JP3433049B2 - Non-sintered nickel electrode for alkaline storage batteries - Google Patents
Non-sintered nickel electrode for alkaline storage batteriesInfo
- Publication number
- JP3433049B2 JP3433049B2 JP17631497A JP17631497A JP3433049B2 JP 3433049 B2 JP3433049 B2 JP 3433049B2 JP 17631497 A JP17631497 A JP 17631497A JP 17631497 A JP17631497 A JP 17631497A JP 3433049 B2 JP3433049 B2 JP 3433049B2
- Authority
- JP
- Japan
- Prior art keywords
- hydroxide
- cobalt
- electrode
- nickel
- 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
Links
Classifications
-
- 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
Landscapes
- Battery Electrode And Active Subsutance (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は、アルカリ蓄電池用
非焼結式ニッケル極に係わり、詳しくは、常温下におい
て充電した場合はもとより、高温雰囲気下で充電した場
合にも、高い活物質利用率を発現するアルカリ蓄電池用
非焼結式ニッケル極を提供することを目的とした、活物
質の改良に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-sintered nickel electrode for an alkaline storage battery, and more specifically, it has a high active material utilization rate not only when it is charged at normal temperature but also when it is charged at high temperature atmosphere. The present invention relates to an improvement of an active material for the purpose of providing a non-sintered nickel electrode for an alkaline storage battery that exhibits the above-mentioned.
【0002】[0002]
【従来の技術及び発明が解決しようとする課題】従来、
ニッケル−水素蓄電池、ニッケル−カドミウム蓄電池な
どの正極として、ニッケル粉末を穿孔鋼板等に焼結させ
て得た焼結基板に活物質(水酸化ニッケル)を含浸させ
てなる焼結式ニッケル極がよく知られている。2. Description of the Related Art Conventionally, the problems to be solved by the invention
As a positive electrode for nickel-hydrogen storage batteries, nickel-cadmium storage batteries, etc., a sintered nickel electrode is often used, which is obtained by impregnating a sintered substrate obtained by sintering nickel powder into a perforated steel plate or the like and impregnating it with an active material (nickel hydroxide). Are known.
【0003】焼結式ニッケル極において活物質の充填量
を多くするためには、多孔度の大きい焼結基板を用いる
必要がある。しかし、焼結によるニッケル粒子間の結合
は弱いので、焼結基板の多孔度を大きくするとニッケル
粒子が焼結基板から脱落し易くなる。従って、実用上
は、焼結基板の多孔度を80%より大きくすることがで
きず、それゆえ焼結式ニッケル極には、活物質の充填量
が少ないという問題がある。また、一般に、ニッケル粉
末の焼結体の孔径は10μm以下と小さいため、活物質
の焼結基板への充填を、煩雑な含浸工程を数回繰り返し
行う必要がある溶液含浸法により行わなければならない
という問題もある。In order to increase the filling amount of the active material in the sintered nickel electrode, it is necessary to use a sintered substrate having high porosity. However, since the bond between the nickel particles due to sintering is weak, increasing the porosity of the sintered substrate makes it easier for the nickel particles to fall off the sintered substrate. Therefore, practically, the porosity of the sintered substrate cannot be made higher than 80%, and therefore, the sintered nickel electrode has a problem that the filling amount of the active material is small. In addition, since the pore size of the sintered body of nickel powder is generally as small as 10 μm or less, the filling of the active material into the sintered substrate must be performed by a solution impregnation method that requires repeated complicated impregnation steps several times. There is also a problem.
【0004】このようなことから、最近、非焼結式ニッ
ケル極が提案されている。非焼結式ニッケル極は、活物
質(水酸化ニッケル)と結着剤(メチルセルロース水溶
液など)との混練物(ペースト)を多孔度の大きい基板
に充填することにより作製される。非焼結式ニッケル極
では、多孔度の大きい基板を用いることができるので
(多孔度95%以上の基板を用いることができる)、活
物質の充填量を多くすることができるとともに、活物質
の基板への充填が容易である。Under these circumstances, a non-sintered nickel electrode has recently been proposed. The non-sintered nickel electrode is prepared by filling a kneaded material (paste) of an active material (nickel hydroxide) and a binder (aqueous solution of methylcellulose etc.) into a substrate having high porosity. In the non-sintered nickel electrode, since a substrate having a high porosity can be used (a substrate having a porosity of 95% or more can be used), the filling amount of the active material can be increased and the active material Easy to fill the substrate.
【0005】しかしながら、非焼結式ニッケル極には、
活物質利用率、特に高温雰囲気下での活物質利用率が低
いという欠点が有る。高温になると、電極の酸素過電圧
が低下するため、充電電気量が、水酸化ニッケルのオキ
シ水酸化ニッケルへの充電反応以外に、水(アルカリ電
解液中の水)が分解することによる酸素発生反応にも消
費されるからである。However, in the non-sintered nickel electrode,
There is a drawback that the active material utilization rate is low, especially in a high temperature atmosphere. When the temperature rises, the oxygen overvoltage of the electrode decreases, so the amount of charged electricity is not only the charge reaction of nickel hydroxide to nickel oxyhydroxide, but also the oxygen generation reaction due to the decomposition of water (water in the alkaline electrolyte). Because it is also consumed.
【0006】そこで、幅広い温度範囲(0〜45°C)
にわたって高い活物質利用率を発現する非焼結式ニッケ
ル極として、水酸化ニッケル粉末に金属コバルト、水酸
化コバルト及びイットリウム化合物を添加したものが、
先に提案されている(特開平5−28992号公報参
照)。Therefore, a wide temperature range (0 to 45 ° C)
As a non-sintered nickel electrode that exhibits a high utilization rate of active material over a range of nickel hydroxide powder to which metallic cobalt, cobalt hydroxide and yttrium compound are added,
It has been previously proposed (see Japanese Patent Application Laid-Open No. 5-28992).
【0007】しかしながら、本発明者らが検討した結
果、上記の従来の非焼結式ニッケル極には、60°C程
度の高温雰囲気下で充電すると、活物質利用率が大きく
低下するという課題があることが分かった。However, as a result of the study by the present inventors, the conventional non-sintered nickel electrode described above has a problem that the utilization factor of the active material is significantly reduced when charged in a high temperature atmosphere of about 60 ° C. I knew it was.
【0008】本発明は、上記の課題を解決するべくなさ
れたものであって、常温下で充電した場合はもとより、
高温雰囲気下で充電した場合にも、高い活物質利用率を
発現するアルカリ蓄電池用非焼結式ニッケル極を提供す
ることを目的とする。The present invention has been made to solve the above-mentioned problems, and not only when it is charged at room temperature,
An object of the present invention is to provide a non-sintered nickel electrode for an alkaline storage battery, which exhibits a high utilization rate of an active material even when it is charged in a high temperature atmosphere.
【0009】[0009]
【課題を解決するための手段】本発明に係るアルカリ蓄
電池用非焼結式ニッケル極(本発明電極)においては、
活物質粉末が、水酸化ニッケル基体粒子と、当該水酸化
ニッケル基体粒子を被覆する、イットリウムの水酸化
物、又は、ランタノイド(但し、ランタンを除く)の水
酸化物からなる被覆内層と、当該被覆内層を被覆するコ
バルト又はコバルト化合物からなる被覆外層とからなる
複合体粒子からなる。In the non-sintered nickel electrode for an alkaline storage battery (electrode of the present invention) according to the present invention,
The active material powder is composed of nickel hydroxide base particles and the hydroxide.
Hydroxylation of yttrium coating nickel-based particles
Or water of lanthanoids (excluding lanthanum)
The composite particles are composed of an inner coating layer made of an oxide and an outer coating layer made of cobalt or a cobalt compound coating the inner coating layer.
【0010】本発明電極の活物質粉末は、水酸化ニッケ
ル基体粒子を、被覆内層と、被覆外層との二層で被覆し
た複合体粒子からなる。The active material powder of the electrode of the present invention is nickel hydroxide.
The base particles are composed of composite particles coated with two layers, an inner coating layer and an outer coating layer.
【0011】水酸化ニッケル基体粒子としては、水酸化
ニッケルのみからなる単一成分粒子の外、水酸化ニッケ
ルに、コバルト、亜鉛、カドミウム、カルシウム、マン
ガン、マグネシウム、ビスマス、アルミニウム、ランタ
ノイド及びイットリウムから選ばれた少なくとも一種の
元素が固溶した粒子(固溶体粒子)も含まれる。水酸化
ニッケルに、上記の元素を一種又は二種以上固溶させる
ことにより、非焼結式ニッケル極の充電時の膨化が抑制
される。As the nickel hydroxide base particles , in addition to single component particles consisting of nickel hydroxide alone, nickel hydroxide is selected from cobalt, zinc, cadmium, calcium, manganese, magnesium, bismuth, aluminum, lanthanoids and yttrium. Particles (solid solution particles) in which at least one of the above-described elements are in solid solution are also included. Swelling of the non-sintered nickel electrode at the time of charging is suppressed by solid-solving one or more of the above elements in nickel hydroxide.
【0012】水酸化ニッケル基体粒子を被覆する被覆内
層は、イットリウムの水酸化物(Y(OH) 3 )、又
は、ランタノイド(但し、ランタンを除く)の水酸化物
からなる。ランタノイドの水酸化物としては、Ce(O
H)3 、Pr(OH)3 、Nd(OH)3 、Pm(O
H)3 、Eu(OH)3 、Gd(OH)3 、Tb(O
H)3 、Dy(OH)3 、Ho(OH)3 、Er(O
H)3 、Tm(OH)3 が例示される。 The coating inner layer for coating the nickel hydroxide base particles is yttrium hydroxide (Y (OH) 3 ), or
Is a hydroxide of a lanthanoid (excluding lanthanum) . As the lanthanoid hydroxide, Ce (O
H) 3 , Pr (OH) 3 , Nd (OH) 3 , Pm (O
H) 3 , Eu (OH) 3 , Gd (OH) 3 , Tb (O
H) 3 , Dy (OH) 3 , Ho (OH) 3 , Er (O
H) 3 and Tm (OH) 3 are exemplified.
【0013】イットリウムの水酸化物、又は、ランタノ
イド(但し、ランタンを除く)の水酸化物からなる被覆
内層を水酸化ニッケル基体粒子の表面に形成する方法と
しては、例えば、イットリウム又はランタノイド(但
し、ランタンを除く)の塩水溶液(例えば、硫酸イット
リウム水溶液など)に水酸化ニッケル粉末を添加し、攪
拌しながらアルカリ水溶液(例えば、水酸化ナトリウム
水溶液など)を滴下してpHを9〜12(通常11程
度)に調整した後、pHが低下した時点でアルカリ水溶
液を適宜滴下してpHをほぼ一定に保持しつつ所定時間
攪拌して、水酸化ニッケル粒子の表面にイットリウムの
水酸化物、又は、ランタノイド(但し、ランタンを除
く)の水酸化物を析出させる方法が挙げられる。 Yttrium hydroxide or lanthanum
Examples of the method for forming the coating inner layer composed of a hydroxide of an id (excluding lanthanum) on the surface of the nickel hydroxide base particles include yttrium or lanthanoid (provided that
Then, the nickel hydroxide powder is added to a salt aqueous solution ( excluding lanthanum) (for example, yttrium sulfate aqueous solution), and an alkaline aqueous solution (for example, sodium hydroxide aqueous solution) is added dropwise with stirring to adjust the pH to 9 to 12 ( After adjusting the pH to about 11), when the pH is lowered, an aqueous alkaline solution is appropriately added dropwise and the mixture is stirred for a predetermined time while keeping the pH substantially constant, so that the surface of the nickel hydroxide particles is covered with yttrium .
Hydroxide or lanthanoid (excluding lanthanum
The method of precipitating the hydroxide of
【0014】イットリウムの水酸化物、又は、ランタノ
イド(但し、ランタンを除く)の水酸化物からなる被覆
内層は、水酸化ニッケル粉末とイットリウムの水酸化物
粉末、又は、ランタノイド(但し、ランタンを除く)の
水酸化物粉末とを不活性ガス中にて圧縮磨砕粉砕機を用
いて乾式混合するメカニカルチャージ法によっても形成
することができる。 Yttrium hydroxide or lanthanum
The inner coating layer consisting of hydroxide of Id (excluding lanthanum) is nickel hydroxide powder and yttrium hydroxide.
It can also be formed by a mechanical charge method in which a powder or a hydroxide powder of a lanthanoid (excluding lanthanum) is dry-mixed in an inert gas using a compression grinder / mill .
【0015】水酸化ニッケル基体粒子中の水酸化ニッケ
ルに対する被覆内層中のイットリウム又はランタノイド
(但し、ランタンを除く)の比率は、0.05〜5重量
%が好ましい。この比率が0.05重量%未満の場合
は、高温雰囲気下で充電した場合の活物質利用率の低下
を充分に抑制することが困難となり、一方同比率が5重
量%を超えた場合は、活物質(水酸化ニッケル)の充填
密度が小さくなり、電極の比容量(放電容量)が減少す
る。Yttrium or lanthanide in the coating inner layer for nickel hydroxide in nickel hydroxide substrate particles
The ratio (excluding lanthanum) is preferably 0.05 to 5% by weight. When this ratio is less than 0.05% by weight, it becomes difficult to sufficiently suppress the decrease in the active material utilization rate when charged in a high temperature atmosphere, while when the ratio exceeds 5% by weight, The packing density of the active material (nickel hydroxide) decreases, and the specific capacity (discharge capacity) of the electrode decreases.
【0016】被覆内層を被覆する被覆外層は、コバルト
又はコバルト化合物からなる。コバルト化合物として
は、一酸化コバルト、水酸化コバルト、オキシ水酸化コ
バルト、ナトリウム含有コバルト化合物が例示される。The outer coating layer coating the inner coating layer is made of cobalt or a cobalt compound. Examples of cobalt compounds include cobalt monoxide, cobalt hydroxide, cobalt oxyhydroxide, and sodium-containing cobalt compounds.
【0017】水酸化コバルトからなる被覆外層を被覆内
層の上に形成する方法としては、例えば、コバルト塩水
溶液(例えば、硫酸コバルト水溶液など)に、被覆内層
で粒子表面を被覆した水酸化ニッケル粉末を添加し、攪
拌しながらアルカリ水溶液(例えば、水酸化ナトリウム
水溶液など)を滴下してpHを9〜12(通常11程
度)に調整した後、pHが低下した時点でアルカリ水溶
液を適宜滴下してpHをほぼ一定に保持しつつ所定時間
攪拌して、被覆内層の表面に水酸化コバルトを析出させ
る方法が挙げられる。As a method of forming the outer coating layer made of cobalt hydroxide on the inner coating layer, for example, nickel hydroxide powder obtained by coating the particle surface with the inner coating layer in a cobalt salt aqueous solution (for example, cobalt sulfate aqueous solution) is used. After adding and stirring, an alkaline aqueous solution (for example, sodium hydroxide aqueous solution) is added dropwise to adjust the pH to 9 to 12 (usually about 11), and when the pH is lowered, an alkaline aqueous solution is appropriately added dropwise to adjust the pH. Is kept constant and stirred for a predetermined time to deposit cobalt hydroxide on the surface of the coating inner layer.
【0018】水酸化コバルトからなる被覆外層は、水酸
化ニッケル粉末と水酸化コバルト粉末とを不活性ガス中
にて圧縮磨砕粉砕機を用いて乾式混合するメカニカルチ
ャージ法によっても形成することができる。このメカニ
カルチャージ法において、水酸化コバルト粉末に代えて
一酸化コバルト粉末又はコバルト粉末を用いれば、それ
ぞれ一酸化コバルトからなる被覆外層、及び、コバルト
からなる被覆外層を形成することができる。The coating outer layer made of cobalt hydroxide can also be formed by a mechanical charge method in which nickel hydroxide powder and cobalt hydroxide powder are dry-mixed in an inert gas by using a compression grinding mill. . In this mechanical charge method, by using cobalt monoxide powder or cobalt powder instead of cobalt hydroxide powder, it is possible to form a coating outer layer made of cobalt monoxide and a coating outer layer made of cobalt, respectively.
【0019】オキシ水酸化コバルトからなる被覆外層
は、例えば、被覆内層の表面に水酸化コバルト層を形成
した後、この水酸化コバルト層を40°C程度に加熱し
た過酸化水素水で酸化することにより形成することがで
きる。ナトリウム含有コバルト化合物からなる被覆外層
は、例えば、被覆内層の表面に、コバルト層、又は、水
酸化コバルト層、一酸化コバルト層、オキシ水酸化コバ
ルト層等のコバルト化合物層を形成した粒子粉末に、水
酸化ナトリウム水溶液を添加し、酸素存在下にて加熱処
理することにより形成することができる。水酸化ナトリ
ウム水溶液を添加するだけではナトリウム含有コバルト
化合物からなる被覆層は形成されず、酸素存在下にて加
熱処理することが必要である。このときの加熱処理温度
は、50〜200°Cが好ましい。加熱処理温度が50
°C未満の場合は、電導率の低いCoHO2 が多く析出
し、一方加熱処理温度が200°Cを越えた場合は、電
導率の低い四酸化三コバルト(Co3 O4 )が多く析出
する。なお、コバルト化合物層がオキシ水酸化コバルト
層の場合は、50°C未満で加熱処理してもCoHO2
が析出することはないが、ナトリウムが挿入されにくく
なる。加熱処理時間は、使用する水酸化ナトリウム水溶
液の量、濃度、加熱処理温度等によって異なる。一般的
には、0.5〜10時間である。For the outer coating layer made of cobalt oxyhydroxide, for example, after forming a cobalt hydroxide layer on the surface of the inner coating layer, the cobalt hydroxide layer is oxidized with hydrogen peroxide solution heated to about 40 ° C. Can be formed by. The outer coating layer made of a sodium-containing cobalt compound is, for example, on the surface of the inner coating layer, a cobalt layer, or a cobalt hydroxide layer, a cobalt monoxide layer, a particle powder having a cobalt compound layer such as a cobalt oxyhydroxide layer formed, It can be formed by adding a sodium hydroxide aqueous solution and performing heat treatment in the presence of oxygen. A coating layer made of a cobalt compound containing sodium is not formed only by adding an aqueous solution of sodium hydroxide, and it is necessary to perform heat treatment in the presence of oxygen. The heat treatment temperature at this time is preferably 50 to 200 ° C. Heat treatment temperature is 50
When the temperature is lower than ° C, a large amount of CoHO 2 having a low electric conductivity is deposited, while when the heat treatment temperature exceeds 200 ° C, a large amount of tricobalt tetroxide (Co 3 O 4 ) having a low electric conductivity is precipitated. . In addition, when the cobalt compound layer is a cobalt oxyhydroxide layer, even if it is heat-treated at less than 50 ° C., CoHO 2
Does not precipitate, but it becomes difficult for sodium to be inserted. The heat treatment time varies depending on the amount and concentration of the aqueous sodium hydroxide solution used, the heat treatment temperature, and the like. Generally, it is 0.5 to 10 hours.
【0020】ナトリウム含有コバルト化合物の具体例と
しては、ナトリウム含有水酸化コバルト、ナトリウム含
有オキシ水酸化コバルト及びこれらの混合物が挙げられ
る。ナトリウム含有コバルト化合物の化学構造は、本発
明者らにおいても現在のところ定かでないが、これが極
めて高い電導率を有することから、コバルト化合物とナ
トリウムとの単なる混合物ではなく、コバルト化合物の
結晶中にナトリウムが取り込まれた形の特殊な結晶構造
を有する化合物ではないかと推察される。ナトリウム含
有コバルト化合物の好適なナトリウム含有率は、0.1
〜10重量%である。ナトリウム含有率がこの範囲を外
れると被覆層の導電性が悪くなり、活物質利用率が低下
する傾向がある。Specific examples of the sodium-containing cobalt compound include sodium-containing cobalt hydroxide, sodium-containing cobalt oxyhydroxide and a mixture thereof. The chemical structure of the sodium-containing cobalt compound has not yet been clarified by the present inventors, but since it has an extremely high conductivity, it is not a mere mixture of the cobalt compound and sodium, but sodium in the crystal of the cobalt compound. It is presumed that it is a compound having a special crystal structure in which is incorporated. The preferred sodium content of the sodium-containing cobalt compound is 0.1
10 to 10% by weight. If the sodium content is out of this range, the conductivity of the coating layer tends to deteriorate, and the active material utilization rate tends to decrease.
【0021】複合体粒子に対する被覆外層の比率は、3
〜15重量%が好ましい。この比率が3重量%未満の場
合は、活物質粒子の表面の電子伝導性が不充分となり、
活物質利用率の高い非焼結式ニッケル極を得ることが困
難となる。一方、同比率が15重量%を超えた場合は、
活物質(水酸化ニッケル)の充填密度が小さくなり、電
極の比容量が減少する。The ratio of coating outer layer to composite particles is 3
-15% by weight is preferred. If this ratio is less than 3% by weight, the electron conductivity of the surface of the active material particles becomes insufficient,
It becomes difficult to obtain a non-sintered nickel electrode having a high utilization ratio of the active material. On the other hand, if the ratio exceeds 15% by weight,
The packing density of the active material (nickel hydroxide) is reduced, and the specific capacity of the electrode is reduced.
【0022】本発明を適用して好適なアルカリ蓄電池用
非焼結式ニッケル極としては、導電性芯体に、活物質を
含有するペーストを塗布し、乾燥してなるペースト式ニ
ッケル極が挙げられる。このときの導電性芯体の具体例
としては、ニッケル発泡体、フェルト状金属繊維多孔体
及びパンチングメタルが挙げられる。その外、本発明
は、チューブ状の金属導電体の中に活物質を充填するチ
ューブ式ニッケル極、ポケット状の金属導電体の中に活
物質を充填するポケット式ニッケル極、活物質を網目状
の金属導電体とともに加圧成形するボタン型電池用ニッ
ケル極などにも、適用して好適である。As a non-sintered nickel electrode for an alkaline storage battery to which the present invention is preferably applied, a paste nickel electrode obtained by applying a paste containing an active material to a conductive core and drying the paste is cited. . Specific examples of the conductive core at this time include a nickel foam, a felt-like metal fiber porous body, and a punching metal. In addition, the present invention relates to a tubular nickel electrode in which a tube-shaped metal conductor is filled with an active material, a pocket-type nickel electrode in which a pocket-shaped metal conductor is filled with an active material, and a mesh-shaped active material. It is also suitable to be applied to a nickel electrode for a button battery, which is pressure-molded together with the metal conductor.
【0023】本発明電極を正極として用いて好適なアル
カリ蓄電池の具体例としては、ニッケル−水素蓄電池
(負極:水素吸蔵合金電極)、ニッケル−カドミウム蓄
電池(負極:カドミウム電極)及びニッケル−亜鉛蓄電
池(負極:亜鉛電極)が挙げられる。Specific examples of alkaline storage batteries suitable for using the electrode of the present invention as a positive electrode include nickel-hydrogen storage batteries (negative electrode: hydrogen storage alloy electrode), nickel-cadmium storage batteries (negative electrode: cadmium electrode) and nickel-zinc storage batteries ( Negative electrode: zinc electrode).
【0024】本発明電極は、水酸化ニッケル基体粒子
と、高温充電時の酸素過電圧の低下を抑制するイットリ
ウムの水酸化物、又は、ランタノイド(但し、ランタン
を除く)の水酸化物からなる被覆内層と、電子伝導性を
付与するコバルト又はコバルト化合物からなる被覆外層
とからなる複合体粒子からなる活物質粉末を使用してい
るので、高温雰囲気下で充電した場合の活物質利用率の
低下が少ない。被覆内層により、高温充電時の酸素過電
圧の低下が抑制されて、充電電気量が活物質の充電反応
に有効に消費されるとともに、被覆外層により、活物質
粒子表面の電子伝導性が高められるからである。The electrode of the present invention isNickel hydroxide base particles
And it suppresses the decrease of oxygen overvoltage during high temperature charging.
UmmHydroxides or lanthanoids (however, lanthanum
Hydroxide)The inner layer consisting of
Coated outer layer made of cobalt or cobalt compound to be applied
Using an active material powder consisting of composite particles consisting of
The active material utilization rate when charged in a high temperature atmosphere.
Little decrease. Oxygen overcharge during high temperature charging due to inner layer of coating
The decrease in pressure is suppressed, and the amount of electricity charged is the charge reaction of the active material.
Is effectively consumed by the
This is because the electron conductivity on the particle surface is enhanced.
【0025】因みに、水酸化ニッケル粉末に、金属コバ
ルト、水酸化コバルト及びイットリウム化合物を粉体混
合する先に挙げた特開平5−28992号公報に開示の
方法では、本発明電極の如き優れた高温での充電特性を
有する非焼結式ニッケル極は得られない。金属コバルト
及び水酸化コバルトの水酸化ニッケル粒子表面に対する
電子伝導性付与効果が、イットリウム化合物の添加によ
り減殺されるからである。By the way, in the method disclosed in Japanese Patent Laid-Open No. 28992/1993 mentioned above, in which nickel hydroxide powder is mixed with metallic cobalt, cobalt hydroxide and yttrium compound, excellent high temperature such as the electrode of the present invention can be obtained. It is not possible to obtain a non-sintered nickel electrode having the charging characteristics in 1. This is because the effect of imparting electron conductivity to the surfaces of nickel hydroxide particles of metallic cobalt and cobalt hydroxide is reduced by the addition of the yttrium compound.
【0026】[0026]
【実施例】以下、本発明を実施例に基づいてさらに詳細
に説明するが、本発明は下記実施例に何ら限定されるも
のではなく、その要旨を変更しない範囲において適宜変
更して実施することが可能なものである。EXAMPLES The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited to the following examples, and various modifications may be made without departing from the scope of the invention. Is possible.
【0027】(予備実験)水酸化コバルトと、25重量
%水酸化ナトリウム水溶液とを、重量比1:10で混合
し、85°Cで8時間加熱処理した後、水洗し、60°
Cで乾燥して、ナトリウム含有コバルト化合物を作製し
た。作製したナトリウム含有コバルト化合物のナトリウ
ム含有率を原子吸光分析により求めたところ、1重量%
であった。(Preliminary Experiment) Cobalt hydroxide and a 25 wt% sodium hydroxide aqueous solution were mixed at a weight ratio of 1:10, heat treated at 85 ° C. for 8 hours, washed with water, and then 60 °
It was dried at C to prepare a sodium-containing cobalt compound. The sodium content of the prepared sodium-containing cobalt compound was determined by atomic absorption spectrometry to be 1% by weight.
Met.
【0028】(実施例1)下記のステップ1〜5の操作
により、本発明電極及びアルカリ蓄電池を作製した。Example 1 An electrode and an alkaline storage battery of the present invention were produced by the following steps 1 to 5.
【0029】ステップ1:硫酸イットリウム2.62g
の水溶液1リットルに、水酸化ニッケル粉末(平均粒径
10μm)100gを入れ、攪拌しながら1Mの水酸化
ナトリウム水溶液を加えて液のpHを11に調整した
後、1時間攪拌を続けて反応させた。なお、液のpHが
若干低下した時点で1M水酸化ナトリウム水溶液を適宜
滴下して液のpHを11に保持した。このときのpHの
監視は自動温度補償付きガラス電極(pHメータ)にて
行った。Step 1: 2.62 g of yttrium sulfate
100 g of nickel hydroxide powder (average particle size 10 μm) was added to 1 liter of the above aqueous solution, and the pH of the solution was adjusted to 11 by adding a 1 M sodium hydroxide aqueous solution with stirring, and then the reaction was continued by stirring for 1 hour. It was When the pH of the liquid was slightly lowered, a 1M aqueous sodium hydroxide solution was appropriately added dropwise to maintain the pH of the liquid at 11. The pH was monitored with a glass electrode (pH meter) with automatic temperature compensation.
【0030】次いで、沈殿物をろ別し、水洗し、真空乾
燥して、水酸化ニッケル基体粒子の表面に水酸化イット
リウムからなる被覆内層が形成された粒子粉末を得た。
水酸化ニッケル基体粒子中の水酸化ニッケルに対する被
覆内層中のイットリウムの比率を、発光分析によりイッ
トリウム量を測定して求めたところ、1重量%であっ
た。Next, the precipitate was filtered off, washed with water, and dried in vacuum to obtain particle powder in which a coating inner layer made of yttrium hydroxide was formed on the surface of nickel hydroxide base particles .
The ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide substrate particles was determined by measuring the amount of yttrium by optical emission analysis and found to be 1% by weight.
【0031】ステップ2:硫酸コバルト13.1gの水
溶液1リットルに、ステップ1で得た粒子粉末100g
を入れ、攪拌しながら1Mの水酸化ナトリウム水溶液を
加えて液のpHを11に調整した後、1時間攪拌を続け
て反応させた。なお、ステップ1と同様に、液のpHが
若干低下した時点で1M水酸化ナトリウム水溶液を適宜
滴下して液のpHを11に保持した。Step 2: 100 g of the particle powder obtained in Step 1 is added to 1 liter of an aqueous solution of 13.1 g of cobalt sulfate.
Was added and the pH of the solution was adjusted to 11 by adding a 1 M sodium hydroxide aqueous solution with stirring, and then the reaction was continued by stirring for 1 hour. As in step 1, the pH of the liquid was maintained at 11 by appropriately dropping a 1M aqueous sodium hydroxide solution when the pH of the liquid slightly decreased.
【0032】次いで、沈殿物をろ別し、水洗し、真空乾
燥して、ステップ1で得た粒子の表面に水酸化コバルト
からなる被覆層が形成された粒子粉末を得た。Next, the precipitate was filtered off, washed with water, and vacuum dried to obtain particle powder having a coating layer made of cobalt hydroxide formed on the surface of the particle obtained in step 1.
【0033】ステップ3:ステップ2で得た粒子粉末
と、25重量%水酸化ナトリウム水溶液とを、重量比
1:10で混合し、85°Cで8時間加熱処理した後、
水洗し、65°Cで乾燥して、水酸化イットリウムから
なる被覆内層の上に、ナトリウム含有コバルト化合物か
らなる被覆外層が形成された複合体粒子からなる活物質
粉末を作製した。被覆外層のナトリウム含有率は、先の
予備実験から、1重量%と推定される。複合体粒子に対
する被覆外層の比率を、原子吸光分析によりコバルト量
を測定して求めたところ、5重量%であった。Step 3: The particle powder obtained in Step 2 and a 25% by weight aqueous solution of sodium hydroxide were mixed in a weight ratio of 1:10 and heat-treated at 85 ° C. for 8 hours.
It was washed with water and dried at 65 ° C. to prepare an active material powder composed of composite particles in which a coating outer layer made of a sodium-containing cobalt compound was formed on a coating inner layer made of yttrium hydroxide. The sodium content of the coating outer layer is estimated to be 1% by weight from the previous preliminary experiment. The ratio of the outer coating layer to the composite particles was determined by measuring the amount of cobalt by atomic absorption spectrometry and found to be 5% by weight.
【0034】ステップ4:ステップ3で得た活物質粉末
(平均粒径10μm)100重量部と、結着剤としての
1重量%メチルセルロース水溶液20重量部とを混練し
てペーストを調製し、このペーストをニッケル発泡体
(多孔度95%、平均孔径200μm)からなる多孔性
の基板に充填し、乾燥し、加圧成形して、非焼結式ニッ
ケル極(本発明電極)a1を作製した。本発明電極a1
の寸法は、縦70mm、横40mm、厚み0.70mm
であった。以下で作製した非焼結式ニッケル極の寸法
も、全てこれに統一した。Step 4: 100 parts by weight of the active material powder (average particle size 10 μm) obtained in step 3 and 20 parts by weight of a 1% by weight aqueous solution of methylcellulose as a binder are kneaded to prepare a paste. Was filled in a porous substrate made of nickel foam (porosity 95%, average pore diameter 200 μm), dried and pressure-molded to prepare a non-sintered nickel electrode (electrode of the present invention) a1. The present invention electrode a1
Dimensions are 70mm long, 40mm wide, 0.70mm thick
Met. The dimensions of the non-sintered nickel electrodes produced below were also unified.
【0035】ステップ5:ステップ4で作製した本発明
電極a1(正極)、この正極の1.5倍の容量を有する
従来公知のペースト式カドミウム極(負極)、ポリアミ
ド不織布(セパレータ)、30重量%水酸化カリウム水
溶液(アルカリ電解液)、金属製の電池缶、金属製の電
池蓋などを用いて、AAサイズのアルカリ蓄電池(電池
容量:約1000mAh)A1を作製した。カドミウム
極の寸法は、縦85mm、横40mm、厚み0.35m
mであった。非焼結式ニッケル極の特性を調べるべく、
負極の容量を正極のそれの約1.5倍とした。なお、以
下の実施例及び比較例で作製した電池についても、同様
に、負極の容量を正極のそれの約1.5倍とした。Step 5: The electrode a1 of the present invention (positive electrode) produced in Step 4, a conventionally known paste type cadmium electrode (negative electrode) having a capacity 1.5 times that of the positive electrode, polyamide nonwoven fabric (separator), 30% by weight. An AA-sized alkaline storage battery (battery capacity: about 1000 mAh) A1 was produced using a potassium hydroxide aqueous solution (alkali electrolyte solution), a metal battery can, a metal battery lid, and the like. The size of the cadmium pole is 85mm long, 40mm wide, and 0.35m thick.
It was m. To investigate the characteristics of non-sintered nickel electrode,
The capacity of the negative electrode was about 1.5 times that of the positive electrode. In the batteries manufactured in the following Examples and Comparative Examples, the capacity of the negative electrode was set to about 1.5 times that of the positive electrode.
【0036】(実施例2〜15)
ステップ1において、硫酸イットリウムに代えて、表1
に示すランタノイド(但し、ランタンを除く)の硝酸塩
を使用したこと以外は実施例1と同様にして、本発明電
極a4〜a17及びアルカリ蓄電池A4〜A17を作製
した。( Examples 2 to 15 ) In Step 1, instead of yttrium sulfate, Table 1
Inventive electrodes a4 to a17 and alkaline storage batteries A4 to A17 were prepared in the same manner as in Example 1 except that the lanthanoid nitrate (excluding lanthanum) shown in 1 was used.
【0037】[0037]
【表1】 [Table 1]
【0038】(比較例1)ステップ1を実施しなかった
こと以外は実施例1と同様にして、比較電極b及び比較
電池Bを作製した。Comparative Example 1 Comparative electrode b and comparative battery B were prepared in the same manner as in Example 1 except that step 1 was not carried out.
【0039】(比較例2)水酸化ニッケル100重量
部、金属コバルト7重量部、水酸化コバルト5重量部、
三酸化二イットリウム(平均粒径1μm)3重量部、結
着剤としての1重量%メチルセルロース水溶液20重量
部とを混練してペーストを調製し、このペーストをニッ
ケル発泡体(多孔度95%、平均孔径200μm)から
なる多孔性の基板に充填し、乾燥し、加圧成形して、比
較電極cを作製した。次いで、ステップ5においてこの
比較電極cを使用したこと以外は実施例1と同様にし
て、比較電池Cを作製した。この電池は、特開平5−2
8992号公報に開示の方法に準拠して作製したもので
ある。Comparative Example 2 100 parts by weight of nickel hydroxide, 7 parts by weight of metallic cobalt, 5 parts by weight of cobalt hydroxide,
A paste was prepared by kneading 3 parts by weight of yttrium trioxide (average particle size: 1 μm) and 20 parts by weight of a 1% by weight aqueous solution of methylcellulose as a binder, and using this paste, a nickel foam (porosity 95%, average) A reference electrode c was prepared by filling a porous substrate having a pore size of 200 μm), drying and pressure molding. Next, a comparative battery C was produced in the same manner as in Example 1 except that this comparative electrode c was used in step 5. This battery is disclosed in Japanese Patent Laid-Open No. 5-2
It was produced according to the method disclosed in Japanese Patent No. 8992.
【0040】(比較例3)
ステップ2及び3を実施せずに、ステップ1で作製した
粒子粉末に、予備実験で作製したナトリウム含有コバル
ト化合物を、水酸化ニッケル基体粒子中の水酸化ニッケ
ル100重量部に対して5重量部の割合で、添加したこ
と以外は実施例1と同様にして、比較電極d及び比較電
池Dを作製した。Comparative Example 3 Without carrying out Steps 2 and 3, the sodium-containing cobalt compound prepared in the preliminary experiment was added to the particle powder prepared in Step 1 in an amount of 100% by weight of nickel hydroxide in the nickel hydroxide base particles. Comparative electrode d and comparative battery D were produced in the same manner as in Example 1 except that 5 parts by weight to 5 parts by weight was added.
【0041】〈各非焼結式ニッケル極の活物質利用率〉
各電池について、25°Cにて0.1Cで160%充電
した後、25°Cにて1Cで1.0Vまで放電する充放
電を10サイクル行い、各電池に使用した非焼結式ニッ
ケル極の10サイクル目の活物質利用率を求めた。続け
て、各電池を60°Cにて0.1Cで160%充電した
後、25°Cにて1Cで1.0Vまで放電して、高温雰
囲気下で充電した時の活物質利用率を求めた。活物質利
用率は、下式に基づき算出した。<Active material utilization rate of each non-sintered nickel electrode>
Each battery was charged 160% at 0.1C at 25 ° C and then charged / discharged up to 1.0V at 1C at 25 ° C for 10 cycles. The non-sintered nickel electrode used for each battery The utilization rate of the active material at the 10th cycle was calculated. Continuously, each battery was charged at 0.1 ° C at 160 ° C and 160%, and then discharged at 25 ° C at 1C to 1.0V to obtain the active material utilization rate when charged in a high temperature atmosphere. It was The active material utilization rate was calculated based on the following formula.
【0042】活物質利用率(%)={放電容量(mA
h)/〔水酸化ニッケル量(g)×288(mAh/
g)〕}×100Utilization rate of active material (%) = {discharge capacity (mA
h) / [amount of nickel hydroxide (g) × 288 (mAh /
g)]} × 100
【0043】結果を表2に示す。但し、表2中の活物質
利用率は、本発明電極a1の活物質利用率を100とし
たときの相対指数である。The results are shown in Table 2. However, the active material utilization rate in Table 2 is a relative index when the active material utilization rate of the electrode a1 of the present invention is 100.
【0044】[0044]
【表2】 [Table 2]
【0045】表2に示すように、本発明電極a1、a4
〜a17は、25°C充電時及び60°C充電時のいず
れの場合にも、活物質利用率が高い。これに対して、比
較電極bは、25°C充電時の活物質利用率は本発明電
極a1、a4〜a17と同程度であるものの、60°C
充電時の活物質利用率が本発明電極a1に比べて低い。
水酸化ニッケル粒子の表面に水酸化イットリウムからな
る被覆内層を形成しなかったために、高温充電時の酸素
過電圧の低下が充分に抑制されなかったためと考えられ
る。比較電極cの25°C充電時及び60°C充電時の
活物質利用率がいずれも極めて低いのは、金属コバルト
及び水酸化コバルトの添加による電子伝導性付与効果
が、三酸化二イットリウムの同時添加により減殺された
ためと考えられる。比較電極dの25°C充電時の活物
質利用率が低いのは、被覆外層を形成せずに、単にナト
リウム含有コバルト化合物を添加しただけであるため、
水酸化ニッケル粒子の表面の電子伝導性が有効に高めら
れなかったためと考えられる。As shown in Table 2, the electrodes a1 and a4 of the present invention
In the cases of charging at 25 ° C. and charging at 60 ° C., a to a17 have high active material utilization rates. On the other hand, the comparative electrode b has an active material utilization rate at the time of charging at 25 ° C of about the same as those of the electrodes a1 and a4 to a17 of the present invention, but at 60 ° C.
The active material utilization rate during charging is lower than that of the electrode a1 of the present invention.
It is considered that the decrease in oxygen overvoltage during high temperature charging was not sufficiently suppressed because the coating inner layer made of yttrium hydroxide was not formed on the surface of the nickel hydroxide particles. The comparatively low utilization rates of the active material at the time of charging the reference electrode c at 25 ° C. and 60 ° C. are due to the fact that the addition of metallic cobalt and cobalt hydroxide has the effect of imparting electronic conductivity to the simultaneous use of yttrium trioxide. It is thought that this was due to the addition. The reason why the active material utilization rate of the comparative electrode d at the time of charging at 25 ° C. is low is that the sodium-containing cobalt compound is simply added without forming the coating outer layer.
It is considered that the electron conductivity on the surface of the nickel hydroxide particles was not effectively increased.
【0046】〈水酸化ニッケル基体粒子中の水酸化ニッ
ケルに対する被覆内層中のイットリウムの比率と高温充
電時の活物質利用率及び放電容量の関係〉
ステップ1において、硫酸イットリウム2.62gの水
溶液1リットルに代えて、硫酸イットリウム0.079
g、0.13g、1.31g、7.86g、13.1
g、15.7g又は20.9gの水溶液1リットルを用
いたこと以外は実施例1と同様にして、非焼結式ニッケ
ル極e1〜e7及びアルカリ蓄電池E1〜E7を作製し
た。非焼結式ニッケル極e1〜e7について、水酸化ニ
ッケル基体粒子中の水酸化ニッケルに対する被覆内層中
のイットリウムの比率を発光分析によりイットリウム量
を測定して求めたところ、表3に示すように、順に、
0.03重量%、0.05重量%、0.5重量%、3重
量%、5重量%、6重量%及び8重量%であった。<Relationship between the ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide base particles and the active material utilization rate and discharge capacity during high temperature charging> In step 1, 1 liter of an aqueous solution of 2.62 g of yttrium sulfate is used. Instead of yttrium sulfate 0.079
g, 0.13 g, 1.31 g, 7.86 g, 13.1
Non-sintered nickel electrodes e1 to e7 and alkaline storage batteries E1 to E7 were produced in the same manner as in Example 1 except that 1 liter of an aqueous solution of g, 15.7 g or 20.9 g was used. For non-sintered nickel electrode E1 to E7, hydroxide two
The ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel base particles was determined by measuring the amount of yttrium by optical emission analysis, and as shown in Table 3,
The amounts were 0.03% by weight, 0.05% by weight, 0.5% by weight, 3% by weight, 5% by weight, 6% by weight and 8% by weight.
【0047】[0047]
【表3】 [Table 3]
【0048】次いで、各電池について、先と同じ充放電
試験(25°C充放電を10サイクル、次いで60°C
充電及び25°C放電を1サイクル)を行い、各電池に
使用した非焼結式ニッケル極の25°C充放電での10
サイクル目の放電容量及び60°C充電時の活物質利用
率を求めた。それぞれの結果を、図1及び図2に示す。Then, for each battery, the same charge / discharge test as described above (10 cycles of 25 ° C charge / discharge, then 60 ° C) was performed.
After charging and discharging at 25 ° C for 1 cycle, the non-sintered nickel electrode used for each battery was charged at 10 ° C at 25 ° C.
The discharge capacity at the cycle and the utilization rate of the active material at the time of charging at 60 ° C were determined. The respective results are shown in FIGS. 1 and 2.
【0049】図1は、水酸化ニッケル基体粒子中の水酸
化ニッケルに対する被覆内層中のイットリウムの比率と
高温充電時の活物質利用率の関係を、縦軸に60°C充
電時の活物質利用率を、横軸に水酸化ニッケル基体粒子
中の水酸化ニッケルに対する被覆内層中のイットリウム
の比率(重量%)をとって示したグラフである。図1に
は、本発明電極a1の60°C充電時の活物質利用率も
示してあり、図1の縦軸の活物質利用率は、本発明電極
a1の60°C充電時の活物質利用率を100としたと
きの相対指数である。FIG. 1 shows the relationship between the ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide substrate particles and the active material utilization rate at high temperature charging, and the vertical axis represents the active material utilization at 60 ° C. charging. 3 is a graph in which the abscissa represents the ratio (% by weight) of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide base particles . FIG. 1 also shows the active material utilization rate of the electrode a1 of the present invention at 60 ° C. charge. The active material utilization rate of the vertical axis of FIG. 1 is the active material utilization rate of the electrode a1 of the present invention at 60 ° C. charge. It is a relative index when the utilization rate is 100.
【0050】図1より、高温充電時の活物質利用率が高
い非焼結式ニッケル極を得るためには、水酸化ニッケル
基体粒子中の水酸化ニッケルに対する被覆内層中のイッ
トリウムの比率を、0.05重量%以上とすることが好
ましいことが分かる。From FIG. 1, in order to obtain a non-sintered nickel electrode having a high utilization ratio of the active material during high temperature charging, nickel hydroxide was used.
It can be seen that the ratio of yttrium in the coating inner layer to nickel hydroxide in the base particles is preferably 0.05% by weight or more.
【0051】また、図2は、水酸化ニッケル基体粒子中
の水酸化ニッケルに対する被覆内層中のイットリウムの
比率と放電容量の関係を、縦軸に25°C充電時の10
サイクル目の放電容量を、横軸に水酸化ニッケル基体粒
子中の水酸化ニッケルに対する被覆内層中のイットリウ
ムの比率(重量%)をとって示したグラフである。図2
には、本発明電極a1の25°C充電時の10サイクル
目の放電容量も示してあり、図2の縦軸の放電容量は、
本発明電極a1の25°C充電時の10サイクル目の放
電容量を100としたときの相対指数である。FIG. 2 shows the relationship between the discharge capacity and the ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide base particles , and the vertical axis represents 10 at the time of charging at 25 ° C.
Discharge capacity at the cycle cycle, nickel hydroxide base particles on the horizontal axis
6 is a graph showing a ratio (% by weight) of yttrium in a coating inner layer to nickel hydroxide in a child . Figure 2
2 also shows the discharge capacity at the 10th cycle when the electrode a1 of the present invention was charged at 25 ° C., and the discharge capacity on the vertical axis in FIG.
It is a relative index when the discharge capacity at the 10th cycle when the electrode a1 of the present invention was charged at 25 ° C was 100.
【0052】図2より、放電容量の大きい非焼結式ニッ
ケル極を得るためには、水酸化ニッケル基体粒子中の水
酸化ニッケルに対する被覆内層中のイットリウムの比率
を、5重量%以下とすることが好ましいことが分かる。From FIG. 2, in order to obtain a non-sintered nickel electrode having a large discharge capacity, the ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide substrate particles should be 5% by weight or less. It turns out that is preferable.
【0053】図1及び図2より、水酸化ニッケル基体粒
子中の水酸化ニッケルに対する被覆内層中のイットリウ
ムの比率は、0.05〜5重量%とすることが好ましい
ことが分かる。ランタノイド(但し、ランタンを除く)
の場合も、水酸化ニッケル基体粒子中の水酸化ニッケル
に対する被覆内層中のこれらの比率を、0.05〜5重
量%とすることが好ましいことを別途確認した。From FIGS. 1 and 2, nickel hydroxide base particles
It is understood that the ratio of yttrium in the coating inner layer to nickel hydroxide in the child is preferably 0.05 to 5% by weight. Lanthanoid (excluding lantern)
Also in this case, it was separately confirmed that the ratio of these to the nickel hydroxide in the nickel hydroxide base particles in the coating inner layer is preferably 0.05 to 5% by weight.
【0054】〈複合体粒子に対する被覆外層の比率と高
温充電時の活物質利用率及び放電容量の関係〉ステップ
2において、硫酸コバルト13.1gの水溶液1リット
ルに代えて、硫酸コバルト1.31g、5.25g、
7.88g、26.3g、39.4g、44.7g又は
52.5gの水溶液1リットルを用いたこと以外は実施
例1と同様にして、非焼結式ニッケル極f1〜f7及び
アルカリ蓄電池F1〜F7を作製した。非焼結式ニッケ
ル極f1〜f7について、複合体粒子に対する被覆外層
の比率を原子吸光分析によりコバルト量を測定して求め
たところ、表4に示すように、順に、0.5重量%、2
重量%、3重量%、10重量%、15重量%、17重量
%、20重量%であった。<Relationship between the ratio of the outer coating layer to the composite particles and the utilization rate of the active material during high temperature charging and the discharge capacity> In step 2, 1.31 g of cobalt sulfate was used instead of 1 liter of an aqueous solution of 13.1 g of cobalt sulfate. 5.25g,
Non-sintered nickel electrodes f1 to f7 and an alkaline storage battery F1 were prepared in the same manner as in Example 1 except that 1 liter of an aqueous solution of 7.88 g, 26.3 g, 39.4 g, 44.7 g or 52.5 g was used. ~ F7 were produced. For the non-sintered nickel electrodes f1 to f7, the ratio of the coating outer layer to the composite particles was determined by measuring the amount of cobalt by atomic absorption spectrometry.
%, 3% by weight, 10% by weight, 15% by weight, 17% by weight, 20% by weight.
【0055】[0055]
【表4】 [Table 4]
【0056】次いで、各電池について、先と同じ条件の
充放電試験(25°C充放電を10サイクル)を行い、
各電池に使用した非焼結式ニッケル極の25°C充電時
の10サイクル目の放電容量を求めた。結果を、図3に
示す。図3は、複合体粒子に対する被覆外層の比率と放
電容量の関係を、縦軸に25°C充放電での10サイク
ル目の放電容量を、横軸に複合体粒子に対する被覆外層
の比率(重量%)をとって示したグラフである。図3に
は、本発明電極a1の25°C充電時の10サイクル目
の放電容量も示してあり、図3の縦軸の放電容量は、本
発明電極a1の25°C充電時の10サイクル目の放電
容量を100としたときの相対指数である。Then, each battery was subjected to a charge / discharge test (10 cycles of 25 ° C. charge / discharge) under the same conditions as above.
The discharge capacity at the 10th cycle when the non-sintered nickel electrode used in each battery was charged at 25 ° C was determined. The results are shown in Fig. 3. FIG. 3 shows the relationship between the ratio of the coating outer layer to the composite particles and the discharge capacity, the vertical axis represents the discharge capacity at the 10th cycle at 25 ° C. charge and discharge, and the horizontal axis represents the ratio of the coating outer layer to the composite particles (weight. %) Is the graph shown. FIG. 3 also shows the discharge capacity at the 10th cycle when the electrode a1 of the invention was charged at 25 ° C., and the discharge capacity on the vertical axis of FIG. 3 is the 10th cycle when the electrode a1 of the invention was charged at 25 ° C. It is a relative index when the discharge capacity of the eye is 100.
【0057】図3より、放電容量の大きい非焼結式ニッ
ケル極を得るためには、複合体粒子に対する被覆外層の
比率を、3〜15重量%とすることが好ましいことが分
かる。From FIG. 3, it is understood that in order to obtain a non-sintered nickel electrode having a large discharge capacity, the ratio of the outer coating layer to the composite particles is preferably 3 to 15% by weight.
【0058】上記の実施例では、水酸化ニッケル基体粒
子として水酸化ニッケルのみからなる単一成分粒子を使
用したが、水酸化ニッケルに、コバルト、亜鉛、カドミ
ウム、カルシウム、マンガン、マグネシウム、ビスマ
ス、アルミニウム、ランタノイド及びイットリウムから
選ばれた少なくとも1種の元素が固溶した固溶体粒子を
水酸化ニッケル基体粒子として用いた場合にも上記と同
様に優れた効果が得られることを別途確認した。In the above embodiment, nickel hydroxide base particles
Single component particles consisting of only nickel hydroxide were used as a child , but nickel hydroxide was added to at least one element selected from cobalt, zinc, cadmium, calcium, manganese, magnesium, bismuth, aluminum, lanthanoid and yttrium. Solid solution particles
It was separately confirmed that the same excellent effects as above can be obtained when used as nickel hydroxide base particles .
【0059】[0059]
【発明の効果】本発明により、常温下で充電した場合は
もとより、高温雰囲気下で充電した場合においても、高
い活物質利用率を発現するアルカリ蓄電池用非焼結式ニ
ッケル極が提供される。According to the present invention, there is provided a non-sintered nickel electrode for an alkaline storage battery, which exhibits a high utilization rate of the active material not only when it is charged at room temperature but also when it is charged at high temperature atmosphere.
【図1】水酸化ニッケル基体粒子中の水酸化ニッケルに
対する被覆内層中のイットリウムの比率と高温充電時の
活物質利用率の関係を示すグラフである。FIG. 1 is a graph showing a relationship between a ratio of yttrium in a coating inner layer to nickel hydroxide in nickel hydroxide base particles and an active material utilization rate at high temperature charging.
【図2】水酸化ニッケル基体粒子中の水酸化ニッケルに
対する被覆内層中のイットリウムの比率と放電容量の関
係を示すグラフである。FIG. 2 is a graph showing the relationship between the discharge capacity and the ratio of yttrium in the coating inner layer to nickel hydroxide in the nickel hydroxide base particles .
【図3】複合体粒子に対する被覆外層の比率と放電容量
の関係を示すグラフである。FIG. 3 is a graph showing the relationship between the ratio of the outer coating layer to the composite particles and the discharge capacity.
フロントページの続き (72)発明者 藤谷 伸 大阪府守口市京阪本通2丁目5番5号 三洋電機株式会社内 (72)発明者 西尾 晃治 大阪府守口市京阪本通2丁目5番5号 三洋電機株式会社内 (56)参考文献 特開 平7−45281(JP,A) 特開 平9−147904(JP,A) 特開 平8−287907(JP,A) 特開 平7−320737(JP,A) (58)調査した分野(Int.Cl.7,DB名) H01M 4/52 H01M 4/24 - 4/34 Front page continuation (72) Inventor Shin Fujitani 2-5-5 Keihan Hondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Nishio 2-5-5 Keihan-hondori, Moriguchi-shi, Osaka Sanyo (56) Reference JP-A-7-45281 (JP, A) JP-A-9-147904 (JP, A) JP-A-8-287907 (JP, A) JP-A-7-320737 (JP , A) (58) Fields investigated (Int.Cl. 7 , DB name) H01M 4/52 H01M 4/24-4/34
Claims (5)
蓄電池用非焼結式ニッケル極であって、前記複合体粒子
が、水酸化ニッケル基体粒子と、当該水酸化ニッケル基
体粒子を被覆する、イットリウムの水酸化物又はランタ
ノイド(但し、ランタンを除く)の水酸化物からなる被
覆内層と、当該被覆内層を被覆するコバルト又はコバル
ト化合物からなる被覆外層とからなるアルカリ蓄電池用
非焼結式ニッケル極。1. A non-sintered nickel electrode for an alkaline storage battery, wherein the active material powder is composite particles, wherein the composite particles are nickel hydroxide base particles and the nickel hydroxide group.
Yttrium hydroxide or lanta coating body particles
A non-sintered nickel electrode for an alkaline storage battery, which comprises an inner coating layer made of a hydroxide of a nonoid (excluding lanthanum) and an outer coating layer made of cobalt or a cobalt compound coating the inner coating layer.
ッケルに、コバルト、亜鉛、カドミウム、カルシウム、
マンガン、マグネシウム、ビスマス、アルミニウム、ラ
ンタノイド及びイットリウムから選ばれた少なくとも1
種の元素が固溶した固溶体粒子である請求項1記載のア
ルカリ蓄電池用非焼結式ニッケル極。2. The nickel hydroxide base particles are nickel hydroxide, cobalt, zinc, cadmium, calcium,
At least one selected from manganese, magnesium, bismuth, aluminum, lanthanoids and yttrium
The non-sintered nickel electrode for an alkaline storage battery according to claim 1, wherein the non-sintered nickel electrode is a solid solution particle in which a seed element is solid-dissolved.
水酸化コバルト、オキシ水酸化コバルト又はナトリウム
含有コバルト化合物である請求項1記載のアルカリ蓄電
池用非焼結式ニッケル極。3. The cobalt compound is cobalt monoxide,
Cobalt hydroxide, cobalt oxyhydroxide or sodium
The non-sintered nickel electrode for an alkaline storage battery according to claim 1 , which is a contained cobalt compound .
ッケルに対する前記被覆内層中のイットリウム又はラン
タノイド(但し、ランタンを除く)の比率が、0.05
〜5重量%である請求項1記載のアルカリ蓄電池用非焼
結式ニッケル極。 4. The nickel hydroxide contained in the nickel hydroxide substrate particles.
Yttrium or run in the coating inner layer for the shell
Tanoid (excluding lanthanum) ratio is 0.05
The non-sintered nickel electrode for an alkaline storage battery according to claim 1, wherein the non-sintered nickel electrode is about 5% by weight .
率が、3〜15重量%である請求項1記載のアルカリ蓄
電池用非焼結式ニッケル極。 5. The ratio of the outer coating layer to the composite particles.
The non-sintered nickel electrode for an alkaline storage battery according to claim 1 , wherein the rate is 3 to 15% by weight .
Priority Applications (4)
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JP17631497A JP3433049B2 (en) | 1997-06-16 | 1997-06-16 | Non-sintered nickel electrode for alkaline storage batteries |
EP98110938A EP0886331B1 (en) | 1997-06-16 | 1998-06-15 | Non-sintered nickel for alkaline storage battery |
DE69801870T DE69801870T2 (en) | 1997-06-16 | 1998-06-15 | Unsintered nickel electrode for alkaline storage cells |
US09/097,679 US6077625A (en) | 1997-06-16 | 1998-06-16 | Non-sintered nickel electrode for alkaline storage battery |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP17631497A JP3433049B2 (en) | 1997-06-16 | 1997-06-16 | Non-sintered nickel electrode for alkaline storage batteries |
Publications (2)
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JPH117949A JPH117949A (en) | 1999-01-12 |
JP3433049B2 true JP3433049B2 (en) | 2003-08-04 |
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CA2377062A1 (en) | 2001-03-15 | 2002-09-15 | Powergenix Systems Inc. | Alkaline cells having positive nickel hydroxide electrodes with fluoride salt additives |
JP4956863B2 (en) * | 2001-03-29 | 2012-06-20 | パナソニック株式会社 | Cathode active material for alkaline storage battery and alkaline storage battery using the same |
JP5743185B2 (en) * | 2011-01-18 | 2015-07-01 | 株式会社Gsユアサ | Positive electrode active material for alkaline storage battery and alkaline storage battery |
JP5700282B2 (en) | 2011-01-11 | 2015-04-15 | 株式会社Gsユアサ | Alkaline storage battery |
WO2012096294A1 (en) * | 2011-01-11 | 2012-07-19 | 株式会社Gsユアサ | Positive electrode active material for alkaline storage battery, manufacturing method for positive electrode active material, and alkaline storage battery |
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1997
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