Secondary battery including electrolyte additive

摘要

Disclosed is a secondary battery including a cathode, an anode, and an electrolyte including a lithium salt and a non-aqueous organic solvent, wherein the electrolyte includes an electrolyte additive to be decomposed at 4.5 V or higher to less than 5.5 V vs. reduction voltage of Li+.

主权项

1. A secondary battery comprising a cathode, an anode, and an electrolyte consisting of a lithium salt, a non-aqueous organic solvent, and an electrolyte additive, wherein the electrolyte additive decomposes at 4.5 V or higher to less than 5.5 V vs. reduction voltage of Li+,
wherein an amount of the electrolyte additive is in a range of 0.1 to 1 wt % based on a total weight of the electrolyte and the electrolyte additive consists of diacetoxy biphenyl or cyclohexyl benzene, wherein at least one of the cathode and the anode has a surface layer formed by decomposition of the electrolyte additive, and wherein the cathode comprises a spinel-structure lithium metal oxide as a cathode active material is represented by Formula 2 below,
LixNiyMn2−yO4  (2) wherein 0.9≦x≦1.2 and 0.4≦y≦0.5, and the anode comprises an anode active material represented by Formula 4 below:
LiaTibO4  (4)wherein 0.1≦a≦4 and 0.2≦b≦4.