Abstract: Disclosed is a nonaqueous electrolyte secondary battery which is suppressed in increase of internal resistance, while having high capacity retention rate and small battery swelling even after a long use. Specifically disclosed is a method for manufacturing a nonaqueous electrolyte secondary battery, which is characterized by using a positive electrode containing a positive electrode active material having an ?-NaFeO2 crystal structure and the following chemical composition: LixMnaNibCocOd (wherein 0<x<1.3, a+b+c=1, 1.7?d?2.3), while satisfying |a?b|<0.03 and 0.33?c<1, a negative electrode, and a nonaqueous electrolyte containing an unsaturated sultone and a sulfate ester compound.

Abstract: Disclosed is a nonaqueous electrolyte secondary battery which is suppressed in increase of internal resistance, while having high capacity retention rate and small battery swelling even after a long use. Specifically disclosed is a method for manufacturing a nonaqueous electrolyte secondary battery, which is characterized by using a positive electrode containing a positive electrode active material having an ?-NaFeO2 crystal structure and the following chemical composition: LixMnaNibCocOd (wherein 0<x<1.3, a+b+c=1, 1.7?d?2.3), while satisfying |a?b|<0.03 and 0.33?c<1, a negative electrode, and a nonaqueous electrolyte containing an unsaturated sultone and a sulfate ester compound.

Abstract: An object of the present invention is to provide a nonaqueous electrolyte battery which restrains swelling of the battery during high-temperature storage and is excellent in battery performance after storage. The invention is characterized by a specific constitution of a nonaqueous electrolyte and a combination thereof with a positive active material having specific crystal structure and composition. Namely, it is characterized by a nonaqueous electrolyte battery containing a positive electrode, a negative electrode, and a nonaqueous electrolyte, wherein the above nonaqueous electrolyte contains at least a cyclic carbonate having a carbon-carbon ? bond and the above positive electrode contains a positive active material comprising a composite oxide represented by a composite formula: LixMnaNibCOcO2 (wherein 0?x?1.1, a+b+c=1, |a-b|<0.05, 0<c<1) and having an ?-NaFeO2-type crystal structure.