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

Disclosed is an electrolyte solution for a lithium secondary battery, which can improve the performance of the battery by combining a highly reactive solvent and lithium salt that can increase the capacity of the battery, and a highly stable solvent and lithium salt that can increase the lifetime of the battery, and a lithium secondary battery comprising the same. The electrolyte solution for a lithium secondary battery comprises a first solvent containing 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 containing at least one of an ether-based compound that does not contain fluorine, an ester-based compound, an amide-based compound, and a carbonate-based compound; a third solvent containing a hydrofluoro ether-based compound; lithium salt; lanthanum nitrate; and lithium nitrate.