Electrolyte Solution for Lithium Secondary Battery and Lithium Secondary Battery Including the Same

Provided is an electrolyte solution for a lithium secondary battery including an organic solvent, a lithium salt, an additive including at least one of isothiocyanate-based compounds represented by Chemical Formula 1 or Chemical Formula 2, and an auxiliary additive including at least one of a fluorine-containing carbonate-based compound, a lithium phosphate-based compound, a sultone-based compound, or a sulfate-based compound. A lithium secondary including the electrolyte solution is also provided.