JP2001216965A - Positive electrode for lithium secondary battery - Google Patents

Positive electrode for lithium secondary battery

Info

Publication number
JP2001216965A
JP2001216965A JP2000024635A JP2000024635A JP2001216965A JP 2001216965 A JP2001216965 A JP 2001216965A JP 2000024635 A JP2000024635 A JP 2000024635A JP 2000024635 A JP2000024635 A JP 2000024635A JP 2001216965 A JP2001216965 A JP 2001216965A
Authority
JP
Japan
Prior art keywords
positive electrode
active material
secondary battery
lithium secondary
lithium
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.)
Pending
Application number
JP2000024635A
Other languages
Japanese (ja)
Inventor
Yoji Takeuchi
要二 竹内
Yoshio Ukiyou
良雄 右京
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toyota Central R&D Labs Inc
Original Assignee
Toyota Central R&D Labs Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Toyota Central R&D Labs Inc filed Critical Toyota Central R&D Labs Inc
Priority to JP2000024635A priority Critical patent/JP2001216965A/en
Publication of JP2001216965A publication Critical patent/JP2001216965A/en
Pending legal-status Critical Current

Links

Classifications

    • 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

Landscapes

  • Inorganic Compounds Of Heavy Metals (AREA)
  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a positive electrode for a lithium secondary battery capable of constituting the lithium secondary battery having low cost, high energy density, and superior cycling characteristics, in particular, cycling characteristics in high-temperature use by optimizing the type of an active material to be used and the density of the active material. SOLUTION: The positive electrode for the lithium secondary battery formed by binding an active material with a binder has an active material density (the weight of the active material existing in a unit volume of the positive electrode) being 2.3 g/cm3 or more and 3 g/cm3 or less, using a layered rock-salt structure lithium-nickel combined oxide as the active material.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、リチウムの吸蔵・
脱離現象を利用したリチウム二次電池に用いる正極に関
する。TECHNICAL FIELD The present invention relates to a method for storing and storing lithium.
The present invention relates to a positive electrode used for a lithium secondary battery utilizing a desorption phenomenon.

【０００２】[0002]

【従来の技術】携帯電話、パソコン等の小型化に伴い、
エネルギー密度の高い二次電池が必要とされ、通信機
器、情報関連機器の分野では、リチウム二次電池が広く
普及するに至っている。また、資源問題、環境問題か
ら、自動車の分野でも電気自動車に対する要望が高ま
り、電気自動車用電源等の大容量用途の二次電池とし
て、安価であってかつ容量が大きく、サイクル特性が良
好なリチウム二次電池の開発が急がれている。2. Description of the Related Art As mobile phones and personal computers become smaller,
Secondary batteries with high energy density are required, and lithium secondary batteries have come into widespread use in the fields of communication devices and information-related devices. In addition, due to resource and environmental issues, demands for electric vehicles are increasing in the field of automobiles. As a secondary battery for large-capacity applications such as power supplies for electric vehicles, lithium batteries that are inexpensive, have a large capacity, and have good cycle characteristics are used. The development of secondary batteries is urgent.

【０００３】現在、リチウム二次電池の正極活物質に
は、４Ｖ級の二次電池を構成できるものとして、層状岩
塩構造のＬｉＣｏＯ2が採用されるに至っている。Ｌｉ
ＣｏＯ2は、合成が容易でかつ取り扱いも比較的容易で
あることに加え、充放電サイクル特性において優れるこ
とから、このＬｉＣｏＯ2を正極活物質に使用する二次
電池が主流となっている。At present, as a positive electrode active material of a lithium secondary battery, LiCoO 2 having a layered rock salt structure has been adopted as a material capable of constituting a 4 V class secondary battery. Li
Since CoO 2 is easy to synthesize and relatively easy to handle and has excellent charge-discharge cycle characteristics, secondary batteries using this LiCoO 2 as a positive electrode active material have become mainstream.

【０００４】ところが、ＬｉＣｏＯ2を構成する元素で
あるコバルトは、資源量として少なく極めて高価な元素
であることから、リチウム二次電池のコストを押し上げ
る大きな要因となっている。したがって、例えばリチウ
ム二次電池を電気自動車用の電源として用いるような場
合、大きな容量を必要とすることから、大量の正極活物
質を用いなければならず、高価なＬｉＣｏＯ2を正極活
物質に用いたリチウムイオン二次電池は実用化が非常に
困難であると考えられる。However, cobalt, which is an element constituting LiCoO 2 , is an extremely expensive element with a small amount of resources, and is a major factor that increases the cost of a lithium secondary battery. Therefore, for example, when a lithium secondary battery is used as a power source for an electric vehicle, a large capacity is required, so that a large amount of a positive electrode active material must be used, and expensive LiCoO 2 is used for the positive electrode active material. It is considered that the lithium ion secondary battery that has been used is very difficult to put into practical use.

【０００５】このＬｉＣｏＯ2に代わって期待されるの
が、ＬｉＮｉＯ2を代表的組成とする層状岩塩構造リチ
ウムニッケル複合酸化物である。コバルトと比較して安
価なニッケルを構成元素とすることから、コスト面で優
れ、また、理論放電容量においてはＬｉＣｏＯ2と大差
ないが実効容量（電池を構成した場合に実際取り出すこ
とのできる容量）において優れるという利点から、大き
な容量の電池を構成できるものとして期待されている。What is expected to replace this LiCoO 2 is a lithium nickel composite oxide having a layered rock salt structure having a typical composition of LiNiO 2 . Since nickel, which is cheaper than cobalt, is used as a constituent element, the cost is excellent, and the theoretical discharge capacity is not much different from LiCoO 2 , but the effective capacity (capacity that can be actually taken out when a battery is formed) Therefore, it is expected that a battery having a large capacity can be formed.

【０００６】ところが、このリチウムニッケル複合酸化
物は、実効容量が大きいことにより充放電に伴い多くの
リチウムを吸蔵・脱離するため、自身が大きな膨張・収
縮を繰り返すことで構造が崩壊しやすいという欠点があ
る。したがって、電池を構成した場合に、繰り返される
充放電によって電池の放電容量が減少するという、いわ
ゆるサイクル劣化が問題となる。特に、電池反応が活性
化する高温下では一層劣化が進むことから、例えば屋外
放置される可能性のある電気自動車用電源等の用途の場
合、高温下でのサイクル劣化の少ないことも二次電池に
求められる重要な特性の一つとなる。However, since the lithium-nickel composite oxide has a large effective capacity, it absorbs and desorbs a large amount of lithium as it is charged and discharged. Therefore, the structure easily collapses due to repeated expansion and contraction of itself. There are drawbacks. Therefore, when a battery is configured, there is a problem of so-called cycle deterioration in which the discharge capacity of the battery is reduced by repeated charging and discharging. In particular, in the case of an application such as a power source for an electric vehicle that may be left outdoors, the secondary battery also has a small cycle deterioration at a high temperature because the deterioration proceeds further at a high temperature at which the battery reaction is activated. It is one of the important characteristics required for

【０００７】[0007]

【発明が解決しようとする課題】本発明者は、度重なる
実験を経て、リチウム二次電池のサイクル劣化の機構、
特に、リチウムニッケル複合酸化物を活物質とする正極
に起因するサイクル劣化の機構を調査した。その結果、
リチウムニッケル複合酸化物は、１次粒子が凝集結合し
てして２次粒子を形成する粒子構造となっており、充放
電を繰り返すことで、１次粒子の膨張・収縮によるスト
レスから１次粒子がその結合を解かれることにより、２
次粒子内の電子伝導性が悪化することが、サイクル劣化
の主原因であることが解った。SUMMARY OF THE INVENTION The inventor of the present invention has conducted numerous experiments to find out the mechanism of cycle deterioration of a lithium secondary battery,
In particular, the mechanism of cycle deterioration caused by a positive electrode using a lithium nickel composite oxide as an active material was investigated. as a result,
The lithium-nickel composite oxide has a particle structure in which primary particles are aggregated and bonded to form secondary particles. By repeating charge and discharge, primary particles are subjected to stress caused by expansion and contraction of the primary particles. Is dissociated by
It has been found that the deterioration of the electron conductivity in the secondary particles is the main cause of the cycle deterioration.

【０００８】リチウム二次電池の正極は、活物質を結着
剤で結着して形成されるが、この際、エネルギー密度の
向上を目的として、プレス等の手段により、正極におけ
る活物質密度を高めることが行われている。本発明者
は、このプレス等による手段での圧縮が、正極を緊密化
させ、２次粒子内の電子伝導性を良好に保つ手段として
も有効であると考えた。そこで、この考えの下、種々の
活物質密度の正極を作製して実験を行ったが、活物質密
度を高めるべく圧縮を行う場合、過度の圧縮は、その圧
縮過程において、その圧縮力によって２次粒子が崩壊
し、かえって正極の電子伝導性が悪化してしまうとの知
見を得た。[0008] The positive electrode of a lithium secondary battery is formed by binding an active material with a binder. At this time, the active material density in the positive electrode is reduced by means of a press or the like in order to improve the energy density. Enhancing has been done. The present inventor has considered that compression by means such as a press is effective as a means for densifying the positive electrode and maintaining good electron conductivity in the secondary particles. Therefore, based on this idea, positive electrodes having various active material densities were produced and experiments were conducted. When compression was performed to increase the active material density, excessive compression was caused by the compression force during the compression process. It has been found that the secondary particles are disintegrated and the electron conductivity of the positive electrode is rather deteriorated.

【０００９】本発明は、上記知見に基づくものであり、
用いる活物質の種類と活物質密度を適正化することによ
り、安価でエネルギー密度が高く、かつサイクル特性、
特に高温使用時におけるサイクル特性の良好なリチウム
二次電池を構成することのできるリチウム二次電池用正
極を提供することを課題としている。The present invention is based on the above findings,
By optimizing the type of active material used and the active material density, it is inexpensive, has a high energy density,
In particular, it is an object of the present invention to provide a positive electrode for a lithium secondary battery capable of forming a lithium secondary battery having good cycle characteristics when used at a high temperature.

【００１０】[0010]

【課題を解決するための手段】本発明のリチウム二次電
池用正極は、活物質を結着剤で結着して形成されたリチ
ウム二次電池用正極であって、前記活物質は、層状岩塩
構造リチウムニッケル複合酸化物であり、活物質密度
（正極単位体積中に存在する活物質の重量）は、２．３
ｇ／ｃｍ3以上３ｇ／ｃｍ3以下であることを特徴とす
る。A positive electrode for a lithium secondary battery according to the present invention is a positive electrode for a lithium secondary battery formed by binding an active material with a binder, wherein the active material has a layered shape. It is a lithium nickel composite oxide having a rock salt structure, and has an active material density (weight of the active material present in a unit volume of the positive electrode) of 2.3.
characterized in that g / cm 3 or more 3 g / cm 3 or less.

【００１１】つまり、本発明のリチウム二次電池用正極
では、活物質に安価であってかつ放電容量の大きな層状
岩塩構造リチウムニッケル複合酸化物を用いることで、
リチウム二次電池自体を安価でかつエネルギー密度を高
くすることができる。そしてそれに加え、上記所定範囲
に緊密化された構造の正極とすることにより、充放電初
期においても大きな放電容量を有し、繰り返される充放
電によって生じるリチウムニッケル複合酸化物の２次粒
子の崩壊に起因する正極内の電子伝導性の悪化を効率よ
く防止し、サイクル特性の良好なリチウム二次電池を構
成することのできる正極となる。That is, in the positive electrode for a lithium secondary battery of the present invention, by using a low-cost lithium nickel composite oxide having a layered rock salt structure having a large discharge capacity as an active material,
The lithium secondary battery itself can be inexpensive and have high energy density. In addition, the positive electrode having a structure tightly packed in the above-mentioned predetermined range has a large discharge capacity even at the initial stage of charging and discharging, and is capable of preventing the secondary particles of the lithium nickel composite oxide from being broken by repeated charging and discharging. The positive electrode can efficiently prevent the deterioration of electron conductivity in the positive electrode due to the positive electrode and can form a lithium secondary battery having good cycle characteristics.

【００１２】[0012]

【発明の実施の形態】以下に、本発明のリチウム二次電
池用正極の実施形態について、正極活物質となるリチウ
ムニッケル複合酸化物、正極の構成と製造、本正極を用
いたリチウム二次電池の順に詳しく説明する。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of a positive electrode for a lithium secondary battery according to the present invention will be described with reference to a lithium nickel composite oxide serving as a positive electrode active material, the structure and manufacture of the positive electrode, and a lithium secondary battery using the present positive electrode. Will be described in detail in this order.

【００１３】〈リチウムニッケル複合酸化物〉本発明の
リチウム二次電池用正極においては、活物質として、層
状岩塩構造リチウムニッケル複合酸化物を用いる。この
層状岩塩構造リチウムニッケル複合酸化物は、基本組成
をＬｉＮｉＯ2とするもので、現在の主流をなす正極活
物質であるＬｉＣｏＯ2と同じ結晶構造をしており、４
Ｖ級のリチウム二次電池を構成できるものである。中心
となる構成元素がＮｉであるため、安価なリチウム二次
電池を構成することのできる正極活物質となり得る。<Lithium Nickel Composite Oxide> In the positive electrode for a lithium secondary battery of the present invention, a layered rock salt structure lithium nickel composite oxide is used as an active material. This layered rock salt structure lithium nickel composite oxide has a basic composition of LiNiO 2, and has the same crystal structure as the current mainstream cathode active material LiCoO 2.
It can constitute a V-class lithium secondary battery. Since the central constituent element is Ni, it can be a positive electrode active material that can form an inexpensive lithium secondary battery.

【００１４】本発明のリチウム二次電池用正極では、上
記基本組成のものの他、活物質としての特性を改善すべ
く、Ｎｉサイトの一部をリチウム元素で置換した組成式
Ｌｉ 1+xＮｉ1-yＯ2で表されるもの、Ｎｉサイトの一部
を他の遷移金属元素等（Ｍｅ）で置換した組成式ＬｉＮ
ｉ1-xＭｅxＯ2で表されるもの等を用いることができ
る。また、化学量論組成のものだけでなく、Ｌｉサイ
ト、Ｎｉサイト、Ｏサイト等に欠損等が生じている非化
学量論組成ものもをも用いることができる。さらにま
た、上記種々のリチウムニッケル複合酸化物のうちいず
れか１種を単独で活物質とするだけでなく、２種以上を
混合して活物質とすることもできる。In the positive electrode for a lithium secondary battery of the present invention,
In addition to the basic composition, the characteristics of the active material should be improved.
Composition formula in which a part of Ni site is replaced by lithium element
Li 1 + xNi1-yOTwo, Part of Ni site
Is substituted by another transition metal element or the like (Me).
i1-xMexOTwoCan be used.
You. In addition to the stoichiometric composition,
, Ni site, O site, etc. are missing
Stoichiometric compositions can also be used. Even better
Further, any of the above various lithium nickel composite oxides
Not only one of them can be used as the active material alone,
An active material can be mixed.

【００１５】本発明のリチウム二次電池用電極の活物質
としては、Ｎｉサイトを２種の元素Ｃｏ、Ａｌで置換し
た組成式ＬｉＮｉxＣｏyＡｌzＯ2（ｘ＋ｙ＋ｚ＝１、
０．０５≦ｙ≦０．４、０．０１≦ｚ≦０．０９）で表
されるものを用いるのが望ましい。その理由を以下に説
明する。As an active material of the electrode for a lithium secondary battery of the present invention, a composition formula LiNi x Co y Al z O 2 (x + y + z = 1, in which Ni site is substituted by two kinds of elements Co and Al).
It is desirable to use the one represented by 0.05 ≦ y ≦ 0.4, 0.01 ≦ z ≦ 0.09). The reason will be described below.

【００１６】ここでＬｉＮｉＯ2の充放電による構造を
追跡すると、その構造は六方晶→単斜晶→六方晶→層間
の縮みと変化し、ほぼ六方晶を保ったまま充放電するＬ
ｉＣｏＯ2と比較して、ＬｉＮｉＯ2はサイクル特性にお
いて劣るものとなっている。置換元素のうちのＣｏは、
主に、結晶構造の転移の抑制（単斜晶領域の低減）とい
う作用により、リチウムニッケル複合酸化物の結晶構造
を安定化する役割を果たしている。また、Ｃｏには、元
素置換による容量低下を抑えるとともに、得られる複合
酸化物Ｌｉ（Ｃｏ，Ｎｉ）Ｏ2は全固溶型であり、結晶
性の低下を最小限にとどめるという利点がある。Ｃｏで
の結晶構造安定化により、リチウム二次電池のサイクル
特性は良好に保たれ、特に高温下での充放電および高温
下での貯蔵による電池容量の劣化が抑制される。サイク
ル特性の改善効果を充分に発揮させるために、Ｃｏでの
置換割合つまり組成式におけるｙの値は０．０５≦ｙ≦
０．４とする。ｙ＜０．０５の場合は、結晶構造安定化
が充分でないため、構成される二次電池のサイクル特性
がやや劣り、ｙ＞０．４の場合はリチウムニッケル複合
酸化物の結晶性が低く容量が低下して好ましくないこと
に加え、正極活物質のコストが高くなり、比較的安価な
リチウムニッケル複合酸化物の優位性を失うからであ
る。Here, when the structure of LiNiO 2 due to charging and discharging is traced, the structure changes from hexagonal to monoclinic to hexagonal to contraction between layers, and L is charged and discharged while maintaining substantially hexagonal.
Compared with iCoO 2 , LiNiO 2 is inferior in cycle characteristics. Co of the substitution elements is
It mainly plays a role of stabilizing the crystal structure of the lithium-nickel composite oxide by the action of suppressing the transition of the crystal structure (reducing the monoclinic region). In addition, Co has the advantage of suppressing a decrease in capacity due to element substitution, and obtaining a composite oxide Li (Co, Ni) O 2 of an all-solid solution type so that a decrease in crystallinity is minimized. By stabilizing the crystal structure of Co, the cycle characteristics of the lithium secondary battery are kept good, and particularly, deterioration of the battery capacity due to charge / discharge at high temperature and storage at high temperature is suppressed. In order to sufficiently exhibit the effect of improving the cycle characteristics, the substitution ratio with Co, that is, the value of y in the composition formula, is 0.05 ≦ y ≦
0.4. In the case of y <0.05, the crystal structure is not sufficiently stabilized, so that the cycle characteristics of the formed secondary battery are slightly inferior. In the case of y> 0.4, the crystallinity of the lithium nickel composite oxide is low and the capacity is low. This is because the cost of the positive electrode active material increases, and the advantage of the relatively inexpensive lithium nickel composite oxide is lost.

【００１７】もう一つの置換元素であるＡｌは、主に、
酸素放出に伴う活物質の分解反応を抑え、熱安定性を向
上させるという役割を果たしている。この役割のため、
Ａｌでの置換割合、つまり組成式におけるｚの値は、
０．０１≦ｚ≦０．０９とする。置換割合が小さくｚ＜
０．０１の場合は、置換効果を充分に発揮できず、ま
た、置換割合が大きくｚ＞０．０９の場合は、正極製造
時の圧縮工程において２次粒子内の１次粒子の結合がと
れる、つまり２次粒子が割れるという現象を引き起こ
し、電子伝導性が悪化して容量が低下してしまうため好
ましくない。Ａｌの置換割合が大きい場合に２次粒子の
割れが発生する原因は定かではないが、結晶粒界付近に
Ａｌが偏在しており、より一層歪みが発生しやすいため
であると考えられる。Al, which is another substitution element, is mainly
It plays the role of suppressing the decomposition reaction of the active material due to the release of oxygen and improving the thermal stability. For this role,
The substitution ratio with Al, that is, the value of z in the composition formula, is
0.01 ≦ z ≦ 0.09. The substitution ratio is small and z <
In the case of 0.01, the substitution effect cannot be sufficiently exhibited, and in the case where the substitution ratio is large and z> 0.09, the primary particles in the secondary particles can be bonded in the compression step at the time of manufacturing the positive electrode. In other words, a phenomenon in which the secondary particles are cracked is caused, and the electron conductivity is deteriorated to lower the capacity, which is not preferable. Although the cause of the occurrence of cracks in the secondary particles when the substitution ratio of Al is large is not clear, it is considered that Al is unevenly distributed in the vicinity of the crystal grain boundaries, and distortion is more likely to occur.

【００１８】上記リチウムニッケル複合酸化物は、その
製造方法を限定するものではなく、例えば、固相反応
法、共沈法、噴霧乾燥法等によって製造することができ
る。固相反応法による場合は、Ｌｉ源となるリチウム化
合物、Ｎｉ源となるニッケル化合物、必要に応じＣｏ源
となるコバルト化合物、Ａｌ源となるアルミニウム化合
物等を、合成しようとするリチウムニッケル複合酸化物
の構成元素の組成比に応じて混合させ、この混合物を７
００〜９００℃の温度下、酸素雰囲気あるいは空気中
で、８〜２４時間焼成して合成することができる。この
際、Ｌｉ源となるリチウム化合物としては、水酸化リチ
ウム、炭酸リチウム等を用いることができ、Ｎｉ源とな
るニッケル化合物には、水酸化ニッケル、硝酸ニッケル
等を、Ｃｏ源となるコバルト化合物には、四酸化三コバ
ルト、硝酸コバルト等を、Ａｌ源となるアルミニウム化
合物には、硝酸アルミニウム等をそれぞれ用いることが
できる。The method for producing the lithium nickel composite oxide is not limited, and it can be produced by, for example, a solid phase reaction method, a coprecipitation method, a spray drying method, or the like. In the case of the solid-phase reaction method, a lithium-nickel composite oxide to synthesize a lithium compound serving as a Li source, a nickel compound serving as a Ni source, a cobalt compound serving as a Co source, and an aluminum compound serving as an Al source, if necessary. Are mixed according to the composition ratio of the constituent elements of
It can be synthesized by firing at a temperature of 00 to 900 ° C. in an oxygen atmosphere or air for 8 to 24 hours. At this time, lithium hydroxide, lithium carbonate, or the like can be used as the lithium compound serving as the Li source. Nickel hydroxide, nickel nitrate, or the like may be used as the nickel compound serving as the Ni source, and the cobalt compound serving as the Co source may be used as the nickel compound serving as the Ni source. Can be used, such as tricobalt tetroxide, cobalt nitrate and the like, and aluminum nitrate and the like can be used as the aluminum compound serving as the Al source.

【００１９】リチウムニッケル複合酸化物は、粉状体と
して用いる。この場合の粉体粒子構造は、１次粒子が凝
集結合して２次粒子を形成する構造となっている。この
１次粒子および２次粒子のそれぞれの粒子径も、正極活
物質としての特性を左右する要素となる。The lithium nickel composite oxide is used as a powder. The powder particle structure in this case is a structure in which the primary particles are cohesively bonded to form secondary particles. The particle diameter of each of the primary particles and the secondary particles is also an element that affects the characteristics as a positive electrode active material.

【００２０】本発明のリチウム二次電池用正極の活物質
として用いるリチウムニッケル複合酸化物では、１次粒
子の多くが０．５μｍ以上の粒子径であることが望まし
い。具体的には、総数の８０％以上が０．５μｍ以上で
ある１次粒子が凝集結合して２次粒子を形成しているこ
とが望ましい。０．５μｍ未満の粒子径を有する１次粒
子が数多く凝集結合している２次粒子は、格子歪が多い
粒界面積が広いため、正極製造の際の圧縮工程におい
て、２次粒子が崩壊し易い構造となり、また、充放電に
おけるリチウムの吸蔵・脱離によっても、２次粒子が崩
壊し易い構造となる。In the lithium nickel composite oxide used as the active material of the positive electrode for a lithium secondary battery according to the present invention, it is desirable that most of the primary particles have a particle diameter of 0.5 μm or more. Specifically, it is preferable that 80% or more of the total number of primary particles having a size of 0.5 μm or more is cohesively bonded to form secondary particles. Secondary particles in which a large number of primary particles having a particle diameter of less than 0.5 μm are cohesively bonded have a large lattice boundary and a large grain boundary area. Therefore, in the compression step in manufacturing the positive electrode, the secondary particles collapse. The secondary particles are easily broken, and the secondary particles are easily broken by the insertion and extraction of lithium during charge and discharge.

【００２１】また、本発明のリチウム二次電池用正極の
活物質として用いるリチウムニッケル複合酸化物では、
２次粒子の平均粒径が、４μｍ以上５０μｍ以下のもの
を用いることが望ましい。平均粒径が４μｍ未満の場合
は、結着剤と混合してペースト状の正極合材を調製する
際にゲル化し、逆に、５０μｍ以上の場合は、粒子が大
きすぎ、正極合材調製時に粒子の沈降が早く、いずれも
塗工性が悪くなるからである。Further, in the lithium nickel composite oxide used as the active material of the positive electrode for a lithium secondary battery of the present invention,
It is desirable to use secondary particles having an average particle diameter of 4 μm or more and 50 μm or less. When the average particle size is less than 4 μm, gelation occurs when preparing a paste-like positive electrode mixture by mixing with a binder. Conversely, when the average particle size is 50 μm or more, the particles are too large, and when preparing the positive electrode mixture, This is because the particles settle quickly and the coatability is deteriorated.

【００２２】さらに、本発明のリチウム二次電池用正極
の活物質として用いるリチウムニッケル複合酸化物で
は、その比表面積が０．１ｍ2／ｇ以上１ｍ2／ｇ以下で
あることが望ましい。比表面積が０．１ｍ2／ｇ未満の
場合は、Ｌｉの吸蔵・脱離する面積が減少するため、ハ
イレート特性が低下することとなり、また、１ｍ2／ｇ
を超える場合は、表面と結着剤が反応して正極合材がゲ
ル化しやすく、塗工性が悪化するからである。なお、比
表面積は、ＢＥＴ比表面積であり、液体窒素温度での窒
素の物理的吸着を利用する方法により測定するものとす
る。Further, the specific surface area of the lithium nickel composite oxide used as the active material of the positive electrode for a lithium secondary battery of the present invention is desirably 0.1 m 2 / g or more and 1 m 2 / g or less. When the specific surface area is less than 0.1 m 2 / g, the area for absorbing and desorbing Li is reduced, so that the high-rate characteristics are reduced, and 1 m 2 / g.
If the ratio exceeds the range, the surface and the binder react with each other to cause the positive electrode mixture to easily gel, thereby deteriorating the coatability. The specific surface area is a BET specific surface area, which is measured by a method utilizing physical adsorption of nitrogen at the temperature of liquid nitrogen.

【００２３】〈正極の構成および製造〉本発明のリチウ
ム二次電池用正極は、上記リチウムニッケル複合酸化物
を活物質とし、これを結着剤で結着して形成する。その
構成および製造方法は、特に限定するものではなく。既
に公知の形態に従えばよい。例えば、本発明のリチウム
二次電池用正極は、金属箔製の集電体の表面に、上記リ
チウムニッケル複合酸化物、導電材、結着剤を混合した
正極合材を層状に結着させて形成することができる。<Structure and Production of Positive Electrode> The positive electrode for a lithium secondary battery of the present invention is formed by using the above-mentioned lithium nickel composite oxide as an active material and binding it with a binder. The configuration and manufacturing method are not particularly limited. A known form may be followed. For example, the positive electrode for a lithium secondary battery of the present invention is obtained by binding a positive electrode mixture obtained by mixing the above-mentioned lithium nickel composite oxide, a conductive material, and a binder on a surface of a current collector made of a metal foil in a layered manner. Can be formed.

【００２４】まず、活物質としての粉末状の上記リチウ
ムニッケル複合酸化物と、導電材と、結着剤とを混合
し、これらを分散させるための溶剤を添加して、ペース
ト状の正極合材を調製する。次に、この正極合材をアル
ミニウム箔等の正極集電体の表面に塗工機等により塗布
し、乾燥して固形分のみの正極合材を層状に形成すれば
良い。そしてこの後に、ロールプレス等の圧縮機により
圧縮を行い、活物質密度を高める。この形態の正極はシ
ート状であり、作製しようとする電池に適合する大きさ
に裁断等して完成させればよい。First, the powdered lithium-nickel composite oxide as an active material, a conductive material, and a binder are mixed, and a solvent for dispersing these is added. Is prepared. Next, this positive electrode mixture may be applied to the surface of a positive electrode current collector such as an aluminum foil with a coating machine or the like, and dried to form a positive electrode mixture containing only solids in a layered form. Thereafter, compression is performed by a compressor such as a roll press to increase the active material density. The positive electrode in this form is sheet-shaped, and may be completed by cutting or the like into a size suitable for a battery to be manufactured.

【００２５】なお、導電材は、正極の電気伝導性を確保
するためのものであり、カーボンブラック、アセチレン
ブラック、黒鉛等の炭素物質粉状体の１種又は２種以上
を混合したものを用いることができる。結着剤は、活物
質粒子および導電材粒子を繋ぎ止める役割を果たすもの
でポリテトラフルオロエチレン、ポリフッ化ビニリデ
ン、フッ素ゴム等の含フッ素樹脂、ポリプロピレン、ポ
リエチレン等の熱可塑性樹脂を用いることができる。ま
た、分散させるための溶剤としては、Ｎ−メチル−２−
ピロリドン等の有機溶剤を用いることができる。なお、
正極合材中の活物質、導電材、結着剤（固形分のみ）の
混合比は、重量比において、正極活物質１００重量部に
対して、導電材２〜２０重量部、正極結着剤１〜２０重
量部とすればよく、溶剤の添加量は、塗工機等の特性に
応じ適量とすればよい。The conductive material is used to secure the electrical conductivity of the positive electrode, and one or a mixture of two or more powdered carbon materials such as carbon black, acetylene black, and graphite is used. be able to. The binding agent plays a role of binding the active material particles and the conductive material particles, and may be a fluororesin such as polytetrafluoroethylene, polyvinylidene fluoride, or fluororubber, or a thermoplastic resin such as polypropylene or polyethylene. . Further, as a solvent for dispersing, N-methyl-2-
Organic solvents such as pyrrolidone can be used. In addition,
The mixing ratio of the active material, the conductive material, and the binder (only solid content) in the positive electrode mixture is 2 to 20 parts by weight of the conductive material, 100 parts by weight of the positive electrode active material, and the positive electrode binder in weight ratio. The amount may be 1 to 20 parts by weight, and the amount of the solvent added may be an appropriate amount according to the characteristics of the coating machine or the like.

【００２６】本発明のリチウム二次電池用正極では、上
記圧縮工程において、圧縮機の加圧力を調整すること等
により、活物質密度を調整する。ここで活物質密度と
は、正極単位体積中に存在する活物質の重量を意味し、
上記実施形態においては、単位面積当たりの正極合材の
重量と合材層の層厚から単位体積当たりの正極合材重量
を求め、これに正極合材中における活物質の重量比（活
物質となるリチウムニッケル複合酸化物、導電材および
結着剤（固形分のみ）総重量に対するリチウムニッケル
複合酸化物の重量比）を乗じたものが、活物質密度とな
る。In the positive electrode for a lithium secondary battery of the present invention, in the compression step, the active material density is adjusted by adjusting the pressure of the compressor. Here, the active material density means the weight of the active material present in the positive electrode unit volume,
In the above embodiment, the weight of the positive electrode mixture per unit volume is determined from the weight of the positive electrode mixture per unit area and the thickness of the mixture layer, and the weight ratio of the active material in the positive electrode mixture (active material and Multiplied by the total weight of the lithium-nickel composite oxide, the conductive material, and the binder (only the solid content) is the active material density.

【００２７】活物質密度が高い正極は、強い加圧力によ
り圧縮され、緊密化したものとなっている。本発明のリ
チウム二次電池用正極では、活物質密度を２．３ｇ／ｃ
ｍ3以上３ｇ／ｃｍ3以下となるように正極を構成する。
活物質密度が２．３ｇ／ｃｍ3未満の場合は、体積エネ
ルギー密度が低いことに加え、緊密化されてないため、
充放電の繰り返しにより、リチウムニッケル複合酸化物
の２次粒子が容易に崩壊する（割れる）ことで、サイク
ル特性が良好なものとはならない。逆に、３ｇ／ｃｍ3
を超える正極を製造しようとする場合は、強い加圧力に
て圧縮しなければならず、圧縮の際に２次粒子が崩壊
し、その結果、リチウム二次電池を完成させた初期にお
いても、その二次電池の放電容量は小さいものとなって
しまうからである。The positive electrode having a high active material density is compressed by a strong pressing force and becomes tight. In the positive electrode for a lithium secondary battery of the present invention, the active material density is 2.3 g / c.
The positive electrode is configured to have a value of m 3 or more and 3 g / cm 3 or less.
When the active material density is less than 2.3 g / cm 3 , the volume energy density is low, and the density is not reduced.
The repetition of charge and discharge causes the secondary particles of the lithium-nickel composite oxide to be easily disintegrated (broken), thereby failing to provide good cycle characteristics. Conversely, 3 g / cm 3
If it is intended to produce a positive electrode exceeding, it must be compressed with a strong pressing force, the secondary particles collapse during compression, as a result, even in the initial stage of completing a lithium secondary battery, This is because the discharge capacity of the secondary battery becomes small.

【００２８】〈リチウム二次電池〉本発明のリチウム二
次電池用電極の利用形態であるリチウム二次電池は、特
にその構成を限定するものではなく、既に公知のリチウ
ム二次電池の構成に従えばよい。<Lithium Secondary Battery> The configuration of the lithium secondary battery, which is an application form of the electrode for a lithium secondary battery of the present invention, is not particularly limited. I just need.

【００２９】本発明のリチウム二次電池用正極を正極と
し、これに対向させる負極は、金属リチウム、リチウム
合金等を、シート状にして、あるいはシート状にしたも
のをニッケル、ステンレス等の集電体網に圧着して形成
するものであってもよい。しかしデンドライトの析出等
を考慮し、安全性に優れたリチウム二次電池とするため
に、リチウムイオンを吸蔵・脱離できる炭素物質を活物
質とする負極を用いることができる。使用できる炭素物
質としては、天然あるいは人造の黒鉛、フェノール樹脂
等の有機化合物焼成体、コークス等の粉状体が挙げられ
る。この場合は、負極活物質に結着剤を混合し、適当な
溶媒を加えてペースト状にした負極合材を、銅等の金属
箔集電体の表面に塗布乾燥して形成する。なお、炭素物
質を負極活物質とした場合、正極同様、負極結着剤とし
てはポリフッ化ビニリデン等の含フッ素樹脂等を、溶剤
としてはＮ−メチル−２−ピロリドン等の有機溶剤を用
いることができる。The positive electrode for a lithium secondary battery of the present invention is used as a positive electrode, and the negative electrode opposed to the positive electrode is formed of a sheet of metal lithium, a lithium alloy, or the like, or a sheet of nickel, stainless steel or the like. It may be formed by crimping on a body net. However, in consideration of precipitation of dendrite and the like, a negative electrode using a carbon material capable of inserting and extracting lithium ions as an active material can be used in order to obtain a lithium secondary battery having excellent safety. Examples of the carbon substance that can be used include natural or artificial graphite, fired organic compounds such as phenolic resins, and powders such as coke. In this case, the binder is mixed with the negative electrode active material, and a suitable solvent is added thereto to form a paste-like negative electrode mixture on a surface of a metal foil current collector of copper or the like, followed by drying. When the carbon material is used as the negative electrode active material, a fluorinated resin such as polyvinylidene fluoride or the like is used as the negative electrode binder, and an organic solvent such as N-methyl-2-pyrrolidone is used as the solvent, similarly to the positive electrode. it can.

【００３０】本発明のリチウム二次電池用正極を用いた
リチウム二次電池では、一般のリチウム二次電池と同
様、正極および負極の他に、正極と負極の間に挟装され
るセパレータ、非水電解液等を構成要素とする。セパレ
ータは、正極と負極とを分離し電解液を保持するもので
あり、ポリエチレン、ポリプロピレン等の薄い微多孔膜
を用いることができる。また非水電解液は、有機溶媒に
電解質であるリチウム塩を溶解させたもので、有機溶媒
としては、非プロトン性有機溶媒、例えばエチレンカー
ボネート、プロピレンカーボネート、ジメチルカーボネ
ート、ジエチルカーボネート、エチルメチルカーボネー
ト、γ−ブチロラクトン、アセトニトリル、１，２−ジ
メトキシエタン、テトラヒドロフラン、ジオキソラン、
塩化メチレン等の１種またはこれらの２種以上の混合溶
媒を用いることができる。また、溶解させる電解質とし
ては、ＬｉＩ、ＬｉＣｌＯ4、ＬｉＡｓＦ6、ＬｉＢ
Ｆ4、ＬｉＰＦ6、ＬｉＮ（ＣＦ3ＳＯ2）2等のリチウム
塩を用いることができる。In a lithium secondary battery using the positive electrode for a lithium secondary battery according to the present invention, as in a general lithium secondary battery, in addition to the positive electrode and the negative electrode, a separator sandwiched between the positive electrode and the negative electrode, A water electrolyte or the like is a constituent element. The separator separates the positive electrode and the negative electrode and holds the electrolyte, and a thin microporous film of polyethylene, polypropylene, or the like can be used. The non-aqueous electrolyte is a solution in which a lithium salt as an electrolyte is dissolved in an organic solvent.As the organic solvent, an aprotic organic solvent, for example, ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, γ-butyrolactone, acetonitrile, 1,2-dimethoxyethane, tetrahydrofuran, dioxolan,
One kind such as methylene chloride or a mixed solvent of two or more kinds thereof can be used. The electrolyte to be dissolved is LiI, LiClO 4 , LiAsF 6 , LiB
Lithium salts such as F 4 , LiPF 6 , and LiN (CF 3 SO 2 ) 2 can be used.

【００３１】以上のように構成される本発明の電極を用
いたリチウム二次電池であるが、その形状は円筒型、積
層型、コイン型等、種々のものとすることができる。い
ずれの形状を採る場合であっても、正極および負極にセ
パレータを挟装させ電極体とし、正極集電体および負極
集電体から外部に通ずる正極端子および負極端子までの
間を集電用リード等を用いて接続し、この電極体を非水
電解液とともに電池ケースに密閉して電池が完成させら
れる。The lithium secondary battery using the electrode of the present invention configured as described above can have various shapes such as a cylindrical type, a laminated type and a coin type. Regardless of the shape used, a separator is sandwiched between the positive electrode and the negative electrode to form an electrode body, and a current collecting lead extends from the positive electrode current collector and the negative electrode current collector to the positive electrode terminal and the negative electrode terminal that lead to the outside. The electrode body is sealed together with the non-aqueous electrolyte in a battery case to complete the battery.

【００３２】以上、本発明のリチウム二次電池用正極の
実施形態について説明したが、上述した実施形態は一実
施形態にすぎず、本発明のリチウム二次電池用正極は、
上記実施形態を始めとして、当業者の知識に基づいて種
々の変更、改良を施した種々の形態で実施することがで
きる。While the embodiment of the positive electrode for a lithium secondary battery of the present invention has been described above, the above-described embodiment is merely an embodiment, and the positive electrode for a lithium secondary battery of the present invention
The present invention can be implemented in various forms including various modifications and improvements based on the knowledge of those skilled in the art, including the above embodiment.

【００３３】[0033]

【実施例】上記実施形態に基づき、実際に、Ｎｉサイト
の一部をＣｏおよびＡｌで置換した種々組成有するリチ
ウムニッケル複合酸化物を活物質に用い、活物質密度を
適正な範囲とした正極を、実施例として作製した。ま
た、比較例として、活物質密度が適正な範囲から外れる
正極をも作製した。そして、これら実施例および比較例
のそれぞれの正極を用いて、１８６５０型円筒形リチウ
ム二次電池を作製し、充放電サイクル試験を行うこと
で、本発明のリチウム二次電池用正極の特性が優れてい
ることを確認した。以下に、これらについて説明する。EXAMPLE Based on the above embodiment, a positive electrode having an active material density in an appropriate range was actually formed using lithium nickel composite oxides having various compositions in which Ni sites were partially substituted with Co and Al. , As an example. Further, as a comparative example, a positive electrode whose active material density was out of an appropriate range was also manufactured. Using the positive electrodes of these Examples and Comparative Examples, 18650-type cylindrical lithium secondary batteries were manufactured and subjected to a charge / discharge cycle test, whereby the characteristics of the positive electrode for lithium secondary batteries of the present invention were excellent. Confirmed that. Hereinafter, these will be described.

【００３４】〈実施例１のリチウム二次電池用正極〉本
正極では、活物質として、組成式ＬｉＮｉ0.85Ｃｏ0.1
Ａｌ0.05Ｏ2で表される層状岩塩構造リチウムニッケル
複合酸化物を用いた。このＬｉＮｉ0.85Ｃｏ0. 1Ａｌ
0.05Ｏ2は、２ＭのＮＨ3水溶液の１Ｌに、１．９Ｍの硝
酸ニッケル水溶液５０ｍＬと０．１Ｍの硝酸コバルト水
溶液５０ｍＬとの混合水溶液を、１．５ｍＬ／ｍｉｎの
速度で滴下し、同時に４Ｍの水酸化ナトリウム水溶液を
１．５ｍＬ／ｍｉｎの速度で滴下し、ニッケルコバルト
複合水酸化物を析出させ、こうして得られたニッケルコ
バルト複合水酸化物２７０ｇと、水酸化アルミニウム３
２ｇと、水酸化リチウム一水和物１３８．５ｇとを混合
し、この混合物を酸素雰囲気下、８００℃で２４時間焼
成することにより合成した。なお、このＬｉＮｉ0.85Ｃ
ｏ0.1Ａｌ0.05Ｏ2は、電子顕微鏡で観察できる粒子径が
０．８〜３μｍの１次粒子が凝集結合し、平均粒径が１
３μｍの２次粒子として形成されており、また、ＢＥＴ
比表面積が０．３ｍ2／ｇであった。<Positive electrode for lithium secondary battery of Example 1>
In the positive electrode, the composition formula LiNi is used as the active material.0.85Co0.1
Al0.05OTwoLayered rock salt structure lithium nickel represented by
A composite oxide was used. This LiNi0.85Co0. 1Al
0.05OTwoIs 2M NHThreeIn 1 L of aqueous solution, 1.9 M nitric acid
Nickel acid aqueous solution 50mL and 0.1M cobalt nitrate water
A mixed aqueous solution with 50 mL of the solution was added at 1.5 mL / min.
At the same time, simultaneously adding 4M aqueous sodium hydroxide solution
Drop at a rate of 1.5 mL / min.
The composite hydroxide is precipitated, and the nickel
270 g of Baltic composite hydroxide and aluminum hydroxide 3
2 g and 138.5 g of lithium hydroxide monohydrate are mixed
This mixture was baked at 800 ° C. for 24 hours in an oxygen atmosphere.
And synthesized. Note that this LiNi0.85C
o0.1Al0.05OTwoHas a particle size that can be observed with an electron microscope.
0.8 to 3 μm primary particles are aggregated and bonded, and the average particle size is 1
It is formed as 3 μm secondary particles.
0.3m specific surface areaTwo/ G.

【００３５】まず、上記ＬｉＮｉ0.85Ｃｏ0.1Ａｌ0.05
Ｏ2の８５重量部に、導電材としてのカーボンブラック
を１０重量部、結着剤としてのポリフッ化ビニリデンを
５重量部それぞれ混合し、溶剤として適量のＮ−メチル
−２−ピロリドンを添加し、ペースト状の正極合材を調
製した。次いで、このペースト状の正極合材をアルミニ
ウム箔集電体の表面に塗布し、乾燥させ、固形分のみか
らなる層状の正極合材を有する正極を作製した。さら
に、ロールプレスを用い、所定の加圧力を加えてこの正
極を圧縮し、活物質密度が２．３ｇ／ｃｍ3となるよう
に調整した。こうして完成した正極を、実施例１のリチ
ウム二次電池用正極とした。First, the above-mentioned LiNi 0.85 Co 0.1 Al 0.05
To 85 parts by weight of O 2 , 10 parts by weight of carbon black as a conductive material and 5 parts by weight of polyvinylidene fluoride as a binder were mixed, and an appropriate amount of N-methyl-2-pyrrolidone was added as a solvent, A paste-like positive electrode mixture was prepared. Next, this paste-like positive electrode mixture was applied to the surface of an aluminum foil current collector, and dried to prepare a positive electrode having a layered positive electrode mixture consisting of only solid components. Further, the positive electrode was compressed by applying a predetermined pressing force using a roll press, and the active material density was adjusted to 2.3 g / cm 3 . The positive electrode thus completed was used as a positive electrode for a lithium secondary battery of Example 1.

【００３６】〈実施例２のリチウム二次電池用正極〉本
正極は、上記実施例１の正極の製造において、ロールプ
レスを用いた圧縮工程での加圧力を変更し、活物質密度
が２．５ｇ／ｃｍ3となるように調整した正極である。
他の構成は、実施例１の場合と同じであり、本正極を実
施例２のリチウム二次電池用正極とした。<Positive Electrode for Lithium Secondary Battery of Example 2> In the present positive electrode, in the production of the positive electrode of Example 1, the pressing force in the compression step using a roll press was changed, and the active material density was 2. The positive electrode was adjusted to 5 g / cm 3 .
The other configuration is the same as that of the first embodiment. This positive electrode was used as the positive electrode for a lithium secondary battery of the second embodiment.

【００３７】〈実施例３のリチウム二次電池用正極〉本
正極は、上記実施例１の正極の製造において、ロールプ
レスを用いた圧縮工程での加圧力を変更し、活物質密度
が３．０ｇ／ｃｍ3となるように調整した正極である。
他の構成は、実施例１の場合と同じであり、本正極を実
施例２のリチウム二次電池用正極とした。<Positive Electrode for Lithium Secondary Battery of Example 3> In the present positive electrode, in the production of the positive electrode of Example 1, the pressing force in the compression step using a roll press was changed, and the active material density was 3. The positive electrode was adjusted to be 0 g / cm 3 .
The other configuration is the same as that of the first embodiment. This positive electrode was used as the positive electrode for a lithium secondary battery of the second embodiment.

【００３８】〈実施例４のリチウム二次電池用正極〉本
正極では、組成式ＬｉＮｉ0.81Ｃｏ0.1Ａｌ0.09Ｏ2で表
される層状岩塩構造リチウムニッケル複合酸化物を活物
質とした。このＬｉＮｉ0.81Ｃｏ0.1Ａｌ0.0 9Ｏ2は、上
記実施例１で示す製造方法においてそれぞれの原料の混
合比を変更させることにより合成したものである。１次
粒子の粒子径、２次粒子の平均粒径、ＢＥＴ比表面積に
ついては、実施例１のＬｉＮｉ0.85Ｃｏ0.1Ａｌ0.05Ｏ2
と同程度であることを確認した。<Positive electrode for lithium secondary battery of Example 4>
In the positive electrode, the composition formula LiNi0.81Co0.1Al0.09OTwoIn table
Active lithium-nickel composite oxide with layered rock salt structure
Quality. This LiNi0.81Co0.1Al0.0 9OTwoIs on
In the production method shown in Example 1, mixing of
It was synthesized by changing the ratio. Primary
Particle size of particles, average particle size of secondary particles, BET specific surface area
As for the LiNi of Example 1,0.85Co0.1Al0.05OTwo
It was confirmed that it was about the same.

【００３９】上記ＬｉＮｉ0.81Ｃｏ0.1Ａｌ0.09Ｏ2を活
物質とし、上記実施例１に示す方法により、正極を作製
した。活物質を除き、実施例１の正極と同じ構成であ
り、活物質密度は、圧縮工程の加圧力を変更することで
２．５ｇ／ｃｍ3となるように調整し、この正極を、実
施例４のリチウム二次電池用正極とした。Using LiNi 0.81 Co 0.1 Al 0.09 O 2 as an active material, a positive electrode was produced by the method described in Example 1 above. Except for the active material, it has the same configuration as the positive electrode of Example 1, and the active material density was adjusted to 2.5 g / cm 3 by changing the pressing force in the compression step. This was used as a positive electrode for a lithium secondary battery of No. 4.

【００４０】〈実施例５のリチウム二次電池用正極〉本
正極では、組成式ＬｉＮｉ0.89Ｃｏ0.1Ａｌ0.01Ｏ2で表
される層状岩塩構造リチウムニッケル複合酸化物を活物
質とした。このＬｉＮｉ0.89Ｃｏ0.1Ａｌ0.0 1Ｏ2は、上
記実施例１で示す製造方法においてそれぞれの原料の混
合比を変更させることにより合成したものである。１次
粒子の粒子径、２次粒子の平均粒径、ＢＥＴ比表面積に
ついては、実施例１のＬｉＮｉ0.85Ｃｏ0.1Ａｌ0.05Ｏ2
と同程度であることを確認した。<Positive electrode for lithium secondary battery of Example 5>
In the positive electrode, the composition formula LiNi0.89Co0.1Al0.01OTwoIn table
Active lithium-nickel composite oxide with layered rock salt structure
Quality. This LiNi0.89Co0.1Al0.0 1OTwoIs on
In the production method shown in Example 1, mixing of
It was synthesized by changing the ratio. Primary
Particle size of particles, average particle size of secondary particles, BET specific surface area
As for the LiNi of Example 1,0.85Co0.1Al0.05OTwo
It was confirmed that it was about the same.

【００４１】上記ＬｉＮｉ0.89Ｃｏ0.1Ａｌ0.01Ｏ2を活
物質とし、上記実施例１に示す方法により、正極を作製
した。活物質を除き、実施例１の正極と同じ構成であ
り、活物質密度は、圧縮工程の加圧力を変更することで
２．５ｇ／ｃｍ3となるように調整し、この正極を、実
施例５のリチウム二次電池用正極とした。A positive electrode was produced in the same manner as in Example 1 except that LiNi 0.89 Co 0.1 Al 0.01 O 2 was used as an active material. Except for the active material, it has the same configuration as the positive electrode of Example 1, and the active material density was adjusted to 2.5 g / cm 3 by changing the pressing force in the compression step. The positive electrode for a lithium secondary battery of No. 5 was obtained.

【００４２】〈実施例６のリチウム二次電池用正極〉本
正極では、組成式ＬｉＮｉ0.94Ｃｏ0.05Ａｌ0.01Ｏ2で
表される層状岩塩構造リチウムニッケル複合酸化物を活
物質とした。このＬｉＮｉ0.94Ｃｏ0.05Ａｌ 0.01Ｏ
2は、上記実施例１で示す製造方法においてそれぞれの
原料の混合比を変更させることにより合成したものであ
る。１次粒子の粒子径、２次粒子の平均粒径、ＢＥＴ比
表面積については、実施例１のＬｉＮｉ0.85Ｃｏ0.1Ａ
ｌ0.05Ｏ2と同程度であることを確認した。<Positive electrode for lithium secondary battery of Example 6>
In the positive electrode, the composition formula LiNi0.94Co0.05Al0.01OTwoso
Utilizing the layered rock salt structure lithium nickel composite oxide
Substance. This LiNi0.94Co0.05Al 0.01O
TwoAre the same as those in the manufacturing method shown in the first embodiment.
Synthesized by changing the mixing ratio of the raw materials
You. Particle size of primary particles, average particle size of secondary particles, BET ratio
Regarding the surface area, LiNi of Example 1 was used.0.85Co0.1A
l0.05OTwoIt was confirmed that it was about the same.

【００４３】上記ＬｉＮｉ0.94Ｃｏ0.05Ａｌ0.01Ｏ2を
活物質とし、上記実施例１に示す方法により、正極を作
製した。活物質を除き、実施例１の正極と同じ構成であ
り、活物質密度は、圧縮工程の加圧力を変更することで
２．５ｇ／ｃｍ3となるように調整し、この正極を、実
施例６のリチウム二次電池用正極とした。Using LiNi 0.94 Co 0.05 Al 0.01 O 2 as an active material, a positive electrode was produced by the method described in Example 1 above. Except for the active material, it has the same configuration as the positive electrode of Example 1, and the active material density was adjusted to 2.5 g / cm 3 by changing the pressing force in the compression step. This was used as a positive electrode for a lithium secondary battery of No. 6.

【００４４】〈実施例７のリチウム二次電池用正極〉本
正極では、組成式ＬｉＮｉ0.69Ｃｏ0.3Ａｌ0.01Ｏ2で表
される層状岩塩構造リチウムニッケル複合酸化物を活物
質とした。このＬｉＮｉ0.69Ｃｏ0.3Ａｌ0.0 1Ｏ2は、上
記実施例１で示す製造方法においてそれぞれの原料の混
合比を変更させることにより合成したものである。１次
粒子の粒子径、２次粒子の平均粒径、ＢＥＴ比表面積に
ついては、実施例１のＬｉＮｉ0.85Ｃｏ0.1Ａｌ0.05Ｏ2
と同程度であることを確認した。<Positive electrode for lithium secondary battery of Example 7>
In the positive electrode, the composition formula LiNi0.69Co0.3Al0.01OTwoIn table
Active lithium-nickel composite oxide with layered rock salt structure
Quality. This LiNi0.69Co0.3Al0.0 1OTwoIs on
In the production method shown in Example 1, mixing of
It was synthesized by changing the ratio. Primary
Particle size of particles, average particle size of secondary particles, BET specific surface area
As for the LiNi of Example 1,0.85Co0.1Al0.05OTwo
It was confirmed that it was about the same.

【００４５】上記ＬｉＮｉ0.69Ｃｏ0.3Ａｌ0.01Ｏ2を活
物質とし、上記実施例１に示す方法により、正極を作製
した。活物質を除き、実施例１の正極と同じ構成であ
り、活物質密度は、圧縮工程の加圧力を変更することで
２．５ｇ／ｃｍ3となるように調整し、この正極を、実
施例７のリチウム二次電池用正極とした。A positive electrode was produced by the method described in Example 1 above using the above-mentioned LiNi 0.69 Co 0.3 Al 0.01 O 2 as an active material. Except for the active material, it has the same configuration as the positive electrode of Example 1, and the active material density was adjusted to 2.5 g / cm 3 by changing the pressing force in the compression step. 7 was used as a positive electrode for a lithium secondary battery.

【００４６】〈実施例８のリチウム二次電池用正極〉本
正極では、組成式ＬｉＮｉ0.78Ｃｏ0.1Ａｌ0.12Ｏ2で表
される層状岩塩構造リチウムニッケル複合酸化物を活物
質とした。このＬｉＮｉ0.78Ｃｏ0.1Ａｌ0.1 2Ｏ2は、上
記実施例１で示す製造方法においてそれぞれの原料の混
合比を変更させることにより合成したものである。１次
粒子の粒子径、２次粒子の平均粒径、ＢＥＴ比表面積に
ついては、実施例１のＬｉＮｉ0.85Ｃｏ0.1Ａｌ0.05Ｏ2
と同程度であることを確認した。<Positive electrode for lithium secondary battery of Example 8>
In the positive electrode, the composition formula LiNi0.78Co0.1Al0.12OTwoIn table
Active lithium-nickel composite oxide with layered rock salt structure
Quality. This LiNi0.78Co0.1Al0.1 TwoOTwoIs on
In the production method shown in Example 1, mixing of
It was synthesized by changing the ratio. Primary
Particle size of particles, average particle size of secondary particles, BET specific surface area
As for the LiNi of Example 1,0.85Co0.1Al0.05OTwo
It was confirmed that it was about the same.

【００４７】上記ＬｉＮｉ0.78Ｃｏ0.1Ａｌ0.12Ｏ2を活
物質とし、上記実施例１に示す方法により、正極を作製
した。活物質を除き、実施例１の正極と同じ構成であ
り、活物質密度は、圧縮工程の加圧力を変更することで
２．５ｇ／ｃｍ3となるように調整し、この正極を、実
施例８のリチウム二次電池用正極とした。Using LiNi 0.78 Co 0.1 Al 0.12 O 2 as an active material, a positive electrode was produced by the method shown in Example 1 above. Except for the active material, it has the same configuration as the positive electrode of Example 1, and the active material density was adjusted to 2.5 g / cm 3 by changing the pressing force in the compression step. The positive electrode of No. 8 for a lithium secondary battery was obtained.

【００４８】〈比較例１のリチウム二次電池用正極〉本
正極は、活物質密度が、本発明のリチウム二次電池用正
極における適正範囲を上回る正極である。上記実施例１
の正極の製造において、ロールプレスを用いた圧縮工程
での加圧力を変更し、活物質密度が３．１ｇ／ｃｍ3と
なるように調整した正極である。他の構成は、実施例１
の場合と同じであり、本正極を比較例１のリチウム二次
電池用正極とした。<Positive Electrode for Lithium Secondary Battery of Comparative Example 1> This positive electrode is a positive electrode having an active material density exceeding an appropriate range of the positive electrode for a lithium secondary battery of the present invention. Example 1 above
In the production of the positive electrode, the pressure applied in the compression step using a roll press was changed to adjust the active material density to 3.1 g / cm 3 . Other configurations are described in the first embodiment.
This positive electrode was used as the positive electrode for a lithium secondary battery of Comparative Example 1.

【００４９】〈比較例２のリチウム二次電池用正極〉本
正極は、活物質密度が、本発明のリチウム二次電池用正
極における適正範囲を下回る正極である。上記実施例１
の正極の製造において、ロールプレスを用いた圧縮工程
での加圧力を変更し、活物質密度が２．２ｇ／ｃｍ3と
なるように調整した正極である。他の構成は、実施例１
の場合と同じであり、本正極を比較例２のリチウム二次
電池用正極とした。<Positive Electrode for Lithium Secondary Battery of Comparative Example 2> This positive electrode has an active material density lower than the proper range of the positive electrode for a lithium secondary battery of the present invention. Example 1 above
In the production of the positive electrode, the pressing force in the compression step using a roll press was changed to adjust the active material density to 2.2 g / cm 3 . Other configurations are described in the first embodiment.
This positive electrode was the same as the positive electrode of Comparative Example 2 for a lithium secondary battery.

【００５０】〈リチウム二次電池〉上記実施例および比
較例のリチウム二次電池用正極をそれぞれ用いてリチウ
ム二次電池を作製した。対向させる負極は、人造黒鉛の
一種である黒鉛化メソフェーズ小球体（ＭＣＭＢ）を活
物質とした。まず、ＭＣＭＢの９５重量部に、結着剤と
してのポリフッ化ビニリデンを５重量部混合し、溶剤と
して適量のＮ−メチル−２−ピロリドンを添加し、ペー
スト状の負極合材を調製した。次いで、このペースト状
の負極合材を銅箔集電体の表面に塗布し、乾燥させ、固
形分のみからなる層状の負極合材を有する負極を作製し
た。さらに、ロールプレスを用い、所定の加圧力を加え
てこの負極を圧縮し、活物質密度が１．１ｇ／ｃｍ3と
なるように調整した。<Lithium Secondary Battery> Lithium secondary batteries were manufactured using the positive electrodes for lithium secondary batteries of the above Examples and Comparative Examples. The negative electrode to be opposed was made of graphitized mesophase microspheres (MCMB), which is a kind of artificial graphite, as an active material. First, 5 parts by weight of polyvinylidene fluoride as a binder was mixed with 95 parts by weight of MCMB, and an appropriate amount of N-methyl-2-pyrrolidone was added as a solvent to prepare a paste-like negative electrode mixture. Next, this paste-like negative electrode mixture was applied to the surface of the copper foil current collector, and dried to prepare a negative electrode having a layered negative electrode mixture consisting of only solid components. Further, the negative electrode was compressed by applying a predetermined pressure using a roll press to adjust the active material density to 1.1 g / cm 3 .

【００５１】上記それぞれ正極と負極と間にポリエチレ
ン製セパレータを挟んでこれらを捲回しロール状の電極
体を形成した。そして、その電極体を電池ケースに挿設
し、非水電解液を注入し、その電池ケースを密閉してリ
チウム二次電池を完成させた。なお、非水電解液は、エ
チレンカーボネートとジエチルカーボネートとを体積比
で７：３に混合した混合溶媒に、ＬｉＰＦ6を１Ｍの濃
度で溶解したものを用いた。These were wound with a polyethylene separator interposed between the positive electrode and the negative electrode, respectively, to form a roll-shaped electrode body. Then, the electrode body was inserted into a battery case, a non-aqueous electrolyte was injected, and the battery case was sealed to complete a lithium secondary battery. The non-aqueous electrolyte used was a solution obtained by dissolving LiPF 6 at a concentration of 1 M in a mixed solvent of ethylene carbonate and diethyl carbonate mixed at a volume ratio of 7: 3.

【００５２】実施例１のリチウム二次電池用正極を用い
たリチウム二次電池を実施例１のリチウム二次電池と
し、以下同様に実施例２〜実施例８、比較例１、比較例
２のリチウム二次電池用正極を用いたリチウム二次電池
を、それぞれ実施例２〜実施例８、比較例１、比較例２
のリチウム二次電池とした。The lithium secondary battery using the positive electrode for a lithium secondary battery of Example 1 was used as the lithium secondary battery of Example 1, and the same applies to Examples 2 to 8 and Comparative Examples 1 and 2. Lithium secondary batteries using the positive electrode for a lithium secondary battery were prepared in Examples 2 to 8, Comparative Examples 1 and 2, respectively.
Lithium secondary battery.

【００５３】〈充放電サイクル試験〉上記実施例および
比較例のリチウム二次電池に対して充放電サイクル試験
を行った。充放電サイクル試験は、リチウム二次電池が
実際に使用される上限温度と見込まれる６０℃の高温環
境下で行った。その条件は、充電終止電圧４．１Ｖまで
電流密度２ｍＡ／ｃｍ2の定電流で充電を行った後、放
電終止電圧３．０Ｖまで電流密度２ｍＡ／ｃｍ2の定電
流で放電を行うサイクルを１サイクルとし、これを３０
０サイクルまで繰り返して、各サイクルにおける放電容
量を測定するものとした。<Charge / Discharge Cycle Test> A charge / discharge cycle test was performed on the lithium secondary batteries of the above Examples and Comparative Examples. The charge / discharge cycle test was performed in a high temperature environment of 60 ° C., which is expected to be the upper limit temperature at which the lithium secondary battery is actually used. The conditions are as follows: a charge is performed at a constant current of 2 mA / cm 2 at a current density of 2 mA / cm 2 until a charge termination voltage of 4.1 V, and then a discharge is performed at a constant current of 2 mA / cm 2 at a current density of 3.0 V until a discharge end voltage of 3.0 V. Cycle and this is 30
The cycle was repeated until 0 cycle, and the discharge capacity in each cycle was measured.

【００５４】この充放電サイクル試験の結果として、そ
れぞれのリチウム二次電池の正極活物質単位重量当たり
の初期放電容量（１サイクル目の放電容量）、３００サ
イクル後の容量維持率（３００サイクル目の放電容量／
５サイクル目の放電容量×１００％）、電池内部抵抗
を、それぞれの正極の活物質としたリチウムニッケル複
合酸化物の組成およびそれぞれの正極の活物質密度とと
もに、下記表１に示す。なお、電池内部抵抗は、５サイ
クル目の充放電における充放電電流、平均充電電圧およ
び平均放電電圧から、｛電池内部抵抗＝（平均充電電圧
−平均放電電圧）／２／電流｝という式を使って計算に
より求めた値である。また、代表的な例として、実施例
１および比較例１のリチウム二次電池の各サイクルにお
ける正極活物質単位重量当たりの放電容量を図１に示
す。As a result of the charge / discharge cycle test, the initial discharge capacity per unit weight of the positive electrode active material of each lithium secondary battery (discharge capacity at the first cycle) and the capacity retention rate after 300 cycles (at the 300th cycle) Discharge capacity /
The discharge capacity of the fifth cycle × 100%) and the internal resistance of the battery are shown in Table 1 below, together with the composition of the lithium nickel composite oxide used as the active material of each positive electrode and the active material density of each positive electrode. The internal resistance of the battery is calculated from the charge / discharge current, the average charge voltage, and the average discharge voltage in the fifth cycle of charge / discharge, using the formula {Battery internal resistance = (average charge voltage−average discharge voltage) / 2 / current}. It is a value obtained by calculation. As a typical example, FIG. 1 shows the discharge capacity per unit weight of the positive electrode active material in each cycle of the lithium secondary batteries of Example 1 and Comparative Example 1.

【００５５】[0055]

【表１】 [Table 1]

【００５６】〈それぞれのリチウム二次電池用正極の特
性評価〉図１を参照しつつ、上記表１のデータを分析す
れば、以下のことが判る。同じリチウムニッケル複合酸
化物を正極活物質として用い正極活物質密度の異なる実
施例１〜実施例３、比較例１、比較例２のリチウム二次
電池に関するデータを比較すれば、正極の活物質密度が
２．３ｇ／ｃｍ3を下回る比較例２のリチウム二次電池
が容量維持率において低い値を示しているのに対して、
正極の活物質密度が２．３ｇ／ｃｍ3以上である実施例
１〜実施例３、比較例１のリチウム二次電池は、容量維
持率が高く、良好な高温サイクル特性を示している。<Evaluation of Characteristics of Each Positive Electrode for Lithium Secondary Battery> By analyzing the data in Table 1 with reference to FIG. 1, the following can be understood. Comparing the data on the lithium secondary batteries of Examples 1 to 3, Comparative Example 1 and Comparative Example 2 using the same lithium nickel composite oxide as the positive electrode active material and having different positive electrode active material densities, the active material density of the positive electrode was compared. Is less than 2.3 g / cm 3 , whereas the lithium secondary battery of Comparative Example 2 shows a low value in the capacity retention ratio,
The lithium secondary batteries of Examples 1 to 3 and Comparative Example 1, in which the active material density of the positive electrode is 2.3 g / cm 3 or more, have a high capacity retention ratio and show good high-temperature cycle characteristics.

【００５７】しかし、正極の活物質密度が３ｇ／ｃｍ3
を上回る比較例１のリチウム二次電池は、初期充放電容
量が小さく、また、サイクルが進行していない段階から
電池内部抵抗が高いリチウム二次電池となっている。こ
のことは、正極製造の際の高い加圧力による圧縮で、既
にリチウムニッケル複合酸化物の２次粒子が崩壊してし
まっている結果と考えられる。However, the active material density of the positive electrode was 3 g / cm 3
The lithium secondary battery of Comparative Example 1 has a smaller initial charge / discharge capacity, and has a higher battery internal resistance from the stage where the cycle does not proceed. This is considered to be a result of the secondary particles of the lithium-nickel composite oxide having already collapsed due to the compression by the high pressure applied during the production of the positive electrode.

【００５８】以上の結果を総合すれば、層状岩塩構造リ
チウムニッケル複合酸化物を活物質とする正極において
は、活物質密度が２．３〜３ｇ／ｃｍ3の範囲にある本
発明のリチウム二次電池用正極が、放電容量が大きくか
つサイクル特性、特に高温サイクル特性の良好なリチウ
ム二次電池を構成できる正極となり得ることが確認でき
る。なお、比較例１のリチウム二次電池は、サイクルが
進行していない段階での電池内部抵抗は小さい値となっ
ているが、サイクル特性が良好でないことから、サイク
ルの進行につれてその値が大きくなるものと考えられ
る。Summarizing the above results, in the positive electrode using the layered rock salt structure lithium nickel composite oxide as the active material, the lithium secondary battery of the present invention having an active material density of 2.3 to 3 g / cm 3 was used. It can be confirmed that the battery positive electrode can be a positive electrode that can constitute a lithium secondary battery having a large discharge capacity and good cycle characteristics, particularly good high-temperature cycle characteristics. In the lithium secondary battery of Comparative Example 1, the internal resistance of the battery at a stage where the cycle was not progressing was a small value, but the value was increased as the cycle progressed because the cycle characteristics were not good. It is considered something.

【００５９】次に、正極活物質密度が同じ値であり、組
成の異なるリチウムニッケル複合酸化物を正極活物質と
して用いた実施例２、実施例４〜実施例８のリチウムに
関するデータを比較すれば、Ｎｉサイトを置換するＡｌ
の置換割合の大きな比較例８のリチウム二次電池は、容
量維持率においては良好な値を示すものの、サイクルが
進行していない段階から電池内部抵抗が大きく、初期放
電容量が小さいこが判る。この結果からすれば、Ｎｉサ
イトの一部をＣｏおよびＡｌで置換した層状岩塩構造リ
チウムニッケル複合酸化物を活物質とする本発明のリチ
ウム二次電池用正極においては、組成式ＬｉＮｉxＣｏy
ＡｌzＯ2（ｘ＋ｙ＋ｚ＝１、０．０５≦ｙ≦０．４、
０．０１≦ｚ≦０．０９）で表される範囲のものを活物
質とすることにより、容量が大きくかつサイクル特性の
良好なリチウム二次電池を構成できる正極となることが
確認できる。Next, the data on lithium in Examples 2 and 4 to 8 using lithium nickel composite oxides having the same positive electrode active material density and different compositions as the positive electrode active material were compared. , Al replacing Ni site
It can be seen that the lithium secondary battery of Comparative Example 8 having a large replacement ratio shows a good value in the capacity retention ratio, but has a large battery internal resistance and a small initial discharge capacity from the stage where the cycle does not proceed. According to these results, in the positive electrode for a lithium secondary battery of the present invention using a layered rock-salt structure lithium nickel composite oxide in which a part of the Ni site was substituted with Co and Al as an active material, the composition formula LiNi x Co y
Al z O 2 (x + y + z = 1, 0.05 ≦ y ≦ 0.4,
By using an active material in the range represented by 0.01 ≦ z ≦ 0.09), it can be confirmed that a positive electrode which can form a lithium secondary battery having a large capacity and good cycle characteristics can be obtained.

【００６０】[0060]

【発明の効果】本発明は、リチウム二次電池用正極にお
いて、活物質を層状岩塩構造リチウムニッケル複合酸化
物とし、活物質密度を２．３ｇ／ｃｍ3以上３ｇ／ｃｍ3
以下となるように構成するものである。このように構成
された本発明のリチウム二次電池用正極を用いることに
より、そのリチウム二次電池は、安価であって、放電容
量が大きく、つまりエネルギー密度が高く、かつ、サイ
クル特性、特に高温使用時におけるサイクル特性の良好
なリチウム二次電池となる。According to the present invention, in a positive electrode for a lithium secondary battery, the active material is a layered rock-salt lithium nickel composite oxide, and the active material density is 2.3 g / cm 3 or more and 3 g / cm 3.
The configuration is as follows. By using the thus configured positive electrode for a lithium secondary battery of the present invention, the lithium secondary battery is inexpensive, has a large discharge capacity, that is, has a high energy density, and has cycle characteristics, particularly at high temperatures. A lithium secondary battery having good cycle characteristics during use is obtained.

【図面の簡単な説明】[Brief description of the drawings]

【図１】 充放電サイクル試験の代表的結果として、実
施例１および比較例１のリチウム二次電池の各サイクル
の正極単位重量当たりの放電容量を示す。FIG. 1 shows a discharge capacity per unit weight of a positive electrode in each cycle of the lithium secondary batteries of Example 1 and Comparative Example 1 as a representative result of a charge / discharge cycle test.

フロントページの続き Ｆターム(参考） 4G048 AA04 AC06 AD03 AD06 AE05 5H029 AJ03 AJ05 AK03 AL06 AM03 AM04 AM05 AM07 HJ02 HJ08 5H050 AA07 BA17 CA08 CB08 EA24 FA17 FA19 HA02 HA08 HA13Continued on front page F term (reference) 4G048 AA04 AC06 AD03 AD06 AE05 5H029 AJ03 AJ05 AK03 AL06 AM03 AM04 AM05 AM07 HJ02 HJ08 5H050 AA07 BA17 CA08 CB08 EA24 FA17 FA19 HA02 HA08 HA13

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】 活物質を結着剤で結着して形成されたリ
チウム二次電池用正極であって、 前記活物質は、層状岩塩構造リチウムニッケル複合酸化
物であり、 活物質密度（正極単位体積中に存在する活物質の重量）
は、２．３ｇ／ｃｍ3以上３ｇ／ｃｍ3以下であることを
特徴とするリチウム二次電池用正極。1. A positive electrode for a lithium secondary battery formed by binding an active material with a binder, wherein the active material is a layered rock salt structure lithium nickel composite oxide, and an active material density (positive electrode Weight of active material present in unit volume)
Is a positive electrode for a lithium secondary battery, having a weight of 2.3 g / cm 3 or more and 3 g / cm 3 or less. 【請求項２】 前記層状岩塩構造リチウムニッケル複合
酸化物は、組成式ＬｉＮｉxＣｏyＡｌzＯ2（ｘ＋ｙ＋ｚ
＝１、０．０５≦ｙ≦０．４、０．０１≦ｚ≦０．０
９）で表されるものである請求項１に記載のリチウム二
次電池用正極。2. The lithium nickel composite oxide having a layered rock salt structure has a composition formula of LiNi x Co y Al z O 2 (x + y + z
= 1, 0.05 ≦ y ≦ 0.4, 0.01 ≦ z ≦ 0.0
The positive electrode for a lithium secondary battery according to claim 1, which is represented by 9).
JP2000024635A 2000-02-02 2000-02-02 Positive electrode for lithium secondary battery Pending JP2001216965A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2000024635A JP2001216965A (en) 2000-02-02 2000-02-02 Positive electrode for lithium secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2000024635A JP2001216965A (en) 2000-02-02 2000-02-02 Positive electrode for lithium secondary battery

Publications (1)

Publication Number Publication Date
JP2001216965A true JP2001216965A (en) 2001-08-10

Family

ID=18550587

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2000024635A Pending JP2001216965A (en) 2000-02-02 2000-02-02 Positive electrode for lithium secondary battery

Country Status (1)

Country Link
JP (1) JP2001216965A (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005036680A1 (en) * 2003-10-07 2005-04-21 Gs Yuasa Corporation Non-aqueous electrolyte secondary cell
JP2007258087A (en) * 2006-03-24 2007-10-04 Dainippon Printing Co Ltd Nonaqueous electrolytic solution secondary battery, and electrode plate therefor and its manufacturing method
KR20120104484A (en) * 2011-03-09 2012-09-21 삼성에스디아이 주식회사 Positive active material, and electrode and lithium battery containing the material
US20170084916A1 (en) * 2014-03-17 2017-03-23 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary battery
JP2019009130A (en) * 2010-02-08 2019-01-17 キネテイツク・リミテツド Thin electrochemical cell
WO2019171623A1 (en) * 2018-03-07 2019-09-12 日立金属株式会社 Positive electrode active material for lithium ion secondary batteries, and lithium ion secondary battery
WO2021039240A1 (en) 2019-08-30 2021-03-04 パナソニックＩｐマネジメント株式会社 Non-aqueous electrolyte secondary battery

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7527896B2 (en) 2003-10-07 2009-05-05 Gs Yuasa Corporation Nonaqueous electrolyte secondary battery
JP4720505B2 (en) * 2003-10-07 2011-07-13 株式会社Ｇｓユアサ Nonaqueous electrolyte secondary battery
WO2005036680A1 (en) * 2003-10-07 2005-04-21 Gs Yuasa Corporation Non-aqueous electrolyte secondary cell
JP2007258087A (en) * 2006-03-24 2007-10-04 Dainippon Printing Co Ltd Nonaqueous electrolytic solution secondary battery, and electrode plate therefor and its manufacturing method
JP2019009130A (en) * 2010-02-08 2019-01-17 キネテイツク・リミテツド Thin electrochemical cell
JP2020191293A (en) * 2010-02-08 2020-11-26 キネテイツク・リミテツド Thin electrochemical cell
US10777782B2 (en) 2010-02-08 2020-09-15 Qinetiq Limited Thin electrochemical cell
KR20120104484A (en) * 2011-03-09 2012-09-21 삼성에스디아이 주식회사 Positive active material, and electrode and lithium battery containing the material
KR101718054B1 (en) * 2011-03-09 2017-03-21 삼성에스디아이 주식회사 Positive active material, and electrode and lithium battery containing the material
JPWO2015141179A1 (en) * 2014-03-17 2017-04-06 三洋電機株式会社 Nonaqueous electrolyte secondary battery
US10511021B2 (en) 2014-03-17 2019-12-17 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary battery
US20170084916A1 (en) * 2014-03-17 2017-03-23 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary battery
WO2019171623A1 (en) * 2018-03-07 2019-09-12 日立金属株式会社 Positive electrode active material for lithium ion secondary batteries, and lithium ion secondary battery
JP2019160801A (en) * 2018-03-07 2019-09-19 日立金属株式会社 Positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery
JP6601593B1 (en) * 2018-03-07 2019-11-06 日立金属株式会社 Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery
JP7180532B2 (en) 2018-03-07 2022-11-30 日立金属株式会社 Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery
US11646412B2 (en) 2018-03-07 2023-05-09 Hitachi Metals, Ltd. Cathode active material used for lithium ion secondary battery and lithium ion secondary battery
WO2021039240A1 (en) 2019-08-30 2021-03-04 パナソニックＩｐマネジメント株式会社 Non-aqueous electrolyte secondary battery

Similar Documents

Publication Publication Date Title
JP4878687B2 (en) Lithium secondary battery
JP4963330B2 (en) Lithium iron composite oxide for positive electrode active material of lithium secondary battery, method for producing the same, and lithium secondary battery using the same
JP2001325988A (en) Charging method of non-aqueous electrolyte secondary battery
JP2007317534A (en) Non-aqueous electrolyte secondary battery
JP2003034534A (en) Carbon-containing lithium iron complex oxide for positive electrode active substance for lithium secondary cell and method for producing the same
JP2000294240A (en) Lithium composite oxide for lithium secondary battery positive electrode active material and lithium secondary battery using this
JP7262419B2 (en) Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery
JP5026629B2 (en) Positive electrode for non-aqueous electrolyte battery and non-aqueous electrolyte battery
JP4656349B2 (en) Lithium transition metal composite oxide for positive electrode active material of lithium secondary battery, its production method and lithium secondary battery using the same
JP5586116B2 (en) Positive electrode mixture for lithium secondary battery and use thereof
JP2003017055A (en) Lithium transition-metal compound oxide for positive electrode active material for lithium secondary battery, and manufacturing method thereof
JP2000311689A (en) Nonaqueous electrolyte secondary battery
JP2003017056A (en) Lithium transition-metal compound oxide for positive electrode active material for lithium secondary battery, and lithium secondary battery using the same
JP2000260479A (en) Lithium ion secondary battery
JP4678457B2 (en) Lithium transition metal composite oxide for positive electrode active material of lithium secondary battery and lithium secondary battery using the same
JP2002151154A (en) Lithium secondary battery
JP2001216965A (en) Positive electrode for lithium secondary battery
JP2001256975A (en) Lithium nickel compound oxide for lithium secondary battery positive electrode active material, manufacturing method thereof, and lithium secondary battery using the same
JP4581196B2 (en) Positive electrode for lithium secondary battery
JP2002117845A (en) Lithium iron complex oxide for lithium secondary battery positive electrode active material
JP2002025626A (en) Aging method for lithium secondary battery
JP5189466B2 (en) Lithium secondary battery
JP2001118567A (en) Positive electrode for lithium secondary battery
JP3793054B2 (en) Nonaqueous electrolyte secondary battery
JP2001110424A (en) Conductive material for positive electrode of lithium secondary battery and positive electrode for the lithium secondary battery using the conductive material