Patent ID: 7435510

Claim:
A nonaqueous electrolyte secondary battery comprising a positive electrode containing a positive active material, a negative electrode containing a negative active material and a nonaqueous electrolyte, wherein a lithium transition metal complex oxide A formed by allowing LiCoO 2 to contain at least both of Zr and Mg, and which is expressed by a chemical formula: Li a Co l-x-y-z Zr x Mg y M z O 2 , where M is at least one element selected from Al, Ti and Sn and a, x, y, and z are numerals satisfying equations of 0<a≦1.1, x>0, y>0, z≧0 and 0<x+y+z≦0.03, and a lithium transition metal complex oxide B having a layered structure and containing at least both of Mn and Ni as transition metals and containing molybdenum (Mo) are mixed and used as said positive active material.