JP2000223147A - Alkaline storage battery - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkaline storage battery having satisfactory characteristics in a wide range of temperatures by improving charging efficiency in high-temperature environments. SOLUTION: A positive electrode 1 made of a Ni oxide with crystals containing Cr as an essential constituent and an alkaline electrolytic solution containing chromic acid ions are used in this alkaline storage battery. Or, at least one selected from among a Cr compound, Cr metal, and an alloy containing Cr as a main constituent, is caused to exist around an active material or deposited on surfaces of the active material, and this is used together with an alkaline electrolytic solution containing chromic acid ions.

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、高容量かつ高信頼
性のアルカリ蓄電池に関する。更に詳細には高温での充
電効率の高いアルカリ蓄電池に関するものである。The present invention relates to a high capacity and high reliability alkaline storage battery. More specifically, the present invention relates to an alkaline storage battery having high charging efficiency at high temperatures.

【０００２】[0002]

【従来の技術】ニッケル・カドミウム蓄電池（以下、Ｎ
ｉ／Ｃｄと略称する）やニッケル・水素蓄電池（以下、
Ｎｉ／ＭＨと略称する）等に代表されるアルカリ蓄電
池、特に小型の密閉式電池は、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、パーソナルコンピュータ等の事務
機、通信機、家電および雑貨等の各種のポ−タブル機器
用主電源として普及が著しい。また、電気自動車や据え
置き用の中大型の電源としても注目されている。2. Description of the Related Art Nickel-cadmium storage batteries (hereinafter referred to as N
i / Cd) or nickel-metal hydride storage battery (hereinafter, referred to as i / Cd).
Alkaline storage batteries such as Ni / MH), especially small sealed batteries, have a better balance of charge / discharge characteristics, cycle life and safety / reliability than other battery systems. It has been widely used as a main power supply for various portable devices such as office machines such as computers, communication devices, home appliances and miscellaneous goods. It is also drawing attention as a medium-sized power supply for electric vehicles and stationary.

【０００３】近年のこのような用途の拡大に伴い、従来
より広範囲の環境温度の下で良好な特性を有することが
求められるようになってきた。特にパーソナルコンピュ
ータの分野では機器の消費電力量の増加に伴って電池周
囲温度が上昇し、従来の環境温度は４５〜５０℃であっ
たものが、５０〜６０℃にも達するようになってきた。[0003] With the recent expansion of such applications, it has been required to have good characteristics over a wider range of environmental temperatures than in the past. In particular, in the field of personal computers, the ambient temperature of the battery rises with the increase in the power consumption of the equipment, and the conventional environmental temperature has reached 45-60 ° C., but has now reached 50-60 ° C. .

【０００４】多数の電池をモジュール化して用いる電気
自動車では使用条件が更に厳しく、充電時に電池自身が
発熱することによって電池周囲の温度は６０℃以上にも
達するという極めて過酷な作動環境での良好な特性を有
することが必要とされている。[0004] In an electric vehicle using a large number of batteries in a modular form, the operating conditions are more severe, and the temperature around the batteries reaches over 60 ° C due to the generation of heat by the batteries themselves during charging. There is a need to have properties.

【０００５】しかしながら、Ｎｉ極を正極に用いたアル
カリ蓄電池では充電時の酸素発生電位が温度と共に低下
し、副反応として酸素発生が生じ、活物質への充電反応
と共存するために充電効率が著しく低下する。そのため
従来はＮｉ（ＯＨ）₂のＮｉの一部を他の金属元素で置
換固溶したり、Ｎｉ正極に添加剤を加えることによって
高温での充電効率の改善を図ってきた。However, in an alkaline storage battery using a Ni electrode as a positive electrode, the oxygen generation potential at the time of charging decreases with temperature, oxygen is generated as a side reaction, and the coexistence with the charging reaction to the active material causes a significant reduction in charging efficiency. descend. Therefore, conventionally, a part of Ni of Ni (OH) ₂ has been replaced with another metal element to form a solid solution, or an additive has been added to the Ni positive electrode to improve the charging efficiency at high temperatures.

【０００６】例えばＣｏ、Ｃｄの二元素の固溶につい
て、特公平３−２６９０３号公報／出願１９８４年、特
公平３−５０３８４号公報／出願１９８４年、電気化学
Ｖｏｌ．５４，Ｎo．２，Ｐ．１６４（１９８６）），
Ｐｏｗｅｒ Ｓｏｕｒｃｅｓ１２， Ｐ．２０３（１９
８８）などが挙げられる。For example, regarding the solid solution of two elements of Co and Cd, Japanese Patent Publication No. 3-26903 / Application 1984, Japanese Patent Publication No. 3-50384 / Application 1984, Electrochemical Vol. 54, No. 2, P. 164 (1986)),
Power Sources 12, p. 203 (19
88).

【０００７】Ｃｄの代替元素としてＺｎ、あるいはＣ
ｏ，ＺｎおよびＢａなどの三元素の固溶体も提案されて
いる。（米国特許５３６６８３１号／出願１９９２
年）。As an alternative to Cd, Zn or C
Solid solutions of three elements such as o, Zn and Ba have also been proposed. (US Pat. No. 5,366,831 / application 1992)
Year).

【０００８】また、電解液の改良によって高温での充電
特性の改善も試みられてきた。例えば、特開平１０−２
８４１１３号公報では電解液としてＫＯＨ，ＮａＯＨ，
ＬｉＯＨの混合アルカリ溶液を用いることが提案されて
いる。Attempts have also been made to improve the charging characteristics at high temperatures by improving the electrolytic solution. For example, JP-A-10-2
No. 84113 discloses KOH, NaOH,
It has been proposed to use a mixed alkaline solution of LiOH.

【０００９】その他、Ｎｉ正極への添加剤の改良の例と
してはＺｎＯ、ＣａＦ，Ｙ₂Ｏ₃等の添加について、特開
平６−１０３９７２号公報が挙げられる。このうちＹ₂
Ｏ₃のＮｉ極への添加が充電効率向上の効果が最も大き
く４５℃では２０℃での場合に比して約８５％程度の充
電効率が得られる。As another example of the improvement of the additive to the Ni positive electrode, Japanese Patent Application Laid-Open No. 6-103972 discloses the addition of ZnO, CaF, Y ₂ O _{3 and the} like. Y ₂
The addition of O _{3 to} the Ni electrode has the largest effect of improving the charging efficiency, and at 45 ° C., a charging efficiency of about 85% can be obtained as compared with the case at 20 ° C.

【００１０】さらに、特開平１０−１４９８２１号公報
ではＣｒを複数酸化物の一種として含むＮｉ酸化物正極
を用いることにより、アルカリ蓄電池の高温における充
電効率を改善できることを開示している。Further, Japanese Patent Application Laid-Open No. 10-149821 discloses that the charging efficiency of an alkaline storage battery at a high temperature can be improved by using a Ni oxide positive electrode containing Cr as one kind of a plurality of oxides.

【００１１】しかしながら、以上のような方法をそれぞ
れ、単独で実施したとしても、高温での充電効率の改善
を図ることができるのはいずれも精々４５〜５０℃まで
の温度範囲であり、それ以上の場合には十分な効果を得
ることはできておらず、この領域での充電特性の改良が
強く求められていた。However, even if each of the above methods is carried out independently, the improvement of charging efficiency at high temperatures can be achieved only in the temperature range of at most 45 to 50 ° C. In the case of (1), a sufficient effect could not be obtained, and improvement of the charging characteristics in this region was strongly demanded.

【００１２】[0012]

【発明が解決しようとする課題】本発明は、上記のよう
に４５℃以上の高温環境下での電池特性、特に６０℃程
度の環境で充電効率を改良し、高容量かつ長寿命のアル
カリ蓄電池を提供するものである。SUMMARY OF THE INVENTION As described above, the present invention relates to a high-capacity and long-life alkaline storage battery which has improved battery characteristics in a high-temperature environment of 45.degree. Is provided.

【００１３】[0013]

【課題を解決するための手段】上記のように５０℃以上
の高温環境の下で充電特性に優れ、高容量かつ長寿命の
アルカリ蓄電池を提供するため本発明では、正極、負
極、セパレータ及びアルカリ電解液を発電要素として備
えた蓄電池において、Ｎｉを主たる金属元素とし、少な
くともＣｒがその結晶中に存在していることを特徴とす
る複数金属元素の酸化物粉末を主たる活物質とする正
極、あるいは、Ｃｒ化合物、または金属Ｃｒ、もしくは
Ｃｒを成分として含む合金のうち少なくとも一種を表面
付近に存在させた、あるいは、これらの物質を表面上に
析出させたＮｉを主たる金属元素とする酸化物を活物質
とする正極と、クロム酸イオンまたはクロム錯体を含む
電解液とを同時に使用することを特徴としている。SUMMARY OF THE INVENTION As described above, in order to provide an alkaline storage battery having excellent charge characteristics under a high temperature environment of 50 ° C. or higher, high capacity and long life, the present invention provides a positive electrode, a negative electrode, a separator and an alkaline storage battery. In a storage battery provided with an electrolytic solution as a power generation element, a positive electrode having Ni as a main metal element and an oxide powder of a plurality of metal elements as a main active material, characterized in that at least Cr is present in its crystal, or , A Cr compound, or at least one of metal Cr or an alloy containing Cr as a component is present in the vicinity of the surface, or an oxide containing Ni as a main metal element formed by depositing these substances on the surface is activated. It is characterized in that a positive electrode as a substance and an electrolytic solution containing a chromate ion or a chromium complex are used simultaneously.

【００１４】アルカリ蓄電池における高温環境下での充
電効率の低下の主たる要因はＮｉ正極での副反応である
酸素発生にあるとの認識から、活物質のＮｉ酸化物のＮ
ｉの一部を様々な金属元素で置換する方法によりその改
良が図られてきたが、いずれも５０℃以上の高温環境の
下では十分な効果は得られていなかった。Recognizing that the main cause of the decrease in the charging efficiency in an alkaline storage battery under a high-temperature environment is oxygen generation, which is a side reaction at the Ni positive electrode, the N oxide of Ni oxide as an active material is recognized.
Improvements have been made by a method of substituting a part of i with various metal elements, but none of them has been able to obtain a sufficient effect under a high temperature environment of 50 ° C. or higher.

【００１５】しかし、他の元素の固溶がある無しに関わ
らず、正極活物質であるＮｉ酸化物にＣｒを必須成分と
して固溶させ、クロム酸イオンを含有させた電解液を用
いた場合に、６０℃での充電効率が４５℃での充電効率
を上回るというこれまでの常識を覆す特異な現象を新た
に見出された。However, irrespective of the presence or absence of the solid solution of other elements, when an electrolytic solution containing Cr as an essential component in Ni oxide as a positive electrode active material and containing chromate ions is used. , A unique phenomenon that overturns the conventional wisdom that charging efficiency at 60 ° C. exceeds charging efficiency at 45 ° C.

【００１６】一般に環境温度の上昇と共に活物質表面の
固液界面での副反応である酸素発生反応が促進され、充
電効率が著しく低下する。このように既存の電気化学理
論では上記のような現象は説明できないがＣｒが活物質
表面で何らかの酸素発生反応を抑制しているためと推察
され、したがって、Ｃｒは活物質の表面近傍に存在する
ことが望ましいと考えられる。In general, as the environmental temperature rises, an oxygen generation reaction, which is a side reaction at the solid-liquid interface on the surface of the active material, is promoted, and the charging efficiency is significantly reduced. As described above, the existing electrochemical theory cannot explain the above phenomenon, but it is presumed that Cr suppresses some oxygen generation reaction on the active material surface, and therefore, Cr exists near the surface of the active material. It is considered desirable.

【００１７】但し、Ｃｒはアルカリ水溶液中に溶解する
ため、活物質中、特に表面付近に存在するＣｒは活物質
の極僅かな溶解析出平衡反応によって選択的に溶出する
ので、少なくとも上記特性の改善はアルカリ電解液中に
予めクロム酸イオンまたはクロム錯体を含有させること
により、このような表面近傍からのＣｒの選択的な溶出
が抑制された結果であると考えられる。However, since Cr dissolves in an alkaline aqueous solution, Cr present in the active material, particularly in the vicinity of the surface, is selectively eluted by a very slight dissolution / equilibrium reaction of the active material. This is considered to be the result of suppressing the selective elution of Cr from the vicinity of the surface by adding a chromate ion or a chromium complex in the alkaline electrolyte in advance.

【００１８】しかし上記のような改良によっても４５℃
程度の環境温度の下ではＣｒを含んだ場合の充電効率の
改善は、さほど大きいとはいえない。このような温度領
域では更にＣａ，Ｔｉ，Ｚｎ，Ｓｒ，Ｂａ，Ｙ，Ｃｄ，
Ｃｏ，ランタン族金属, Ａｌ，Ｖ，Ｍｎから選ばれた一
種以上の元素を正極活物質に同時に含ませることにより
更に広範囲な環境温度で安定した特性を得ることができ
る。このうち特にＣａは４５℃程度での充電効率の改善
の効果が著しく、Ｔｉ，Ｚｎ，Ｓｒ，Ｂａ，Ｙ，Ｃｄ，
Ｃｏはそれに次ぐ効果を有する。However, even with the above-mentioned improvement, 45 ° C.
Under a certain environmental temperature, the improvement in charging efficiency when Cr is contained is not so large. In such a temperature range, Ca, Ti, Zn, Sr, Ba, Y, Cd,
By simultaneously including one or more elements selected from Co, a lanthanum group metal, Al, V, and Mn in the positive electrode active material, stable characteristics can be obtained over a wider range of environmental temperatures. Among these, Ca has a remarkable effect of improving the charging efficiency at about 45 ° C., and Ti, Zn, Sr, Ba, Y, Cd,
Co has the next effect.

【００１９】また同様の効果はＮｉ正極に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化合物，Ｚｎ化合物，ランタン族金属化合
物のうち一種以上が添加、 もしくは活物質表面上にＣｒ
と共に析出されている場合にも得ることができる。A similar effect is obtained by adding a Ca compound to the Ni positive electrode,
Ti compound, Sr compound, Ba compound, Y compound, Cd
One or more of a compound, a Co compound, a Zn compound and a lanthanum group metal compound, or Cr on the surface of the active material
It can also be obtained when it is precipitated together with.

【００２０】さらに用いるアルカリ電解液の主成分は電
導度の面からＫが用いられることが多いが、Ｎａを全ア
ルカリ総量の０〜４０mol%および／あるいはＬｉを０〜
５mol%の範囲で加えることにより４５℃程度での充電効
率の改善の効果が著しく、好ましい。Further, K is often used as a main component of the alkaline electrolyte to be used from the viewpoint of electric conductivity, but Na is used in an amount of 0 to 40 mol% of the total alkali and / or Li is used in an amount of 0 to 40 mol%.
By adding in the range of 5 mol%, the effect of improving the charging efficiency at about 45 ° C. is remarkable, which is preferable.

【００２１】結晶中にＣｒを含有するＮｉを主とする金
属酸化物活物質を用いる代わりに、Ｎｉを主とする金属
酸化物活物質にＣｒ化合物、 または金属Ｃｒ、もしくは
Ｃｒを成分として含む合金のうち少なくとも一種以上が
活物質の表面付近に存在させ、あるいはこれらの物質を
活物質の表面上に析出させ、クロム酸イオンを含む電解
液と共に用いることによっても類似の効果は得られる
が、Ｎｉ酸化物活物質の結晶中にＣｒを含有させた場合
に比して、その効果は小さい。Instead of using a metal oxide active material mainly containing Ni containing Cr in the crystal, a Cr compound or a metal Cr or an alloy containing Cr as a component in a metal oxide active material mainly containing Ni is used. A similar effect can be obtained by causing at least one or more of these to be present near the surface of the active material, or by precipitating these materials on the surface of the active material and using them together with the electrolytic solution containing chromate ions. The effect is smaller than when Cr is contained in the crystal of the oxide active material.

【００２２】しかるに、Ｎｉ正極材料の反応の主な担い
手はＮｉ元素であるので、他の元素を多量に含有させる
ことは容量の減少を来たし、製品として不利である。ま
たＣｒを表面に均一に分散させるために十分な量だけ含
有させることが必要である。適切な含有量はＣｒがＮｉ
酸化物結晶中に含まれる場合、活物質中の全金属元素に
対して２〜１０mol%であり、また、活物質中に固溶する
Ｃｒを表面近傍で多くなるよう、その固溶量の分布を制
御することは一層効果的である。Ｃｒ化合物をを表面付
近に存在または表面上に析出させる場合には全合剤の重
量に対して５〜１５wt%であることが好ましい。However, since the main cause of the reaction of the Ni positive electrode material is the Ni element, including a large amount of other elements decreases the capacity and is disadvantageous as a product. Further, it is necessary to contain Cr in an amount sufficient to uniformly disperse Cr on the surface. Suitable content is Cr
When contained in an oxide crystal, the content is 2 to 10 mol% with respect to all metal elements in the active material, and the amount of solid solution in the active material is increased so as to increase the amount of Cr dissolved in the active material near the surface. Is more effective. When the Cr compound is present near the surface or deposited on the surface, the content is preferably 5 to 15% by weight based on the total weight of the mixture.

【００２３】以上の構成により、５０℃以上の高温環境
下での放電容量の極端な低下を防止し、充電特性、従っ
て容量に優れたアルカリ蓄電池を作製することができ
る。With the above configuration, it is possible to prevent an extreme decrease in the discharge capacity in a high-temperature environment of 50 ° C. or more, and to manufacture an alkaline storage battery having excellent charge characteristics and thus excellent capacity.

【００２４】これまでにも活物質、特に水素吸蔵合金負
極の成分溶出を防止するためにアルカリ電解液中に金属
イオンまたは錯体を配する試みが成されてきた。しかる
に、上記のような作用はＣｒを含有するＮｉ酸化物活物
質表面でのＮｉ酸化物とＣｒの作用によるものであるの
で、活物質上における存在位置を規制することが極めて
重要である。Attempts have been made to arrange metal ions or complexes in an alkaline electrolyte in order to prevent the elution of components of the active material, particularly the hydrogen storage alloy negative electrode. However, since the above-described action is due to the action of the Ni oxide and Cr on the surface of the Cr-containing Ni oxide active material, it is extremely important to regulate the position on the active material.

【００２５】しかし、寿命特性の改善を目指し成分溶出
を防止するためにＴｉ，Ｎｂ，Ｃｒ，Ａｌの各イオンを
含有するアルカリ電解液を水素吸蔵合金負極と共に用い
る手段(例えば、特開平９−２８３１７４号公報、特開
平７−２３５３０４号公報)では、それらの存在位置を
規制しておらず、Ｎｉ正極中の活物質の結晶中または表
面に特にＣｒを含有していない構成であるので上記のよ
うな高温での特性の大幅な改善は得られない。However, means for using an alkaline electrolyte containing Ti, Nb, Cr and Al ions together with a hydrogen storage alloy negative electrode in order to improve the life characteristics and prevent elution of components (for example, Japanese Patent Application Laid-Open No. 9-283174). Japanese Patent Application Laid-Open No. Hei 7-235304) does not regulate the position of the active material and has a structure in which the Cr or the surface of the active material in the Ni positive electrode does not particularly contain Cr. No significant improvement in properties at very high temperatures can be obtained.

【００２６】なお本発明による効果は、負極、セパレー
ター等の部品の材質や電池の形状には依存せず、例えば
ＡＢ５系の水素吸蔵合金を用いたＮｉ／ＭＨ蓄電池のほ
か、Ｃｄ負極を用いたＮｉ／Ｃｄ蓄電池、Ｚｎ負極を用
いたＮｉ／Ｚｎ蓄電池などに適用することができる。The effect of the present invention does not depend on the material of parts such as the negative electrode and the separator and the shape of the battery. For example, a Ni / MH storage battery using an AB5-based hydrogen storage alloy and a Cd negative electrode are used. The present invention can be applied to a Ni / Cd storage battery, a Ni / Zn storage battery using a Zn negative electrode, and the like.

【００２７】[0027]

【発明の実施の形態】以下、本発明の一実施の形態につ
いて、図１および図２を用いて説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

【００２８】図１は本発明の一実施例として円筒型密閉
電池を図示したものである。図１において、正極１はＮ
ｉ酸化物を主活物質として構成されている。負極２は組
成ＭｍＮｉ_3.55ＣＯ_0.75Ｍｎ_0.4Ａｌ_0.5の水素吸蔵合金
を主活物質として構成されている。電解液３はＫ⁺, Ｎ
ａ⁺を主成分とするアルカリ水溶液でＣｒ酸イオンを
０．００３mol/l含有する。セパレーター４は正極と負
極を隔離し短絡を防止し、スルフォン化ポリプロピレン
で構成されている。FIG. 1 illustrates a cylindrical sealed battery as one embodiment of the present invention. In FIG. 1, the positive electrode 1 is N
It is composed of i-oxide as a main active material. The negative electrode 2 is composed of a hydrogen storage alloy having a composition of MmNi _3.55 CO _0.75 Mn _0.4 Al _0.5 as a main active material. The electrolyte 3 is K ⁺ , N
An alkaline aqueous solution containing a ⁺ as a main component and containing 0.003 mol / l of Cr acid ion. The separator 4 separates the positive electrode and the negative electrode to prevent a short circuit, and is made of sulfonated polypropylene.

【００２９】Ｎｉメッキされた亜鉛缶で構成されている
電槽５に、渦巻き状に構成された正極、負極、セパレー
ターが挿入され、電解液を保持する。この電槽５は安全
弁７を有する封口体８で密閉されている。安全弁７は電
池内で酸素ガスもしくは水素ガスが発生した場合に電槽
５外へ放出し電池の破裂を防止する作用を行うもので、
弁作動圧は２０Kgf/cm²程度であることが多い。正極集
電体１０はＮｉ金属のリード線で構成される。大電流を
流す場合、あるいは大型の電池の場合、正極と接触する
面積が多い方または複数の点で正極と接触することが有
利であるA spirally formed positive electrode, negative electrode and separator are inserted into a battery case 5 formed of a Ni-plated zinc can to hold an electrolytic solution. The battery case 5 is sealed by a sealing body 8 having a safety valve 7. The safety valve 7 releases oxygen gas or hydrogen gas inside the battery when the oxygen gas or hydrogen gas is generated, thereby preventing the battery from bursting.
The valve operating pressure is often about 20 kgf / cm ² . The positive electrode current collector 10 is formed of a Ni metal lead wire. When a large current flows, or in the case of a large battery, it is advantageous to make contact with the positive electrode at one or more points where the area of contact with the positive electrode is larger.

【００３０】なお、上記の説明では電解液にクロム酸イ
オンを含有した例で説明したが例えば［Ｃｒ（Ｎ
Ｈ₃）₆］³⁺等のクロム錯体を単独または併用して用いる
場合にも同様に実施することが可能である。In the above description, an example was described in which the electrolytic solution contained chromate ions.
The same can be applied to the case where a chromium complex such as H ₃ ) ₆ ] ³⁺ is used alone or in combination.

【００３１】さらに、負極をＭｍＮｉ_3.55ＣＯ_0.75Ｍｎ
_0.4Ａｌ_0.5の組成を有する水素吸蔵合金で構成した例で
説明したが、他の水素吸蔵合金、例えばＬａＮｉ₅など
の他のＡＢ₅系水素吸蔵合金、Ｚｒ-Ｔｉ-Ｍｎ-Ｎｉ系な
どのＡＢ₂系水素吸蔵合金、Ｍｇ-Ｎｉ系などのＡ₂Ｂ系
水素吸蔵合金などを用いた場合、あるいはＣｄ負極やＺ
ｎ極を用いた場合にも同様に実施することができる。Further, the negative electrode was made of MmNi _3.55 CO _0.75 Mn.
_{Although the} description has been given of the case where the structure is made of a hydrogen storage alloy having a composition of _0.4 Al _0.5 , other hydrogen storage alloys, for example, other AB ₅ -based hydrogen storage alloys such as LaNi ₅ , and Zr-Ti-Mn-Ni-based ABs _{When using a 2} hydrogen storage alloy, an A ₂ B hydrogen storage alloy such as a Mg-Ni alloy, or a Cd negative electrode or Z
The same can be applied to the case where n poles are used.

【００３２】上記の例では、円筒型密閉電池を用いて説
明したが角形密閉電池や電気自動車用あるいは据え置き
型の大型密閉電池であっても同様に実施可能である。In the above example, a cylindrical sealed battery has been described. However, a square sealed battery, a large sealed battery for an electric vehicle or a stationary type can be similarly implemented.

【００３３】図２は本発明の一実施例として発泡状ニッ
ケル基板に活物質を充填したＮｉ正極を図示したもので
ある。図２において、基板１１は発泡状ニッケルから構
成されている。活物質粉末１２は、Ｃｒ、Ｃａを原子比
でＮｉ:Ｃｒ:Ｃａ＝９０：７：３の割合で固溶させたＮ
ｉ酸化物粉末である。FIG. 2 illustrates a nickel positive electrode in which a foamed nickel substrate is filled with an active material as one embodiment of the present invention. In FIG. 2, the substrate 11 is made of foamed nickel. The active material powder 12 is a solid solution of Cr and Ca in an atomic ratio of Ni: Cr: Ca = 90: 7: 3.
i oxide powder.

【００３４】なお高容量密度の電極を構成するためには
活物質粉末は基板への充填性が高い必要があり、球状に
近い形状を持ち、タップ密度が１．８g/cm³以上である
ことが望ましい。活物質表面、もしくは活物質−基体間
には更に活物質粉末−活物質粉末間のおよび活物質−基
板間の導電性を補填する作用を有する多孔質の導電剤１
３としてＣｏＯＯＨが存在しており、そのＣｏの一部は
Ｃｒでもって置換されている。添加剤１４は充電時の酸
素発生過電圧を向上させ、特に高温での充電効率を向上
させる作用を行っており、Ｃｒ₂Ｏ₃およびＹ₂Ｏ₃によっ
て構成される。結着剤１５、及び電極表面を被覆したフ
ッ素樹脂皮膜１６は共に活物質粉末の膨張収縮による脱
落を防止する作用を行っており、共にＰＴＦＥを主成分
とする。In order to form an electrode having a high capacity density, the active material powder needs to have a high filling property to the substrate, and has a shape close to a sphere and a tap density of 1.8 g / cm ³ or more. Is desirable. A porous conductive agent 1 having an action of supplementing the conductivity between the active material powder and the active material powder and between the active material and the substrate between the active material surface and the active material-substrate.
3, CoOOH exists, and a part of Co is substituted by Cr. The additive 14 has a function of improving oxygen generation overvoltage during charging, and particularly improving charging efficiency at high temperature, and is composed of Cr ₂ O ₃ and Y ₂ O ₃ . The binder 15 and the fluororesin film 16 covering the electrode surface both act to prevent the active material powder from falling off due to expansion and contraction, and both contain PTFE as a main component.

【００３５】なお、以上の説明では基板を発泡ニッケル
で構成した例で示したが、その他のニッケルフエルトな
どの三次元金属多孔体もしくはパンチングメタルなどの
二次元的な金属多孔板を用いても同様に実施可能であ
る。また、活物質粉末としてＣｒを固溶させたＮｉを主
たる金属元素とし、Ｃｒに加えてＣａのほかに、Ｔｉ，
Ｚｎ，Ｓｒ，Ｂａ，Ｙ，Ｃｄ，Ｃｏ，ランタン族金属，
Ａｌ，Ｍｎなど他の元素を同時に固溶させた複数金属元
素の酸化物粉末を用いた場合でも同様に実施可能であ
る。In the above description, an example is shown in which the substrate is made of foamed nickel. However, the same applies when using a three-dimensional metal porous body such as nickel felt or a two-dimensional metal porous plate such as punching metal. Can be implemented. Further, Ni in which Cr is dissolved as a main metal element is used as a main metal element as an active material powder, and in addition to Cr, in addition to Ca, Ti,
Zn, Sr, Ba, Y, Cd, Co, lanthanum group metal,
The present invention can be similarly carried out when using an oxide powder of a plurality of metal elements in which other elements such as Al and Mn are simultaneously dissolved.

【００３６】[0036]

【実施例】以下、本発明の具体例を説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of the present invention will be described below.

【００３７】（実施例１）１ｌ中にＮｉＳＯ₄を１．６
１mol、Ｃｒ（ＮＯ₃)₃・９Ｈ₂Ｏを０．０８５mol含む混
合溶液、８mol/lのＮａＯＨ溶液、８．５mol/lのＮＨ₃
水を準備し、反応晶析装置にそれぞれ２．２４ml/min、
１ml/min、１．０６ml/min、の割合で連続的に供給、撹
拌し反応槽内の状態が安定した後、懸濁液を採集し、こ
れを水洗乾燥させたところ、平均粒径１５μmの粉末を
得た。(Example 1) 1.6 l of NiSO ₄ in 1 l
_{1mol, Cr (NO 3) 3} · 9H 2 O and containing 0.085mol mixed solution, NaOH solution 8 mol / l, NH of 8.5 mol / l ₃
Water was prepared, and each reaction crystallizer was 2.24 ml / min,
After continuously supplying and stirring at a rate of 1 ml / min and 1.06 ml / min to stabilize the state in the reaction tank, the suspension was collected, washed and dried, and the average particle size was 15 μm. A powder was obtained.

【００３８】この様にして得られたＮｉを主体とする酸
化物粉末１００gに１０gのＣｏ(ＯＨ)₂粉末、０．５gの
ＰＴＦＥ粉末、３０gのエタノール、３０gの水を加え混
練しペースト状にした。これを多孔度９５%の発泡ニッ
ケル基板に充填し、乾燥後加圧成形することによって厚
さ０．６mm、容量密度６００mAh/cm³のニッケル正極板
を得た。但しここでのＮｉ極の容量密度はＮｉに対し一
電子反応を仮定した場合のものである。なお発泡ニッケ
ル基板に充填する際に、粉末の形状は球状又はそれに近
い形状である方が充填が行われ易い。また発泡ニッケル
基板の空隙部の大きさが１００μm程度であることか
ら、充填する粉末の大きさは５０μm程度以下であるこ
とが望ましい。この様にして得られた正極板を３９×８
６mmに切断した後、ＰＴＦＥディスパージョン溶液に浸
漬し、基板中に予め設けたリード接続部に電極リードを
スポット溶接し理論容量１２００mAhのニッケル正極と
した。なおここでの理論容量とはＮｉの１電子反応に基
づいた計算値である。一方、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。ここでは一例としてＭｍＮｉ_3.55Ｃｏ_0.75Ｍｎ_0.4
Ａｌ_0.3の水素吸蔵合金負極を用いた場合を示す。10 g of Co (OH) ₂ powder, 0.5 g of PTFE powder, 30 g of ethanol and 30 g of water were added to 100 g of the Ni-based oxide powder thus obtained, and kneaded to form a paste. did. This was filled into a foamed nickel substrate having a porosity of 95%, dried and pressed to obtain a nickel positive electrode plate having a thickness of 0.6 mm and a capacity density of 600 mAh / cm ³ . However, the capacity density of the Ni electrode here is based on the assumption of a one-electron reaction with Ni. When the powder is filled in the foamed nickel substrate, the filling is easier if the powder has a spherical shape or a shape close thereto. Further, since the size of the void portion of the foamed nickel substrate is about 100 μm, the size of the powder to be filled is desirably about 50 μm or less. The thus obtained positive electrode plate was 39 × 8
After cutting to 6 mm, it was immersed in a PTFE dispersion solution, and an electrode lead was spot-welded to a lead connection portion provided in advance in the substrate to obtain a nickel positive electrode having a theoretical capacity of 1200 mAh. Here, the theoretical capacity is a calculated value based on the one-electron reaction of Ni. On the other hand, a known negative electrode for an alkaline storage battery, whose capacity is sufficiently larger than that of the positive electrode, is used as the counter electrode. Here, as an example, MmNi _3.55 Co _0.75 Mn _0.4
The case where a hydrogen storage alloy negative electrode of Al _0.3 is used is shown.

【００３９】所望の割合で混合したＭｍ、Ｎｉ、Ｃｏ、
Ｍｎ、Ａｌをアーク溶解炉にて溶解して所望の組成の水
素吸蔵合金を得た。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。これに水と結
着剤としてＣＭＣを加えた後ペースト状に混練し、つい
で電極支持体に加圧充填して厚さ０．４５mm、容量密度
１３５０mAh/cm³の水素吸蔵負極板を得た。この負極板
を３９×８１mmに切断し容量１９２０mAhの負極とし
た。Mm, Ni, Co, mixed in a desired ratio
Mn and Al were melted in an arc melting furnace to obtain a hydrogen storage alloy having a desired composition. This alloy lump was mechanically pulverized in an inert atmosphere to obtain a powder having a particle size of 30 μm. After adding water and CMC as a binder, the mixture was kneaded into a paste, and then filled under pressure into an electrode support to obtain a hydrogen storage negative electrode plate having a thickness of 0.45 mm and a capacity density of 1350 mAh / cm ³ . This negative electrode plate was cut into 39 × 81 mm to obtain a negative electrode having a capacity of 1920 mAh.

【００４０】電解液として１l中に７．５molのＫＯＨ、
０．００２molのＣｒ₂Ｏ₃を溶解させた水溶液を作製し
た。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、この電極群を外装缶内に挿入し
た。これに上記電解液を２．２ml注入後、作動弁圧が２
０Kgf/cm₂の安全弁を持つ封口体により密閉し公称容量
１２００mAhのＡＡサイズの円筒密閉形ニッケル水素蓄
電池を製作した。As an electrolytic solution, 7.5 mol of KOH in 1 liter,
An aqueous solution in which 0.002 mol of Cr ₂ O ₃ was dissolved was prepared. 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 therebetween, and this electrode group was inserted into an outer can. After injecting 2.2 ml of the above electrolyte, the operating valve pressure was increased to 2
A sealed AA size nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured by sealing with a sealing member having a safety valve of 0 kgf / cm ₂ .

【００４１】（比較例１）１ｌ中にＮｉＳＯ₄を１．７m
ol含む溶液、８mol/lのＮａＯＨ溶液、８．５mol/lのＮ
Ｈ₃水を準備し、反応晶析装置にそれぞれ２．２４ml/mi
n、１ml/min、１．０６ml/min、の割合で連続的に供
給、撹拌し反応槽内の状態が安定した後、懸濁液を採集
し、これを水洗乾燥させたところ、平均粒径１５μmの
Ｎｉ（ＯＨ）₂粉末を得た。(Comparative Example 1) 1.7 m2 of NiSO ₄ in 1 l
ol-containing solution, 8 mol / l NaOH solution, 8.5 mol / l N
Prepare H ₃ water and add 2.24 ml / mi to the reaction crystallization apparatus.
n After continuously supplying and stirring at a rate of 1 ml / min and 1.06 ml / min to stabilize the condition in the reaction tank, the suspension was collected, washed and dried, and the average particle diameter was determined. A 15 μm Ni (OH) ₂ powder was obtained.

【００４２】実施例１に於いて正極活物質として上記の
ようにして得られた粉末を用い、電解液として７．５mo
l/lのＫＯＨ水溶液を用いた以外は実施例１と同様にし
て公称容量１２００mAhのＡＡサイズの円筒密閉形ニッ
ケル水素蓄電池を製作した。In Example 1, the powder obtained as described above was used as a positive electrode active material, and 7.5 mol of an electrolytic solution was used.
An AA size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured in the same manner as in Example 1 except that a 1 / l KOH aqueous solution was used.

【００４３】(比較例２)電解液として1l中に７．５mol
のＫＯＨ、０．００２molのＣｒ₂Ｏ₃を溶解させたアルカ
リ水溶液を用いた以外は比較例１と同様にして公称容量
１２００mAhのＡＡサイズの円筒密閉形ニッケル水素蓄
電池を製作した。Comparative Example 2 7.5 mol per liter of electrolyte
In the same manner as in Comparative Example 1 except that an alkaline aqueous solution in which 0.002 mol of KOH and 0.002 mol of Cr ₂ O ₃ were dissolved was used, a nickel-metal hydride storage battery having a nominal capacity of 1200 mAh and an AA size was manufactured.

【００４４】(比較例３)電解液として７．５mol/lのＫ
ＯＨ水溶液を用いた以外は実施例１と同様にして公称容
量１２００mAhのＡＡサイズの円筒密閉形ニッケル水素
蓄電池を製作した。Comparative Example 3 7.5 mol / L of K as an electrolyte
An AA size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured in the same manner as in Example 1 except that an OH aqueous solution was used.

【００４５】(比較例４)比較例１で得られたＮｉ（Ｏ
Ｈ）₂粉末１００ｇに１０gのＣｏ(ＯＨ)₂粉末、５gのＣ
ｒ₂Ｏ₃粉末、０．５gのＰＴＦＥ粉末、３０gのエタノー
ル、３０gの水を加え混練しペースト状にした。これを
多孔度９５%の発泡ニッケル基板に充填し、乾燥後加圧
成形することによって厚さ０．６mm、容量密度６００mA
h/cm³のニッケル正極板を得た。これを用いた以外は比
較例１と同様にして公称容量１２００mAhのＡＡサイズ
の円筒密閉形ニッケル水素蓄電池を製作した。(Comparative Example 4) The Ni (O
H) ₂ powder 100g to 10g of Co (OH) ₂ powder, C of 5g
r ₂ O ₃ powder, 0.5 g of PTFE powder, 30 g of ethanol and 30 g of water were added and kneaded to form a paste. This was filled into a foamed nickel substrate having a porosity of 95%, dried, and pressed to form a plate having a thickness of 0.6 mm and a capacity density of 600 mA.
A nickel positive electrode plate of h / cm ³ was obtained. Except that this was used, an AA size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was produced in the same manner as in Comparative Example 1.

【００４６】(比較例５)１ｌ中にＮｉＳＯ₄を１．５６
４mol、ＣｏＳＯ₄を０．０５１mol,ＺｎＳＯ₄を０．０
８５mol含む混合溶液を用いた以外は実施例１と同様に
して正極活物質を合成した。このようにして得られたＮ
ｉを主とする酸化物粉末１００gに１０gのＣｏ(ＯＨ)₂
粉末、０．８gの平均粒径０．５mmのＹ₂Ｏ₃粉末、 ０．
５gのＰＴＦＥ粉末、３０gのエタノール、３０gの水を
加え混練しペースト状にした。これを多孔度９５%の発
泡ニッケル基板に充填し、乾燥後加圧成形することによ
って厚さ０．６mm、容量密度６００mAh/cm³のニッケル
正極板を得た。これを用いた以外は実施例３と同様にし
て公称容量１２００mAhのＡＡサイズの円筒密閉形ニッ
ケル水素蓄電池を製作した。(Comparative Example 5) NiSO ₄ was added in an amount of 1.56
4mol, the CoSO ₄ 0.051mol, the ZnSO ₄ 0.0
A positive electrode active material was synthesized in the same manner as in Example 1 except that a mixed solution containing 85 mol was used. The N obtained in this way
10 g of Co (OH) ₂ per 100 g of oxide powder mainly containing i
Powder, 0.8 g of Y ₂ O ₃ powder having an average particle size of 0.5 mm;
5 g of PTFE powder, 30 g of ethanol and 30 g of water were added and kneaded to form a paste. This was filled into a foamed nickel substrate having a porosity of 95%, dried and pressed to obtain a nickel positive electrode plate having a thickness of 0.6 mm and a capacity density of 600 mAh / cm ³ . Except that this was used, an AA size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured in the same manner as in Example 3.

【００４７】これらの電池の充電温度特性を以下のよう
にして調べた。２０℃で１２０mAの電流で１６時間充電
し、２０℃で２４０mAの電流で電池電圧１．０Ｖまで連
続して放電するサイクルを繰り返し、放電容量が安定し
た後、充電時の雰囲気温度を４５℃あるいは６０℃とし
て１６時間充電し、２０℃で２４０mAの電流で電池電圧
１．０Ｖまで連続して放電し、その容量を測定した。２
０℃充電時容量は安定した電池容量（mAh）で表し、４
５℃,６０℃充電時の容量は２０℃充電時容量を１００%
として表した。The charging temperature characteristics of these batteries were examined as follows. The battery was charged for 16 hours at a current of 120 mA at 20 ° C. and continuously discharged at a current of 240 mA at a temperature of 20 ° C. to a battery voltage of 1.0 V. After the discharge capacity was stabilized, the ambient temperature at the time of charging was changed to 45 ° C. The battery was charged at 60 ° C. for 16 hours, continuously discharged at 20 ° C. with a current of 240 mA to a battery voltage of 1.0 V, and its capacity was measured. 2
The capacity at the time of charging at 0 ° C is expressed as a stable battery capacity (mAh).
Capacity at 5 ℃ and 60 ℃ charge is 100% of capacity at 20 ℃ charge
Expressed as

【００４８】表１に実施例１、比較例１から５の電池の
充電温度特性を示す。Table 1 shows the charging temperature characteristics of the batteries of Example 1 and Comparative Examples 1 to 5.

【００４９】[0049]

【表１】 [Table 1]

【００５０】表１から明らかなように、Ｃｒを固溶した
Ｎｉ酸化物正極にクロム酸イオン含む電解液を用いた実
施例１は比較例１〜５とは異なり、４５℃充電時の放電
容量に対して６０℃充電時の容量の方が優っていること
が著しい特徴である。比較例１〜４に対しては４５℃，
６０℃充電共に優れており、比較例５に対しては４５℃
充電での容量は及ばないが、６０℃充電での容量は格段
に向上していることが判る。As is clear from Table 1, Example 1 in which the electrolytic solution containing chromate ions was used for the Ni oxide positive electrode in which Cr was dissolved was different from Comparative Examples 1 to 5 in that the discharge capacity when charged at 45 ° C. It is a remarkable feature that the capacity at the time of charging at 60 ° C. is superior to that of the battery. 45 ° C for Comparative Examples 1-4,
Excellent at both 60 ° C charging and 45 ° C for Comparative Example 5.
It can be seen that the capacity at the time of charging is inferior, but the capacity at the time of charging at 60 ° C. is remarkably improved.

【００５１】同様に２種類の元素を含むニッケル酸化物
であっても少なくともＣｒを含有し、クロム酸イオンを
含む電解液を用いた場合に広い温度領域で良好な特性を
得ることができる。Similarly, even if the nickel oxide contains two types of elements, at least Cr is contained, and good characteristics can be obtained in a wide temperature range when an electrolytic solution containing chromate ions is used.

【００５２】（実施例２）１ｌ中にＮｉＳＯ₄を１．５
３mol、Ｃｒ(ＮＯ₃)₃を０．０８５mol,ＭｎＳＯ₄を０．
０８５mol含む混合溶液を用いた以外は実施例１と同様
の方法により正極活物質を合成した。これを正極活物質
に用いた以外は実施例１と同様にして公称容量１２００
mAhの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 2) NiSO ₄ was added to 1 l
3 mol, 0.085 mol of Cr (NO ₃ ) ₃ and 0.1 mol of MnSO ₄ .
A positive electrode active material was synthesized in the same manner as in Example 1 except that a mixed solution containing 085 mol was used. Except that this was used for the positive electrode active material, the nominal capacity was 1200 in the same manner as in Example 1.
An AA size cylindrical sealed nickel-metal hydride battery of mAh was manufactured.

【００５３】（実施例３)電解液として１ｌ中に５molの
ＫＯＨ、２molのＮａＯＨ、０．５molのＬｉＯＨ、及び
０．００２molのＣｒ₂Ｏ₃を溶解させたアルカリ水溶液
を用いた以外は実施例２と同様にして公称容量１２００
mAhの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 3 Example 1 was repeated except that an alkaline aqueous solution in which 5 mol of KOH, 2 mol of NaOH, 0.5 mol of LiOH, and 0.002 mol of Cr ₂ O ₃ were dissolved in 1 liter was used as the electrolytic solution. Nominal capacity 1200 as in 2
An AA size cylindrical sealed nickel-metal hydride battery of mAh was manufactured.

【００５４】（実施例４)１ｌ中にＮｉSＯ₄を１．５６
４mol、Ｃｒ(ＮＯ₃)₃を０．０５１mol，ＭｎＳＯ ₄を
０．０８５mol含む混合溶液を用いた以外は実施例１と
同様の方法により正極活物質を合成した。このようにし
て得られたＮｉを主とする酸化物粉末１００gを１ｌ中
にＮｉＳＯ₄を１．４４５mol、Ｃｒ（ＮＯ₃)₃を０．１
７mol,ＭｎＳＯ₄を０．０８５mol含む混合溶液中に浸漬
し、ＮａＯＨ水溶液、ＮＨ₃水溶液を一定流量で供給
し、温度４０℃, ｐＨが約１０．５に保った状態で攪拌
を行い、粒子表面にＣｒ及びＭｎを含有するＮｉ（Ｏ
Ｈ）₂相を析出させた。これを水洗乾燥し、正極材料と
して用いた以外は実施例３と同様にして公称容量１２０
０mAhのＡＡサイズの円筒密閉形ニッケル水素蓄電池を
製作した。(Embodiment 4) NiSO in 1 l_Four1.56
4mol, Cr (NO_Three)_ThreeTo 0.051 mol, MnSO _FourTo
Example 1 was repeated except that a mixed solution containing 0.085 mol was used.
A positive electrode active material was synthesized in the same manner. Like this
100 g of Ni-based oxide powder obtained in 1 l
NiSO_Four1.445 mol, Cr (NO_Three)_ThreeTo 0.1
7mol, MnSO_FourImmersed in a mixed solution containing 0.085 mol of
NaOH aqueous solution, NH_ThreeSolution is supplied at a constant flow rate
And stir at a temperature of 40 ° C and a pH of about 10.5
To obtain Ni (O) containing Cr and Mn on the particle surface.
H)_TwoThe phases were precipitated. This is washed with water and dried, and
Except that the nominal capacity was 120
0Ah AA size cylindrical sealed nickel-metal hydride battery
Made.

【００５５】（比較例６)１ｌ中にＮｉＳＯ₄を１．５３
mol、ＣｏＳＯ₄を０．８５mol,ＭｎＳＯ₄を０．８５mol
含む混合溶液を用いた以外は実施例２と同様にして正極
活物質を合成した。これを正極活物質に用いた以外は実
施例１と同様にして公称容量１２００mAhのＡＡサイズ
の円筒密閉形ニッケル水素蓄電池を製作した。(Comparative Example 6) 1.53 of NiSO ₄ in 1 l
mol, CoSO ₄ 0.85 mol, MnSO ₄ 0.85 mol
A positive electrode active material was synthesized in the same manner as in Example 2 except that a mixed solution containing the positive electrode was used. An AA-size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured in the same manner as in Example 1 except that this was used as the positive electrode active material.

【００５６】（実施例５)１ｌ中にＮｉSＯ₄を１．５６
４mol、Ｃｒ（ＮＯ₃)₃を０．０５１mol,ＭｎＳＯ４を
０．０８５mol含む混合溶液を用いた以外は実施例１と
同様の方法により正極活物質を合成した。このようにし
て得られたＮｉを主とする酸化物粉末１００gを１ｌ中
にＮｉSＯ₄を１．４４５mol、Ｃｒ（ＮＯ₃)₃を０．１７
mol,Ｃａ（ＮＯ₃)₂を０．０８５mol含む混合溶液中に浸
漬し、ＮａＯＨ水溶液、ＮＨ₃水溶液を一定流量で供給
し、温度４０℃, ｐＨが約１０．５に保った状態で攪拌
を行い、粒子表面にＣｒ及びＣａを含有するＮｉ（Ｏ
Ｈ）₂相を析出させた。これを水洗乾燥し、正極材料と
して用いた以外は実施例３と同様にして公称容量１２０
０mAhの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 5) 1.56 of NiSO ₄ was added to 1 liter.
A positive electrode active material was synthesized in the same manner as in Example 1, except that a mixed solution containing 4 mol, 0.051 mol of Cr (NO ₃ ) ₃ , and 0.085 mol of MnSO 4 was used. 1.445 mol of NiSO ₄ and 0.17 mol of Cr (NO ₃ ) ₃ were contained in 1 l of 100 g of the oxide powder mainly containing Ni thus obtained.
mol, Ca (NO ₃ ) ₂ immersed in a mixed solution containing 0.085 mol, NaOH aqueous solution and NH ₃ aqueous solution were supplied at a constant flow rate, and the mixture was stirred at a temperature of 40 ° C. and a pH of about 10.5. Then, Ni (O containing Cr and Ca was
H) _Two phases were precipitated. This was washed with water, dried and used in the same manner as in Example 3 except that it was used as a positive electrode material.
An AA size cylindrical sealed nickel-metal hydride battery of 0 mAh was manufactured.

【００５７】（実施例６)実施例５で作製した粒子表面
にＣｒ及びＣａを含有するＮｉ（ＯＨ）₂相を析出させ
たニッケル酸化物粉末１００gに１０gのＣｏ(ＯＨ)₂粉
末、０．８gの平均粒径０．５mmのＹ₂Ｏ₃粉末、 ０．５g
のＰＴＦＥ粉末、３０gのエタノール、３０gの水を加え
混練しペースト状にした。これを多孔度９５%の発泡ニ
ッケル基板に充填し、乾燥後加圧成形することによって
厚さ０．６mm、容量密度６００mAh/cm ³のニッケル正極
板を得た。これを用いた以外は実施例３と同様にして公
称容量１２００mAhの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 6) Surface of particles prepared in Example 5
(Ni) containing Cr and Ca_TwoPrecipitate the phase
10 g of Co (OH) per 100 g of the nickel oxide powder_Twopowder
Powder, 0.8g Y having an average particle size of 0.5mm_TwoO_ThreePowder, 0.5g
Of PTFE powder, 30 g of ethanol and 30 g of water
It was kneaded to make a paste. This is 95% porosity foam
By filling the substrate into a substrate, drying and pressing.
0.6mm thickness, 600mAh / cm capacity density ^ThreeNickel positive electrode
I got a board. Except that this was used, the procedure was the same as in Example 3 for public use.
AA size cylindrical sealed nickel with a nominal capacity of 1200 mAh
A hydrogen storage battery was manufactured.

【００５８】表２に実施例２から６、比較例６の電池の
充電温度特性を示す。Table 2 shows the charging temperature characteristics of the batteries of Examples 2 to 6 and Comparative Example 6.

【００５９】[0059]

【表２】 [Table 2]

【００６０】表２から明らかなように同時に２種類の元
素を含むニッケル酸化物であってもＣｒを必須成分とし
て含有し、クロム酸イオンを必須成分として含む電解液
を用いた実施例２は比較例６に対し、４５℃での容量が
向上しており、６０℃でも実施例１と同等以上の放電容
量を示し、高温充電特性が著しく向上していることが判
る。なお２０℃容量が１２００mAhを超えているが、こ
れはＭｎを固溶させたことによってＮｉ原子あたり約
１．５電子の電荷移動を伴うβ−Ｎｉ（ＯＨ）₂とγ−
ＮｉＯＯＨとの間での反応が生じたためである。As is clear from Table 2, even in the case of a nickel oxide containing two kinds of elements at the same time, Example 2 using Cr containing an essential component and chromate ion as an essential component was compared with Example 2. Compared with Example 6, the capacity at 45 ° C. was improved, and at 60 ° C., the discharge capacity was equal to or more than that of Example 1, indicating that the high-temperature charging characteristics were significantly improved. The capacity at 20 ° C. exceeds 1200 mAh. This is because β-Ni (OH) ₂ and γ- with charge transfer of about 1.5 electrons per Ni atom by solid solution of Mn.
This is because a reaction with NiOOH occurred.

【００６１】またＮａＯＨ, ＬｉＯＨを含む電解液を用
いた実施例３は実施例２に対し４５℃充電時の容量が大
幅に向上していることが判る。また活物質粉末内部でＣ
ｒ濃度が低く、表面付近でＣｒの濃度の高いＣｒ,Ｍｎ
を含有するＮｉ酸化物を用いた実施例４は実施例３とほ
ぼ同等の特性を示した。従って粉末内部のＣｒ含有量を
低減し、Ｎｉ含有量を多くとることができるため電池容
量を向上させることができ好ましい。Further, it can be seen that Example 3 using the electrolytic solution containing NaOH and LiOH has a remarkably improved capacity at 45 ° C. charging as compared to Example 2. Also, C inside the active material powder
Cr and Mn with low r concentration and high Cr concentration near the surface
Example 4 using Ni oxide containing Ni showed almost the same characteristics as Example 3. Therefore, since the Cr content in the powder can be reduced and the Ni content can be increased, the battery capacity can be improved, which is preferable.

【００６２】更にＣａを含有する実施例５は実施例３に
対し４５℃,６０℃の充電特性に優れ、これにＹ₂Ｏ₃粉
末を添加した実施例６では４５℃,６０℃の充電特性共
に更に優れることが判る。Further, Example 5 containing Ca was superior to Example 3 in the charge characteristics at 45 ° C. and 60 ° C., and Example 6 in which Y ₂ O ₃ powder was added was used in Example 6 at 45 ° C. and 60 ° C. It turns out that both are more excellent.

【００６３】ここでは例としてＮｉ正極としてＣｒおよ
びＣｒ,Ｍｎを固溶する場合のみを取り上げたが、Ｎｉ
正極活物質中にＣｒを含み、更にＣａ，Ｔｉ，Ｚｎ，Ｓ
ｒ，Ｂａ，Ｙ，Ｃｄ，Ｃｏ，ランタン族金属，Ａｌ，Ｍ
ｎなど他の元素、あるいはそれらを複合して固溶させた
Ｎｉ酸化物を用いた場合であっても、クロム酸イオンを
含有する電解液を用いることにより同様の効果を得るこ
とが出来る。Here, as an example, only the case where Cr and Cr, Mn are dissolved as a Ni positive electrode is taken as an example.
The cathode active material contains Cr, and further contains Ca, Ti, Zn, S
r, Ba, Y, Cd, Co, lanthanum group metal, Al, M
Even when other elements such as n, or a Ni oxide in which they are dissolved in a solid solution are used, the same effect can be obtained by using an electrolytic solution containing chromate ions.

【００６４】表３にＭｎＳＯ₄を他の金属の硫酸塩また
は硝酸塩で置き換えた以外は実施例２と同様の方法によ
り作製された公称容量１２００mAhのＡＡサイズの円筒
密閉形ニッケル水素蓄電池の充電温度特性を示す。Table 3 shows the charging temperature characteristics of an AA-size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh and manufactured by the same method as in Example 2 except that MnSO ₄ was replaced with a sulfate or nitrate of another metal. Is shown.

【００６５】[0065]

【表３】 [Table 3]

【００６６】表３から明らかなようなようにＮｉ正極活
物質中にＣｒと、Ｍｎに代えて上記のような他の金属元
素を固溶し電解液中のクロム酸イオンを含むことによ
り、６０℃における充電効率に優れていることが判る。As is clear from Table 3, the above-mentioned other metal elements are solid-dissolved in place of Cr and Mn in the Ni positive electrode active material and the chromate ions in the electrolyte are contained, whereby It turns out that the charging efficiency in ° C is excellent.

【００６７】(実施例７)比較例１で合成したＮｉ酸化物
粉末１００gをＣｏ（ＮＯ₃)₂を０．３２mol/l、Ｃｒ（Ｎ
Ｏ₃)₃を０．１mol/l含む水溶液中に浸漬し、ＮａＯＨ水
溶液、ＮＨ₃水溶液を一定流量で供給し、温度４０℃,
ｐＨを約１０．５に保った状態で攪拌を行い、粒子表面
にＣｒを含有するＣｏ(ＯＨ)₂相を析出させた。これを
水洗乾燥し、正極材料として用いた以外は実施例１と同
様にして公称容量１２００mAhの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 7 100 g of the Ni oxide powder synthesized in Comparative Example 1 was 0.32 mol / l of Co (NO ₃ ) ₂ and Cr (N
O ₃ ) ₃ was immersed in an aqueous solution containing 0.1 mol / l, and an NaOH aqueous solution and an NH ₃ aqueous solution were supplied at a constant flow rate.
Stirring was performed while maintaining the pH at about 10.5 to precipitate a Co (OH) ₂ phase containing Cr on the particle surface. This was washed and dried, and an AA-size cylindrical sealed nickel-metal hydride battery having a nominal capacity of 1200 mAh was produced in the same manner as in Example 1 except that the battery was used as a positive electrode material.

【００６８】(実施例８)比較例１で作成したにニッケル
酸化物粉末１００gに対し平均粒径０．５mmの金属Ｃｒ
粉末を５gの割合で混合し,回転速度１０００rpmで機械
的に擦りつける、いわゆるメカノフュージョン処理を５
分間施した粉末を用いた以外は実施例１と同様にして公
称容量１２００mAhの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 8) Metal Cr having an average particle size of 0.5 mm per 100 g of nickel oxide powder prepared in Comparative Example 1
The powder was mixed at a rate of 5 g and mechanically rubbed at a rotation speed of 1000 rpm, so-called mechanofusion treatment.
An AA-size cylindrical sealed nickel-metal hydride storage battery having a nominal capacity of 1200 mAh was manufactured in the same manner as in Example 1 except that the powder applied for 5 minutes was used.

【００６９】表４に実施例７、８の電池の充電温度特性
を示す。Table 4 shows the charging temperature characteristics of the batteries of Examples 7 and 8.

【００７０】[0070]

【表４】 [Table 4]

【００７１】表４から明らかなように実施例７、８共に
比較例１〜４に対し６０℃での充電効率が格段に優れる
ことが判る。As is evident from Table 4, the charging efficiency at 60 ° C. in Examples 7 and 8 is much superior to Comparative Examples 1 to 4.

【００７２】[0072]

【発明の効果】以上説明したように本発明によれば、Ｃ
ｒを固溶させたＮｉ酸化物を用いる正極と、クロム酸イ
オンを含むアルカリ電解液とを備えるか、あるいはＣｒ
化合物,金属Ｃｒ,Ｃｒを成分として含む合金のうち少な
くとも一種を表面に含有するＮｉ酸化物を用いた正極と
クロム酸イオンを含むアルカリ電解液とを備えることに
より、４５℃以上,特に６０℃という高温での正極活物
質の充電特性を著しく改善することができ、活物質利用
率を高めるので、密閉電池のエネルギー密度を飛躍的に
向上させることが可能である。As described above, according to the present invention, C
a positive electrode using a Ni oxide in which r is dissolved, and an alkaline electrolyte containing chromate ions, or
Compound, metal Cr, by providing a positive electrode using Ni oxide containing at least one of the alloys containing Cr as a component and an alkaline electrolyte containing chromate ions, at least 45 ° C, especially 60 ° C The charging characteristics of the positive electrode active material at a high temperature can be remarkably improved, and the utilization rate of the active material can be increased, so that the energy density of the sealed battery can be dramatically improved.

【００７３】これによって高温充電特性に優れる工業的
価値の大きいアルカリ蓄電池を提供するものである。Thus, an alkaline storage battery excellent in high-temperature charging characteristics and of great industrial value is provided.

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

【図１】本発明における密閉電池の一例の構造を示す斜
視図FIG. 1 is a perspective view showing the structure of an example of a sealed battery according to the present invention.

【図２】本発明に用いられるニッケル正極の構造を模式
的に示した図FIG. 2 is a diagram schematically showing the structure of a nickel positive electrode used in the present invention.

【符号の説明】[Explanation of symbols]

１ 正極 ２ 負極 ３ 電解液 ４ セパレータ ５ 電槽 ６ キャップ ７ 安全弁 ８ 封口板 ９ 絶縁ガスケット １０ 正極集電体 １１ 基板 １２ 活物質粉末 １３ 導電性多孔層 １４ 添加剤 １５ 結着剤 １６ フッ素樹脂皮膜 １７ 空間 REFERENCE SIGNS LIST 1 positive electrode 2 negative electrode 3 electrolyte 4 separator 5 battery case 6 cap 7 safety valve 8 sealing plate 9 insulating gasket 10 positive electrode current collector 11 substrate 12 active material powder 13 conductive porous layer 14 additive 15 binder 16 fluorine resin film 17 space

───────────────────────────────────────────────────── フロントページの続き (72)発明者 坂本 弘之 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 和泉 陽一 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 森脇 良夫 大阪府門真市大字門真1006番地 松下電器 産業株式会社内 Ｆターム(参考） 5H003 AA04 BB02 BB04 BD03 5H016 AA02 CC04 EE01 EE05 HH08 5H028 AA06 EE01 EE05 FF03 HH02 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroyuki Sakamoto 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Yoshio Moriwaki 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd.

Claims (6)

【特許請求の範囲】[Claims] 【請求項１】 Ｎｉを主たる金属元素とし、Ｃｒを必須
成分として結晶中に含有していることを特徴とする複数
金属元素の酸化物粉末を主たる活物質とする正極と、負
極と、セパレータと、クロム酸イオンまたはクロム錯体
とを必須成分として含むアルカリ電解液とを発電要素と
するアルカリ蓄電池。1. A positive electrode, a negative electrode, and a separator, each of which contains Ni as a main metal element and Cr as an essential component in a crystal, and an oxide powder of a plurality of metal elements as a main active material. And an alkaline electrolyte containing chromate ions or a chromium complex as an essential component. 【請求項２】 正極活物質の結晶中に含まれるＣｒの含
有量は活物質内部に比して表面付近の含有量が大である
請求項１記載のアルカリ蓄電池。2. The alkaline storage battery according to claim 1, wherein the content of Cr contained in the crystals of the positive electrode active material is larger near the surface than inside the active material. 【請求項３】 Ｎｉを主たる金属元素とした酸化物粉末
を主活物質とする正極、負極、セパレータと、クロム酸
イオンまたはクロム錯体とを必須成分として含むアルカ
リ電解液とを発電要素として備えたアルカリ蓄電池であ
って、 前記正極はＣｒ化合物、金属Ｃｒ、Ｃｒを成分として含
む合金のうち、少なくとも一種以上を活物質の表面付近
に存在させた、あるいは、これらの物質を活物質の表面
上に析出させたことを特徴とするアルカリ蓄電池。3. A power generating element comprising: a positive electrode, a negative electrode, and a separator having an oxide powder containing Ni as a main metal element as a main active material, and an alkaline electrolyte containing chromate ions or a chromium complex as essential components. An alkaline storage battery, wherein the positive electrode has at least one or more of a Cr compound, a metal Cr, and an alloy containing Cr as a component near the surface of the active material, or has these materials on the surface of the active material. An alkaline storage battery characterized by being deposited. 【請求項４】 正極活物質は他に，Ｃａ，Ｔｉ，Ｚｎ，
Ｓｒ，Ｂａ，Ｙ，Ｃｄ，Ｃｏ，ランタン族金属，Ａｌ，
Ｍｎから選ばれた少なくとも一種以上の元素が含まれて
いることを特徴とする請求項１または３に記載のアルカ
リ蓄電池。4. The cathode active material further comprises Ca, Ti, Zn,
Sr, Ba, Y, Cd, Co, lanthanum group metal, Al,
The alkaline storage battery according to claim 1, wherein the alkaline storage battery includes at least one element selected from Mn. 【請求項５】 正極には、Ｃａ化合物、Ｔｉ化合物、Ｚ
ｎ化合物、Ｓｒ化合物、Ｂａ化合物、Ｙ化合物、Ｃｄ化
合物、Ｃｏ化合物、ランタン族金属化合物のうち少なく
とも一種以上を活物質の周囲に存在させた、あるいは活
物質表面上に析出させた請求項１または３に記載のアル
カリ蓄電池。5. The positive electrode includes a Ca compound, a Ti compound, Z
The compound according to claim 1, wherein at least one or more of an n compound, a Sr compound, a Ba compound, a Y compound, a Cd compound, a Co compound, and a lanthanum group metal compound are present around the active material or deposited on the surface of the active material. 4. The alkaline storage battery according to 3. 【請求項６】 アルカリ電解液はＫを主成分としＮａお
よび／またはＬｉをそれぞれ０〜４０mol%、０〜１０mo
l%含有する請求項１または３に記載のアルカリ蓄電池。6. An alkaline electrolyte comprising K as a main component and Na and / or Li in an amount of 0 to 40 mol% and 0 to 10 mol, respectively.
4. The alkaline storage battery according to claim 1, which contains 1% by weight.