| abstract |
An object of the invention is to provide a non-aqueous electrolyte secondary battery having a plateau in voltage in the 4-V region well comparable to that of lithium cobalt oxide, a high energy density, and cell characteristics such as safety, cycle properties, and high temperature storage properties. n [Means for Resolution] A non-aqueous electrolyte secondary battery according to the present invention comprises a positive electrode containing a positive electrode active material admixed therein a lithium-containing complex oxide having a layered crystalline structure expressed by general formula Li X Mn a Co b O 2 (where X is a value of 0.9 or greater but not greater than 1.1, a is a value of 0.45 or greater but not greater than 0.55, b is a value of 0.45 or greater but not greater than 0.55, and the sum of a and b is greater than 0.9 but not greater than 1.1), together with either of a lithium cobalt oxide and a spinel-type lithium manganate; a negative electrode containing a negative electrode active material capable of intercalating and deintercalating lithium ions; a separator separating the positive electrode and the negative electrode; and a non-aqueous electrolyte. |