ELECTROLYTE FOR LITHIUM SECONDARY BATTERY OF IMPROVED LOW-TEMPERATURE PROPERTY AND SECONDARY BATTERY CONTAINING THE SAME

摘要

Provided is a lithium secondary battery which uses a lithium manganese metal oxide as a cathode active material and a non-graphitic carbon material as an anode active material, and based on the total weight of the electrolyte, contains 0.1 to 20% by weight of a salt represented by Formula I in a lithium salt-containing non-aqueous electrolyte: R4X+YZn−  (I) wherein R, X, Y, Z and n are as defined in the specification. The lithium secondary battery of the present invention can improve low-temperature properties of the battery by increasing the lithium ion-electrode reactivity and decreasing the electrode-interface resistance, via the formation of a charge double layer at the cathode-anode interface upon charging/discharging of the battery at a low temperature, and therefore can be preferably used in medium/large battery systems such as power sources for electric vehicles (EVs) and hybrid electric vehicles (HEVs) requiring operation under severe conditions.