Patent ID: 8343666

Claim:
A nonaqueous electrolyte secondary battery comprising: a positive electrode having an active material of a complex oxide capable of storing and emitting lithium ions; a negative electrode capable of storing and emitting lithium ions; a separator disposed between the positive electrode and the negative electrode; and an electrolytic solution containing a nonaqueous solvent, wherein discharge-end voltage of the nonaqueous electrolyte secondary battery is within 2.5V to 3.0V, the positive electrode contains a positive electrode active material comprising a first active material of lithium-based complex oxide and a second active material of another lithium-based complex oxide having an average discharge voltage lower than an average discharge voltage of the first active material, an added amount of the second active material is at least 5% and at most 20% in capacity of a total amount of capacity of the positive electrode active material, and the first active material is a composite “A” expressed as Li x MO 2 , “M” denoting a 3d transition metal, x being given as 0.9≦x≦0.98, and the second active material is LiMnO 2 of which average discharge voltage is within 2V to 3V.