Non-aqueous electrolyte secondary battery with high capacity and good life characteristics

摘要

Disclosed is a non-aqueous electrolyte secondary battery comprising a positive electrode containing a nickel-containing lithium composite oxide, a negative electrode containing graphite, and a non-aqueous electrolyte. The cut-off voltage of charge of this non-aqueous electrolyte secondary battery is 4.25 to 4.6 V. The negative electrode contains an additive that reacts with lithium at a potential higher than the potential of graphite. The ratio A/B of a positive electrode capacity A based on the weight of the nickel-containing lithium composite oxide and the cut-off voltage of charge relative to a weight B of the graphite contained in a portion of a negative electrode material mixture layer opposing to a positive electrode material mixture layer is 300 to 340 mAh/g, and the irreversible capacity C of the positive electrode and the irreversible capacity D of the negative electrode in the portion opposing to the positive electrode satisfies C>=D.