Rechargeable lithium ion battery

A rechargeable lithium ion battery comprising:

• a positive active material comprising a lithium compound;
• and
• a non-aqueous electrolyte comprising:
• at least one linear disulfonate ester represented by Chemical Formula 2, and
• at least one carbonate having an unsaturated bond selected from vinylene carbonate and vinylethylene carbonate:
• wherein, in Chemical Formula 2,
• R3 and R4 are each independently selected from a substituted or unsubstituted C1 to C4 alkyl group, and
• x and y are each independently integers of 4 or 5,
• wherein the substituted C1 to C4 alkyl group is substituted with a substituent selected from a hydroxy group, an alkoxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C20 alkyl group, a C2 to C20 alkenyl group, a C2 to C20 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C3 to C30 heterocycloalkyl group, and a combination thereof, in place of a hydrogen atom,
• wherein the non-aqueous electrolyte comprises about 0.05 wt % to about 0.5 wt % of the linear disulfonate ester based on the total weight of the non-aqueous electrolyte, and about 0.2 wt % to about 1.5 wt % of the carbonate having the unsaturated bond based on the total weight of the non-aqueous electrolyte, and
• wherein the non-aqueous electrolyte further comprises an imide lithium salt included in an amount of about 0.5 wt % to about 2.0 wt % based on the total weight of the non-aqueous electrolyte and represented by Chemical Formula 3:
• wherein, in Chemical Formula 3,
• Rf1 and Rf2 are each independently selected from fluorine and a C1 to C4 fluoro alkyl group.

A rechargeable lithium ion battery comprising:

• a positive active material comprising a lithium compound;
• and
• a non-aqueous electrolyte comprising:
• at least one disulfonate ester selected from Compound 11, Compound 12, Compound 21, Compound 22, Compound 23, and Compound 24, and
• at least one carbonate having an unsaturated bond selected from vinylene carbonate and vinylethylene carbonate:
• wherein the non-aqueous electrolyte comprises about 0.05 wt % to about 0.5 wt % of the disulfonate ester based on the total weight of the non-aqueous electrolyte, and about 0.2 wt % to about 1.5 wt % of the carbonate having the unsaturated bond based on the total weight of the non-aqueous electrolyte, and
• wherein the non-aqueous electrolyte further comprises an imide lithium salt included in an amount of about 0.5 wt % to about 2.0 wt % based on the total weight of the non-aqueous electrolyte and represented by Chemical Formula 3:
• wherein, in Chemical Formula 3,
• Rf1 and Rf2 are each independently selected from fluorine and a C1 to C4 fluoro alkyl group.