TW201432980A - Non-aqueous electrolyte secondary battery - Google Patents

Non-aqueous electrolyte secondary battery Download PDF

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TW201432980A
TW201432980A TW102144046A TW102144046A TW201432980A TW 201432980 A TW201432980 A TW 201432980A TW 102144046 A TW102144046 A TW 102144046A TW 102144046 A TW102144046 A TW 102144046A TW 201432980 A TW201432980 A TW 201432980A
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composite oxide
lithium
positive electrode
secondary battery
mixture layer
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Katsuya Mitani
Satoshi Kono
Toshiharu Shimooka
Masayuki Yamada
Tomohito Sekiya
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Hitachi Maxell
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/364—Composites as mixtures
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/621—Binders
    • H01M4/622—Binders being polymers
    • H01M4/623—Binders being polymers fluorinated polymers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

To provide a non-aqueous electrolyte secondary battery, which uses materials including constituent elements of Si and O as cathode active substances in order to ensure a good charge-discharge cycle characteristic and inhibit inflation. A non-aqueous electrolyte secondary battery of the present invention is characterized by comprising an anode and a cathode; the anode is provided with an anode mixture layer containing anode active substances and binders at a single side or two sides of a current collector, in which the anode mixture layer uses a lithium-containing compound oxide having a certain amount of nickel of transition metal element as the anode active substances, and uses the copolymer of polyvinylidene fluoride-Trifluorochloroethylene as the binders; and the cathode has a cathode mixture layer containing cathode active substances at a single side or two sides of the current collector, in which the cathode mixture layer uses constituent elements of Si and O (in which the atomic ratio x of O over Si is 0.5≤x≤1.5) and a graphite carbon material as cathode active substances. Through the non-aqueous electrolyte secondary battery of the present invention, the abovementioned problem can be solved.

Description

非水電解質二次電池 Nonaqueous electrolyte secondary battery

本發明係關於一種具有良好之充放電循環特性、可抑制膨脹的非水電解質二次電池。 The present invention relates to a nonaqueous electrolyte secondary battery which has good charge and discharge cycle characteristics and can suppress expansion.

以鋰離子二次電池為首之非水電解質二次電池，由於高電壓、高容量，廣泛被採用為各種攜帶式機器之電源。又，近年來，亦增廣至電動工具等之Power tools、或電動車、電動腳踏車等之中型、大型尺寸的用途。 A nonaqueous electrolyte secondary battery including a lithium ion secondary battery is widely used as a power source for various portable machines due to high voltage and high capacity. In recent years, it has also expanded to include medium-sized and large-sized applications such as power tools such as electric tools and electric vehicles and electric bicycles.

特別是，使用於小型化及多機能化持續進展之行動電話或遊戲機等之電池，要求更進一步之高容量化，其之手段，係進行顯示高充放電容量之電極活性物質的研究、開發。其中，作為負極之活性物質材料，取代以往之鋰離子二次電池所採用之石墨等之碳質材料，而以矽(Si)、錫(Sn)等之能進行更多之鋰(離子)之吸附、放出的材料受到注目。特別是，具有Si之超微粒子分散於SiO2中之構造的SiOx，有報告指出其同時具有負載特性優異之特徵(專利文獻1、2等)。 In particular, batteries such as mobile phones and game consoles that have been used for miniaturization and multi-functionality are required to be further increased in capacity, and the means for research and development of electrode active materials exhibiting high charge and discharge capacities are required. . In addition, as the active material material of the negative electrode, in place of the carbonaceous material such as graphite used in the conventional lithium ion secondary battery, more lithium (ion) can be performed by using cerium (Si) or tin (Sn). The adsorbed and discharged materials are attracting attention. In particular, SiO x having a structure in which ultrafine particles of Si are dispersed in SiO 2 has been reported to have excellent characteristics of load characteristics (Patent Documents 1, 2, etc.).

然而，上述SiOx，由於伴隨充放電反應之體積收縮膨 脹大，故於每次之電池的充放電循環粒子粉碎，於表面析出之Si與非水電解液溶劑反應而使不可逆之容量增大，已知由於該反應於電池內產生氣體而產生電池罐膨脹等之問題。 However, since the above-mentioned SiO x has a large volume shrinkage expansion accompanying the charge and discharge reaction, the particles are pulverized every time the battery is charged and discharged, and the Si precipitated on the surface reacts with the nonaqueous electrolyte solvent to increase the irreversible capacity. It is known that the reaction generates a gas in the battery to cause problems such as expansion of the battery can.

由於該等情事，而提出：併用SiOx與石墨質碳材料以抑制伴隨充放電反應之負極(負極合劑層)之體積變化量的技術(專利文獻3等)；以及，限制SiOx之利用率以抑制伴隨充放電反應之體積膨脹收縮，並藉由使用添加鹵素取代之環狀碳酸酯(例如4-氟-1,3-二氧五環烷-2-酮等)等的非水電解液，以改善電池之充放電循環特性，而抑制伴隨氣體產生之電池罐膨脹的技術(專利文獻4)。 In view of such a situation, it is proposed to use SiO x and a graphite carbon material to suppress the volume change amount of the negative electrode (negative electrode mixture layer) accompanying the charge and discharge reaction (Patent Document 3, etc.); and, to limit the utilization ratio of SiO x . A nonaqueous electrolyte which suppresses volume expansion and contraction accompanying a charge and discharge reaction, and uses a cyclic carbonate (for example, 4-fluoro-1,3-dioxopentan-2-one) substituted with a halogen. In order to improve the charge and discharge cycle characteristics of the battery, the technique of suppressing the expansion of the battery can with gas generation (Patent Document 4).

〔先前技術文獻〕 [Previous Technical Literature] 〔專利文獻〕 [Patent Document]

專利文獻1：日本特開2004-047404號公報 Patent Document 1: Japanese Patent Laid-Open Publication No. 2004-047404

專利文獻2：日本特開2005-259697號公報 Patent Document 2: Japanese Laid-Open Patent Publication No. 2005-259697

專利文獻3：日本特開2011-233369號公報 Patent Document 3: Japanese Laid-Open Patent Publication No. 2011-233369

專利文獻4：日本特開2008-210618號公報 Patent Document 4: Japanese Laid-Open Patent Publication No. 2008-210618

藉由專利文獻3或專利文獻4之技術，可良好地達成於負極使用SiOx之非水電解質二次電池中之充放電循環特性的提升及膨脹的抑制。然而，另一方面，對非水電解質二次電池所要求之充放電循環特性或膨脹抑制的等級， 預測於今後會日益升高，故於專利文獻3或專利文獻4之技術，亦仍有改善的空間。 According to the technique of Patent Document 3 or Patent Document 4, the improvement of the charge-discharge cycle characteristics and the suppression of expansion in the non-aqueous electrolyte secondary battery using SiO x for the negative electrode can be satisfactorily achieved. On the other hand, the level of charge/discharge cycle characteristics or expansion suppression required for the nonaqueous electrolyte secondary battery is expected to increase in the future, so that the technique of Patent Document 3 or Patent Document 4 is still improved. Space.

本發明，係有鑑於上述情事所完成者，其之目的在於提供一種非水電解質二次電池，其係於負極活性物質使用於構成元素含有Si與O的材料，而可確保良好的充放電循環特性、並且可抑制膨脹。 The present invention has been made in view of the above circumstances, and an object thereof is to provide a nonaqueous electrolyte secondary battery which is used in a material in which a negative electrode active material is contained in a constituent element containing Si and O, thereby ensuring a good charge and discharge cycle. Characteristics, and can inhibit expansion.

可達成上述目的之本發明之非水電解質二次電池，係具有正極、負極、非水解電解質及間隔物者，其特徵係，前述正極，係於集電器之單面或雙面具有含正極活性物質及黏結劑之正極合劑層者，前述正極合劑層，含有含作為過渡金屬元素之鎳之含有鋰的複合氧化物作為正極活性物質，並且含有二氟亞乙烯-氯三氟乙烯共聚物作為黏結劑，前述含作為過渡金屬元素之鎳之含有鋰的複合氧化物，當總過渡金屬元素之量為100(mol%)時，鎳之比例a(mol%)，為30≦a≦100，前述負極，係於集電器之單面或雙面具有含負極活性物質之負極合劑層者，前述負極合劑層，含有於構成元素含有Si與O之材料(其中，相對於Si之O的原子比x為0.5≦x≦1.5，以下將該材料記載為「SiOx」)，與石墨質碳材料作為負極活性物質。 A nonaqueous electrolyte secondary battery of the present invention which achieves the above object, comprising a positive electrode, a negative electrode, a non-hydrolyzed electrolyte, and a separator, wherein the positive electrode has a positive electrode activity on one or both sides of the current collector. In the positive electrode mixture layer of the substance and the binder, the positive electrode mixture layer contains a lithium-containing composite oxide containing nickel as a transition metal element as a positive electrode active material, and contains a difluoroethylene-chlorotrifluoroethylene copolymer as a binder. The lithium-containing composite oxide containing nickel as a transition metal element, when the amount of the total transition metal element is 100 (mol%), the ratio of nickel a (mol%) is 30 ≦ a ≦ 100, the aforementioned The negative electrode is a negative electrode mixture layer containing a negative electrode active material on one or both sides of the current collector, and the negative electrode mixture layer is contained in a material containing Si and O as a constituent element (wherein an atomic ratio with respect to O of X) It is 0.5 ≦ x ≦ 1.5, and this material is described below as "SiO x "), and a graphite carbon material is used as a negative electrode active material.

藉由本發明可提供一種非水電解質二次電池，其係於 負極活性物質使用於構成元素含有Si與O的材料，而可確保良好的充放電循環特性、並且可抑制膨脹。 A nonaqueous electrolyte secondary battery can be provided by the present invention, which is tied to The negative electrode active material is used for a material containing Si and O as constituent elements, and can ensure good charge and discharge cycle characteristics and can suppress expansion.

1‧‧‧正極 1‧‧‧ positive

2‧‧‧負極 2‧‧‧negative

3‧‧‧間隔物 3‧‧‧ spacers

4‧‧‧電池外盒 4‧‧‧Battery case

5‧‧‧絕緣體 5‧‧‧Insulator

6‧‧‧扁平狀捲繞電極體 6‧‧‧Flat wound electrode body

7‧‧‧正極導線體 7‧‧‧ positive lead body

8‧‧‧負極導線體 8‧‧‧Negative lead body

9‧‧‧蓋板 9‧‧‧ Cover

10‧‧‧絕緣襯墊 10‧‧‧Insulation liner

11‧‧‧端子 11‧‧‧ Terminal

12‧‧‧絕緣體 12‧‧‧Insulator

13‧‧‧導線板 13‧‧‧Wire plate

14‧‧‧非水電解液注入口 14‧‧‧ Non-aqueous electrolyte injection port

15‧‧‧開裂通氣孔 15‧‧‧ cracking vents

圖1，係表示本發明之非水電解質二次電池之一例的模式圖，(a)為俯視圖，(b)為局部縱截面圖。 Fig. 1 is a schematic view showing an example of a nonaqueous electrolyte secondary battery of the present invention, wherein (a) is a plan view and (b) is a partial longitudinal sectional view.

圖2，係圖1之立體圖。 Figure 2 is a perspective view of Figure 1.

非水電解質二次電池，例如，由高容量化的觀點考量，有於負極活性物質使用SiOx，而如此之電池，伴隨充放電之SiOx的膨脹收縮量大，故負極容易劣化、充放電循環特性容易降低。 In the non-aqueous electrolyte secondary battery, for example, SiO x is used as the negative electrode active material, and such a battery has a large expansion-contraction amount of SiO x accompanying charge and discharge, so that the negative electrode is easily deteriorated, charged and discharged. The cycle characteristics are easily reduced.

本發明之非水電解質二次電池，首先，作為負極活性物質，併用SiOx、與容量雖較SiOx差，但伴隨充放電之膨脹收縮量較SiOx小的石墨質碳材料，藉此，可盡可能地抑制由於減低負極活性物質整體所佔之SiOx之比例所造成的容量降低，並且減小但伴隨充放電之負極合劑層的體積變化量，而能抑制由於高容量化與反覆充放電所致之負極的劣化。 A non-aqueous electrolyte secondary battery of the present invention, first, as a negative electrode active material, and with SiO x, SiO x with more capacity, although poor, but the amount of expansion and contraction accompanying charge and discharge of SiO x smaller than graphite carbon material, whereby, The capacity reduction due to the reduction of the ratio of SiO x occupied by the entire negative electrode active material can be suppressed as much as possible, and the volume change amount of the negative electrode mixture layer accompanying charge and discharge can be reduced, and the increase in capacity and the reverse charge can be suppressed. Deterioration of the negative electrode due to discharge.

然而，非水電解質二次電池之充放電循環特性的降低，亦有負極劣化以外的原因。例如，當伴隨電池之充放電之負極合劑層的體積變化大時，該負極、與和其相對向之正極(其之正極合劑層)的間隔，由該等正負極之對向 面整體觀看時，有不均一之虞，特別是於負極與正極之間隔較其他部分大的部位，於充放電時無法產生反應，故其會損及電池之充放電循環特性、並成為電池膨脹的產生要因。 However, the decrease in the charge-discharge cycle characteristics of the non-aqueous electrolyte secondary battery has a cause other than the deterioration of the negative electrode. For example, when the volume change of the negative electrode mixture layer accompanying charge and discharge of the battery is large, the interval between the negative electrode and the positive electrode (the positive electrode mixture layer thereof) opposed thereto is opposed by the positive and negative electrodes. When the whole surface is viewed, there is a non-uniformity, especially in a portion where the distance between the negative electrode and the positive electrode is larger than that of other portions, and the reaction does not occur during charging and discharging, so that it may damage the charge-discharge cycle characteristics of the battery and become a battery expansion. The cause of the occurrence.

因此，本發明人等，為了發現含有SiOx與石墨質碳材料作為負極活性物質之負極合劑層、與伴隨電池充放電之膨脹收縮之平衡良好之正極與負極之間隔於該等之對向面整體可保持均一性高之狀態之正極合劑層的構成，而努力研究。並且發現，若為含有過渡金屬元素之含特定量鎳之含有鋰的複合氧化物作為正極活性物質、含有二氟亞乙烯-氯三氟乙烯共聚物(VDF-CTFE)作為黏結劑的正極合劑層，可得即使反覆進行電池的充放電，亦可使正極與負極之間隔於該等之對向面整體保持均一性高的狀態，而完成本發明。 Therefore, the present inventors have found that the positive electrode mixture layer containing SiO x and the graphite carbon material as the negative electrode active material and the positive electrode and the negative electrode having a good balance of expansion and contraction accompanying charge and discharge of the battery are spaced apart from each other. Efforts have been made to study the composition of the positive electrode mixture layer in a state in which the uniformity is high as a whole. Further, it has been found that a composite oxide containing a specific amount of nickel containing a transition metal element as a positive electrode active material and a positive electrode mixture layer containing a difluoroethylene-chlorotrifluoroethylene copolymer (VDF-CTFE) as a binder is used. Further, even if the charge and discharge of the battery are repeatedly performed, the present invention can be completed by keeping the positive electrode and the negative electrode at a high uniformity in the entire opposing surfaces.

本發明之非水電解質二次電池之負極，係於集電器之單面或雙面具有含負極活性物質之負極合劑層的構造者。 The negative electrode of the nonaqueous electrolyte secondary battery of the present invention is a structure having a negative electrode mixture layer containing a negative electrode active material on one or both sides of a current collector.

於負極活性物質，併用SiOx與石墨質碳材料。藉此，可謀求非水電解質二次電池的高容量化，並且藉由與特性之正極的組合，可確保優異之充放電循環特性。 For the negative electrode active material, SiO x and a graphite carbon material are used in combination. As a result, the capacity of the nonaqueous electrolyte secondary battery can be increased, and the combination of the positive electrode and the positive electrode can ensure excellent charge and discharge cycle characteristics.

SiOx，亦可包含Si之細晶或非晶質相，於該場合，Si與O之原子比，係包含Si之細晶或非晶質相之Si的比率。亦即，於SiOx，亦包含於非晶質之SiO2基質中之Si(例如，細晶Si)為分散之結構者，該非晶質之SiO2、與分散於其中之Si合併使前述之原子比x滿足0.5≦x≦ 1.5即可。例如，於非晶質之SiO2基質中Si為分散之結構，當為SiO2與Si之莫耳比為1：1之材料時，由於x=1，故以結構式SiO標記。當為如此之結構的材料時，例如，於X射線繞射分析，雖亦會未觀察到起因於Si(細晶Si)之存在的波峰，但若以透過型電子顯微鏡觀察，則可確認微細之Si的存在。 SiO x may also contain a fine crystal or amorphous phase of Si. In this case, the atomic ratio of Si to O is a ratio of Si of fine crystals of Si or amorphous phase. That is, in the case where SiO x is also contained in the amorphous SiO 2 matrix, Si (for example, fine-grained Si) is a dispersed structure, and the amorphous SiO 2 is combined with Si dispersed therein to make the foregoing The atomic ratio x satisfies 0.5≦x≦ 1.5. For example, in the amorphous SiO 2 matrix, Si is a dispersed structure, and when it is a material having a molar ratio of SiO 2 to Si of 1:1, since x=1, it is labeled with the structural formula SiO. In the case of a material having such a structure, for example, in the X-ray diffraction analysis, a peak due to the presence of Si (fine crystal Si) is not observed, but if observed by a transmission electron microscope, fineness can be confirmed. The existence of Si.

而SiOx，較佳為與碳材料複合化之複合體，例如，較佳為，以碳材料被覆SiOx之表面。由於SiOx之導電性差，故當將其作為負極活性物質使用時，由確保良好之電池特性的觀點，必須使用導電性材料(導電助劑)，使負極內之SiOx與導電性材料良好地混合、分散，以形成優異之導電網。只要將SiOx與碳材料複合化作成複合體，例如，較使用單純地混合SiOx與碳材料等導電性材料所得之材料，可於負極中更良好地形成導電網。 Further, SiO x is preferably a composite compounded with a carbon material, and for example, it is preferable to coat the surface of SiO x with a carbon material. Since SiO x has poor conductivity, when it is used as a negative electrode active material, it is necessary to use a conductive material (conductive auxiliary agent) to ensure good SiO x and conductive material in the negative electrode from the viewpoint of ensuring good battery characteristics. Mix and disperse to form an excellent conductive mesh. When SiO x is combined with a carbon material to form a composite, for example, a conductive mesh can be formed more satisfactorily in the negative electrode than a material obtained by simply mixing a conductive material such as SiO x or a carbon material.

SiOx與碳材料之複合體，如前述，除了以碳材料被覆SiOx表面之外，可舉例如SiOx與碳材料之造粒體。 SiO x and carbon composite materials, as described above, in addition to SiO x surface-coated carbon material includes, for example granules with a carbon material of SiO x.

又，藉由將前述之以碳材料被覆SiOx表面之複合體，再與導電性材料(碳材料等)複合化來使用，可於負極中形成更良好的導電網，故可實現更高容量、電池特性(例如，充放電循環特性)更優異之非水電解質二次電池。以碳材料被覆之SiOx與碳材料之複合體，可舉例如，將以碳材料被覆之SiOx與碳材料之混合物，進一步造粒之造粒體等。 Further, by coating the composite of the SiO x surface with a carbon material as described above and then using it in combination with a conductive material (carbon material or the like), a more favorable conductive mesh can be formed in the negative electrode, so that a higher capacity can be realized. A nonaqueous electrolyte secondary battery having more excellent battery characteristics (for example, charge and discharge cycle characteristics). The composite of the SiO x and the carbon material coated with the carbon material may, for example, be a granulated body obtained by further granulating a mixture of SiO x and a carbon material coated with a carbon material.

又，表面以碳材料被覆之SiOx，較佳亦可使用SiOx 與比電阻值較SiOx小之碳材料的複合體(例如造粒體)之表面，再以碳材料被覆所成者。前述造粒體內部，若SiOx與碳材料為分散的狀態，則可形成更良好之導電網，故於具有含SiOx作為負極活性物質之負極的非水電解質二次電池，可更提升重負載放電特性等之電池特性。 Further, it is preferable to use SiO x whose surface is coated with a carbon material, and it is preferable to use a surface of a composite of SiO x and a carbon material having a specific resistance smaller than SiO x (for example, granules), and then coated with a carbon material. In the granules, if the SiO x and the carbon material are in a dispersed state, a more favorable conductive mesh can be formed, so that the nonaqueous electrolyte secondary battery having the negative electrode containing SiO x as the negative electrode active material can further increase the weight. Battery characteristics such as load discharge characteristics.

可於與SiOx之複合體之形成使用之前述碳材料，較佳者可舉例如，低結晶性碳、碳奈米管、氣相成長碳纖維等之碳材料。 The carbon material which can be used for the formation of a composite with SiO x is preferably a carbon material such as low crystalline carbon, carbon nanotube or vapor grown carbon fiber.

前述碳材料之詳細，較佳為，選自纖維狀或線圈狀之碳材料、碳黑(含乙炔黑、科琴黑)、人造石墨、易石墨化碳及難石墨化碳所成群中之至少1種材料。纖維狀或線圈狀之碳材料，於容易形成導電網、且表面積大等方面較佳。碳黑(含乙炔黑、科琴黑)、易石墨化碳及難石墨化碳，具有高導電性、高液體保持性，並且具有即使SiOx粒子膨脹收縮、亦容易保持與該粒子之接觸的性質，於上述方面較佳。 The carbon material is preferably selected from the group consisting of a fibrous or coiled carbon material, carbon black (containing acetylene black, Ketjen black), artificial graphite, easily graphitizable carbon, and non-graphitizable carbon. At least 1 material. The fibrous or coil-shaped carbon material is preferable in that it is easy to form a conductive mesh and has a large surface area. Carbon black (including acetylene black, Ketjen black), easily graphitizable carbon and non-graphitizable carbon, has high conductivity, high liquid retention, and has easy to maintain contact with the particles even if the SiO x particles expand and contract. Properties are preferred in the above aspects.

於負極活性物質，可與SiOx一同併用之石墨質碳材料作為負極活性物質，亦可將該石墨質碳材料作為SiOx與碳材料之複合體的碳材料來使用。石墨質碳材料，以與碳黑等同樣地，具有高導電性、高液體保持性，並且具有即使SiOx粒子膨脹收縮、亦容易保持與該粒子之接觸的性質，故較佳可使用於與SiOx之複合體形成。 As the negative electrode active material, a graphite carbon material which can be used together with SiO x is used as the negative electrode active material, and the graphite carbon material can also be used as a carbon material of a composite of SiO x and a carbon material. The graphite carbon material has high conductivity and high liquid retention as in the case of carbon black or the like, and has a property of easily maintaining contact with the particles even if the SiO x particles expand and contract, so that it can be preferably used in combination with A composite of SiO x is formed.

前述例示之碳材料之中，當使用於與SiOx之複合體為造粒體的情況下時，以纖維狀之碳材料為特佳。其係因 纖維狀之碳材料，由於其之形狀為細絲狀、柔軟性高，故容易追隨伴隨電池之充放電所致之SiOx之膨脹收縮，又，由於體密度大，故與SiOx粒子具有很多的接合點之故。纖維狀之碳，可舉例如聚丙烯腈(PAN)系碳纖維、瀝青系碳纖維、氣相成長碳纖維、碳奈米管等，可使用該等之任一者。 Among the carbon materials exemplified above, when the composite with SiO x is used as a granule, a fibrous carbon material is particularly preferable. Since the fibrous carbon material has a filament shape and high flexibility, it is easy to follow the expansion and contraction of SiO x caused by charge and discharge of the battery, and since the bulk density is large, it is combined with SiO x . Particles have many joints. Examples of the fibrous carbon include polyacrylonitrile (PAN)-based carbon fibers, pitch-based carbon fibers, vapor-grown carbon fibers, and carbon nanotubes, and any of these may be used.

又，纖維狀之碳材料，例如，亦可以氣相法形成於SiOx粒子之表面。 Further, the fibrous carbon material may be formed on the surface of the SiO x particles by, for example, a vapor phase method.

SiOx之比電阻值，通常為103~107kΩcm，相對於此，前述例示之碳材料之比電阻值，通常為10-5~10kΩcm。 The specific resistance value of SiO x is usually 10 3 to 10 7 kΩcm. On the other hand, the specific resistance of the carbon material exemplified above is usually 10 -5 to 10 kΩcm.

又，SiOx與碳材料之複合體，亦可進一步具有被覆粒子表面之碳材料被覆層的材料層(含難石墨化碳之材料層)。 Further, the composite of SiO x and the carbon material may further have a material layer (a material layer containing a non-graphitizable carbon) covering the carbon material coating layer on the surface of the particles.

當於負極使用SiOx與碳材料之複合體時，SiOx與碳材料之比率，由可良好發揮因與碳材料複合化所致之作用的觀點考量，相對於SiOx：100質量份，碳材料以5質量份以上為佳、10質量份以上為更佳。又，於前述複合體，若與SiOx複合化之碳材料的比率過多，則會使負極合劑層中之SiOx量降低，而有高容量化之效果減小之虞，故相對於SiOx：100質量份，碳材料以50質量份以下為佳、40質量份以下為更佳。 When a composite of SiO x and a carbon material is used for the negative electrode, the ratio of SiO x to the carbon material is considered to be good from the viewpoint of the effect of compounding with the carbon material, and carbon is relative to SiO x : 100 parts by mass. The material is preferably 5 parts by mass or more, more preferably 10 parts by mass or more. Further, when the ratio of the carbon material to be composited with SiO x is too large, the amount of SiO x in the negative electrode mixture layer is lowered, and the effect of increasing the capacity is reduced, so that it is relative to SiO x . : 100 parts by mass, and the carbon material is preferably 50 parts by mass or less, more preferably 40 parts by mass or less.

上述SiOx與碳材料之複合體，例如可藉下述之方法製得。 The composite of the above SiO x and carbon material can be obtained, for example, by the following method.

首先，說明將SiOx複合化之情形之製作方法。準備 將SiOx分散於分散介質之分散液，將其噴霧乾燥，製作成含有複數之粒子的複合粒子。分散介質，例如可使用乙醇等。分散液之噴霧，通常以於50~300℃之環境氣氛內進行為宜。除了前述之方法以外，藉由振動型或行星式之球磨機或棒磨機等之機械式方法的造粒方法，亦可製作同樣的複合粒子。 First, a method of producing a case where SiO x is composited will be described. A dispersion in which SiO x is dispersed in a dispersion medium is prepared and spray-dried to prepare composite particles containing a plurality of particles. As the dispersion medium, for example, ethanol or the like can be used. The spray of the dispersion is usually carried out in an atmosphere of 50 to 300 ° C. In addition to the above methods, the same composite particles can be produced by a granulation method by a mechanical method such as a vibrating type or a planetary ball mill or a rod mill.

又，當製作SiOx、與比電阻值較SiOx小之碳材料的造粒體時，可於SiOx分散於分散介質之分散液中添加前述碳材料，使用該分散液，藉由與將SiOx複合化之情形同樣的手法作成複合粒子(造粒體)。又，藉由與前述同樣之藉由機械式方法的造粒方法，亦可製作SiOx與碳材料之造粒體。 Further, when the granules produced SiO x, and SiO x representing a resistance value smaller than the carbon material, SiO x may be in a dispersion medium in a dispersion of the carbon material is added, with this dispersion liquid, and by the In the case of SiO x compositing, composite particles (granules) are produced in the same manner. Further, granules of SiO x and carbon material can be produced by the granulation method by a mechanical method similar to the above.

接著，當將SiOx粒子(SiOx複合粒子、或SiOx與碳材料之造粒體)之表面以碳材料被覆作成複合體時，例如，將SiOx粒子與烴系氣體於氣相中加熱，而使因烴系氣體之熱分解所生成之碳，堆積於粒子的表面上。如此，藉由氣相成長(CVD)法，使烴系氣體遍布複合粒子之各角落，而可於粒子之表面或表面之空孔內，形成含有導電性之碳材料之薄且均勻的皮膜(碳材料被覆層)，故藉由少量之碳材料可對SiOx粒子賦予均一性佳之導電性。 Next, when the surface of the SiO x particles (SiO x composite particles or SiO x and the granules of the carbon material) is coated with a carbon material to form a composite, for example, the SiO x particles and the hydrocarbon-based gas are heated in the gas phase. On the other hand, carbon generated by thermal decomposition of the hydrocarbon-based gas is deposited on the surface of the particles. Thus, by the vapor phase growth (CVD) method, the hydrocarbon-based gas is spread over the corners of the composite particles, and a thin and uniform film containing the conductive carbon material can be formed on the surface of the particles or in the pores of the surface ( Since the carbon material is coated, a uniform amount of conductivity can be imparted to the SiO x particles by a small amount of the carbon material.

以碳材料被覆之SiOx之製造中，關於氣相成長(CVD)法之處理溫度(環境氣氛溫度)，雖亦隨烴系氣體之種類而異，通常以600~1200℃為宜，其中，以700℃以上為佳、800℃以上為更佳。其係因處理溫度愈高雜質之殘存 愈少、且可形成導電性高之含碳之被覆層之故。 In the production of SiO x coated with a carbon material, the treatment temperature (ambient atmosphere temperature) of the vapor phase growth (CVD) method varies depending on the type of the hydrocarbon gas, and is usually 600 to 1200 ° C. It is preferably 700 ° C or more, more preferably 800 ° C or more. This is because the higher the treatment temperature, the less the residual of impurities, and the formation of a carbon-containing coating layer having high conductivity.

烴系氣體之液體源，可使用甲苯、苯、二甲苯、均三甲苯等，以操作容易之甲苯為特佳。藉由使該等氣化(例如，以氮氣起泡)可得烴系氣體。又，亦可使用甲烷氣體或乙炔氣體等。 As the liquid source of the hydrocarbon-based gas, toluene, benzene, xylene, mesitylene or the like can be used, and toluene which is easy to handle is particularly preferable. The hydrocarbon-based gas can be obtained by vaporizing the gas (for example, by bubbling with nitrogen). Further, methane gas, acetylene gas or the like can also be used.

又，亦可藉氣相成長(CVD)法將SiOx粒子(SiOx複合粒子、或SiOx與碳材料之造粒體)之表面以碳材料被覆之後，將選自石油系瀝青、石炭系瀝青、熱硬化性樹脂、及萘磺酸鹽與醛類之縮合物所構成群中之至少1種有機化合物，附著於含碳材料之被覆層後，將附著有前述有機化合物之粒子進行燒成。 Further, the surface of the SiO x particles (SiO x composite particles or SiO x and granules of the carbon material) may be coated with a carbon material by a vapor phase growth (CVD) method, and then selected from petroleum pitch and carboniferous. At least one organic compound of the group consisting of a pitch, a thermosetting resin, and a condensate of a naphthalenesulfonate and an aldehyde adheres to a coating layer of a carbonaceous material, and then fires particles in which the organic compound adheres .

具體而言，係準備將以碳材料被覆之SiOx粒子(SiOx複合粒子、或SiOx與碳材料之造粒體)、與前述有機化合物分散於分散介質之分散液，將該分散液噴霧乾燥，而形成以有機化合物被覆之粒子，將以該有機化合物被覆之粒子進行燒成。 Specifically, it is prepared to spray a dispersion of SiO x particles (SiO x composite particles or granules of SiO x and carbon material) coated with a carbon material and the organic compound dispersed in a dispersion medium. After drying, particles coated with an organic compound are formed, and particles coated with the organic compound are fired.

前述瀝青可使用等向性瀝青，熱硬化性樹脂可使用苯酚樹脂、呋喃樹脂、糠醛樹脂等。萘磺酸鹽與醛類之縮合物，可使用萘磺酸甲醛縮合物。 An isotropic pitch can be used for the above-mentioned pitch, and a phenol resin, a furan resin, a furfural resin, or the like can be used as the thermosetting resin. As the condensate of the naphthalenesulfonate and the aldehyde, a naphthalenesulfonic acid formaldehyde condensate can be used.

作為以碳材料被覆之SiOx粒子與前述有機化合物分散的分散介質，例如可使用水、醇類(乙醇等)。分散液之噴霧，通常以於50~300℃之環境氣氛內進行為宜。燒成溫度，通常以600~1200℃為宜，其中以700℃以上為佳、800℃以上為更佳。處理溫度愈高，可形成雜質之殘 存愈少、且導電性高之良質之含碳的被覆層。然而，處理溫度必須為SiOx之熔點以下。 As the dispersion medium in which the SiO x particles coated with the carbon material and the organic compound are dispersed, for example, water or an alcohol (ethanol or the like) can be used. The spray of the dispersion is usually carried out in an atmosphere of 50 to 300 ° C. The firing temperature is usually 600 to 1200 ° C, preferably 700 ° C or higher, and more preferably 800 ° C or higher. The higher the processing temperature, the better the carbon-containing coating layer having less residual impurities and high conductivity. However, the treatment temperature must be below the melting point of SiO x .

與前述之SiOx共同作為負極活性物質來使用之石墨質碳材料，可舉例如磷片狀石墨等之天然石墨；將熱分解碳類、介相碳微粒(MCMB)、碳纖維等之易石墨化碳，以2800℃以上進行石墨化處理之人造石墨等。 The graphite carbon material used as the negative electrode active material together with the above-mentioned SiO x may, for example, be natural graphite such as phosphorus flake graphite; and may be easily graphitized by thermal decomposition of carbon, mesocarbon fine particles (MCMB), carbon fiber or the like. Carbon, artificial graphite or the like which is graphitized at 2800 ° C or higher.

負極活性物質總量中之SiOx的比例，由藉由使用SiOx以良好地確保高容量化效果的觀點考量，以0.01質量%以上為佳、1質量%以上為較佳、3質量%以上為更佳。又，由可良好地避免伴隨充放電之SiOx體積變化所造成之問題的觀點，負極活性物質總量中之SiOx的比例，以20質量%以下為佳、15質量%以下為更佳。 The ratio of SiO x in the total amount of the negative electrode active material is preferably 0.01% by mass or more, more preferably 1% by mass or more, and 3% by mass or more, from the viewpoint of ensuring a high capacity-enhancing effect by using SiO x . For better. In addition, the ratio of SiO x in the total amount of the negative electrode active material is preferably 20% by mass or less and preferably 15% by mass or less, from the viewpoint of the problem of the SiO x volume change accompanying charge and discharge.

於負極合劑層，通常含有黏結劑。負極合劑層之黏結劑，例如，較佳可使用PVDF、聚四氟乙烯(PTFE)、苯乙烯丁二烯橡膠(SBR)、羧基甲基纖維素(CMC)等。 The negative electrode mixture layer usually contains a binder. As the binder of the negative electrode mixture layer, for example, PVDF, polytetrafluoroethylene (PTFE), styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), or the like can be preferably used.

又，於負極合劑層，亦可視需要含有乙炔黑等之各種碳黑或碳奈米管等之導電助劑。 Further, in the negative electrode mixture layer, a conductive auxiliary agent such as various carbon black or carbon nanotubes such as acetylene black may be used as needed.

負極，例如，可將負極活性物質及黏結劑、以及視需要之導電助劑，分散於N-甲基-2-吡咯酮(NMP)或水等溶劑調製成含有負極合劑之組成物(惟，其中，亦可將黏結劑溶解於溶劑)，將其塗布於集電器之單面或兩面，於乾燥之後，視需要經由施以壓光機處理等之加壓處理的步驟來製造。又，負極，並不限於以前述之方法所製造者，亦可為以其他製造方法製造者。 The negative electrode, for example, a negative electrode active material, a binder, and optionally a conductive auxiliary agent, may be dispersed in a solvent such as N-methyl-2-pyrrolidone (NMP) or water to prepare a composition containing a negative electrode mixture. Here, the binder may be dissolved in a solvent, and applied to one surface or both surfaces of the current collector, and after drying, it may be produced by a pressure treatment step such as a calender treatment as needed. Further, the negative electrode is not limited to those manufactured by the above-described method, and may be manufactured by another manufacturing method.

負極合劑層之厚度，每集電器之單面，每集電器之單面以10~100μm為佳。又，負極合劑層之組成，例如，負極活性物質之量以80~95質量%為佳、黏結劑之量以1~20質量%為佳，當使用導電助劑時，其之量以1~10質量%為佳。 The thickness of the negative electrode mixture layer is preferably 10 to 100 μm on one side of each current collector on one side of each current collector. Further, the composition of the negative electrode mixture layer, for example, the amount of the negative electrode active material is preferably 80 to 95% by mass, and the amount of the binder is preferably 1 to 20% by mass, and when the conductive auxiliary agent is used, the amount is 1~. 10% by mass is preferred.

負極之集電器，可使用銅製或鎳製之箔、衝孔金屬、網、多孔金屬等，通常係使用銅箔。該負極集電器，當為了得到高能量密度之電池而使負極整體厚度變薄時，厚度之上限以30μm為佳、下限以5μm為佳。 As the current collector of the negative electrode, a foil made of copper or nickel, a punched metal, a mesh, a porous metal or the like can be used, and a copper foil is usually used. In the negative electrode current collector, when the thickness of the entire negative electrode is made thin in order to obtain a battery having a high energy density, the upper limit of the thickness is preferably 30 μm, and the lower limit is preferably 5 μm.

本發明之非水電解質二次電池之正極，係於集電器之單面或兩面具有含正極活性物質及黏結劑之正極合劑層的構造。 The positive electrode of the nonaqueous electrolyte secondary battery of the present invention has a structure in which a positive electrode mixture layer containing a positive electrode active material and a binder is provided on one surface or both surfaces of the current collector.

於正極活性物質，當總過渡金屬元素之量為100(mol%)時，過渡金屬元素之含鎳(Ni)之含有鋰的複合氧化物，係使用鎳之比例a(mol%)為30≦a≦100者。前述之正極活性物質，例如，較作為非水電解質二次電池之正極活性物質所汎用之LiCoO2相比容量大，而可謀求非水電解質二次電池之高容量化。又，前述含過渡金屬元素之Ni之含有鋰的複合氧化物，較LiCoO2，可構成含有SiOx及石墨質碳材料之負極合劑層、與伴隨電池之充放電之膨脹收縮之平衡良好的正極合劑層。 In the positive electrode active material, when the amount of the total transition metal element is 100 (mol%), the lithium-containing composite oxide containing nickel (Ni) of the transition metal element is a ratio of nickel (a) of 30 Å. a≦100. The positive electrode active material has a larger capacity than LiCoO 2 which is widely used as a positive electrode active material of a nonaqueous electrolyte secondary battery, and can increase the capacity of the nonaqueous electrolyte secondary battery. Further, the composite oxide containing lithium of the transition metal element-containing Ni may constitute a positive electrode mixture layer containing SiO x and a graphite carbon material and a positive electrode having a good balance of expansion and contraction accompanying charge and discharge of the battery than LiCoO 2 . Mixture layer.

作為前述含過渡金屬元素，含Ni之含有鋰的複合氧化物，當使總過渡金屬元素之量為100(mol%)時，Ni之比例a(mol%)為30≦a≦100，可不含Ni以外之過渡金屬元 素、亦可含有。惟，其中，由於可更提升正極合劑層之充填密度，亦可提高含有鋰的複合氧化物之熱安定性，故作為前述過渡金屬元素，含Ni之含有鋰的複合氧化物，較佳為，作為過渡金屬元素除Ni以外含有鈷(Co)及錳(Mn)之鋰鎳鈷錳複合氧化物。 When the amount of the total transition metal element is 100 (mol%), the Ni-containing lithium-containing composite oxide containing the transition metal element has a ratio a (mol%) of 30 ≦a ≦ 100, which may be excluded. Transition metal elements other than Ni It can also be contained. However, it is preferable that the lithium-containing composite oxide containing Ni is preferable as the transition metal element because the charge density of the positive electrode mixture layer can be further increased and the thermal stability of the lithium-containing composite oxide can be improved. A lithium nickel cobalt manganese composite oxide containing cobalt (Co) and manganese (Mn) in addition to Ni as a transition metal element.

鋰鎳鈷錳複合氧化物，較佳為，下述一般組成式(1)所表示者。 The lithium nickel cobalt manganese composite oxide is preferably represented by the following general composition formula (1).

Li1+sM1O2 (1) Li 1+s M 1 O 2 (1)

[前述一般組成式(1)中，-0.3≦s≦0.3，M1係至少含有Ni、Co及Mn之3種以上之元素群，構成M1之各元素中，當Ni、Co及Mn之比例(mol%)分別為a、b及c時，30<a<65、5<b<35、15<c<50]。 [In the above general composition formula (1), -0.3≦s≦0.3, M 1 contains at least three or more element groups of Ni, Co and Mn, and among the elements constituting M 1 , when Ni, Co and Mn are When the ratio (mol%) is a, b, and c, respectively, 30 < a < 65, 5 < b < 35, and 15 < c < 50].

於前述一般組成式(1)所表示之鋰鎳鈷錳複合氧化物中，Ni係有助於鋰鎳鈷錳複合氧化物之容量提升的成分，當元素群M1之總元素數為100mol%時，Ni之比例a，係以超過30mol%為佳、50mol%以上為更佳。又，前述一般組成式(1)所表示之鋰鎳鈷錳複合氧化物中，由確保因含有Ni以外之元素所致之效果為良好的觀點考量，當元素群M1之總元素數為100mol%時，Ni之比例a，以未滿65mol%為佳、60mol%以下為更佳。 In the lithium nickel cobalt manganese composite oxide represented by the above general composition formula (1), Ni is a component which contributes to the capacity increase of the lithium nickel cobalt manganese composite oxide, and the total element number of the element group M 1 is 100 mol%. When the ratio a of Ni is more than 30 mol%, more preferably 50 mol% or more. Further, in the lithium nickel cobalt manganese composite oxide represented by the above general composition formula (1), the effect of ensuring the effect of the element other than Ni is good, and the total element number of the element group M 1 is 100 mol. In the case of %, the ratio a of Ni is preferably less than 65 mol%, more preferably 60 mol% or less.

於前述一般組成式(1)所表示之鋰鎳鈷錳複合氧化物中，Co亦與Ni同樣的為有助於鋰鎳鈷錳複合氧化物之容量提升的成分，亦有提升正極合劑層中之充填密度的作用，另一方面，若過多則有導致成本增大或安全性降低之 虞。除了該等理由之外，由可良好地確保後述之Mn之平均價數之安定化作用的觀點，當表示鋰鎳鈷錳複合氧化物之前述一般組成式(1)中之元素群M1之總元素數為100mol%時，Co之比例b，以超過5mol%為佳、20mol%以上為更佳，又，以未滿35mol%為佳、30mol%以下為更佳。 In the lithium nickel cobalt manganese composite oxide represented by the above general composition formula (1), Co is also a component which contributes to the capacity increase of the lithium nickel cobalt manganese composite oxide as well as Ni, and also improves the positive electrode mixture layer. The effect of the packing density, on the other hand, if there is too much, there is a risk of an increase in cost or a decrease in safety. In addition to these reasons, the element group M 1 in the above general composition formula (1) representing the lithium nickel cobalt manganese composite oxide is represented by the viewpoint of ensuring the stability of the average valence of Mn which will be described later. When the total number of elements is 100 mol%, the ratio b of Co is preferably more than 5 mol%, more preferably 20 mol% or more, more preferably less than 35 mol%, more preferably 30 mol% or less.

再者，於鋰鎳鈷錳複合氧化物中，當前述一般組成式(1)中之元素群M1之總元素數為100mol%時，Mn之比例c，以超過15mol%為佳、20mol%以上為更佳，又，以未滿50mol%為佳、30mol%以下為更佳。藉由使鋰鎳鈷錳複合氧化物以前述之量含有Mn、使晶格中一定存在有Mn，可提高鋰鎳鈷錳複合氧化物的熱安定性，而能構成安全性更高的電池。 Further, in the lithium nickel cobalt manganese composite oxide, when the total element number of the element group M 1 in the above general composition formula (1) is 100 mol%, the ratio c of Mn is preferably more than 15 mol%, preferably 20 mol%. The above is more preferable, and more preferably less than 50 mol% and more preferably 30 mol% or less. When the lithium nickel cobalt manganese composite oxide contains Mn in the above amount and Mn is present in the crystal lattice, the thermal stability of the lithium nickel cobalt manganese composite oxide can be improved, and a battery having higher safety can be formed.

再者，於鋰鎳鈷錳複合氧化物中，藉由與Mn一同含有Co，Co具有抑制伴隨電池之充放電之Li之摻雜及脫摻雜之Mn之價數變動的作用，故使Mn之平均價數為安定於4價附近之值，可更提高充放電的可逆性。因此，藉由使用如此之鋰鎳鈷錳複合氧化物，可構成充放電循環特性更優異之電池。 Further, in the lithium nickel cobalt manganese composite oxide, Co contains Co together with Mn, and Co has a function of suppressing fluctuation in the valence of Mn doping and dedoping of Li accompanying charge and discharge of the battery, so that Mn is used. The average valence is a value that is stable near the valence of 4, which can further improve the reversibility of charge and discharge. Therefore, by using such a lithium nickel cobalt manganese composite oxide, a battery having more excellent charge and discharge cycle characteristics can be formed.

於鋰鎳鈷錳複合氧化物中，元素群M1可僅由Ni、Co、及Mn構成，亦可與該等元素一同含有選自Mg、Ti、Zr、Nb、Mo、W、Al、Si、Ga、Ge及Sn所成群中之至少1種元素。其中，當元素群M1之總元素數為100mol%時，Mg、Ti、Zr、Nb、Mo、W、Al、Si、Ga、 Ge及Sn之合計d，以5mol%以下為佳、1mol%以下為更佳。元素群M1中之Ni、Co及Mn以外之元素，可均勻地分布於鋰鎳鈷錳複合氧化物中、亦可偏析於粒子表面等。 In the lithium nickel cobalt manganese composite oxide, the element group M 1 may be composed only of Ni, Co, and Mn, and may also be selected from the group consisting of Mg, Ti, Zr, Nb, Mo, W, Al, Si together with the elements. At least one of the groups of Ga, Ge, and Sn. Wherein, when the total number of elements of the element group M 1 is 100 mol%, the total d of Mg, Ti, Zr, Nb, Mo, W, Al, Si, Ga, Ge, and Sn is preferably 5 mol% or less, and 1 mol%. The following is better. The elements other than Ni, Co, and Mn in the element group M 1 may be uniformly distributed in the lithium nickel cobalt manganese composite oxide or may be segregated on the surface of the particles.

具有前述組成之鋰鎳鈷錳複合氧化物，其之真密度成為4.55~4.95g/cm3之大的值，為具有高體積能量密度之材料。又，以依定範圍含有Mn之鋰鎳鈷錳複合氧化物之真密度，隨其之組成有很大的變化，但如前述以窄組成範圍可使構造安定化、提高均一性，故考量為例如接近於LiCoO2之真密度之大的值。又，可增大真密度鋰鎳鈷錳複合氧化物之單位質量的容量，故可作成可逆性優異的材料。 The lithium nickel cobalt manganese composite oxide having the above composition has a true density of 4.55 to 4.95 g/cm 3 and is a material having a high volume energy density. Further, the true density of the lithium nickel cobalt manganese composite oxide containing Mn in a predetermined range varies greatly depending on the composition thereof. However, as described above, the structure can be stabilized and the uniformity is improved by a narrow composition range, so the consideration is For example, a value close to the true density of LiCoO 2 . Further, since the capacity per unit mass of the true-density lithium nickel cobalt manganese composite oxide can be increased, a material excellent in reversibility can be obtained.

前述鋰鎳鈷錳複合氧化物，特別是當為化學計量比相近之組成時，其之真密度增大，具體而言，前述一般組成式(1)中，較佳為-0.3≦s≦0.3，藉由如此調整s之值，可提高真密度及可逆性。s更佳為-0.05以上0.05以下，於該場合，鋰鎳鈷錳複合氧化物之真密度，可為4.6g/cm3以上之更高的值。 The lithium nickel cobalt manganese composite oxide, particularly when it is a composition having a stoichiometric ratio, has an increased true density. Specifically, in the above general composition formula (1), it is preferably -0.3 ≦s ≦ 0.3. By adjusting the value of s in this way, the true density and reversibility can be improved. More preferably, s is -0.05 or more and 0.05 or less. In this case, the true density of the lithium nickel cobalt manganese composite oxide may be a higher value of 4.6 g/cm 3 or more.

前述一般組成式(1)所表示之鋰鎳鈷錳複合氧化物，可混合含有Li之化合物(氫氧化鋰等)、含有Ni之化合物(硫酸鎳等)、含有Co之化合物(硫酸鈷等)、含有Mn之化合物(硫酸錳等)、及元素群M1所含之含有其他元素之化合物(氧化物、氫氧化物、硫酸鹽等)，進行燒成等來製造。又，以更高純度合成鋰鎳鈷錳複合氧化物時，較佳為，混合元素群M1所含之含有複數元素之複合 化合物(氫氧化物、氧化物等)與含有Li之化合物，進行燒成。 The lithium nickel cobalt manganese composite oxide represented by the above general composition formula (1) may be a compound containing Li (such as lithium hydroxide), a compound containing Ni (such as nickel sulfate), or a compound containing Co (cobalt sulfate or the like). A compound containing Mn (manganese sulfate or the like) and a compound (oxide, hydroxide, sulfate, etc.) containing other elements contained in the element group M 1 are produced by firing or the like. Further, when the lithium nickel cobalt manganese composite oxide is synthesized with higher purity, it is preferred that the composite compound (hydroxide, oxide, or the like) containing a plurality of elements contained in the mixed element group M 1 and the compound containing Li are carried out. Burnt.

燒成條件係例如能以800~1050℃進行1~24小時，較佳為，一旦加熱至較燒成溫度低之溫度(例如，250~850℃)，便保持該溫度以進行預備加熱，之後升溫至燒成溫度使反應進行。關於預備加熱之時間並無特別限制，但通常可為0.5~30小時左右。又，燒成之環境氣氛，可為含氧之環境氣氛(亦即，大氣中)、惰性氣體(氬、氙、氮等)與氧氣之混合環境氣氛、氧氣環境氣氛等，而此時之氧濃度(體積基準)，以15%以上為佳、18%以上為更佳。 The firing conditions can be, for example, 800 to 1050 ° C for 1 to 24 hours, preferably, once heated to a temperature lower than the firing temperature (for example, 250 to 850 ° C), the temperature is maintained for preliminary heating, and then The temperature was raised to the firing temperature to allow the reaction to proceed. The time for preliminary heating is not particularly limited, but it is usually about 0.5 to 30 hours. Moreover, the ambient atmosphere of the firing may be an oxygen-containing ambient atmosphere (that is, in the atmosphere), a mixed atmosphere of an inert gas (argon, helium, nitrogen, etc.) and oxygen, an oxygen atmosphere, etc., and oxygen at this time. The concentration (volume basis) is preferably 15% or more, and more preferably 18% or more.

於正極活性物質，可僅使用前述含過渡金屬元素之Ni之含有鋰的複合氧化物(較佳為鋰鎳鈷錳複合氧化物、更佳為以前述一般組成式(1)所表示者)，亦可併用如此之含有鋰的複合氧化物與其他之含有鋰的複合氧化物。 The positive electrode active material may be a lithium-containing composite oxide containing Ni as the transition metal element (preferably a lithium nickel cobalt manganese composite oxide, more preferably represented by the above general composition formula (1)). Such a lithium-containing composite oxide and other lithium-containing composite oxide may be used in combination.

例如，較佳為，將鋰鎳鈷錳複合氧化物、與含有鋰、鎳、鈷、錳以外之異種金屬元素之鋰鈷複合氧化物作為正極活性物質來使用。 For example, a lithium nickel cobalt manganese composite oxide and a lithium cobalt composite oxide containing a dissimilar metal element other than lithium, nickel, cobalt, and manganese are preferably used as the positive electrode active material.

而於該場合，於前述鋰鎳鈷錳複合氧化物，較佳為，使用平均粒徑A(μm)超過10μm且30μm以下之鋰鈷複合氧化物(A)、與平均粒徑B(μm)為1μm以上且10μm以下之鋰鈷複合氧化物(B)，並且使鋰鈷複合氧化物(A)之平均粒徑A與鋰鈷複合氧化物(B)之平均粒徑B的差「A-B」 為5(μm)以上。又，鋰鎳鈷錳複合氧化物，較佳為使用當其之平均粒徑為C(μm)時，與鋰鈷複合氧化物(B)之平均粒徑B的關係為C>B者。 In this case, the lithium nickel cobalt manganese composite oxide is preferably a lithium cobalt composite oxide (A) having an average particle diameter A (μm) of more than 10 μm and 30 μm or less, and an average particle diameter B (μm). a lithium cobalt composite oxide (B) of 1 μm or more and 10 μm or less, and a difference "AB" between the average particle diameter A of the lithium cobalt composite oxide (A) and the average particle diameter B of the lithium cobalt composite oxide (B) It is 5 (μm) or more. Further, the lithium nickel cobalt manganese composite oxide preferably has a relationship of C>B with respect to the average particle diameter B of the lithium cobalt composite oxide (B) when the average particle diameter thereof is C (μm).

藉由併用如上述之鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)、與鋰鎳鈷錳複合氧化物，於正極合劑層內，於鋰鈷複合氧化物(A)或鋰鎳鈷錳複合氧化物之粒子彼此之間隙，可充填粒徑小的鋰鈷複合氧化物(B)，故可提高正極合劑層之密度而增多正極合劑層之正極活性物質量。 By using the lithium cobalt composite oxide (A), the lithium cobalt composite oxide (B), and the lithium nickel cobalt manganese composite oxide as described above in combination with the lithium cobalt composite oxide (A) or lithium in the positive electrode mixture layer The particles of the nickel-cobalt-manganese composite oxide can be filled with a lithium cobalt composite oxide (B) having a small particle diameter, so that the density of the positive electrode mixture layer can be increased and the positive electrode active material mass of the positive electrode mixture layer can be increased.

又，作為正極活性物質使用之鋰鎳鈷錳複合氧化物，例如，於高電壓下之安定性較LiCoO2高，再者，鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，由於前述之異種金屬元素之作用，例如，於高電壓下之安定性較LiCoO2高。因此，除了鋰鎳鈷錳複合氧化物之外，當使用鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)於正極活性物質時，即使使用以4.3V以上之終止電壓進行定電流-定電壓充電的方法，亦不易產生正極活性物質的劣化，故可更提高非水電解質二次電池之充放電循環特性。 Further, the lithium nickel cobalt manganese composite oxide used as the positive electrode active material has higher stability at high voltage than LiCoO 2 , and further, lithium cobalt composite oxide (A) and lithium cobalt composite oxide (B). Due to the action of the aforementioned dissimilar metal elements, for example, the stability at high voltage is higher than that of LiCoO 2 . Therefore, in addition to the lithium nickel cobalt manganese composite oxide, when a lithium cobalt composite oxide (A) and a lithium cobalt composite oxide (B) are used for the positive electrode active material, a constant current is used even with a termination voltage of 4.3 V or more. - The method of constant voltage charging also does not easily cause deterioration of the positive electrode active material, so that the charge and discharge cycle characteristics of the nonaqueous electrolyte secondary battery can be further improved.

又，鋰鎳鈷錳複合氧化物，特別是粒徑小時，於電池內容易引起氣體產生。然而，藉由於進入粒徑大之正極活性物質彼此之間隙的粒徑小之正極活性物質，使用較鋰鎳鈷錳複合氧化物不易引起電池內之氣體產生的鋰鈷複合氧化物(B)，例如，可抑制貯藏時之膨脹。因此，於正極活性物質，除鋰鎳鈷錳複合氧化物之外，亦使用鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)時，非水電解質二次電池之 貯藏特性亦良好。 Further, the lithium nickel cobalt manganese composite oxide, particularly when the particle diameter is small, is likely to cause gas generation in the battery. However, the lithium cobalt composite oxide (B) which is less likely to cause gas generation in the battery than the lithium nickel cobalt manganese composite oxide is used as the positive electrode active material having a small particle diameter which is small in the gap between the positive electrode active materials having a large particle diameter, For example, swelling during storage can be suppressed. Therefore, in the case of using the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) in addition to the lithium nickel cobalt manganese composite oxide as the positive electrode active material, the nonaqueous electrolyte secondary battery The storage characteristics are also good.

鋰鈷複合氧化物(A)之平均粒徑A，以17μm以上較佳，又，24μm以下為更佳。再者，鋰鈷複合氧化物(B)之平均粒徑B，以5μm以上較佳，又，10μm以下為更佳。 The average particle diameter A of the lithium cobalt composite oxide (A) is preferably 17 μm or more, and more preferably 24 μm or less. Further, the average particle diameter B of the lithium cobalt composite oxide (B) is preferably 5 μm or more, more preferably 10 μm or less.

而鋰鎳鈷錳複合氧化物之平均粒徑，以10μm以上為佳、11μm以上為更佳，又，17μm以下為佳、16μm以下為更佳。 The average particle diameter of the lithium nickel cobalt manganese composite oxide is preferably 10 μm or more, more preferably 11 μm or more, and more preferably 17 μm or less and more preferably 16 μm or less.

又，鋰鈷複合氧化物(A)之平均粒徑A、鋰鈷複合氧化物(B)之平均粒徑B、及鋰鎳鈷錳複合氧化物之平均粒徑C(μm)，以滿足A≧C>B之關係為佳、滿足A>C>B之關係為更佳。於該場合，可更良好地確保正極合劑層之密度提升所致之正極活性物質之填充量的提高效果、伴隨正極活性物質之安定性提升之充放電循環特性提升效果、藉由某程度地增大鋰鎳鈷錳複合氧化物之粒徑所致之貯藏特性提升效果。 Further, the average particle diameter A of the lithium cobalt composite oxide (A), the average particle diameter B of the lithium cobalt composite oxide (B), and the average particle diameter C (μm) of the lithium nickel cobalt manganese composite oxide satisfy the A. The relationship between ≧C>B is better, and the relationship of A>C>B is better. In this case, the effect of improving the filling amount of the positive electrode active material due to the increase in the density of the positive electrode mixture layer and the effect of improving the charge and discharge cycle characteristics with the stability of the positive electrode active material can be more satisfactorily increased. The storage property improvement effect of the particle size of the large lithium nickel cobalt manganese composite oxide.

本說明書之鋰鈷複合氧化物(A)、鋰鈷複合氧化物(B)及鋰鎳鈷錳複合氧化物之平均粒徑，係由使用日機裝股份有限公司製MicroTrack粒度分布測定裝置「HRA9320」所測定之粒度分布之由小粒子求出累積體積時之體積基準之累積分率中之50%徑之值(d50)中位徑。 The average particle diameter of the lithium-cobalt composite oxide (A), the lithium-cobalt composite oxide (B), and the lithium nickel-cobalt-manganese composite oxide in the present specification is a MicroTrack particle size distribution measuring device "HRA9320" manufactured by Nikkiso Co., Ltd. The median diameter of the 50% diameter (d 50 ) of the cumulative fraction of the volume basis when the cumulative volume is determined by the small particle.

又，具有前述之平均粒徑A之鋰鈷複合氧化物(A)及具有前述之平均粒徑B之鋰鈷複合氧化物(B)中，鈷與前述異種金屬元素之合計量中之前述異種金屬元素的比例，以鋰鈷複合氧化物(B)較鋰鈷複合氧化物(A)大為佳。 Further, in the lithium cobalt composite oxide (A) having the above average particle diameter A and the lithium cobalt composite oxide (B) having the above average particle diameter B, the aforementioned heterogeneous species in the total amount of cobalt and the dissimilar metal element The proportion of the metal element is preferably larger than that of the lithium cobalt composite oxide (B).

鋰鈷複合氧化物，粒徑愈小、於高電壓下之安定性及對熱之安定性愈差。因此，於平均粒徑較小之鋰鈷複合氧化物(B)，藉由含有多數之具有提高其之安定性之作用的前述異種金屬元素，可提高電池之充放電及對熱之安定性，而能良好地確保非水電解質二次電池之充放電循環特性及貯藏特性。 The lithium-cobalt composite oxide has a smaller particle size, stability at high voltage, and poorer heat stability. Therefore, in the lithium-cobalt composite oxide (B) having a small average particle diameter, the charge and discharge of the battery and the stability to heat can be improved by containing a plurality of the above-mentioned dissimilar metal elements having an effect of improving the stability thereof. Further, the charge and discharge cycle characteristics and storage characteristics of the nonaqueous electrolyte secondary battery can be satisfactorily ensured.

然而，前述異種金屬元素，係對鋰鈷複合氧化物之容量沒有幫助的成分，故於鋰鈷複合氧化物中之量若增多，則鋰鈷複合氧化物之容量會變小。因此，於平均粒徑較大、安定性較高之鋰鈷複合氧化物(A)，藉由減小前述異種金屬元素之含量，可盡可能地抑制該異種金屬元素之含有所致之容量降低，而能更提高安定性與容量之平衡。 However, the above-mentioned dissimilar metal element is a component which does not contribute to the capacity of the lithium cobalt composite oxide. Therefore, if the amount in the lithium cobalt composite oxide is increased, the capacity of the lithium cobalt composite oxide becomes small. Therefore, in the lithium-cobalt composite oxide (A) having a large average particle diameter and high stability, the capacity reduction due to the content of the dissimilar metal element can be suppressed as much as possible by reducing the content of the dissimilar metal element. , can improve the balance between stability and capacity.

鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，較佳為，以下述一般組成式(2)所表示者。 The lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) are preferably represented by the following general composition formula (2).

Li1+yCozM2 1-zO2 (2) Li 1+y Co z M 2 1-z O 2 (2)

[前述一般組成式(2)中，-0.3≦y≦0.3、0.095≦z<1.0，M2係選自由Mg、Zr、Al及Ti所構成群中之至少1種元素]。 [In the above general composition formula (2), -0.3≦y≦0.3, 0.095≦z<1.0, and M 2 is at least one element selected from the group consisting of Mg, Zr, Al, and Ti].

前述一般組成式(2)中，M2相當於前述異種金屬元素。鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)所含有之異種金屬元素M2，係如前述，可為Mg、Zr、Al及Ti之任一者，可為該等中之1種或2種以上即可，但由於提高鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)之於高電壓下之安定性及熱安定性的作用更良好，而以Mg及/或Zr為更 佳。 In the above general composition formula (2), M 2 corresponds to the aforementioned dissimilar metal element. The dissimilar metal element M 2 contained in the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) may be any of Mg, Zr, Al, and Ti as described above, and may be any of these. One type or two or more types may be used, but the effect of improving the stability and thermal stability of the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) at a high voltage is better, and Mg and / or Zr is better.

又，於鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)中，Co係有助於容量提升之成分，另一方面，異種金屬元素M2則對容量提升沒有幫助。因此，於表示鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)之前述一般組成式(2)中，由維持該等之容量為高的觀點，以使Co之量z為0.95以上為佳。又，於前述一般組成式(2)中，當Co之量z為未滿1.0，但由良好地確保含有異種金屬元素M2所致之前述效果的觀點考量，異種金屬元素M2之量「1-z」，以0.005以上為更佳，因此，Co之量z，以0.995以下為更佳。 Further, in the lithium-cobalt composite oxide (A) and the lithium-cobalt composite oxide (B), Co contributes to a component of capacity increase, and on the other hand, the dissimilar metal element M 2 does not contribute to capacity increase. Therefore, in the above general composition formula (2) indicating the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B), the amount Z of the Co is 0.95 from the viewpoint of maintaining the capacity of the above. The above is better. Further, in the above general composition formula (2), when the amount z of Co is less than 1.0, the amount of the dissimilar metal element M 2 is considered from the viewpoint of satisfactorily securing the effect of the dissimilar metal element M 2 . 1-z" is more preferably 0.005 or more. Therefore, the amount z of Co is preferably 0.995 or less.

鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，當為前述一般組成式(2)所表示者時，鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)，作為異種金屬元素M2，可含有相同元素、亦可含有不同元素，當鋰鈷複合氧化物(A)所含之異種金屬元素M2之量為「1-z1」、鋰鈷複合氧化物(B)所含之異種金屬元素M2之量為「1-z2」時，以滿足(1-z1)<(1-z2)為佳。更具體而言，「1-z1」以0.01以上為更佳，又，以0.02以下為更佳。而「1-z2」以0.02以上為更佳，又，以0.03以下為更佳。 Lithium cobalt composite oxide (A) and lithium cobalt composite oxide (B), when expressed by the above general composition formula (2), lithium cobalt composite oxide (A) and lithium cobalt composite oxide (B), The dissimilar metal element M 2 may contain the same element or a different element, and the amount of the dissimilar metal element M 2 contained in the lithium cobalt composite oxide (A) is "1-z1" or a lithium cobalt composite oxide ( B) When the amount of the dissimilar metal element M 2 contained is "1-z2", it is preferable to satisfy (1-z1) < (1-z2). More specifically, "1-z1" is more preferably 0.01 or more, and further preferably 0.02 or less. Further, "1-z2" is preferably 0.02 or more, and more preferably 0.03 or less.

鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，特別是當為化學計量比相近之組成時，其之真密度增大，為具有更高之能量體積密度之材料，具體而言，前述組成式中，較佳為-0.3≦y≦0.3，藉由如此調整y之值，可提高真密度及充放電時的可逆性。 The lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B), especially when the stoichiometric ratio is similar, the true density thereof is increased, and the material has a higher energy bulk density, specifically In the above composition formula, it is preferably -0.3 ≦ y ≦ 0.3, and by adjusting the value of y in this way, the true density and the reversibility at the time of charge and discharge can be improved.

鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，可混合含有Li之化合物(氫氧化鋰等)、含有Co之化合物(硫酸鈷等)、及含有異種金屬元素M1之化合物(氧化物、氫氧化物、硫酸鹽等)，將該原料混合物進行燒成來合成。 又，欲以更高純度合成鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)時，較佳為混合含有Co及異種金屬元素M1之複合化合物(氫氧化物、氧化物等)與含有Li之化合物等，將該原料混合物進行燒成。 The lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) may be mixed with a compound containing Li (such as lithium hydroxide), a compound containing Co (such as cobalt sulfate), and a compound containing a dissimilar metal element M 1 . (Oxide, hydroxide, sulfate, etc.), the raw material mixture is calcined and synthesized. Further, when the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) are to be synthesized with higher purity, it is preferred to mix a composite compound (hydroxide, oxide, etc.) containing Co and a dissimilar metal element M 1 . The raw material mixture is fired with a compound containing Li or the like.

用以合成鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)之原料混合物之燒成條件，例如能以800~1050℃進行1~24小時，較佳為一旦加熱至較燒成溫度低之溫度(例如，250~850℃)，便保持該溫度以進行預備加熱，之後升溫至燒成溫度使反應進行。關於預備加熱之時間並無特別限制，但通常可為0.5~30小時左右。又，燒成之環境氣氛，可為含氧之環境氣氛(亦即，大氣中)、惰性氣體(氬、氙、氮等)與氧氣之混合環境氣氛、氧氣環境氣氛等，而此時之氧濃度(體積基準)，以15%以上為佳、18%以上為更佳。 The firing conditions for synthesizing the raw material mixture of the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) can be carried out, for example, at 800 to 1050 ° C for 1 to 24 hours, preferably once heated to a lower firing temperature. When the temperature is low (for example, 250 to 850 ° C), the temperature is maintained for preliminary heating, and then the temperature is raised to the firing temperature to carry out the reaction. The time for preliminary heating is not particularly limited, but it is usually about 0.5 to 30 hours. Moreover, the ambient atmosphere of the firing may be an oxygen-containing ambient atmosphere (that is, in the atmosphere), a mixed atmosphere of an inert gas (argon, helium, nitrogen, etc.) and oxygen, an oxygen atmosphere, etc., and oxygen at this time. The concentration (volume basis) is preferably 15% or more, and more preferably 18% or more.

於非水電解質二次電池，當於正極活性物質使用鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)時，當鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)之合計為100質量%時，鋰鈷複合氧化物(A)之含有率，以50質量%以上為佳、更佳為70質量%以上，又，以未滿100質量%為佳、90質量%以下為更佳。 In the nonaqueous electrolyte secondary battery, when the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) are used as the positive electrode active material, the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) When the total content is 100% by mass, the content of the lithium cobalt composite oxide (A) is preferably 50% by mass or more, more preferably 70% by mass or more, and more preferably 100% by mass or less, and 90% by mass. % below is better.

又，於非水電解質二次電池，當使用鋰鎳鈷錳複合氧化物、鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)時，當鋰鎳鈷錳複合氧化物、鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)之合計為100質量%時，鋰鎳鈷錳複合氧化物之含有率，以15質量%以上為佳、更佳為20質量%以上，又，以45質量%以下為佳、30質量%以下為更佳。 Further, in the nonaqueous electrolyte secondary battery, when lithium nickel cobalt manganese composite oxide, lithium cobalt composite oxide (A) and lithium cobalt composite oxide (B) are used, lithium nickel cobalt manganese composite oxide, lithium cobalt When the total of the composite oxide (A) and the lithium-cobalt composite oxide (B) is 100% by mass, the content of the lithium nickel cobalt manganese composite oxide is preferably 15% by mass or more, more preferably 20% by mass or more. Further, it is preferably 45 mass% or less and more preferably 30 mass% or less.

於正極活性物質，亦可與前述之含作為過渡金屬元素之鎳之含有鋰的複合氧化物[較佳為鋰鎳鈷錳複合氧化物、更佳為以前述一般組成式(1)所表示者]，共同使用前述之鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)以外之其他活性物質。於該場合，例如，可使用前述之含作為過渡金屬元素之鎳之含有鋰的複合氧化物[較佳為鋰鎳鈷錳複合氧化物、更佳為以前述一般組成式(1)所表示者]與其他活性物質、亦可使用鋰鎳鈷錳複合氧化物、鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)與其他活性物質。 The positive electrode active material may be a lithium-containing composite oxide containing nickel as a transition metal element, preferably a lithium nickel cobalt manganese composite oxide, more preferably represented by the above general composition formula (1). ], the above-mentioned lithium cobalt composite oxide (A) and other active materials other than the lithium cobalt composite oxide (B) are used in combination. In this case, for example, a lithium-containing composite oxide containing nickel as a transition metal element (preferably a lithium nickel cobalt manganese composite oxide, more preferably represented by the above general composition formula (1)) can be used. Further, a lithium nickel cobalt manganese composite oxide, a lithium cobalt composite oxide (A), a lithium cobalt composite oxide (B), and other active materials may be used together with other active materials.

如此之其他活性物質，可例示如LiCoO2；LiMnO2、Li2MnO3等鋰錳氧化物；LiMn2O4、Li4/3Ti5/3O4等之尖晶石構造之含有鋰之複合氧化物；LiFePO4等之橄欖石構造之含有鋰之複合氧化物；以前述之氧化物為基本組成之以各種元素取代之氧化物等，可使用該等中之1種或2種以上。 Examples of such other active material include lithium manganese oxides such as LiCoO 2 , LiMnO 2 , and Li 2 MnO 3 , and lithium-containing spinel structures such as LiMn 2 O 4 and Li 4/3 Ti 5/3 O 4 . A composite oxide, a lithium-containing composite oxide having an olivine structure such as LiFePO 4 , or an oxide substituted with various elements as a basic composition, and one or more of these may be used.

然而，從良好地確保本發明之效果的觀點考量，正極活性物質總量中之前述其他活性物質的含有率，以10質量%以下為佳、5質量%以下為更佳。 However, from the viewpoint of ensuring the effect of the present invention, the content of the other active material in the total amount of the positive electrode active material is preferably 10% by mass or less and more preferably 5% by mass or less.

正極合劑層之黏結劑，係使用VDF-CTFE。含有正極活性物質之含作為前述過渡金屬元素之鎳之含有鋰的複合氧化物之正極合劑層、與含有SiOx及石墨質碳材料作為負極活性物質之負極合劑層之伴隨電池之充放電之膨脹收縮之平衡，與例如含有LiCoO2作為正極活性物質之正極合劑層的情形相比為良好。然而，除了使用如此之正極活性物質之外，當於正極合劑層之黏結劑使用VDF-CTFE時，與使用例如作為非水電解質二次電池之正極合劑層的黏結劑所汎用之聚二氟亞乙烯(PVDF)的情形相比，能於該等之對向面整體以均一性更高的狀態維持正極與負極的間隔。其係推測為VDF-CTFE，係於以正極合劑層接受伴隨電池之充放電所產生之負極合劑層之膨脹收縮時，緩和其之體積變化的作用較PVDF高之故。 The binder of the positive electrode mixture layer was VDF-CTFE. The positive electrode mixture layer containing the lithium-containing composite oxide containing nickel as the transition metal element, and the expansion and discharge of the battery accompanying the negative electrode mixture layer containing SiO x and the graphite carbon material as the negative electrode active material The balance of shrinkage is good as compared with the case of, for example, a positive electrode mixture layer containing LiCoO 2 as a positive electrode active material. However, in addition to the use of such a positive electrode active material, when VDF-CTFE is used as the binder of the positive electrode mixture layer, polydifluoroethylene which is generally used as a binder using, for example, a positive electrode mixture layer of a nonaqueous electrolyte secondary battery In the case of ethylene (PVDF), the interval between the positive electrode and the negative electrode can be maintained in a state where the uniformity of the opposite faces is higher. This is presumed to be VDF-CTFE. When the positive electrode mixture layer is subjected to expansion and contraction of the negative electrode mixture layer caused by charge and discharge of the battery, the effect of relaxing the volume change is higher than that of PVDF.

又，當併用如前述鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)、與鋰鎳鈷錳複合氧化物以提高正極合劑層之密度時，由於正極合劑層之硬度增大，故例如若將正極與負極透過間隔物重疊、並捲繞成漩渦狀以製作捲繞電極體(特別是橫切面為扁平狀之捲繞電極體)，則於正極合劑層容易產生破裂。然而，於本發明作為正極合劑層之黏結劑使用之VDF-CTFE，其緩和所施加應力之作用，例如較PVDF優異，故即使使正極活性物質之構成為如前述而使正極合劑層之密度增高，亦能抑制捲繞電極體(特別是橫切面為扁平狀之捲繞電極體)之正極合劑層的破裂。 When the lithium cobalt composite oxide (A), the lithium cobalt composite oxide (B), and the lithium nickel cobalt manganese composite oxide are used in combination to increase the density of the positive electrode mixture layer, the hardness of the positive electrode mixture layer increases. For example, when the positive electrode and the negative electrode are passed through a separator and wound into a spiral shape to form a wound electrode body (particularly, a wound electrode body having a flat cross-sectional shape), cracking easily occurs in the positive electrode mixture layer. However, the VDF-CTFE used as the binder of the positive electrode mixture layer of the present invention has an effect of alleviating the applied stress, for example, is superior to PVDF, so that the composition of the positive electrode active material is increased as described above to increase the density of the positive electrode mixture layer. Also, it is possible to suppress cracking of the positive electrode mixture layer of the wound electrode body (particularly, the wound electrode body having a flat cross-sectional shape).

再者，當使用PVDF作為黏結劑時，會於作成電池後 引起脫氟，其會與不可避免地混入電池內的水分反應而產生氟化氫，而由於氟化氫所致之正極活性物質的腐蝕，會產生Co或Mn等之金屬離子的溶出。於本發明之構成，亦可抑制如此之氟化氫的產生，藉此，亦可期待充放電循環特性等之電池特性的提升效果。 Furthermore, when using PVDF as a binder, it will be made after the battery is fabricated. Defluorination causes decomposition of hydrogen which is inevitably mixed into the battery to generate hydrogen fluoride, and elution of metal ions such as Co or Mn occurs due to corrosion of the positive electrode active material due to hydrogen fluoride. According to the configuration of the present invention, the generation of such hydrogen fluoride can be suppressed, and the effect of improving the battery characteristics such as the charge and discharge cycle characteristics can be expected.

使用於正極合劑層之VDF-CTFE的組成，由更良好地確保VDF-CTFE之使用所致之非水電解質二次電池之充放電循環特性之提升效果的觀點，當來自二氟亞乙烯之單元與來自氯三氟乙烯之單元的合計為100mol%時，來自氯三氟乙烯之單元的比例，以0.5mol%以上為佳、1mol%以上為更佳。然而，若VDF-CTFE中之來自氯三氟乙烯之單元的比例過高，則容易吸收非水電解質(非水電解液)而膨潤，正極之特性有降低之虞。因此，使用於正極合劑層之VDF-CTFE，當來自二氟亞乙烯之單元與來自氯三氟乙烯之單元的合計為100mol%時，來自氯三氟乙烯之單元的比例，以15mol%以下為佳。 The composition of the VDF-CTFE used for the positive electrode mixture layer is improved from the viewpoint of improving the charge-discharge cycle characteristics of the non-aqueous electrolyte secondary battery due to the use of the VDF-CTFE, when the unit derived from difluoroethylene When the total amount of the unit derived from chlorotrifluoroethylene is 100 mol%, the ratio of the unit derived from chlorotrifluoroethylene is preferably 0.5 mol% or more, more preferably 1 mol% or more. However, if the proportion of the unit derived from chlorotrifluoroethylene in the VDF-CTFE is too high, the nonaqueous electrolyte (nonaqueous electrolyte) is easily absorbed and swollen, and the characteristics of the positive electrode are lowered. Therefore, when VDF-CTFE used for the positive electrode mixture layer is 100 mol% of the unit derived from difluoroethylene and the unit derived from chlorotrifluoroethylene, the ratio of the unit derived from chlorotrifluoroethylene is 15 mol% or less. good.

正極合劑層之黏結劑，可僅使用VDF-CTFE，亦可併用VDF-CTFE與其他黏結劑(例如，如PVDF等之VDF-CTFE以外之氟樹脂之非水電解質二次電池之正極合劑層所汎用之黏結劑)。然而，由良好地確保VDF-CTFE之使用所致之前述各效果的觀點，正極合劑層中之黏結劑總量中之VDF-CTFE以外之黏結劑的量，以50質量%以下為佳。 As the binder of the positive electrode mixture layer, only VDF-CTFE may be used, or VDF-CTFE and other bonding agents (for example, a positive electrode mixture layer of a non-aqueous electrolyte secondary battery other than VDF-CTFE such as PVDF) may be used in combination. General purpose binder). However, the amount of the binder other than the VDF-CTFE in the total amount of the binder in the positive electrode mixture layer is preferably 50% by mass or less from the viewpoint of the above-described respective effects of ensuring the use of the VDF-CTFE.

於正極合劑層，通常係含有導電助劑。正極合劑層之 導電助劑，例如，較佳可使用天然石墨(磷片狀石墨等)、人造石墨等之石墨類；乙炔黑、科琴黑、槽黑、爐黑、燈黑、熱碳黑等碳黑類；碳纖維等之碳材料，又，亦可使用金屬纖維等之導電性纖維類；氟化碳；鋁等之金屬粉末類；氧化鋅；鈦酸鉀等之導電性晶鬚類；氧化鈦等之導電性金屬氧化物；聚伸苯衍生物等之有機導電性材料等。 The positive electrode mixture layer usually contains a conductive auxiliary agent. Positive electrode mixture layer As the conductive auxiliary agent, for example, graphite such as natural graphite (phosphorus flake graphite) or artificial graphite; graphite blacks such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal carbon black can be preferably used. Carbon materials such as carbon fibers, conductive fibers such as metal fibers; carbon powders; metal powders such as aluminum; zinc oxide; conductive whiskers such as potassium titanate; Conductive metal oxide; organic conductive material such as polyphenylene derivative.

正極合劑層之厚度，例如，每集電器之單面以10~100μm為佳。又，正極合劑層之組成，例如，正極活性物質之量以60~95質量%為佳、黏結劑之量以1~15質量%為佳、導電助劑之量以3~20質量%為佳。 The thickness of the positive electrode mixture layer is preferably, for example, 10 to 100 μm per one side of each current collector. Further, the composition of the positive electrode mixture layer is, for example, preferably 60 to 95% by mass of the positive electrode active material, preferably 1 to 15% by mass of the binder, and 3 to 20% by mass of the conductive auxiliary agent. .

於正極之集電器，可使用自以往習知之非水電解質二次電池之正極所使用者同樣者，例如鋁(包含鋁合金。除了特別說明之外，以下相同)製之衝孔金屬、網、多孔金屬等，而以厚度為10~30μm之鋁箔為佳。 For the current collector of the positive electrode, the same can be used for the positive electrode of the conventional nonaqueous electrolyte secondary battery, for example, aluminum (including aluminum alloy. Unless otherwise specified, the following is the same), punched metal, mesh, A porous metal or the like is preferable, and an aluminum foil having a thickness of 10 to 30 μm is preferred.

本發明之非水電解質二次電池，係具有正極、負極、非水解電解質及間隔物，負極為前述負極、且正極為前述正極即可，關於其他之構成及構造並無特別限制，可使用自以往習知之非水電解質二次電池所採用之各種構成及構造。 The nonaqueous electrolyte secondary battery of the present invention has a positive electrode, a negative electrode, a non-hydrolyzed electrolyte, and a separator. The negative electrode is the negative electrode and the positive electrode is the positive electrode. The other structures and structures are not particularly limited, and the self-use can be used. Various configurations and structures used in conventional nonaqueous electrolyte secondary batteries.

本發明之非水電解質二次電池之間隔物，可使用通常之非水電解質二次電池所使用之間隔物，例如，聚乙烯(PE)或聚丙烯(PP)等之聚烯烴製之微多孔膜。構成間隔物之微多孔膜，例如，可為僅使用PE者或僅使用PP者， 又，亦可為PE製之微多孔膜與PP製之微多孔膜的層合體。 The spacer of the nonaqueous electrolyte secondary battery of the present invention may be a spacer used in a general nonaqueous electrolyte secondary battery, for example, a microporous polyolefin such as polyethylene (PE) or polypropylene (PP). membrane. The microporous film constituting the spacer may be, for example, only PE or PP only. Further, it may be a laminate of a microporous membrane made of PE and a microporous membrane made of PP.

又，於前述之微多孔膜的表面，亦可使用形成有含耐熱性之無機填料之耐熱性之多孔質層的層合型間隔物。當使用如此之層合型之間隔物時，即使電池內之溫度上升亦可抑制間隔物之收縮，可抑制正極與負極之接觸所致之短路，故可成為安全性更高之非水電解質二次電池。 Further, a laminate type spacer in which a heat-resistant porous layer containing a heat-resistant inorganic filler is formed on the surface of the microporous film may be used. When such a laminated spacer is used, even if the temperature in the battery rises, the shrinkage of the spacer can be suppressed, and the short circuit caused by the contact between the positive electrode and the negative electrode can be suppressed, so that the non-aqueous electrolyte can be safer. Secondary battery.

耐熱性之多孔質層所含有之無機填料，以水鋁石、氧化鋁、氧化矽等較佳，可使用該等中之1種或2種以上。 The inorganic filler contained in the heat-resistant porous layer is preferably boehmite, alumina, cerium oxide, or the like, and one or more of these may be used.

又，於耐熱性之多孔質層，較佳為含有用以將前述之無機填料彼此黏著、或將耐熱性之多孔質層與微多孔膜接著的黏結劑。黏結劑，以使用乙烯-乙酸乙烯共聚物(EVA，來自乙酸乙烯之構造單位為20~35莫耳%者)、乙烯-丙烯酸乙酯共聚物等之乙烯-丙烯酸共聚物、氟系橡膠、乙烯丁二烯橡膠(SBR)、羧基甲基纖維素(CMC)、羥基乙基纖維素(HEC)、聚乙烯醇(PVA)、聚乙烯丁醛(PVB)、聚乙烯吡咯酮(PVP)、交聯丙烯酸酯、聚胺基甲酸酯、環氧樹脂等為佳，可使用該等中之1種或2種以上。 Moreover, it is preferable that the heat resistant porous layer contains a binder for adhering the above-mentioned inorganic fillers to each other or a heat-resistant porous layer and a microporous film. As the binder, an ethylene-vinyl acetate copolymer (EVA, a structural unit derived from vinyl acetate of 20 to 35 mol%), an ethylene-acrylic acid ethyl ester copolymer, an ethylene-acrylic acid copolymer, a fluorine rubber, and ethylene are used. Butadiene rubber (SBR), carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyvinylpyrrolidone (PVP), The acrylate, the urethane, the epoxy resin, etc. are preferable, and one type or two or more types can be used.

間隔物(聚烯烴製之微多孔膜所構成之間隔物、或前述層合型之間隔物)之厚度，例如，以10~30μm為佳。又，當為前述層合型之間隔物時，耐熱性之多孔質層之厚度，例如，以3~8μm為佳。 The thickness of the spacer (the spacer formed of the polyolefin microporous film or the spacer of the laminate type) is preferably, for example, 10 to 30 μm. Moreover, in the case of the above-mentioned laminated type spacer, the thickness of the heat-resistant porous layer is preferably, for example, 3 to 8 μm.

本發明之非水電解質二次電池之非水電解質，例如，可使用將鋰鹽溶解於有機溶劑之溶液(非水電解液)。鋰 鹽，只要可於溶劑中解離形成Li+離子，而於作為電池使用之電壓範圍不易產生分解等之副反應者即可，並無特別限制。例如，可使用LiClO4、LiPF6、LiBF4、LiAsF6、LiSbF6等之無機鋰鹽、LiCF3SO3、LiCF3CO2、Li2C2F4(SO3)2、LiN(CF3SO2)2、LiC(CF3SO2)3、LiCnF2n+1SO3(n≧2)、LiN(RfOSO2)2[此處，Rf為氟烷基]等之有機鋰鹽等。 In the nonaqueous electrolyte of the nonaqueous electrolyte secondary battery of the present invention, for example, a solution (nonaqueous electrolyte) in which a lithium salt is dissolved in an organic solvent can be used. The lithium salt is not particularly limited as long as it can be dissociated in a solvent to form Li + ions, and is a side reaction which is less likely to cause decomposition or the like in a voltage range used as a battery. For example, an inorganic lithium salt such as LiClO 4 , LiPF 6 , LiBF 4 , LiAsF 6 , LiSbF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , Li 2 C 2 F 4 (SO 3 ) 2 , LiN (CF 3 ) may be used. An organic lithium salt such as SO 2 ) 2 , LiC(CF 3 SO 2 ) 3 , LiC n F 2n+1 SO 3 (n≧2), LiN(RfOSO 2 ) 2 [wherein, Rf is a fluoroalkyl group] .

使用於非水電解質之有機溶劑，只要可溶解前述之鋰鹽，而於作為電池使用之電壓範圍不會產生分解等之副反應者即可，並無特別限制。可舉例如，碳酸乙烯酯、碳酸丙烯酯、碳酸丁烯酯等之環狀環狀碳酸酯；碳酸二甲酯、碳酸二乙酯、碳酸甲基乙酯等之鏈狀碳酸酯；丙酸甲酯等之鏈狀酯；γ-丁內酯等之環狀酯；二甲氧乙烷、二***、1,3-二氧戊環、二甘二甲醚、三甘二甲醚、四甘二甲醚等之鏈狀醚；二噁烷、四氫呋喃、2-甲基四氫呋喃等之環狀醚；乙腈、丙腈、甲氧基丙腈等之腈類；亞硫酸乙二醇酯等之亞硫酸酯類等，該等亦可混合2種以上使用。又，為了作成特性更良好的電池，較佳為，使用碳酸乙烯酯與鏈狀碳酸酯之混合溶劑等之可得高導電率的組合。又，於該等之非水電解液，於改善充放電循環特性、提升高溫貯藏性或防止過充電等之安全性之目的下，亦可適當添加酸酐、磺酸酯、二腈、碳酸伸乙烯酯類、1,3-丙烷磺內酯、二硫化二苯、環己基苯、聯苯、氟苯、三級丁基苯等之添加劑(含該等之衍生物)。 The organic solvent to be used in the nonaqueous electrolyte is not particularly limited as long as it can dissolve the lithium salt described above and does not cause decomposition or the like in the voltage range used as the battery. For example, a cyclic cyclic carbonate such as ethylene carbonate, propylene carbonate or butylene carbonate; a chain carbonate such as dimethyl carbonate, diethyl carbonate or methyl ethyl carbonate; a chain ester of an ester or the like; a cyclic ester such as γ-butyrolactone; dimethoxyethane, diethyl ether, 1,3-dioxolane, diglyme, triglyme, tetraglycan a chain ether such as dimethyl ether; a cyclic ether such as dioxane, tetrahydrofuran or 2-methyltetrahydrofuran; a nitrile such as acetonitrile, propionitrile or methoxypropionitrile; Sulfate or the like may be used in combination of two or more kinds. Moreover, in order to produce a battery having better characteristics, it is preferable to use a combination of a mixture of ethylene carbonate and a chain carbonate to obtain a high conductivity. Further, in the non-aqueous electrolyte solution, an acid anhydride, a sulfonate, a dinitrile, and a carbonic acid-extended ethylene may be appropriately added for the purpose of improving the charge-discharge cycle characteristics, improving the high-temperature storage property, or preventing the safety of overcharge. Additives (including such derivatives) of esters, 1,3-propane sultone, diphenyl disulfide, cyclohexylbenzene, biphenyl, fluorobenzene, tert-butylbenzene, and the like.

該鋰鹽於非水電解液中之濃度，較佳為0.5~1.5mol/l、更佳為0.9~1.25mol/l。 The concentration of the lithium salt in the nonaqueous electrolytic solution is preferably 0.5 to 1.5 mol/l, more preferably 0.9 to 1.25 mol/l.

又，於前述之非水電解液添加周知之聚合物等之凝膠化劑以作成凝膠狀者(凝膠狀電解質)，亦可使用於本發明之非水電解質二次電池。 In addition, a gelling agent such as a well-known polymer or the like is added to the non-aqueous electrolyte solution to form a gel (gel electrolyte), and may be used in the nonaqueous electrolyte secondary battery of the present invention.

本發明之非水電解質二次電池之形態，可舉例如使用不鏽鋼罐或鋁罐等作為外裝罐之圓柱狀(三角柱狀、圓柱狀等)等。又，亦可作成將蒸鍍有金屬之層合薄膜作為外裝體之軟包裝電池。 In the form of the non-aqueous electrolyte secondary battery of the present invention, for example, a stainless steel tank or an aluminum can is used as a cylindrical shape (triangular column shape, columnar shape, or the like) of the outer can. Further, a flexible packaging battery in which a laminate film in which a metal is vapor-deposited is used as an exterior body can also be used.

本發明之非水電解質二次電池，為高容量、且充放電循環特性優異，故除較佳可使用於要求如此特定之用途之外，亦可使用於習知之非水電解質二次電池適用之各種用途。 The nonaqueous electrolyte secondary battery of the present invention has high capacity and excellent charge and discharge cycle characteristics, and therefore can be used for a specific non-aqueous electrolyte secondary battery, and can be used for a conventional nonaqueous electrolyte secondary battery. Various uses.

〔實施例〕 [Examples]

以下，根據實施例以詳細說明本發明，但下記實施例並非限制本發明。 Hereinafter, the present invention will be described in detail based on examples, but the following examples are not intended to limit the invention.

實施例1 Example 1 <鋰複合氧化物之合成> <Synthesis of lithium composite oxide>

調製分別以3.78mol/dm3、0.25mol/dm3、0.08mol/dm3、0.08mol/dm3之濃度含有硫酸鎳、硫酸鈷、硫酸錳及硫酸鎂的混合水溶液。接著，將藉由氫氧化鈉之添加使pH調整為約12的氨水置入反應容器，將其於劇烈攪拌之下，於其中，使用定量泵將前述混合水溶液、與 25質量%濃度之氨水，分別以23cm3/分、6.6cm3/分的比例滴下，合成Ni、Co、Mn與Mg之共沉澱化合物(球狀之共沉澱化合物)。又，此時，將反應液之溫度保持於50℃，又，同時進行3mol/dm3濃度氫氧化鈉水溶液之滴下以使反應液之pH維持於12附近，再以1dm3/分之流量將氮氣起泡。 A mixed aqueous solution of nickel sulfate, cobalt sulfate, manganese sulfate, and magnesium sulfate was prepared at a concentration of 3.78 mol/dm 3 , 0.25 mol/dm 3 , 0.08 mol/dm 3 , and 0.08 mol/dm 3 , respectively. Next, the ammonia water having a pH adjusted to about 12 by the addition of sodium hydroxide is placed in the reaction vessel, and the mixture is stirred under vigorous stirring, and the mixed aqueous solution and the ammonia aqueous solution having a concentration of 25% by mass are used therein. respectively 23cm 3 / min, the proportion of 6.6cm 3 / min dropping, synthetic Ni, co, Mn and Mg co-precipitation (co-precipitation of spherical compound) compound. Further, at this time, the temperature of the reaction liquid was maintained at 50 ° C, and a 3 mol/dm 3 aqueous sodium hydroxide solution was simultaneously dropped to maintain the pH of the reaction liquid at around 12, and then at a flow rate of 1 dm 3 /min. Nitrogen foaming.

將前述共沉澱化合物水洗、過濾及乾燥，得氫氧化物，將該氫氧化物、與LiOH．H2O、BaSO4與Al(OH)3，以莫耳比成為1：1：0.01：0.01的方式分散於乙醇中作成漿料狀後，以行星式球磨機混合40分鐘，以室溫乾燥得混合物。接著，將前述混合物置入氧化鋁製之坩堝，於2dm3/分之乾燥空氣流中加熱至600℃，保持該溫度2小時以進行預備加熱，再升溫至900℃以進行12小時燒成，藉此合成含有鋰之複合氧化物。 The coprecipitated compound is washed with water, filtered and dried to obtain a hydroxide, the hydroxide, and LiOH. H 2 O, BaSO 4 and Al(OH) 3 were dispersed in ethanol as a slurry in a molar ratio of 1:1:0.01:0.01, and then mixed in a planetary ball mill for 40 minutes and dried at room temperature. mixture. Next, the mixture was placed in a crucible made of alumina, heated to 600 ° C in a dry air stream of 2 dm 3 /min, maintained at this temperature for 2 hours to be preheated, and further heated to 900 ° C for 12 hours of firing. Thereby, a composite oxide containing lithium is synthesized.

將所得之含有鋰之複合氧化物以水洗淨後，於大氣中(氧濃度約20vol%)，以700℃熱處理12小時，之後於研缽粉碎作成粉體。粉碎後之含有鋰之複合氧化物，係保存於乾燥器中。 The obtained lithium-containing composite oxide was washed with water, and then heat-treated at 700 ° C for 12 hours in the air (oxygen concentration: about 20 vol%), and then pulverized in a mortar to prepare a powder. The pulverized composite oxide containing lithium is stored in a desiccator.

對前述含有鋰之複合氧化物，使用ICP(Inductive Coupled Plasma，感應耦合電漿)法以如下之方式進行其之組成分析。首先，採取前述含有鋰之複合氧化物0.2g置入100mL容器。之後，依序加入純水5mL、王水2mL、純水10mL以加熱溶解，冷卻後，再稀釋25倍以ICP(JARRELASH公司製「ICP-757」)分析組成(檢量線法) 。由所得之結果，導出前述含有鋰之複合氧化物之組成的結果，判明係Li1.0Ni0.89Co0.05Mn0.02Mg0.02Ba0.01Al0.01O2所表示之組成。又，前述鋰鎳鈷錳複合氧化物之平均粒徑為15μm。 The composition analysis of the lithium-containing composite oxide was carried out in the following manner using an ICP (Inductive Coupled Plasma) method. First, 0.2 g of the lithium-containing composite oxide was placed in a 100 mL container. Then, 5 mL of pure water, 2 mL of aqua regia, and 10 mL of pure water were added in order to be dissolved by heating, and after cooling, the composition was analyzed by ICP ("ICP-757" manufactured by JARRELASH Co., Ltd.) by a 25-fold dilution (measurement line method). From the results obtained, the results of the composition of the lithium-containing composite oxide were derived, and the composition represented by Li 1.0 Ni 0.89 Co 0.05 Mn 0.02 Mg 0.02 Ba 0.01 Al 0.01 O 2 was found. Further, the lithium nickel cobalt manganese composite oxide has an average particle diameter of 15 μm.

<鋰鈷複合氧化物(A)之合成> <Synthesis of lithium cobalt composite oxide (A)>

將Co(OH)2、Mg(OH)2、Al(OH)3、與Li2CO3以使莫耳比為1.97：0.02：0.01：1.02的方式混合，將該混合物於大氣中(氧濃度為約20vol%)、以950℃熱處理12小時以合成鋰鈷複合氧化物(A)，之後以研缽粉碎作成粉體。粉碎後之鋰鈷複合氧化物(A)，係保存於乾燥器中。 Co(OH) 2 , Mg(OH) 2 , Al(OH) 3 , and Li 2 CO 3 are mixed so that the molar ratio is 1.97:0.02:0.01:1.02, and the mixture is in the atmosphere (oxygen concentration) It was about 20 vol%), heat-treated at 950 ° C for 12 hours to synthesize a lithium cobalt composite oxide (A), and then pulverized in a mortar to prepare a powder. The pulverized lithium cobalt composite oxide (A) is stored in a desiccator.

對前述鋰鈷複合氧化物(A)，使用ICP法以進行組成分析之結果，判明係以Li1.0Co0.985Mg0.01Al0.005O2所表示之組成。又，前述鋰鈷複合氧化物(A)之平均粒徑為20μm。 As a result of performing composition analysis using the ICP method, the lithium-cobalt composite oxide (A) was found to have a composition represented by Li 1.0 Co 0.985 Mg 0.01 Al 0.005 O 2 . Further, the lithium cobalt composite oxide (A) has an average particle diameter of 20 μm.

<鋰鈷複合氧化物(B)之合成> <Synthesis of lithium cobalt composite oxide (B)>

將Co(OH)2、Mg(OH)2、Al(OH)3、ZrO2與Li2CO3以使莫耳比為1.946：0.03：0.02：0.004：1.02的方式混合，將該混合物於大氣中(氧濃度為約20vol%)、以950℃熱處理12小時以合成鋰鈷複合氧化物(B)，之後以研缽粉碎作成粉體。粉碎後之鋰鈷複合氧化物(B)，係保存於乾燥器中。 Co(OH) 2 , Mg(OH) 2 , Al(OH) 3 , ZrO 2 and Li 2 CO 3 are mixed so that the molar ratio is 1.946:0.03:0.02:0.004:1.02, and the mixture is brought to the atmosphere. In the middle (oxygen concentration: about 20 vol%), heat treatment was performed at 950 ° C for 12 hours to synthesize a lithium cobalt composite oxide (B), followed by pulverization in a mortar to prepare a powder. The pulverized lithium cobalt composite oxide (B) is stored in a desiccator.

對前述鋰鈷複合氧化物(B)，使用ICP法以進行組成 分析之結果，判明係以Li1.0Co0.973Mg0.015Al0.01Zr0.002O2所表示之組成。又，前述鋰鈷複合氧化物(B)之平均粒徑為8μm。 The composition of the lithium cobalt composite oxide (B) represented by Li 1.0 Co 0.973 Mg 0.015 Al 0.01 Zr 0.002 O 2 was determined by the ICP method. Further, the lithium cobalt composite oxide (B) had an average particle diameter of 8 μm.

<正極之製作> <Production of positive electrode>

將以80：20之質量比混合之前述鋰鈷複合氧化物(A)與前述鋰鈷複合氧化物(B)之混合物：74質量份、前述鋰鎳鈷錳複合氧化物：18質量份、含有3質量%的濃度之黏結劑之VDF-CTFE之NMP溶液：20質量份、與導電助劑之人造石墨：1.5質量份及科琴黑：1.5質量份，使用雙軸混練機混練，再加入NMP以調節黏度，調製成含有正極合劑之漿料。 a mixture of the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) in a mass ratio of 80:20: 74 parts by mass, the lithium nickel cobalt manganese composite oxide: 18 parts by mass, and containing NMP solution of VDF-CTFE with a binder of 3 mass%: 20 parts by mass, artificial graphite with conductive additive: 1.5 parts by mass and Ketjen black: 1.5 parts by mass, mixed with a biaxial kneading machine, and then added with NMP The viscosity is adjusted to prepare a slurry containing a positive electrode mixture.

將前述含有正極合劑之漿料，塗布於厚度為15μm之鋁鉑(正極集電器)之兩面後，以120℃進行真空乾燥12小時，於鋁鉑之兩面形成正極合劑層。之後，進行加壓處理，以調節正極合劑層之厚度及密度，於鋁鉑之露出部焊接鎳製之導線體，以製作54mm之帶狀的正極。所得之正極的正極合劑層，總厚度為145μm，正極合劑層之密度為3.85g/cm3。 The slurry containing the positive electrode mixture was applied to both surfaces of aluminum platinum (positive electrode current collector) having a thickness of 15 μm, and then vacuum-dried at 120 ° C for 12 hours to form a positive electrode mixture layer on both surfaces of aluminum platinum. Thereafter, a pressure treatment was performed to adjust the thickness and density of the positive electrode mixture layer, and a lead body made of nickel was welded to the exposed portion of the aluminum platinum to prepare a strip-shaped positive electrode of 54 mm. The positive electrode mixture layer of the obtained positive electrode had a total thickness of 145 μm, and the density of the positive electrode mixture layer was 3.85 g/cm 3 .

<負極之製作> <Production of negative electrode>

將以碳材料被覆負極活性物質之平均粒徑d50為8μm之SiO表面之複合體(複合體中之碳材料之量為10質量%)、與平均粒徑D50%為16μm之石墨，以使以碳材料 被覆SiO表面之複合體之量為3.75質量%之量混合的混合物：97.5質量份、黏結劑之SBR：1.5質量份、及增黏劑之羧基甲基纖維素：1質量份，於其加水混合，調製成含有負極合劑之漿料。 A composite of an SiO surface having an average particle diameter d 50 of an anode active material d of 8 μm (the amount of the carbon material in the composite is 10% by mass) and graphite having an average particle diameter D50% of 16 μm are coated with a carbon material. a mixture in which the amount of the composite of the carbon material coated SiO surface is 3.75 mass%: 97.5 parts by mass, SBR of the binder: 1.5 parts by mass, and carboxymethyl cellulose of the tackifier: 1 part by mass, It is mixed with water to prepare a slurry containing a negative electrode mixture.

將前述含有負極合劑之漿料，塗布於厚度為8μm之銅鉑(負極集電器)之兩面後，以120℃進行真空乾燥12小時，於銅鉑之兩面形成負極合劑層。之後，進行加壓處理，以調節負極合劑層之厚度及密度，於銅鉑之露出部焊接鎳製之導線體，以製作寬度55mm之帶狀的負極。所得之負極的負極合劑層，總厚度為136μm。 The slurry containing the negative electrode mixture was applied to both surfaces of copper platinum (negative electrode current collector) having a thickness of 8 μm, and then vacuum-dried at 120 ° C for 12 hours to form a negative electrode mixture layer on both sides of copper platinum. Thereafter, a pressure treatment was performed to adjust the thickness and density of the negative electrode mixture layer, and a lead body made of nickel was welded to the exposed portion of copper platinum to prepare a strip-shaped negative electrode having a width of 55 mm. The negative electrode mixture layer of the obtained negative electrode had a total thickness of 136 μm.

<電池之組裝> <Battery Assembly>

接著，將前述之負極與前述之正極，透過微孔性聚乙烯薄膜製之間隔物(厚度18μm、空孔率50%)重疊捲繞成滾筒狀後，於正負極焊接端子，***厚度49mm、寬度42mm、高度61mm(494261型)之鋁合金製外裝罐，將蓋焊接以安裝。之後，由蓋之注液口，將於EC：DEC=3：7(體積比)溶解3質量%之碳酸伸乙烯酯之溶液、再以使LiPF6成為1mol%的方式溶解所調製之非水電解液注入容器內、並密閉，製得圖1所示之構造、圖2所示之外觀之方形非水二次電池。 Then, the negative electrode and the positive electrode described above were passed through a separator made of a microporous polyethylene film (thickness: 18 μm, porosity: 50%) and wound into a roll shape, and then inserted into a positive and negative electrode terminal to have a thickness of 49 mm and a width of 42 mm. An aluminum alloy outer can of height 61mm (494261 type), the cover is welded for installation. Thereafter, a solution of 3% by mass of a carbonic acid-extended vinyl ester was dissolved in EC:DEC=3:7 (volume ratio) from the liquid inlet of the lid, and the prepared non-aqueous solution was dissolved so that LiPF 6 became 1 mol%. The electrolyte was injected into the container and sealed, and a square nonaqueous secondary battery having the structure shown in Fig. 1 and the appearance shown in Fig. 2 was obtained.

此處，說明圖1及圖2所示之電池，圖1之(a)為俯視圖、(b)為局部縱截面圖，如圖1(b)所示，正極1與負極2係透過間隔物3捲繞成漩渦狀，加壓成扁平狀作成扁平狀 之捲繞電極體6，而與非水電解液共同收納於方形(長方柱體)之電池外盒4。其中，於圖1，為了避免複雜化，於正極1或負極2之製作時所使用之集電器之金屬箔或非水電解液等並未圖示。 Here, the battery shown in FIGS. 1 and 2 will be described. FIG. 1(a) is a plan view and (b) is a partial longitudinal cross-sectional view. As shown in FIG. 1(b), the positive electrode 1 and the negative electrode 2 are permeated through the spacer. 3 is wound into a spiral shape, and is pressed into a flat shape to form a flat shape. The wound electrode body 6 is wound around the battery outer case 4 of a square (rectangular column) together with the non-aqueous electrolyte. In addition, in FIG. 1, in order to avoid complication, the metal foil or non-aqueous electrolyte etc. of the collector used at the time of manufacture of the positive electrode 1 or the negative electrode 2 are not shown.

電池外盒4係以鋁合金製構成電池之外裝體者，該電池外盒4係兼作正極端子。而於電池外盒4之底部配置PE薄片所構成之絕緣體5，由正極1、負極2及間隔物3所構成之扁平狀捲繞電極體6，拉出分別連接於正極1及負極2之一端之正極導線體7與負極導線體8。又，於將電池外盒4開口部封口之鋁合金製之封口用蓋板9，透過聚丙烯製之絕緣襯墊10安裝不鏽鋼製之端子11，於該端子11透過絕緣體12安裝不鏽鋼製之導線板13。 The battery case 4 is made of an aluminum alloy, and the battery case 4 is also used as a positive electrode terminal. The insulator 5 composed of a PE sheet is disposed at the bottom of the battery case 4, and the flat wound electrode body 6 composed of the positive electrode 1, the negative electrode 2, and the spacer 3 is pulled out and connected to one end of the positive electrode 1 and the negative electrode 2, respectively. The positive lead body 7 and the negative lead body 8. Moreover, the sealing cover 9 made of an aluminum alloy which seals the opening of the battery case 4 is attached to the terminal 11 made of stainless steel through the insulating spacer 10 made of polypropylene, and the wire of the stainless steel is attached to the terminal 11 through the insulator 12. Board 13.

而該蓋板9係***電池外盒4之開口部，藉由將兩者之接合部焊接，使電池外盒4開口部封口，而使電池內部密閉。又，於圖1之電池，於蓋板9設置有非水電解液注入口14，於該非水電解液注入口14，以密封構件***的狀態，例如藉由雷射焊接等焊接密封，以確保電池之密閉性。再者，於蓋板9，作為電池之溫度上升之際將內部之氣體排出至外部的機構，設置有開裂通氣孔15。 The cover 9 is inserted into the opening of the battery case 4, and the joint portion of the battery is welded to seal the opening of the battery case 4 to seal the inside of the battery. Further, in the battery of Fig. 1, the non-aqueous electrolyte injection port 14 is provided in the cover plate 9, and the non-aqueous electrolyte injection port 14 is sealed by welding, for example, by a laser welding or the like in a state in which the sealing member is inserted. The tightness of the battery. Further, in the cover plate 9, as a mechanism for discharging the internal gas to the outside as the temperature of the battery rises, the crack vent hole 15 is provided.

於該實施例1之電池，藉由將正極導線體7直接焊接於蓋板9可使外裝罐5與蓋板9具有作為正極端子之機能，將負極導線體8焊接於導線板13，透過該導線板13使負極導線體8與端子11通導，藉此使端子11具有作為負極端子之機能，而視電池外盒4之材質等，該正負亦有 相反的情形。 In the battery of the first embodiment, the outer can 5 and the cover 9 have functions as positive terminals by directly soldering the positive lead body 7 to the cover 9, and the negative lead body 8 is welded to the lead plate 13 to pass through. The lead plate 13 leads the negative lead body 8 to the terminal 11, whereby the terminal 11 has a function as a negative terminal, and depending on the material of the battery case 4, etc. The opposite situation.

圖2係前述圖1所示之電池之外觀的模式立體圖，該圖2係以顯示前述電池為方形電池為目的所圖示者，於該圖1係概略地顯示電池，除電池之構成構件中之特定者並無圖示。又，於圖1，電極體之內周側部分並無顯示截面。 2 is a schematic perspective view showing the appearance of the battery shown in FIG. 1, and FIG. 2 is a view showing the purpose of the battery as a prismatic battery. FIG. 1 schematically shows a battery, except for a component of the battery. The specific person is not shown. Further, in Fig. 1, the inner peripheral side portion of the electrode body does not have a cross section.

實施例2 Example 2 <鋰鎳鈷錳複合氧化物之合成> <Synthesis of lithium nickel cobalt manganese composite oxide>

將藉由氫氧化鈉之添加使pH調整為約12的氨水置入反應容器，將其於劇烈攪拌之下，於其中，將分別以2.0mol/dm3、0.8mol/dm3、1.2mol/dm3之濃度含有硫酸鎳、硫酸鈷及硫酸錳的混合水溶液、與25質量%濃度之氨水，使用定量泵分別以23cm3/分、6.6cm3/分的比例滴下，合成Ni、Co與Mn之共沉澱化合物(球狀之共沉澱化合物)。又，此時，將反應液之溫度保持於50℃，又，同時進行6.4mol/dm3濃度氫氧化鈉水溶液之滴下以使反應液之pH維持於12附近，再以1dm3/分之流量將氮氣起泡。 Ammonia water adjusted to a pH of about 12 by the addition of sodium hydroxide was placed in the reaction vessel, and under vigorous stirring, therein, 2.0 mol/dm 3 , 0.8 mol/dm 3 , 1.2 mol/ respectively. dm 3 concentration in the mixed aqueous solution containing nickel sulfate, cobalt sulfate and manganese sulfate with a concentration of 25 mass% aqueous ammonia, using a metering pump, respectively 23cm 3 / min, the proportion of 6.6cm 3 / min dropping, synthetic Ni, Co and Mn The coprecipitated compound (spherical coprecipitated compound). Further, at this time, the temperature of the reaction liquid was maintained at 50 ° C, and at the same time, the dropwise addition of a 6.4 mol/dm 3 aqueous sodium hydroxide solution was carried out to maintain the pH of the reaction liquid at around 12, and then at a flow rate of 1 dm 3 /min. Nitrogen was bubbled.

將前述共沉澱化合物水洗、過濾及乾燥，得以莫耳比5：2：3含有Ni、Co與Mn之氫氧化物。將該氫氧化物0.196mol、與0.204mol之LiOH．H2O分散於乙醇中作成漿料狀後，以行星式球磨機混合40分鐘，以室溫乾燥得混合物。接著，將前述混合物置入氧化鋁製之坩堝，於 2dm3/分之乾燥空氣流中加熱至600℃，保持該溫度2小時以進行預備加熱，再升溫至900℃以進行12小時燒成，藉此合成鋰鎳鈷錳複合氧化物。 The coprecipitated compound was washed with water, filtered and dried to obtain a hydroxide of Ni, Co and Mn at a molar ratio of 5:2:3. The hydroxide was 0.196 mol, and 0.204 mol of LiOH. H 2 O was dispersed in ethanol to form a slurry, and then mixed in a planetary ball mill for 40 minutes, and dried at room temperature to obtain a mixture. Next, the mixture was placed in a crucible made of alumina, heated to 600 ° C in a dry air stream of 2 dm 3 /min, maintained at this temperature for 2 hours to be preheated, and further heated to 900 ° C for 12 hours of firing. Thereby, a lithium nickel cobalt manganese composite oxide is synthesized.

將前述之鋰鎳鈷錳複合氧化物以水洗淨後，於大氣中(氧濃度約20vol%)，以850℃熱處理12小時，之後於研缽粉碎作成粉體。粉碎後之鋰鎳鈷錳複合氧化物，係保存於乾燥器中。 The lithium nickel cobalt manganese composite oxide described above was washed with water, and then heat-treated at 850 ° C for 12 hours in the air (oxygen concentration: about 20 vol%), and then pulverized in a mortar to obtain a powder. The pulverized lithium nickel cobalt manganese composite oxide is stored in a desiccator.

對前述鋰鎳鈷錳複合氧化物，使用ICP法以如下之方式進行其之組成分析。首先，採取前述鋰鎳鈷錳複合氧化物0.2g置入100mL容器。之後，依序加入純水5mL、王水2mL、純水10mL以加熱溶解，冷卻後，再稀釋25倍以ICP(JARRELASH公司製「ICP-757」)分析組成(檢量線法)。由所得之結果，導出前述鋰鎳鈷錳複合氧化物之組成的結果，判明係Li1.02Ni0.5Co0.2Mn0.3O2所表示之組成。又，前述鋰鎳鈷錳複合氧化物之平均粒徑為15μm。 The composition analysis of the lithium nickel cobalt manganese composite oxide was carried out by the ICP method in the following manner. First, 0.2 g of the above lithium nickel cobalt manganese composite oxide was placed in a 100 mL container. Then, 5 mL of pure water, 2 mL of aqua regia, and 10 mL of pure water were added in order to dissolve by heating, and after cooling, the composition was analyzed by ICP ("ICP-757" manufactured by JARRELASH Co., Ltd.) by a 25-fold dilution (measurement line method). From the results obtained, the composition of the lithium nickel cobalt manganese composite oxide was derived, and the composition represented by Li 1.02 Ni 0.5 Co 0.2 Mn 0.3 O 2 was found. Further, the lithium nickel cobalt manganese composite oxide has an average particle diameter of 15 μm.

除了使鋰鎳鈷錳複合氧化物為前述之物以外，與實施例1同樣地製作正極，除了使用該正極之外與實施例1同樣地製作非水電解質二次電池。 A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the positive electrode was produced in the same manner as in Example 1 except that the lithium nickel cobalt manganese composite oxide was used as the above.

比較例1 Comparative example 1

除了將黏結劑變更為PVDF之外與實施例1同樣地製作正極，除了使用該正極之外與實施例1同樣地製作非水電解質二次電池。 A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the positive electrode was produced in the same manner as in Example 1 except that the binder was changed to PVDF.

比較例2 Comparative example 2

除了將黏結劑變更為PVDF之外與實施例2同樣地製作正極，除了使用該正極之外與實施例1同樣地製作非水電解質二次電池。 A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that the positive electrode was produced in the same manner as in Example 2 except that the binder was changed to PVDF.

對實施例及比較例之非水電解質二次電池，進行下述之各評價。 The following evaluations were performed on the nonaqueous electrolyte secondary batteries of the examples and the comparative examples.

<電池容量> <Battery capacity>

對實施例及比較例之各電池，於初次充放電後，於常溫(25℃)下，以1C之定電流充電至到達4.35V為止，之後以4.35V之定電壓充電以進行定電流-定電壓充電(總充電時間：2.5小時)，之後，進行0.2C之定電流放電(放電終止電壓：3.0V)，所得之放電容量(mAh)作為電池容量。 Each of the batteries of the examples and the comparative examples was charged at a normal temperature (25 ° C) at a constant current of 1 C until reaching 4.35 V after the initial charge and discharge, and then charged at a constant voltage of 4.35 V to perform a constant current-determination. Voltage charging (total charging time: 2.5 hours), after that, a constant current discharge of 0.2 C (discharge termination voltage: 3.0 V) was performed, and the resulting discharge capacity (mAh) was taken as the battery capacity.

<充放電循環特性> <Charge and discharge cycle characteristics>

對實施例及比較例之各電池，於初次充放電後，以與電池容量之測定相同條件之充電及放電的一系列操作作為1循環，反覆進行充放電1000循環，測定第200循環、第400循環、第600循環、第800循環及第1000循環之放電容量，將各放電容量除以第1循環所得之放電容量之值以百分率表示，求出容量維持率。該容量維持率愈大，表示電池之充放電循環特性愈良好。 In each of the batteries of the examples and the comparative examples, after a first charge and discharge, a series of operations of charging and discharging under the same conditions as the measurement of the battery capacity were performed as one cycle, and charging and discharging were repeated for 1,000 cycles, and the 200th cycle and the 400th cycle were measured. The discharge capacity of the cycle, the 600th cycle, the 800th cycle, and the 1000th cycle was expressed as a percentage of the discharge capacity divided by the discharge capacity obtained in the first cycle, and the capacity retention ratio was determined. The larger the capacity retention rate, the better the charge-discharge cycle characteristics of the battery.

<60℃之貯藏試驗(電池膨脹)> <60 ° C storage test (battery expansion)>

對實施例及比較例之各電池，於初次充放電後，以與電池容量之測定相同條件進行充電。充電之後，事先測定電池外裝罐之厚度T1，之後，將電池於設定為60℃之恆溫槽內貯藏既定時間之後，由恆溫槽取出，放置於常溫下1分鐘之後，再度測定電池外裝罐之厚度T2。又，本試驗所謂之電池外裝罐厚度，係指外裝罐之側面部之寬廣面間之厚度之意。電池外裝罐之厚度測定，係使用游標尺(Mitutoyo公司製「CD-15CX」)，以寬廣面之中央部為測定對象，以1/100mm單位計測。又，恆溫槽內之貯藏日數，為1天、10天、20天、40天、60天及80天，分別以不同電池，測定經過各貯藏日數後之電池外裝罐之厚度T2。 Each of the batteries of the examples and the comparative examples was charged under the same conditions as the measurement of the battery capacity after the first charge and discharge. After charging, the thickness T 1 of the battery can is measured in advance, and then the battery is stored in a thermostat set at 60 ° C for a predetermined period of time, and then taken out from the constant temperature bath, placed at room temperature for 1 minute, and then the battery exterior is measured again. The thickness of the can is T 2 . In addition, the thickness of the battery outer can is referred to as the thickness of the wide side of the side portion of the outer can. The thickness of the battery can was measured using a vernier scale ("CD-15CX" manufactured by Mitutoyo Co., Ltd.) in the center of the wide surface, and measured in units of 1/100 mm. Moreover, the storage days in the constant temperature bath are 1 day, 10 days, 20 days, 40 days, 60 days, and 80 days, and the thickness T 2 of the battery outer can after each storage day is measured by using different batteries. .

電池膨脹，係由相對於60℃貯藏前之外裝罐厚度T1之貯藏前後之外裝罐厚度T1及至T2之變化比例來評價。亦即，電池膨脹(%)係由下述式所求得。 The battery expansion was evaluated from the change ratio of the can thickness T 1 and T 2 before and after storage relative to the thickness T 1 of the can before storage at 60 ° C. That is, the battery expansion (%) is obtained by the following formula.

電池膨脹(%)=100×(T2-T1)/(T1) Battery expansion (%) = 100 × (T 2 - T 1 ) / (T 1 )

將前述之各評價結果示於表1及表2。 The evaluation results described above are shown in Tables 1 and 2.

如表1及表2所示，於負極活性物質使用SiOx與石墨質碳材料、於正極活性物質使用含作為過渡金屬元素之Ni之含有鋰的複合氧化物、於正極合劑層之黏結劑使用VDF-CTFE之實施例1、2的電池，與於正極合劑層之黏結劑使用PVDF之比較例1、2的電池相比，充放電循環評價時之各循環數的容量維持率為高、充放電循環特性為良好，又，貯藏特性評價時，特別是貯藏日數長時膨脹量小、貯藏特定異良好。 As shown in Table 1 and Table 2, SiO x and a graphite carbon material are used for the negative electrode active material, and a lithium-containing composite oxide containing Ni as a transition metal element and a binder for the positive electrode mixture layer are used for the positive electrode active material. In the batteries of Examples 1 and 2 of the VDF-CTFE, compared with the batteries of Comparative Examples 1 and 2 in which the PVDF was used as the binder in the positive electrode mixture layer, the capacity retention rate of each cycle number during charge and discharge cycle evaluation was high, and the charge was high. The discharge cycle characteristics were good, and in the evaluation of storage characteristics, particularly when the number of storage days was long, the amount of expansion was small, and the storage specificity was good.

Claims (9)

一種非水電解質二次電池，其係具有正極、負極、非水解電解質及間隔物之非水電解質二次電池，其特徵係，前述正極，係於集電器之單面或雙面具有含正極活性物質及黏結劑之正極合劑層者，前述正極合劑層，含有含作為過渡金屬元素之鎳之含有鋰的複合氧化物作為正極活性物質，並且含有二氟亞乙烯-氯三氟乙烯共聚物作為黏結劑，前述含作為過渡金屬元素之鎳之含有鋰的複合氧化物，當總過渡金屬元素之量為100mol%時，鎳之比例a(mol%)，為30≦a≦100，前述負極，係於集電器之單面或雙面具有含負極活性物質之負極合劑層者，前述負極合劑層，含有於構成元素含有Si與O之材料(其中，相對於Si之O的原子比x為0.5≦x≦1.5)，與石墨質碳材料作為負極活性物質。 A nonaqueous electrolyte secondary battery comprising a positive electrode, a negative electrode, a non-hydrolyzed electrolyte, and a separator, wherein the positive electrode is positively active on one or both sides of the current collector. In the positive electrode mixture layer of the substance and the binder, the positive electrode mixture layer contains a lithium-containing composite oxide containing nickel as a transition metal element as a positive electrode active material, and contains a difluoroethylene-chlorotrifluoroethylene copolymer as a binder. The lithium-containing composite oxide containing nickel as a transition metal element, when the amount of the total transition metal element is 100 mol%, the ratio a (mol%) of nickel is 30 ≦ a ≦ 100, and the negative electrode is In the negative electrode mixture layer containing a negative electrode active material on one or both sides of the current collector, the negative electrode mixture layer is contained in a material containing Si and O as constituent elements (wherein the atomic ratio x of O with respect to Si is 0.5 ≦). x≦1.5), and a graphite carbon material as a negative electrode active material. 如申請專利範圍第1項之非水電解質二次電池，其中，正極之正極合劑層，作為含作為過渡金屬元素之鎳之含有鋰的複合氧化物，含有鋰鎳鈷錳複合氧化物。 The non-aqueous electrolyte secondary battery of the first aspect of the invention, wherein the positive electrode mixture layer of the positive electrode contains a lithium-nickel-cobalt-manganese composite oxide as a composite oxide containing lithium as a transition metal element. 如申請專利範圍第2項之非水電解質二次電池，其中，鋰鎳鈷錳複合氧化物，係以下述一般組成式(1)所表示者；Li1+sM1O2 (1) (前述一般組成式(1)中，-0.3≦s≦0.3，M1係至少含有Ni、Co及Mn之3種以上之元素群，構成M1之各元素中，當Ni、Co及Mn之比例(mol%)分別為a、b及c時，30<a<65、5<b<35、15<c<50)。 A nonaqueous electrolyte secondary battery according to claim 2, wherein the lithium nickel cobalt manganese composite oxide is represented by the following general composition formula (1); Li 1+s M 1 O 2 (1) ( In the above general composition formula (1), -0.3 ≦s ≦ 0.3, and M 1 contains at least three or more element groups of Ni, Co, and Mn, and the ratio of Ni, Co, and Mn among the elements constituting M 1 . When (mol%) is a, b, and c, respectively, 30 < a < 65, 5 < b < 35, and 15 < c < 50). 如申請專利範圍第2或3項之非水電解質二次電池，其中，正極之正極合劑層，與鋰鎳鈷錳複合氧化物一同，含有含鋰、鎳、鈷及錳以外之異種金屬元素的鋰鈷複合氧化物，於前述鋰鈷複合氧化物，係使平均粒徑A(μm)超過10μm且30μm以下之鋰鈷複合氧化物(A)、與平均粒徑B(μm)為1μm以上且10μm以下之鋰鈷複合氧化物(B)，以滿足A-B≧5之關係的方式使用，於前述鋰鈷複合氧化物(B)中之鈷與異種金屬元素之合計量中之異種金屬元素的比例，係比前述鋰鈷複合氧化物(A)中之鈷與異種金屬元素之合計量中之異種金屬元素的比例為更大，當作為正極活性物質使用之鋰鎳鈷錳複合氧化物的平均粒徑為C(μm)時，C>B。 The nonaqueous electrolyte secondary battery according to claim 2, wherein the positive electrode mixture layer of the positive electrode, together with the lithium nickel cobalt manganese composite oxide, contains a dissimilar metal element other than lithium, nickel, cobalt and manganese. In the lithium cobalt composite oxide, the lithium cobalt composite oxide (A) having an average particle diameter A (μm) of more than 10 μm and not more than 30 μm and an average particle diameter B (μm) of 1 μm or more are used. A lithium cobalt composite oxide (B) of 10 μm or less is used in a manner to satisfy the relationship of AB≧5, and the ratio of the dissimilar metal elements in the total amount of cobalt and dissimilar metal elements in the lithium cobalt composite oxide (B) is used. The ratio of the dissimilar metal elements in the total amount of cobalt and dissimilar metal elements in the lithium-cobalt composite oxide (A) is larger, and the average particle size of the lithium nickel cobalt manganese composite oxide used as the positive electrode active material When the diameter is C (μm), C>B. 如申請專利範圍第4項之非水電解質二次電池，其中，鋰鈷複合氧化物(A)之平均粒徑A(μm)，與鋰鈷複合氧化物(B)之平均粒徑B(μm)，與鋰鎳鈷錳複合氧化物之平均粒徑C(μm)，係滿足A≧C>B的關係。 The nonaqueous electrolyte secondary battery of claim 4, wherein the average particle diameter A (μm) of the lithium cobalt composite oxide (A) and the average particle diameter B of the lithium cobalt composite oxide (B) (μm) The average particle diameter C (μm) of the lithium nickel cobalt manganese composite oxide satisfies the relationship of A ≧ C > B. 如申請專利範圍第4或5項之非水電解質二次電 池，其中，鋰鈷複合氧化物(A)及鋰鈷複合氧化物(B)，係以下述一般組成式(2)所表示者；Li1+yCozM2 1-zO2 (2)(前述一般組成式(2)中，-0.3≦y≦0.3、0.95≦z<1.0，M2係選自Mg、Zr、Al及Ti所成群中之至少1種的元素)。 The nonaqueous electrolyte secondary battery according to the fourth or fifth aspect of the invention, wherein the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) are represented by the following general composition formula (2); Li 1+y Co z M 2 1-z O 2 (2) (in the above general composition formula (2), -0.3≦y≦0.3, 0.95≦z<1.0, M 2 is selected from Mg, Zr, Al and At least one element of the group of Ti). 如申請專利範圍第6項之非水電解質二次電池，其中，前述一般組成式(2)中之M2，係Mg及/或Zr。 The nonaqueous electrolyte secondary battery according to claim 6, wherein M 2 in the above general composition formula (2) is Mg and/or Zr. 如申請專利範圍第4至7項中任一項之非水電解質二次電池，其中，當於正極合劑層所使用之鋰鈷複合氧化物(A)與鋰鈷複合氧化物(B)之合計為100質量%時，鋰鈷複合氧化物(A)之含有率為50質量%以上。 The nonaqueous electrolyte secondary battery according to any one of claims 4 to 7, wherein the lithium cobalt composite oxide (A) and the lithium cobalt composite oxide (B) used in the positive electrode mixture layer are combined. When it is 100% by mass, the content of the lithium cobalt composite oxide (A) is 50% by mass or more. 如申請專利範圍第4至8項中任一項之非水電解質二次電池，其中，當於正極合劑層所使用之鋰鈷複合氧化物(A)，與鋰鈷複合氧化物(B)與鋰鎳鈷錳複合氧化物之合計為100質量%時，鋰鎳鈷錳複合氧化物之含有率為15質量%以上45質量%以下。 The nonaqueous electrolyte secondary battery according to any one of claims 4 to 8, wherein the lithium cobalt composite oxide (A) used in the positive electrode mixture layer and the lithium cobalt composite oxide (B) When the total amount of the lithium nickel cobalt manganese composite oxide is 100% by mass, the content of the lithium nickel cobalt manganese composite oxide is 15% by mass or more and 45% by mass or less.
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