JP2000154022A - Lithium manganese double oxide, its production and its use - Google Patents
Lithium manganese double oxide, its production and its useInfo
- Publication number
- JP2000154022A JP2000154022A JP10327738A JP32773898A JP2000154022A JP 2000154022 A JP2000154022 A JP 2000154022A JP 10327738 A JP10327738 A JP 10327738A JP 32773898 A JP32773898 A JP 32773898A JP 2000154022 A JP2000154022 A JP 2000154022A
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- JP
- Japan
- Prior art keywords
- lithium
- manganese
- compound
- temperature
- composite oxide
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は新規なリチウムマン
ガン酸化物に関するものであって、詳しくは、一般式Ｌ
ｉ1+xＭｎ2-y-zＭyＯ4+δ（式中ＭはＮｉ、Ｃｏ、Ｆ
ｅ、Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の金
属元素であり、０≦ｘ≦１／３，０≦ｙ≦１／３，０＜
ｚ≦０．２５，−０．１４≦δ≦０．５）で表され、ホ
ールの方法で求めた結晶の不均一歪みの値ηが０．００
０５≦η≦０．００５である、スピネル型結晶構造のリ
チウムマンガン複合酸化物とその製造方法及びこのリチ
ウムマンガン複合酸化物を正極活物質に用いるリチウム
二次電池に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel lithium manganese oxide.
i 1 + x Mn 2-yz M y O 4 + δ (M in the formula Ni, Co, F
e, at least one metal element selected from Cr and Cu, and 0 ≦ x ≦ 1/3, 0 ≦ y ≦ 1/3, 0 <
z ≦ 0.25, −0.14 ≦ δ ≦ 0.5), and the value η of the non-uniform strain of the crystal obtained by the method of Hall is 0.00
The present invention relates to a lithium manganese composite oxide having a spinel type crystal structure in which 05 ≦ η ≦ 0.005, a method for producing the same, and a lithium secondary battery using the lithium manganese composite oxide as a positive electrode active material.
【０００２】リチウムマンガン複合酸化物は、安価で、
原料のマンガンが資源的に豊富で、環境に対して優しい
材料であることから、各種用途に関して有望な材料のひ
とつである。特に、リチウム二次電池用正極活物質材料
として、実用化が最も期待されている材料である。[0002] Lithium manganese composite oxide is inexpensive,
Manganese as a raw material is rich in resources and is environmentally friendly, so it is one of the promising materials for various applications. In particular, it is the material most expected to be put to practical use as a positive electrode active material for a lithium secondary battery.
【０００３】リチウム二次電池は、理論上、高いエネル
ギー密度の電池が構成可能であることから、次世代を担
う新型二次電池として幅広い分野への適用が進められて
おり、一部で既に実用化されたものも含めて、さらに高
性能化を目指した研究が進められている。[0003] Since lithium secondary batteries can theoretically be constructed with a high energy density, they are being applied to a wide range of fields as new types of secondary batteries for the next generation. Research aimed at further improving the performance, including those that have been developed, is underway.
【０００４】[0004]
【従来の技術】パーソナルユースのモバイル機器の普及
に伴って、小型、軽量でエネルギー密度の高いリチウム
二次電池の開発が強く望まれてきた。2. Description of the Related Art With the spread of personal use mobile devices, there has been a strong demand for the development of small, lightweight, and high energy density lithium secondary batteries.
【０００５】最近、負極にリチウムを吸蔵、放出可能な
炭素質材料を用いたリチウムイオン電池が実用化され、
急速に市場が拡大している。Recently, a lithium ion battery using a carbonaceous material capable of occluding and releasing lithium for a negative electrode has been put into practical use.
The market is expanding rapidly.
【０００６】現在のリチウムイオン電池の正極材料に
は、リチウムコバルト酸化物（以下LiCoO2と表記）が主
に使用されているが、コバルト原料が高価であることか
ら代替材料の開発が望まれている。At present, lithium cobalt oxide (hereinafter referred to as LiCoO 2 ) is mainly used as a positive electrode material of a lithium ion battery. However, since a cobalt raw material is expensive, development of an alternative material is desired. I have.
【０００７】４V級の起電力を示すLiCoO2に代わる正極
材料としては、リチウムニッケル酸化物（以下LiNiO2と
表記）やリチウムマンガンスピネル（以下LiMn2O4と表
記）が挙げられる。[0007] As a positive electrode material instead of LiCoO 2 exhibiting an electromotive force of 4V class, lithium nickel oxide (hereinafter referred to as LiNiO 2 ) and lithium manganese spinel (hereinafter referred to as LiMn 2 O 4 ) can be given.
【０００８】LiNiO2はニッケル原料がコバルト原料に比
べて安価であることや、電気化学容量が大きいことから
実用化に向けた開発が進められているが、LiNiO2は合成
が難しく、充電状態で熱的に不安定であり、電池を構成
した場合の安全性が十分に確保できないことから、現在
までのところ実用化されていない。[0008] and that LiNiO 2 is inexpensive nickel raw material compared with the cobalt raw material, but development for practical use has been promoted since the electrochemical capacity is large, LiNiO 2 synthesis is difficult, in a charged state It has not been put to practical use until now because it is thermally unstable and cannot secure sufficient safety when a battery is configured.
【０００９】一方、LiMn2O4はマンガン原料が資源的に
も豊富で安価であること、環境への影響が小さいこと、
合成が容易であること、熱的な安定性が４V級正極の中
で最も安定なことなどから、最も実用化が期待されてい
る材料ではあるが、LiCoO2やLiNiO2に比べて電気化学容
量が小さいことから、一部の用途で実用化されているの
みであり、高容量化が望まれている。On the other hand, LiMn 2 O 4 is rich in resources of manganese and is inexpensive, has a small effect on the environment,
Although it is the most promising material due to its ease of synthesis and the most stable thermal stability among 4V-class cathodes, its electrochemical capacity is higher than that of LiCoO 2 and LiNiO 2. Because of its small size, it has only been put to practical use in some applications, and higher capacity is desired.
【００１０】スピネル構造のLiMn2O4は、８ａサイトをリ
チウムが、１６ｄサイトをマンガンが、３２ｅサイトを
酸素が占有した正スピネルタイプの化合物である。言い
換えると、立方最密充填酸素の四面***置の１／８をリ
チウムが、八面***置の１／２をマンガンが占有した構
造を示す。LiMn 2 O 4 having a spinel structure is a positive spinel type compound in which lithium is occupied at the 8a site, manganese is occupied at the 16d site, and oxygen is occupied at the 32e site. In other words, it shows a structure in which 1/8 of the tetrahedral position of cubic close-packed oxygen is occupied by lithium and 1/2 of the octahedral position is occupied by manganese.
【００１１】LiMn2O4をリチウム二次電池の正極活物質
に用いた場合には、リチウムの酸化還元電位に対して約
４Vで機能する領域と、約３Vで作動する領域のあること
が報告されている。（小槻ら，第２９回電池討論会講演
要旨集，P１３５，１９８８年） 約４Vで機能する領域では、LiMn2O4の８aサイトのリチ
ウムが空の酸素八面***置の１６ｃサイトを介して結晶
構造中のリチウム占有サイトを移動することによって充
放電反応が進むと考えられている。When LiMn 2 O 4 is used as a positive electrode active material of a lithium secondary battery, it is reported that there are a region that functions at about 4 V and a region that operates at about 3 V with respect to the oxidation-reduction potential of lithium. Have been. (Kotsuki et al., Proceedings of the 29th Battery Symposium, P135, 1988) In the region functioning at about 4 V, lithium at the 8a site of LiMn 2 O 4 crystallized via the 16c site at the vacant oxygen octahedral position It is considered that the charge / discharge reaction proceeds by moving the lithium occupation site in the structure.
【００１２】これに対して、約３Vで機能する領域で
は、空の１６ｃサイトにリチウムが挿入・脱離されるこ
とで充放電反応が進むと考えられている。On the other hand, in a region that functions at about 3 V, it is considered that the charge / discharge reaction proceeds by insertion / desorption of lithium into / from an empty 16c site.
【００１３】すなわち、８aサイトのリチウムの脱離・
挿入によって約４Vでの充放電反応が、１６ｃサイトへ
のリチウムの挿入・脱離によって約３Vでの充放電反応
が起こる。That is, desorption of lithium at the 8a site
The insertion causes a charge / discharge reaction at about 4 V, and the insertion / desorption of lithium at the 16c site causes a charge / discharge reaction at about 3 V.
【００１４】これら２つの領域のうち、約４Vの領域でL
iMn2O4を機能させた場合には、基本骨格の立方晶を維持
した状態で、結晶構造の変化無しに充放電反応が進むこ
とから、可逆的な充放電反応が期待され、この領域の利
用に関して数多くの検討が成されてきた。[0014] Of these two regions, in the region of about 4V, L
When iMn 2 O 4 was made to function, the charge / discharge reaction proceeded without any change in the crystal structure while maintaining the cubic crystal of the basic skeleton, so a reversible charge / discharge reaction was expected. Numerous considerations have been made regarding its use.
【００１５】しかし、上述したように、約４Vで機能す
る領域だけでは、LiCoO2やLiNiO2の約半分の電気化学容
量しか得ることができず、高容量が要求されるモバイル
機器などへの適用は困難であると考えられる。However, as described above, only about half the capacity of LiCoO 2 or LiNiO 2 can be obtained in a region that functions at about 4 V, and the present invention is applied to mobile devices and the like that require a high capacity. Is considered difficult.
【００１６】高容量化を達成するための手段として、約
３Vの領域を利用することが考えられる。As a means for achieving high capacity, it is conceivable to use a region of about 3 V.
【００１７】約３Vで機能する領域では、放電反応によ
ってスピネル構造中の3価マンガンの割合が増加した場
合、３価マンガンの生成に由来するヤーンテラー歪みの
発生により、結晶構造の立方晶から正方晶への相転移が
起こり、約４Vで機能する領域に比べて大きな結晶の膨
張・収縮が起ることから、これまで提案されている材料
では、安定にサイクルさせることができなかった。In the region functioning at about 3 V, when the ratio of trivalent manganese in the spinel structure increases due to the discharge reaction, Jahn-Teller distortion due to the generation of trivalent manganese occurs, and the crystal structure changes from cubic to tetragonal. Phase transition occurs and the crystal expands and contracts larger than the region that functions at about 4 V. Therefore, the materials proposed so far cannot be cycled stably.
【００１８】これは、LiMn2O4の結晶構造が大きな膨張
・収縮を繰り返し受けた場合、結晶構造の崩壊や正極粒
子の微細化に伴う導電助剤（例えば、アセチレンブラッ
クやグラファイトなど）との接触不良などによる容量の
低下が起こるためと考えられてきた。This is because, when the crystal structure of LiMn 2 O 4 repeatedly undergoes a large expansion and contraction, the crystal structure of the LiMn 2 O 4 may be mixed with a conductive auxiliary (eg, acetylene black or graphite) accompanying the collapse of the crystal structure or the miniaturization of the positive electrode particles. It has been considered that the capacity is reduced due to poor contact or the like.
【００１９】以上のように、これまでに提案されている
LiMn2O4材料では高容量が要求される用途への適用は困
難であった。As described above, there has been proposed so far.
LiMn 2 O 4 materials have been difficult to apply to applications requiring high capacity.
【００２０】一方、パーソナルユースのモバイル機器の
普及に伴って、より小型、より軽量、よりエネルギー密
度の高いリチウム二次電池の開発が強く要望されてい
る。On the other hand, with the spread of mobile devices for personal use, there is a strong demand for the development of lithium secondary batteries that are smaller, lighter, and have higher energy density.
【００２１】さらに、電気自動車用の電源やオンサイト
型電力貯蔵用の電源として幅広く普及するためにも、安
価で安全な高容量の電極材料材料の開発が望まれてい
る。Further, in order to widely spread as a power supply for electric vehicles and a power supply for on-site power storage, it is desired to develop an inexpensive, safe and high-capacity electrode material.
【００２２】[0022]
【発明が解決しようとする課題】本発明の目的は、新規
なリチウムマンガン複合酸化物とその製造方法を提案
し、さらに、これを正極活物質に用いた高容量なリチウ
ム二次電池を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to propose a novel lithium manganese composite oxide and a method for producing the same, and to provide a high capacity lithium secondary battery using the same as a positive electrode active material. It is in.
【００２３】[0023]
【課題を解決するための手段】本発明者らは、上記課題
を解決することを目的に鋭意検討を行った結果、マンガ
ンの平均酸化数が３．０以上のマンガン化合物と、リチ
ウム化合物と、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ば
れる少なくとも一種類以上の金属の化合物との混合物
を、最初に５００℃以下の温度で焼成を行った後に、５
００℃を越え、且つ、９５０℃以下の温度でさらに焼成
を行うことで、一般式Ｌｉ1+xＭｎ2-y-zＭyＯ4+δ（式
中ＭはＮｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ばれる少な
くとも一種類以上の金属元素であり、０≦ｘ≦１／３，
０≦ｙ≦１／３，０＜ｚ≦０．２５，−０．１４≦δ≦
０．５）で表され、ホールの方法で求めた結晶の不均一
歪みの値ηが０．０００５≦η≦０．００５である、ス
ピネル型結晶構造のリチウムマンガン複合酸化物が合成
可能であり、さらに、これをリチウム二次電池の正極活
物質に用いることで、従来の材料では達成することがで
きなかった、高容量で可逆性に優れたマンガン系リチウ
ム二次電池が構成できることを見出し、本発明を完成す
るに至った。Means for Solving the Problems The present inventors have conducted intensive studies with the aim of solving the above problems, and as a result, have found that a manganese compound having an average manganese oxidation number of 3.0 or more, a lithium compound, After baking a mixture with a compound of at least one metal selected from Ni, Co, Fe, Cr, and Cu at a temperature of 500 ° C. or less,
Exceed 00 ° C., and, by performing the calcination at 950 ° C. temperature below the general formula Li 1 + x Mn 2-yz M y O 4 + δ ( wherein M is Ni, Co, Fe, Cr, Cu At least one or more metal elements selected from the group consisting of 0 ≦ x ≦ 1/3
0 ≦ y ≦ 1/3, 0 <z ≦ 0.25, −0.14 ≦ δ ≦
0.5), and a lithium-manganese composite oxide having a spinel-type crystal structure in which the value of the heterogeneous strain η of the crystal determined by the method of Hall is 0.0005 ≦ η ≦ 0.005. Further, by using this as a positive electrode active material of a lithium secondary battery, it was found that a manganese-based lithium secondary battery having high capacity and excellent reversibility, which could not be achieved with conventional materials, could be constructed. The present invention has been completed.
【００２４】[0024]
【作用】以下、本発明を具体的に説明する。The present invention will be specifically described below.
【００２５】本発明の、一般式Ｌｉ1+xＭｎ2-y-zＭyＯ
4+δ（式中ＭはＮｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ば
れる少なくとも一種類以上の金属元素であり、０≦ｘ≦
１／３，０≦ｙ≦１／３，０＜ｚ≦０．２５，−０．１
４≦δ≦０．５）で表されるリチウムマンガン酸化物
は、スピネル型結晶構造のみの単相構造の酸化物であ
る。[0025] of the present invention, the general formula Li 1 + x Mn 2-yz M y O
4 + δ (wherein M is at least one or more metal elements selected from Ni, Co, Fe, Cr and Cu, and 0 ≦ x ≦
1/3, 0 ≦ y ≦ 1/3, 0 <z ≦ 0.25, −0.1
The lithium manganese oxide represented by (4 ≦ δ ≦ 0.5) is a single-phase oxide having only a spinel-type crystal structure.
【００２６】この化合物は、リチウム，マンガン，酸
素、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ばれる少なく
とも一種類以上の金属元素で構成され、立方密充填した
酸素配列中の四面***置の８aサイトをリチウムが、八
面***置の１６dサイトをマンガンとＮｉ、Ｃｏ、Ｆ
ｅ、Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の金
属元素が又はリチウムとマンガンとＮｉ、Ｃｏ、Ｆｅ、
Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の金属元
素が占有している。This compound is composed of at least one metal element selected from the group consisting of lithium, manganese, oxygen, Ni, Co, Fe, Cr and Cu, and has an 8a site at a tetrahedral position in a cubic densely packed oxygen array. Lithium and manganese, Ni, Co, F
e, Cr, at least one or more metal elements selected from Cu or lithium, manganese and Ni, Co, Fe,
At least one metal element selected from Cr and Cu occupies.
【００２７】リチウム、マンガンおよびＮｉ、Ｃｏ、Ｆ
ｅ、Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の各
金属元素のサイト占有率は、上記一般式の範囲であれば
スピネル型構造のみの単相構造の酸化物となり、各サイ
トのリチウム、マンガンおよびＮｉ、Ｃｏ、Ｆｅ、Ｃ
ｒ、Ｃｕから選ばれる少なくとも一種類以上の金属元素
の占有率は上記範囲に制限される。Lithium, manganese and Ni, Co, F
The site occupancy of at least one or more of each metal element selected from e, Cr, and Cu is an oxide having a single-phase structure having only a spinel structure within the range of the general formula, and lithium, manganese, and Ni, Co, Fe, C
The occupancy of at least one or more metal elements selected from r and Cu is limited to the above range.
【００２８】また、リチウムマンガン酸化物は熱的に酸
素を放出吸収する性質を示し、合成条件や熱処理によっ
て容易に酸素量の過不足を生じるが、酸素量が上記一般
式の範囲であればスピネル型構造のみの単相構造の酸化
物となる。Further, lithium manganese oxide has a property of thermally releasing and absorbing oxygen, and the amount of oxygen easily becomes excessive or insufficient depending on synthesis conditions or heat treatment. It becomes an oxide having a single-phase structure having only a mold structure.
【００２９】本発明のリチウムマンガン複合酸化物は、
ホールの方法で求めた結晶の不均一歪みの値ηが０．０
００５≦η≦０．００５であることが必須である。ηの
値が上記範囲であれば、結晶構造の立方晶から正方晶へ
の相転移が可逆的に進む。The lithium manganese composite oxide of the present invention comprises
The value of the non-uniform strain η of the crystal obtained by the method of Hall is 0.0
It is essential that 005 ≦ η ≦ 0.005. When the value of η is within the above range, the phase transition from cubic to tetragonal in the crystal structure proceeds reversibly.
【００３０】詳細については不明だが、本発明者らの検
討によれば、ηの値が０．０００５未満では、立方晶か
ら正方晶への相転移が不可逆的となり、本発明の目的と
する、リチウムマンガンスピネルの高容量化は達成でき
ない。また、ηの値が０．００５を超えると、結晶構造
がアモルファスな材料となり、電池の正極材料に適さな
い、充放電の可逆性が低い材料となる。Although the details are unknown, according to the study of the present inventors, when the value of η is less than 0.0005, the phase transition from cubic to tetragonal becomes irreversible, which is the object of the present invention. High capacity lithium manganese spinel cannot be achieved. If the value of η exceeds 0.005, the crystal structure becomes an amorphous material, and the material is not suitable for a positive electrode material of a battery and has low charge / discharge reversibility.
【００３１】本発明で示した結晶の不均一歪みは、例え
ば、X線回折の手引改定第四版（理学電機株式会社）の
７５ページ以降に記載されているように、粒子を構成し
ている結晶子が、隣接する結晶子間で歪みを受け、また
は一つの結晶子内で場所により異なる歪みを受け、格子
面間隔がランダムに変化した場合の歪みを表す。The non-uniform strain of the crystal shown in the present invention constitutes grains as described in, for example, page 75 and subsequent pages of the fourth revised edition of the X-ray diffraction guide (Rigaku Corporation). It represents the distortion when a crystallite receives a distortion between adjacent crystallites or a distortion different from one place to another within one crystallite, and the lattice spacing changes randomly.
【００３２】不均一歪みの大きさは係数ηとして表さ
れ、Hallの方法を用いて、粉末X線回折測定によって得
られる各回折ピークの回折位置と、ピークの広がり、す
なわち半値幅から求められる。The magnitude of the non-uniform distortion is expressed as a coefficient η, and is determined from the diffraction position of each diffraction peak obtained by powder X-ray diffraction measurement and the spread of the peak, that is, the half width, using the method of Hall.
【００３３】本発明者らは、鋭意検討を行った結果、こ
のηの値は、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ばれ
る少なくとも一種類以上の金属元素でマンガンを置換す
ることで制御することができることが分かった。また、
置換量を多くすることで、大きなηの値を示すリチウム
マンガン複合酸化物が合成できることも分かった。The present inventors have made intensive studies and as a result, the value of η is controlled by substituting manganese with at least one or more metal elements selected from Ni, Co, Fe, Cr and Cu. I found that I could do it. Also,
It was also found that by increasing the substitution amount, a lithium manganese composite oxide having a large value of η can be synthesized.
【００３４】本発明者らは、特開平８−２１７４５１お
よび特開平８−２１７４５２で、マンガンの一部を他の
元素で置換することで、約４Ｖの領域で充放電を行った
場合の充放電のサイクル安定性が向上することを提案し
ている。The inventors of the present invention disclosed in Japanese Patent Application Laid-Open Nos. 8-217451 and 8-217452 that the manganese was partially substituted with another element to thereby perform charging and discharging in a region of about 4 V. Cycle stability is improved.
【００３５】従って、マンガンの一部を上記元素の少な
くとも1種類以上で置換することによって、約３Ｖ領域
と約４Ｖ領域の両方の充放電サイクル安定性を向上させ
ることが可能となる。Accordingly, by partially replacing manganese with at least one of the above-mentioned elements, it is possible to improve the charge / discharge cycle stability in both the approximately 3 V region and the approximately 4 V region.
【００３６】しかし、置換量が０．２５を越えると正ス
ピネル構造単相の化合物を合成することが困難になる。
従って、置換量は０．２５以下であることが必須であ
る。However, when the substitution amount exceeds 0.25, it becomes difficult to synthesize a compound having a single phase of the positive spinel structure.
Therefore, it is essential that the replacement amount is 0.25 or less.
【００３７】本発明のリチウムマンガン複合酸化物は、
マンガンの平均酸化数が３．０以上のマンガン化合物
と、リチウム化合物と、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕ
から選ばれる少なくとも一種類以上の金属元素化合物と
の混合物を、最初に５００℃以下の温度で焼成を行った
後に、５００℃を越え、且つ、９５０℃以下の温度でさ
らに焼成を行うことで製造できる。The lithium manganese composite oxide of the present invention comprises
A manganese compound having an average oxidation number of manganese of 3.0 or more, a lithium compound, Ni, Co, Fe, Cr, Cu
A mixture with at least one or more metal element compounds selected from the group consisting of: first firing at a temperature of 500 ° C. or less, and then further firing at a temperature exceeding 500 ° C. and 950 ° C. or less it can.
【００３８】詳細については不明だが、本発明者らは以
下のように考えている。Although the details are unknown, the present inventors think as follows.
【００３９】リチウムとマンガンとの複合化反応を考え
た場合、同じリチウム化合物を用いて、平均酸化数の異
なるマンガン化合物と反応させた場合には、平均酸化数
が高いものほど低い温度からリチウムとの反応が始ま
り、さらに、リチウム化合物自身の分解温度よりも低い
温度からリチウムとマンガンとの複合化反応が始まるこ
とが分かっている。Considering the complexing reaction of lithium and manganese, when the same lithium compound is used to react with manganese compounds having different average oxidation numbers, the higher the average oxidation number, the lower the temperature. It has been found that the reaction of the compound starts with a temperature lower than the decomposition temperature of the lithium compound itself.
【００４０】反応初期においては、リチウム化合物の分
解反応と生成物のマンガン化合物固相内部への拡散が律
速反応になると考えられる。At the beginning of the reaction, it is considered that the decomposition reaction of the lithium compound and the diffusion of the product into the solid phase of the manganese compound are rate-determining reactions.
【００４１】また、マンガンとリチウムとの複合化反応
は接触界面から起こると考えられることから、反応初期
では、マンガン化合物内部において、接触界面近傍とそ
の周辺部では化学組成や結晶構造の不均一さが顕著にな
ると考えられる。Further, since the complexing reaction of manganese and lithium is considered to take place from the contact interface, in the initial stage of the reaction, the chemical composition and the non-uniformity of the crystal structure in the vicinity of the contact interface and in the periphery thereof are inside the manganese compound. Is considered to be remarkable.
【００４２】さらに、マンガンとリチウムとの反応生成
物のマンガン化合物内部への拡散、言い換えれば、リチ
ウムのマンガン化合物固相内部への拡散は、反応温度に
よって影響を受けると考えられ、低い温度で複合化反応
が始まる条件では、マンガン化合物内部における、接触
界面近傍とその周辺部の組成の不均一さが著しくなると
考えられる。Furthermore, the diffusion of the reaction product of manganese and lithium into the manganese compound, in other words, the diffusion of lithium into the manganese compound solid phase is considered to be affected by the reaction temperature. It is considered that, under the conditions at which the formation reaction starts, the composition in the manganese compound becomes extremely non-uniform in the vicinity of the contact interface and in the periphery thereof.
【００４３】この不均一さは、生成物の結晶構造の不均
一性、即ち不均一歪みを引き起こす原因となり、従っ
て、低い温度でリチウムとの複合化反応が進む場合に
は、結晶の不均一歪みを持ったリチウムマンガン酸化物
が生成し易くなると考えられる。This non-uniformity causes non-uniformity of the crystal structure of the product, that is, non-uniform distortion. Therefore, when the compounding reaction with lithium proceeds at a low temperature, the non-uniform distortion of the crystal may occur. It is thought that a lithium manganese oxide having
【００４４】本発明のリチウムマンガン複合酸化物の合
成において、初めに５００℃以下の温度で焼成を行い、
５００℃を越え、且つ、９５０℃以下の温度でさらに焼
成を行うことが必須である。In synthesizing the lithium manganese composite oxide of the present invention, first, firing is performed at a temperature of 500 ° C. or less,
It is essential that the calcination be further performed at a temperature exceeding 500 ° C. and 950 ° C. or less.
【００４５】初めに５００℃を超える温度でリチウム化
合物と、Ｎｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ばれる少
なくとも一種類以上の金属元素の化合物との混合物の焼
成を行った場合、リチウムおよびＮｉ、Ｃｏ、Ｆｅ、Ｃ
ｒ、Ｃｕから選ばれる少なくとも一種類以上の金属元素
の化合物のマンガン化合物固相内部への拡散が進み易く
なり、生成物であるリチウムマンガン複合酸化物の結晶
の不均一歪みの原因となる結晶構造の不均一性が得られ
なくなる。併せて、マンガン化合物および生成物の還元
反応が起こり易くなり、スピネル型構造のみの単相構造
のリチウムマンガン複合酸化物の生成が困難になる。First, when a mixture of a lithium compound and a compound of at least one metal element selected from Ni, Co, Fe, Cr and Cu is fired at a temperature exceeding 500 ° C., lithium and Ni, Co, Fe, C
A crystal structure that causes the compound of at least one or more metal elements selected from r and Cu to easily diffuse into the solid phase of the manganese compound and causes non-uniform distortion of the crystal of the product lithium manganese composite oxide Cannot be obtained. In addition, the reduction reaction of the manganese compound and the product is likely to occur, and it becomes difficult to produce a single-phase lithium manganese composite oxide having only a spinel structure.
【００４６】本発明のリチウムマンガン酸化物の合成に
おいて、二番目の焼成温度は、最初の焼成温度を超える
温度で焼成を行うことが必須となるが、９５０℃を越え
る温度で焼成を行った場合には、酸素の放出が起こり易
くなり、本発明のスピネル型構造のみの単相構造のリチ
ウムマンガン複合酸化物を合成することが困難になる。In the synthesis of the lithium manganese oxide of the present invention, it is essential that the second calcination temperature is higher than the first calcination temperature, but if the calcination is performed at a temperature higher than 950 ° C. In this case, oxygen is easily released, and it becomes difficult to synthesize the single-phase lithium manganese composite oxide having only the spinel structure of the present invention.
【００４７】なお、最初の焼成から次の焼成に移る際
に、そのまま昇温しても良く、室温まで降温した後に昇
温しても良く、さらに、昇温の前に粉砕・混合を行って
も良い。When the process proceeds from the first firing to the next firing, the temperature may be raised as it is, or may be lowered to room temperature, and then may be further crushed and mixed before raising the temperature. Is also good.
【００４８】本発明のリチウムマンガン複合酸化物の合
成において、マンガンの平均酸化数が３．０以上のマン
ガン化合物を用いることが重要である。In the synthesis of the lithium-manganese composite oxide of the present invention, it is important to use a manganese compound having an average manganese oxidation number of 3.0 or more.
【００４９】詳細については不明だが、マンガンの平均
酸化数が３．０以上のマンガン化合物を用いた場合、本
発明の不均一歪みの値ηを持つリチウムマンガン複合酸
化物を合成するための、最適な反応開始温度になると考
えられる。Although the details are unknown, when a manganese compound having an average oxidation number of manganese of 3.0 or more is used, an optimum manganese compound oxide having a nonuniform strain value η of the present invention is synthesized. It is considered that the reaction start temperature is high.
【００５０】合成に用いるマンガン化合物は、化合物中
のマンガンの平均酸化数が３．０以上で５００℃以下の
温度でリチウム化合物と反応し、９５０℃以下の温度で
スピネル構造のリチウムマンガン酸化物を生成する化合
物であればいかなるものを用いても良い。本発明を制限
するものではないが、例えば、酸化物としては、各種結
晶形態のいわゆる二酸化マンガン、三二酸化マンガン、
水和酸化マンガン（ＭｎＯＯＨ）などの酸化物や、マン
ガン化合物を５００℃以上の温度で酸素含有雰囲気中で
熱処理して合成したマンガンの平均酸化数が３．０以上
のマンガン酸化物が例示される。さらに、３００℃以下
の温度でマンガンの平均酸化数が４．０のβ型二酸化マ
ンガンを生成するマンガナイト（γ−ＭｎＯＯＨ）およ
び、γ−ＭｎＯＯＨを予め酸素含有雰囲気中で熱処理し
て合成したβ型二酸化マンガンや三二酸化マンガンが好
ましい。さらに、各種マンガン化合物の加熱処理によっ
て合成した、三二酸化マンガンも好ましい。The manganese compound used in the synthesis reacts with the lithium compound at a temperature of 500 ° C. or less when the average oxidation number of manganese in the compound is 3.0 or more, and forms a lithium manganese oxide having a spinel structure at a temperature of 950 ° C. or less. Any compound may be used as long as it is a compound to be generated. Although not limiting the present invention, for example, as oxides, various crystalline forms of so-called manganese dioxide, manganese trioxide,
Oxides such as hydrated manganese oxide (MnOOH) and manganese oxides having an average oxidation number of 3.0 or more of manganese synthesized by heat-treating a manganese compound at a temperature of 500 ° C. or more in an oxygen-containing atmosphere are exemplified. . Furthermore, manganite (γ-MnOOH), which generates β-type manganese dioxide having an average manganese oxidation number of 4.0 at a temperature of 300 ° C. or less, and β synthesized by previously heat-treating γ-MnOOH in an oxygen-containing atmosphere. Manganese dioxide and trimanganese dioxide are preferred. Further, manganese trioxide synthesized by heat treatment of various manganese compounds is also preferable.
【００５１】一方、合成に用いるリチウム化合物は、マ
ンガンの平均酸化数が３．０以上の化合物と５００℃以
下の温度で反応が始まる化合物であればいかなるものを
用いても良い。本発明を制限するものではないが、例え
ば、炭酸リチウム、水酸化リチウム、硝酸リチウム、酢
酸リチウム、ヨウ化リチウムなどが例示されるが、平均
粒径が１０μｍ以下のリチウム化合物を用いることが好
ましい。On the other hand, as the lithium compound used in the synthesis, any compound may be used as long as it starts reacting with a compound having an average oxidation number of manganese of 3.0 or more at a temperature of 500 ° C. or less. Although the present invention is not limited thereto, for example, lithium carbonate, lithium hydroxide, lithium nitrate, lithium acetate, lithium iodide and the like are exemplified, and it is preferable to use a lithium compound having an average particle diameter of 10 μm or less.
【００５２】また、合成に用いるＮｉ、Ｃｏ、Ｆｅ、Ｃ
ｒ、Ｃｕから選ばれる少なくとも一種類以上の金属元素
の化合物には、９５０℃以下の温度でマンガンの一部と
置換したリチウムマンガン複合酸化物を生成することが
できる化合物であればいかなるものを用いても良い。本
発明を制限するものではないが、例えば、各金属の水酸
化物、硝酸塩、シュウ酸塩などが例示されるが、硝酸塩
がより好ましい。In addition, Ni, Co, Fe, C
As the compound of at least one kind of metal element selected from r and Cu, any compound can be used as long as it can generate a lithium manganese composite oxide substituted with part of manganese at a temperature of 950 ° C. or lower. May be. Although the present invention is not limited thereto, for example, hydroxide, nitrate, oxalate and the like of each metal are exemplified, but nitrate is more preferable.
【００５３】本発明のリチウムマンガン複合酸化物の合
成において、焼成雰囲気は酸素含有雰囲気であることが
望ましい。In the synthesis of the lithium manganese composite oxide of the present invention, the firing atmosphere is desirably an oxygen-containing atmosphere.
【００５４】本発明のリチウム二次電池の負極として
は、リチウム金属、リチウム合金、リチウムを予め吸蔵
した、リチウムを吸蔵放出可能な化合物を用いることが
できる。As the negative electrode of the lithium secondary battery of the present invention, a lithium metal, a lithium alloy, or a compound which can occlude and release lithium and which has occluded lithium can be used.
【００５５】リチウム合金としては、本発明を制限する
ものではないが、例えば、リチウム／スズ合金、リチウ
ム／アルミニウム合金、リチウム／鉛合金等が例示され
る。The lithium alloy is not limited to the present invention, and examples thereof include a lithium / tin alloy, a lithium / aluminum alloy, and a lithium / lead alloy.
【００５６】リチウムを吸蔵放出可能な化合物として
は、本発明を制限するものではないが、例えば、グラフ
ァイトや黒鉛等の炭素材料や、鉄の酸化物、コバルトの
酸化物が例示される。The compound capable of inserting and extracting lithium is not limited to the present invention, and examples thereof include carbon materials such as graphite and graphite, iron oxides, and cobalt oxides.
【００５７】また、本発明のリチウム二次電池の電解質
は、特に制限されないが、例えば、炭酸プロレン、炭酸
ジエチル等のカーボネート類や、スルホラン、ジメチル
スルホキシド等のスルホラン類、γブチロラクトン等の
ラクトン類、ジメチルスルホキシド等のエーテル類の少
なくとも１種類以上の有機溶媒に、過塩素酸リチウム、
四フッ化ホウ酸リチウム、六フッ化リン酸リチウム、ト
リフルオロメタンスルホン酸等のリチウム塩の少なくと
も１種類以上を溶解したものや、無機系および有機系の
リチウムイオン導電性の固体電解質などを用いることが
できる。The electrolyte of the lithium secondary battery of the present invention is not particularly limited. Examples thereof include carbonates such as prolene carbonate and diethyl carbonate, sulfolane such as sulfolane and dimethyl sulfoxide, and lactones such as γ-butyrolactone. Lithium perchlorate, at least one organic solvent of ethers such as dimethyl sulfoxide,
Use a solution in which at least one lithium salt such as lithium tetrafluoroborate, lithium hexafluorophosphate, trifluoromethanesulfonic acid or the like is dissolved, or an inorganic or organic lithium ion conductive solid electrolyte. Can be.
【００５８】本発明で得られたリチウムマンガン酸化物
を正極活物質に用いて、図１に示す電池を構成した。A battery shown in FIG. 1 was constructed using the lithium manganese oxide obtained in the present invention as a positive electrode active material.
【００５９】図中において、：蓋、：テフロン製絶
縁体、：負極集電用メッシュ、：負極、：セパレ
ーター、：正極、：正極集電用メッシュ、：容器
を示す。In the figure,: lid,: Teflon insulator,: negative electrode current collecting mesh,: negative electrode,: separator,: positive electrode,: positive electrode current collecting mesh,: container.
【００６０】以下に、本発明の具体例として実施例を示
すが、本発明はこれらの実施例により制限されるもので
はない。Examples are shown below as specific examples of the present invention, but the present invention is not limited to these examples.
【００６１】なお、本発明の実施例および比較例におけ
る粉末X線回折測定、不均一歪みηの算出は、以下に示
す方法で行った。The powder X-ray diffraction measurement and the calculation of the non-uniform strain η in Examples and Comparative Examples of the present invention were performed by the following methods.
【００６２】粉末X線回折測定 測定機種 マックサイエンス社製 MXP３ 照射X線 Cu Kα線 測定モード ステップスキャン スキャン条件 ２θとして０．０４° 計測時間 ５秒 測定範囲 ２θとして５°から８０° 不均一歪みηの算出 Hallの方法：β・cosθ／λ＝２・η・sinθ／λ＋１／ε ２本以上の回折線のプロファイルを測定して、β・cosθ
／λをY軸に、２・η・sinθ／λをX軸にプロットして得
られた直線の勾配の１／２が不均一歪みηの値になる。Powder X-ray diffraction measurement Measurement model MXS3 manufactured by Mac Science Inc. Irradiated X-ray Cu Kα ray Measurement mode Step scan Scan condition 0.04 ° as 2θ Measurement time 5 seconds Measurement range 5 ° to 80 ° as 2θ Non-uniform distortion η Hall method: β · cos θ / λ = 2 · η · sin θ / λ + 1 / ε The profile of two or more diffraction lines is measured, and β · cos θ
/ Λ is plotted on the Y-axis and 2 · η · sin θ / λ is plotted on the X-axis.
【００６３】ここで、β：半値幅、λ：測定Ｘ線波長、
θ：回折線のブラック角 ε：結晶子径の平均の大きさを表わす。Here, β: half width, λ: measured X-ray wavelength,
θ: Black angle of diffraction line ε: Indicates the average size of crystallite diameter.
【００６４】[0064]
【実施例】［マンガン酸化物の製造］ 実施例１ （LiMn1.8Ｎｉ0.2O4の合成）実施例１として、LiMn1.8
Ｎｉ0.2O4を以下の方法によって作成した。EXAMPLES [Manufacture of Manganese Oxide] Example 1 (Synthesis of LiMn 1.8 Ni 0.2 O 4 ) As Example 1, LiMn 1.8
Ni 0.2 O 4 was prepared by the following method.
【００６５】硝酸リチウム、硝酸ニッケルの６水和物と
針状水和酸化マンガン（γ−ＭｎＯＯＨ）をモル比でL
i：Mn：Ｎｉ比が１．０：１．８：０．２になるように
混合した後に、第１の焼成として、大気中で２６０℃の
温度で２４時間焼成を行った。Lithium nitrate, nickel nitrate hexahydrate and acicular hydrated manganese oxide (γ-MnOOH) are expressed in molar ratio L
After mixing so that the i: Mn: Ni ratio was 1.0: 1.8: 0.2, the first baking was performed in the air at a temperature of 260 ° C. for 24 hours.
【００６６】次に、これを室温まで降温した後に、粉砕
・混合処理を行った後に、第２の焼成として大気中で６
５０℃の温度で２４時間焼成した。Next, after the temperature is lowered to room temperature, a pulverization and mixing process is performed, and then a second baking is performed in the atmosphere in air.
It was baked at a temperature of 50 ° C. for 24 hours.
【００６７】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
った。From the result of powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure.
【００６８】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００６９】実施例２ （LiMn1.5Ｃｏ0.5O4の合成）実施例２として、金属材料
に硝酸コバルトの６水和物を用いて、モル比でLi：Mn：
Ｃｏ比が１．０：１．５：２．０になるように混合した
以外は、実施例１と同様にしてリチウムマンガン複合酸
化物を合成した。Example 2 (Synthesis of LiMn 1.5 Co 0.5 O 4 ) As Example 2, a hexahydrate of cobalt nitrate was used as a metal material, and Li: Mn:
A lithium-manganese composite oxide was synthesized in the same manner as in Example 1, except that the Co ratio was changed to 1.0: 1.5: 2.0.
【００７０】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
った。From the result of powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure.
【００７１】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００７２】実施例３ （LiMn1.9Ｆｅ0.1O4の合成）実施例３として、金属材料
に硝酸鉄の９水和物を用いて、モル比でLi：Mn：Ｆｅ比
が１．０：１．９：０．１になるように混合した以外
は、実施例１と同様にしてリチウムマンガン複合酸化物
を合成した。Example 3 (Synthesis of LiMn 1.9 Fe 0.1 O 4 ) As Example 3, a 9: 1 hydrate of iron nitrate was used as a metal material, and a Li: Mn: Fe ratio of 1.0: 1 was used. A lithium manganese composite oxide was synthesized in the same manner as in Example 1 except that the components were mixed so as to be 0.9: 0.1.
【００７３】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
った。From the results of the powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure.
【００７４】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００７５】実施例４ （LiMn1.8Ｃｒ0.2O4の合成）実施例４として、金属材料
に硝酸クロムの９水和物を用いて、モル比でLi：Mn：Ｃ
ｒ比が１．０：１．８：０．２になるように混合した以
外は、実施例１と同様にしてリチウムマンガン複合酸化
物を合成した。Example 4 (Synthesis of LiMn 1.8 Cr 0.2 O 4 ) In Example 4, chromium nitrate nonahydrate was used as the metal material, and a molar ratio of Li: Mn: C was used.
A lithium manganese composite oxide was synthesized in the same manner as in Example 1, except that the mixture was performed so that the r ratio was 1.0: 1.8: 0.2.
【００７６】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
った。From the result of the powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure.
【００７７】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００７８】実施例５ （LiMn1.8Ｃu0.2O4の合成）実施例５として、金属材料
に硝酸銅の３水和物を用いて、モル比でLi：Mn：Cu比が
１．０：１．８：０．２になるように混合した以外は、
実施例１と同様にしてリチウムマンガン複合酸化物を合
成した。Example 5 (Synthesis of LiMn 1.8 Cu 0.2 O 4 ) As Example 5, using a nitrate of copper nitrate as the metal material, the Li: Mn: Cu ratio was 1.0: 1 in molar ratio. .8: 0.2 except that they were mixed
A lithium manganese composite oxide was synthesized in the same manner as in Example 1.
【００７９】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
った。From the result of powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure.
【００８０】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００８１】比較例 （LiMn2.0O4の合成）比較例として、硝酸リチウムと四
三酸化マンガンをモル比でLi：Mn比が１．０：２．０に
なるように混合した後に、第１の焼成として、大気中で
２６０℃の温度で２４時間焼成を行った。Comparative Example (Synthesis of LiMn 2.0 O 4 ) As a comparative example, lithium nitrate and manganese tetroxide were mixed so that the molar ratio of Li: Mn was 1.0: 2.0. Was fired in the atmosphere at a temperature of 260 ° C. for 24 hours.
【００８２】次に、これを室温まで降温した後に、粉砕
・混合処理を行った後に、第２の焼成として大気中で６
５０℃の温度で２４時間焼成した。Next, after the temperature is lowered to room temperature, a pulverization / mixing process is performed, and a second baking is performed in the atmosphere in air.
It was baked at a temperature of 50 ° C. for 24 hours.
【００８３】粉末Ｘ線回折測定の結果から、得られた化
合物はスピネル型構造のみの単相構造であることが分か
ったが、ηの値は０．００００１であった。。From the results of powder X-ray diffraction measurement, it was found that the obtained compound had a single-phase structure having only a spinel structure, but the value of η was 0.00001. .
【００８４】化学組成分析の結果、およびηの値を表１
に示した。Table 1 shows the results of the chemical composition analysis and the value of η.
It was shown to.
【００８５】［電池の構成］実施例１〜５及び比較例で
製造したリチウムマンガン複合酸化物を、導電剤のポリ
テトラフルオロエチレンとアセチレンブラックとの混合
物（商品名：ＴＡＢ−2）を重量比で２：１になるよう
に混合した。混合物の７５ｍｇを１ｔｏｎ・ｃｍ-2の圧
力で、２０ｍｍφのメッシュ（ＳUＳ ３１６）上にペ
レット状に成形した後に、２００℃で５時間、減圧乾燥
処理を行った。[Structure of Battery] The lithium manganese composite oxides produced in Examples 1 to 5 and Comparative Example were mixed with a mixture of a conductive agent of polytetrafluoroethylene and acetylene black (trade name: TAB-2) in a weight ratio. And mixed at 2: 1. After 75 mg of the mixture was formed into a pellet on a 20 mmφ mesh (SUS 316) at a pressure of 1 ton · cm −2 , a vacuum drying treatment was performed at 200 ° C. for 5 hours.
【００８６】これを、図１のの正極に用いて、図１の
の負極には、リチウム箔（厚さ０．２mm）から切り抜
いたリチウム片を用いて、電解液には、プロピレンカー
ボネートと炭酸ジエチルの体積比１：４の混合溶媒に、
六フッ化リン酸リチウムを１mol・dm-3の濃度に溶解し
た有機電解液を図１ののセパレータに含浸させて、断
面積２．５ｃｍ2の図１に示した電池を構成した。This was used for the positive electrode in FIG. 1, the negative electrode in FIG. 1 was a lithium piece cut out of a lithium foil (0.2 mm thick), and the electrolyte was propylene carbonate and carbonate. In a mixed solvent of diethyl in a volume ratio of 1: 4,
An organic electrolyte solution in which lithium hexafluorophosphate was dissolved at a concentration of 1 mol · dm −3 was impregnated into the separator shown in FIG. 1 to form the battery shown in FIG. 1 having a cross-sectional area of 2.5 cm 2 .
【００８７】［電池性能の評価］上記方法で作成した電
池を用いて、１．０ｍＡ・ｃｍ-2の一定電流で、電池電
圧が４．２Ｖから２．０Ｖの間で充放電を繰り返した。[Evaluation of Battery Performance] Using the battery prepared by the above method, charging and discharging were repeated at a constant current of 1.0 mA · cm −2 and a battery voltage of 4.2 V to 2.0 V.
【００８８】表１に、実施例及び比較例で合成したリチ
ウムマンガン複合酸化物の化学組成分析の結果、不均一
歪みηの値、これを正極活物質に用いて構成した電池の
１サイクル目の放電容量に対する５０サイクル目の放電
容量の維持率を示す。Table 1 shows the results of the chemical composition analysis of the lithium manganese composite oxides synthesized in Examples and Comparative Examples, the value of the non-uniform strain η, and the value of the first cycle of the battery constituted by using this as the positive electrode active material. The retention rate of the discharge capacity at the 50th cycle with respect to the discharge capacity is shown.
【００８９】[0089]
【表１】 [Table 1]
【００９０】実施例１〜５で合成したリチウムマンガン
酸化物は、いずれも８０％以上の高い容量維持率を示し
た。The lithium manganese oxides synthesized in Examples 1 to 5 all exhibited high capacity retention rates of 80% or more.
【００９１】一方、比較例で合成したリチウムマンガン
酸化物を用いた電池の容量維持率は、３５％であった。On the other hand, the capacity retention of the battery using the lithium manganese oxide synthesized in the comparative example was 35%.
【００９２】[0092]
【発明の効果】以上述べてきたとおり、本発明者らの検
討によって、マンガンの平均酸化数が３．０以上のマン
ガン化合物と、リチウム化合物と、Ｎｉ、Ｃｏ、Ｆｅ、
Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の金属材
料との混合物を、最初に５００℃以下の温度で焼成を行
った後に、５００℃を越えて９５０℃以下の温度で第２
の焼成を行うことで、一般式Ｌｉ1+xＭｎ2-y-zＭyＯ
4+δ（式中ＭはＮｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ば
れる少なくとも一種類以上の金属元素であり、０≦ｘ≦
１／３，０≦ｙ≦１／３，０＜ｚ≦０．２５，−０．１
４≦δ≦０．５）で表され、ホールの方法で求めた結晶
の不均一歪みの値ηが０．０００５≦η≦０．００５で
ある、スピネル型結晶構造のリチウムマンガン複合酸化
物が合成可能であり、さらに、これをリチウム二次電池
の正極活物質に用いることで、従来の材料では達成する
ことができなかった、高容量で可逆性に優れたマンガン
系リチウム二次電池が構成できることを見出した。As described above, according to the study of the present inventors, a manganese compound having an average manganese oxidation number of 3.0 or more, a lithium compound, Ni, Co, Fe,
A mixture with at least one kind of metal material selected from Cr and Cu is first fired at a temperature of 500 ° C. or less, and then the second mixture is heated at a temperature exceeding 500 ° C. and 950 ° C. or less.
By performing the calcination, the general formula Li 1 + x Mn 2-yz M y O
4 + δ (where M is at least one or more metal elements selected from Ni, Co, Fe, Cr and Cu, and 0 ≦ x ≦
1/3, 0 ≦ y ≦ 1/3, 0 <z ≦ 0.25, −0.1
4 ≦ δ ≦ 0.5), and a lithium-manganese composite oxide having a spinel-type crystal structure in which the value of the non-uniform strain η of the crystal determined by the method of Hall is 0.0005 ≦ η ≦ 0.005. By using this as a positive electrode active material of a lithium secondary battery, it is possible to synthesize a manganese-based lithium secondary battery with high capacity and excellent reversibility, which could not be achieved with conventional materials. I found what I can do.
【００９３】リチウム二次電池正極活物質に適用可能な
高容量を達成できるリチウムマンガン複合酸化物を見出
したことは、産業上有益な知見である。It is an industrially useful finding that a lithium manganese composite oxide capable of achieving a high capacity applicable to a positive electrode active material of a lithium secondary battery has been found.
【図１】実施例及び比較例で構成した電池の実施態様を
示す図である。FIG. 1 is a diagram showing an embodiment of a battery constituted by an example and a comparative example.
【符号の説明】 ：蓋 ：テフロン製絶縁体 ：負極集電用メッシュ ：負極 ：セパレーター ：正極 ：正極集電用メッシュ ：容器[Explanation of symbols]: Lid: Teflon insulator: Negative electrode current collector mesh: Negative electrode: Separator: Positive electrode: Positive electrode current collector mesh: Container
フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０１Ｍ 4/02 Ｈ０１Ｍ 4/02 Ｄ 4/58 4/58 10/40 10/40 Ｚ Ｆターム(参考） 4G002 AA06 AA10 AB01 AD04 AE05 4G048 AA04 AB05 AC06 AD06 AE05 5H003 AA02 BA01 BA03 BB05 BC01 BC06 BD00 BD01 5H014 AA01 BB01 EE05 EE10 HH00 HH08 5H029 AJ03 AK03 AL06 AL12 AM03 AM04 AM05 AM07 CJ02 CJ28 HJ00 HJ02 HJ13 HJ14 Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat II (reference) H01M 4/02 H01M 4/02 D 4/58 4/58 10/40 10/40 Z F term (reference) 4G002 AA06 AA10 AB01 AD04 AE05 4G048 AA04 AB05 AC06 AD06 AE05 5H003 AA02 BA01 BA03 BB05 BC01 BC06 BD00 BD01 5H014 AA01 BB01 EE05 EE10 HH00 HH08 5H029 AJ03 AK03 AL06 AL12 AM03 AM04 AM05 AM07 CJ02 CJ28 HJ00 HJ
Claims (4)
ＭはＮｉ、Ｃｏ、Ｆｅ、Ｃｒ、Ｃｕから選ばれる少なく
とも一種類以上の金属元素であり、０≦ｘ≦１／３，０
≦ｙ≦１／３，０＜ｚ≦０．２５，−０．１４≦δ≦
０．５）で表され、ホールの方法で求めた結晶の不均一
歪みの値ηが０．０００５≦η≦０．００５である、ス
ピネル型結晶構造のリチウムマンガン複合酸化物。1. A general formula Li 1 + x Mn 2-yz M y O 4 + δ ( wherein M is Ni, Co, Fe, Cr, at least one kind or more metal element selected from Cu, 0 ≦ x ≦ 1 / 3,0
≦ y ≦ 1/3, 0 <z ≦ 0.25, −0.14 ≦ δ ≦
0.5) A lithium manganese composite oxide having a spinel-type crystal structure, wherein the value of the non-uniform strain η of the crystal determined by the method of Hall is 0.0005 ≦ η ≦ 0.005.
ガン化合物と、リチウム化合物と、Ｎｉ、Ｃｏ、Ｆｅ、
Ｃｒ、Ｃｕから選ばれる少なくとも一種類以上の金属化
合物との混合物を、最初に５００℃以下の温度で焼成を
行った後に、５００℃を超え、且つ、９５０℃以下の温
度でさらに焼成を行うことを特徴とする請求項１のリチ
ウムマンガン複合酸化物の製造方法。2. A manganese compound having an average manganese oxidation number of 3.0 or more, a lithium compound, Ni, Co, Fe,
After first baking a mixture with at least one or more metal compounds selected from Cr and Cu at a temperature of 500 ° C. or less, further baking at a temperature exceeding 500 ° C. and 950 ° C. or less The method for producing a lithium manganese composite oxide according to claim 1, wherein:
室温まで降温したのちに粉砕・混合し、５００℃を越
え、且つ、９５０℃以下の温度でさらに焼成を行う、請
求項２に記載のリチウムマンガン複合酸化物の製造方
法。3. After the first firing at a temperature below 500 ° C.,
The method for producing a lithium manganese composite oxide according to claim 2, wherein the mixture is pulverized and mixed after cooling to room temperature, and further calcined at a temperature exceeding 500 ° C and 950 ° C or less.
化物を正極に使用し、リチウム、リチウム合金及び予め
リチウムを導入したリチウムを吸蔵放出可能な化合物か
ら選ばれる少なくとも１種類以上を負極に、非水電解質
を電解質に使用することを特徴とするリチウム二次電
池。4. The lithium manganese composite oxide according to claim 1 is used for a positive electrode, and at least one selected from lithium, a lithium alloy, and a compound capable of inserting and extracting lithium into which lithium is previously introduced is used as a negative electrode. A lithium secondary battery using a non-aqueous electrolyte as an electrolyte.
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|---|---|---|---|
| JP10327738A JP2000154022A (en) | 1998-11-18 | 1998-11-18 | Lithium manganese double oxide, its production and its use |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP10327738A JP2000154022A (en) | 1998-11-18 | 1998-11-18 | Lithium manganese double oxide, its production and its use |
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| Publication Number | Publication Date |
|---|---|
| JP2000154022A true JP2000154022A (en) | 2000-06-06 |
Family
ID=18202441
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|---|---|---|---|
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002042814A (en) * | 2000-07-28 | 2002-02-08 | Hitachi Maxell Ltd | Positive electrode active material for non-aqueous secondary battery and non-aqueous secondary battery using the same |
| JP2002226214A (en) * | 2001-01-26 | 2002-08-14 | Tosoh Corp | New lithium manganese complex oxide and its production method and application thereof |
| JP2007103339A (en) * | 2005-09-08 | 2007-04-19 | Sanyo Electric Co Ltd | Nonaqueous electrolyte secondary battery |
| JP2009274940A (en) * | 2008-05-19 | 2009-11-26 | National Institute Of Advanced Industrial & Technology | Monoclinic lithium manganese-based compound oxide having cation ordered structure and method for producing the same |
| JP2012036085A (en) * | 2011-09-20 | 2012-02-23 | Tosoh Corp | Novel lithium manganese composite oxide, and production method thereof and use thereof |
| JP2012216548A (en) * | 2011-03-31 | 2012-11-08 | Toda Kogyo Corp | Active material powder for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery |
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1998
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002042814A (en) * | 2000-07-28 | 2002-02-08 | Hitachi Maxell Ltd | Positive electrode active material for non-aqueous secondary battery and non-aqueous secondary battery using the same |
| JP2002226214A (en) * | 2001-01-26 | 2002-08-14 | Tosoh Corp | New lithium manganese complex oxide and its production method and application thereof |
| JP2007103339A (en) * | 2005-09-08 | 2007-04-19 | Sanyo Electric Co Ltd | Nonaqueous electrolyte secondary battery |
| JP2009274940A (en) * | 2008-05-19 | 2009-11-26 | National Institute Of Advanced Industrial & Technology | Monoclinic lithium manganese-based compound oxide having cation ordered structure and method for producing the same |
| JP2012216548A (en) * | 2011-03-31 | 2012-11-08 | Toda Kogyo Corp | Active material powder for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery |
| JP2012036085A (en) * | 2011-09-20 | 2012-02-23 | Tosoh Corp | Novel lithium manganese composite oxide, and production method thereof and use thereof |
| WO2015083788A1 (en) * | 2013-12-04 | 2015-06-11 | 三井金属鉱業株式会社 | Spinel-type lithium cobalt manganese-containing complex oxide |
| JP5813277B1 (en) * | 2013-12-04 | 2015-11-17 | 三井金属鉱業株式会社 | Spinel-type lithium cobalt manganese-containing composite oxide |
| GB2536166A (en) * | 2013-12-04 | 2016-09-07 | Mitsui Mining & Smelting Co | Spinel-type lithium cobalt manganese-containing complex oxide |
| US9786914B2 (en) | 2013-12-04 | 2017-10-10 | Mitsui Mining & Smelting Co., Ltd. | Spinel-type lithium cobalt manganese-containing complex oxide |
| GB2536166B (en) * | 2013-12-04 | 2018-03-07 | Mitsui Mining & Smelting Co | Spinel-type lithium cobalt manganese-containing complex oxide |
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