Non-aqueous electrolyte for lithium secondary battery and lithium secondary battery comprising same

A non-aqueous electrolyte for a lithium secondary battery comprising:

• a lithium salt;
• an organic solvent comprising a mixed solvent of a carbonate-based solvent and an aromatic hydrocarbon solvent;
• and
• a compound represented by Formula (1), wherein the content of the compound ranges from 0.1 to 1 wt % based on a total weight of the electrolyte:
• wherein R1, R2, and R3 are each independently selected from the group consisting of hydrogen, primary, secondary, and tertiary alkyl groups, alkenyl groups, and aryl groups.

A method of preparing a lithium secondary battery comprising:

• providing a positive electrode comprising a material selected from the group consisting of lithium chalcogenides, lithium transition metal oxides, TiS, MoS, organic sulfides, and organic polysulfides;
• providing a negative electrode comprising a material selected from the group consisting of carbon, carbon composites, lithium metal, and lithium alloys;
• interposing a liquid electrolyte comprising a lithium salt, an organic solvent, and an additive comprising a compound represented by Formula (1) between the positive electrode and the negative electrode to fabricate the battery:
• wherein R1, R2, and R3 are each independently selected from the group consisting of hydrogen, primary, secondary, and tertiary alkyl groups, alkenyl groups, and aryl groups and the content of the compound in the electrolyte ranges from 0.1 to 1 wt %;
• and
• forming a film with the additive on the negative electrode.