Organic electrolytic solution and lithium battery including the same

An organic electrolytic solution, comprising:

• a first lithium salt;
• an organic solvent;
• a bicyclic sulfate-based compound represented by Formula 1 below;
• and
• a nitrile group-containing compound,
• wherein:
• the nitrile group-containing compound includes a plurality of nitrile groups:
• in Formula 1, each of A1, A2, A3, and A4 is independently a covalent bond, a substituted or unsubstituted C1-C5 alkylene group, a carbonyl group, or a sulfinyl group,
• both A1 and A2 are not a covalent bond and both A3 and A4 are not a covalent bond,
• the nitrile group-containing compound is represented by Formula L1 or L2 below:
• in Formulae L1 and L2, a is an integer of 0 to 10, each of b, c, and d is independently an integer of 0 to 10, and e is an integer of 1 to 5,
• an amount of the bicyclic sulfate-based compound is from about 0.1 wt % to about 5 wt % based on a total weight of the organic electrolytic solution, and
• an amount of the nitrile group-containing compound is from about 0.1 wt % to about 5 wt % based on the total weight of the organic electrolytic solution.