부산대학교 도서관

A nonaqueous electrolyte secondary battery 10 according to an embodiment of the present invention includes a positive electrode 11 having a positive electrode active material that can intercalate and deintercalate lithium, a negative electrode 12 having a negative electrode active material that can intercalate and deintercalate lithium, and a nonaqueous electrolyte having lithium ion conductivity. The positive electrode active material is a layered lithium transition metal composite oxide (for example, one represented by Li1+x(NiyCozMn1−y−z)1−xO2 (where 0≦x≦0.15, 0.1≦y≦0.6, and 0≦z≦0.5)) to which an IVa group element (Zr) and a Va group element (Nb) are added. According to these features, it is possible to provide a nonaqueous electrolyte secondary battery with a selected element to be added to the lithium transition metal composite oxide to reduce the I-V resistance (improve the I-V characteristic), and thereby improving the output/input characteristics.