A non-aqueous electrolyte includes (i) a cyclic anhydride; (ii) an electrolyte solvent containing carbonate and linear saturated ester; and (iii) an electrolyte salt. Since the linear saturated ester and cyclic anhydride are used in mixture as components of an electrolyte, it is possible to minimize problems caused by using either of the linear saturated ester or cyclic anhydride and to improve life cycle performance of the secondary battery and charging/discharging characteristics at room temperature or a high temperature.