ELECTROLYTE FOR LITHIUM SECONDARY BATTERY, AND LITHIUM SECONDARY BATTERY COMPRISING THE SAME

Disclosed are an electrolyte solution for the lithium secondary battery, which can improve the performance of the battery, by combining a highly reactive solvent and lithium salt which can increase the capacity of the battery, and a highly stable solvent and lithium salt which can increase the lifetime of the battery, and a lithium secondary battery comprising the same. The electrolyte solution for the lithium secondary battery comprises a first solvent comprising a heterocyclic compound containing one or more double bonds and at the same time, containing any one of an oxygen atom and a sulfur atom; a second solvent comprising at least one of an ether-based compound, an ester-based compound, an amide-based compound, and a carbonate-based compound; lithium salt; lanthanum nitrate; and an additive comprising lithium nitrate.