US Patent 7923150 Non-aqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery including a positive electrode, a negative electrode, and a non-aqueous electrolyte. The positive electrode includes a positive electrode active material that comprises a lithium-containing manganese oxide, and the negative electrode includes a negative electrode active material that comprises silicon and a transition metal element. When the battery voltage is 0 V, the positive electrode and the negative electrode have a potential of 1.8 V or higher relative to lithium metal (Li/Li+). Since the deterioration of the positive and negative electrode active materials is suppressed, this non-aqueous electrolyte secondary battery has both high capacity and excellent deep discharge cycle life.