| abstract |
A non-aqueous electrolyte secondary battery having improved rapid charge / discharge cycle characteristics at a high temperature without impairing the discharge capacity is provided. A positive electrode including a positive electrode active material containing a lithium composite oxide containing at least one transition metal element selected from the group consisting of Ni, Co, and Mn, a negative electrode, and a non-aqueous electrolyte. A non-aqueous electrolyte secondary battery having an element abundance ratio x by X-ray photoelectron spectroscopy on the surface of the positive electrode in a discharged state satisfies the following formula (1), and in the non-aqueous electrolyte in the discharged state: The sulfur concentration is less than 0.05% by weight (including 0% by weight). 5 ≦ x ≦ 100 (1) However, the element abundance ratio x is the atomic number% of sulfur when the atomic number of at least one transition metal element selected from the group consisting of Ni, Co and Mn is 100 atomic%. [Selection] Figure 1 |