In order to manufacture a lithium secondary battery having excellent performances in safety under overcharge condition, cycle property, electric capacity, and storage endurance, 0.1 wt. % to 10 wt. % of a tert-alkylbenzene compound is favorably incorporated into a non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, preferably in combination with 0.1 wt. % to 1.5 wt. % of a biphenyl compound.