Patent ID: 8435675

Claim:
A non-aqueous electrolyte secondary battery comprising: a positive electrode comprising a positive electrode material mixture layer including a nickel-containing lithium composite oxide, a negative electrode comprising a negative electrode material mixture layer including graphite, said negative electrode including an additive that reacts with the lithium at a potential higher than a maximum potential of said graphite during charge and discharge, and a non-aqueous electrolyte, wherein: said battery has a cut-off voltage of charge of 4.25 to 4.6 V, a ratio A/B of a positive electrode capacity A based on a weight of said nickel-containing lithium composite oxide and said cut-off voltage of charge relative to a weight B of said graphite in a portion of said negative electrode material mixture layer opposing to said positive electrode material mixture layer is 300 to 340 mAh/g, an irreversible capacity C of said positive electrode and an irreversible capacity D in the portion of said negative electrode material mixture layer opposite said positive electrode material mixture layer satisfies a relation of C>D, an amount of said additive is 0.5 to 2.9 parts by weight per 100 parts by weight of said graphite, and said additive is at least one selected from the group consisting of SiO and SiO n (0<n≦1.5).