JPH10270024A5

JPH10270024A5 -

Info

Publication number: JPH10270024A5
Application number: JP1997093005A
Authority: JP
Filing date: 1997-03-26
Publication date: 2005-02-17

Description

【０００９】
【課題を解決するための手段】
本発明は、このような欠点を除去して非水電解質電池用正極板のエネルギー密度を向上させるためになされた製造方法であり、球状又は／および球状に近似した形状であって、その表面が曲面を主体として構成された粒子を主として含有する水酸化ニッケルを化学的もしくは電気化学的に酸化する工程を備えたことを特徴とし、さらに、コバルトを含む水酸化ニッケルを用いることを特徴とするものである。[0009]
[Means for solving the problem]
The present invention provides a manufacturing method that has been made to eliminate such drawbacks and improve the energy density of positive electrode plates for nonaqueous electrolyte batteries, and is characterized by comprising a step of chemically or electrochemically oxidizing nickel hydroxide that mainly contains particles that are spherical or/and approximately spherical in shape and whose surfaces are mainly composed of curved surfaces , and further characterized by using nickel hydroxide that contains cobalt.

【００１０】
なお、水酸化ニッケルの平均粒子径が１〜１００μｍであり、水酸化ニッケルが三次元的構造を有する導電性多孔体に保持させることが好ましい。 [0010]
It is preferable that the nickel hydroxide has an average particle size of 1 to 100 μm, and that the nickel hydroxide is held in a conductive porous body having a three-dimensional structure.

【００１３】
さらに、水酸化ニッケルの平均粒子径を１〜１００μｍの範囲で選択することにより高率放電特性とエネルギー密度とのバランスに優れた極板を得ることができる。[0013]
Furthermore, by selecting the average particle size of nickel hydroxide within the range of 1 to 100 μm , an electrode plate having an excellent balance between high rate discharge characteristics and energy density can be obtained.

【００２１】
そして、球状及び球状に近似した粒子形状を有する水酸化ニッケル粉末、導電材としてアセチレンブラック５ｗｔ％、結着剤として二フッ化ポリビニリデン５ｗｔ％とＮ−メチル−２−ピロリドン３ｗｔ％との混合液とをドライルームで混合して、ペースト状にしたのち、集電体のステンレス箔に塗布・乾燥をして本発明による正極板Ａ’を得た。[0021]
Then, nickel hydroxide powder having spherical or nearly spherical particle shapes, 5 wt % acetylene black as a conductive material, and a mixed solution of 5 wt % polyvinylidene difluoride and 3 wt % N-methyl-2-pyrrolidone as a binder were mixed in a dry room to form a paste, which was then applied to a stainless steel foil current collector and dried to obtain a positive electrode plate A' according to the present invention.

【００２２】
加えて、通常用いられる水酸化ニッケル粉末、導電材としてアセチレンブラック５ｗｔ％、結着剤として二フッ化ポリビニリデン５ｗｔ％とＮ−メチル−２−ピロリドン３ｗｔ％との混合液とをドライルームで混合して、ペースト状にしたのち、集電体のステンレス箔に塗布・乾燥をして従来の正極板Ｂ’を製作した。[0022]
In addition, commonly used nickel hydroxide powder, 5 wt% acetylene black as a conductive material, and a mixture of 5 wt% polyvinylidene difluoride and 3 wt% N-methyl-2-pyrrolidone as a binder were mixed in a dry room to form a paste, which was then applied to a stainless steel foil current collector and dried to produce a conventional positive electrode plate B'.

【００３０】
すなわち、平均粒子径が１００μｍ程度の水酸化ニッケル粉末を用いた場合には、粒子が大きいために多孔体中にペーストが充分に充填できない。従来の水酸化ニッケル粉末を用いた場合には、粒子径が７０μｍ程度に小さくなると、ペーストが充填しやすくなるためエネルギー密度が若干向上するが、粒子径がさらに小さくなると粒子の比表面積の増大によって練液量が増加し、エネルギー密度が著しく低下する。[0030]
That is, when nickel hydroxide powder having an average particle size of about 100 μm is used, the paste cannot be sufficiently filled into the porous body due to the large size of the particles. When conventional nickel hydroxide powder is used, when the particle size is reduced to about 70 μm , the paste can be easily filled, and the energy density is slightly improved. However, when the particle size is further reduced, the specific surface area of the particles increases, which increases the amount of kneading liquid, and the energy density is significantly reduced.

【００３１】
一方、本発明のように球状及び球状に近い形状の粒子形状を有する水酸化ニッケル粉末を用いた場合には、粒子径が２５〜７０μｍ程度に小さくなってもその比表面積が極めて小さいため、粒子径が小さくなることによって練液量の増加に起因する活物質粒子の含有率低下よりも、ペーストが充填しやすくなるという効果の方が大きいので、エネルギー密度が向上するものと考えられる。このとき、Ａで用いたスポンジ状ニッケル多孔体のような、三次元的構造を有する導電性多孔体に水酸化ニッケル粉末を保持させると、ペーストを集電体上に塗布してなるＡ’にくらべてさらにエネルギー密度が向上していることが確認される。[0031]
On the other hand, when nickel hydroxide powder having a spherical or nearly spherical particle shape is used as in the present invention, even if the particle diameter is reduced to about 25 to 70 μm , the specific surface area is extremely small, so the effect of making the paste easier to fill is greater than the decrease in the content of active material particles due to the increase in the amount of kneading liquid caused by the smaller particle diameter, and it is thought that this is why the energy density is improved.In this case, when the nickel hydroxide powder is held in a conductive porous body having a three-dimensional structure, such as the sponge-like nickel porous body used in A, it has been confirmed that the energy density is further improved compared to A', in which the paste is applied to a current collector.

【００３２】
次に、平均粒子径７０μｍの水酸化ニッケル粒子を用いた正極板Ａ、Ａ’およびＢ’について、放電電流密度を変えた場合の極板のエネルギー密度の変化を図３に示す。[0032]
Next, FIG. 3 shows the change in the energy density of the positive electrode plates A, A' and B' using nickel hydroxide particles with an average particle size of 70 μm when the discharge current density is changed.

Claims

A method for manufacturing a positive electrode plate for a non-aqueous electrolyte battery, comprising a step of chemically or electrochemically oxidizing nickel hydroxide that mainly contains particles that are spherical or/and approximately spherical in shape and whose surfaces are mainly composed of curved surfaces.

2. The method for producing a positive electrode plate for a non-aqueous electrolyte battery according to claim 1, wherein nickel hydroxide containing cobalt is used.