Abstract: The purpose of the present invention is to provide a nonaqueous electrolyte secondary battery which has excellent charge/discharge cycle characteristics. A nonaqueous electrolyte secondary battery negative electrode which is an example of an embodiment of the present invention comprises, as negative electrode active materials, a carbon active material and a Si active material comprising Si particles dispersed in an oxide phase containing at least silicon (Si). The Si active material includes a first Si active material and a second Si active material. The first Si active material has a median size on a volume basis that is greater than that of the second Si active material and has an Si particle content that is higher than that of the second Si active material.

Abstract: A non-aqueous electrolyte secondary battery with excellent discharge cycle characteristics and a charging termination potential ranging from 4.4 to 4.6 V based on lithium, consisting of a positive electrode comprising a positive electrode active material, a negative electrode, and a non-aqueous electrolyte containing a non-aqueous solvent and an electrolyte salt, in which the positive electrode active material comprises a mixture of a lithium-cobalt composite oxide containing at least both zirconium and magnesium in LiCoO2, and a lithium-manganese-nickel composite oxide having a layered structure and containing at least both manganese and nickel, and the potential of the positive electrode active material ranges from 4.4 to 4.6 V based on lithium, and the non-aqueous electrolyte contains at least one of aromatic compounds selected from the group consisting at least of toluene derivatives, anisole derivatives, biphenyl, cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene, and diphenyl ether.

Abstract: The preservation performance of a nonaqueous electrolyte secondary cell charged to high potential is improved while the initial capacity and the cycle property of the cell are also improved. The nonaqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material containing lithium cobalt compound oxide and lithium manganese nickel compound oxide having a layer structure, the lithium cobalt compound oxide having at least zirconium and magnesium added in LiCoO2; a negative electrode having a negative electrode active material; and a nonaqueous electrolyte having a nonaqueous solvent and an electrolytic salt. The potential of the positive electrode is more than 4.3 V and 5.1 V or less based on lithium. The nonaqueous electrolyte contains vinylene carbonate as the nonaqueous solvent and, as the electrolytic salt, at least one of lithium bis(pentafluoroethane sulfonyl)imide and lithium bis(trifluoromethane sulfonyl)imide at 0.1 M or more and 0.

Abstract: The present invention aims to provide a non-aqueous electrolyte secondary cell having high capacity and capable of preventing elution of cobalt and decomposition of the electrolyte. This aim can be accomplished by providing a non-aqueous electrolyte secondary cell comprising a positive electrode having a positive electrode active material, an negative electrode having an negative electrode active material, and non-aqueous electrolyte, wherein the positive electrode active material comprises lithium cobalt oxide to which at least one material selected from the group consisting of Mg, Al, Ti, and Zr was added, and the positive electrode comprises lithium phosphate.

Abstract: The present invention improves the cycle characteristics of a non-aqueous electrolyte secondary cell that uses lithium cobalt oxide as a positive electrode active material. To this end, an element different from cobalt such as zirconium and titanium is added to the lithium cobalt oxide, acting as the positive electrode active material. The non-aqueous electrolyte contains a non-aqueous solvent containing diethyl carbonate at 10 to 30 volume percent on a base of 25 degree Celsius and contains an electrolyte salt.

Abstract: In a nonaqueous electrolytic secondary battery according to the invention, hexagonal system lithium containing cobalt composite oxide having a crystallite size in a (110) vector direction of 1000 ? or more and having a halogen compound added thereto by burning at time of synthesis is used as a positive electrode active material. By measuring a pH value of a filtrate obtained by dispersing, in water, the lithium containing cobalt composite oxide having the halogen compound added thereto by the burning at time of the synthesis and a crystallite size in the (110) vector direction of 1000 ? or more, a value of 9.6 to 10.1 is obtained. By using the lithium containing cobalt composite oxide as a positive electrode active material, a high temperature cycle property can be enhanced.

Abstract: The preservation performance of a nonaqueous electrolyte secondary cell charged to high potential is improved while the initial capacity and the cycle property of the cell are also improved. The nonaqueous electrolyte secondary cell includes: a positive electrode having lithium phosphate and a positive electrode active material containing lithium cobalt compound oxide and lithium manganese nickel compound oxide having a layer structure, the lithium cobalt compound oxide having at least zirconium and magnesium added in LiCoO2; a negative electrode having a negative electrode active material; and a nonaqueous electrolyte having a nonaqueous solvent and an electrolytic salt. The potential of the positive electrode is more than 4.3 V and 5.1 V or less based on lithium. The nonaqueous electrolyte contains vinylene carbonate as the nonaqueous solvent and, as the electrolytic salt, at least one of lithium bis(pentafluoroethane sulfonyl)imide and lithium bis(trifluoromethane sulfonyl)imide at 0.1 M or more and 0.

Abstract: A non-aqueous electrolyte secondary cell having a high cycle characteristic and excellence in continuous charging characteristic at high potential is provided. The non-aqueous electrolyte secondary cell comprises a positive electrode having a positive electrode active material, a negative electrode having a negative electrode active material, and a non-aqueous electrolyte having a non-aqueous solvent and electrolytic salt. The positive electrode contains lithium phosphate. The non-aqueous solvent contains a halogenated ethylene carbonate compound represented by chemical formula 1: where W, X, Y, and Z independently represent a halogen or a hydrogen atom, at least one selected from W, X, Y, and Z being a halogen.

Abstract: The invention provides a non-aqueous electrolyte secondary cell that has high capacity and excels in cycle characteristics. The non-aqueous electrolyte secondary cell functions stably at a high potential of from 4.4 to 4.6 V with respect to lithium and inhibits the decomposition of the electrolytic solution at high potential. This is accomplished as follows. The non-aqueous electrolyte secondary cell has a positive electrode having a positive electrode active material; a negative electrode having a negative electrode active material; and a non-aqueous electrolyte having a non-aqueous solvent and electrolytic salt. The positive electrode active material has: lithium cobalt compound oxide having added therein at least zirconium and magnesium; and lithium-nickel-manganese compound oxide having a layered structure. The positive electrode active material has a potential of from 4.4 to 4.6 V with respect to lithium. The non-aqueous solvent contains diethyl carbonate of 10 vol. % or higher at 25° C.

Abstract: A positive electrode active material of a nonaqueous electrolyte secondary battery according to an embodiment of the invention includes lithium cobalt compound oxide in which at least zirconium and magnesium are added, and lithium nickel manganese compound oxide having a layered structure. The lithium cobalt compound oxide contains at least two types of zirconium- and magnesium-added lithium cobalt compound oxides having zirconium added amounts different from each other. The charging potential of the positive electrode active material is more than 4.3 V and 4.6 V or less versus lithium. With such a constitution, a nonaqueous electrolyte secondary battery using a plurality of positive electrode active materials having different physical properties which not only is capable of being charged at a high charging voltage of more than 4.3 V and 4.6 V or less versus lithium, but also has excellent charging/discharging cycle property and excellent charged storage properties without lowering the battery capacity.

Abstract: A positive electrode used in the non-aqueous electrolyte secondary battery of the present invention includes a hexagonal system lithium-containing cobalt composite oxide represented by the general expression ?LiCo1-XMXO2 (M=Zr, Mg, Al)? obtained by synthesizing a lithium compound as a lithium source with a cobalt compound as a cobalt source to which 0.01 mol % or more and 1.0 mol % or less of zirconium is added and magnesium and/or aluminum is added through coprecipitation, as the positive electrode active material, whereby the thermal stability, load performance and charging/discharging cycle performance characteristics of the non-aqueous electrolyte secondary battery are improved without lowering its capacity and charging/discharging efficiency.

Abstract: The present invention aims to provide a non-aqueous electrolyte secondary cell having high capacity and capable of preventing elution of cobalt and decomposition of the electrolyte. This aim can be accomplished by providing a non-aqueous electrolyte secondary cell comprising a positive electrode having a positive electrode active material, an negative electrode having an negative electrode active material, and non-aqueous electrolyte, wherein the positive electrode active material comprises lithium cobalt oxide to which at least one material selected from the group consisting of Mg, Al, Ti, and Zr was added, and the positive electrode comprises lithium phosphate.

Abstract: In a nonaqueous electrolytic secondary battery according to the invention, hexagonal system lithium containing cobalt composite oxide having a crystallite size in a (110) vector direction of 1000 ? or more and having a halogen compound added thereto by burning at time of synthesis is used as a positive electrode active material. By measuring a pH value of a filtrate obtained by dispersing, in water, the lithium containing cobalt composite oxide having the halogen compound added thereto by the burning at time of the synthesis and a crystallite size in the (110) vector direction of 1000 ? or more, a value of 9.6 to 10.1 is obtained. By using the lithium containing cobalt composite oxide as a positive electrode active material, a high temperature cycle property can be enhanced.

Abstract: A non-aqueous electrolyte secondary battery with excellent discharge cycle characteristics and a charging termination potential ranging from 4.4 to 4.6 V based on lithium, consisting of a positive electrode comprising a positive electrode active material, a negative electrode, and a non-aqueous electrolyte containing a non-aqueous solvent and an electrolyte salt, in which the positive electrode active material comprises a mixture of a lithium-cobalt composite oxide containing at least both zirconium and magnesium in LiCoO2, and a lithium-manganese-nickel composite oxide having a layered structure and containing at least both manganese and nickel, and the potential of the positive electrode active material ranges from 4.4 to 4.6 V based on lithium, and the non-aqueous electrolyte contains at least one of aromatic compounds selected from the group consisting at least of toluene derivatives, anisole derivatives, biphenyl, cyclohexyl benzene, tert-butyl benzene, tert-amyl benzene, and diphenyl ether.

Abstract: A non-aqueous electrolyte secondary battery with excellent cycle characteristics and thermal stability in which the potential of the positive electrode active material ranges from 4.4V to 4.6 V based on lithium, and-charging method therefor are provided, wherein the positive electrode active substance of a non-aqueous electrolyte secondary battery comprises a hexagonal system of lithium-containing transition metal composite oxide formed by adding zirconium, magnesium, and aluminum as foreign elements upon synthesis of lithium cobalt oxide, with zirconium content ranging from 0.01 to 1 mol %, magnesium content ranging from 0.01 to 3 mol %, and aluminum content ranging from 0.01 to 3 mol %, and an Li/Co molar ratio ranging from 1.00 to 1.05.

Abstract: The invention provides a non-aqueous electrolyte secondary cell that has high capacity and excels in cycle characteristics. The non-aqueous electrolyte secondary cell functions stably at a high potential of from 4.4 to 4.6 V with respect to lithium and inhibits the decomposition of the electrolytic solution at high potential. This is accomplished as follows. The non-aqueous electrolyte secondary cell has a positive electrode having a positive electrode active material; a negative electrode having a negative electrode active material; and a non-aqueous electrolyte having a non-aqueous solvent and electrolytic salt. The positive electrode active material has: lithium cobalt compound oxide having added therein at least zirconium and magnesium; and lithium-nickel-manganese compound oxide having a layered structure. The positive electrode active material has a potential of from 4.4 to 4.6 V with respect to lithium. The non-aqueous solvent contains diethyl carbonate of 10 vol. % or higher at 25° C.

Abstract: The present invention provides a nonaqueous electrolyte secondary cell having a positive electrode comprising mainly of a positive electrode active material, a negative electrode, and a nonaqueous electrolyte. The positive electrode active material is a lithium-containing transition metal composite oxide of a hexagonal crystal system that includes a compound represented by the general formula LiCo1-xMxO2, where M is at least one species selected from the group consisting of V, Cr, Fe, Mn, Ni, Al, and Ti, and x is a decimal number in a range 0<x<1, magnesium, and halogen. In a nonaqueous electrolyte secondary cell having such a construction, the high-temperature characteristics are improved without reducing the cell capacity.

Abstract: The present invention improves the cycle characteristics of a non-aqueous electrolyte secondary cell that uses lithium cobalt oxide as a positive electrode active material. To this end, an element different from cobalt such as zirconium and titanium is added to the lithium cobalt oxide, acting as the positive electrode active material. The non-aqueous electrolyte contains a non-aqueous solvent containing diethyl carbonate at 10 to 30 volume percent on a base of 25 degree Celcius and contains an electrolyte salt.

Abstract: A positive electrode used in the non-aqueous electrolyte secondary battery of the present invention includes a hexagonal system lithium-containing cobalt composite oxide represented by the general expression ?LiCo1-XMXO2 (M=Zr, Mg, Al)? obtained by synthesizing a lithium compound as a lithium source with a cobalt compound as a cobalt source to which 0.01 mol % or more and 1.0 mol % or less of zirconium is added and magnesium and/or aluminum is added through coprecipitation, as the positive electrode active material, whereby the thermal stability, load performance and charging/discharging cycle performance characteristics of the non-aqueous electrolyte secondary battery are improved without lowering its capacity and charging/discharging efficiency.

Abstract: The present invention provides a nonaqueous electrolyte secondary cell having a positive electrode composed mainly of a positive electrode active material, a negative electrode, and a nonaqueous electrolyte. The positive electrode active material is a lithium-containing transition metal composite oxide of a hexagonal crystal system that includes a compound represented by the general formula LiCo1-xMxO2, where M is at least one species selected from the group consisting of V, Cr, Fe, Mn, Ni, Al, and Ti, magnesium, and halogen. In a nonaqueous electrolyte secondary cell having such a construction, the high-temperature characteristics are improved without reducing the cell capacity.