JP6179374B2 - Cobalt hydroxide particles, method for producing the same, and method for producing positive electrode active material for non-aqueous electrolyte secondary battery - Google Patents

Cobalt hydroxide particles, method for producing the same, and method for producing positive electrode active material for non-aqueous electrolyte secondary battery Download PDF

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JP6179374B2
JP6179374B2 JP2013245186A JP2013245186A JP6179374B2 JP 6179374 B2 JP6179374 B2 JP 6179374B2 JP 2013245186 A JP2013245186 A JP 2013245186A JP 2013245186 A JP2013245186 A JP 2013245186A JP 6179374 B2 JP6179374 B2 JP 6179374B2
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cobalt hydroxide
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一臣 漁師
一臣 漁師
充 山内
充 山内
牛尾　亮三
亮三 牛尾
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Sumitomo Metal Mining Co Ltd
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本発明は、リチウムイオン二次電池などの非水系電解質二次電池で用いられる正極活物質、具体的には、該正極活物質として用いられるリチウムコバルト複合酸化物の製造方法、ならびに、リチウムコバルト複合酸化物の前駆体として用いる水酸化コバルト粒子およびその製造方法に関する。 The present invention relates to a positive electrode active material used in a non-aqueous electrolyte secondary battery such as a lithium ion secondary battery, specifically, a method for producing a lithium cobalt composite oxide used as the positive electrode active material, and a lithium cobalt composite. The present invention relates to cobalt hydroxide particles used as an oxide precursor and a method for producing the same.

近年、携帯電話やノート型パソコンなどの携帯機器の普及にともない、高いエネルギー密度を有する小型で軽量な二次電池の開発が強く望まれている。該二次電池として、リチウム、リチウム合金、金属酸化物、カーボンなどを負極として用いるリチウムイオン二次電池があり、研究開発が盛んに行われている。   In recent years, with the widespread use of portable devices such as mobile phones and notebook computers, development of small and lightweight secondary batteries having high energy density is strongly desired. As the secondary battery, there is a lithium ion secondary battery using lithium, a lithium alloy, a metal oxide, carbon, or the like as a negative electrode, and research and development are actively performed.

リチウム金属複合酸化物、特に合成が比較的容易なリチウムコバルト複合酸化物を正極活物質に用いたリチウムイオン二次電池は、４Ｖ級の高い電圧が得られるため、高エネルギー密度を有する二次電池として期待され、実用化が進んでいる。リチウムコバルト複合酸化物は、リチウムニッケル複合酸化物、リチウムニッケルコバルトマンガン複合酸化物などの他の正極活物質と比較して充填性が高いという特徴がある。   A lithium ion secondary battery using a lithium metal composite oxide, particularly a lithium cobalt composite oxide that is relatively easy to synthesize as a positive electrode active material, provides a high voltage of 4V, and therefore has a high energy density. Is expected to be put to practical use. The lithium cobalt composite oxide is characterized by high filling properties compared to other positive electrode active materials such as lithium nickel composite oxide and lithium nickel cobalt manganese composite oxide.

一般的に、正極活物質の充填性の向上には、正極活物質となる粒子の球状性を向上させること、粒子自体の密度を向上させること、粒度分布に適正な幅を持たせること、粒径を適正な範囲で大きくすることが有効である。また、正極活物質の充填性は、正極活物質の前駆体として用いられる水酸化コバルトなどの水酸化物や、酸化コバルトなどの酸化物の充填性をそのまま反映する傾向がある。   In general, to improve the filling property of the positive electrode active material, it is necessary to improve the sphericity of the particles serving as the positive electrode active material, to improve the density of the particles themselves, to give a proper width to the particle size distribution, It is effective to increase the diameter within an appropriate range. The filling property of the positive electrode active material tends to reflect the filling property of hydroxide such as cobalt hydroxide used as a precursor of the positive electrode active material or oxide such as cobalt oxide.

上述の水酸化物や酸化物の粉体特性に関して、例えば、特許文献１には、酸化コバルトの粒形がほぼ球形であり、５０％粒径（Ｄ５０）が１．５〜１５μｍ、Ｄ９０がＤ５０の２倍以下、Ｄ１０がＤ５０の１／５以上であり、かつ比表面積が２〜１５ｍ２／ｇである酸化コバルト粉が開示されている。また、特許文献２には、タッピング密度が２．３ｇ／ｃｍ３以上であり、かつほぼ球状であって、さらに平均粒径が５μｍ〜１５μｍであるオキシ水酸化コバルト粒子が開示されている。さらに、特許文献３には、約０．５乃至２．２ｇ／ｃｍ３の密度、約１μｍを超える、典型的には約１乃至２０μｍの粒径、および約０．５乃至２０ｍ２／ｇの比表面積を有する水酸化コバルトまたはコバルトと他の金属から形成される合金の水酸化物が開示されている。 Regarding the powder characteristics of the hydroxides and oxides described above, for example, in Patent Document 1, the particle shape of cobalt oxide is almost spherical, the 50% particle size (D50) is 1.5 to 15 μm, and D90 is D50. The cobalt oxide powder whose D10 is 1/5 or more of D50 and whose specific surface area is 2-15 m < 2 > / g is disclosed. Patent Document 2 discloses cobalt oxyhydroxide particles having a tapping density of 2.3 g / cm 3 or more, a substantially spherical shape, and an average particle size of 5 μm to 15 μm. In addition, US Pat. No. 6,057,059 has a density of about 0.5 to 2.2 g / cm 3 , a particle size of greater than about 1 μm, typically about 1 to 20 μm, and about 0.5 to 20 m 2 / g A hydroxide of cobalt hydroxide having a specific surface area or an alloy formed from cobalt and other metals is disclosed.

しかしながら、特許文献１〜３に記載の水酸化物や酸化物は、粒径が十分に大きなものとは言えず、得られるリチウムコバルト複合酸化物の充填性が十分なものとなるとは言いがたい。   However, the hydroxides and oxides described in Patent Documents 1 to 3 cannot be said to have a sufficiently large particle size, and it is difficult to say that the resulting lithium cobalt composite oxide has sufficient filling properties. .

一方、特許文献４には、底面の平均粒子径が１〜３０μｍ、かつ平均粒子高さが０．２〜１０μｍであり、六角柱状の水酸化コバルト粒子が開示されているが、このようなアスペクト比の低い形状は、充填性の向上に不利である。   On the other hand, Patent Document 4 discloses hexagonal columnar cobalt hydroxide particles having an average particle diameter of 1 to 30 μm at the bottom and an average particle height of 0.2 to 10 μm. A shape with a low ratio is disadvantageous for improving the filling property.

すなわち、リチウムコバルト複合酸化物の充填性を向上させるためには、該複合酸化物の前駆体である水酸化コバルト粒子の充填性を向上させる必要がある。しかしながら、特許文献１〜４に記載の製法では、十分な充填性を有する水酸化コバルト粒子を得ることができない。そこで、水酸化コバルト粒子の充填性の更なる改善が望まれている。   That is, in order to improve the filling properties of the lithium cobalt composite oxide, it is necessary to improve the filling properties of the cobalt hydroxide particles that are precursors of the composite oxide. However, the manufacturing methods described in Patent Documents 1 to 4 cannot obtain cobalt hydroxide particles having sufficient filling properties. Therefore, further improvement of the packing property of cobalt hydroxide particles is desired.

特開２００１−３５４４２８号公報JP 2001-354428 A 特開２００７−００１８０９号公報JP 2007-001809 A 特表２００３−５０３３００号公報Special table 2003-503300 gazette 特開平１１−２９２５４９号公報JP 11-292549 A

本発明は、上記のような問題点に鑑みてなされたものであり、その目的とするところは、高充填性を有する非水系電解質二次電池の正極活物質用の水酸化コバルト粒子およびその製造方法を提供することにある。   The present invention has been made in view of the above-described problems, and the object of the present invention is to provide cobalt hydroxide particles for a positive electrode active material of a non-aqueous electrolyte secondary battery having high filling properties and the production thereof. It is to provide a method.

また、本発明の他の目的とするところは、高充填性を有する非水系電解質二次電池用の正極活物質およびその製造方法を提供することにある。   Another object of the present invention is to provide a positive electrode active material for a non-aqueous electrolyte secondary battery having high fillability and a method for producing the same.

本発明者は、非水系電解質二次電池用の正極活物質の高充填性を可能とする前駆体に関して鋭意検討した結果、塩素含有コバルト水溶液を原料として反応容器内の雰囲気を制御することにより、高い充填性を有する水酸化コバルト粒子が得られるとの知見を得て、本発明を完成した。   As a result of earnestly examining the precursor that enables high filling property of the positive electrode active material for the non-aqueous electrolyte secondary battery, the present inventor has controlled the atmosphere in the reaction vessel using a chlorine-containing cobalt aqueous solution as a raw material, The present invention was completed by obtaining knowledge that cobalt hydroxide particles having high filling properties can be obtained.

すなわち、本発明の水酸化コバルト粒子は、非水系電解質二次電池の正極活物質用の水酸化コバルト粒子であって、前記水酸化コバルト粒子は、一次粒子が凝集した二次粒子からなり、前記一次粒子は柱状、直方体または立方体の形状を有し、前記一次粒子の平均アスペクト比が０．５以上であり、平均二次粒子径に対する平均一次粒子径の比が１／１０〜１／２であり、平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２である。   That is, the cobalt hydroxide particles of the present invention are cobalt hydroxide particles for a positive electrode active material of a non-aqueous electrolyte secondary battery, and the cobalt hydroxide particles are composed of secondary particles in which primary particles are aggregated, The primary particles have a columnar, rectangular parallelepiped or cubic shape, the average aspect ratio of the primary particles is 0.5 or more, and the ratio of the average primary particle diameter to the average secondary particle diameter is 1/10 to 1/2. The average secondary particle diameter is 20 μm to 50 μm, and the value of (d90−d10) / mv, which is an index indicating the spread of the particle size distribution, is 0.6 to 1.2.

また、本発明の水酸化コバルト粒子の製造方法は、塩素含有コバルト塩水溶液、無機アルカリ水溶液およびアンモニウムイオン含有水溶液を反応容器に供給して得られた反応液を用いて、非水系電解質二次電池の正極活物質用の水酸化コバルト粒子を製造する方法であって、前記反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整し、前記反応液中のアンモニア濃度を５ｇ／Ｌ〜２０ｇ／Ｌに調整し、前記反応容器内を非酸性雰囲気に調整し、前記塩素含有コバルト塩水溶液は、塩素の含有量がコバルトの含有量に対してモル比で０．５〜３である。 The method for producing cobalt hydroxide particles of the present invention is a non-aqueous electrolyte secondary battery using a reaction solution obtained by supplying a chlorine-containing cobalt salt aqueous solution, an inorganic alkali aqueous solution and an ammonium ion-containing aqueous solution to a reaction vessel. In which the pH value of the reaction solution is adjusted to 10.0 to 12.0 on the basis of a liquid temperature of 25 ° C., and the ammonia concentration in the reaction solution is adjusted. The inside of the reaction vessel is adjusted to a non-acidic atmosphere, and the chlorine-containing cobalt salt aqueous solution has a chlorine content in a molar ratio of 0.5 to the cobalt content. 3 .

一方、本発明の正極活物質の製造方法は、水酸化コバルト粒子を用いて非水系電解質二次電池の正極活物質を製造する方法であって、前記水酸化コバルト粒子を酸化雰囲気中で熱処理して酸化コバルト粒子を生成し、該酸化コバルト粒子とリチウム化合物とを混合して焼成してリチウムコバルト複合酸化物を得る。   Meanwhile, the method for producing a positive electrode active material of the present invention is a method for producing a positive electrode active material of a non-aqueous electrolyte secondary battery using cobalt hydroxide particles, wherein the cobalt hydroxide particles are heat-treated in an oxidizing atmosphere. Cobalt oxide particles are produced, and the cobalt oxide particles and the lithium compound are mixed and fired to obtain a lithium cobalt composite oxide.

本発明により、非水系電解質二次電池の正極活物質の前駆体として好適な高充填性を有する水酸化コバルト粒子を提供することができる。また、この水酸化コバルト粒子を原材料として用いた正極活物質は、該水酸化コバルト粒子の性能を引き継いで、高い充填性を有することができ、電池の体積当たりに充填される正極活物質を多くすることができ、高容量化が可能となる。   According to the present invention, cobalt hydroxide particles having high filling properties suitable as a precursor of a positive electrode active material of a nonaqueous electrolyte secondary battery can be provided. In addition, the positive electrode active material using the cobalt hydroxide particles as a raw material can take over the performance of the cobalt hydroxide particles and have high filling properties, and a large amount of the positive electrode active material filled per volume of the battery. The capacity can be increased.

実施例１で作製した水酸化コバルト粒子のＳＥＭ像である。2 is a SEM image of cobalt hydroxide particles produced in Example 1. FIG.

本発明は、非水系電解質二次電池の正極活物質用の水酸化コバルト粒子（以下、「水酸化コバルト粒子」という。）およびその製造方法、非水系電解質二次電池用の正極活物質（以下、「正極活物質」という。）およびその製造方法に関するものである。以下、本発明について詳細に説明する。なお、本発明は、以下の実施の形態に限定されるものではなく、本発明の要旨を逸脱しない範囲で種々の変更が可能である。   The present invention relates to a cobalt hydroxide particle for a positive electrode active material of a non-aqueous electrolyte secondary battery (hereinafter referred to as “cobalt hydroxide particle”) and a method for producing the same, a positive electrode active material for a non-aqueous electrolyte secondary battery (hereinafter referred to as “cobalt hydroxide particle”). , “Positive electrode active material”) and a method for producing the same. Hereinafter, the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.

（１）水酸化コバルト粒子
水酸化コバルト粒子は、一次粒子が凝集した二次粒子から構成されている。一次粒子は、柱状、直方体または立方体の形状を有し、一次粒子の平均アスペクト比が０．５以上であり、平均二次粒子径に対する平均一次粒子径の比が１／１０〜１／２である。また、二次粒子は、平均二次粒子径が２０μｍ〜５０μｍであると共に、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２である。なお、ここでいう「平均一次粒径」とは、一次粒子の平均粒径のことであり、「平均二次粒径」とは、二次粒子の平均粒径のことである。 (1) Cobalt hydroxide particle The cobalt hydroxide particle is comprised from the secondary particle which the primary particle aggregated. The primary particles have a columnar, rectangular parallelepiped or cubic shape, the average aspect ratio of the primary particles is 0.5 or more, and the ratio of the average primary particle diameter to the average secondary particle diameter is 1/10 to 1/2. is there. The secondary particles have an average secondary particle diameter of 20 μm to 50 μm and a value of (d90−d10) / mv, which is an index indicating the spread of the particle size distribution, is 0.6 to 1.2. Here, the “average primary particle size” is the average particle size of the primary particles, and the “average secondary particle size” is the average particle size of the secondary particles.

水酸化コバルト粒子は、平均二次粒子径に対する平均一次粒子径の比（粒径比）が１／１０〜１／２（０．１〜０．５）である。粒径比をこの範囲とすることで、非常に緻密な二次粒子が形成され、後述する水酸化コバルト粒子を用いた非水系電解質二次電池用の正極活物質の緻密性も向上し、充填性が向上する。粒径比が１／１０未満になると、二次粒子内部に空隙が生まれて緻密性が低下し、正極活物質の緻密性も低下するため、この充填性が低下する。一方、粒径比が１／２を超えると、水酸化コバルト粒子の比表面積が小さくなりすぎて後述するリチウム化合物との反応性が低下し、リチウム化合物と水酸化コバルト粒子を混合して熱処理した際に十分に反応せず、正極活物質の電池容量やサイクル特性などが低下する。   The ratio of the average primary particle diameter to the average secondary particle diameter (particle diameter ratio) of the cobalt hydroxide particles is 1/10 to 1/2 (0.1 to 0.5). By setting the particle size ratio within this range, very dense secondary particles are formed, and the denseness of the positive electrode active material for non-aqueous electrolyte secondary batteries using cobalt hydroxide particles described later is also improved. Improves. When the particle size ratio is less than 1/10, voids are created inside the secondary particles, the compactness is lowered, and the denseness of the positive electrode active material is also lowered, so that the filling property is lowered. On the other hand, when the particle size ratio exceeds 1/2, the specific surface area of the cobalt hydroxide particles becomes too small and the reactivity with the lithium compound described later decreases, and the lithium compound and cobalt hydroxide particles are mixed and heat-treated. In this case, the battery does not react sufficiently, and the battery capacity and cycle characteristics of the positive electrode active material decrease.

水酸化コバルト粒子の構成要素の１つである一次粒子は、柱状、直方体または立方体のいずれかの形状を有する。一次粒子がこれらの形状以外になると、水酸化コバルト粒子の緻密性が低下するため、正極活物質の充填性が低下する。なお、柱状の一次粒子における断面形状としては、状況に応じて適宜選択され、特に限定されるものではないが、例えば、略円形、略楕円形、多角形などが挙げられる。   The primary particles that are one of the constituent elements of the cobalt hydroxide particles have a columnar shape, a rectangular parallelepiped shape, or a cubic shape. If the primary particles have a shape other than these, the compactness of the cobalt hydroxide particles decreases, and the filling property of the positive electrode active material decreases. The cross-sectional shape of the columnar primary particles is appropriately selected depending on the situation and is not particularly limited, and examples thereof include a substantially circular shape, a substantially elliptical shape, and a polygonal shape.

一次粒子の平均一次粒子径は、１．０μｍ〜２５μｍ、好ましくは５．０μｍ〜１５μｍである。平均一次粒子径をこの範囲にすることにより、後述する二次粒子の平均二次粒子径を所定の範囲内に収めることができる。水酸化コバルト粒子の平均一次粒子径が１．０μｍ未満になると、二次粒子内部に空隙が生まれて緻密性が低下し、得られる正極活物質の緻密性も低下することがある。一方、平均一次粒子径が２５μｍを超えると、上記粒径比が１／２を超えることがある。   The average primary particle diameter of the primary particles is 1.0 μm to 25 μm, preferably 5.0 μm to 15 μm. By setting the average primary particle diameter within this range, the average secondary particle diameter of the secondary particles described later can be kept within a predetermined range. When the average primary particle diameter of the cobalt hydroxide particles is less than 1.0 μm, voids are generated inside the secondary particles, and the compactness is lowered, and the denseness of the obtained positive electrode active material may be lowered. On the other hand, when the average primary particle size exceeds 25 μm, the particle size ratio may exceed 1/2.

一次粒子のアスペクト比は、０．５以上である。これにより、上述の形状による緻密性の向上効果が十分に得られ、水酸化コバルト粒子の高い緻密性が得られるため、正極活物質の充填性も良好なものとなる。一次粒子のアスペクト比が０．５未満になると、一次粒子が板状となるため、水酸化コバルト粒子の緻密性が低下し、正極活物質の充填性が低下する。   The aspect ratio of the primary particles is 0.5 or more. Thereby, the effect of improving the density due to the above-described shape is sufficiently obtained, and the high density of the cobalt hydroxide particles is obtained, so that the filling property of the positive electrode active material is also good. When the aspect ratio of the primary particles is less than 0.5, the primary particles are plate-like, so that the denseness of the cobalt hydroxide particles is lowered and the filling property of the positive electrode active material is lowered.

水酸化コバルト粒子の構成要素の１つである二次粒子の形状は、略球状であることが、充填性向上に有効であるため好ましい。ここで、略球状とは、球状に加えて外観上の最小径と最大径の比（最小径／最大径）が０．６以上の楕円状、塊状などを含む形状であることを意味する。   The shape of the secondary particles that are one of the constituent elements of the cobalt hydroxide particles is preferably substantially spherical because it is effective for improving the filling property. Here, “substantially spherical” means a shape including an oval shape or a lump shape having a ratio of the minimum diameter to the maximum diameter (minimum diameter / maximum diameter) of 0.6 or more in addition to the spherical shape.

一次粒子の凝集により得られる二次粒子の平均二次粒子径は、２０μｍ〜５０μｍである。平均二次粒子径をこの範囲とすることにより、後述するリチウム化合物と水酸化コバルト粒子との高い反応性を確保しながら、正極活物質の充填性も高いものとすることができる。水酸化コバルト粒子の平均二次粒子径が２０μｍ未満になると、正極活物質の平均粒径も小さくなるため、充填性が低下する。一方、平均二次粒子径が５０μｍを超えると、水酸化コバルト粒子の比表面積が小さくなりすぎるため、リチウム化合物との反応性が低下すると共に、正極活物質の平均粒径も大きくなりすぎるという問題が生じやすくなる。   The average secondary particle diameter of the secondary particles obtained by aggregation of the primary particles is 20 μm to 50 μm. By setting the average secondary particle diameter within this range, the positive electrode active material can be filled well while ensuring high reactivity between the lithium compound and cobalt hydroxide particles described later. When the average secondary particle diameter of the cobalt hydroxide particles is less than 20 μm, the average particle diameter of the positive electrode active material is also reduced, so that the filling property is lowered. On the other hand, when the average secondary particle diameter exceeds 50 μm, the specific surface area of the cobalt hydroxide particles becomes too small, so that the reactivity with the lithium compound is lowered and the average particle diameter of the positive electrode active material is too large. Is likely to occur.

「（ｄ９０−ｄ１０）／ｍｖ」とは、水酸化コバルト粒子の粒度分布の広がりを示す指標である。この値は、０．６〜１．２の範囲内にあることが好ましく、これにより、正極活物質の粒度分布の広がりを適正な範囲とすることができ、高い充填性を持った正極活物質となる。（ｄ９０−ｄ１０）／ｍｖの値が０．６未満になると、正極活物質の粒径の均一性が高くなりすぎて充填性が向上しない。一方、（ｄ９０−ｄ１０）／ｍｖの値が１．２を超えると、得られる正極活物質の微細粒子の増加によるサイクル特性の悪化や、粗大粒子増加による非水系電解質二次電池内の短絡という問題を生じる原因となる。   “(D90−d10) / mv” is an index indicating the spread of the particle size distribution of the cobalt hydroxide particles. This value is preferably in the range of 0.6 to 1.2. Thereby, the spread of the particle size distribution of the positive electrode active material can be within an appropriate range, and the positive electrode active material having high filling properties It becomes. When the value of (d90−d10) / mv is less than 0.6, the uniformity of the particle size of the positive electrode active material becomes too high and the filling property is not improved. On the other hand, when the value of (d90-d10) / mv exceeds 1.2, the cycle characteristics are deteriorated due to the increase in fine particles of the obtained positive electrode active material, and the short circuit in the nonaqueous electrolyte secondary battery due to the increase in coarse particles. Cause problems.

水酸化コバルト粒子の組成としては、Ｃｏ（ＯＨ）２で表される２価の水酸化コバルトが好ましく、充填性が向上するモフォロジーの水酸化コバルト粒子となるように、容易に制御することができる。また、水酸化コバルト粒子は、後述する正極活物質の特性を改善するため、通常添加される元素を含んでもよい。一方、Ｃｏ（ＯＨ）３やＣｏＯＯＨといった３価のコバルト塩では、高充填性のモフォロジーの水酸化コバルト粒子となるように制御することが困難であり、好ましくない。なお、ここでいう「モフォロジー」とは、粒子の外形、平均アスペクト比、平均粒径、粒径比、粒度分布の広がりを示す指標、結晶構造、タップ密度などの粒子の形態、構造に関わる特性である。 The composition of the cobalt hydroxide particles is preferably divalent cobalt hydroxide represented by Co (OH) 2 , and can be easily controlled so as to obtain a morphological cobalt hydroxide particle with improved filling properties. . Further, the cobalt hydroxide particles may contain an element that is usually added in order to improve the characteristics of the positive electrode active material described later. On the other hand, trivalent cobalt salts such as Co (OH) 3 and CoOOH are not preferable because they are difficult to control so as to be highly packed morphological cobalt hydroxide particles. “Morphology” as used herein refers to particle shape and structure-related characteristics such as particle shape, average aspect ratio, average particle size, particle size ratio, index indicating the spread of particle size distribution, crystal structure, tap density, etc. It is.

また、水酸化コバルト粒子は、タップ密度が２ｇ／ｃｍ３〜３ｇ／ｃｍ３であることが好ましい。このような充填性の高い水酸化コバルト粒子を原料とすることで、得られる正極活物質の充填性もより高いものとなり、該正極活物質を用いて形成された電極もより高い充填密度を持つため、好ましい。 Also, the cobalt particles hydroxide is preferably tap density of 2g / cm 3 ~3g / cm 3 . By using such cobalt hydroxide particles having a high filling property, the filling property of the obtained positive electrode active material becomes higher, and the electrode formed using the positive electrode active material also has a higher filling density. Therefore, it is preferable.

したがって、水酸化コバルト粒子は、一次粒子が凝集した二次粒子からなり、一次粒子は柱状、直方体または立方体の形状を有し、一次粒子の平均アスペクト比が０．５以上であり、平均二次粒子径に対する平均一次粒子径の比が１／１０〜１／２であり、平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２である。このような水酸化コバルト粒子によれば、従来の水酸化コバルト粒子と比較して充填性を大幅に向上させることができるので、非水系電解質二次電池用の正極活物質の前駆体として極めて有用である。   Accordingly, the cobalt hydroxide particles are composed of secondary particles in which primary particles are aggregated, and the primary particles have a columnar shape, a rectangular parallelepiped shape, or a cubic shape, and the average aspect ratio of the primary particles is 0.5 or more. The ratio of the average primary particle diameter to the particle diameter is 1/10 to 1/2, the average secondary particle diameter is 20 μm to 50 μm, and the value of (d90−d10) / mv is an index indicating the spread of the particle size distribution Is 0.6 to 1.2. According to such cobalt hydroxide particles, the filling property can be greatly improved as compared with the conventional cobalt hydroxide particles, so it is extremely useful as a precursor of a positive electrode active material for a non-aqueous electrolyte secondary battery. It is.

（２）水酸化コバルト粒子の製造方法
水酸化コバルト粒子の製造方法では、塩素含有コバルト塩水溶液、無機アルカリ水溶液およびアンモニウムイオン含有水溶液を反応容器に供給して得られた反応液を用い、反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整し、反応液中のアンモニア濃度を５ｇ／Ｌ〜２０ｇ／Ｌに調整し、反応容器内を非酸性雰囲気に調整して水酸化コバルト粒子を得る。 (2) Cobalt hydroxide particle production method In the cobalt hydroxide particle production method, a reaction solution obtained by supplying a chlorine-containing cobalt salt aqueous solution, an inorganic alkali aqueous solution and an ammonium ion-containing aqueous solution to a reaction vessel is used. The pH value of the reaction liquid was adjusted to 10.0 to 12.0 based on a liquid temperature of 25 ° C., the ammonia concentration in the reaction liquid was adjusted to 5 g / L to 20 g / L, and the inside of the reaction vessel was adjusted to a non-acidic atmosphere Cobalt hydroxide particles are obtained.

水酸化コバルト粒子の製造方法においては、塩素含有コバルト塩水溶液を使用することで、反応液中に存在する塩素により、反応液中で生成される一次粒子のアスペクト比の低下が抑制され、一次粒子の形状を柱状、直方体または立方体に制御することが可能となる。   In the method for producing cobalt hydroxide particles, the use of a chlorine-containing cobalt salt aqueous solution suppresses a decrease in the aspect ratio of the primary particles produced in the reaction solution due to the chlorine present in the reaction solution. Can be controlled to be columnar, rectangular parallelepiped or cubic.

水酸化コバルト粒子の原材料の１つである塩素含有コバルト塩水溶液は、塩素の含有量がコバルトの含有量に対してモル比で０．１〜３であることが好ましく、０．５〜３であることがより好ましい。塩素の含有量をモル比で０．１〜３とすることで、水酸化コバルト粒子の緻密性をより向上させることができる。モル比が１未満になると、一次粒子のアスペクト比の低下を抑制する効果が十分に得られず、緻密性が低下することがある。一方、モル比が３を超えると、二価のコバルトイオンに対して大過剰な塩素が存在することになり、中和に必要な無機アルカリが多くなるため、水酸化コバルト粒子に無機アルカリが過剰に残留することがある。なお、塩素含有コバルト塩水溶液として、塩化コバルトの水溶液の他、コバルトやコバルト化合物を塩酸のような塩素を含む酸に溶解させたものを用いることができる。また、塩素含有コバルト塩水溶液に塩酸などを添加することにより、塩素の含有量を調整してもよい。   The chlorine-containing cobalt salt aqueous solution that is one of the raw materials of the cobalt hydroxide particles preferably has a chlorine content of 0.1 to 3 in terms of molar ratio to the cobalt content, and 0.5 to 3 More preferably. By setting the content of chlorine to a molar ratio of 0.1 to 3, the denseness of the cobalt hydroxide particles can be further improved. When the molar ratio is less than 1, the effect of suppressing the reduction in the aspect ratio of the primary particles cannot be sufficiently obtained, and the denseness may be lowered. On the other hand, when the molar ratio exceeds 3, a large excess of chlorine is present with respect to the divalent cobalt ion, and the amount of inorganic alkali necessary for neutralization increases. May remain. In addition, as a chlorine containing cobalt salt aqueous solution, what dissolved cobalt and the cobalt compound in the acid containing chlorine like hydrochloric acid besides the aqueous solution of cobalt chloride can be used. Moreover, you may adjust content of chlorine by adding hydrochloric acid etc. to chlorine containing cobalt salt aqueous solution.

また、塩素含有コバルト塩水溶液の濃度は、コバルトとして１ｍｏｌ／Ｌ〜２．６ｍｏｌ／Ｌとすることが好ましく、さらには１．５ｍｏｌ／Ｌ〜２．２ｍｏｌ／Ｌとすることが好ましい。塩素含有コバルト塩水溶液の濃度が１ｍｏｌ／Ｌ未満では、反応容器当たりの晶析物量が少なくなるために生産性が低下して好ましくない。一方、塩素含有コバルト塩水溶液の塩濃度が２．６ｍｏｌ／Ｌを超えると、常温での飽和濃度を超えるため、結晶が再析出して設備の配管を詰まらせるなどの危険がある。   The concentration of the chlorine-containing cobalt salt aqueous solution is preferably 1 mol / L to 2.6 mol / L as cobalt, and more preferably 1.5 mol / L to 2.2 mol / L. If the concentration of the chlorine-containing cobalt salt aqueous solution is less than 1 mol / L, the amount of crystallized material per reaction vessel is decreased, which is not preferable because productivity decreases. On the other hand, when the salt concentration of the chlorine-containing cobalt salt aqueous solution exceeds 2.6 mol / L, the saturation concentration at room temperature is exceeded, so there is a risk that crystals re-deposit and clog the equipment piping.

水酸化コバルト粒子の原材料の１つである無機アルカリ水溶液としては、反応液のｐＨ値が、所定の数値となるように制御できれば特に限定されず、例えば、水酸化ナトリウム、水酸化カリウムなどのアルカリ金属水酸化物水溶液などを適宜使用することができる。水酸化コバルト粒子の製造方法においては、反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整する。ｐＨ値が１０．０未満になると、一次粒子の成長が相対的に進むため、狙いとするモフォロジーに水酸化コバルト粒子を制御することが困難となる。一方、ｐＨ値が１２．０を超えると、水酸化コバルト粒子の形状が板状になりやすくなり、緻密性が低下する。   The inorganic aqueous alkali solution that is one of the raw materials for the cobalt hydroxide particles is not particularly limited as long as the pH value of the reaction solution can be controlled to a predetermined value. For example, an alkali such as sodium hydroxide or potassium hydroxide can be used. Metal hydroxide aqueous solution etc. can be used suitably. In the method for producing cobalt hydroxide particles, the pH value of the reaction solution is adjusted to 10.0 to 12.0 on the basis of the liquid temperature of 25 ° C. When the pH value is less than 10.0, the primary particles grow relatively, so that it becomes difficult to control the cobalt hydroxide particles to have a targeted morphology. On the other hand, when the pH value exceeds 12.0, the shape of the cobalt hydroxide particles tends to be plate-like and the compactness is lowered.

水酸化コバルト粒子の原材料の１つであるアンモニウムイオン含有水溶液としては、反応液のアンモニア濃度が、所定の濃度となるように制御できれば特に限定されず、例えば、アンモニア水のほか、硫酸アンモニウム、塩化アンモニウム、炭酸アンモニウム、フッ化アンモニウムなどを含む水溶液などを適宜使用することができる。水酸化コバルト粒子の製造方法においては、反応液のアンモニア濃度を５ｇ／Ｌ〜２０ｇ／Ｌ、好ましくは７．５ｇ／Ｌ〜１５ｇ／Ｌに調整する。アンモニア濃度が５ｇ／Ｌ未満になると、水酸化コバルト粒子の形状が板状になりやすくなり、緻密性が低下する。一方、アンモニア濃度が２０ｇ／Ｌを超えると、モフォロジーの制御には効果が無く、薬品費用や排水処理費用が大きくなり、コスト高になるという問題が生じる。   The ammonium ion-containing aqueous solution that is one of the raw materials of the cobalt hydroxide particles is not particularly limited as long as the ammonia concentration of the reaction solution can be controlled to a predetermined concentration. For example, ammonium sulfate, ammonium sulfate, ammonium chloride in addition to aqueous ammonia An aqueous solution containing ammonium carbonate, ammonium fluoride, or the like can be used as appropriate. In the method for producing cobalt hydroxide particles, the ammonia concentration of the reaction solution is adjusted to 5 g / L to 20 g / L, preferably 7.5 g / L to 15 g / L. When the ammonia concentration is less than 5 g / L, the shape of the cobalt hydroxide particles tends to be plate-like and the denseness is lowered. On the other hand, if the ammonia concentration exceeds 20 g / L, there is a problem that the morphology control is not effective, the chemical cost and the wastewater treatment cost are increased, and the cost is increased.

水酸化コバルト粒子の製造方法においては、非酸性雰囲気、好ましくは酸素濃度が５容量％以下の不活性ガス混合雰囲気に反応容器内を調整する。塩素を反応液中に含有させると共に、反応容器内を非酸化性雰囲気に制御することにより、一次粒子のアスペクト比の低下をさらに抑制することが可能となり、狙いの粒子モフォロジーの水酸化コバルト粒子を得ることができる。一方、反応容器内を酸化性雰囲気に制御すると、水酸化コバルト粒子の形状が板状になりやすくなると共に、粒径が微細化して、平均二次粒子径に対する平均一次粒子径の比（粒径比）が下限値未満となり、水酸化コバルト粒子の緻密性が低下する。また、酸化性雰囲気では、二次粒子の成長が抑制されるため、平均粒径が小さくなる。反応容器内の雰囲気の制御方法としては、窒素ガス、アルゴンガスなどの不活性ガスを反応容器に導入する方法が好ましい。   In the method for producing cobalt hydroxide particles, the inside of the reaction vessel is adjusted to a non-acidic atmosphere, preferably an inert gas mixed atmosphere having an oxygen concentration of 5% by volume or less. By containing chlorine in the reaction liquid and controlling the inside of the reaction vessel to a non-oxidizing atmosphere, it becomes possible to further suppress the decrease in the aspect ratio of the primary particles, and the cobalt hydroxide particles having a target particle morphology can be obtained. Can be obtained. On the other hand, when the inside of the reaction vessel is controlled to be an oxidizing atmosphere, the shape of the cobalt hydroxide particles tends to be plate-like, and the particle size becomes finer, and the ratio of the average primary particle size to the average secondary particle size (particle size Ratio) is less than the lower limit, and the denseness of the cobalt hydroxide particles is reduced. Further, in an oxidizing atmosphere, the growth of secondary particles is suppressed, so the average particle size becomes small. As a method for controlling the atmosphere in the reaction vessel, a method of introducing an inert gas such as nitrogen gas or argon gas into the reaction vessel is preferable.

水酸化コバルト粒子の製造方法においては、反応液の液温を４０℃〜６０℃に調整することが好ましい。反応液の液温が４０℃未満になると、一次粒子のアスペクト比が下がり、板状粒子が生成しやすくなり、粒子の緻密性が低下することがある。一方、液温が６０℃を超えると、コバルトとのアンモニアの錯体形成能力が低くなって粒径制御が困難となり、粒径の均一性が低下することがある。   In the method for producing cobalt hydroxide particles, the temperature of the reaction solution is preferably adjusted to 40 ° C to 60 ° C. When the liquid temperature of the reaction solution is lower than 40 ° C., the aspect ratio of the primary particles is lowered, plate-like particles are likely to be generated, and the density of the particles may be lowered. On the other hand, when the liquid temperature exceeds 60 ° C., the ability to form a complex of ammonia with cobalt is lowered, making it difficult to control the particle size, and the uniformity of the particle size may be reduced.

また、水酸化コバルト粒子の製造方法においては、バッチ法または連続法のいずれにも適用可能であるが、撹拌機、オーバーフロー口、および温度制御手段を備えた反応容器を用いて、塩素含有コバルト塩水溶液およびアンモニウムイオン含有水溶液を連続的に反応容器に供給し、無機アルカリ水溶液を反応容器に供給することにより反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整して反応液中に水酸化コバルト粒子を生成し、反応容器からオーバーフローした水酸化コバルト粒子を連続的に回収する連続法が好ましい。   In addition, the method for producing cobalt hydroxide particles can be applied to either a batch method or a continuous method, but a chlorine-containing cobalt salt is prepared using a reaction vessel equipped with a stirrer, an overflow port, and a temperature control means. An aqueous solution and an aqueous solution containing ammonium ions are continuously supplied to the reaction vessel, and an inorganic alkaline aqueous solution is supplied to the reaction vessel to adjust the pH value of the reaction solution to 10.0 to 12.0 based on a liquid temperature of 25 ° C. A continuous method is preferred in which cobalt hydroxide particles are produced in the reaction solution and the cobalt hydroxide particles overflowed from the reaction vessel are continuously recovered.

したがって、水酸化コバルト粒子の製造方法は、塩素含有コバルト塩水溶液、無機アルカリ水溶液およびアンモニウムイオン含有水溶液を反応容器に供給して得られた反応液を用い、反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整し、反応液中のアンモニア濃度を５ｇ／Ｌ〜２０ｇ／Ｌに調整し、反応容器内を非酸性雰囲気に調整する。このような水酸化コバルト粒子の製造方法によれば、充填性が向上するモフォロジーを有する水酸化コバルト粒子を得ることができ、好適な非水系電解質二次電池正極活物質の前駆体を市場に提供することができる。   Therefore, the method for producing cobalt hydroxide particles uses a reaction solution obtained by supplying a chlorine-containing cobalt salt aqueous solution, an inorganic alkali aqueous solution and an ammonium ion-containing aqueous solution to a reaction vessel, and the pH value of the reaction solution is adjusted to a liquid temperature of 25 ° C. The standard is adjusted to 10.0 to 12.0, the ammonia concentration in the reaction solution is adjusted to 5 g / L to 20 g / L, and the inside of the reaction vessel is adjusted to a non-acidic atmosphere. According to such a method for producing cobalt hydroxide particles, cobalt hydroxide particles having a morphology that improves filling properties can be obtained, and a suitable non-aqueous electrolyte secondary battery positive electrode active material precursor is provided to the market. can do.

（３）正極活物質
正極活物質は、上述の水酸化コバルト粒子を用いた非水系電解質二次電池用の正極活物質である。例えば、正極活物質は、一次粒子が凝集した二次粒子からなるリチウムコバルト複合酸化物である。リチウムコバルト複合酸化物の構成要素の１つである二次粒子は、平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２である。 (3) Positive electrode active material The positive electrode active material is a positive electrode active material for a non-aqueous electrolyte secondary battery using the above-described cobalt hydroxide particles. For example, the positive electrode active material is a lithium cobalt composite oxide composed of secondary particles in which primary particles are aggregated. The secondary particles as one of the constituent elements of the lithium cobalt composite oxide have an average secondary particle diameter of 20 μm to 50 μm, and the value of (d90−d10) / mv, which is an index indicating the spread of the particle size distribution, is 0. .6 to 1.2.

正極活物質の平均二次粒子径は、２０μｍ〜５０μｍであり、この範囲に制御することにより、高い充填性と非水系電解質二次電池に用いた場合に高い電池容量を有するようになる。平均二次粒子径が２０μｍ未満になると、充填性が低下して、非水系電解質二次電池の電極を作製した際に十分な充填密度が得られない。一方、平均二次粒子径が５０μｍを超えると、非水系電解質二次電池の作製時に粒子がセパレーターを突き破って短絡を起こすという問題が生じやすくなる。さらに、非水系電解質二次電池を高出力化するための電極の薄層化に対応することが困難となる。   The average secondary particle diameter of the positive electrode active material is 20 μm to 50 μm, and by controlling within this range, the battery has a high filling capacity and a high battery capacity when used in a non-aqueous electrolyte secondary battery. When the average secondary particle diameter is less than 20 μm, the filling property is lowered, and a sufficient packing density cannot be obtained when an electrode of a non-aqueous electrolyte secondary battery is produced. On the other hand, when the average secondary particle diameter exceeds 50 μm, a problem that the particles break through the separator and cause a short circuit when the non-aqueous electrolyte secondary battery is manufactured easily occurs. Furthermore, it becomes difficult to cope with the thinning of the electrode for increasing the output of the non-aqueous electrolyte secondary battery.

正極活物質における粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値は、０．６〜１．２の範囲内にあることが好ましく、これにより、正極活物質の粒度分布の広がりを適正な範囲とすることができ、高い充填性を持った正極活物質となる。（ｄ９０−ｄ１０）／ｍｖが０．６未満になると、正極活物質の粒径の均一性が高くなりすぎて充填性が向上しない。一方、（ｄ９０−ｄ１０）／ｍｖが１．２を超えると、微細粒子の増加により、正極活物質を用いた非水系電解質二次電池のサイクル特性の悪化や、粗大粒子増加による非水系電解質二次電池内の短絡という問題を生じる原因となる。   The value of (d90−d10) / mv, which is an index indicating the spread of the particle size distribution in the positive electrode active material, is preferably in the range of 0.6 to 1.2. The spread can be in an appropriate range, and a positive electrode active material having high filling properties can be obtained. When (d90-d10) / mv is less than 0.6, the uniformity of the particle size of the positive electrode active material becomes too high and the filling property is not improved. On the other hand, when (d90−d10) / mv exceeds 1.2, the increase in fine particles causes deterioration of the cycle characteristics of the nonaqueous electrolyte secondary battery using the positive electrode active material, and the nonaqueous electrolyte secondary due to the increase in coarse particles. This causes a problem of short circuit in the secondary battery.

また、正極活物質は、上述した通りリチウムコバルト複合酸化物からなり、その組成は、ＬｉＣｏＯ２として表せるものであり、非水系電解質二次電池の特性を改善するために通常添加される元素を含んでもよい。また、正極活物質は、充填性をより高いものとするため、上述した水酸化コバルト粒子と同様にして、二次粒子の形状は略球状であることが好ましい。 Further, the positive electrode active material is composed of a lithium cobalt composite oxide as described above, and its composition can be expressed as LiCoO 2 , and includes an element that is usually added to improve the characteristics of the nonaqueous electrolyte secondary battery. But you can. Moreover, in order to make the positive electrode active material have a higher filling property, it is preferable that the secondary particles have a substantially spherical shape in the same manner as the cobalt hydroxide particles described above.

したがって、正極活物質は、一次粒子が凝集した二次粒子からなるリチウムコバルト複合酸化物であり、二次粒子は、平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２である。このような正極活物質によれば、上述した水酸化コバルト粒子の二次粒子に関するモフォロジーを継承し、好適な高い充填性を有するので、高い充填性を有する正極活物質は、非水系電解質二次電池用の正極の充填密度を高くすることができる。その結果、高充填密度の正極を備えた非水系電解質二次電池は高い容量を得る。したがって、上述のリチウムコバルト複合酸化物は、非水系電解質二次電池用の正極活物質として極めて有用である。   Therefore, the positive electrode active material is a lithium cobalt composite oxide composed of secondary particles in which primary particles are aggregated, and the secondary particles have an average secondary particle diameter of 20 μm to 50 μm, and an index indicating the spread of the particle size distribution. The value of a certain (d90−d10) / mv is 0.6 to 1.2. According to such a positive electrode active material, since the morphology related to the secondary particles of the cobalt hydroxide particles described above is inherited and has a suitable high filling property, the positive electrode active material having a high filling property is a non-aqueous electrolyte secondary material. The packing density of the positive electrode for a battery can be increased. As a result, the nonaqueous electrolyte secondary battery provided with a positive electrode having a high packing density obtains a high capacity. Therefore, the above-described lithium cobalt composite oxide is extremely useful as a positive electrode active material for a non-aqueous electrolyte secondary battery.

（４）正極活物質の製造方法
正極活物質の製造方法では、上述した水酸化コバルト粒子を用いて非水系電解質二次電池用の正極活物質を製造する。例えば、正極活物質の製造方法では、上述した水酸化コバルト粒子を酸化雰囲気中で熱処理して酸化コバルト粒子を生成し、該酸化コバルト粒子とリチウム化合物とを混合して焼成して、リチウムコバルト複合酸化物を得る。 (4) Manufacturing method of positive electrode active material In the manufacturing method of a positive electrode active material, the positive electrode active material for nonaqueous electrolyte secondary batteries is manufactured using the cobalt hydroxide particle mentioned above. For example, in the method for producing a positive electrode active material, the above-described cobalt hydroxide particles are heat-treated in an oxidizing atmosphere to produce cobalt oxide particles, and the cobalt oxide particles and a lithium compound are mixed and fired to form a lithium cobalt composite. An oxide is obtained.

正極活物質の原材料の１つである酸化コバルト粒子の製造方法においては、上述した水酸化コバルト粒子を原料とし、その他の製造工程や条件は、通常の酸化コバルト粒子の製造方法と同等のものとすることができる。例えば、酸化コバルト粒子の製造方法としては、水酸化コバルト粒子を好ましくは２００℃〜９００℃、より好ましくは３００℃〜８００℃の温度に加熱し、水酸化コバルト粒子に含有されている水分を除去して酸化コバルト粒子とする。   In the method for producing cobalt oxide particles, which is one of the raw materials for the positive electrode active material, the above-described cobalt hydroxide particles are used as raw materials, and other production steps and conditions are the same as those for ordinary cobalt oxide particle production methods. can do. For example, as a method for producing cobalt oxide particles, the cobalt hydroxide particles are preferably heated to a temperature of 200 ° C. to 900 ° C., more preferably 300 ° C. to 800 ° C., to remove moisture contained in the cobalt hydroxide particles. Thus, cobalt oxide particles are obtained.

なお、熱処理を行う雰囲気は、特に制限されるものではなく、非還元性雰囲気であればよいが、簡易的に行える空気気流中において行うことが好ましい。また、熱処理時間は、特に制限されないが、１時間未満では水酸化コバルト粒子の余剰水分の除去が十分に行われない場合があるので、少なくとも１時間以上が好ましく、５〜１５時間がより好ましい。   The atmosphere in which the heat treatment is performed is not particularly limited and may be a non-reducing atmosphere, but is preferably performed in an air stream that can be easily performed. In addition, the heat treatment time is not particularly limited, but if it is less than 1 hour, the excess moisture of the cobalt hydroxide particles may not be sufficiently removed, so that it is preferably at least 1 hour and more preferably 5 to 15 hours.

正極活物質の製造方法においては、上述した水酸化コバルト粒子より得られた酸化コバルト粒子を原料とし、その他の製造工程や条件は、通常のリチウムコバルト複合酸化物の製造方法と同等のものとすることができる。   In the method for producing the positive electrode active material, the cobalt oxide particles obtained from the above-described cobalt hydroxide particles are used as raw materials, and the other production steps and conditions are the same as those of the ordinary method for producing lithium cobalt composite oxide. be able to.

正極活物質の製造方法においては、上述した水酸化コバルト粒子を熱処理して得られた酸化コバルト粒子とリチウム化合物との混合物（以下、「リチウムコバルト混合物」という。）の焼成における雰囲気を、酸化性雰囲気、好ましくは大気雰囲気に調整する。また、リチウムコバルト混合物の熱処理は、好ましくは７５０℃〜１１００℃で、より好ましくは８００℃〜１０５０℃で行う。熱処理温度が７５０℃未満であると、酸化コバルト粒子へのリチウムの拡散が十分に行われず、余剰のリチウムや未反応の粒子が残るだけでなく、結晶構造が十分整わなくなり、非水系電解質二次電池に用いられた場合に十分な電池特性が得られないことがある。また、熱処理温度が１１００℃を超えると、粒子間で激しく焼結が生じるとともに、異常粒成長を生じる可能性があり、このため、熱処理後の粒子が粗大となって上述の二次粒の粒子形状を保持できなくなる可能性がある。このような正極活物質は、上述した二次粒子の形状による効果が得られないことがある。   In the method for producing a positive electrode active material, the atmosphere in firing a mixture of cobalt oxide particles obtained by heat-treating the above-described cobalt hydroxide particles and a lithium compound (hereinafter referred to as “lithium cobalt mixture”) is oxidized. Adjust to atmosphere, preferably air atmosphere. The heat treatment of the lithium cobalt mixture is preferably performed at 750 ° C to 1100 ° C, more preferably 800 ° C to 1050 ° C. When the heat treatment temperature is less than 750 ° C., lithium is not sufficiently diffused into the cobalt oxide particles, and not only excess lithium and unreacted particles remain, but also the crystal structure becomes insufficient, and the non-aqueous electrolyte secondary When used in a battery, sufficient battery characteristics may not be obtained. In addition, when the heat treatment temperature exceeds 1100 ° C., intense sintering occurs between the particles, and abnormal grain growth may occur. For this reason, the particles after the heat treatment become coarse and the particles of the secondary particles described above. There is a possibility that the shape cannot be maintained. In such a positive electrode active material, the effect due to the shape of the secondary particles described above may not be obtained.

したがって、正極活物質の製造方法は、上述した水酸化コバルト粒子を酸化雰囲気中で熱処理して酸化コバルト粒子を生成し、該酸化コバルト粒子とリチウム化合物とを混合して焼成して、非水系電解質二次電池用の正極活物質であるリチウムコバルト複合酸化物を得る。このような正極活物質の製造方法によれば、高い充填性を有する水酸化コバルト粒子のモフォロジーを継承し、高充填性のリチウムコバルト複合酸化物を製造することができる。高充填性のリチウムコバルト複合酸化物は、非水系電解質二次電池に適用される正極活物質として好適であり、非水系電解質二次電池の正極に用いられた際に、該電池は高容量を示す。   Accordingly, a method for producing a positive electrode active material is a non-aqueous electrolyte in which cobalt hydroxide particles are heat-treated in an oxidizing atmosphere to produce cobalt oxide particles, and the cobalt oxide particles and a lithium compound are mixed and fired. A lithium cobalt composite oxide which is a positive electrode active material for a secondary battery is obtained. According to such a method for producing a positive electrode active material, it is possible to inherit a morphology of cobalt hydroxide particles having high filling properties and to produce a lithium cobalt composite oxide having high filling properties. The highly-fillable lithium cobalt composite oxide is suitable as a positive electrode active material applied to a non-aqueous electrolyte secondary battery. When used as a positive electrode of a non-aqueous electrolyte secondary battery, the battery has a high capacity. Show.

（５）非水系電解質二次電池
非水系電解質二次電池は、上述の正極活物質を用いた正極を採用したものである。まず、非水系電解質二次電池の構造を説明する。非水系電解質二次電池は、正極材料に上述した正極活物質を用いたこと以外は、一般的な非水系電解質二次電池と実質的に同様の構造を備えているため、簡単に説明する。 (5) Non-aqueous electrolyte secondary battery The non-aqueous electrolyte secondary battery employs a positive electrode using the above-described positive electrode active material. First, the structure of the nonaqueous electrolyte secondary battery will be described. Since the nonaqueous electrolyte secondary battery has substantially the same structure as a general nonaqueous electrolyte secondary battery except that the positive electrode active material described above is used as the positive electrode material, it will be briefly described.

非水系電解質二次電池は、ケースと、このケース内に収容された正極、負極、非水系電解液およびセパレーターを備えた構造を有している。   The nonaqueous electrolyte secondary battery has a structure including a case, and a positive electrode, a negative electrode, a nonaqueous electrolyte solution, and a separator housed in the case.

正極は、シート状の部材であり、正極活物質を含有する正極合材ペーストを、例えば、アルミニウム箔製の集電体の表面に塗布し乾燥して形成することができる。   The positive electrode is a sheet-like member, and can be formed by applying a positive electrode mixture paste containing a positive electrode active material to the surface of a current collector made of aluminum foil, for example, and drying it.

正極合材ペーストは、正極合材に、溶剤を添加して混練して形成されたものである。正極合材は、上述の正極活物質と、導電材および結着剤とを混合して形成されたものである。   The positive electrode mixture paste is formed by adding a solvent to the positive electrode mixture and kneading. The positive electrode mixture is formed by mixing the above-described positive electrode active material, a conductive material, and a binder.

導電材は、特に限定されないが、例えば、天然黒鉛、人造黒鉛、膨張黒鉛などの黒鉛や、アセチレンブラックやケッチェンブラックなどのカーボンブラック系材料を用いることができる。   The conductive material is not particularly limited. For example, graphite such as natural graphite, artificial graphite, and expanded graphite, and carbon black materials such as acetylene black and ketjen black can be used.

正極合材に使用される結着剤は、特に限定されないが、例えば、ポリフッ化ビニリデン（ＰＶＤＦ）、ポリテトラフルオロエチレン（ＰＴＦＥ）、フッ素ゴム、エチレンプロピレンジエンゴム、スチレンブタジエン、セルロース系樹脂、ポリアクリル酸などを用いることができる。なお、正極合材には、活性炭などを添加してもよく、活性炭などを添加することによって、正極の電気二重層容量を増加させることができる。   The binder used for the positive electrode mixture is not particularly limited. For example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), fluorine rubber, ethylene propylene diene rubber, styrene butadiene, cellulose resin, poly Acrylic acid or the like can be used. In addition, activated carbon etc. may be added to a positive electrode compound material, and the electric double layer capacity | capacitance of a positive electrode can be increased by adding activated carbon etc.

溶剤は、特に限定されないが、例えばＮ−メチル−２−ピロリドンなどの有機溶剤を用いることができる。   The solvent is not particularly limited, and for example, an organic solvent such as N-methyl-2-pyrrolidone can be used.

負極は、銅などの金属箔集電体の表面に、負極合材ペーストを塗布し、乾燥して形成されたシート状の部材である。   The negative electrode is a sheet-like member formed by applying a negative electrode mixture paste to the surface of a metal foil current collector such as copper and drying it.

負極活物質は、例えば、金属リチウムやリチウム合金などのリチウムを含有する物質や、リチウムイオンを吸蔵および脱離できる吸蔵物質を採用することができる。   As the negative electrode active material, for example, a material containing lithium, such as metallic lithium or a lithium alloy, or an occlusion material that can occlude and desorb lithium ions can be employed.

吸蔵物質は、特に限定されないが、例えば、天然黒鉛、人造黒鉛、フェノール樹脂などの有機化合物焼成体、およびコークスなどの炭素物質の粉状体を用いることができる。   The occlusion material is not particularly limited, and for example, natural graphite, artificial graphite, an organic compound fired body such as phenol resin, and a carbon material powder such as coke can be used.

セパレーターは、例えば、ポリエチレンやポリプロピレンなどの薄い膜で、微細な孔を多数有する膜を用いることができる。なお、セパレーターの機能を有するものであれば、特に限定されない。   As the separator, for example, a thin film such as polyethylene or polypropylene and a film having many fine holes can be used. In addition, if it has a function of a separator, it will not specifically limit.

非水系電解液は、支持塩としてのリチウム塩を有機溶媒に溶解したものである。有機溶媒としては、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、トリフルオロプロピレンカーボネートなどの環状カーボネート；ジエチルカーボネート、ジメチルカーボネート、エチルメチルカーボネート、ジプロピルカーボネートなどの鎖状カーボネート；テトラヒドロフラン、２−メチルテトラヒドロフラン、ジメトキシエタンなどのエーテル化合物；エチルメチルスルホンやブタンスルトンなどの硫黄化合物；リン酸トリエチルやリン酸トリオクチルなどのリン化合物などから選ばれる１種を、単独で、あるいは２種以上を混合して用いることができる。支持塩としては、ＬｉＰＦ６、ＬｉＢＦ４、ＬｉＣｌＯ４、ＬｉＡｓＦ６、ＬｉＮ（ＣＦ３ＳＯ２）２、およびそれらの複合塩などを用いることができる。 The nonaqueous electrolytic solution is obtained by dissolving a lithium salt as a supporting salt in an organic solvent. Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and trifluoropropylene carbonate; chain carbonates such as diethyl carbonate, dimethyl carbonate, ethylmethyl carbonate, and dipropyl carbonate; tetrahydrofuran, 2-methyltetrahydrofuran, and dimethoxy Ether compounds such as ethane; sulfur compounds such as ethyl methyl sulfone and butane sultone; phosphorus compounds such as triethyl phosphate and trioctyl phosphate can be used alone or in admixture of two or more. . As the supporting salt, LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiN (CF 3 SO 2 ) 2 , and complex salts thereof can be used.

上述の構成を有する非水系電解質二次電池は、上述の正極活物質を用いた正極を有しているので、正極活物質と非水系電解液との接触面積が増加し、正極活物質の充填密度が高くなるため、高い出力特性と電池容量が得られ、高い電極密度を得ることができる。これにより、非水系電解質二次電池では、高い初期放電容量、低い正極抵抗が得られ、高容量で高出力となる。また、非水系電解質二次電池は、高い体積エネルギー密度を有する。さらに、従来の正極活物質と比較して、熱安定性が高く、安全性においても優れている。   Since the non-aqueous electrolyte secondary battery having the above-described configuration has a positive electrode using the above-described positive electrode active material, the contact area between the positive electrode active material and the non-aqueous electrolyte increases, and the positive electrode active material is filled. Since the density increases, high output characteristics and battery capacity can be obtained, and a high electrode density can be obtained. Thereby, in a non-aqueous electrolyte secondary battery, a high initial discharge capacity and a low positive electrode resistance are obtained, and a high capacity and a high output are obtained. Moreover, the nonaqueous electrolyte secondary battery has a high volume energy density. Furthermore, compared with the conventional positive electrode active material, heat stability is high and it is excellent also in safety.

以下、各実施例および各比較例によって、本発明をさらに詳細に説明するが、本発明はこれらによって何ら限定されるものではない。   Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

以下の各実施例および各比較例における評価方法を以下に示す。
１）体積平均粒径および粒度分布測定
レーザ回折式粒度分布計（商品名マイクロトラック、日機装株式会社製）を用いて測定した。
２）粒子の外観
走査型電子顕微鏡（ＳＥＭ、商品名Ｓ−４７００、株式会社日立ハイテクノロジーズ製）により観察して評価した。
３）平均一次粒子径および一次粒子のアスペクト比
ＳＥＭ（Ｓｃａｎｎｉｎｇ Ｅｌｅｃｔｒｏｎ Ｍｉｃｒｏｓｃｏｐｅ）を用いて粒子断面を観察し、任意に選択した２０個の粒子を断面上で測定した値から、平均値を算出することにより求めた。
４）金属成分の分析
試料を溶解した後、ＩＣＰ発光分光法（ＩＣＰ:Ｉｎｄｕｃｔｉｖｅｌｙ Ｃｏｕｐｌｅｄ Ｐｌａｓｍａ）により分析した。
５）結晶構造の同定
Ｘ線回折測定装置（パナリティカル社製、Ｘ‘Ｐｅｒｔ ＰＲＯ）により得られたＸ線回折パターンを用いて同定した。 Evaluation methods in the following examples and comparative examples are shown below.
1) Volume average particle size and particle size distribution measurement The measurement was performed using a laser diffraction particle size distribution meter (trade name: Microtrack, manufactured by Nikkiso Co., Ltd.).
2) Appearance of particles The particles were observed and evaluated with a scanning electron microscope (SEM, trade name S-4700, manufactured by Hitachi High-Technologies Corporation).
3) Average primary particle diameter and aspect ratio of primary particles Observe the particle cross section using SEM (Scanning Electron Microscope), and calculate the average value from the values measured on the cross section of 20 particles selected arbitrarily. Determined by
4) Analysis of metal component After dissolving a sample, it analyzed by ICP emission spectroscopy (ICP: Inductively Coupled Plasma).
5) Identification of crystal structure It identified using the X-ray-diffraction pattern obtained by the X-ray-diffraction measuring apparatus (the product made by Panalical, X'Pert PRO).

（実施例１）
実施例１では、４枚の邪魔板を取り付けた槽容積６Ｌのオーバーフロー式晶析反応槽に、純水を３Ｌ、および２５重量％アンモニア水を１４０ｍｌそれぞれ投入して、恒温槽および加温ジャケットにて６０℃に加温し、反応槽内に２５％苛性ソーダ溶液を添加して、２５℃を基準とした槽内ｐＨ値を１１．２に調整した。また、反応槽内に窒素ガスを３Ｌ／分で供給し、反応槽内の酸素濃度を１％以下に制御した。 Example 1
In Example 1, 3 L of pure water and 140 ml of 25% by weight ammonia water were respectively added to an overflow crystallization reaction tank having a tank volume of 6 L equipped with four baffle plates, and the thermostatic tank and the heating jacket were added. The mixture was heated to 60 ° C., a 25% sodium hydroxide solution was added to the reaction vessel, and the pH value in the vessel was adjusted to 11.2 based on 25 ° C. Moreover, nitrogen gas was supplied into the reaction tank at 3 L / min, and the oxygen concentration in the reaction tank was controlled to 1% or less.

次に、６０℃に保持した反応槽内を撹拌しつつ、定量ポンプを用いて、反応槽内にコバルトモル濃度が１．２ｍｏｌ／Ｌの塩化コバルト水溶液を１０ｍｌ／分で供給し、２５質量％アンモニア水を１．５ｍｌ／分で供給して反応液とし、反応槽内に２５％苛性ソーダ溶液を断続的に添加し、２５℃を基準としたｐＨ値が１１．４になるように制御して晶析反応を行った。なお、塩化コバルト水溶液中の塩素含有量は、塩化コバルト水溶液中のコバルト含有量に対してモル比で２．１であった。また、反応液中のアンモニア濃度は１０ｇ／Ｌであった。   Next, while stirring the inside of the reaction vessel maintained at 60 ° C., a cobalt chloride aqueous solution having a cobalt molar concentration of 1.2 mol / L was supplied into the reaction vessel at 10 ml / min using a metering pump. Ammonia water is supplied at a rate of 1.5 ml / min to form a reaction solution, and a 25% sodium hydroxide solution is intermittently added to the reaction vessel, and the pH value based on 25 ° C. is controlled to be 11.4. A crystallization reaction was performed. In addition, the chlorine content in cobalt chloride aqueous solution was 2.1 by molar ratio with respect to the cobalt content in cobalt chloride aqueous solution. The ammonia concentration in the reaction solution was 10 g / L.

反応槽内が安定した後、生成した水酸化コバルト粒子をオーバーフローにて連続的に回収し、これを適宜固液分離し、水洗し、乾燥して粉末状の水酸化コバルト粒子を得た。反応開始から４８〜７２時間にかけて取り出された水酸化コバルト粒子は、平均一次粒子径が７．３μｍ、平均二次粒子径が２８．７μｍ、平均二次粒子径に対する平均一次粒子径の比が０．２５、一次粒子の平均アスペクト比が０．８１、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖが０．８４であった。   After the inside of the reaction vessel was stabilized, the produced cobalt hydroxide particles were continuously recovered by overflow, and this was appropriately solid-liquid separated, washed with water, and dried to obtain powdered cobalt hydroxide particles. The cobalt hydroxide particles taken out from the start of the reaction for 48 to 72 hours have an average primary particle size of 7.3 μm, an average secondary particle size of 28.7 μm, and a ratio of the average primary particle size to the average secondary particle size of 0. .25, the average aspect ratio of the primary particles was 0.81, and (d90-d10) / mv, which is an index indicating the spread of the particle size distribution, was 0.84.

得られた水酸化コバルト粒子のＳＥＭ像を図１に示す。図１に示した通り、水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。また、水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。さらに、水酸化コバルト粒子のタップ密度を測定したところ、２．２ｇ／ｃｍ３であった。 An SEM image of the obtained cobalt hydroxide particles is shown in FIG. As shown in FIG. 1, the primary particle shape of the cobalt hydroxide particles was a columnar shape, a rectangular parallelepiped or a cube, and the secondary particle shape was substantially spherical. Moreover, it was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . Furthermore, when the tap density of the cobalt hydroxide particles was measured, it was 2.2 g / cm 3 .

また、得られた水酸化コバルト粒子を空気気流中にて８５０℃で７時間焙焼し、一般式Ｃｏ３Ｏ４で表される酸化コバルト粒子を得た。得られた酸化コバルト粒子と炭酸リチウムとを、酸化コバルト粒子に含まれるコバルト（Ｍｅ）に対する炭酸リチウムに含まれるリチウム（Ｌｉ）の比（Ｌｉ／Ｍｅ）が１．０となるように炭酸リチウムと混合し、空気気流中にて、９８０℃で１０時間焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．５ｇ／ｃｍ３であった。 Moreover, the obtained cobalt hydroxide particles were roasted at 850 ° C. for 7 hours in an air stream to obtain cobalt oxide particles represented by the general formula Co 3 O 4 . The obtained cobalt oxide particles and lithium carbonate were mixed with lithium carbonate so that the ratio (Li / Me) of lithium (Li) contained in lithium carbonate to cobalt (Me) contained in cobalt oxide particles was 1.0. The mixture was mixed, fired at 980 ° C. for 10 hours in an air stream, cooled, and crushed to obtain a positive electrode active material. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.5 g / cm 3 .

（実施例２）
実施例２では、塩素を含むコバルト塩水溶液として塩化コバルトと硫酸コバルトとの混合物を使用し、コバルト水溶液中の塩素含有量を、コバルト水溶液中のコバルト含有量に対してモル比で０．５とした以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Example 2)
In Example 2, as a cobalt salt aqueous solution containing chlorine, a mixture of cobalt chloride and cobalt sulfate was used, and the chlorine content in the cobalt aqueous solution was 0.5 in terms of molar ratio with respect to the cobalt content in the cobalt aqueous solution. Except that, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1.

得られた水酸化コバルト粒子は、平均一次粒子径が６．８μｍ、平均二次粒子径が２３．２μｍ、平均二次粒子径に対する平均一次粒子径の比が０．２９、一次粒子の平均アスペクト比が０．６３、（ｄ９０−ｄ１０）／ｍｖが０．９１であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．０ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle diameter of 6.8 μm, an average secondary particle diameter of 23.2 μm, a ratio of the average primary particle diameter to the average secondary particle diameter of 0.29, and an average aspect ratio of the primary particles. The ratio was 0.63 and (d90-d10) / mv was 0.91. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.0 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．２ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.2 g / cm 3 .

（実施例３）
実施例３では、反応槽内の温度を３０℃とした以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Example 3)
In Example 3, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the temperature in the reaction vessel was 30 ° C.

得られた水酸化コバルト粒子は、平均一次粒子径が６．９μｍ、平均二次粒子径が４１．３μｍ、平均二次粒子径に対する平均一次粒子径の比が０．１７、一次粒子の平均アスペクト比が０．７１、（ｄ９０−ｄ１０）／ｍｖが０．８６であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．１ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle size of 6.9 μm, an average secondary particle size of 41.3 μm, a ratio of the average primary particle size to the average secondary particle size of 0.17, and an average aspect ratio of the primary particles. The ratio was 0.71 and (d90-d10) / mv was 0.86. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.1 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．４ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.4 g / cm 3 .

（実施例４）
実施例４では、２５℃を基準とした槽内ｐＨ値を１０．２に調整した以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 Example 4
In Example 4, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the pH value in the tank based on 25 ° C. was adjusted to 10.2.

得られた水酸化コバルト粒子は、平均一次粒子径が６．３μｍ、平均二次粒子径が３８．７μｍ、平均二次粒子径に対する平均一次粒子径の比が０．１６、一次粒子の平均アスペクト比が０．８０、（ｄ９０−ｄ１０）／ｍｖが０．９０であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．２ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle size of 6.3 μm, an average secondary particle size of 38.7 μm, a ratio of the average primary particle size to the average secondary particle size of 0.16, and an average aspect ratio of the primary particles. The ratio was 0.80 and (d90-d10) / mv was 0.90. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.2 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．４ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.4 g / cm 3 .

（実施例５）
実施例５では、２５℃を基準とした槽内ｐＨ値を１１．８に調整した以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Example 5)
In Example 5, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the pH value in the tank based on 25 ° C. was adjusted to 11.8.

得られた水酸化コバルト粒子は、平均一次粒子径が６．５μｍ、平均二次粒子径が２１．２μｍ、平均二次粒子径に対する平均一次粒子径の比が０．３１、一次粒子の平均アスペクト比が０．５２、（ｄ９０−ｄ１０）／ｍｖが０．９３であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．０ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle diameter of 6.5 μm, an average secondary particle diameter of 21.2 μm, a ratio of the average primary particle diameter to the average secondary particle diameter of 0.31, and an average aspect ratio of the primary particles. The ratio was 0.52, and (d90-d10) / mv was 0.93. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.0 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．２ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.2 g / cm 3 .

（実施例６）
実施例６では、反応液中のアンモニア濃度を７．５ｇ／Ｌに調整した以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Example 6)
In Example 6, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the ammonia concentration in the reaction solution was adjusted to 7.5 g / L.

得られた水酸化コバルト粒子は、平均一次粒子径が７．１μｍ、平均二次粒子径が２５．１μｍ、平均二次粒子径に対する平均一次粒子径の比が０．２８、一次粒子の平均アスペクト比が０．６７、（ｄ９０−ｄ１０）／ｍｖが０．８９であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．０ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle diameter of 7.1 μm, an average secondary particle diameter of 25.1 μm, a ratio of the average primary particle diameter to the average secondary particle diameter of 0.28, and an average aspect ratio of the primary particles. The ratio was 0.67 and (d90-d10) / mv was 0.89. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.0 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．２ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.2 g / cm 3 .

（実施例７）
実施例７では、反応液中のアンモニア濃度を１８ｇ／Ｌに調整した以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Example 7)
In Example 7, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the ammonia concentration in the reaction solution was adjusted to 18 g / L.

得られた水酸化コバルト粒子は、平均一次粒子径が８．９μｍ、平均二次粒子径が３９．４μｍ、平均二次粒子径に対する平均一次粒子径の比が０．２３、一次粒子の平均アスペクト比が０．８４、（ｄ９０−ｄ１０）／ｍｖが０．８６であった。水酸化コバルト粒子の一次粒子形状は柱状、直方体または立方体であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、２．３ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle diameter of 8.9 μm, an average secondary particle diameter of 39.4 μm, a ratio of the average primary particle diameter to the average secondary particle diameter of 0.23, and an average aspect ratio of the primary particles The ratio was 0.84 and (d90-d10) / mv was 0.86. The primary particle shape of the cobalt hydroxide particles was columnar, rectangular parallelepiped or cubic, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 2.3 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．６ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.6 g / cm 3 .

（比較例１）
比較例１では、２５℃を基準とした槽内ｐＨ値を９．５に調整した以外は実施例１と同様にして水酸化コバルト粒子を得るとともに評価した。 (Comparative Example 1)
In Comparative Example 1, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the pH value in the tank based on 25 ° C. was adjusted to 9.5.

得られた水酸化コバルト粒子は、平均一次粒子径が０．１μｍ、平均二次粒子径が６．３μｍ、平均二次粒子径に対する平均一次粒子径の比が０．０２、一次粒子の平均アスペクト比が０．６３、（ｄ９０−ｄ１０）／ｍｖが１．２６であった。水酸化コバルト粒子の一次粒子、二次粒子の形状は共に不定形であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、１．２ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles have an average primary particle size of 0.1 μm, an average secondary particle size of 6.3 μm, a ratio of the average primary particle size to the average secondary particle size of 0.02, and an average aspect ratio of the primary particles. The ratio was 0.63 and (d90-d10) / mv was 1.26. The shapes of the primary and secondary particles of the cobalt hydroxide particles were both indefinite. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 1.2 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、１．６ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Moreover, it was 1.6 g / cm < 3 > when the tap density of the particle | grains of lithium cobaltate was measured.

（比較例２）
比較例２では、２５℃を基準とした槽内ｐＨ値を１２．３に調整した以外は実施例１と同様にして水酸化コバルト粒子を得ると共に評価した。 (Comparative Example 2)
In Comparative Example 2, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the pH value in the tank based on 25 ° C. was adjusted to 12.3.

得られた水酸化コバルト粒子は、平均一次粒子径４．０μｍ、平均二次粒子径が１４．８μｍ、平均二次粒子径に対する平均一次粒子径の比が０．２７、一次粒子の平均アスペクト比が０．３８、（ｄ９０−ｄ１０）／ｍｖが０．８８であった。水酸化コバルト粒子の一次粒子形状は板状であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、１．７ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle diameter of 4.0 μm, an average secondary particle diameter of 14.8 μm, a ratio of the average primary particle diameter to the average secondary particle diameter of 0.27, and an average aspect ratio of the primary particles Was 0.38 and (d90-d10) / mv was 0.88. The primary particle shape of the cobalt hydroxide particles was plate-like, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . When the tap density of the cobalt hydroxide particles was measured, it was 1.7 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．０ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.0 g / cm 3 .

（比較例３）
比較例３では、反応液中のアンモニア濃度を３ｇ／Ｌに調整した以外は実施例１と同様にして水酸化コバルト粒子を得ると共に評価した。 (Comparative Example 3)
In Comparative Example 3, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that the ammonia concentration in the reaction solution was adjusted to 3 g / L.

得られた水酸化コバルト粒子は、平均一次粒子径が４．９μｍ、平均二次粒子径が１６．０μｍ、平均二次粒子径に対する平均一次粒子径の比が０．３１、一次粒子の平均アスペクト比が０．７１、（ｄ９０−ｄ１０）／ｍｖが０．９１であった。水酸化コバルト粒子の一次粒子形状は板状であり、二次粒子形状は略球状であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、１．８ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle size of 4.9 μm, an average secondary particle size of 16.0 μm, a ratio of the average primary particle size to the average secondary particle size of 0.31, and an average aspect ratio of primary particles The ratio was 0.71, and (d90-d10) / mv was 0.91. The primary particle shape of the cobalt hydroxide particles was plate-like, and the secondary particle shape was substantially spherical. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 1.8 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．０ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Further, the tap density of the lithium cobalt oxide particles was measured and found to be 2.0 g / cm 3 .

（比較例４）
比較例４では、反応槽内に窒素ガスを供給しなかった以外は実施例１と同様にして水酸化コバルト粒子を得ると共に評価した。なお、窒素ガスを供給しなかったため、反応槽内の雰囲気は大気雰囲気（酸素濃度２１容量％）となった。 (Comparative Example 4)
In Comparative Example 4, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that nitrogen gas was not supplied into the reaction vessel. Since nitrogen gas was not supplied, the atmosphere in the reaction vessel was an atmospheric atmosphere (oxygen concentration 21% by volume).

得られた水酸化コバルト粒子は、平均一次粒子径が０．２μｍ、平均二次粒子径が８．１μｍ、平均二次粒子径に対する平均一次粒子径の比が０．０２、一次粒子の平均アスペクト比が０．５２、（ｄ９０−ｄ１０）／ｍｖが１．４１であった。水酸化コバルト粒子の一次粒子形状は板状であり、二次粒子形状は不定形であった。水酸化コバルト粒子の結晶構造は、ＣｏＯＯＨで表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、１．１ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles have an average primary particle size of 0.2 μm, an average secondary particle size of 8.1 μm, a ratio of the average primary particle size to the average secondary particle size of 0.02, and an average aspect ratio of primary particles. The ratio was 0.52 and (d90-d10) / mv was 1.41. The primary particle shape of the cobalt hydroxide particles was a plate shape, and the secondary particle shape was indefinite. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by CoOOH. The tap density of the cobalt hydroxide particles was measured and found to be 1.1 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、１．６ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Moreover, it was 1.6 g / cm < 3 > when the tap density of the particle | grains of lithium cobaltate was measured.

（比較例５）
比較例５では、コバルト原料として硫酸コバルトを使用し、塩素を含まないコバルト水溶液を用いた以外は実施例１と同様にして水酸化コバルト粒子を得ると共に評価した。 (Comparative Example 5)
In Comparative Example 5, cobalt hydroxide particles were obtained and evaluated in the same manner as in Example 1 except that cobalt sulfate was used as a cobalt raw material and a cobalt aqueous solution containing no chlorine was used.

得られた水酸化コバルト粒子は、平均一次粒子径が４．８μｍ、平均二次粒子径が２６．２μｍ、平均二次粒子径に対する平均一次粒子径の比が０．１８、一次粒子の平均アスペクト比が０．２１、（ｄ９０−ｄ１０）／ｍｖが０．９３であった。水酸化コバルト粒子の一次粒子形状は板状であり、二次粒子形状は不定形であった。水酸化コバルト粒子の結晶構造は、Ｃｏ（ＯＨ）２で表されることが確認された。水酸化コバルト粒子のタップ密度を測定したところ、１．９ｇ／ｃｍ３であった。 The obtained cobalt hydroxide particles had an average primary particle size of 4.8 μm, an average secondary particle size of 26.2 μm, a ratio of the average primary particle size to the average secondary particle size of 0.18, and an average aspect ratio of the primary particles. The ratio was 0.21 and (d90-d10) / mv was 0.93. The primary particle shape of the cobalt hydroxide particles was a plate shape, and the secondary particle shape was indefinite. It was confirmed that the crystal structure of the cobalt hydroxide particles is represented by Co (OH) 2 . The tap density of the cobalt hydroxide particles was measured and found to be 1.9 g / cm 3 .

また、得られた水酸化コバルト粒子を実施例１と同様にして焼成した後に、実施例１と同様にして得られた酸化コバルト粒子とリチウム化合物とを混合して焼成し、冷却した後に解砕して正極活物質を得た。得られた正極活物質の結晶構造は、ＬｉＣｏＯ２で表されるコバルト酸リチウムであることが確認された。また、コバルト酸リチウムの粒子のタップ密度を測定したところ、２．１ｇ／ｃｍ３であった。 Moreover, after calcining the obtained cobalt hydroxide particles in the same manner as in Example 1, the cobalt oxide particles obtained in the same manner as in Example 1 and a lithium compound were mixed and calcined, cooled, and then crushed. Thus, a positive electrode active material was obtained. It was confirmed that the crystal structure of the obtained positive electrode active material was lithium cobaltate represented by LiCoO 2 . Moreover, it was 2.1 g / cm < 3 > when the tap density of the particle | grains of lithium cobaltate was measured.

上述した実施例１〜実施例７および比較例１〜比較例５の結果をまとめて表１に示した。表１に示した通り、実施例１〜実施例７で得られた水酸化コバルト粒子は、一次粒子の平均アスペクト比が０．５以上であり、平均二次粒子径に対する平均一次粒子径の比が１／１０〜１／２であることがわかった。また、二次粒子の平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２であることがわかった。さらに、実施例１〜実施例７で得られた水酸化コバルト粒子を原材料として得られたコバルト酸リチウムのタップ密度は、２ｇ／ｃｍ３〜３ｇ／ｃｍ３であることがわかった。 The results of Examples 1 to 7 and Comparative Examples 1 to 5 described above are shown together in Table 1. As shown in Table 1, the cobalt hydroxide particles obtained in Examples 1 to 7 have an average aspect ratio of primary particles of 0.5 or more, and the ratio of the average primary particle diameter to the average secondary particle diameter. Was found to be 1/10 to 1/2. Moreover, it turned out that the average secondary particle diameter of a secondary particle is 20 micrometers-50 micrometers, and the value of (d90-d10) / mv which is an parameter | index which shows the breadth of a particle size distribution is 0.6-1.2. . Moreover, the tap density of the obtained lithium cobaltate cobalt hydroxide particles obtained in Examples 1 to 7 as a raw material was found to be 2g / cm 3 ~3g / cm 3 .

したがって、実施例１〜実施例７で得られた水酸化コバルト粒子を前駆体としてコバルト酸リチウム粒子を製造した場合、表１に示したタップ密度測定の測定結果より、高い充填性を有する前駆体のモフォロジーを継承し、充填性の高い正極活物質が得られることがわかった。このことから、この正極活物質を非水系電解質二次電池の正極として用いた場合に、該二次電池は高容量を示すことがわかる。














Therefore, when lithium cobaltate particles were produced using the cobalt hydroxide particles obtained in Examples 1 to 7 as precursors, a precursor having higher filling properties than the measurement results of the tap density measurement shown in Table 1 It was found that a positive electrode active material having high filling properties can be obtained by inheriting the above morphology. This shows that when this positive electrode active material is used as the positive electrode of a non-aqueous electrolyte secondary battery, the secondary battery exhibits a high capacity.














Claims (8)

非水系電解質二次電池の正極活物質用の水酸化コバルト粒子であって、
前記水酸化コバルト粒子は、一次粒子が凝集した二次粒子からなり、
前記一次粒子は柱状、直方体または立方体の形状を有し、前記一次粒子の平均アスペクト比が０．５以上であり、平均二次粒子径に対する平均一次粒子径の比が１／１０〜１／２であり、平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ９０−ｄ１０）／ｍｖの値が０．６〜１．２であることを特徴とする水酸化コバルト粒子。 Cobalt hydroxide particles for a positive electrode active material of a non-aqueous electrolyte secondary battery,
The cobalt hydroxide particles are composed of secondary particles in which primary particles are aggregated,
The primary particles have a columnar, rectangular parallelepiped or cubic shape, the average aspect ratio of the primary particles is 0.5 or more, and the ratio of the average primary particle diameter to the average secondary particle diameter is 1/10 to 1/2. The average secondary particle diameter is 20 μm to 50 μm, and the value of (d90−d10) / mv, which is an index indicating the spread of the particle size distribution, is 0.6 to 1.2. Cobalt particles. タップ密度が２ｇ／ｃｍ３〜３ｇ／ｃｍ３であることを特徴とする請求項１に記載の水酸化コバルト粒子。 Cobalt hydroxide particles according to claim 1, tap density, characterized in that a 2g / cm 3 ~3g / cm 3 . 塩素含有コバルト塩水溶液、無機アルカリ水溶液およびアンモニウムイオン含有水溶液を反応容器に供給して得られた反応液を用いて、非水系電解質二次電池の正極活物質用の水酸化コバルト粒子を製造する方法であって、
前記反応液のｐＨ値を液温２５℃基準において１０．０〜１２．０に調整し、前記反応液中のアンモニア濃度を５ｇ／Ｌ〜２０ｇ／Ｌに調整し、前記反応容器内を非酸性雰囲気に調整し、
前記塩素含有コバルト塩水溶液は、塩素の含有量がコバルトの含有量に対してモル比で０．５〜３であることを特徴とする水酸化コバルト粒子の製造方法。 Method for producing cobalt hydroxide particles for a positive electrode active material of a non-aqueous electrolyte secondary battery using a reaction solution obtained by supplying a chlorine-containing cobalt salt aqueous solution, an inorganic alkali aqueous solution and an ammonium ion-containing aqueous solution to a reaction vessel Because
The pH value of the reaction solution is adjusted to 10.0 to 12.0 based on a liquid temperature of 25 ° C., the ammonia concentration in the reaction solution is adjusted to 5 g / L to 20 g / L, and the inside of the reaction vessel is non-acidic Adjust to the atmosphere ,
The method for producing cobalt hydroxide particles, wherein the chlorine-containing cobalt salt aqueous solution has a chlorine content in a molar ratio of 0.5 to 3 with respect to the cobalt content . 前記塩素含有コバルト塩水溶液は、塩素の含有量がコバルトの含有量に対してモル比で１〜３であることを特徴とする請求項３に記載の水酸化コバルト粒子の製造方法。   The method for producing cobalt hydroxide particles according to claim 3, wherein the chlorine-containing cobalt salt aqueous solution has a chlorine content of 1 to 3 in terms of a molar ratio with respect to the cobalt content. 前記反応液の液温を４０℃〜６０℃に調整することを特徴とする請求項３または請求項４に記載の水酸化コバルト粒子の製造方法。   The method for producing cobalt hydroxide particles according to claim 3 or 4, wherein a temperature of the reaction solution is adjusted to 40 ° C to 60 ° C. 前記塩素含有コバルト塩水溶液および前記アンモニウムイオン含有水溶液を連続的に前記反応容器に供給し、前記無機アルカリ水溶液を前記反応容器に供給することにより前記反応液を前記ｐＨ値に調整して前記水酸化コバルト粒子を生成し、
前記反応容器からオーバーフローした前記水酸化コバルト粒子を連続的に回収することを特徴とする請求項３乃至請求項５の何れか１項に記載の水酸化コバルト粒子の製造方法。 The chlorine-containing cobalt salt aqueous solution and the ammonium ion-containing aqueous solution are continuously supplied to the reaction vessel, and the inorganic alkaline aqueous solution is supplied to the reaction vessel to adjust the reaction solution to the pH value and to perform the hydroxylation. Produce cobalt particles,
The method for producing cobalt hydroxide particles according to any one of claims 3 to 5, wherein the cobalt hydroxide particles overflowed from the reaction vessel are continuously collected. 水酸化コバルト粒子を用いて非水系電解質二次電池の正極活物質を製造する方法であって、
請求項１または請求項２に記載の水酸化コバルト粒子を酸化雰囲気中で熱処理して酸化コバルト粒子を生成し、該酸化コバルト粒子とリチウム化合物とを混合して焼成してリチウムコバルト複合酸化物を得ることを特徴とする正極活物質の製造方法。 A method for producing a positive electrode active material of a non-aqueous electrolyte secondary battery using cobalt hydroxide particles,
The cobalt hydroxide particles according to claim 1 or 2 are heat-treated in an oxidizing atmosphere to produce cobalt oxide particles, and the cobalt oxide particles and the lithium compound are mixed and fired to form a lithium cobalt composite oxide. A method for producing a positive electrode active material, characterized by comprising: 前記リチウムコバルト複合酸化物は、一次粒子が凝集した二次粒子からなり、
平均二次粒子径が２０μｍ〜５０μｍであり、粒度分布の広がりを示す指標である（ｄ
９０−ｄ１０）／ｍｖの値が０．６〜１．２であることを特徴とする請求項７に記載の正極活物質の製造方法。 The lithium cobalt composite oxide is composed of secondary particles in which primary particles are aggregated ,
The average secondary particle diameter is 20 μm to 50 μm and is an index indicating the spread of the particle size distribution (d
The value of 90-d10) / mv is 0.6-1.2, The manufacturing method of the positive electrode active material of Claim 7 characterized by the above-mentioned .
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WO2004023583A1 (en) * 2002-09-03 2004-03-18 Seimi Chemical Co., Ltd. Process for producing lithium cobalt composite oxide for positive electrode of lithium secondary battery
BRPI0813395A2 (en) * 2007-06-29 2014-12-30 Umicore Nv COBALT LYRIC OXIDE POWDER, POWDER MIXTURE, PRECURSOR COMPOUND, ELECTRODE MIXTURE, LITIO-ION BATTERY, AND SINGLE BURNING PROCESS FOR THE MANUFACTURE OF A COBALT LIOXIDE POWDER.
JP5758743B2 (en) * 2010-09-02 2015-08-05 日本化学工業株式会社 Cobalt hydroxide and method for producing the same, and cobalt oxide and method for producing the same
JP5938614B2 (en) * 2011-05-31 2016-06-22 フリーポート・コバルト・オーワイ Lithium cobalt oxide material

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