JP3941341B2

JP3941341B2 - Alkaline battery and nickel plate

Info

Publication number: JP3941341B2
Application number: JP2000146546A
Authority: JP
Inventors: 英樹笠原; 達彦鈴木; 慶孝暖水
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Corp; Panasonic Holdings Corp
Priority date: 2000-05-18
Filing date: 2000-05-18
Publication date: 2007-07-04
Anticipated expiration: 2020-05-18
Also published as: JP2001325956A

Description

【０００１】
【発明の属する技術分野】
本発明は、ニッケル・カドミウム蓄電池やニッケル・水素蓄電池等のアルカリ蓄電池用ニッケル極板とそれを用いたアルカリ蓄電池に関するものである。
【０００２】
【従来の技術】
近年、二次電池は通信機器等の普及に伴い、その電源として高容量化が強く望まれてきている。これまでの高容量化の対応は、正，負極自体の高容量化およびセパレータの薄膜化等によってなされてきた。特にニッケル／水素蓄電池は、正極規制によって電池設計がなされるため、正極板の高容量化が急務とされていた。
【０００３】
以下に上記のアルカリ蓄電池用正極板として用いられるニッケル極板について説明する。
【０００４】
従来、アルカリ蓄電池用の正極板としては、ニッケル粉末を焼結して得た多孔度８０％程度のニッケルの多孔質焼結基板に硝酸ニッケル水溶液等のニッケル塩溶液に含浸し、次いでこれをアルカリ水溶液中に浸漬するなどしてアルカリ転換を施して、前記基板の孔部に水酸化ニッケル活物質を生成させて製造する焼結式極板がある。焼結基板の場合、多孔度をこれ以上向上させるのは通常では困難であり、従って充填される水酸化ニッケル量を簡単に増加させることができず、極板の高容量化には適していない。
【０００５】
また、非焼結式正極に関しては、例えば特開昭６０−１３１７６５号公報に球状水酸化ニッケルを、スポンジ状基板の孔部に充填することが提案されている。これによれば、基板に活物質を均一にかつ高密度に充填することが可能になり、焼結式基板に比べ高容量化に有効である。
【０００６】
しかしながら、金属多孔体基板の孔部のサイズは２００〜５００μｍ程度であり、この孔部に平均粒径が約５μｍ〜１５０μｍの球状水酸化ニッケルを活物質として充填するため、金属多孔体基板の孔部に臨んで細孔を構成する導電性骨格と球状水酸化ニッケルとの間には導電性が不十分な部分が存在する。
【０００７】
さらに、高温雰囲気下での充電を行なうと、導電性骨格の酸素発生電位が低下し、十分な活物質利用率を得ることはできない。
【０００８】
本発明は、このような課題を解決するものであり、常温における活物質利用率を低下させることなく、高温雰囲気下における活物質利用率を向上させることができるアルカリ蓄電池を提供することを目的とする。
【０００９】
【課題を解決するための手段】
上記目的を達成するために本発明は、金属多孔質基板の孔部に臨んだ導電性骨格の表面に少なくともコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の薄層を形成し、前記多孔質基板の孔部に球状の水酸化ニッケルからなる活物質を充填したアルカリ蓄電池用ニッケル極板である。
【００１０】
これにより、常温における活物質利用率を低下させることなく、高温雰囲気下における活物質利用率を向上させたものである。
【００１１】
【発明の実施の形態】
本発明の請求項１に記載の発明は、３次元的に連なる空間を有するＮｉ金属多孔質基板の孔部に臨んだ導電性骨格の表面に少なくとも１０ｎｍ〜１０００ｎｍの厚みを有するコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の酸化物層を形成するとともに、前記孔部に球状の水酸化ニッケルからなる活物質を充填することで、活物質の充填密度および容量密度を向上させたアルカリ蓄電池用ニッケル極板が得られる。
【００１２】
請求項１は、３次元的に連なる空間を有するＮｉ金属多孔質基板の表面を被覆させる薄層の厚さを規定するものであり、１０ｎｍよりも薄い層では導電性骨格の表面を十分に覆いきれず、また１０００ｎｍよりも厚い層では導電性骨格と活物質との導電性を低下させてしまう。そのことから、導電性骨格表面の薄層の厚さは、１０ｎｍ〜１０００ｎｍであることが好ましい。
【００１３】
請求項２に記載の発明は、球状水酸化ニッケル粉末の粒径を規定したものであり、これとコバルト化合物等の導電剤の組み合わせにより充填をすることで充填密度および容量密度が従来品と比較して向上するニッケル極が得られる。
【００１４】
請求項３に記載の発明は、３次元的に連なる空間を有するＮｉ金属多孔質基板の表面に少なくともコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の酸化物層を形成するとともに、前記孔部に球状の水酸化ニッケル粉末からなる活物質を充填した正極と、負極とセパレータからなるアルカリ蓄電池であり、導電性骨格表面での酸素発生電位の低下を抑制し、常温における活物質利用率を低下させることなく、高温雰囲気下における活物質利用率を向上させることができる。
【００１５】
本発明のニッケル極板は、Ｎｉ金属多孔質基板をコバルト塩溶液、イットリウム塩溶液、イッテルビウム塩溶液、ルテチウム塩溶液の内、少なくとも１種の溶液に、浸漬、乾燥する工程と、つづいてアルカリ水溶液に浸漬して水酸化物に転換させる一連の操作を少なくとも一回行い、酸素雰囲気下で熱処理を行う工程と、前記基板に水酸化ニッケル粉末を主体とした活物質を充填する工程とを有するニッケル極板の製造方法で作製できる。前記基板の骨格表面にコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の酸化物層を簡単な操作によって低コストで形成できる。
【００１６】
また本発明のニッケル極板は、Ｎｉ金属多孔質基板の孔部に臨んだ導電性骨格の表面の薄層は、コバルト塩溶液、イットリウム塩溶液、イッテルビウム塩溶液、ルテチウム塩溶液の内、少なくとも１種を用い、電解析出により水酸化物として前記基板の骨格表面に析出させる操作を少なくとも一回行い、つづいて酸素雰囲気下での熱処理を行う工程と、前記基板に水酸化ニッケル粉末を主体とした活物質を充填する工程とを有するニッケル極板の製造方法でも作製できる。前記基板の骨格表面にコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の酸化物層を電解析出させるので、均一に骨格を覆うことができる。
【００１７】
【実施例】
以下、本発明の実施例について説明する。
【００１８】
（実施例１）
まず、第１工程として金属多孔質基板の骨格部分１に水酸化イットリウムを電解析出させる。この電解析出の方法は、１モル／リットルのイットリウム塩溶液を電析槽の中に入れ、ついでニッケル多孔質極板を浸漬し、この多孔質極板をカソードとし、対極をニッケル板として、これらの接触を防ぐためのポリエステル製ネットを両極間に配置する。電析条件は電流密度５ｍＡ／ｃｍ²、電析時間を２００（秒）で行った。このときの電析量は、電析効率１００％として通電電気量から求めた。
【００１９】
導電性骨格に水酸化イットリウム層２を備えた本発明の金属多孔質基板を、第２工程として熱酸化処理を施す。熱酸化処理条件は、アルカリ雰囲気下の乾燥炉にて９０℃、１０分間、酸化処理を行ない、水洗、乾燥した。
【００２０】
酸化処理後の多孔質基板を用い、その孔部に平均粒径が約１０μｍの球状の水酸化ニッケル粉末を１００ｇと水酸化コバルト粉末を１０ｇを、水で練合し、活物質ペーストとして充填した。
【００２１】
上記のように電析処理を施し、酸化イットリウムが導電性骨格を被覆している金属多孔質基板を用い、活物質ペーストを充填した本発明の極板をＡ、比較例として、電析処理なしの金属多孔質基板をＢ１、電析処理なしの金属多孔質基板を用い、活物質ペーストに酸化イットリウムを電析量と同じ量、外部添加し充填したニッケル極板をＢ２、イットリウムを内部添加した水酸化ニッケル粉末を用いた活物質ペーストを電析処理なしの金属多孔質基板に充填したニッケル極板をＢ３とした。
【００２２】
上記の本発明の極板Ａの模式断面図を図１に示す。
【００２３】
充填された極板をプレスによって所定の厚みにし、所定の電池サイズ、たとえばＡサイズ用に裁断した。
【００２４】
負極板は、水素吸蔵合金粉末を主に調合したペーストをパンチングメタル基板の両面に塗着し、所定の厚みにプレスし、所定の寸法に裁断した。
【００２５】
このようにして得られた正極板Ａ，Ｂ１，Ｂ２、Ｂ３のそれぞれと、負極板をポリプロピレンの不織布製セパレータを間に介在して、渦巻状に構成した電池群を外装缶に収納した。アルカリ電解液としては、従来から通信機やコンピュータ用ニッケル−水素蓄電池に使用されている濃度７．５ｍｏｌ／ｌの水酸化カリウムに１ｍｏｌ／ｌの水酸化リチウムを混合したアルカリ電解液を使用し、所定量注液して、定格容量２０００ｍＡｈのＦＡサイズの電池を組み立てた。これを周囲温度２５℃で１２時間放置後、初充放電（充電は０．１Ｃの電流値で１５時間、放電は０．２Ｃの電流値で４時間）行い、ニッケル・水素蓄電池Ａ，Ｂ１，Ｂ２，Ｂ３を得た。正極板の内容を（表１）に示す。
【００２６】
【表１】

【００２７】
上記で作製した電池Ａ，Ｂ１，Ｂ２，Ｂ３のそれぞれについて、１．０Ｃの電流値で１．５時間充電し、１．０放電の電流値で電池の端子電圧が１．０Ｖに至るまで放電し、２５℃〜６０℃までの充放電温度特性を試験した結果を図２に示す。
【００２８】
本発明の極板Ａを用いた電池は、比較例の電池Ｂ１〜Ｂ３よりも充電温度特性が向上していることがわかる。これは、Ｎｉ金属多孔質基板の骨格表面での酸素発生を被覆した酸化イットリウムが抑制することにより、水酸化ニッケルのオキシ水酸化ニッケルへの充電反応が十分行われる。
【００２９】
また、実施例１では金属多孔質基板の骨格表面の被覆を酸化イットリウムで行なったが、酸化コバルト，酸化イッテルビウム，酸化ルテチウムで行っても同様な効果が得られる。
【００３０】
（実施例２）
まず、第１工程として金属多孔質基板の骨格部分に水酸化イッテルビウムを浸漬析出させる。この浸漬析出の方法は、１モル／リットルのイッテルビウム塩溶液の中に入れ、ついでニッケル多孔質極板を浸漬し、８０℃の温度雰囲気下で十分乾燥させた後、１モル／リットルの水酸化ナトリウム水溶液中に浸漬し、イッテルビウム塩を水酸化イッテルビウムに転換させ、ついで、充分に水洗を行ないアルカリ溶液を除去、乾燥を経て一連の操作を繰返すことで導電性骨格を被覆する水酸化イッテルビウム層の厚みを制御した。
【００３１】
また、導電性骨格に水酸化イッテルビウム層を備えた本発明の金属多孔質基板を、実施例１と同様、第２工程として熱酸化処理を施す。熱酸化処理条件は、アルカリ雰囲気下の乾燥炉にて９０℃、１０分間、酸化処理を行ない、充分に水洗し、８０℃の温度雰囲気下で充分に乾燥した。
【００３２】
酸化処理後の多孔質基板を用い、その孔部に平均粒径が約１０μｍの球状の水酸化ニッケル粉末を１００ｇと水酸化コバルト粉末を１０ｇを、水で練合し、活物質ペーストとして充填した。電析処理をしなかった金属多孔質基板をＣ０、浸漬析出処理を１回行なった金属多孔質基板をＣ１、浸漬析出処理を３回行なった金属多孔質基板をＣ２、浸漬析出処理を６回行なった金属多孔質基板をＣ３、浸漬析出処理を１０回行なった金属多孔質基板をＣ４とした。（表２）に浸漬析出処理の回数と被覆された酸化イッテルビウム層の厚みの関係を示す。
【００３３】
【表２】

【００３４】
以下、実施例１と同様に定格容量２０００ｍＡｈのＡサイズのニッケル・水素蓄電池を得た。(表３)
に初期活物質利用率と高温（６０℃）０．１Ｃ充電特性の結果を示す
【００３５】
【表３】

【００３６】
実施例１と同様、高温での充電特性は、Ｎｉ金属多孔質基板の骨格表面を被覆している方が、充電効率が高いことがわかる。これは、前述したＮｉ金属多孔質基板の骨格表面の酸素発生を、骨格表面を被覆することで抑制し、水酸化ニッケルからオキシ水酸化ニッケルへの充電反応が充分に行われることによる。
【００３７】
しかし、Ｎｉ金属多孔質基板の骨格表面を被覆している薄層の厚みが、１０００ｎｍ以上になると、Ｎｉ金属多孔質基板の骨格表面と活物質である水酸化ニッケル粉末との導電性が不十分になり、活物質の利用率を低下させてしまう。よって、金属多孔質基板の骨格表面を被覆する薄層の厚みは、１０〜１０００ｎｍにすることが好ましい。
【００３８】
【発明の効果】
以上のように、Ｎｉ金属多孔質基板の孔部に臨んだ導電性骨格の表面に少なくともコバルト、イットリウム、イッテルビウム、ルテチウムの単層あるいは積層の薄層を形成し、前記多孔質基板の孔部に球状の水酸化ニッケル粉末からなる活物質を充填したアルカリ蓄電池用ニッケル極板を用いた、本発明のアルカリ蓄電池は、常温における活物質利用率を低下させることなく、高温雰囲気下における活物質利用率を向上させることができる。
【図面の簡単な説明】
【図１】本発明の実施例１におけるアルカリ蓄電池用極板の模式断面図
【図２】電池充電時の温度と充電効率との関係を示す図
【符号の説明】
１金属多孔質基板
２金属多孔質基板の骨格表面を被覆している薄層
３球状水酸化ニッケルからなる活物質[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a nickel electrode plate for an alkaline storage battery such as a nickel / cadmium storage battery or a nickel / hydrogen storage battery, and an alkaline storage battery using the same.
[0002]
[Prior art]
In recent years, with the spread of communication devices and the like, secondary batteries have been strongly desired to have a high capacity as a power source. The response to the increase in capacity has been achieved by increasing the capacity of the positive and negative electrodes themselves and reducing the thickness of the separator. In particular, since nickel / hydrogen storage batteries are designed according to positive electrode regulations, it has been an urgent task to increase the capacity of the positive electrode plate.
[0003]
The nickel electrode plate used as the positive electrode plate for alkaline storage battery will be described below.
[0004]
Conventionally, as a positive electrode plate for an alkaline storage battery, a nickel sintered solution such as an aqueous nickel nitrate solution is impregnated on a porous sintered substrate of nickel having a porosity of about 80% obtained by sintering nickel powder, and then this is alkaline. There is a sintered electrode plate that is produced by immersing it in an aqueous solution, etc. to produce alkali hydroxide active material in the holes of the substrate. In the case of a sintered substrate, it is usually difficult to improve the porosity. Therefore, the amount of nickel hydroxide to be filled cannot be increased easily, and is not suitable for increasing the capacity of the electrode plate. .
[0005]
As for the non-sintered positive electrode, for example, Japanese Laid-Open Patent Application No. 60-131765 proposes filling spherical nickel hydroxide into the holes of a sponge substrate. According to this, it becomes possible to fill the substrate with the active material uniformly and at a high density, which is effective in increasing the capacity as compared with the sintered substrate.
[0006]
However, the size of the hole of the metal porous substrate is about 200 to 500 μm, and since the spherical nickel hydroxide having an average particle size of about 5 μm to 150 μm is filled as the active material, There is a portion with insufficient conductivity between the conductive skeleton constituting the pores facing the portion and the spherical nickel hydroxide.
[0007]
Furthermore, when charging is performed in a high-temperature atmosphere, the oxygen generation potential of the conductive skeleton is lowered, and a sufficient active material utilization rate cannot be obtained.
[0008]
The present invention solves such problems, and an object thereof is to provide an alkaline storage battery capable of improving the active material utilization rate in a high-temperature atmosphere without reducing the active material utilization rate at room temperature. To do.
[0009]
[Means for Solving the Problems]
To achieve the above object, the present invention forms at least a single layer or a thin layer of cobalt, yttrium, ytterbium, and lutetium on the surface of the conductive skeleton facing the pores of the metal porous substrate, It is the nickel electrode plate for alkaline storage batteries which filled the hole of the board | substrate with the active material which consists of spherical nickel hydroxide.
[0010]
Thus, the active material utilization rate in a high temperature atmosphere is improved without reducing the active material utilization rate at normal temperature.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, cobalt, yttrium and ytterbium having a thickness of at least 10 nm to 1000 nm on the surface of the conductive skeleton facing the pores of the Ni metal porous substrate having a three-dimensionally continuous space. In addition, an alkaline storage battery having an improved active material filling density and capacity density by forming a single or laminated oxide layer of lutetium and filling the hole with an active material made of spherical nickel hydroxide. A nickel electrode plate is obtained.
[0012]

Claim

1 defines the thickness of the thin layer covering the surface of the Ni metal porous substrate having a three-dimensionally continuous space, and the layer thinner than 10 nm sufficiently covers the surface of the conductive skeleton. In addition, in a layer thicker than 1000 nm, the conductivity between the conductive skeleton and the active material is lowered. Therefore, the thickness of the thin layer on the surface of the conductive skeleton is preferably 10 nm to 1000 nm.
[0013]
The invention according to claim 2 defines the particle diameter of the spherical nickel hydroxide powder, and the filling density and capacity density are compared with the conventional product by filling with a combination of this and a conductive agent such as a cobalt compound. And an improved nickel electrode is obtained.
[0014]
According to a third aspect of the present invention, at least a single layer or stacked oxide layer of cobalt, yttrium, ytterbium, and lutetium is formed on the surface of a Ni metal porous substrate having a three-dimensionally continuous space, and the pores Is an alkaline storage battery consisting of a positive electrode filled with spherical nickel hydroxide powder and a negative electrode and a separator, suppressing the decrease in oxygen generation potential on the surface of the conductive skeleton and reducing the active material utilization rate at room temperature Without making it possible, the utilization factor of the active material in a high temperature atmosphere can be improved.
[0015]
The nickel electrode plate of the present invention comprises a step of immersing and drying a Ni metal porous substrate in at least one of a cobalt salt solution, an yttrium salt solution, an ytterbium salt solution and a lutetium salt solution, followed by an alkaline aqueous solution. Nickel having a step of performing a series of operations to be converted into hydroxides by immersing in a substrate at least once, and performing a heat treatment in an oxygen atmosphere, and a step of filling the substrate with an active material mainly composed of nickel hydroxide powder It can be produced by a method for producing an electrode plate . A single layer or stacked oxide layer of cobalt, yttrium, ytterbium, and lutetium can be formed on the skeleton surface of the substrate at a low cost by a simple operation.
[0016]
In the nickel electrode plate of the present invention, the thin layer on the surface of the conductive skeleton facing the hole of the Ni metal porous substrate has at least one of a cobalt salt solution, an yttrium salt solution, an ytterbium salt solution, and a lutetium salt solution. Using a seed, and performing an operation of precipitating as a hydroxide on the skeleton surface of the substrate by electrolytic deposition at least once, followed by a heat treatment in an oxygen atmosphere, and mainly using nickel hydroxide powder on the substrate It can also be produced by a method of manufacturing a nickel electrode plate having a step of filling the active material . Since a single layer or stacked oxide layer of cobalt, yttrium, ytterbium, and lutetium is electrolytically deposited on the skeleton surface of the substrate, the skeleton can be uniformly covered.
[0017]
【Example】
Examples of the present invention will be described below.
[0018]
Example 1
First, as a first step, yttrium hydroxide is electrolytically deposited on the skeleton portion 1 of the metal porous substrate. In this electrolytic deposition method, a 1 mol / liter yttrium salt solution is placed in an electrodeposition tank, and then a nickel porous electrode plate is immersed, the porous electrode plate is used as a cathode, and the counter electrode is used as a nickel plate. A polyester net to prevent these contacts is placed between the two poles. The electrodeposition conditions were a current density of 5 mA / cm ² and an electrodeposition time of 200 (seconds). The amount of electrodeposition at this time was calculated | required from the electricity supply amount as electrodeposition efficiency 100%.
[0019]
The metal porous substrate of the present invention provided with the yttrium hydroxide layer 2 on the conductive skeleton is subjected to thermal oxidation treatment as the second step. The thermal oxidation treatment conditions were as follows: oxidation treatment was performed at 90 ° C. for 10 minutes in a drying furnace under an alkaline atmosphere, washed with water, and dried.
[0020]
Using the porous substrate after the oxidation treatment, 100 g of spherical nickel hydroxide powder having an average particle diameter of about 10 μm and 10 g of cobalt hydroxide powder were kneaded with water and filled as an active material paste. .
[0021]
The electrode plate of the present invention filled with an active material paste was used as a comparative example, using a metal porous substrate subjected to electrodeposition treatment as described above and coated with a conductive skeleton of yttrium oxide. B1 was used as the metal porous substrate, and the metal porous substrate without electrodeposition treatment was used. The nickel electrode plate was added to the active material paste by adding yttrium oxide in the same amount as the electrodeposited amount, and B2 and yttrium were added internally. A nickel electrode plate obtained by filling an active material paste using nickel hydroxide powder in a metal porous substrate without electrodeposition was designated as B3.
[0022]
A schematic cross-sectional view of the electrode plate A of the present invention is shown in FIG.
[0023]
The filled electrode plate was pressed to a predetermined thickness and cut for a predetermined battery size, for example, A size.
[0024]
For the negative electrode plate, a paste mainly composed of hydrogen storage alloy powder was applied to both sides of the punching metal substrate, pressed to a predetermined thickness, and cut into a predetermined dimension.
[0025]
Each of the positive electrode plates A, B1, B2 and B3 thus obtained and the negative electrode plate interposing a polypropylene non-woven fabric separator, the battery group configured in a spiral shape was housed in an outer can. As the alkaline electrolyte, an alkaline electrolyte in which 1 mol / l lithium hydroxide is mixed with 7.5 mol / l potassium hydroxide, which is conventionally used in nickel-hydrogen storage batteries for communication devices and computers, is used. A predetermined amount of liquid was injected to assemble an FA size battery with a rated capacity of 2000 mAh. This was left for 12 hours at an ambient temperature of 25 ° C., and then charged and discharged for the first time (charging was performed at a current value of 0.1 C for 15 hours, and discharging was performed at a current value of 0.2 C for 4 hours). B2 and B3 were obtained. The contents of the positive electrode plate are shown in (Table 1).
[0026]
[Table 1]

[0027]
Each of the batteries A, B1, B2 and B3 produced above was charged for 1.5 hours at a current value of 1.0 C, and discharged until the terminal voltage of the battery reached 1.0 V at a current value of 1.0 discharge. And the result of having tested the charging / discharging temperature characteristic to 25 to 60 degreeC is shown in FIG.
[0028]
It can be seen that the battery using the electrode plate A of the present invention has improved charging temperature characteristics as compared with the batteries B1 to B3 of the comparative example. This is because the yttrium oxide covering the generation of oxygen on the skeleton surface of the Ni metal porous substrate suppresses the charge reaction of nickel hydroxide to nickel oxyhydroxide.
[0029]
Further, in Example 1, the skeleton surface of the metal porous substrate was coated with yttrium oxide, but the same effect can be obtained even when it is performed with cobalt oxide, ytterbium oxide, or lutetium oxide.
[0030]
(Example 2)
First, as a first step, ytterbium hydroxide is immersed and deposited on the skeleton portion of the metal porous substrate. In this immersion precipitation method, a nickel porous electrode plate is immersed in a 1 mol / liter ytterbium salt solution, sufficiently dried in a temperature atmosphere at 80 ° C., and then 1 mol / liter hydroxylated. The ytterbium hydroxide layer covering the conductive skeleton is immersed in an aqueous sodium solution to convert the ytterbium salt to ytterbium hydroxide, and then washed thoroughly with water to remove the alkaline solution, followed by drying and a series of operations. The thickness was controlled.
[0031]
Further, the metal porous substrate of the present invention provided with a ytterbium hydroxide layer on the conductive skeleton is subjected to a thermal oxidation treatment as the second step in the same manner as in Example 1. The thermal oxidation treatment conditions were as follows: oxidation treatment was performed at 90 ° C. for 10 minutes in a drying furnace under an alkaline atmosphere, washed thoroughly with water, and sufficiently dried under a temperature atmosphere of 80 ° C.
[0032]
Using the porous substrate after the oxidation treatment, 100 g of spherical nickel hydroxide powder having an average particle diameter of about 10 μm and 10 g of cobalt hydroxide powder were kneaded with water and filled as an active material paste. . The metal porous substrate that was not subjected to the electrodeposition treatment was C0, the metal porous substrate that was subjected to the immersion precipitation treatment once was C1, the metal porous substrate that was subjected to the immersion precipitation treatment three times was C2, and the immersion precipitation treatment was six times. The metal porous substrate thus obtained was designated as C3, and the metal porous substrate subjected to the immersion precipitation treatment 10 times was designated as C4. Table 2 shows the relationship between the number of immersion precipitation treatments and the thickness of the coated ytterbium oxide layer.
[0033]
[Table 2]

[0034]
Thereafter, similarly to Example 1, an A size nickel-hydrogen storage battery having a rated capacity of 2000 mAh was obtained. (Table 3)
Shows the results of initial active material utilization and high temperature (60 ° C.) 0.1 C charging characteristics.
[Table 3]

[0036]
As in Example 1, it can be seen that the charging characteristics at high temperature are higher when the skeleton surface of the Ni metal porous substrate is coated. This is because the generation of oxygen on the skeleton surface of the Ni metal porous substrate described above is suppressed by coating the skeleton surface, and the charging reaction from nickel hydroxide to nickel oxyhydroxide is sufficiently performed.
[0037]
However, when the thickness of the thin layer covering the skeleton surface of the Ni metal porous substrate is 1000 nm or more, the conductivity between the skeleton surface of the Ni metal porous substrate and the nickel hydroxide powder as the active material is insufficient. As a result, the utilization factor of the active material is reduced. Therefore, the thickness of the thin layer covering the skeleton surface of the metal porous substrate is preferably 10 to 1000 nm.
[0038]
【The invention's effect】
As described above, at least a single layer or a thin layer of cobalt, yttrium, ytterbium, and lutetium is formed on the surface of the conductive skeleton facing the pores of the Ni metal porous substrate, and the pores of the porous substrate are formed. The alkaline storage battery of the present invention, which uses a nickel electrode plate for alkaline storage batteries filled with an active material made of spherical nickel hydroxide powder, has an active material utilization rate in a high-temperature atmosphere without reducing the active material utilization rate at room temperature. Can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an alkaline storage battery electrode in Example 1 of the present invention. FIG. 2 is a diagram showing a relationship between temperature and charging efficiency during battery charging.
DESCRIPTION OF SYMBOLS 1 Metal porous substrate 2 Thin layer which coat | covers the frame | skeleton surface of a metal porous substrate 3 Active material which consists of spherical nickel hydroxide

Claims

A nickel electrode plate in which pores of a Ni metal porous substrate having a three-dimensionally connected space are filled with an active material mainly composed of nickel hydroxide powder, wherein the substrate has a thickness of at least 10 nm to 1000 nm. A nickel electrode plate on which a single layer or a multilayer oxide layer of cobalt, yttrium, ytterbium, and lutetium is formed.

Water nickel oxide powder, nickel plate of claim 1, wherein the particle size of 5Myuemu～150myuemu.

A cobalt or yttrium, ytterbium or lutetium single layer or stacked oxide layer having a thickness of at least 10 nm to 1000 nm is formed on the skeleton surface of a Ni metal porous substrate having a three-dimensionally continuous space, and the pores of the substrate An alkaline storage battery comprising a positive electrode having a portion filled with an active material made of nickel hydroxide powder, a negative electrode, a separator, and an alkaline electrolyte.