A non-aqueous electrolyte secondary battery comprises: a positive electrode sheet comprising a positive electrode mixture containing a lithium-containing transition metal oxide as an active material and a particulate binder; a negative electrode sheet comprising a negative electrode mixture containing a carbon material; a separator interposed between the positive electrode sheet and the negative electrode sheet; and a non-aqueous electrolyte containing a lithium salt, wherein the positive electrode sheet and the negative electrode sheet are wound with the separator interposed therebetween to form an electrode assembly, and the positive electrode mixture has an active material density of 3.0 to 4.0 g/ml. The battery has a long life, high energy density and high output.