Abstract: A non-aqueous electrolyte solution for a lithium secondary battery comprises a lithium salt and an organic solvent. The non-aqueous electrolyte solution further comprises a specific siloxane compound and a sulfonate compound. This non-aqueous electrolyte solution solves the capacity degradation phenomenon, which appears in a lithium secondary battery using a non-aqueous electrolyte solution containing only a specific siloxane compound when the lithium secondary battery is used for a long time, so this non-aqueous electrolyte solution is especially useful for high-capacity batteries.

Abstract: Disclosed is an electrolyte comprising a compound having both a sulfonate group and a cyclic carbonate group. The electrolyte forms a more stable and dense SEI layer on the surface of an anode, and thus improves the capacity maintenance characteristics and lifespan characteristics of a battery. Also, disclosed is a compound represented by the following Formula 1, and a method for preparing the same by reacting 4-(hydroxyalkyl)-1,3-dioxolan-2-one with a sulfonyl halide compound: wherein each of R1 and R2 independently represents a C1˜C6 alkylene group optionally containing a C1˜C6 alkyl group or C2˜C6 alkenyl group introduced thereto; R3 is selected from the group consisting of a hydrogen atom, C1˜C20 alkyl group, C3˜C8 cyclic alkyl group, C2˜C6 alkenyl group, halo-substituted alkyl group, phenyl group and benzyl group.

Abstract: A non-aqueous electrolyte solution for a lithium secondary battery comprises a lithium salt and an organic solvent. The non-aqueous electrolyte solution further comprises a specific siloxane compound and a sulfonate compound. This non-aqueous electrolyte solution solves the capacity degradation phenomenon, which appears in a lithium secondary battery using a non-aqueous electrolyte solution containing only a specific siloxane compound when the lithium secondary battery is used for a long time, so this non-aqueous electrolyte solution is especially useful for high-capacity batteries.

Abstract: Disclosed is an electrolyte comprising a compound having both a sulfonate group and a cyclic carbonate group. The electrolyte forms a more stable and dense SEI layer on the surface of an anode, and thus improves the capacity maintenance characteristics and lifespan characteristics of a battery. Also, disclosed is a compound represented by the following Formula 1, and a method for preparing the same by reacting 4-(hydroxyalkyl)-1,3-dioxolan-2-one with a sulfonyl halide compound: wherein each of R1 and R2 independently represents a C1˜C6 alkylene group optionally containing a C1˜C6 alkyl group or C2˜C6 alkenyl group introduced thereto; R3 is selected from the group consisting of a hydrogen atom, C1˜C20 alkyl group, C3˜C8 cyclic alkyl group, C2˜C6 alkenyl group, halo-substituted alkyl group, phenyl group and benzyl group.