Non-Aqueous Electrolyte and Lithium Secondary Battery Including the Same

A non-aqueous electrolyte includes a lithium, an organic solvent, and an additive. The additive includes a compound having a cyclic borate-based substituent and an oxazolidone-based matrix substituted with a fused ring, so that a lithium secondary battery applying the same has improved high-temperature cycle characteristics and high-temperature storage characteristics, thereby improving overall performance.