Patent ID: 8338030

Claim:
A non-aqueous electrolyte secondary battery 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 LiCoO 2 , and a lithium-manganese-nickel composite oxide having a layered structure and containing at least both of manganese and nickel, 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 biphenyl, cyclohexyl benzene, tert-amyl benzene, and diphenyl ether; whereby the content of the aromatic compound is 0.5 mass % or more and 5 mass % or less based on the entire electrolyte.