JP2008124038A - Cathode active material for lithium ion non-aqueous electrolyte secondary battery and method for producing the same - Google Patents

Abstract

The present invention provides a lithium ion non-aqueous electrolyte secondary battery that increases the discharge capacity of the secondary battery and is excellent in cost.
In a secondary battery including a positive electrode using a lithium-containing metal composite oxide as an active material, a negative electrode using a metal composite oxide having an amorphous structure, and a non-aqueous electrolyte, the positive electrode active material includes: , group II _{Li x Ni 1-y M y} O 2-z X a (M is the periodic table, group 13, an element of group 14, one or more elements selected from transition metal elements, X is A nickel-containing lithium composite oxide which is a halogen element and has a composition of 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z). Lithium ion non-aqueous electrolyte secondary battery characterized.
[Selection figure] None

Description

  The present invention relates to a lithium ion non-aqueous electrolyte secondary battery having a high capacity.

Currently, in general-purpose lithium ion secondary batteries, various carbonaceous materials are used for the negative electrode as a material for reversibly intercalating lithium in an ionic state, and lithium ions can be reversibly inserted and released in the positive electrode as well. A so-called rocking chair type lithium ion secondary battery in which these lithium storage / release materials are combined using a lithium-containing metal composite oxide is used. As the positive electrode active material, LiCoO ₂ , LiCo _1-x Ni _x O ₂ , LiNiO ₂ , LiMn ₂ O _{4 and the} like are widely used, and among these, LiCoO ₂ disclosed in Patent Document 1 is particularly 3.5 Vvs. This is advantageous in that it provides a charge / discharge potential higher than that of Li and has a high capacity. In addition, secondary batteries using LiMn ₂ O ₄ as a positive electrode material have been proposed in Patent Document 2, Patent Document 3, and the like because of the merit of a large supply amount and low cost compared to Co-based. Examples of the carbonaceous material used as the negative electrode active material include graphitic carbon material, pitch coke, fibrous carbon, and high-capacity soft carbon fired at a low temperature. The carbon material usually has a bulk density of 2.20. Since it is relatively small as described below, it is difficult to design a battery with a high effective capacity when used at a lithium insertion capacity (372 mAh / g) up to the stoichiometric limit. Therefore, Patent Document 4, Patent Document 5, Patent Document 6, Patent Document 7, and Patent Document 8 are mainly composed of tin oxide or the like as a negative electrode active material capable of inserting lithium having a high capacity density exceeding that of a carbonaceous material. An amorphous active material made of a composite oxide is disclosed. These amorphous oxide negative electrodes, when combined with cobalt oxide-based positive electrodes, can provide the highest energy density batteries, but have the problem of high cost, while they are combined with manganese oxide-based positive electrode materials. In such a case, a battery with high cost efficiency can be provided, but the problem of low energy density arises. In order to provide a secondary battery excellent in cost efficiency while maintaining the high capacity that is a feature of the amorphous oxide-based negative electrode material, it is considered to use a nickel oxide-based positive electrode. Describes that an amorphous oxide negative electrode and a Ni oxide positive electrode such as LiNiO ₂ or LixCo _a Ni _1-a O ₂ are used.

JP-A-55-136131 Japanese Patent Laid-Open No. 3-147276 JP-A-4-123769 JP-A-6-60867 Japanese Patent Laid-Open No. 7-220721 JP-A-7-122274 JP 7-288123 A International Patent Publication No. WO96-33519 European Patent Publication EP 0651450

However, LiNiO ₂ which is a basic composition of a nickel oxide positive electrode has a discharge average voltage lower by 0.2 V or more than LiCoO ₂ and generally has a poor charge / discharge cycle life. Because the average voltage is low, depending on the operating voltage range of the secondary battery discharge and the conditions of the discharge end voltage, the capacity of LiNiO ₂ cannot be effectively exhibited in the low voltage part, and the increase in battery capacity is suppressed. Connected. The object of the present invention is to solve the above-mentioned problems, use a non-crystalline oxide negative electrode and a nickel oxide-based positive electrode to increase the discharge capacity of the secondary battery, which is excellent in terms of cost. An electrolyte secondary battery is provided.

The above-described problems of the present invention include a positive electrode using a lithium-containing metal composite oxide as an active material, a negative electrode having a metal composite oxide having an amorphous structure, and a non-aqueous electrolyte. The active material is Li _x Ni _{1 -y My} O _{2 -z} X _a (M is one or more elements selected from Group 2, Group 13, Group 14 elements and transition metal elements of the periodic table) , X is a halogen element, and is a nickel-containing lithium composite oxide having a composition of 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z) A lithium ion non-aqueous electrolyte secondary battery, which is characterized by the above, has been solved.

  By using a non-aqueous electrolyte secondary battery in which the composition of the positive electrode active material is a lithium nickel composite oxide and the negative electrode active material is a composite oxide having an amorphous structure and mainly composed of tin oxide, cobalt oxide is used for the positive electrode. Provided is a lithium ion secondary battery having a higher capacity and excellent cycle performance than a secondary battery using a system active material.

Although the form of this invention is demonstrated below, this invention is not limited to these.
(1) In a secondary battery composed of a positive electrode using a lithium-containing metal composite oxide as an active material, a negative electrode using a metal composite oxide having an amorphous structure, and a non-aqueous electrolyte, the positive electrode active material comprises: _{Lix Ni 1-y M y O} 2-z X a (M is a group 2 of the periodic table, group 13, an element of group 14, one or more elements selected from transition metal elements, X is a halogen element And 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z). Lithium ion non-aqueous electrolyte secondary battery.
(2) The lithium ion non-aqueous electrolyte secondary battery according to item 1, wherein the composition of the positive electrode active material is 0.01 ≦ z ≦ 0.25 and 0.02 ≦ a ≦ 0.5. .
(3) The positive electrode active material is characterized in that M is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W. Item 3. The lithium ion nonaqueous electrolyte secondary battery according to Item 1 or 2.
(4) M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W and Co. Item 3. The lithium ion nonaqueous electrolyte secondary battery according to Item 1 or 2.
(5) The lithium ion nonaqueous electrolyte secondary battery according to item 4, wherein the amount of Co in M of the positive electrode active material is 10 mol% or more.
(6) The negative electrode active material contains tin oxide as a main component and contains at least one selected from Group 1, Group 2, Group 13, Group 14, Group 15, transition metal, and halogen element in the periodic table. Item 4. The lithium ion non-aqueous electrolyte secondary battery according to any one of Items 1 to 3.
(7) In a secondary battery including a positive electrode using a lithium-containing metal composite oxide as an active material, a negative electrode having at least one metal composite oxide and a carbonaceous material, and a non-aqueous electrolyte, the positive electrode active material _{but, Li x Ni 1-y M} y O 2-z X a (M is a group 2 of the periodic table, group 13, an element of group 14, one or more elements selected from transition metal elements, X Is a halogen element and is a nickel-containing lithium composite oxide having a composition of 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z) A lithium ion non-aqueous electrolyte secondary battery characterized by
(8) The lithium ion nonaqueous electrolyte secondary battery according to item 7, wherein the composition of the positive electrode active material is 0.01 ≦ z ≦ 0.25 and 0.02 ≦ a ≦ 0.5. .
(9) The positive electrode active material M is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W. Item 9. The lithium ion nonaqueous electrolyte secondary battery according to Item 7 or 8.
(10) M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W and Co. Item 9. The lithium ion nonaqueous electrolyte secondary battery according to Item 7 or 8.
(11) The lithium ion nonaqueous electrolyte secondary battery according to item 10, wherein the amount of Co in M of the positive electrode active material is 10 mol% or more.
(12) The lithium ion non-aqueous electrolyte according to Item 7-11, wherein the amount of the carbon composite material and the carbon composite material of the negative electrode is 10 wt% or more and 70 wt% or less. Next battery.
(13) The lithium ion non-aqueous electrolyte 2 according to any one of Items 7 to 11, wherein the amount of the carbon composite material and the carbon composite material of the negative electrode is 20 wt% or more and 50 wt% or less. Next battery.
(14) The lithium ion non-aqueous electrolyte secondary battery according to any one of items 7 to 13, wherein at least two or more metal composite oxides are used for the negative electrode.
(15) The lithium according to item 14, wherein at least one of the two or more metal composite oxides is a crystalline metal composite oxide, and the other is an amorphous metal composite oxide. Ion non-aqueous electrolyte secondary battery.
(16) The lithium ion nonaqueous electrolyte secondary battery according to item 1-15, wherein the nonaqueous electrolytic solution contains ethylene carbonate and LiPF ₆ .
(17) The lithium ion nonaqueous electrolyte secondary battery according to item 16, wherein the nonaqueous electrolytic solution contains ethylene carbonate, diethyl carbonate, and LiPF ₆ .
(18) The lithium ion nonaqueous electrolyte secondary battery according to item 16, wherein the nonaqueous electrolytic solution contains ethylene carbonate, dimethyl carbonate and LiPF ₆ .
(19) The lithium ion non-aqueous electrolyte secondary battery according to item 1 to 18, wherein X of the positive electrode active material is fluorine.

The lithium ion non-aqueous electrolyte secondary battery of the present invention has a basic structure comprising a positive electrode active material, a negative electrode material and a non-aqueous electrolyte containing a lithium salt, which will be described in detail below, and is a conventional lithium battery using a carbon material negative electrode. It is characterized by a high capacity. The first element having a high capacity is a negative electrode material, and the negative electrode material of the present invention is a metal composite oxide and a carbonaceous material, and a metal composite oxide having an amorphous structure mainly containing tin oxide A composite of an amorphous structure metal complex oxide and / or a crystal structure metal complex oxide and a carbonaceous material is preferable. This negative electrode material is obtained by a process in which lithium ions are synthesized outside of the battery system, or lithium ions are electrochemically inserted (intercalated) into the metal composite oxide corresponding to the active material precursor in the battery, Acts as a negative electrode using lithium as an active material. The second element responsible for high capacity is a lithium nickel composite oxide used as a positive electrode active material. The positive electrode active material of the present invention preferably uses a layered structure of LiNiO ₂ as a basic skeleton and is mixed with another element for improving performance to form a solid solution, and is synthesized as a lithium compound outside the battery.

The positive electrode active material of the present invention is a nickel-containing lithium composite oxide represented by a composition of _{Li x Ni 1-y M y} O 2-z X a. Here, M is a metal or semimetal element substituting a part of Ni or Li among the skeletal structure of LiNiO _2, batteries such as the improvement of growth and cycle life of the average discharge voltage in the charge and discharge performance of LiNiO ₂ positive It is an element that contributes to improved performance. M is one or more elements selected from Group 2, Group 13, Group 14 and transition metal elements of the periodic table, X is a halogen element, and the amount of these elements in the composition is 0.00. 2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z). More preferred form of the positive electrode active material, the _{Li x Ni 1-y M y} O 2-z X a (M Group 13 of the periodic table, elements of Group 14, one or more selected from transition metal elements Element, X is a halogen element, and has a composition of 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0.01 ≦ z ≦ 0.25, 0.02 ≦ a ≦ 0.5). The nickel-containing lithium composite oxide shown. Another more preferable form of the positive electrode active material is Li _x Ni _{1 -y My} O _{2 -z} X _a (M is Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, One or more elements selected from Mo and W, X is a halogen element, 0.2 <x ≦ 1.2, 0.01 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z The nickel-containing lithium composite oxide represented by the composition of A further preferred embodiment of the positive electrode active _{material, Li x Ni 1-y M} y O 2-z X a (M is Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, One or more elements selected from W, X is a halogen element, 0.2 <x ≦ 1.2, 0.01 ≦ y ≦ 0.5, 0.01 ≦ z ≦ 0.25, 0.02 A nickel-containing lithium composite oxide having a composition of ≦ a ≦ 0.5).

Another embodiment of the positive electrode active material of the present invention is a lithium composite oxide that simultaneously contains nickel and cobalt represented by the composition Li _x Ni _1-y Co _yz M _z O _{2 -a} X _b . Here, M is a metal or semimetal element substituting a part of Ni or Li among the skeletal structure of LiNiO _2, batteries such as the improvement of growth and cycle life of the average discharge voltage in the charge and discharge performance of LiNiO ₂ positive It is an element that contributes to improved performance. M is an element of Groups 13 and 14 of the periodic table, one or more elements selected from transition metal elements other than Ni and Co, X is a halogen element, and the amount of these elements in the composition is 0 2 <x ≦ 1.2, 0 <y ≦ 0.5, z <y, 0 <z <0.5, 0 ≦ a ≦ 1.0, and 0 ≦ b ≦ 2a. Among these, one of the preferable compositions of the positive electrode active material has a structure containing at least elemental halogen X that substitutes oxygen in addition to M, and Li _x Ni _1-y Co _yz M _z O _{2 -a} X _b (M is an element of Groups 13 and 14 of the periodic table, one or more elements selected from transition metal elements other than Ni and Co, X is a halogen element, and 0.2 <x ≦ 1.2. 0 <y ≦ 0.5, z <y, 0 <z <0.5, 0.01 ≦ a ≦ 0.5, 0.01 ≦ b ≦ 2a). Also, further preferred composition is a composition fluorine is substituted as _{X, Li x Ni 1-y} Co yz M z O 2-a F b (M is Group 13 of the periodic table, elements of Group 14 , One or more elements selected from transition metal elements other than Ni and Co, 0.2 <x ≦ 1.2, 0 <y ≦ 0.5, z <y, 0 <z <0.5, 0. A nickel-cobalt-containing lithium composite oxide having a composition of 01 ≦ a ≦ 0.5 and 0.01 ≦ b ≦ 2a). As M in the composition of the positive electrode active material, one or more elements selected from Mn, Fe, Ti, B, Al, Sn, Si, Ga, and Mg are preferably used, and a preferable content of M is 0. .01 ≦ z ≦ 0.5. Particularly preferable as M is one or more elements selected from Mn, B, Al, and Si, and a preferable content at this time is in a range of 0.01 ≦ z ≦ 0.3.

The synthesis of the lithium nickel composite oxide of the present invention includes a lithium compound that is a lithium material, a nickel compound that is a nickel material, and Co, Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, A compound containing another element M typified by Mo, W or the like is mixed, and the raw material powder is fired in a high temperature dry state, or by a chemical reaction in a solution state typified by a solugel method. As the lithium raw material, LiOH, Li ₂ CO ₃ , Li ₂ O, LiNO ₃ , Li ₂ SO ₄ , LiHCO ₃ , Li (CH ₃ COO), alkyl lithium, etc. are used, and NiO, NiCO ₃ are used as the Ni raw material. Ni (NO ₃ ) ₂ , Ni powder, NiCl ₂ , NiSO ₄ , Ni ₃ (PO ₄ ) ₂ , Li (CH ₃ COO) ₂ , Ni (OH) ₂ , NiOOH, Ni alkoxide and the like are useful. Further, as the raw material of the other element M, Co ₂ O ₃ , Co ₃ O ₄ , CoCO ₃ , Co (NO ₃ ) ₂ , CoCl ₂ , MnCO ₃ , MnO ₂ , Mn (NO) ₃ , B ₂ O ₃ , B (OH) ₃ , Al ₂ O ₃ , Al (NO ₃ ) ₃ , Al (OH) ₃ , SnO ₂ , SnO, SnCl ₂ , Sn alkoxide, SiO ₂ , SiO, alkoxysilane, Mg (OH) ₂ , MgCO ₃ , MgCl ₂ , Fe ₂ O ₃ , FeCl ₃ , FeOOH, Fe (NO ₃ ) ₃ , TiO ₂ , GeO ₂ , ZrO ₂ , Nd ₂ O ₃ , La ₂ O ₃ , BaO, SrCO ₃ , La ₂ O ₃ , Zn (NO ₃ ) ₂ , WO ₃ , Ga (NO ₃ ) ₂ , CuO, V ₂ O ₅ , Sm ₂ O ₃ , Y ₂ O ₃ , AlF ₃ , BaF ₂ , LiF, LaF ₃ , SnF ₂ , Li ₃ PO ₄ , AlPO ₄ , Cs ₂ CO ₃ , Ca (OH) ₂ , Na ₂ CO ₃ etc. can be used. These raw materials may be mixed in the form of a solid powder, or a plurality of raw materials may be dissolved in a solvent to form a mixed solution, which may be dried, solidified or slurried to form a mixture. In the case of synthesizing by firing, the above raw material powder or slurry mixture is preferably used at a temperature of 400 ° C. to 1000 ° C., preferably 600 ° C. to 900 ° C. in the presence of oxygen or an oxygen partial pressure of 0.2 atm or higher. The synthesis is carried out by reacting for 4 to 48 hours in an atmosphere having an oxygen partial pressure of 0.5 or more. Firing may be performed a plurality of times under the same conditions or under different conditions as necessary. The raw material mixture may be previously filled in a pellet and molded. Examples of the firing method include powder mixing methods described in JP-A-62-264560, JP-A-2-40861, JP-A-6-267538, and JP-A-6-231767, JP-A-4-237793, JP-A-5-325966, and JP-A-6-208334. The solution mixing method described in JP-A-62-211565, the synthesis method by coprecipitation described in JP-A-62-211565, the method of quenching the fired product described in JP-A-5-198301 and JP-A-5-205741, JP-A-5-283076, A method of firing by pellet molding described in JP-A-6-310145, a method of firing in a molten state using LiOH hydrate described in JP-A-5-325969, and synthesis under oxygen partial pressure control described in JP-A-6-60887 Method, a fluorine doping method described in JP-A-6-243871, and active materials having different internal and surface compositions of particles described in JP-A-8-138670. And a method in which it is effective.

The content of elements other than elements (Li, Ni, Co and other elements M) in the composition formula that the positive electrode active material contains as impurities is, for example, 0.01% or less for Fe and 0.01% or less for Cu as weight concentrations, It is preferable that Ca, Na, and sulfate radicals (SO ₄ ) each have a concentration of 0.05% or less. The water content in the active material is preferably 0.1% or less.

  The preferable particle diameter of the positive electrode active material is that the particle diameter of the secondary particles is 1 to 30 μm, the particle diameter of the primary particles is 0.1 to 1 μm, and more preferably the particle diameter of the secondary particles is 3 to 15 μm. Has a particle size of 0.1 to 0.5 μm. Here, the secondary particle means a particle formed by agglomeration of fine primary particles, and corresponds to a particle size usually measured by a laser scattering particle size distribution measurement or the like, and corresponds to a normally defined particle size. As for the shape of the particles, the secondary particles are particularly preferably spherical. Moreover, it is preferable that the surface of the secondary particle is porous.

The specific surface area of the positive electrode active material is preferably in the range of 0.1 to 10 m ² / g as measured by BET method, and more preferably in the range of 0.3~3m ² / g. Moreover, the tap density of the positive electrode active material is preferably in the range of 2.3 to 2.9, and more preferably in the range of 2.5 to 2.8.

  The positive electrode active material particles used in the present invention may be crystalline or may contain an amorphous structure inside or on the surface, but are preferably crystalline. When crystalline positive electrode active material particles are used, the a-axis lattice constant measured by X-ray diffraction is preferably in the range of 2.81 to 2.91 and preferably in the range of 13.7 to 14.4. . Further, the ratio of the diffraction peak intensity of the (104) plane to the peak intensity of the (003) plane is in the range of 0.1 to 0.9, and preferably in the range of 0.3 to 0.8. . In addition, it is preferable that no peak of impurities derived from firing raw materials or side reactions such as lithium carbonate and nickel oxide is observed in the crystal diffraction spectrum.

Although the example of the preferable composition of a positive electrode active material is shown below, the scope of the present invention is not limited to these. Li _1.04 Ni _0.96 O _1.9 F _0.2 , LiNi _0.95 B _0.05 O ₂ , LiNi _0.92 Al _0.08 O ₂ , LiNi _0.98 Mg _0.02 O ₂ , LiNi _0.95 Ga _0.05 O ₂ , LiNi _0.90 Mn _0.10 O ₂ , LiNi _0.90 Mn _0.07 B _0.03 O ₂ , LiNi _0.90 Mn _0.07 B _0.03 O _1.95 F _0.1 , LiNi _0.92 Sn _0.08 O ₂ , LiNi _0.97 Si _0.03 O ₂ , LiNi _0.9 Cu _0.1 O ₂ , LiNi _0.9 Zn _0.1 O ₂ , LiNi _0.95 Zr _0.05 O ₂ , LiNi _0.95 P _0.05 O ₂ , LiNi _0.90 Fe _0.10 O ₂ , LiNi _0.95 Ti _0.05 O ₂ , LiNi _0.95 Tb _0.05 O _1.95 F _0.1 , LiNi _0.95 Zr _0.95 O _1.95 F _0.1 , LiNi _0.95 Mo _0.05 O _1.95 F _0.1 , LiNi _0.95 W _0.05 O _1.95 F _0.1 , LiNi _0.95 Ge _0.05 O ₂ , LiNi _0.97 Sm _0.03 O ₂ .

LiNi _0.7 Co _0.26 B _0.04 O ₂ , Li _1.03 Ni _0.67 Co _0.26 B _0.04 O ₂ , LiNi _0.7 Co _0.3 O _1.9 F _0.2 , LiNi _0.7 Co _0.26 B _0.04 O _1.9 F _0.2 , LiNi _0.7 Co _0.26 Al _0.04 O ₂ , LiNi _0.7 Co _0.26 Al _0.04 O _1.9 F _0.2 , Li _1.03 Ni _0.67 Co _0.26 Al _0.04 O _1.9 F _0.2 , LiNi _0.7 Co _0.28 Mg _0.02 O ₂ , LiNi _0.7 Co _0.25 Ga _0.05 O ₂ , LiNi _0.80 Co _0.10 Mn _0.10 O ₂ , LiNi _0.80 Co _0.10 Mn _0.07 B _0.03 O ₂ , LiNi _0.08 Co _0.10 Mn _0.07 B _0.03 O _0.95 F _0.05 , Li _1.03 Ni _0.67 Co _0.10 Mn _0.07 B _0.03 O _0.95 F _0.05 , LiNi _0.75 Co _0.15 Cu _0.1 O ₂ , LiNi _0.75 Co _0.15 Zn _0.1 O ₂ , LiNi _0.7 Co _0.20 Fe _0.10 O ₂ , LiNi _0.7 Co _0.25 Ti _0.05 O ₂ , LiNi _0.75 Co _0.17 Sn _0.08 O ₂ , Li Ni _0.75 Co _0.22 Si _0.03 O ₂ , LiNi _0.7 Co _0.25 Zr _0.05 O ₂ , LiNi _0.7 Co _0.25 P _0.05 O ₂ , LiNi _0.7 Co _0.25 Ge _0.05 O ₂ , LiNi _0.7 Co _0.27 Sm _0.03 O ₂ , LiNi _0.80 Co _0.15 B _0.03 Al _0.02 O ₂ , Li _1.03 Ni _0.77 Co _0.15 B _0.03 Al _0.02 O _0.9 F _0.1 .

  The negative electrode material used for the secondary battery of the present invention includes a metal composite oxide and a carbonaceous material. Metal composite oxide with amorphous structure mainly containing tin oxide, metal composite oxide with amorphous structure and / or metal composite oxide with crystal structure, or composite of these composite metal oxide and carbonaceous material Things are preferred. Since these negative electrode materials feature high capacity lithium occlusion, the high capacity of the rocking chair type secondary battery, which is the object of the present invention, can be obtained by combining the negative electrode material with the high capacity nickel oxide positive electrode in balance. Can be efficiently achieved. Examples of the carbon material used in the present invention include non-graphitizable carbon materials and graphite-based carbon materials. Specifically, carbon materials having surface spacing, density, and crystallite size described in JP-A-62-122066, JP-A-2-66856, JP-A-3-245473, etc. A mixture of natural graphite and artificial graphite described in Japanese Patent No. -290844, and vapor-grown carbon materials described in Japanese Patent Laid-Open Nos. 63-24555, 63-13282, 63-58763, and Japanese Patent Laid-Open No. 6-212617 A material obtained by heating and baking non-graphitizable carbon described in JP-A-5-182664 at a temperature exceeding 2400 ° C. and having a peak of X-ray diffraction corresponding to a plurality of 002 planes, No. 307957, JP-A-5-307958, JP-A-7-85862, and JP-A-8-315820, a mesophase carbon material synthesized by pitch firing described in JP-A-6-84516 Graphite with the above coating layer, various granular materials, microspheres, flat bodies, microfibers, whisker-shaped carbon materials, phenolic resins, acrylonitrile resins, furfuryl alcohol resin fired bodies, hydrogen atoms Examples thereof include carbon materials such as polyacene material. In particular, the carbon material described in JP-A-5-182664, various granular materials, microspheres, flat bodies, fibers, whisker-shaped carbon materials, mesophase pitch, phenol resin, acrylonitrile resin fired bodies, Polyacene materials containing hydrogen atoms are preferred.

  The composite metal oxide used in the present invention includes a crystalline compound and an amorphous compound. In the present invention, two or more of these compounds may be used in combination. For example, an amorphous compound may be used in combination, or a crystalline compound and an amorphous compound may be used in combination. It is also a more preferable form to use the carbonaceous material and the composite metal oxide in combination. The composite metal oxide is preferably an oxide containing a periodic table, Group 1, Group 2, Group 13, Group 14, Group 15, Group 15, a transition metal, and a halogen element. When the carbonaceous material and the composite metal oxide are used in combination, the ratio is preferably 10% or more and 70% or less, preferably 20% or more, by weight of the carbonaceous material relative to the total weight of the carbonaceous material and the composite metal oxide. 50% or less is more preferable.

Examples of the crystalline metal oxide include Ag ₂ O, TiO ₂ , Fe ₂ O ₃ , MgO, V ₂ O ₅ , NiO, CuO, ZnO, Mo ₂ O ₃ , In ₂ O ₃ , SnO, SnO ₂ , SnSiO. ₃ and In ₂ Sn ₂ O ₇ are preferable, and these compounds occlude lithium to form a composite oxide containing lithium. The amorphous composite metal oxide is mainly composed of tin oxide, and one or more kinds selected from Group 1, Group 2, Group 13, Group 14, Group 15, transition metal and halogen element in the periodic table It is a compound containing. These metal oxides are also called negative electrode active material precursors. More specifically, it is an amorphous composite oxide mainly containing tin, and is obtained by electrochemically inserting lithium ions into a negative electrode active material precursor represented by the following general formula.

Sn _x M ¹ _1−x M ² _y O _z
Here, M ¹ is one or more selected from Mn, Fe, Pb, and Ge, and M ² is Al, B, P, Si, Periodic Table 1st, 2nd, 3rd, and halogen elements 2 or more selected elements are shown, 0 <x ≦ 1, 0.1 ≦ y ≦ 3, 1 ≦ z ≦ 8. A more preferable composition according to the above structural formula will be described. M ¹ is an element selected from Pb and Ge, and M ² is selected from B, P, Si, Periodic Table 1 and 2 It is an element of seeds or more, and M ² is particularly preferably an element other than Al.

  The insertion of lithium ions into the active material precursor is carried out by cathodic polarization of the negative electrode in the presence of lithium ions in the battery and electrochemical insertion of the lithium ions into the structure.

  The composite oxide as the precursor of the present invention is characterized in that the structure contains an amorphous structure or is amorphous. The complex oxide of the present invention includes an amorphous structure, specifically, a diffraction scattering band having a broad apex with a weak intensity from 20 ° to 40 ° as a 2θ value by an X-ray diffraction method using CuKα rays. In this broad scattering band, a crystalline diffraction line may be included. This crystalline diffraction line is a reflection of a slightly ordered structure in the amorphous structure. More preferably, when a crystalline diffraction line is observed at a 2θ value of 40 ° or more and 70 ° or less, the strongest intensity of the crystalline diffraction lines is observed at a 2θ value of 20 ° or more and 40 ° or less. The intensity of the diffraction line at the apex of the broad scattering band is preferably 500 times or less, more preferably 100 times or less, particularly preferably 5 times or less, and most preferably no crystalline diffraction line. .

The negative electrode active material precursor is prepared by mixing a tin compound, which is a tin raw material, and a powder of a compound containing an element other than tin, and melting the mixture at a high temperature of 800 ° C. to 1500 ° C., preferably 900 ° C. to 1200 ° C. for 4 hours to Synthesize by reacting for 48 hours. The synthesis atmosphere is preferably an inert gas atmosphere such as nitrogen or argon. In particular, the reaction is preferably carried out under conditions where the oxygen partial pressure is 10 ⁻¹ or less, preferably 10 −2 or less. The reaction may be quenched at a rate of 50 ° C. to 500 ° C./min to promote amorphization. Conversely, slow cooling can be performed for the purpose of increasing the density of the amorphous structure and increasing the strength. The glassy negative electrode material obtained by these methods is pulverized to obtain a particle size distribution and used as negative electrode particles. A preferable range of the negative electrode particles is 0.5 to 20 μm as an average particle diameter, and more preferably 1 to 10 μm. In addition to the melting method, a synthesis method using a solution reaction, for example, synthesis by a sol-gel method can be used. The range of the preferable average particle diameter of the particle | grains synthesize | combined by a solugel method is 0.1-10 micrometers as a particle diameter of a secondary particle, More preferably, it is 0.2-5 micrometers.

Below, the preferable example of the negative electrode active material precursor used by this invention is shown.
SnSi _0.8 P _0.2 O _3.1
SnSi _0.5 B _0.2 P _0.2 O _1.85
SnSi _0.8 B _0.2 O _2.9
SnSi _0.8 Al _0.2 O _2.9
SnSi _0.6 Al _0.1 B _0.2 O _1.65
SnSi _0.3 Al _0.1 P _0.6 O _2.25
SnSi _0.4 B _0.2 P _0.4 O _2.1
SnSi _0.6 Al _0.1 B _0.5 O _2.1
SnB _0.5 P _0.5 O ₃
SnK _0.2 PO _3.6
SnRb _0.2 P _0.8 O _3.2
SnBa _0.1 P _1.45 O _4.5
SnLa _0.1 P _0.9 O _3.4
SnNa _0.1 B _0.45 O _1.75
SnLi _0.2 B _0.5 P _0.5 O _3.1
SnCs _0.1 B _0.4 P _0.4 O _2.65
SnBa _0.1 B _0.4 P _0.4 O _2.7
SnCa _0.1 Al _0.15 B _0.45 P _0.55 O _3.9
SnY _0.1 B _0.6 P _0.6 O _3.55
SnRb _0.2 B _0.3 P _0.4 O _2.55
SnCs _0.2 B _0.3 P _0.4 O _2.55
SnCs _0.1 B _0.4 P _0.4 O _2.65
SnK _0.1 Cs _0.1 B _0.4 P _0.4 O _2.7
SnBa _0.1 Cs _0.1 B _0.4 P _0.4 O _2.75
SnMg _0.1 K _0.1 B _0.4 P _0.4 O _2.75
SnCa _0.1 K _0.1 B _0.4 P _0.5 O ₃
SnBa _0.1 K _0.1 Al _0.1 B _0.3 P _0.4 O _2.75
SnMg _0.1 Cs _0.1 Al _0.1 B _0.3 P _0.4 O _2.75
SnCa _0.1 K _0.1 Al _0.1 B _0.3 P _0.4 O _2.75
SnMg _0.1 Rb _0.1 Al _0.1 B _0.3 P _0.4 O _2.75
SnCa _0.1 B _0.2 P _0.2 F _0.2 O _2.6
SnMg _0.1 Cs _0.1 B _0.4 P _0.4 F _0.2 O _3.3
Sn _0.5 Mn _0.5 Mg _0.1 B _0.9 O _2.45
Sn _0.5 Mn _0.5 Ca _0.1 P _0.9 O _3.35
Sn _0.5 Ge _0.5 Mg _0.1 P _0.9 O _3.35
Sn _0.5 Fe _0.5 Ba _0.1 P _0.9 O _3.35
Sn _0.8 Fe _0.2 Ca _0.1 P _0.9 O _3.35
Sn _0.3 Fe _0.7 Ba _0.1 P _0.9 O _3.35
Sn _0.9 Mn _0.1 Mg _0.1 P _0.9 O _3.35
Sn _0.2 Mn _0.8 Mg _0.1 P _0.9 O _3.35
Sn _0.7 Pb _0.3 Ca _0.1 P _0.9 O _3.35
Sn _0.2 Ge _0.8 Ba _0.1 P _0.9 O _3.35
SnAl _0.1 B _0.5 P _0.5 O _3.15
SnCs _0.1 Al _0.4 B _0.5 P _0.5 O _3.65
SnCs _0.1 B _0.5 P _0.5 O _3.05
SnCs _0.1 Ge _0.05 B _0.5 P _0.5 O _3.15
SnCs _0.1 Ge _0.05 Al _0.3 B _0.5 P _0.5 O _3.60

  Examples of the negative electrode active material that can be used with the negative electrode material in the secondary battery of the present invention include lithium metal and the above lithium alloy. The purpose of the combined use of the lithium metal and lithium alloy is to insert lithium ions into the negative electrode material in the battery, and does not use a dissolution and precipitation reaction of lithium metal or the like as the battery reaction.

  A conductive agent, a binder, a filler, or the like can be added to the electrode mixture. The conductive agent may be anything as long as it is an electron conductive material that does not cause a chemical change in the constructed battery. Usually, natural graphite (scale-like graphite, scale-like graphite, earth-like graphite, etc.), artificial graphite, carbon black, acetylene black, ketjen black, carbon fiber and metal (copper, nickel, aluminum, silver (JP-A-63-148)) , 554) etc.) Conductive materials such as powder, metal fibers or polyphenylene derivatives (Japanese Patent Laid-Open No. 59-20,971) can be included as one kind or a mixture thereof. The combined use of graphite and acetylene black is particularly preferred. The addition amount is not particularly limited, but is preferably 1 to 50% by weight, particularly preferably 2 to 30% by weight. In the case of carbon or graphite, 2 to 15% by weight is particularly preferable.

  The binder is usually starch, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, regenerated cellulose, diacetyl cellulose, polyvinyl chloride, polyvinyl pyrrolidone, tetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, ethylene-propylene-di. Enter polymers (EPDM), sulfonated EPDM, styrene butadiene rubber, polybutadiene, fluororubber, polyethylene oxide and other polysaccharides, thermoplastic resins, rubber elastic polymers and the like are used as one kind or a mixture thereof. The addition amount of the binder is preferably 2 to 30% by weight. Any filler can be used as long as it is a fibrous material that does not cause a chemical change in the constructed battery. Usually, olefin polymers such as polypropylene and polyethylene, fibers such as glass and carbon are used. Although the addition amount of a filler is not specifically limited, 0 to 30 weight% is preferable.

Non-aqueous electrolytes used for the production of secondary batteries include propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, γ-butyrolactone, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfate. Foxide, 1,3-dioxolane, formamide, dimethylformamide, dioxolane, acetonitrile, nitromethane, methyl formate, methyl acetate, phosphoric acid triester (JP 60-23973), trimethoxymethane (JP 61- 4,170), dioxolane derivatives (Japanese Patent Laid-Open Nos. 62-15771, 62-22,372, 62-108,474), sulfolane (Japanese Patent Laid-Open No. 62-31,959), 3-methyl-2- Oxazolidinone ( No. 62-44,961), propylene carbonate derivatives (JP-A 62-290,069, 62-290,071), tetrahydrofuran derivatives (JP-A 63-32,872), diethyl ether (JP-A 63) -62,166), 1,3-propane sultone (Japanese Patent Laid-Open No. Sho 63-102,173) and a mixture of at least one aprotic organic solvent and a lithium salt soluble in the solvent, such as LiClO _{4, LiBF 4, LiPF 6,} LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiSbF 6, LiB 10 Cl 10 ( JP-57-74,974), lithium lower aliphatic carboxylic acid (JP-60 -41,773), LiAlCl ₄ , LiCl, LiBr, LiI (JP 60-247265), lithium chloroborane (JP Sho 61-165,957) and lithium tetraphenylborate (Japanese Patent Laid-Open No. 61-214,376). Among them, electrolytes containing LiCF ₃ SO ₃ , LiClO ₄ , LiBF ₄ and / or LiPF ₆ in a mixed solution of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate are preferable in the battery. Although the amount to be added is not particularly limited, a necessary amount can be used depending on the amount of the positive electrode active material and the negative electrode active material and the size of the battery. The volume ratio of the solvent is not particularly limited, but is 0.4 / 0.6 to 0.6 / 0.4 in the case of a mixed solution of propylene carbonate or ethylene carbonate and 1,2-dimethoxyethane and / or diethyl carbonate. (The mixing ratio when both 1,2-dimethoxyethane and diethyl carbonate are used is preferably 0.4 / 0.6 to 0.6 / 04). The concentration of the supporting electrolyte is not particularly limited, but is preferably 0.2 to 3 mol per liter of the electrolytic solution. Among the above electrolytic solutions, particularly preferable as the electrolytic solution composition of the present invention in terms of the effect of improving the charge / discharge cycle life of the secondary battery, at least ethylene carbonate is the solvent, and at least LiPF ₆ is the lithium salt. Another preferred composition is a composition containing at least ethylene carbonate and diethyl carbonate as a solvent and at least LiPF ₆ as a lithium salt, and another preferred composition is at least both ethylene carbonate and dimethyl carbonate. It is a composition containing at least LiPF ₆ as a lithium salt as a solvent.

  In addition to the electrolytic solution, the following organic solid electrolyte can also be used. For example, a polyethylene oxide derivative or a polymer containing the derivative (Japanese Patent Laid-Open No. 63-135447), a polypropylene oxide derivative or a polymer containing the derivative, a polymer containing an ionic dissociation group (Japanese Patent Laid-Open Nos. 62-254,302 and 62-254, 303, 63-193, 954), a mixture of an ion-dissociable group-containing polymer and the above aprotic electrolyte (US Pat. Nos. 4,792,504, 4,830,939, JP-A-62-222,375, 62-22,376, 63-22,375, 63-22,776, JP-A-1-95,117), and phosphate polymer (JP-A-61-256,573) are effective. Furthermore, there is a method of adding polyacrylonitrile to the electrolytic solution (Japanese Patent Laid-Open No. 62-278,774). In addition, a method using an inorganic and organic solid electrolyte in combination (Japanese Patent Laid-Open No. 60-1,768) is also known.

  As a separator used for the secondary battery, an insulating thin film having a large ion permeability and a predetermined mechanical strength is used. Sheets and non-woven fabrics made from olefin polymers such as polypropylene, glass fibers or polyethylene are used because of their organic solvent resistance and hydrophobicity. A range useful for batteries is generally used as the pore diameter of the separator. For example, 0.01 to 10 μm is used. The thickness of the separator is generally used in the battery range. For example, 5 to 300 μm is used. When a solid electrolyte such as a polymer is used as the electrolyte, the solid electrolyte may also serve as a separator.

  In order to improve discharge and charge / discharge characteristics, it is known to add the following compounds to the electrolyte. For example, pyridine (JP 49-108,525), triethyl phosphite (JP 47-4,376), triethanolamine (JP 52-72,425), cyclic ether (JP 57-57). 152, 684), ethylene diamine (JP 58-87,777), n-glyme (JP 58-87,778), hexaphosphoric triamide (JP 58-87,779), nitrobenzene derivatives (JP 58-214,281), sulfur (JP 59-8,280), quinoneimine dyes (JP 59-68,184), N-substituted oxazolidinones and N, N'-substituted imidazolidinones (JP No. 59-154,778), ethylene glycol dialkyl ether (JP 59-205,167), quaternary ammonium salt (JP 60-30,065) Polyethylene glycol (JP 60-41,773), pyrrole (JP 60-79,677), 2-methoxyethanol (JP 60-89,075), aluminum trichloride (JP 61-88) , 466), monomers of conductive polymer electrode active materials (JP 61-161,673), triethylenephosphonamide (JP 61-208,758), trialkylphosphine (JP 62-80, JP). 976), morpholine (JP 62-80,977), aryl compounds having a carbonyl group (JP 62-86,673), hexamethylphosphoric triamide and 4-alkyl morpholine (JP 62). -217,575), bicyclic tertiary amines (JP 62-217,578), oils (JP 62-287,580), quaternary phosphoniu Salt (JP-63-121,268), and a tertiary sulfonium salt (JP 63-121,269).

  In order to make the electrolyte nonflammable, a halogen-containing solvent such as carbon tetrachloride or ethylene trifluoride chloride can be contained in the electrolyte (Japanese Patent Laid-Open No. 48-36,632). In addition, carbon dioxide gas can be included in the electrolytic solution to make it suitable for high-temperature storage (Japanese Patent Laid-Open No. 59-134,567).

  The mixture of the positive electrode and the negative electrode may contain an electrolytic solution or a supporting salt. For example, a method is known in which the ion conductive polymer, nitromethane (Japanese Patent Laid-Open No. 48-36,633), and electrolytic solution (Japanese Patent Laid-Open No. 57-124,870) are included. In addition, the surface of the positive electrode active material can be modified. For example, the surface of the metal oxide is treated with an esterifying agent (Japanese Patent Laid-Open No. 55-163,779) or a chelating agent (Japanese Patent Laid-Open No. 55-163,780), or a conductive polymer (Japanese Patent Laid-Open No. 58-163). 163, 188, 59-14, 274), and a method of modification by covering with a surface layer of polyethylene oxide or the like (JP-A-60-97,561). Similarly, the surface of the negative electrode active material can be modified. For example, an ion conductive polymer or a polyacetylene layer can be coated (Japanese Patent Laid-Open No. 58-111,276), or surface treatment can be performed with a Li salt (Japanese Patent Laid-Open No. 58-142,771).

The current collector of the electrode active material may be anything as long as it is an electronic conductor that does not cause a chemical change in the constructed battery. For example, in addition to stainless steel, nickel, aluminum, titanium, calcined carbon, etc. as materials for the positive electrode, the surface of aluminum or stainless steel is treated with carbon, nickel, titanium, or silver. In addition to stainless steel, nickel, copper, titanium, aluminum, calcined carbon, etc., the surface of copper or stainless steel treated with carbon, nickel, titanium or silver), Al—Cd alloy, or the like is used. Oxidizing the surface of these materials is also used. As the shape, a film, a sheet, a net, a punched product, a lath body, a porous body, a foamed body, a molded body of a fiber group, and the like are used in addition to the foil. The thickness is not particularly limited, but a thickness of 5 to 100 μm is used.

  The battery shape can be applied to any of coins, buttons, sheets, cylinders, and corners. In coins and buttons, a mixture of a positive electrode active material and a negative electrode active material is used after being pressed into a pellet shape. In the sheet, cylinder, and corner, the positive electrode active material and the negative electrode active material mixture are applied onto a current collector, dried, dehydrated, and pressed. The coating thickness is determined by the size of the battery, and is preferably 10 to 500 μm in a compressed state after drying. The use of the non-aqueous secondary battery of the present invention is not particularly limited. For example, when mounted on an electronic device, a color notebook computer, a monochrome notebook computer, a pen input personal computer pocket (palmtop) personal computer, a notebook word processor, a pocket word processor , Electronic book player, mobile phone, cordless phone, pager, handy terminal, mobile fax, mobile copy, mobile printer, headphones stereo video movie, LCD TV, handy cleaner, portable CD, mini desk, electric shaver, electronic translation Machine, car phone, transceiver, electric tool, electronic notebook, calculator, memory card, tape recorder, radio, backup power supply, memory card, etc. Others for consumer use include automobiles, electric vehicle motors, lighting equipment, toys, game equipment, road conditioners, irons, watches, strobes, cameras, medical equipment (pacemakers, hearing aids, shoulder grinders, etc.). Furthermore, it can be used for various military use and space use. It can also be combined with solar cells. Hereinafter, the present invention will be described in more detail with reference to examples of battery production. However, the scope of the present invention is not limited to these examples as long as the gist of the invention is not exceeded.

Example 1
[Synthesis Example of Composite Metal Oxide as Negative Electrode Material, Melting Method] 67.4 g of SnO, 17.4 g of B ₂ O ₃ , 102.8 g of Sn ₂ P ₂ O ₇ were mixed and sufficiently pulverized and mixed in an automatic mortar After that, it was set in an alumina crucible and fired at 1000 ° C. for 10 hours in an argon gas atmosphere. After firing, it was rapidly cooled at a rate of 100 ° C./min to obtain a yellow transparent glassy negative electrode active material precursor SnB _0.5 P _0.5 O ₃ (compound A-1). When X-ray diffraction of the active material was measured, it showed a broad diffraction band in the region of 2θ = 20-35 ° under the irradiation of Cu-α ray, but a sharp diffraction line attributed to the crystal structure was detected. Thus, the active material structure was found to be amorphous (amorphous).

[Example of Preparation of Positive Electrode Active Material] LiNi _0.8 Mn _0.2 O ₂ (Compound C-1) was synthesized by the following method. LiOH.H ₂ O, Ni (OH) ₂ and Mn (OH) ₂ powders were thoroughly mixed in a mortar under dry air at a molar ratio of 1: 0.8: 0.2, and 650 in an oxygen atmosphere. After calcination at 6 ° C. for 6 hours, calcination was carried out at 750 ° C. for 8 hours to synthesize Compound C-1 having the above composition. The obtained particles had a shape close to a sphere, and the average particle size of primary particles was 0.3 μm, and the average particle size of secondary particles was 7 μm. The specific surface area by the BET method was 0.7 m ² / g. The peak ratio of (104) plane / (003) plane obtained by X-ray diffraction was 0.6, the a-axis lattice constant was 2.83, and the c-axis lattice constant was 13.89. Gave a pH of 10.5. An active material having the same composition could be synthesized by using LiNO ₃ or LiCO ₃ instead of LiOH · H ₂ O as a lithium source, and NiCO ₃ instead of Ni (OH) ₂ as a Ni source. Furthermore, LiNi _0.95 Al _0.05 O ₂ (Compound C-2) was synthesized using Al (OH) ₃ as a raw material. Further, by using LiF as the fluorine raw material, was synthesized LiNi _0.8 Mn _0.2 O _1.9 F _0.2 (Compound C-3).

As a comparative active material for the positive electrode, LiCoO ₂ (Comparative 1) is mixed with a mixture of Co ₃ O ₄ and Co ₂ O ₃ and lithium carbonate so that the Li / Co molar ratio is 1.05, and is 600 ° C. in air. And then baked at 880 ° C. for 8 hours. In addition, Li _1.05 Mn _1.95 Co _0.05 O ₄ (Comparative 2) as a comparative active material, chemically synthesized manganese dioxide (CMD), lithium hydroxide and cobalt carbonate were mixed in a stoichiometric ratio of the above chemical formula, and at 700 ° C. Synthesized by firing in air for 18 hours.

[Preparation Example of Electrode Mixture Sheet] As the positive electrode mixture, 90% by weight of the positive electrode active material compound C-1, 6% by weight of acetylene black, and 3% by weight of an aqueous dispersion of polytetrafluoroethylene as the binder, Water was added to a mixture of 1% by weight of sodium polyacrylate and kneaded, and the resulting slurry was applied to both sides of an aluminum film having a thickness of 30 μm to produce a positive electrode sheet. As a result of drying and pressing the coated sheet, the coating amount of the dry film was 230 g / m ² and the thickness of the coated film was about 90 μm.

86% by weight of compound A-1 as a negative electrode active material precursor, 3% by weight of flake graphite, 6% by weight of acetylene black, 4% by weight of an aqueous dispersion of styrene-butadiene rubber as a binder, and 1% by weight of carboxymethylcellulose Water was added to the mixture and kneaded with a homogenizer at 10,000 rpm for 10 minutes or more to prepare a negative electrode mixture slurry. The obtained slurry was applied on both sides of a 18 μm thick copper film to prepare a negative electrode sheet. As a result of drying and pressing the coated sheet, the coating amount of the dry film was about 70 g / m ² and the thickness of the coated film was about 30 μm. Next, a protective layer (average thickness 5 μm) made of a 1: 4 (weight ratio) mixture of scaly graphite and aluminum oxide is applied to the surface of the active material layer of the negative electrode sheet, and the negative electrode with the surface protective layer A sheet was produced.

[Cylinder-type battery production example] A metal Li foil having a thickness of 35 μm was cut into pieces having a width of 5 mm and a length of 37 mm, and the negative electrode active material precursor A-1 was applied in dry air having a dew point of −60 ° C. It was made to adhere on the surface protective layer of both surfaces of a negative electrode sheet using the press roller at regular intervals of 2 mm. The amount of Li attached to the negative electrode sheet was approximately 110 mg as a weight. This lithium is used for electrolytically inserting lithium into the negative electrode active material precursor in the battery and converting the negative electrode active material precursor into an active material. The positive electrode sheet was cut to a width of 35 mm, the negative electrode sheet was cut to a width of 37 mm, and aluminum and nickel lead plates were spot welded to the ends of the sheet, respectively, and then 150 ° C. in dry air with a dew point of −40 ° C. Dehydrated and dried at 2 ° C. for 2 hours. As shown in the cross-sectional view of the battery in FIG. 1, a positive electrode sheet (8) that has been dehydrated and dried, a porous polyethylene film (10) as a separator, a negative electrode sheet (9) that has been dehydrated and dried, and a separator (10) These were laminated and wound in a spiral shape with a winder. The wound body was stored in a nickel-plated iron-bottomed cylindrical battery can (11) (also serving as a negative electrode terminal). 1 mol / liter LiPF ₆ (2: 2: 6 (volume ratio) mixture of ethylene carbonate, butylene carbonate, and dimethyl carbonate) was injected as an electrolyte into the battery can. A battery lid (12) having a positive electrode terminal was caulked through a gasket (13) to produce a cylindrical battery having a diameter of 14 mm and a height of 50 mm. The positive electrode terminal (12) was connected to the positive electrode sheet (8) and the battery can (11) was previously connected to the negative electrode sheet (9) by a lead terminal. (14) is a safety valve.

  In the same manner as described above, the batteries shown in Table 1 were produced using C-2 and 3 as the positive electrode active material.

The battery produced as described above is a battery precursor in which the process of electrochemically inserting lithium on the coating sheet protective layer into the negative electrode active material precursor is not completed. Therefore, an operation for converting the battery precursor into a negative electrode active material by inserting lithium into the negative electrode active material precursor and making the battery precursor a chargeable / discharge cycleable secondary battery was performed as follows. The battery precursor was allowed to stand at room temperature for 12 hours, precharged for 1 hour under a constant current of 0.1 A, and then aged at 50 ° C. for 10 days. In this aging step, it was confirmed that Li supported on the negative electrode was dissolved and inserted into the negative electrode active material precursor. In order to activate this battery, it was charged to 4.2 V at room temperature at ² mA / cm ² . Further, the battery was kept at 55 ° C. in a charged state, and aging was performed for 3 days. The above battery was repeatedly charged / discharged under the conditions of a final charge voltage of 4.2 V (open circuit voltage (OCV)), a final discharge voltage of 2.8 V (circuit voltage), and a current density of ² mA / cm ² (equivalent to 0.2 C). I let you. In addition, when the battery was charged and discharged at a current of 10 mA / cm ² (1.0 C), the maintenance ratio of the discharge capacity of 0.2 C discharge after the end of 100 cycles to the initial capacity was measured, and the cycle life of the battery was measured. Was evaluated.

  The results of evaluation of discharge capacity and cycle life of the above batteries are summarized in Table 1.

  From the comparison of Table 1, the secondary battery according to the constitution of the positive electrode and negative electrode materials described in the present invention is compared with the secondary battery using a cobalt oxide active material or a manganese oxide active material for the positive electrode. Thus, it can be seen that it is excellent in terms of capacity and cycle life.

Example 2
By the same melt quenching method as in Example 1, SnO and SiO ₂ were used as raw materials and fired at 1200 ° C. for 12 hours in an Ar gas to synthesize an amorphous glass body having a composition of SnSiO ₃ , and this was vibrated. A negative electrode active material precursor (compound A-2) having an average particle size of 3 μm and a specific surface area of 3 m ² / g was prepared by grinding with a mill. Next, compound A-2 was mixed with natural graphite carbon powder at a weight ratio of 1/19 to 8/2, and 5% by weight of PVDF was added as a binder to the obtained mixture. These were dispersed in N-methyl-2-pyrrolidone and kneaded with a homogenizer in the same manner as in Example 1 to prepare a negative electrode slurry. A negative electrode sheet in the range of m ² was produced. The negative electrode sheet was wound according to the method of Example 1 together with the positive electrode sheet coated with Compound C-1 without electrolytic insertion of lithium by supporting the surface protective layer and metal Li, and pouring the electrolytic solution. The liquid was applied to produce the cylinder type battery shown in FIG. This battery was charged to 4.2 V at ² mA / cm ² as in Example 1, held at 55 ° C., aged for 3 days, activated, and then charged to a final charge voltage of 4.2 V and discharged. The battery was repeatedly charged and discharged under conditions of a voltage of 2.8 V and a current density of ² mA / cm ² . Table 2 compares the current capacity and energy capacity of the discharge in the first cycle and the current capacity maintenance rate after the end of 100 cycles for the above battery.

  From the comparison of Table 2, it can be seen that in the negative electrode composition, the battery capacity is high when the weight ratio of carbon to metal oxide is between 1/9 and 7/3, particularly between 2/8 and 5/5.

Sectional drawing of the cylinder type battery used for the Example is shown.

Explanation of symbols

8 Positive electrode sheet 9 Negative electrode sheet 10 Separator 11 Negative electrode can (battery can)
12 Positive terminal 13 Gasket 14 Safety valve

Claims (15)

In a secondary battery composed of a positive electrode using a lithium-containing metal composite oxide as an active material, a negative electrode using a metal composite oxide having an amorphous structure, and a non-aqueous electrolyte, the positive electrode active material is Li _x Ni _{1-y M y O 2-} z X a (M is a group 2 of the periodic table, group 13, an element of group 14, one or more elements selected from transition metal elements, X is a halogen element 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z) Ion non-aqueous electrolyte secondary battery.   2. The lithium ion nonaqueous electrolyte secondary battery according to claim 1, wherein the composition of the positive electrode active material is 0.01 ≦ z ≦ 0.25 and 0.02 ≦ a ≦ 0.5.   The M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W. 3. The lithium ion nonaqueous electrolyte secondary battery according to 1 or 2.   M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W and Co. Item 3. The lithium ion nonaqueous electrolyte secondary battery according to Item 1 or 2.   The lithium ion nonaqueous electrolyte secondary battery according to claim 4, wherein an amount of Co in M of the positive electrode active material is 10 mol% or more.   The negative electrode active material is mainly composed of tin oxide and contains at least one selected from Group 1, Group 2, Group 13, Group 14, Group 15, transition metal, and halogen element in the periodic table. The lithium ion non-aqueous electrolyte secondary battery according to any one of claims 1 to 5. In a secondary battery composed of a positive electrode having a lithium-containing metal composite oxide as an active material, a negative electrode having at least one metal composite oxide and a carbonaceous material, and a non-aqueous electrolyte, the positive electrode active material is Li _{x Ni 1-y M y O} 2-z X a (M is a group 2 of the periodic table, group 13, an element of group 14, one or more elements selected from transition metal elements, X is a halogen element And a nickel-containing lithium composite oxide having a composition of 0.2 <x ≦ 1.2, 0 ≦ y ≦ 0.5, 0 ≦ z ≦ 1, 0 ≦ a ≦ 2z) Lithium ion non-aqueous electrolyte secondary battery.   The lithium ion nonaqueous electrolyte secondary battery according to claim 7, wherein the composition of the positive electrode active material is 0.01 ≦ z ≦ 0.25 and 0.02 ≦ a ≦ 0.5.   The M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W. The lithium ion nonaqueous electrolyte secondary battery according to 7 or 8.   M of the positive electrode active material is one or more elements selected from Mg, B, Al, Sn, Si, Ga, Mn, Fe, Ti, Nb, Zr, Mo, and W and Co. Item 9. The lithium ion nonaqueous electrolyte secondary battery according to Item 7 or 8.   11. The lithium ion nonaqueous electrolyte secondary battery according to claim 10, wherein the amount of Co in M of the positive electrode active material is 10 mol% or more.   12. The lithium ion non-aqueous electrolyte secondary battery according to claim 7, wherein the amount of the carbon composite material and the carbon composite material of the negative electrode is 10 wt% or more and 70 wt% or less. .   12. The lithium ion nonaqueous electrolyte secondary battery according to claim 7, wherein the amount of the carbon composite material and the carbon composite material of the negative electrode is 20 wt% or more and 50 wt% or less. .   The lithium ion non-aqueous electrolyte secondary battery according to claim 7, wherein at least two kinds of metal composite oxides are used for the negative electrode.   15. The lithium ion non-oxide according to claim 14, wherein at least one of the two or more metal composite oxides is a crystalline metal composite oxide and the other is an amorphous metal composite oxide. Water electrolyte secondary battery.

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