NOVELTY - A non-aqueous electrolyte secondary battery (100) comprises positive electrode (30) which has positive electrode active material, negative electrode (40) which has negative electrode active material, and non-aqueous electrolyte (90) which is arranged in contact with both positive electrode active material and negative electrode active material and contains oxalate complex compound consists of boron (B) and phosphorus (P) and dibutyl phthalate (DBP) as non-aqueous solvent.    USE - A non-aqueous electrolyte secondary battery used as power supply for vehicle motors, such as electric vehicle and hybrid vehicle.    ADVANTAGE - Additives in non-aqueous electrolyte improve battery performance.    DETAILED DESCRIPTION - A non-aqueous electrolyte secondary battery (100) comprises positive electrode (30) which has positive electrode active material, negative electrode (40) which has negative electrode active material, and non-aqueous electrolyte (90) which is arranged in contact with both positive electrode active material and negative electrode active material and contains oxalate complex compound consists of boron (B) and phosphorus (P) and dibutyl phthalate (DBP) as non-aqueous solvent, wherein relationship between DBP absorbed quantity X with respect to whole quantity of positive electrode active material (ml) and DBP absorbed quantity Y with respect to whole quantity of negative electrode active material (ml) satisfy equation X/Y=0.6-1.25. An INDEPENDENT CLAIM is included for manufacturing method of non-aqueous electrolyte secondary battery which involves preparing positive electrode which has positive electrode active material and negative electrode which has negative electrode active material, preparing non-aqueous electrolyte containing oxalate complex compound consists of B, P, and non-aqueous solvent, accommodating positive electrode, negative electrode, and non-aqueous electrolyte in container, and assembling battery.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional diagram taken on line II-II.    Battery case (10)    Positive electrode (30)    Negative electrode (40)    Non-aqueous electrolyte (90)    Non-aqueous electrolyte secondary battery (100)