JP3362564B2 - Non-aqueous electrolyte secondary battery, and its positive electrode active material and method for producing positive electrode plate - Google Patents
Non-aqueous electrolyte secondary battery, and its positive electrode active material and method for producing positive electrode plateInfo
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- JP3362564B2 JP3362564B2 JP16848895A JP16848895A JP3362564B2 JP 3362564 B2 JP3362564 B2 JP 3362564B2 JP 16848895 A JP16848895 A JP 16848895A JP 16848895 A JP16848895 A JP 16848895A JP 3362564 B2 JP3362564 B2 JP 3362564B2
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- positive electrode
- plate
- active material
- particles
- hexagonal
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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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Description
【０００１】[0001]
【産業上の利用分野】本発明は、非水電解液二次電池お
よびその正極活物質の製造法に関するものであり、特に
その電池特性改善に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a non-aqueous electrolyte secondary battery and its positive electrode active material, and more particularly to improving the battery characteristics thereof.
【０００２】[0002]
【従来の技術】近年、民生用電子機器のポータブル化、
コードレス化が急激に進んでいる。現在、これら電子機
器の駆動用電源としての役割を、ニッケル−カドミウム
電池あるいは密閉型小型鉛蓄電池が担っているが、ポー
タブル化、コードレス化が進展し、定着するにしたが
い、駆動用電源となる二次電池の高エネルギー密度化、
小型軽量化の要望が強くなっている。2. Description of the Related Art In recent years, portable electronic devices for consumer use,
Cordless is rapidly progressing. Currently, nickel-cadmium batteries or sealed small lead-acid batteries play a role as driving power sources for these electronic devices, but as they become more portable and cordless, they become the driving power sources. Higher energy density of secondary battery,
There is a strong demand for smaller size and lighter weight.
【０００３】また、近年は携帯電話用の電源として注目
されており、急速な市場の拡大と共に、通話時間の長期
化、サイクル寿命の改善への要望は非常に大きいものと
なっている。Further, in recent years, it has attracted attention as a power source for portable telephones, and along with the rapid expansion of the market, there is a great demand for extending the call duration and improving the cycle life.
【０００４】このような状況から、高い充放電電圧を示
すリチウム複合遷移金属酸化物例えばＬｉＣｏＯ2を正
極活物質に用い、リチウムイオンの挿入、離脱を利用し
た非水電解液二次電池が提案されている。（例えば特開
昭６３−５９５０７号公報）
特にＬｉＣｏＯ2について例えば特開平１−３０４６６
４号公報、平５−１５１９９８号公報、平５−５４８８
８号公報ではその製法や形状、粒子の大きさ等が報告さ
れている。Under these circumstances, a non-aqueous electrolyte secondary battery has been proposed in which a lithium composite transition metal oxide showing a high charge / discharge voltage, such as LiCoO 2 , is used as a positive electrode active material and insertion and removal of lithium ions are utilized. ing. (For example, Japanese Unexamined Patent Publication No. 63-59507) Particularly, regarding LiCoO 2, for example, Japanese Unexamined Patent Publication No. 1-30466
No. 4, Japanese Patent Publication No. 5-151998, No. 5-5488.
The publication No. 8 reports its manufacturing method, shape, particle size and the like.
【０００５】[0005]
【発明が解決しようとする課題】しかし、これまで報告
されているＬｉＣｏＯ2を正極活物質に用いた非水電解
液二次電池では、充放電サイクルを繰り返し行うことに
より、その電池放電容量が徐々に減少するサイクル劣化
の問題が明らかとなった。However, in the non-aqueous electrolyte secondary battery using LiCoO 2 as the positive electrode active material, which has been reported so far, the battery discharge capacity is gradually increased by repeating the charge / discharge cycle. It became clear that the problem of cycle deterioration, which decreased to zero, was found.
【０００６】本発明者らが、十分検討を重ねた結果、こ
のような特性劣化は以下のことが原因であることがわか
った。As a result of thorough investigations by the present inventors, it has been found that such characteristic deterioration is caused by the following.
【０００７】すなわち、サイクル劣化した電池を分解
し、極板の観察を行った結果、充放電サイクルを繰り返
した正極板では、正極活物質の微粉化が起こっているこ
とが判明した。That is, as a result of disassembling the cycle-deteriorated battery and observing the electrode plate, it was found that in the positive electrode plate that was repeatedly charged and discharged, the positive electrode active material was pulverized.
【０００８】ＬｉＣｏＯ2は電池の充放電にともない、
その格子定数が変化することが報告されており（Ｊ．
Ｎ．Ｒｅｉｍｅｒｓ ａｎｄ Ｊ．Ｒ．Ｄａｈｎ Ｊ．
Ｅｌｅｃｔｒｏｃｈｅｍ．Ｓｏｃ，２０９１，ｖｏｌ．
１３９（１９９２））、特に結晶のＣ軸方向の膨張収縮
が大きいことが知られている。LiCoO 2 is used as the battery is charged and discharged,
It has been reported that the lattice constant changes (J.
N. Reimers and J.M. R. Dahn J.
Electrochem. Soc, 2091, vol.
139 (1992)), in particular, it is known that the expansion and contraction of crystals in the C-axis direction are large.
【０００９】このように充放電サイクルを繰り返すこと
によって活物質が膨張、収縮し、粒子の微細化や、極板
からの脱落が生じ、これによって充放電に関与できる活
物質量が減少することがわかった。By repeating the charging / discharging cycle in this way, the active material expands and contracts, and the particles become finer and fall off from the electrode plate, which may reduce the amount of active material that can participate in charging / discharging. all right.
【００１０】本発明の目的は、上記正極に関する問題点
の解決を図るものであり、特定の原料を用いて合成する
ことによって、より良い正極活物質を提供し、且つ、特
定の正極活物質の粒径、粒子形状、充填方法を用いるこ
とによって、充放電特性の優れた非水電解液二次電池を
提供するものである。An object of the present invention is to solve the above-mentioned problems relating to the positive electrode, and to provide a better positive electrode active material by synthesizing using a specific raw material, and to obtain a specific positive electrode active material. By using a particle size, a particle shape, and a filling method, a non-aqueous electrolyte secondary battery having excellent charge / discharge characteristics is provided.
【００１１】[0011]
【課題を解決するための手段】本発明は、ＬｉＣｏＯ2
を正極活物質とした正極板において、板状もしくは六角
板状の微小結晶粒子が多数集合した二次粒子からなる正
極活物質を用い、前記微小結晶粒子のＳＥＭ観察におけ
る定方向径（Ｆｅｒｅｔ ｄｉａｍｅｔｅｒ）を０．１
〜１０μｍの範囲とし、更に前記正極活物質を用いた正
極板の状態で測定したＣｕＫαを線源とするＸ線回折に
おいて、前記正極活物質の２θ＝１８〜２０度付近の
（００３）面回折ピーク強度Ｉ003と、２θ＝４４〜４
６度付近の（１０４）面回折ピーク強度Ｉ104との強度
比Ｉ003／Ｉ104が５以上４０以下として極板表面に（０
０３）面を強く配向させたものである。The present invention is based on LiCoO 2
In the positive electrode plate having a positive electrode active material, plate-like or hexagonal
A positive electrode active material composed of secondary particles in which a large number of plate-shaped fine crystal particles are aggregated is used, and the directional diameter (Feret diameter) of the fine crystal particles in SEM observation is 0.1.
The positive electrode active material is used in the range of 10 μm to 10 μm.
For X-ray diffraction using CuKα as a radiation source measured in the state of the electrode plate
In the above, the positive electrode active material has a (003) plane diffraction peak intensity I 003 near 2θ = 18 to 20 ° and 2θ = 44 to 4
When the intensity ratio I 003 / I 104 to the intensity of the (104) plane diffraction peak I 104 near 6 degrees is 5 or more and 40 or less, (0
03) The surface is strongly oriented.
【００１２】なお、正極板そのもののＸ線回折の測定
は、成型した正極板の平面をＸ線装置の試料台に平行に
設置して行った。The X-ray diffraction of the positive electrode plate itself was measured by setting the flat surface of the molded positive electrode plate parallel to the sample stage of the X-ray apparatus.
【００１３】正極活物質は、一次粒子である微小結晶粒
子の形状が六角板状であり、この六角板状粒子が多数集
合して二次粒子を形成しているとともに、前記六角板状
粒子は六角平面部の最長長さＡと六角板の高さＣの比Ｃ
／Ａが０．０５〜０．５の範囲にあることが望ましい。In the positive electrode active material, the fine crystal particles as primary particles have a hexagonal plate shape, and a large number of the hexagonal plate particles are aggregated to form secondary particles. Ratio C of the maximum length A of the hexagonal flat surface to the height C of the hexagonal plate
It is desirable that / A is in the range of 0.05 to 0.5.
【００１４】このような粒径、粒子形状および結晶配向
性を有する正極活物質ＬｉＣｏＯ2の製造法として、定
方向径（Ｆｅｒｅｔ ｄｉａｍｅｔｅｒ）が０．１〜１
０μｍの範囲にある微小結晶粒子が多数集合した二次粒
子からなるコバルト水酸化物を、熱処理してＣｏ3Ｏ4に
した後、リチウム塩とＣｏ／Ｌｉ原子比が１．０〜１．
０７となるように混合し、この混合物を熱処理してＬｉ
ＣｏＯ2、もしくはＬｉＣｏＯ2とＣｏ3Ｏ4の混合物を得
るものである。 コバルト水酸化物は、ＣｕＫαを線源
とする粉末Ｘ線回折によって測定される２θ＝１８〜２
０度付近の（００１）面回折ピーク強度Ｉ001と、２θ
＝３６〜３８度付近の（１０１）面回折ピーク強度Ｉ
101との強度比Ｉ003／Ｉ101が０．９以上１．７以下の
範囲であることが望ましい。As a method for producing the positive electrode active material LiCoO 2 having such a particle size, particle shape and crystal orientation, the directional diameter (Ferret diameter) is 0.1 to 1.
Cobalt hydroxide, which is composed of secondary particles in which a large number of fine crystal particles in the range of 0 μm are aggregated, is heat-treated into Co 3 O 4 , and then the lithium salt and the Co / Li atomic ratio are 1.0 to 1.
07 so that the mixture is heat treated to obtain Li.
CoO 2 or a mixture of LiCoO 2 and Co 3 O 4 is obtained. Cobalt hydroxide is measured by powder X-ray diffraction using CuKα as a radiation source, 2θ = 18 to 2
(001) plane diffraction peak intensity I 001 near 0 degree and 2θ
= (101) plane diffraction peak intensity I near 36 to 38 degrees
It is desirable intensity ratio I 003 / I 101 of the 101 is in a range of 0.9 to 1.7.
【００１５】また、前記コバルト水酸化物は、一次粒子
である微小結晶粒子の形状が六角板状であり、この六角
板状粒子が多数集合して二次粒子を形成しているととも
に前記六角板状粒子は六角平面部の最長長さＡと六角板
の高さＣの比Ｃ／Ａが０．０５〜０．５の範囲にあると
更に良好な結果が得られる。Further, in the cobalt hydroxide, the shape of the fine crystal particles as primary particles is hexagonal plate-like, and a large number of the hexagonal plate-like particles are aggregated to form secondary particles, and at the same time, the hexagonal plate is formed. If the ratio C / A of the longest length A of the hexagonal plane portion to the height C of the hexagonal plate of the particulate particles is in the range of 0.05 to 0.5, further excellent results can be obtained.
【００１６】そして、上記の方法によって合成された正
極活物質を、Ａｌ等を主体とする金属集電体箔の両面に
塗布して極板を構成した後、１７０〜３２０℃の温度範
囲の間で前記極板を熱処理し、さらにローラープレスに
より、前記正極活物質を前記金属箔集電体表面に埋没さ
せながら圧延し、正極板のＣｕＫαを線源とするＸ線回
折によって測定される２θ＝１８〜２０度付近の（００
３）面回折ピーク強度Ｉ003と、２θ＝４４〜４６度付
近の（１０４）面回折ピーク強度Ｉ104との強度比Ｉ003
／Ｉ104が５以上４０以下となるようにして六法晶の結
晶であるＬｉＣｏＯ2の（００３）面が正極板表面と平
行に配向するようにしたものである。Then, the positive electrode active material synthesized by the above method is applied to both sides of the metal current collector foil mainly composed of Al or the like to form an electrode plate, and then the electrode plate is formed in a temperature range of 170 to 320 ° C. 2θ = measured by X-ray diffraction using CuKα of the positive electrode plate as a radiation source, by subjecting the positive electrode plate to a heat treatment with a roller press and rolling the positive electrode active material while burying the positive electrode active material on the surface of the metal foil current collector. Around (18-20 degrees) (00
3) Intensity ratio I 003 between the plane diffraction peak intensity I 003 and the (104) plane diffraction peak intensity I 104 around 2θ = 44 to 46 degrees.
/ I 104 is set to be 5 or more and 40 or less so that the (003) plane of LiCoO 2 which is a hexagonal crystal is oriented parallel to the surface of the positive electrode plate.
【００１７】なお、一次粒子径の測定法として、ＳＥＭ
観察における定方向径（Ｆｅｒｅｔｄｉａｍｅｔｅｒ）
を採用しており、これはＳＥＭ写真において様々な方向
を向いた粒子の径をある一定方向から読みとり、平均し
た物である。（参考文献：粉末工学の基礎 ｐ．２８５
（日刊工業新聞社編））As a method for measuring the primary particle size, SEM is used.
Fixed direction diameter in observation (Ferretdiameter)
This is the average of the particle diameters of particles oriented in various directions read from a certain direction in an SEM photograph. (Reference: Basics of Powder Engineering p.285
(Edited by Nikkan Kogyo Shimbun))
【００１８】[0018]
【作用】このように板状もしくは六角板状の微少な結晶
粒から構成される正極活物質は、その一次粒子径が０．
１〜１０μｍと小さいため、その粒子自体が充放電に伴
う膨張収縮による微細化の影響を受けにくく、さらに極
板表面に（００３）面を強く配向させるため、膨張収縮
が極板と垂直な方向に集中させることが可能となり、活
物質同士での衝突等に引き起こされる活物質の脱落を防
止することが可能になる。The positive electrode active material composed of such plate-like or hexagonal plate-like fine crystal grains has a primary particle size of 0.
Since the particle size is as small as 1 to 10 μm, the particles themselves are not easily affected by miniaturization due to expansion / contraction due to charge / discharge, and the (003) plane is strongly oriented on the surface of the electrode plate. Therefore, it becomes possible to prevent the active material from falling off due to collision between the active materials.
【００１９】更に、前記正極活物質の形状が六方晶の結
晶であるＬｉＣｏＯ2の単位格子が結晶成長した六角板
状粒子であり、これが多数集合して二次粒子を形成する
ことにより一次粒子内での膨張収縮方向も、一方向に集
中させることが可能となり、更に極板からの活物質の脱
落を防止することが容易となる。Further, the positive electrode active material is a hexagonal plate-shaped particle in which a unit cell of LiCoO 2 which is a hexagonal crystal is crystal-grown, and a large number of these particles are aggregated to form a secondary particle. The expansion and contraction directions can also be concentrated in one direction, and it becomes easier to prevent the active material from falling off the electrode plate.
【００２０】とくに六角板状粒子の六角平面部の最長長
さＡと、六角板の高さＣの比Ｃ／Ａが０．０５〜０．５
の範囲に限定すると、偏平型の粒子となり、特に単位格
子の膨張収縮方向であるＣ軸方向の影響を受けにくい。
また、このような偏平型の粒子を集電体上に構成した場
合には、極板表面上に粒子が同一方向で配列し易く（０
０３）面が特に配向し易くなる。このため、更に良好な
サイクル特性が実現できる。Particularly, the ratio C / A of the maximum length A of the hexagonal plane portion of the hexagonal plate-like particles to the height C of the hexagonal plate is 0.05 to 0.5.
When the range is limited to, the particles become flat type particles, and are not particularly affected by the C-axis direction which is the expansion / contraction direction of the unit lattice.
Further, when such flat particles are formed on the current collector, the particles are easily arranged in the same direction on the surface of the electrode plate (0
The (03) plane is particularly easily oriented. Therefore, even better cycle characteristics can be realized.
【００２１】また、この様なサイクル特性の良好な活物
質の製造方法として、ＬｉＣｏＯ2の原料に同じ六方晶
の結晶であるコバルト水酸化物を用い、その一次粒子径
を０．１〜１０．０μｍとして水分、不純物等を除去す
るための熱処理を行ってＣｏ 3Ｏ4とした後、リチウム塩
をＣｏ／Ｌｉ原子比１．０〜１．０７となるように混合
して合成することにより、リチウムがコバルトホスト内
に拡散する形で合成が進行し、元の粒子形状を維持した
ままで合成させることが可能となる。Also, an active material having such good cycle characteristics
As a quality manufacturing method, LiCoO 22Same hexagonal as raw material
The primary particle size of cobalt hydroxide, which is a crystal of
To 0.1 to 10.0 μm to remove water, impurities, etc.
Heat treatment for 3OFourAnd then the lithium salt
Are mixed so that the Co / Li atomic ratio is 1.0 to 1.07.
By synthesizing the
The synthesis proceeded in the form of diffusing into the particle and maintained the original particle shape.
It is possible to synthesize until now.
【００２２】このコバルト水酸化物がＣｕＫαを線源と
する粉末Ｘ線回折において測定される２θ＝１８〜２０
度付近の（００１）面回折ピーク強度Ｉ001と、２θ＝
３６〜３８度付近の（１０１）面回折ピーク強度Ｉ101
との強度比Ｉ003／Ｉ101が０．９以上１．７以下と、合
成後のＬｉＣｏＯ2の（００３）面に相当する（００
１）面が強く配向する粒子をＣｏ原料として用いること
によって、より容易に（００３）面の配向性の強いＬｉ
ＣｏＯ2を合成することができる。This cobalt hydroxide is measured by powder X-ray diffraction using CuKα as a radiation source, 2θ = 18 to 20
(001) plane diffraction peak intensity I 001 near 2 degrees and 2θ =
(101) plane diffraction peak intensity I 101 around 36 to 38 degrees
And the intensity ratio I 003 / I 101 is 0.9 or more and 1.7 or less, which corresponds to the (003) plane of LiCoO 2 after synthesis.
By using particles having a strongly oriented 1) plane as a Co raw material, Li having a strong (003) plane orientation can be more easily obtained.
CoO 2 can be synthesized.
【００２３】また、コバルト水酸化物の一次粒子の形状
が、六法晶が結晶成長した六角板状とすることによっ
て、同様の形状を有するＬｉＣｏＯ2の合成が容易であ
る。Further, by forming the primary particles of cobalt hydroxide into a hexagonal plate shape in which hexagonal crystals are crystal-grown, it is easy to synthesize LiCoO 2 having a similar shape.
【００２４】この六角板状粒子は、六角平面部の最長長
さＡと六角板の高さＣの比Ｃ／Ａが０．０５〜０．５の
範囲にあるとサイクル特性が著しく改善できる。The hexagonal plate-shaped particles can remarkably improve the cycle characteristics when the ratio C / A of the maximum length A of the hexagonal plane portion to the height C of the hexagonal plate is in the range of 0.05 to 0.5.
【００２５】そして、結晶面が配向し易い粒子を、Ａｌ
等を主体とする金属集電体箔両面に塗布して極板を構成
した後、１７０〜３２０℃の温度範囲の間で前記極板を
熱処理し、ついでローラープレスにより、前記正極活物
質を前記金属箔集電体表面に埋没させながら圧延する
と、集電性、合剤の保持性が向上できる。Then, particles whose crystal planes are easily oriented are
And the like on both sides of the metal current collector foil to form an electrode plate, and then heat-treating the electrode plate in a temperature range of 170 to 320 ° C., and then roller pressing the positive electrode active material Rolling while embedding it in the surface of the metal foil current collector can improve the current collecting property and the holding property of the mixture.
【００２６】更に、ローラープレスにて圧延することに
よって、活物質粒子がより配向することが可能となり、
サイクル特性に優れた非水電解液二次電池を表現するこ
とができる。Further, by rolling with a roller press, the active material particles can be more oriented,
It is possible to represent a non-aqueous electrolyte secondary battery having excellent cycle characteristics.
【００２７】[0027]
【実施例】以下、本発明の実施例を図面を参照にしなが
ら説明する。Embodiments of the present invention will be described below with reference to the drawings.
【００２８】（実施例１）図２に本実施例で用いた円筒
系電池の縦断面図を示す。図１において１は耐有機電解
液性のステンレス鋼板を加工した電池ケース、２は安全
弁を設けた封口板、３は絶縁パッキングを示す。４は極
板群であり、正極板５および負極板６がセパレータ７を
介して複数回渦巻状に巻回されてケース内に収納されて
いる。そして上記正極板５からは正極アルミリード５ａ
が引き出されて封口板２に接続され、負極板６からは負
極ニッケルリード６ａが引き出されて電池ケース１の底
部に接続されている。８は絶縁リングで極板群４の上下
部にそれぞれ設けられている。(Embodiment 1) FIG. 2 shows a vertical sectional view of a cylindrical battery used in this embodiment. In FIG. 1, 1 is a battery case formed by processing a stainless steel plate resistant to organic electrolyte, 2 is a sealing plate provided with a safety valve, and 3 is an insulating packing. Reference numeral 4 denotes an electrode plate group, in which the positive electrode plate 5 and the negative electrode plate 6 are spirally wound a plurality of times via the separator 7 and housed in the case. Then, from the positive electrode plate 5, a positive electrode aluminum lead 5a is formed.
Is drawn out and connected to the sealing plate 2, and the negative electrode nickel lead 6a is drawn out from the negative electrode plate 6 and connected to the bottom portion of the battery case 1. Insulating rings 8 are provided on the upper and lower portions of the electrode plate group 4, respectively.
【００２９】以下、負極板６、電解液等について詳しく
説明する。負極板６は、コークスを加熱処理した炭素粉
１００重量部に、フッ素樹脂系結着剤１０重量部を混合
し、カルボキシメチルセルロース水溶液に懸濁させてペ
ースト状にした。そしてこのペーストを厚さ０．０１５
ｍｍの銅箔の表面に塗着し、乾燥後０．２ｍｍに圧延
し、幅３７ｍｍ、長さ２８０ｍｍの大きさに切り出して
負極板とした。The negative electrode plate 6, the electrolytic solution and the like will be described in detail below. The negative electrode plate 6 was made into a paste by mixing 100 parts by weight of carbon powder obtained by heat-treating coke with 10 parts by weight of a fluororesin-based binder and suspending the mixture in an aqueous carboxymethyl cellulose solution. And this paste is 0.015
It was applied to the surface of a copper foil of mm, dried and rolled to 0.2 mm, and cut into a size of width 37 mm and length 280 mm to obtain a negative electrode plate.
【００３０】以下、正極活物質の合成法について詳しく
説明する。正極活物質は一次粒子が六角板状粒子であ
り、これらが多数集合して二次粒子を形成している。ま
た、六角平面部の最長長さＡと六角板の高さＣの比Ｃ／
Ａの値は０．２であり、ＳＥＭ観察における定方向径
（Ｆｅｒｅｔ ｄｉａｍｅｔｅｒ）がそれぞれ０．０
７、０．１、１．２、６．１、８．７、１６．３μｍで
あるコバルト水酸化物を２５０℃で１０時間熱処理し、
得られたコバルト酸化物を、炭酸リチウムと原子比が１
対１になるように混合して、ついで酸化雰囲気化におい
て９００℃で１０時間焼成し、目的とするＬｉＣｏＯ2
を合成した。The method of synthesizing the positive electrode active material will be described in detail below. The primary particles of the positive electrode active material are hexagonal plate-like particles, and a large number of these particles are aggregated to form secondary particles. In addition, the ratio of the maximum length A of the hexagonal plane portion to the height C of the hexagonal plate C /
The value of A is 0.2, and the directional diameter (Ferret diameter) in SEM observation is 0.0.
Cobalt hydroxide of 7, 0.1, 1.2, 6.1, 8.7, 16.3 μm was heat treated at 250 ° C. for 10 hours,
The obtained cobalt oxide has an atomic ratio of 1 with lithium carbonate.
Mix so as to be 1: 1, and then calcination in an oxidizing atmosphere at 900 ° C. for 10 hours to obtain the target LiCoO 2
Was synthesized.
【００３１】尚、上記コバルト水酸化物のＣｕＫαを線
源とする粉末Ｘ線回折を測定した結果、２θ＝１８〜２
０度付近の（００１）面回折ピーク強度Ｉ001と、２θ
＝３６〜３８度付近の（１０１）面回折ピーク強度Ｉ
101との強度比Ｉ003／Ｉ101は１．３であった。As a result of measuring powder X-ray diffraction using CuKα of the above cobalt hydroxide as a radiation source, 2θ = 18 to 2
(001) plane diffraction peak intensity I 001 near 0 degree and 2θ
= (101) plane diffraction peak intensity I near 36 to 38 degrees
Intensity ratio I 003 / I 101 of the 101 was 1.3.
【００３２】合成によって得られたＬｉＣｏＯ2は、Ｓ
ＥＭ観察における定方向径がそれぞれ０．０５、０．
１、１．０、５．２、８．３、１５．２μｍであり、原
料であるコバルト水酸化物の形状をほぼ維持しており、
合成時にリチウムがコバルトの構造を変えることなく内
部に拡散し、反応が進行している事が確認できた。LiCoO 2 obtained by the synthesis is S
The directional diameters in EM observation were 0.05, 0.
1, 1.0, 5.2, 8.3, 15.2 μm, the shape of the raw material cobalt hydroxide is almost maintained,
During the synthesis, it was confirmed that lithium diffused inside without changing the structure of cobalt and the reaction proceeded.
【００３３】次に、正極板の製造法を説明する。正極板
は、まず正極活物質であるＬｉＣｏＯ2の粉末１００重
量部に、アセチレンブラック３重量部、フッ素樹脂系結
着剤７重量部を混合し、カルボキシメチルセルロース水
溶液に懸濁させてペースト状にする。このペーストをア
ルミニウム（Ａｌ）箔の両面に塗着し、２５０℃で熱処
理を行った後、圧延を行った。Next, a method of manufacturing the positive electrode plate will be described. The positive electrode plate is prepared by first mixing 100 parts by weight of LiCoO 2 powder, which is a positive electrode active material, with 3 parts by weight of acetylene black and 7 parts by weight of a fluororesin binder and suspending them in an aqueous carboxymethylcellulose solution to form a paste. . This paste was applied to both sides of an aluminum (Al) foil, heat-treated at 250 ° C., and then rolled.
【００３４】圧延はローラー式圧延機を使用し、ＣｕＫ
αを線源とするＸ線回折によって測定される２θ＝１８
〜２０度付近の（００３）面回折ピーク強度Ｉ003と、
２θ＝４４〜４６度付近の（１０４）面回折ピーク強度
Ｉ104との強度比Ｉ003／Ｉ10 4が１０．０±１になるよ
うに繰り返して圧延を行い、正極板５とした。Rolling is performed by using a roller type rolling machine and CuK
2θ = 18 measured by X-ray diffraction using α as a radiation source
(003) plane diffraction peak intensity I 003 in the vicinity of -20 degrees,
A positive electrode plate 5 was obtained by rolling repeatedly so that the intensity ratio I 003 / I 10 4 with respect to the (104) plane diffraction peak intensity I 104 near 2θ = 44 to 46 degrees was 10.0 ± 1.
【００３５】そして正極板と負極板を、セパレータを介
して渦巻上に巻回し、直径１３．８ｍｍ、高さ５０ｍｍ
の電池ケース内に収納した。Then, the positive electrode plate and the negative electrode plate are spirally wound with a separator interposed therebetween to have a diameter of 13.8 mm and a height of 50 mm.
It was stored in the battery case.
【００３６】電解液には炭酸エチレンと炭酸ジエチルの
等容積混合溶媒に、六フッ化リン酸リチウム１モル／ｌ
の割合で溶解したものを用いて極板群４に注入した後、
電池を密封口し、試験電池とした。The electrolytic solution was prepared by mixing 1 volume / l of lithium hexafluorophosphate with a mixed solvent of ethylene carbonate and diethyl carbonate in an equal volume.
After injecting into the electrode plate group 4 using the one dissolved at a ratio of
The battery was sealed and used as a test battery.
【００３７】このようにして作成した電池をそれぞれ電
池Ａ，Ｂ，Ｃ，Ｄ，Ｅ，Ｆとした。
（実施例２）一次粒子が六角板状粒子からなる微小な結
晶粒子であり、これらが多数集合して二次粒子を形成し
ているとともに前記六角板状粒子の六角平面部の最長長
さＡと六角板の高さＣの比Ｃ／Ａがそれぞれ０．０２、
０．０５、０．５、１．０であって一次粒子のＳＥＭ観
察における定方向径が１．０μｍであるコバルト水酸化
物を原料とした他は（実施例１）と同様に電池を作成し
た。The batteries thus prepared were designated as batteries A, B, C, D, E and F, respectively. (Example 2) The primary particles are fine crystal particles composed of hexagonal plate-like particles, and a large number of these particles are aggregated to form secondary particles, and the longest length A of the hexagonal plane portion of the hexagonal plate-like particles is A. And the ratio C / A of the height C of the hexagonal plate is 0.02,
A battery was prepared in the same manner as in (Example 1) except that cobalt hydroxide having a constant diameter in the SEM observation of primary particles of 0.05, 0.5, 1.0 was 1.0 μm. did.
【００３８】上記コバルト水酸化物のＣｕＫαを線源と
する粉末Ｘ線回折を測定した結果、２θ＝１８〜２０度
付近の（００１）面回折ピーク強度Ｉ001と、２θ＝３
６〜３８度付近の（１０１）面回折ピーク強度Ｉ101と
の強度比Ｉ003／Ｉ101はそれぞれ０．７、１．０、１．
５、２．０であった。As a result of measurement of powder X-ray diffraction using CuKα of the above cobalt hydroxide as a radiation source, the (001) plane diffraction peak intensity I 001 near 2θ = 18 to 20 ° and 2θ = 3.
The intensity ratio I 003 / I 101 to the (101) plane diffraction peak intensity I 101 around 6 to 38 degrees is 0.7, 1.0, 1.
It was 5, 2.0.
【００３９】上記各電池をそれぞれ電池Ｇ，Ｈ，Ｉ，Ｊ
とした。
（実施例３）一次粒子が六角板状粒子であり、これらが
多数集合して二次粒子を形成しているとともに、六角平
面部の最長長さＡと六角板の高さＣの比Ｃ／Ａが０．２
であり、一次粒子のＳＥＭ観察における定方向径が１．
０μｍであるコバルト水酸化物を原料とした。Each of the above batteries is replaced by a battery G, H, I, J.
And (Example 3) The primary particles are hexagonal plate-like particles, and a large number of these particles are aggregated to form secondary particles, and the ratio C / the longest length A of the hexagonal plane portion to the height C of the hexagonal plate is C / A is 0.2
And the unidirectional diameter of the primary particles in SEM observation is 1.
The raw material was 0 μm cobalt hydroxide.
【００４０】そして、これを２５０℃で１０時間熱処理
して得られたコバルト酸化物を、炭酸リチウムとＣｏ／
Ｌｉ原子比０．９、０．９５、１．０５、１．１０にな
るように混合し、酸化雰囲気において９００℃で１０時
間焼成して目的とするＬｉＣｏＯ2を合成した。The cobalt oxide obtained by heat-treating this at 250 ° C. for 10 hours was treated with lithium carbonate and Co /
Li atom ratios of 0.9, 0.95, 1.05, and 1.10 were mixed, and the mixture was fired in an oxidizing atmosphere at 900 ° C. for 10 hours to synthesize the desired LiCoO 2 .
【００４１】合成されたＬｉＣｏＯ2は、Ｃｏ／Ｌｉ原
子比が１．０５、１．１０であるものについては、ほぼ
原料であるコバルト水酸化物と同等の形状であることが
確認できた。It was confirmed that the synthesized LiCoO 2 had a Co / Li atomic ratio of 1.05 and 1.10, and had a shape almost equivalent to that of the raw material cobalt hydroxide.
【００４２】また、粉末Ｘ線回折の結果からこれらの試
料は過剰のＣｏが、Ｃｏ3Ｏ4として残留していることが
確認できた。From the results of powder X-ray diffraction, it was confirmed that excess Co remained as Co 3 O 4 in these samples.
【００４３】Ｃｏ／Ｌｉ原子比が０．９、０．９５であ
るものについては、過剰のリチウムが焼結し、一次粒子
の粒径がそれぞれ１８μｍ、１２μｍと著しく凝集、成
長して大きくなり、また粒子形状もほぼ塊状となった。With respect to the Co / Li atomic ratios of 0.9 and 0.95, excessive lithium sinters, and the primary particles have a particle size of 18 μm and 12 μm, respectively, which are remarkably aggregated and grown to be large. Also, the particle shape was almost lumpy.
【００４４】上記に示したＬｉＣｏＯ2を正極活物質と
して用いる他は（実施例１）と同様に電池を作成した。A battery was prepared in the same manner as in Example 1 except that LiCoO 2 shown above was used as the positive electrode active material.
【００４５】上記各電池をそれぞれ電池Ｋ，Ｌ，Ｍ，Ｎ
とした。
（実施例４）一次粒子が六角板状粒子であり、これが多
数集合して二次粒子を形成しているとともに、前記六角
板状粒子の六角平面部の最長長さＡと六角板の高さＣの
比Ｃ／Ａが０．２であり、一次粒子のＳＥＭ観察におけ
る定方向径が１．０であるコバルト水酸化物を原料とし
て（実施例１）と同様に正極活物質ＬｉＣｏＯ2を合成
した。そして、ＬｉＣｏＯ2の粉末１００重量部に、ア
セチレンブラック３重量部、フッソ樹脂系結着剤７重量
部を混合し、カルボキシメチルセルロース水溶液に懸濁
させてペースト状にした。このペーストをアルミ箔の両
面に塗着し、２５０℃で熱処理を行った後、ローラー式
圧延機を使用し、ＣｕＫαを線源とするＸ線回折によっ
て測定される２θ＝１８〜２０度付近の（００３）面回
折ピーク強度Ｉ003と、２θ＝４４〜４６度付近の（１
０４）面回折ピーク強度Ｉ104との強度比Ｉ003／Ｉ104
がそれぞれ１．５、６．０、２０．０、３５．０、５
０．０になるように繰り返して圧延を行い、正極板５と
した。The above-mentioned batteries are replaced by batteries K, L, M and N, respectively.
And (Example 4) The primary particles are hexagonal plate-like particles, and a large number of them are aggregated to form secondary particles, and the longest length A of the hexagonal plane portion of the hexagonal plate-like particles and the height of the hexagonal plate are A positive electrode active material LiCoO 2 was synthesized in the same manner as in (Example 1) using a cobalt hydroxide having a C ratio C / A of 0.2 and a unidirectional diameter of 1.0 in SEM observation of primary particles as a raw material. did. Then, 100 parts by weight of LiCoO 2 powder was mixed with 3 parts by weight of acetylene black and 7 parts by weight of a fluororesin-based binder, and the mixture was suspended in a carboxymethylcellulose aqueous solution to form a paste. This paste is applied to both sides of an aluminum foil, heat-treated at 250 ° C., and then, using a roller-type rolling mill, measured by X-ray diffraction using CuKα as a radiation source, 2θ = about 18 to 20 °. The intensity of the (003) plane diffraction peak I 003 and (1 in the vicinity of 2θ = 44 to 46 degrees
04) intensity ratio with plane diffraction peak intensity I 104 I 003 / I 104
Are 1.5, 6.0, 20.0, 35.0, 5 respectively
The positive electrode plate 5 was obtained by repeatedly rolling to 0.0.
【００４６】上記正極板を用いる他は（実施例１）と同
様に電池を作成した。上記各電池をそれぞれ電池Ｏ，
Ｐ，Ｑ，Ｒ，Ｓとした。A battery was prepared in the same manner as in (Example 1) except that the above positive electrode plate was used. Replace each of the above batteries with battery O,
P, Q, R and S were used.
【００４７】（比較例１）一次粒子の形状が塊状であ
り、一次粒子のＳＥＭ観察における定方向径が１．０μ
ｍであるコバルト水酸化物を原材料とする他は（実施例
１）と同様にＬｉＣｏＯ2を合成した。原料に塊状の物
を用いた場合、合成により得られるＬｉＣｏＯ2もほぼ
塊状の物が得られる事が確認できた。(Comparative Example 1) The primary particles were in the form of lumps, and the unidirectional diameter of the primary particles in SEM observation was 1.0 μm.
LiCoO 2 was synthesized in the same manner as in (Example 1) except that cobalt hydroxide of m was used as a raw material. It was confirmed that when a lumpy material was used as the raw material, almost lumpy material was also obtained for LiCoO 2 obtained by the synthesis.
【００４８】上記ＬｉＣｏＯ2を正極活物質として用い
る他は（実施例１）と同様にして電池を作成した。A battery was prepared in the same manner as in (Example 1) except that LiCoO 2 was used as the positive electrode active material.
【００４９】この電池を電池Ｔとした。
（比較例２）一次粒子径のＳＥＭ観察における定方向径
が１．０μｍである炭酸コバルトを原料として用いる他
は（比較例１）と同様の電池を作成した。This battery was designated as battery T. (Comparative Example 2) A battery similar to that of (Comparative Example 1) was prepared except that cobalt carbonate having a fixed direction diameter of 1.0 μm in SEM observation of the primary particle diameter was used as a raw material.
【００５０】上記電池を電池Ｕとした。このようにして
作成した電池Ａ〜Ｕを２０℃、充電終止電圧４．１Ｖ、
放電終止電圧３．０Ｖ、１００ｍＡで充放電を繰り返し
行い、サイクル充放電試験を行った。The above battery was designated as battery U. The batteries A to U prepared in this manner were set at 20 ° C., the end-of-charge voltage of 4.1 V,
A charge / discharge test was performed by repeating charge / discharge at a discharge end voltage of 3.0 V and 100 mA.
【００５１】本発明の実施例および比較例の電池のサイ
クル試験結果を（表１）に示す。尚、電池Ａ〜Ｕはそれ
ぞれ３０個組み立てて試験を行い、（表１）には平均値
を示した。Table 1 shows the cycle test results of the batteries of Examples and Comparative Examples of the present invention. 30 batteries A to U were assembled and tested, and the average value is shown in (Table 1).
【００５２】[0052]
【表１】 [Table 1]
【００５３】この試験結果から、結晶の一次粒子の定方
向径（以下、粒子径）を比較した電池Ａ，Ｂ，Ｃ，Ｄ，
Ｅ，Ｆでは電池Ａのように粒子径が０．１μｍより小さ
い場合、電池への充填性が悪く初期から放電容量が小さ
く、好ましくない。From the results of this test, batteries A, B, C, D, in which the unidirectional diameters (hereinafter, particle diameters) of primary particles of crystals were compared,
In E and F, when the particle size is smaller than 0.1 μm as in the battery A, the filling property into the battery is poor and the discharge capacity is small from the initial stage, which is not preferable.
【００５４】また、粒子径が１０μｍ以上の場合、粒子
の微細化が起こり、サイクル特性が極端に悪いことが分
かる。Further, when the particle size is 10 μm or more, the particles become finer and the cycle characteristics are extremely poor.
【００５５】このようにＬｉＣｏＯ2の一次粒子の粒子
径は０．１〜１０μｍであることが最も好ましい。As described above, the primary particle diameter of LiCoO 2 is most preferably 0.1 to 10 μm.
【００５６】同様の粒子径１．０μｍで粒子の形状を比
較した電池Ｇ，Ｈ，Ｃ，Ｉ，Ｊ，Ｔ，Ｕでは、六角板の
六角平面部の最長長さＡと、六角板の高さＣの比Ｃ／Ａ
が０．０２と極端に偏平型の粒子の場合、充填性が低下
し、初期の容量が小さくなるため好ましくない。In the batteries G, H, C, I, J, T, and U having the same particle diameter of 1.0 μm and comparing the shapes of the particles, the longest length A of the hexagonal plane portion of the hexagonal plate and the height of the hexagonal plate are high. Ratio C / C
Of 0.02 is extremely flat, which is not preferable because the filling property is lowered and the initial capacity is reduced.
【００５７】また、Ｃ／Ａが１．０と結晶子のＣ軸方向
が非常に成長した粒子の場合（電池Ｊ）、サイクル特性
が低下しており、充放電に伴う結晶の膨張収縮の影響が
強く影響した物と考えられる。Further, in the case of particles in which the C / A is 1.0 and the crystallites are very grown in the C-axis direction (Battery J), the cycle characteristics are deteriorated and the influence of the expansion and contraction of the crystals due to charge and discharge is affected. Is thought to have a strong influence.
【００５８】また、粒子形状そのものが塊状である電池
Ｔ，Ｕは充放電に伴う結晶の膨張収縮の影響が強く影響
するためサイクル特性が劣化している。Further, in the batteries T and U in which the particle shape itself is a lump, the cycle characteristics are deteriorated because the influence of the expansion and contraction of crystals due to charge and discharge is strongly influenced.
【００５９】このように一次粒子は、六角板状粒子であ
り、これらが多数集合して二次粒子を形成することが望
ましい。As described above, the primary particles are hexagonal plate-like particles, and it is desirable that a large number of them be aggregated to form secondary particles.
【００６０】また、六角板の六角平面部の最長長さＡと
六角板の高さＣの比Ｃ／Ａが０．０５〜０．５の範囲で
あることが望ましい。The ratio C / A of the maximum length A of the hexagonal plane portion of the hexagonal plate to the height C of the hexagonal plate is preferably in the range of 0.05 to 0.5.
【００６１】ＬｉＣｏＯ2の原材料としては、それ自体
の粒子形状が六角板状粒子であり、これらが多数集合し
て二次粒子を形成しているコバルト水酸化物を用いるこ
とにより、上記のＬｉＣｏＯ2粒子を合成することが可
能であり、その粒子形状はＣ／Ａが０．０５〜０．５の
範囲にある場合に可能となる。[0061] As the raw material of LiCoO 2, it is in particulate form hexagonal plate-like particles themselves, the use of cobalt hydroxide which form a large number set to the secondary particles, the above LiCoO 2 It is possible to synthesize particles, and the particle shape is possible when C / A is in the range of 0.05 to 0.5.
【００６２】この範囲にあるコバルト水酸化物の粉末を
ＣｕＫαを線源とする粉末Ｘ線回折によって測定する
と、２θ＝１８〜２０度付近の（００１）面回折ピーク
強度Ｉ 001と、２θ＝３６〜３８度付近の（１０１）面
回折ピーク強度Ｉ101との強度比Ｉ003／Ｉ101が０．９
〜１．７以下の範囲である場合に、上記の粒子形状と整
合し、電池特性の優れたＬｉＣｏＯ2を合成することが
可能である。Cobalt hydroxide powder in this range
Measured by powder X-ray diffraction using CuKα as a radiation source
And (001) plane diffraction peak near 2θ = 18 to 20 degrees
Strength I 001And the (101) plane near 2θ = 36 to 38 degrees
Diffraction peak intensity I101Intensity ratio with003/ I101Is 0.9
~ 1.7 or less in the range, the above particle shape and
LiCoO with excellent battery characteristics2Can be synthesized
It is possible.
【００６３】ＬｉＣｏＯ2を合成する際のＣｏ／Ｌｉ原
子比を比較した電池Ｋ，Ｌ，Ｃ，Ｍ，Ｎの場合では、
Ｋ，Ｌのようにリチウムが過剰に存在すると、余分のリ
チウムがＬｉＣｏＯ2一次粒子を凝集させ、粒子径が非
常に大きくなる。このため、充放電サイクルにともな
い、粒子の微細化が起こり、容量低下が大きくなる。In the case of the batteries K, L, C, M and N, which compare the Co / Li atomic ratios when synthesizing LiCoO 2 ,
When lithium is present in excess as in K and L, the excess lithium causes the LiCoO 2 primary particles to aggregate, resulting in a very large particle size. For this reason, the particles become finer with the charge / discharge cycle, resulting in a large decrease in capacity.
【００６４】また、Ｃｏ／Ｌｉ原子比が１．１０とコバ
ルトが過剰に存在すると充放電反応に関与しない四酸化
三コバルトが残留するため、初期の放電容量が小さくな
り好ましくない。If the Co / Li atomic ratio is 1.10 and cobalt is present in excess, tricobalt tetroxide that does not participate in the charge / discharge reaction remains, and the initial discharge capacity is reduced, which is not preferable.
【００６５】これらの結果から、Ｃｏ／Ｌｉ原子比は
１．０〜１．０７の範囲で合成することが望ましい。From these results, it is desirable to synthesize the Co / Li atomic ratio in the range of 1.0 to 1.07.
【００６６】極板における粒子の配向性を比較した電池
Ｏ，Ｐ，Ｃ，Ｑ，Ｒ，Ｓの場合、一次粒子の配向の程度
を示す、Ｘ線回折によって測定される２θ＝１８〜２０
度付近の（００３）面回折ピーク強度Ｉ003と、２θ＝
４４〜４６度付近の（１０４）面回折ピーク強度Ｉ104
との強度比Ｉ003／Ｉ104が１．５とほぼ無配向の極板を
用いた電池Ｏでは、サイクル特性が非常に悪く、充放電
に伴い、極板合剤層からの活物質の脱落が生じているも
のと考えられる。In the case of the batteries O, P, C, Q, R and S comparing the orientations of particles on the electrode plate, 2θ = 18 to 20 which indicates the degree of orientation of primary particles and is measured by X-ray diffraction.
(003) plane diffraction peak intensity I 003 near 2 degrees and 2θ =
(104) plane diffraction peak intensity I 104 near 44 to 46 degrees
In battery O using a substantially non-oriented electrode plate having a strength ratio I 003 / I 104 of 1.5, the cycle characteristics were very poor, and the active material fell off from the electrode plate mixture layer with charge and discharge. Is considered to have occurred.
【００６７】ピーク強度比Ｉ003／Ｉ104が５０と極端に
配向させた電池Ｓでは、配向させるために、圧延を重ね
るため、極板自身の多孔度が小さくなり、電解液の含浸
性が低下する。このため、初期の放電容量が小さくなり
好ましくない。In the battery S in which the peak intensity ratio I 003 / I 104 is extremely oriented to 50, rolling is repeated to orient it, so that the porosity of the electrode plate itself becomes small and the impregnation property of the electrolytic solution is lowered. To do. Therefore, the initial discharge capacity becomes small, which is not preferable.
【００６８】これらの結果からＬｉＣｏＯ2を活物質と
する極板のＣｕＫαを線源とするＸ線回折によって測定
される２θ＝１８〜２０度付近の（００３）面回折ピー
ク強度Ｉ003と、２θ＝４４〜４６度付近の（１０４）
面回折ピーク強度Ｉ104との強度比Ｉ003／Ｉ104は、５
〜４０の範囲であることが好ましい。From these results, the (003) plane diffraction peak intensity I 003 and 2θ near 2θ = 18 to 20 degrees measured by X-ray diffraction using CuKα of the electrode plate using LiCoO 2 as the active material as a radiation source and 2θ = (44) around 44 to 46 degrees
Intensity ratio I 003 / I 104 between the surface diffraction peak intensity I 104 is 5
It is preferably in the range of -40.
【００６９】なお、極板を構成する際に、１７０〜３２
０℃のＡｌの熱処理を行うことによって、このような極
板の配向性を制御する事が容易に行う事ができる。When constructing the electrode plate, 170 to 32
The heat treatment of Al at 0 ° C. can easily control the orientation of such an electrode plate.
【００７０】上記実施例においては円筒型の電池を用い
て評価を行ったが、角型など電池形状が異なっても同様
の効果が得られる。In the above examples, the evaluation was performed using a cylindrical battery, but the same effect can be obtained even if the battery shape is different, such as a prismatic battery.
【００７１】さらに、上記実施例において負極には炭素
質材料を用いたが、本発明における効果は正極板におい
て作用するため、リチウム金属や、リチウム合金、Ｆｅ
2Ｏ3、ＷＯ2、ＷＯ3等の酸化物など、他の負極材料を用
いても同様の効果が得られる。Further, although a carbonaceous material was used for the negative electrode in the above-mentioned examples, since the effect of the present invention works on the positive electrode plate, lithium metal, lithium alloy, Fe
Similar effects can be obtained by using other negative electrode materials such as oxides of 2 O 3 , WO 2 , WO 3 and the like.
【００７２】また、上記実施例において電解質として六
フッ化リン酸リチウムを使用したが、他のリチウム含有
塩、例えば過塩素酸リチウム、四フッ化ホウ酸リチウ
ム、トリフルオロメタンスルホン酸リチウム、六フッ化
ヒ酸リチウムなどでも同様の効果が得られた。Although lithium hexafluorophosphate was used as the electrolyte in the above examples, other lithium-containing salts such as lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, and hexafluoride were used. Similar effects were obtained with lithium arsenate and the like.
【００７３】さらに、上記実施例では炭酸エチレンと炭
酸ジエチルの混合溶媒を用いたが、他の非水溶媒例え
ば、プロピレンカーボネートなどの環状エステル、テト
ラヒドロフランなどの環状エーテル、ジメトキシエタン
などの鎖状エーテル、プロピオン酸メチルなどの鎖状エ
ステルなどの非水溶媒や、これらの多元系混合溶媒を用
いても同様の効果が得られた。Further, although a mixed solvent of ethylene carbonate and diethyl carbonate was used in the above examples, other non-aqueous solvents such as cyclic ester such as propylene carbonate, cyclic ether such as tetrahydrofuran, chain ether such as dimethoxyethane, Similar effects were obtained using a non-aqueous solvent such as a chain ester such as methyl propionate or a multi-component mixed solvent thereof.
【００７４】[0074]
【発明の効果】以上の説明から明らかなように、本発明
では活物質の一次粒子の形状や配向性を制御した正極板
を用いることにより、充放電サイクル特性が優れた非水
電解液二次電池を提供することができる。As is apparent from the above description, in the present invention, by using the positive electrode plate in which the shape and orientation of the primary particles of the active material are controlled, the non-aqueous electrolyte secondary battery having excellent charge / discharge cycle characteristics is used. A battery can be provided.
【図１】本発明の正極活物質の六角板粒子のモデル図FIG. 1 is a model diagram of hexagonal plate particles of the positive electrode active material of the present invention.
【図２】円筒型電池の縦断面図FIG. 2 is a vertical sectional view of a cylindrical battery.
１ 電池ケース ２ 封口板 ３ 絶縁パッキング ４ 極板群 ５ 正極板 ５ａ 正極リード ６ 負極板 ６ａ 負極リード ７ セパレータ ８ 絶縁リング 1 battery case 2 Seal plate 3 insulating packing 4 electrode group 5 Positive plate 5a Positive lead 6 Negative plate 6a Negative electrode lead 7 separator 8 insulating ring
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平６−243897（ＪＰ，Ａ) 特開 平５−258751（ＪＰ，Ａ) 特開 平６−333562（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H01M 4/58 H01M 4/02 - 4/04 H01M 10/40 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-243897 (JP, A) JP-A-5-258751 (JP, A) JP-A-6-333562 (JP, A) (58) Field (Int.Cl. 7 , DB name) H01M 4/58 H01M 4/02-4/04 H01M 10/40
Claims (8)
した正極板と、 前記負極板と正極板との間にセパレータを介してなる非
水電解液二次電池において、 前記正極活物質は、板状もしくは六角板状の微小な結晶
粒子が多数集合した二次粒子からなり、前記微小結晶粒
子のＳＥＭ観察における定方向径（Ｆｅｒｅｔｄｉａｍ
ｅｔｅｒ）が０．１〜１０μｍの範囲にあって、 前記正極活物質を用いた正極板の状態で測定したＣｕＫ
αを線源とするＸ線回折において、前記正極活物質の２
θ＝１８〜２０度付近の（００３）面回折ピーク強度Ｉ
003と、２θ＝４４〜４６度付近の（１０４）面回折ピ
ーク強度Ｉ104との強度比Ｉ003／Ｉ104が５以上４０以
下である非水電解液二次電池。1. A non-aqueous electrolyte secondary battery comprising a negative electrode plate, a positive electrode plate using LiCoO 2 as a positive electrode active material, and a separator interposed between the negative electrode plate and the positive electrode plate, wherein the positive electrode active material is , A plate-shaped or hexagonal plate-shaped fine crystal particle is aggregated in a large number of secondary particles, and the fine crystal particle has a unidirectional diameter (Feretdiam) in SEM observation.
CuK measured in the state of the positive electrode plate using the positive electrode active material, wherein
In X-ray diffraction using α as a radiation source, 2
(003) plane diffraction peak intensity I near θ = 18 to 20 degrees
A non-aqueous electrolyte secondary battery in which an intensity ratio I 003 / I 104 between 003 and a (104) plane diffraction peak intensity I 104 in the vicinity of 2θ = 44 to 46 degrees is 5 or more and 40 or less.
角板の六角平面部の最長長さＡと、六角板の高さＣの比
Ｃ／Ａを０．０５〜０．５の範囲とした請求項１記載の
非水電解液二次電池。2. The fine crystal particles are hexagonal plate-shaped , and the ratio C / A of the maximum length A of the hexagonal plane portion of the hexagonal plate to the height C of the hexagonal plate is in the range of 0.05 to 0.5. The non-aqueous electrolyte secondary battery according to claim 1.
ｔ ｄｉａｍｅｔｅｒ）が０．１〜１０μｍの範囲にあ
る板状もしくは六角板状の微小結晶粒子が多数集合した
二次粒子からなるコバルト水酸化物を熱処理し、Ｃｏ3
Ｏ4を得る工程と、 前記Ｃｏ3Ｏ4をリチウム塩とＣｏ／Ｌｉ原子比が１．０
〜１．０７となるように混合し、この混合物を熱処理し
てＬｉＣｏＯ2、もしくはＬｉＣｏＯ2とＣｏ3Ｏ4の混合
物を得る工程とからなる非水電解液二次電池用正極活物
質の製造法。3. A unidirectional diameter (Fere in SEM observation
Cobalt hydroxide consisting of secondary particles in which a large number of plate-like or hexagonal plate-like fine crystal particles having a t diameter of 0.1 to 10 μm are heat treated to form Co 3
O 4 is obtained, and the Co 3 O 4 is mixed with a lithium salt in a Co / Li atomic ratio of 1.0.
To 1.07, and heat-treating this mixture to obtain LiCoO 2 or a mixture of LiCoO 2 and Co 3 O 4 for producing a positive electrode active material for a non-aqueous electrolyte secondary battery. .
化リチウムである請求項３記載の非水電解液二次電池用
正極活物質の製造法。4. The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 3, wherein the lithium salt is lithium carbonate or lithium hydroxide.
する粉末Ｘ線回折によって測定される２θ＝１８〜２０
度付近の（００１）面回折ピーク強度Ｉ001と、 ２θ＝３６〜３８度付近の（１０１）面回折ピーク強度
Ｉ101との強度比Ｉ003／Ｉ101が０．９以上１．７以下
の範囲である請求項３記載の非水電解液二次電池用正極
活物質の製造法。5. The cobalt hydroxide is 2θ = 18 to 20 as measured by powder X-ray diffraction using CuKα as a radiation source.
The intensity ratio I 003 / I 101 between the (001) plane diffraction peak intensity I 001 in the vicinity of 2 degrees and the (101) plane diffraction peak intensity I 101 in the vicinity of 2θ = 36 to 38 degrees is 0.9 or more and 1.7 or less. The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 3, which is in the range.
板状粒子である請求項３記載の非水電解液二次電池用正
極活物質の製造法。6. The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 3, wherein the microcrystalline particles of cobalt hydroxide are hexagonal plate-shaped particles.
板状粒子であり、その六角板の六角平面部の最長長さＡ
と、六角板の高さＣの比Ｃ／Ａが０．０５〜０．５の範
囲にある請求項３記載の非水電解液二次電池用正極活物
質の製造法。7. The fine crystal particles of cobalt hydroxide are hexagonal plate-like particles, and the longest length A of the hexagonal plane portion of the hexagonal plate is A.
And the ratio C / A of the height C of the hexagonal plate is in the range of 0.05 to 0.5, the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 3.
ｔ ｄｉａｍｅｔｅｒ）が０．１〜１０μｍの範囲にあ
る板状もしくは六角板状の微小結晶粒子が多数集合した
二次粒子からなるコバルト水酸化物を熱処理してＣｏ３
Ｏ４を得る工程と、 前記Ｃｏ3Ｏ4をリチウム塩とＣｏ／Ｌｉ原子比が１．０
〜１．０７の範囲で混合し、この混合物を熱処理してＬ
ｉＣｏＯ2、もしくはＬｉＣｏＯ2とＣｏ3Ｏ4の混合物を
得る工程と、 前記ＬｉＣｏＯ2、もしくはＬｉＣｏＯ2とＣｏ3Ｏ4の混
合物からなる正極活物質を金属箔に塗布して極板を構成
する工程と、 この極板を熱処理する工程と、 極板を圧延し極板状態で、ＣｕＫαを線源とするＸ線回
折によって測定される２θ＝１８〜２０度付近の（００
３）面回折ピーク強度Ｉ003と、２θ＝４４〜４６度付
近の（１０４）面回折ピーク強度Ｉ104との強度比Ｉ003
／Ｉ104が５以上４０以下となるようにした非水電解液
二次電池用正極板の製造法。8. A unidirectional diameter (Fere in SEM observation
Co hydrate obtained by heat-treating cobalt hydroxide composed of secondary particles in which a large number of plate-like or hexagonal plate-like fine crystal particles having a t diameter of 0.1 to 10 μm are collected.
Obtaining a O4, wherein Co 3 O 4 lithium salt and Co / Li atomic ratio 1.0
To 1.07, and heat-treat the mixture to obtain L
iCoO 2, or steps constituting the process for obtaining a mixture of LiCoO 2 and Co 3 O 4, wherein LiCoO 2, or a plate a positive electrode active material composed of a mixture of LiCoO 2 and Co 3 O 4 is applied to the metal foil And a step of heat-treating this electrode plate, and in the electrode plate state after rolling the electrode plate, measured by X-ray diffraction using CuKα as a radiation source, 2θ = 18 to 20 degrees or so (00
3) Intensity ratio I 003 between the plane diffraction peak intensity I 003 and the (104) plane diffraction peak intensity I 104 around 2θ = 44 to 46 degrees.
/ I 104 Non-aqueous electrolyte solution with 5 or more and 40 or less
Manufacturing method of positive electrode plate for secondary battery.
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| JP6096101B2 (en) * | 2012-12-18 | 2017-03-15 | 日本碍子株式会社 | Method for producing positive electrode for lithium secondary battery |
| JP6133720B2 (en) | 2013-07-24 | 2017-05-24 | 住友金属鉱山株式会社 | Non-aqueous electrolyte secondary battery positive electrode active material, method for producing the same, and non-aqueous electrolyte secondary battery |
| JP6244713B2 (en) | 2013-07-24 | 2017-12-13 | 住友金属鉱山株式会社 | Method for producing positive electrode active material for non-aqueous electrolyte secondary battery |
| WO2016054530A1 (en) | 2014-10-03 | 2016-04-07 | Massachusetts Institute Of Technology | Pore orientation using magnetic fields |
| US10675819B2 (en) | 2014-10-03 | 2020-06-09 | Massachusetts Institute Of Technology | Magnetic field alignment of emulsions to produce porous articles |
| JP7466211B2 (en) * | 2019-04-10 | 2024-04-12 | パナソニックＩｐマネジメント株式会社 | Positive electrode for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery |
-
1995
- 1995-07-04 JP JP16848895A patent/JP3362564B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0922693A (en) | 1997-01-21 |
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