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

An electrolyte solution for a lithium secondary battery and a lithium secondary battery including the electrolyte solution are provided. The electrolyte solution includes an additive represented by Chemical Formula 1, an organic solvent and a lithium salt: wherein in Chemical Formula 1, Rand Rare each independently hydrogen or a substituted or unsubstituted C-Calkyl group, X is O or S, and L is a substituted or unsubstituted C-Calkylene group. The lithium secondary battery including the electrolyte solution provides enhanced high-temperature properties.