発
生電位が高く、充電が十分に行われていることがわか
る。一方、粉末全体にわたって結晶中にＣａを含有する
Ｎｉ（ＯＨ）2粉末を使用した比較例３、および電極構
成時に添加剤としてＣａ（ＯＨ）2を加えた比較例４に
おいては、実施例４、５ほど酸素発生電位と充電電位と
の差ηが大きくなく、Ｃａ量を多く使用したにも拘わら
ず、容量的に劣ることが認められる。これは上記酸素発
生電位の上昇による充電量の増加が不十分であること、
並びにＣａの含有による容量密度の減少によるものと推
察される。また、実施例６は、現在汎用の、Ｃｏおよび
Ｚｎを固溶したＮｉ（ＯＨ）2に、Ｃｏ、ＣｄおよびＣ
ａを固溶したＮｉ（ＯＨ）2の表面層を付与した活物質
粒子を用いたものである。このように複数の元素を組み
合わせて用いることにより、表面層への固溶量が少なく
とも十分な充電効率の向上をもたらす。なお、内部にＣ
ｏおよびＺｎを固溶したＮｉ（ＯＨ）2を用いることに
より、サイクル特性の向上もみられた。FIG. 6 shows Examples 4, 5, 6 and Comparative Example 2,
A charge / discharge curve is shown when a battery using the electrodes of 4 and 5 was charged at a current of 40 mA at 45 ° C. for 15 hours and discharged at a current of 80 mA at 20 ° C. until the battery voltage dropped to 1.0 V or less. As shown in the charging curve of FIG.
It can be seen that the electrodes of Examples 4 and 5 have a higher oxygen generation potential than the electrodes of Comparative Example 2 and are sufficiently charged. On the other hand, in Comparative Example 3 in which Ni (OH) 2 powder containing Ca in the entire powder was used and Comparative Example 4 in which Ca (OH) 2 was added as an additive during electrode construction, Example 4, It is recognized that the difference η between the oxygen generation potential and the charging potential is not so large as 5 and the capacity is inferior in spite of using a large amount of Ca. This is because the increase in the charge amount due to the increase in the oxygen generation potential is insufficient.
In addition, it is presumed that the capacity density is reduced due to the inclusion of Ca. In addition, in Example 6, Co, Cd, and C are added to Ni (OH) 2 which is a general-purpose solid solution of Co and Zn.
The active material particles are provided with a surface layer of Ni (OH) 2 in which a is solid-dissolved. By using a plurality of elements in combination as described above, the amount of solid solution in the surface layer provides at least sufficient improvement in charging efficiency. In addition, C
Improvement in cycle characteristics was also observed by using Ni (OH) 2 in which o and Zn were solid-dissolved.

【００６４】図７に実施例７、９、１０及び比較例２、
３、６の電極を用いた電池を２０℃において４０ｍＡの
電流で１５時間充電し、２０℃において８０ｍＡの電流
で電池電圧１．０Ｖ以下に至るまで放電したときの充放
電曲線を示す。図７の充電曲線に示されるように、実施
例７、９、１０の電極は、比較例２の電極、あるいは改
良された、ＣｏおよびＺｎを固溶した粉末を用いた比較
例３の電極を用いた場合に比して放電容量密度が著しく
増大している。また、同じγ相の生成を多く伴う比較例
６とは容量密度に関して際だった差異は認められない
が、Ｍｎを固溶しない表面層を持つ実施例７、９は比較
例３に対し放電平均電圧が約５０ｍＶ程度高い。また、
実施例１０のように、Ａｌを固溶したものに関しては、
例外的に高い放電電圧を持つことがわかる。このような
電圧の向上は、高率放電またはＷｈ／ｌもしくはＷｈ／
ｋｇで表される電池のエネルギー密度の向上を考えると
き、きわめて重要であることは既に述べた通りである。FIG. 7 shows Examples 7, 9, 10 and Comparative Example 2,
The charge-discharge curve when the battery using the electrodes of Nos. 3 and 6 was charged at a current of 40 mA at 20 ° C. for 15 hours and discharged at a current of 80 mA at 20 ° C. to a battery voltage of 1.0 V or less is shown. As shown in the charge curve of FIG. 7, the electrodes of Examples 7, 9 and 10 were the electrodes of Comparative Example 2 or the improved electrodes of Comparative Example 3 using Co and Zn solid solution powders. The discharge capacity density is remarkably increased as compared with the case where it is used. In addition, no significant difference in capacity density was observed between Comparative Example 6 in which a large amount of the same γ phase was generated, but Examples 7 and 9 having a surface layer in which Mn did not form a solid solution were compared with Comparative Example 3 in discharge average. The voltage is about 50 mV higher. Also,
Regarding the solid solution of Al as in Example 10,
It turns out that it has an exceptionally high discharge voltage. Such an increase in voltage may be due to high rate discharge or Wh / l or Wh /
As mentioned above, it is extremely important when considering the improvement of the energy density of the battery expressed in kg.

【００６５】図８に実施例７、８および比較例２の電極
を用いた電池を２０℃において４０ｍＡの電流で１５時
間充電し、同じく２０℃において８０ｍＡの電流で１．
０Ｖに至るまで放電したときの電極容量密度をＭｎの固
溶割合に対してプロットして示している。図８から明ら
かなように、Ｍｎの固溶割合が０．３５以上の場合に
は、Ｍｎの固溶によるＮｉの利用率の向上の効果に比べ
て、含有するＮｉ量の低下による容量密度の低下が著し
い。そのため、電極容量密度は、比較例２（ｘ＝０に相
当）に比べて、かえって低下することがわかる。表３
に、実施例８、および比較例５に示されたのに類似の方
法で作成された、各種金属元素を含有するＮｉ（ＯＨ）
2の表面層を有する電極について、２０℃において４０
ｍＡの電流で１５時間充電し、２０℃において８０ｍＡ
の電流で電池電圧１．０Ｖに至るまで放電したときの放
電容量、および平均電圧を示す。In FIG. 8, the batteries using the electrodes of Examples 7 and 8 and Comparative Example 2 were charged at 20 ° C. with a current of 40 mA for 15 hours, and at the same temperature of 20 ° C. with a current of 80 mA.
The electrode capacity density when discharged to 0 V is plotted against the solid solution ratio of Mn. As is clear from FIG. 8, when the solid solution ratio of Mn is 0.35 or more, compared with the effect of improving the utilization rate of Ni by the solid solution of Mn, the capacity density of The decrease is remarkable. Therefore, it can be seen that the electrode capacitance density is rather lower than that of Comparative Example 2 (corresponding to x = 0). Table 3
Ni (OH) containing various metal elements prepared by a method similar to that shown in Example 8 and Comparative Example 5.
For electrodes with 2 surface layers, 40 at 20 ° C
Charged for 15 hours at a current of mA, 80 mA at 20 ° C
2 shows the discharge capacity and the average voltage when the battery voltage was discharged to 1.0 V with the current.

【００６６】[0066]

【表３】 [Table 3]

【００６７】図９は実施例１１、１２、および比較例
２、３の電極を用いた電池を２０℃において４０ｍＡの
電流で１５時間充電し、２０℃において８０ｍＡの電流
で電池電圧１．０Ｖに至るまで放電したときの充放電曲
線を示す。図９から明らかなように、本発明による電極
では、電極容量密度の向上、酸素発生電位と充電電位と
の差ηの増大に顕著な効果が見られ、放電電圧の低下も
見られない。特に、表面層にもＡｌを含有する実施例１
２の電極は、比較例２、３以上に高い放電電圧を示して
いることがわかる。表４および表５に、実施例１１およ
び１２に示されたのと類似の方法で作製された、各種金
属元素を内部および表面層に含有するＮｉ（ＯＨ）2粉
末を用いた電極について、２０℃または４５℃において
４０ｍＡの電流で１５時間充電し、２０℃において８０
ｍＡの電流で電池電圧１．０Ｖに至るまで放電したとき
の放電容量、酸素発生電位と充電電位との差η、および
平均電圧を示す。FIG. 9 shows that batteries using the electrodes of Examples 11 and 12 and Comparative Examples 2 and 3 were charged at 20 ° C. with a current of 40 mA for 15 hours, and at 20 ° C. with a current of 80 mA, the battery voltage became 1.0 V. The charging / discharging curve at the time of electric discharge is shown. As is clear from FIG. 9, in the electrode according to the present invention, the effect of improving the electrode capacity density, increasing the difference η between the oxygen generation potential and the charging potential, and the discharge voltage are not reduced. In particular, Example 1 in which the surface layer also contains Al
It can be seen that the electrode No. 2 exhibits a higher discharge voltage than Comparative Examples 2 and 3. Tables 4 and 5 show the results for electrodes using Ni (OH) 2 powder containing various metal elements inside and in the surface layer, prepared by a method similar to that shown in Examples 11 and 12. Charge at 40 ° C or 45 ° C for 15 hours at 80 ° C at 80 ° C
The discharge capacity, the difference η between the oxygen generation potential and the charging potential, and the average voltage when the battery voltage is discharged to 1.0 V with a current of mA are shown.

【００６８】[0068]

【表４】 [Table 4]

【００６９】[0069]

【表５】 [Table 5]

【００７０】表６は実施例１１及び比較例７、８の粉末
のタップ密度、電極への充填密度、及び電極の電極容量
密度を示したものである。比較例７は、電極多孔度が同
じであるにも関わらず電極容量密度が極めて低い。これ
は層間の広いα相を含むことにより粉末の密度が低下
し、Ｎｉの含有量が極端に低下したためである。比較例
７のうち粒径２００μｍ以上および３０μｍ以下のそれ
ぞれの粉末を用いた場合には、共に多孔度２５％の所定
の電極を作製することが不可能であった。このことか
ら、電極容量密度は実施例１１に対して低いことがわか
る。これは金属多孔体の孔径が１００から２００μｍ程
度であったことを考えれば、粒径２００μｍ程度の粉末
が充填され難いことは明らかである。また、充填に際し
ては形状的な因子が大きく、球状である方が充填に適し
ていることを示している。現状を越えるような高容量密
度の電極を作成するためには、このような電極への充填
性を高める努力を行うことも重要である。Table 6 shows the tap density of the powder of Example 11 and Comparative Examples 7 and 8, the packing density of the electrode, and the electrode capacity density of the electrode. Comparative Example 7 has an extremely low electrode capacity density despite having the same electrode porosity. This is because the density of the powder was lowered by including the wide α phase between the layers, and the Ni content was extremely lowered. In Comparative Example 7, when the powders having a particle size of 200 μm or more and 30 μm or less were used, it was impossible to produce a predetermined electrode having a porosity of 25%. From this, it can be seen that the electrode capacitance density is lower than that in Example 11. Considering that the pore diameter of the metal porous body was about 100 to 200 μm, it is clear that it is difficult to fill the powder with a particle diameter of about 200 μm. Further, it is shown that the shape factor is large at the time of filling, and the spherical shape is more suitable for filling. In order to produce an electrode having a high capacity density that exceeds the current situation, it is important to make efforts to improve the filling property of such an electrode.

【００７１】[0071]

【表６】 [Table 6]

【００７２】《実施例１３》実施例１２の電極作成にお
いて、Ｙ2Ｏ3を活物質重量に対して０．５ｗｔ％加えた
他は、実施例１２と同様にしてニッケル正極板を得た。Example 13 A nickel positive electrode plate was obtained in the same manner as in Example 12 except that 0.5 wt% of Y 2 O 3 was added to the weight of the active material in the production of the electrode of Example 12.

【００７３】《比較例９》実施例１２の電極作成におい
て、Ｃｏ（ＯＨ）2を添加しないことを除いて、実 施例
１２と同様にしてニッケル正極板を得た。Comparative Example 9 A nickel positive electrode plate was obtained in the same manner as in Example 12 except that Co (OH) 2 was not added in the production of the electrode of Example 12.

【００７４】図１０に実施例１２、１３、および比較例
９の電極を用いた電池を２０℃において４０ｍＡの電流
で１５時間充電し、２０℃において８０ｍＡの電流で電
池電圧１．０Ｖ以下にいたるまで放電したときの充放電
曲線を示す。図１０から明らかなように、Ｃｏ（ＯＨ）
2の添加のない、即ち初充電を行った後にも導電性を有
するＣｏＯＯＨが活物質および基体を被覆しない比較例
９は、実施例１２に比して著しく放電特性が劣り、電極
として使用するのに支障を来す。また、Ｙ2Ｏ3を微量添
加した実施例１３は、酸素発生電位と充電電位の差ηが
実施例１２より若干増加することが認められる。In FIG. 10, batteries using the electrodes of Examples 12 and 13 and Comparative Example 9 were charged at 20 ° C. with a current of 40 mA for 15 hours, and at 20 ° C. with a current of 80 mA, the battery voltage was 1.0 V or less. The charging / discharging curve at the time of discharging is shown. As is clear from FIG. 10, Co (OH)
Comparative Example 9 without the addition of 2 , that is, CoOOH having conductivity even after the initial charge does not cover the active material and the substrate, is significantly inferior to Example 12 in discharge characteristics and is used as an electrode. Interfere with. Further, it is recognized that in Example 13 in which a small amount of Y 2 O 3 was added, the difference η between the oxygen generation potential and the charging potential was slightly increased as compared with Example 12.

【００７５】《比較例１０》実施例１２の電極作成にお
いて、ＰＴＦＥを添加しないことを除いて、実施例１２
と同様にしてニッケル正極板を得た。Comparative Example 10 Example 12 was repeated except that PTFE was not added in the production of the electrode of Example 12.
A nickel positive electrode plate was obtained in the same manner as in.

【００７６】図１１は実施例１２および比較例１０の電
極を用いた電池を、２０℃において４０ｍＡの電流で１
５時間充電し、２０℃において８０ｍＡの電流で電池電
圧１．０Ｖに至るまで放電したときの放電容量を充放電
サイクルに対してプロットして示す。図１１より明らか
なように、ＰＴＦＥを含まない比較例１０に比して実施
例１２はサイクル特性が向上していることがわかる。こ
れはＰＴＦＥの結着作用によって、活物質粉末の膨張・
収縮による脱落が抑制されたためであると考えられる。
なお、結着剤を添加してペースト状にすることにより、
Ｃｏ（ＯＨ）2など導電剤微粉末の分散性を向上するに
も効果があった。FIG. 11 shows a battery using the electrodes of Example 12 and Comparative Example 10 at 20 ° C. and a current of 40 mA.
The discharge capacity when the battery was charged for 5 hours and discharged at a current of 80 mA at 20 ° C. to a battery voltage of 1.0 V is plotted against the charge / discharge cycle. As is clear from FIG. 11, the cycle characteristics of Example 12 are improved as compared with Comparative Example 10 containing no PTFE. This is due to the expansion of the active material powder due to the binding action of PTFE.
It is thought that this is because the dropout due to contraction was suppressed.
By adding a binder to form a paste,
It was also effective in improving the dispersibility of the conductive agent fine powder such as Co (OH) 2 .

【００７７】《実施例１４》実施例１３と同様にして得
られた正極板を３９×８６ｍｍに切断し、基板中にあら
かじめ設けたリード接続部に電極リードをスポット溶接
してニッケル正極とした。一方、負極には、前記の実施
例と同様にして得た、厚さ０．４５ｍｍ、容量密度１３
５０ｍＡｈ／ｃｃの水素吸蔵合金負極板を、３９×９１
ｍｍに切断した容量２１５０ｍＡｈのものを用いた。こ
の正極と負極を厚さ０．１５ｍｍのスルフォン化ポリプ
ロピレン不織布からなるセパレーターを間に介して渦巻
状の電極群に構成した。この電極群を電池ケース内に挿
入し、３０ｗｔ％のＫＯＨ水溶液からなる電解液を２．
２ｍｌ注入後、作動弁圧が２０ｋｇｆ／ｃｍ2の安全弁
を持つ封口体により電池ケースの開口部を密閉してＡＡ
サイズの円筒密閉形ニッケル−水素蓄電池を製作した。Example 14 A positive electrode plate obtained in the same manner as in Example 13 was cut into a size of 39 × 86 mm, and an electrode lead was spot-welded to a lead connecting portion previously provided in the substrate to obtain a nickel positive electrode. On the other hand, for the negative electrode, a thickness of 0.45 mm and a capacity density of 13 were obtained in the same manner as in the above example.
50mAh / cc hydrogen storage alloy negative electrode plate, 39 × 91
A product having a capacity of 2150 mAh cut into mm was used. The positive electrode and the negative electrode were formed into a spiral electrode group with a separator made of a sulfonated polypropylene nonwoven fabric having a thickness of 0.15 mm interposed therebetween. This electrode group was inserted into a battery case, and an electrolytic solution containing a 30 wt% KOH aqueous solution was added to 2.
After injecting 2 ml, the opening of the battery case was sealed with a sealing body having a safety valve with an operating valve pressure of 20 kgf / cm 2
A size sealed cylindrical nickel-hydrogen storage battery was manufactured.

【００７８】《比較例１１》比較例３と同様にして作成
した正極板を３９×８６ｍｍに切断して使用した他は実
施例１４と同様にしてＡＡサイズの円筒密閉形ニッケル
−水素蓄電池を製作した。表７に実施例１４および比較
例１１の電池を、２０℃または４５℃において４０ｍＡ
の電流で１５時間充電し、２０℃において８０ｍＡの電
流で電池電圧１．０Ｖに至るまで放電したときのエネル
ギー密度、および酸素発生電位と充電電位の差ηを示
す。Comparative Example 11 AA size cylindrical sealed nickel-hydrogen storage battery was manufactured in the same manner as in Example 14 except that the positive electrode plate prepared in the same manner as in Comparative Example 3 was cut to 39 × 86 mm and used. did. Table 7 shows the batteries of Example 14 and Comparative Example 11 at 40 ° C at 20 ° C or 45 ° C.
Shows the energy density and the difference η between the oxygen generation potential and the charging potential when the battery is charged for 15 hours at 20 ° C. and discharged at a current of 80 mA at 20 ° C. until the battery voltage reaches 1.0 V.

【００７９】[0079]

【表７】 [Table 7]

【００８０】表７から明らかなように、実施例１４の電
池は、比較例１１の電池に比してエネルギー密度の飛躍
的な向上が見られる。また、酸素発生電位と充電電位の
差が大きく、充電時の酸素発生過電圧の上昇に格段の効
果を有し、高温充電時の容量においても大きな効果が認
められる。As is clear from Table 7, the battery of Example 14 shows a dramatic improvement in energy density as compared with the battery of Comparative Example 11. Further, the difference between the oxygen generation potential and the charging potential is large, and it has a remarkable effect on the increase of the oxygen generation overvoltage during charging, and a large effect is also recognized on the capacity during high temperature charging.

【００８１】[0081]

【発明の効果】以上説明したように本発明によれば、正
極活物質表面の酸素発生過電圧を高めることができ、こ
れによって高温における充電効率を著しく改善すること
ができる。また、表面付近のみで、このような作用を有
効に行わせるため、従来に比して容量密度の点で優れ
る。活物質内部は、従来より利用率の高い活物質に改質
して、電極容量密度の飛躍的な向上をも達成することが
できる。本発明によって、広い温度範囲で容量密度の優
れるアルカリ蓄電池用正極を提供することができる。As described above, according to the present invention, the oxygen generation overvoltage on the surface of the positive electrode active material can be increased, whereby the charging efficiency at high temperature can be remarkably improved. Further, since such an effect is effectively performed only in the vicinity of the surface, the capacity density is superior to the conventional one. The inside of the active material can be reformed into an active material having a higher utilization rate than in the past, and a dramatic improvement in the electrode capacity density can be achieved. According to the present invention, it is possible to provide a positive electrode for an alkaline storage battery, which has an excellent capacity density in a wide temperature range.

【図面の簡単な説明】[Brief description of drawings]

【図１】本発明による活物質粉末を模式的に示した図で
ある。FIG. 1 is a diagram schematically showing an active material powder according to the present invention.

【図２】本発明による活物質の充填された正極の要部を
模式的に示した図である。FIG. 2 is a view schematically showing a main part of a positive electrode filled with an active material according to the present invention.

【図３】同正極の一部を拡大して示す模式図である。FIG. 3 is a schematic view showing an enlarged part of the positive electrode.

【図４】Ｃａを固溶した水酸化ニッケルの表面層を有す
る活物質を用いた電極における前記表面層の厚さと、酸
素発生電位と充電電位の差ηとの関係を示した図であ
る。FIG. 4 is a diagram showing the relationship between the thickness of the surface layer of an electrode using an active material having a surface layer of nickel hydroxide in which Ca is solid-dissolved and the difference η between the oxygen generation potential and the charging potential.

【図５】Ｚｎを固溶した水酸化ニッケルの表面層を有す
る活物質を用いた電極における前記表面層のＺｎ固溶割
合と、酸素発生電位と充電電位の差ηとの関係を示した
図である。FIG. 5 is a diagram showing a relationship between a Zn solid solution ratio of the surface layer of an electrode using an active material having a surface layer of nickel hydroxide in which Zn is solid-dissolved and a difference η between an oxygen generation potential and a charging potential. Is.

【図６】実施例４、５、６および比較例２、４、５の電
極を用いた電池の充放電曲線を示した図である。FIG. 6 is a diagram showing charge / discharge curves of batteries using the electrodes of Examples 4, 5, and 6 and Comparative Examples 2, 4, and 5.

【図７】実施例７、９、１０および比較例２、３、６の
電極を用いた電池の充放電曲線を示した図である。FIG. 7 is a diagram showing charge / discharge curves of batteries using the electrodes of Examples 7, 9, 10 and Comparative Examples 2, 3, 6;

【図８】内部にＭｎを固溶させた水酸化ニッケル活物質
を用いた電極におけるＭｎ固溶割合と電極容量密度との
関係を示した図である。FIG. 8 is a diagram showing a relationship between an Mn solid solution ratio and an electrode capacitance density in an electrode using a nickel hydroxide active material having Mn dissolved therein.

【図９】実施例１１、１２および比較例２、３の電極を
用いた電池の充放電曲線を示した図である。FIG. 9 is a diagram showing charge / discharge curves of batteries using the electrodes of Examples 11 and 12 and Comparative Examples 2 and 3.

【図１０】実施例１２、１３、および比較例９の電池の
充放電曲線を示した図である。FIG. 10 is a diagram showing charge / discharge curves of batteries of Examples 12 and 13 and Comparative Example 9.

【図１１】実施例１２、および比較例１０の電池の放電
容量のサイクル変化を示した図である。FIG. 11 is a diagram showing cycle changes in discharge capacities of batteries of Example 12 and Comparative Example 10.

【符号の説明】[Explanation of symbols]

１ 発泡状ニッケル基板 ２ 活物質粉末 ３ 導電性多孔層 ４ Ｙ2Ｏ3粉末 ５ 結着剤 ６ フッ素樹脂皮膜 ７ 空間部1 Foamed Nickel Substrate 2 Active Material Powder 3 Conductive Porous Layer 4 Y 2 O 3 Powder 5 Binder 6 Fluororesin Film 7 Space

───────────────────────────────────────────────────── フロントページの続き (72)発明者 泉 秀勝 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (72)発明者 松本 功 大阪府門真市大字門真1006番地 松下電 器産業株式会社内 (56)参考文献 特開 平８−213010（ＪＰ，Ａ) 特開 平８−162106（ＪＰ，Ａ) 特開 平５−41212（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/32 H01M 4/48 H01M 4/52 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hidekatsu Izumi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Isao Matsumoto 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56) References JP-A-8-213010 (JP, A) JP-A-8-162106 (JP, A) JP-A-5-41212 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H01M 4/32 H01M 4/48 H01M 4/52

Claims (19)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 Ｎｉを主とする複数金属元素の酸化物か
らなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｒ、Ｂｉ、およびＬａ族金属元素からなる群より選ばれ
た少なくとも一種の元素が含まれているという点で、ま
たは前記元素が内部より高濃度に含まれているという点
で内部とは平均組成が異なっていることを特徴とするア
ルカリ蓄電池用正極。1. An oxide of a plurality of metal elements mainly containing Ni
It is a positive electrode for an alkaline storage battery that has an active material consisting of
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
In addition to i, Ca, Ti, Zn, Sr, Ba, Y, C
selected from the group consisting of r, Bi, and La group metal elements
In addition, it contains at least one element.
Or that the above elements are contained in a higher concentration than the inside
And the average composition is different from the inside.
Positive electrode for Lucari battery. 【請求項２】 Ｎｉを主とする複数金属元素の酸化物か
らなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族金属元素からなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が内部より高濃度に含まれて
いるという点で内部とは平均組成が異なっており、 前記複数金属元素の酸化物の表面層を除く内部には、Ｎ
ｉのほかに、Ａｌ、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｕ、Ｇ
ｅ、Ｚｒ、Ｎｂ、Ｍｏ、Ａｇ、Ｓｎ、Ｓｂ、およびＷか
らなる群より選ばれた少なくとも一種の元素が含まれて
いるという点で、または前記元素が表面層より高濃度に
含まれているという点で、表面層とは平均組成がさらに
異なっているアルカリ蓄電池用正極。2. Is it an oxide of a plurality of metal elements mainly containing Ni
It is a positive electrode for an alkaline storage battery that has an active material consisting of
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
i, Ca, Ti, Zn, Sr, Ba, Y, C
Consists of d, Co, Cr, Bi, and La group metal elements
If it contains at least one element selected from the group
In that respect, or the element is contained in a higher concentration than the inside
The average composition is different from that of the inside, and the inside of the inside except the surface layer of the oxide of the plural metal elements is N
i, Al, V, Cr, Mn, Fe, Cu, G
e, Zr, Nb, Mo, Ag, Sn, Sb, and at least one element selected from the group consisting of W is contained, or the element is contained in a higher concentration than the surface layer. in that, the positive electrode for luer alkaline storage battery as the surface layer even more different average composition. 【請求項３】 前記複数金属元素の酸化物の表面層に含
まれたＮｉ以外の全金属元素の平均的な含有割合ｘが、
Ｎｉを含む全金属元素の原子数を１としたとき、０．０
１≦ｘ≦０．４である請求項１に記載のアルカリ蓄電池
用正極。3. The average content ratio x of all metal elements other than Ni contained in the surface layer of the oxide of a plurality of metal elements is:
When the number of atoms of all metal elements including Ni is 1, 0.0
The positive electrode for an alkaline storage battery according to claim 1, wherein 1 ≦ x ≦ 0.4. 【請求項４】 Ｎｉを主とする複数金属元素の酸化物か
らなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記複数金属元素の
酸化物の表面層を除く内部には、Ｎｉのほかに、Ａｌ、
Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｕ、Ｇｅ、Ｚｒ、Ｎｂ、Ｍ
ｏ、Ａｇ、Ｓｎ、Ｓｂ、およびＷからなる群より選ばれ
た少なくとも一種の元素が含まれているという点で、ま
たは前記元素が表面層より高濃度に含まれているという
点で、表面層とは平均組成が異なっているアルカリ蓄電
池用正極。4. A positive electrode for an alkaline storage battery, comprising an active material composed of an oxide of a plurality of metal elements containing Ni as a main component, wherein the oxide of a plurality of metal elements has a large number of fine pores in at least a surface layer. The average composition of the surface layer is different from the average composition of the inside thereof, and in addition to Ni, Al, and
V, Cr, Mn, Fe, Cu, Ge, Zr, Nb, M
surface layer in that it contains at least one element selected from the group consisting of o, Ag, Sn, Sb, and W, or in that it contains a higher concentration than the surface layer. A positive electrode for alkaline storage batteries whose average composition is different from. 【請求項５】 前記複数金属元素の酸化物の表面層を除
く内部に含まれたＮｉ以外の全金属元素の平均的な含有
割合ｙは、Ｎｉを含む全金属元素の原子数を１としたと
き、０．０１≦ｙ≦０．３５である請求項２または４に
記載のアルカリ蓄電池用正極。5. The average content ratio y of all the metal elements other than Ni contained in the inside excluding the surface layer of the oxide of the plurality of metal elements is set such that the number of atoms of all the metal elements including Ni is 1. The positive electrode for an alkaline storage battery according to claim 2 or 4, wherein 0.01 ≦ y ≦ 0.35. 【請求項６】 Ｎｉを主とする複数金属元素の酸化物か
らなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族金属元素からなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が内部より高濃度に含まれて
いるという点で内部とは平均組成が異なっており、 前記複数金属元素の酸化物が、前記Ｎｉ以外の金属元素
を固溶したニッケル酸化物、並びに、ＮｉおよびＮｉ以
外の各金属元素の酸化物の共晶の少なくとも一方である
アルカリ蓄電池用正極。 6. An oxide of a plurality of metal elements mainly containing Ni
It is a positive electrode for an alkaline storage battery that has an active material consisting of
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
i, Ca, Ti, Zn, Sr, Ba, Y, C
Consists of d, Co, Cr, Bi, and La group metal elements
If it contains at least one element selected from the group
In that respect, or the element is contained in a higher concentration than the inside
The average composition is different from that of the inside, and the oxide of the plurality of metal elements is a metal element other than Ni.
Nickel oxide in solid solution of Ni, Ni and Ni or less
It is at least one of the eutectics of the oxide of each metal element outside
Positive electrode for alkaline storage batteries. 【請求項７】 前記複数金属元素の酸化物が、前記Ｎｉ
以外の金属元素を固溶したニッケル酸化物、並びに、Ｎ
ｉおよびＮｉ以外の各金属元素の酸化物の共晶の少なく
とも一方である請求項４に記載のアルカリ蓄電池用正
極。7. The oxide of the plurality of metal elements is the Ni
Oxides containing solid-solution metal elements other than N, and N
The positive electrode for an alkaline storage battery according to claim 4 , which is at least one of eutectic crystals of oxides of metal elements other than i and Ni. 【請求項８】 前記複数金属元素の酸化物の多数の微細
孔は、平均孔径２００オングストローム以下であり、表
面層付近の微細孔同士は互いに連通している請求項１ま
たは４に記載のアルカリ蓄電池用正極。8. The alkaline storage battery according to claim 1, wherein a large number of micropores of the oxide of a plurality of metal elements have an average pore diameter of 200 angstroms or less, and the micropores near the surface layer communicate with each other. For positive electrode. 【請求項９】 Ｎｉを主とする複数金属元素の酸化物か
らなる活物質を具備するアル カリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族金属元素からなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が内部より高濃度に含まれて
いるという点で内部とは平均組成が異なっており、 前記複数金属元素の酸化物における表面層の厚さは、１
０〜５００ｎｍであるアルカリ蓄電池用正極。 9. An oxide of a plurality of metal elements mainly containing Ni
There is a positive electrode for alkaline storage battery having a Ranaru active material
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
i, Ca, Ti, Zn, Sr, Ba, Y, C
Consists of d, Co, Cr, Bi, and La group metal elements
If it contains at least one element selected from the group
In that respect, or the element is contained in a higher concentration than the inside
The average composition is different from that in the inside, and the thickness of the surface layer in the oxide of the plurality of metal elements is 1
Positive electrode for alkaline storage battery having a thickness of 0 to 500 nm. 【請求項１０】 前記複数金属元素の酸化物における表
面層の厚さは、１０〜５００ｎｍである請求項４に記載
のアルカリ蓄電池用正極。10. The positive electrode for an alkaline storage battery according to claim 4 , wherein the thickness of the surface layer of the oxide of a plurality of metal elements is 10 to 500 nm. 【請求項１１】 前記複数金属元素の酸化物は、平均径
１００μｍ以下の粉末であって、主に球状または球状に
近い形状の粉末であり、タップ密度が１．５ｇ／ｃｃ以
上である請求項１または４に記載のアルカリ蓄電池用正
極。11. The oxide of a plurality of metal elements is a powder having an average diameter of 100 μm or less, which is mainly spherical or nearly spherical, and has a tap density of 1.5 g / cc or more. The positive electrode for an alkaline storage battery according to 1 or 4. 【請求項１２】 Ｎｉを主とする複数金属元素の酸化物
からなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族金属元素からなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が内部より高濃度に含まれて
いるという点で内部とは平均組成が異なっており、 前記活物質が、反応晶析法により作製された粉末である
アルカリ蓄電池用正極。 12. An oxide of a plurality of metal elements mainly containing Ni
It is a positive electrode for an alkaline storage battery that has an active material consisting of
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
i, Ca, Ti, Zn, Sr, Ba, Y, C
Consists of d, Co, Cr, Bi, and La group metal elements
If it contains at least one element selected from the group
In that respect, or the element is contained in a higher concentration than the inside
The average composition is different from that of the inside, and the active material is a powder produced by the reaction crystallization method.
Positive electrode for alkaline storage batteries. 【請求項１３】 前記活物質が、反応晶析法により作製
された粉末である請求項４に記載のアルカリ蓄電池用正
極。13. The positive electrode for an alkaline storage battery according to claim 4, wherein the active material is a powder produced by a reaction crystallization method. 【請求項１４】 前記活物質が、多孔性の導電性支持体
に電気化学的に析出されたものである請求項１または１
１に記載のアルカリ蓄電池用正極。14. The active material, according to claim 1 or 1 in which is electrochemically deposited on the porous conductive support
1. The positive electrode for an alkaline storage battery according to 1 . 【請求項１５】 Ｎｉを主とする複数金属元素の酸化物
からなる活物質を具備するアルカリ蓄電池用正極であっ
て、前記複数金属元素の酸化物は、少なくとも表面層に
は多数の微細孔を有し、その表面層の平均組成とその内
部の平均組成は異なるものであり、前記表面層には、Ｎ
ｉのほかに、Ｃａ、Ｔｉ、Ｚｎ、Ｓｒ、Ｂａ、Ｙ、Ｃ
ｄ、Ｃｏ、Ｃｒ、Ｂｉ、およびＬａ族金属元素からなる
群より選ばれた少なくとも一種の元素が含まれていると
いう点で、または前記元素が内部より高濃度に含まれて
いるという点で内部とは平均組成が異なっており、 前記活物質の粉末を含む活物質混合物が導電性支持体に
支持されたアルカリ蓄電池用正極。 15. An oxide of a plurality of metal elements mainly containing Ni
It is a positive electrode for an alkaline storage battery that has an active material consisting of
The oxide of the plurality of metal elements is present in at least the surface layer.
Has a large number of fine pores, and the average composition of the surface layer and
The average composition of the parts is different, and the surface layer contains N
i, Ca, Ti, Zn, Sr, Ba, Y, C
Consists of d, Co, Cr, Bi, and La group metal elements
If it contains at least one element selected from the group
In that respect, or the element is contained in a higher concentration than the inside
The average composition is different from that of the inside, and the active material mixture containing the powder of the active material is used as the conductive support.
Supported positive electrode for alkaline storage battery. 【請求項１６】 前記活物質の粉末を含む活物質混合物
が導電性支持体に支持された請求項４に記載のアルカリ
蓄電池用正極。16. The positive electrode for an alkaline storage battery according to claim 4, wherein the active material mixture containing the powder of the active material is supported by a conductive support. 【請求項１７】 前記活物質粉末が、導電性を有する金
属酸化物または金属による多孔層で被覆されている請求
項１５または１６に記載のアルカリ蓄電池用正極。17. The positive electrode for an alkaline storage battery according to claim 15 , wherein the active material powder is covered with a porous layer made of a conductive metal oxide or metal. 【請求項１８】 前記活物質混合物が、Ｎｉ、グラファ
イト、Ｃａ化合物、Ｔｉ化合物、Ｓｒ化合物、Ｂａ化合
物、Ｙ化合物、Ｃｄ化合物、Ｃｏ、Ｃｏ化合物、Ｚｎ化
合物、および希土類金属化合物からなる群より選ばれた
少なくとも一種の粉末を前記活物質粉末の重量の０．５
〜２０．０ｗｔ％相当を含む請求項１５または１６に記
載のアルカリ蓄電池用正極。18. The active material mixture is selected from the group consisting of Ni, graphite, Ca compounds, Ti compounds, Sr compounds, Ba compounds, Y compounds, Cd compounds, Co, Co compounds, Zn compounds, and rare earth metal compounds. 0.5% by weight of the active material powder.
The positive electrode for an alkaline storage battery according to claim 15 or 16, containing about 20.0 wt% of the positive electrode. 【請求項１９】 請求項１〜１８のいずれかに記載の正
極を用いたアルカリ蓄電池。 19. The positive structure according to claim 1.
Alkaline storage battery using poles.
JP21520397A 1996-09-20 1997-08-08 Positive electrode for alkaline storage battery and alkaline storage battery Expired - Lifetime JP3518975B2 (en)

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US6416903B1 (en) * 1998-08-17 2002-07-09 Ovonic Battery Company, Inc. Nickel hydroxide electrode material and method for making the same
US6177213B1 (en) * 1998-08-17 2001-01-23 Energy Conversion Devices, Inc. Composite positive electrode material and method for making same
JP2000113904A (en) 1998-10-07 2000-04-21 Matsushita Electric Ind Co Ltd Alkaline storage battery
EP1901373A1 (en) 1998-11-30 2008-03-19 Sanyo Electric Co., Ltd. Nickel electrodes for alkaline secondary battery and alkaline secondary batteries
JP3728143B2 (en) * 1999-06-22 2005-12-21 三洋電機株式会社 Sealed alkaline storage battery
JP2001332257A (en) * 1999-10-08 2001-11-30 Hitachi Maxell Ltd Non-baking type positive electrode for alkaline battery, its manufacturing method and the alkaline battery using the non-baking type positive electrode
CN1233055C (en) 2000-06-16 2005-12-21 松下电器产业株式会社 Anode active material for alkali storage battery, anode including samd, and alkali storage battery
EP1168471B1 (en) 2000-06-30 2011-01-12 Sanyo Electric Co., Ltd. Nickel electrode for alkaline storage battery and alkaline storage battery
JP3685704B2 (en) 2000-10-03 2005-08-24 三洋電機株式会社 Method for producing nickel electrode for alkaline storage battery
JP4458725B2 (en) 2001-01-30 2010-04-28 三洋電機株式会社 Alkaline storage battery
JP4578038B2 (en) 2001-04-17 2010-11-10 三洋電機株式会社 Nickel electrode for alkaline storage battery and alkaline storage battery
JP4710225B2 (en) * 2001-09-03 2011-06-29 株式会社Ｇｓユアサ Method for producing nickel electrode material
JP4127990B2 (en) 2001-09-18 2008-07-30 三洋電機株式会社 Nickel electrode for alkaline storage battery, method for producing nickel electrode for alkaline storage battery, and alkaline storage battery
FR2872346B1 (en) * 2004-06-25 2006-09-29 Accumulateurs Fixes ALKALINE ELECTROCHEMICAL GENERATOR WITH IMPROVED LIFETIME
JP2006059807A (en) * 2004-07-23 2006-03-02 M & G Eco Battery Institute Co Ltd Nickel electrode and alkali storage battery using the same
JP2013134904A (en) * 2011-12-27 2013-07-08 Sanyo Electric Co Ltd Alkaline storage battery and alkaline storage battery system including the same
JP5853799B2 (en) * 2012-03-22 2016-02-09 三洋電機株式会社 Alkaline storage battery

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