JP2008198364A - Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and nonaqueous electrolyte secondary battery using it - Google Patents

Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and nonaqueous electrolyte secondary battery using it Download PDF

Info

Publication number
JP2008198364A
JP2008198364A JP2007029055A JP2007029055A JP2008198364A JP 2008198364 A JP2008198364 A JP 2008198364A JP 2007029055 A JP2007029055 A JP 2007029055A JP 2007029055 A JP2007029055 A JP 2007029055A JP 2008198364 A JP2008198364 A JP 2008198364A
Authority
JP
Japan
Prior art keywords
positive electrode
secondary battery
active material
electrolyte secondary
nickel
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.)
Granted
Application number
JP2007029055A
Other languages
Japanese (ja)
Other versions
JP5045135B2 (en
Inventor
Atsushi Fukui
篤 福井
Riyuuichi Kuzuo
竜一 葛尾
Hideo Sasaoka
英雄 笹岡
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.)
Sumitomo Metal Mining Co Ltd
Original Assignee
Sumitomo Metal Mining Co Ltd
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 Sumitomo Metal Mining Co Ltd filed Critical Sumitomo Metal Mining Co Ltd
Priority to JP2007029055A priority Critical patent/JP5045135B2/en
Publication of JP2008198364A publication Critical patent/JP2008198364A/en
Application granted granted Critical
Publication of JP5045135B2 publication Critical patent/JP5045135B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

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)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positive electrode active material for a nonaqueous electrolyte secondary battery, made from lithium nickel cobaltate titanium composite oxide powder which is excellent in thermal stability, and provides high charge/discharge capacitance, and also to provide its manufacturing method suitable for industrial production and a nonaqueous electrolyte secondary battery of high capacitance and safety which uses the same. <P>SOLUTION: After the surface of nickel cobaltate composite hydroxide (A) is coated with titanium compound, or after it is further roasted at 700°C or less, it is mixed with lithium compound, and the resultant mixture is baked at 650-850°C in the oxygen atmosphere, to provide the powder of lithium nickel cobaltate titanium composite oxide (B) represented by a composition formula (1): Li<SB>1+z</SB>Ni<SB>1-x-y</SB>Co<SB>x</SB>Ti<SB>y</SB>O<SB>2</SB>(where x, y, and z represent 0.10≤x≤0.21, 0.01≤y<0.04, and -0.05≤z≤0.10, respectively). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

本発明は、非水系電解質二次電池用正極活物質、その製造方法及びそれを用いた非水系電解質二次電池に関し、さらに詳しくは、熱安定性に優れ、かつ高い充放電容量が得られるリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質とその工業的生産に適した製造方法、及びそれを用いた高容量で安全性の高い非水系電解質二次電池に関する。   The present invention relates to a positive electrode active material for a non-aqueous electrolyte secondary battery, a method for producing the same, and a non-aqueous electrolyte secondary battery using the positive electrode active material. More specifically, the lithium is excellent in thermal stability and provides high charge / discharge capacity. TECHNICAL FIELD The present invention relates to a positive electrode active material for a non-aqueous electrolyte secondary battery made of nickel-cobalt-titanium composite oxide powder, a manufacturing method suitable for industrial production thereof, and a high-capacity, high-safety non-aqueous electrolyte secondary battery using the same. .

近年、携帯電話及びノート型パソコンなどの携帯電子機器の普及にともない、高いエネルギー密度を有し、小型で軽量な非水系電解質二次電池の開発が強く望まれている。このような二次電池として、リチウムイオン二次電池が挙げられ、現在、研究開発が盛んに行われているところである。
この中でも、リチウム金属複合酸化物、特に合成が比較的容易なリチウムコバルト複合酸化物（ＬｉＣｏＯ２）を正極材料に用いたリチウムイオン二次電池は、４Ｖ級の高い電圧が得られるため、高いエネルギー密度を有する電池として期待され実用化が進んでいる。このリチウムコバルト複合酸化物を用いたリチウムイオン二次電池については、優れた初期容量特性とサイクル特性を得るための開発がこれまで数多く行われてきており、すでにさまざまな成果が得られている。 In recent years, with the widespread use of portable electronic devices such as mobile phones and notebook personal computers, development of non-aqueous electrolyte secondary batteries having high energy density, small size and light weight is strongly desired. As such a secondary battery, a lithium ion secondary battery can be cited, and research and development are currently being actively conducted.
Among these, a lithium ion secondary battery using a lithium metal composite oxide, in particular, a lithium cobalt composite oxide (LiCoO 2 ), which is relatively easy to synthesize, as a positive electrode material can obtain a high voltage of 4 V, and thus has high energy. It is expected to be a battery having a high density and is being put to practical use. With respect to lithium ion secondary batteries using this lithium cobalt composite oxide, many developments have been made so far to obtain excellent initial capacity characteristics and cycle characteristics, and various results have already been obtained.

しかしながら、リチウムコバルト複合酸化物は、希少で高価なコバルトを原料に用いているため、電池のコストアップの原因となっていた。このため、正極活物質としてリチウムコバルト複合酸化物よりも安価なものが望まれている。さらに、最近、リチウムイオン二次電池の用途として、携帯電子機器用の小型二次電池だけではなく、電力貯蔵用、電気自動車用などの大型二次電池として適用することへの期待も高まってきている。したがって、活物質のコストを下げて、より安価なリチウムイオン二次電池の製造を可能とすることは、これらの広範な分野への大きな波及効果が期待できる。さらに、ハイブリッド自動車用、電気自動車用の電源として用いられる場合には、安全性に劣るというリチウムニッケル複合酸化物の問題点の解消は大きな課題である。   However, since the lithium cobalt composite oxide uses rare and expensive cobalt as a raw material, it has been a cause of cost increase of the battery. For this reason, what is cheaper than a lithium cobalt complex oxide as a positive electrode active material is desired. In addition, recently, as a use of lithium ion secondary batteries, not only small secondary batteries for portable electronic devices but also expectation to be applied as large secondary batteries for power storage, electric vehicles, etc. Yes. Therefore, reducing the cost of the active material and making it possible to manufacture a cheaper lithium ion secondary battery can be expected to have a large ripple effect in these wide fields. Furthermore, when used as a power source for a hybrid vehicle or an electric vehicle, it is a big problem to solve the problem of the lithium nickel composite oxide that is inferior in safety.

このような状況下、リチウムイオン二次電池用正極活物質として、コバルトよりも安価なマンガンを用いたリチウムマンガン複合酸化物（ＬｉＭｎ２Ｏ４）或いはニッケルを用いたリチウムニッケル複合酸化物（ＬｉＮｉＯ2）が新たな材料として提案されている。ここで、リチウムマンガン複合酸化物は、その原料が安価である上、熱安定性、特に、発火などについての安全性に優れるため、リチウムコバルト複合酸化物の有力な代替材料であるといえる。しかしながら、その理論容量がリチウムコバルト複合酸化物のおよそ半分程度しかないため、年々高まるリチウムイオン二次電池の高容量化の要求に応えるのが難しいという欠点を有している。また、４５℃以上の温度では、自己放電が激しく、充放電寿命も低下するという欠点もある。 Under such circumstances, as a positive electrode active material for a lithium ion secondary battery, lithium manganese composite oxide (LiMn 2 O 4 ) using manganese, which is cheaper than cobalt, or lithium nickel composite oxide (LiNiO 2 ) using nickel. ) Has been proposed as a new material. Here, the lithium manganese composite oxide is an effective alternative to the lithium cobalt composite oxide because its raw material is inexpensive and has excellent thermal stability, in particular, safety with respect to ignition and the like. However, since its theoretical capacity is only about half that of the lithium cobalt composite oxide, it has a drawback that it is difficult to meet the demand for higher capacity of lithium ion secondary batteries, which is increasing year by year. Further, at a temperature of 45 ° C. or higher, there is a drawback that self-discharge is intense and the charge / discharge life is also reduced.

一方、リチウムニッケル複合酸化物は、リチウムコバルト複合酸化物とほぼ同じ理論容量を持ち、リチウムコバルト複合酸化物よりもやや低い電池電圧を示すため、電解液の酸化による分解が問題になりにくく、より高い容量が期待できることから、開発が盛んに行われている。しかしながら、ニッケルの一部を他の元素で置換せずに、ニッケルのみで構成したリチウムニッケル複合酸化物を正極活物質として用いてリチウムイオン二次電池を作製した場合、リチウムコバルト複合酸化物に比べサイクル特性が劣るという問題がある。また、高温環境下で使用されたり、保存されたりした場合には、電池性能が比較的損なわれやすいという欠点も有している。   On the other hand, the lithium nickel composite oxide has almost the same theoretical capacity as the lithium cobalt composite oxide, and shows a slightly lower battery voltage than the lithium cobalt composite oxide. Therefore, decomposition due to oxidation of the electrolyte is less likely to be a problem. Since high capacity can be expected, development is actively conducted. However, when a lithium-ion secondary battery is produced using a lithium-nickel composite oxide composed only of nickel as a positive electrode active material without replacing a part of nickel with another element, compared to lithium cobalt composite oxide There is a problem that the cycle characteristics are inferior. In addition, when used or stored in a high-temperature environment, the battery performance is relatively easily lost.

この解決策として、例えば、高温環境下での保存や使用に際して良好な電池性能を維持することのできる正極活物質として、ＬｉｗＮｉｘＣｏｙＢＺＯ２（式中、ｗ、ｘ、ｙ、ｚは、０．０５≦ｗ≦１．１０、０．５≦ｘ≦０．９９５、０．００５≦ｚ≦０．２０、ｘ＋ｙ＋ｚ＝１である。）で表されるリチウムニッケル複合酸化物、すなわち、コバルトとホウ素が添加されたリチウムニッケル複合酸化物が提案されている（例えば、特許文献１参照。）。
また、リチウムイオン二次電池の自己放電特性やサイクル特性を向上させることを目的として、ＬｉｚＮｉａＣｏｂＭｃＯｚ（式中、Ｍは、Ａｌ、Ｖ、Ｍｎ、Ｆｅ、Ｃｕ又はＺｎから選ばれる少なくとも１種の元素であり、ｘ、ａ、ｂ、ｃは、０．８≦ｘ≦１．２、０．０１≦ａ≦０．９９、０．０１≦ｂ≦０．９９、０．０１≦ｃ≦０．３、０．８≦ａ＋ｂ＋ｃ≦１．２である。）で表されるリチウムニッケル系複合酸化物が提案されている（例えば、特許文献２参照。）。
しかしながら、これらのリチウムニッケル複合酸化物では、リチウムコバルト複合酸化物に比べて充電容量と放電容量ともに高く、サイクル特性も改善されているが、満充電状態で高温環境下に放置しておくと、リチウムコバルト複合酸化物に比べて低い温度から酸素放出を伴うという熱安定性の問題がある。 As this solution, for example, Li w Ni x Co y B Z O 2 (wherein w, x, y) can be used as a positive electrode active material capable of maintaining good battery performance during storage and use in a high temperature environment. , Z is 0.05 ≦ w ≦ 1.10, 0.5 ≦ x ≦ 0.995, 0.005 ≦ z ≦ 0.20, and x + y + z = 1.) That is, a lithium nickel composite oxide to which cobalt and boron are added has been proposed (for example, see Patent Document 1).
Further, for the purpose of improving the self-discharge characteristics and cycle characteristics of the lithium ion secondary battery, Li z Ni a Co b M c O z (wherein M is Al, V, Mn, Fe, Cu or Zn). X, a, b, c are 0.8 ≦ x ≦ 1.2, 0.01 ≦ a ≦ 0.99, 0.01 ≦ b ≦ 0.99, Lithium-nickel based composite oxide represented by 0.01 ≦ c ≦ 0.3 and 0.8 ≦ a + b + c ≦ 1.2 is proposed (for example, see Patent Document 2).
However, in these lithium nickel composite oxides, both the charge capacity and the discharge capacity are higher than those of the lithium cobalt composite oxide, and the cycle characteristics are improved, but when left in a fully charged state in a high temperature environment, There is a problem of thermal stability that involves oxygen release from a lower temperature than lithium cobalt composite oxide.

このような問題を解決するために、例えば、リチウムイオン二次電池正極材料の熱安定性を向上させることを目的として、ＬｉaＭｂＮｉｃＣｏｄＯｅ（式中、Ｍは、Ａｌ、Ｍｎ、Ｓｎ、Ｉｎ、Ｆｅ、Ｖ、Ｃｕ、Ｍｇ、Ｔｉ、Ｚｎ又はＴｉから選ばれる少なくとも一種の元素であり、ａ、ｂ、ｃ、ｄ、ｅは、０＜ａ＜１．３、０．０２≦ｂ≦０．５、０．０２≦ｄ／ｃ＋ｄ≦０．９、１．８＜ｅ＜２．２、ｂ＋ｃ＋ｄ＝１である。）で表されるリチウムニッケル系複合酸化物等が提案されている（例えば、特許文献３参照。）。ここで、添加元素Ｍとして、例えば、アルミニウムを選択した場合、ニッケルからアルミニウムへの置換量を多くすれば、正極活物質の分解反応は抑えられ、熱安定性が向上することが確かめられている。しかしながら、十分な安定性を確保するため有効なアルミニウム量でニッケルを置換すると、充放電反応にともなう酸化還元反応に寄与するニッケルの量が減少するため、電池性能として最も重要である初期容量が大きく低下してしまうという問題を有していた。これは、Ａｌは３価で安定していることから、Ｎｉも電荷を合わせるため３価で安定化させると、酸化還元反応（Ｒｅｄｏｘ反応）に寄与しない部分が生ずるために容量低下が起こるものと考えられる。したがって、この提案においても、なお、充放電容量の確保と熱安定性の向上という課題が解決されているとは言い難い。 In order to solve such a problem, for example, for the purpose of improving the thermal stability of the positive electrode material of the lithium ion secondary battery, Li a M b Ni c Co d O e (where M is Al, It is at least one element selected from Mn, Sn, In, Fe, V, Cu, Mg, Ti, Zn or Ti, and a, b, c, d and e are 0 <a <1.3, 0. 02 ≦ b ≦ 0.5, 0.02 ≦ d / c + d ≦ 0.9, 1.8 <e <2.2, and b + c + d = 1)) (For example, see Patent Document 3). Here, for example, when aluminum is selected as the additive element M, it is confirmed that if the amount of substitution from nickel to aluminum is increased, the decomposition reaction of the positive electrode active material is suppressed and the thermal stability is improved. . However, if nickel is replaced with an effective amount of aluminum to ensure sufficient stability, the amount of nickel that contributes to the oxidation-reduction reaction accompanying the charge / discharge reaction decreases, so the initial capacity, which is the most important for battery performance, is large. It had the problem of being lowered. This is because Al is stable at trivalent, and Ni also stabilizes at trivalent in order to match the charge, so that a portion that does not contribute to the oxidation-reduction reaction (Redox reaction) occurs, resulting in a decrease in capacity. Conceivable. Therefore, even in this proposal, it cannot be said that the problems of securing charge / discharge capacity and improving thermal stability are solved.

また、一般式ＬｉＮｉ１−ｘＣｏｙＭｚＯ２（式中、Ｍは、Ｍｇ、Ａｌ、Ｃａ、Ｔｉ、Ｖ、Ｃｒ、Ｍｎ、又はＦｅから選ばれる少なくとも一種からなり、ｘ、ｙ、ｚは、０．１≦ｘ≦０．３、０．０５≦ｙ≦０．２８、０．０２≦ｚ≦０．２５、ｘ＝ｙ＋ｚである。）で表されるリチウムニッケル系複合酸化物が提案されている（例えば、特許文献４参照。）。 In general formula LiNi 1-x Co y M z O 2 ( where, M is made Mg, Al, Ca, Ti, V, Cr, Mn, or at least one selected from Fe, x, y, z Is 0.1 ≦ x ≦ 0.3, 0.05 ≦ y ≦ 0.28, 0.02 ≦ z ≦ 0.25, and x = y + z.) It has been proposed (see, for example, Patent Document 4).

ここで、このリチウムニッケル系複合酸化物の製造方法としては、次の方法が開示されている。反応槽内に、塩濃度が調整されたニッケル−コバルト−添加元素（Ｍ）系水溶液、その水溶液と錯塩を形成する錯化剤、及びアルカリ金属水酸化物をそれぞれ連続的に供給し、ニッケル、コバルト及び添加元素（Ｍ）を含む錯塩を生成させる。次いで、この錯塩をアルカリ金属水酸化物により分解してニッケル−コバルト−添加元素（Ｍ）系水酸化物を析出させ、上記錯塩の生成及び分解を槽内で循環させながら繰り返し行わせ、粒子形状が略球状であるニッケル、コバルト及び添加元素（Ｍ）を含む水酸化物をオ−バーフローさせて取り出す。得られたニッケル、コバルト及び添加元素（Ｍ）を含む水酸化物を原料として用いるか、或いはさらにこれを焙焼してニッケル、コバルト及び添加元素（Ｍ）を含む酸化物とした後に、これにリチウム塩を混合し、焼成してリチウムニッケルコバルト複合酸化物を得るものである。この方法は、水酸化ニッケルに二種以上の水酸化物を共沈させ、そのうちの一種をコバルトに限定することによって、リチウム含有複合酸化物活物質の分極特性を改善し、さらにニッケル及びコバルト以外の添加元素（Ｍ）を水酸化物中を共沈させることにより、格子の安定化を図ったものである。この添加元素（Ｍ）を共沈させた水酸化物を、リチウムイオン二次電池の正極活物質材料として用いた場合、２元素共沈水酸化物であるコバルト−ニッケル水酸化物を用いた場合に比べて、初期容量が上昇し、かつ充放電の繰り返しによるサイクル劣化が抑制されるとしている。   Here, the following method is disclosed as a manufacturing method of this lithium nickel type complex oxide. In the reaction vessel, a nickel-cobalt-added element (M) aqueous solution whose salt concentration is adjusted, a complexing agent that forms a complex salt with the aqueous solution, and an alkali metal hydroxide are continuously supplied to each of the nickel, A complex salt containing cobalt and the additive element (M) is produced. Next, the complex salt is decomposed with an alkali metal hydroxide to precipitate a nickel-cobalt-added element (M) hydroxide, and the formation and decomposition of the complex salt is repeated while circulating in the tank to form a particle shape. A hydroxide containing nickel, cobalt, and additive element (M) having a substantially spherical shape is taken out by overflowing. The obtained hydroxide containing nickel, cobalt and additive element (M) is used as a raw material, or it is further baked to obtain an oxide containing nickel, cobalt and additive element (M). A lithium salt is mixed and fired to obtain a lithium nickel cobalt composite oxide. This method improves the polarization characteristics of the lithium-containing composite oxide active material by coprecipitation of two or more hydroxides in nickel hydroxide and restricts one of them to cobalt. The additive element (M) was coprecipitated in the hydroxide to stabilize the lattice. When the hydroxide in which the additive element (M) is co-precipitated is used as a positive electrode active material of a lithium ion secondary battery, when a cobalt-nickel hydroxide that is a two-element co-precipitated hydroxide is used. In comparison, the initial capacity increases and cycle deterioration due to repeated charge and discharge is suppressed.

しかしながら、この提案においても、放電容量の増加と充放電の繰り返しによるサイクル劣化の抑制という効果について記載されているが、熱的安定性の向上に関する記載はなく、充放電容量の確保と熱的安定性の向上という重要な課題の解決策としては十分と言えない。しかも、添加元素（Ｍ）塩として、硫酸チタンを用いる場合、硫酸チタンは３価ではほとんど水に不溶であり、かつ４価では水溶性であるが、多量の硫酸中に溶解しているため、硫酸を中和するための中和剤が余分に必要なこと、及び加水分解を起こしやすいことから偏析しやすい上、ニッケルコバルト水酸化物の粒子成長を阻害する問題もあり、得られるリチウムニッケルコバルト複合酸化物中にチタン化合物が偏析するため、有効な効果が得られず、工業的な生産には不向きであるという問題があった。   However, this proposal also describes the effect of increasing the discharge capacity and suppressing cycle deterioration due to repeated charge and discharge, but there is no description regarding the improvement of thermal stability, ensuring the charge and discharge capacity and thermal stability. It is not enough as a solution to the important problem of improving the performance. Moreover, when titanium sulfate is used as the additive element (M) salt, titanium sulfate is almost insoluble in water at trivalent and water-soluble at tetravalent, but is dissolved in a large amount of sulfuric acid. Lithium nickel cobalt is obtained because of the necessity of an extra neutralizing agent to neutralize the sulfuric acid and the tendency to hydrolyze, which causes segregation and obstructs nickel cobalt hydroxide particle growth. Since the titanium compound segregates in the composite oxide, there is a problem that an effective effect cannot be obtained and it is not suitable for industrial production.

以上より、リチウムニッケルコバルトチタン複合酸化物粉末からなる非水電解質二次電池用正極活物質において、充放電容量の確保とさらなる熱的安定性の向上が求められている。   From the above, in a positive electrode active material for a non-aqueous electrolyte secondary battery made of lithium nickel cobalt titanium composite oxide powder, it is required to secure charge / discharge capacity and further improve thermal stability.

特開平８−４５５０９号公報（第１頁、第２頁）JP-A-8-45509 (first page, second page) 特開平８−２１３０１５号公報（第１頁、第２頁）Japanese Patent Laid-Open No. 8-213015 (first page, second page) 特開平５−２４２８９１号公報（第１頁、第２頁）JP-A-5-242891 (first and second pages) 特開平１０−２７６１１号公報（第１頁、第２頁）JP 10-27611 A (first page, second page)

本発明の目的は、上記の従来技術の問題点に鑑み、熱安定性に優れ、かつ高い充放電容量が得られるリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質とその工業的生産に適した製造方法、及びそれを用いた高容量で安全性の高い非水系電解質二次電池を提供することにある。   In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a positive electrode active for a non-aqueous electrolyte secondary battery comprising a lithium nickel cobalt titanium composite oxide powder that is excellent in thermal stability and obtains a high charge / discharge capacity. It is an object of the present invention to provide a material and a production method suitable for industrial production thereof, and a non-aqueous electrolyte secondary battery having high capacity and high safety using the material.

本発明者らは、上記目的を達成するために、リチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用正極活物質とそれを用いた非水系電解質二次電池について、鋭意研究を重ねた結果、ニッケルコバルト複合水酸化物（Ａ）に、その表面をチタン化合物で被覆処理を行った後、或いは、それに続いて特定の温度で焙焼した後、リチウム化合物と混合し、特定の温度で焼成に付し、特定の組成式で表されるリチウムニッケルコバルトチタン複合酸化物の粉末を得たところ、均一にチタンが固溶されたリチウムニッケルコバルトチタン複合酸化物（Ｂ）が生成され、熱安定性に優れ、かつ高い充放電容量を有する非水系電解質二次電池用の正極活物質が得られることを見出し、本発明を完成した。
なお、従来、非水系電解質二次電池用正極活物質の製造方法においては、その中間材料として均一なニッケルコバルト複合水酸化物を製造するため、ニッケルとコバルトを含む混合溶液と水酸化ナトリウム水溶液等の中和剤を同時に添加することが一般的に行われていたが、チタンを添加した複合水酸化物を製造する場合においては、ニッケルとコバルトとともにチタンを含む混合溶液を上記のように中和する方法では、十分な量のチタンが均一に固溶された複合水酸化物を得ることはできない。 In order to achieve the above object, the present inventors have conducted intensive research on a positive electrode active material for a non-aqueous electrolyte secondary battery made of lithium nickel cobalt titanium composite oxide powder and a non-aqueous electrolyte secondary battery using the same. As a result, the nickel-cobalt composite hydroxide (A) was coated with a lithium compound after the surface was coated with a titanium compound, or subsequently baked at a specific temperature. When subjected to firing at a temperature to obtain a powder of lithium nickel cobalt titanium composite oxide represented by a specific composition formula, lithium nickel cobalt titanium composite oxide (B) in which titanium is uniformly dissolved is produced. The present inventors have found that a positive electrode active material for a non-aqueous electrolyte secondary battery having excellent thermal stability and high charge / discharge capacity can be obtained.
Conventionally, in the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery, in order to produce a uniform nickel-cobalt composite hydroxide as an intermediate material, a mixed solution containing nickel and cobalt, an aqueous sodium hydroxide solution, etc. In the case of producing a composite hydroxide containing titanium, the mixed solution containing titanium together with nickel and cobalt is neutralized as described above. In this method, a composite hydroxide in which a sufficient amount of titanium is uniformly dissolved cannot be obtained.

すなわち、本発明の第１の発明によれば、ニッケルコバルト複合水酸化物（Ａ）の表面をチタン化合物で被覆処理を行った後、或いは、それに続いて７００℃未満の温度で焙焼した後、リチウム化合物と混合し、得られた混合物を、酸素雰囲気下、６５０〜８５０℃の温度で焼成に付し、次の組成式（１）で表されるリチウムニッケルコバルトチタン複合酸化物（Ｂ）の粉末を得ることを特徴とするリチウムニッケルコバルトチタン複合酸化物粉末からなる非水電解質二次電池用正極活物質の製造方法が提供される。
組成式（１）：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＴｉｙＯ２ ……（１）
（式中、ｘ、ｙ、ｚは、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０である。）。 That is, according to the first invention of the present invention, after the surface of the nickel cobalt composite hydroxide (A) is coated with a titanium compound, or subsequently roasted at a temperature of less than 700 ° C. The lithium nickel cobalt titanium composite oxide (B) represented by the following composition formula (1) is subjected to firing at a temperature of 650 to 850 ° C. in an oxygen atmosphere. A method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery comprising a lithium nickel cobalt titanium composite oxide powder is provided.
Composition formula (1): Li 1 + z Ni 1-xy Co x Ti y O 2 (1)
(In the formula, x, y, and z are 0.10 ≦ x ≦ 0.21, 0.01 ≦ y <0.04, and −0.05 ≦ z ≦ 0.10).

また、本発明の第２の発明によれば、第１の発明において、前記ニッケルコバルト複合水酸化物（Ａ）は、ニッケル塩とコバルト塩を含む水溶液に、５０〜８０℃の温度下、ｐＨが１０.０〜１２．５になるように錯化剤及びアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製されることを特徴とする非水電解質二次電池用正極活物質の製造方法が提供される。   According to the second invention of the present invention, in the first invention, the nickel cobalt composite hydroxide (A) is added to an aqueous solution containing a nickel salt and a cobalt salt at a temperature of 50 to 80 ° C. at a pH of 50 to 80 ° C. A positive electrode for a non-aqueous electrolyte secondary battery prepared by adding a complexing agent and an alkaline aqueous solution so that the pH becomes 10.0 to 12.5 and coprecipitating nickel and cobalt hydroxides A method for producing an active material is provided.

また、本発明の第３の発明によれば、第２の発明において、前記錯化剤は、アンモニウムイオン供給体であることを特徴とする非水電解質二次電池用正極活物質の製造方法が提供される。   According to a third aspect of the present invention, there is provided the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to the second aspect, wherein the complexing agent is an ammonium ion supplier. Provided.

また、本発明の第４の発明によれば、第１の発明において、前記ニッケルコバルト複合水酸化物（Ａ）は、ニッケル塩とコバルト塩を含む水溶液に、６０〜８０℃の温度下、ｐＨが１０〜１１になるようにアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製されることを特徴とする非水電解質二次電池用正極活物質の製造方法が提供される。   According to a fourth invention of the present invention, in the first invention, the nickel cobalt composite hydroxide (A) is added to an aqueous solution containing a nickel salt and a cobalt salt at a temperature of 60 to 80 ° C. at a pH of 60 ° C. A method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery is provided, which is prepared by adding an alkaline aqueous solution so as to be 10 to 11 and coprecipitating nickel and cobalt hydroxides. The

また、本発明の第５の発明によれば、第１の発明において、前記被覆処理は、ニッケルコバルト複合水酸化物（Ａ）のスラリーに、チタン塩水溶液とアルカリ水溶液を同時に添加してｐＨを８〜１１に調整することを特徴とする非水系電解質二次電池用正極活物質の製造方法が提供される。   According to a fifth aspect of the present invention, in the first aspect, the coating treatment is performed by simultaneously adding a titanium salt aqueous solution and an alkaline aqueous solution to the nickel cobalt composite hydroxide (A) slurry to adjust the pH. The manufacturing method of the positive electrode active material for nonaqueous electrolyte secondary batteries characterized by adjusting to 8-11 is provided.

また、本発明の第６の発明によれば、第５の発明において、前記チタン塩水溶液は、硫酸チタニル水溶液であることを特徴とする非水系電解質二次電池用正極活物質の製造方法が提供される。   According to a sixth aspect of the present invention, there is provided the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to the fifth aspect, wherein the titanium salt aqueous solution is a titanyl sulfate aqueous solution. Is done.

また、本発明の第７の発明によれば、第６の発明において、前記硫酸チタニル水溶液は、事前に、過剰に含有される硫酸の中和処理を行ったものであることを特徴とする非水系電解質二次電池用正極活物質の製造方法が提供される。   According to a seventh aspect of the present invention, in the sixth aspect, the aqueous solution of titanyl sulfate is obtained by previously neutralizing an excessive amount of sulfuric acid. A method for producing a positive electrode active material for an aqueous electrolyte secondary battery is provided.

また、本発明の第８の発明によれば、第７の発明において、前記中和処理は、ｐＨを０〜２に調整することを特徴とする非水系電解質二次電池用正極活物質の製造方法が提供される。   According to an eighth aspect of the present invention, in the seventh aspect, the neutralization treatment is carried out by adjusting the pH to 0 to 2, wherein the positive electrode active material for a non-aqueous electrolyte secondary battery is produced. A method is provided.

また、本発明の第９の発明によれば、第１の発明において、前記リチウム化合物は、炭酸リチウム若しくは水酸化リチウム、またはこれらの水和物であることを特徴とする非水系電解質二次電池用正極活物質の製造方法が提供される。   According to a ninth aspect of the present invention, in the first aspect, the lithium compound is lithium carbonate, lithium hydroxide, or a hydrate thereof. A method for producing a positive electrode active material is provided.

また、本発明の第１０の発明によれば、第１〜９いずれかの発明の非水系電解質二次電池用正極活物質の製造方法によって得られるリチウムニッケルコバルトチタン複合酸化物の粉末からなることを特徴とする非水系電解質二次電池用正極活物質が提供される。   According to the tenth aspect of the present invention, the lithium nickel cobalt titanium composite oxide powder is obtained by the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to any one of the first to ninth aspects. A positive electrode active material for a non-aqueous electrolyte secondary battery is provided.

また、本発明の第１１の発明によれば、第１０の発明において、非水系電解質二次電池の正極に用いた場合の初期放電容量は、１８０ｍＡｈ／ｇ以上であることを特徴とする非水系電解質二次電池用正極活物質が提供される。   According to an eleventh aspect of the present invention, in the tenth aspect, the initial discharge capacity when used for the positive electrode of the nonaqueous electrolyte secondary battery is 180 mAh / g or more. A positive electrode active material for an electrolyte secondary battery is provided.

また、本発明の第１２の発明によれば、第１０又は１１の発明の非水系電解質二次電池用正極活物質を正極に用いてなる非水系電解質二次電池が提供される。   According to the twelfth aspect of the present invention, there is provided a nonaqueous electrolyte secondary battery using the positive electrode active material for a nonaqueous electrolyte secondary battery according to the tenth or eleventh aspect of the present invention as a positive electrode.

本発明の非水系電解質二次電池用正極活物質の製造方法は、熱安定性に優れ、かつ高い充放電容量が得られるリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質の工業的生産に適した製造方法であり、また、本発明の非水系電解質二次電池は、上記製造方法で得られた本発明の正極活物質を用いてなる高容量で安全性の高い非水系電解質二次電池であるので、その工業的価値は極めて大きい。
これによって、携帯電子機器等の小型二次電池における高容量化の要求に応えることができるとともに、ハイブリッド自動車用、電気自動車用の電源である大型二次電池に求められる安全性も確保することができるので、より有利である。 The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to the present invention is for a non-aqueous electrolyte secondary battery comprising a lithium nickel cobalt titanium composite oxide powder having excellent thermal stability and high charge / discharge capacity. This is a manufacturing method suitable for industrial production of a positive electrode active material, and the non-aqueous electrolyte secondary battery of the present invention has a high capacity and safety using the positive electrode active material of the present invention obtained by the above manufacturing method. The non-aqueous electrolyte secondary battery has a high industrial value.
As a result, it is possible to meet the demand for higher capacity in small secondary batteries such as portable electronic devices, and to ensure the safety required for large secondary batteries that are power sources for hybrid vehicles and electric vehicles. It is more advantageous because it can.

以下、本発明の非水系電解質二次電池用正極活物質、その製造方法及びそれを用いた非水系電解質二次電池を詳細に説明する。
１．非水系電解質二次電池用正極活物質の製造方法
本発明の非水系電解質二次電池用正極活物質の製造方法は、ニッケルコバルト複合水酸化物（Ａ）の表面をチタン化合物で被覆処理を行った後、或いは、それに続いて７００℃未満の温度で焙焼した後、リチウム化合物と混合し、得られた混合物を、酸素雰囲気下、６５０〜８５０℃の温度で焼成に付し、次の組成式（１）で表されるリチウムニッケルコバルトチタン複合酸化物（Ｂ）の粉末を得ることを特徴とするリチウムニッケルコバルトチタン複合酸化物粉末からなる正極活物質の製造方法である。
組成式（１）：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＴｉｙＯ２ ……（１）
（式中、ｘ、ｙ、ｚは、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０である。）。 Hereinafter, the positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention, the production method thereof, and the non-aqueous electrolyte secondary battery using the same will be described in detail.
1. Method for producing positive electrode active material for non-aqueous electrolyte secondary battery The method for producing a positive electrode active material for non-aqueous electrolyte secondary battery according to the present invention comprises coating the surface of nickel-cobalt composite hydroxide (A) with a titanium compound. Or subsequent baking at a temperature of less than 700 ° C., followed by mixing with a lithium compound, and subjecting the resulting mixture to firing at a temperature of 650 to 850 ° C. in an oxygen atmosphere. It is a manufacturing method of the positive electrode active material which consists of lithium nickel cobalt titanium complex oxide powder characterized by obtaining the powder of lithium nickel cobalt titanium complex oxide (B) represented by Formula (1).
Composition formula (1): Li 1 + z Ni 1-xy Co x Ti y O 2 (1)
(In the formula, x, y, and z are 0.10 ≦ x ≦ 0.21, 0.01 ≦ y <0.04, and −0.05 ≦ z ≦ 0.10).

本発明において、ニッケルコバルト複合水酸化物の表面を所定割合のチタン化合物で被覆処理を行った後、或いは、それに続いて７００℃未満の温度で焙焼した後、リチウム化合物を添加混合して焼成することが重要である。これにより、均一にチタンが分散されたリチウムニッケルコバルトチタン複合酸化物が得られ、充放電容量の確保と熱的安定性の向上が同時に達成される。   In the present invention, the surface of the nickel-cobalt composite hydroxide is coated with a predetermined proportion of the titanium compound, or subsequently roasted at a temperature of less than 700 ° C., and then the lithium compound is added and mixed and fired. It is important to. Thereby, a lithium nickel cobalt titanium composite oxide in which titanium is uniformly dispersed is obtained, and securing of charge / discharge capacity and improvement of thermal stability are achieved at the same time.

すなわち、一般に、非水電解質二次電池の充放電反応は、正極活物質内のリチウムイオンが可逆的に出入りすることで進行する。この充電時にリチウムが引き抜かれた正極活物質は、高温において不安定であり、加熱すると活物質が分解して酸素を放出するため、この酸素が電解液の燃焼を引き起こし発熱反応が起こる。したがって、正極材料の熱安定性を改善するということは、リチウムが引き抜かれた正極活物質の分解反応を抑えるということに他ならない。従来開示されている正極活物質の分解反応を抑える方法としては、酸素の放出を抑えるため、アルミニウムのような酸素との共有結合性の強い元素でニッケルを置換することが一般的に行なわれてきた。このようにニッケルからアルミニウムへの置換量を多くすれば、確かに正極活物質の分解反応は抑えられ、熱安定性が向上するが、充放電反応にともなう酸化還元反応に寄与するニッケルの量が減少することになり、充放電容量の低下を招くため、アルミニウムへの置換量は、ある程度以下に留めなければならなかった。その結果、十分な熱安定性を確保した場合には、十分な充放電容量を得ることができず、逆にある程度以上の容量を得るためには、熱安定性を犠牲にしなければならなかった。   That is, generally, the charge / discharge reaction of the nonaqueous electrolyte secondary battery proceeds by reversibly entering and exiting lithium ions in the positive electrode active material. The positive electrode active material from which lithium is extracted at the time of charging is unstable at a high temperature, and when heated, the active material is decomposed to release oxygen, so that this oxygen causes combustion of the electrolyte and an exothermic reaction occurs. Therefore, improving the thermal stability of the positive electrode material is nothing but suppressing the decomposition reaction of the positive electrode active material from which lithium has been extracted. As a method for suppressing the decomposition reaction of the positive electrode active material disclosed heretofore, in order to suppress the release of oxygen, it has been generally performed to replace nickel with an element having a strong covalent bond with oxygen such as aluminum. It was. If the amount of substitution from nickel to aluminum is increased in this way, the decomposition reaction of the positive electrode active material is surely suppressed and the thermal stability is improved, but the amount of nickel contributing to the oxidation-reduction reaction accompanying the charge / discharge reaction is small. In order to reduce the charge / discharge capacity, the amount of replacement with aluminum had to be kept below a certain level. As a result, when sufficient thermal stability was ensured, sufficient charge / discharge capacity could not be obtained, and conversely, thermal stability had to be sacrificed in order to obtain a certain level of capacity. .

これに対して、本発明の製造方法において得られるリチウムニッケルコバルトチタン複合酸化物では、一般式：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＭｙＯ２（但し、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０）で表されるリチウム金属複合酸化物の粉末において、添加元素（Ｍ）を４価のＴｉにより置換することにより、３価であったＮｉの一部が２価となって安定化され、分解反応が抑えられる。このため、熱安定性の向上のために添加元素（Ｍ）と置換するニッケルを減少させることができるので、電池の初期容量の低下を防止することができる。しかも、チタン化合物は、ニッケルコバルト複合水酸化物の表面被覆により添加され、或いはさらに焙焼されてチタンを含むニッケルコバルト複合酸化物が形成されるので、従来のニッケルコバルト複合水酸化物中にチタンを共沈させる方法と比べて、チタン化合物の偏析が防止され効果的に作用するので、電池容量を低下させる原因となる過大な添加量が不要である。 In contrast, in the lithium-nickel-cobalt-titanium composite oxide obtained in the production method of the present invention have the general formula: Li 1 + z Ni 1- x-y Co x M y O 2 ( where, 0.10 ≦ x ≦ 0. 21, 0.01 ≦ y <0.04, −0.05 ≦ z ≦ 0.10) In the powder of lithium metal composite oxide, the additive element (M) is replaced with tetravalent Ti. Thus, a part of the trivalent Ni is divalent and stabilized, and the decomposition reaction is suppressed. For this reason, since nickel substituted for the additive element (M) can be reduced to improve the thermal stability, it is possible to prevent a decrease in the initial capacity of the battery. Moreover, since the titanium compound is added by surface coating of nickel cobalt composite hydroxide or is further baked to form a nickel cobalt composite oxide containing titanium, titanium in the conventional nickel cobalt composite hydroxide is formed. Compared with the method of coprecipitation, segregation of the titanium compound is prevented and it works effectively, so that an excessive amount of addition that causes a decrease in battery capacity is unnecessary.

以上のように、本発明の製造方法では、所定組成のニッケルコバルト複合水酸化物を調製した後、チタン化合物をニッケルコバルト複合水酸化物の表面に被覆させたもの、又はそれを所定条件で焙焼して得られるニッケルコバルトチタン複合酸化物の粉末と、リチウム化合物とを混合する方法を採用して、その後の焼成で均一に固溶させることに特徴がある。   As described above, in the production method of the present invention, a nickel-cobalt composite hydroxide having a predetermined composition is prepared, and then a titanium compound is coated on the surface of the nickel-cobalt composite hydroxide, or roasted under predetermined conditions. It is characterized in that a nickel cobalt titanium composite oxide powder obtained by firing and a method of mixing a lithium compound are employed, and the solid solution is uniformly dissolved by subsequent firing.

上記ニッケルコバルト複合水酸化物（Ａ）としては、特に限定されるものではなく、所定割合に配合されたニッケル塩とコバルト塩を含む水溶液を原料として、結晶性の良い沈殿が生成される晶析法により調製されたものが用いられるが、例えば下記の調製方法（ａ）、（ｂ）により得られたものが好ましい。
（ａ）ニッケル塩とコバルト塩を含む水溶液に、５０〜８０℃の温度下、ｐＨが１０.０〜１２．５になるように錯化剤及びアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製される。
（ｂ）ニッケル塩とコバルト塩を含む水溶液に、６０〜８０℃の温度下、ｐＨが１０〜１１になるようにアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製される。 The nickel-cobalt composite hydroxide (A) is not particularly limited. Crystallization in which a precipitate having good crystallinity is produced using an aqueous solution containing nickel salt and cobalt salt mixed in a predetermined ratio as a raw material. Although those prepared by the method are used, for example, those obtained by the following preparation methods (a) and (b) are preferable.
(A) A complexing agent and an alkaline aqueous solution are added to an aqueous solution containing a nickel salt and a cobalt salt at a temperature of 50 to 80 ° C. so that the pH is 10.0 to 12.5. Prepared by co-precipitation.
(B) Prepared by adding an aqueous alkaline solution to an aqueous solution containing nickel salt and cobalt salt at a temperature of 60 to 80 ° C. so that the pH becomes 10 to 11, and coprecipitating nickel and cobalt hydroxides. The

なお、調製方法（ａ）と（ｂ）の違いは、錯化剤の添加の有無とｐＨ領域及び温度領域の条件にある。ここで、錯化剤は、液中のニッケル及びコバルトの溶解度を上昇させる作用を有し、水酸化物の生成速度又は晶析物の形状制御に影響を与える。したがって、錯化剤の添加により、生成されるニッケルコバルト複合水酸化物粒子の組成及び形状を所望の組成でかつ略球状になるように制御することができるｐＨ領域の上限と温度領域の下限を広げることができる   The difference between the preparation methods (a) and (b) is in the presence or absence of addition of a complexing agent and the conditions in the pH region and the temperature region. Here, the complexing agent has an action of increasing the solubility of nickel and cobalt in the liquid, and affects the formation rate of hydroxide or the shape control of the crystallized product. Therefore, by adding a complexing agent, the upper limit of the pH range and the lower limit of the temperature range can be controlled so that the composition and shape of the produced nickel cobalt composite hydroxide particles have a desired composition and become substantially spherical. Can be spread

すなわち、調製方法（ａ）では、ｐＨが１０．０未満では、水酸化物の生成速度が著しく遅くなり、ろ液中にニッケルが残留し、ニッケルの沈殿量が目的組成からずれて、目的の比率の複合水酸化物が得られなくなってしまう。一方、ｐＨが１２．５を超えると、晶析物が細かい粒子となり、ろ過性も悪くなり、球状粒子が得られない。
また、水溶液の温度が５０℃未満では、ニッケルの溶解度が小さいため、ニッケルの沈殿量が目的組成からずれ共沈にならない。一方、８０℃を超えると、水の蒸発量が多いためにスラリー濃度が高くなり、ニッケルの溶解度が低下する上、ろ液中に硫酸ナトリウム等の結晶が発生し、不純物濃度が上昇するなど、正極材の充放電容量が低下する問題が出てくる。 That is, in the preparation method (a), when the pH is less than 10.0, the rate of hydroxide formation is remarkably slow, nickel remains in the filtrate, and the amount of nickel precipitated deviates from the target composition. A composite hydroxide of a ratio cannot be obtained. On the other hand, if the pH exceeds 12.5, the crystallized product becomes fine particles, the filterability also deteriorates, and spherical particles cannot be obtained.
In addition, when the temperature of the aqueous solution is less than 50 ° C., the solubility of nickel is small, so that the precipitation amount of nickel deviates from the target composition and does not coprecipitate. On the other hand, when the temperature exceeds 80 ° C., the slurry concentration becomes high due to a large amount of evaporation of water, so that the solubility of nickel decreases, crystals such as sodium sulfate are generated in the filtrate, and the impurity concentration increases. There arises a problem that the charge / discharge capacity of the positive electrode material is lowered.

これに対し、調製方法（ｂ）では、錯化剤の添加が行われないので、好ましいｐＨ領域と温度領域とが狭くなる。すなわち、ｐＨが１１を超えると、晶析物が細かい粒子となり、ろ過性も悪くなり、球状粒子が得られない。また、水溶液の温度が６０℃未満では、ニッケルの溶解度が小さいため、ニッケルの沈殿量が目的組成からずれ、共沈にならない。   On the other hand, in the preparation method (b), since a complexing agent is not added, a preferable pH region and temperature region are narrowed. That is, when the pH exceeds 11, the crystallized product becomes fine particles, the filterability also deteriorates, and spherical particles cannot be obtained. In addition, when the temperature of the aqueous solution is less than 60 ° C., the solubility of nickel is small, so that the amount of nickel precipitated deviates from the target composition and does not coprecipitate.

上記方法に用いるニッケル塩とコバルト塩を含む水溶液としては、特に限定されるものではなく、硫酸塩、塩化物、硝酸塩等の水溶性塩を所望の配合で溶解したものが用いられる。また、前記水溶液の濃度としては、特に限定されるものではなく、液量を抑える目的から飽和濃度が望ましいが、常温放置で結晶が析出しない程度の濃度が好ましい。例えば、ニッケルとコバルトの合計で１〜２モル／Ｌが好ましく、１.５〜２モル／Ｌがより好ましい。   The aqueous solution containing a nickel salt and a cobalt salt used in the above method is not particularly limited, and an aqueous solution in which a water-soluble salt such as sulfate, chloride or nitrate is dissolved in a desired composition is used. Further, the concentration of the aqueous solution is not particularly limited, and a saturated concentration is desirable for the purpose of reducing the amount of the solution, but a concentration that does not cause crystals to precipitate when left at room temperature is preferable. For example, the total of nickel and cobalt is preferably 1 to 2 mol / L, and more preferably 1.5 to 2 mol / L.

上記ニッケル塩とコバルト塩の配合割合としては、得られるリチウムニッケルコバルトチタン複合酸化物粉末中のニッケル、コバルト及びチタンの全量に対し、コバルトをモル比で０．１０〜０．２１の範囲で含有するように調整する。これは、上記組成式（１）中のｘが、０．１０≦ｘ≦０．２１の範囲を満足するように行われることにあたる。すなわち、コバルトのモル比が０．１０未満では、熱安定性が低下し、一方、コバルトのモル比が０．２１を超えると、充放電容量が低下する   As a mixing ratio of the nickel salt and the cobalt salt, cobalt is contained in a molar ratio of 0.10 to 0.21 with respect to the total amount of nickel, cobalt and titanium in the obtained lithium nickel cobalt titanium composite oxide powder. Adjust to This means that x in the composition formula (1) is performed so as to satisfy the range of 0.10 ≦ x ≦ 0.21. That is, when the molar ratio of cobalt is less than 0.10, the thermal stability decreases, and when the molar ratio of cobalt exceeds 0.21, the charge / discharge capacity decreases.

上記方法に用いるアルカリ水溶液としては、特に限定されるものではなく、水酸化ナトリウム等のアルカリ金属水酸化物を溶解したものが用いられる。前記アルカリ水溶液の濃度としては、特に限定されるものではなく液量を抑える目的から、１２重量％以上で、飽和濃度以下で行うのが好ましい。   The aqueous alkali solution used in the above method is not particularly limited, and a solution in which an alkali metal hydroxide such as sodium hydroxide is dissolved is used. The concentration of the alkaline aqueous solution is not particularly limited, and is preferably 12% by weight or more and not more than a saturated concentration for the purpose of suppressing the liquid amount.

上記方法に用いる錯化剤としては、特に限定されるものではなく、ニッケル及びコバルトの溶解度を上げる作用のある薬剤が用いられるが、この中で、アンモニア、硫酸アンモニウムの他に塩化アンモニウム、炭酸アンモニウム、弗化アンモニウム等が挙げられるが挙げられるが、アンモニウムイオン供給体が好ましい。   The complexing agent used in the above method is not particularly limited, and a drug having an action of increasing the solubility of nickel and cobalt is used. Among them, ammonium chloride, ammonium carbonate, ammonium carbonate, Examples thereof include ammonium fluoride, and an ammonium ion supplier is preferable.

上記両法のより具体的な方法としては、まず、反応槽内で、原子比が所定の割合となるようにニッケル塩とコバルト塩を含む水溶液に、アルカリ水溶液と必要により錯化剤を同時に加えながら、一定速度で攪拌し、共沈殿させる。その後、反応槽内の生成物が定常状態になった後に、沈殿物を採取し、ろ過、水洗してニッケルコバルト複合水酸化物を得る。   As a more specific method of both the above methods, first, an alkaline aqueous solution and, if necessary, a complexing agent are simultaneously added to an aqueous solution containing a nickel salt and a cobalt salt so that the atomic ratio becomes a predetermined ratio in a reaction vessel. While stirring, coprecipitate at a constant speed. Thereafter, after the product in the reaction vessel reaches a steady state, a precipitate is collected, filtered and washed with water to obtain a nickel cobalt composite hydroxide.

上記被覆処理としては、特に限定されるものではなく、例えば、上記ニッケルコバルト複合水酸化物（Ａ）のスラリーに、チタン塩水溶液とアルカリ水溶液を同時に添加してｐＨを８〜１１に調整することにより行われる。その後、水酸化物スラリーを濾過し、水洗を行うことで、所定割合でチタンを含有するように、表面がチタン化合物で被覆されたニッケルコバルト複合水酸化物が得られる。   The coating treatment is not particularly limited. For example, the titanium salt aqueous solution and the alkaline aqueous solution are simultaneously added to the nickel cobalt composite hydroxide (A) slurry to adjust the pH to 8 to 11. Is done. Thereafter, the hydroxide slurry is filtered and washed with water, whereby a nickel cobalt composite hydroxide whose surface is coated with a titanium compound so as to contain titanium in a predetermined ratio is obtained.

上記チタン塩水溶液中のチタンの含有量としては、得られるリチウムニッケルコバルトチタン複合酸化物（Ｃ）粉末中のニッケル、コバルト及びチタンの全量に対し、チタンをモル比で０．０１以上、０．０４未満の範囲で含有するように調整する。これは、上記組成式（１）中のｙが、０．０１≦ｙ＜０．０４の範囲を満足するように行われることにあたる。すなわち、チタンのモル比が０．０１未満では、熱安定性改善の効果が少なく、一方、チタンのモル比が０．０４以上では、チタン化合物に由来して粒子表面に存在する硫酸基等の無機イオン等により、十分な充放電容量が得られない。   As content of titanium in the said titanium salt aqueous solution, 0.01 mol or more of titanium is molar ratio with respect to the total amount of nickel, cobalt, and titanium in lithium nickel cobalt titanium complex oxide (C) powder obtained, and 0.00. It adjusts so that it may contain in less than 04 range. This is performed so that y in the composition formula (1) satisfies a range of 0.01 ≦ y <0.04. That is, when the molar ratio of titanium is less than 0.01, the effect of improving the thermal stability is small. On the other hand, when the molar ratio of titanium is 0.04 or more, sulfate groups and the like that are derived from the titanium compound and exist on the particle surface. Sufficient charge / discharge capacity cannot be obtained due to inorganic ions or the like.

上記チタン塩水溶液としては、特に限定されるものではなく、例えば、硫酸チタニル水溶液が好ましい。すなわち、チタン塩としては、水への溶解度の高い硫酸チタニルを用い、かつ硫酸水溶液であることが工業上の取り扱いが容易であり好ましい。一般的な塩化チタン又は硫酸チタンでは、加水分解、又はその時点で酸化によりチタン化合物又は酸化チタンが発生し、チタンの偏析が起きるからである。
このとき、上記硫酸チタニル水溶液としては、事前に、過剰に含有される硫酸の中和処理を行ったものが好ましい。ここで、前記中和処理としては、好ましくはｐＨを０〜２、より好ましくは１程度に調整することが好ましい。すなわち、中和処理することにより、水酸化物が溶解するのを防止することができる。 The titanium salt aqueous solution is not particularly limited, and for example, a titanyl sulfate aqueous solution is preferable. That is, as the titanium salt, titanyl sulfate having high solubility in water and an aqueous sulfuric acid solution are preferable because industrial handling is easy. This is because in general titanium chloride or titanium sulfate, a titanium compound or titanium oxide is generated by hydrolysis or oxidation at that time, and segregation of titanium occurs.
At this time, as the above-mentioned titanyl sulfate aqueous solution, a solution obtained by previously neutralizing an excessively contained sulfuric acid is preferable. Here, as the neutralization treatment, the pH is preferably adjusted to 0 to 2, more preferably about 1. That is, the neutralization treatment can prevent the hydroxide from dissolving.

上記被覆処理において、ニッケルコバルト複合水酸化物（Ａ）のスラリーのｐＨ調整を事前に行わない状態で、硫酸チタニル水溶液とアルカリ水溶液を同時に添加してｐＨを調整することが好ましい。すなわち、別途添加によりｐＨが高い液に硫酸チタニル水溶液を添加すると、急激に中和が進むので、すべての水酸化チタンをニッケルコバルト複合水酸化物（Ａ）の表面に被覆することが困難となる。   In the coating treatment, it is preferable to adjust the pH by simultaneously adding a titanyl sulfate aqueous solution and an alkaline aqueous solution in a state where the pH of the nickel cobalt composite hydroxide (A) slurry is not adjusted in advance. That is, when a titanyl sulfate aqueous solution is added to a solution having a high pH by addition separately, neutralization proceeds rapidly, so that it becomes difficult to coat all titanium hydroxide on the surface of the nickel cobalt composite hydroxide (A). .

上記混合物の原料として、表面がチタン化合物で被覆されたニッケルコバルト複合水酸化物、或いはこれを焙焼したニッケルコバルトチタン複合酸化物のいずれもが用いられるが、得られるリチウムニッケルコバルトチタン複合酸化物（Ｂ）を安定化させるため、所定条件で焙焼されたニッケルコバルトチタン複合酸化物の方が好ましい。すなわち、前記複合水酸化物は、その結晶水により嵩高いため焼成容器への充填量が焼成後の複合酸化物より少なくなり、生産量が減少すること、及び乾燥状態の違いで水分が変動することもあり、焼成後の収縮が大きいこと等の課題がある。   As the raw material of the above mixture, either a nickel cobalt composite hydroxide whose surface is coated with a titanium compound or a nickel cobalt titanium composite oxide obtained by baking this is used, and the resulting lithium nickel cobalt titanium composite oxide In order to stabilize (B), the nickel cobalt titanium complex oxide baked on predetermined conditions is more preferable. That is, since the composite hydroxide is bulky due to its crystal water, the filling amount in the firing container is less than the composite oxide after firing, the production amount decreases, and the moisture varies depending on the dry state. There are also problems such as large shrinkage after firing.

上記ニッケルコバルトチタン複合酸化物の粉末は、被覆処理で得られた表面がチタン化合物で被覆されたニッケルコバルト複合水酸化物を、７００℃未満、好ましくは３００℃以上、７００℃未満の温度で焙焼することにより得られる。ここで、焙焼の温度が７００℃以上では、酸化チタンとしてのチタンの分離が進み、チタンの偏析が発生し、放電容量が低下する。なお、水酸化物の分解を十分に行うためには、焙焼の温度が３００℃以上が好ましい。また、焙焼雰囲気としては、特に限定されるものではなく、空気気流中、酸素気流中等の酸化性雰囲気下で問題ない。   The nickel-cobalt-titanium composite oxide powder is obtained by roasting nickel-cobalt composite hydroxide whose surface obtained by coating treatment is coated with a titanium compound at a temperature of less than 700 ° C., preferably 300 ° C. or more and less than 700 ° C. Obtained by baking. Here, when the roasting temperature is 700 ° C. or higher, separation of titanium as titanium oxide proceeds, segregation of titanium occurs, and the discharge capacity decreases. In order to sufficiently decompose the hydroxide, the roasting temperature is preferably 300 ° C. or higher. Further, the roasting atmosphere is not particularly limited, and there is no problem in an oxidizing atmosphere such as an air stream or an oxygen stream.

上記リチウム化合物としては、特に限定されるものではなく、リチウムの水酸化物、オキシ水酸化物、酸化物、炭酸塩、硝酸塩及びハロゲン化物からなる群から選ばれる少なくとも１種が用いられるが、この中で、炭酸リチウム、水酸化リチウム、またはこれらの水和物であることが好ましい。   The lithium compound is not particularly limited, and at least one selected from the group consisting of lithium hydroxide, oxyhydroxide, oxide, carbonate, nitrate and halide is used. Among these, lithium carbonate, lithium hydroxide, or a hydrate thereof is preferable.

上記リチウム化合物の混合割合としては、得られるリチウムニッケルコバルトチタン複合酸化物粉末中のニッケル、コバルト及びチタンの全量に対し、リチウムをモル比で０．９５〜１．１０含有するように調整する。これは、上記組成式（１）中のｚが、−０．０５≦ｚ≦０．１０の範囲を満足するように行われることにあたる。すなわち、リチウムのモル比が０．９５未満では、層状構造を形成する上で本来リチウムが居るべきサイトにニッケルが存在することとなり、得られる粉末の結晶性が非常に悪くなる。また、充放電に関わるリチウムが不足するため、充放電サイクル時の電池容量の大きな低下を引き起こす要因となる。一方、リチウムのモル比が１．１０を超えると、層状構造を形成する上で本来ニッケルが居るべきサイトにリチウムが存在することとなり、得られる粉末の結晶性が非常に悪くなる。また、得られる粉末の表面に余剰のリチウム化合物が多量に存在し、これを水洗で除去するのが難しくなる。   The mixing ratio of the lithium compound is adjusted so that lithium is contained in a molar ratio of 0.95 to 1.10 with respect to the total amount of nickel, cobalt and titanium in the obtained lithium nickel cobalt titanium composite oxide powder. This is performed so that z in the composition formula (1) satisfies the range of −0.05 ≦ z ≦ 0.10. That is, when the molar ratio of lithium is less than 0.95, nickel is present at a site where lithium should originally exist in forming a layered structure, and the crystallinity of the obtained powder becomes very poor. Moreover, since the lithium related to charging / discharging is insufficient, it causes a large decrease in battery capacity during the charging / discharging cycle. On the other hand, when the molar ratio of lithium exceeds 1.10, lithium is present at a site where nickel should originally exist in forming a layered structure, and the crystallinity of the obtained powder becomes very poor. Further, a large amount of excess lithium compound is present on the surface of the obtained powder, and it becomes difficult to remove this by washing with water.

上記混合物の焼成温度としては、６５０〜８５０℃、好ましくは７００〜８００℃であり、焼成時間としては、特に限定されるものではないが、１０〜２０時間程度とすることが好ましい。また、焼成時の雰囲気としては、酸素気流等、酸化性雰囲気下で行われる。
すなわち、焼成温度が６５０℃未満では、リチウム化合物との反応が十分に進まず、所望の層状構造をもったリチウムニッケル複合酸化物を合成することが難しくなる。一方、８５０℃を超えると、Ｌｉ層にＮｉが、Ｎｉ層にＬｉが混入して層状構造が乱れ、３ａサイトにおけるリチウム以外の金属イオンのサイト占有率が２％より大きくなってしまい、リチウムのサイトである３ａサイトに金属イオンの混入率が高くなり、リチウムイオンの拡散パスが阻害され、その正極を用いた電池は初期容量や出力が低下してしまう。 The firing temperature of the mixture is 650 to 850 ° C., preferably 700 to 800 ° C. The firing time is not particularly limited, but is preferably about 10 to 20 hours. In addition, the firing atmosphere is performed in an oxidizing atmosphere such as an oxygen stream.
That is, when the firing temperature is less than 650 ° C., the reaction with the lithium compound does not proceed sufficiently, and it becomes difficult to synthesize a lithium nickel composite oxide having a desired layered structure. On the other hand, when the temperature exceeds 850 ° C., Ni is mixed into the Li layer, Li is mixed into the Ni layer, the layered structure is disturbed, and the site occupancy rate of metal ions other than lithium at the 3a site becomes larger than 2%. The mixing rate of metal ions at the 3a site, which is the site, is increased, the lithium ion diffusion path is obstructed, and the battery using the positive electrode has a reduced initial capacity and output.

さらに、必要に応じて、得られたリチウムニッケルコバルトチタン複合酸化物（Ｂ）の粉末を、水洗に付し、ろ過、乾燥する工程を行うことができる。従来、水洗はおこなわれていなかったが、水洗により、焼成後のリチウムニッケルコバルトチタン複合酸化物（Ｂ）の粒子表面に存在するチタン化合物に由来する硫酸基等の無機イオンが除去されることにより、高い充放電容量が安定的に得られる。   Furthermore, the process of attaching | subjecting the powder of the obtained lithium nickel cobalt titanium complex oxide (B) to water washing, and filtering and drying as needed can be performed. Conventionally, washing with water has not been performed, but by washing with water, inorganic ions such as sulfate groups derived from titanium compounds present on the surface of the particles of the lithium nickel cobalt titanium composite oxide (B) after firing are removed. High charge / discharge capacity can be obtained stably.

２．非水電解質二次電池用正極活物質
本発明の非水電解質二次電池用正極活物質としては、上記製造方法によって得られる、熱安定性に優れ、かつ高い充放電容量が得られる、次の組成式（１）で表されるリチウムニッケルコバルトチタン複合酸化物の粉末からなる正極活物質である。
組成式（１）：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＴｉｙＯ２ ……（１）
（式中、ｘ、ｙ、ｚは、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０である。）
ここで、ｙの値が０．０１未満では、熱安定性改善の効果が少なく、一方、０．０４以上では、十分な充放電容量が得られない。また、ｘの値が０．１０未満では、熱安定性が低下し、一方、０．２１を超えると、充放電容量が低下する。また、ｚの値が−０．０５未満では、充放電容量が低下し、一方０．１０を超えると、熱安定性が低下してしまう。 2. Positive electrode active material for nonaqueous electrolyte secondary battery The positive electrode active material for nonaqueous electrolyte secondary battery of the present invention is obtained by the above production method, has excellent thermal stability and high charge / discharge capacity. It is a positive electrode active material made of lithium nickel cobalt titanium composite oxide powder represented by the composition formula (1).
Composition formula (1): Li 1 + z Ni 1-xy Co x Ti y O 2 (1)
(In the formula, x, y, and z are 0.10 ≦ x ≦ 0.21, 0.01 ≦ y <0.04, and −0.05 ≦ z ≦ 0.10.)
Here, if the value of y is less than 0.01, the effect of improving the thermal stability is small, while if it is 0.04 or more, sufficient charge / discharge capacity cannot be obtained. Moreover, if the value of x is less than 0.10, thermal stability will fall, and when it exceeds 0.21, charging / discharging capacity will fall. On the other hand, if the value of z is less than −0.05, the charge / discharge capacity decreases, whereas if it exceeds 0.10, the thermal stability decreases.

上記非水電解質二次電池用正極活物質の粒度分布としては、Ｄ５０が５〜１５μｍであり、タップ密度は１〜３ｇ／ｍＬであり、より好ましくは２〜３ｇ／ｍＬである。上記範囲を外れると、正極を作製するときに正極活物質の充填性が低下してしまう。
また、上記非水電解質二次電池用正極活物質を正極に用いた場合の初期放電容量としては、１８０ｍＡｈ／ｇ以上が得られる。さらに、充電後に加熱した時の示差走査熱量計（ＤＳＣ）による発熱速度が、１１Ｗ／ｇ以下である。これにより、電池としての安全性で実用上の問題はない。 As a particle size distribution of the positive electrode active material for a non-aqueous electrolyte secondary battery, D50 is 5 to 15 μm, a tap density is 1 to 3 g / mL, and more preferably 2 to 3 g / mL. If it is out of the above range, the filling property of the positive electrode active material is lowered when the positive electrode is produced.
Moreover, 180 mAh / g or more is obtained as an initial discharge capacity when the positive electrode active material for a non-aqueous electrolyte secondary battery is used for a positive electrode. Furthermore, the heating rate by a differential scanning calorimeter (DSC) when heated after charging is 11 W / g or less. Thereby, there is no practical problem in safety as a battery.

３．非水電解質二次電池
本発明の非水電解質二次電池は、上記非水電解質二次電池用正極活物質を用いてなる高容量で安全性の高いものである。
ここで、上記リチウムイオン二次電池の形態について、各構成要素ごとにそれぞれ詳しく説明する。本発明に係るリチウムイオン二次電池は、正極、負極、非水電解液等、一般のリチウムイオン二次電池と同様の構成要素から構成される。なお、以下で説明する形態は例示に過ぎず、本発明の非水系電解質二次電池は、下記形態をはじめとして、当業者の知識に基づいて種々の変更、改良を施した形態で実施することができる。また、本発明の非水系電解質二次電池は、その用途を特に限定するものではない。 3. Non-aqueous electrolyte secondary battery The non-aqueous electrolyte secondary battery of the present invention has a high capacity and high safety using the positive electrode active material for a non-aqueous electrolyte secondary battery.
Here, the configuration of the lithium ion secondary battery will be described in detail for each component. The lithium ion secondary battery according to the present invention is composed of the same components as those of a general lithium ion secondary battery, such as a positive electrode, a negative electrode, and a non-aqueous electrolyte. The forms described below are merely examples, and the nonaqueous electrolyte secondary battery of the present invention should be implemented in various modified and improved forms based on the knowledge of those skilled in the art, including the following forms. Can do. Moreover, the use of the nonaqueous electrolyte secondary battery of the present invention is not particularly limited.

上記正極活物質としては、前述のとおり、組成式：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＴｉｙＯ２（式中、ｘ、ｙ、ｚは、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０である。）で表されるリチウムニッケルコバルトチタン複合酸化物の粉末からなる。 As described above, the positive electrode active material has a composition formula: Li 1 + z Ni 1-xy Co x Ti y O 2 (where x, y, and z are 0.10 ≦ x ≦ 0.21, 0 .01 ≦ y <0.04, −0.05 ≦ z ≦ 0.10.) Lithium nickel cobalt titanium composite oxide powder.

上記正極としては、特に限定されるものではなく、例えば、次のようにして作製する。粉末状の正極活物質、導電材、バインダー、及び結着剤とを混合し、さらに必要に応じて、活性炭及び粘度調整等の目的の溶剤を添加し、これを混練して正極合材ペーストを作製する。正極合材中のそれぞれの混合比も、リチウム二次電池の性能を決定する重要な要素となる。例えば、溶剤を除いた正極合材の固形分の全質量を１００質量％とした場合、一般のリチウム二次電池の正極と同様、それぞれ、正極活物質の含有量を６０〜９５質量％、導電材の含有量を１〜２０質量％、結着剤の含有量を１〜２０質量％とすることが望ましい。
得られた正極合材ペーストを、例えば、アルミニウム箔製の集電体の表面に塗布し、乾燥して溶剤を飛散させる。また、必要に応じて、電極密度を高めるべくロールプレス等により加圧することもある。このようにしてシート状の正極を作製することができる。得られたシート状の正極は、目的とする電池に応じて適当な大きさに裁断等し、電池の作製に供することができる。 The positive electrode is not particularly limited, and is produced, for example, as follows. The powdered positive electrode active material, conductive material, binder, and binder are mixed, and if necessary, the target solvent such as activated carbon and viscosity adjustment is added and kneaded to prepare the positive electrode mixture paste. Make it. The respective mixing ratios in the positive electrode mixture are also important factors that determine the performance of the lithium secondary battery. For example, when the total mass of the solid content of the positive electrode mixture excluding the solvent is 100% by mass, the content of the positive electrode active material is 60 to 95% by mass, as in the case of the positive electrode of a general lithium secondary battery. It is desirable that the content of the material is 1 to 20% by mass and the content of the binder is 1 to 20% by mass.
The obtained positive electrode mixture paste is applied to the surface of a current collector made of, for example, aluminum foil, and dried to scatter the solvent. Moreover, it may pressurize with a roll press etc. to raise an electrode density as needed. In this way, a sheet-like positive electrode can be produced. The obtained sheet-like positive electrode can be cut into an appropriate size according to the intended battery and used for battery production.

上記導電剤としては、例えば、黒鉛（天然黒鉛、人造黒鉛、膨張黒鉛など）、アセチレンブラック、ケッチェンブラックなどのカーボンブラック系材料などを用いることができる。また、上記バインダーとしては、例えば、ポリフッ化ビニリデン、ポリテトラフルオロエチレン、エチレンプロピレンジエンゴム、フッ素ゴム、スチレンブタジエン、セルロース系樹脂、ポリアクリル酸などを用いることができる。 また、上記結着剤としては、活物質粒子をつなぎ止める役割を果たすもので、例えば、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等を用いることができる。
さらに、必要に応じて、正極活物質、導電材、活性炭を分散させ、結着剤を溶解する溶剤を正極合材に添加する。この溶剤としては、具体的には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。また、正極合材には電気二重層容量を増加させるために活性炭を添加することができる。 As the conductive agent, for example, carbon black materials such as graphite (natural graphite, artificial graphite, expanded graphite, etc.), acetylene black, ketjen black and the like can be used. Examples of the binder that can be used include polyvinylidene fluoride, polytetrafluoroethylene, ethylene propylene diene rubber, fluororubber, styrene butadiene, cellulose resin, and polyacrylic acid. Moreover, as the binder, it plays a role of keeping the active material particles together, and for example, a fluorine-containing resin such as polytetrafluoroethylene, polyvinylidene fluoride, or fluororubber, or a thermoplastic resin such as polypropylene or polyethylene is used. be able to.
Furthermore, if necessary, a positive electrode active material, a conductive material, and activated carbon are dispersed, and a solvent that dissolves the binder is added to the positive electrode mixture. Specifically, an organic solvent such as N-methyl-2-pyrrolidone can be used as this solvent. Moreover, activated carbon can be added to the positive electrode mixture in order to increase the electric double layer capacity.

次いで、本発明の非水電解質二次電池に用いる正極以外の構成要素について説明する。
ただし、本発明の非水電解質二次電池は、上記正極活物質を用いる点に特徴を有するものであり、その他の構成要素は特に限定されるものではない。
上記負極としては、例えば、金属リチウム、リチウム合金等、また、リチウムイオンを吸蔵・脱離できる負極活物質に結着剤を混合し、適当な溶剤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、必要に応じて電極密度を高めるべく圧縮して形成したものを使用する。
上記負極活物質としては、例えば、天然黒鉛、人造黒鉛、フェノール樹脂等の有機化合物焼成体、コークス等の炭素物質の粉状体を用いることができる。この場合、負極結着剤としては、正極同様、ポリフッ化ビニリデン等の含フッ素樹脂等を用いることができ、これら活物質および結着剤を分散させる溶剤としては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。 Next, components other than the positive electrode used in the nonaqueous electrolyte secondary battery of the present invention will be described.
However, the nonaqueous electrolyte secondary battery of the present invention is characterized in that the positive electrode active material is used, and other components are not particularly limited.
Examples of the negative electrode include metallic lithium, lithium alloys, and the like, and a negative electrode mixture in which a binder is mixed with a negative electrode active material capable of inserting and extracting lithium ions, and an appropriate solvent is added to form a paste. It is applied to the surface of a metal foil current collector such as copper, dried, and compressed to increase the electrode density as necessary.
As the negative electrode active material, for example, a fired organic compound such as natural graphite, artificial graphite, or a phenol resin, or a powdery carbon material such as coke can be used. In this case, as the negative electrode binder, a fluorine-containing resin such as polyvinylidene fluoride can be used as in the case of the positive electrode, and the active material and the solvent for dispersing the binder include N-methyl-2-pyrrolidone. Organic solvents can be used.

上記セパレータは、正極と負極との間に挟み込んで配置する。このセパレータは、正極と負極とを分離し電解質を保持するものであり、例えば、ポリエチレン、ポリプロピレン等の薄い膜で、微少な穴を多数有する膜を用いることができる。   The separator is disposed between the positive electrode and the negative electrode. This separator separates a positive electrode and a negative electrode and retains an electrolyte. For example, a thin film of polyethylene, polypropylene or the like and a film having many minute holes can be used.

上記非水系電解液は、支持塩としてのリチウム塩を有機溶媒に溶解したものである。上記有機溶媒としては、例えば、エチレンカーボネート、プロピレンカーボネート、ブチレンカーボネート、トリフルオロプロピレンカーボネート等の環状カーボネート、ジエチルカーボネート、ジメチルカーボネート、エチルメチルカーボネート、ジプロピルカーボネート等の鎖状カーボネート、テトラヒドロフラン、２−メチルテトラヒドロフラン、ジメトキシエタン等のエーテル化合物、エチルメチルスルホン、ブタンスルトン等の硫黄化合物、又はリン酸トリエチル、リン酸トリオクチル等のリン化合物等から選ばれる少なくとも１種を用いることができる。上記支持塩としては、例えば、ＬｉＰＦ6、ＬｉＢＦ4、ＬｉＣｌＯ4、ＬｉＡｓＦ6、ＬｉＮ（ＣＦ3ＳＯ2）2等、およびそれらの複合塩を用いることができる。さらに、上記非水系電解液には、ラジカル補足剤、界面活性剤および難燃剤等を含んでいてもよい。 The non-aqueous electrolyte solution is obtained by dissolving a lithium salt as a supporting salt in an organic solvent. Examples of the organic solvent include cyclic carbonates such as ethylene carbonate, propylene carbonate, butylene carbonate, and trifluoropropylene carbonate, chain carbonates such as diethyl carbonate, dimethyl carbonate, ethyl methyl carbonate, and dipropyl carbonate, tetrahydrofuran, and 2-methyl. At least one selected from ether compounds such as tetrahydrofuran and dimethoxyethane, sulfur compounds such as ethyl methyl sulfone and butane sultone, or phosphorus compounds such as triethyl phosphate and trioctyl phosphate can be used. Examples of the supporting salt include LiPF 6 , LiBF 4 , LiClO 4 , LiAsF 6 , LiN (CF 3 SO 2 ) 2 , and complex salts thereof. Furthermore, the non-aqueous electrolyte solution may contain a radical scavenger, a surfactant, a flame retardant, and the like.

上記正極、負極、セパレータおよび非水系電解液で構成される本発明に係るリチウム二次電池の形状は、円筒型、積層型等、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、正極および負極を、セパレータを介して積層させて電極体とし、この電極体に上記非水電解液を含浸させる。正極集電体と外部に通ずる正極端子との間、並びに負極集電体と外部に通ずる負極端子との間を集電用リード等を用いて接続する。以上の構成のものを電池ケースに密閉して電池を完成させることができる。   The shape of the lithium secondary battery according to the present invention composed of the positive electrode, the negative electrode, the separator, and the non-aqueous electrolyte can be various, such as a cylindrical type and a laminated type. In any case, the positive electrode and the negative electrode are laminated via a separator to form an electrode body, and this electrode body is impregnated with the non-aqueous electrolyte. The positive electrode current collector and the positive electrode terminal communicating with the outside, and the negative electrode current collector and the negative electrode terminal communicating with the outside are connected using a current collecting lead or the like. The battery having the above structure can be sealed in a battery case to complete the battery.

以下に、本発明の実施例及び比較例によって本発明をさらに詳細に説明するが、本発明は、これらの実施例によってなんら限定されるものではない。なお、実施例及び比較例で用いた組成、結晶構造、粒度分布、粉体充填密度、充放電容量及び正極の安全性の評価方法は、以下の通りである。   Hereinafter, the present invention will be described in more detail by way of examples and comparative examples of the present invention, but the present invention is not limited to these examples. In addition, the composition, crystal structure, particle size distribution, powder packing density, charge / discharge capacity and positive electrode safety evaluation method used in Examples and Comparative Examples are as follows.

（１）組成の分析：ＩＣＰ発光分析装置（Ｓｅｉｋｏ Ｉｎｓｔｒｕｍｅｎｔｓ Ｉｎｃ製Ｐｌａｓｍａ Ｓｐｅｃｔｒｏｍｅｔｅｒ ＳＰＳ３０００）で行った。
（２）正極活物質の結晶構造の分析：Ｘ線回折装置（リガク電機社製：ＲＩＮＴ−１４００）で分析した。
（３）正極活物質の粒度分布の測定：レーザー散乱式粒度測定装置（日機装製 マイクロトラックＨＲＡ）で測定した粒度分布から、Ｄ５０（累積分布率５０質量％での粒度を求めた。
（４）正極活物質の粉体充填密度（タップ密度）の測定：粉末１２ｇを２０ｍｌのガラス製メスシリンダーに入れ、振とう比重測定器（蔵持科学器械製作所製ＫＲＳ−４０９）にて５００回タップした後の粉体充填密度を求めた。 (1) Composition analysis: The analysis was performed using an ICP emission spectrometer (Plasma Spectrometer SPS3000 manufactured by Seiko Instruments Inc).
(2) Analysis of crystal structure of positive electrode active material: Analysis was performed with an X-ray diffractometer (manufactured by Rigaku Electric Co., Ltd .: RINT-1400).
(3) Measurement of the particle size distribution of the positive electrode active material: The particle size at a D50 (cumulative distribution rate of 50% by mass) was determined from the particle size distribution measured with a laser scattering particle size measuring device (Nikkiso Microtrac HRA).
(4) Measurement of powder packing density (tap density) of positive electrode active material: 12 g of powder was put into a 20 ml glass graduated cylinder and tapped 500 times with a shaking specific gravity measuring instrument (KRS-409 manufactured by Kuramochi Scientific Instruments). After that, the powder packing density was determined.

（５）正極活物質の充放電容量評価：活物質粉末７０質量部にアセチレンブラック２０質量部およびＰＴＦＥ１０質量部を混合し、ここから１５０ｍｇを取り出してペレットを作製し正極とした。負極としてリチウム金属を用い、電解液には１ＭのＬｉＣｌＯ4を支持塩とするエチレンカーボネート（ＥＣ）とジエチルカーボネート（ＤＥＣ）の等量混合溶液（富山薬品工業製）を用いた。露点が−８０℃に管理されたＡｒ雰囲気のグローブボックス中で、２０３２型のコイン電池を作製した。図１に、２０３２型のコイン電池の概略構造を示す。ここで、コイン電池は、正極缶６中の正極（評価用電極）３、負極缶５中のリチウム金属負極１、電解液含浸のセパレータ２、ガスケット４及び集電体７から構成される。
作製した電池は２４時間程度放置し、開路電圧ＯＣＶ（ｏｐｅｎ ｃｉｒｃｕｉｔ ｖｏｌｔａｇｅ）が安定した後、正極に対する電流密度を０．５ｍＡ／ｃｍ2としてカットオフ電圧４．３Ｖまで充電して初期充電容量とし、１時間の休止後カットオフ電圧３．０Ｖまで放電したときの容量を初期放電容量とした。充放電容量の測定には，ＡＤＶＡＮＴＥＳＴ社製マルチチャンネル電圧／電流発生器（Ｒ６７４１Ａ）を用いた。 (5) Evaluation of charge / discharge capacity of positive electrode active material: 70 parts by mass of active material powder was mixed with 20 parts by mass of acetylene black and 10 parts by mass of PTFE. Lithium metal was used as the negative electrode, and an equivalent mixed solution of ethylene carbonate (EC) and diethyl carbonate (DEC) (made by Toyama Pharmaceutical Co., Ltd.) using 1M LiClO 4 as a supporting salt was used as the electrolyte. A 2032 type coin battery was produced in a glove box in an Ar atmosphere in which the dew point was controlled at −80 ° C. FIG. 1 shows a schematic structure of a 2032 type coin battery. Here, the coin battery includes a positive electrode (evaluation electrode) 3 in a positive electrode can 6, a lithium metal negative electrode 1 in a negative electrode can 5, an electrolyte-impregnated separator 2, a gasket 4, and a current collector 7.
The prepared battery is left for about 24 hours, and after the open circuit voltage OCV (open circuit voltage) is stabilized, the current density with respect to the positive electrode is set to 0.5 mA / cm 2 and charged to a cutoff voltage of 4.3 V to obtain an initial charge capacity. The capacity when the battery was discharged to a cutoff voltage of 3.0 V after a one hour rest was defined as the initial discharge capacity. A multi-channel voltage / current generator (R6741A) manufactured by ADVANTEST was used for measuring the charge / discharge capacity.

（６）正極の安全性の評価：上記と同様な方法で作製した２０３２型のコイン電池をカットオフ電圧４．５ＶまでＣＣＣＶ充電（定電流−定電圧充電。まず、充電が、定電流で動作し、それから定電圧で充電を終了するという２つのフェーズの充電過程を用いる充電方法。）した後、短絡しないように注意しながら解体して正極を取り出した。この電極を３．０ｍｇ計り取り、電解液を１．３ｍｇ加えて、アルミニウム製測定容器に封入し、示差走査熱量計（ＰＴＣ−１０Ａ、Ｒｉｇａｋｕ社製）を用いて昇温速度１０℃／ｍｉｎで室温から４００℃まで発熱挙動を測定し、発熱速度を求めた。 (6) Evaluation of safety of positive electrode: CCCV charging (constant current-constant voltage charging. First, charging is operated at a constant current) for a 2032 type coin battery manufactured by the same method as above. Then, a charging method using a two-phase charging process of terminating charging at a constant voltage.), And then disassembling with care not to short-circuit, and taking out the positive electrode. 3.0 mg of this electrode was measured, 1.3 mg of the electrolyte was added, sealed in an aluminum measurement container, and heated at a rate of temperature increase of 10 ° C./min using a differential scanning calorimeter (PTC-10A, manufactured by Rigaku). The heat generation behavior was measured from room temperature to 400 ° C., and the heat generation rate was determined.

（実施例１）
（１）ニッケルコバルト複合水酸化物の調製
ニッケルとコバルトの配合割合がモル比で８４：１５となるように、硫酸ニッケル(和光純薬工業製、試薬特級)と硫酸コバルト(和光純薬工業製、試薬特級)の混合水溶液を準備した。次いで、反応槽内に、前記混合溶液とともに、水酸化ナトリウム (和光純薬工業製、試薬特級)を用いて調製した濃度２５重量％の水酸化ナトリウム水溶液と錯化剤として濃度２５重量％アンモニア水(和光純薬工業製、試薬特級)を同時に添加した。このとき、ｐＨを１０〜１２．５の範囲、及び反応温度を５０〜８０℃の範囲に保持した。その後、反応槽内が定常状態になった後に、オーバーフローした沈殿物を採取し、ろ過、水洗して、ニッケルコバルト複合水酸化物を得た。 (Example 1)
(1) Preparation of nickel-cobalt composite hydroxide Nickel sulfate (made by Wako Pure Chemical Industries, reagent grade) and cobalt sulfate (made by Wako Pure Chemical Industries) so that the mixing ratio of nickel and cobalt is 84:15. , Reagent special grade) mixed aqueous solution was prepared. Next, in the reaction tank, together with the mixed solution, a sodium hydroxide aqueous solution having a concentration of 25% by weight prepared using sodium hydroxide (made by Wako Pure Chemical Industries, Ltd., reagent grade), and a 25% by weight aqueous ammonia solution as a complexing agent. (Wako Pure Chemical Industries, reagent special grade) was added simultaneously. At this time, the pH was maintained in the range of 10 to 12.5, and the reaction temperature was maintained in the range of 50 to 80 ° C. Then, after the inside of the reaction vessel was in a steady state, the overflowed precipitate was collected, filtered and washed with water to obtain a nickel cobalt composite hydroxide.

（２）チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製
得られたニッケルコバルト複合水酸化物を、常温で、水でスラリー化させた後、スラリーのｐＨは調整しない状態で、ニッケル、コバルト及びチタンの配合割合が、モル比でニッケル：コバルト：チタン＝８４：１５：１となるように、ｐＨ１に水酸化ナトリウム水溶液で調整した硫酸チタニル水溶液と濃度１２重量％の水酸化ナトリウム水溶液を同時に添加して攪拌し、ｐＨが８〜１０．５になるよう調整した。その後、反応槽内の水酸化物スラリーを全量回収し、濾過、水洗後に乾燥させ、チタン化合物で被覆されたニッケルコバルト複合水酸化物の乾燥粉末を得た。 (2) Preparation of nickel-cobalt composite hydroxide coated with titanium compound After the obtained nickel-cobalt composite hydroxide was slurried with water at room temperature, the pH of the slurry was not adjusted, nickel, A titanyl sulfate aqueous solution adjusted to pH 1 with a sodium hydroxide aqueous solution and a sodium hydroxide aqueous solution with a concentration of 12% by weight so that the mixing ratio of cobalt and titanium is nickel: cobalt: titanium = 84: 15: 1 in molar ratio. Simultaneously added and stirred to adjust the pH to 8 to 10.5. Thereafter, the entire amount of the hydroxide slurry in the reaction tank was recovered, filtered, washed with water and dried to obtain a dry powder of nickel-cobalt composite hydroxide coated with a titanium compound.

（３）リチウムニッケルコバルトチタン複合酸化物の合成
得られたチタン化合物で被覆されたニッケルコバルト複合水酸化物の乾燥粉末と市販の水酸化リチウム（ＦＭＣ社製）とを、ニッケル、コバルト及びチタンの合計とリチウムの原子比が、１：１．０５になるように秤量した後、これらを球状の二次粒子の形骸が維持される程度の強さでシェーカーミキサー装置（ＷＡＢ社製ＴＵＲＢＵＬＡ ＴｙｐｅＴ２Ｃ）を用いて十分に混合した。
次いで、得られた混合物３０ｇを、５ｃｍ×１２ｃｍ×３ｃｍのマグネシア製の焼成容器に入れ、密閉式電気炉を用いて、流量３Ｌ／ｍｉｎの酸素気流中で５００℃で２時間仮焼した後、昇温速度５℃／ｍｉｎで７３０℃まで昇温し、その温度で１０時間焼成した後、室温まで炉内で冷却して、正極活物質を得た。 (3) Synthesis of Lithium Nickel Cobalt Titanium Composite Oxide Dry powder of nickel cobalt composite hydroxide coated with the obtained titanium compound and commercially available lithium hydroxide (manufactured by FMC) were mixed with nickel, cobalt and titanium. After weighing so that the atomic ratio of the total to lithium is 1: 1.05, shaker mixer device (TURBULA Type T2C manufactured by WAB Co., Ltd.) is used with such a strength that the shape of spherical secondary particles is maintained. Used and mixed well.
Next, 30 g of the obtained mixture was put into a 5 cm × 12 cm × 3 cm magnesia firing container and calcined at 500 ° C. for 2 hours in an oxygen stream at a flow rate of 3 L / min using a sealed electric furnace. After heating up to 730 degreeC with the temperature increase rate of 5 degree-C / min and baking for 10 hours at the temperature, it cooled in the furnace to room temperature, and obtained the positive electrode active material.

（４）正極活物質及び正極の評価
得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、充放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (4) Evaluation of positive electrode active material and positive electrode The composition of the obtained positive electrode active material, D50 of the particle size distribution, powder packing density (tap density), charge / discharge capacity, and safety of the positive electrode were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

（実施例２）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で８３：１５となるようにしたこと、チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、ニッケル、コバルト及びチタンの配合割合が、モル比でニッケル：コバルト：チタン＝８３：１５：２になるようにしたこと、リチウムニッケルコバルトチタン複合酸化物の合成において、焼成温度を７８０℃としたこと以外は、実施例１と同様に行い、正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、充放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (Example 2)
In the preparation of the nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was set to 83:15, and in the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound, nickel, cobalt And the mixing ratio of titanium was such that the molar ratio was nickel: cobalt: titanium = 83: 15: 2, and in the synthesis of the lithium nickel cobalt titanium composite oxide, the firing temperature was 780 ° C. The same procedure as in Example 1 was performed to obtain a positive electrode active material, and the composition of the obtained positive electrode active material, D50 of the particle size distribution, powder packing density (tap density), charge / discharge capacity, and safety of the positive electrode were evaluated as described above. The method was evaluated. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

（実施例３）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で８２：１５となるようにしたこと、チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、ニッケル、コバルト及びチタンの配合割合がモル比でニッケル：コバルト：チタン＝８２：１５：３となるようにしたこと、及び硫酸チタニル水溶液と水酸化ナトリウム水溶液を添加する際にｐＨが１０〜１１になるよう調整したこと、並びにリチウムニッケルコバルトチタン複合酸化物の合成において、チタン化合物で被覆されたニッケルコバルト複合水酸化物の代わりに、下記の焙焼方法で合成されたニッケルコバルトチタン複合酸化物を用いたこと、及び焼成温度を７６０℃としたことこと以外は、実施例１と同様にして正極活物質を得て、その後、さらに、得られた正極活物質を、５０ｍＬのビーカーに入れ、スラリー濃度が１５００ｇ／Ｌとなるように純水を加え、次いで２０分間スターラーで攪拌した後、ろ過した。得られたろ過物を、真空乾燥器を用いて１５０℃で１２時間乾燥した。得られた乾燥後の正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、初期放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。
［チタン化合物で被覆されたニッケルコバルト複合水酸化物の焙焼方法］
実施例１の（２）チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製により得られた該複合水酸化物５０ｇを５ｃｍ×１２ｃｍ×３ｃｍのマグネシア製の焼成容器に挿入し、密閉式電気炉を用いて、流量３Ｌ／ｍｉｎの空気気流中で昇温速度５℃／ｍｉｎで５５０℃まで昇温し、その温度で１０時間焙焼した後、室温まで炉内で冷却した。 (Example 3)
In the preparation of the nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was set to 82:15, and in the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound, nickel, cobalt In addition, the mixing ratio of titanium and titanium was adjusted to be nickel: cobalt: titanium = 82: 15: 3, and the pH was adjusted to 10 to 11 when the titanyl sulfate aqueous solution and the sodium hydroxide aqueous solution were added. In addition, in the synthesis of lithium nickel cobalt titanium composite oxide, instead of nickel cobalt composite hydroxide coated with a titanium compound, nickel cobalt titanium composite oxide synthesized by the following roasting method was used. And the positive electrode active material in the same manner as in Example 1 except that the firing temperature was 760 ° C. Te, then further the obtained cathode active material, placed in a beaker of 50 mL, of pure water so that the slurry concentration becomes 1500 g / L was added, followed after stirring for 20 minutes with a stirrer, and filtered. The obtained filtrate was dried at 150 ° C. for 12 hours using a vacuum dryer. The composition of the obtained positive electrode active material after drying, D50 of the particle size distribution, powder packing density (tap density), initial discharge capacity, and safety of the positive electrode were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.
[Roasting method of nickel-cobalt composite hydroxide coated with titanium compound]
50 g of the composite hydroxide obtained by the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound of Example 1 (2) was inserted into a 5 cm × 12 cm × 3 cm magnesia firing container, and sealed electric Using a furnace, the temperature was raised to 550 ° C. at a heating rate of 5 ° C./min in an air stream having a flow rate of 3 L / min, roasted at that temperature for 10 hours, and then cooled to room temperature in the furnace.

（実施例４）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で８１：１５となるようにしたこと、チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、濃度１２重量％の水酸化ナトリウム水溶液でスラリーのｐＨをアルカリ性に調製した後、３倍に希釈した硫酸チタニル水溶液を添加してｐＨが９〜１０になるよう調整したこと、リチウムニッケルコバルトチタン複合酸化物の合成において、焼成温度を７６０℃としたことこと以外は、実施例１と同様にして正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、充放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。また、得られた組成は、調合からずれていた。 Example 4
In the preparation of the nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was adjusted to be 81:15, and in the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound, the concentration was 12 wt. The pH of the slurry was adjusted to alkaline with an aqueous sodium hydroxide solution of 3% and then adjusted to a pH of 9 to 10 by adding a 3-fold diluted titanyl sulfate aqueous solution. Synthesis of lithium nickel cobalt titanium composite oxide In Example 1, except that the firing temperature was 760 ° C., a positive electrode active material was obtained in the same manner as in Example 1, the composition of the obtained positive electrode active material, D50 of the particle size distribution, powder packing density (tap density) The charge / discharge capacity and the safety of the positive electrode were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure. Moreover, the obtained composition shifted | deviated from preparation.

（比較例１）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で８１：１５となるようにしたこと、チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、ニッケル、コバルト及びチタンの配合割合が、モル比でニッケル：コバルト：チタン＝８１：１５：４になるようにしたこと、リチウムニッケルコバルトチタン複合酸化物の合成において、仮焼温度を４５０℃及び焼成温度を７８０℃としたこと以外は、実施例１と同様に行い、正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、充放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (Comparative Example 1)
In the preparation of the nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was adjusted to 81:15, and in the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound, nickel, cobalt In addition, in the synthesis of lithium nickel cobalt titanium composite oxide, the calcining temperature is 450 ° C. and the calcining temperature is 780. Except that it was set to ° C., the same procedure as in Example 1 was performed to obtain a positive electrode active material, the composition of the obtained positive electrode active material, D50 of particle size distribution, powder packing density (tap density), charge / discharge capacity, and The safety of the positive electrode was evaluated by the above evaluation method. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

（比較例２）
［チタン化合物で被覆されたニッケルコバルト複合水酸化物の焙焼方法］において、８００℃まで昇温して焙焼したこと以外は、実施例１と同様にして正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、初期放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (Comparative Example 2)
In [Roasting Method of Nickel Cobalt Composite Hydroxide Coated with Titanium Compound], a positive electrode active material was obtained and obtained in the same manner as in Example 1 except that it was heated to 800 ° C. and roasted. The composition of the positive electrode active material, D50 of the particle size distribution, powder packing density (tap density), initial discharge capacity, and safety of the positive electrode were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

（比較例３）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で７５：１５となるようにしたこと、及びチタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、ニッケル、コバルト及びチタンの配合割合がモル比でニッケル：コバルト：チタン＝７５：１５：１０となるようにしたこと以外は、実施例１と同様にして正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、初期放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (Comparative Example 3)
In the preparation of the nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was 75:15 in molar ratio, and in the preparation of the nickel-cobalt composite hydroxide coated with the titanium compound, nickel, A positive electrode active material was obtained in the same manner as in Example 1 except that the mixing ratio of cobalt and titanium was such that the molar ratio was nickel: cobalt: titanium = 75: 15: 10. , D50 of particle size distribution, powder packing density (tap density), initial discharge capacity, and positive electrode safety were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

（比較例４）
ニッケルコバルト複合水酸化物の調製おいて、ニッケルとコバルトの配合割合がモル比で８４．５：１５となるようにしたこと、チタン化合物で被覆されたニッケルコバルト複合水酸化物の調製において、ニッケル、コバルト及びチタンの配合割合が、モル比でニッケル：コバルト：チタン＝８４．５：１５：０．５になるようにしたこと、リチウムニッケルコバルトチタン複合酸化物の合成において、仮焼温度を４５０℃及び焼成温度を７８０℃としたこと以外は、実施例１と同様に行い、正極活物質を得て、得られた正極活物質の組成、粒度分布のＤ５０、粉体充填密度（タップ密度）、充放電容量、及び正極の安全性を上記評価方法により評価した。結果を表１、２に示す。なお、結晶構造は、六方晶系の層状構造を有する複合酸化物単相であった。 (Comparative Example 4)
In the preparation of nickel-cobalt composite hydroxide, the mixing ratio of nickel and cobalt was 84.5: 15, and in the preparation of nickel-cobalt composite hydroxide coated with a titanium compound, nickel The mixing ratio of cobalt and titanium was such that the molar ratio was nickel: cobalt: titanium = 84.5: 15: 0.5, and the calcining temperature was 450 in the synthesis of lithium nickel cobalt titanium composite oxide. The positive electrode active material was obtained in the same manner as in Example 1 except that the temperature and the baking temperature were 780 ° C. The positive electrode active material was obtained, the composition of the obtained positive electrode active material, the particle size distribution D50, and the powder packing density (tap density). The charge / discharge capacity and the safety of the positive electrode were evaluated by the above evaluation methods. The results are shown in Tables 1 and 2. The crystal structure was a complex oxide single phase having a hexagonal layered structure.

Figure 2008198364
Figure 2008198364

Figure 2008198364
Figure 2008198364

表１、２より、実施例１〜４では、ニッケルコバルト複合水酸化物の調製、チタン化合物で被覆されたニッケルコバルト複合水酸化物の焙焼方法、リチウムニッケルコバルトチタン複合酸化物の合成、及びリチウムニッケルコバルトチタン複合酸化物の組成、特にチタンの含有割合において、本発明の方法に従って行われたので、熱安定性に優れ、かつ高い充放電容量が得られるリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質とそれを用いた高容量で安全性の高い非水系電解質二次電池が得られることが分かる。すなわち、初期放電容量が１８０ｍＡｈ／ｇを超えるとともに、ＤＳＣ測定による発熱速度が１１Ｗ／ｇ以下であり、リチウムコバルト複合酸化物に代わる新たな電池材料として使用することができる材料であることが分かる。   From Tables 1 and 2, in Examples 1 to 4, preparation of nickel cobalt composite hydroxide, roasting method of nickel cobalt composite hydroxide coated with titanium compound, synthesis of lithium nickel cobalt titanium composite oxide, and The composition of the lithium nickel cobalt titanium composite oxide, in particular the content of titanium, was carried out according to the method of the present invention, so that the lithium nickel cobalt titanium composite oxide powder has excellent thermal stability and high charge / discharge capacity. It can be seen that a positive electrode active material for a non-aqueous electrolyte secondary battery and a high-capacity, high-safety non-aqueous electrolyte secondary battery using the same can be obtained. That is, the initial discharge capacity exceeds 180 mAh / g, and the heat generation rate by DSC measurement is 11 W / g or less, which indicates that the material can be used as a new battery material in place of the lithium cobalt composite oxide.

これに対して、比較例１〜４では、リチウムニッケルコバルトチタン複合酸化物のチタンの含有割合、又はチタン化合物で被覆されたニッケルコバルト複合水酸化物の焙焼温度のいずれかがこれらの条件に合わないので、熱安定性又は初期放電容量のいずれかによって満足すべき結果が得られないことが分かる。   On the other hand, in Comparative Examples 1 to 4, either the content ratio of titanium of the lithium nickel cobalt titanium composite oxide or the roasting temperature of the nickel cobalt composite hydroxide coated with the titanium compound satisfies these conditions. Since it does not match, it can be seen that either thermal stability or initial discharge capacity does not give satisfactory results.

以上より明らかなように、本発明の非水系電解質二次電池用正極活物質の製造方法は、熱安定性に優れ、かつ高い充放電容量が得られるリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質の工業的生産に適した製造方法であり、また、本発明の非水系電解質二次電池は、上記製造方法で得られた、本発明のリチウムニッケルコバルトチタン複合酸化物粉末からなる非水系電解質二次電池用の正極活物質を用いてなる高容量で安全性の高い非水系電解質二次電池であるので、安全性に優れていながら高い充放電容量を有しているメリットを活かすためには、常に高容量を要求される小型携帯電子機器の電源としての用途に好適である。
また、電気自動車用の電源においては、電池の大型化による安全性の確保が課題となっていることに加え、より高度な安全性を確保するための高価な保護回路の装着が必要不可欠であるが、本発明の非水系電解質二次電池は優れた安全性を有しているため、安全性の確保が容易になるばかりでなく、高価な保護回路を簡略化し、より低コストにでき、電気自動車用電源として好適である。なお、電気自動車用電源とは、純粋に電気エネルギーで駆動する電気自動車のみならず、ガソリンエンジン、ディーゼルエンジン等の燃焼機関と併用する、いわゆるハイブリッド車用の電源も含むものである。 As is clear from the above, the method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery of the present invention is a non-lithium nickel cobalt titanium composite oxide powder having excellent thermal stability and high charge / discharge capacity. This is a manufacturing method suitable for industrial production of a positive electrode active material for an aqueous electrolyte secondary battery, and the non-aqueous electrolyte secondary battery of the present invention is the lithium nickel cobalt titanium of the present invention obtained by the above manufacturing method. High capacity and high safety non-aqueous electrolyte secondary battery using a positive electrode active material for non-aqueous electrolyte secondary battery made of composite oxide powder. In order to take advantage of the advantages, it is suitable for use as a power source for small portable electronic devices that always require high capacity.
Moreover, in the power supply for electric vehicles, it is indispensable to install an expensive protection circuit for ensuring higher safety in addition to ensuring safety by increasing the size of the battery. However, since the non-aqueous electrolyte secondary battery of the present invention has excellent safety, not only is it easy to ensure safety, but also an expensive protection circuit can be simplified and the cost can be reduced. It is suitable as a power source for automobiles. The electric vehicle power source includes not only an electric vehicle driven purely by electric energy but also a so-called hybrid vehicle power source used in combination with a combustion engine such as a gasoline engine or a diesel engine.

電池評価に用いたコイン電池の断面の概略図である。It is the schematic of the cross section of the coin battery used for battery evaluation.

符号の説明Explanation of symbols

１ リチウム金属負極
２ セパレータ（電解液含浸）
３ 正極（評価用電極）
４ ガスケット
５ 負極缶
６ 正極缶
７ 集電体 1 Lithium metal negative electrode 2 Separator (electrolyte impregnation)
3 Positive electrode (Evaluation electrode)
4 Gasket 5 Negative electrode can 6 Positive electrode can 7 Current collector

Claims (12)

ニッケルコバルト複合水酸化物（Ａ）の表面をチタン化合物で被覆処理を行った後、或いは、それに続いて７００℃未満の温度で焙焼した後、リチウム化合物と混合し、得られた混合物を、酸素雰囲気下、６５０〜８５０℃の温度で焼成に付し、次の組成式（１）で表されるリチウムニッケルコバルトチタン複合酸化物（Ｂ）の粉末を得ることを特徴とするリチウムニッケルコバルトチタン複合酸化物粉末からなる非水電解質二次電池用正極活物質の製造方法。
組成式（１）：Ｌｉ１＋ｚＮｉ１−ｘ−ｙＣｏｘＴｉｙＯ２ ……（１）
（式中、ｘ、ｙ、ｚは、０．１０≦ｘ≦０．２１、０．０１≦ｙ＜０．０４、−０．０５≦ｚ≦０．１０である。）。 After the surface of the nickel cobalt composite hydroxide (A) is coated with a titanium compound, or subsequently roasted at a temperature of less than 700 ° C., mixed with the lithium compound, and the resulting mixture is Lithium nickel cobalt titanium, characterized by obtaining a powder of lithium nickel cobalt titanium composite oxide (B) represented by the following composition formula (1) by firing at a temperature of 650 to 850 ° C. in an oxygen atmosphere A method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery comprising a composite oxide powder.
Composition formula (1): Li 1 + z Ni 1-xy Co x Ti y O 2 (1)
(In the formula, x, y, and z are 0.10 ≦ x ≦ 0.21, 0.01 ≦ y <0.04, and −0.05 ≦ z ≦ 0.10). 前記ニッケルコバルト複合水酸化物（Ａ）は、ニッケル塩とコバルト塩を含む水溶液に、５０〜８０℃の温度下、ｐＨが１０.０〜１２．５になるように錯化剤及びアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製されることを特徴とする請求項１に記載の非水電解質二次電池用正極活物質の製造方法。   The nickel-cobalt composite hydroxide (A) is prepared by adding a complexing agent and an aqueous alkaline solution to an aqueous solution containing a nickel salt and a cobalt salt so that the pH becomes 10.0 to 12.5 at a temperature of 50 to 80 ° C. The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the method is prepared by adding and coprecipitating nickel and cobalt hydroxides. 前記錯化剤は、アンモニウムイオン供給体であることを特徴とする請求項２に記載の非水電解質二次電池用正極活物質の製造方法。   The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 2, wherein the complexing agent is an ammonium ion supplier. 前記ニッケルコバルト複合水酸化物（Ａ）は、ニッケル塩とコバルト塩を含む水溶液に、６０〜８０℃の温度下、ｐＨが１０〜１１になるようにアルカリ水溶液を添加し、ニッケルとコバルトの水酸化物を共沈させて調製されることを特徴とする請求項１に記載の非水電解質二次電池用正極活物質の製造方法。   The nickel-cobalt composite hydroxide (A) is prepared by adding an alkaline aqueous solution to an aqueous solution containing a nickel salt and a cobalt salt at a temperature of 60 to 80 ° C. so as to have a pH of 10 to 11. The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the method is prepared by coprecipitation of an oxide. 前記被覆処理は、ニッケルコバルト複合水酸化物（Ａ）のスラリーに、チタン塩水溶液とアルカリ水溶液を同時に添加してｐＨを８〜１１に調整することを特徴とする請求項１に記載の非水系電解質二次電池用正極活物質の製造方法。   2. The non-aqueous system according to claim 1, wherein the coating treatment is performed by simultaneously adding a titanium salt aqueous solution and an alkaline aqueous solution to the slurry of nickel cobalt composite hydroxide (A) to adjust the pH to 8 to 11. A method for producing a positive electrode active material for an electrolyte secondary battery. 前記チタン塩水溶液は、硫酸チタニル水溶液であることを特徴とする請求項５に記載の非水系電解質二次電池用正極活物質の製造方法。   The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 5, wherein the titanium salt aqueous solution is a titanyl sulfate aqueous solution. 前記硫酸チタニル水溶液は、事前に、過剰に含有される硫酸の中和処理を行ったものであることを特徴とする請求項６に記載の非水系電解質二次電池用正極活物質の製造方法。   The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 6, wherein the aqueous solution of titanyl sulfate is obtained by neutralizing an excessive amount of sulfuric acid in advance. 前記中和処理は、ｐＨを０〜２に調整することを特徴とする請求項７に記載の非水系電解質二次電池用正極活物質の製造方法。   The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 7, wherein the neutralization treatment adjusts the pH to 0 to 2. 9. 前記リチウム化合物は、炭酸リチウム若しくは水酸化リチウム、またはこれらの水和物であることを特徴とする請求項１に記載の非水系電解質二次電池用正極活物質の製造方法。   The method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 1, wherein the lithium compound is lithium carbonate, lithium hydroxide, or a hydrate thereof. 請求項１〜９のいずれかに記載の非水系電解質二次電池用正極活物質の製造方法によって得られるリチウムニッケルコバルトチタン複合酸化物の粉末からなることを特徴とする非水系電解質二次電池用正極活物質。   It consists of the powder of the lithium nickel cobalt titanium complex oxide obtained by the manufacturing method of the positive electrode active material for nonaqueous electrolyte secondary batteries in any one of Claims 1-9, For nonaqueous electrolyte secondary batteries characterized by the above-mentioned Positive electrode active material. 非水系電解質二次電池の正極に用いた場合の初期放電容量は、１８０ｍＡｈ／ｇ以上であることを特徴とする請求項１０に記載の非水系電解質二次電池用正極活物質。   The positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 10, wherein the initial discharge capacity when used for the positive electrode of the non-aqueous electrolyte secondary battery is 180 mAh / g or more. 請求項１０又は１１に記載の非水系電解質二次電池用正極活物質を正極に用いてなる非水系電解質二次電池。   A non-aqueous electrolyte secondary battery using the positive electrode active material for a non-aqueous electrolyte secondary battery according to claim 10 or 11 as a positive electrode.
JP2007029055A 2007-02-08 2007-02-08 Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same Active JP5045135B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2007029055A JP5045135B2 (en) 2007-02-08 2007-02-08 Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2007029055A JP5045135B2 (en) 2007-02-08 2007-02-08 Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same

Publications (2)

Publication Number Publication Date
JP2008198364A true JP2008198364A (en) 2008-08-28
JP5045135B2 JP5045135B2 (en) 2012-10-10

Family

ID=39757123

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2007029055A Active JP5045135B2 (en) 2007-02-08 2007-02-08 Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same

Country Status (1)

Country Link
JP (1) JP5045135B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010044963A (en) * 2008-08-13 2010-02-25 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery
JP2012043716A (en) * 2010-08-20 2012-03-01 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery and method for producing the same, and nonaqueous electrolyte secondary battery using the positive electrode active material
CN113659214A (en) * 2021-07-12 2021-11-16 深圳市比克动力电池有限公司 Design method of high specific energy lithium ion battery with electrochemical performance and safety performance

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1027611A (en) * 1996-07-12 1998-01-27 Tanaka Kagaku Kenkyusho:Kk Lithium-containing compound oxide for lithium ion secondary battery and its manufacture
JP2000323122A (en) * 1999-05-14 2000-11-24 Sumitomo Metal Mining Co Ltd Positive electrode active material for non-aqueous electrolyte secondary battery and manufacture thereof
JP2001035492A (en) * 1999-07-23 2001-02-09 Seimi Chem Co Ltd Positive electrode active material for lithium secondary battery
JP2002063901A (en) * 2000-08-14 2002-02-28 Mitsui Chemicals Inc Positive electrode active material for lithium secondary battery, its manufacturing method and battery using same
JP2002170562A (en) * 2000-11-30 2002-06-14 Nikko Materials Co Ltd Positive electrode material for lithium secondary battery and method for manufacturing the same
JP2005044743A (en) * 2003-07-25 2005-02-17 Nichia Chem Ind Ltd Positive electrode activator of nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
JP2006127955A (en) * 2004-10-29 2006-05-18 Sumitomo Metal Mining Co Ltd Positive electrode active substance for nonaqueous secondary cell and its manufacturing method
JP2006147499A (en) * 2004-11-24 2006-06-08 Sumitomo Metal Mining Co Ltd Positive electrode active material for non-aqueous electrolyte secondary battery, its manufacturing method, and non-aqueous electrolyte secondary battery using this
JP2006286614A (en) * 2005-03-09 2006-10-19 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
JP2006310181A (en) * 2005-04-28 2006-11-09 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
JP2007265784A (en) * 2006-03-28 2007-10-11 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and nonaqueous electrolyte secondary battery using it
JP2008117729A (en) * 2006-11-08 2008-05-22 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and non-aqueous type electrolyte secondary battery using it

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1027611A (en) * 1996-07-12 1998-01-27 Tanaka Kagaku Kenkyusho:Kk Lithium-containing compound oxide for lithium ion secondary battery and its manufacture
JP2000323122A (en) * 1999-05-14 2000-11-24 Sumitomo Metal Mining Co Ltd Positive electrode active material for non-aqueous electrolyte secondary battery and manufacture thereof
JP2001035492A (en) * 1999-07-23 2001-02-09 Seimi Chem Co Ltd Positive electrode active material for lithium secondary battery
JP2002063901A (en) * 2000-08-14 2002-02-28 Mitsui Chemicals Inc Positive electrode active material for lithium secondary battery, its manufacturing method and battery using same
JP2002170562A (en) * 2000-11-30 2002-06-14 Nikko Materials Co Ltd Positive electrode material for lithium secondary battery and method for manufacturing the same
JP2005044743A (en) * 2003-07-25 2005-02-17 Nichia Chem Ind Ltd Positive electrode activator of nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery
JP2006127955A (en) * 2004-10-29 2006-05-18 Sumitomo Metal Mining Co Ltd Positive electrode active substance for nonaqueous secondary cell and its manufacturing method
JP2006147499A (en) * 2004-11-24 2006-06-08 Sumitomo Metal Mining Co Ltd Positive electrode active material for non-aqueous electrolyte secondary battery, its manufacturing method, and non-aqueous electrolyte secondary battery using this
JP2006286614A (en) * 2005-03-09 2006-10-19 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
JP2006310181A (en) * 2005-04-28 2006-11-09 Matsushita Electric Ind Co Ltd Nonaqueous electrolyte secondary battery
JP2007265784A (en) * 2006-03-28 2007-10-11 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and nonaqueous electrolyte secondary battery using it
JP2008117729A (en) * 2006-11-08 2008-05-22 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and non-aqueous type electrolyte secondary battery using it

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010044963A (en) * 2008-08-13 2010-02-25 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery, manufacturing method thereof, and nonaqueous electrolyte secondary battery
JP2012043716A (en) * 2010-08-20 2012-03-01 Sumitomo Metal Mining Co Ltd Positive electrode active material for nonaqueous electrolyte secondary battery and method for producing the same, and nonaqueous electrolyte secondary battery using the positive electrode active material
CN113659214A (en) * 2021-07-12 2021-11-16 深圳市比克动力电池有限公司 Design method of high specific energy lithium ion battery with electrochemical performance and safety performance

Also Published As

Publication number Publication date
JP5045135B2 (en) 2012-10-10

Similar Documents

Publication Publication Date Title
JP5076448B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
KR101612591B1 (en) Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing same, and nonaqueous electrolyte secondary battery
JP5614513B2 (en) Method for producing positive electrode active material for non-aqueous electrolyte secondary battery, positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery using the same
JP6167822B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP6201277B2 (en) Cathode active material for non-aqueous electrolyte secondary battery and method for producing the same
JP5114998B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP2019186220A (en) Method for manufacturing positive electrode active material for nonaqueous electrolyte secondary battery, positive electrode active material for nonaqueous electrolyte secondary battery and nonaqueous electrolyte secondary battery using the same
JP4984593B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP7131056B2 (en) Positive electrode active material for non-aqueous electrolyte secondary battery, non-aqueous electrolyte secondary battery
JP5103923B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP5776996B2 (en) Non-aqueous secondary battery positive electrode active material and non-aqueous electrolyte secondary battery using the positive electrode active material
JP2013229339A (en) Positive electrode active material for nonaqueous secondary battery and nonaqueous electrolyte secondary battery using positive electrode active material
JP4655599B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP5181482B2 (en) Method for producing positive electrode active material for non-aqueous electrolyte secondary battery
JP6201146B2 (en) Method for producing positive electrode active material for non-aqueous electrolyte secondary battery, positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery
JP5109447B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
WO2020027158A1 (en) Positive electrode active material for lithium ion secondary battery, method for producing positive electrode active material for lithium ion secondary battery, and lithium ion secondary battery
JP2006344567A (en) Positive electrode active material for nonaqueous electrolyte secondary battery, its manufacturing method, and nonaqueous electrolyte secondary battery using the positive electrode active material
JP2006147500A (en) Positive electrode active material for non-aqueous electrolyte secondary battery, its manufacturing method, and non-aqueous electrolyte secondary battery using this
JP2013012336A (en) Secondary battery and charging method of the same
JP4915227B2 (en) Positive electrode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the positive electrode active material
JP5045135B2 (en) Cathode active material for non-aqueous electrolyte secondary battery, method for producing the same, and non-aqueous electrolyte secondary battery using the same
JP2006228604A (en) Anode active substance for lithium ion secondary batterry, and its manufacturing method
JP5510528B2 (en) Positive electrode active material for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery using the same
US20220238874A1 (en) Positive-electrode active material precursor for lithium-ion secondary battery, positive-electrode active material for lithium-ion secondary battery, methods of manufacturing thereof, and lithium-ion secondary battery

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20090526

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20120229

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20120403

A521 Written amendment

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20120523

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20120619

A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20120702

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20150727

Year of fee payment: 3

R150 Certificate of patent or registration of utility model

Ref document number: 5045135

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R150

Free format text: JAPANESE INTERMEDIATE CODE: R150