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

An electrolyte for a lithium secondary battery, the electrolyte comprising:

• a lithium salt;
• an organic solvent;
• and
• an oligomer represented by Formula 1 or a polymer derived from the oligomer represented by Formula 1:
• wherein, in Formula 1,
• R1 and R2 are each independently a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms,
• R3 and R4 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 3 carbon atoms,
• R5 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms,
• R′ is an aliphatic hydrocarbon group or an aromatic hydrocarbon group,
• z and x are the numbers of repeating units,
• z is an integer of 1 to 10,
• x is an integer of 1 to 15, and
• n is an integer of 1 to 3.