LITHIUM SECONDARY BATTERY CAPABLE OF INHIBITING DECREASE IN INITIAL DISCHARGE CAPACITY AND IN CHARGE/DISCHARGE EFFICIENCY AND IMPROVING CYCLE LIFE AND SAFETY BY USING ANIONIC ADDITIVE

摘要

PURPOSE: A lithium secondary battery is provided to inhibit a decrease in initial discharge capacity and in charge/discharge efficiency, to improve charge/discharge cycle life characteristics and to prevent a drop in safety. CONSTITUTION: The lithium secondary battery includes: an anode comprising a graphite- or non-graphite-based carbonaceous material capable of lithium ion intercalation/deintercalation and an anionic quaternary borate salt present in an amount of 0.01-5.0 wt% based on the weight of the carbonaceous material; a cathode comprising a lithium-containing metal oxide; and a lithium ion conductive electrolyte. Particularly, the anionic quaternary borate salt includes potassium tetrakis£3,5-bis(trifluoromethyl) phenyl|borate and potassium tetrakis(4-chlorophenyl)borate.