JP2001015173A - Lithium secondary battery - Google Patents
Lithium secondary batteryInfo
- Publication number
- JP2001015173A JP2001015173A JP2000131537A JP2000131537A JP2001015173A JP 2001015173 A JP2001015173 A JP 2001015173A JP 2000131537 A JP2000131537 A JP 2000131537A JP 2000131537 A JP2000131537 A JP 2000131537A JP 2001015173 A JP2001015173 A JP 2001015173A
- Authority
- JP
- Japan
- Prior art keywords
- composite oxide
- secondary battery
- lithium secondary
- density
- negative electrode
- 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
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- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、リチウム二次電池
に関する。[0001] The present invention relates to a lithium secondary battery.
【０００２】[0002]
【従来の技術】非水電解液を用いたリチウム二次電池は
電池電圧が高く高エネルギー密度であるため、開発が盛
んであり、コンピュータや携帯電話等の情報機器用とし
て既に実用化が進んでいる。2. Description of the Related Art A lithium secondary battery using a non-aqueous electrolyte has a high battery voltage and a high energy density, and therefore has been actively developed, and has already been put into practical use for information devices such as computers and mobile phones. I have.
【０００３】しかし、高入力、高出力、大容量の産業用
電池では、大量の活物質を必要とするため情報機器に用
いられているＣｏ系やＮｉ系材料ではコスト面、資源量
の両面から実用化は不可能とされている。このため、こ
れらの問題点を解決するものとしてスピネル型Ｍｎ系材
料が期待されている。しかし、スピネル型Ｍｎ系材料で
は産業用電池の最重要課題である高温でのサイクル寿命
や、出力特性、入力特性が悪いと云った問題があった。However, industrial batteries of high input, high output, and large capacity require a large amount of active material. Therefore, Co-based and Ni-based materials used in information equipment have cost and resource requirements. Practical use is considered impossible. Therefore, a spinel-type Mn-based material is expected to solve these problems. However, spinel-type Mn-based materials have problems such as poor cycle life at high temperatures, output characteristics, and input characteristics, which are the most important issues for industrial batteries.
【０００４】電気自動車やパラレルハイブリッド電気自
動車、電力貯蔵システムや、エレベータ、電動工具等の
電源にリチウム二次電池を応用するためには、５０℃以
上の高温で１０００サイクル以上（容量維持率７０％以
上）の寿命、および５００Ｗ／ｋｇ以上の出力が必要と
されているが、従来のＭｎ系材料ではこのような長寿命
化、高出力密度化は不可能であった。In order to apply a lithium secondary battery to a power supply of an electric vehicle, a parallel hybrid electric vehicle, a power storage system, an elevator, a power tool, and the like, it is necessary to use a high temperature of 50 ° C. or more for 1000 cycles or more (capacity maintenance rate 70% Above) and an output of 500 W / kg or more are required, but such a long life and high output density cannot be achieved with a conventional Mn-based material.
【０００５】特開平６−１８７９９３号公報によると、
ＬｉとＭｎの組成比であるＬｉ／Ｍｎ比を大きくするこ
とで長寿命化を試みている。しかし、室温でも１０サイ
クルの充放電を経ることで、数％程度の容量低下が起こ
っている。リチウム二次電池のサイクル寿命は周囲の温
度に大きく左右され、特に５０℃以上の高温では室温よ
りも寿命が著しく短かくなってしまう。従って、Ｌｉ／
Ｍｎ比を大きくするだけでは、５０℃以上の高温で１０
００サイクル以上のサイクル寿命を得ることは困難であ
る。According to Japanese Patent Application Laid-Open No. 6-187993,
An attempt is made to extend the life by increasing the Li / Mn ratio, which is the composition ratio of Li and Mn. However, even at room temperature, after 10 cycles of charging and discharging, the capacity has decreased by about several percent. The cycle life of a lithium secondary battery greatly depends on the ambient temperature, and particularly at a high temperature of 50 ° C. or higher, the life is significantly shorter than at room temperature. Therefore, Li /
By simply increasing the Mn ratio, 10
It is difficult to obtain a cycle life of 00 cycles or more.
【０００６】また、特公平８−２４０４３号公報でも同
様にＬｉ／Ｍｎ比を大きくし、これを４３０〜５１０℃
で焼成して格子定数が８.２２Å以下の材料でこれを試
みている。しかし、室温でも２００サイクル程度、５０
℃以上では１０００サイクル以上のサイクル寿命が得ら
れる見通しはない。また、特開平７−２８２７９８号公
報では、やはりＬｉ／Ｍｎ比の大きい材料であるＬｉ
(Ｍｎ2-xＬｉx)Ｏ4（０.０２０≦ｘ≦０.０８１）を用
いて長寿命化を図っているが、ｘ＝０.０８１（Ｌｉ／
Ｍｎ＝０.５８）とした場合でも室温で１００サイクル
程度経過すると５％の容量低下が生じ、５０℃以上の高
温では１０００サイクル以上のサイクル寿命を得ること
はできない。In Japanese Patent Publication No. 8-24043, the Li / Mn ratio is similarly increased, and the Li / Mn ratio is increased to 430-510 ° C.
This has been attempted with a material having a lattice constant of 8.22 ° or less after firing. However, even at room temperature, about 200 cycles, 50
There is no prospect that a cycle life of 1000 cycles or more can be obtained at a temperature of not less than ° C. In Japanese Patent Application Laid-Open No. 7-282798, Li, which is also a material having a large Li / Mn ratio, is used.
(Mn 2-x Li x ) O 4 (0.020 ≦ x ≦ 0.081) is used to extend the life, but x = 0.081 (Li /
Even when (Mn = 0.58), a capacity reduction of 5% occurs after about 100 cycles at room temperature, and a cycle life of 1000 cycles or more cannot be obtained at a high temperature of 50 ° C. or more.
【０００７】[0007]
【発明が解決しようとする課題】こうした寿命の短い原
因としては、いずれも複数回の充放電のくり返しにより
正極活物質も膨張収縮を繰り返し、その結果、結晶が崩
壊してリチウムの可逆的な吸蔵放出ができなくなるため
である。そして、高温下ではＭｎイオンが電解液中に溶
け出し、室温よりもさらに正極活物質の結晶が崩壊し易
くなるためである。また、溶け出したＭｎイオンが負極
に析出して負極の充放電反応を阻害し、負極の寿命を短
くする。As a cause of such a short life, the positive electrode active material repeatedly expands and contracts due to repeated charging and discharging of a plurality of times, and as a result, the crystal collapses and reversible occlusion of lithium occurs. This is because release cannot be performed. Then, at a high temperature, Mn ions dissolve into the electrolytic solution, and the crystal of the positive electrode active material is more easily broken than at room temperature. In addition, the dissolved Mn ions precipitate on the negative electrode and hinder the charge / discharge reaction of the negative electrode, thereby shortening the life of the negative electrode.
【０００８】また、リチウム二次電池の出力特性、入力
特性が低い原因は、電解液としてイオン伝導度が水溶液
系に比べて低い有機溶媒を用いているので、リチウムイ
オンの挿入・放出に係わる拡散速度が低いためである。
特に、負極表面では反応しきれなくなって遊離したリチ
ウムイオンが有機溶媒と反応して皮膜を形成し、該皮膜
の抵抗によりさらにリチウムイオンの拡散速度が低下し
て、出力特性、入力特性が悪くなる。また、電解液であ
る有機溶媒は低温でのイオン伝導度が著しく低下するた
め、低温時の出力特性、入力特性がさらに悪くなる。[0008] Further, the reason why the output characteristics and the input characteristics of the lithium secondary battery are low is that the organic solvent having a lower ionic conductivity than the aqueous solution is used as the electrolytic solution, so that the diffusion related to the insertion / release of lithium ions is caused. This is because the speed is low.
In particular, on the negative electrode surface, the lithium ions that cannot be completely reacted and are released react with the organic solvent to form a film, and the resistance of the film further reduces the diffusion rate of lithium ions, resulting in poor output characteristics and input characteristics. . Further, since the ionic conductivity at a low temperature of an organic solvent as an electrolytic solution is significantly reduced, output characteristics and input characteristics at a low temperature are further deteriorated.
【０００９】本発明の第１の目的は、これらの問題点を
解決し高温下で長寿命な材料を用いることによる長寿命
と、電源あるいは負荷の変動に対応して速やかに電力を
受電、あるいは、供給できるリチウム二次電池を提供す
ることにある。A first object of the present invention is to solve these problems and to use a material having a long life at a high temperature and to have a long life, and to receive electric power promptly in response to a change in power supply or load, or To provide a rechargeable lithium secondary battery.
【００１０】本発明の第２の目的は、電気自動車、パラ
レルハイブリッド電気自動車、電力貯蔵システム、エレ
ベータ、電動工具等の電源用として特性の優れたリチウ
ム二次電池を提供することにある。A second object of the present invention is to provide a lithium secondary battery having excellent characteristics as a power source for an electric vehicle, a parallel hybrid electric vehicle, a power storage system, an elevator, a power tool, and the like.
【００１１】[0011]
【課題を解決するための手段】本発明のリチウム二次電
池は負極として非晶質炭素を含む材料を用い、正極とし
て、スピネル型結晶構造を有し、かつ、ＬｉとＭｎを含
む複合酸化物からなることを特徴とする。The lithium secondary battery of the present invention uses a material containing amorphous carbon as a negative electrode, and a composite oxide having a spinel type crystal structure and containing Li and Mn as a positive electrode. It is characterized by consisting of.
【００１２】本発明の正極として複合酸化物はＬｉとＭ
ｎを必須元素とするが、Ｍｎを除く他の遷移金属，IIａ
族またはIIIｂ族の元素を含んでもよい。こうしたもの
としては、例えば、Ｔｉ，Ｖ，Ｃｒ，Ｆｅ，Ｃｏ，Ｎ
ｉ，Ｃｕ，Ｚｎ，Ｂｅ，Ｍｇ，Ｃａ，Ｓｒ，Ｂａ，Ｒ
ａ，Ｂ，Ａｌ，Ｇａ，Ｉｎ，Ｔｌ等である。The composite oxide used as the positive electrode of the present invention is Li and M
n is an essential element, but other transition metals except Mn, IIa
It may contain Group IIIb or IIIb elements. These include, for example, Ti, V, Cr, Fe, Co, N
i, Cu, Zn, Be, Mg, Ca, Sr, Ba, R
a, B, Al, Ga, In, Tl, and the like.
【００１３】[0013]
【発明の実施の形態】まず始めに、正極と負極の構成を
説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the structure of a positive electrode and a negative electrode will be described.
【００１４】本発明の正極活物質としては、複合酸化物
のＬｉ／Ｍｎ原子比が０.５５よりも大きく０.８０より
も小さいものを用いる。Ｌｉ／Ｍｎ原子比が０.５５以
下では５０℃以上で充放電サイクルを繰り返すとＭｎイ
オンが電解液中に溶解して結晶構造が崩壊し、サイクル
寿命が短かくなる。また、Ｌｉ／Ｍｎ原子比が０.８０
以上では放電容量が小さくなる。As the positive electrode active material of the present invention, an active material in which the Li / Mn atomic ratio of the composite oxide is larger than 0.55 and smaller than 0.80 is used. When the Li / Mn atomic ratio is 0.55 or less, when the charge / discharge cycle is repeated at 50 ° C or more, Mn ions dissolve in the electrolytic solution, the crystal structure is collapsed, and the cycle life is shortened. The Li / Mn atomic ratio is 0.80.
Above, the discharge capacity becomes small.
【００１５】本発明の複合酸化物のスピネル型結晶にお
ける格子定数は、８.２３０Åより小さく８.０３１Åよ
りも大きことを特徴とする。格子定数が８.２３０Å以
上では５０℃以上で充放電サイクルを繰り返すとＭｎイ
オンが電解液中に溶解して結晶構造が崩壊し、サイクル
寿命が短い。また、格子定数が８.０３１Å以下では放
電容量が小さなる。The complex oxide according to the present invention is characterized in that the lattice constant of the spinel crystal is smaller than 8.230 ° and larger than 8.031 °. When the lattice constant is 8.230 ° or more, when the charge / discharge cycle is repeated at 50 ° C. or more, Mn ions dissolve in the electrolytic solution, the crystal structure is collapsed, and the cycle life is short. When the lattice constant is 8.031 ° or less, the discharge capacity is small.
【００１６】さらに、本発明の複合酸化物は、Ｘ線回折
パターンの（４００）ピークの２θ角の半値幅が０.２
０゜より小さいことを特徴とする。Ｘ線回折の測定には
線源としてＣｕ−ｋα線を用い、スリットとしてＤＳ＝
ＳＳ＝０.５、ＲＳ＝０.１５のスリット幅のものを使用
した。半値幅が０.２０゜以上では５０℃以上で充放電
サイクルを繰り返すとＭｎイオンが電解液中に溶解して
結晶構造が崩壊し、サイクル寿命が短くなる。Furthermore, the composite oxide of the present invention has a half value width of the 2θ angle of the (400) peak of the X-ray diffraction pattern of 0.2.
It is characterized by being smaller than 0 °. In the measurement of X-ray diffraction, Cu-kα ray was used as a radiation source, and DS =
A slit width of SS = 0.5 and RS = 0.15 was used. When the half width is 0.20 ° or more, when the charge / discharge cycle is repeated at 50 ° C. or more, Mn ions dissolve in the electrolytic solution, the crystal structure is collapsed, and the cycle life is shortened.
【００１７】また、本発明の複合酸化物の２次粒子の比
表面積は１.５ｍ2／ｇより小さく０.１０ｍ2／ｇよりも
大きいことを特徴とする。比表面積が１.５ｍ2／ｇ以上
では５０℃以上で充放電サイクルを繰り返すとＭｎイオ
ンが電解液中に溶解して結晶構造が崩壊し、サイクル寿
命が短い。また、比表面積が０.１０ｍ2／ｇ以下では急
速充放電において、電極活物質自身の反応場が小さいた
めに電力効率が低くなる。Further, the specific surface area of secondary particles of the composite oxide of the present invention may be greater than the small 0.10 m 2 / g than 1.5 m 2 / g. When the specific surface area is 1.5 m 2 / g or more, when the charge and discharge cycle is repeated at 50 ° C. or more, Mn ions dissolve in the electrolytic solution, the crystal structure is collapsed, and the cycle life is short. Further, when the specific surface area is 0.10 m 2 / g or less, the power efficiency is reduced due to a small reaction field of the electrode active material itself in rapid charging and discharging.
【００１８】さらに本発明の複合酸化物の１次粒子の平
均粒径が１μｍよりも大きく、２０μｍよりも小さいこ
とを特徴とする。平均粒径が１μｍ以下では５０℃以上
で充放電サイクルを繰り返すとＭｎイオンが電解液中に
溶解して結晶構造が崩壊し、サイクル寿命が短い。ま
た、平均粒径が２０μｍ以上では急速充電や急速放電に
おいて、電極活物質自身の反応場が小さいために電力効
率が低くなる。Further, the average particle diameter of the primary particles of the composite oxide of the present invention is larger than 1 μm and smaller than 20 μm. When the average particle size is 1 μm or less, Mn ions dissolve in the electrolytic solution when the charge / discharge cycle is repeated at 50 ° C. or more, the crystal structure collapses, and the cycle life is short. When the average particle size is 20 μm or more, the power efficiency is reduced in rapid charging and rapid discharging because the reaction field of the electrode active material itself is small.
【００１９】本発明の正極は、非晶質炭素を含む負極と
組合せることによって初めて、高温での寿命が長く、目
的とするリチウム二次電池が得られる。さらに、本発明
のリチウム二次電池の負極活物質には、非晶質炭素を含
み、かつ、負極密度が０.９５ｇ／ｃｍ3より大きく１.
５ｇ／ｃｍ3よりも小さいことを特徴とする。Only when the positive electrode of the present invention is combined with the negative electrode containing amorphous carbon, the life at a high temperature is long and the intended lithium secondary battery can be obtained. Furthermore, the negative electrode active material of the lithium secondary battery of the present invention contains amorphous carbon and has a negative electrode density of more than 0.95 g / cm 3 and 1.
It is characterized by being smaller than 5 g / cm 3 .
【００２０】５０℃以上で充放電サイクルを繰り返すと
正極活物質からＭｎイオンが電解液中に溶解してＭｎイ
オンの析出開始電位、即ち、２Ｖ以下の電位となる部分
に析出する。負極やセパレータ、集電箔、電池缶などが
析出部位となる。負極密度が０.９５ｇ／ｃｍ3以下では
負極の空隙が多く、電極としての比表面積も大きいた
め、Ｍｎイオンが負極表面および内部に多量に析出す
る。析出したＭｎは負極の容量を大きく低下させるた
め、サイクル寿命が短い。負極密度が１.５ｇ／ｃｍ3以
上では負極の空隙部分が少ないため電解液が電極内部に
浸透せず、負極容量が低くなる。When the charge / discharge cycle is repeated at 50 ° C. or higher, Mn ions dissolve in the electrolyte from the positive electrode active material and precipitate at a portion where the potential at which Mn ions precipitate is reached, that is, a potential of 2 V or less. A negative electrode, a separator, a current collector foil, a battery can, or the like is a deposition site. When the negative electrode density is 0.95 g / cm 3 or less, the negative electrode has many voids and a large specific surface area as an electrode, so that a large amount of Mn ions precipitate on the negative electrode surface and inside. Since the deposited Mn greatly reduces the capacity of the negative electrode, the cycle life is short. When the density of the negative electrode is 1.5 g / cm 3 or more, the electrolyte does not penetrate into the inside of the electrode because the void portion of the negative electrode is small, and the capacity of the negative electrode decreases.
【００２１】さらに、本発明のリチウム二次電池の負極
活物質には、非晶質炭素を含み、その真密度が１.２〜
１.８ｇ／ｃｍ3であることを特徴とする。５０℃以上で
充放電サイクルを繰り返すと正極活物質からＭｎイオン
が電解液中に溶解してＭｎイオンの析出開始電位、即
ち、２Ｖ以下の電位となる部分、例えば、負極やセパレ
ータ、集電箔、電池缶などが析出部位となる。Further, the negative electrode active material of the lithium secondary battery of the present invention contains amorphous carbon and has a true density of 1.2 to 1.2.
It is characterized by 1.8 g / cm 3 . When the charge / discharge cycle is repeated at 50 ° C. or higher, Mn ions dissolve in the electrolytic solution from the positive electrode active material, and the precipitation starting potential of Mn ions, that is, a portion having a potential of 2 V or less, such as a negative electrode, a separator, or a current collector foil , Battery cans and the like become deposition sites.
【００２２】炭素の真密度が１.２ｇ／ｃｍ3より小さい
と炭素内部の空隙が多く、比表面積も大きいため、Ｍｎ
イオンが炭素表面および内部に多量に析出する。析出し
たＭｎは負極の容量を大きく低下させるため、サイクル
寿命が短かくなる。また、炭素の真密度が１.８ｇ／ｃ
ｍ3より大きいと、負極の空隙部分が少ないため電解液
が電極内部に浸透せず、負極容量が低くなり、目的とす
るリチウム二次電池が得にくくなる。When the true density of carbon is less than 1.2 g / cm 3, there are many voids inside the carbon and the specific surface area is large.
Ions are deposited in large amounts on the carbon surface and inside. Precipitated Mn greatly reduces the capacity of the negative electrode, so that the cycle life is shortened. Further, the true density of carbon is 1.8 g / c.
When it is larger than m 3 , the electrolyte does not penetrate into the inside of the electrode because the void portion of the negative electrode is small, the capacity of the negative electrode is reduced, and it is difficult to obtain a desired lithium secondary battery.
【００２３】さらに、本発明のリチウム二次電池の負極
活物質には、非晶質炭素を含み、その結晶厚みＬｃが５
〜１５０Åであることを特徴とする。炭素の結晶厚みＬ
ｃは炭素の結晶性を表す指標の一つであり、Ｌｃが小さ
いと非晶質化が強く、Ｌｃが大きいと黒鉛化が強いこと
を示している。Further, the negative electrode active material of the lithium secondary battery of the present invention contains amorphous carbon and has a crystal thickness Lc of 5%.
Å150 °. Crystal thickness L of carbon
c is one of the indices indicating the crystallinity of carbon, and indicates that when Lc is small, amorphousization is strong, and when Lc is large, graphitization is strong.
【００２４】また、Ｌｃは六員環網目面に対して垂直な
方向の積層数を表す指標でもある。Ｌｃが小さいと積層
数が少なく、さらに六員環末端部、即ち、リチウムの挿
入・放出サイトが少ないことを意味し、Ｌｃが大きいと
積層数が多く、六員環末端部、即ち、リチウムの挿入・
放出サイトが多いことを意味する。Lc is also an index representing the number of layers in the direction perpendicular to the six-membered ring network plane. When Lc is small, the number of laminations is small, and furthermore, the six-membered ring terminal, that is, the insertion / release site of lithium is small. Insertion
It means that there are many release sites.
【００２５】炭素の結晶厚みＬｃが５Åより小さいとリ
チウムの挿入・放出サイトが確保されないために挿入・
放出反応が円滑に進まず、リチウムイオンが炭素内に強
くトラップされた状態になって、出力特性、入力特性が
大幅に低下する。また、炭素の結晶厚みＬｃが１５０Å
よりも大きいと非晶質的な性質よりも黒鉛的な性質が強
まるため、六員環網目面が平行に積み重なり、六員環末
端部が一方向に集中してしまう。そのため、リチウムの
挿入・放出サイトに方向性を生じてリチウムの挿入・放
出が一方向でしか進まなくなり、出力特性、入力特性が
大幅に低下する。If the carbon crystal thickness Lc is less than 5 °, the insertion and emission sites of lithium cannot be secured, so
The release reaction does not proceed smoothly, and lithium ions are strongly trapped in the carbon, so that the output characteristics and the input characteristics are significantly reduced. Further, the crystal thickness Lc of carbon is 150 °.
If it is larger than this, graphite-like properties become stronger than amorphous properties, so that the six-membered ring network faces are stacked in parallel, and the ends of the six-membered ring are concentrated in one direction. For this reason, the directivity is generated at the lithium insertion / release site, so that the lithium insertion / release proceeds only in one direction, and the output characteristics and the input characteristics are significantly reduced.
【００２６】本発明のリチウム二次電池は、単電池で３
００〜１８００Ｗ／ｋｇの入力密度を得ることが可能で
ある。また、単電池で５００〜３５００Ｗ／ｋｇの出力
密度が得ることが可能であり、この範囲で使用すること
が望ましい。The lithium secondary battery of the present invention is a single
It is possible to obtain an input density of 00-1800 W / kg. In addition, it is possible to obtain an output density of 500 to 3500 W / kg with a single cell, and it is desirable to use within this range.
【００２７】さらに、本発明のリチウム二次電池は、組
電池とすることができ、２００〜１３００Ｗ／ｋｇの入
力密度が得られる。該組電池で３６０〜２５２０Ｗ／ｋ
ｇの出力密度を得ることができ、この範囲で使用するこ
とが望ましい。Further, the lithium secondary battery of the present invention can be used as an assembled battery, and an input density of 200 to 1300 W / kg can be obtained. 360 to 2520 W / k with the battery pack
g power density can be obtained and it is desirable to use within this range.
【００２８】本発明のリチウム二次電池は、使用温度が
−１０℃〜５０℃において、単電池では３００〜１８０
０Ｗ／ｋｇ、組電池では２００〜１３００Ｗ／ｋｇの入
力密度が得られる。The lithium secondary battery of the present invention has a working temperature of -10 ° C. to 50 ° C.
An input density of 0 to 1300 W / kg is obtained with a battery pack of 0 W / kg.
【００２９】さらに、本発明のリチウム二次電池は、使
用温度が−１０℃〜５０℃において単電池で５００〜３
５００Ｗ／ｋｇ、組電池で３６０〜２５２０Ｗ／ｋｇの
入力密度を得ることができる。Further, the lithium secondary battery of the present invention has a single cell of 500 to 3 at an operating temperature of -10 to 50 ° C.
An input density of 360 to 2520 W / kg can be obtained with a battery pack of 500 W / kg.
【００３０】本発明の正極活物質を作製する方法とし
て、二酸化マンガンと炭酸リチウムを所定の割合で混合
した後に、空気中で５００〜６５０℃の温度で予備焼成
を行い、その後、空気中で８００〜８７５℃で２０時間
以上焼成し、２℃／分よりも遅い速度で冷却するのがよ
い。このようにして作製した正極活物質は、結晶性が高
く粒成長も顕著であり、高温下でも良好な長寿命サイク
ル特性を示す。As a method for producing the positive electrode active material of the present invention, manganese dioxide and lithium carbonate are mixed at a predetermined ratio, and then prefired in air at a temperature of 500 to 650 ° C. It is preferable to bake at ８875 ° C. for 20 hours or more and cool at a rate lower than 2 ° C./min. The positive electrode active material thus produced has high crystallinity and remarkable grain growth, and exhibits good long life cycle characteristics even at high temperatures.
【００３１】特に、５０℃以上の高温でも１０００サイ
クル以上のサイクル寿命が得られ、−１０℃〜５０℃の
温度範囲において高い入力特性や出力特性を有する。従
って、パワーアシストが必要な電源などに適用可能であ
る。In particular, a cycle life of 1000 cycles or more is obtained even at a high temperature of 50 ° C. or more, and high input and output characteristics are obtained in a temperature range of -10 ° C. to 50 ° C. Therefore, the present invention can be applied to a power supply that requires power assist.
【００３２】高温での充放電サイクル寿命を延長するた
めには、正極活物質の結晶の安定性を高めて、充放電反
応に伴う結晶構造の崩壊を抑制することが重要である。In order to extend the charge / discharge cycle life at a high temperature, it is important to enhance the stability of the crystal of the positive electrode active material and to suppress the collapse of the crystal structure accompanying the charge / discharge reaction.
【００３３】充放電反応に伴う結晶構造の崩壊には２つ
の因子があり、一つは充放電時の格子の膨張収縮によっ
て引き起こされる機械的破壊であり、もう一つは充電時
に生じる４価のＭｎが電解液中の有機溶媒と有機錯体を
形成して、結晶系外へ溶出することによって引き起こさ
れる化学的崩壊である。There are two factors in the collapse of the crystal structure due to the charge / discharge reaction, one is mechanical destruction caused by expansion and contraction of the lattice during charge / discharge, and the other is tetravalent, which occurs during charge. This is a chemical decay caused by Mn forming an organic complex with an organic solvent in the electrolyte and eluting out of the crystal system.
【００３４】本発明の正極活物質は、Ｌｉ／Ｍｎ比の大
きい材料を用いているので、Ｍｎ３＋イオンに比べてイ
オン半径の小さなＭｎ４＋イオンの割合が相対的に増加
し、Ｍｎ３＋イオンのＪａｈｎ−Ｔｅｌｌｅｒ不安定性
を抑えることで格子歪みを低減でき、機械的崩壊も化学
的崩壊も抑制できる。Since the cathode active material of the present invention uses a material having a large Li / Mn ratio, the ratio of Mn4 + ions having a smaller ionic radius as compared with Mn3 + ions is relatively increased, and the Jahn-Teller of Mn3 + ions is increased. By suppressing instability, lattice distortion can be reduced, and both mechanical and chemical collapse can be suppressed.
【００３５】例えば、Ｌｉ／Ｍｎ＝０.５０のときに
は、ＬｉＭｎ2Ｏ4の化学組成式に従うならば、電荷の中
性から考えるとＭｎイオンの平均原子価は３.５価、つ
まりＭｎ３＋とＭｎ４＋が同数あることになる。Ｌｉ／
Ｍｎ＝０.５８のときは、Ｌｉ1 +xＭｎ2-xＯ4の組成式か
ら計算すると、Ｍｎイオンの平均原子価は＋３.６３と
なり４価のＭｎ４＋イオンの割合が相対的に増加するこ
とになる。For example, when Li / Mn = 0.50, according to the chemical composition formula of LiMn 2 O 4 , the average valence of Mn ions is 3.5, that is, Mn3 + and Mn4 +, considering the neutrality of charge. Are the same. Li /
When Mn is 0.58, the average valence of Mn ions is +3.63, as calculated from the composition formula of Li 1 + x Mn 2-x O 4 , and the ratio of tetravalent Mn 4+ ions relatively increases. Will be.
【００３６】このとき、格子定数は前者の場合に比べて
小さく、そのため充放電の際の膨張収縮量が減少するの
で機械的崩壊を抑制できる。また、Ｍｎの価数が４価に
近づくとその分、放出できないリチウムが結晶系内に残
存するので、結晶構造を支える支柱となって働き、機械
的崩壊も化学的崩壊も抑制できる。At this time, the lattice constant is smaller than in the former case, so that the amount of expansion and contraction during charging and discharging is reduced, so that mechanical collapse can be suppressed. In addition, when the valence of Mn approaches tetravalence, lithium that cannot be released remains in the crystal system by that much, so that it functions as a support for supporting the crystal structure, and mechanical and chemical collapse can be suppressed.
【００３７】また、本発明の正極活物質は結晶性が高く
粒成長も著しいことから、結晶の安定性が顕著であり、
機械的崩壊も化学的崩壊も抑制できる。Further, since the cathode active material of the present invention has high crystallinity and remarkable grain growth, crystal stability is remarkable.
Both mechanical and chemical breakdown can be suppressed.
【００３８】しかし、本発明の正極活物質を使用しても
充放電の温度条件によっては化学的崩壊までには至らな
くとも、ある程度のＭｎの溶出は避けられない。Ｍｎが
溶出する場合に問題となるのは、溶出したＭｎがどこに
析出するかであり、溶出Ｍｎが優先的に負極に析出する
と、負極容量が低下してサイクル寿命が短くなってしま
う。これを抑制するには負極の密度、あるいは、炭素の
真密度を高くすることによって、負極への析出部位を低
減でき、容量低下を抑制できる。However, even when the positive electrode active material of the present invention is used, some elution of Mn is unavoidable even if chemical decomposition does not occur depending on temperature conditions of charging and discharging. The problem when Mn elutes is where the eluted Mn is deposited. If the eluted Mn is preferentially deposited on the negative electrode, the capacity of the negative electrode is reduced and the cycle life is shortened. In order to suppress this, by increasing the density of the negative electrode or the true density of carbon, the number of deposition sites on the negative electrode can be reduced, and a decrease in capacity can be suppressed.
【００３９】また、長寿命の産業用電池を得るために、
負極として必ず非晶質炭素を含有するものを用いる。非
晶質炭素を含有しない負極を用いた場合には、サイクル
寿命が短いため、５０℃以上の高温でも１０００サイク
ル以上のサイクル寿命を必要とする産業用電池としては
好ましくない。In order to obtain a long-life industrial battery,
A negative electrode always containing amorphous carbon is used. When a negative electrode containing no amorphous carbon is used, the cycle life is short, so that it is not preferable as an industrial battery that requires a cycle life of 1000 cycles or more even at a high temperature of 50 ° C. or more.
【００４０】従来の非晶質炭素以外の炭素負極を使用し
た場合には、電解液として使用している有機溶媒が５０
℃以上では分解し易く、炭酸ガスや炭化水素、あるい
は、リチウムアルコキシドなどを形成し易い。非晶質炭
素は他の炭素材料に比べ、こうした電解液の分解が比較
的少ないために高温での長寿命化を図ることができる。When a carbon anode other than the conventional amorphous carbon is used, the organic solvent used as the electrolyte is 50%.
Above ° C, it is easily decomposed and easily forms carbon dioxide, hydrocarbons, or lithium alkoxides. Amorphous carbon has a relatively low decomposition of the electrolytic solution as compared with other carbon materials, and therefore can have a long life at a high temperature.
【００４１】また、電池を形成する炭素材料には、出力
特性や入力特性を向上させるため、必ず結晶厚みＬｃの
最適範囲にある炭素材料を使用するのがよい。Ｌｃが大
き過ぎても、小さ過ぎてもリチウムの挿入・放出サイト
数が減少したり、方向性が生じて挿入・放出速度が低下
するなど、出力特性や入力特性に影響を及ぼす。As the carbon material forming the battery, it is preferable to use a carbon material having an optimum crystal thickness Lc without fail in order to improve output characteristics and input characteristics. If Lc is too large or too small, output characteristics and input characteristics are affected, such as a decrease in the number of lithium insertion / desorption sites and a decrease in the insertion / desorption speed due to directivity.
【００４２】本発明の正極および負極を組合わせること
によって初めて高い入力特性と出力特性を有するリチウ
ム二次電池が得られる。さらに、本発明の電池は組電池
にした場合でも、高い入力特性と出力特性が得られる。A lithium secondary battery having high input and output characteristics can be obtained only by combining the positive electrode and the negative electrode of the present invention. Further, the battery of the present invention can obtain high input characteristics and output characteristics even when the battery is assembled.
【００４３】以上により、電気自動車、パラレルハイブ
リッド電気自動車、電力貯蔵システム、エレベータ、電
動工具等の５０℃以上の高温でも１０００サイクル以上
のサイクル寿命と、−１０℃〜５０℃の温度範囲でも高
い入力特性、出力特性が必要な産業用電池として適用で
きるチウム二次電池を得ることができる。As described above, the cycle life of 1000 cycles or more even at a high temperature of 50 ° C. or more, such as an electric vehicle, a parallel hybrid electric vehicle, an electric power storage system, an elevator, and a power tool, and a high input even in a temperature range of -10 ° C. to 50 ° C. A titanium secondary battery that can be used as an industrial battery requiring characteristics and output characteristics can be obtained.
【００４４】〔実施例 １〕正極には正極活物質を９０
重量％、結着剤としてポリフッ化ビニリデンを４重量
％，導電剤として黒鉛を６重量％を混合した合剤を、ら
いかい機で３０分混煉後、厚さ２０μｍのアルミニウム
箔の両面に塗布した。Example 1 A positive electrode was filled with 90 positive electrode active materials.
A mixture obtained by mixing 4% by weight of polyvinylidene fluoride as a binder and 6% by weight of graphite as a conductive agent is mixed for 30 minutes with a rake machine, and then applied to both sides of a 20 μm thick aluminum foil. did.
【００４５】負極には非晶質炭素粉末を使用し、これを
８７重量％、導電剤としてアセチレンブラックを６重量
％、結着剤としてポリフッ化ビニリデンを７重量％を混
合した合剤を、らいかい機で３０分混煉後、厚さ１０μ
ｍの銅箔の両面に塗布した。For the negative electrode, an amorphous carbon powder was used, and a mixture prepared by mixing 87% by weight of this powder, 6% by weight of acetylene black as a conductive agent, and 7% by weight of polyvinylidene fluoride as a binder was used. After mixing for 30 minutes with a paddle, thickness 10μ
m of copper foil.
【００４６】上記の正負両極はプレス機で圧延成型し、
端子をスポット溶接した後、１５０℃で５時間真空乾燥
した。The above positive and negative electrodes are rolled and formed by a press machine.
After spot welding the terminals, they were vacuum dried at 150 ° C. for 5 hours.
【００４７】微多孔性ポリプロピレン製セパレータを介
して正極と負極を積層し、これを渦巻状に捲回し、ＳＵ
Ｓ製の電池缶に挿入した。負極端子は電池缶に、正極端
子は電池蓋にそれぞれ溶接した。電解液には１ｍｏｌの
ＬｉＰＦ6を１リットルのエチレンカーボネートとジエ
チルカーボネートとの混合溶液に溶解したものを電池缶
内に注液し、電池蓋をかしめて８００ｍＡｈ容量の円筒
型電池を作製した。電池は周囲温度５０℃で８００ｍＡ
で４．２Ｖ、７時間の定電流定電圧充電後、８００ｍＡ
で２．８Ｖまで放電するサイクルを繰り返した。A positive electrode and a negative electrode are laminated with a microporous polypropylene separator interposed therebetween, and this is spirally wound.
It was inserted into an S battery can. The negative electrode terminal was welded to the battery can, and the positive electrode terminal was welded to the battery lid. A solution of 1 mol of LiPF 6 dissolved in 1 liter of a mixed solution of ethylene carbonate and diethyl carbonate was poured into the battery can as an electrolytic solution, and the battery lid was crimped to produce a 800 mAh capacity cylindrical battery. Battery is 800mA at ambient temperature 50 ℃
800mA after charging at 4.2V, constant current and constant voltage for 7 hours
The cycle of discharging to 2.8 V was repeated.
【００４８】図１に正極活物質のＬｉ／Ｍｎ比に対する
サイクル寿命，放電容量を示す。なお、その他の条件に
ついては本発明が特定する最適範囲内となるようにし
た。Ｌｉ／Ｍｎ比は０．５５よりも大きく０．８よりも
小さい範囲でサイクル寿命も放電容量も良好な特性を示
した。FIG. 1 shows the cycle life and discharge capacity with respect to the Li / Mn ratio of the positive electrode active material. The other conditions were set so as to be within the optimum range specified by the present invention. In the range where the Li / Mn ratio was larger than 0.55 and smaller than 0.8, good characteristics were exhibited in both cycle life and discharge capacity.
【００４９】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the unit cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００５０】また、この電池を９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the discharge depth is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００５１】〔実施例 ２〕実施例１と同様にして電池
を作製した。正極活物質粉末をＸ線回折で測定し、最小
二乗法を用いてスピネル型立方晶の格子定数を求めた。
その他の条件については本発明が特定する最適範囲内と
した。図２に正極活物質の格子定数に対するサイクル寿
命，放電容量の関係を示す。図より格子定数は８.０３
１Åよりも大きく８.２３０Åよりも小さい範囲でサイ
クル寿命も放電容量も良好な特性を示した。Example 2 A battery was manufactured in the same manner as in Example 1. The positive electrode active material powder was measured by X-ray diffraction, and the lattice constant of the spinel-type cubic crystal was obtained by using the least square method.
Other conditions were within the optimum range specified by the present invention. FIG. 2 shows the relationship between the cycle constant and the discharge capacity with respect to the lattice constant of the positive electrode active material. From the figure, the lattice constant is 8.03
In the range of more than 1 ° and less than 8.230 °, both cycle life and discharge capacity showed good characteristics.
【００５２】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００５３】また、この電池を９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００５４】〔実施例 ３〕実施例１と同様にして電池
を作製した。（４００）ピークの半値幅はＸ線回折によ
り正極活物質粉末をＣｕＫα線源を用いてスリット幅を
ＤＳ＝ＳＳ＝０.５、ＲＳ＝０.１５として求めた。その
他の条件については本発明が特定する最適範囲内とし
た。図３に正極活物質の（４００）ピークの半値幅とサ
イクル寿命との関係を示す。図より（４００）ピークの
半値幅は０.２(deg.)よりも小さい範囲でサイクル寿命
が良好であった。Example 3 A battery was manufactured in the same manner as in Example 1. The half-width of the (400) peak was determined by X-ray diffraction using a positive electrode active material powder with a CuKα radiation source and a slit width of DS = SS = 0.5 and RS = 0.15. Other conditions were within the optimum range specified by the present invention. FIG. 3 shows the relationship between the half width of the (400) peak of the positive electrode active material and the cycle life. As shown in the figure, the cycle life was good when the half width of the (400) peak was smaller than 0.2 (deg.).
【００５５】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００５６】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００５７】〔実施例 ４〕実施例１と同様にして電池
を作製した。その他の条件については本発明が特定する
最適範囲内とした。また、急速放電効率に関しては周囲
温度２０℃で８００ｍＡで４.２Ｖ、７時間の定電流定
電圧充電後、１６００ｍＡで２.８Ｖまで放電したとき
の充電容量に対する放電容量の比率とした。Example 4 A battery was manufactured in the same manner as in Example 1. Other conditions were within the optimum range specified by the present invention. The rapid discharge efficiency was defined as the ratio of the discharge capacity to the charge capacity when the battery was discharged to 2.8 V at 1600 mA after being charged at 4.2 V at 800 mA for 7 hours at an ambient temperature of 20 ° C. and discharged at 2.8 V at 1600 mA.
【００５８】図４に正極活物質の二次粒子の比表面積に
対するサイクル寿命，急速放電効率との関係を示す。図
より比表面積は０.１ｍ2／ｇよりも大きく１.５ｍ2／ｇ
よりも小さい範囲でサイクル寿命も急速放電効率も良好
な特性を示した。FIG. 4 shows the relationship between the specific surface area of the secondary particles of the positive electrode active material, the cycle life, and the rapid discharge efficiency. From the figure, the specific surface area is larger than 0.1 m 2 / g and 1.5 m 2 / g.
In the range smaller than the above, both cycle life and rapid discharge efficiency showed good characteristics.
【００５９】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００６０】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００６１】〔実施例 ５〕実施例１，４と同様にして
電池を作製した。その他の条件については本発明が特定
する最適範囲内とした。Example 5 A battery was manufactured in the same manner as in Examples 1 and 4. Other conditions were within the optimum range specified by the present invention.
【００６２】図５に正極活物質の平均一次粒子径に対す
るサイクル寿命，急速放電効率との関係を示す。図より
平均一次粒子径は１μｍよりも大きく２０μｍよりも小
さい範囲でサイクル寿命も急速放電効率も良好な特性を
示した。FIG. 5 shows the relationship between the cycle life and the rapid discharge efficiency with respect to the average primary particle diameter of the positive electrode active material. As shown in the figure, when the average primary particle size is larger than 1 μm and smaller than 20 μm, good characteristics are exhibited in both cycle life and rapid discharge efficiency.
【００６３】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００６４】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００６５】〔実施例 ６〕実施例１と同様にして電池
を作製した。その他の条件については本発明が特定する
最適範囲内とした。負極放電容量に関してはＬｉ金属を
対極として負極単極の容量を評価した。Example 6 A battery was manufactured in the same manner as in Example 1. Other conditions were within the optimum range specified by the present invention. Regarding the negative electrode discharge capacity, the capacity of the negative electrode single electrode was evaluated using Li metal as a counter electrode.
【００６６】図６に負極密度に対するサイクル寿命，負
極放電容量との関係を示す。図より負極密度は０.９５
ｇ／ｃｍ3よりも大きく１.５ｇ／ｃｍ3よりも小さい範
囲でサイクル寿命も負極放電容量も良好な特性を示し
た。FIG. 6 shows the relationship between the cycle life and the anode discharge capacity with respect to the anode density. From the figure, the negative electrode density is 0.95.
Cycle life negative electrode discharge capacity range smaller than larger 1.5 g / cm 3 than g / cm 3 also showed good characteristics.
【００６７】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００６８】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００６９】〔実施例 ７〕本発明の正極材料の合成方
法について説明する。原料として電解二酸化マンガンと
炭酸リチウムをＬｉ／Ｍｎ比が０.６２となるように配
合した。これを６１５℃で１５時間仮焼成し、再度混合
した後に８２５℃で３０時間の焼成を行なった。ここで
仮焼成工程は材料の均一性と結晶性を高め、良好なサイ
クル寿命を得るために重要な工程である。また、冷却速
度を１℃／分とし室温まで冷却した。Example 7 A method for synthesizing the positive electrode material of the present invention will be described. As raw materials, electrolytic manganese dioxide and lithium carbonate were blended so that the Li / Mn ratio became 0.62. This was calcined at 615 ° C. for 15 hours, mixed again, and then calcined at 825 ° C. for 30 hours. Here, the calcination step is an important step for improving the uniformity and crystallinity of the material and obtaining a good cycle life. The cooling rate was 1 ° C./min, and the mixture was cooled to room temperature.
【００７０】このようにして得られた正極材料の粉末Ｘ
線回折をＣｕｋα線源を用いて測定したところ異相のな
いスピネル型の結晶構造であることを確認した。この時
の格子定数は８.２１１Åであり、（４００）ピークの
半値幅は０.０９度であった。さらに平均一次粒径は３.
１μｍで、二次粒子の比表面積は０.３２ｍ2／ｇである
ことを確認した。The powder X of the positive electrode material thus obtained was
When the line diffraction was measured using a Cuka radiation source, it was confirmed that the crystal had a spinel-type crystal structure having no foreign phase. At this time, the lattice constant was 8.211 °, and the half width of the (400) peak was 0.09 °. Furthermore, the average primary particle size is 3.
At 1 μm, it was confirmed that the specific surface area of the secondary particles was 0.32 m 2 / g.
【００７１】また、負極には非晶質炭素を使用し、密度
を１.０５ｇ／ｃｍ3とした。実施例１と同様にして電池
を作製し、周囲温度が６０℃の場合のサイクル特性を評
価した。図７にサイクル数と放電容量との関係を示す。The negative electrode was made of amorphous carbon and had a density of 1.05 g / cm 3 . A battery was manufactured in the same manner as in Example 1, and the cycle characteristics when the ambient temperature was 60 ° C. were evaluated. FIG. 7 shows the relationship between the number of cycles and the discharge capacity.
【００７２】本実施例電池Ａは１０００サイクル以上の
サイクル寿命が得られた。さらに、単電池において、温
度が−１０℃〜５０℃の範囲、放電深度が３０〜８０％
の範囲で、入力密度は３００〜１８００Ｗ／ｋｇの範囲
にあり、出力密度は５００〜３５００Ｗ／ｋｇの範囲に
あった。The battery A of this example had a cycle life of 1,000 cycles or more. Further, in the single cell, the temperature is in the range of -10 ° C to 50 ° C, and the depth of discharge is 30 to 80%.
, The input density was in the range of 300-1800 W / kg and the output density was in the range of 500-3500 W / kg.
【００７３】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【００７４】〔比較例 １〕原料として電解二酸化マン
ガンと炭酸リチウムをＬｉ／Ｍｎ比が０.６２となるよ
うに配合し７５０℃で５時間の焼成を行なった。また、
冷却速度を５℃／分として室温まで冷却した。この時得
られた活物質の格子定数は８.２２Åであり、本発明の
格子定数の範囲内にあることが分かった。しかし、（４
００）ピークの半値幅は０.４度であり、平均一次粒径
は０.６μｍ、二次粒子の比表面積は２.２ｍ2／ｇで、
本発明が特定する範囲から外れていた。[Comparative Example 1] Electrolytic manganese dioxide and lithium carbonate were mixed as raw materials so that the Li / Mn ratio became 0.62, and the mixture was fired at 750 ° C for 5 hours. Also,
The cooling was performed at a cooling rate of 5 ° C./min to room temperature. The active material obtained at this time had a lattice constant of 8.22 °, which was within the range of the lattice constant of the present invention. However, (4
00) The half width of the peak is 0.4 degree, the average primary particle size is 0.6 μm, the specific surface area of the secondary particles is 2.2 m 2 / g,
It was out of the range specified by the present invention.
【００７５】負極密度を本発明の特定範囲内の１.０５
ｇ／ｃｍ3として、実施例１と同様にして電池を作製し
周囲の温度を６０℃としてサイクル特性を評価した。図
７より本比較例電池Ｂは、１００サイクル程度のサイク
ル寿命しか得られないことが分かった。The negative electrode density was adjusted to 1.05 within the specific range of the present invention.
g / cm 3 , a battery was fabricated in the same manner as in Example 1, and the ambient temperature was 60 ° C., and the cycle characteristics were evaluated. From FIG. 7, it was found that the battery B of this comparative example can only obtain a cycle life of about 100 cycles.
【００７６】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は１５０〜１３００Ｗ／ｋｇの範囲であり、出力
密度は４００〜２８００Ｗ／ｋｇの範囲であり、入力特
性も出力特性も劣るものであった。Further, in the single cell, the temperature is -10 ° C.
-50 ° C, discharge depth 30-80%, input density 150-1300 W / kg, output density 400-2800 W / kg, poor input and output characteristics. Was something.
【００７７】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は９０〜７８０Ｗ
／ｋｇの範囲であり、出力密度は２４０〜１６８０Ｗ／
ｋｇの範囲であり、入力特性も出力特性も劣ることが分
かった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of −10 ° C. to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 90 to 780 W.
/ Kg, and the power density is 240 to 1680 W /
It was found that both the input characteristics and the output characteristics were inferior.
【００７８】〔比較例 ２〕原料として電解二酸化マン
ガンと炭酸リチウムをＬｉ／Ｍｎ比が０.６５となるよ
うに配合した。これを６３５℃で１５時間仮焼成し、再
度混合した後に８５５℃で３０時間の焼成を行なった。
また、冷却速度は１℃／分である。この時、活物質の格
子定数は８.１９０Åであり、（４００）ピークの半値
幅は０.０８度で、さらに平均一次粒径は１５μｍ、二
次粒子の比表面積は０.１２ｍ2／ｇであることから、本
発明の正極活物質が得られていることが分かった。Comparative Example 2 As raw materials, electrolytic manganese dioxide and lithium carbonate were blended so that the Li / Mn ratio became 0.65. This was temporarily calcined at 635 ° C. for 15 hours, mixed again, and then calcined at 855 ° C. for 30 hours.
The cooling rate is 1 ° C./min. At this time, the lattice constant of the active material was 8.190 °, the half-width of the (400) peak was 0.08 °, the average primary particle size was 15 μm, and the specific surface area of the secondary particles was 0.12 m 2 / g. Therefore, it was found that the positive electrode active material of the present invention was obtained.
【００７９】一方、負極に関しては、密度が０.９２ｇ
／ｃｍ3と本発明の範囲よりも低い。実施例１と同様に
して電池を作製し周囲温度が６０℃の場合のサイクル特
性を評価した。図７より本比較例電池Ｃは５０サイクル
程度のサイクル寿命しか得られない。On the other hand, for the negative electrode, the density was 0.92 g.
/ Cm 3, which is lower than the range of the present invention. A battery was manufactured in the same manner as in Example 1, and the cycle characteristics when the ambient temperature was 60 ° C. were evaluated. As shown in FIG. 7, the battery C of this comparative example has a cycle life of only about 50 cycles.
【００８０】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は１５０〜１３００Ｗ／ｋｇの範囲であり、出力
密度は４００〜２８００Ｗ／ｋｇの範囲であり、入力特
性も出力特性も劣る。Further, in the single cell, the temperature is -10 ° C.
-50 ° C, discharge depth 30-80%, input density 150-1300 W / kg, output density 400-2800 W / kg, poor input and output characteristics. .
【００８１】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は９０〜７８０Ｗ
／ｋｇの範囲であり、出力密度は２４０〜１６８０Ｗ／
ｋｇの範囲であり、入力特性も出力特性も劣る。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of −10 ° C. to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 90 to 780 W
/ Kg, and the power density is 240 to 1680 W /
kg, and both input characteristics and output characteristics are inferior.
【００８２】〔比較例 ３〕原料として電解二酸化マン
ガンと炭酸リチウムをＬｉ／Ｍｎ比が０.５１となるよ
うに混合し９００℃で５時間の焼成を行なった。また、
冷却速度は１℃／分である。この時の格子定数は８.２
３７Åと本発明の範囲外であったが、（４００）ピーク
の半値幅は０.０８度、平均一次粒径は１０μｍ、二次
粒子の比表面積は０.１５ｍ2／ｇと本発明の範囲内であ
ることが分かった。Comparative Example 3 As raw materials, electrolytic manganese dioxide and lithium carbonate were mixed so that the Li / Mn ratio became 0.51 and baked at 900 ° C. for 5 hours. Also,
The cooling rate is 1 ° C./min. The lattice constant at this time is 8.2
Although it was out of the range of the present invention as 37 °, the half width of the (400) peak was 0.08 °, the average primary particle size was 10 μm, and the specific surface area of the secondary particles was 0.15 m 2 / g, which is the range of the present invention. Turned out to be within.
【００８３】また、負極密度は１.０５ｇ／ｃｍ3とし
た。実施例１と同様にして電池を作製し周囲の温度が６
０℃の場合のサイクル特性を評価した。図７の本比較例
電池Ｄは１５０サイクル程度のサイクル寿命しか得られ
ていない。The negative electrode density was 1.05 g / cm 3 . A battery was manufactured in the same manner as in Example 1, and the ambient temperature was 6
The cycle characteristics at 0 ° C. were evaluated. The comparative battery D of FIG. 7 has a cycle life of only about 150 cycles.
【００８４】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は１５０〜１３００Ｗ／ｋｇの範囲であり、出力
密度は４００〜２８００Ｗ／ｋｇの範囲であり、入力特
性も出力特性も劣る。Further, in the single cell, the temperature is -10 ° C.
-50 ° C, discharge depth 30-80%, input density 150-1300 W / kg, output density 400-2800 W / kg, poor input and output characteristics. .
【００８５】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は９０〜７８０Ｗ
／ｋｇの範囲であり、出力密度は２４０〜１６８０Ｗ／
ｋｇの範囲であり、入力特性も出力特性も劣る。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of −10 ° C. to 50 ° C., the discharge depth is in the range of 30 to 80%, and the input density is 90 to 780 W
/ Kg, and the power density is 240 to 1680 W /
kg, and both input characteristics and output characteristics are inferior.
【００８６】〔比較例 ４〕原料として電解二酸化マン
ガンと炭酸リチウムをＬｉ／Ｍｎ比が０.６２となるよ
うに配合し８５０℃で５時間の焼成を行なった。また、
冷却速度は１℃／分である。この時の格子定数は８.２
２Åであり、（４００）ピークの半値幅は０.１度であ
った。さらに平均一次粒径は２μｍで本発明の範囲内に
ある。しかし、二次粒子の比表面積は１.８ｍ2／ｇと大
きい。Comparative Example 4 As raw materials, electrolytic manganese dioxide and lithium carbonate were blended so that the Li / Mn ratio became 0.62, and the mixture was fired at 850 ° C. for 5 hours. Also,
The cooling rate is 1 ° C./min. The lattice constant at this time is 8.2
It was 2 ° and the half width of the (400) peak was 0.1 °. Further, the average primary particle size is 2 μm, which is within the scope of the present invention. However, the specific surface area of the secondary particles is as large as 1.8 m 2 / g.
【００８７】負極密度は１.０５ｇ／ｃｍ3である。実施
例１と同様にして電池を作製し周囲の温度が６０℃の場
合のサイクル特性を評価した。図７より本比較例電池Ｅ
は、５００サイクル程度のサイクル寿命しか得られない
ことが分かった。The negative electrode density is 1.05 g / cm 3 . A battery was fabricated in the same manner as in Example 1, and the cycle characteristics when the ambient temperature was 60 ° C. were evaluated. From FIG. 7, this comparative example battery E was obtained.
Has a cycle life of only about 500 cycles.
【００８８】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は１５０〜１３００Ｗ／ｋｇの範囲であり、出力
密度は４００〜２８００Ｗ／ｋｇの範囲であり、入力特
性も出力特性も劣る。Further, in the single cell, the temperature is -10 ° C.
-50 ° C, discharge depth 30-80%, input density 150-1300 W / kg, output density 400-2800 W / kg, poor input and output characteristics. .
【００８９】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は９０〜７８０Ｗ
／ｋｇの範囲であり、出力密度は２４０〜１６８０Ｗ／
ｋｇの範囲であり、入力特性も出力特性も劣る。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 90 to 780 W
/ Kg, and the power density is 240 to 1680 W /
kg, and both input characteristics and output characteristics are inferior.
【００９０】〔実施例 ８〕正極に本発明の複合酸化物
を使用したリチウム２次電池は、上述の効果の他に充放
電効率がほぼ１００％で、Ｌｉの挿入・放出の可逆性が
良好な特徴を有する。Example 8 In addition to the above-mentioned effects, a lithium secondary battery using the composite oxide of the present invention for the positive electrode has a charge / discharge efficiency of almost 100% and a good reversibility of insertion and release of Li. It has various features.
【００９１】図８に本発明のリチウム２次電池の部分断
面模式図を示す。微多孔性ポリプロピレン性のセパレー
タ１を介して負極２と正極３を積層し、これを渦巻状に
捲回し、ＳＵＳ製の電池缶４に挿入した。FIG. 8 is a schematic partial cross-sectional view of the lithium secondary battery of the present invention. The negative electrode 2 and the positive electrode 3 were laminated with a microporous polypropylene separator 1 interposed therebetween, spirally wound, and inserted into a battery can 4 made of SUS.
【００９２】負極２は負極リード線２ａを介して電池缶
４に接続している。正極３は正極リード線３ａを介して
金属部材の蓋４に接続している。蓋４と電池缶４と間に
絶縁部５を介して電池缶４内を気密にしている。電池缶
４内には電解液を注液した。また蓋４の突起部には正極
端子６を、また、突起部と反対側の電池缶４の底部は負
極端子７である。The negative electrode 2 is connected to the battery can 4 via the negative electrode lead wire 2a. The positive electrode 3 is connected to a lid 4 of a metal member via a positive electrode lead wire 3a. The inside of the battery can 4 is made airtight via an insulating portion 5 between the lid 4 and the battery can 4. An electrolytic solution was injected into the battery can 4. A positive terminal 6 is provided on the protrusion of the lid 4, and a negative terminal 7 is provided on the bottom of the battery can 4 opposite to the protrusion.
【００９３】図９の模式説明図に示すように、負極２は
集電体２Ｂにカーボン層２Ｃを設けている。正極３は集
電体３Ｂに本発明のＬｉとＭｎを含む複合酸化物層３Ｃ
を設けている。両極間に電流を流すと、複合酸化物層３
ＣからＬｉイオンがカーボン層２Ｃに何ら障害なく移動
できる。As shown in the schematic explanatory view of FIG. 9, the negative electrode 2 is provided with a carbon layer 2C on a current collector 2B. The positive electrode 3 is composed of a current collector 3B and a composite oxide layer 3C containing Li and Mn of the present invention.
Is provided. When a current flows between the two electrodes, the composite oxide layer 3
Li ions can move from C to the carbon layer 2C without any obstacle.
【００９４】この理由について図１０に複合酸化物層の
結晶組織を示す模式斜視図により説明する。複合酸化物
層３Ｃは複数の規則正しい結晶格子３Ｄから構成されて
いる。結晶格子３ＤからＬｉイオンが放出する時、図１
２、図１３のように欠陥３Ｆや転移３Ｇなど、邪魔され
るものが少ないから、後述する従来技術より速やかにカ
ーボン層２Ｃに拡散する。The reason will be described with reference to FIG. 10 which is a schematic perspective view showing the crystal structure of the composite oxide layer. The composite oxide layer 3C is composed of a plurality of regular crystal lattices 3D. When Li ions are released from the crystal lattice 3D, FIG.
2. Since there are few obstacles such as defects 3F and transitions 3G as shown in FIG. 13, they diffuse into the carbon layer 2C more quickly than in the prior art described later.
【００９５】一方、図１１の従来の結晶格子３ＤではＬ
ｉイオンが放出する時に結晶の規則性を欠いた変形部分
３Ｅによって邪魔され、カーボン層２Ｃに移動できなく
なり、放電効率が低下してしまう。反対にカーボン層２
Ｃから複合酸化物層３ＣにＬｉイオンが挿入する時も同
様である。On the other hand, in the conventional crystal lattice 3D of FIG.
When the i-ions are released, they are hindered by the deformed portion 3E lacking the regularity of the crystal, cannot move to the carbon layer 2C, and the discharge efficiency is reduced. Conversely, carbon layer 2
The same applies when Li ions are inserted from C into the composite oxide layer 3C.
【００９６】このように本発明のＬｉとＭｎを含む複合
酸化物層３Ｃを使用したリチウム２次電池は、Ｌｉの挿
入・放出の可逆性が良く、充放電効率においてほぼ１０
０％維持できる。As described above, the lithium secondary battery using the composite oxide layer 3C containing Li and Mn according to the present invention has good reversibility of insertion and emission of Li, and has a charge-discharge efficiency of about 10%.
0% can be maintained.
【００９７】〔実施例 ９〕実施例１と同様にして電池
を作製した。その他の条件については本発明が特定する
最適範囲内とした。負極放電容量に関してはＬｉ金属を
対極として負極単極の容量を評価した。図１４に負極炭
素の負極真密度に対するサイクル寿命，負極放電容量と
の関係を示す。図より負極真密度は１.２ｇ／ｃｍ3より
も大きく１.８ｇ／ｃｍ3よりも小さい範囲で、サイクル
寿命も負極放電容量も良好な特性を示した。Example 9 A battery was manufactured in the same manner as in Example 1. Other conditions were within the optimum range specified by the present invention. Regarding the negative electrode discharge capacity, the capacity of the negative electrode single electrode was evaluated using Li metal as a counter electrode. FIG. 14 shows the relationship between the true density of the negative electrode carbon, the cycle life, and the negative electrode discharge capacity. As shown in the figure, the negative electrode true density was in a range of more than 1.2 g / cm 3 and less than 1.8 g / cm 3 , and both the cycle life and the negative electrode discharge capacity showed good characteristics.
【００９８】さらに、単電池において、温度が−１０℃
〜５０℃の範囲、放電深度が３０〜８０％の範囲で、入
力密度は３００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は５００〜３５００Ｗ／ｋｇの範囲にあった。Further, in the single cell, the temperature is -10 ° C.
The input density was in the range of 300-1800 W / kg, and the output density was in the range of 500-3500 W / kg, in the range of ５０50 ° C., in the range of discharge depth of 30-80%.
【００９９】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は２００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は３６０〜２５２０
Ｗ／ｋｇの範囲にあった。In the case of an assembled battery in which 96 of these batteries are connected in series, the temperature is in the range of -10 ° C. to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 200 to 130.
0W / kg, power density is 360-2520
W / kg range.
【０１００】〔実施例 １０〕実施例１と同様にして電
池を作製た。その他の条件については本発明が特定する
最適範囲内とした。負極炭素の結晶厚みＬｃと入力密度
と出力密度との関係を評価した。負極炭素の結晶厚みＬ
ｃは５〜１５０Åの範囲において入力密度と出力密度は
良好な特性を示し、単電池において、温度が−１０℃〜
５０℃の範囲、放電深度が３０〜８０％の範囲で、入力
密度は１０００〜１８００Ｗ／ｋｇの範囲にあり、出力
密度は２５００〜３５００Ｗ／ｋｇの範囲にあった。Example 10 A battery was manufactured in the same manner as in Example 1. Other conditions were within the optimum range specified by the present invention. The relationship between the crystal thickness Lc of the negative electrode carbon, the input density, and the output density was evaluated. Crystal thickness L of negative electrode carbon
In the range of 5 to 150 ° c, the input density and the output density show good characteristics.
The input density was in the range of 1000-1800 W / kg, and the output density was in the range of 2500-3500 W / kg, in the range of 50 ° C., the depth of discharge was in the range of 30-80%.
【０１０１】また、この電池の９６本を直列に接続した
組電池の場合、温度が−１０℃〜５０℃の範囲、放電深
度が３０〜８０％の範囲で、入力密度は８００〜１３０
０Ｗ／ｋｇの範囲にあり、出力密度は２０００〜２５２
０Ｗ／ｋｇの範囲にあった。In the case of a battery pack in which 96 of these batteries are connected in series, the temperature is in the range of -10 ° C. to 50 ° C., the depth of discharge is in the range of 30 to 80%, and the input density is 800 to 130.
0W / kg, power density is 2000-252
It was in the range of 0 W / kg.
【０１０２】[0102]
【発明の効果】本発明によれば、５０℃の高温下で本発
明の長寿命材料を用いることにより、長寿命のリチウム
２次電池を得ることができた。また、本発明のＬｉとＭ
ｎを含む複合酸化物を使用したリチウム２次電池は負荷
の変動に対応して、速やかに電力を供給することができ
る。According to the present invention, a long-life lithium secondary battery can be obtained by using the long-life material of the present invention at a high temperature of 50 ° C. In addition, Li and M of the present invention
A lithium secondary battery using a composite oxide containing n can quickly supply power in response to a change in load.
【図１】本発明のリチウム二次電池のＬｉ／Ｍｎ比に対
するサイクル寿命，放電容量との関係を示すグラフであ
る。FIG. 1 is a graph showing a relationship between a Li / Mn ratio, a cycle life, and a discharge capacity of a lithium secondary battery of the present invention.
【図２】本発明のリチウム二次電池の正極活物質の格子
定数に対するサイクル寿命，放電容量との関係を示すグ
ラフである。FIG. 2 is a graph showing a relationship between a lattice constant of a positive electrode active material of a lithium secondary battery of the present invention, a cycle life, and a discharge capacity.
【図３】本発明のリチウム二次電池の正極活物質の（４
００）ピークの半値幅とサイクル寿命との関係を示すグ
ラフである。FIG. 3 shows (4) the positive electrode active material of the lithium secondary battery of the present invention.
00) A graph showing the relationship between the peak half width and the cycle life.
【図４】本発明のリチウム二次電池の正極活物質の二次
粒子の比表面積に対するサイクル寿命，急速放電効率と
の関係を示すグラフである。FIG. 4 is a graph showing the relationship between the specific surface area of the secondary particles of the positive electrode active material of the lithium secondary battery of the present invention, the cycle life, and the rapid discharge efficiency.
【図５】本発明のリチウム二次電池の正極活物質の平均
一次粒子径に対するサイクル寿命，急速放電効率との関
係を示すグラフである。FIG. 5 is a graph showing the relationship between the average primary particle diameter of the positive electrode active material of the lithium secondary battery of the present invention, the cycle life, and the rapid discharge efficiency.
【図６】本発明のリチウム二次電池の負極密度に対する
サイクル寿命，負極放電容量との関係をを示すグラフで
ある。FIG. 6 is a graph showing the relationship between the cycle life and the anode discharge capacity with respect to the anode density of the lithium secondary battery of the present invention.
【図７】リチウム二次電池のサイクル数と放電容量との
関係を示すグラフである。FIG. 7 is a graph showing the relationship between the number of cycles and the discharge capacity of a lithium secondary battery.
【図８】本発明のリチウム二次電池の部分断面図であ
る。FIG. 8 is a partial cross-sectional view of the lithium secondary battery of the present invention.
【図９】使用した正極と負極との関係を説明する模式説
明図である。FIG. 9 is a schematic explanatory view illustrating a relationship between a used positive electrode and a used negative electrode.
【図１０】使用した複合酸化物層の結晶組織を示す模式
斜視図である。FIG. 10 is a schematic perspective view showing a crystal structure of a composite oxide layer used.
【図１１】従来の複合酸化物層の結晶組織を示す模式斜
視図である。FIG. 11 is a schematic perspective view showing a crystal structure of a conventional composite oxide layer.
【図１２】複合酸化物層の結晶組織を示す模式斜視図で
ある。FIG. 12 is a schematic perspective view showing a crystal structure of a composite oxide layer.
【図１３】複合酸化物層の結晶組織を示す模式斜視図で
ある。FIG. 13 is a schematic perspective view showing a crystal structure of a composite oxide layer.
【図１４】本発明のリチウム二次電池の負極炭素の負極
真密度に対するサイクル寿命，負極放電容量との関係を
示すグラフである。FIG. 14 is a graph showing the relationship between the cycle life and the negative electrode discharge capacity with respect to the negative electrode true density of the negative electrode carbon of the lithium secondary battery of the present invention.
１…セパレータ、２…負荷、３…正極、３Ｃ…複合酸化
物層、４…電池缶、５…絶縁部、６…正極端子、７…負
極端子。DESCRIPTION OF SYMBOLS 1 ... separator, 2 ... load, 3 ... positive electrode, 3C ... composite oxide layer, 4 ... battery can, 5 ... insulating part, 6 ... positive electrode terminal, 7 ... negative electrode terminal.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 葛西 昌弘 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 後藤 明弘 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 (72)発明者 堀田 好寿 茨城県日立市大みか町七丁目１番１号 株 式会社日立製作所日立研究所内 Ｆターム(参考） 5H029 AJ04 AK03 AL06 AM03 AM05 AM07 BJ02 BJ06 BJ14 DJ16 DJ18 HJ00 HJ02 HJ04 HJ05 HJ07 HJ08 HJ13 HJ16 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masahiro Kasai 7-1-1, Omikacho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (72) Inventor Akihiro Goto 7-1 Omikacho, Hitachi City, Ibaraki Prefecture No. 1 Inside Hitachi, Ltd. Hitachi Research Laboratories (72) Inventor Yoshihisa Hotta 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture F-term inside Hitachi Ltd. Hitachi Research Laboratory F-term (reference) AM07 BJ02 BJ06 BJ14 DJ16 DJ18 HJ00 HJ02 HJ04 HJ05 HJ07 HJ08 HJ13 HJ16
Claims (8)
ム二次電池において、 前記負極の活物質が非晶質炭素
を含み、その負極密度が０.９５ｇ／ｃｍ3より大きく
１.５ｇ／ｃｍ3よりも小さく、 前記正極の活物質がＸ線回折パターンの（４００）ピー
クの２θ角の半値幅が０.２゜より小さく、 スピネル型結晶構造をするＬｉとＭｎとを含む複合酸化
物を含み、前記複合酸化物のＬｉ／Ｍｎ原子比が０.５
５よりも大きく０.８よりも小さく、 スピネル型結晶構造における格子定数が８.０３１Åよ
りも大きく８.２３０Åより小さく、 前記複合酸化物の２次粒子の比表面積が０.１ｍ2／ｇよ
りも大きく１.５ｍ2／ｇより小さく、 前記複合酸化物の１次粒子の平均粒径が１μｍよりも大
きく２０μｍよりも小さいことを特徴とするリチウム二
次電池。1. A lithium secondary battery having a negative electrode, a non-aqueous electrolyte, and a positive electrode, wherein the active material of the negative electrode includes amorphous carbon, and the negative electrode density is greater than 0.95 g / cm 3 and 1.5 g / cm 3. less than 3, the positive electrode active material is X-ray diffraction pattern (400) half-value width of 2θ angles of the peaks is less than 0.2 °, the composite oxide containing Li, Mn for the spinel-type crystal structure The composite oxide has a Li / Mn atomic ratio of 0.5.
The lattice constant of the spinel crystal structure is larger than 8.031 ° and smaller than 8.230 °, and the specific surface area of the secondary particles of the composite oxide is larger than 0.1 m 2 / g. less than large 1.5 m 2 / g even, a lithium secondary battery having an average particle size of the primary particles being smaller than larger 20μm than 1μm of the composite oxide.
ム二次電池において、前記負極の活物質が非晶質炭素を
含み、その真密度が１.２〜１.８ｇ／ｃｍ3であり、 前記正極の活物質がＸ線回折パターンの（４００）ピー
クの２θ角の半値幅が０.２゜より小さく、 スピネル型結晶構造をするＬｉとＭｎとを含む複合酸化
物を含み、前記複合酸化物のＬｉ／Ｍｎ原子比が０.５
５よりも大きく０.８よりも小さく、 スピネル型結晶構造における格子定数が８.０３１Åよ
りも大きく８.２３０Åより小さく、 前記複合酸化物の２次粒子の比表面積が０.１ｍ2／ｇよ
りも大きく１.５ｍ2／ｇより小さく、 前記複合酸化物の１次粒子の平均粒径が１μｍよりも大
きく２０μｍよりも小さいことを特徴とするリチウム二
次電池。2. A lithium secondary battery having a negative electrode, a non-aqueous electrolyte, and a positive electrode, wherein the active material of the negative electrode contains amorphous carbon, and has a true density of 1.2 to 1.8 g / cm 3 , The active material of the positive electrode includes a composite oxide containing Li and Mn having a spinel-type crystal structure, wherein the half-width at 2θ angle of the (400) peak of the X-ray diffraction pattern is smaller than 0.2 °. Has a Li / Mn atomic ratio of 0.5
The lattice constant of the spinel crystal structure is larger than 8.031 ° and smaller than 8.230 °, and the specific surface area of the secondary particles of the composite oxide is larger than 0.1 m 2 / g. less than large 1.5 m 2 / g even, a lithium secondary battery having an average particle size of the primary particles being smaller than larger 20μm than 1μm of the composite oxide.
ム二次電池において、前記負極の活物質が非晶質炭素を
含み、その結晶厚みＬｃが５Å〜１５０Åであり、 前記正極の活物質がＸ線回折パターンの（４００）ピー
クの２θ角の半値幅が０.２゜より小さく、 スピネル型結晶構造をするＬｉとＭｎとを含む複合酸化
物を含み、前記複合酸化物のＬｉ／Ｍｎ原子比が０.５
５よりも大きく０.８０よりも小さく、 スピネル型結晶構造における格子定数が８.０３１Åよ
りも大きく８.２３０Åより小さく、 前記複合酸化物の２次粒子の比表面積が０.１ｍ2／ｇよ
りも大きく１.５ｍ2／ｇより小さく、 前記複合酸化物の１次粒子の平均粒径が１μｍよりも大
きく２０μｍよりも小さいことを特徴とするリチウム二
次電池。3. A lithium secondary battery having a negative electrode, a non-aqueous electrolyte and a positive electrode, wherein the active material of the negative electrode contains amorphous carbon, the crystal thickness Lc thereof is 5 ° to 150 °, and the active material of the positive electrode is A half-width at 2θ angle of the (400) peak of the X-ray diffraction pattern is smaller than 0.2 °, and a composite oxide containing Li and Mn having a spinel-type crystal structure; and a Li / Mn atom of the composite oxide The ratio is 0.5
Greater than 5 and less than 0.80; the lattice constant of the spinel crystal structure is greater than 8.031 ° and less than 8.230 °; and the specific surface area of the secondary particles of the composite oxide is 0.1 m 2 / g or more. less than large 1.5 m 2 / g even, a lithium secondary battery having an average particle size of the primary particles being smaller than larger 20μm than 1μm of the composite oxide.
００〜１８００Ｗ／ｋｇである請求項１，２または３に
記載のリチウム二次電池。4. An input density at -10 ° C. to 50 ° C. of 3
The lithium secondary battery according to claim 1, wherein the lithium secondary battery has a power of 00 to 1800 W / kg.
００〜３５００Ｗ／ｋｇである請求項１，２または３に
記載のリチウム二次電池。5. The power density at -10 ° C. to 50 ° C. is 5
The lithium secondary battery according to claim 1, wherein the lithium secondary battery has a power of 00 to 3500 W / kg.
２個以上組み合わせた組電池の入力密度が２００〜１３
００Ｗ／ｋｇであることを特徴とするリチウム二次電
池。6. An assembled battery obtained by combining two or more of the cells according to claim 1, 2, or 3 has an input density of 200 to 13.
A lithium secondary battery characterized by being 00 W / kg.
２個以上組み合わせた組電池の出力密度が３６０〜２５
２０Ｗ／ｋｇであることを特徴とするリチウム二次電
池。7. An assembled battery obtained by combining two or more of the unit cells according to claim 1, 2, or 3 has an output density of 360 to 25.
A lithium secondary battery having a power of 20 W / kg.
５０℃における値である請求項６または７に記載のリチ
ウム二次電池。8. The method according to claim 1, wherein said input density or output density is from -10.degree.
The lithium secondary battery according to claim 6, which is a value at 50 ° C.
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| JP2000131537A JP3764320B2 (en) | 1999-04-27 | 2000-04-26 | Lithium secondary battery |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11-119537 | 1999-04-27 | ||
| JP11953799 | 1999-04-27 | ||
| JP2000131537A JP3764320B2 (en) | 1999-04-27 | 2000-04-26 | Lithium secondary battery |
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| Publication Number | Publication Date |
|---|---|
| JP2001015173A true JP2001015173A (en) | 2001-01-19 |
| JP3764320B2 JP3764320B2 (en) | 2006-04-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000131537A Expired - Fee Related JP3764320B2 (en) | 1999-04-27 | 2000-04-26 | Lithium secondary battery |
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| JP (1) | JP3764320B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6706446B2 (en) | 2000-12-26 | 2004-03-16 | Shin-Kobe Electric Machinery Co., Ltd. | Non-aqueous electrolytic solution secondary battery |
| US6803149B2 (en) | 2000-12-04 | 2004-10-12 | Shin-Kobe Electric Machinery Co., Ltd. | Non-aqueous electrolytic solution secondary battery |
| JP2006164859A (en) * | 2004-12-10 | 2006-06-22 | Shin Kobe Electric Mach Co Ltd | Positive electrode material for lithium secondary battery, its manufacturing method and lithium secondary battery |
| JP2006236753A (en) * | 2005-02-24 | 2006-09-07 | Hitachi Chem Co Ltd | Lithium secondary battery and automobile using it |
| JP2006286841A (en) * | 2005-03-31 | 2006-10-19 | Daihatsu Motor Co Ltd | Electrochemical capacitor |
| JP2009146868A (en) * | 2007-12-18 | 2009-07-02 | Nec Tokin Corp | Lithium polymer battery |
| JP2013129589A (en) * | 2011-11-22 | 2013-07-04 | Tanaka Chemical Corp | Composite oxide, method for producing the same, positive electrode for lithium secondary battery, and lithium secondary battery |
| WO2014007330A1 (en) * | 2012-07-05 | 2014-01-09 | 昭和電工株式会社 | Method for using electrochemical element |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5105765B2 (en) * | 2006-04-20 | 2012-12-26 | Ｎｅｃエナジーデバイス株式会社 | Lithium ion secondary battery |
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2000
- 2000-04-26 JP JP2000131537A patent/JP3764320B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6803149B2 (en) | 2000-12-04 | 2004-10-12 | Shin-Kobe Electric Machinery Co., Ltd. | Non-aqueous electrolytic solution secondary battery |
| US6706446B2 (en) | 2000-12-26 | 2004-03-16 | Shin-Kobe Electric Machinery Co., Ltd. | Non-aqueous electrolytic solution secondary battery |
| JP2006164859A (en) * | 2004-12-10 | 2006-06-22 | Shin Kobe Electric Mach Co Ltd | Positive electrode material for lithium secondary battery, its manufacturing method and lithium secondary battery |
| JP2006236753A (en) * | 2005-02-24 | 2006-09-07 | Hitachi Chem Co Ltd | Lithium secondary battery and automobile using it |
| JP2006286841A (en) * | 2005-03-31 | 2006-10-19 | Daihatsu Motor Co Ltd | Electrochemical capacitor |
| JP4611082B2 (en) * | 2005-03-31 | 2011-01-12 | ダイハツ工業株式会社 | Electrochemical capacitor |
| JP2009146868A (en) * | 2007-12-18 | 2009-07-02 | Nec Tokin Corp | Lithium polymer battery |
| JP2013129589A (en) * | 2011-11-22 | 2013-07-04 | Tanaka Chemical Corp | Composite oxide, method for producing the same, positive electrode for lithium secondary battery, and lithium secondary battery |
| WO2014007330A1 (en) * | 2012-07-05 | 2014-01-09 | 昭和電工株式会社 | Method for using electrochemical element |
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