Patent ID: 8283075

Claim:
A non-aqueous electrolyte secondary battery comprising: a positive electrode; a negative electrode; a separator interposed between the positive electrode and the negative electrode; and a non-aqueous electrolyte solution in which a solute is dissolved in a non-aqueous solvent, wherein: the positive electrode comprises a positive electrode active material which is a lithium cobalt oxide to which zirconium is added; the negative electrode comprises a negative electrode active material capable of alloying with lithium; the non-aqueous solvent of the non-aqueous electrolyte solution consists of (a) one or more fluorinated cyclic carbonates selected from the group consisting of 4-fluoro-1,3-dioxolane-2-one and 4,5-difluoro-1,3-dioxolane-2-one and (b) a carboxylic ester; the non-aqueous electrolyte solution contains a nitrile compound having a chain saturated hydrocarbon group having two or more carbon atoms; and wherein the negative electrode active material capable of alloying with lithium is a material containing silicon.